大黄素、小檗碱对HepG2细胞胰岛素抵抗的预防作用研究

目的：研究大黄素、小檗碱对HepG2细胞产生胰岛素抵抗的预防作用及机制。方法：首先用MTT法筛选大黄素、小檗碱作用于HepG2细胞的实验浓度,然后用软脂酸诱导HepG2细胞,同时分别加入大黄素、小檗碱干预,并设正常组、对照组进行比较,通过葡萄糖氧化酶法、蒽酮法、RT-PCR法,观察大黄素、小檗碱对HepG2细胞上糖代谢及瘦素长型受体、短型受体mRNA表达水平的影响。结果：对照组成为具有胰岛素抵抗的HepG2细胞,且细胞上瘦素长型及短型受体mRNA的表达水平较正常纽显著下降（P〈0．01）;而大黄素、小檗碱组培养液中葡萄糖含量、细胞内糖原含量以及细胞上瘦素长型及短型受体mRNA的表达水平较正常组无明显改变（P〉0．05）。结论：大黄素、小檗碱均能预防HepG2细胞产生胰岛素抵抗,这一作用与它们影响HepG2细胞上糖代谢及瘦素受体mRNA表达水平有关。     

Association between Excessive Dietary Branched-Chain Amino Acids Intake and Hypertension Risk in Chinese Population

The dietary intake of branched-chain amino acids (BCAAs) has been reported to be associated with both elevated blood pressure (BP) and hypertension risk, while published findings were inconsistent, and the causality has never been well disclosed. We performed this prospective study aiming to find out the relationship between dietary BCAAs intake and hypertension risk in the Chinese population. A total of 8491 participants (40,285 person-years) were selected. The levels of dietary BCAAs intake were estimated using the 24-h Food Frequency Questionnaire. Associations of both BP values and hypertension risk with per standard deviation increase of BCAAs were estimated using linear and COX regression analysis, respectively. The hazard ratios and 95% confidence interval were given. Restricted cubic spline analysis (RCS) was used to estimate the nonlinearity. Both systolic and diastolic BP values at the end points of follow-up were positively associated with dietary BCAAs intake. Positive associations between BCAAs intake and hypertension risk were shown in both men and women. By performing a RCS analysis, the nonlinear relationship between BCAAs intake and hypertension was shown. As the intake levels of Ile, Leu, and Val, respectively, exceeded 2.49 g/day, 4.91 g/day, and 2.88 g/day in men (2.16 g/day, 3.84 g/day, and 2.56 g/day in women), the hypertension risk increased. Our findings could provide some concrete evidence in the primary prevention of hypertension based on dietary interventions.     

Essential Amino Acids-Rich Diet Decreased Adipose Tissue Storage in Adult Mice: A Preliminary Histopathological Study

Background: Excess body adipose tissue accumulation is a common and growing health problem caused by an unbalanced diet and/or junk food. Although the effects of dietary fat and glucose on lipid metabolism regulation are well known, those of essential amino acids (EAAs) have been poorly investigated. Our aim was to study the influence of a special diet containing all EAAs on retroperitoneal white adipose tissue (rpWAT) and interscapular brown adipose tissue (BAT) of mice. Methods: Two groups of male Balb/C mice were used. The first was fed with a standard diet. The second was fed with an EAAs-rich diet (EAARD). After 3 weeks, rpWAT and BAT were removed and prepared for subsequent immunohistochemical analysis. Results: EAARD, although consumed significantly less, moderately reduced body weight and BAT, but caused a massive reduction in rpWAT. Conversely, the triceps muscle increased in mass. In rpWAT, the size of adipocytes was very small, with increases in leptin, adiponectin and IL-6 immunostaining. In BAT, there was a reduction in lipid droplet size and a simultaneous increase in UCP-1 and SIRT-3. Conclusions: A diet containing a balanced mixture of free EAA may modulate body adiposity in mice, promoting increased thermogenesis.     

Tris(2-butoxyethyl)phosphate and triethyl phosphate alter embryonic development,hepatic mRNA expression,thyroid hormone levels,and circulating bile acid concentrations in chicken embryos

The organophosphate flame retardants tris(2-butoxyethyl) phosphate (TBOEP) and triethyl phosphate (TEP) are used in a wide range of applications to suppress or delay the ignition and spread of fire. Both compounds have been detected in the environment and TBOEP was recently measured in free-living avian species. In this study, TBOEP and TEP were injected into the air cell of chicken embryos at concentrations ranging from 0 to 45,400 ng/g and 0 to 241,500 ng/g egg, respectively. Pipping success, development, hepatic mRNA expression of 9 target genes, thyroid hormone levels, and circulating bile acid concentrations were determined. Exposure to the highest doses of TBOEP and TEP resulted in negligible detection of the parent compounds in embryonic contents at pipping indicating their complete metabolic degradation. TBOEP exposure had limited effects on chicken embryos, with the exception of hepatic CYP3A37 mRNA induction. TEP exposure decreased pipping success to 68%, altered growth, increased liver somatic index (LSI) and plasma bile acids, and modulated genes associated with xenobiotic and lipid metabolism and the thyroid hormone pathway. Plasma thyroxine levels were decreased at all TEP doses, including an environmentally-relevant concentration (8 ng/g), and gallbladder hypotrophy was evident at ≥ 43,200 ng/g. Tarsus length and circulating thyroxine concentration emerged as potential phenotypic anchors for the modulation of transthyretin mRNA. The increase in plasma bile acids and LSI, gallbladder hypotrophy, and discoloration of liver tissue represented potential phenotypic outcomes associated with modulation of hepatic genes involved with xenobiotic and lipid metabolism.     

选择性保护合成2-〔4(S)-4-酰氨基-3-氧代-2-异噁唑烷基〕-5-氧代-2-四氢呋喃甲酸类化合物及其体外抑菌活性

采用两种新选择性保护方法由L-丝氨酸和α-酮戊二酸为原料经几步合成了8个目标化合物。体外抑菌该验表明除TMV外,对金葡球菌209P和大肠杆菌44822具有中等到强的活性。     

Dietary Fibre and Organic Acids in Kiwifruit Suppress Glycaemic Response Equally by Delaying Absorption—A Randomised Crossover Human Trial with Parallel Analysis of 13C-Acetate Uptake

Non-sugar components of kiwifruit reduce the amplitude of the glycaemic response to co-consumed cereal starch. We determined the relative contribution of different non-sugar kiwifruit components to this anti-glycaemic effect. Healthy participants (n = 9) ingested equal carbohydrate meals containing 20 g starch as wheat biscuit (WB, 30 g), and the sugar equivalent of two kiwifruit (KFsug, 20.4 g), either intrinsic or added as glucose, fructose and sucrose (2:2:1). The meals were WB+KFsug (control, no non-sugar kiwifruit components), WB + whole kiwifruit pulp (WB+KF), WB + neutralised kiwifruit pulp (WB+KFneut), WB + low-fibre kiwifruit juice (WB+KFjuice) and WB+KFsug + kiwifruit organic acids (WB+KFsug+OA). All meals were spiked with 100 mg sodium [1-¹³C] acetate to measure intestinal absorption. Each participant ingested all meals in random order. Blood glucose and breath ¹³CO₂ were measured at ingestion and at 15 min intervals up to 180 min. Compared with WB+KFsug, whole kiwifruit pulp (WB+KF) almost halved glycaemic response amplitude (p < 0.001), reduced incremental area under the blood glucose response curve (iAUC) at 30 min (peak) by 50% (p < 0.001), and averted late postprandial hypoglycaemia. All other treatments suppressed response amplitude half as much as whole kiwifruit and averted acute hypoglycaemia, with little effect on iAUC. Effects on ¹³CO₂ exhalation paralleled effects on blood glucose (R² = 0.97). Dietary fibre and organic acids contributed equally to the anti-glycaemic effect of kiwifruit by reducing intestinal absorption rate. Kiwifruit flesh effectively attenuates glycaemic response in carbohydrate exchange, as it contains fructose, dietary fibre and organic acids.     

Indexing of Fatty Acids in Poultry Meat for Its Characterization in Healthy Human Nutrition: A Comprehensive Application of the Scientific Literature and New Proposals

Chicken meat is becoming the most consumed in the world for both economic and nutritional reasons; regarding the latter, the lipid profile may play positive or negative roles in the prevention and treatment of diseases. In this study, we define the state of the art of lipid-based nutritional indexes and used the lipid content and fatty acid profile (both qualitative and quantitative) of breast meat of two poultry genotypes with different growth rates and meat traits. Further, we summarize and review the definitions, implications, and applications of nutritional indexes used in recent years and others of our own design to provide a useful tool to researchers working in the field of meat quality (not only in poultry) to select the most appropriate index for their own scientific purposes. All indexes show advantages and disadvantages; hence, a rational choice should be applied to consider the nutritional effect of meat on human health and for a possible assessment of the most suitable rearing systems (genotype, feeding, farming system or postmortem handling).     

病毒性脑炎患者BDVp24、p40基因片段的核酸检测

目的分别检测病毒性脑炎患者脑脊液有核细胞（CSFMCs）中博尔纳病病毒（BDV）p24、p40基因片段,探讨病毒性脑炎患者与BDV感染的关系及阳性患者的临床特征。方法用荧光定量巢式逆转录聚合酶链反应（FQ—nRT—PCR）方法检测病毒性脑炎患者及对照者CSFMCs中BDVp24、p40基因片段,将两个保守区p24和p40检测均为阳性的标本再做进一步分析,并总结阳性患者的临床特征,同时用β-肌动蛋白（B—actin）作为内参照。结果实验组102例病毒性脑炎患者CSFMCs中BDVp24基因片段检测中有11例阳性,BDVp40基因片段检测中有10例阳性,两个保守区p24和p40检测均为阳性标本10例,对照组84例中均为阴性,两者比较阳性率差异有统计学意义（P〈0．05）。阳性基因片段产物测序后与BDV标准病毒株V和马源的BDV病毒株H1766序列比较,同源性分别为96．35％和98．85％,在4个位点出现基因突变（nt1649T→C,nt1656G→A,nt1670C→T,nt1676C→T）;8例阳性患者主要以精神行为异常为起病方式,患者与动物关系密切,其他临床特征无特殊。结论病毒性脑炎的发生与BDV感染有关,主要以精神行为异常为临床特征。     

妊娠期糖尿病营养治疗进展

妊娠期糖尿病(GDM)营养治疗主要通过评估患者个人情况后制订合适的能量摄入计划,如限制糖类的摄入量,通过血糖指数/血糖负荷理论配合食品交换份法来搭配食物。科学搭配膳食三大营养素可为孕妇提供最佳的营养,促进适当的孕期体质量增加,达到理想的血糖控制水平,为胎儿正常生长发育提供足够的能量。该文就GDM营养治疗的基本治疗和最新进展进行综述。