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Nguyen AT, Aquino M. Association Between Short-Term Exposure to Environmental Air Pollution and Atopic Dermatitis Flare in Patients Treated With Dupilumab. Pediatrics 2023; 152:S29-S30. [PMID: 38038566 DOI: 10.1542/peds.2023-064344hl] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2023] Open
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Nguyen AT, Aquino M. Atopic Dermatitis and Eczema Association Between Early Life Antibiotic Exposure and Development of Early Childhood Atopic Dermatitis. Pediatrics 2023; 152:S21-S22. [PMID: 38038534 DOI: 10.1542/peds.2023-064344h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2023] Open
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Stevens S, Jang JK, Kershaw K, Viramontes J, Dar TB, Nguyen AT, Henson R, Guarnerio J, Underhill D, Shiao SL. Fungal Depletion Bolsters Anti-Tumor Immune Response Elicited by Anti-PD1 Alone and in Combination with Radiation Therapy. Int J Radiat Oncol Biol Phys 2023; 117:S166. [PMID: 37784414 DOI: 10.1016/j.ijrobp.2023.06.265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) Pembrolizumab in combination with chemotherapy has become the standard of care treatment for both metastatic and early-stage triple negative breast cancer (TNBC). Clinical trials are currently underway investigating the use of pembrolizumab with radiation in the neoadjuvant setting in early TNBC. Several groups have described a link between the microbiome and the efficacy of chemotherapy and anti-PD1 immune checkpoint inhibitors (ICIs) in preclinical models. Recent work from our lab has shown that targeting commensal fungi in the microbiome enhances the radiation induced antitumor immune response. Therefore, we hypothesized that fungal depletion might positively impact anti-PD1 therapy and combination treatment with anti-PD1 and radiation therapy (RT). MATERIALS/METHODS This study utilized an orthotopic syngeneic breast tumor model in which the syngeneic cell line E0771 was injected into the mammary fat pad of female C57BL/6 mice. Tumor-bearing mice were then treated with and without the antifungal fluconazole, anti-PD1, and radiation (16 Gy single fraction) using the X-RAD SmART platform with CT guidance. Tumor volumes were compared using 2-way ANOVA and survival curves analyzed using log rank. In a separate set of experiments, tumor-infiltrating immune cells were isolated and analyzed by high-dimensional multiplex flow cytometry. RESULTS We found that fungal depletion with fluconazole prior to treatment with anti-PD1 reduced the tumor volume and significantly improved survival in comparison to those treated with anti-PD1 alone (P = 0.0016). To identify what changes in the tumor immune microenvironment is driving this increased anti-tumor response, we performed flow cytometry on immune cells isolated from the tumors. We found that the use of fluconazole prior to anti-PD1 treatment reduced the proportion of CD11b+F4/80+ tumor-associated macrophages (TAMs) (P = 0.01) and increased tumor infiltrating cytotoxic T cell population (P = 0.04) when compared with the use of anti-PD1 alone. We also evaluated the effect of fungal depletion on combination therapy with RT and anti-PD1. Strikingly, we found that mice depleted of fungi with fluconazole prior to radiation and anti-PD1 therapy, have decreased tumor burden and significantly increased survival when compared to their fungally-intact counterparts (P = 0.043). CONCLUSION Our data indicates that the depletion of the gut fungal populations induces an increased antitumor response following anti-PD1 alone and in combination with radiation. This increased antitumor immune response is associated with an increase in the cytotoxic CD8+ T cell compartment with concomitant decrease in immunosuppressive tumor associated macrophages.
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Affiliation(s)
- S Stevens
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - J K Jang
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - K Kershaw
- Cedars-Sinai Medical Center, Los Angeles, CA
| | - J Viramontes
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - T B Dar
- Cedars-Sinai Medical Center, Los Angeles, CA
| | - A T Nguyen
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - R Henson
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - J Guarnerio
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - D Underhill
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA
| | - S L Shiao
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
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Nguyen AT, Dar TB, Viramontes J, Stevens S, Jang JK, Ko E, Lu DJ, Chung EM, Zhang SC, Atkins KM, Kamrava M, Sandler HM, Guarnerio J, Knott S, Zumsteg ZS, Underhill D, Shiao SL. Non-Redundant Mechanisms of Immune Resistance to Radiotherapy Converge on Innate Immunity. Int J Radiat Oncol Biol Phys 2023; 117:S71. [PMID: 37784560 DOI: 10.1016/j.ijrobp.2023.06.379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) Despite evidence of preclinical synergy between radiotherapy (RT) and immune checkpoint blockade (ICB), randomized trials of RT/ICB have demonstrated limited benefit in solid tumors. We performed single-cell RNA sequencing (scRNA-seq) and CITE-seq (cellular indexing of transcriptomes and epitopes) to address the discordance between preclinical and clinical data. We hypothesized that multiple orthogonal inhibitory immune pathways restrain the local and systemic efficacy of RT beyond T-cell oriented immune checkpoints. MATERIALS/METHODS We used the EO771 syngeneic murine model of breast cancer to characterize the immune tumor microenvironment following RT with or without ICB. RT (16 Gy x 1) was delivered using the X-RAD SmART platform with CT image guidance. Neutralizing antibodies (anti-PD-1/Ly6G/Gr-1/CD47) were delivered by intraperitoneal injections. scRNA-seq analysis were performed by Seurat and BBrowser (BioTuring). RESULTS We found that adaptive ICB (anti-PD-1) reprogrammed the immune response to RT by promoting an M1-like interferon-primed state (ISG15, CXCL10) in tumor associated macrophages (TAMs) and by increasing the late recruitment of intratumoral neutrophils. Given that neutrophils may drive resistance to RT in other models, we evaluated the effect of intratumoral neutrophil depletion using anti-Ly6G or anti-Gr-1 on the antitumor efficacy of RT/ICB. Both neutrophil depletion strategies led to enhanced tumor control and improved survival in advanced EO771 tumors compared to RT/ICB alone (P<0.001). In parallel to this approach, we found that TAMs upregulated several innate immune checkpoints including SIRPα in response to RT. Disruption of the SIRPα-CD47 interaction by anti-CD47 antibodies similarly enhanced the antitumor efficacy of RT/ICB by improving tumor control and survival (P<0.001). Using scRNA-seq and unbiased clustering, we found that anti-CD47 eliminated an entire cluster of chronically inflamed TAMs, characterized by pro-inflammatory markers (IL1A, NOS2) and chemokines (CCL3, CXCL1/2/3). Anti-CD47 also reduced intratumoral neutrophils by eliminating a cluster of pathologically activated neutrophils, termed myeloid-derived suppressor cells (PMN-MDSCs) that expressed several markers of ferroptosis (TFRC, PTGS2, SLC3A2). Consistent with the potent immunosuppressive capacity of PMN-MDSCs, we found that anti-CD47 increased tumor-infiltrating lymphocytes including central memory TCF7+ T cells and CD19+ B cells. Lastly, by inference and analysis of cell-cell communication (CellChat), we found that anti-CD47 strengthened the interactions between TAMs and CD8+ T cells compared to RT/ICB alone. CONCLUSION Our data collectively indicate that resistance to RT/ICB in the EO771 model Is driven by innate immune cells including neutrophils and chronically inflamed TAMs. Targeted disruption of the CD47-SIRPα axis is a promising approach to overcoming immune resistance by reprogramming TAMs and eliminating PMN-MDSCs.
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Affiliation(s)
- A T Nguyen
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - T B Dar
- Cedars-Sinai Medical Center, Los Angeles, CA
| | - J Viramontes
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - S Stevens
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - J K Jang
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - E Ko
- Cedars-Sinai Medical Center, Los Angeles, CA
| | - D J Lu
- Cedars-Sinai Medical Center, Los Angeles, CA
| | - E M Chung
- Cedars-Sinai Medical Center, Los Angeles, CA
| | - S C Zhang
- Cedars-Sinai Medical Center, Los Angeles, CA
| | - K M Atkins
- Cedars-Sinai Medical Center, Los Angeles, CA
| | - M Kamrava
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - H M Sandler
- Cedars-Sinai Medical Center, Los Angeles, CA
| | - J Guarnerio
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - S Knott
- Cedars-Sinai Medical Center, Los Angeles, CA
| | - Z S Zumsteg
- Cedars-Sinai Medical Center, Los Angeles, CA
| | - D Underhill
- Cedars-Sinai Medical Center, Los Angeles, CA
| | - S L Shiao
- Cedars-Sinai Medical Center, Los Angeles, CA
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Dar TB, Nguyen AT, Stevens S, Viramontes J, Henson R, Jang JK, Guarnerio J, Underhill D, Shiao SL. Reshaping Macrophage Polarization Potential Enhances Antitumor Immune Response to Radiation Therapy. Int J Radiat Oncol Biol Phys 2023; 117:e225-e226. [PMID: 37784913 DOI: 10.1016/j.ijrobp.2023.06.1133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) Although radiation therapy (RT) remains a cornerstone in the treatment of breast cancer, many trials combining RT with immune checkpoint blockade (ICB) have failed to demonstrate benefit in solid tumors including breast cancer. Maximal efficacy of RT relies on the generation of antitumor immunity following treatment which largely consists of cytotoxic T cells and macrophages. Broad depletion of macrophages modestly enhances tumor responses to RT suggesting that they can shape RT-induced antitumor immunity. Although IL4 signaling through GATA-3 is known to polarize T cells into the protumor Th2 phenotype, such central drivers of macrophage polarization are not well established. Given that macrophages abundantly express IL4 receptor, we hypothesized that GATA-3 may direct the transition of macrophages to M2/alternative phase and that genetic ablation of GATA-3 in macrophages can enhance antitumor immunity by arresting macrophage transition to an M2-like pro-tumor state. MATERIALS/METHODS We generated a macrophage specific GATA-3 KO mouse model (mG3KO) driven by the LysM-Cre promoter. Using a syngeneic orthotopic murine model of breast cancer (EO771), we evaluated the differential effect of RT (16Gy x 1) in WT and mG3KO mice. Multiparametric flow cytometry was performed to investigate the immune changes within the tumor microenvironment on day 3, day 5 and day 10 after RT. T cell depletion was performed using antibodies to CD4 and CD8 by intraperitoneal injections to understand the role of adaptive immunity in the response to RT in WT and mG3KO mice. RESULTS We found that mG3KO mice bearing advanced EO771 tumors demonstrated significantly improved tumor regression compared to WT mice (p<0.001), which translated to increased overall survival. In vitro characterization of bone-marrow derived macrophages from mG3KO and WT mice suggest that macrophages with ablated GATA-3 expressed increased levels of iNOS and decreased levels of Arginase (Arg-1), consistent with an M1-like phenotype. Immune profiling of the tumors also revealed that mGATA-3 KO animals have significant enrichment of CD8+ T cells in the tumor milieu post RT and these CD8+ T cells express higher amounts of interferon gamma (p<0.001) and Granzyme B (p<0.0015) than their WT counterparts. Using neutralizing antibodies to deplete CD8+ T cells, we show that anti-tumor effects in the mG3KO mice were abolished, suggesting that mG3KO macrophages impact survival, at least, in part by enhancing cytotoxic CD8+T cells. Studies are currently ongoing to reveal the detailed mechanism of GATA-3 ablation in improving the efficacy of RT. CONCLUSION Our data indicates that GATA-3 is a central regulator of macrophage polarization in response to RT. Further, directed ablation of GATA-3 appears to drive macrophages towards an M1-like phenotype, which enhances T cell recruitment to irradiated tumors. These data suggest that the antitumor efficacy of RT can be prolonged by targeting GATA-3-dependent signaling within myeloid cells.
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Affiliation(s)
- T B Dar
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - A T Nguyen
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - S Stevens
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - J Viramontes
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - R Henson
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - J K Jang
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - J Guarnerio
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - D Underhill
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA
| | - S L Shiao
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
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Chung EM, Zhang SC, Nguyen AT, Atkins KM, Kamrava M. Feasibility and Acceptability of ChatGPT Generated Radiology Report Summaries for Cancer Patients. Int J Radiat Oncol Biol Phys 2023; 117:e463. [PMID: 37785481 DOI: 10.1016/j.ijrobp.2023.06.1662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) Patients now have direct access to their diagnostic imaging reports. However, they can include complex terminology that can be difficult for patients to understand. ChatGPT (OpenAI, San Francisco, CA) is an artificial intelligence (AI) text-generating model that can simplify complex text and generate human-like responses. We assessed ChatGPT's ability to generate summarized MRI reports for patients with prostate cancer and evaluated physician satisfaction with providing patients with an AI-summarized report. MATERIALS/METHODS We used ChatGPT to summarize five prostate cancer MRI reports performed at our institution from 2021-2022. Using a standard prompt, we asked ChatGPT to summarize the full MRI reports into a patient letter at a 6th grade reading level. To account for variability in text output, we generated three different summarized reports per unique MRI report. Full MRI and summarized reports were assessed for readability using Flesch-Kincaid Grade Level (FK) score. Radiation oncologists at our institution were asked to evaluate the summarized reports with an anonymous questionnaire. Physicians were shown two full MRI reports and three summarized versions for each full report. For each summarized report, physicians were asked six questions assessing the following: factual correctness, ease of understanding, completeness, potential for harm, overall quality, and likelihood they would send the report to a patient. Qualitative responses were given on a 1-5 Likert-type scale. RESULTS A total of 15 summarized reports were generated from five full MRI reports using ChatGPT. The median FK score for the full MRI reports and summarized reports was 9.6 vs. 5.0, (p<0.05), respectively. 12 radiation oncologists responded to our questionnaire with experience levels of: resident (25%), attending <5 years (33%), attending 5-10 years (17%), and attending >10 years (25%). The mean [SD] rating across all six summarized reports for each of the questions were: factual correctness (4.0 [0.6], understanding 4.0 [0.7]), completeness (4.1 [0.5]), potential for harm (3.5 [0.9]), overall quality (3.4 [0.9]), and likelihood to send to patient (3.1 [1.1]). 89%, 78%, and 93% of respondents answered agree or strongly agree for correctness, ease of understanding, and completeness of the summarized reports. 51%, 53%, and 46% of respondents answered agree or strongly agree for potential for harm, overall quality, and likelihood to send to patient. CONCLUSION ChatGPT was able to summarize prostate MRI reports at a reading level appropriate for patients. Physicians were likely to be satisfied with the summarized reports with respect to factual correctness, ease of understanding, and completeness. They were less likely to be satisfied with respect to potential for harm, overall quality, and likelihood to send to patients. Further research is needed to optimize ChatGPT's ability to summarize radiology reports for patients and understand what factors influence physician trust in AI-summarized reports.
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Affiliation(s)
- E M Chung
- Cedars-Sinai Medical Center, Los Angeles, CA; Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - S C Zhang
- Cedars-Sinai Medical Center, Los Angeles, CA; Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - A T Nguyen
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - K M Atkins
- Cedars-Sinai Medical Center, Los Angeles, CA; Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - M Kamrava
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
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Neelamraju Y, Gjini E, Chhangawala S, Fan H, He S, Jing CB, Nguyen AT, Prajapati S, Sheridan C, Houvras Y, Melnick A, Look AT, Garrett-Bakelman FE. Depletion of tet2 results in age-dependent changes in DNA methylation and gene expression in a zebrafish model of myelodysplastic syndrome. Front Hematol 2023; 2:1235170. [PMID: 37937078 PMCID: PMC10629367 DOI: 10.3389/frhem.2023.1235170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/09/2023]
Abstract
Introduction Myelodysplastic syndrome (MDS) is a heterogeneous group of clonal hematopoietic disorders characterized by ineffective hematopoiesis, cytopenias, and dysplasia. The gene encoding ten-eleven translocation 2 (tet2), a dioxygenase enzyme that catalyzes the conversion of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine, is a recurrently mutated tumor suppressor gene in MDS and other myeloid malignancies. Previously, we reported a stable zebrafish line with a loss-of-function mutation in the tet2 gene. The tet2m/m-mutant zebrafish developed a pre-MDS state with kidney marrow dysplasia, but normal circulating blood counts by 11 months of age and accompanying anemia, signifying the onset of MDS, by 24 months of age. Methods In the current study, we collected progenitor cells from the kidney marrows of the adult tet2m/m and tet2wt/wt fish at 4 and 15 months of age and conducted enhanced reduced representation of bisulfite sequencing (ERRBS) and bulk RNA-seq to measure changes in DNA methylation and gene expression of hematopoietic stem and progenitor cells (HSPCs). Results and discussion A global increase in DNA methylation of gene promoter regions and CpG islands was observed in tet2m/m HSPCs at 4 months of age when compared with the wild type. Furthermore, hypermethylated genes were significantly enriched for targets of SUZ12 and the metal-response-element-binding transcription factor 2 (MTF2)-involved in the polycomb repressive complex 2 (PRC2). However, between 4 and 15 months of age, we observed a paradoxical global decrease in DNA methylation in tet2m/m HSPCs. Gene expression analyses identified upregulation of genes associated with mTORC1 signaling and interferon gamma and alpha responses in tet2m/m HSPCs at 4 months of age when compared with the wild type. Downregulated genes in HSPCs of tet2-mutant fish at 4 months of age were enriched for cell cycle regulation, heme metabolism, and interleukin 2 (IL2)/signal transducer and activator of transcription 5 (STAT5) signaling, possibly related to increased self-renewal and clonal advantage in HSPCs with tet2 loss of function. Finally, there was an overall inverse correlation between overall increased promoter methylation and gene expression.
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Affiliation(s)
- Yaseswini Neelamraju
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, United States
| | - Evisa Gjini
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, United States
| | | | - Hao Fan
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, United States
| | - Shuning He
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, United States
| | | | - Ashley T. Nguyen
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, United States
| | - Subhash Prajapati
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, United States
| | - Caroline Sheridan
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY, United States
| | | | - Ari Melnick
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY, United States
| | - A. Thomas Look
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
| | - Francine E. Garrett-Bakelman
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, United States
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY, United States
- Department of Medicine, University of Virginia, Charlottesville, VA, United States
- University of Virginia Cancer Center, Charlottesville, VA, United States
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Nguyen AT, Settipane RA. Erratum to "A potpourri of summer allergic environmental disorders" [Ann Allergy Asthma Immunol 130 (2023) 415-418]. Ann Allergy Asthma Immunol 2023; 130:823. [PMID: 37270228 DOI: 10.1016/j.anai.2023.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Affiliation(s)
- Ashley T Nguyen
- Brown University Warren Alpert Medical School, Providence, Rhode Island
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Nguyen AT, Lewis C, Geary M. It's Never the Right Time to Say Goodbye…Until It Is: Transitioning from Pediatric to Adult Primary Care. R I Med J (2013) 2022; 105:74-75. [PMID: 36413457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Affiliation(s)
- Ashley T Nguyen
- Department of Internal Medicine-Pediatrics at Brown University, Rhode Island Hospital and Hasbro Children's Hospital, Providence, RI
| | - Carol Lewis
- Department of Pediatrics at Brown University, Hasbro Children's Hospital, Providence, RI
| | - Megan Geary
- Department of Medicine at Brown University, Rhode Island Hospital, Providence, RI
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Nguyen TH, Nguyen CX, Luu MQ, Nguyen AT, Bui DH, Pham DK, Do DN. Mathematical models to describe the growth curves of Vietnamese Ri chicken. BRAZ J BIOL 2021; 83:e249756. [PMID: 34755795 DOI: 10.1590/1519-6984.249756] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 06/28/2021] [Indexed: 11/21/2022] Open
Abstract
Ri chicken is the most popular backyard chicken breed in Vietnam, but little is known about the growth curve of this breed. This study compared the performances of models with three parameters (Gompertz, Brody, and Logistic) and models containing four parameters (Richards, Bridges, and Janoschek) for describing the growth of Ri chicken. The bodyweight of Ri chicken was recorded weekly from week 1 to week 19. Growth models were fitted using minpack.lm package in R software and Akaike's information criterion (AIC), Bayesian information criterion (BIC), and root mean square error (RMSE) were used for model comparison. Based on these criteria, the models having four parameters showed better performance than the ones with three parameters, and the Richards model was the best one for males and females. The lowest and highest value of asymmetric weights (α) were obtained by Bridges and Brody models for each of sexes, respectively. Age and weight estimated by the Richard model were 8.46 and 7.51 weeks and 696.88 and 487.58 g for males and for females, respectively. Differences in the growth curves were observed between males and female chicken. Overall, the results suggested using the Richards model for describing the growth curve of Ri chickens. Further studies on the genetics and genomics of the obtained growth parameters are required before using them for the genetic improvement of Ri chickens.
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Affiliation(s)
- T H Nguyen
- Faculty of Animal Science, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - C X Nguyen
- Faculty of Biotechnology, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - M Q Luu
- Ministry of Science and Technology, Hanoi, Vietnam
| | - A T Nguyen
- Faculty of Animal Science, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - D H Bui
- Faculty of Animal Science, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - D K Pham
- Faculty of Animal Science, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - D N Do
- Department of Animal Science and Aquaculture, Dalhousie University, Truro, Canada
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Nguyen AT, Némery J, Gratiot N, Garnier J, Dao TS, Thieu V, Laruelle GG. Biogeochemical functioning of an urbanized tropical estuary: Implementing the generic C-GEM (reactive transport) model. Sci Total Environ 2021; 784:147261. [PMID: 34088067 DOI: 10.1016/j.scitotenv.2021.147261] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/12/2021] [Accepted: 04/16/2021] [Indexed: 06/12/2023]
Abstract
Estuaries are amongst the most productive ecosystems of the land ocean continuum, but they are also under high anthropic pressures due to coastal urbanization. Too sparse observations have hindered the understanding of complex interactions between water quality and estuarine hydrodynamics and biogeochemical transformations. Until now, estuarine modelling studies have mainly focused on temperate estuarine systems in industrialized countries. This study investigates the responses of a tropical estuary to pollution load from a megacity (Ho Chi Minh City, Southern Vietnam) by applying a one-dimensional, biogeochemical estuarine model (C-GEM). The Saigon River Estuary flows through the megacity of Ho Chi Minh (HCMC) and is subject to episodic hypoxia events due to wastewater inputs from urban discharges. Good agreements are found between simulation outputs and observations for tidal propagation, salinity, total suspended sediment, and water quality variables in dry season in Saigon River Estuary. C-GEM reproduces the increases in ammonium, total organic carbon, phytoplankton and dissolved oxygen depletion in the urban section of the Saigon River as an impact of untreated wastewaters from HCMC. The steady-state version of C-GEM also reveals the formation of a pollutant cloud (30-km stretch) resulting from the combined effects of tidal fluctuation and low flushing capacity during the dry season. Furthermore, the quantification of the reaction fluxes simulated by the model demonstrates that nitrification is the main process removing NH4+ from the Saigon River. For the first time in such a type of environment, our study demonstrates the effectiveness of C-GEM at unraveling the complex interplay between biogeochemical reactions and transport in a tropical estuary with a minimized data requirement. This is significant for tropical estuaries in developing countries, where intensive monitoring programs are rare and have thus been rarely the object of modelling investigations.
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Affiliation(s)
- A T Nguyen
- Univ. Grenoble Alpes, IRD, CNRS, Grenoble INP(1), IGE, F-38000 Grenoble, France; CARE, Hochiminh City University of Technology, VNU-HCM, 268 Ly Thuong Kiet Street, District 10, Hochiminh City, Viet Nam.
| | - J Némery
- Univ. Grenoble Alpes, IRD, CNRS, Grenoble INP(1), IGE, F-38000 Grenoble, France; CARE, Hochiminh City University of Technology, VNU-HCM, 268 Ly Thuong Kiet Street, District 10, Hochiminh City, Viet Nam
| | - N Gratiot
- Univ. Grenoble Alpes, IRD, CNRS, Grenoble INP(1), IGE, F-38000 Grenoble, France; CARE, Hochiminh City University of Technology, VNU-HCM, 268 Ly Thuong Kiet Street, District 10, Hochiminh City, Viet Nam
| | - J Garnier
- Sorbonne Université, CNRS, EPHE, UMR 7619 Metis, BP 123, Tour 56-55, Etage 4, 4 Place Jussieu, 7500 Paris, France
| | - T S Dao
- FERN, Hochiminh City University of Technology, VNU-HCM, 268 L Thuong Kiet Street, District 10, Hochiminh City, Viet Nam
| | - V Thieu
- Sorbonne Université, CNRS, EPHE, UMR 7619 Metis, BP 123, Tour 56-55, Etage 4, 4 Place Jussieu, 7500 Paris, France
| | - G G Laruelle
- Université Libres de Bruxelles, Department of Geoscience, Environment & Society (DGES), CP 160/02, 1050 Brussels, Belgium
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12
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Nguyen AT. Calling a Death for the First Time. Acad Med 2020; 95:1134-1135. [PMID: 32101923 DOI: 10.1097/acm.0000000000003233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Affiliation(s)
- Ashley T Nguyen
- First-year resident, Department of Internal Medicine-Pediatrics, Rhode Island Hospital/Hasboro Children's Hospital/Brown University, Providence, Rhode Island; ; ORCID: http://orcid.org/0000-0002-8717-0269
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13
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Gjini E, Jing CB, Nguyen AT, Reyon D, Gans E, Kesarsing M, Peterson J, Pozdnyakova O, Rodig SJ, Mansour MR, Joung K, Look AT. Disruption of asxl1 results in myeloproliferative neoplasms in zebrafish. Dis Model Mech 2019; 12:12/5/dmm035790. [PMID: 31064769 PMCID: PMC6550042 DOI: 10.1242/dmm.035790] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 03/29/2019] [Indexed: 01/04/2023] Open
Abstract
Somatic loss-of-function mutations of the additional sex combs-like transcriptional regulator 1 (ASXL1) gene are common genetic abnormalities in human myeloid malignancies and induce clonal expansion of mutated hematopoietic stem cells (HSCs). To understand how ASXL1 disruption leads to myeloid cell transformation, we generated asxl1 haploinsufficient and null zebrafish lines using genome-editing technology. Here, we show that homozygous loss of asxl1 leads to apoptosis of newly formed HSCs. Apoptosis occurred via the mitochondrial apoptotic pathway mediated by upregulation of bim and bid. Half of the asxl1+/− zebrafish had myeloproliferative neoplasms (MPNs) by 5 months of age. Heterozygous loss of asxl1 combined with heterozygous loss of tet2 led to a more penetrant MPN phenotype, while heterozygous loss of asxl1 combined with complete loss of tet2 led to acute myeloid leukemia (AML). These findings support the use of asxl1+/− zebrafish as a strategy to identify small-molecule drugs to suppress the growth of asxl1 mutant but not wild-type HSCs in individuals with somatically acquired inactivating mutations of ASXL1. Summary: Homozygous loss of asxl1 in zebrafish leads to apoptosis of newly formed HSCs by upregulation of bim and bid. Half of the asxl1+/− zebrafish had MPNs by 5 months of age.
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Affiliation(s)
- Evisa Gjini
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Massachusetts 02215, USA
| | - Chang-Bin Jing
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Massachusetts 02215, USA
| | - Ashley T Nguyen
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Massachusetts 02215, USA
| | - Deepak Reyon
- Molecular Pathology Unit, Center for Computational and Integrative Biology, and Center for Cancer Research, Massachusetts General Hospital, Charlestown, Massachusetts 02129, USA.,Department of Pathology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Emma Gans
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Massachusetts 02215, USA
| | - Michiel Kesarsing
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Massachusetts 02215, USA
| | - Joshua Peterson
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Massachusetts 02215, USA
| | - Olga Pozdnyakova
- Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA
| | - Scott J Rodig
- Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA
| | - Marc R Mansour
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Massachusetts 02215, USA.,Department of Haematology, UCL Cancer Institute, University College London, London WC1E 6AG, United Kingdom
| | - Keith Joung
- Molecular Pathology Unit, Center for Computational and Integrative Biology, and Center for Cancer Research, Massachusetts General Hospital, Charlestown, Massachusetts 02129, USA.,Department of Pathology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - A Thomas Look
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Massachusetts 02215, USA
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14
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Andree KC, Mentink A, Nguyen AT, Goldsteen P, van Dalum G, Broekmaat JJ, van Rijn CJM, Terstappen LWMM. Tumor cell capture from blood by flowing across antibody-coated surfaces. Lab Chip 2019; 19:1006-1012. [PMID: 30762848 DOI: 10.1039/c8lc01158c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The load of circulating tumor cells (CTC) is related to poor outcomes in cancer patients. A sufficient number of these cells would enable a full characterization of the cancer. An approach to probe larger blood volumes, allowing for the detection of more of these very rare CTC, is the use of leukapheresis. Currently available techniques allow only the analysis of a small portion of leukapheresis products. Here, we present a method that uses flow rather than static conditions which allows processing of larger volumes. We evaluated the conditions needed to isolate tumor cells from blood while passing antibody coated surfaces. Results show that our set-up efficiently captures cancer cells from whole blood. Results show that the optimal velocity at which cells are captured from blood is 0.6 mm s-1. Also, it can be concluded that the VU1D9 antibody targeting the EpCAM antigen has very high capture efficiency. When using an antibody that does not capture 100% of all cells, combining multiple antibodies on the capture surface is very beneficial leading to an increase in cell capture and is therefore worthwhile considering in any cancer cell capture methodology.
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Affiliation(s)
- K C Andree
- Medical Cell Biophysics Group, Technical Medical Centre, Faculty of Science and Technology, University of Twente, The Netherlands.
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15
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Cata JP, Bhavsar S, Hagan KB, Arunkumar R, Grasu R, Dang A, Carlson R, Arnold B, Popat K, Rao G, Potylchansky Y, Lipski I, Ratty S, Nguyen AT, McHugh T, Feng L, Rahlfs TF. Intraoperative serum lactate is not a predictor of survival after glioblastoma surgery. J Clin Neurosci 2017; 43:224-228. [PMID: 28601568 DOI: 10.1016/j.jocn.2017.05.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 03/21/2017] [Accepted: 05/21/2017] [Indexed: 01/15/2023]
Abstract
BACKGROUND Cancer cells can produce lactate in high concentrations. Two previous studies examined the clinical relevance of serum lactate as a biomarker in patients with brain tumors. Patients with high-grade tumors have higher serum concentrations of lactate than those with low-grade tumors. We hypothesized that serum lactic could be used of biomarker to predictor of survival in patients with glioblastoma (GB). METHODS This was a retrospective study. Demographic, lactate concentrations and imaging data from 275 adult patients with primary GB was included in the analysis. The progression free survival (PFS) and overall survival (OS) rates were compared in patients who had above and below the median concentrations of lactate. We also investigated the correlation between lactate concentrations and tumor volume. Multivariate analyses were conducted to test the association lactate, tumor volume and demographic variables with PFS and OS. RESULTS The median serum concentration of lactate was 2.3mmol/L. A weak correlation was found between lactate concentrations and tumor volume. Kaplan-Meier curves demonstrated similar survival in patients with higher or lower than 2.3mmol/L of lactate. The multivariate analysis indicated that the intraoperative levels of lactate were not independently associated with changes in survival. On another hand, a preoperative T1 volume was an independent predictor PFS (HR 95%CI: 1.41, 1.02-1.82, p=0.006) and OS (HR 95%CI: 1.47, 1.11-1.96, p=0.006). CONCLUSION This retrospective study suggests that the serum concentrations of lactate cannot be used as a biomarker to predict survival after GB surgery. To date, there are no clinically available serum biomarkers to determine prognosis in patients with high-grade gliomas. These tumors may produce high levels of lactic acid. We hypothesized that serum lactic could be used of biomarker to predictor of survival in patients with glioblastoma (GB). In this study, we collected perioperative and survival data from 275 adult patients with primary high-grade gliomas to determine whether intraoperative serum acid lactic concentrations can serve as a marker of prognosis. The median serum concentration of lactate was 2.3mmol/L. Our analysis indicated the intraoperative levels of lactate were not independently associated with changes in survival. This retrospective study suggests that the serum concentrations of lactate cannot be used as a biomarker to predict survival after GB surgery.
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Affiliation(s)
- J P Cata
- Department of Anesthesiology and Perioperative Medicine, The University of Texas - MD Anderson Cancer Center, Houston, TX, USA; Anesthesiology and Surgical Oncology Research Group, Houston, TX, USA.
| | - S Bhavsar
- Department of Anesthesiology and Perioperative Medicine, The University of Texas - MD Anderson Cancer Center, Houston, TX, USA
| | - K B Hagan
- Department of Anesthesiology and Perioperative Medicine, The University of Texas - MD Anderson Cancer Center, Houston, TX, USA
| | - R Arunkumar
- Department of Anesthesiology and Perioperative Medicine, The University of Texas - MD Anderson Cancer Center, Houston, TX, USA
| | - R Grasu
- Department of Anesthesiology and Perioperative Medicine, The University of Texas - MD Anderson Cancer Center, Houston, TX, USA
| | - A Dang
- Department of Anesthesiology and Perioperative Medicine, The University of Texas - MD Anderson Cancer Center, Houston, TX, USA
| | - R Carlson
- Department of Anesthesiology and Perioperative Medicine, The University of Texas - MD Anderson Cancer Center, Houston, TX, USA
| | - B Arnold
- Department of Anesthesiology and Perioperative Medicine, The University of Texas - MD Anderson Cancer Center, Houston, TX, USA
| | - K Popat
- Department of Anesthesiology and Perioperative Medicine, The University of Texas - MD Anderson Cancer Center, Houston, TX, USA
| | - Ganesh Rao
- Department of Neurosurgery, The University of Texas - MD Anderson Cancer Center, Houston, TX, USA
| | - Y Potylchansky
- Department of Anesthesiology and Perioperative Medicine, The University of Texas - MD Anderson Cancer Center, Houston, TX, USA
| | - I Lipski
- Department of Anesthesiology and Perioperative Medicine, The University of Texas - MD Anderson Cancer Center, Houston, TX, USA
| | - Sally Ratty
- Department of Anesthesiology and Perioperative Medicine, The University of Texas - MD Anderson Cancer Center, Houston, TX, USA
| | - A T Nguyen
- Department of Anesthesiology and Perioperative Medicine, The University of Texas - MD Anderson Cancer Center, Houston, TX, USA
| | - Thomas McHugh
- Department of Anesthesiology and Perioperative Medicine, The University of Texas - MD Anderson Cancer Center, Houston, TX, USA
| | - L Feng
- Department of Biostatistics, The University of Texas - MD Anderson Cancer Center, Houston, TX, USA
| | - T F Rahlfs
- Department of Anesthesiology and Perioperative Medicine, The University of Texas - MD Anderson Cancer Center, Houston, TX, USA
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16
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Santa-Maria CA, Dantzer J, Li L, Skaar T, Oesterreich S, Rae JM, Zeruesenay D, Nguyen AT, Henry NL, Storniolo AM, Hayes DF, Blumenthal RS, Ouyang P, Post W, Flockhart DA, Stearns V. Abstract P1-08-11: Association of variants in candidate genes on lipid profiles in women with early breast cancer on adjuvant aromatase inhibitor therapy. Cancer Res 2013. [DOI: 10.1158/0008-5472.sabcs13-p1-08-11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background
Aromatase inhibitors (AI) can exert unfavorable effects on lipid profiles, but previous studies have reported inconsistent results. Given the intricate biological relationship between estrogen and lipid profiles, these mixed results may be explained in part by variation in genes encoding proteins involved in the drug's target and in estrogen metabolism and signaling. The purpose of this study was to investigate associations of single-nucleotide polymorphisms (SNP) in candidate genes with AI-mediated changes in lipid profiles.
Methods
We completed a prospective multicenter randomized observational open-label study to test the association of SNPs in candidate genes on biomarkers of estrogenic and anti-estrogenic activity in post-menopausal women with early breast cancer who were recommended adjuvant AI therapy. Eligible women were randomly assigned to exemestane or letrozole, and were followed for 2 years. We genotyped 137 SNPs from germ line DNA in the following candidate genes: ARVCF, COMT, CYP19A1, ESR1, ESR2, PGR, EP300, EZH2, NCOA1-3, NCOR1-2, NRIP, and PELP1. Lipid profiles including total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglycerides (TG) were measured at baseline and 3 months after initiating AI. We conducted genetic association data analysis and multivariate linear regressions to analyze the genetic effects using dominant, recessive, and additive models. Multivariate analysis included age, body mass index, prior hormone replacement therapy, and prior tamoxifen. To adjust for multiple comparisons, only SNPs with a p<0.0003 were considered significant.
Results
We enrolled 502 women in to the study, but for this analysis we excluded women who did not have genetic data (n = 33), had incomplete data (n = 23), discontinued or crossed over AI therapy (n = 48), women not fasting at both time points (n = 89), or those on lipid-lowering medications (n = 162). A total of 200 women were evaluable (letrozole 107, exemestane 93). Lipid profiles in all patients (n = 200) at baseline and 3 months after initiating AI, respectively, were as follows: TC 204.9 and 203.3 (unchanged, p = 0.43); HDL 61.3 and 56.8 (decreased, p = 6.3E-10); LDL 122.2 and 124.6 (unchanged, p = 0.22); and TG 107.1 and 103.6 (unchanged, p = 0.26). Genetic association and multivariate analysis revealed that SNPs in ESR1 and NCOR1 are significantly associated with additional changes in lipid parameters as summarized in Table 1.
Table 1.Significant findings of multivariate linear regressions analyzing genetic associations between candidate gene SNPs and lipid profiles of AI-treated women.CohortNumberSNP (gene)Minor Allele FrequencyLipid ParameterModel UsedMean Absolute Change (mg/dL)P-valueAll patients184rs9340958 (ESR1)0.07TCRecessive-2.250.0003Letrozole96rs9340958 (ESR1)0.07TCRecessive5.280.00009 101rs3020368 (ESR1)0.09TCRecessive6.350.00007Exemestane93rs3798758 (ESR1)0.03HDLDominant, additive-7.970.00001 88rs926848 (ESR1)0.03HDLDominant, additive-7.970.00002 93rs61753150 (NCOR1)0.01TGDominant, additive-11.630.00003
Conclusions
Variants in genes involved in estrogen metabolism and signaling are associated with changes in lipid profiles in AI-treated women and should be validated in other studies.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-08-11.
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Affiliation(s)
- CA Santa-Maria
- Johns Hopkins Sidney Kimmel Comprehensive Cancer Center; Indiana University School of Medicine; University of Pittsburgh Cancer Institute; University of Michigan Comprehensive Cancer Center; Johns Hopkins University School of Medicine
| | - J Dantzer
- Johns Hopkins Sidney Kimmel Comprehensive Cancer Center; Indiana University School of Medicine; University of Pittsburgh Cancer Institute; University of Michigan Comprehensive Cancer Center; Johns Hopkins University School of Medicine
| | - L Li
- Johns Hopkins Sidney Kimmel Comprehensive Cancer Center; Indiana University School of Medicine; University of Pittsburgh Cancer Institute; University of Michigan Comprehensive Cancer Center; Johns Hopkins University School of Medicine
| | - T Skaar
- Johns Hopkins Sidney Kimmel Comprehensive Cancer Center; Indiana University School of Medicine; University of Pittsburgh Cancer Institute; University of Michigan Comprehensive Cancer Center; Johns Hopkins University School of Medicine
| | - S Oesterreich
- Johns Hopkins Sidney Kimmel Comprehensive Cancer Center; Indiana University School of Medicine; University of Pittsburgh Cancer Institute; University of Michigan Comprehensive Cancer Center; Johns Hopkins University School of Medicine
| | - JM Rae
- Johns Hopkins Sidney Kimmel Comprehensive Cancer Center; Indiana University School of Medicine; University of Pittsburgh Cancer Institute; University of Michigan Comprehensive Cancer Center; Johns Hopkins University School of Medicine
| | - D Zeruesenay
- Johns Hopkins Sidney Kimmel Comprehensive Cancer Center; Indiana University School of Medicine; University of Pittsburgh Cancer Institute; University of Michigan Comprehensive Cancer Center; Johns Hopkins University School of Medicine
| | - AT Nguyen
- Johns Hopkins Sidney Kimmel Comprehensive Cancer Center; Indiana University School of Medicine; University of Pittsburgh Cancer Institute; University of Michigan Comprehensive Cancer Center; Johns Hopkins University School of Medicine
| | - NL Henry
- Johns Hopkins Sidney Kimmel Comprehensive Cancer Center; Indiana University School of Medicine; University of Pittsburgh Cancer Institute; University of Michigan Comprehensive Cancer Center; Johns Hopkins University School of Medicine
| | - AM Storniolo
- Johns Hopkins Sidney Kimmel Comprehensive Cancer Center; Indiana University School of Medicine; University of Pittsburgh Cancer Institute; University of Michigan Comprehensive Cancer Center; Johns Hopkins University School of Medicine
| | - DF Hayes
- Johns Hopkins Sidney Kimmel Comprehensive Cancer Center; Indiana University School of Medicine; University of Pittsburgh Cancer Institute; University of Michigan Comprehensive Cancer Center; Johns Hopkins University School of Medicine
| | - RS Blumenthal
- Johns Hopkins Sidney Kimmel Comprehensive Cancer Center; Indiana University School of Medicine; University of Pittsburgh Cancer Institute; University of Michigan Comprehensive Cancer Center; Johns Hopkins University School of Medicine
| | - P Ouyang
- Johns Hopkins Sidney Kimmel Comprehensive Cancer Center; Indiana University School of Medicine; University of Pittsburgh Cancer Institute; University of Michigan Comprehensive Cancer Center; Johns Hopkins University School of Medicine
| | - W Post
- Johns Hopkins Sidney Kimmel Comprehensive Cancer Center; Indiana University School of Medicine; University of Pittsburgh Cancer Institute; University of Michigan Comprehensive Cancer Center; Johns Hopkins University School of Medicine
| | - DA Flockhart
- Johns Hopkins Sidney Kimmel Comprehensive Cancer Center; Indiana University School of Medicine; University of Pittsburgh Cancer Institute; University of Michigan Comprehensive Cancer Center; Johns Hopkins University School of Medicine
| | - V Stearns
- Johns Hopkins Sidney Kimmel Comprehensive Cancer Center; Indiana University School of Medicine; University of Pittsburgh Cancer Institute; University of Michigan Comprehensive Cancer Center; Johns Hopkins University School of Medicine
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Weng L, Ziliak D, Im HK, Gamazon ER, Philips S, Nguyen AT, Desta Z, Skaar TC, Flockhart DA, Huang RS. Genome-wide discovery of genetic variants affecting tamoxifen sensitivity and their clinical and functional validation. Ann Oncol 2013; 24:1867-1873. [PMID: 23508821 PMCID: PMC3690911 DOI: 10.1093/annonc/mdt125] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 02/12/2013] [Accepted: 02/14/2013] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Beyond estrogen receptor (ER), there are no validated predictors for tamoxifen (TAM) efficacy and toxicity. We utilized a genome-wide cell-based model to comprehensively evaluate genetic variants for their contribution to cellular sensitivity to TAM. DESIGN Our discovery model incorporates multidimensional datasets, including genome-wide genotype, gene expression, and endoxifen-induced cellular growth inhibition in the International HapMap lymphoblastoid cell lines (LCLs). Genome-wide findings were further evaluated in NCI60 cancer cell lines. Gene knock-down experiments were performed in four breast cancer cell lines. Genetic variants identified in the cell-based model were examined in 245 Caucasian breast cancer patients who underwent TAM treatment. RESULTS We identified seven novel single-nucleotide polymorphisms (SNPs) associated with endoxifen sensitivity through the expression of 10 genes using the genome-wide integrative analysis. All 10 genes identified in LCLs were associated with TAM sensitivity in NCI60 cancer cell lines, including USP7. USP7 knock-down resulted in increasing resistance to TAM in four breast cancer cell lines tested, which is consistent with the finding in LCLs and in the NCI60 cells. Furthermore, we identified SNPs that were associated with TAM-induced toxicities in breast cancer patients, after adjusting for other clinical factors. CONCLUSION Our work demonstrates the utility of a cell-based model in genome-wide identification of pharmacogenomic markers.
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Affiliation(s)
| | | | - H K Im
- Health Studies, University of Chicago, Chicago
| | | | - S Philips
- Department of Medicine, Division of Clinical Pharmacology, School of Medicine, Indiana University, Indianapolis, USA
| | - A T Nguyen
- Department of Medicine, Division of Clinical Pharmacology, School of Medicine, Indiana University, Indianapolis, USA
| | - Z Desta
- Department of Medicine, Division of Clinical Pharmacology, School of Medicine, Indiana University, Indianapolis, USA
| | - T C Skaar
- Department of Medicine, Division of Clinical Pharmacology, School of Medicine, Indiana University, Indianapolis, USA
| | - D A Flockhart
- Department of Medicine, Division of Clinical Pharmacology, School of Medicine, Indiana University, Indianapolis, USA
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Hartmaier RJ, Richter AS, Gillihan RM, Sallit JZ, McGuire SE, Wang J, Lee AV, Osborne CK, O'Malley BW, Brown PH, Xu J, Skaar TC, Philips S, Rae JM, Azzouz F, Li L, Hayden J, Henry NL, Nguyen AT, Stearns V, Hayes DF, Flockhart DA, Oesterreich S. A SNP in steroid receptor coactivator-1 disrupts a GSK3β phosphorylation site and is associated with altered tamoxifen response in bone. Mol Endocrinol 2011; 26:220-7. [PMID: 22174377 DOI: 10.1210/me.2011-1032] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The coregulator steroid receptor coactivator (SRC)-1 increases transcriptional activity of the estrogen receptor (ER) in a number of tissues including bone. Mice deficient in SRC-1 are osteopenic and display skeletal resistance to estrogen treatment. SRC-1 is also known to modulate effects of selective ER modulators like tamoxifen. We hypothesized that single nucleotide polymorphisms (SNP) in SRC-1 may impact estrogen and/or tamoxifen action. Because the only nonsynonymous SNP in SRC-1 (rs1804645; P1272S) is located in an activation domain, it was examined for effects on estrogen and tamoxifen action. SRC-1 P1272S showed a decreased ability to coactivate ER compared with wild-type SRC-1 in multiple cell lines. Paradoxically, SRC-1 P1272S had an increased protein half-life. The Pro to Ser change disrupts a putative glycogen synthase 3 (GSK3)β phosphorylation site that was confirmed by in vitro kinase assays. Finally, knockdown of GSK3β increased SRC-1 protein levels, mimicking the loss of phosphorylation at P1272S. These findings are similar to the GSK3β-mediated phospho-ubiquitin clock previously described for the related coregulator SRC-3. To assess the potential clinical significance of this SNP, we examined whether there was an association between SRC-1 P1272S and selective ER modulators response in bone. SRC-1 P1272S was associated with a decrease in hip and lumbar bone mineral density in women receiving tamoxifen treatment, supporting our in vitro findings for decreased ER coactivation. In summary, we have identified a functional genetic variant of SRC-1 with decreased activity, resulting, at least in part, from the loss of a GSK3β phosphorylation site, which was also associated with decreased bone mineral density in tamoxifen-treated women.
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Affiliation(s)
- R J Hartmaier
- Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, Texas 77030, USA
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Desta Z, Kreutz Y, Nguyen AT, Li L, Skaar T, Kamdem LK, Henry NL, Hayes DF, Storniolo AM, Stearns V, Hoffmann E, Tyndale RF, Flockhart DA. Plasma letrozole concentrations in postmenopausal women with breast cancer are associated with CYP2A6 genetic variants, body mass index, and age. Clin Pharmacol Ther 2011; 90:693-700. [PMID: 21975350 DOI: 10.1038/clpt.2011.174] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The associations between plasma letrozole concentrations and CYP2A6 and CYP3A5 genetic variants were tested in the Exemestane and Letrozole Pharmacogenomics (ELPH) trial. ELPH is a multicenter, open-label prospective clinical trial in women randomly assigned (n≈250 in each arm) to receive 2 years of treatment with either oral letrozole (2.5 mg/day) or oral exemestane (25 mg/day). CYP2A6 and CYP3A showed effects on letrozole metabolism in vitro. DNA samples were genotyped for variants in the CYP2A6 and CYP3A5 genes. Plasma letrozole concentrations showed high interpatient variability (>10-fold) and were associated significantly with CYP2A6 genotypes (P<0.0001), body mass index (BMI) (P<0.0001), and age (P=0.0035). However, CYP3A5 genotypes showed no association with plasma letrozole concentrations. These data suggest that CYP2A6 is the principal clearance mechanism for letrozole in vivo. CYP2A6 metabolic status, along with BMI and age, may serve as a biomarker of the efficacy of letrozole treatment or a predictor of adverse effects.
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Affiliation(s)
- Z Desta
- Department of Medicine, Indiana University, Indianapolis, Indiana, USA.
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20
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Rae JM, Sikora MJ, Henry NL, Li L, Kim S, Oesterreich S, Skaar TC, Nguyen AT, Desta Z, Storniolo AM, Flockhart DA, Hayes DF, Stearns V. Cytochrome P450 2D6 activity predicts discontinuation of tamoxifen therapy in breast cancer patients. Pharmacogenomics J 2009; 9:258-64. [PMID: 19421167 DOI: 10.1038/tpj.2009.14] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The selective estrogen receptor modulator tamoxifen is routinely used for treatment and prevention of estrogen-receptor-positive breast cancer. Studies of tamoxifen adherence suggest that over half of patients discontinue treatment before the recommended 5 years. We hypothesized that polymorphisms in CYP2D6, the enzyme responsible for tamoxifen activation, predict for tamoxifen discontinuation. Tamoxifen-treated women (n=297) were genotyped for CYP2D6 variants and assigned a 'score' based on predicted allele activities from 0 (no activity) to 2 (high activity). Correlation between CYP2D6 score and discontinuation rates at 4 months was tested. We observed a strong nonlinear correlation between higher CYP2D6 score and increased rates of discontinuation (r(2)=0.935, P=0.018). These data suggest that presence of active CYP2D6 alleles may predict for higher likelihood of tamoxifen discontinuation. Therefore, patients who may be most likely to benefit from tamoxifen may paradoxically be most likely to discontinue treatment prematurely.
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Affiliation(s)
- J M Rae
- Breast Oncology Program, Department of Internal Medicine, University of Michigan Comprehensive Cancer Center, Ann Arbor, MI 48109-0612, USA.
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Ntukidem NI, Nguyen AT, Stearns V, Rehman M, Schott A, Skaar T, Jin Y, Blanche P, Li L, Lemler S, Hayden J, Krauss RM, Desta Z, Flockhart DA, Hayes DF. Estrogen receptor genotypes, menopausal status, and the lipid effects of tamoxifen. Clin Pharmacol Ther 2007; 83:702-10. [PMID: 17713466 PMCID: PMC2782693 DOI: 10.1038/sj.clpt.6100343] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Tamoxifen induces important changes in serum lipid profiles in some women; however, little information is available to predict which women will experience improved lipid profiles during tamoxifen therapy. As part of a multicenter prospective observational trial in 176 breast cancer patients, we tested the hypothesis that tamoxifen-induced lipid changes were associated with genetic variants in candidate target genes (CYP2D6, ESR1, and ESR2). Tamoxifen lowered low-density lipoprotein cholesterol (P<0.0001) by 23.5 mg/dl (13.5-33.5 mg/dl) and increased triglycerides (P=0.006). In postmenopausal women, the ESR1-XbaI and ESR2-02 genotypes were associated with tamoxifen-induced changes in total cholesterol (P=0.03; GG vs GA/AA) and triglycerides (P=0.01; gene-dose effect), respectively. In premenopausal women, the ESR1-XbaI genotypes were associated with tamoxifen-induced changes in triglycerides (P=0.002; gene-dose effect) and high-density lipoprotein (P=0.004; gene-dose effect). Our results suggest that estrogen receptor genotyping may be useful in predicting which women would benefit more from tamoxifen.
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Affiliation(s)
- NI Ntukidem
- Department of Medicine, Indiana University, Indianapolis, Indiana, USA
| | - AT Nguyen
- Department of Medicine, Indiana University, Indianapolis, Indiana, USA
| | - V Stearns
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, Maryland, USA
| | - M Rehman
- Department of Medicine, Indiana University, Indianapolis, Indiana, USA
| | - A Schott
- Department of Internal Medicine and Breast Oncology Program, Comprehensive Cancer Center, University of Michigan Health and Hospitals System, Ann Arbor, Michigan, USA
| | - T Skaar
- Department of Medicine, Indiana University, Indianapolis, Indiana, USA
| | - Y Jin
- Department of Medicine, Indiana University, Indianapolis, Indiana, USA
| | - P Blanche
- Children's Hospital Oak land Research Institute, Oakland, California, USA
| | - L Li
- Department of Medicine, Indiana University, Indianapolis, Indiana, USA
| | - S Lemler
- Department of Medicine, Indiana University, Indianapolis, Indiana, USA
| | - J Hayden
- Department of Internal Medicine and Breast Oncology Program, Comprehensive Cancer Center, University of Michigan Health and Hospitals System, Ann Arbor, Michigan, USA
| | - RM Krauss
- Children's Hospital Oak land Research Institute, Oakland, California, USA
| | - Z Desta
- Department of Medicine, Indiana University, Indianapolis, Indiana, USA
| | - DA Flockhart
- Department of Medicine, Indiana University, Indianapolis, Indiana, USA
| | - DF Hayes
- Department of Internal Medicine and Breast Oncology Program, Comprehensive Cancer Center, University of Michigan Health and Hospitals System, Ann Arbor, Michigan, USA
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Giacomini KM, Brett CM, Altman RB, Benowitz NL, Dolan ME, Flockhart DA, Johnson JA, Hayes DF, Klein T, Krauss RM, Kroetz DL, McLeod HL, Nguyen AT, Ratain MJ, Relling MV, Reus V, Roden DM, Schaefer CA, Shuldiner AR, Skaar T, Tantisira K, Tyndale RF, Wang L, Weinshilboum RM, Weiss ST, Zineh I. The pharmacogenetics research network: from SNP discovery to clinical drug response. Clin Pharmacol Ther 2007; 81:328-45. [PMID: 17339863 PMCID: PMC5006950 DOI: 10.1038/sj.clpt.6100087] [Citation(s) in RCA: 186] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The NIH Pharmacogenetics Research Network (PGRN) is a collaborative group of investigators with a wide range of research interests, but all attempting to correlate drug response with genetic variation. Several research groups concentrate on drugs used to treat specific medical disorders (asthma, depression, cardiovascular disease, addiction of nicotine, and cancer), whereas others are focused on specific groups of proteins that interact with drugs (membrane transporters and phase II drug-metabolizing enzymes). The diverse scientific information is stored and annotated in a publicly accessible knowledge base, the Pharmacogenetics and Pharmacogenomics Knowledge base (PharmGKB). This report highlights selected achievements and scientific approaches as well as hypotheses about future directions of each of the groups within the PGRN. Seven major topics are included: informatics (PharmGKB), cardiovascular, pulmonary, addiction, cancer, transport, and metabolism.
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Affiliation(s)
- K M Giacomini
- Department of Biopharmaceutical Sciences, University of California San Francisco, San Francisco, California, USA.
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Foltz DW, Bolton MT, Kelley SP, Kelley BD, Nguyen AT. Combined mitochondrial and nuclear sequences support the monophyly of forcipulatacean sea stars. Mol Phylogenet Evol 2006; 43:627-34. [PMID: 17113315 DOI: 10.1016/j.ympev.2006.10.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2006] [Revised: 09/21/2006] [Accepted: 10/11/2006] [Indexed: 10/24/2022]
Abstract
Previous molecular phylogenetic analyses of forcipulatacean sea stars (Echinodermata: Asteroidea) have reconstructed a non-monophyletic order Forcipulatida, provided that two or more forcipulate families are included. This result could mean that one or more assumptions of the reconstruction method was violated, or else the traditional classification could be erroneous. The present molecular phylogenetic analysis included 12 non-forcipulatacean and 39 forcipulatacean sea stars, with multiple representatives of all but one of the forcipulate families and/or subfamilies. Bayesian analysis of approximately 4.2kb of sequence data representing seven partitions (nuclear 18S rRNA and 28S rRNA, mitochondrial 12S rRNA, 16S rRNA, 5 tRNAs and cytochrome oxidase I with first and second codon positions analyzed separately from third codon positions) recovered a consensus tree with three well-supported clades (78%-100% bootstrap support) that corresponded at least approximately to traditional taxonomic ranks: the superorder Forcipulatacea (Forcipulatida + Brisingida) + Pteraster, the Brisingida/Brisingidae and Asteriidae + Rathbunaster + Pycnopodia. When a molecular clock was enforced, the partitioned Bayesian analysis recovered the traditional Forcipulatacea. Five of six genera represented by two or more species were monophyletic with 100% bootstrap support. Most of the traditional subfamilial and familial groupings within the Forcipulatida were either unresolved or non-monophyletic. The separate partitions differed considerably in estimates of model parameters, mainly between nuclear sequences (with high GC content, low rates of sequence substitution and high transition/transversion rate ratios) and mitochondrial sequences.
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Affiliation(s)
- D W Foltz
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA.
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Nguyen AT, Donaldson RP. Metal-catalyzed oxidation induces carbonylation of peroxisomal proteins and loss of enzymatic activities. Arch Biochem Biophys 2005; 439:25-31. [PMID: 15922287 DOI: 10.1016/j.abb.2005.04.018] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2005] [Revised: 04/23/2005] [Accepted: 04/25/2005] [Indexed: 11/21/2022]
Abstract
Peroxisomes are involved in oxidative metabolic reactions and have the capacity to generate large amounts of reactive oxygen species that could damage biomolecules including their own resident proteins. The purpose of this study was to determine whether peroxisomal proteins are susceptible to oxidation and whether oxidative damage affects their enzymatic activity. Peroxisomal proteins were subjected to metal-catalyzed oxidation (MCO) with CuCl(2)/ascorbate and derivatized with 2,4-dinitrophenylhydrazine which allowed for spectrophotometric quantification of carbonylation. Immunochemical detection of carbonylated peroxisomal proteins, resolved by gel electrophoresis and detected with anti-DNP antibodies, revealed five oxidatively modified proteins with the following molecular weights: 80, 66, 62, 55, and 50 kDa. The proteins at 66, 62, and 55 kDa were identified as malate synthase (MS), isocitrate lyase, and catalase (CAT), respectively. MS and CAT were estimated to contain 2-3 mol of carbonyl/mol of protein as a result of MCO. Enzymatic assays revealed varying degrees of activity loss. Isocitrate lyase and malate synthase showed significant loss of activity while catalase and malate dehydrogenase were less inhibited by carbonylation. Our findings show that peroxisomal proteins are vulnerable to MCO damage and thus may also be affected by in vivo exposure to reactive oxygen species.
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Affiliation(s)
- A T Nguyen
- Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA
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Nguyen AT, Malonne H, Duez P, Vanhaelen-Fastre R, Vanhaelen M, Fontaine J. Cytotoxic constituents from Plumbago zeylanica. Fitoterapia 2004; 75:500-4. [PMID: 15261389 DOI: 10.1016/j.fitote.2004.03.009] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2003] [Accepted: 03/29/2004] [Indexed: 11/25/2022]
Abstract
The bioassay-guided fractionation of the dichloromethane extract of aerial parts of Plumbago zeylanica led to the isolation of beta-sitosterol, beta-sitosteryl-3beta-glucopyranoside, beta-sitosteryl-3beta-glucopyranoside-6'-O-palmitate (1), lupenone, lupeol acetate, plumbagin and trilinolein. Compound 1 showed cytotoxic activity against MCF7 and Bowes cancer cell lines (IC50 113 microM and 152 microM, respectively), beta-sitosterol inhibited Bowes cell growth (IC50 36.5 microM) and plumbagin was cytotoxic against MCF7 and Bowes cells (IC50 1.28 microM and 1.39 microM, respectively).
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Affiliation(s)
- A T Nguyen
- Laboratoire de Physiologie et de Pharmacologie Fondamentales, Institut de Pharmacie CP-205/7, Université Libre de Bruxelles, B-1050 Brussels, Belgium.
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Djabarouti S, Boselli E, Allaouchiche B, Ba B, Nguyen AT, Gordien JB, Bernadou JM, Saux MC, Breilh D. Determination of levofloxacin in plasma, bronchoalveolar lavage and bone tissues by high-performance liquid chromatography with ultraviolet detection using a fully automated extraction method. J Chromatogr B Analyt Technol Biomed Life Sci 2004; 799:165-72. [PMID: 14659449 DOI: 10.1016/j.jchromb.2003.10.031] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The aim of this study was to develop a specific and sensitive high-performance liquid chromatographic (HPLC) assay for the determination of levofloxacin in human plasma, bronchoalveolar lavage and bone tissues. The sample extraction was based on a fully automated liquid-solid extraction with an OASIS cartridge. The method used ultraviolet detection set at a wavelength of 299 nm and a separation with a Supelcosil ABZ+ column. The assay has been found linear over the concentration range 0.25-25 microg/ml for levofloxacin in plasma, 1-6 microg/ml in bronchoalveolar lavage and 0.5-10 microg/g for bone tissues and it provided good validation data for accuracy and precision. The assay will be applied to determine the penetration of levofloxacin in human bronchoalveolar lavage (BAL) and bone tissues during pharmacokinetic steady state.
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Affiliation(s)
- S Djabarouti
- Pharmacy Haut-Lévêque Hospital, Magellan Avenue, 33604 Pessac, France
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Jungers P, Massy ZA, Nguyen-Khoa T, Choukroun G, Robino C, Fakhouri F, Touam M, Nguyen AT, Grünfeld JP. Longer duration of predialysis nephrological care is associated with improved long-term survival of dialysis patients. Nephrol Dial Transplant 2001; 16:2357-64. [PMID: 11733627 DOI: 10.1093/ndt/16.12.2357] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Late nephrological referral of chronic renal failure patients has been shown to be associated with high morbidity and short-term mortality on dialysis. However, the impact of predialysis nephrological care duration (PNCD) on the long-term survival of dialysis patients had not been evaluated. METHODS We studied data from all 1057 consecutive patients who started dialysis treatment at the Necker Hospital from 1989 to 1998 (mean age at start of dialysis 53.8+/-17.2 years (range 18-91 years), excluding from analysis patients who presented with acute renal failure (n=60) or advanced malignancy (n=35). We evaluated the effects of PNCD and clinical risk factors on all-cause mortality after long-term follow-up on dialysis. RESULTS Among the 1057 patients analysed (13.2% diabetics), PNCD was <6 months in 258 patients, 6-35 months in 267 patients, 36-71 months in 227 patients and >or=72 months in 307 patients. Cardiovascular (CV) morbidity, namely a history of myocardial or cerebral infarction, peripheral arteriopathy, and/or cardiac failure, before starting dialysis was 39.6% and 37.4%, respectively, in patients followed for <6 months or 6-35 months, compared with 24.4% in those followed for 36-71 months and 19.9% in those followed for >or=72 months (P<0.001). Five-year survival was significantly lower in patients with a PNCD of <6 months (59+/-4.1%) than for 36-71 months or >or=72 months (77.1+/-3.7 and 73.3+/-3.6%, respectively, P<0.001), but similar to those followed for 6-35 months (65.3+/-3.9%, NS). By Cox proportional hazard analysis, PNCD <6 months, age, diabetes and prior CV disease were independent predictive factors of all-cause death on dialysis. CONCLUSIONS This study provides suggestive evidence that longer duration of regular nephrological care in the predialysis period, at least for several years prior to the start of dialysis, is associated with a better long-term survival on dialysis. Such data strongly support the argument for early referral and regular nephrological care of chronic renal failure patients.
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Affiliation(s)
- P Jungers
- Department of Nephrology, Necker Hospital, Paris, France.
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Stoll HP, Hutchins GD, Winkle WL, Nguyen AT, Appledorn CR, Janzen I, Seifert H, Rübe C, Schieffer H, March KL. Advantages of short-lived positron-emitting radioisotopes for intracoronary radiation therapy with liquid-filled balloons to prevent restenosis. J Nucl Med 2001; 42:1375-83. [PMID: 11535728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
UNLABELLED Balloon catheters filled with liquid radioisotopes provide excellent dose homogeneity for intracoronary radiation therapy but are associated with risk for rupture or leakage. We hypothesized that the safety of liquid-filled balloons may be improved once positron emitters with half-lives below 2 h are used instead of the high-energy beta-emitters 166Ho, 186Re, or 188Re, all of which have a longer half-life of at least 17 h. METHODS To support this concept, the suitability of 18F (half-life, 109.8 min), 68Ga (half-life, 67.6 min), 11C (half-life, 20.4 min), 13N (half-life, 9.97 min), and 15O (half-life, 2.04 min) for intracoronary radiation therapy was evaluated. Potential tissue penetration of positron radiation was assessed in a series of phantom experiments using Gafchromic film. Antiproliferative efficacy of positrons emitted by 68Ga was investigated in vitro using cultured bovine aortic smooth muscle cells (BASMCs), and was compared with gamma-radiation emitted by 137Cs. To characterize the remaining risk, we estimated radiotoxicity after accidental intravascular balloon rupture on the basis of tabulated isotope-specific doses (ICRP 53) and compared these values with 188Re. RESULTS Half-dose depth of tissue penetration measured in phantom experiments was 0.29 mm for 18F, 0.42 mm for 11C, 0.54 mm for 13N, 0.79 mm for 15O, and 0.9 mm for 68Ga. Irradiation of cultured BASMCs with positron radiation (68Ga) induced dose-dependent inhibition of proliferation with complete proliferative arrest at doses exceeding 6 Gy. ED(50) and ED(80) were 2.5 +/- 0.4 Gy (mean +/- SD) and 4.4 +/- 0.8 Gy, respectively. Antiproliferative efficacy was equal to that of the 662-keV gamma-radiation emitted by 137Cs (ED(50), 3.8 +/- 0.2 Gy; ED(80), 8.0 +/- 0.3 Gy). Estimates made for patient whole-body and organ doses were generally below 50 mSv/1.85 GBq for all investigated positron emitters. The same dose estimates for 188Re were 6-20 fold higher. CONCLUSION Among the studied radioisotopes, 68Ga is the most attractive source for liquid-filled balloons because of its convenient half-life, sufficient positron energy (2.92 MeV), documented antiproliferative efficacy, and uncomplicated availability from a radioisotope generator. The safety profile for 68Ga is significantly better than that of 188Re, which suggests this radioisotope should be evaluated further in preclinical studies.
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Affiliation(s)
- H P Stoll
- Medical Clinic III, Cardiology, Department of Radiation Oncology, University Hospital Homburg/Saar, Germany
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Stoll HP, Hutchins GD, Winkle WL, Nguyen AT, Hou D, Appledorn CR, Romeike B, March KL. Liquid-filled balloon brachytherapy using (68)Ga is effective and safe because of the short 68-minute half-life: results of a feasibility study in the porcine coronary overstretch model. Circulation 2001; 103:1793-8. [PMID: 11282912 DOI: 10.1161/01.cir.103.13.1793] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Liquid-filled balloons for coronary brachytherapy provide significant advantages over solid sources in dose homogeneity but carry the risk of life-threatening radiointoxication after balloon rupture and laboratory contamination in case of a spill. We hypothesized that the positron emitter (68)Ga, with a half-life of only 68 minutes, was well suited to overcome these safety obstacles while providing full therapeutic efficacy. METHODS AND RESULTS The feasibility, efficacy, and safety of (68)Ga liquid-filled balloon brachytherapy were investigated in the porcine coronary overstretch model. Four groups of 5 balloon-induced coronary lesions were irradiated with 8, 12, 16, and 24 Gy targeted to the adventitia. Ten unirradiated lesions served as controls. Segments treated with 16 or 24 Gy exhibited marked suppression of neointimal proliferation at 28-day follow-up, with quantitative parameters of intraluminal proliferation reduced to <20%. This beneficial effect was not compromised by untoward edge effects. Uninjured but irradiated vessels did not show histological signs of radiation damage. The (68)Ga whole-body dose due to balloon rupture was estimated to be 5 rem/50 mCi treatment activity and compared favorably with that of (188)Re (78 rem/50 mCi). CONCLUSIONS (68)Ga positron radiation suppresses neointimal proliferation at doses of 16 and 24 Gy. This biological efficacy, coupled with the attractive safety profile, suggests the selection of (68)Ga as an attractive isotope for liquid-filled balloon brachytherapy.
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Affiliation(s)
- H P Stoll
- Krannert Institute of Cardiology, Indianapolis, IN, USA.
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Abstract
OBJECTIVES To describe the presentation, management, and clinical outcome of patients with genitourinary melanoma. METHODS We identified 14 patients with genitourinary melanoma treated at Memorial Sloan-Kettering Cancer Center, New York and Tripler Army Medical Center, Honolulu, Hawaii. The presentation, surgical treatment, disease progression, and outcome of these patients were reviewed. Survival was analyzed, using the Kaplan-Meier product limit method. RESULTS The presentation and management of patients with genitourinary melanoma were varied. Overall, the prognosis was poor, with a median survival of 43 months, and only 3 patients were alive, without disease, at last follow-up. Our findings confirm a poor prognosis in patients with this rare disease. CONCLUSIONS Genitourinary melanoma is a rare form of the disease with an unfavorable clinical outcome. Less than one third of patients survive long term, although patients with scrotal melanomas may have a better prognosis.
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Affiliation(s)
- A T Nguyen
- Weill Medical College of Cornell University, New York, New York, USA
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Jungers P, Choukroun G, Oualim Z, Robino C, Nguyen AT, Man NK. Beneficial influence of recombinant human erythropoietin therapy on the rate of progression of chronic renal failure in predialysis patients. Nephrol Dial Transplant 2001; 16:307-12. [PMID: 11158405 DOI: 10.1093/ndt/16.2.307] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Partial correction of anaemia with recombinant human erythropoietin (rHuEpo) has been shown to markedly improve the general condition and quality of life of predialysis patients, but the effects of rHuEpo therapy on blood pressure and the rate of progression of chronic renal failure (CRF) are still disputed. In particular, no study evaluated the time duration until the start of maintenance dialysis in treated patients, compared to untreated predialysis patients. METHODS We retrospectively evaluated the rate of decline of creatinine clearance (Delta Ccr) and the duration of the predialysis period in 20 patients with advanced CRF treated with rHuEpo (Epo+ group), and in 43 patients with a similar degree of CRF but with less marked, asymptomatic anaemia, not requiring rHuEpo therapy (Epo- group). All patients were submitted to identical clinical and laboratory surveillance. All received similar oral supplementation with B(6), B(9), and B(12) vitamins and oral iron supplementation. Maintenance dose of subcutaneous epoetin was 54.3+/-16.5 U/kg/week (median dose 3300 U/week). RESULTS Initial and final haemoglobin (Hb) levels were 8.8+/-0.7 and 11.3+/-0.9 g/dl in the Epo+ group, vs 10.9+/-1.2 and 9.5+/-0.9 g/dl in the Epo- group. In the Epo+ group, Delta Ccr declined from 0.36+/-0.16 during the preceding 24 months to 0.26+/-0.15 ml/min/ 1.73 m(2)/month after the start of rHuEpo therapy (P<0.05). No significant variation was observed in the Epo- group. Time duration until the start of dialysis was 16.2+/-11.9 in the Epo+ group, compared to 10.6+/-6.1 months in the Epo- group (P<0.01). Slowing of progression was observed in 10 Epo+ patients, whereas no significant variation in Delta Ccr occurred in the other 10. There was no difference in previous Delta Ccr rate, nor in Hb or blood pressure levels while on rHuEpo therapy between the two subgroups. CONCLUSIONS Our study affords conclusive evidence that rHuEpo therapy did not result in accelerated progression of CRF in any treated predialysis patients, nor deleterious increase in blood pressure, but instead resulted in significant slowing of progression and substantial retardation of maintenance dialysis. Such encouraging results remain to be validated in a large prospective, randomized study.
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Affiliation(s)
- P Jungers
- Department of Nephrology and INSERM U 507, Necker Hospital, Paris, France
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Abstract
CONTEXT The effectiveness of dietary modification in reducing low-density lipoprotein cholesterol (LDL-C) levels can be reliably predicted for populations, but not for individuals. OBJECTIVE To determine whether individual variation in cholesterol response to dietary modification is a familial trait. DESIGN Two-period, outpatient crossover trial conducted from September 1997 to September 1999. SETTING AND PARTICIPANTS Fifty-six families from the Dallas-Ft Worth, Tex, area with 2 biological parents and at least 2 children aged 5 years or older volunteered; 46 families (n = 92 adults and n = 134 children) completed the study. INTERVENTION All families followed two 5-week dietary regimens that included individualized daily dietary prescriptions and emphasized a low-saturated fat diet supplemented with specially manufactured baked goods and spreadable fat. One regimen used butter only and the other used margarine only. MAIN OUTCOME MEASURE Mean LDL-C levels during the last 2 weeks of each dietary period. RESULTS Margarine intake compared with butter intake lowered LDL-C levels 11% in adults (95% confidence interval [CI], 13% to 9%) and 9% in children (95% CI, 12% to 6%) (P<.001 for both adults and children). The distribution of individual responses were peaked around the mean response. For adults and children together, family membership accounted for 19% of variability in response (P =.007). In children, family membership accounted for 40% of variability in response of percent change in LDL-C levels (P =.002). Body mass index and change in cholesterol ester (CE) 18:2/18:1 ratio accounted for 26% of variation, leaving 26% still attributable to family membership. In all participants, BMI predicted response-heavier individuals had higher LDL-C levels, less excursion in CE fatty acids, and less LDL-C response to dietary change. CONCLUSIONS Our results suggest that individual variation in response to a cholesterol-lowering diet is a familial trait. Body weight is an important modifiable factor that influences response. JAMA. 2000;284:2740-2747.
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Affiliation(s)
- M A Denke
- Department of Internal Medicine, Center for Human Nutrition, 5323 Harry Hines Blvd, Room Y3.234, Dallas, TX 75390-9052, USA.
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Abstract
OBJECTIVE A novel lipodystrophy syndrome characterized by truncal adiposity, peripheral fat atrophy, type 2 diabetes mellitus, and dyslipidemia occurs in HIV-infected individuals, and may be aggravated by HIV-1 protease inhibitors. The increase in truncal fat could be due to enhanced preadipocyte differentiation. Using the 3T3-L1 preadipocyte model, we reported that ritonavir enhances adipocyte differentiation in culture. The goal of this study was to characterize the molecular mechanism of ritonavir on preadipocyte differentiation. DESIGNS AND METHODS Time course studies of 3T3-L1 preadipocytes placed in standard differentiation medium (insulin, dexamethasone, and isobutylmethylxanthine) were performed. Glycerol phosphate dehydrogenase (GPDH) was assayed enzymatically, and triacylglycerol (TG) mass was quantified. The adipogenic transcription factors adipocyte determination and differentiation-dependent factor 1 (ADD-1)/sterol regulatory element binding protein 1 (SREBP-1), CCAAT/enhancer-binding protein-alpha (CEBPalpha), and peroxisome proliferator activated receptor-gamma (PPARgamma), were measured by Western analysis. RESULTS Ritonavir (10 microg/ml) enhanced 3T3-L1 preadipocyte differentiation (30% increase in TG mass; 50% increase in GPDH activity), and transiently raised levels of the 68 kDa active mature form of ADD-1/SREBP-1 during adipogenesis by threefold, compared with standard differentiation. In contrast, ritonavir attenuated the differentiation-induced increase in CEBPalpha and PPARgamma. CONCLUSIONS Our data suggest that ritonavir enhances 3T3-L1 adipogenesis by increasing the level of active mature ADD-1/SREBP-1. This effect may be due to reduced proteolysis of ADD-1/SREBP-1, as ritonavir inhibits an N-acetyl-leucyl-leucyl-norleucinal (ALLN)-sensitive proteosomal degradation pathway in lymphocytes, and ALLN itself inhibits the breakdown of mature ADD-1/SREBP-1. As mature ADD-1/SREBP-1 regulates several lipogenic enzymes, higher levels may explain the effect of ritonavir on TG accumulation and GPDH activity. Studying ADD-1/SREBP-1 may lead to better understanding and prevention of the lipodystrophy syndrome.
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Affiliation(s)
- A T Nguyen
- Department of Medicine and Biochemistry, Ottawa Hospital Loeb Research Institute, University of Ottawa, ON, Canada
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Abstract
Posterior microphthalmos is a rare condition in which the anterior segment is normal in size and configuration, but the posterior segment is reduced in size; this results in axial hyperopia and retinal folding. Patients have decreased vision that is caused by posterior segment abnormalities, high refractive error, and amblyopia. We present a case of posterior microphthalmos in which retinal function was relatively intact and visual loss was believed to be primarily caused by refractive error and amblyopia. After treatment, the child's visual acuity and school performance improved. This case emphasizes the need for careful examination, refraction, and follow-up for these children because their visual potential may be reasonably good.
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Affiliation(s)
- A T Nguyen
- Department of Ophthalmology, University of Maryland School of Medicine, Baltimore 21201, USA
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Nguyen BH, Nguyen KP, McPhee SJ, Nguyen AT, Tran DQ, Jenkins CN. Promoting cancer prevention activities among Vietnamese physicians in California. J Cancer Educ 2000; 15:82-85. [PMID: 10879896 DOI: 10.1080/08858190009528662] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
BACKGROUND To promote prevention and early detection of cancer, the authors conducted a three-year intervention targeting Vietnamese physicians in solo practice in California. METHODS Twenty subjects who had received their medical training in Vietnam were recruited into a randomized controlled trial. The intervention included computerized or manual cancer screening reminders, continuing medical education seminars, Vietnamese-language health education materials, newsletters, and oncology data-query programs. Evaluation included chart audits for eight targeted activities pre- and post-intervention. RESULTS Before the intervention, annual physician performance rates were low for all eight activities: routine checkups (65.6%), Pap testing (13.8%), pelvic examinations (19.8%), clinical breast examinations (13.3%), mammography (6.4%), hepatitis B serologies (21.9%), hepatitis B immunizations (12.8%), and smoking cessation counseling (1.6%). After the intervention, performance rates increased significantly for smoking cessation counseling (p = 0.02), Pap testing (p = 0.004), and pelvic examinations (p = 0.01). CONCLUSIONS The results demonstrate the efficacy of an intervention targeting Vietnamese primary care physicians in promoting smoking cessation counseling, Pap testing, and pelvic examinations, but not other cancer prevention activities.
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Affiliation(s)
- B H Nguyen
- Vietnamese Community Health Promotion Project, Department of Medicine, University of California, San Francisco 94102, USA
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Jungers P, Joly D, Massy Z, Chauveau P, Nguyen AT, Aupetit J, Chadefaux B. Sustained reduction of hyperhomocysteinaemia with folic acid supplementation in predialysis patients. Nephrol Dial Transplant 1999; 14:2903-6. [PMID: 10570095 DOI: 10.1093/ndt/14.12.2903] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Moderate hyperhomocysteinaemia, as occurs in chronic renal failure patients, is an established independent risk factor for atherosclerotic arterial occlusive accidents, the incidence of which is abnormally high in such patients. Folic acid supplementation has been shown to reduce plasma homocysteine level in end-stage renal disease patients treated with haemodialysis or peritoneal dialysis, but its long-term effects in predialysis patients had not been assessed. METHODS We prospectively treated a total of 78 predialysis patients with folic acid for at least 1 year (range 12-74 months) together with oral pyridoxine and vitamin B12 supplements. Of the patients, 67 received 5 mg folic acid three times per week, whereas the other 11 patients who were treated with recombinant erythropoietin received 5 mg/day. Plasma fasting total homocysteine concentration was determined at baseline, after 3 months and at the end of follow-up. RESULTS Mean (+/-SD) plasma total homocysteine level decreased from 21.2+/-6.4 micromol/l at baseline to 14.2+/-4.6 at 3 months and remained at 12.8+/-3.7 micromol/l at the end of follow-up (average duration 2.8 years), whereas plasma creatinine rose from 268+/-129 to 399+/-234 micromol/l. Mean plasma folate concentration rose from 19+/-12 to 47+/-13 nmol/l and mean plasma vitamin B12 rose from 237+/-119 to 347+/-191 pmol/l from baseline to end of follow-up. CONCLUSIONS Moderate folic acid supplementation (2.15 mg/day) allows a substantial (40% as a mean) and sustained (up to 6 years) reduction of plasma total homocysteine level in predialysis uraemic patients without any detectable side effect. Folic acid supplementation may thus contribute to lower the risk of accelerated atherosclerosis in such patients.
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Affiliation(s)
- P Jungers
- Departments of Nephrology and Biochemistry, Necker Hospital, Paris, France
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Sherwood AL, Nguyen AT, Whitaker JM, Macher BA, Stroud MR, Holmes EH. Human alpha1,3/4-fucosyltransferases. III. A Lys/Arg residue located within the alpha1,3-FucT motif is required for activity but not substrate binding. J Biol Chem 1998; 273:25256-60. [PMID: 9737990 DOI: 10.1074/jbc.273.39.25256] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Amino acid sequence alignment of human alpha1, 3/4-fucosyltransferases (FucTs) demonstrates that three highly conserved Lys residues are present in the catalytic domain of FucTs III, IV, V, and VI. Two of these sites are conserved in FucT VII, with the third located within the alpha1,3-FucT motif as a conservative change to Arg at position 223. Site-directed mutagenesis experiments were conducted to change Lys255 of FucT V (equivalent to Arg223 of FucT VII) to either Arg255 or Ala255. Enzyme assays demonstrate that the FucT V K255R mutant has a 34-fold lower specific activity than native FucT V and that the K255A mutant is inactive. Site-directed mutagenesis of FucT VII was also conducted to change Arg223 to Lys223 for analysis of the effect on enzyme kinetic parameters. No differences in acceptor specificities or Km values for either substrate were observed between native FucT VII and the R223K mutant; however, the purified R223K mutant enzyme had a 2-fold increased specific activity compared with purified native FucT VII. No change in GDP-fucose-protectable pyridoxal-P/NaBH4 inactivation was observed for native or mutant FucT V or VII, further supporting the absence of involvement of this residue in sugar nucleotide binding. The results indicate that a basic residue in this position is required for enzyme activity, with a Lys residue providing higher intrinsic activity. The lack of influence of this site on substrate binding parameters and its location within the alpha1,3-FucT motif suggest that at least some of the residues within this motif are involved in catalysis rather than substrate binding.
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Affiliation(s)
- A L Sherwood
- Division of Cell Surface Biochemistry, Northwest Hospital, Pacific Northwest Cancer Foundation, Seattle, Washington 98125, USA
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Nguyen AT, Holmes EH, Whitaker JM, Ho S, Shetterly S, Macher BA. Human alpha1,3/4-fucosyltransferases. I. Identification of amino acids involved in acceptor substrate binding by site-directed mutagenesis. J Biol Chem 1998; 273:25244-9. [PMID: 9737988 DOI: 10.1074/jbc.273.39.25244] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
In a previous study (Xu, Z., Vo, L., and Macher, B. A. (1996) J. Biol. Chem. 271, 8818-8823), a domain swapping approach demonstrated that a region of amino acids found in human alpha1, 3/4-fucosyltransferase III (FucT III) conferred a significant increase in alpha1,4-FucT acceptor substrate specificity into alpha1, 3-fucosyltransferase V (FucT V), which, under the same assay conditions, has extremely low alpha1,4-FucT acceptor substrate specificity. In the current study, site-directed mutagenesis was utilized to identify which of the eight amino acids, associated with alpha1,4-FucT acceptor substrate specificity, is/are responsible for conferring this new property. The results demonstrate that increased alpha1,4-FucT activity with both disaccharide and glycolipid acceptors can be conferred on FucT V by modifying as few as two (Asn86 to His and Thr87 to Ile) of the eight amino acids originally swapped from FucT III into the FucT V sequence. Neither single amino acid mutant had increased alpha1,4-FucT activity relative to that of FucT V. Kinetic analyses of FucT V mutants demonstrated a reduced Km for Galbeta1,3GlcNAc (type 1) acceptor substrates compared with native FucT V. However, this was about 20-fold higher than that found for native FucT III, suggesting that other amino acids in FucT III must contribute to its overall binding site for type 1 substrates. These results demonstrate that amino acid residues near the amino terminus of the catalytic domain of FucT III contribute to its acceptor substrate specificity.
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Affiliation(s)
- A T Nguyen
- Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, California 94132, USA
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Witko-Sarsat V, Friedlander M, Nguyen Khoa T, Capeillère-Blandin C, Nguyen AT, Canteloup S, Dayer JM, Jungers P, Drüeke T, Descamps-Latscha B. Advanced oxidation protein products as novel mediators of inflammation and monocyte activation in chronic renal failure. J Immunol 1998; 161:2524-32. [PMID: 9725252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
We previously demonstrated the presence of advanced oxidation protein products (AOPP), a novel marker of oxidative stress in the plasma of uremic patients receiving maintenance dialysis. The present study in a cohort of 162 uremic patients showed that plasma concentrations of AOPP increased with progression of chronic renal failure and were closely related to advanced glycation end products (AGE)-pentosidine (r = 0.52, p < 0.001), taken as a marker of AGE. In vivo, the relevance of AOPP and AGE-pentosidine in monocyte-mediated inflammatory syndrome associated with uremia was evidenced by close correlations between AOPP or AGE-pentosidine and monocyte activation markers, including neopterin, IL-1R antagonist, TNF-alpha, and TNF soluble receptors (TNF-sR55 and TNF-sR75). To determine the mechanisms by which AOPP and AGE could be directly involved in monocyte activation, AOPP-human serum albumin (HSA) and AGE-HSA were produced in vitro by treating HSA with oxidants or glucose, respectively. Spectroscopic analysis confirmed that AOPP-HSA contains carbonyls and dityrosine. Both AOPP-HSA and AGE-HSA, but not purified dityrosine, were capable of triggering the oxidative burst of human monocytes in cultures. The AOPP-HSA-induced respiratory burst was dependent on the chlorinated nature of the oxidant and on the molar ratio HSA/HOCI. Collectively, these data first demonstrate that AOPP act as a mediator of oxidative stress and monocyte respiratory burst, which points to monocytes as both target and actor in the immune dysregulation associated with chronic uremia.
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Affiliation(s)
- V Witko-Sarsat
- Institut National de la Santé et de la Recherche Médicale, Unit 90, Paris, France
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Abstract
The mechanism by which increased dietary intake of calcium reduces blood pressure in the spontaneously hypertensive rat is unknown. The present studies were designed to determine if there were alterations in the activity of the major membrane ion translocating pump, sodium, potassium-ATPase (NKA), in the kidneys of hypertensive rats and whether increased dietary calcium intake affected the activity of this enzyme. Fifteen-week old SHR's were found to have lower total ATPase activity in microsomal preparations from the kidney than age matched Wistar-Kyoto animals. Both the ouabain-sensitive component (NKA) and the ouabain-insensitive component were lower in SHR. Increasing dietary calcium intake from 1% to 3% elevated both components of the ATPase activity in SHR, but was without effect in WKY. Measurement of membrane phospholipid composition suggested that altered phospholipid composition did not account for the reduced ATPase activity observed, but indicated a reduced density of ATPase in SHR. A technique has been devised for qualitative and quantitative analysis of Na, K-ATPase alpha isoforms using RT-PCR. This technique reveals that the alpha 1 isoform is the sole catalytic isoform present in the nephron. Accurate and precise quantification of the amount of gene expression in individual nephron segments is reported and will be applied to determine whether dietary calcium influences blood pressure by a mechanism which alters nephron NKA gene expression.
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Affiliation(s)
- A T Nguyen
- Institute of Molecular Medicine, University of Texas Health Science Center, Houston 77030, USA
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Jungers P, Skhiri H, Zingraff J, Muller S, Fumeron C, Giatras I, Touam M, Nguyen AT, Man NK, Grünfeld JP. [Benefits of early nephrological management of chronic renal failure]. Presse Med 1997; 26:2-5. [PMID: 9615701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVES We evaluated whether early nephrological referral of patients with chronic renal failure (CRF) resulted in improved condition of patients at initiation of maintenance dialysis and in better outcome on dialysis. PATIENTS AND METHODS We prospectively recorded clinical status, laboratory parameters, length of hospital stay and outcome of 900 CRF patients who started maintenance dialysis at Necker hospital between January 1989 and December 1996. We compared patients who benefited regular nephrological follow-up, and patients who were referred in emergency conditions at the ultimate stage of CRF. RESULTS Among the 900 patients, 731 (81.2%) had regular nephrological follow-up, including 632 (70.2%, group IA) with optimal preparation to dialysis and 99 (11%, group IB) whose clinical course was complicated due to heavy comorbidity, whereas 169 (18.8%, group II) had no previous nephrological management. Over the 8-year observation period, the proportion of the latter group did not decrease. Late referred patients had higher blood pressure level, more frequent fluid overload, higher serum levels of urea, creatinine, uric acid and phosphate, and lower levels of bicarbonate, calcium, albumin and creatinine clearance that did well-prepared patients. Mean (+/- SD) hospital stay was 29.7 +/- 15.8 days in the former compared to only 4.8 +/- 3.3 days (p < 0.001) in the latter. Early deaths within 3 months of dialysis initiation were more frequent (7.1 vs 1.6% p < 0.05) and less patients subsequently were able to be treated out-center (20.1 vs 40.7%, p < 0.05) in group II than in group IA. The overcost induced by late referral may be estimated at 0.25 million French francs per patient. CONCLUSION An unjustified late nephrological referral of CRF patients still is observed in nearly 20% of cases. Such late referral is detrimental to both patients in terms of altered quality of life and long hospital stay, and to the collectivity due to heavy overcost. Closer cooperation between family physicians and nephrologists is needed to provide optimal management and allow timely preparation to maintenance dialysis of CRF patients.
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Affiliation(s)
- P Jungers
- Département de Néphrologie, Hôpital Necker, Paris
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Jungers P, Skhiri H, Zingraff J, Muller S, Fumeron C, Giatras I, Touam M, Nguyen AT, Man NK, Grünfeld JP. [Benefits of early nephrological management in chronic renal failure]. Presse Med 1997; 26:1325-9. [PMID: 9365486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVES We evaluated whether early nephrological referral of patients with chronic renal failure (CRF) resulted in improved condition of patients at initiation of maintenance dialysis and in better outcome on dialysis. PATIENTS AND METHODS We prospectively recorded clinical status, laboratory parameters, length of hospital stay and outcome of 900 CRF patients who started maintenance dialysis at Necker hospital between January 1989 and December 1996. We compared patients who benefited regular nephrological follow-up, and patients who were referred in emergency conditions at the ultimate stage of CRF. RESULTS Among the 900 patients, 731 (81.2%) had regular nephrological follow-up, including 632 (70.2%, group IA) with optimal preparation to dialysis and 99 (11%, group IB) whose clinical course was complicated due to heavy comorbidity, whereas 169 (18.8%, group II) had no previous nephrological management. Over the 8-year observation period, the proportion of the latter group did not decrease. Late referred patients had higher blood pressure level, more frequent fluid overload, higher serum levels of urea, creatinine, uric acid and phosphate, and lower levels of bicarbonate, calcium, albumin and creatinine clearance that did well-prepared patients. Mean (+/- SD) hospital stay was 29.7 +/- 15.8 days in the former compared to only 4.8 +/- 3.3 days (p < 0.001) in the latter. Early deaths within 3 months of dialysis initiation were more frequent (7.1 vs 1.6%, p < 0.05) and less patients subsequently were able to be treated out-center (20.1 vs 40.7%, p < 0.05) in group II than in group IA. The overcost induced by late referral may be estimated at 0.25 million French francs per patient. CONCLUSION An unjustified late nephrological referral of CRF patients still is observed in nearly 20% of cases. Such late referral is detrimental to both patients in terms of altered quality of life and long hospital stay, and to the collectivity due to heavy overcost. Closer cooperation between family physicians and nephrologists is needed to provide optimal management and allow timely preparation to maintenance dialysis of CRF patients.
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Affiliation(s)
- P Jungers
- Département de Néphrologie, Hôpital Necker, Paris.
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Ramsay MA, Simpson BR, Nguyen AT, Ramsay KJ, East C, Klintmalm GB. Severe pulmonary hypertension in liver transplant candidates. Liver Transpl Surg 1997; 3:494-500. [PMID: 9346791 DOI: 10.1002/lt.500030503] [Citation(s) in RCA: 187] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Advanced liver disease with portal hypertension may be associated with pulmonary hypertension. A review of 1,205 consecutive liver transplant patients was made to assess the incidence and severity of pulmonary hypertension in patients with end-stage liver disease. Postoperative data were reviewed to determine if outcome was influenced and, in patients with severe pulmonary hypertension, whether pulmonary hypertension was reversed after transplantation. The hemodynamic data of 5 patients who were found to have severe pulmonary hypertension before transplantation and did not receive transplants were also reviewed. The incidence of pulmonary hypertension in the patients who received transplants was 8.5% (n = 102; mean pulmonary artery pressure, > 25 mmHg). The incidence of mild pulmonary hypertension was 6.72% (n = 81; systolic pulmonary artery pressure, 30 to 44 mmHg); that of moderate pulmonary hypertension was 1.16% (n = 14; systolic pulmonary artery pressure, 45 to 59 mmHg); and that of severe pulmonary hypertension was 0.58% (n = 7; systolic pulmonary artery pressure, > 60 mmHg). Mild and moderate pulmonary hypertension did not influence the outcome of the procedure. Severe pulmonary hypertension was associated with mortality rates of 42% at 9 months posttransplantation and 71% at 36 months posttransplantation. Only 2 of 7 patients with severe pulmonary hypertension have survived liver transplantation with a good quality of life. The remaining 5 patients continued to deteriorate with progressive right heart failure with no evidence of amelioration of the pulmonary hypertension. This experience supports the view that in most patients who have severe pulmonary hypertension associated with advanced liver disease, it is caused by fixed pathological changes in the pulmonary vasculature, is not reversible with liver transplantation, and is associated with a very high perioperative mortality rate.
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Affiliation(s)
- M A Ramsay
- Department of Anesthesiology and Pain Management, Baylor University Medical Center, Dallas, TX 75246, USA
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Kaspar M, Ramsay MA, Nguyen AT, Cogswell M, Hurst G, Ramsay KJ. Continuous small-dose tranexamic acid reduces fibrinolysis but not transfusion requirements during orthotopic liver transplantation. Anesth Analg 1997; 85:281-5. [PMID: 9249100 DOI: 10.1097/00000539-199708000-00007] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Tranexamic acid (TA) is a synthetic drug that inhibits fibrinolysis. It has been administered to decrease the use of blood products during cardiac surgery and orthotopic liver transplantation when infused in larger doses. A small-dose infusion of aprotinin causes a reduction in fibrinolysis and blood product requirement during orthotopic liver transplantation without apparent risk of intravascular thrombosis. This prospective study was designed to investigate whether a small-dose infusion of TA would be equally effective in reducing fibrinolysis and blood product transfusions during orthotopic liver transplantation. A double-blind, controlled study was undertaken to compare the efficacy of a small-dose TA infusion with that of a placebo. Thirty-two consecutive patients were randomized either to the TA group (n = 16), which received an intravenous infusion of 2 mg x kg(-1) x h(-1), or to the control group (n = 16), which received an identical volume of normal saline. Coagulation values were measured, a field rating was made by the surgeon, and a thromboelastogram was produced at four predetermined intervals throughout the case-before TA infusion was started, after portal vein ligation, 10 min after reperfusion, and at the end of surgery. Intraoperative transfusion requirements were recorded during the procedure and for the first 24 h postoperatively. A record was kept of any intraoperative epsilon-aminocaproic acid administered for uncontrolled fibrinolysis. The thromboelastogram clot lysis index was significant for lysis in the control group during both the anhepatic and the neohepatic phases (P < 0.01 and P < 0.05, respectively) when compared with the TA group. Fibrin degradation products were significantly increased (>20 microg/mL) in the control group at reperfusion (P < 0.03) and at the end of surgery (P < 0.01). D-dimers were also significantly increased (>1 mg/L) in the control group at the end of surgery (P < 0.04). Nine of the 16 control patients versus 3 of the 16 TA patients required epsilon-aminocaproic acid rescue for fibrinolysis. There were no other significant differences between groups. Transfusion requirements during surgery and for the first 24 h postoperatively did not differ significantly between the two groups. We conclude that the use of small-dose TA reduces fibrinolysis but not transfusion requirements during orthotopic liver transplantation.
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Affiliation(s)
- M Kaspar
- Department of Anesthesiology, Baylor University Medical Center, Dallas, Texas 75246, USA
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Marcel RJ, Ramsay MA, Hein HA, Nguyen AT, Ramsay KJ, Suit CT, Miller RD. Duration of rocuronium-induced neuromuscular block during liver transplantation: a predictor of primary allograft function. Anesth Analg 1997; 84:870-4. [PMID: 9085973 DOI: 10.1097/00000539-199704000-00031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The prolongation of vecuronium-induced neuromuscular block has been reported as a predictor of hepatic allograft dysfunction. This study investigates the duration of action of rocuronium, which also relies on hepatic clearance, to examine whether it also is prolonged with allograft dysfunction. Fifty-seven patients undergoing orthotopic liver transplant were given rocuronium (0.6 mg/kg) prior to allograft placement and the recovery of contraction of the orbicularis oculi muscle to a 2-Hz train-of-four stimulus was recorded. Fifteen minutes after reperfusion of the allograft, rocuronium (0.6 mg/kg) was administered and the time to recovery of muscle contraction to a train-of-four stimulus (train-of-four time) was again recorded. The patients were divided into two groups according to posttransplant liver function. Group I consisted of 50 patients with immediate normal liver function. Group II contained 7 patients with primary dysfunctional livers. Primary dysfunction was determined by peak serum aspartate aminotransferase and alanine aminotransferase levels > 2000 U/L, and prothrombin time > 16 s. The train-of-four time in Group II was prolonged compared with Group I (P < 0.05). Immediate graft function testing using the recovery time from rocuronium of > 150 min has a positive predictive value of 100% and a negative predictive value of 96%. The sensitivity and specificity is 71% and 100%, respectively. Receiver operating characteristic analysis supports this conclusion.
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Affiliation(s)
- R J Marcel
- Department of Anesthesiology, Baylor University Medical Center, Dallas, Texas 75246, USA
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Ramsay MA, Schmidt A, Hein HA, Nguyen AT, Lynch K, East CA, Ramsay KJ, Klintmalm GB. Nitric oxide does not reverse pulmonary hypertension associated with end-stage liver disease: a preliminary report. Hepatology 1997; 25:524-7. [PMID: 9049191 DOI: 10.1002/hep.510250304] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Pulmonary hypertension is a well known, though uncommon complication of end-stage liver disease (ESLD). Patients with severe pulmonary hypertension and ESLD undergoing orthotopic liver transplantation (OLT) may develop right ventricular failure and death. This study investigates the reversibility of pulmonary hypertension by the inhalation of nitric oxide in patients under evaluation for OLT. Ten patients with ESLD who were discovered to have moderate to severe pulmonary hypertension were administered nitric oxide via face mask in concentrations ranging from 0 to 80 ppm. Inhaled nitric oxide is a potent pulmonary vasodilator without apparent systemic effects. Nitric oxide had no demonstrable effect on mean pulmonary artery pressure (PAP) (37 vs. 37 mm Hg), transpulmonary gradient (TPG) (26 vs. 26 mm Hg), or pulmonary vascular resistance (PVR) (295 vs. 288 dynes x sec x cm (-5)). Two patients were discovered to have an elevated pulmonary artery occlusion pressure (PAOP) on baseline readings. The cause of pulmonary hypertension in these two patients was secondary to volume overload as a result of hepato-renal syndrome rather than primary pulmonary arteriolar pathology and was responsive to diuresis or dialysis but not to nitric oxide therapy. In conclusion nitric oxide does not reverse pulmonary hypertension associated with ESLD.
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Affiliation(s)
- M A Ramsay
- Department of Anesthesiology & Pain Management, Baylor University Medical Center, Dallas, TX 75246, USA
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47
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Witko-Sarsat V, Allen RC, Paulais M, Nguyen AT, Bessou G, Lenoir G, Descamps-Latscha B. Disturbed myeloperoxidase-dependent activity of neutrophils in cystic fibrosis homozygotes and heterozygotes, and its correction by amiloride. The Journal of Immunology 1996. [DOI: 10.4049/jimmunol.157.6.2728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
The present study addresses the question of a possible linkage between the cystic fibrosis (CF) genetic autosomal recessive disorder and disturbance in neutrophil function. Neutrophil-dominated chronic airway inflammation is present at an early age in children with CF, even in the absence of detectable infection. As evidenced by extracellular superoxide anion release (measured by lucigenin luminescence) or intracellular hydrogen peroxide production (measured by 2',7'-dichlorofluorescein (DCF) fluorescence), no significant difference in the nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase activity of isolated neutrophils was observed in noninfected CF children (homozygotes), their mothers or fathers (CF heterozygotes), and controls. In contrast, both myeloperoxidase (MPO)-dependent oxygenation activity (measured by luminol luminescence) and chloramine release were increased significantly in both CF homozygotes and heterozygotes as compared with controls. In the presence of either amiloride (a sodium channel inhibitor and sodium/proton antiport blocker) or EIPA (5-ethyl-N-isopropyl-amiloride, a specific inhibitor of the antiport), or choline buffer, intracellular MPO activity was decreased significantly in controls and in the CF homozygotes and heterozygotes, thus bringing intracellular MPO-dependent activity in CF subjects back to the level of controls. Extracellular release of MPO, measured by an ELISA to provide an activity-independent assessment of the enzyme, was increased only in CF homozygotes, and was decreased by amiloride and choline buffer, but not by EIPA. We conclude that a modification of intracellular pH and/or ionic concentrations may be related to the altered MPO enzymatic activity observed in CF neutrophils.
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Affiliation(s)
| | - R C Allen
- INSERM Unit 90, The Necker Hospital, Paris, France
| | - M Paulais
- INSERM Unit 90, The Necker Hospital, Paris, France
| | - A T Nguyen
- INSERM Unit 90, The Necker Hospital, Paris, France
| | - G Bessou
- INSERM Unit 90, The Necker Hospital, Paris, France
| | - G Lenoir
- INSERM Unit 90, The Necker Hospital, Paris, France
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48
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Witko-Sarsat V, Allen RC, Paulais M, Nguyen AT, Bessou G, Lenoir G, Descamps-Latscha B. Disturbed myeloperoxidase-dependent activity of neutrophils in cystic fibrosis homozygotes and heterozygotes, and its correction by amiloride. J Immunol 1996; 157:2728-35. [PMID: 8805680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The present study addresses the question of a possible linkage between the cystic fibrosis (CF) genetic autosomal recessive disorder and disturbance in neutrophil function. Neutrophil-dominated chronic airway inflammation is present at an early age in children with CF, even in the absence of detectable infection. As evidenced by extracellular superoxide anion release (measured by lucigenin luminescence) or intracellular hydrogen peroxide production (measured by 2',7'-dichlorofluorescein (DCF) fluorescence), no significant difference in the nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase activity of isolated neutrophils was observed in noninfected CF children (homozygotes), their mothers or fathers (CF heterozygotes), and controls. In contrast, both myeloperoxidase (MPO)-dependent oxygenation activity (measured by luminol luminescence) and chloramine release were increased significantly in both CF homozygotes and heterozygotes as compared with controls. In the presence of either amiloride (a sodium channel inhibitor and sodium/proton antiport blocker) or EIPA (5-ethyl-N-isopropyl-amiloride, a specific inhibitor of the antiport), or choline buffer, intracellular MPO activity was decreased significantly in controls and in the CF homozygotes and heterozygotes, thus bringing intracellular MPO-dependent activity in CF subjects back to the level of controls. Extracellular release of MPO, measured by an ELISA to provide an activity-independent assessment of the enzyme, was increased only in CF homozygotes, and was decreased by amiloride and choline buffer, but not by EIPA. We conclude that a modification of intracellular pH and/or ionic concentrations may be related to the altered MPO enzymatic activity observed in CF neutrophils.
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Welton TH, Townsend JC, Bright DC, Anderson SF, Nguyen AT, Ilsen PF. Presumed ocular tuberculosis in an AIDS patient. J Am Optom Assoc 1996; 67:350-7. [PMID: 8888856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND Prior to the advent of anti-tuberculosis medications, ocular manifestations of tuberculosis, including choroidal tubercles, were common. METHODS A 46-year-old Hispanic male with a history of AIDS, tuberculosis and treated neurosyphilis presented for examination complaining of decreased vision in the left eye. Ophthalmoscopy revealed a large, elevated, juxtapapillary lesion consistent with a choroidal tubercle or an intraocular lymphoma. RESULTS During follow-up, the lesion responded well to systemic anti-tuberculosis therapy. CONCLUSIONS With the recent increase in incidence of tuberculosis in both th general population and AIDS patients, ocular manifestations of tuberculosis once thought to be rare may be increasing. Ocular tuberculosis should be considered in the differential diagnosis of patients presenting with intraocular masses, especially in individuals at high risk for exposure.
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Friedlander MA, Witko-Sarsat V, Nguyen AT, Wu YC, Labrunte M, Verger C, Jungers P, Descamps-Latscha B. The advanced glycation endproduct pentosidine and monocyte activation in uremia. Clin Nephrol 1996; 45:379-82. [PMID: 8793229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
RATIONALE Advanced glycation endproducts (AGEs) contribute to the pathogenesis of vascular complications in diabetes, aging and end-stage renal disease (ESRD). Immune abnormalities in patients with chronic renal failure and those treated by dialysis contribute to high rates of morbidity and mortality. We therefore sought a relationship between a circulating marker of immune dysfunction and plasma levels of the AGE pentosidine. METHOD We studied non-diabetic patients with mild to advanced renal failure (n = 60), and with ESRD treated by hemodialysis (HD) (n = 44) and peritoneal dialysis (PD) (n = 19). The plasma protein content of the well characterized AGE, pentosidine was measured using HPLC. In the same samples the monocyte activation product neopterin was measured by RIA. RESULTS Plasma levels of pentosidine and neopterin increased in parallel with the progression of renal failure. Pentosidine and neopterin were highly correlated in all patients even after adjustment for Ccr. This correlation was also present in patients with ESRD. CONCLUSION These data suggest that the AGE pentosidine is associated with monocyte activation in renal failure, an interaction which may contribute to accelerated rates of complication and death by as yet unknown mechanisms.
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Affiliation(s)
- M A Friedlander
- Department of Medicine, Case-Western Reserve University, Cleveland, Ohio, USA
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