人参皂甙Rb1和Rg1对小鼠中枢神经递质受体和脑内蛋白质合成的影响

应用放射配基结合法测定了人参皂甙Rb₁和Rg₁对α₁,α₂,β肾上腺素能受体、M胆碱能受体、5-羟色胺、多巴胺及GABA等七种受体的作用。结果均不能证明它们对这七种受体有亲和力。但给动物ip药物连续5天,Rb₁和Rg₁均能使中枢M胆碱受体密度显著增高。Rb₁及Rg₁还能显著增加脑内蛋白质的含量。上述实验结果对解释人参的中枢作用提供了重要证据。     

Fatty acid nomenclature. A short review

The nomenclature of the chemical structure of fatty acids can be confusing and should be standardized. Criteria for a suitable terminology are proposed, and the recommendation is made that use of the 'n' and 'omega' systems comes closest to meeting these criteria.     

Magnetic resonance imaging following unilateral occlusion of the renal circulation in rabbits

Magnetic resonance studies at 0.12 T were performed following acute unilateral occlusion of the renal artery or vein in rabbits. Prior to occlusion, in vivo and in vitro relaxation times of the renal cortex and outer medulla were similar. After venous occlusion, T1 and T2 were prolonged on the occluded side, while the contralateral side remained unchanged. After arterial occlusion, the outer medulla of both the occluded and contralateral kidney exhibited prolonged relaxation times. There was a significant linear correlation between T1, T2, and the water content of the tissue. The authors conclude that quantitative in vivo relaxation times may eventually prove to be useful in diagnosis, although at present they are less reliable than those obtained in vitro.     

基于受体结构的药物分子设计系统:维甲类分子与其结合蛋白之间相互作用的研究

大分子解剖程序,配体分子契合适配和DOCK程序,以及计算化学的其它程序等,已集成为基于受体结构和分子间相互作用的进行分子设计的软件系统,定名为BIOS(Biomolecularinteractionsandorientationsimulator)。BIOS软件可在普通的微机上运行。使用BIOS分别剥离了细胞浆维甲结合蛋白(CRBP)和副睾维甲酸结合蛋白(E-RABP)两种蛋白的配体结合腔,剥离是围绕配体以同样的分子距离进行的。从而得到了芳香性残基分布相似的两个结合腔,其结合位点的几何排布却有相当差别。揭示出的结合腔已用于一系列的维甲类化合物的DOCK研究。E-RABP的结合腔可做为设计新维甲类分子的模板。     

Glomus tympanicum chemodectomas: radiographic and clinical characteristics

Glomus tympanicum chemodectomas are benign neoplasms that develop from normal glomus bodies located along the Jacobson (tympanic) nerve in the middle ear. The medical charts and radiographic studies of 55 patients with these tumors were reviewed. Women outnumbered men in a ratio of 3.5:1, and the patients' average age when they initially reported symptoms was 52 years. Tinnitus, ear pulsations, and diminished hearing were the most frequent symptoms. No patient had a second chemodectoma, and none of seven patients who were tested had elevated neuroendocrine compounds. Review of the radiographic examinations showed that direct coronal, thin-section computed tomography (CT) was the most sensitive means of demonstrating glomus tympanicum chemodectomas. Magnification angiography was also a sensitive diagnostic study, typically depicting a trapezoidal, hypervascular, middle-ear mass that appeared initially in the middle-to-late arterial phase and quickly disappeared in the venous phase. Differentiation from an aberrant internal carotid artery is critical to prevent arterial biopsy.     

The contribution of risk factors to the effect of early otitis media with effusion on later language, reading, and spelling

A cohort of 946 children who were screened for otitis media with effusion (OME) from the ages of 2 to 4 were studied for language, reading, and spelling at 7 years of age. The effects of OME in combination with single risk factors and with increasing numbers of risk factors were investigated. An interaction with an additional risk factor was found only for gender and OME, with boys' spelling influenced negatively by a history of OME. OME in combination with preterm birth and low birthweight also appears to put children at risk for later langauage and educational problems. Although a negative linear relation between the number of risk factors and later functioning was found, it is suggested that OME, even when combined with a number of other risk factors, produces only minor effects on later language, reading, and spelling.     

Central pontine myelinolysis and its imitators: MR findings

The clinical, radiologic, and neuropathologic findings in 13 patients with central pontine myelinolysis were reviewed. Antemortem computed tomography (CT) had been performed in nine, and ante- or postmortem magnetic resonance (MR) imaging in 11. Chronic alcoholism or rapid correction of hyponatremia was present in over 75% of cases. One CT scan was positive, but only on retrospective review. In all but one patient, MR imaging eventually revealed an abnormality within the pons; in two patients the initial study was normal. The lesions varied in shape, with peripheral involvement in two patients and extrapontine involvement in four. The abnormality was smaller at 6-month follow-up in one patient and unchanged at 1 year in another. One patient never had a demonstrable pontine lesion but did have symmetric basal ganglia abnormalities, which were consistent with extrapontine myelinolysis. MR imaging disclosed similar central pontine alterations resulting from infarct, metastasis, glioma, multiple sclerosis, encephalitis, and radiation or chemotherapy; thus, such changes are not unique.     

人工牛黄的光解

人工牛黄是广泛用于中成药配方的中药代用品。本文用漫反射光谱法研究了人工牛黄样品在人工光源照射下发生颜色变化的光解规律:在三种光源下,其光解均属二步表观一级反应动力学,即光解曲线是由两段斜率不同的直线组成,初期的光解速度较其后的快2倍左右;不同光源下,紫外灯光解速度最快,荧光高压汞灯次之,碘钨灯最慢;表观光解常数与光波长有关,但基本不随光强度和照射时间乘积改变。而光解时间则与光强度成反比。从得到的动力学方程可预测不同条件下的褪色时间。研究表明,人工牛黄复方中,发生光解的主要成分是胆红素,其余成分不发生引起颜色变化的光解,但在第二步反应中对胆红素的光解有明显影响。