Linkage of the MHC to familial multiple sclerosis suggests genetic heterogeneity. The Multiple Sclerosis Genetics Group

Multiple sclerosis (MS) is a demyelinating autoimmune disease of the central nervous system. While its etiology is not well understood, genetic factors are clearly involved. Until recently, most genetic studies in MS have been association studies using the case-control design testing specific candidate genes and studying only sporadic cases. The only consistently replicated finding has been an association with the HLA-DR2 allele within the major histocompatibility complex (MHC) on chromosome 6. Using the genetic linkage design, however, evidence for and against linkage of the MHC to MS has been found, fostering suggestions that sporadic and familial MS have different etiologies. Most recently, two of four genomic screens demonstrated linkage to the MHC, although specific allelic associations were not tested. Here, a dataset of 98 multiplex families was studied to test for an association to the HLA-DR2 allele in familial MS and to determine if genetic linkage to the MHC was due solely to such an association. Three highly polymorphic markers (HLA-DR, D6S273 and TNFbeta) in the MHC demonstrated strong genetic linkage (parametric lod scores of 4.60, 2.20 and 1.24, respectively) and a specific association with the HLA-DR2 allele was confirmed (TDT; P < 0.001). Stratifying the results by HLA-DR2 status showed that the linkage results were limited to families segregating HLA-DR2 alleles. These results demonstrate that genetic linkage to the MHC can be explained by the HLA-DR2 allelic association. They also indicate that sporadic and familial MS share a common genetic susceptibility. In addition, preliminary calculations suggest that the MHC explains between 17 and 62% of the genetic etiology of MS. This heterogeneity is also supported by the minority of families showing no linkage or association with loci within the MHC.      

安宫牛黄丸中小檗碱的HPLC法测定

本文报道用HPLC法测定黄连及含黄连中成药安宫牛黄丸中小檗碱型生物碱。实验结果表明选用硅胶柱为固定相,以醋酸乙酯—甲酸—乙醇(15:3:2)为流动相,能使样品中四种小檗碱型的生物碱获得最佳分离。用此法测得不同厂家生产的安宫牛黄丸中盐酸小檗碱的含量为0.331～0.456%,平均回收率为97.23%,变异系数为1.2%。     

The role of the angular gyrus in visual conjunction search investigated using signal detection analysis and transcranial magnetic stimulation

Transcranial magnetic stimulation (TMS) delivered over the posterior parietal cortex increases choice reaction times in visual search for a target defined by a conjunction of features. Some recent studies of visual search have taken an approach based on signal detection theory, the findings of which are not addressed by studying the disruptive effects of TMS on reaction time. Here we investigated the role of the posterior parietal cortex in visual search by applying TMS while subjects performed unspeeded feature and conjunction visual search tasks matched for level of difficulty. TMS over the right, but not the left angular gyrus (AG) in the parietal cortex, nor vertex decreased subjects' sensitivity on the conjunction but not the feature search task, as measured by the signal detection measure, d'. Changes in bias, specifically the tendency to make false positive responses, were less clear. We consider the findings in terms of four possible explanation: binding, attentional control, spatial localisation and visuomotor co-ordinate transformations.     

Primary tuberculous nasal polypi—A case report

Primary tuberculous pathology in nasolpolypi is a rare condition. A case of bilateral ethmoidal polypi with tubercular lesion diagnosed on histopathologlcal examination is being reported and the available relevant literature has been reviewed.     

The projection of the temporal retina in rats,studied by retrograde transport of horseradish peroxidase

Summary Horseradish peroxidase (HRP) was injected unilaterally into the lateral geniculate nucleus or tectum, or both, in 26 hooded rats in order to mark the exact extent of the retina from which uncrossed optic axons arise. This region occupied about a quarter of the retina, in the temporal periphery, following thalamic injections, but a much smaller region following tectal injections. By comparing the proportions of HRP positive neurones in nasal and temporal retinae of both eyes it was shown that: (1) within the region supplying uncrossed axons the majority of the ganglion cells nevertheless project contralaterally, (2) a large proportion of the ganglion cells from the temporal crescent project bilaterally, which does not occur from the remainder of the retina, (3) ganglion cells of all sizes contribute to both ipsilateral and contralateral projections. The results also support earlier suggestions that the smallest neurones in the ganglion cell layer do not send an axon into the brain, and are therefore not ganglion cells     

高效液相色谱法测定消痰咳片的含量

目的：采用反相色谱法同时测定消痰咳片中两种主要成分甲氧苄啶和磺胺体的含量。方法：以乙腈：0.1%H3PO4(15:85)为流动相，检测波长254nm，HPLC法测定含量。结果：试验表明，甲氧苄啶和磺胺林在0.8-8ug范围内呈良好的线性关系，回归方程分别为Y＝－1127.1＋110.2x(r=0.9994),Y=-1852.3 256.2x(r=0.9996),相对标准偏差分别为2.1%和0.8%。结论：该方法简便、准确、可靠。     

5种注射剂的细菌内毒素检查法初步考察

目的：考察５种注射剂盐酸林可霉素注射液，盐酸精氨酸注射液，注射用玻璃酸酶，肝素钠注射液和顺铂注射液的细菌内毒素检查法可行性。方法：中国药典细菌内毒素检查法。结果；除ｄ外，其余原液及稀释液均于有干扰作用。结论：ｄ的原液及ａ的２０倍以上稀释液可用灵敏度为０．５ＥＵ／ｍｌ的鲎试剂作细菌内毒素检查，而ｂ，ｃ和ｅ尚需进一步探讨。     

磁性明胶微球体内分布实验研究

对磁性明胶微球进行了同位素标记。用γ-闪烁照相技术观察了磁性明胶微球在兔体内的分布。结果表明:靶部位的放射活性加磁场是未加磁场的15倍,而且施加磁场时间长和磁场强度大有利于磁性明胶微球定位于靶区。文中也介绍了自行设计的外加磁场装置。