小体重先天性心脏病患儿的体外循环管理

目的：回顾我院16例小体重先天性心脏病患儿的体外循环(CPB)状况,总结其灌注技术。方法：对我院1995-1996年的16例小体重先天性心脏病患儿临床资料及CPB情况(人工心肺机类型、预充液组成、CPB操作步骤、CPB时间、升主动脉阻断时间、心肌保护等)做一回顾性总结。结果：16例患儿。年龄5个月。2岁,平均1．2岁;体重4.5-9.5kg,平均8．2kg。CPB时间32-284min(平均92min),升主动脉阻断时间14-121min(平均64min)。冷晶体高钾停搏液经滚压泵自主动脉根部间断灌注较好的保护了心肌。结论：适宜的血液稀释,根据不同疾病选择正确的灌注方法,良好的术中管理及心肌保护,可有效的使小体重先天性心脏病患儿在CPB中平稳过渡,减少术后的并发症和死亡率。     

Variability of the immunoglobulin light chain in the Siberian sturgeon, Acipenser baeri

All sturgeon VL segments isolated in this study belong to a single family, VLI, which can be divided into two subfamilies. Of the 79 cDNA clones isolated, 76 belong to the larger subfamily, VLIa, and only 3 clones constitute the smaller subfamily, VLIb. To evaluate variability, the Shannon entropy was estimated for each individual amino acid position, and to facilitate comparisons of variability between species the mean entropy of the CDR regions was calculated. In such a comparison, the sturgeon was found to have CDR1 and CDR3 variability approaching those found in mouse and clawed frog, but showed very low variability for CDR2. Amino acid position 50 does however display variability in the range of mouse and clawed frog. It is further confirmed that the sturgeon has numerous J segments, but that the junctional diversity does not contribute greatly to the diversity of the light chain. Comparisons of cDNA clones and a genomic VL segment indicate that the VL undergoes changes, particularly in the CDR regions, in a manner that can be explained by somatic hypermutation and/or gene conversion.     

Effect of novel environmental stimuli on rat behaviour and central noradrenaline function measured by in vivo microdialysis

Rationale: Although physically aversive stimuli induce functional changes in central noradrenergic neurones, little is known about the noradrenergic response to environmentally aversive stimuli. Objectives: The first aim was to characterise environmental features that are perceived as stressful by rats. The second was to investigate whether changes in the concentration of extracellular noradrenaline are induced by these environmental features. Methods: A light/dark shuttle-box was used to test rats’ behavioural response to a range of stimuli (novelty, bright light, and the presence of an unfamiliar rat), either before or after microdialysis probe implantation. Changes in the concentration of extracellular noradrenaline in the frontal cortex and hypothalamus in vivo were then evaluated on exposure to these same test conditions. Results: Naive rats spent less time in a brightly-lit test arena than a dark one. However, the behavioural response to the light arena was attenuated by the presence of an unfamiliar rat. Probe implantation intensified the response to the light arena but did not affect behaviour in the dark arena. In the microdialysis studies, there was no change in the concentration of extracellular noradrenaline on transfer of rats to the dark arena but there was an increase in both the frontal cortex (+45%) and hypothalamus (+75%) on exposure to the light arena. A similar increase was induced in both brain regions when the light arena contained an unfamiliar rat. Conclusions: Implantation of a microdialysis probe modifies the behavioural responses to certain environmental stimuli. Regardless of this, the extent to which rats perceive a novel environment as aversive is not the only determinant of the noradrenergic response to such stimuli. However, differences in stimulus controllability in the microdialysis and the behavioural experiments could influence the apparent intensity of the stress. Received: 29 October 1998 / Final version: 19 March 1999     

Marijuana,alcohol, and combined drug effects on the time course of glare recovery

The time course of light adaptation after intense light exposure is significantly delayed by alcohol, marijuana, and a combined dose of alcohol and marijuana. These effects were found in a double blind experiment, using 10 subjects. The experimental treatements were placebo, 0.75 ml/kg of 95% ethanol, 8 and 15 mg of ⁹ tetrahydrocannabinol (THC), and 0.75 ml/kg of 95% ethanol together with 15 mg of THC. The marijuana-induced delay in recovery is doserelated. Both drugs produce delayed recovery for at least 2 h after drug ingestion. The combined alcohol and marijuana treatment produces little more than the effect produced by either drug alone, suggesting some antagonism between the drugs — a suggestion supported by a significantly lower blood alcohol level for the alcohol dose when combined with marijuana than when taken alone.     

Photodynamic therapy in the bladder: Can the light dose be easily quantified?

The shape of the bladder and the optical characteristics of the tissue within the wall can be shown to play an important role in the amount of light actually received at the wall. The use of estimated doses even assuming spherical geometry, cannot therefore be relied upon. This paper describes some experimental work carried out on a glass model that was used to simulate the bladder. A specially constructed dual detector was used which consisted of an isotropic probe and semiconductor detector. This enabled measurements of irradiance and space irradiance (light energy fluence rate) to be made simultaneously. By changing the optical characteristics of the wall a four-fold increase in space irradiance was measured. Contamination of the water contained within the model by blood was also investigated and has shown that with concentrations as low as 0.5% the delivered light dose reaching the wall can be reduced by up to 50% at a wavelength of 510 nm. Some in vivo measurements are also presented together with some comments on the difficulties that have been encountered when transferring measurements from the model to the patient.     

金钗石斛光合作用特征的初步研究

利用LiCor-6400光合测定系统测定了不同天气条件下，金钗石斛叶片24hCO2吸收的动态变化，以及CO2吸收对有效光合辐射的响应。结果表明：晴天，白天和夜间金钗石斛都能吸收CO2，中午有光下呼吸现象，CO2的交换方式具景天酸代谢途径（CAM）的特点；阴雨天，中午没有光下呼吸现象，白天都在吸收CO2，夜间21：00仍有CO2吸收，23：00以后至次日凌晨处于暗呼吸状态。金钗石斛叶片CO2吸收对光照强度的效应表现出强光抑制现象，饱和光照强度为1000μmol/m^2s。叶片受到强光照射后，光合饱和点降低，CO2吸收速率下降，说明金钗石现象，饱和光照强度为1000μmol/m^2s。叶片受到强光照射后，光合饱和点降低，CO2吸收速率下降。说明金钗石斛是兼性景天酸代谢植物，随着环境条件变化，光合作用可在CAM途径与C3途径间变化，这一光合特性可能是金钗石斛适应需荫环境和生物缓慢，稀少的主要原因之一。     

注射用头孢呋辛钠稳定性的研究

目的：探讨注射用头孢呋辛钠的稳定性。方法：通过加速、温度、光照、充氮影响实验，以含量（％）、聚合物（％）、溶液的颜色和澄清度为指标，考察不同原料厂家注射用头孢呋辛钠的稳定性。结果：样品A的含量变化最小，其溶液的澄清度和颜色最好，3个样品的聚合物（％）则相差不大。结论：头孢呋辛钠原料质量是影响产品稳定性的主要因素。     

不同光照对盐酸左氧氟沙星注射液稳定性的影响

目的 :探讨不同光源照射对盐酸左氧氟沙星注射液稳定性的影响程度。方法 :分别选择紫外光、太阳光、自然光作为照射光源 ,观察盐酸左氧氟沙星注射液在3种光源下照射不同时间后的光谱变化并测定其含量 ,另用薄层色谱法检查有无分解产物生成。结果 :盐酸左氧氟沙星注射液在3种光照下均有分解 ,以太阳光照射下分解最快 ;以薄层色谱法检查出降解产物的Rf值为0 .72。结论 :盐酸左氧氟沙星注射液应避开紫外光、太阳光、自然光保存。     

Chronic cocaine treatment induces dysregulation in the circadian pattern of rats' feeding behavior

The effects of protracted cocaine administration (15 mg/kg i.p., twice a day for 9 days) on the circadian pattern of feeding behavior was studied in individually housed male Sprague-Dawley rats, maintained under a 12:12 light:dark cycle. Water and food were available ad libitum and food intake was measured twice a day before, during and after withdrawal of cocaine (or saline) treatment. Neither total 24-h food intake, nor body mass at the end of the experiment, was significantly different between cocaine-treated and control animals. However, cocaine administration affected the temporal distribution of food consumption. During the dark (activity) phase, rats receiving cocaine injections consumed significantly less food than control animals, and this effect persisted for up to 3 days of cocaine withdrawal. During the light (rest) phase, cocaine administration promoted food consumption and a significantly higher food intake was also observed during the first five cocaine withdrawal days. Continuous monitoring of locomotor activity did not reveal significant changes in the circadian pattern of activity between the two experimental groups during different treatment periods, except for an acute increase in locomotion within an hour after daytime cocaine injection. The results of this study demonstrate that sub-chronic cocaine administration alters the circadian pattern of rats' feeding behavior.     

无瘤接触及杀瘤技术在胃癌根治术中的应用

目的　探讨无瘤接触及杀瘤技术在胃癌根治术中的应用。方法　我院从 1997-10～ 2 0 0 3 -0 8共施行了胃癌D4根治术 5 2例 ,术中全部严格进行无瘤接触及杀瘤技术的应用。并与同期 44例行D1术式但无严格行无瘤接触及杀瘤技术的胃癌患者作一比较 ,从而了解两者 5年生存率的情况。结果　术后均无明显的并发症 ,全部患者治愈出院 ,D4及D1组两者 5年生存率分别为42 3 %及 18 2 % (P <0 0 5 )。结论　在胃癌D4根治术的基础上进行严格的无瘤接触及杀瘤技术 ,是一种安全、合理有效的治疗方法。