锌、铜对染砷小鼠肝及肾毒作用的干预研究

为观察补充锌、铜对染砷小鼠的肝、肾脏组织超氧化物歧化酶 (SOD)水平、丙二醛 (MDA)含量并初步探讨其作用机制 ,对染砷小鼠同步进行锌、铜干预试验 ,同时作肝脏、肾脏组织SOD活性及MDA含量测定和病理学观察。干预后 ,与阳性对照组相比 ,锌干预组肝脏、肾脏SOD活性升高 ,MDA含量下降 (P <0 .0 1) ,锌加铜组仅肾脏SOD活性升高 (P <0 .0 1) ,铜组肝、肾脏SOD活性及MDA含量均无显著性差异 (P >0 .0 5 )。病理学观察可见 ,锌干预组效果最好 ,其次为锌加铜组 ,而铜组无干预效果。提示补充一定剂量锌对染砷小鼠的脂质过氧化程度、抗氧化能力以及组织病理改变均有一定的干预效应。铜在该剂量下与锌起拮抗作用。     

Influence of Smoking on Basal and on Vagally and Maximally Stimulated Gastric Acid and Pepsin Secretion

Published data show that smokers have greater basal or peak acid and pepsin outputs, but the mechanisms underlying these effects are unknown. To confirm this and to determine whether these findings extend to, and implicate, any vagal overactivity, gastric secretions collected for 1 h basally, 1 h after 15 min of modified sham feeding (MSF), and 1 h after pentagastrin (6 μg/kg subcutaneously) were analyzed for acid and pepsin content in 204 subjects, 104 with duodenal ulcer (66 smokers) and 101 without (57 smokers). Maximal acid outputs (MAO, μeq/kg/h, x + SEM) were higher in smokers than in non-smokers in both duodenal ulcer (DU) (623 + 35 versus 491 + 35, p < 0.005) and non-DU (502 + 32 versus 376 + 20, p < 0.005). Basal and MSF secretions were generally increased in smokers but, when expressed as a percentage of MAO, were not different in smokers and non-smokers (18% versus 17% and 43% versus 39%, respectively, in DU, and 13% versus 16% and 40% versus 36% in non-DU). Maximal pepsin outputs (units + 10 ²/kg/h) were also higher in smokers than in non-smokers (DU, 129 + 7.9 versus 105 + 9.5, p = 0.05, and non-DU, 101 + 7.5 versus 77 + 10, p = 0.05). Basal and MSF secretions as a percentage of maximal pepsin output were not different in smokers versus non-smokers. Multivariate logistic regression shows that smoking was most strongly associated with MAO and sham feeding outputs, but the duration-intensity (pack-years) of smoking was associated only with elevated MAO. We conclude that smoking is associated with increased maximal acid and pepsin output in both DU and non-DU populations. Smoking does not seem to affect independently vagal stimulation of gastric secretion.     

Effects of therapeutic paracentesis on systemic and hepatic hemodynamics and on renal and hormonal function

Thirteen patients with cirrhosis and tense ascites (six with and seven without peripheral edema) underwent 4- to 15-liter paracentesis without intravenous "colloid" replacement. Cardiac output increased from 6.6 +/- 0.7 liters per min at baseline to 8.2 +/- 0.7 liters per min (p less than 0.003) 1 hr after large-volume paracentesis completion and fell to 7.5 +/- 0.69 liters per min (p less than 0.05 vs. baseline, p less than 0.02 vs. 1 hr) 24 hr after large-volume paracentesis completion. There was no change in mean arterial pressure or mean pulmonary artery pressure. Central venous pressure fell from 9.1 +/- 0.8 mm Hg at baseline to 8.6 +/- 1.4 mm Hg 1 hr post-large-volume paracentesis to 6.8 +/- 1.0 mm Hg (p less than 0.005 vs. baseline, p less than 0.02 vs. 1 hr value) at 24 hr, and pulmonary capillary wedge pressure fell from 13.1 +/- 0.9 to 11.1 +/- 1.3 mm Hg 1 hr after large-volume paracentesis and to 9.89 +/- 1.2 (p less than 0.01 vs. baseline, p less than 0.03 vs. 1 hr after large-volume paracentesis) at 24 hr. Heart rate fell from 90 +/- 3.0 to 85 +/- 2.9 beats per min (p less than 0.01) 1 hr after large-volume paracentesis completion, but increased to 89 +/- 2.5 beats per min (p less than 0.02 vs. 1 hr after large-volume paracentesis) at 24 hr.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of particle size on quartz-induced hemolysis and on lung inflammation and fibrosis

To assess the role of crystal size in biologic responses, we quantitated red blood cell lysis and lung inflammation and fibrosis in the mouse using 4 alpha-quartz preparations with average diameters of 1, 5, 7.8, and 11.2 microns. When compared on the basis of identical crystal surface areas, the 1-micron fraction was more hemolytic than the other 3 fractions. The three larger fractions had equivalent membranolytic activities. After 6 weeks of postintratracheal instillation of the crystals into mice, the 1-micron-diameter crystal fraction increased wet lung weights by 1.25 x that of saline controls, while a 1.75 x increase was found for the three larger crystal fractions. A similar response was found when evaluating fibrosis development by determining lung hydroxyproline levels. Measurement of the percentage of the crystal dose remaining in the lungs revealed that the biologic differences observed were not due to a difference in the clearance of the smaller crystal fraction. Thus, larger crystals of alpha-quartz produce a greater degree of inflammation and fibrosis when instilled into the lung than those of 1 micron diameter, even though the smaller crystals are more membranolytic in vitro and appear to be cleared from the lung at the same rate as the larger crystals.     

Effects of trenbolone acetate and testosterone on growth and on plasma concentrations of corticosterone and ACTH in rats

The effects of trenbolone acetate (TBA) on growth and on plasma concentrations of corticosterone were examined in male and female rats. At 5 weeks of age, rats were injected with TBA (0.8 mg/kg) dissolved in peanut oil, or with oil alone, daily for 10 days. In female rats, TBA caused an increase in weight gain (20-38%), a reduction in adrenal weight (19%) and a reduction in plasma concentrations of corticosterone (55%). In contrast, TBA-treated male rats showed no significant increase in weight gain, no significant change in adrenal weight and no reduction in plasma concentrations of corticosterone. The mechanism by which adrenal activity was suppressed in TBA-treated female rats was examined and the response compared with that to testosterone. Female rats (8 weeks old) were injected daily either with oil vehicle, TBA (0.8 mg/kg) or testosterone propionate (0.8 mg/kg). Testosterone increased weight gain (24%), but the growth response to TBA treatment was significantly greater (97%). A reduction in plasma concentrations of corticosterone (45%) was again observed in response to TBA. However, testosterone increased plasma concentrations of corticosterone (52%) above those of control values. Neither androgen affected plasma concentrations of ACTH. Finally, the effects of TBA were examined in 6-week-old female rats, to characterize further the apparent age-related increase in responsiveness. The growth response of 6-week-old rats (60-74%) was intermediate between that seen in 5- and 8-week-old animals. It is concluded that part of the anabolic activity of TBA may be related to a reduction in circulating concentrations of corticosterone.(ABSTRACT TRUNCATED AT 250 WORDS)     

缬沙坦和培哚普利对大鼠肝纤维化模型肠通透性的影响

目的 观察血管紧张素受体阻滞剂缬沙坦和血管紧张素转换酶抑制剂培哚普利对四氯化碳诱导大鼠肝纤维化模型的疗效及对其肠通透性的影响。方法 将大鼠分为A组(正常对照组)、B组(模型对照组)、C组(缬沙坦治疗组)和D组(培哚普利治疗组)，于造模第4周C组开始用缬沙坦(10mg／kg)，D组开始用培哚普利(0.5mg／kg)治疗，共4周，进行肝组织及小肠组织苏木精-伊红染包，检测血浆D乳酸、DAO和内毒素浓度。结果经治疗后肝纤维化大鼠肝小叶结构趋于正常，纤维间隔变薄，血浆D-乳酸、DAO和内毒素浓度下降。结论 培哚普利和缬沙坦能有效地减轻四氯化碳诱导肝纤维化大鼠的损伤及纤维化程度，减轻肠源性内毒素血症和肠通透性增加。     

Impact of adiponectin and ghrelin on incident glucose intolerance and on weight change

Objectives Adiponectin and ghrelin are associated with adiposity and type 2 diabetes in several studies. We sought to prospectively determine the interaction of adiponectin and ghrelin in the development of adiposity and hyperglycaemia. Design Prospective observational study. Participants 393 community‐dwelling Afro‐Jamaicans (mean age 47 ± 13 years; BMI 27·3 ± 6·3 kg/m²; 63% women) without glucose intolerance at baseline. Measurements Anthropometry, fasting plasma glucose, 2‐h plasma glucose, insulin resistance (HOMA‐IR), adiponectin and ghrelin concentrations were measured at baseline and 4·1 ± 0·9 years later. Multivariate analyses were used to explore the associations of HOMA‐IR, adiponectin and ghrelin with weight change and glycaemia. Results The mean weight change was 2·6 ± 5·5 kg. There were 114 incident cases of impaired glucose tolerance (IGT) and 35 cases of diabetes mellitus. Adiponectin was positively correlated with age and female sex (P‐values < 0·01). After adjusting for age and sex, adiponectin and ghrelin were significantly correlated with weight at baseline and follow‐up. However, they were not associated with weight change even after further adjustment for baseline weight. Adiponectin, but not ghrelin, was associated with 2‐h glucose concentrations at follow‐up even after adjusting for age, sex, HOMA‐IR and BMI (P = 0·04). In the fully adjusted logistic regression model, adiponectin predicted incident IGT (OR 0·93; 95% CI: 0·87–0·99) and attenuated the effect of BMI on incident IGT. Conclusions These longitudinal data show that adiponectin and ghrelin may not be causally involved in the development of obesity. However, adiponectin is independently associated with decreased risk of incident IGT.     

潜克病人血清及尿中17种游离氨基酸含量初测

对潜在型克山病(潜克)病人血清及尿中17种氨基酸含量测定结果表明,除病人尿中丝氨酸含量明显低于正常人外,病人血清中17种氨基酸和尿中16种氨基酸含量与正常人相比无明显差异。     

高脂血症及肝脏脂肪变性调节相关因素的研究

目的探讨雌激素缺乏、高脂饮食、运动等因素对高脂血症形成及肝脏脂肪变性的调节作用。方法本实验采用C57BL/6J雌性小鼠,随机分为:正常对照组,OVX(卵巢切除后雌激素缺乏)组、OVX+高脂组、OVX+运动组、OVX+高脂+运动组,观察和分析雌激素缺乏、高脂饮食、运动等因素对小鼠血脂及相关的肝脏脂肪变性的影响。结果各组小鼠血脂水平及肝脏组织学改变的结果显示:OVX组较正常对照组血脂升高明显(P0.01),而OVX+高脂组又较OVX组血脂升高明显(P0.05),OVX+运动组较OVX组血脂降低明显(P0.05),其脂肪肝变性程度也较轻;OVX+高脂+运动组较OVX+高脂组血脂明显降低(P0.01),较OVX+运动组血脂明显升高(P0.05),OVX+高脂组、OVX+高脂+运动组小鼠脂肪肝变性程度较重。血脂水平与肝脏脂肪变性程度有相关的趋势。结论雌激素缺乏、高脂饮食增加小鼠血脂水平及加重肝细胞脂肪沉积,运动可以降低去势小鼠血脂水平及肝脏脂肪沉积。     

Preliminary observations on the effects of acute infusion of growth hormone on coronary vasculature and on myocardial function and energetics of an isolated and blood-perfused heart

Recent studies have shown that growth hormone (GH) deficiency may deteriorate post-ischemic myocardial reperfusion damage. Furthermore, GH has been reported to be a promising therapeutic option in the treatment of chronic myocardial dysfunction. However, the exact mechanisms of action of GH on the cardiovascular system, particularly in the acute setting, are still unclear. The aim of our study consisted of monitoring the acute effects of GH infusion on isolated blood-perfused rabbit heart according to dose-response pattern and during ischemic conditions to test its anti-ischemic property. Seven blood-donors perfused isolated hearts were used as experimental model. The mechanical and metabolic data of the isolated organs were continuously monitored. Under aerobic conditions, dose-response curves were initially tested after intracoronary infusion of GH at increasing dosages (1, 2, 3 mg/l). After a stabilization period, the effects of GH infusion (5 mg/kg) administered 30 minutes prior to acute global myocardial ischemia (30 minutes) were also investigated. At the doses tested, GH did not induce any changes either in the developed or in the diastolic pressures of the isolated organ. However, transient reduction of the coronary perfusion pressure was observed at the dosage of 3 mg/l. During the ischemia/reperfusion study, at the dosages used in this study, GH did not modify either the degree of stunning in the early reperfusion or the recovery of the developed pressure at the end of reperfusion. In addition, GH did not prevent either the increase of diastolic pressure during ischemia or the release of lactate and CPK during reperfusion. Tissue content of high-energy phosphates was also not changed by GH infusion. In our experimental model, acute GH infusion did not reduce the ischemic/reperfusion damage of the myocardium. However, GH transiently induced coronary vasodilation without modifying the myocardial contractility. Acute effects of GH appear, therefore, to predominantly relate to vascular dilation suggesting that the effects on myocardial contractility may require long-lasting intake being likely linked to enhancement of specific protein synthesis or gene expression of cardiac myocytes.     

Impact of COVID-19 and comorbidities on health and economics: Focus on developing countries and India

Background and aimsPresence of comorbidities in patients with Coronavirus disease 2019 (COVID-19) have often been associated with increased in-hospital complications and mortality. Intriguingly, several developed countries with a higher quality of life have relatively higher mortality with COVID-19, compared to the middle- or low-income countries. Moreover, certain ethnic groups have shown a higher predilection to contract COVID-19, with heightened mortality. We sought to review the available literature with regards to impact of COVID-19 and comorbidities on the health and economics, especially in context to the developing countries including India.MethodsA Boolean search was carried out in PubMed, MedRxiv and Google Scholar databases up till August 23, 2020 using the specific keywords, to find the prevalence of comorbidities and its outcome in patients with COVID-19.ResultsAll available evidence consistently suggests that presence of comorbidities is associated with a poor outcome in patients with COVID-19. Diabetes prevalence is highest in Indian COVID-19 patients, compared to other countries. Majority of the patients with COVID-19 are asymptomatic ranging from 26 to 76%.ConclusionsUniversal masking is the need of hour during unlock period. Low-income countries such as India, Brazil and Africa with less resources and an average socio-economic background, must adopt a strict policy for an affordable testing programs to trace, test, identify and home quarantine of asymptomatic cases. Despite the huge number of COVID-19 patients, India still has low volume research at the moment.     

Inhibitory effects of pirenzepine on cholecystokinin and secretin stimulation on exocrine and endocrine rat pancreas

Effects of pirenzepine, a newly developed anticholinergic drug, on exocrine and endocrine pancreatic functions stimulated by cholecystokinin octapeptide and secretin were studied in both isolated pancreatic acini and the isolated perfused pancreas of rats. In the isolated acini, pirenzepine did not have any significant effect on cholecystokinin-inducec amylase release but caused an inhibition of amylase secretion initiated by secretin and shifted the dose-response curve for amylase secretion to the right. In the isolated perfused pancreas stimulated with 100 pM cholecystokinin octapeptide, addition of 10 M pirenzepine before as well as after 20 min of perfusion significantly inhibited pancreatic juice flow but not enzyme output. In contrast, pirenzepine caused an inhibition of secretin-stimulated enzyme secretion, but not pancreatic juice flow. The stimulatory effect of both cholecystokinin octapeptide and secretin on insulin secretion was also inhibited by pirenzepine. The present data indicate that pirenzepine may have an influence on pancreatic exocrine and endocrine function by inhibiting endogenous cholinergic activity of the pancreas when a large dose is given.