Dogs lacking Apolipoprotein E show advanced atherosclerosis leading to apparent clinical complications

Science China Life Sciences - Atherosclerotic cardiovascular disease resulting from dysregulated lipid metabolism is the leading cause of morbidity and mortality worldwide. Apolipoprotein E (ApoE)...     

Seasonal variations of changes in lipid and glucidic variables after bariatric surgery

Seasonality is a phenomenon that is characterized by changes over the year in sleep, mood, behaviour, appetite and body weight. In humans, seasonal variations have been found in certain variables, such as lipid variables and body mass index. We hypothesize that this rhythm could influence the expected variation of the levels of biochemical variables in cases of body weight loss. Thus, the goal of this study was to observe whether the time of year in which bariatric surgery (BS) took place modulated the changes in several variables related to glucidic and lipid metabolism. Blood samples were obtained from 24 women and 10 men before BS and 1 and 3 months after BS. We calculated the percentage of variation that occurred for each individual and for each variable as a function of the time of the year. Data were adjusted to a 12-month period sinusoidal curve, with significance being set at p < 0.05. The results showed that almost all of the studied variables changed due to the BS according to a seasonal rhythm. Most of the variables showed a decrease that was most prominent in winter. In the cases of body mass index (BMI), adrenocorticotropin hormone (ACTH), and cortisol, the highest variation occurred in winter. Insulin and cholesterol in high-density lipoproteins (cHLD) variations were higher in springtime. Glucose variation showed a decrease after surgery with acrophase in summer-fall and plasminogen activator inhibitor-1 (PAI-1) and homeostatic model assessment-insulin resistance (HOMA-IR) in spring-summer. Ghrelin levels showed increases with a rhythm of variation with an acrophase in summer-fall. The seasonal rhythm found in this study fits nearly with the inverse of the endogenous circannual rhythm of the variables studied. The time of the year when the highest variation takes place is related to the circannual rhythm of the variable. The results agree with the manifestation of seasonal rhythm in human biochemical variables, which are reflected in the responses to weight loss after BS.     

龙脑香热带雨林附生苔藓沿宿主垂直梯度的微生境偏好及其指示作用

该研究首次借助林冠塔吊调查了西双版纳国家级自然保护区龙脑香热带雨林样地内69棵树13个垂直高度上的附生苔藓植物,结果表明:目标样树上共记录到隶属于25科60属的90种附生苔藓,其中细鳞苔科物种数最多,占比达25.6%。13个垂直高度上共划分出三种生态类型:喜阳苔藓(散生巨树上45 m的区域),喜阴苔藓(乔木树干上15 m的区域),广布苔藓(广泛分布于宿主各个垂直高度上,生态位宽),并筛选出对微生境有特殊偏好的17种苔藓指示种(IndVal≥0.7,P0.05)。随宿主垂直高度的升高,扇型和交织型的苔藓占比降低,悬垂型苔藓占比先升高后降低,细平铺型和粗平铺型的苔藓占比升高。大气湿度、水汽压、胸径以及树皮粗糙度对附生苔藓生活型的分布偏好具有显著影响。总之,沿宿主垂直高度上的附生苔藓对微环境变化在生活型和形态结构上有着不同的响应方式,而同一种生态型的苔藓群落有相似的适应机制。因此,在森林林冠生境变化的监测和管理中,对微生境具有明显偏好的附生苔藓物种可作为有效的指示材料。     

3D-QSAR based optimization of insect neuropeptide allatostatin analogs

Allatostatins (AST) are neuropeptides originally described as inhibitors of juvenile hormone (JH) synthesis in insects. Consequently, they have been considered as potential lead compounds for the discovery of new insect growth regulators (IGRs). In the present work, receptor-based three-dimensional quantitative structure-activity relationship (3D-QSAR) was studied with 48 AST analogs, and a general approach for novel potent bioactive AST analogs is proposed. Hence, six novel AST analogs were designed and synthesized. Bioassays indicated that the majority novel analogs exhibited potent JH inhibitory activity, especially analog A6 (IC₅₀: 3.79?nmol/L), which can be used as lead compound to develop new IGRs.     

基于AFM单细胞力谱技术的淋巴瘤细胞黏附力测量

细胞黏附在细胞生理功能中起着重要的调控作用,对细胞黏附行为进行定量研究有助于理解生命活动内在机制.原子力显微镜（AFM）的出现为研究溶液环境下微纳尺度生物系统的生物物理特性提供了强大工具,特别是AFM单细胞力谱（SCFS）技术可以对单细胞黏附力进行测量.但目前利用SCFS技术进行的研究主要集中在贴壁细胞,对于动物悬浮细胞黏附行为进行的研究还较为缺乏.本文利用AFM单细胞力谱技术（SCFS）对淋巴瘤细胞黏附行为进行了定量测量.研究了淋巴瘤细胞与其单克隆抗体药物利妥昔（利妥昔单抗与淋巴瘤细胞表面的CD20结合后激活免疫攻击）之间的黏附力,分析了利妥昔浓度及SCFS测量参数对黏附力的影响,并对淋巴瘤细胞之间的黏附力进行了测量.实验结果证明了SCFS技术探测动物悬浮细胞黏附行为的能力,加深了对淋巴瘤细胞黏附作用的认识,为单细胞尺度下生物力学探测提供了新的可能.     

Will Pollution Taxes Improve Joint Ecological and Economic Efficiency of Thermal Power Industry in China?: A DEA‐Based Materials Balance Approach

Previous studies of the efficiency of Chinese electricity industry have been limited in providing insights regarding policy implications of inherent trade‐offs of economic and environmental outcomes. This study proposes a modified data envelopment analysis method combined with materials balance principle to estimate ecological and cost efficiency in the Chinese electricity industry. The economic cost and ecological impact of energy input reallocation strategies for improving efficiency are identified. The possible impacts of pollution taxes upon the levels of sulfur dioxide (SO₂) emissions are assessed. Estimation results show that (1) both energy input costs and SO₂ could be reduced through increasing technical efficiency. (2) It is possible to adjust energy input mix to attain ecological efficiency, and, correspondingly, SO₂ would be reduced by 15%. (3) The Chinese electricity industry would reduce its unit cost by 9% if optimal ecological efficiency is attained and reduce its unit pollution by 13% if optimal cost efficiency is attained, implying that there are positive ecological synergy effects associated with energy cost savings and positive economic synergy effects associated with SO₂ pollution reductions. (4) Estimated shadow costs of SO₂ reduction are very high, suggesting that, in the short term, the Chinese electricity industry should pursue cost efficiency instead of ecological efficiency, since alternative abatement activities are less costly and some of the abatement cost could be further offset by energy input cost savings. (5) There would be no significant difference between the impacts of pollution discharge fees and pollution taxes on SO₂ emissions levels because of the relatively low pollution tax rate.     

The effects of cold acclimation and nitric oxide on antioxidative enzymes in rat pancreas

Alterations of pancreatic antioxidative defense (AD) and possible nitric oxide (NO) role in AD organization of adult rats receiving l-arginine.HCl (2.25%) or N(omega)-nitro-l-arginine methyl ester (L-NAME.HCl, 0.01%) as drinking liquids and maintained at room (22+/-1 degrees C) or low (4+/-1 degrees C) temperature for 45 days were studied. For that purpose, copper, zinc- and manganese superoxide dismutase (CuZnSOD, MnSOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione S-transferase (GST) and glutathione reductase (GR) activities were determined. Cold-induced decrease of CuZnSOD was inhibited with L-NAME, while l-arginine produced the same effect as cold in both supplemented groups. Cold acclimation elevated GSH-Px activity. l-Arginine and L-NAME expressed no effect on GSH-Px in rats kept at room temperature. L-NAME additionally elevated cold-induced GSH-Px activity, l-arginine expressing a similar trend. Cold-induced increase in GST activity was inhibited by L-NAME, while l-arginine inhibited this enzyme in both supplemented groups. Cold acclimation increased GR activity in control and L-NAME-treated group and l-arginine expressed a similar trend. Neither of the treatments affected MnSOD and CAT activities. Cold-induced changes of pancreatic AD were additionally affected by the alterations in l-arginine-NO-producing pathway. Some AD changes in the same direction with l-arginine or L-NAME point to the complexity of nitrogen compounds metabolism and function, accompanied by tissue-specific response.