1
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Billingsley MM, Gong N, Mukalel AJ, Thatte AS, El-Mayta R, Patel SK, Metzloff AE, Swingle KL, Han X, Xue L, Hamilton AG, Safford HC, Alameh MG, Papp TE, Parhiz H, Weissman D, Mitchell MJ. In Vivo mRNA CAR T Cell Engineering via Targeted Ionizable Lipid Nanoparticles with Extrahepatic Tropism. Small 2024; 20:e2304378. [PMID: 38072809 DOI: 10.1002/smll.202304378] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 10/16/2023] [Indexed: 03/16/2024]
Abstract
With six therapies approved by the Food and Drug Association, chimeric antigen receptor (CAR) T cells have reshaped cancer immunotherapy. However, these therapies rely on ex vivo viral transduction to induce permanent CAR expression in T cells, which contributes to high production costs and long-term side effects. Thus, this work aims to develop an in vivo CAR T cell engineering platform to streamline production while using mRNA to induce transient, tunable CAR expression. Specifically, an ionizable lipid nanoparticle (LNP) is utilized as these platforms have demonstrated clinical success in nucleic acid delivery. Though LNPs often accumulate in the liver, the LNP platform used here achieves extrahepatic transfection with enhanced delivery to the spleen, and it is further modified via antibody conjugation (Ab-LNPs) to target pan-T cell markers. The in vivo evaluation of these Ab-LNPs confirms that targeting is necessary for potent T cell transfection. When using these Ab-LNPs for the delivery of CAR mRNA, antibody and dose-dependent CAR expression and cytokine release are observed along with B cell depletion of up to 90%. In all, this work conjugates antibodies to LNPs with extrahepatic tropism, evaluates pan-T cell markers, and develops Ab-LNPs capable of generating functional CAR T cells in vivo.
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Affiliation(s)
| | - Ningqiang Gong
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Alvin J Mukalel
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Ajay S Thatte
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Rakan El-Mayta
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Savan K Patel
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Ann E Metzloff
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Kelsey L Swingle
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Xuexiang Han
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Lulu Xue
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Alex G Hamilton
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Hannah C Safford
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Mohamad-Gabriel Alameh
- Department of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Tyler E Papp
- Department of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Hamideh Parhiz
- Department of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Drew Weissman
- Department of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Michael J Mitchell
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Penn Institute for RNA Innovation, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
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2
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Patel SK, Billingsley MM, Mukalel AJ, Thatte AS, Hamilton AG, Gong N, El-Mayta R, Safford HC, Merolle M, Mitchell MJ. Bile acid-containing lipid nanoparticles enhance extrahepatic mRNA delivery. Theranostics 2024; 14:1-16. [PMID: 38164140 PMCID: PMC10750194 DOI: 10.7150/thno.89913] [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] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 10/10/2023] [Indexed: 01/03/2024] Open
Abstract
Lipid nanoparticles (LNPs) have emerged as a viable, clinically-validated platform for the delivery of mRNA therapeutics. LNPs have been utilized as mRNA delivery systems for applications including vaccines, gene therapy, and cancer immunotherapy. However, LNPs, which are typically composed of ionizable lipids, cholesterol, helper lipids, and lipid-anchored polyethylene glycol, often traffic to the liver which limits the therapeutic potential of the platform. Several approaches have been proposed to resolve this tropism such as post-synthesis surface modification or the addition of synthetic cationic lipids. Methods: Here, we present a strategy for achieving extrahepatic delivery of mRNA involving the incorporation of bile acids, a naturally-occurring class of cholesterol analogs, during LNP synthesis. We synthesized a series of bile acid-containing C14-4 LNPs by replacing cholesterol with bile acids (cholic acid, chenodeoxycholic acid, deoxycholic acid, or lithocholic acid) at various ratios. Results: Bile acid-containing LNPs (BA-LNPs) were able to reduce delivery to liver cells in vitro and improve delivery in a variety of other cell types, including T cells, B cells, and epithelial cells. Our subsequent in vivo screening of selected LNP candidates injected intraperitoneally or intravenously identified a highly spleen tropic BA-LNP: CA-100, a four-component LNP containing cholic acid and no cholesterol. These screens also identified BA-LNP candidates demonstrating promise for other mRNA therapeutic applications such as for gastrointestinal or immune cell delivery. We further found that the substitution of cholic acid for cholesterol in an LNP formulation utilizing a different ionizable lipid, C12-200, also shifted mRNA delivery from the liver to the spleen, suggesting that this cholic acid replacement strategy may be generalizable. Conclusion: These results demonstrate the potential of a four-component BA-LNP formulation, CA-100, for extrahepatic mRNA delivery that could potentially be utilized for a range of therapeutic and vaccine applications.
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Affiliation(s)
- Savan K. Patel
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | - Alvin J. Mukalel
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ajay S. Thatte
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Alex G. Hamilton
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ningqiang Gong
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Rakan El-Mayta
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hannah C. Safford
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Maria Merolle
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Michael J. Mitchell
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
- Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Penn Institute for RNA Innovation, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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3
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Billingsley MM, Hamilton AG, Mai D, Patel SK, Swingle KL, Sheppard NC, June CH, Mitchell MJ. Orthogonal Design of Experiments for Optimization of Lipid Nanoparticles for mRNA Engineering of CAR T Cells. Nano Lett 2022; 22:533-542. [PMID: 34669421 PMCID: PMC9335860 DOI: 10.1021/acs.nanolett.1c02503] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Viral engineered chimeric antigen receptor (CAR) T cell therapies are potent, targeted cancer immunotherapies, but their permanent CAR expression can lead to severe adverse effects. Nonviral messenger RNA (mRNA) CAR T cells are being explored to overcome these drawbacks, but electroporation, the most common T cell transfection method, is limited by cytotoxicity. As a potentially safer nonviral delivery strategy, here, sequential libraries of ionizable lipid nanoparticle (LNP) formulations with varied excipient compositions were screened in comparison to a standard formulation for improved mRNA delivery to T cells with low cytotoxicity, revealing B10 as the top formulation with a 3-fold increase in mRNA delivery. When compared to electroporation in primary human T cells, B10 LNPs induced comparable CAR expression with reduced cytotoxicity while demonstrating potent cancer cell killing. These results demonstrate the impact of excipient optimization on LNP performance and support B10 LNPs as a potent mRNA delivery platform for T cell engineering.
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Affiliation(s)
- Margaret M Billingsley
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Alex G Hamilton
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - David Mai
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Savan K Patel
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Kelsey L Swingle
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Neil C Sheppard
- Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Carl H June
- Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Michael J Mitchell
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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4
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Swingle KL, Billingsley MM, Bose SK, White B, Palanki R, Dave A, Patel SK, Gong N, Hamilton AG, Alameh MG, Weissman D, Peranteau WH, Mitchell MJ. Amniotic fluid stabilized lipid nanoparticles for in utero intra-amniotic mRNA delivery. J Control Release 2022; 341:616-633. [PMID: 34742747 PMCID: PMC8776620 DOI: 10.1016/j.jconrel.2021.10.031] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 10/03/2021] [Accepted: 10/31/2021] [Indexed: 01/03/2023]
Abstract
Congenital disorders resulting in pathological protein deficiencies are most often treated postnatally with protein or enzyme replacement therapies. However, treatment of these disorders in utero before irreversible disease onset could significantly minimize disease burden, morbidity, and mortality. One possible strategy for the prenatal treatment of congenital disorders is in utero delivery of messenger RNA (mRNA). mRNA is a nucleic acid therapeutic that has previously been investigated as a platform for protein replacement therapies and gene editing technologies. While viral vectors have been explored to induce intracellular expression of mRNA, they are limited in their clinical application due to risks associated with immunogenicity and genomic integration. As an alternative to viral vectors, safe and efficient in utero mRNA delivery can be achieved using ionizable lipid nanoparticles (LNPs). While LNPs have demonstrated potent in vivo mRNA delivery to the liver following intravenous administration, intra-amniotic delivery has the potential to deliver mRNA to cells and tissues beyond those in the liver, such as in the skin, lung, and digestive tract. However, LNP stability in fetal amniotic fluid and how this stability affects mRNA delivery has not been previously investigated. Here, we engineered a library of LNPs using orthogonal design of experiments (DOE) to evaluate how LNP structure affects their stability in amniotic fluid ex utero and whether a lead candidate identified from these stability measurements enables intra-amniotic mRNA delivery in utero. We used a combination of techniques including dynamic light scattering (DLS), transmission electron microscopy (TEM), and chromatography followed by protein content quantification to screen LNP stability in amniotic fluids. These results identified multiple lead LNP formulations that are highly stable in amniotic fluids ranging from small animals to humans, including mouse, sheep, pig, and human amniotic fluid samples. We then demonstrate that stable LNPs from the ex utero screen in mouse amniotic fluid enabled potent mRNA delivery in primary fetal lung fibroblasts and in utero following intra-amniotic injection in a murine model. This exploration of ex utero stability in amniotic fluids demonstrates a means by which to identify novel LNP formulations for prenatal treatment of congenital disorders via in utero mRNA delivery.
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Affiliation(s)
- Kelsey L. Swingle
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | - Sourav K. Bose
- The Center for Fetal Research, Division of Pediatric General, Thoracic, and Fetal Surgery, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Brandon White
- The Center for Fetal Research, Division of Pediatric General, Thoracic, and Fetal Surgery, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Rohan Palanki
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.,The Center for Fetal Research, Division of Pediatric General, Thoracic, and Fetal Surgery, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Apeksha Dave
- The Center for Fetal Research, Division of Pediatric General, Thoracic, and Fetal Surgery, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Savan K. Patel
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ningqiang Gong
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Alex G. Hamilton
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | - Drew Weissman
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - William H. Peranteau
- The Center for Fetal Research, Division of Pediatric General, Thoracic, and Fetal Surgery, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Michael J. Mitchell
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.,Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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5
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Hamilton G, Patel SK, Azraai M, Burrell LM. No dynamic changes in plasma ACE2 activity in patients with acute coronary syndrome. Eur Heart J 2021. [DOI: 10.1093/eurheartj/ehab724.3280] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Angiotensin converting enzyme 2 (ACE2) is expressed in the human myocardium and blood vessels and degrades the vasoconstrictor peptide angiotensin (Ang) II. Plasma ACE2 activity is elevated in patients with cardiovascular disease (CVD) and is a predictor of major adverse cardiovascular events (MACE) in obstructive coronary artery disease. However, it is unknown whether acute coronary syndrome (ACS) causes dynamic changes in plasma ACE2 activity.
Purpose
We investigated dynamic changes in serial troponin-T and plasma ACE2 activity in patients presenting with ACS who underwent invasive coronary angiography (ICA).
Methods
Consecutive patients admitted with ACS from October-November 2019 were screened. Those meeting the Fourth Universal Definition of Myocardial Infarction who had both ICA and serial troponin-T testing were included. The study was approved by the hospitals Human Research Ethics Committee. All patients had routine plasma samples taken over 3 time-points for measurement of troponin-T; the same sample was used to measure plasma ACE2 activity. Catalytic ACE2 activity was measured using a validated, sensitive quenched fluorescent substrate-based assay. Serial median troponin and ACE2 activity levels were analysed using the Friedman test for repeated measures.
Results
Forty-nine patients were included. The mean age of participants was 63.9±11.0 years, and 36 (74%) patients were male. Overall, 16 (36%) patients presented with ST-elevation myocardial infarction (STEMI) and 29 (74%) with non-ST-elevation myocardial infarction (NSTEMI). Twenty-nine (59%) patients had a history of hypertension and 14 (29%) a history of ischaemic heart disease; 13 (27%) with priorMI, 11 (22%) had previous PCI and 2 (4%) had prior coronary artery bypass grafting. Over the 3 time points, there was a clear rise in median troponin-T levels representing myocardial injury (p<0.001), with no change in median plasma ACE2 activity (p=0.23, table 1). There was no difference in median ACE2 activity in those presenting with STEMI vs. NSTEMI (6.9 [2.1–9.5] vs. 6.0 [1.8–12.1], p=0.87), nor in those who underwent PCI to a culprit lesion compared to those who did not have a culprit lesion stented (5.8 [0.9–10.5] vs. 7.3 [2.8–14.9], p=0.37).
Conclusions
Patients with ACS had higher plasma ACE2 levels compared to levels previously reported in healthy controls. There were no dynamic changes in ACE2 activity in the setting of ACS, despite a significant rise in troponin-T. These results suggest that plasma ACE2 levels reflect underlying endothelial dysfunction rather than acute myocardial injury or infarction. Studies are now underway to assess if plasma ACE2 activity in ACS predicts MACE.
Funding Acknowledgement
Type of funding sources: None. Table 1
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Affiliation(s)
- G Hamilton
- Austin Health, Department of Cardiology, Melbourne, Australia
| | - S K Patel
- University of Melbourne, Department of Medicine, Melbourne, Australia
| | - M Azraai
- University of Melbourne, Department of Medicine, Melbourne, Australia
| | - L M Burrell
- Austin Hospital, Department of Medicine, Melbourne, Australia
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6
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Dilawari A, Rentscher KE, Zhai W, Zhou X, Ahles TA, Ahn J, Bethea TN, Carroll JE, Cohen HJ, Graham DA, Jim H, McDonald B, Nakamura ZM, Patel SK, Root JC, Small BJ, Saykin AJ, Tometich D, Van Dyk K, Mandelblatt JS. Medical Care Disruptions During the First Six-Months of the COVID19 Pandemic: The Experience of Older Breast Cancer Survivors. Res Sq 2021. [PMID: 33880464 PMCID: PMC8057243 DOI: 10.21203/rs.3.rs-416077/v1] [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] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Purpose. Older cancer survivors required medical care during the COVID-19 pandemic despite infection risks, but there are limited data on medical care in this age group. Methods. We evaluated care disruptions in a longitudinal cohort of non-metastatic breast cancer survivors ages 60–98 from five US regions (n=321). Survivors completed a web-based or telephone survey from May 27, 2020 to September 11, 2020. Care disruptions included self-reported interruptions in ability to see doctors, receive treatment or supportive therapies, or fill prescriptions. Logistic regression models evaluated bivariate and multivariate associations between care disruptions and education, medical, psychosocial and COVID-19-related factors. Multivariate models included age, county COVID-19 rates, comorbidity and post-diagnosis time. Results. There was a high response rate (n=262, 81.6%). Survivors were 32.2 months post-diagnosis (SD 17.5, range 4–73). Nearly half (48%) reported a medical disruption. The unadjusted odds of care disruptions were significantly higher with more education (OR 1.23 per one-year increase, 95% CI 1.09–1.39, p =0.001) and greater depression (OR 1.04 per one-point increase in CES-D score, CI 1.003–1.08, p=0.033); tangible support decreased the odds of disruptions (OR 0.99, 95% CI 0.97–0.99 per one-point increase, p=0.012). There was a trend for associations between disruptions and comorbidity (unadjusted OR 1.13 per 1 added comorbidity, 95% CI 0.99–1.29, p=0.07). Adjusting for covariates, only higher education (p=0.001) and tangible social support (p=0.006) remained significantly associated with having care disruptions. Conclusions. Older breast cancer survivors reported high rates of medical care disruptions during the COVID-19 pandemic and psychosocial factors were associated with care disruptions.
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Affiliation(s)
- A Dilawari
- Medstar Washington Hospital Center Washington, DC.,Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC
| | - K E Rentscher
- Cousins Center for Psychoneuroimmunology, University of California, Los Angeles, Los Angeles, CA.,Semel Institute for Neuroscience and Human Behavior, Department of Psychiatry & Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA
| | - W Zhai
- Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC.,Department of Biostatistics, Bioinformatics, and Biomathematics, Georgetown University, Washington, DC
| | - X Zhou
- Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC.,Department of Biostatistics, Bioinformatics, and Biomathematics, Georgetown University, Washington, DC
| | - T A Ahles
- Memorial Sloan Kettering Cancer Center, New York, NY
| | - J Ahn
- Cousins Center for Psychoneuroimmunology, University of California, Los Angeles, Los Angeles, CA
| | - T N Bethea
- Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC
| | - J E Carroll
- Semel Institute for Neuroscience and Human Behavior, Department of Psychiatry & Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA.,Department of Biostatistics, Bioinformatics, and Biomathematics, Georgetown University, Washington, DC
| | - H J Cohen
- Center for the Study of Aging and Human Development, Duke University Medical Center, Durham, NC
| | - D A Graham
- John Theurer Cancer Center, Hackensack University Medical Center, Hackensack, NJ
| | - Hsl Jim
- Moffitt Cancer Center, Tampa, FL
| | - B McDonald
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine and Indiana University Melvin and Bren Simon Cancer Center, Indianapolis, IN
| | - Z M Nakamura
- Department of Psychiatry, University of North Carolina-Chapel Hill, Chapel Hill, NC
| | - S K Patel
- City of Hope National Medical Center, Los Angeles, CA
| | - J C Root
- Memorial Sloan Kettering Cancer Center, New York, NY
| | - B J Small
- University of South Florida, Tampa, FL
| | - A J Saykin
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine and Indiana University Melvin and Bren Simon Cancer Center, Indianapolis, IN
| | | | - K Van Dyk
- Department of Biostatistics, Bioinformatics, and Biomathematics, Georgetown University, Washington, DC
| | - J S Mandelblatt
- Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC
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7
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Sajeev J, Burrell LM, Dewey H, Kalman JM, Chou B, Frost T, Patel SK, Roberts L, Cooke JC, Gould M, Ngoh J, Koshy AN, Denver R, Teh AW. P5740ACE2 activity level is associated with embolic stroke of undetermined source. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz746.0680] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
ACE2 activity levels correlate with adverse left atrial remodelling in patients with atrial fibrillation (AF). Several biochemical and structural markers have been associated with embolic stroke of undetermined source (ESUS). The relationship between ACE2 activity and ESUS is unknown.
Purpose
Randomised controlled trials failed to demonstrate a clear benefit of oral anticoagulation in an unselected ESUS population. As selective use of oral anticoagulation guided by biomarker risk-profiling may benefit these patients, we evaluated the association between ACE2 activity and ESUS.
Methods
This prospective case control study compared patients with ESUS against a control group matched for vascular risk factors. ESUS was diagnosed following cerebral vascular imaging and 24 hours of cardiac monitoring to exclude AF. Blood samples were collected for measurement of ACE2 activity, D-Dimer and high sensitivity troponin T (hsTnT).
Results
A total of 51 patients in the ESUS group were compared with 47 patients in the Control group. ACE2 activity and D-Dimer levels were significantly higher in the ESUS group. There was a significant but weak positive correlation between ACE2 activity and hsTnT (r=0.20, p<0.05). Left atrial volume index (LAVI) on echocardiography was significantly higher in the ESUS group. On regression modelling adjusting for LAVI, only ACE2 activity remained significant for ESUS, with a 20% rise in odds for every 4 unit increase in ACE2 activity (OR 1.20; 95% CI: 1.01 - 1.36, p=0.04).
Participant characteristics Control (n=47) ESUS (n=51) P value Age (years) 65.65±6.78 67.20±6.89 0.26 Female gender 22 (45.8) 19 (38.0) 0.43 Hypertension 22 (45.8) 24 (48.0) 0.83 Diabetes mellitus 9 (18.8) 12 (24.0) 0.53 CHA2DS2VASc score 2 (1–3) 2 (1–3) 0.50 LA size & Biomarkers LA volume index (ml/m2) 36.5 (32.6–42.5) 39.1 (36.2–46.0) 0.04 ACE2 (pmol/ml/min) 7.24 (2.66–14.64) 10.16 (4.54–18.80) 0.04 D-Dimer (mg/L) 0.35 (0.3–0.5) 0.40 (0.30–0.60) 0.02 hsTroponin T (ng/L) 7.0 (5–10) 9.00 (6.0–13.5) 0.05 Values are expressed as mean ± standard deviation, median (IQR), or n (%).
Median ACE2 activity
Conclusion(s)
ACE2 activity is associated with ESUS independent of left atrial volume and correlate with elevated Troponin. Further studies are warranted to investigate the utility of ACE2 activity in identifying ESUS patients that may benefit from oral anticoagulation.
Acknowledgement/Funding
This study received project funding from the Eastern Health Foundation
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Affiliation(s)
- J Sajeev
- Eastern Health, Department of Cardiology, Melbourne, Australia
| | - L M Burrell
- University of Melbourne, Department of Medicine, Melbourne, Australia
| | - H Dewey
- Eastern Health, Department of Neuroscience, Melbourne, Australia
| | - J M Kalman
- Royal Melbourne Hospital, Department of Cardiology, Melbourne, Australia
| | - B Chou
- Eastern Health, Department of Cardiology, Melbourne, Australia
| | - T Frost
- Eastern Health, Department of Neuroscience, Melbourne, Australia
| | - S K Patel
- University of Melbourne, Department of Medicine, Melbourne, Australia
| | - L Roberts
- Eastern Health, Department of Cardiology, Melbourne, Australia
| | - J C Cooke
- Eastern Health, Department of Cardiology, Melbourne, Australia
| | - M Gould
- Eastern Health, Department of Cardiology, Melbourne, Australia
| | - J Ngoh
- Eastern Health, Department of Cardiology, Melbourne, Australia
| | - A N Koshy
- Austin Health Hospital, Department of Cardiology, Melbourne, Australia
| | - R Denver
- Eastern Health, Department of Cardiology, Melbourne, Australia
| | - A W Teh
- Eastern Health, Department of Cardiology, Melbourne, Australia
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8
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Ramchand J, Patel SK, Kearney LG, Matalanis G, Farouque O, Srivastava PM, Burrell LM. P6304Role of novel biomarkers to improve risk stratification in aortic stenosis: focus on plasma ACE2 activity. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy566.p6304] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- J Ramchand
- University of Melbourne, Department of Medicine, Austin Health, Melbourne, Australia
| | - S K Patel
- University of Melbourne, Department of Medicine, Austin Health, Melbourne, Australia
| | - L G Kearney
- University of Melbourne, Department of Medicine, Austin Health, Melbourne, Australia
| | - G Matalanis
- Austin Health Hospital, Department of Cardiac Surgery, Melbourne, Australia
| | - O Farouque
- University of Melbourne, Department of Medicine, Austin Health, Melbourne, Australia
| | - P M Srivastava
- University of Melbourne, Department of Medicine, Austin Health, Melbourne, Australia
| | - L M Burrell
- University of Melbourne, Department of Medicine, Austin Health, Melbourne, Australia
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Ramchand J, Patel SK, Srivastava PM, Farouque O, Burrell LM. P6430Elevated plasma angiotensin converting enzyme 2 activity is an independent predictor of major adverse cardiac events in patients with obstructive coronary artery disease. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy566.p6430] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- J Ramchand
- University of Melbourne, Department of Medicine, Austin Health, Melbourne, Australia
| | - S K Patel
- University of Melbourne, Department of Medicine, Austin Health, Melbourne, Australia
| | - P M Srivastava
- University of Melbourne, Department of Medicine, Austin Health, Melbourne, Australia
| | - O Farouque
- University of Melbourne, Department of Medicine, Austin Health, Melbourne, Australia
| | - L M Burrell
- University of Melbourne, Department of Medicine, Austin Health, Melbourne, Australia
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10
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Restrepo C, Patel SK, Rethnam V, Werden E, Ramchand J, Churilov L, Burrell LM, Brodtmann A. Left ventricular hypertrophy and cognitive function: a systematic review. J Hum Hypertens 2018; 32:171-179. [PMID: 29330420 DOI: 10.1038/s41371-017-0023-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 07/11/2017] [Accepted: 07/26/2017] [Indexed: 02/07/2023]
Abstract
Cognitive impairment is common in patients with hypertension. Left ventricular hypertrophy (LVH) is recognised as a marker of hypertension-related organ damage and is a strong predictor of coronary artery disease, heart failure and stroke. There is evidence that LVH is independently associated with cognitive impairment, even after adjustment for the presence of hypertension. We conducted a systematic review that examined cognitive impairment in adults with LVH. Independent searches were performed in Ovid MEDLINE, Ovid psycInfo and PubMed with the terms left ventricular hypertrophy and cognition. Seventy-three studies were identified when both searches were combined. After limiting the search to studies that were: (1) reported in English; (2) conducted in humans; (3) in adults aged 50 years and older; and (4) investigated the relationship between LVH and cognitive performance, nine papers were included in this systematic review. The majority of studies found an association between LVH and cognitive performance. Inspection of results indicated that individuals with LVH exhibited a lower performance in cognitive tests, when compared to individuals without LVH. Memory and executive functions were the cognitive domains that showed a specific vulnerability to the presence of LVH. A possible mechanism for the relationship between LVH and cognition is the presence of cerebral white matter damage. White matter lesions occur frequently in patients with LVH and may contribute to cognitive dysfunction. Together, the results of this review suggest that memory impairment and executive dysfunction are the cognitive domains that showed a particular association with the presence of LVH.
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Affiliation(s)
- C Restrepo
- The Florey Institute of Neuroscience and Mental Health, Austin Health, Heidelberg, VIC, Australia
| | - S K Patel
- The Florey Institute of Neuroscience and Mental Health, Austin Health, Heidelberg, VIC, Australia.,Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, VIC, Australia
| | - V Rethnam
- The Florey Institute of Neuroscience and Mental Health, Austin Health, Heidelberg, VIC, Australia
| | - E Werden
- The Florey Institute of Neuroscience and Mental Health, Austin Health, Heidelberg, VIC, Australia
| | - J Ramchand
- Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, VIC, Australia.,Department of Cardiology, Austin Health, Heidelberg, VIC, Australia
| | - L Churilov
- The Florey Institute of Neuroscience and Mental Health, Austin Health, Heidelberg, VIC, Australia
| | - L M Burrell
- Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, VIC, Australia. .,Department of Cardiology, Austin Health, Heidelberg, VIC, Australia.
| | - A Brodtmann
- The Florey Institute of Neuroscience and Mental Health, Austin Health, Heidelberg, VIC, Australia.,Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, VIC, Australia.,Department of Neurology, Austin Health, Heidelberg, VIC, Australia
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11
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Patel PS, Patel SK, Patel KC. Arylene Azo p-Hydroxy Benzoic Acid–Formaldehyde Oligomer Dyes. HIGH PERFORM POLYM 2016. [DOI: 10.1088/0954-0083/10/4/006] [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: 11/12/2022]
Abstract
A series of oligomeric azo dyes has been synthesized by coupling various aromatic diazonium salts to p-hydroxy benzoic acid–formaldehyde ( p-HBAF) oligomer. They were evaluated in terms of their softening points, yields, colour, UV–visible spectra, IR spectra and PMR spectra. Dyeing on wool and nylon resulted in yellow to red shades having moderate to good fastness to light and good to very good fastness to washing.
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Affiliation(s)
| | | | - K C Patel
- Department of Chemistry, South Gujarat University, Surat-395 007, India
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12
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Chen J, Patel SK, Lin S, Zhu YY. Letter: the liver to abdominal area ratio--a novel imaging score for prognostication in cirrhosis. Aliment Pharmacol Ther 2016; 43:659-60. [PMID: 26843350 DOI: 10.1111/apt.13520] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- J Chen
- Liver Research Center, the First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - S K Patel
- Department of cardiology, the First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - S Lin
- Liver Research Center, the First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Y Y Zhu
- Liver Research Center, the First Affiliated Hospital of Fujian Medical University, Fuzhou, China.
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13
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Walsh KS, Noll RB, Annett RD, Patel SK, Patenaude AF, Embry L. Standard of Care for Neuropsychological Monitoring in Pediatric Neuro-Oncology: Lessons From the Children's Oncology Group (COG). Pediatr Blood Cancer 2016; 63:191-5. [PMID: 26451963 PMCID: PMC5222571 DOI: 10.1002/pbc.25759] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 08/27/2015] [Indexed: 11/10/2022]
Abstract
As the mortality of pediatric cancers has decreased, focus on neuropsychological morbidities of treatment sequelae have increased. Neuropsychological evaluations are essential diagnostic tools that assess cognitive functioning and neurobiological integrity. These tests provide vital information to support ongoing medical care, documenting cognitive morbidity and response to interventions. We frame standards for neuropsychological monitoring of pediatric patients with CNS malignancy or who received cancer-directed therapies involving the CNS and discuss billing for these services in the United States in the context of clinical research. We describe a cost-effective, efficient model of neuropsychological monitoring that may increases access to neuropsychological care.
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Affiliation(s)
- KS Walsh
- Children’s National Health System & The George Washington University School of Medicine, Washington, DC
| | - RB Noll
- University of Pittsburgh, Pittsburgh, PA
| | - RD Annett
- University of Colorado Denver; Children’s Hospital of Colorado
| | - SK Patel
- City of Hope Medical Center, Duarte, California
| | - AF Patenaude
- Dana-Farber Cancer Institute, Harvard Medical School, Boston MA
| | - L Embry
- University of Texas Health Science Center at San Antonio, San Antonio, TX
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Tiwari S, Patel SK, Shah DR. Bioadhesive films containing fluconazole for mucocutaneous candidiasis. Indian J Pharm Sci 2015; 77:55-61. [PMID: 25767319 PMCID: PMC4355883 DOI: 10.4103/0250-474x.151601] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2013] [Revised: 10/21/2014] [Accepted: 01/16/2015] [Indexed: 11/22/2022] Open
Abstract
Fluconazole is a broad spectrum antifungal agent that has been extensively applied for the management of oral, pharyngeal and cutaneous candidiasis. Fluconazole has a high volume of distribution (0.55–0.65 l/kg) and has systemic toxicity due to high drug-drug interaction. The present study focuses on the formulation of bioadhesive film as a controlled release carrier for fluconazole. The formulation was intended to provide localized delivery of fluconazole exclusively at the site of infection, thereby reducing its total dose and hence, dose-related toxicities. Bioadhesive films were prepared by solvent casting method using sodium alginate and polyvinyl alcohol alone as well as in various combinations. Prepared films were evaluated for physical characteristics like, weight and content uniformity, film thickness, swelling index, microenvironment pH and folding endurance. In vitro drug release, in vitro and ex vivo residence time, bioadhesive strength and skin irritation were also studied. Accelerated stability study was conducted on the optimized formulation as per ICH guidelines. Weight of all the films were not more than 20 mg. Thickness of the films ranged between 0.09 to 0.15 mm whereas swelling indices showed a high extent of variation. Films composed of polyvinyl alcohol alone provided a swelling index of 6%. Bioadhesive strength was found to be more than 18 g. Microenvironment pH was near to 7.0 for most of the formulations. Ex vivo residence time of optimized batch was more than 5 h and it provided controlled drug release up to 8 h. As revealed in FT-IR and DSC studies, drug was found to be compatible with the excipients used in this study.
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15
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Pan WJ, Hsu H, Rees WA, Lear SP, Lee F, Foltz IN, Rathanaswami P, Manchulenko K, Chan BM, Zhang M, Xia XZ, Patel SK, Prince PJ, Doherty DR, Sheckler CM, Reynhardt KO, Krill CD, Harder BJ, Wisler JA, Brandvig JL, Lynch JL, Anderson AA, Wienkers LC, Borie DC. Pharmacology of AMG 181, a human anti-α4 β7 antibody that specifically alters trafficking of gut-homing T cells. Br J Pharmacol 2014; 169:51-68. [PMID: 23425116 DOI: 10.1111/bph.12134] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 12/15/2012] [Accepted: 12/20/2012] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND AND PURPOSE AMG 181 is a human anti-α4 β7 antibody currently in phase 1 and 2 trials in subjects with inflammatory bowel diseases. AMG 181 specifically targets the α4 β7 integrin heterodimer, blocking its interaction with mucosal addressin cell adhesion molecule-1 (MAdCAM-1), the principal ligand that mediates α4 β7 T cell gut-homing. EXPERIMENTAL APPROACH We studied the in vitro pharmacology of AMG 181, and the pharmacokinetics and pharmacodynamics of AMG 181 after single or weekly i.v. or s.c. administration in cynomolgus monkeys for up to 13 weeks. KEY RESULTS AMG 181 bound to α4 β7 , but not α4 β1 or αE β7 , and potently inhibited α4 β7 binding to MAdCAM-1 (but not vascular cell adhesion molecule-1) and thus inhibited T cell adhesion. Following single i.v. administration, AMG 181 Cmax was dose proportional from 0.01 to 80 mg·kg(-1) , while AUC increased more than dose proportionally. Following s.c. administration, dose-proportional exposure was observed with single dose ranging from 5 to 80 mg·kg(-1) and after 13 weekly doses at levels between 20 and 80 mg·kg(-1) . AMG 181 accumulated two- to threefold after 13 weekly 80 mg·kg(-1) i.v. or s.c. doses. AMG 181 had an s.c. bioavailability of 80%. The linear elimination half-life was 12 days, with a volume of distribution close to the intravascular plasma space. The mean trend for the magnitude and duration of AMG 181 exposure, immunogenicity, α4 β7 receptor occupancy and elevation in gut-homing CD4+ central memory T cell count displayed apparent correlations. CONCLUSIONS AND IMPLICATIONS AMG 181 has in vitro pharmacology, and pharmacokinetic/pharmacodynamic and safety characteristics in cynomolgus monkeys that are suitable for further investigation in humans.
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Affiliation(s)
- W J Pan
- Department of Pharmacokinetics and Drug Metabolism, Amgen Inc., Seattle, WA 98119-3105, USA.
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17
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Patel SK, Pankewycz OG, Nader ND, Zachariah M, Kohli R, Laftavi MR. Prognostic utility of hypothermic machine perfusion in deceased donor renal transplantation. Transplant Proc 2013; 44:2207-12. [PMID: 22974956 DOI: 10.1016/j.transproceed.2012.07.129] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
UNLABELLED Pulsatile pump perfusion of kidney transplants is known to decrease delayed graft function (DGF) and improve 1 year graft survival when compared to static cold preservation. Kidneys with better flow and resistance parameters on perfusion are likely to have a better post transplant function. These parameters are commonly used to evaluate kidneys being considered for transplantation. This study assesses the time frame for a kidney within which it reaches optimal perfusion parameters. All kidneys pumped between 5/2006 and 9/2009 on a Lifeport© kidney transporter at our local organ procurement agency were studied. 190 kidneys were evaluated and then divided into two groups based on whether terminal flows increased or declined after prolonged perfusion. All kidneys were assessed for changes in flow (F), resistance (R) and temperature at 15 minute intervals. Discards, DGF and one year graft survival were noted. The Student paired t test and Chi-square analysis were used to compare data. A multiple logistic regression analysis was performed to study independent predictors of DGF on pump perfusion. RESULTS For all kidneys, the mean initial flow was 59 ± 35 mL/min which improved to an average flow of 128 ± 38 mL/min with continued perfusion. The maximal flow and terminal flows were 148 ± 51 and 135 ± 38 mL/min respectively. The flows at 2, 4, and 6 hours was 125 ± 41, 128 ± 42 and 130 ± 39 mL/min respectively. Kidneys that improved on continued perfusion had a significantly lower discard rate (20 vs 34% p < 0.05), but a higher incidence of DGF (64 vs 39%, P < .05). One year graft loss (death censored) was comparable in the two groups. (4/42 vs. 3/33, P = .94). Resistance at 2, 4, and 6 hours was predictive of DGF, as was donor anoxia and cerebrovascular accident (CVA) as the cause of death. CONCLUSIONS Kidneys on pulsatile pump perfusion tend to show improved flows and decreased resistance over time. The average flow for a kidney is reached by 2 hours. Those kidneys that start with lower flow rates that improve after 2 hours with continued perfusion are less likely to be discarded but are still associated with a greater incidence of delayed graft function. Resistance at 2 hours predicts DGF while initial resistance predicts one year graft survival.
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Affiliation(s)
- S K Patel
- Transplantation Surgery, Department of Surgery, University at Buffalo (SUNY), Buffalo, NY 14215, USA.
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18
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Patel SK, Pankewycz OG, Weber-Shrikant E, Zachariah M, Kohli R, Nader ND, Laftavi MR. Effect of increased pressure during pulsatile pump perfusion of deceased donor kidneys in transplantation. Transplant Proc 2013; 44:2202-6. [PMID: 22974955 DOI: 10.1016/j.transproceed.2012.07.109] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
INTRODUCTION Pulsatile pump perfusion of potential kidneys for transplantation is known to decrease the rate of delayed graft function (DGF) and improve their 1-year survival. Flow and resistance parameters are often used to determine the suitability of kidneys for transplantation. Kidneys with low flow rates are often subjected to higher pressures to improve flow. This study evaluated the effect of higher pump pressures on posttransplant renal function. METHODS We performed a retrospective analysis of 73 deceased donor kidneys preserved using pump perfusion (LifePort) at our center between May 2006 and September 2009. We calculated the mean pump pressure (MP) for the duration of perfusion of each kidney, using systolic pressure (SP) and diastolic pressure (DP) readings with the following formula: (MP = DP + 1/3 (SP - DP). The kidneys were divided into a low (LP; n = 49) and a high-pressure group (HP; n = 24) based on a MP cutoff value of 23 mm Hg. The two groups were then compared for differences in perfusion dynamics and primary endpoints including DGF and 1-year graft survival. Statistical analysis was performed using paired Student t test and chi-square analysis. RESULTS The two groups were comparable for donor age, extended criteria, sensitization, and cold ischemic times. They differed significantly in higher initial (0.65 ± 0.4 versus 0.4 ± 0.2, P = .01), average (0.25 ± 0.08 versus 0.18 ± 0.06, P = .0006), and terminal resistance (0.21 ± 0.07 versus 0.17 ± 0.06, P = .008) of HP versus LP kidneys. Flow rates were comparable between the two groups. DGF was higher in HP kidneys (75% versus 40%, P = .006) with similar 1-year graft survival (87.5% versus 89%, P = .7). CONCLUSIONS Perfusate flow through a kidney can be improved by increasing pressure settings to overcome elevated resistance. This maneuver was not associated with a lower rate of DGF after transplantation. One-year graft survival remained unaffected.
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Affiliation(s)
- S K Patel
- Transplantation Surgery, Department of Surgery, University at Buffalo (SUNY), Buffalo, New York, USA.
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Alegria LD, Schroer MD, Chatterjee A, Poirier GR, Pretko M, Patel SK, Petta JR. Structural and electrical characterization of Bi₂Se₃ nanostructures grown by metal-organic chemical vapor deposition. Nano Lett 2012; 12:4711-4. [PMID: 22827514 DOI: 10.1021/nl302108r] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We characterize nanostructures of Bi(2)Se(3) that are grown via metal-organic chemical vapor deposition using the precursors diethyl selenium and trimethyl bismuth. By adjusting growth parameters, we obtain either single-crystalline ribbons up to 10 μm long or thin micrometer-sized platelets. Four-terminal resistance measurements yield a sample resistivity of 4 mΩ·cm. We observe weak antilocalization and extract a phase coherence length l(ϕ) = 178 nm and spin-orbit length l(so) = 93 nm at T = 0.29 K. Our results are consistent with previous measurements on exfoliated samples and samples grown via physical vapor deposition.
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Affiliation(s)
- L D Alegria
- Department of Physics, Princeton University, Princeton, New Jersey 08544, United States
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20
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Kearney LG, Lu K, Ord M, Patel SK, Profitis K, Matalanis G, Burrell LM, Srivastava PM. Global longitudinal strain is a strong independent predictor of all-cause mortality in patients with aortic stenosis. Eur Heart J Cardiovasc Imaging 2012; 13:827-33. [PMID: 22736713 DOI: 10.1093/ehjci/jes115] [Citation(s) in RCA: 160] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
AIMS To assess the capacity of global longitudinal strain (GLS) in patients with aortic stenosis (AS) to (i) detect the subclinical left ventricular (LV) dysfunction [LV ejection fraction (LVEF) ≥50% patients]; (ii) predict all-cause mortality and major adverse cardiac events (MACE) (all patients), and (iii) provide incremental prognostic information over current risk markers. METHODS AND RESULTS Patients with AS (n = 146) and age-matched controls (n = 12) underwent baseline echocardiography to assess AS severity, conventional LV parameters and GLS via speckle tracking echocardiography. Baseline demographics, symptom severity class and comorbidities were recorded. Outcomes were identified via hospital record review and subject/physician interview. The mean age was 75 ± 11, 62% were male. The baseline aortic valve (AV) area was 1.0 ± 0.4 cm(2) and LVEF was 59 ± 11%. In patients with a normal LVEF (n = 122), the baseline GLS was controls -21 ± 2%, mild AS -18 ± 3%, moderate AS -17 ± 3% and severe AS -15 ± 3% (P< 0.001). GLS correlated with the LV mass index, LVEF, AS severity, and symptom class (P< 0.05). During a median follow-up of 2.1 (inter-quartile range: 1.8-2.4) years, there were 20 deaths and 101 MACE. Unadjusted hazard ratios (HRs) for GLS (per %) were all-cause mortality (HR: 1.42, P< 0.001) and MACE (HR: 1.09, P< 0.001). After adjustment for clinical and echocardiographic variables, GLS remained a strong independent predictor of all-cause mortality (HR: 1.38, P< 0.001). CONCLUSIONS GLS detects subclinical dysfunction and has incremental prognostic value over traditional risk markers including haemodynamic severity, symptom class, and LVEF in patients with AS. Incorporation of GLS into risk models may improve the identification of the optimal timing for AV replacement.
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Affiliation(s)
- L G Kearney
- Department of Medicine, The University of Melbourne, Austin Health, Victoria, Australia.
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Kearney LG, Ord M, Buxton BF, Matalanis G, Patel SK, Burrell LM, Srivastava PM. Progression of aortic stenosis in elderly patients over long-term follow up. Int J Cardiol 2012; 167:1226-31. [PMID: 22483251 DOI: 10.1016/j.ijcard.2012.03.139] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Revised: 02/07/2012] [Accepted: 03/15/2012] [Indexed: 11/28/2022]
Abstract
BACKGROUND The natural history of aortic stenosis (AS) in elderly patients remains poorly defined. In an elderly cohort over long-term follow-up, we assessed: 1) rates and predictors of hemodynamic progression and 2) composite aortic valve replacement (AVR) or death endpoint. METHODS Consecutive Department of Veterans' Affairs patients with AS (>60 years) were prospectively enrolled between 1988 and 1994 (n=239) and followed until 2008. Patients with ≥ 2 trans-thoracic echocardiograms >6 months apart were included in the progression analysis (n=147). Baseline demographics, comorbidities and echocardiography parameters were recorded. Follow-up was censored at AVR/death. RESULTS The age of patients was 73 ± 6 years; 82% were male. Baseline AS severity was mild (67%), moderate (23%) and severe (10%). Follow-up was 6.5 ± 4 years (range: 1-17 years). Annualized mean aortic valve gradient progression rates were: mild AS 4 ± 4 mmHg/year; moderate AS 6 ± 5 mmHg/year and severe AS 10 ± 8 mmHg/year (p<0.001). Five-year event-free survival was 66 ± 5%, 23 ± 7% and 20 ± 10% for mild, moderate and severe AS respectively. Progression to severe AS occurred in 35% and 74% of patients with mild and moderate AS respectively. Independent predictors of rapid progression were: baseline AS severity (per grade) (OR 2.6, p=0.001), aortic valve calcification (per grade) (OR 2.1, p=0.01), severe renal impairment (OR 4.0, p=0.04) and anemia (OR 2.3, p=0.05). CONCLUSIONS In elderly patients, hemodynamic progression of AS is predicted by AS severity, renal function, aortic valve calcification and history of anemia. These factors identify patients at high risk of rapid hemodynamic progression, for whom more frequent clinical and echocardiographic surveillance is advisable.
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Affiliation(s)
- L G Kearney
- Department of Cardiology, Austin Health, VIC, Australia.
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Burrell LM, Burchill L, Dean RG, Griggs K, Patel SK, Velkoska E. Chronic kidney disease: cardiac and renal angiotensin-converting enzyme (ACE) 2 expression in rats after subtotal nephrectomy and the effect of ACE inhibition. Exp Physiol 2011; 97:477-85. [PMID: 22198016 DOI: 10.1113/expphysiol.2011.063156] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Renin-angiotensin system blockade slows but does not prevent the cardiovascular complications of chronic kidney disease (CKD). Angiotensin-converting enzyme (ACE) 2 is differentially regulated in acute kidney injury, with increased cardiac ACE2 but decreased kidney ACE2 levels. This study investigated the effect of long-term ACE inhibition on cardiac and renal ACE2 in rats with CKD induced by subtotal nephrectomy (STNx). Sprague-Dawley rats had sham (control) or STNx surgery. Control rats received vehicle (n = 9) and STNx rats ramipril (1 mg kg(-1) day(-1); n = 10) or vehicle (n = 10) for 28 days. Subtotal nephrectomy resulted in impaired creatinine clearance (P < 0.05), proteinuria (P < 0.05), renal fibrosis (P < 0.05) and reduced renal cortical ACE2 mRNA (P < 0.05) and activity (P < 0.05). In rats with CKD, ramipril improved creatinine clearance (P < 0.05) and was associated with an increase in cortical but not medullary ACE2 activity (P < 0.05). Compared with control rats, STNx rats were hypertensive (P < 0.01), with increased left ventricular end-diastolic pressure (LVEDP; P < 0.01), left ventricular hypertrophy (LVH; P < 0.05) and interstitial (P < 0.05) and perivascular fibrosis (P < 0.01). In rats with CKD, ramipril decreased blood pressure (P < 0.001) and reduced LVEDP (P < 0.01), LVH (P < 0.01) and perivascular fibrosis (P < 0.05) but did not significantly reduce interstitial fibrosis. There was no change in cardiac ACE2 in rats with CKD compared with control rats. In rats with CKD, ACE inhibition had major benefits to reduce blood pressure and cardiac hypertrophy and to improve creatinine clearance, but did not significantly impact on cardiac ACE2, cardiac interstitial fibrosis, renal fibrosis or proteinuria. Thus, in rats with CKD, renal ACE2 deficiency and lack of activation of cardiac ACE2 may contribute to the progression of cardiac and renal tissue injury. As long-term ACE inhibition only partly ameliorated the adverse cardio-renal effects of CKD, adjunctive therapies that lead to further increases in ACE2 activity may be needed to combat the cardio-renal complications of CKD.
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Affiliation(s)
- L M Burrell
- Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Victoria, Australia.
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Menon BK, Smith EE, Modi J, Patel SK, Bhatia R, Watson TWJ, Hill MD, Demchuk AM, Goyal M. Regional leptomeningeal score on CT angiography predicts clinical and imaging outcomes in patients with acute anterior circulation occlusions. AJNR Am J Neuroradiol 2011; 32:1640-5. [PMID: 21799045 DOI: 10.3174/ajnr.a2564] [Citation(s) in RCA: 249] [Impact Index Per Article: 19.2] [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: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The regional leptomeningeal score is a strong and reliable imaging predictor of good clinical outcomes in acute anterior circulation ischemic strokes and can therefore be used for imaging based patient selection. Efforts to determine biological determinants of collateral status are needed if techniques to alter collateral behavior and extend time windows are to succeed. MATERIALS AND METHODS This was a retrospective Institutional Review Board-approved study of patients with acute ischemic stroke and M1 middle cerebral artery+/- intracranial internal carotid artery occlusion at our center from 2003 to 2009. The rLMC score is based on scoring pial and lenticulostriate arteries (0, no; 1, less; 2, equal or more prominent compared with matching region in opposite hemisphere) in 6 ASPECTS regions (M1-6) plus anterior cerebral artery region and basal ganglia. Pial arteries in the Sylvian sulcus are scored 0, 2, or 4. Good clinical outcome was defined as mRS ≤ 2 at 90 days. RESULTS The analysis included 138 patients: 37.6% had a good (17-20), 40.5% a medium (11-16), and 21.7% a poor (0-10) rLMC score. Interrater reliability was high, with an intraclass correlation coefficient of 0.87 (95% CI, 0.77%-0.95%). On univariate analysis, no single vascular risk factor was associated with the presence of poor rLMCs (P ≥ .20 for all comparisons). In multivariable analysis, the rLMC score (good versus poor: OR, 16.7; 95% CI, 2.9%-97.4%; medium versus poor: OR, 9.2, 95% CI, 1.7%-50.6%), age (< 80 years), baseline ASPECTS (≥ 8), and clot burden score (≥ 8) were independent predictors of good clinical outcome. CONCLUSIONS The rLMC score is a strong imaging parameter on CT angiography for predicting clinical outcomes in patients with acute ischemic strokes.
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Affiliation(s)
- B K Menon
- Department of Clinical Neuroscience, University of Calgary, Calgary, Alberta, Canada
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Patel SK, Mullins WA, O'Neil SH, Wilson K. Neuropsychological differences between survivors of supratentorial and infratentorial brain tumours. J Intellect Disabil Res 2011; 55:30-40. [PMID: 21121992 DOI: 10.1111/j.1365-2788.2010.01344.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
BACKGROUND The purpose of this study is to evaluate the relationship between brain tumour location and core areas of cognitive and behavioural functioning for paediatric brain tumour survivors. The extant literature both supports and refutes an association between paediatric brain tumour location and neurocognitive outcomes. We examined neuropsychological test data to identify any differences in neurocognitive and behavioural profile associated with supratentorial versus infratentorial tumour location. METHODS Following Institutional Review Board approval, the medical records and neuropsychological test data collected between 1997 and 2002 for 70 children treated for brain tumour at Children's Hospital Los Angeles were reviewed. Fifty-one per cent of the participants had tumours located in the supratentorial regions of the brain, whereas 49% had infratentorial tumours. Primary medical treatments involved tumour resection (90%), cranial radiation therapy (76%), chemotherapy (71%), and 59% all three medical procedures. The two tumour location groups did not differ significantly in the cumulative treatment dose of irradiation to the tumour bed or in the dose delivered to the whole brain. Neuropsychological test data included measures of verbal and non-verbal intellectual functioning, attention/working memory, processing speed, verbal and visual memory, fine motor skills, visual-motor integration, academic achievement, and social-emotional functioning. Differences between the two groups were evaluated using anova, t-tests and chi-squared statistical tests. RESULTS The supratentorial and infratentorial tumour location groups did not differ on measures of intellectual functioning. However, survivors of infratentorial tumours performed more poorly on selected measures of more specific cognitive functions and on parent-report of social-emotional functioning relative to survivors of supratentorial tumours, even when age at diagnosis was held as a covariate. Higher frequency of auditory deficits was noted in the infratentorial tumour group and was associated with lowered academic achievement scores. CONCLUSIONS The differences by location found in more specific neurocognitive and social-emotional variables, after controlling for age at diagnosis, may possibly reflect tumour location-specific effects. However, this interpretation remains tentative given the limitations in our study and inability to control for the range of medical and treatment-related factors that may have contributed towards the outcomes observed in our sample. At the same time, most of our findings appear consistent with reports from recent studies in this area.
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Affiliation(s)
- S K Patel
- City of Hope Medical Center and Beckman Research Institute, Duarte, CA, USA.
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Patel DB, Patel NJ, Patel SK, Prajapati AM, Patel SA. RP-HPLC Method for the Estimation of Dutasteride in Tablet Dosage Form. Indian J Pharm Sci 2010; 72:113-6. [PMID: 20582201 PMCID: PMC2883211 DOI: 10.4103/0250-474x.62247] [Citation(s) in RCA: 4] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2009] [Revised: 09/15/2009] [Accepted: 01/06/2010] [Indexed: 11/17/2022] Open
Abstract
A simple, sensitive and precise RP-HPLC method was developed for the determination of dutasteride in tablet dosage form. The RP-HPLC separation was achieved on phenomenex C18 column (250 mm, id 4.6 mm, 5 μm) using mobile phase methanol:water (90:10 v/v) at a flow rate of 1 ml/min at an ambient temperature. Quantification was achieved with photodiode array detection at 235 nm over the concentration range 1-12 μg/ml. The method was validated statistically and was applied successfully for the determination of dutasteride in tablets.
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Affiliation(s)
- Dipti B Patel
- S. K. Patel College of Pharmaceutical Education & Research, Department of Pharmaceutical Chemistry, Ganpat University, Kherva-382 711, India
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Cree LM, Patel SK, Pyle A, Lynn S, Turnbull DM, Chinnery PF, Walker M. Age-related decline in mitochondrial DNA copy number in isolated human pancreatic islets. Diabetologia 2008; 51:1440-3. [PMID: 18528676 DOI: 10.1007/s00125-008-1054-4] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2008] [Accepted: 04/30/2008] [Indexed: 11/28/2022]
Abstract
AIM/HYPOTHESIS Pancreatic beta cell function has been shown to decline with age in man. Depletion of mitochondrial DNA (mtDNA) copy number is associated with impaired insulin secretion in pancreatic beta cell lines, and decreased mtDNA copy number has been observed with age in skeletal muscle in man. We investigated whether mtDNA copy number decreases with age in human pancreatic beta cells, which might in turn contribute to the age-related decline in insulin secretory capacity. METHODS We quantified mtDNA copy number in isolated human islet preparations from 15 pancreas donors aged between 17 and 75 years. Islets (n = 20) were individually hand-picked and pooled from each donor isolate for the quantification of mtDNA copy number and deleted mtDNA (%), which were determined using real-time PCR methods. RESULTS There was a significant negative correlation between mtDNA copy number and islet donor age (r = -0.53, p = 0.044). mtDNA copy number was significantly decreased in islet preparations from donors aged > or =50 years (n = 8) compared with those aged <50 years (n = 7) (median [interquartile range]: 418 [236-503] vs 596 [554-729] mtDNA copy number/diploid genome; p = 0.032). None of the islet preparations harboured high levels of deleted mtDNA affecting the major arc. CONCLUSION/INTERPRETATION Given the correlation between mtDNA content and respiratory chain activity, the age-related decrease in mtDNA copy number that we observed in human pancreatic islet preparations may contribute to the age-dependent decline in pancreatic beta cell insulin secretory capacity.
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Affiliation(s)
- L M Cree
- Mitochondrial Research Group, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
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Chinnery PF, Mowbray C, Patel SK, Elson JL, Sampson M, Hitman GA, McCarthy MI, Hattersley AT, Walker M. Mitochondrial DNA haplogroups and type 2 diabetes: a study of 897 cases and 1010 controls. J Med Genet 2007; 44:e80. [PMID: 17551080 PMCID: PMC2740896 DOI: 10.1136/jmg.2007.048876] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [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: 11/03/2022]
Abstract
Mitochondria play a central role in the secretion of insulin by pancreatic beta-cells, and pathogenic mutations of mitochondrial DNA (mtDNA) can cause diabetes. The aetiology of type 2 diabetes has a strong genetic component, raising the possibility that genetic variants of mtDNA alter the risk of developing the disorder. Recent studies have produced conflicting results. By studying 897 UK cases of type 2 diabetes and 1010 population-matched controls, it is shown that European mtDNA haplogroups are unlikely to play a major role in the risk of developing the disorder.
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Affiliation(s)
- P F Chinnery
- Mitochondrial Research Group, Newcastle University, Newcastle upon Tyne, UK.
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Abstract
The treatment of allergic rhinitis has been revolutionized by the introduction of topical nasal steroids, which are one of the commonest prescriptions from otolaryngology departments. With so many different sprays available on the market, the literature was reviewed for the efficacy, side-effect profile and relative cost of each product and the following conclusions made: (1) A meta-analysis of randomized controlled trials comparing the efficacy of intranasal corticosteroids and oral antihistamines in the treatment of allergic rhinitis showed a clear benefit in favour of intranasal steroids in relieving nasal symptoms. (2) There is no clear evidence to support the suggestion that one steroid spray is more effective than another in the treatment of seasonal or perennial allergic rhinitis. (3) All the sprays have a similar side-effect profile; the commonest being epistaxis with a reported incidence between 17 and 23 per cent. In all the clinical trials, the placebo spray had an appreciable rate of epistaxis of between 10 to 15 per cent. (4) Fluticasone causes a reduction in endogenous cortisol secretion but no significant adrenal suppression was seen with triamcinolone, beclomethasone, budesonide or mometasone. (5) There is little evidence that skeletal growth is restricted by the administration of topical nasal steroid sprays. (6) There is considerable variation in the daily cost of each spray. Beclomethasone, dexamethasone and budesonide are significantly cheaper than fluticasone, mometasone or triamcinolone.
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Affiliation(s)
- A N Waddell
- University Department of Otolaryngology, St Michael's Hospital, Bristol, UK
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Patel SK, Fleckenstein JM. 323 FUNCTIONAL CHARACTERIZATION OF EATA, AN AUTOTRANSPORTER PROTEN OF ENTEROTOXIGENIC E. COLI. J Investig Med 2004. [DOI: 10.1136/jim-52-suppl1-876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Patel SK, Fleckenstein JM. 158 FUNCTIONAL CHARACTERIZATION OF EATA, AN AUTOTRANSPORTER PROTEN OF ENTEROTOXIGENIC E. COLI. J Investig Med 2004. [DOI: 10.1136/jim-52-suppl1-711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Lau SS, Yoon HS, Patel SK, Everitt JI, Walker CL, Monks TJ. Mutagenicity and carcinogenicity of biological reactive intermediate's derived from a "non-genotoxic" carcinogen. Adv Exp Med Biol 2002; 500:83-92. [PMID: 11765020] [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] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Affiliation(s)
- S S Lau
- Center for Molecular and Cellular Toxicology, Division of Pharmacology and Toxicology, College of Pharmacy, University of Texas at Austin, 78712-1074, USA
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Patel SK, Tomlinson M, Anjum A, Quarmby J. Paradoxical embolus: an unusual indication for upper limb amputation. Ann R Coll Surg Engl 2001; 83:386-7. [PMID: 11777131 PMCID: PMC2503684] [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: 02/23/2023] Open
Abstract
Paradoxical emboli occur when venous embolic material passes into the arterial circulation (via a right-to-left cardiac shunt). The association of paradoxical emboli and arterial ischaemia has been described previously, especially with respect to cerebral infarcts. We describe a case in which double paradoxical emboli following a long haul flight, resulted in emergency amputation of an upper limb. Amputation resulting from a paradoxical embolus has not previously been described.
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Affiliation(s)
- S K Patel
- Department of Vascular Surgery, St George's Hospital, London, UK
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Abstract
Topical vasoconstriction using four to 10 per cent cocaine is widely used for nasal surgery. A number of techniques are being used with equally satisfactory results. Here we describe a novel method of topical application of cocaine for nasal surgery. The method is simple, cheap and effective.
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Affiliation(s)
- P Kothari
- Department of Otolaryngology Head and Neck Surgery, Milton Keynes General Hospital, Milton Keynes, UK.
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Bhadelia RA, Bengoa F, Gesner L, Patel SK, Uzun G, Wolpert SM, Caplan LR. Efficacy of MR Angiography in the Detection and Characterization of Occlusive Disease in the Vertebrobasilar System. J Comput Assist Tomogr 2001; 25:458-65. [PMID: 11351199 DOI: 10.1097/00004728-200105000-00021] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [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: 11/25/2022]
Abstract
PURPOSE The purpose of this work was to determine the efficacy of MR angiography (MRA) in the detection and characterization of occlusive disease in the vertebrobasilar system. METHOD We retrospectively reviewed the posterior circulation registry of our institution to select 42 consecutive patients with posterior circulation ischemic symptoms who underwent both MRA and angiography. The extracranial vertebral arteries (ECVAs) were examined by two-dimensional time-of-flight MRA above the C6 level, and the intracranial vertebral arteries (ICVAs) and basilar arteries (BAs) were examined by three-dimensional time-of-flight MRA. Sixty-two ECVAs, 63 ICVAs, and 39 BAs were examined by the readers. RESULTS Occlusive disease was seen on angiography in 22 of the 42 patients. The sensitivity and specificity values for detection of lesions in 12 ECVA, 19 ICVA, and 12 BA abnormalities were as follows: ECVA, 92 and 96% for Reader A and 100 and 90% for Reader B; ICVA, 84 and 93% for Reader A and 74 and 82% for Reader B; and BA, 100 and 88% for Reader A and 100 and 78% for Reader B. For ICVA, the sensitivity of MRA was less than that of angiography because of lesions missed by the readers at the junctional area of the extra-and intracranial MRA. MRA accurately characterized 9 of the 12 (75%) ECVA, 10 of the 19 (43%) ICVA, and 11 of the 12 (92%) BA lesions. CONCLUSION MRA is an effective method for detection of occlusive lesions in the ECVAs and BAs. Clinically important lesions can be missed by MRA in the ICVA. MRA is more accurate in characterization of occlusive lesions in BAs than in ECVAs or ICVAs.
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Affiliation(s)
- R A Bhadelia
- Department of Radiology, New England Medical Center Hospitals, Boston, MA 02111, USA.
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Patel SK. The black box of the ITU. Ann R Coll Surg Engl 2000; 82:229-30. [PMID: 11026847] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
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Wilkinson JR, Ruff C, Patel SK, Venn RM, Rhodes A, Bennett ED. A comparison between oesophageal Doppler and continuous thermodilution for the measurement of cardiac output in critically ill patients. Crit Care 2000. [PMCID: PMC3332933 DOI: 10.1186/cc729] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Abstract
We present a case of a 63-year-old diabetic male who developed malignant otitis externa following mastoidectomy. Extensive skull base osteomyelitis caused thrombosis of the jugular bulb and subsequent paralysis of cranial nerves VII, IX, X and XII. He was treated aggressively with intravenous antibiotics and debridement of granulation tissue in the mastoid bowl with full recovery of the cranial nerve palsies associated with recanalization of the jugular bulb. We believe this is the first reported case of malignant otitis externa to occur following mastoidectomy with complete recovery of the cranial nerve paresis.
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Affiliation(s)
- S K Patel
- Department of Otolaryngology-Head and Neck Surgery, St Mary's Hospital, London, UK
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Patel SK, Ghufoor K, Jayaraj SM, McPartlin DW, Philpott J. Pictorial assessment of the delivery of oropharyngeal rinse versus oropharyngeal spray. J Laryngol Otol 1999; 113:1092-4. [PMID: 10767923 DOI: 10.1017/s0022215100157974] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [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: 11/07/2022]
Abstract
Oral rinses/gargles and oral sprays are frequently used in the management of oropharyngeal inflammation. This pictorial study, using methylene blue dye as a marker of the distribution of these topical preparations in the oropharynx, suggests that oral sprays are more effective in coating the oropharynx than oral rinses, whilst oral rinses are better at staining the oral cavity and base of tongue. The authors therefore suggest that oral rinses should be used to treat disease in the oral cavity and oral sprays should be used to treat ailments in the oropharynx.
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Affiliation(s)
- S K Patel
- Department of Otolaryngology-Head and Neck Surgery, St. Mary's Hospital, London, UK
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McPartlin DW, Ghufoor K, Patel SK, Jayaraj S. A rare case of cutaneous kaposiform haemangioendothelioma. Int J Clin Pract 1999; 53:562-3. [PMID: 10692745] [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: 02/15/2023] Open
Abstract
Kaposiform haemangioendothelioma is a rare vascular neoplasm with a wide anatomical distribution. We describe an unusual case arising in the post-auricular skin of a male infant overlying a ventriculoperitoneal shunt.
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Affiliation(s)
- D W McPartlin
- Department of Otolaryngology and Head & Neck Surgery, St Mary's Hospital, London, UK
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Jayaraj SM, Patel SK, Ghufoor K, Frosh AC. Mucocoeles of the maxillary sinus. Int J Clin Pract 1999; 53:391-3. [PMID: 10695108] [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: 02/15/2023] Open
Abstract
Mucocoeles of the paranasal sinuses most commonly occur in the frontal or anterior ethmoidal sinuses. We report two rare cases of mucocoele of the maxillary sinus and describe the presentation, investigations and treatment. A review of the literature on this rare clinical entity is included, with specific reference to diagnostic imaging to distinguish mucocoeles from neoplastic sinus disease.
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Affiliation(s)
- S M Jayaraj
- Department of Otolaryngology-Head and Neck Surgery, St Mary's Hospital, London, UK
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Abstract
Extrapulmonary involvement of organs with the protozoan Pneumocystis carinii is rare. We describe a case of Pneumocystis carinii presenting as an erosive aural mass in a young male patient with acquired immunodeficiency syndrome. As far as the authors are aware such an example has never been described in a British journal and is the first case worldwide where otic pneumocystosis has extended into the middle cranial fossa. We also present a review of the literature on otological manifestations of Pneumocystis carinii.
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Affiliation(s)
- S K Patel
- Department of Otolaryngology-Head and Neck Surgery, St Mary's Hospital, London, UK
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Abstract
Hexafluorocyclobutene (HFCB) and derivatives have been used as fumigants, refrigerants and polymerization monomers. When inhaled they produce a potentially fatal pulmonary oedema similar to that induced by perfluoroisobutene (PFIB), a by-product of Teflon manufacture. This study determined the relationship between the chemical structure, respiratory retention and toxicity of HFCB and five analogues in rats and mice. Retention in the rat was determined using a flow-through system combining nose-only exposure and plethysmography. Structural changes to HFCB modified retention. At concentrations of ca. 1 ppm, where uptake was independent of exposure time, the rate of uptake was increased by halogen substitution in the order 3-Br = 1-Br = 1-Cl > 3-Cl = 1-H > HFCB, and was a function of volatility. At concentrations of 6 or 30 ppm, the percentage retained and rate of uptake decreased with time. The total mass retained (micromol kg(-1)) was not proportional to inhaled concentration and was best described by the calculated partition coefficient (octane-water). No clear relationship between retention and reactivity was apparent. The contribution of volatility, partition coefficient and reactivity to the uptake process depended on inhaled concentration. The toxicity of the fluorocyclobutenes agreed with reactivity relationships based on electrophilicity (lowest unoccupied molecular orbital energy), carbanion stability and leaving-group mobility. Toxicity is based principally on the number of successive alkylations (1, 2 or 3) that can occur with tissue nucleophiles.
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Affiliation(s)
- M P Maidment
- Defence Evaluation and Research Agency, Chemical and Biological Defence Sector, Salisbury, Wiltshire, UK
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Abstract
In this study, we have compared the uptake of L-cysteine (L-CySH), D-cysteine (D-CySH), L-cysteine isopropyl ester (L-CIPE) and D-cysteine isopropyl ester (D-CIPE) in rat lung slices and tracheal sections and determined the effectiveness of glutathione (GSH), GSH isopropyl monoester, GSH isopropyl diester, gamma-glutamylcysteine (gamma-glu-cys) isopropyl monoester and gamma-glu-cys isopropyl diester to elevate and prolong intracellular GSH concentrations in rat lung slices. Lung slices were incubated with 1.0 mM of thiol and the concentrations determined intracellularly and extracellularly with time. Slices incubated with GSH, GSH isopropyl diester and gamma-glu-cys isopropyl diester had cellular GSH concentrations increased by up to 60%, 95% and 58%, respectively, whereas GSH isopropyl monoester and gamma-glu-cys isopropyl monoester did not increase the intracellular GSH concentration. Extracellularly, the GSH concentration had decreased by 15%, GSH isopropyl diester by 27%, gamma-glu-cys isopropyl diester by 66% and both isopropyl monoesters by over 90% at 120 min. Lung slices and tracheal sections incubated with L- or D-CySH at 37 degrees had increased cellular concentrations of L- and D-CySH which ranged between 0.88-1.25 nmol mg(-1) and 1.35-2.25 nmol mg(-1) , respectively. Reducing the incubation temperature to 4 degrees had little effect on the accumulation of D-CySH; however, L-CySH concentrations increased progressively in the trachea and lung to reach 2.73 and 2.63 nmol mg(-1) at 90 min, respectively. Lung slices incubated with L- or D-CIPE had increased L- or D-CySH concentrations up to a max of 13.7 and 11.1 nmol mg(-1) and tracheal sections up to a max of 5.56 and 11.09 nmol mg(-1). In the lung slice medium, L- and D-CIPE levels had decreased by 75.2% and 74.0% at 90 min, respectively, and from the tracheal section medium, L- and D-CIPE concentrations had decreased by 66.7% and 32.7%, respectively. Preincubation of lung slices and tracheal sections with the carboxylesterase inhibitor, bis (p-nitrophenyl) phosphate (BNPP), almost completely prevented the disappearance of L- and D-CIPE extracellularly and greatly reduced the appearance of cellular L- and D-CySH. GSH, GSH isopropyl diester and gamma-glu-cys isopropyl diester elevated and prolonged GSH concentrations in rat lung slices, but GSH isopropyl monoester and gamma-glu-cys isopropyl monoester did not increase GSH levels. The uptake of L-CySH, but not D-CySH, is temperature sensitive in rat lung slices and tracheal sections and carboxylesterases appear to have a major influence on the uptake and metabolism of L- and D-CIPE by rat lung slices and tracheal sections.
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Affiliation(s)
- M J Hobbs
- Medical Countermeasures Department, CBD, Salisbury, Wiltshire, UK
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Abstract
The fusion of endoplasmic reticulum (ER) membranes in yeast does not require Sec18p/NSF and Sec17p, two proteins needed for docking of vesicles with their target membrane. Instead, ER membranes require a NSF-related ATPase, Cdc48p. Since both vesicular and organelle fusion events use related ATPases, we investigated whether both fusion events are also SNARE mediated. We present evidence that the fusion of ER membranes requires Ufe1p, a t-SNARE that localizes to the ER, but no known v-SNAREs. We propose that the Ufe1 protein acts in the dual capacity of an organelle membrane fusion-associated SNARE by undergoing direct t-t-SNARE and Cdc48p interactions during organelle membrane fusion as well as a t-SNARE for vesicular traffic.
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Affiliation(s)
- S K Patel
- The Salk Institute, La Jolla, California 92037, USA
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Affiliation(s)
- S K Patel
- Department of Anesthesiology & Pain Management, University of Texas Southwestern Medical Center, Dallas 75235-9068, USA
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Abstract
BACKGROUND Yersinia enterocolitica is frequently identified in cases of bacterial sepsis due to red cell transfusion. One of the features that makes Y. enterocolitica particularly dangerous is that, unlike most other bacterial contaminants of blood components, this organism can actively multiply in currently recommended refrigerator temperatures (1-6 degrees C). The effect of a colder than normal storage temperature on Y. enterocolitica growth was investigated to determine whether bacteria growth could be reduced or inhibited at 0 degree C. STUDY DESIGN AND METHODS Twenty-four units of freshly collected donated blood were obtained. Three sets of 7 units each were inoculated with Y. enterocolitica O:3, Y. enterocolitica O:20, and Y. enterocolitica O:5, 27, respectively. The remaining 3 units served as uninoculated controls. Each of the 24 bags was split into two equal aliquots, with one aliquot stored at 4 degrees C and the other at 0 degree C. Bacteria growth was measured twice weekly for 6 weeks. Endotoxin and hemoglobin levels were also measured at selected intervals. RESULTS Bacteria growth was detected earlier and in higher concentrations in the aliquots stored at 4 degrees C. Twenty-two of the 42 inoculated aliquots had measureable bacteria growth. Thirteen aliquots had been maintained at 4 degrees C, and nine had been stored at 0 degree C. Sixteen of these 22 aliquots were matched pairs. Exponential growth was detected after 14 to 32 days in the 4 degrees C aliquots and after 28 to 39 days in the 0 degree C aliquots. Final bacteria counts were much higher in the 4 degrees C aliquots (10(5)-10(14) colony-forming units/mL) than in the 0 degree C aliquots (10(1)-10(4) colony-forming units/mL) on Day 42. Endotoxin was present in all 13 of the 4 degrees C aliquots with actively growing Y. enterocolitica. CONCLUSION Storage of red cells at 0 degree C markedly prolongs the time required for Y. enterocolitica to achieve exponential grwoth and results in lower concentrations of bacteria.
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Affiliation(s)
- R M Bradley
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, USA
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49
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Kornel L, Patel SK, Ezzeraimi E, Shackleton CH. Corticosteroids in human blood: IX. Evidence for adrenal secretion of sulfate-conjugated cortisol, 11 beta,17 alpha-dihydroxy-4-pregnene-3,20-dione-21-yl-sulfate. Steroids 1995; 60:817-23. [PMID: 8650705 DOI: 10.1016/0039-128x(95)00141-c] [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] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A method was developed for the estimation of levels of cortisol-21-sulfate (F KS), cortisone-21-sulfate (ES), and 20(alpha + beta)-reduced cortisol-21-sulfates in blood plasma. Levels of these conjugates were determined in peripheral vein plasma of 42 normal subjects, 21 men, and 21 women (age range 20-64 years) and in adrenal vein plasma of patients with various adrenocortical disorders, six patients with primary hyperaldosteronism, five patients with Cushing's syndrome, and in two obese patients, suspected to have Cushing's syndrome, but with inconclusive laboratory findings. Adrenal vein blood was obtained by percutaneous, trans-femoral adrenal vein catheterization. Levels of non-conjugated (free) cortisol were determined in all plasma samples along with those of the sulfated steroids. F kappa S was found in all plasma samples, both in men and women. The variation in F kappa S levels paralleled that in the free cortisol levels, thus the ratio of F kappa/F kappa S was the same in the blood samples drawn at 8 AM as in those drawn at 4 PM or 5 PM (ranges: 17.5-36.3 in men, 23.6-45.8 in women). The levels of F kappa S were relatively lower in women than in men (women 610-880 ng/100 mL at AM, 300-510 ng/100 mL at PM; men: 760-1,220 ng/100 mL at AM, 380-760 ng/100 mL at PM). Plasma levels of total sulfate-conjugated delta 4-3-keto-C-21 steroids (F kappa S + E kappa S + 20(alpha+beta)-dihydrocortisol-21-sulfates) were 30-40% higher than those of the levels of cortisol-21-sulfate alone (separated by thin-layer chromatography). In the adrenal vein plasma, levels of delta 4-3-keto-C-21-steroid-21-yl sulfates were 20 to 40 times higher than levels of these steroids in the peripheral blood. The bulk of the steroid sulfate measured in the adrenal vein plasma consisted of cortisol-21-sulfate. The ratio of F kappa/F kappa S in the adrenal vein plasma was markedly smaller than in the peripheral vein plasma; it was 6.9-12.3 in males and 4.9-6.7 in females, whereas in the peripheral vein of the same subjects it was 19.2-43.7 in males and 21.4-48.3 in females. Cortisol-21-sulfate isolated from adrenal vein plasma was identified by mass spectrometry. The data presented provide evidence for the secretion of this conjugate by the adrenal cortex. Its secretion appears to be markedly elevated in patients with Cushing's syndrome, both due to hyperplasia and due to adrenal adenoma, as compared with normal subjects and patients with primary aldosteronism, both males and females. However, the F kappa/F kappa S ratio was markedly lower in Cushing's patients due to adrenal adenoma than due to adrenal hyperplasia, this suggesting that ACTH is stimulating intra-adrenal hydrolysis of cortisol sulfate.
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Affiliation(s)
- L Kornel
- Department of Medicine, Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois 60612, USA
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50
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Brunner MC, Matalon TA, Patel SK, Siliunas DA, McDonald V, Merkel FK. Percutaneous interventions in adults receiving pediatric "en bloc" double renal grafts. Cardiovasc Intervent Radiol 1995; 18:291-5. [PMID: 8846467 DOI: 10.1007/bf00203678] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
PURPOSE To present technical adaptations of percutaneous interventional techniques required for the small size vessels and ureters of "en bloc" transplanted pediatric kidneys. METHODS Over a 4-year period, 12 adult patients received en bloc pediatric double renal transplants. Small system percutaneous interventional techniques were used in seven patients to approach the infantile renal arteries and urinary collecting systems for 11 percutaneous transluminal renal angioplasties, 4 antegrade pyelograms, and 3 nephrostomies. RESULTS Prior to intervention, these patients averaged a creatinine of 2.5 mg%, which decreased to 1.4 mg% at 46 months (range, 22-68) following the first intervention. With a mean follow-up of 42 months (range, 5-47), 9 of 12 (75%) transplants are functioning with an average serum creatinine of 1.3 mg%. CONCLUSION With the assistance of percutaneous management of postoperative arterial and ureteral lesions, the prognosis of en bloc renal grafts can approach that of the standard adult renal allograft.
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Affiliation(s)
- M C Brunner
- Department of Diagnostic Radiology and Nuclear Medicine, Rush-Presbyterian-St. Luke's Medical Center, Chicago, IL 60612, USA
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