聚甲氧基硅氧烷及其功能化产物研究Ⅱ.分子结构表征

通过正硅酸甲酯(TMOS)的水解缩合反应制备了聚甲氧基硅氧烷(PMOS)，其分子式可表示为：[SiOa(OH)b(OCH3)c]n。用丙烯酸-2-羟乙酯(HEA)进行酯交换后，制的功能化产物聚丙烯酰氧基甲基硅氧：烷(PAMOS)，其分子式可表示为：[SiOd(OH)c(OCH3)f(OCH2CH2OCOCH=CH2)g]k。通过二氧化硅分析、红外光谱(FTIR)、凝胶渗透色谱(GPC)等方法确定了分子式中a、b、c、n及d、e、f、g、k的值，是一种比较方便、快捷且准确的方法。     

Involvement of Cerulospinal Glutamatergic Neurotransmission in Fentanyl-induced Muscular Rigidity in the Rat

Background: Investigators in the authors' laboratory previously established the critical participation of the cerulospinal noradrenergic pathway in muscular rigidity elicited by fentanyl. The identification of colocalization of glutamate with tyrosine hydroxylase in most locus ceruleus neurons suggests a role for cerulospinal glutamatergic neurotransmission in fentanyl-induced muscular rigidity. This suggestion and the subtype(s) of glutamate receptors involved were investigated here.

Methods: Electromyographic signals activated by bilateral microinjection of 2.5 micro gram fentanyl into the locus ceruleus were recorded differentially from the left sacrococcygeus dorsi lateralis muscle of adult male Sprague-Dawley rats. The effect of intrathecal administration at the lower lumbar spinal cord of various N-methyl-D-aspartate (NMDA) and non-NMDA receptor antagonists or agonists on this index of muscular rigidity was studied. Rats were under mechanical ventilation, and intravenous infusion of ketamine (30 mg [center dot] kg sup -1 [center dot] h sup -1) was maintained until 10 min before fentanyl was administered.

Results: Microinjection of fentanyl bilaterally into the locus ceruleus increased the root mean square and decreased the mean power frequency values of electromyographic signals. The efficacy of fentanyl to elicit muscular rigidity in this manner was significantly reduced by previous intrathecal administration of either 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate (MK-801), D-(-)-2-amino-5-phosphonovaleric acid (AP5), or (+/- (CPP). Intrathecal administration of kainic acid or NMDA also resulted in significant electromyographic activation.     

中药饮片加工炮炙在临床中的意义

本文简述了中药炮炙的根据、原理、方法以及各种不同辅料和炮炙方法对饮片药性与作用的影响。说明不同的炮炙方法可以直接影响和改变中药的药性和作用,影响到临床疗效,因此,必须重视中药饮片的炮炙工作。以确保临床安全有效的用药。     

Purification and characterization of a kinase specific for the serine- and arginine-rich pre-mRNA splicing factors.

Members of the SR family of pre-mRNA splicing factors are phosphoproteins that share a phosphoepitope specifically recognized by monoclonal antibody (mAb) 104. Recent studies have indicated that phosphorylation may regulate the activity and the intracellular localization of these splicing factors. Here, we report the purification and kinetic properties of SR protein kinase 1 (SRPK1), a kinase specific for SR family members. We demonstrate that the kinase specifically recognizes the SR domain, which contains serine/arginine repeats. Previous studies have shown that dephosphorylated SR proteins did not react with mAb 104 and migrated faster in SDS gels than SR proteins from mammalian cells. We show that SRPK1 restores both mobility and mAB 104 reactivity to a SR protein SF2/ASF (splicing factor 2/alternative splicing factor) produced in bacteria, suggesting that SRPK1 is responsible for the generation of the mAb 104-specific phosphoepitope in vivo. Finally, we have correlated the effects of mutagenesis in the SR domain of SF2/ASF on splicing with those on phosphorylation of the protein by SRPK1, suggesting that phosphorylation of SR proteins is required for splicing.     

Enhancement of fibronectin synthesis and fibrillogenesis by BMP-4 in cultured rat osteoblast.

The skeletal extracellular matrix produced by osteoblasts contains the glycoprotein fibronectin (Fn), which regulates the adhesion, differentiation, and function of osteoblasts. Fn fibrillogenesis is involved in the process of bone mineralization. Bone morphogenetic proteins (BMPs) can be isolated from organic bone matrix and are able to initiate de novo cartilage and bone formation. In this study, the effect of BMP-4 on Fn fibrillogenesis in cultured rat osteoblasts was examined. BMP-4 enhanced Fn synthesis and extracellular Fn assembly in primary cultured osteoblasts. In addition, the extracellular assembly of Fn from exogenously applied soluble human Fn was also increased by BMP-4. It has been reported that alpha5beta1 integrin is related to Fn fibrillogenesis. The synthesis of both alpha5 and beta1 integrins was upregulated by BMP-4. Immunocytochemistry showed that the clustering of alpha5 and beta1 integrins was also increased by BMP-4. BMP-4 increased fibril formation of Fn and the adhesion of osteoblasts onto Fn matrix, which was inhibited by disintegrin triflavin and Gly-Arg-Gly-Asp-Ser (GRGDS) peptide. Phosphorylation of extracellular signal-regulated kinase (ERK) and focal adhesion kinase (FAK) was increased by BMP-4. Enhancement of extracellular Fn fibrillogenesis and the mRNA expression of beta1 integrin by BMP-4 were inhibited by ERK kinase (MEK) inhibitor PD98059. These results suggest that the enhancement of extracellular Fn fibrillogenesis by BMP-4 in cultured osteoblasts is related to the increase of the synthesis of Fn and clustering of alpha5 and beta1 integrins. ERK is involved in the signaling pathway of BMP-4 in regulating Fn fibrillogenesis in osteoblasts.     

Relation between exposure to respirable silica dust and silicosis in a tungsten mine in China.

To estimate the quantitative relation between exposure to respirable silica dust and risk of an attack of silicosis, 1151 workers exposed to silica dust and employed from 1958 to 1987 in a tungsten mine in China were investigated. The results showed that the ratio of respirable silica dust concentration to total silica dust concentration was 0.529. Then, the total silica dust concentration in historical surveillance and monitoring data was converted to respirable silica dust concentration. The free silica content in respirable dust determined by x ray diffraction averaged 24.7%. Multiple logistic regression was used for the dichotomous dependent variables (presence or absence of silicosis). The independent variables in the multiple logistic regression with presence of silicosis as the dependent variable were age when first exposed, tuberculosis (presence or absence), and cumulative exposure to respirable silica dust. The partial regression coefficient of individual cumulative exposure was estimated as 0.079. It implied a positive association between exposure to respirable silica dust and risk of an attack of silicosis. The exposure limit for respirable silica dust was estimated as 0.24 mg/m3 under given conditions.     

实验动物大白鼠型流行性出血热流行病学和临床症状调查

本文对59名接触实验动物大白鼠引起23例流行性出血热(EHF)的流行病学和临床症状进行了调查,发病率为38.98%。发病的有副教授、讲师、助教、研究生等。发病多在春季,年龄组在21～40岁,男多于女。经间接免疫荧光技术检查,大白鼠肺EHFV抗原阳性率为32.69%。临床分型以中型为多,其次为重型和轻型。临床症状以发热、头痛、腰痛、全身痛、食欲不振、酒醉貌为主,没有死亡病例。血清间接免疫荧光抗体IgG在1:320～1:5 120之间的占91.30%。     

逆行灌注心脏不停跳心肌保护的实验研究

目的：探讨逆行灌注心脏不停跳心肌保护的效果。方法：中国大白兔32只随机分为4组，每组8只，A组（对照组），B组（心脏不停跳组，血温34℃），C组（温血心脏麻痹液组，血温34℃），D组（冷血心脏麻痹液组，血温4℃）。采用离体兔心左室做功模型，经冠状静脉窦逆行灌注稀释血液或血停搏液60min。比较观察心功能、冠脉排出液心肌酶谱、心肌组织乳酸、心肌细胞内游离钙浓度、心肌细胞膜ATP酶活性、心肌细胞膜脂质过氧化产物丙二醛含量的变化。结果：B组心功能恢复、心肌细胞膜ATP酶活性显著优于C组和D组，C组优于D组；B组心肌酶漏出、乳酸生成量、心肌细胞内游离钙浓度、心肌细胞膜丙二醛（MDA）含量低于C组和D组，C组低于D组。结论：常温氧合血逆灌心脏不停跳良好的心肌保护效果与其减轻自由基损伤，较好地保持细胞内外Ca^2 平衡，减轻细胞内钙超载，保护细胞膜酶功能有关。     

病毒性心肌炎及扩张型心肌病患者心内膜心肌活检标本中免疫球蛋白的检测

对病理学确诊的25例病毒性心肌炎（VMC）和10例扩张型心肌病（DCM）患者心内膜心肌活检标本，运用ABC技术，进行了免疫球蛋白IgG、IgM、IgA和补体C3的检测。结果：20例VMC和9例DCM的标本中，发现了IgG和IgM的沉积，主要分布于心肌肌膜和毛细血管内皮，IgG的肌膜沉积与同步做的病理切片中观察到的心肌细胞坏死和炎性细胞浸润有病理形态学联系。两组患者中均未发现IgA和C3沉积。结果显示，IgG是参与VMC和DCM心肌损伤的主要免疫球蛋白，心肌病变与抗体诱导的免疫反应有关。     

经皮肺活检及支气管肺泡灌洗对周围性肺疾病诊断的临床价值

目的：探讨经皮肺活检及支气管肺泡灌洗(BAL)对周围性肺疾病诊断的价值。方法：对以结节或块状阴影为主的52例病人行经皮肺活检；对以弥漫性周围性肺疾病为主的33例病人行BAL检查；对采用两种不同方法的检查结果进行阳性率分析。结果：52例经皮肺活检对肺周围性病变诊断敏感性为88％，特异性100％。33例行BAL检查对结核及恶性弥漫性肺周围性病变诊断敏感性为75％～80％，特异性100％。结论：BAL检查及经皮肺活检对肺周围块状阴影或弥漫性病变的确诊有很高价值。