Study on structural gene expression in human insulinoma

A human insulinoma cDNA library was constructed in the expression plasmid vector pUEX1. The clone pUEX1Ins12 was selected by means of hybridization with an insulin probe. It codes for full size amino acid sequence preproinsulin. The bacterial strain pUEX3Ins8 producing proinsulin as beta-galactosidase fusion protein was obtained for the use of recombinant protein as an antigen in an ELISA to detect serum antibodies in subjects with IDDM. Recombinant clones containing the middle, N- and C-terminal domains of the GAD65, the major autoantigen in IDDM, were constructed in pVEX1. These clones may become important tools to study the nature of GAD autoreactivity in IDDM. The clone pHICEO.9 was selected from the human insulinoma cDNA library by immunoscreening with total human insulinoma protein antibodies. This clone expresses the C-terminal fragment of human cholesterol esterase/lipase containing its antigenic determinant and can be used for blood lipase determination. Four clones containing cDNA inserts (0.47-1.42 kb) without any significant homologies to the known sequences in the Gene Bank were obtained by means of statistic selection.     

Suicide in patients with Parkinson''s disease. An epidemiological study

The purpose of this study was to estimate the risk of suicide for patients with Parkinson's disease (PD) in Denmark compared with that in the background population. The study involved 458 patients with a PD diagnosis, 226 men and 232 women. The follow-up period to either death or end of follow-up on December 31, 1990 was 0 to 17 years, mean 5.7 years. Deaths in the follow-up period amounted to 254, 135 men and 119 women. Two women committed suicide. The number of expected suicides was 1.06 for men and 0.55 for women, a total of 1.62. Neither for men nor for women was the difference between expected and observed suicides statistically significant.     

Validation of an inhibition ELISA using a monoclonal antibody for foot-and-mouth disease (FMD) primary diagnosis

An inhibition ELISA (IH-ELISA) test for foot-and-mouth disease virus (FMDV) was validated using 106 epithelial samples from suspected cases of FMD in Argentina submitted to the Argentine National Diagnostics Laboratory (GELAB) over a period of 12 months and examined in parallel with the complement fixation test (CFT). IH-ELISA was found to be more sensitive, detecting 25% (26 samples) more FMDV positives than the CFT in original suspensions of field samples. The effect of storage conditions on 12S stability was examined. Plates stored at 4 degrees C blocked with 1% ovalbumin and plates stored at -20 degrees C with or without blocking buffer could be used for at least 90 days. When various brands of polystyrene plates were compared for 12ps adsorption it was found that those microplates of higher binding capacity were more efficient.     

Envelope glycoprotein gp120 of human immunodeficiency virus type 1 alters ion transport in astrocytes: implications for AIDS dementia complex

Infection by human immunodeficiency virus type 1 (HIV-1) is often complicated by a variety of neurological abnormalities. The most common clinical syndrome, termed acquired immunodeficiency syndrome (AIDS) dementia complex, presents as a subcortical dementia with cognitive, motor, and behavioral disturbances and is unique to HIV-1 infection. The pathogenesis of this syndrome is poorly understood but is believed to involve interactions among virally infected macrophages/microglia, astrocytes, and neurons. In this study, we show that exposure of primary rat and human astrocytes to heat-activated HIV-1 virions, or to eukaryotically expressed HIV-1 and HIV-2 envelope glycoproteins (gp120) stimulates amiloride-sensitive Na+/H+ antiport, potassium conductance, and glutamate efflux. These effects are blocked specifically by amiloride, an inhibitor of Na+/H+ antiport and by the selective removal of gp120 with immobilized monoclonal antibody. As a result of modulation of astrocytic function by gp120, the ensuing neuronal depolarization and glutamate exposure could activate both voltage-gated and N-methyl-D-aspartate-regulated Ca2+ channels, leading to increases in intraneuronal Ca2+ and neuronal death. These findings implicate the astrocyte directly in the pathogenesis of AIDS dementia complex.     

编码器自动监测与故障诊断系统的研究与实现

文中介绍了某大型机电设备编码器的实时监测与故障诊断系统的设计工作.系统采用在线和离线两种工作方式,实现了接触式编码器的监测和诊断.系统硬件主要电路板基于PC104总线结构,18路I/O通道(9路输入,9路输出)完成9位编码器的检测和诊断.系统软件界面友好,巧妙地实现了格雷码与角度值的转换.本系统对其他编码器自动监测和故障诊断系统具有重要的借鉴意义.     

形势要求机床工具工业必须加快增长方式的转型(一)

1999年以来，我国国民生产总值持续快速稳定增长。表1是这期间国民生产总值增长情况。     

成都市彭青公路后张法预应力混凝土空心梁板施工技术研究

成都市彭青公路长25．83km,采用后张法预应力混凝土空心梁板施工,在施工中通过关注混凝土浇筑和钢绞线张拉两大关键技术。提出了自己的见解。