A human B cell differentiation antigen selectively expressed on mature B cells identified by a monoclonal antibody (HB-2)

A monoclonal IgM antibody (HB-2), produced against a membrane antigen on the Raji, B cell line, reacted by indirect immunofluorescence with 2 to 40% of lymphoblasts from the B cell lines, Raji, Daudi, SN-1036, and SB but not with other types of cell lines, including pre-B, myeloid, melanoma, or T cells. HB-2 antibody reacted with 10 ± 3% of normal blood mononuclear cells, and was unreactive with monocytes, granulocytes, platelets, or erythrocytes. Two-color immunofluorescence revealed that HB-2 antigen expression was confined to cells bearing surface Ig. An interesting finding was the fact that 25% of plasmablasts induced by pokeweed mitogen also expressed the HB-2 antigen. However, pre-B and plasma cells from normal bone marrow did not express the HB-2 antigen either on their membrane surface or in their cytoplasm. Analysis of 85 leukemias revealed that the HB-2 antigen was expressed on acute and chronic B cell leukemias and Burkitt's lymphomas, but not on malignacies of pre-B, T, myelocytic, or plasma cells. The results suggest that expression of the HB-2 antigen is confined to mature B cells.     

健康婴幼儿早期教育的效果及影响因素

目的:探讨健康足月婴幼儿早期教育(简称早教)的效果及其影响因素,为开展健康足月婴幼儿早教工作提供理论和实践依据.方法:以自愿来早教中心进行早教的健康足月婴幼儿52名为实验组.另选择与其基本条件相同的婴幼儿52名为对照组.实验组除进行早教的各项培训工作外,还于培训前和培训3、6、9个月后各测评发育商(DQ)1次,以评定早教的效果.对照组无早教,于入组时和9个月后各测评DQ 1次.结果:①实验组经培训9个月后,其DQ平均值提高21.9±13.6分,高于对照组观察9个月后DQ平均值提高分3.0±3.0,差异有统计学意义(t=9.757,P＜0.001).②实验组培训前DQ值有23例低于中等水平;培训后有27例高于中等水平,其中8例DQ≥130.③多元逐步回归分析结果表明,影响DQ增加的主要因素是完成家庭训练作业的程度(R2=0.57),其次是到早教中心训练的次数(R2=0.019),再次是性别(R2=0.016).结论:早教对健康足月婴幼儿的大脑发育、智能发展、运动发育具有显著效果,是提高婴幼儿DQ的有效措施.     

Gastrointestinal stromal tumours (GISTs) negative for KIT (CD117 antigen) immunoreactivity

Gastrointestinal stromal tumours (GISTs) are currently defined as mesenchymal tumours of the gastrointestinal tract that express KIT receptor tyrosine kinase. However, a small subgroup of tumours that fulfil the clinical and morphological criteria for GISTs lack KIT expression. So far, the biological features of these tumours have rarely been addressed. The present study describes seven gastrointestinal stromal neoplasms that presented clinicopathological features typical of GISTs but showed absence of CD117 expression as detected by immunohistochemistry. The tumours originated from the stomach (n = 5), duodenum (n = 1), and colon (n = 1), showing histologically either predominantly epithelioid (n = 3), mixed spindled and epithelioid (n = 2), or anaplastic/spindle cell (n = 2) type features. CD34 and alpha-smooth muscle actin (alpha-SMA) positivity was present in four and three tumours, respectively. Chromosomal analysis was performed in two cases, both showing losses of chromosomes 14, 22, and 1p, which is the characteristic feature of GISTs. Dual-colour interphase fluorescence in situ hybridization (FISH) analysis, utilizing chromosome 1p-, 14-, and 22-specific probes, revealed a similar cytogenetic profile in the remaining five tumour specimens. Mutational analysis of exons 9, 11, 13, and 17 of KIT, and exons 12 and 18 of PDGFRA was performed in all cases by denaturing high-pressure liquid chromatography (DHPLC) pre-screening, followed by direct sequencing. None of the tumours showed KIT mutant isoforms. Three tumours harboured PDGFRA exon 18 activating mutations; two were Asp --> Val(842) missense substitutions and one was a DIM842-844 amino acid deletion. KIT and PKC theta (protein activated in interstitial cells of Cajal and GISTs) expression was determined by western immunoblotting of the total cell lysates from three tumour biopsies. None of these three tumours expressed KIT, while all specimens showed expression of PKC theta protein. These findings indicate that there is a subgroup of KIT-negative GISTs that exhibit the same morphological, cytogenetic, and molecular features as KIT-positive tumours. While intragenic PDGFRA activating mutations are present in some of these tumours, the oncogenic events underlying the pathogenesis of the others remain unknown.     

大学生特殊完美主义量表的编制

目的:编制大学生特殊完美主义量表。方法:用探索性因素分析发展量表的初步理论结构,再用验证性因素分析证明理论结构的合理性和正确性,以此为基础编制了大学生特殊完美主义量表,并对正式问卷测量结果进行探索性因素分析和验证性因素分析。结果:探索性因素分析确定量表含5个因素,解释了总变异的57.54%;#系数、分半信度、重测信度分别为0.648～0.781,0.664～0.790,0.720～0.779;验证性因素分析显示拟合指数χ2/df,GFI,AGFI,NFI,NNFI,RMSEA,CFI,IFI分别为2.32,0.91,0.88,0.84,0.88,0.06,0.90,0.90。结论:该量表的信效度都达到了测量学的要求。     

Changes in myocardial capillary diffusion capacity during infusion of vasoactive drugs

The present study investigated how variations in coronary vascular resistance and metabolic demand affected myocardial capillary diffusion capacity. Hearts from Wistar rats were perfused with Krebs-Henseleit-albumin buffer in a Langendorff preparation, where heart rate (HR), contractility (dP/dt_max) and myocardial oxygen consumption (MVO₂) were recorded continuously. Myocardial capillary diffusion capacity was measured as the permeability surface area product (PS) for Cr-EDTA and vitamin B₁₂ by the single injection colorimetric indicator dilution method. After base-line recordings without drugs, angiotensin II + arginine-vasopressin was infused, which increased coronary vascular resistance by 90%, stimulated HR by 11%, decreased dP/dt_max by 21% and reduced MVO₂ by 4%. PS_Cr-EDTA and PS_B12, decreased by 24 and 27%, respectively, leaving the ratio PS_Cr-EDTA/PS_B12 unchanged indicating unaltered capillary permeability. Moreover, the reductions in MVO₂ and PS correlated significantly. During vasodilation: (1) nitroprusside-NA stimulated HR by 7% and decreased dP/dt_max by 14%; (2) adenosine reduced dP/dt_max by 37% and decreased MVO₂ by 9%; and (3) isoproterenol increased HR, dP/dt_max and MVO₂ by 53, 76 and 9%, respectively. However, all three vasodilators reduced PS_Cr-EDTA and PS_B12 in parallel by 7–25% leaving PS_Cr-EDTA/PS_B12 unchanged. Thus, maximal estimated diffusion capacities were obtained during spontaneous coronary vascular tone, most likely reflecting maximal capillary recruitment in the Krebs-Henseleit-albumin perfused heart. The derecruiting effects of the vasoconstrictors were partly overridden by metabolic factors, while the reductions of PS after vasodilation more likely were due to increased heterogeneity in coronary flow.     

内骨架一体化小腿假肢的生物力学研究

一体化假肢是以聚合物为材料从接受腔到假腿一体成型的新型下肢假肢，它比传统型假肢更经济、美观、轻便，具有较大的应用前景。目前的相关研究主要集中在设计与制作及少量的临床研究方面。由于一体化假肢与传统型假肢在结构上的差异，有必要对其进行应力分析。本研究的目的是开展内骨架一体化假肢的生物力学研究，本研究基于内骨架一体化小腿假肢的真实几何构型，建立三维有限元模型，计算该模型在模拟Heel OH步态时相的载荷作用下的应力分布；在保持该模型的几何形状不变的情况下，建立了三个不同壁面厚度的一体化小腿假肢的有限元模型，分析壁面厚度对一体化小腿假肢应力分布的影响；通过分别赋予模型四种不同高分子聚合物的材料力学特性值，分析不同材料的一体化假肢的应力分布特点；分别对模型施加与正常步态的五个典型时相对应的载荷，分析一体化小腿假肢在各步态时相的应力分布特点。本研究结果对一体化假肢设计有指导价值。     

Trabecular Shear Stresses Predict <Emphasis Type="Italic">In Vivo</Emphasis> Linear Microcrack Density but not Diffuse Damage in Human Vertebral Cancellous Bone

Linear microcracks and diffuse damage (staining over a broad region) are two types of microscopic damage known to occur in vivo in human vertebral trabecular bone. These damage types might be associated with vertebral failure. Using microcomputed tomography and finite element analysis for specimens of cancellous bone, we estimated the stresses in the trabeculae of human vertebral tissue for inferosuperior loading. Microdamage was quantified histologically. The density of in vivo linear microcracks was, but the diffuse damage area was not, related to the estimates of von Mises stress distribution in the tissue. In vivo linear microcrack density increased with increasing coefficient of variation of the trabecular von Mises stress and with increasing average trabecular von Mises stress generated per superoinferior apparent axial stress. Nonlinear increase in linear crack density, similar to the increase of the coefficient of variation of trabecular shear stresses, with decreasing bone stiffness and bone volume fraction suggests that damage may accumulate rather rapidly in diseases associated with low bone density due to the dramatic increase of shear stresses in the tissue. © 2003 Biomedical Engineering Society. PAC2003: 8719Rr, 8719Xx, 8759Ls, 8759Fm, 8710+e     

逆转录病毒载体介导的HBsAg抗原表达及其稳定性研究

目的 探讨逆转录病毒载体介导的HBsAg抗原的表达及其稳定性。方法 将HBsAg基因插入逆转录病毒载体PLXSN中，构建成重组逆转录病毒载体。用电穿孔法转染PA317细胞，包装成假病毒颗粒，在不同温度下冻存。于不同时间用假病毒颗粒感染HepG2、NIH3T3及293细胞，用RT—PCR及ELISA法检测HBsAg表达；以感染后G418抗性克隆形成数确定假病毒颗粒的活力。结果 在各个时间段HBsAg表达量均差异无显著性。在-20℃冻存时，6个月后克隆数即下降过半，12个月后仅形成少数克隆，24个月后无克隆形成；在-40℃冻存时12个月后HepG2、NIH3T3、293形成的克隆数分别为121、332和89，24个月后分别为42、137和43，与冻存前比较差异有显著性；-70℃冻存时，24个月后克隆数分别为159、463和112，与冻存前比较差异无显著性。结论 HBsAg重组逆转录病毒颗粒在-70℃保存2年后，病毒活力未受明显影响，HBsAg表达量亦无明显改变。     

基于主成分分析-神经网络的非编码RNA预测

预测非编码RNA对认识其调控功能具有重要意义。选择单核苷酸和二核苷酸出现频率作为神经网络分类特征,运用主成分分析方法降低输入数据的维数,去除数据间的相关性,采用Levenberg-Marquardt算法改善网络训练速度。对数据集的测试结果表明,此方法对细菌混合ncRNA的预测精度达到81.3%,对原核生物tRNA的预测精度达到93.3%,表明该方法能有效预测原核生物ncRNA。预测结果还发现两种古细菌的ORF序列在序列特征上与其它细菌和古细菌存在差别。