Hyperexcitability associated with localizable lesions in epileptic patients

Intracellular recordings from neurons were carried out in cortical slices obtained from tissue removed from patients suffering from intractable seizures. The patients were divided into two groups based on the presence or absence of an anatomical abnormality that could be imaged preoperatively. The lesion or its surround was the presumptive epileptogenic area. The tissue removed from the patients without lesions was removed either for biopsy purposes or for access to epileptic tissue and was not considered epileptogenic. All neurons from patients without an imageable lesion, and some (19%) from patients with an imageable lesion, responded to orthodromic stimuli with a sequence of synaptic excitation followed by inhibition; these properties resembled those of normal rodent cortical slices. Different responses, classified as abnormal, were observed in 81% of the neurons in tissue specimens obtained near lesions. The most common was prolonged synaptic excitation with no noticeable inhibition, even at high stimulus strengths. In three resections, long latency all-or-none depolarization shifts were observed that resemble the classic paradoxical depolarization shift seen in in vivo extracellular recordings. Loss of specific inhibitory systems within the cortex may contribute in part to these abnormal responses.     

Time course of the effects of diazepam and lorazepam on perceptual priming and explicit memory

The effects of diazepam and lorazepam on explicit memory and perceptual priming were studied 50, 130 and 300 min after drug administration. Sixty healthy volunteers were randomly assigned to one of five parallel groups (placebo, diazepam 0.2 or 0.3 mg/kg, lorazepam 0.026 or 0.038 mg/kg). The corresponding doses of benzodiazepines exerted a similar negative effect on explicit performance. Lorazepam markedly impaired priming performance, whereas the effect of diazepam was intermediate between that of placebo and that of lorazepam 0.038 mg/kg. The impairment was maximal at the theoretical peak plasma concentration. Contamination by explicit memory could account for the decrease in priming performance observed in the diazepam groups.     

Human cyclovergence as a function of stimulus frequency and amplitude

Summary By the use of scleral search coils a continuous record of human cyclovergence was obtained while two identical 80° textured patterns, presented dichoptically, oscillated in the frontal plane in counterphase through 1, 3 and 6° of cyclorotation at frequencies between 0.05 and 2 Hz. The amplitude and gain of the response decreased exponentially with increasing stimulus frequency. As stimulus amplitude increased, response amplitude also increased but gain was highest for low-amplitude cyclorotations. For an amplitude of 1° and a frequency of 0.05 Hz the gain reached 0.87 for two subjects. The phase lag increased from a few degrees at a frequency of 0.05 Hz to over 100° at a frequency of 2 Hz. These results suggest that cyclovergence is designed to correct for small, slow drifts in the stereoscopic alignment of the images in the two eyes. Although the disparity in the textured display was not interpreted as slant, it provided a strong stimulus for cyclovergence. The cyclovergence caused a transfer of cyclodisparity into a superimposed vertical line, which was then perceived as slanting in depth.     

重组人生长激素在体外对人直肠癌细胞株HR8348增殖的影响

目的　探讨重组人生长激素 (rhGH )在体外对人直肠癌细胞增殖的影响。方法　实验分为对照组、rhGH组、奥沙利铂 (L OHP)组和rhGH +L OHP组 4组 ,利用体外细胞培养、MTT比色技术及流式细胞仪等方法 ,测定不同浓度的rhGH对人直肠癌细胞株HR83 48细胞倍增时间、细胞抑制率、细胞周期、增殖指数 (PI)和DNA抑制率的影响。结果　rhGH在体外不促进HR83 48细胞的分裂增殖 ,rhGH组与对照组比较 ,以及rhGH +L OHP组与L OHP组比较 ,其差异均无统计学意义 (P>0 .0 5 ) ;rhGH +L OHP组与对照组比较及rhGH +L OHP组与对应的rhGH组配对比较 ,细胞倍增时间明显延长 ,细胞抑制率增加 ,阻滞于G0 ～G1期的细胞数增加 ,S期和G2 ～M期细胞明显减少 ,PI明显降低 ,DNA抑制率显著升高 (P<0 .0 1,S期P<0 .0 5 )。结论　rhGH在体外不促进直肠癌细胞的分裂增殖。     

输精管结扎干扰前列腺增生过程的机制探讨——精浆睾酮双氢睾酮的放射免疫测定

本文应用放射免疫测定的方法检测了13例输精管结扎后(平均15.3年,平均年龄50岁)的男性精浆双氢睾酮和睾酮的浓度,另取同年龄组男性13例作为对照。结果表明,精浆睾酮在结扎组(374.54p/ml)和正常对照组(315.64Pg/ml)中没有明显差异,而结扎组精浆中双氢睾酮(46.21pg/ml)却明显低子对照组(184.27pg/ml(p<0.01)。作者认为,输精管结扎对精浆DHT有长期影响,这可能是其对前列腺增生过程产生抑制作用的原因之一。     

妇科疾病中人乳头瘤病毒感染的分子流行病学调查

目的:探讨各种妇科疾病与人乳头瘤病毒感染的关系,建立不同妇科疾病和不同年龄段妇女人乳头瘤病毒感染的流行病学资料库。方法:应用反向点杂交技术分别对疾病组1 512例病人标本和正常组500例标本进行HPV检测,所得数据用SPSS 13.0软件包进行统计分析。结果:正常组500例标本中,阳性标本101例,感染率为20.2%,疾病组1 512例标本中,阳性标本523例,感染率为34.6%,其中双重感染82例,占阳性标本的15.7%,多重感染34例,占阳性标本的6.5%,而高危感染340例,感染率为22.5%,占阳性标本的65.0%,其中单纯HPV16亚型感染155例,占所有阳性标本的29.6%;不同年龄段、不同性生活史、不同妇科疾病以及不同首次性生活年龄的HPV感染检出率都有显著性差异。结论:正常组和疾病组的HPV感染率有显著性差异(2χ=36.37,P<0.01)。在HPV感染的普查中可以有重点的选择高危人群,这样更加有针对性,从而大大降低普查成本。     

高原地区部队医院谋求新发展应处理好七个关系

从高原部队医院实际出发,阐述了适应新形势谋求新发展应处理好的七个关系:即继承与创新的关系;坚持“姓军为兵的服务方向与对外有偿服务的关系;基础建设与人才建设的关系;日常医疗保障与科研的关系;发挥自身特色与学习借鉴的关系;硬件建设与软件建设的关系;科技研究与成果转化的关系。     

Optic chiasm glioma associated with inappropriate secretion of antidiuretic hormone,cerebral ischemia,nonobstructive hydrocephalus and chronic ascites following ventriculoperitoneal shunting

An optic chiasm glioma may cause loss of vision, endocrine disturbances, hydrocephalus and cerebral ischemia due to its proximity to the pituitary, hypothalamus, III ventricle and internal carotids. A 3-month-old infant with optic chiasm glioma developed hypopituitarism and inappropriate secretion of antidiuretic hormone with plasma hypo-osmolality. The cerebrospinal fluid (CSF) protein concentration was markedly elevated. The impairment of fluid absorption via arachnoid villi and peritoneum by the high protein content, and reversed osmotic gradient between protein-rich CSF and hypo-osmolar plasma may have contributed to both nonobstructive hydrocephalus and recurrent ascites following ventriculoperitoneal shunting. Cerebral ischemia from carotid compression may have led to cerebral atrophy.     

Inward rectifying potassium channels in human malignant glioma cells

Human glioma cells obtained from established cell lines (Tp-276MG, Tp-301MG, Tp-378MG, Tp-483MG and U-251MG) were analyzed for the presence of ion channels with the tight-seal voltage clamp technique. The current-voltage relation revealed a marked inward rectification at hyperpolarizing voltages, due to the presence of inward rectifying K-channels in cells from all studied cell lines. These channels were conducting when the membrane potential was more negative than the K-equilibrium potential. The slope conductance for the inward K-currents (g_Ki) was affected both by [K⁺]_i and [K⁺]₀. g_Ki was proportional to [K⁺]₀ raised to 0.35 or 0.50, of which the larger value was measured in the presence of low [K⁺]_i (25mM). The rectification was not significantly different in cells perfused with Mg-free EDTA-buffered internal solution. Tl⁺ was 3.5 times more permaant than K⁺. g_ki was blocked by Cs⁺ (1 mM) in a voltage-dependent way (more effective in the hyperpolarized membrane), and by Na⁺ (154 mM) depending on voltage and time. From measurements of unitary current events in membrane patches (outside out or cell attached) the conductance of the single inward rectifying channel was estimated to be 27 ± 7 pS. This type of ion channel may be important for K-uptake by glial cells and hence for the K-homeostasis in the brain.     

In vitro and in vivo evaluation of seven 50 mg and 100 mg nitrofurantoin tablets

Four 50 mg and three 100 mg marketed nitrofurantoin tablets were studied in 14 healthy male subjects. Urine was collected 1, 2, 3, 4, 6, 8, 12, and 23 h after each dose, and nitrofurantoin was assayed by HPLC. The in vitro dissolution of the tablets was determined using USP Apparatus 1 and 2, with 0.1 N hydrochloric acid and pH 7.2 buffer as the dissolution fluids. One of the 50 mg tablets was more rapidly and completely absorbed than the other six products. The incidence of side-effects for this product was as low or lower than the other products. It was determined that the use of the USP Apparatus 1, at 100 rev min-1, with sampling of the pH 7.2 fluid at 30 min, provided for the best overall relationship between the urinary excretion and in vitro dissolution.