Wheat leaf lipids during heat stress: I. High day and night temperatures result in major lipid alterations

Understanding how wheat (Triticum aestivum L.) plants under high temperature (HT) regulate lipid composition is critical to developing climate‐resilient varieties. We measured 165 glycerolipids and sterol derivatives under optimum and high day and night temperatures in wheat leaves using electrospray ionization‐tandem mass spectrometry. Levels of polar lipid fatty acyl chain unsaturation were lower in both heat‐tolerant genotype Ventnor and susceptible genotype Karl 92 under HT, compared with optimum temperature. The lower unsaturation was predominantly because of lower levels of 18:3 acyl chains and higher levels of 18:1 and 16:0 acyl chains. Levels of 18:3‐containing triacylglycerols increased threefold/more under HT, consistent with their possible role in sequestering fatty acids during membrane lipid remodelling. Phospholipids containing odd‐numbered or oxidized acyl chains accumulated in leaves under HT. Sterol glycosides (SG) and 16:0‐acylated sterol glycosides (ASG) were higher under HT than optimum temperatures. Ventnor had lower amounts of phospholipids with oxidized acyl chains under HT and higher amounts of SG and 16:0‐ASG than Karl 92. Taken together, the data demonstrate that wheat leaf lipid composition is altered by HT, in which some lipids are particularly responsive to HT, and that two wheat genotypes, chosen for their differing physiological responses to HT, differ in lipid profile under HT.     

靶控输注依托咪脂在老年患者颌面外科手术中的应用效果

目的:研究靶控输注依托咪脂在老年患者颌面外科手术中的应用效果。方法:选择60例美国麻醉医师协会(ASA)分级I～II级行颌面外科手术的患者,并将其随机分为靶控输注丙泊酚组(P组,n=30)和靶控输注依托咪酯组(E组,n=30),记录麻醉诱导前、气管插管前、气管插管后5 min、手术开始时、停药时的有创收缩压、有创舒张压、心率,并记录手术时间、拔管时间、麻醉维持时依托咪酯和丙泊酚的靶控输注浓度。结果:P组气管插管前、气管插管后5 min、手术开始时、停药时血压均低于麻醉诱导前,且低于E组各对应时间点,差异均具有统计学意义(P0.05),P组气管插管前心率显著低于麻醉诱导前和E组(P0.05);E组气管插管前、气管插管后5 min和手术开始时血压均低于麻醉诱导前(P0.05),但各时间点心率无显著变化(P0.05)。P组靶控浓度为(1.95±0.54)μg/m L～(4.48±0.61)μg/mL,E组靶控浓度为(0.20±0.05)μg/mL～(0.51±0.05)μg/mL。两组药物拔管时间、术后恶心呕吐和躁动发生率差异无统计学意义(P0.05),但P组低血压发生率显著高于E组(P0.05)。结论:在颌面外科手术中,靶控输注依托咪脂,能有效减少麻醉诱导和维持中低血压发生,维持血流动力学稳定,对于老年患者而言,是一种比丙泊酚更为安全可靠的静脉麻醉药。     

Post-ruminal or intravenous infusions of carbohydrates or amino acids to dairy cows 2. Late lactation

The objectives of this study were to compare the effects of post-ruminal and intravenous infusions of wheat starch or glucose (CHO) or a mixture of amino acids (AA) on milk protein yield, nitrogen (N) utilisation, plasma metabolites and mammary extraction rate of dairy cows in late lactation. Eight cow, ruminally fistulated, was assigned to two 4 × 4 Latin squares during 14-day periods, where the last 7 days were for infusions. Infusions were: (1) starch in the abomasum (SP), (2) glucose in the blood (GB), (3) AA in the abomasum (AP), and (4) AA in the blood (AB). The experiment started 165 ± 4 days (mean ± s.e.) post partum (milk yield 22.5 ± 1.1 kg) Daily amounts of nutrients infused were 257, 283, 233, and 260 g for SP, GB, AP and AB, respectively. The cows were fed a basal diet consisting of a concentrate mixture and grass silage (55:45 on a dry-matter (DM) basis), where total dry-matter intake (DMI) was 13.3 kg/day. Milk production was affected by site of infusion within substrate, whereas infusion substrates within infusion site (CHO or AA) were of minor importance. Responses to intravenous infusions (GB or AB) were similar to those in early lactation, but more pronounced. Compared with SP infusion, GB infusion increased ( P < 0.05) milk yield, energy-corrected milk (ECM), protein and lactose yield by 1.4 and 0.9 kg, 38 and 59 g, respectively. The AB infusion had 1.4 and 1.3 kg, 51, 52 and 50 g higher ( P < 0.05) milk yield, ECM, protein, fat and lactose yields than the AP infusion, respectively. N balance data indicated higher losses of metabolic faecal nitrogen (MFN) by abomasal than by intravenous infusions, but the catabolism of AA was lower than in early lactation indicated by no difference ( P < 0.05) in urinary N excretion between treatments. Intravenous AA infusion increased plasma glucose and insulin above that of intravenous glucose infusion. The treatment effects on plasma insulin concentrations were higher in late than in early lactation, suggesting a higher sensitivity in late lactation even at similar negative energy balance. Compared with the SP infusion, GB infusion showed lower ( P < 0.05) concentrations of essential AA (EAA) and branched-chain AA (BCAA) resulting in a higher AA utilisation because of a higher milk protein production. AP infusion increased ( P < 0.05) plasma non-essential AA concentration compared with AB infusion, but infusion site of AA had no effect ( P>0.05) on plasma EAA or BCAA. It is concluded that it is the nutrient supply and not the lactation stage per se that is important for the response in milk production. Nevertheless, stage of lactation affects the N metabolism and the response in plasma hormone concentrations even when cows are in negative energy balance in both lactation stages.     

Continuous infusion of cholecystokinin and meal pattern in the rat

Purified natural cholecystokinin (CCK-33) was infused continuously for two days at a rate of 5.9 μg/hr in two rats trained to bar-press for food (Noyes pellet 45 mg) on a fixed ratio of five bar presses to obtain one pellet. The animals also received control surgery and were tested in the operant chamber for two days, one prior to and the other following the CCK-33 treatment. CCK-33 suppressed the number of meals, the total amount of food eaten, and the total duration of time spent eating. However, the size of each meal and the rate of intake were not affected. The CCK effect did not interact with the light-dark phases of diurnal cycle. It appears that a major effect of continuous systemic elevation of CCK-33 is to reduce food intake by prolonging the satiety period rather than by decreasing the individual meal size.     

Resistance to IP leptin-induced adipose apoptosis caused by high-fat diet in mice

The objectives of this experiment were to determine whether leptin causes adipocyte apoptosis in mice, whether peripheral administration is an effective means of studying leptin-induced adipocyte apoptosis, and whether high-fat feeding results in reduced responsiveness to leptin-induced adipocyte apoptosis. Continuous 13-day intraperitoneal infusion of 10 microg/day leptin significantly increased adipocyte apoptosis in the epididymal/parametrial fat pads of male and female mice, but only male mice developed reduced responsiveness to leptin-induced adipocyte apoptosis after high-fat (45% fat) feeding for 5 or 15 weeks. There was a positive correlation between serum leptin concentration and percent apoptotic adipocytes. These findings demonstrate that leptin administered peripherally is effective in inducing adipocyte apoptosis in mice, thus extending the possibility of studying this effect of leptin in a wider variety of animal models. In addition, high-fat feeding has a gender-specific effect on development of reduced responsiveness to leptin-induced adipocyte apoptosis.     

Stereotaxic Infusion of Oligomeric Amyloid-beta into the Mouse Hippocampus

Alzheimer’s disease is a neurodegenerative disease affecting the aging population. A key neuropathological feature of the disease is the over-production of amyloid-beta and the deposition of amyloid-beta plaques in brain regions of the afflicted individuals. Throughout the years scientists have generated numerous Alzheimer’s disease mouse models that attempt to replicate the amyloid-beta pathology. Unfortunately, the mouse models only selectively mimic the disease features. Neuronal death, a prominent effect in the brains of Alzheimer’s disease patients, is noticeably lacking in these mice. Hence, we and others have employed a method of directly infusing soluble oligomeric species of amyloid-beta - forms of amyloid-beta that have been proven to be most toxic to neurons - stereotaxically into the brain. In this report we utilize male C57BL/6J mice to document this surgical technique of increasing amyloid-beta levels in a select brain region. The infusion target is the dentate gyrus of the hippocampus because this brain structure, along with the basal forebrain that is connected by the cholinergic circuit, represents one of the areas of degeneration in the disease. The results of elevating amyloid-beta in the dentate gyrus via stereotaxic infusion reveal increases in neuron loss in the dentate gyrus within 1 week, while there is a concomitant increase in cell death and cholinergic neuron loss in the vertical limb of the diagonal band of Broca of the basal forebrain. These effects are observed up to 2 weeks. Our data suggests that the current amyloid-beta infusion model provides an alternative mouse model to address region specific neuron death in a short-term basis. The advantage of this model is that amyloid-beta can be elevated in a spatial and temporal manner.     

肝炎治疗药苦参碱葡萄糖注射液的研制

为研制供临床直接使用的大容量苦参碱葡萄糖注射液,采用苦参碱浓配,葡萄糖先浓配除热原、后稀配混合苦参碱溶液、精滤、灌封、灭菌等制得苦参碱葡萄糖注射液,并建立质量标准。结果表明：试制3批样品均符合质量标准要求,稳定性考察未见明显变化。研制的苦参碱葡萄糖注射液处方及工艺合理可行、质量标准可控、稳定性良好。     

氰戊菊酯在茶叶和茶汤中的残留动态及最大残留限量评价

在生长均匀的茶园喷施氰戊菊酯(fenvalerate),采摘施药后2 h和1 h、2 h、3 h、5 h、7 h、9 h、14 h、21天的茶树鲜叶加工成绿茶,用气相色谱法测定成茶、茶汤和茶渣中反式氰戊菊酯和顺式氰戊菊酯的含量,研究了氰戊菊酯在成茶、茶汤中的残留动态。结果表明:反式氰戊菊酯和顺式氰戊菊酯在成茶中的残留水平随施药间隔天数的增加呈下降趋势,20 mL/667 m2施药剂量下,分别由施药当天2 h的9.40 mg/kg和17.51 mg/kg减小到第21天的1.07 mg/kg和1.53 mg/kg,消解幅度为88.62%和91.26%,40 mL/667 m2施药剂量下,分别由施药当天2 h的20.37 mg/kg和38.67 mg/kg减小到第21天的1.94 mg/kg和3.06 mg/kg,消解幅度为90.49%和92.09%。茶汤中氰戊菊酯含量(y)与成茶中氰戊菊酯含量(x)呈二项式函数关系,反式氰戊菊酯的函数关系为y=-0.0007x2 0.0242x,顺式氰戊菊酯的函数关系为y=-0.0002x2 0.0114x。按我国标准饮茶摄入的氰戊菊酯占每日允许摄入量的0.049%,足以达到保护人体健康水平的要求。而按欧盟的标准,饮茶摄入的氰戊菊酯占每日允许摄入量的0.0019%,即在10-5水平上,这样的风险水平已接近对非阈效应化学物质的风险控制水平(10-6)。