Caffeine and light effects on nighttime melatonin and temperature levels in sleep-deprived humans

The effects of caffeine ingestion and exposure to bright light, both separately and in combination, on salivary melatonin and tympanic temperature were assessed in humans. Four treatments during a 45.5 h sleep deprivation period were compared: Dim Light-Placebo, Dim Light-Caffeine, Bright Light-Placebo and Bright-Light Caffeine. The Dim Light-Caffeine condition (200 mg twice each night) relative to the Dim Light-Placebo condition suppressed nighttime melatonin levels and attenuated the normal decrease in temperature. Combining caffeine ingestion with bright light exposure (≥2000 lux) suppressed melatonin and attenuated the normal nighttime drop in temperature to a larger degree than either condition alone; i.e. effects were additive. Circadian effects were also observed in that the amplitude and phase of the temperature rhythm were altered during treatment. These findings establish that the human melatonin system is responsive to caffeine. Other evidence suggests that caffeine may influence melatonin and temperature levels through antagonism of the neuromodulator adenosine.     

YAG激光器谐振腔光振状态的调整

本文介绍了调整谐振腔光振状态的方法和要点，它包括调整谐振腔体和其它的光学部件。本法可应用于YAG激光器谐振腔的维修拆卸重装工作中。     

荞麦花粉抗贫血作用的实验研究

用荞麦花粉的水提取液进行了抗大白鼠缺铁性贫血的研究，结果表明：荞麦花粉具有和硫酸亚铁相似的抗缺铁性贫血作用．饮用荞麦花粉提取液３５ｄ的大白鼠，生长发育良好，主要脏器未见损害．该研究为荞麦花粉的开发利用提供了实验依据．     

内镜下乳头气囊扩张术治疗胆囊切除术后胆总管结石

目的　探讨经内镜乳头气囊扩张术 (EPBD)治疗胆囊切除术后胆总管结石的安全性和疗效。方法　对胆囊切除术后出现黄疸或胆管炎的 31例患者 ,利用EPBD结合取石篮、取石球囊或总攻方法 ,使梗阻于胆总管下段的结石排入肠道。结果　 31例患者全部顺利实施EPBD ,共排除结石37颗 ,4例行 2次扩张术 ,术后患者均痊愈出院 ,复查B超无结石残存或胆管扩张。结论　经内镜治疗胆囊切除术后胆总管结石 ,安全、无创、有效 ,有望成为治疗LC术后胆总管结石的首选方法     

胃癌的危险因素调查及癌前病变动态观察

报道温州地区胃癌高发区瑞安塘下的致癌危险因素的调查情况,结果表明它是由多种致癌危险因素的综合影响。作者应用内镜活检在18000例慢性胃病患者中查出癌前病变(高危人群)1132例,经3月～14年活检随访,表明胃癌前病变有一定的可逆转性;癌变率较高的是胃溃疡(GU)+不典型增生(ATP)组、GU+慢性萎缩性胃炎(CAG)组及CAG+ATP组均为4.1％;总癌变率为3.1％。早癌检出率占胃癌总数的48.6％,为门诊早癌检出率的6.8倍。此方法简单、经济实用。     

我国3属10种蚊幼虫颏光镜与扫描电镜形态特征研究

本文首次报告了我国脉毛蚊属、库蚊属和按蚊属10种蚊Ⅳ龄幼虫颏的光镜与扫描电镜的形态特征。结果表明,利用颏进行分类鉴定,在某些种类具有一定的意义。     

Binswanger's disease in the absence of chronic arterial hypertension

Summary The cerebral changes are described in a woman of 54 who suffered from Binswanger's encephalopathy: there were no signs or symptoms of chronic arterial hypertension. The disease presented as dementia of about 3 years duration. Computed tomography of the brain 2. 5 years before her death showed bilateral widespread hypodense lesions in the cerebral white matter. She died of an asthmatic attack. Autopsy disclosed extensive bilateral degeneration of the central white matter, lacunes and gliosis. Severe obliterative arteriolosclerosis occurred in the meningeal vessels and those supplying the affected parts of the brain. Light microscopy showed that the most severe lesions occurred in the arterioles. Immunohistochemistry demonstrated profound extravasation of plasma proteins chiefly albumin, indicating dysfunction of the blood-brain barrier. Thus, the lesions characteristic of Binswanger's encephalopathy may develop in the absence of chronic arterial hypertension. Additional pathogenic factors, possibly genetic predisposition to vascular injury may play a role in the development of this condition.Supported by grants from the Swedish Medical Research Council, Project No 12X-03020 and 1987 Års Stiftelse för Strokeforskning     

Localization of small intestinal bleeding

The preoperative identification of a bleeding site is not always possible, particularly when bleeding originates in the small intestine. Small vascular abnormalities, such as the telangiectatic lesion described in this report, comprise about 40–60% of such cases. Preoperative location using arteriography, radionuclide bleeding scan, and enteroclysis were nondiagnostic. The lesion was demonstrated by intraoperative endoscopy. A segment of small intestine was resected, and the patient made an uneventful recovery.     

Light-emitting diodes and half-cell electrodes in experimental recording of electroretinogram c-wave

A method of electroretinogram c-wave recording in the rat was developed that uses a contact lens electrode connected through a saline bridge with a silver-silver chloride half-cell. A cluster of light-emitting diodes, regulated by an electronic light-emitting diode stimulator, was used as a light source. The method enables recordings of c-waves of 0.4–1.6 mV amplitude as well as other electroretinogram components in narrow limits of variation. The two main sources of response variability are voltage shunting and eyeball protrusion.