极低体质量近存活期分娩儿一例的出生后早期管理

近存活期分娩（PVB）儿各组织系统发育极不成熟,易发生各种器官功能损害和并发症,预后常不佳。目前关于PVB儿出生后早期管理的报道不多,诸多尚待解决的问题仍是围产医学所面临的挑战。经有效的新生儿复苏和呼吸循环支持、积极的营养支持和喂养、防治感染、内分泌和代谢性疾病管理、积极处理早产儿相关并发症,以及发育支持护理、家庭参与式护理等一系列个体化管理和精细化护理,四川省医学科学院·四川省人民医院成功救治了1例胎龄23周,出生体质量（BW）为450 g的PVB儿。本文通过总结1例PVB儿的出生后早期管理,并结合文献复习进行归纳总结,以期为提高BW<500 g的PVB儿存活率并获得良好预后提供经验及借鉴。     

针灸治疗慢性非特异性腰痛随机对照试验结局指标的现状研究

背景 针灸是治疗慢性非特异性腰痛(CNSLBP)的重要方法。随着研究的发展,大量针灸治疗CNSLBP的随机对照试验(RCT)已经发表,但由于在结局指标选择方面存在一定的问题,严重限制了高质量临床证据的产生。目的 评价针灸治疗CNSLBP RCT选用的结局指标情况,为针灸治疗CNSLBP相关研究提供参考依据。方法 系统检索4个中文数据库(中国知网、维普网、万方数据知识服务平台、中国生物医学文献服务系统)、3个英文数据库(PubMed、Embase、Cochrane Library)2017-01-01至2022-03-15发布的针灸治疗CNSLBP的文献,以及自建库以来至2022-03-15发表的非特异性腰痛(NSLBP)的核心结局指标集(COS)。对纳入的针灸治疗CNSLBP的文献基本特征进行分析,对文献的临床结局指标进行归类,对文献中的结局指标及《中医病证诊断疗效标准》的应用现状进行分析。分析NSLBP研究的COS现状,比较其与现有针灸治疗CNSLBP文献结局指标的异同。结果 本研究纳入的针灸治疗CNSLBP的49篇文献均为RCT,共包含4篇英文文献和45篇中文文献。共包含4 272...     

Central and peripheral contributions to control of heart rate during heat acclimation

The contributions of the autonomic nervous system and the cardiac pacing cells in the development of heat-acclimation-induced bradycardia were analyzed, and the effect of heat acclimation on the chronotropic response of the heart to heat stress (40° C) was studied. Rats were acclimated at 34° C for 0, 5, 14, 30 and 60 days. Heart rate (HR) was measured in conscious animals, using chronic subcutaneous electrodes. Sympathetic and parasympathetic influences were studied by IP administration of 0.1 and 1 mg/100 g body weight atropine and propranolol respectively, while intrinsic HR (HR_i) was measured following administration of both drugs simultaneously. The effects of carbamylcholine and norepinephrine on the beating rate of isolated rat atria were investigated to study pacemaker responsiveness to neutrotransmitters. Up to day 14 of heat acclimation, bradycardia was attained by tonic parasympathetic acceleration (18%) and temporal sympathetic withdrawal (0.8% on day 14), to compensate for the gradually augmented HR_i (2.5% and 8% on days 5 and 14, respectively). Following long-term acclimation HR_i declined below pre-acclimation rate. This was associated with resumed sympathetic activity (16% and 10% on days 30 and 60 respectively) while parasympathetic activity continued to be high (18%). Tachycardia, known to occur with severe uncontrolled body hyperthermia, was attenuated following heat acclimation by 42%. It was concluded that during the initial phase of heat acclimation bradycardia is achieved primarily by changes in autonomic influences, while following long-term acclimation, changes in the intrinsic properties of the pacing cells (HR_i) and the autonomic system both play a role.     

Selection for high and low mating propensity inDrosophila ananassae

InDrosophila ananassae, artificial selection was carried out for high and low mating propensity for 15 generations. Response to selection was from about F₅, with rapid divergence in mating frequencies in replicates of both fast and slow lines. To assess the effect of selection on the two sexes, females and males of the selected lines were tested against their respective counterparts of the control line after 15 generations. Significant differences in mating propensity were observed when selected males were tested against the control females, which suggests that males were much more affected by selection than females. After 15 generations the fast and slow lines (both replicates) were crossedinter se and mating frequencies of F₁ hybrids were studied in the same way as during the selection experiment. F₁ flies had a higher mating activity compared to their parental lines when males were derived from fast lines to produce hybrids. On the other hand, F₁ hybrids produced by crossing slow-line males with fast-line females showed mating frequencies similar to those of the slow parental lines. These findings suggest that mating propensity inD. ananassae is under the control of polygenes. Furthermore, the significant differences in mating propensity of hybrids produced by the fast and slow males indicate the possibility of a Y-linked influence on mating propensity inD. ananassae.The present investigation was carried out during the tenure of a senior research fellowship of the CSIR, New delhi, to S.C.     

Fluid Flow through Filtering Appendages of Insects

Many organisms use structures composed of arrays of cylindersto capture particulate food or molecules form the water or airaround them. The performance of such filters depends on thevelocity of fluid movement through them; hence, mathematicalmodels of flow through fibrous structures can provide insightsabout the functional morphology of biological filters. In thispaper, the authors address the case of feather-like biologicalfilters of finite width and assess several possible models forfluid motion through them by comparing model predictions withobservational data. Two examples of insect appendages are considered:the cephalic fans of black fly aquatic larvae that capture particulatefood and the antennae of adult male moths that catch sex-attractantmolecules released by female moths. The results suggest thatflow through such structures can be much slower than ambientcurrents, that the finest hairs in the structure are the morphologicalfeatures with the greatest effect on leakiness, and that thevelocity of movement (or of ambient flow), as well as the morphologyof such filters, can be critical in determining their performance.     

磷酸盐型低密度脂蛋白亲和吸附剂制备与体外吸附试验研究

研究目的是制备低密度脂蛋白亲和吸附剂,用于去除高脂血症患者血液中高含量的低密度脂蛋白。首先以悬浮分散法制备壳聚糖微球和纤维素微球载体,然后固定磷酸吡哆醛和磷酸盐配基,制备出三种吸附剂,并进行体外静态吸附性能测试。结果表明,壳聚糖-磷酸吡哆醛吸附剂对LDL最大吸附量为1.30mg/mL,磷酸盐型壳聚糖和纤维素吸附剂对LDL的最大吸附量分别为2.72mg/mL和3.12mg/mL,并且吸附量随配基含量的增加呈增大趋势,3种吸附剂对高密度脂蛋白均无明显吸附。对吸附剂的灭菌和储存稳定性的研究表明,磷酸盐型纤维素吸附剂具有较好的稳定性。本研究第一次报道磷酸盐型低密度脂蛋白吸附剂。     

凋亡抑制蛋白XIAP和促凋亡因子Smac在胰腺癌化疗抵抗中的作用

目的探讨x-相关凋亡抑制蛋白（XIAP）和促凋亡因子Smac在胰腺癌细胞化疗抵抗中的作用，以及转染胞浆表达型Smac基因靶向下凋XIAP对化疗药物诱导的胰腺癌细胞凋亡的影响。方法应用流式细胞术检测顺铂、5-FU介导的Panc-1、BXPC-3的凋亡率及胞浆染色分析细胞XIAP表达变化，Western blot分析XIAP、Smac、Caspase-3表达水平；构建pEGFP-NI／Smac真核表达载体并转染胰腺癌Panc-1细胞，流式细胞术检测转染Smac基因前后Panc-1细胞的凋亡敏感性。结果与BXPC-3细胞相比，Panc-1对顺铂或5-FU介导的凋亡具有较强抵抗性，Western blot分析显示Panc-1细胞高表达XIAP，在化疗药物作用下化疗敏感细胞BXPC-3胞浆内XIAP水平下降明显多于Panc-1细胞，而且凋亡的BXPC-3细胞释放入胞浆内的成熟Smac蛋白水平明显高于Panc-1细胞。转染胞浆表达型Smac基因至化疗抵抗Panc-1细胞，可明显下调其XIAP表达水平，促进效应Caspase-3分子活化，显著提高顺铂、5-FU诱导的细胞凋亡率。结论胰腺癌细胞XIAP的表达水平下调与其化疗敏感性有关，XIAP是克服化疗抵抗的重要靶分子，而上调Smac活性蛋白的胞浆表达作为一种有效调节信号，通过拮抗XIAP的凋亡抑制作用协同化疗药物促进胰腺癌细胞凋亡。     

Lp(a) lipoprotein is a major risk factor for cardiovascular disease: pathogenic mechanisms and clinical significance

The results of two previous and two recent studies of middle-aged males and females are presented to exemplify the clinical importance of lipoprotein (a) (Lp(a)) as a risk factor for atherosclerosis and coronary heart disease. In these studies various conventional and recently suggested risk factors were included and different methods for Lp(a) quantification were used. Lp(a) was a significant risk factor in all four studies. In the recent prospective case-control study, Lp(a) and cholesterol were found to act synergistically and predict primary acute myocardial infarction in Swedish males. A cholesterol level above 6.5 mmol/1 increased the risk of acute myocardial infarction if the Lp(a) level was above 200 mg/1. The plasma apo A-I level was a protective factor. In the other recent case-control study, an Lp(a) level above 500 mg/1 was a highly significant risk factor in Black and White US women with myocardial infarction or advanced coronary artery disease in addition to low density lipoprotein cholesterol levels above 130 mg/dl. A high apo A-I level was a protective factor. In these studies no other factors tested reached significance in multivariate logistic regression analysis. A hypothetical association between high Lp(a) levels and intracellular infection with Chlamydia pneumoniae is discussed. The results suggest that the Lp(a) level is useful in identifying high-risk individuals. Lowering low density lipoprotein cholesterol below 100 mg/dl (7lt;2.6 mmol/1) seems to be most important in both males and females with high-risk Lp(a) levels.     

Reactive Compatibilization of PA6/LDPE Blends with Glycidyl Methacrylate Functionalized Polyolefins

Summary: Blends of polyamide‐6 (PA6) and low density polyethylene (LDPE) were compatibilized by melt mixing with various polyolefins functionalized with glycidyl methacrylate (GMA), i.e., GMA grafted LDPE (LDPE‐g‐GMA), GMA grafted styrene‐ethylene/butylene‐styrene block copolymer (SEBS‐g‐GMA) and ethylene‐co‐glycidyl methacrylate copolymer (E‐GMA). Blends with PA6/LDPE composition ratios of 25/75 and 75/25 wt.‐%/wt.‐% were prepared in a Brabender internal mixer and their properties were evaluated by SEM, rheological measurements and DSC. Morphological investigation by SEM showed a neat improvement of phase dispersion and interfacial adhesion in all compatibilized blends when compared to PA6/LDPE binary blends. The variation of the dispersed phase size was analyzed as a function of blend composition, compatibilizer concentration and GMA content. The emulsification curves of compatibilized blends showed that the equilibrium size of dispersed particles at the saturation concentration of copolymer was lower when PA6 was the major component. The finest dispersion of the LDPE phase (<0.25 μm) was observed in the presence of SEBS‐g‐GMA copolymer. LDPE‐g‐GMA and E‐GMA displayed a similar compatibilizing efficiency. In all cases, the blends with a polyamide matrix presented a marked rise in torque and melt viscosity with increasing compatibilizer content. These effects were accounted for by a reaction between the epoxide groups of LDPE‐g‐GMA and the carboxyl/amine end‐groups of PA6, leading to the formation of an interchain graft copolymer. The phase transition processes of PA6 in the blends were influenced by the compatibilizer content and the interfacial interactions between the polymer components, suggesting a different role for the compatibilizer at the PA6/LDPE interface.

SEM micrograph of PA6/LDPE 25/75 blend compatibilized with 2.5 phr SEBS‐g‐GMA.     

Predominance of a 6 bp deletion in exon 2 of the LDL receptor gene in Africans with familial hypercholesterolaemia

In South Africa, the high prevalence of familial hypercholesterolaemia (FH) among Afrikaners, Jews, and Indians as a result of founder genes is in striking contrast to its reported virtual absence in the black population in general. In this study, the molecular basis of primary hypercholesterolaemia was studied in 16 Africans diagnosed with FH. DNA analysis using three screening methods resulted in the identification of seven different mutations in the coding region of the low density lipoprotein (LDLR) gene in 10 of the patients analysed. These included a 6 bp deletion (GCGATG) accounting for 28% of defective alleles, and six point mutations (D151H, R232W, R385Q, E387K, P678L, and R793Q) detected in single families. The Sotho patient with missense mutation R232W was also heterozygous for a de novo splicing defect 313+1G→A. Several silent mutations/polymorphisms were detected in the LDLR and apolipoprotein B genes, including a base change (g→t) at nucleotide position −175 in the FP2 LDLR regulatory element. This promoter variant was detected at a significantly higher (p<0.05) frequency in FH patients compared to controls and occurred in cis with mutation E387K in one family. Analysis of four intragenic LDLR gene polymorphisms showed that the same chromosomal background was identified at this locus in the four FH patients with the 6 bp deletion. Detection of the 6 bp deletion in Xhosa, Pedi, and Tswana FH patients suggests that it is an ancient mutation predating tribal separation approximately 3000 years ago.


Keywords: apolipoprotein B; hypercholesterolaemia; low density lipoprotein receptor; mutation