Myelinated Herring bodies in the posterior part of the median eminence of the mouse

Summary The posterior part of the median eminence of the albino mouse (CF # 1-JCL) contains a cluster of myelinated axons beneath the tanycyte layer. Among them, small Herring bodies surrounded by myelin sheaths are revealed by electron microscopy. These structures contain electron-dense bodies, lamellar bodies, autophagic bodies, autophagic vacuoles, and neurofilaments. A few neurosecretory granules and mitochondria are also present. Some myelinated axons contain mostly accumulated neurosecretory granules.     

PLGA-奥沙利铂缓释微球急性毒性实验

目的了解PLGA-奥沙利铂缓释微球和奥沙利铂小鼠皮下给药的急性毒性。方法采用Bliss法分别测定PLGA-奥沙利铂缓释微球和奥沙利铂小鼠皮下给药对动物的半数致死量（LD50）。结果PLGA-奥沙利铂缓释微球小鼠皮下给药时的LD50为660.90 mg/kg,奥沙利铂小鼠皮下给药时的LD50为15.24 mg/kg,相差达43.37倍。结论PLGA-奥沙利铂缓释微球能够显著降低药物对动物的急性毒性。     

Quantitative data on the fine structural organization of the palisade zone of the median eminence

Summary In order to characterize different sub-zones in the palisade zone of the rat median eminence, quantitative ultrastructural parameters were applied to brains fixed in aldehyde-osmium tetroxide. The palisade zone has been subdivided in 4 successive sub-zones. Increasing numbers of granular vesicles (GV), especially those smaller than 110 nm, are observed from dorsal to ventral sub-zones. There also are more GV per unit area of nervous tissue in the perivascular than in the more dorsal sub-zones. The individual nerve profiles exhibit a larger size in the perivascular layer than in the more dorsal areas, whereas the number and size of nerve profiles devoid of vesicles diminish from dorsal to ventral. As a consequence more GV occur in the perivascular nerve profiles. In the GV containing nerve profiles the concentration of GV is, however, constant in the different sub-zones. A fluctuating size of the preterminal and terminal parts of the nerve fibres is suggested.We are indebted to Mrs. R. M. Y. Hartsteen for technical assistance. The constructive criticism of Prof. J. Moll is acknowledged, as well as the photographic assistance of Miss P. C. Delfos.     

Function of dorsal fins in bamboo shark during steady swimming

To gain insight into the function of the dorsal fins in white-spotted bamboo sharks (Orectolobiformes: Hemiscyillidae) during steady swimming, data on three-dimensional kinematics and electromyographic recordings were collected. Bamboo sharks were induced to swim at 0.5 and 0.75 body lengths per second in a laminar flow tank. Displacement, lag and angles were analyzed from high-speed video images. Onset, offset, duration, duty cycle and asynchrony index were calculated from three muscle implants on each side of each dorsal fin. The dorsal fins were displaced more laterally than the undulating body. In addition, the dorsal tips had larger lateral displacement than the trailing edges. Increased speed was accompanied by an increase in tail beat frequency with constant tail beat amplitude. However, lateral displacement of the fins and duration of muscle bursts remained relatively constant with increased speed. The range of lateral motion was greater for the second dorsal fin (mean 33.3°) than for the first dorsal fin (mean 28.4°). Bending within the fin was greater for the second dorsal fin (mean 43.8°) than for the first dorsal fin (mean 30.8°). Muscle onset and offset among implants on the same side of each dorsal fin was similar. Three-dimensional conformation of the dorsal fins was caused by interactions between muscle activity, material properties, and incident flow. Alternating bilateral activity occurred in both dorsal fins, further supporting the active role of these hydrofoils in thrust production during steady swimming. The dorsal fins in bamboo sharks are capable of thrust production during steady swimming and do not appear to function as stabilizing structures.     

右腋下小切口与胸骨正中切口入路手术治疗儿童简单先天性心脏病疗效比较的回顾性研究

摘要 目的：对比右腋下小切口、胸骨正中切口入路手术治疗儿童简单先天性心脏病（CHD）的疗效。方法：回顾性分析2019年4月~2020年12月期间我院收治的简单CHD患儿100例的临床资料。根据不同的手术方法将接受胸骨正中切口入路的48例纳为A组,将接受右腋下小切口入路的52例纳为B组,观察两组患儿手术指标、术后恢复指标、瘢痕情况及术后并发症发生率。结果：两组患儿主动脉阻断、体外循环、手术时间对比无统计学差异（P>0.05）,与A组相比,B组的术中失血量较少,组间对比差异有统计学意义（P<0.05）。与A组相比,B组住院费用、胸腔引流量均减少,术后辅助通气、监护及住院时间均明显缩短,组间对比差异有统计学意义（P<0.05）。B组血管分布、皮肤色泽、皮肤柔软、皮肤厚度的各维度评分及总分均低于A组（P<0.05）。两组患儿术后并发症发生率组间对比无统计学差异（P>0.05）。结论：右腋下小切口入路手术治疗简单CHD患儿,可获得与胸骨正中切口入路相当的治疗效果,同时还可减少术中出血量,促进患儿术后恢复,改善伤口瘢痕情况。     

原矛头蝮蛇毒毒性及恢复规律

目的:对原矛头蝮(P.mucrosquamatus)的毒性及其恢复规律进行考察,增进对该蛇毒性的认识。方法:用该蛇连续攻击小鼠,用梯度剂量蛇毒对小鼠进行腹腔注射,统计死亡率,以折算绝对毒性和半数致死量。对毒性耗竭个体,在梯度时间间隔采集蛇毒,以考察毒性恢复规律。结果:原矛头蝮在2 h内可导致6只小鼠死亡。蛇毒对小鼠的半数致死量为12.204μL/Kg。毒性耗竭后,在间隔21天所获得蛇毒的容积达到最大值即190μL,湿重为149.7 mg。结论:毒蛇在攻击猎物时,并不一次性排完毒腺中的所有毒液,随着攻击次数的增多,毒腺中毒液量逐步减少直至耗竭。其毒液量的恢复需要约3周时间,期间,单次排毒量逐渐增加,干物质的含量也基本呈递增趋势。就单次最大排毒量而言,原矛头蝮高于竹叶青、蝮蛇和银环蛇。其单位剂量毒性高于五步蛇和竹叶青。