Restricted expression of transgenic HLA-DRA gene in thymic epithelial cells and its role in acquisition of T cell tolerance to self-superantigens and processed DRα-derived peptide

We have established a set of transgenic mouse lines in which the HLA-DRA gene was expressed in different cell types. In one line (DRα-24), DRαEβ^b molecules were expressed on thymic medullary and cortical epithelial cells and all lineages of bone marrow-derived antigen-presenting cells (APC) except for thymic macrophages. By contrast, expression of the molecules in another line (DRα-30) was found on thymic medullary and cortical epithelial cells but not on bone marrow-derived APC in the thymus and periphery. To evaluate the role of thymic epithelial cells in acquisition of T cell tolerance, comparative analysis of DRα-24 and DRα-30 was performed. In DRα-30, T cells expressing TcR Vβ5 and Vβ11 were eliminated to comparable levels to those in DRα-24, suggesting that expression of the DRαEβ^b molecules on thymic epithelial cells are sufficient for clonal deletion of the self-superantigen-reactive T cells. In addition, CD4⁺ T cells from DRa-30 as well as those from DRα-24 were tolerant to DRα-derived peptide/I-A^b complex expressed on spleen cells from DRα-24 even in the presence of exogenous interleukin-2. These observations suggest that expression of the DRα chain in thymic epithelial cells could induce T cell tolerance directed toward naturally processed DRα-derived peptide bound to I-A^b molecules, probably via clonal deletion of the self-reactive T cells.     

A new method for histamine release from purified peripheral blood basophils using monoclonal antibody-coated magnetic beads

A new method for evaluating histamine release from purified basophils was developed. Basophil-containing leukocytes were directly purified from a small amount of peripheral blood using monoclonal antibody BA312-coated magnetic beads. The purified basophils still rosetted to magnetic beads maintained a normal response to anti-IgE and to dust mite allergen in comparison with the conventional method using washed leukocytes. This methodology facilitates the purification of basophils, anti-IgE- and allergen-induced histamine release, and subsequent histamine determination within only 3 h. The released histamine was analyzed by an enzyme-linked immunosorbent assay (ELISA) with a characteristic detection profile. Since all steps were performed in 96-well microplates, many clinical samples could be analyzed at the same time, permitting easy applications in routine laboratories.     

基于稀疏表示变量选择方法的影像遗传学数据分析

目的:采用影像遗传学研究方法探索精神分裂症的影像遗传学特征。方法:在传统稀疏回归模型的基础上，改进 了其在不同范数条件下进行变量选择的能力，形成一种基于稀疏表示变量选择算法，并将该算法应用于208 个受试者的 41 236个功能磁共振成像数据和722 177个单核苷酸多态性数据的综合分析。通过对两类数据施加不同的权重因子，并 使用不同的Lp （p=0、0.5、1）范数分别对模型进行求解，筛选出两类数据在不同条件下的显著特征。结果:基因DAOA和 HTR2A在3种范数下均被筛选出。此外，在影像学数据方面，发现中央前回、枕上回、顶下缘角回、角回、内侧和旁扣带脑 回、后扣带回脑区与精神分裂症相关，此发现与先前精神分裂症的临床医学研究结果一致。结论:基于稀疏表示变量选择 方法应用于影像遗传学数据分析是一个有效可行的途径，为今后精神分裂症的影像遗传学研究提供了一种新的研究 思路。     

妊高征患者产前及产后血小板活化状态的研究

采用流式细胞术对４２例正常晚孕妇女及５０例妊高征患者产前及产后７２小时Ｐ－选择素进行对比研究。结果：妊高征患者Ｐ－选择素含量明显大于正常晚孕妇女，Ｐ－选择素含量在轻、中及重度妊高征患者呈递增趋势，差异均有显著性，产后７２小时其Ｐ－选择素含量降至正常晚孕妇女水平。提示：Ｐ－选择素可作为妊高征早期诊断及监测病情的一个重要指标     

TCRγδ cells: Mysterious cells of the immune system

γδ cells participate in pathogenic infections and autoimmune conditions, yet, almost a decade after their discovery, little is known regarding their TCR repertoire or effector functions. Unlike MHC-restricted antigen recognition employed by TCRαβ cells, TCRγδ cells can recognize whole unprocessed antigens in an MHC-independent manner. The nature of positive and negative selection used to shape the repertoire of TCRγδ cells is unclear, especially in the nonlymphoid tissues where these cells predominate. While TCRγδ cells express an activated phenotype and are present in pathological conditions, their roles in immunological protection is unknown. This review will focus on our efforts to study these issues of TCRγδ biology.     

Fuzzy rules to predict degree of malignancy in brain glioma

The current pre-operative assessment of the degree of malignancy in brain glioma is based on magnetic resonance imaging (MRI) findings and clinical data. 280 cases were studied, of which 111 were high-grade malignancies and 169 were low-grade, so that regular and interpretable patterns of the relationships between glioma MRI features and the degree of malignancy could be acquired. However, as uncertainties in the data and missing values existed, a fuzzy rule extraction algorithm based on a fuzzy min-max neural network (FMMNN) was used. The performance of a multi-layer perceptron network (MLP) trained with the error back-propagation algorithm (BP), the decision tree algorithm ID3, nearest neighbour and the original fuzzy min-max neural network were also evaluated. The results showed that two fuzzy decision rules on only six features achieved an accuracy of 84.6% (89.9% for low-grade and 76.6% for high-grade cases). Investigations with the proposed algorithm revealed that age, mass effect, oedema, post-contrast enhancement, blood supply, calcification, haemorrhage and the signal intensity of the T1-weighted image were important diagnostic factors.     

Dietary selection for lysine by the chick

Broiler chicks were provided choices of synthetic diets (a) adequate or low in lysine, and (b) adequate in or devoid of lysine. In each case, chicks consumed some of each diet offered, but preference was shown for the adequate lysine diet. Growth rates of chicks given choices ranged from 80% of that of chicks fed an adequate lysine diet with no choice for two weeks, then growth rates fell to about 60% of those fed adequate lysine. In another study, chicks were fed a diet devoid of lysine but were offered pure L-lysine HCl in a separate feeder. These chicks selected some of the supplementary lysine, but their body weights were only 68% of the body weight of chicks fed an adequate lysine diet after 21 days. Chicks given a choice of diets prepared with an adequate quantity of either L- or D-lysine preferred with L-lysine diet but did not select sufficient quantity to reach normal growth. These observations indicate that chicks can discern the presence of L-lysine in diets or separately, but will not select sufficient quantity for maximum growth potential. A diet prepared with D-lysine was more acceptable than one completely devoid of lysine, suggesting some sensory recognition for lysine.     

Regulation and selection of patients

During the past decades health legislation and regulation have been on the increase in most industrialized countries. The growing role of government in the provision and financing of health care, the need to correct given aspects of health care and the mandate to protect the underprivileged have been some of the many reasons for increased regulation. Different regulatory approaches and their respective advantages and disadvantages are reviewed in this paper. Particular attention is given to the crucial issue of how to regulate the access to scarce resources and how to cope within a legislative approach with the resulting patient selection.     

中医穴位贴敷结合孟鲁司特钠治疗支气管哮喘患儿临床疗效

目的：分析中医穴位贴敷结合孟鲁司特钠治疗支气管哮喘患儿的临床效果。方法：选取河南省中医院2019年8月至2022年2月收治的90例支气管哮喘患儿,采用信封法分为对照组和观察组,各45例。对照组患儿采取孟鲁司特钠治疗,观察组患儿在对照组上联合中医穴位贴敷,比较两组患儿治疗效果。结果：治疗后观察组患儿用力肺活量（FVC）、第1秒用力呼气容积（FEV1）、呼气峰值流速（PEF）均高于对照组,差异具有统计学意义（P <0.05）;治疗后观察组患儿血清肿瘤坏死因子–α(TNF–α)、免疫球蛋白E(IgE)、降钙素原（PCT）水平均低于对照组,差异具有统计学意义（P <0.05）;治疗后观察组患儿日间及夜间哮喘症状评分均低于对照组,差异具有统计学意义（P <0.05）。结论：对支气管哮喘患儿采取中医穴位贴敷结合孟鲁司特钠可有效提高疗效,显著改善哮喘症状,改善血清学指标。