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Li W, Vazvaei-Smith F, Dear G, Boer J, Cuyckens F, Fraier D, Liang Y, Lu D, Mangus H, Moliner P, Pedersen ML, Romeo AA, Spracklin DK, Wagner DS, Winter S, Xu XS. Metabolite Bioanalysis in Drug Development: Recommendations from the IQ Consortium Metabolite Bioanalysis Working Group. Clin Pharmacol Ther 2024; 115:939-953. [PMID: 38073140 DOI: 10.1002/cpt.3144] [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] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 12/05/2023] [Indexed: 03/13/2024]
Abstract
The intent of this perspective is to share the recommendations of the International Consortium for Innovation and Quality in Pharmaceutical Development Metabolite Bioanalysis Working Group on the fit-for-purpose metabolite bioanalysis in support of drug development and registration. This report summarizes the considerations for the trigger, timing, and rigor of bioanalysis in the various assessments to address unique challenges due to metabolites, with respect to efficacy and safety, which may arise during drug development from investigational new drug (IND) enabling studies, and phase I, phase II, and phase III clinical trials to regulatory submission. The recommended approaches ensure that important drug metabolites are identified in a timely manner and properly characterized for efficient drug development.
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Affiliation(s)
- Wenkui Li
- Pharmacokinetic Sciences, Novartis Biomedical Research, East Hanover, New Jersey, USA
| | - Faye Vazvaei-Smith
- Pharmacokinetics, Dynamics, Metabolism and Bioanalytics, Merck & Co., Inc., West Point, Pennsylvania, USA
| | - Gordon Dear
- Drug Metabolism and Pharmacokinetics, GSK, Ware, UK
| | - Jason Boer
- Drug Metabolism and Pharmacokinetics, Incyte Corporation, Wilmington, Delaware, USA
| | - Filip Cuyckens
- Drug Metabolism and Pharmacokinetics, Janssen R & D, Beerse, Belgium
| | - Daniela Fraier
- Pharmaceutical Sciences, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Yuexia Liang
- Pharmacokinetics, Dynamics, Metabolism and Bioanalytics, Merck & Co., Inc., West Point, Pennsylvania, USA
| | - Ding Lu
- Drug Metabolism and Pharmacokinetics, Vertex Pharmaceuticals Inc., Boston, Massachusetts, USA
| | - Heidi Mangus
- Drug Metabolism and Pharmacokinetics, Agios Pharmaceuticals Inc., Cambridge, Massachusetts, USA
| | - Patricia Moliner
- Enzymology and Metabolism, Department of Translational Medicine and Early Development, Sanofi, Montpellier, Occitanie, France
| | - Mette Lund Pedersen
- DMPK, Research and Early Development, CVRM, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Andrea A Romeo
- Pharmaceutical Sciences, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Douglas K Spracklin
- Pharmacokinetics, Dynamics, and Metabolism, Pfizer Inc., Groton, Connecticut, USA
| | - David S Wagner
- Drug Metabolism and Disposition, AbbVie, North Chicago, Illinois, USA
| | - Serge Winter
- Pharmacokinetic Sciences, Novartis Biomedical Research, Basel, Switzerland
| | - Xiaohui Sophia Xu
- Clinical Bioanalysis, Translation Medicine, Daiichi Sankyo, Inc., Basking Ridge, New Jersey, USA
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Xu XS, Ding H, Zhang X, Liao Y, Li H, Liu QY, Liu JZ, Zhang L, Huang J, Gong YP, Ma HB, Xiang B, Dai Y, Hou L, Shuai X, Niu T, Wu Y. [Clinical characteristics and prognosis of patients with therapy-related myelodysplastic syndrome and acute myeloid leukemia arising from malignant tumors]. Zhonghua Xue Ye Xue Za Zhi 2023; 44:742-748. [PMID: 38049318 PMCID: PMC10630571 DOI: 10.3760/cma.j.issn.0253-2727.2023.09.007] [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] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Indexed: 12/06/2023]
Abstract
Objective: To investigate the clinical characteristics, cytogenetics, molecular biology, treatment, and prognosis of patients with therapy-related myelodysplastic syndrome and acute myeloid leukemia (t-MDS/AML) secondary to malignancies. Methods: The clinical data of 86 patients with t-MDS/AML in West China Hospital of Sichuan University between January 2010 and April 2023 were retrospectively analyzed. The clinical characteristics, primary tumor types, and tumor-related therapies were analyzed. Results: The study enrolled a total of 86 patients with t-MDS/AML, including 67 patients with t-AML, including 1 patient with M(0), 6 with M(1), 27 with M(2), 9 with M(3), 12 with M(4), 10 with M(5), 1 with M(6), and 1 with M(7). Sixty-two patients could be genetically stratified, with a median overall survival (OS) of 36 (95% CI 22-52) months for 20 (29.9%) patients in the low-risk group and 6 (95% CI 3-9) months for 10 (14.9%) in the intermediate-risk group. The median OS time was 8 (95% CI 1-15) months in 32 (47.8%) patients in the high-risk group. For patients with non-acute promyelocytic leukemia (APL) and AML, the median OS of the low-risk group was 27 (95% CI 18-36) months, which was significantly longer than that of the non-low-risk group (χ(2)=5.534, P=0.019). All 9 APL cases were treated according to the initial treatment, and the median OS was not reached, and the 1-, 2-, and 3-year OS rates were 100.0%, (75.0±6.2) %, and (75.0±6.2) % respectively. Of the 58 patients with non-APL t-AML (89.7%), 52 received chemotherapy, and 16 achieved complete remission (30.8%) after the first induction chemotherapy. The 1-, 2-, and 3-year OS rates of the non-APL t-AML group were (42.0 ± 6.6) %, (22.9±5.7) %, and (13.4±4.7) %, respectively. The median OS of patients who achieved remission was 24 (95% CI 18-30) months, and the median OS of those who did not achieve remission was 6 (95% CI 3-9) months (χ(2)=10.170, P=0.001). Bone marrow CR was achieved in 7 (53.8%) of 13 patients treated with vineclar-containing chemotherapy, with a median OS of 12 (95% CI 9-15) months, which was not significantly different from that of vineclar-containing chemotherapy (χ(2)=0.600, P=0.437). In 19 patients with t-MDS, the 1-, 2-, and 3-year OS rates were (46.8±11.6) %, (17.5±9.1) %, and (11.7±9.1) % with a median OS of 12 (95% CI 7-17) months, which was not significantly different from that in t-AML (χ(2)=0.232, P=0.630) . Conclusions: Breast cancer, bowel cancer, and other primary tumors are common in patients with t-MDS/AML, which have a higher risk of adverse genetics. Patients with APL had a high induction remission rate and a good long-term prognosis, whereas patients without APL had a low remission rate and a poor long-term prognosis.
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Affiliation(s)
- X S Xu
- Department of Hematology, West China Hospital, Sichuan University, Chengdu 610041, China Department of Hematology, Jiujiang First People's Hospital, Jiujiang 332000, China
| | - H Ding
- Department of Hematology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - X Zhang
- Department of Hematology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Y Liao
- Department of Hematology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - H Li
- Department of Hematology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Q Y Liu
- Department of Hematology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - J Z Liu
- Department of Hematology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - L Zhang
- Department of Hematology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - J Huang
- Department of Hematology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Y P Gong
- Department of Hematology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - H B Ma
- Department of Hematology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - B Xiang
- Department of Hematology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Y Dai
- Department of Hematology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - L Hou
- Department of Hematology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - X Shuai
- Department of Hematology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - T Niu
- Department of Hematology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Y Wu
- Department of Hematology, West China Hospital, Sichuan University, Chengdu 610041, China
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Liang PF, Xu XS, Zhang PH, Bi CL, Zhang H, Huang MT, He ZY, Zeng JZ, Huang Y, Li J, Cui X, Zhou ST, Zhang MH, Huang XY. [Repair methods of complex facial defect wounds involving paranasal sinuses and their clinical effectiveness]. Zhonghua Shao Shang Yu Chuang Mian Xiu Fu Za Zhi 2023; 39:221-227. [PMID: 37805717 DOI: 10.3760/cma.j.cn501225-20221130-00520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 10/09/2023]
Abstract
Objective: To explore the repair methods of complex facial defect wounds involving paranasal sinuses and their clinical effectiveness. Methods: A retrospective observational study was conducted. From January 2020 to May 2022, 5 patients admitted to the Department of Burns and Plastic Surgery of Xiangya Hospital of Central South University and 4 patients admitted to the Department of Burns and Plastic Surgery of Chenzhou First People's Hospital with complex facial defect wounds involving paranasal sinuses met the inclusion criteria, including 6 males and 3 females, aged 35-69 years, including 4 patients with titanium mesh exposure combined with paranasal sinuses injury and 5 patients with tumor involving paranasal sinuses. After an adequate assessment of the damage by a multiple discipline team, titanium mesh removal, paranasal sinus debridement, and paranasal sinus mucosa removal were performed in patients with exposed titanium mesh, and radical tumor resection was performed in patients with tumors, with postoperative skin and soft tissue defects areas of 5.0 cm×2.5 cm to 18.0 cm×7.0 cm, anterior paranasal sinus wall defects/absence areas of 3 cm×2 cm to 6 cm×4 cm, and sinus cavity depths of 1 to 4 cm. Depending on the perforator course of the descending branch of the lateral circumflex femoral artery, the anterolateral femoral chimeric flap or anterolateral femoral myocutaneous flap (with flap area of 9 cm×4 cm to 19 cm×8 cm, muscle size of 5 cm×3 cm×3 cm to 11 cm×6 cm×3 cm) was transplanted to repair the defect, and the donor site wound was sutured directly. The type of tissue flap transplanted, the blood vessel of the recipient area, and the vascular anastomosis way during the operation, the recovery of the donor and recipient areas and the occurrence of complications after operation were observed. The appearance and blood supply of the recipient area and the recurrence of ulcers and tumors were followed up. Results: The anterolateral femoral myocutaneous flap transplantation was performed in 6 patients, and the anterolateral femoral chimeric flap transplantation was performed in 3 patients. The blood vessels in recipient areas were facial arteries and veins in 3 cases and superficial temporal arteries and veins in 6 cases. The superficial temporal arteries and veins were bridged with blood vessels in tissue flaps by flow-through way in 2 patients, and end-to-end anastomosis of blood vessels in donor and recipient areas was performed in 7 patients. After operation, all the tissue flaps survived, and the facial defect wounds were well repaired without cerebrospinal fluid leakage or paranasal sinus secretion leakage, no intracranial infection occurred, and the wounds in donor areas were healed well. Follow-up of 6-35 months after operation showed that all the patients had good blood supply in the recipient area, and the shape was acceptable; 4 patients with exposed titanium mesh had no recurrence of ulceration, and 5 patients with tumor had no local tumor recurrence or metastasis. Conclusions: Based on an adequate assessment of the extent of paranasal sinuses involved in the facial wound and the nature of the defect, good clinical effects can be achieved by using the anterolateral femoral muscle flap or the anterolateral femoral chimeric flap transplantation to repair complex facial defect wounds with open paranasal sinuses.
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Affiliation(s)
- P F Liang
- Department of Burns and Plastic Surgery, Xiangya Hospital, Central South University, Changsha 410008, China
| | - X S Xu
- Department of Burns and Plastic Surgery, Chenzhou First People's Hospital, Chenzhou 423099, China
| | - P H Zhang
- Department of Burns and Plastic Surgery, Xiangya Hospital, Central South University, Changsha 410008, China
| | - C L Bi
- Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha 410008, China
| | - H Zhang
- Department of Otolaryngology-Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha 410008, China
| | - M T Huang
- Department of Burns and Plastic Surgery, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Z Y He
- Department of Burns and Plastic Surgery, Xiangya Hospital, Central South University, Changsha 410008, China
| | - J Z Zeng
- Department of Burns and Plastic Surgery, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Y Huang
- Department of Burns and Plastic Surgery, Chenzhou First People's Hospital, Chenzhou 423099, China
| | - J Li
- Department of Burns and Plastic Surgery, Chenzhou First People's Hospital, Chenzhou 423099, China
| | - X Cui
- Department of Burns and Plastic Surgery, Xiangya Hospital, Central South University, Changsha 410008, China
| | - S T Zhou
- Department of Burns and Plastic Surgery, Xiangya Hospital, Central South University, Changsha 410008, China
| | - M H Zhang
- Department of Burns and Plastic Surgery, Xiangya Hospital, Central South University, Changsha 410008, China
| | - X Y Huang
- Department of Burns and Plastic Surgery, Xiangya Hospital, Central South University, Changsha 410008, China
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Wang ZY, Gao WF, Shao YM, Gao YC, Xu XS, Liu BJ, Zhang MS. [Clinical evaluation of platelet-rich plasma in the treatment of early and middle stage knee osteoarthritis under 3.0T MRI T2 mapping sequence]. Zhonghua Wai Ke Za Zhi 2023; 61:138-144. [PMID: 36720623 DOI: 10.3760/cma.j.cn112139-20220703-00296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Objective: To quantitatively evaluate the clinical effect of platelet-rich plasma(PRP) intra-articular injection for early and middle stage knee osteoarthritis(KOA) treatment by 3.0T MRI T2 mapping sequence. Methods: Clinical data of 26 patients with early or middle stage KOA who received treatment from April to December 2021 at Department of Orthopaedic Surgery,the Second Affiliated Hospital,Zhengzhou University were retrospectively analyzed. In total, 8 patients were male and 18 were female,with age of (66.4±12.0)years(range:51 to 94 years). Four patients were bilateral KOA and 22 patients were unilateral KOA.All patients received PRP intra-articular injection. Patients underwent 3.0T MRI T2 mapping sequence scanning pre-treatment,3-month-after and 6-month-after treatment respectively. Those were used to measure and compare T2 values of medial and lateral femoral articular surface and patellofemoral articular surface. Visual analogue scale(VAS) and Western Ontario and McMaster Osteoarthritis Index (WOMAC) score were recorded and evaluated. The results were analyzed using repeated measure ANOVA followed by Bonferroni multiple comparison test.The correlation between WOMAC scores and T2 values at pre-treatment and 6 months post-treatment was analyzed using Pearson correlation test. Results: After treatment, the patients' International Cartilage Regeneration&Joint Preservation Society(ICRS) classification were partly improved(one case improved from grade Ⅲ to grade Ⅱ, one case improved from grade Ⅱ to grade Ⅰ),and all patients generally improved after treatment in clinical symptoms. Compared with pre-treatment,VAS and WOMAC scores of grade Ⅰ,Ⅱ,and Ⅲ of 6-month after treatment were declined significantly(all P<0.05).The T2 values of articular cartilage declined to varying degrees(the decrease in T2 values was about 2.06 ms in grade Ⅰ, 2.66 ms in grade Ⅱ, and 3.72 ms in grade Ⅲ).Three-month (VAS:4.8±1.3,WOMAC:21.5±4.0) and 6-month (VAS:4.2±1.4,WOMAC:17.2±2.9) after treatment, the VAS and WOMAC score were significantly higher than those before treatment (VAS:6.0±1.2, WOMAC:29.0±2.3) (F=48.846, F=346.746;both P<0.01). Multiple comparisons showed a statistically significant difference between pre-treatment and post-treatment VAS (P<0.01) and it also was significantly different between 3-month and 6-month post-treatment (P<0.01).At 3- and 6-month after treatment,WOMAC scores were significantly different from before treatment.And it also was significantly different between 3-month and 6-month post-treatment (P<0.01).There was a statistically significant improvement in T2 values of patellofemoral articular surface, medial and lateral femoral articular surface at pre-treatment((44.64±4.02)ms,(44.17±3.64)ms and(43.53±3.91)ms) and 3-month ((43.19±3.91)ms,(43.24±3.34)ms and (42.47±3.80)ms), 6-month ((41.49±3.64)ms,(41.83±3.15)ms and (41.10±3.42)ms) after treatment(F=148.845,F=73.657,F=86.268;all P<0.01).The results of the multiple comparisons showed a statistically significant difference in the T2 values of medial and lateral femoral articular surface and patellofemoral articular surface at each time point(all P<0.01).The Pearson correlation analysis suggested that the WOMAC score at pre-treatment was positively correlated with the medial condyle (r=0.856,P<0.01) and the patellofemoral joint surface T2 values (r=0.840,P<0.01);The WOMAC score at 6-month post-treatment was positively correlated with the medial condyle (r=0.731,P<0.01) and the patellofemoral joint surface T2 values (r=0.691,P<0.01). Conclusions: In the treatment of early and mid-stage KOA,MRI T2 mapping sequences are able to indicate the integrity of cartilage morphology and quantitatively evaluate cartilage repair. PRP has a good therapeutic effect on cartilage repair and reconstruction.
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Affiliation(s)
- Z Y Wang
- Department of Orthopaedic Surgery,the Second Affiliated Hospital,Zhengzhou University,Zhengzhou 450003,China
| | - W F Gao
- Department of Orthopaedic Surgery,the Second Affiliated Hospital,Zhengzhou University,Zhengzhou 450003,China
| | - Y M Shao
- Department of Orthopaedic Surgery,the Second Affiliated Hospital,Zhengzhou University,Zhengzhou 450003,China
| | - Y C Gao
- Department of Orthopaedic Surgery,the Second Affiliated Hospital,Zhengzhou University,Zhengzhou 450003,China
| | - X S Xu
- Department of Orthopaedic Surgery,the Second Affiliated Hospital,Zhengzhou University,Zhengzhou 450003,China
| | - B J Liu
- Department of Orthopaedic Surgery,the Second Affiliated Hospital,Zhengzhou University,Zhengzhou 450003,China
| | - M S Zhang
- Department of Orthopaedic Surgery,the Second Affiliated Hospital,Zhengzhou University,Zhengzhou 450003,China
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Xu XS, Wang XA, Chen W, Liu YB. [The treatment strategies for complications after pancreaticoduodenectomy]. Zhonghua Yi Xue Za Zhi 2022; 102:3658-3662. [PMID: 36509535 DOI: 10.3760/cma.j.cn112137-20220506-01004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The most common complications after pancreaticoduodenectomy include pancreatic fistula, biliary fistula, delayed gastric emptying, bleeding, and abdominal infection. Although advances in surgery have led to a significant decrease in perioperative mortality in recent years, the risk of complications after pancreaticoduodenectomy remains. Thus, prevention and treatment of various complications are important to improve the prognosis of patients.
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Affiliation(s)
- X S Xu
- Department of Biliary-pancreatic Surgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - X A Wang
- Department of Biliary-pancreatic Surgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - W Chen
- Department of Biliary-pancreatic Surgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Y B Liu
- Department of Biliary-pancreatic Surgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
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Krajnak K, Waugh S, Welcome D, Xu XS, Warren C, McKinney W, Dong RG. Effects of whole-body vibration on reproductive physiology in a rat model of whole-body vibration. J Toxicol Environ Health A 2022; 85:953-971. [PMID: 36165131 PMCID: PMC9885295 DOI: 10.1080/15287394.2022.2128954] [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] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Findings from epidemiological studies suggest that occupational exposure to whole-body vibration (WBV) may increase the risk of miscarriage and contribute to a reduction in fertility rates in both men and women. However, workers exposed to WBV may also be exposed to other risk factors that contribute to reproductive dysfunction. The goal of this experiment was to examine the effects of WBV on reproductive physiology in a rat model. Male and female rats were exposed to WBV at the resonant frequency of the torso (31.5 Hz, 0.3 g amplitude) for 4 hr/day for 10 days. WBV exposure resulted in a significant reduction in number of developing follicles, and decrease in circulating estradiol concentrations, ovarian luteinizing hormone receptor protein levels, and marked changes in transcript levels for several factors involved in follicular development, cell cycle, and steroidogenesis. In males, WBV resulted in a significant reduction in spermatids and circulating prolactin levels, elevation in number of males having higher circulating testosterone concentrations, and marked alterations in levels of transcripts associated with oxidative stress, inflammation, and factors involved in regulating the cell cycle. Based upon these findings data indicate that occupational exposure to WBV contributes to adverse alterations in reproductive physiology in both genders that may lead to reduction in fertility.
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Affiliation(s)
- K Krajnak
- Physical Effects Research Branch, National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - S Waugh
- Physical Effects Research Branch, National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - D Welcome
- Physical Effects Research Branch, National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - X S Xu
- Physical Effects Research Branch, National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - C Warren
- Physical Effects Research Branch, National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - W McKinney
- Physical Effects Research Branch, National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - R G Dong
- Physical Effects Research Branch, National Institute for Occupational Safety and Health, Morgantown, West Virginia
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Xu CC, Bai YZ, Xu XS, Lü GL, Lai XP, Chen R, Lin HG, Kuang WJ. [Gene Analysis for the Sudden Death of Hypertrophic Cardiomyopathy by Whole Exome Sequencing.]. Fa Yi Xue Za Zhi 2017; 33:339-343. [PMID: 29219260 DOI: 10.3969/j.issn.1004-5619.2017.04.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Indexed: 11/18/2022]
Abstract
OBJECTIVES To analyze the related pathogenicity gene mutations in a sudden death of hypertrophic cardiomyopathy (HCM) on whole exome level. METHODS Whole exome sequencing (WES) was been performed on a sudden death case sample with pathological features of HCM by Illumina® Hiseq 2500 platform. Using hg19 as the reference sequences, the sequencing data were analyzed. Suspicious single nucleotide variants (SNV) were screened, and the conservatism and function were analyzed by the software such as PhyloP, PolyPhen-2, SIFT, etc. RESULTS After screening, a heterozygous mutation C719R was finally identified in the gene MYBPC3 of this case. CONCLUSIONS The molecular anatomy on whole exome level by second generation sequencing technology can help to define the molecular mechanism of HCM and provide a new mothed and thought for analysis of death cause.
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Affiliation(s)
- C C Xu
- Guangdong Medical University, Dongguan 523808, China.,Center of Forensic Science, Guangdong Medical University, Dongguan 523808, China
| | - Y Z Bai
- Panyu Branch of Guangzhou Public Security Bureau, Guangzhou 511400, China
| | - X S Xu
- Guangzhou Institute of Forensic Science and Technology, Guangzhou 510030, China
| | - G L Lü
- Guangzhou Institute of Forensic Science and Technology, Guangzhou 510030, China
| | - X P Lai
- Guangdong Medical University, Dongguan 523808, China.,Center of Forensic Science, Guangdong Medical University, Dongguan 523808, China
| | - R Chen
- Guangdong Medical University, Dongguan 523808, China.,Center of Forensic Science, Guangdong Medical University, Dongguan 523808, China
| | - H G Lin
- Guangdong Medical University, Dongguan 523808, China.,Center of Forensic Science, Guangdong Medical University, Dongguan 523808, China
| | - W J Kuang
- Guangdong Medical University, Dongguan 523808, China.,Center of Forensic Science, Guangdong Medical University, Dongguan 523808, China
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Xu XS, Yan X, Puchalski T, Lonial S, Lokhorst HM, Voorhees PM, Plesner T, Liu K, Khan I, Jansson R, Ahmadi T, Ruixo JJP, Zhou H, Clemens PL. Clinical Implications of Complex Pharmacokinetics for Daratumumab Dose Regimen in Patients With Relapsed/Refractory Multiple Myeloma. Clin Pharmacol Ther 2017; 101:721-724. [PMID: 27859027 PMCID: PMC5485722 DOI: 10.1002/cpt.577] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 11/11/2016] [Accepted: 11/12/2016] [Indexed: 01/28/2023]
Abstract
New therapeutic strategies are urgently needed to improve clinical outcomes in patients with multiple myeloma (MM). Daratumumab is a first-in-class, CD38 human immunoglobulin G1κ monoclonal antibody approved for treatment of relapsed or refractory MM. Identification of an appropriate dose regimen for daratumumab is challenging due to its target-mediated drug disposition, leading to time- and concentration-dependent pharmacokinetics. We describe a thorough evaluation of the recommended dose regimen for daratumumab in patients with relapsed or refractory MM.
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Affiliation(s)
- XS Xu
- Janssen Research & Development, LLCRaritanNew JerseyUSA
| | - X Yan
- Janssen Research & Development, LLCRaritanNew JerseyUSA
| | - T Puchalski
- Janssen Research & Development, LLCSpring HousePennsylvaniaUSA
| | - S Lonial
- Department of Hematology and Medical Oncology, Winship Cancer InstituteEmory UniversityAtlantaGeorgiaUSA
| | - HM Lokhorst
- VU University Medical CenterAmsterdamThe Netherlands
| | - PM Voorhees
- Division of Hematology/Oncology, Lineberger Comprehensive Cancer CenterUniversity of North Carolina at Chapel HillChapel HillNorth CarolinaUSA
| | - T Plesner
- Vejle Hospital and University of Southern DenmarkVejleDenmark
| | - K Liu
- Janssen Research & Development, LLCRaritanNew JerseyUSA
| | - I Khan
- Janssen Research & Development, LLCRaritanNew JerseyUSA
| | - R Jansson
- Janssen Research & Development, LLCSpring HousePennsylvaniaUSA
| | - T Ahmadi
- Janssen Research & Development, LLCSpring HousePennsylvaniaUSA
| | | | - H Zhou
- Janssen Research & Development, LLCSpring HousePennsylvaniaUSA
| | - PL Clemens
- Janssen Research & Development, LLCSpring HousePennsylvaniaUSA
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Chen ZY, Gao C, Ye T, Zuo XZ, Wang GH, Xu XS, Yao Y. Association between nutritional risk and routine clinical laboratory measurements and adverse outcomes: a prospective study in hospitalized patients of Wuhan Tongji Hospital. Eur J Clin Nutr 2014; 69:552-7. [PMID: 25369828 PMCID: PMC4424800 DOI: 10.1038/ejcn.2014.239] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2014] [Revised: 07/22/2014] [Accepted: 09/27/2014] [Indexed: 01/10/2023]
Abstract
Background/Objectives: Nutritional risk screening (NRS-2002) and routine clinical laboratory measurements (RCLMs) had been shown to have a predictive value in adverse outcomes in some studies, respectively. This study analyzed the association between NRS-2002 and RCLMs and estimated their prospective value in predicting adverse outcomes. Subjects/Methods: A total of 916 hospitalized patients were screened on admission with NRS-2002 and Subjective Global Assessment; RCLMs, which include blood test, kidney and liver function and electrolytes, were recorded. Diagnosis, nutritional support, surgery, radiotherapy, chemotherapy, complications, mortality and hospital stay during hospitalization were collected. The X2-test, odds ratios with 95% confidence intervals, kappa (k) statistic and regression analyses were conducted. Results: An overall 48.1% of the 916 patients were at nutritional risk on admission. Comparing ‘at risk' with ‘no risk', a significantly higher incidence of abnormality was found not only in nutritional markers but also in other parameters of RCLMs (OR ranged from 1.5 to 3.5). Regression analyses showed that ‘at risk' determined at admission was not a significant predictor of adverse outcomes after adjusting for other confounding factors, although it was a strong predictor in univariate analysis, whereas hypoalbuminemia, low total lymphocyte count, abnormality of hepatic and renal function were predictors after adjusting for confounders. Conclusions: The findings suggest that NRS-2002 might be a global index of ‘sickness' rather than be only a nutritional screening tool. It being rated once at admission is insufficient and should be repeated for using it as a predictor, whereas RCLMs routinely measured at admission may be able to be used to predict adverse outcomes.
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Affiliation(s)
- Z Y Chen
- Department of Clinical Nutrition, Tongji Hospital, Tongji Medical College, Huazhong University Science and Technology, Wuhan, China
| | - C Gao
- Department of Gastrointestinal Surgery, Tongji Hospital, Tongji Medical College, Huazhong University Science and Technology, Wuhan, China
| | - T Ye
- Department of Clinical Nutrition, Tongji Hospital, Tongji Medical College, Huazhong University Science and Technology, Wuhan, China
| | - X Z Zuo
- Department of Clinical Nutrition, Tongji Hospital, Tongji Medical College, Huazhong University Science and Technology, Wuhan, China
| | - G H Wang
- Department of Gastrointestinal Surgery, Tongji Hospital, Tongji Medical College, Huazhong University Science and Technology, Wuhan, China
| | - X S Xu
- Department of Gastrointestinal Surgery, Tongji Hospital, Tongji Medical College, Huazhong University Science and Technology, Wuhan, China
| | - Y Yao
- Department of Clinical Nutrition, Tongji Hospital, Tongji Medical College, Huazhong University Science and Technology, Wuhan, China
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10
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Lee J, Trugman SA, Batista CD, Zhang CL, Talbayev D, Xu XS, Cheong SW, Yarotski DA, Taylor AJ, Prasankumar RP. Probing the interplay between quantum charge fluctuations and magnetic ordering in LuFe2O4. Sci Rep 2013; 3:2654. [PMID: 24030661 PMCID: PMC3772380 DOI: 10.1038/srep02654] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Accepted: 08/23/2013] [Indexed: 12/02/2022] Open
Abstract
The mechanisms producing strong coupling between electric and magnetic order in multiferroics are not always well understood, since their microscopic origins can be quite different. Hence, gaining a deeper understanding of magnetoelectric coupling in these materials is the key to their rational design. Here, we use ultrafast optical spectroscopy to show that the influence of magnetic ordering on quantum charge fluctuations via the double-exchange mechanism can govern the interplay between electric polarization and magnetism in the charge-ordered multiferroic LuFe2O4.
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Affiliation(s)
- J Lee
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM 87545
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11
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Li SF, Zhao XJ, Xu XS, Gao YF, Zhang Z. Stacking principle and magic sizes of transition metal nanoclusters based on generalized Wulff construction. Phys Rev Lett 2013; 111:115501. [PMID: 24074104 DOI: 10.1103/physrevlett.111.115501] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2013] [Indexed: 06/02/2023]
Abstract
Nanoclusters with extra stability at certain cluster sizes are known as magic clusters with exotic properties. The classic Wulff construction principle, which stipulates that the preferred structure of a cluster should minimize its total surface energy, is often invoked in determining the cluster magicity, resulting in close-shelled Mackay icosahedronal clusters with odd-numbered magic sizes of 13, 55, 147, etc. Here we use transition metal clusters around size 55 as prototypical examples to demonstrate that, in the nanometer regime, the classic Wulff construction principle needs to be generalized to primarily emphasize the edge atom effect instead of the surface energy. Specifically, our detailed calculations show that nanoclusters with much shorter total edge lengths but substantially enlarged total surface areas are energetically much more stable. As a consequence, a large majority of the nanoclusters within the 3d-, 4d-, and 5d-transition metal series are found to be fcc or hcp crystal fragments with much lower edge energies, and the widely perceived magic size of 55 is shifted to its nearby even numbers.
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Affiliation(s)
- S F Li
- School of Physics and Engineering, Zhengzhou University, Zhengzhou, Henan 450001, China and Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA and Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA and ICQD, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
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12
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Boulton DW, Kasichayanula S, Keung CFA, Arnold ME, Christopher LJ, Xu XS, Lacreta F. Simultaneous oral therapeutic and intravenous ¹⁴C-microdoses to determine the absolute oral bioavailability of saxagliptin and dapagliflozin. Br J Clin Pharmacol 2013; 75:763-8. [PMID: 22823746 DOI: 10.1111/j.1365-2125.2012.04391.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Accepted: 07/08/2012] [Indexed: 11/27/2022] Open
Abstract
AIM To determine the absolute oral bioavailability (F(p.o.) ) of saxagliptin and dapagliflozin using simultaneous intravenous ¹⁴C-microdose/therapeutic oral dosing (i.v.micro + oraltherap). METHODS The F(p.o.) values of saxagliptin and dapagliflozin were determined in healthy subjects (n = 7 and 8, respectively) following the concomitant administration of single i.v. micro doses with unlabelled oraltherap doses. Accelerator mass spectrometry and liquid chromatography-tandem mass spectrometry were used to quantify the labelled and unlabelled drug, respectively. RESULTS The geometric mean point estimates (90% confidence interval) F(p.o) . values for saxagliptin and dapagliflozin were 50% (48, 53%) and 78% (73, 83%), respectively. The i.v.micro had similar pharmacokinetics to oraltherap. CONCLUSIONS Simultaneous i.v.micro + oraltherap dosing is a valuable tool to assess human absolute bioavailability.
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Affiliation(s)
- David W Boulton
- Bristol-Myers Squibb Research and Development, Princeton, New Jersey, USA.
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13
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Xu XS, Demers R, Gu H, Christopher LJ, Su H, Cojocaru L, Boulton DW, Kirby M, Stouffer B, Humphreys WG, Arnold ME. Liquid chromatography and tandem mass spectrometry method for the quantitative determination of saxagliptin and its major pharmacologically active 5-monohydroxy metabolite in human plasma: method validation and overcoming specific and non-specific binding at low concentrations. J Chromatogr B Analyt Technol Biomed Life Sci 2012; 889-890:77-86. [PMID: 22349123 DOI: 10.1016/j.jchromb.2012.01.033] [Citation(s) in RCA: 16] [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: 10/09/2011] [Revised: 01/24/2012] [Accepted: 01/29/2012] [Indexed: 10/14/2022]
Abstract
A liquid chromatography and tandem mass spectrometry (LC-MS/MS) method was developed and validated to simultaneously determine the concentrations of saxagliptin (Onglyza™, BMS-477118) and its major active metabolite, 5-hydroxy saxagliptin to support pharmacokinetic analyses in clinical studies. The dynamic range of the assay was 0.1-50 ng/mL for saxagliptin and 0.2-100 ng/mL for 5-hydroxy saxagliptin. Protein precipitation (PPT) with acetonitrile was used to extract the analytes from plasma matrix before injecting on an Atlantis(®) dC18 column (50 mm × 2.1 mm, 5 μm) for LC-MS/MS analysis. The sample pre-treatment process was carefully controlled to disrupt DPP4-specific binding and non-specific binding observed at lower concentrations. The recoveries for both analytes were >90%. The assay was selective, rugged and reproducible; storage stability of at least 401 days at -20°C was demonstrated. Under these chromatographic conditions, the isomers of saxagliptin and 5-hydroxy saxagliptin were chromatographically separated from saxagliptin and 5-hydroxy saxagliptin. The assay has been used to support multiple clinical studies and regulatory approvals.
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Affiliation(s)
- Xiaohui Sophia Xu
- Research & Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA.
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14
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Xu XS, Brinzari TV, McGill S, Zhou HD, Wiebe CR, Musfeldt JL. Absence of spin liquid behavior in Nd3Ga5SiO14 using magneto-optical spectroscopy. Phys Rev Lett 2009; 103:267402. [PMID: 20366345 DOI: 10.1103/physrevlett.103.267402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2009] [Indexed: 05/29/2023]
Abstract
We measured the low-lying crystal field levels of Nd3+ in Nd3Ga5SiO14 via magneto-optical spectroscopy and employed the extracted energies, magnetic moments, and symmetries to analyze the magnetic properties and test the spin liquid candidacy of this material. The exchange interaction is surprisingly small, a discovery that places severe constraints on models used to describe the ground state of this system. Further, it demonstrates the value of local-probe photophysical techniques for rare-earth-containing materials where bulk property measurements can be skewed by low-lying electronic structure.
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Affiliation(s)
- X S Xu
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, USA
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15
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Xu XS, Zeng J, Mylott W, Arnold M, Waltrip J, Iacono L, Mariannino T, Stouffer B. Liquid chromatography and tandem mass spectrometry for the quantitative determination of ixabepilone (BMS-247550, Ixempra) in human plasma: method validation, overcoming curve splitting issues and eliminating chromatographic interferences from degradants. J Chromatogr B Analyt Technol Biomed Life Sci 2009; 878:525-37. [PMID: 20083444 DOI: 10.1016/j.jchromb.2009.12.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Revised: 12/01/2009] [Accepted: 12/06/2009] [Indexed: 10/20/2022]
Abstract
A sensitive method was developed and validated for the measurement of ixabepilone (BMS-247550, Ixempra) using a demethylated analogue of ixabepilone (BMS-212188) as an internal standard. A 0.050 mL portion of each plasma sample was extracted with 0.450 mL of acetonitrile containing the internal standard via protein precipitation. The supernatant was analyzed on a LC-MS/MS system. Chromatography was carried out on a 2.0 mm x 100 mm YMC ODS-AQ 3 microm column using an isocractic mobile phase consisting of acetonitrile:10 mM ammonium acetate, pH 5.0 (70:30, v/v) at a flow rate of 0.30 mL/min. The mass spectrometer was fitted with a TurboIonSpray source and operated in negative ionization mode. Detection of ixabepilone and BMS-212188 were accomplished using multiple reaction monitoring (MRM) of precursor>product ion pairs of m/z 505.2>405.2, and 492.1>392.1, respectively. The assay range was 2.00-500 ng/mL and was fitted to a 1/x(2) weighted quadratic regression model. Replicate sample analysis indicated that intra- and inter-day accuracy and precision are within +/-15.0%. The recovery of ixabepilone from 0.050 mL of plasma containing 5.00 and 400 ng/mL was greater than 94%. The method was demonstrated to be sensitive, selective and robust, and was successfully used to support clinical studies. This paper also discussed approaches used for resolving a curve splitting issue observed during quantitative analysis of ixabepilone in biological matrices. Finally, to adapt the methodology to pharmacokinetics of ixabepilone after oral administration, the potential interference of chemical degradants on the determination of ixabepilone was evaluated.
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Affiliation(s)
- Xiaohui Sophia Xu
- Bioanalytical Sciences, Research & Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA.
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16
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Xu XS, Angst M, Brinzari TV, Hermann RP, Musfeldt JL, Christianson AD, Mandrus D, Sales BC, McGill S, Kim JW, Islam Z. Charge order, dynamics, and magnetostructural transition in multiferroic LuFe2O4. Phys Rev Lett 2008; 101:227602. [PMID: 19113523 DOI: 10.1103/physrevlett.101.227602] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2008] [Indexed: 05/27/2023]
Abstract
We investigated the series of temperature and field-driven transitions in LuFe2O4 by optical and Mössbauer spectroscopies, magnetization, and x-ray scattering in order to understand the interplay between charge, structure, and magnetism in this multiferroic material. We demonstrate that charge fluctuation has an onset well below the charge ordering transition, supporting the "order by fluctuation" mechanism for the development of charge order superstructure. Bragg splitting and large magneto-optical contrast suggest a low-temperature monoclinic distortion that can be driven by both temperature and magnetic field.
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Affiliation(s)
- X S Xu
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, USA
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17
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Xu XS, Yan KX, Song H, Lo MW. Quantitative determination of a novel dual PPAR α/γ agonist using on-line turbulent flow extraction with liquid chromatography–tandem mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 2005; 814:29-36. [PMID: 15675045 DOI: 10.1016/j.jchromb.2004.09.033] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Turbulent flow chromatograph (TFC) is a technique for the direct and efficient analysis of drugs and metabolites in biological matrices. We report here TFC on-line with an HPLC-MS/MS assay for the determination of 5-[2,4-dioxothiazolidin-5-yl)methyl]-2-methoxy-N-[[(4-trifluoromethyl)phenyl]methyl]benzamide (I, MK-0767, KRP297, Fig. 1) in plasma. Samples were transferred using an automated system followed by the addition of internal standard (II), prepared in 0.1 M ammonium acetate (pH 4.0). The plasma samples were directly injected onto a C18 turbulent flow column on-line with an HPLC-MS/MS system, and the analytical column used was a ThermoHypersil Keystone C18. Detection was achieved by MS/MS, using positive ionization on a TurboIonSpray probe, operated in multiple reaction monitoring (MRM) mode. The linear range was 4-2000 ng/mL for I when using 50 microL of plasma. The method exhibited good linearity and reproducibility. The method also showed good selectivity and ruggedness when applied to clinical samples, and was successfully cross-validated with a conventional off-line SPE, LC-MS/MS method.
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Affiliation(s)
- Xiaohui Sophia Xu
- Merck Research Laboratories, Department of Drug Metabolism, West point, PA 19486, USA.
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18
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Gan WQ, Gu DF, Xu XS, Duan XF, Xie BY, Huang GY, Chen JC, Wu XG. [The effect of Beijing Fangshan Cardiovascular Prevention Program on the incidence and mortality of stroke]. Zhongguo Yi Xue Ke Xue Yuan Xue Bao 2001; 23:428-31. [PMID: 12905855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
OBJECTIVE To explore potential effective measures for lowering incidence and mortality of stroke in rural community population of China. METHODS Beijing Fangshan Cardiovascular Prevention Program (BFCP), under whole population and high risk individuals strategies with measures of health education and hypertension control, were launched in 1991 in five communities including intervention communities (IC), about 66,000 residents, and control communities (CC), about 54,000 residents, in Fangshan, Beijing suburb. RESULT Incidences of stroke averaged 235.23 per 100,000 and 289.22 per 100,000, for IC and CC respectively, with a statistically significant difference, and mortalities of stroke averaged 80.63 per 100,000 and 98.01 per 100,000, for IC and CC respectively, with a statistically significant difference, during years of 1992 to 1999. The net change of stroke incidence was 126.13 per 100,000 in IC versus CC, with a statistically significant difference. Incidences of stroke increased by 11.63% and 75.27%, for IC and CC respectively, while mortalities of stroke decreased by 46.80% and 22.82%, respectively, for IC and CC from years of 1992 to 1999. CONCLUSION BFCP has yielded obvious effect on controlling incidence and mortality of stroke in rural community population, but the trend of stroke incidence increasing was still not restrained radically.
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Affiliation(s)
- W Q Gan
- Division of Population Genetics and Prevention, Cardiovascular Institute, Fu Wai Hospital, CAMS, PUMC, Beijing 100037, China
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19
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Xu XS, Narayanan L, Dunklee B, Liskay RM, Glazer PM. Hypermutability to ionizing radiation in mismatch repair-deficient, Pms2 knockout mice. Cancer Res 2001; 61:3775-80. [PMID: 11325851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
DNA mismatch repair (MMR) has been shown to play a role in the cytotoxicity of ionizing radiation (IR), as cell lines established from MMR-deficient mice exhibit higher clonogenic survival after IR than do cell lines from wild-type littermates. To test whether this tolerance phenotype would render MMR-deficient animals hypermutable to IR, we compared IR mutagenesis of Pms2-deficient versus wild-type transgenic mice carrying a lambda shuttle vector for mutation detection. In Pms2 nullizygous animals, the mutation frequency in the supFG1 reporter gene was increased from 210 x 10(-5) in untreated animals to 734 x 10(-5) after 6 Gy of IR (an increase of 524 mutants per 10(5)), whereas the frequency in wild-type mice increased from 1.9 x 10(-5) to 10.2 x 10(-5) (an increase of only 8.3 mutants per 10(5)). Similarly, when the lambda cII gene was used as a reporter, the mutation frequency in nullizygous mice was increased from 16.3 x 10(-5) to 42.3 x 10(-5) after IR (an increase of 26.0 x 10(-5)), whereas the frequency in wild-type mice increased from 2.4 x 10(-5) to 9.4 x 10(-5) (an increase of only 7.0 x 10(-5)). The pattern of IR-induced mutations in the MMR-deficient animals was notable for single bp deletions and insertions in mononucleotide repeat sequences, along with a slight increase in transversions. Overall, these results suggest that MMR-deficiency confers hypermutability to IR, and that much of this hypermutability can be attributed to induced instability of simple sequence repeats. Hence, MMR influences not only the survival but also the mutability of cells in response to IR.
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Affiliation(s)
- X S Xu
- Departments of Therapeutic Radiology and Genetics, Yale University School of Medicine, New Haven, Connecticut 06520-8040, USA
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20
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Xu XS, Lee E, Chen T, Kuczmarski E, Chisholm RL, Knecht DA. During multicellular migration, myosin ii serves a structural role independent of its motor function. Dev Biol 2001; 232:255-64. [PMID: 11254362 DOI: 10.1006/dbio.2000.0132] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [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: 11/22/2022]
Abstract
We have shown previously that cells lacking myosin II are impaired in multicellular motility. We now extend these results by determining whether myosin contractile function is necessary for normal multicellular motility and shape control. Myosin from mutants lacking the essential (mlcE(-)) myosin light chain retains the ability to form bipolar filaments that bind actin, but shows no measurable in vitro or in vivo contractile function. The contractile function is necessary for cell shape control since mlcE(-) cells, like myosin heavy-chain null mutants (mhcA(-)), were defective in their ability to control their three-dimensional shape. When mixed with wild-type cells in chimeric aggregation streams, the mlcE(-) cells were able to move normally, unlike mhcA(-) cells which accumulated at the edges of the stream and became distorted by their interactions with wild-type cells. When mhcA(-) cells were mixed with mlcE(-) streams, the mhcA(-) cells were excluded. The normal behavior of the mlcE(-) cells in this assay suggests that myosin II, in the absence of motor function, is sufficient to allow movement in this constrained, multicellular environment. We hypothesize that myosin II is a major contributor to cortical integrity even in the absence of contractile function.
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Affiliation(s)
- X S Xu
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, 06269, USA
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21
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Huang GY, Gu DF, Duan XF, Xu XS, Gan WQ, Chen JC, Xie BY, Wu XG. [Effects of 8 years community intervention on risk factors of cardiovascular diseases in Fangshan Beijing]. Zhongguo Yi Xue Ke Xue Yuan Xue Bao 2001; 23:15-8. [PMID: 12905810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
OBJECTIVE To study the changes of risk factors of cardiovascular disease in the rural community population after intervention. METHODS The Beijing Fangshan cardiovascular prevention program was a community-based comprehensive intervention study which was launched from 1991 and ended in 2000 in five communities including three as intervention communities (IC) and two as control communities (CC) in Fangshan, Beijing suburb. The intervention measures were focused on health education and hypertension control. The changes of risk factors of cardiovascular disease in IC and CC were analyzed using random sample in the year 1991, 1995 and 1999, respectively. The risk factors include systolic and diastolic blood pressure (SBP and DBP), body mass index(BMI), serum total cholesterol(TC), triglyceride(TG), high-density lipoprotein cholesterol(HDL), smoking, and drinking. RESULTS From the year 1991 to 1999, the risk factors of cardiovascular disease such as SBP, DBP, smoking rate and drinking rate were reduced in the population of IC. For male in IC, the decline of SBP, DBP, smoking rate, and drinking rate were 1.6 mmHg, 1.1 mmHg, 14.5% (P < 0.01) and 3.7%, respectively. For female of IC, SBP and DBP declined 4.8 mmHg (P < 0.01) and 3.2 mmHg (P < 0.01), respectively. SBP, DBP and smoking rate in the population of CC had a little reduction while BMI, TC and TG increased in both IC and CC. During the period of 1991 to 1999, most cardiovascular risk factors in the population of IC had net reduction compared to that of CC. CONCLUSIONS Except for BMI and lipids, rural community intervention, as focused on health education and hypertension control, has resulted in the reduction of most risk factors of cardiovascular disease.
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Affiliation(s)
- G Y Huang
- Division of Population Genetics and Prevention, Cardiovascular Institute, Fu Wai Hospital, CAMS, PUMC, Beijing 100037, China
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Zimmer WE, Zhao Y, Sikorski AF, Critz SD, Sangerman J, Elferink LA, Xu XS, Goodman SR. The domain of brain beta-spectrin responsible for synaptic vesicle association is essential for synaptic transmission. Brain Res 2000; 881:18-27. [PMID: 11033089 DOI: 10.1016/s0006-8993(00)02796-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [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: 01/06/2023]
Abstract
We have examined the interaction between synapsin I, the major phosphoprotein on the membrane of small synaptic vesicles, and brain spectrin. Using recombinant peptides we have localized the synapsin I attachment site upon the beta-spectrin isoform betaSpIISigmaI to a region of 25 amino acids, residues 211 through 235. This segment is adjacent to the actin binding domain and is within the region of the betaSpIISigmaI that we previously predicted as a candidate synapsin I binding domain based upon sequence homology. We used differential centrifugation techniques to quantitatively assess the interaction of spectrin with synaptic vesicles. Using this assay, high affinity saturable binding of recombinant betaSpIISigmaI proteins was observed with synaptic vesicles. Binding was only observed when the 25 amino acid synapsin I binding site was included on the recombinant peptides. Further, we demonstrate that antibodies directed against 15 amino acids of the synapsin I binding domain specifically blocked synaptic transmission in cultured hippocampal neurons. Thus, the synapsin I attachment site on betaSpIISigmaI spectrin comprises a approximately 25 amino acid segment of the molecule and interaction of these two proteins is an essential step for the process of neurotransmission.
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Affiliation(s)
- W E Zimmer
- Department of Cell Biology and Neuroscience, University of South Alabama, Mobile, AL 36688, USA.
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Zeng M, Narayanan L, Xu XS, Prolla TA, Liskay RM, Glazer PM. Ionizing radiation-induced apoptosis via separate Pms2- and p53-dependent pathways. Cancer Res 2000; 60:4889-93. [PMID: 10987303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
The cytotoxicity of ionizing radiation (IR) has been associated with both the p53 pathway and with DNA mismatch repair (MMR). p53 mediates cell cycle arrest and apoptosis in response to X-ray damage, whereas the MMR complex is thought to recognize damaged bases and initiate a signal transduction pathway that can include phosphorylation of p53. To determine whether p53 and MMR mediate X-ray cytotoxicity via the same pathway, mice with targeted disruptions in either the p53 gene or the MutL homologue MMR gene Pms2 were interbred and primary fibroblasts were established from the progeny with genotypes of either wild type, p53 null, Pms2 null, or double null. Cells with either p53 or Pms2 separately disrupted showed reduced levels of apoptosis after IR in comparison with wild type, but the double null cells showed even lower levels, consistent with nonoverlapping roles for p53 and PMS2 in the X-ray response. In transformed cell lines established from the primary cells at early passage, similar differences in the apoptotic response to IR were seen, and clonogenic survival assays following low dose rate IR further showed that nullizygosity for Pms2 confers increased survival on cells in both wild-type and p53 null backgrounds. These results indicate that both p53 and MMR contribute to X-ray-induced apoptosis and that the role of MMR in the cytotoxicity of IR does not depend on p53.
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Affiliation(s)
- M Zeng
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut 06520-8040, USA
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Andrew SE, Xu XS, Baross-Francis A, Narayanan L, Milhausen K, Liskay RM, Jirik FR, Glazer PM. Mutagenesis in PMS2- and MSH2-deficient mice indicates differential protection from transversions and frameshifts. Carcinogenesis 2000; 21:1291-5. [PMID: 10874005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
Abstract
DNA mismatch repair (MMR) deficiency leads to an increased mutation frequency and a predisposition to neoplasia. 'Knockout' mice deficient in the MMR proteins Msh2 and Pms2 crossed with mutation detection reporter (supF, lacI and cII) transgenic mice have been used to facilitate a comparison of the changes in mutation frequency and spectra. We find that the mutation frequency was consistently higher in Msh2-deficient mice than Pms2-deficient mice. The lacI target gene, which is highly sensitive to point mutations, demonstrated that both Msh2- and Pms2-deficient mice accumulate transition mutations as the predominant mutation. However, when compared with Msh2(-/-) mice, lacI and cII mutants from Pms2-deficient mice revealed an increased proportion of +/-1 bp frameshift mutations and a corresponding decrease in transversion mutations. The supF target gene, which is sensitive to frameshift mutations, and the cII target gene revealed a strong tendency for -1 bp deletions over +1 bp insertions in Msh2(-/-) compared with Pms2(-/-) mice. These data indicate that Msh2 and Pms2 deficiency have subtle but differing effects on mutation avoidance which may contribute to the differences in tumor spectra observed in the two 'knockout' mouse models. These variances in mutation accumulation may also play a role, in part, in the differences seen in prevalence of MSH2 and PMS2 germline mutations in hereditary non-polyposis colorectal cancer patients.
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Affiliation(s)
- S E Andrew
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7 Canada.
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25
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Xu XS, Glazer PM, Wang G. Activation of human gamma-globin gene expression via triplex-forming oligonucleotide (TFO)-directed mutations in the gamma-globin gene 5' flanking region. Gene 2000; 242:219-28. [PMID: 10721715 DOI: 10.1016/s0378-1119(99)00522-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [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: 11/20/2022]
Abstract
Human beta-globin disorders, such as sickle cell anemia and beta-thalassemia, are relatively common genetic diseases cause by mutations in the beta-globin gene. Increasing gamma-globin gene expression has been found to greatly reduce the disease symptom. However, the gamma-globin gene is developmentally regulated and normally expressed at high levels only during the fetal stage of human development. We have explored the possibility of activating the gamma-globin gene expression by triplex-forming oligonucleotide (TFO)-directed targeted mutagenesis. Using a psoralen-conjugated TFO designed to bind to a site overlapping with an Oct-1 binding site at the -280 region of the gamma-globin gene, targeted mutagenesis of the Oct-1 binding site has been achieved by transfecting the in-vitro-formed plasmid-oligo complex into human normal fibroblast (NF) cells. The mutation frequency at the target site was estimated to be 20% by direct DNA sequencing analysis. In-vitro protein binding assays indicated that these mutations reduced Oct-1 binding to the target site. In-vivo gene expression assays demonstrated activation of gamma-globin gene expression from these mutations in mouse erythroleukemia (MEL) cells. The levels of the gamma-globin gene expression increased by as much as fourfold in mutants with single base changes. These results suggest that the -280 region of the Agamma-globin gene negatively regulates the gamma-globin gene expression, and mutations at the Oct-1 binding site can lead to activation of the gamma-globin gene and generate the hereditary persistence of fetal hemoglobin (HPFH) condition. This study may provide a novel approach for gene therapy of sickle cell disease. The data may also have implications in gene therapy for other diseases including genetic diseases and cancers by introducing mutations into transcription factor binding sites to alter the levels of target gene expression.
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Affiliation(s)
- X S Xu
- Department of Structural and Cellular, University of South Alabama College of Medicine, Mobile 36688, USA
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26
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Abstract
Cytokines such as tumor necrosis factor (TNFalpha) play fundamental roles in the pathophysiology of inflammation and immunity-related diseases. Despite rapid advances in our understanding of cytokine biology in recent years, definitive knowledge of the cytokine cell signaling pathways remains elusive due to the enormous complexity of these pathways and the lack of specific biological tools and reagents. Using highly specific antisense oligonucleotides that target the mRNA encoding c-Raf kinase and Ha-Ras, we show here that inhibition of c-raf and Ha-ras expression blocks the up-regulation of E-selectin and vascular adhesion molecule-1 induced by TNFalpha in endothelial cells. Induction of intercellular adhesion molecule-1 was also reduced, although to a much lesser extent, by treatment with antisense oligonucleotides. We also show that inhibition of c-raf kinase expression decreased extracellular signal-regulated kinase and c-Jun N-terminal kinase (JNK) kinase stimulation by TNFalpha. Furthermore, antisense inhibition of JNK2 also blocked TNFalpha-mediated induction of E-selectin, whereas PD98059 (mitogen-activated protein kinase kinase 1 and 2 inhibitor) had no effect on this process. These results indicate that TNFalpha induction of E-selectin and vascular adhesion molecule-1 in endothelial cells occurs through signaling pathways that are, at least in part, dependent on c-Raf kinase, Ha-Ras, and JNK2.
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Affiliation(s)
- X S Xu
- Department of Molecular Pharmacology, ISIS Pharmaceuticals, Carlsbad, California 92008, USA
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27
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Abstract
In previous studies, Bacteroides fragilis group organisms isolated from Korean patients were more frequently resistant to various antimicrobial agents, including clindamycin, than were isolates in other countries. A recent report of increased resistance of Peptostreptococcus species prompted us to include such isolates in a study of antimicrobial susceptibility. anaerobes isolated in 1994 at a tertiary care hospital in Seoul were tested by agar dilution method. None of the B. fragilis group organisms were resistant to imipenem, cefoxitin, chloramphenicol, or metronidazole. However, 6.7% were resistant to ampicillin/sulbactam, 20.2% to cefotetan, 30.3% to piperacillin, 48.3% to cefotaxime, and 42.7% to clindamycin. Almost all of the Clostridium perfringens isolates were susceptible to all of the agents tested, except tetracycline. Peptostreptococcus isolates were susceptible to piperacillin, cefotaxime, and imipenem, while 7.4% were resistant to penicillin G, cefotetan, and metronidazole, and 25.9% were resistant to clindamycin. The isolates resistant to penicillin G, cefotetan, and metronidazole were identified as Peptostreptococcus anaerobius. In conclusion, besides the well-known high rate of resistance of B. fragilis group organisms to clindamycin, the emergence of resistance of Peptostreptococcus species isolates to beta-lactam drugs has become obvious in Korea.
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Affiliation(s)
- K Lee
- Department of Clinical Pathology, Yonsei University College of Medicine, Seoul, Korea
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28
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Cleveland DW, Bruijn LI, Wong PC, Marszalek JR, Vechio JD, Lee MK, Xu XS, Borchelt DR, Sisodia SS, Price DL. Mechanisms of selective motor neuron death in transgenic mouse models of motor neuron disease. Neurology 1996; 47:S54-61; discussion S61-2. [PMID: 8858052 DOI: 10.1212/wnl.47.4_suppl_2.54s] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
To examine the mechanism(s) of disease underlying ALS, transgenic mouse models have been constructed that express aberrant neurofilaments or mutations in the abundant, cytoplasmic enzyme superoxide dismutase 1 (SOD1). In addition to progressive weakness arising from selective motor neuron death, mice expressing a modest level of a point mutant in neurofilament subunit NF-L show most of the pathologic hallmarks observed in familial and sporadic ALS, including perikaryal proximal axonal swellings, axonal degeneration, and severe skeletal muscle atrophy. Additional mice expressing familial ALS-linked mutations in the cytoplasmic enzyme SOD1, the only proven cause of ALS and which accounts for approximately 20% of familial disease, have demonstrated that at least one mutation causes disease through acquisition of an adverse property by the mutant enzyme, rather than elevation or loss of SOD1 activity. These animals not only provide a detailed look at the pathogenic progression of disease, but also represent a tool for testing hypotheses concerning the specific mechanism(s) of neuronal death and for testing therapeutic strategies.
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Affiliation(s)
- D W Cleveland
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla 92093, USA
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29
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Chen YC, Zheng XY, Lai TS, Xu XS, Mo D, Lin WZ. Resonators for self-mode-locking Ti:sapphire lasers without apertures. Opt Lett 1996; 21:1469-1471. [PMID: 19881694 DOI: 10.1364/ol.21.001469] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
It is advantageous to achieve stable self-mode locking without hard apertures by designing resonators to minimize cavity-dispersion noncoaxiality in Brewster-cut gain media. The cavity-loss modulation introduced by Kerr effects is then optimized.
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30
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Xu XS, Kuspa A, Fuller D, Loomis WF, Knecht DA. Cell-cell adhesion prevents mutant cells lacking myosin II from penetrating aggregation streams of Dictyostelium. Dev Biol 1996; 175:218-26. [PMID: 8626027 DOI: 10.1006/dbio.1996.0109] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
When a small number of fluorescently labeled myosin II mutant cells (mhcA-) are mixed with wild-type cells and development of the chimeras is observed by confocal microscopy, the mutant cells are localized to the edges of aggregation streams and mounds. Moreover, the mutant cells stick to wild-type cells and become distorted (Shelden and Knecht, 1995). Two independent adhesion mechanisms, Contact Sites A and Contact Sites B, function during the aggregation stage and either one or both might be responsible for excluding the myosin II null cells. We have mixed mhcA- cells with cells in which the appearance of Contact Sites B is delayed (strain TL72) as well as cells which lack Contact Sites A (strain GT10) and double mutants in which both adhesion mechanisms are affected (strain TL73). In all chimeras, the mhcA- cells were distorted by interactions with the adhesion mutant cells, indicating that it does not require significant adhesive interaction to distort the flaccid cortex of mhcA- cells mhcA- cells were excluded from streams composed of cells lacking either Contact Sites A or Contact Sites B but mixed randomly with cells lacking both adhesion systems. By 10 hr of development, cells of strain TL73 acquire Contact Sites B adhesion. If cells of this strain were mixed with labeled mhcA- cells, allowed to develop for 9 hr, and then dissociated before replating, the myosin II null cells were seen to be distorted and excluded from the reaggregates. Thus, the exclusion of mhcA- cells from streams can be accomplished by either Contact Sites A or B. When chimeras of labeled TL73 and wild-type cells were made, the TL73 cells were found to be randomly mixed into aggregation streams. This result indicates that adhesive sorting does not function during aggregation and so cannot account for the exclusion of mhcA- cells from streams. We hypothesize that the flaccid cortex of mhcA- cells cannot generate sufficient protrusive force to break the contacts between adhered cells in aggregation streams but can enter streams where the cells are weakly adherent.
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Affiliation(s)
- X S Xu
- Department of Molecular and Cell Biology, University of Connecticut, Storrs 06269, USA
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31
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Niitsu M, Ohya T, Xu XS, Samejima K. Identification of N4-(2-propenal)spermidine as a major reaction product of malondialdehyde and spermidine. Biol Pharm Bull 1995; 18:1162-4. [PMID: 8535418 DOI: 10.1248/bpb.18.1162] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The reactivity of malondialdehyde(MDA) with spermidine at the physiological pH was considerably higher than that with putrescine, glycine, lysine, methylamine or dimethylamine, and the major reaction product of MDA-spermidine adduct was identified as N4-(2-propenal)spermidine.
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Affiliation(s)
- M Niitsu
- Faculty of Pharmaceutical Sciences, Josai University, Saitama, Japan
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32
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Xu XS. [Mechanism of post-ischemic reperfusion damage of myocardium and the protective and therapeutic effects with traditional Chinese medicine]. Zhong Xi Yi Jie He Za Zhi 1991; 11:124-6. [PMID: 2060053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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33
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Xu XS, Xu TS, Robertson DG, Lambeth JD. GTP stimulates pregnenolone generation in isolated rat adrenal mitochondria. J Biol Chem 1989; 264:17674-80. [PMID: 2808340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Pregnenolone synthesis from cholesterol by adrenal mitochondria isolated from ether-stressed rats exhibits a biphasic time course: upon the addition of a reducing substrate (e.g. malate), a rapid phase of pregnenolone formation occurs during the first 5 min, which has been interpreted as the metabolism of a steroidogenic pool of cholesterol, probably in the inner membrane. A slower rate follows, which is interpreted as translocation of cholesterol into the steroidogenic pool. While a 30-min preincubation of mitochondria with cholesterol alone did not affect the extent of the rapid phase, preincubation with GTP plus cholesterol extended the first phase, resulting in an up to 2-fold increase in pregnenolone synthesis by 20-30 min. The apparent Km for GTP was 0.1-0.4 mM, and stimulation was maximal with preincubation times of 10-30 min, depending upon incubation conditions. Exogenous cholesterol was not required to observe a stimulatory effect, indicating that GTP reorganizes the endogenous mitochondrial cholesterol pools. Nevertheless, stimulation was greater when exogenous cholesterol was provided, consistent with enhanced utilization of both endogenous and exogenous cholesterol. Stimulation by GTP was also seen in mitochondria isolated from cycloheximide-injected/ether-stressed rats, although the activity in these preparations was always lower than that in mitochondria from ether-stressed rats. The stimulation was specific for GTP, since many other nucleotides (e.g. ATP, GDP, and ITP) and GTP analogues (guanosine 5'-O-(3-thiotriphosphate and guanosine 5'-(beta,gamma-imino)triphosphate) had no effect. The GTP-activated state was reversible: after GTP hydrolysis by a mitochondrial GTPase, pregnenolone synthesis returned to the basal level. Sonic disruption of mitochondria abolished the stimulatory effect of GTP. These results suggest that GTP enhances pregnenolone synthesis by promoting the movement of cholesterol to the steroidogenic pool, consistent with a recently proposed general role for GTP in some vectorial transport processes (Bourne, H. R. (1988) Cell 53, 669-671).
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Affiliation(s)
- X S Xu
- Department of Biochemistry, Emory University Medical School, Atlanta, Georgia 30322
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34
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Liu ZP, Yu SZ, Xu XS. [Characteristics of soman diffusion in tissues studied by sticking of pig bristles]. Zhongguo Yao Li Xue Bao 1988; 9:526-9. [PMID: 3256216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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35
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Yuan BL, Xu XS. [Antagonistic effects of 6 drugs on myopathy induced by soman intoxication]. Zhongguo Yao Li Xue Bao 1988; 9:111-5. [PMID: 3188944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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36
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Zhao MS, Qiu N, Wang HY, Xu XS, Cao SL, Liang ZQ. [Tumor transforming growth factor II. Growth inhibition of human pulmonary adenocarcinoma cell lines with antiepidermal growth factor receptor antibody]. Zhongguo Yi Xue Ke Xue Yuan Xue Bao 1985; 7:89-92. [PMID: 3004766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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37
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Liang ZQ, Wang HY, Cao SL, Xu XS, Zhao MS, Wu GY, Si JY, Zhu YJ. [Tumor transforming growth factor. I. Isolation and purification of tumor transforming growth factor from the urine of patients with small cell lung cancer and its biological activity]. Zhongguo Yi Xue Ke Xue Yuan Xue Bao 1984; 6:236-9. [PMID: 6098383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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38
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Xu XS. [Mildew of tortoise-plastron gelatin and 3 other Chinese medicinal herbs]. Zhong Yao Tong Bao 1984; 9:164-7. [PMID: 6241105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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39
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Zhang JW, Xu XS, Wang LM, Wu GY, Guo XZ, Zhang AC, Li CQ, Hao Y, Yu WX, Hu LY. [Organization of alpha-globin genes in Chinese with HbH diseases in Guangdong Province]. Zhongguo Yi Xue Ke Xue Yuan Xue Bao 1984; 6:79-83. [PMID: 6242368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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40
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Wu GY, Zhang JW, Wang SW, Xu XS. [Application of cloned plasmid-pRB alpha I for detection of human alpha-globin gene]. Zhongguo Yi Xue Ke Xue Yuan Xue Bao 1983; 5:275-9. [PMID: 6329532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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41
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Xu XS. [Histochemical changes in central cholinesterases inhibited by soman]. Zhongguo Yao Li Xue Bao 1983; 4:10-4. [PMID: 6223489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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42
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Wang SW, Wu GY, Shen Y, Xu XS. [In vitro expression of human fetal liver albumin mRNA]. Zhongguo Yi Xue Ke Xue Yuan Xue Bao 1982; 4:336-40. [PMID: 6221812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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