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。     

隐睾患儿血清FSH、LH、T水平及其临床意义

目的研究隐睾患儿血中促卵泡激素(FSH)、促黄体激素(LID和睾酮(T)激素水平变化,探讨其临床意义及在隐睾症发病中的作用。方法应用化学发光免疫技术检测42例隐睾症和23例斜疝(对照组)患儿血清FSH、LH、T水平。结果单侧隐睾症组和斜疝组之间血清FSH、LH和T水平无显著性差异(P＞0．05)；(2)双侧隐睾组血清FSH水平高于斜疝组,差别有统计学意义(P＜0．05)；单侧隐睾症组血清FSH高于斜疝组,低于双侧隐睾症组,差别无统计学意义(P＞0．05)。结论(1)血清中性激素LH和T水平的变化在隐睾发生中并不起主要作用；(2)血清FSH水平的升高可能反映睾丸功能损害严重程度。     

精神分裂症服用氯氮平能降低其甲状腺素水平的对照分析

目的探索氯氮平治疗是否影响T3、T4和TSH水平.方法对17例精神分裂症患者,给予氯氮平治疗第4天和第4周末分别测定T3、T4和TSH水平.结果治疗第4周末的T3(3.309±0.689)、T4(9.449±1.941)水平比第4天的T3(3.915±0.850)、T4(11.178±2.180)水平明显降低(P均＜0.05).结论氯氮平治疗能降低甲状腺素水平.     

有机氮源对红霉素发酵影响的具体分析

红色糖多孢菌的摇瓶培养基中使用不同有机氮源时红霉素的效价明显不同。通过对不同有机氮源所含营养成分的逐步回归分析,我们得到有机氮源中的苏氨酸为影响红霉素效价的主要因子。最后向对照培养基中添加苏氨酸,则使红霉素的效价比对照培养基提高了22.85%。     

131Ⅰ治疗Graves病剂量探讨

目的　探讨1 31 Ⅰ治疗Graves病时 ,不同的剂量计算方法与治愈率以及治疗后并发症的关系。方法　在计算治疗Graves病所需1 31 Ⅰ时 ,分别采取不同的两种计算方法 ,观察两者治愈率及并发症的发生情况 ,并做多因素对比分析。结果　治疗组较对照组 1次治愈率提高约 12 % ,近期甲状腺功能减退延续为永久性甲状腺功能减退者亦明显减少 ,治疗效果明显优于后者。结论　1 31 Ⅰ治疗剂量计算时 ,既要有公式的规范性 ,又要有根据具体情况调节的灵活性 ,即可明显提高治疗效果     

病毒感染与小儿短暂性滑膜炎关系的研究

探讨小儿短暂性滑膜炎与病毒感染 ,特别是柯萨奇B组病毒 (CVB)感染的关系。方法 :采用酶联免疫吸附试验 (ELISA)对 16 2例小儿髋关节短暂性滑膜炎患儿静脉血和其中的 2 1例关节腔液进行病毒IgM抗体检测 ,柯萨奇病毒B组 (CVB)阳性者进行血清学分型及病毒分离。结果 :在 16 2例静脉血样本中病毒IgM阳性 6 2例 ,占总检数的 38.2 7% ,CVB -IgM2 6例占 16 .0 5 % ,AdV -IgM 19例占 11.73% ,CMV -IgM 10例占 6 .17% ,RSV -IgM 4例占 2 .4 7% ;在关节腔液中检出 9例CVB阳性 ,血清学分型 8例为CVB3,1例为CVB4 ,并分离出 1例CVB3。结论 :CVB和腺病毒 (AdV)是小儿髋关节短暂性滑膜炎感染的主要病毒 ,而且以CVB3为主。     

A PRELIMINARY STUDY OF THE ACTION OF MALE HOR MONE ON HIGH DENSITY LIPOPROTEIN-CHOLESTEROL

Plasma testosterone and estradiol are determined in 72 patients with abnormal high density lipoprotein. cholesterol (HDL-C) and high density lipoprotein cholesterol/total cholesterol (H/T) ratio values, and in 72 randomly chosen males with normal HDLC and H/T values. The results showed that plasma testosterone levels in the groups with abnormal HDL-C and H/T were obviously lower than those in the controls. Statistically significant differences were found in all the abnormal groups in comparison with the controls (P0.20). Testosterone levels lowered further with increasing age in the groups with abnormal HDL-C and H/T., the most obvious drops were in the groups around 56 years of age (P<0.005). The data indicate that male hormone deficiency may reduce HDL-C and H.'T and facilitate the process of atherosclero_is. Therefore, it seems rational to treat such patients with male sex hormone preparations or to use the traditional Chinese medicines which strengthen Yang (maleness) in a new attempt to treat and prevent CHD.