MR imaging of viscoelastic properties

Mechanical waves in magnetic resonance imaging, which have been suggested for possible clinical applications, were analyzed with regard to imaging of the viscoelastic properties of large objects. The method is based on the Larmor frequency modulation caused by the application of mechanical waves. Possible clinical applications include all diseases that result in a change in the mechanical properties of biologic tissues (eg, atherosclerosis).     

Measurement of contact impedance of electrodes used for deep brain stimulation

High frequency electrical stimulation by means of electrodes implanted into the brain has become an accepted technique for treatment of Parkinson's disease. The electrical field distribution normally inserted into the sub thalamic nucleus minimise abnormal brain activity. Square wave pulses of 1–3.6 V with duration of 60–90 μs at a frequency range of 130–185 pps are generally used. Every electrode unit consists of four cylindrical electrodes positioned in a row and can be switched on independently. This paper determines the contact impedance of the electrodes for different frequencies and proposes improvement to reduce the contact impedance between the electrodes and the brain. Measurements were performed by placing the electrodes in a tank filled with saline. Different frequencies were applied on two electrodes via a resistor. The current was measured through the resistor and the voltage was registered between one of the electrodes and a third non current carrying electrode. The obtained values were used to calculate the contact impedance. The result shows large contact impedance for the used frequency compared to the impedance of the treated tissue, which means that variation in contact impedance can result in variation in the electrical field applied to the tissue.     

赖型钩端螺旋体重组DNApCX7的特异性鉴定和限制性内切酶谱分析

本实验将赖型钩端螺旋体（简称钩体）ＤＮＡ基因库的克隆ｐＣＸ７制备成￣（３２）Ｐ－重组ＤＮＡ探针，对８个不同血清群的１７株问号状钩体、双曲钩体ＰａｔｏｃⅠ株以及细螺旋体３０５５株ＤＮＡ进行打点杂交；同时用１５种ＤＮＡ片断进行限制性内切酶谱分析。结果表明，该重组ＤＮＡ具有问号状钩体种（Ｓｐｅｃｉｅｓ）特异性，但与不同问号状钩体之间的同源性程度有差别；限制性内切酶谱分析发现ｐＣＸ７重组ＤＮＡ片段长约１．７ｋｂ，具有１个Ｂｇ１Ⅱ识别位点和３个ＢｓｔＢ１识别位点。     

HLA-A9 antibodies and epitopes

Fifty pregnancy alloantisera directed towards HLA-A23 and/or A24 antigens were investigated serologically in titration studies against the three sequenced HLA-A9 specificities, A23 (A*2301), A24 (A*2402) and A2403 (A*2403). The reaction patterns of the antisera fell into five categories which allowed the three HLA-A9 specificities to be easily differentiated. Based on the various titre cytotoxicity scores of the antisera five possible antibody specificities were defined: anti-A23; -A24; -A23/24; -A24/2403 and anti-A23/24/2403. One antiserum crossreacted with HLA-A1 and A24. Inspection of the amino acid sequences of 136 HLA-A, B and C molecules allowed the prediction of five unique epitopes corresponding to these antibody specificities, a possible epitope unique to A2403 and confirmation of a likely epitope shared by A1 and A24. These, together with the previously suggested epitopes HLA-A9/ A2/A28 and A1/A23/A24 together with the presence of Bw4 on the three HLA-A9 antigens suggests that the HLA-A9 family of antigens is characterized by a minimum of nine serologically definable epitopes.     

肾病患儿免疫细胞对肾小球上皮细胞合成基质的影响

目的为了明确免疫细胞对肾小球上皮细胞（ｇｌｏｍｅｒｕｌａｒｅｐｉｔｈｅｌｉａｌｃｅｌＧＥＣ）合成功能的直接作用。方法应用肾小球细胞体外培养，同位素掺入及放射免疫技术，以总胶原，层粘连蛋白，Ⅲ型前胶原及Ⅳ型胶原的合成为观察指标，动态研究了不同病理类型原发性肾病综合征（ＩＮＳ）患儿外周血单个核细胞（ｐｅｒｉｐｈｅｒａｌｂｌｏｏｄｍｏｎｏｎｕｃｌｅａｒｃｅｌＰＢＭＣ）对ＧＥＣ生物功能的影响。结果（１）肾病极期未经激素治疗组（未治组）ＰＢＭＣ上清明显促进了ＧＥＣ合成层粘连蛋白；（２）未治ＰＢＭＣ上清抑制了ＧＥＣ合成总胶原；（３）未治组ＰＢＭＣ上清促进了Ⅲ型前胶原的合成，而对Ⅳ型胶原的合成无明显影响；（４）肾病患儿ＰＢＭＣ的上述作用与是否足量激素治疗有关，而与尿蛋白能否阴转、肾组织病理类型、肾病临床类型等无直线相关关系。结论原发性肾病患儿循环免疫细胞可影响ＧＥＣ合成细胞外基质的功能。免疫细胞的这种活性可被激素治疗改变。     

急性病毒性肝炎住院患者血清学分型与流行病学分布研究

本文收集了西安市住院急性病毒性肝炎患者血清标本２９３份，用ＥＬＩＳＡ进行分型检测，并作流行病学调查。结果发现：甲肝占６５．１９％，乙肝占１０．９２％，丙肝占４．７８％，丁肝占３．７５％，戊肝占４．４４％，诊断不明者占１０．９２％。结果表明，在西安市住院的急性病毒性肝炎中，甲肝为主要类型；与以往结果比较，甲肝患者的发病年龄明显后移；除乙肝外，各型肝炎中男性均多于女性，尤以丁肝和戊肝为著；甲肝有明显的     

Bcl-2和Caspase-9对儿童癫痫持续状态近期预后的预测价值

目的探讨血清B细胞淋巴瘤相关蛋白-2(Bcl-2)和半胱氨酸天冬氨酸蛋白酶-9(Caspase-9)对儿童癫痫持续状态(SE)近期预后的预测价值。 方法选择SE患儿62例为SE组,选择同期体检健康儿童62例为对照组;按照预后将SE患儿分为预后不良组和预后良好组。癫痫持续状态严重程度量表(STESS)评估SE患儿SE严重程度。ELISA检测各组血清Bcl-2和Caspase-9水平。结果SE组Bcl-2和Caspase-9水平高于对照组(P＜0.05)。预后不良组和预后良好组STESS评分、Bcl-2和Caspase-9水平比较,差异有显著性(P＜0.05)。STESS评分、Bcl-2和Caspase-9是影响SE患儿近期预后的独立影响因素(P＜0.05);入院血清Bcl-2和Caspase-9联合检测对SE患者近期预后具有较好的预测效能(P＜0.05)。 结论血清Bcl-2和Caspase-9是SE患儿近期预后的有效预测指标。     

SNHG6靶向miR-101/TGFBR1促进AMI小鼠左心室心肌纤维化

目的探讨SNHG6对急性心肌梗死(AMI)小鼠左心室心肌的影响。 方法将30只雄性C57/BL6小鼠构建成AMI小鼠后随机均分为AMI组、AMI+SNHG6组、AMI+miR-101-3p组、AMI+SNHG6+miR-101-3p组、AMI+miR-101-3p+TGFBR1组,另设正常小鼠6只为假手术组。qRT-PCR检测AMI小鼠SNHG6、miR-101-3p表达水平。心脏彩超检测各组小鼠左室射血分数(LVEF);马松和天狼星红染色法以及免疫组化分析各组小鼠左心室心肌纤维化变化。将H9C2细胞株分为阴性对照组(转染空质粒)、SNHG6组(转染质粒SNHG6)、miR-101-3p组(转染质粒miR-101-3p)。Western blotting检测各组TGFBR1蛋白表达;采用双荧光素酶报告基因法预测并验证SNHG6/miR-101-3p/TGFBR1荧光素酶活性及调控机制。 结果AMI小鼠较假手术组SNHG6表达显著增加,miR-101-3p降低(P＜0.05)。与AMI组比较,AMI+SNHG6组小鼠LVEF降低,心肌纤维化程度加重(P＜0.05);AMI+miR-101-3p组LVEF升高,心肌纤维化程度减轻(P＜0.05)。AMI+SNHG6+miR-101-3p组较AMI+SNHG6组LVEF升高、心肌纤维化程度减轻(P＜0.05),而AMI+miR-101-3p+TGFBR1组较AMI+miR-101-3p组LVEF降低、心肌纤维化程度加重(P＜0.05)。双荧光素酶报告基因法验证显示,miR-101-3p组SNHG6、TGFBR1野生型质粒的荧光素酶活性较阴性对照组明显降低(P＜0.05)。 结论SNHG6抑制miR-101-3p上调TGFBR1加重AMI小鼠左心室心肌纤维化。     

Diffuse type of senile plaques in the cerebellum of Alzheimer-type dementia demonstrated byβ protein immunostain

Summary We studied senile plaques (SP) in the cerebella of six autopsied subjects with Alzheimer-type dementia (ATD) and ten non-ATD autopsied subjects between the ages of 78 and 90. Neither SP nor amyloid angiopathy (AA) was observed in any of the non-ATD subjects. In the four of the six ATD subjects, diffuse plaques in the molecular layer were seen as ill-defined areas of fine fibrillar materials by protein immunostaining with formic acid pretreatment, the modified Bielschowsky stain, and periodic acid-methenamine silver (PAM) stain. The plaques were not visible with Bodian, Congo red, or periodic acid-Schiff stains. Compact plaques in the Purkinje cell or in the granular cell layers were found in three of the six subjects. Their amyloid core was often surrounded by areolar amyloid deposits. AA was observed in three of the six subjects. The argyrophilia of the diffuse and compact plaques, demonstrated by the modified Bielschowsky and PAM stains, became undetectable when the sections were first treated with formic acid. Such treatment made the plaques immunoreactive with protein antiserum. The findings suggested that cerebellar diffuse plaques and compact plaques consist mainly of an amyloid component, and are characteristic of ATD.