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Qin Y, Hamilton JL, Bird MD, Chen MM, Ramirez L, Zahs A, Kovacs EJ, Makowski L. Adipose inflammation and macrophage infiltration after binge ethanol and burn injury. Alcohol Clin Exp Res 2013; 38:204-13. [PMID: 23909743 DOI: 10.1111/acer.12210] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Accepted: 05/06/2013] [Indexed: 02/06/2023]
Abstract
BACKGROUND Ethanol (EtOH) exposure prior to traumatic injury, such as a burn, elevates systemic and local inflammatory responses and increases morbidity and mortality. Adipose is a large tissue mass that is often inflamed during obesity or other stresses, which disturbs metabolic homeostasis. To date, there has been little investigation into the inflammatory response of adipose tissue after combined EtOH exposure and burn injury. METHODS Two EtOH exposure regimens were utilized to examine the role of inflammation in adipose tissue after EtOH and burn injury. Mice were either given a single or episodic binge exposure to EtOH or saline followed by scald (burn) or sham injury 30 minutes later. Twenty-four hours post injury, serum and adipose tissue were collected for assessment of inflammatory mediators. RESULTS Single binge EtOH alone induced no inflammation in adipose when compared with sham vehicle-treated mice. However, single binge EtOH followed by burn injury induced significant elevations in mRNA and protein concentrations of pro-inflammatory mediators interleukin-6 (IL-6), KC, and monocyte chemoattractant protein 1 compared with either insult alone or sham vehicle group. Additionally, EtOH exposure and burn injury significantly blunted inducible nitric oxide synthase (iNOS), indicating a complex inflammatory response. Episodic binge EtOH exposure followed by burn injury exacerbated the postburn adipose inflammatory response. The magnitude of the episodic binge-induced inflammatory parameters postburn were 2- to 5-fold greater than the response detected after a single exposure of EtOH, indicating EtOH-induced potentiation of burn-induced inflammatory response. Finally, inflammatory loci and crown-like structures in adipose were significantly increased by episodic binge EtOH and burn injury. CONCLUSIONS This is the first report of binge and burn-induced crown-like structure formation. Evidence presented herein suggests an important role for alcohol and burn as an additional mediator of adipose inflammation in postburn injury, a common complication in burn patients.
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Palmer JL, Deburghgraeve CR, Bird MD, Hauer-Jensen M, Chen MM, Yong S, Kovacs EJ. Combined radiation and burn injury results in exaggerated early pulmonary inflammation. Radiat Res 2013; 180:276-83. [PMID: 23899376 DOI: 10.1667/rr3104.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Events such as a nuclear meltdown accident or nuclear attack have potential for severe radiation injuries. Radiation injury frequently occurs in combination with other forms of trauma, most often burns. Thus far, combined injury studies have focused mainly on skin wound healing and damage to the gut. Since both radiation exposure and remote burn have pulmonary consequences, we examined the early effects of combined injury on the lung. C57BL/6 male mice were irradiated with 5 Gy of total body irradiation followed by a 15% total body surface area scald burn. Lungs from surviving animals were examined for evidence of inflammation and pneumonitis. At 48 h post-injury, pathology of the lungs from combined injury mice showed greater inflammation compared to all other treatment groups, with marked red blood cell and leukocyte congestion of the pulmonary vasculature. There was excessive leukocyte accumulation, primarily neutrophils, in the vasculature and interstitium, with occasional cells in the alveolar space. At 24 and 48 h post-injury, myeloperoxidase levels in lungs of combined injury mice were elevated compared to all other treatment groups (P < 0.01), confirming histological evidence of neutrophil accumulation. Pulmonary levels of the neutrophil chemoattractant KC (CXCL1) were 3 times above that of either injury alone (P < 0.05). Further, monocyte chemotactic protein-1 (MCP-1, CCL2) was increased two- and threefold compared to burn injury or radiation injury, respectively (P < 0.05). Together, these data suggest that combined radiation and burn injury augments early pulmonary congestion and inflammation. Currently, countermeasures for this unique type of injury are extremely limited. Further research is needed to elucidate the mechanisms behind the synergistic effects of combined injury in order to develop appropriate treatments.
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Tagliaferri MA, Schwartzberg LS, Chen MM, Camacho LH, Kaplan EH, Arena FP, Bienvenu BJ, North SE, Patel H, Li D. A phase IIb trial of coix seed injection for advanced pancreatic cancer. J Clin Oncol 2013. [DOI: 10.1200/jco.2013.31.15_suppl.e15023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
e15023 Background: Kanglaite injection (KLTi) is a purified botanical extract injection tested for pancreatic cancer. KLTi is derived from Coix seed of the plant Coix lacrama-jobi. KLTi demonstrated growth inhibitory effects in vitro. In xenograft models with PANC-1 cell lines in BALB/C mice, KLTi combined with gemcitabine had synergistic tumor inhibitory activity greater than gemcitabine alone. KLTi is approved and widely used in China to treat non-small cell lung cancer and primary liver cancer. We report final cohort 1 results from a US phase 2b clinical trial. Methods: Eligible patients with histologically confirmed unresectable pancreatic cancer were randomized to a regimen of either KLTi 30g/day plus a standard course of gemcitabine or a standard course of gemcitabine only. The two groups were compared in efficacy, measure by progression-free survival (PFS), and safety. Results: Forty-one patients were randomized to cohort 1 and 38 patients received treatment: 26 received KLTi plus gemcitabine, 12 received gemcitabine only, and 3 received no treatment. The KLTi plus gemcitabine group had a median PFS of 114 days, significantly longer than the median PFS of 57.5 days in the gemcitabine only group (HR 0.338, 95% CI: 0.145, 0.788, p=0.008). The overall response rates were 15.5% (4/26) and 8.3% (1/12) for KLTi plus gemcitabine and gemcitabine only, respectively. Two serious adverse events were possibly related to KLTi; one subject had a pulmonary embolism and the other experienced transient confusion. The adverse events were similar between the groups and consistent with gemcitabine toxicities. Conclusions: Combined with gemcitabine, KLTi injection showed favorable tolerability and encouraging clinical activity for the treatment of advanced pancreatic cancer. Clinical trial information: NCT00733850.
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Chen MM, Bird MD, Zahs A, Deburghgraeve C, Posnik B, Davis CS, Kovacs EJ. Pulmonary inflammation after ethanol exposure and burn injury is attenuated in the absence of IL-6. Alcohol 2013; 47:223-9. [PMID: 23462222 DOI: 10.1016/j.alcohol.2013.01.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 01/04/2013] [Accepted: 01/23/2013] [Indexed: 11/16/2022]
Abstract
Alcohol consumption leads to an exaggerated inflammatory response after burn injury. Elevated levels of interleukin-6 (IL-6) in patients are associated with increased morbidity and mortality after injury, and high systemic and pulmonary levels of IL-6 have been observed after the combined insult of ethanol exposure and burn injury. To further investigate the role of IL-6 in the pulmonary inflammatory response, we examined leukocyte infiltration and cytokine and chemokine production in the lungs of wild-type and IL-6 knockout mice given vehicle or ethanol (1.11 g/kg) and subjected to a sham or 15% total body surface area burn injury. Levels of neutrophil infiltration and neutrophil chemoattractants were increased to a similar extent in wild-type and IL-6 knockout mice 24 h after burn injury. When ethanol exposure preceded the burn injury, however, a further increase of these inflammatory markers was seen only in the wild-type mice. Additionally, signal transducer and activator of transcription-3 (STAT3) phosphorylation did not increase in response to ethanol exposure in the IL-6 knockout mice, in contrast to their wild-type counterparts. Visual and imaging analysis of alveolar wall thickness supported these findings and similar results were obtained by blocking IL-6 with antibody. Taken together, our data suggest a causal relationship between IL-6 and the excessive pulmonary inflammation observed after the combined insult of ethanol and burn injury.
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Chen MM, Tsai AC. The effectiveness of IDF and ATP-III in identifying metabolic syndrome and the usefulness of these tools for health-promotion in older Taiwanese. J Nutr Health Aging 2013; 17:413-6. [PMID: 23538668 DOI: 10.1007/s12603-012-0440-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVES The aim of this study was to compare the effectiveness of IDF (International Diabetes Federation) and ATP-III (National Cholesterol Education Program-Adult Treatment Panel III) for predicting metabolic syndrome, and to evaluate the usefulness of these definitions for health promotion. DESIGN A cross-sectional study. SETTING A national random sample. PARTICIPANTS A population representative sample of 1021 54-91 year-old Taiwanese. MEASUREMENTS Subjects were measured for anthropometric and biochemical indicators and rated for the presence of metabolic syndrome using the two definitions. We evaluated the effectiveness of the two definitions in predicting MetS among those who had specific metabolic disorders. Results were analyzed with Student t-test and McNemar's test. RESULTS Among the 918 subjects who had one or more MetS-item disorders, ATP-III rated greater proportions of subjects as having MetS than IDF, but both definitions predicted less than 50% (37.7% and 45.4%, respectively) as having MetS. CONCLUSION Compared to IDF, ATP-III rated a greater proportion of subjects as having MetS, but both definitions missed more than 50% of subjects who had metabolic disorder(s). Since those who are missed have as much need for lifestyle intervention, the definitions appear not appropriate for health promotion.
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Chen MM, Liu QH, Xin GR, Zhang JG. Characteristics of lactic acid bacteria isolates and their inoculating effects on the silage fermentation at high temperature. Lett Appl Microbiol 2012; 56:71-8. [PMID: 23106758 DOI: 10.1111/lam.12018] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2012] [Revised: 10/20/2012] [Accepted: 10/22/2012] [Indexed: 10/27/2022]
Abstract
UNLABELLED Thermotolerant strains of lactic acid bacteria (LAB) were screened for their suitability for silage making at high temperatures. Four selected strains were identified by 16S rRNA sequencing analyses and added to unwilted and wilted Italian ryegrass for ensiling at 45°C. All four strains (HT1, HT2, HT3 and HT4) grew at 50°C and pH 4·0. Strains HT1 and HT2 were identified as Lactobacillus rhamnosus; HT3 and HT4 were identified as Lact. fermentum. Strains HT1 and HT2 were the most effective at improving the fermentation quality of Italian ryegrass silage, irrespective of wilting, as indicated by lower pH values, less NH(3) -N, and more lactic acid. In contrast, strains HT3, HT4 and a commercial inoculant consisting of Lact. plantarum and Pediococcus acidilactici conferred no or reduced benefits. Wilting alone did not improve the fermentation quality of Italian ryegrass at 45°C. Inoculating with thermotolerant Lact. rhamnosus HT1 and HT2 could improve the fermentation quality of silage at high temperatures. Lactobacillus rhamnosus HT1 and HT2 can be used as inoculants for silage making in the tropics and subtropics and could play an important role in developing silage production in such regions. SIGNIFICANCE AND IMPACT OF THE STUDY Grasses are often difficult to ensile in the tropics and subtropics because of the high temperatures there. To solve this problem, we screened for thermotolerant lactic acid bacteria and obtained two valuable strains of Lactobacillus rhamnosus, HT1 and HT2, which proved to be beneficial to silage fermentation at high temperatures. Lactobacillus rhamnosus HT1 and HT2 can be used as inoculants for silage making in the tropics and subtropics, and will play an important role in developing silage production in such regions.
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Russell AJ, Hartman JJ, Hinken AC, Muci AR, Kawas R, Driscoll L, Godinez G, Lee KH, Marquez D, Browne WF, Chen MM, Clarke D, Collibee SE, Garard M, Hansen R, Jia Z, Lu PP, Rodriguez H, Saikali KG, Schaletzky J, Vijayakumar V, Albertus DL, Claflin DR, Morgans DJ, Morgan BP, Malik FI. Activation of fast skeletal muscle troponin as a potential therapeutic approach for treating neuromuscular diseases. Nat Med 2012; 18:452-5. [PMID: 22344294 PMCID: PMC3296825 DOI: 10.1038/nm.2618] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Accepted: 12/01/2011] [Indexed: 11/09/2022]
Abstract
Limited neural input results in muscle weakness in neuromuscular disease because of a reduction in the density of muscle innervation, the rate of neuromuscular junction activation or the efficiency of synaptic transmission. We developed a small-molecule fast-skeletal-troponin activator, CK-2017357, as a means to increase muscle strength by amplifying the response of muscle when neural input is otherwise diminished secondary to neuromuscular disease. Binding selectively to the fast-skeletal-troponin complex, CK-2017357 slows the rate of calcium release from troponin C and sensitizes muscle to calcium. As a consequence, the force-calcium relationship of muscle fibers shifts leftwards, as does the force-frequency relationship of a nerve-muscle pair, so that CK-2017357 increases the production of muscle force in situ at sub-maximal nerve stimulation rates. Notably, we show that sensitization of the fast-skeletal-troponin complex to calcium improves muscle force and grip strength immediately after administration of single doses of CK-2017357 in a model of the neuromuscular disease myasthenia gravis. Troponin activation may provide a new therapeutic approach to improve physical activity in diseases where neuromuscular function is compromised.
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Teerlink JR, Clarke CP, Saikali KG, Lee JH, Chen MM, Escandon RD, Elliott L, Bee R, Habibzadeh MR, Goldman JH, Schiller NB, Malik FI, Wolff AA. Dose-dependent augmentation of cardiac systolic function with the selective cardiac myosin activator, omecamtiv mecarbil: a first-in-man study. Lancet 2011; 378:667-75. [PMID: 21856480 DOI: 10.1016/s0140-6736(11)61219-1] [Citation(s) in RCA: 185] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND Decreased systolic function is central to the pathogenesis of heart failure in millions of patients worldwide, but mechanism-related adverse effects restrict existing inotropic treatments. This study tested the hypothesis that omecamtiv mecarbil, a selective cardiac myosin activator, will augment cardiac function in human beings. METHODS In this dose-escalating, crossover study, 34 healthy men received a 6-h double-blind intravenous infusion of omecamtiv mecarbil or placebo once a week for 4 weeks. Each sequence consisted of three ascending omecamtiv mecarbil doses (ranging from 0·005 to 1·0 mg/kg per h) with a placebo infusion randomised into the sequence. Vital signs, blood samples, electrocardiographs (ECGs), and echocardiograms were obtained before, during, and after each infusion. The primary aim was to establish maximum tolerated dose (the highest infusion rate tolerated by at least eight participants) and plasma concentrations of omecamtiv mecarbil; secondary aims were evaluation of pharmacodynamic and pharmacokinetic characteristics, safety, and tolerability. This study is registered at ClinicalTrials.gov, number NCT01380223. FINDINGS The maximum tolerated dose of omecamtiv mecarbil was 0·5 mg/kg per h. Omecamtiv mecarbil infusion resulted in dose-related and concentration-related increases in systolic ejection time (mean increase from baseline at maximum tolerated dose, 85 [SD 5] ms), the most sensitive indicator of drug effect (r(2)=0·99 by dose), associated with increases in stroke volume (15 [2] mL), fractional shortening (8% [1]), and ejection fraction (7% [1]; all p<0·0001). Omecamtiv mecarbil increased atrial contractile function, and there were no clinically relevant changes in diastolic function. There were no clinically significant dose-related adverse effects on vital signs, serum chemistries, ECGs, or adverse events up to a dose of 0·625 mg/kg per h. The dose-limiting toxic effect was myocardial ischaemia due to excessive prolongation of systolic ejection time. INTERPRETATION These first-in-man data show highly dose-dependent augmentation of left ventricular systolic function in response to omecamtiv mecarbil and support potential clinical use of the drug in patients with heart failure. FUNDING Cytokinetics Inc.
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McLaughlin RW, Zheng JS, Chen MM, Zhao QZ, Wang D. Detection of Helicobacter in the fecal material of the endangered Yangtze finless porpoise Neophocaena phocaenoides asiaeorientalis. DISEASES OF AQUATIC ORGANISMS 2011; 95:241-245. [PMID: 21932536 DOI: 10.3354/dao02364] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In animals, infection by the Epsilonproteobacteria Helicobacter spp. and H. cetorum is widespread. It has been suggested that H. cetorum may cause gastritis in cetaceans. The aim of our study was to investigate the presence of Helicobacter spp. in the fecal material of the endangered Yangtze finless porpoise Neophocaena phocaenoides asiaeorientalis. The fecal material of 12 porpoises living in the wild in Poyang Lake and 1 porpoise living in captivity at the Wuhan Baiji Dolphinarium were examined by PCR for the presence of Helicobacter spp. The fecal material of 8 of 12 wild porpoises and the captive porpoise were positive for Helicobacter spp. as determined by PCR using Helicobacter-specific primers, which target the 16S rRNA gene. A 16S rRNA clone library was then prepared from 1 sample isolated from a female porpoise living in the wild. DNA sequence analysis from 3 of the clones showed 98 to 99% identity to the H. cetorum 16S rRNA gene. These results demonstrate the prevalence of Helicobacter spp. and H. cetorum in endangered freshwater finless porpoises.
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Habibzadeh MR, Schiller NB, Malik FI, Chen MM, Saikali KG, Wolff AA, Goldman JH, Teerlink JR. Effect of the Selective Cardiac Myosin Activator, Omecamtiv Mecarbil, on Left Atrial Performance in Healthy Men. J Card Fail 2010. [DOI: 10.1016/j.cardfail.2010.06.249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Sah BK, Zhu ZG, Wang XY, Yang QM, Chen MM, Xiang M, Chen J, Yan M. Post-operative complications of gastric cancer surgery: female gender at high risk. Eur J Cancer Care (Engl) 2009; 18:202-8. [PMID: 19267738 PMCID: PMC2702005 DOI: 10.1111/j.1365-2354.2008.01036.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We applied physiological and operative severity score for the enumeration of morbidity and mortality (POSSUM) to evaluate overall surgical outcome and investigated the role of gender for early post-operative complications in gastric cancer surgery. The data from a total of 357 patients of gastric cancer were analysed by univariate and multivariate analysis. Post-operative complications were recorded according to definition of POSSUM. Post-operative complications of male and female patients were compared separately. The observed to estimated morbidity ratio (O:E) was 1.01. Among the pre-operative variables, patient gender was one of the independent risk factors for a higher rate of post-operative complications (risk ratio 1.777, P = 0.024). Post-operative complication was significantly higher in female patients. Similarly, post-operative length of stay was significantly longer and more severe complications were observed in female patients (P = 0.03). In conclusion, POSSUM system is a valid algorithm for risk-adjusted surgical audit. We conclude that a patient's gender influences the early post-operative complications after gastric cancer surgery. A detailed understanding on disparity of early post-operative complications between men and women may provide valuable information to improve surgical outcome of gastric cancer. However, results of this study need further confirmation by a prospective study involving a larger cohort.
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Malik FI, Saikali KG, Chen MM, Lee JH, Goldman JH, Wolff AA, Teerlink JR. An Analysis of the Response to CK-1827452, a Selective Cardiac Myosin Activator, in Stable Heart Failure Patients Stratified by Baseline Cardiac Function. J Card Fail 2009. [DOI: 10.1016/j.cardfail.2009.06.200] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Véniant MM, Hale C, Komorowski R, Chen MM, St Jean DJ, Fotsch C, Wang M. Time of the day for 11beta-HSD1 inhibition plays a role in improving glucose homeostasis in DIO mice. Diabetes Obes Metab 2009; 11:109-17. [PMID: 18479468 DOI: 10.1111/j.1463-1326.2008.00911.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIMS The physiological effects of glucocorticoids in a given tissue are driven by the local level of the active glucocorticoid, which is determined by two sources: the plasma cortisol in human (or corticosterone in rodents) and the cortisol produced locally through 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) activity. Because of the circadian variation of plasma glucocorticoids, the pharmacological efficacy of 11beta-HSD1 inhibition may depend on the time of the day for inhibitor administration. METHODS The circadian profile of corticosterone was established in lean and diet-induced obesity (DIO) C57BL/6 mice from blood collected at different time of the day. 11beta-HSD1 enzyme activity was also measured throughout the day in DIO mice. To determine the optimal timing for administration of an 11beta-HSD1 inhibitor to obtain maximum efficacy, we used a DIO mouse model and a small molecule inhibitor of 11beta-HSD1 from our thiazolinone series. Based on the circadian profile of corticosterone obtained, we administered the 11beta-HSD1 inhibitor to these animals at different times of the day and evaluated the effects on plasma glucose levels and glucose tolerance. RESULTS We report that corticosterone circadian rhythm was similar between lean and DIO C57BL/6 mice, and 11beta-HSD1 enzyme activity undergoes minimal variations throughout the day. Interestingly, the compound exhibited maximum efficacy if dosed in the afternoon when plasma corticosterone is high; the morning dosing when plasma corticosterone is low did not lead to efficacy. CONCLUSION These data suggest that because of the circadian rhythm of circulating glucocorticoids, the time of the day for 11beta-HSD1 inhibitor administration is important in achieving efficacy.
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Chan DC, Chen MM, Ooi EMM, Watts GF. An ABC of apolipoprotein C-III: a clinically useful new cardiovascular risk factor? Int J Clin Pract 2008; 62:799-809. [PMID: 18201179 DOI: 10.1111/j.1742-1241.2007.01678.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Hypertriglyceridaemia, commonly found in subjects with obesity and type 2 diabetes mellitus, is associated with increased risk of coronary heart disease (CHD). Apolipoprotein C-III (apoC-III) plays an important role in regulating the metabolism of triglyceride-rich lipoproteins (TRLs) and may provide a new approach to assessing hypertriglyceridaemia. AIMS We review the role of apoC-III in regulating TRL metabolism and address the potential importance of apoC-III in clinical practice. DISCUSSION Hypertriglyceridaemia is chiefly a consequence of alterations in the kinetics of TRLs, including overproduction and delayed clearance of very-low density lipoprotein (VLDL). ApoC-III is an inhibitor of lipoprotein lipase and of TRLs remnant uptake by hepatic lipoprotein receptors. Elevated apoC-III, usually resulting from hepatic overproduction of VLDL apoC-III, may cause accumulation of plasma TRLs leading to hypertriglyceridaemia. The results from recent observational studies demonstrate that apoC-III is a strong predictor of risk for CHD, but this chiefly relates to apoC-III in apoB-containing lipoproteins. Lifestyle and pharmacological intervention can correct hypertriglyceridaemia by a mechanism of action that regulates apoC-III transport. CONCLUSIONS Targeting apoC-III metabolism may therefore be an important, new therapeutic approach to managing dyslipidaemia and CHD risk in obesity, insulin resistance and type 2 diabetes mellitus. However, further work is required to establish the practical aspects of measuring apoC-III in routine laboratory service and the precise therapeutic targets for serum total apoC-III and/or apoC-III in apoB-containing lipoproteins. While showing much promise as a potentially useful cardiovascular risk factor, apoC-III is not yet ready for prime time use in clinical practice.
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Yang XP, Gallo M, Ngan I, Nocerini M, Chen MM. Use of CMFDA and CMTMR fluorescent dyes in FACS-based antibody screening. Biotechniques 2002; 32:678-80, 682. [PMID: 11911670 DOI: 10.2144/02323dd05] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Cell-based immunizations are often used when membrane antigens are difficult to purify. To confirm that an antibody binding to the surface of a cell line is, in fact, binding to the desired antigen, FACS can be performed independently on two cell lines, a transfected cell line expressing the antigen of interest and a control cell line not expressing the antigen. Antibodies binding only to the transfected cell line are then selected for further analysis. This approach can be challenging if a large number of antibodies need to be screened and the antibody quantities are limited. Here we describe a novel method that combines the above two steps of FACS screening into a single step, based on the use of two fluorochromes, CMFDA and CMTMR, to stain transfected and control cell lines, respectively. Antibodies conjugated to a thirdfluorochrome are then added to the combined cells, followed by three-color FACS analysis. The newly modified FACS method is simple, sensitive, and high throughput. It can be used for antibody screening in multiple cell lines simultaneously.
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Chen MM, Lear SA, Gao M, Frohlich JJ, Birmingham CL. Intraobserver and interobserver reliability of waist circumference and the waist-to-hip ratio. OBESITY RESEARCH 2001; 9:651. [PMID: 11595784 DOI: 10.1038/oby.2001.87] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Twigg SM, Chen MM, Joly AH, Chakrapani SD, Tsubaki J, Kim HS, Oh Y, Rosenfeld RG. Advanced glycosylation end products up-regulate connective tissue growth factor (insulin-like growth factor-binding protein-related protein 2) in human fibroblasts: a potential mechanism for expansion of extracellular matrix in diabetes mellitus. Endocrinology 2001; 142:1760-9. [PMID: 11316739 DOI: 10.1210/endo.142.5.8141] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Expansion of extracellular matrix with fibrosis occurs in many tissues as part of the end-organ complications in diabetes, and advanced glycosylation end products (AGE) are implicated as one causative factor in diabetic tissue fibrosis. Connective tissue growth factor (CTGF), also known as insulin-like growth factor-binding protein-related protein-2 (IGFBP-rP2), is a potent inducer of extracellular matrix synthesis and angiogenesis and is increased in tissues from rodent models of diabetes. The aim of this study was to determine whether CTGF is up-regulated by AGE in vitro and to explore the cellular mechanisms involved. AGE treatment of primary cultures of nonfetal human dermal fibroblasts in confluent monolayer increased CTGF steady state messenger RNA (mRNA) levels in a time- and dose-dependent manner. In contrast, mRNAs for other IGFBP superfamily members, IGFBP-rP1 (mac 25) and IGFBP-3, were not up-regulated by AGE. The effect of the AGE BSA reagent on CTGF mRNA was due to nonenzymatic glycosylation of BSA and, using neutralizing antisera to AGE and to the receptor for AGE, termed RAGE, was seen to be due to late products of nonenzymatic glycosylation and was partly mediated by RAGE. Reactive oxygen species as well as endogenous transforming growth factor-beta1 could not explain the AGE effect on CTGF mRNA. AGE also increased CTGF protein in the conditioned medium and cell-associated CTGF. Thus, AGE up-regulates the profibrotic and proangiogenic protein CTGF (IGFBP-rP2), a finding that may have significance in the development of diabetic complications.
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Chen MM, Shi L, Sullivan DJ. Haemoproteus and Schistosoma synthesize heme polymers similar to Plasmodium hemozoin and beta-hematin. Mol Biochem Parasitol 2001; 113:1-8. [PMID: 11254949 DOI: 10.1016/s0166-6851(00)00365-0] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Many parasites digest hemoglobin as an amino acid source, but only a few produce heme polymer pigment instead of catabolizing heme via heme oxygenase. This work compares purified heme polymers produced by Haemoproteus columbae and Schistosoma mansoni to that of Plasmodium falciparum hemozoin and synthetic beta-hematin. Fourier-transform infrared spectroscopy identifies the signature peaks of the common iron-carboxylate bond characteristic in all four heme polymers. However, all pigments could be distinguished by quite different three-dimensional structure visualized by Field Emission Inlens Scanning Electron Microscopy. Both P. falciparum and H. columbae heme polymers had a symmetrical shape unlike the amorphous S. mansoni heme polymer and beta-hematin. All four heme pigments serve as templates for heme polymer extension, which was inhibitable by chloroquine and other quinoline antimalarials. The polymers showed different levels of resistance to hydrogen peroxide degradation. This work identifies another genus, Haemoproteus, capable of intracellular heme polymer formation. The different three-dimensional structures of each pigment implicate genus specific formation of heme polymer, variation of inhibition of polymer extension by the quinolines and degradation by hydrogen peroxide.
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Chen MM, Lam A, Abraham JA, Schreiner GF, Joly AH. CTGF expression is induced by TGF- beta in cardiac fibroblasts and cardiac myocytes: a potential role in heart fibrosis. J Mol Cell Cardiol 2000; 32:1805-19. [PMID: 11013125 DOI: 10.1006/jmcc.2000.1215] [Citation(s) in RCA: 339] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Connective tissue growth factor (CTGF) is a cysteine-rich protein induced by transforming growth factor beta (TGF- beta) in connective tissue cells. CTGF can trigger many of the cellular processes underlying fibrosis, such as cell proliferation, adhesion, migration and the synthesis of extracellular matrix; however, its role in acute and chronic cardiac injury is not fully understood. Here, we show that TGF- beta is a specific inducer of CTGF expression in both cardiac fibroblasts and cardiac myocytes. The activity of a CTGF promoter-based reporter construct correlated with endogenous CTGF expression, suggesting that TGF- beta induces CTGF expression most likely by activating its promoter. Upregulation of CTGF coincided with an increase in fibronectin, collagen type I and plasminogen activator inhibitor-1 production. Forskolin, a stimulator of cyclic AMP, blocked TGF- beta induced CTGF expression and reduced the basal level of CTGF, whereas an inhibitor that blocks the MAP kinase signaling pathway (PD 98059) significantly enhanced TGF- beta induced CTGF expression. Furthermore, we found that both TGF- beta and CTGF mRNAs were significantly elevated in the left ventricles and septa of rat hearts 2-16 weeks following myocardial infarction. This correlated well with concomitant increases in fibronectin, and type I and type III collagen mRNA levels in these animal hearts. Significant upregulation of CTGF was also detected in human heart samples derived from patients diagnosed with cardiac ischemia. Based on these findings, we propose that CTGF is an important mediator of TGF- beta signaling in the heart and abnormal expression of this gene could be used as a diagnostic marker for cardiac fibrosis.
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Moore SD, Chen MM, Cox DW. Cloning and mapping of murine superoxide dismutase copper chaperone (Ccsd) and mapping of the human ortholog. CYTOGENETICS AND CELL GENETICS 2000; 88:35-7. [PMID: 10773661 DOI: 10.1159/000015480] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Copper does not exist in a free state within cells but is found consistently bound to metalloproteins. Specific metallochaperones escort copper to numerous targets within the cell, providing protection from the toxic effects of intracellular free copper. Many metallochaperones have been characterized in yeast, mouse, and human. To further characterize mouse metallochaperones, we cloned murine Ccsd from an adult mouse cDNA brain library, including both the coding region and the 5' and 3' UTRs. We obtained a 1,174-bp cDNA with an 825-bp open reading frame, translating a 274 amino acid protein that is 86.9% identical to human CCS. Using a mouse x hamster radiation hybrid panel, we mapped Ccsd to a proximal position on mouse chromosome 19. We mapped human CCS to 11q13 (homologous with mouse chromosome 19), utilizing a human x hamster radiation hybrid panel. The human and mouse metallochaperones are ubiquitously expressed in the major tissues of the body but seem to have different transcription products.
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Greiwe JS, Hickner RC, Hansen PA, Racette SB, Chen MM, Holloszy JO. Effects of endurance exercise training on muscle glycogen accumulation in humans. J Appl Physiol (1985) 1999; 87:222-6. [PMID: 10409578 DOI: 10.1152/jappl.1999.87.1.222] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The purpose of this investigation was to determine whether endurance exercise training increases the ability of human skeletal muscle to accumulate glycogen after exercise. Subjects (4 women and 2 men, 31 +/- 8 yr old) performed high-intensity stationary cycling 3 days/wk and continuous running 3 days/wk for 10 wk. Muscle glycogen concentration was measured after a glycogen-depleting exercise bout before and after endurance training. Muscle glycogen accumulation rate from 15 min to 6 h after exercise was twofold higher (P < 0.05) in the trained than in the untrained state: 10.5 +/- 0.2 and 4.5 +/- 1.3 mmol. kg wet wt(-1). h(-1), respectively. Muscle glycogen concentration was higher (P < 0.05) in the trained than in the untrained state at 15 min, 6 h, and 48 h after exercise. Muscle GLUT-4 content after exercise was twofold higher (P < 0.05) in the trained than in the untrained state (10.7 +/- 1.2 and 4.7 +/- 0.7 optical density units, respectively) and was correlated with muscle glycogen concentration 6 h after exercise (r = 0.64, P < 0.05). Total glycogen synthase activity and the percentage of glycogen synthase I were not significantly different before and after training at 15 min, 6 h, and 48 h after exercise. We conclude that endurance exercise training enhances the capacity of human skeletal muscle to accumulate glycogen after glycogen-depleting exercise.
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Prakasam G, Yeh JK, Chen MM, Castro-Magana M, Liang CT, Aloia JF. Effects of growth hormone and testosterone on cortical bone formation and bone density in aged orchiectomized rats. Bone 1999; 24:491-7. [PMID: 10321909 DOI: 10.1016/s8756-3282(99)00018-6] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Osteoporosis in men is a disease that is increasing in incidence, and with an increasing elderly population it poses a serious health problem. Since both testosterone (T) and growth hormone (GH) have an anabolic effect on bone and both decrease with aging, we were prompted to test whether the administration of these hormones in combination would increase bone mass in orchiectomized (orx) senile rats more than administration of either agent alone. Twenty-month-old male Wistar rats were divided into five groups with seven animals each: (a) age-matched intact control, (b) orx, (c) orx+GH (2.5 mg/kg/day), (d) orx+T [10 mg/kg, subcutaneous (s.c.), injection given twice a week], and (e) orx+GH+T. Testosterone and GH were given subcutaneously for 4 weeks. Bone histomorphometry of the tibial shaft showed that the orx group had lower cortical bone area than the intact control group. The decrease in cortical bone area was due to increased intracortical porosis as well as decreased periosteal bone formation rate (BFR). Administration of T to the orx animals prevented the development of the porosis and the decrease in periosteal BFR. The bone mineral content (BMC) and bone mineral density (BMD) of the femur as tested by dual-energy X-ray absorptiometry were significantly higher in the orx+T than in the orx group and were not significantly different from that of the intact control group. Administration of GH to the orx rats increased periosteal BFR significantly; however, the BMC and BMD measured were not increased significantly in comparison to the orx group. When GH and T were combined in treatment, the cortical bone area, periosteal BFR, and femoral BMD were all significantly higher than that of the orx and even higher than the intact control rats. Two-way analysis of variance shows that the individual effect of GH and T treatment on the periosteal BFR and cortical bone area was significant. The effect of T, but not GH, on femoral BMC and BMD was also significant; however, there is no synergistic interaction between the two treatments. Four weeks of orx with or without GH or T administration had no significant effect on tibial metaphyseal cancellous bone volume. In conclusion, this short-term study suggests that the combined intervention of GH and T in androgen-deficient aged male rats may have an independent effect in preventing osteopenia. The significant effect of GH+T may be attributed to the prevention of intracortical porosis, and an increase in periosteal bone formation and cortical bone mass.
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Krein SL, Christianson JB, Chen MM. The composition of rural hospital medical staffs: the influence of hospital neighbors. J Rural Health 1999; 13:306-19. [PMID: 10177152 DOI: 10.1111/j.1748-0361.1997.tb00973.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The local supply of physicians has a strong influence on the availability and the quality of services provided by rural hospitals. Nevertheless, there are no published studies that describe the composition of rural hospital medical staffs and, in particular, the availability of specialists on these staffs. This study uses 1991 and 1994 survey data from rural hospitals located in eight states to describe the specialty composition and factors that influence the presence of specialists on rural hospital medical staffs. The results show a strong, positive association between the level of medical staff specialization in rural hospitals and the level of medical specialization of their closet rural neighbors, which suggests there is competition among rural hospitals based on the composition of the hospital medical staff. Analysis by specialty type, however, indicates that the degree of competition may differ for different types of specialists.
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Yeh JK, Evans JF, Chen MM, Aloia JF. Effect of hypophysectomy on the proliferation and differentiation of rat bone marrow stromal cells. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 276:E34-42. [PMID: 9886948 DOI: 10.1152/ajpendo.1999.276.1.e34] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Conditions such as estrogen deficiency, skeletal unloading, and aging have all been demonstrated to have various effects on the proliferation and differentiation of bone marrow stroma-derived osteoprogenitor cells. Here we have sought to examine the effects of pituitary hormone deficiency on the proliferation and the differentiation of these osteoprogenitor cells using the hypophysectomized (HX) rat as a model. In the present study, we use an in vitro culture system to examine the effects of HX on the osteogenic potential of rat bone marrow stroma. With the intact animal as a control, we used [3H]thymidine incorporation and cell number as indexes of proliferation. We also measured alkaline phosphatase enzyme activity, relative levels of osteocalcin expression with RT-PCR, and osteopontin and bone sialoprotein steady-state levels by Northern blot to delineate the effect on differentiation. Our results indicate that osteoprogenitor cells exposed to a pituitary hormone-deficient environment in vivo demonstrate an enhanced proliferative capacity and also exhibit an augmented expression of differentiation markers when exposed to an optimal environment in vitro.
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Hansen PA, Han DH, Marshall BA, Nolte LA, Chen MM, Mueckler M, Holloszy JO. A high fat diet impairs stimulation of glucose transport in muscle. Functional evaluation of potential mechanisms. J Biol Chem 1998; 273:26157-63. [PMID: 9748297 DOI: 10.1074/jbc.273.40.26157] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
A high fat diet causes resistance of skeletal muscle glucose transport to insulin and contractions. We tested the hypothesis that fat feeding causes a change in plasma membrane composition that interferes with functioning of glucose transporters and/or insulin receptors. Epitrochlearis muscles of rats fed a high (50% of calories) fat diet for 8 weeks showed approximately 50% decreases in insulin- and contraction-stimulated 3-O-methylglucose transport. Similar decreases in stimulated glucose transport activity occurred in muscles of wild-type mice with 4 weeks of fat feeding. In contrast, GLUT1 overexpressing muscles of transgenic mice fed a high fat diet showed no decreases in their high rates of glucose transport, providing evidence against impaired glucose transporter function. Insulin-stimulated system A amino acid transport, insulin receptor (IR) tyrosine kinase activity, and insulin-stimulated IR and IRS-1 tyrosine phosphorylation were all normal in muscles of rats fed the high fat diet for 8 weeks. However, after 30 weeks on the high fat diet, there was a significant reduction in insulin-stimulated tyrosine phosphorylation in muscle. The increases in GLUT4 at the cell surface induced by insulin or muscle contractions, measured with the 3H-labeled 2-N-4-(1-azi-2,2, 2-trifluoroethyl)-benzoyl-1,3-bis-(D-mannose-4-yloxy)-2-propyla min e photolabel, were 26-36% smaller in muscles of the 8-week high fat-fed rats as compared with control rats. Our findings provide evidence that (a) impairment of muscle glucose transport by 8 weeks of high fat feeding is not due to plasma membrane composition-related reductions in glucose transporter or insulin receptor function, (b) a defect in insulin receptor signaling is a late event, not a primary cause, of the muscle insulin resistance induced by fat feeding, and (c) impaired GLUT4 translocation to the cell surface plays a major role in the decrease in stimulated glucose transport.
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