Hepatitis B core-related antigen dynamics and risk of subsequent clinical relapses after nucleos(t)ide analog cessation.

BACKGROUND/AIMS: Finite nucleos(t)ide analog (NA) therapy has been proposed as an alternative treatment strategy for chronic hepatitis B (CHB), but biomarkers for post-treatment monitoring are limited. We investigated whether measuring hepatitis B core-related antigen (HBcrAg) after NA cessation may stratify the risk of subsequent clinical relapse (CR). METHODS: This retrospective multicenter analysis enrolled adults with CHB who were prospectively monitored after discontinuing entecavir or tenofovir with negative HBeAg and undetectable HBV DNA at the end of treatment (EOT). Patients with cirrhosis or malignancy were excluded. CR was defined as serum alanine aminotransferase > two times the upper limit of normal with recurrent viremia. We applied time-dependent Cox proportional hazard models to clarify the association between HBcrAg levels and subsequent CR. RESULTS: The cohort included 203 patients (median age, 49.8 years; 76.8% male; 60.6% entecavir) who had been treated for a median of 36.9 months (interquartile range [IQR], 36.5-40.1). During a median post-treatment follow-up of 31.7 months (IQR, 16.7-67.1), CR occurred in 104 patients with a 5-year cumulative incidence of 54.8% (95% confidence interval [CI], 47.1-62.4%). Time-varying HBcrAg level was a significant risk factor for subsequent CR (adjusted hazard ratio [aHR], 1.53 per log U/mL; 95% CI, 1.12-2.08) with adjustment for EOT HBsAg, EOT anti-HBe, EOT HBcrAg and time-varying HBsAg. During follow-up, HBcrAg <1,000 U/mL predicted a lower risk of CR (aHR, 0.41; 95% CI, 0.21-0.81). CONCLUSION: Dynamic measurement of HBcrAg after NA cessation is predictive of subsequent CR and may be useful to guide post-treatment monitoring.

Recent advances in the structure and activation mechanisms of metabolite-releasing Pannexin 1 channels.

Pannexin 1 (PANX1) is a widely expressed large-pore ion channel located in the plasma membrane of almost all vertebrate cells. It possesses a unique ability to act as a conduit for both inorganic ions (e.g. potassium or chloride) and bioactive metabolites (e.g. ATP or glutamate), thereby activating varying signaling pathways in an autocrine or paracrine manner. Given its crucial role in cell-cell interactions, the activity of PANX1 has been implicated in maintaining homeostasis of cardiovascular, immune, and nervous systems. Dysregulation of PANX1 has also been linked to numerous diseases, such as ischemic stroke, seizure, and inflammatory disorders. Therefore, the mechanisms underlying different modes of PANX1 activation and its context-specific channel properties have gathered significant attention. In this review, we summarize the roles of PANX1 in various physiological processes and diseases, and analyze the accumulated lines of evidence supporting diverse molecular mechanisms associated with different PANX1 activation modalities. We focus on examining recent discoveries regarding PANX1 regulations by reversible post-translational modifications, elevated intracellular calcium concentration, and protein-protein interactions, as well as by irreversible cleavage of its C-terminal tail. Additionally, we delve into the caveats in the proposed PANX1 gating mechanisms and channel open-closed configurations by critically analyzing the structural insights derived from cryo-EM studies and the unitary properties of PANX1 channels. By doing so, we aim to identify potential research directions for a better understanding of the functions and regulations of PANX1 channels.

Trends in all-cause mortality and major causes of death between 2007 and 2018 among patients with diabetes in Taiwan.

Optimal control of diabetes and relevant risk factors substantially reduce the risks of chronic complications and mortality. We investigated all-cause mortality rate and major causes of death between 2007 and 2018 in patients with diabetes in Taiwan. This study was conducted using data from Taiwan National Health Insurance Research Database. We selected patients with diabetes diagnosed between 2007 and 2017 (grouped according to the year of diabetes diagnosis 2007-2010 vs. 2011-2017). Information on mortality and causes of death by the end of 2018 was confirmed through linking to the National Death Registry. Standardized mortality rate (SMR) were calculated by weighting the World Health Organization (WHO) standard population (WHO 2000-2025). More than 2.7 million of patients with diabetes were analyzed and a total of 566121 deaths were identified. Overall, the SMR was 11.72 per 1000 person-years. Patients with diabetes diagnosed in 2011-2017 had a lower SMR (8.42 vs. 12.92 per 1000 person-years) than those diagnosed in 2007-2010. Similar finding were noted regarding the major causes of death (cancer, diabetes, heart disease, hypertensive disease, and cerebrovascular disease). Compared with patients who were diagnosed in 2008-2010, those who were diagnosed in 2011-2014 and 2015-2018 had a higher 3-year survival rate (0.9356 vs. 0.9438 vs. 0.946, log-rank test p<0.001) after the diagnosis of diabetes. Patients who were diagnosed with diabetes after 2011 had a lower rate of all-cause mortality and major causes of death, compared with those who were diagnosed before 2010 in Taiwan.

Experiences with making difficult decisions of the family caregivers of patients on prolonged mechanical ventilation: a qualitative study.

BACKGROUND: Family caregivers of patients on prolonged mechanical ventilation (PMV) may encounter challenges concerning medical decision-making besides witnessing patient suffering. Palliative care (PC) should be a good support for both patients and caregivers; however, for PMV families, PC is not always a choice through long companion time. This qualitative study clarifies family caregivers' burden of assisting patients on PMV and evaluates the need for PC information and support. METHODS: Interviews were caregivers of patients on ventilator support for more than 60 days in five hospitals of the Taipei City Hospital System. Based on phenomenology, this study was conducted by using a semistructured questionnaire comprising three questions: (I) what was the most crucial moment of deciding to intubate? (II) how would you describe the quality of life of your ventilator-dependent family member? (III) what type of assistance do you expect from the PC team for your ventilator-dependent family member? RESULTS: Twenty-one caregivers of patients on PMV in five hospitals of the Taipei City Hospital System agreed to participate in face-to-face interviews. The identified themes, including stressful decision-making, companion pain/discomfort, and unwillingness to accept PC, elucidated the difficulties experienced by caregivers when providing care. CONCLUSIONS: Understanding family caregivers' experiences can enable physicians to improve communication with them, encourage the PC team to support them during surrogate decision-making for patients on PMV during critical moments, and enhance the overall PC service.

Pay-for-performance for shared care of diabetes in Taiwan.

BACKGROUND/PURPOSE: Comprehensive and continuous care is crucial for patients with diabetes. The diabetes pay-for-performance (P4P) program launched by the National Health Insurance (NHI) administration in Taiwan provides a financial incentive to facilitate this goal. In this study, we explored the characteristics of patients in the P4P program between 2005 and 2014. METHODS: Data of patients with diabetes enrolled in the NHI program between 2005 and 2014 were extracted from the NHI research database. Patients were classed as having diabetes if they had three or more outpatient visits within 365 calendar days with an International Classification of Diseases, 9th Revision, Clinical Modification diagnostic code of 250 or hospitalization one or more times with such a diagnosis. The trends of participating in the P4P program were analyzed. RESULTS: Participation rate of the P4P program increased from 12.1% to 19% between 2005 and 2014. Participants were younger and more likely to be female than those not participating in the program. Lower risks of cancer-related mortality, annual mortality and heart failure were seen in patients participating in the P4P program than in those not participating. CONCLUSION: Older, male patients with a high disease severity may be less likely to enroll in the P4P program. Although participation rate is increasing, a broad enrollment is expected.

Trends of mortality in diabetic patients in Taiwan: A nationwide survey in 2005-2014.

BACKGROUND/PURPOSE: Diabetes mellitus has become a major cause of death worldwide. Many technologies have become available for managing diabetes and its complications. This study investigated the mortality trends in people with diabetes in Taiwan between 2005 and 2014. METHODS: We used data from Taiwan's National Health Insurance Research Database, which is linked to the National Death Registry. Patients with at least three outpatient visits in 1 year or at least one hospital admission with the diagnosis of diabetes (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] 250.x) were defined as diabetic patients. The main causes of death were classified using ICD-9-CM or ICD-10-CM. RESULTS: In 2005-2014, the number of diabetic patients increased from 1.3 to 2.2 million in Taiwan, and all-cause mortality in the patients decreased continuously across sexes and age groups (all, 3.45%-3.00%; women, 3.07%-2.70%; men, 3.82%-3.28%, all p < 0.001 for trends). The diabetic patients exhibited a shorter life expectancy than the entire population. The differences decreased from 2005 to 2014 (p < 0.001) and were greater when diabetes was diagnosed early in life. In 2014, the estimated loss of life was 2.6 and 3.2 years in the women and men, respectively, when diabetes was diagnosed at 40 years of age. The top five causes of death in diabetic patients were malignancy, diabetes, heart diseases, cerebrovascular diseases, and pneumonia. CONCLUSION: The mortality and estimated loss of life of diabetic patients decreased significantly from 2005 to 2014, reflecting advancements in diabetes care in Taiwan.

Hospitalization in patients with type 2 diabetes mellitus in Taiwan: A nationwide population-based observational study.

BACKGROUND/PURPOSE: We investigated hospitalization rates of patients with type 2 diabetes mellitus (T2DM) and individuals without diabetes mellitus (non-DM) in a disease-specific manner from 2005 to 2014 in Taiwan. METHODS: This population-based study was conducted using data from the National Health Insurance Research Database. We analyzed the hospitalization rates of patients with and without T2DM. We collected up to five diagnostic codes given at discharge for each hospitalization, and the first one was considered the main diagnosis. Odds ratios were determined to assess the risk of hospitalization according to disease-specific classifications in patients with T2DM compared with those without T2DM. RESULTS: The hospitalization rates of non-DM patients was stable from 2005 to 2014. By contrast, the rate of hospitalization among patients with T2DM decreased from 395.4 (per 1000 person-years) in 2005 to 336.9 (per 1000 person-years) in 2014. An increase in hospitalization rates for malignancies and sepsis/infection (other than pneumonia) was observed from 2005 to 2014 in both patients with and without T2DM. Although patients with T2DM had a higher hospitalization risk for all the disease-specific classifications than non-DM patients, this difference in risk decreased from 2005 to 2014 for all diseases except pneumonia. CONCLUSION: Hospitalization rates for malignancies and sepsis/infection (other than pneumonia) continually increased from 2005 to 2014 in Taiwan. Although patients with T2DM had a greater risk of disease-specific hospitalization than those without, this difference in risk decreased from 2005 to 2014 for all diseases except for pneumonia.

Perioperative/Postoperative Atrial Fibrillation and Risk of Subsequent Stroke and/or Mortality.

Background and Purpose- Although believed to be transient and self-limiting, new-onset perioperative/postoperative atrial fibrillation (POAF) might be a risk factor for stroke and mortality. We conducted a systematic review and meta-analysis to qualitatively and quantitatively evaluate the relationship of POAF with early and late risks of mortality and stroke. Methods- We searched Pubmed, EMBASE, and Cochrane Library (1966 through March 2018) to identify cohort studies that reported stroke and mortality associated with POAF. We computed a random-effects estimate based on the Mantel-Haenszel method. Odds ratios with 95% CI were used as a measure of the association between POAF and early (in-hospital or within 30 days of surgery) stroke and mortality, while hazard ratios (HR) were used for long-term outcomes. Results- Our analysis included 35 studies with 2 458 010 patients. Pooling the results from the random-effects model showed that POAF was associated with increased risks of early stroke (odds ratio, 1.62; 95% CI, 1.47-1.80), early mortality (odds ratios, 1.44; 95% CI, 1.11-1.88), long-term stroke (HR, 1.37; 95% CI, 1.07-1.77), and long-term mortality (HR, 1.37; 95% CI, 1.27-1.49). Analyses focusing on high-quality studies obtained similar results. In subgroup analyses, POAF was more strongly associated with stroke in patients undergoing noncardiac surgery (HR, 2.00; 95% CI, 1.70-2.35) than in patients undergoing cardiac surgery (HR, 1.20; 95% CI, 1.07-1.34). Conclusions- New-onset POAF is associated with an increased risk of stroke and mortality, both in the short-term and long-term. The best strategy to reduce stroke risk among these patients needs to be determined.

Validation of a concise screening tool for the identification of palliative care needs among inpatients: A prospective study in hospital setting.

BACKGROUND/PURPOSE: Very few studies have investigated the screening tools that aim to identify the need of palliative care services among patients with advanced cancer or chronic non-malignant diseases. This study validated the one-page Taiwanese version-Palliative Care Screening Tool (TW-PCST) for screening inpatients with potential palliative care needs. METHOD: ROC curves were produced to examine the sensitivities and specificities at varying cut-off points. The optimal cut-off value to predict mortality was justified using the Youden's index. The screening was conducted on the first day of admission. Patients were prospectively followed-up after the baseline assessment. Three followed-up periods, namely 14 days, 90 days, and 180 days were analyzed. RESULTS: A total of 21,596 patients were screened. AUCs for all cut-off scores varied from 0.84 to 0.88. A total-ABCD score ≥2 gave the highest Youden's index for 90 days and 180 days follow-up periods. The optimal cut-point for 14 days was score ≥3. CONCLUSION: The TW-PCST demonstrated a good sensitivity and specificity in identification of inpatients with palliative care needs. A total-ABCD score ≥2 may be considered as a trigger for further referral.

Antiplatelet Regimen for Patients With Breakthrough Strokes While on Aspirin: A Systematic Review and Meta-Analysis.

BACKGROUND AND PURPOSE: Optimal antiplatelet therapy after an ischemic stroke or transient ischemic attack while on aspirin is uncertain. We, therefore, conducted a systematic review and meta-analysis. METHODS: We searched PubMed (1966 to August 2016) and bibliographies of relevant published original studies to identify randomized trials and cohort studies reporting patients who were on aspirin at the time of an index ischemic stroke or transient ischemic attack and reported hazard ratio for major adverse cardiovascular events or recurrent stroke associated with a switch to or addition of another antiplatelet agent versus maintaining aspirin monotherapy. Estimates were combined using a random effects model. RESULTS: Five studies with 8723 patients with ischemic stroke or transient ischemic attack were identified. Clopidogrel was used in 4 cohorts, and ticagrelor was used in 1 cohort. Pooling results showed that addition of or a switch to another antiplatelet agent, versus aspirin monotherapy, was associated with reduced risks of major adverse cardiovascular events (hazard ratio, 0.68; 95% confidence interval, 0.54-0.85) and recurrent stroke (hazard ratio, 0.70; 95% confidence interval, 0.54-0.92). Each of the strategies of addition of and switching another antiplatelet agent showed benefit versus continued aspirin monotherapy, and studies with regimen initiation in the first days after index event showed more homogenous evidence of benefit. CONCLUSIONS: Among patients who experience an ischemic stroke or transient ischemic attack while on aspirin monotherapy, the addition of or a switch to another antiplatelet agent, especially in the first days after index event, is associated with fewer future vascular events, including stroke.

[Effect of Tongxinluo on Apoptosis of Rat Cardiac Microvascular Endothelial Cells].

OBJECTIVE: To observe the protective effects of Tongxinluo (TXL) on apoptosis of rat cardiac microvascular endothelial cells (RCMECs) resulting from homocysteine (Hcy) induced endoplasmic reticulum stress (ERS), and to determine the signaling pathway behind its protection. METHODS: Primary cultured RCMECs were isolated from neonatal rats using tissue explant method. The morphology of RCMECs was observed using inverted microscope, identified and differentiated by CD31 immunofluorescence method. Selected were well growing 2nd-4th generations of RCMECs. The optimal action time was determined by detecting the expression of glucose regulated protein 78 (GRP78) using immunofluorescence method. In the next experiment RCMECs were divided into 5 groups, i.e., the blank control group, the Hcy induced group (Hcy 10 mmol/L, 10 h), the Hcy + TXL group (Hcy 10 mmol/L + TXL 400 µg/mL), the Hcy +LY294002 group (Hcy 10 mmol/L + LY294002 5 µmol/L, LY294002 as the inhibitor of PI3K), the Hcy + LY294002 + TXL group (Hcy 10 mmol/L + LY294002 5 µmol/L + TXL 400 µg/mL). The apoptosis rate of RCMECs was detected by flow cytometry. mRNA and protein expressions of GRP78, C/ EBP homologous protein (CHOP), and cysteinyl aspartate specific proteinase-12 (caspase12) were detected by real-time reverse transcription PCR (RT-PCR) and Western blot respectively. Expression levels of phosphorylation of phosphatidylinositol 3-kinase (P-PI3K), total phosphatidylinositol 3-kinase (T- P13K) , phosphorylation of kinase B (P-Akt) , and total kinase B (T-Akt) were detected by Western blot. RESULTS: Ten hours Hcy action time was determined. Compared with the blank control group, the apoptosis rate was increased (22.77%), mRNA and protein expressions of GRP78, CHOP, and Caspase-12 were increased, protein expressions of P-PI3K and P-Akt,ratios of P-PI3K/T-PI3K and P-Akt/T-Akt were decreased in the Hcy induced group (P < 0.05, P < 0.01). Compared with the Hcy induced group, the apoptosis rate was decreased (10.17%), mRNA and protein expressions of GRP78, CHOP, and Caspase-12 were decreased, and expression levels of P-PI3K, P-Akt, P-PI3K/T-PI3K, and P-Akt/T-Akt were increased in the Hcy + TXL group (P < 0.05, P < 0.01). Compared with the Hcy + TXL group, the apoptosis rate was increased (17.9%), mRNA and protein expressions of GRP78, CHOP, and Caspase-12 were increased, expression levels of P-PI3K and P-Akt, ratios of P-PI3K/T-PI3K and P-Akt/T-Akt were decreased in the Hcy + TXL + LY294002 group (P < 0.05, P < 0.01). CONCLUSION: TXL could inhibit the apoptosis of RCMECs resulting from Hcy-induced ERS and its mechanism might be associated with activating PI3K/Akt signaling pathway.

ß-1,4-Galactosyltransferase III suppresses ß1 integrin-mediated invasive phenotypes and negatively correlates with metastasis in colorectal cancer.

Metastasis often occurs in colorectal cancer (CRC) patients and is the main difficulty in cancer treatment. The upregulation of poly-N-acetyllactosamine-related glycosylation is found in CRC patients and is associated with progression and metastasis in cancer. ß-1,4-Galactosyltransferase III (B4GALT3) is an enzyme responsible for poly-N-acetyllactosamine synthesis, and therefore, we investigated its expression in CRC patients. We found that B4GALT3 negatively correlated with poorly differentiated histology (P < 0.001), advanced stages (P = 0.0052), regional lymph node metastasis (P = 0.0018) and distant metastasis (P = 0.0463) in CRC patients. B4GALT3 overexpression in CRC cells suppressed cell migration, invasion and adhesion, whereas B4GALT3 knockdown enhanced malignant cell phenotypes. The ß1 integrin-blocking antibody reversed the B4GALT3-mediated increase in cell invasion. B4GALT3 expression altered glycosylation on the N-glycan of ß1 integrin probably through changes in poly-N-acetyllactosamine expression. Furthermore, more activated ß1 integrin along with the activation of its downstream signaling transduction were found in B4GALT3 knockdown cells, whereas overexpression of B4GALT3 suppressed the expression of active ß1 integrin and inhibited its downstream signaling. Our results suggest that B4GALT3 is negatively associated with CRC metastasis and suppresses cell invasiveness through inhibiting activation of ß1 integrin.

Proteomic exploration of the impacts of pomegranate fruit juice on the global gene expression of prostate cancer cell.

Prostate cancer has been known to be the second highest cause of death in cancer among men. Pomegranate is rich in polyphenols with the potent antioxidant activity and inhibits cell proliferation, invasion, and promotes apoptosis in various cancer cells. This study demonstrated that pomegranate fruit juice could effectively hinder the proliferation of human prostate cancer DU145 cell. The results of apoptotic analyses implicated that fruit juice might trigger the apoptosis in DU145 cells via death receptor signaling and mitochondrial damage pathway. In this study, we exploited 2DE-based proteomics to compare nine pairs of the proteome maps collected from untreated and treated DU145 cells to identify the differentially expressed proteins. Comparative proteomics indicated that 11 proteins were deregulated in affected DU145 cells with three upregulated and eight downregulated proteins. These dys-regulated proteins participated in cytoskeletal functions, antiapoptosis, proteasome activity, NF-κB signaling, cancer cell proliferation, invasion, and angiogenesis. Western immunoblotting were implemented to confirm the deregulated proteins and the downstream signaling proteins. The analytical results of this study help to provide insight into the molecular mechanism of inducing prostate cancer cell apoptosis by pomegranate fruit juice and to develop a novel mechanism-based chemopreventive strategy for prostate cancer.

Phosphorylation of endothelial NOS contributes to simvastatin protection against myocardial no-reflow and infarction in reperfused swine hearts: partially via the PKA signaling pathway.

AIM: The cholesterol-lowering drugs statins could enhance the activities of endothelial nitric oxide synthase (eNOS) and protect myocardium during ischemia and reperfusion. The aim of this study was to examine whether protein kinase A (PKA) was involved in statin-mediated eNOS phosphorylation and cardioprotection. METHODS: 6-Month-old Chinese minipigs (20-30 kg) underwent a 1.5-h occlusion and 3-h reperfusion of the left anterior descending coronary artery (LAD). In the sham group, the LAD was encircled by a suture but not occluded. Hemodynamic and cardiac function was monitored using a polygraph. Plasma activity of creatine kinase and the tissue activities of PKA and NOS were measured spectrophotometrically. p-CREB, eNOS and p-eNOS levels were detected using Western blotting. Sizes of the area at risk, the area of no-reflow and the area of necrosis were measured morphologically. RESULTS: Pretreatment of the animals with simvastatin (SIM, 2 mg/kg, po) before reperfusion significantly decreased the plasma activity of creatine kinase, an index of myocardial necrosis, and reduced the no-reflow size (from 50.4%±2.4% to 36.1%±2.1%, P<0.01) and the infarct size (from 79.0%±2.7% to 64.1%±4.5%, P<0.01). SIM significantly increased the activities of PKA and constitutive NOS, and increased Ser(133) p-CREB protein, Ser(1179) p-eNOS, and Ser(635) p-eNOS in ischemic myocardium. Intravenous infusion of the PKA inhibitor H-89 (1 µg·kg(-1)·min(-1)) partially abrogated the SIM-induced cardioprotection and eNOS phosphorylation. In contrast, intravenous infusion of the eNOS inhibitor L-NNA (10 mg·kg(-1)) completely abrogated the SIM-induced cardioprotection and eNOS phosphorylation during ischemia and reperfusion, but did not affect the activity of PKA. CONCLUSION: Pretreatment with a single dose of SIM 2.5 h before reperfusion attenuates myocardial no-reflow and infarction through increasing eNOS phosphorylation at Ser(1179) and Ser(635) that was partially mediated via the PKA signaling pathway.

PKA-mediated eNOS phosphorylation in the protection of ischemic preconditioning against no-reflow.

OBJECTIVE: To investigate whether ischemic preconditioning (IP) can reduce myocardial no-reflow by activating endothelial (e-) nitric oxide synthase (NOS) via the protein kinase A (PKA) pathway. METHODS AND RESULTS: In a 90-min ischemia and 3-h reperfusion model, minipigs were assigned into sham, ischemia-reperfusion (IR), IR+IP, IR+IP+L-NNA (an eNOS inhibitor, 10mg·kg(-1)), IR+IP+H-89 (a PKA inhibitor, 1.0µg·kg(-1)·min(-1)), IR+L-NNA, and IR+H-89 groups. IP pretreatment improved cardiac function and coronary blood flow, decreased the activities of creatine kinase by 36.6% after 90 min of ischemia and by 32.8% after 3 h of reperfusion (P<0.05), reduced the no-reflow areas from 49.9% to 11.0% (P<0.01), and attenuated the infarct size from 78.2% to 35.4% (P<0.01). IP stimulated myocardial PKA activities and the expression of PKA and Ser(133) phosphorylated (p-) cAMP response element-binding protein (CREB) in the reflow and no-reflow myocardium, and enhanced the activities of constitutive NOS and the phosphorylation of eNOS at Ser(1179) and Ser(635) in the no-reflow myocardium. IP suppressed the expression of tumor necrosis factor-α and P-selectin, and attenuated cardiomyocytes apoptosis by regulating the expression of Bcl-2 and caspase-3 in the reflow and no-reflow myocardium. The eNOS inhibitor L-NNA completely canceled these beneficial effects of IP without any influence on PKA activity, whereas the PKA inhibitor H-89 partially blocked the IP cardioprotective effects and eNOS phosphorylation at the same time. CONCLUSION: IP attenuates myocardial no-reflow and infarction after ischemia and reperfusion by activating the phosphorylation of eNOS at Ser(1179) and Ser(635) in a partly PKA-dependent manner.

Exhaustive swimming differentially inhibits P2X1 receptor- and α1-adrenoceptor-mediated vasoconstriction in isolated rat arteries.

AIM: To investigate the effects of exhaustive swimming exercise on P2X1 receptor- and α1-adrenoceptor-mediated vasoconstriction of different types of arteries in rats. METHODS: Male Wistar rats were divided into 2 groups: the sedentary control group (SCG) and the exhaustive swimming exercise group (ESEG). The rats in the ESEG were subjected to a swim to exhaustion once a day for 2 weeks. Internal carotid, caudal, pulmonary, mesenteric arteries and aorta were dissected out. Isometric vasoconstrictive responses of the arteries to α,ß-methylene ATP (α,ß-MeATP) or noradrenaline (NA) were recorded using a polygraph. RESULTS: The exhaustive swimming exercise did not produce significant change in the EC(50) values of α,ß-MeATP or NA in vasoconstrictive response of most of the arteries studied. The exhaustive swimming exercise inhibited the vasoconstrictive responses to P2X1 receptor activation in the internal carotid artery, whereas it reduced the maximal vasoconstrictive responses to α1-adrenoceptor stimulation in the caudal, pulmonary, mesenteric arteries and aorta. The rank order of the reduction of the maximal vasoconstriction was as follows: mesenteric, pulmonary, caudal, aorta. CONCLUSION: Exhaustive swimming exercise differentially affects the P2X1 receptor- and α1-adrenoceptor-regulated vasoconstriction in internal carotid artery and peripheral arteries. The ability to preserve purinergic vasoconstriction in the peripheral arteries would be useful to help in maintenance of the basal vascular tone during exhaustive swimming exercise.

[Active ingredients of Plastrum Testudinis inhibit epidermal stem cell apoptosis in serum-deprived culture].

OBJECTIVE: To investigate the effects of active ingredients of Plastrum Testudinis (PT) on serum deprivation-induced apoptosis of epidermal stem cells (ESCs). METHODS: ESCs were isolated from the back skin of fetal Sprague-Dawley rats with 2 weeks of gestational age and were divided into normal group (10% fetal bovine serum), control group (serum-deprived culture) and groups treated with serum deprivation plus active ingredients of PT, including ethyl acetate extract (2B), stearic acid ethyl ester (S6), tetradecanoic acid sterol ester (S8) and (+)-4-cholesten-3-one (S9). The vitality of ESCs after 24, 48 and 72 h of culture was measured with MTT method; apoptotic ESCs double-stained with Annexin V-FITC and propidium iodine were detected by flow cytometry (FCM); Bcl-2 and caspase-3 expressions were measured by Western blotting. RESULTS: MTT results indicated that the vitality of ESCs in the active ingredients of PT groups at 48 h was increased compared with the control group and 2B had better effects than the others. FCM results indicated that 2B had the most significant anti-apoptotic effect compared with the control as well as S6, S8 and S9. Western blot results indicated that 2B, S6, S8 and S9 up-regulated the expression of Bcl-2 protein and down-regulated the expression of caspase-3 protein compared with the control. CONCLUSION: Ethyl acetate extract of Plastrum Testudinis inhibits epidermal stem cell apoptosis in serum-deprived culture by regulating the expressions of Bcl-2 and caspase-3 proteins and has a stronger anti-apoptotic effect than its constituents S6, S8 and S9.