Endogenous hydrogen sulfide contributes to the cardioprotection by metabolic inhibition preconditioning in the rat ventricular myocytes

The possible role of hydrogen sulfide (H2S) in cardioprotection was investigated in isolated rat ventricular myocytes exposed to severe metabolic inhibition (MI) in glucose-free buffer containing 2-deoxy-D-glucose (2-DOG), an inhibitor of glycolysis. Pretreatment (30 min) with NaHS (a H2S donor) at concentrations of 10(-5) to 10(-4) mol/L caused a concentration related increase in cell viability and the ratio of rod-shaped cells. A time course study showed that NaHS-induced cardioprotection occurred in 2 time windows (approximately 1 h and 16-28 h). To observe whether endogenous H2S may be involved in the delayed cardioprotection response of IP, DL-propargylglycine (PAG) and beta-cyano-L-alanine (BCA; two inhibitors of H2S biosynthesis) were used. Both drugs significantly attenuated the cardioprotection produced by MI using cell viability, cellular injury index, and electrically-induced [Ca2+]i transients as end-points. These data suggest that endogenous H2S plays an important role in the cardioprotection following MI preconditioning. In an attempt to determine the mechanism of the cardioprotective effect of H2S, we examined the effect of blocking KATP channels with glibenclamide (a non-selective KATP channel blocker), 5-hydroxydecanoic acid (5-HD, a mitochondrial KATP blocker), and HMR-1098 (a sarcolemmal KATP blocker). The cardioprotective effects of NaHS were significantly attenuated by glibenclamide and HMR-1098 treatment but not by 5-HD. Inhibition of NO production with L-NG nitroarginine methyl ester (L-NAME) also attenuated the cardioprotection of NaHS. In conclusion, our findings provide the first evidence that H2S may protect the heart most probably by activating sarcolemmal KATP channels and/or provoking NO release and the cardioprotective effects of metabolic ischemic preconditioning is, at least partially, mediated by endogenous H2S.     

Fear of injections and report of negative dentist behavior among Caucasian American and Taiwanese adults from dental school clinics

Abstract Fear of injections and reports of negative dentist behavior and associations with dental anxiety and avoidance of treatment were explored among 951 adults from denial school clinics in Iowa City, Iowa and Taipei. Taiwan. Use and fear of anesthetic injections and negative dentist behavior were assessed by written questionnaire to test associations with demographics, overall dental anxiety (Dental Anxiety Scale or “DAS”) and utilization behaviors. Frequency and logistic regression analyses showed that use of dental anesthetics for routine treatment was much greater overall among Caucasian Americans than Taiwanese, as was fear of injections. Taiwanese and Americans with high dental anxiety (DAS 12) had similar high fear of injections, but inspite of similar fears about dental drilling, high anxiety Taiwanese reported using much less local anesthesia for routine treatments than did high anxiety Americans. Report of condescending remarks to patients (“put downs”) by dentists was mainly an American phenomenon associated with high dental anxiety. Avoidance of appointment making was high for persons afraid of injections and for Americans reporting negative dentist behavior. Avoidance was highest in subjects with high dental anxiety. That predominant characteristics or etiologies of dental anxiety can differ by cultural differences in dental health care systems, dentist beliefs and/or expectations of patients within those systems was discussed in relation to the literature.     

Usefulness of captopril renography to predict the benefits of renal artery revascularization or captopril treatment in hypertensive patients with diabetic nephropathy

This retrospective study aimed to use captopril renography (CR) for predicting the benefits of captopril treatment in hypertensive patients with diabetic nephropathy. CR was utilized in 60 hypertensive patients with diabetic nephropathy for detecting the probability of renovascular hypertension (RVH) and predicting the benefits of renal artery revascularization or captopril treatment. Ten of the 60 patients showed a high probability of RVH with marked changes of the renogram curve after an oral intake of 50-mg captopril compared to baseline findings. All of the 10 patients confirmed significant main renal artery stenosis in all of them, bilaterally in four patients and unilaterally in the remaining six patients by renal angiographic findings. After successful revascularization, blood pressure was well controlled and renal function was preserved in all of the 10 patients. The other 50 patients showed a low or intermediate probability of RVH with normal findings or unchanged on CR after 50-mg captopril. Then, captopril alone or combination treatment started and continued on 50 patients. After monitoring for at least 6 months, blood pressure was well controlled and renal function was preserved in all the 50 patients on captopril treatment. We conclude that CR should be considered as the standard diagnostic criteria of RVH and may be helpful in predicting the beneficial impact of captopril treatment in hypertensive patients with diabetic nephropathy.     

Postinfectious gastrointestinal disorders following norovirus outbreaks

Background.?The US Centers for Disease Control and Prevention estimates 20.9 million norovirus infections annually in the United States. Although the acute disease burden is sizeable, emerging data suggest norovirus may be associated with chronic gastrointestinal problems. We identified known outbreaks in US military recruits and used the Defense Medical Encounter Database (DMED) to identify the risk of new onset functional gastrointestinal disorders (FGD) and gastroesophageal reflux disease (GERD). Methods.?Subjects reporting for care of acute gastroenteritis (AGE) at a military treatment clinic during 3 known norovirus outbreaks were identified. Each AGE subject was matched with up to 4 subjects with unrelated medical encounters. Medical encounter data were analyzed for the duration of military service time (or a minimum of 1 year) to assess for incident FGD or GERD. Relative risks were calculated using regression models. Results.?We identified 1718 subjects from 3 outbreaks. After controlling for important demographic covariates, the incidence of constipation, dyspepsia, and GERD was approximately 1.5-old higher (P?相似文献   

Fecal triglyceride excretion is not excessive in pancreatic insufficiency

Steatorrhea can result from maldigestion or malabsorption. As the pathophysiology underlying impaired digestion differs from impaired absorption, it is important to differentiate these two disorders. It is generally accepted that patients with maldigestion excrete an excessive amount of triglyceride and patients with malabsorption excrete an excess of the lipolytic product of triglyceride, fatty acid. The two-step Sudan stain has been used as a simple test to differentiate these disorders. The validity of the test has not yet been established. In this study, fecal fatty acid and triglyceride were measured after extraction and thin-layer chromatographic separation. Our results indicate that in adult patients with pancreatic insufficiency, the fecal triglyceride content does not differ from the controls. However, a fivefold to sixfold increase in fecal fatty acid content in patients with pancreatic insufficiency was revealed. As patients with maldigestion do not excrete an excess of undigested triglyceride, it is not possible to differentiate maldigestion from malabsorption by quantifying fecal triglyceride and fatty acid.     

Decrease in inner retinal thickness at para- and perifoveal areas before vascular retinopathy in patients with metabolic risk factors

BackgroundHypertension, dyslipidemia, and hyperglycemia are major risk factors for vascular retinopathy. The relationship between retinal thickness at the macular area and metabolic risk factors, as well as visual impairment, in elderly patients before developing vascular occlusion needs to be investigated.MethodsIn this prospective, case-control study, patients >60 years old, without objective visual threatened ocular diseases or systemic abnormalities, except for hypertension, dyslipidemia or/and hyperglycemia, were included for measurement of retinal thickness at the macular area by optical coherence tomography (OCT).ResultsFifty-four patients were analyzed; 11 patients had no metabolic risk factors, 16 had one, 17 had two, and 10 had three. There was no significant difference in age, and full and outer retinal thickness, but there was a significantly lower inner retinal thickness at the parafoveal (p = 0.0013) and perifoveal (p = 0.018) areas in patients with at least one metabolic risk factor. The superior (p = 0.040) and inferior (p = 0.046) inner retina at the perifovea and superior (p = 0.013) inner retinal thickness at the parafovea were sensitive to metabolic abnormalities. Only patients with three factors had significantly reduced best corrected visual acuity (BCVA).ConclusionElderly patients with metabolic risk factors had decreased inner retinal thickness at the para- and perifoveal areas before retinal vascular diseases. Accelerated inner retinal degeneration occurred prior to visual impairment.