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.     

Behavioral model synthesis with Cones

The Cones synthesis system for automatic generation of VLSI implementations is discussed. Named for the cones in sequential logic, Cones takes behavioral models written in C and produces gate-level implementations in technologies such as standard cells and programmable logic arrays or programmable logic devices. The overall design is produced faster, more efficiently, and with fewer errors. Designers are free to concentrate on functions, instead of on the details of the implementation technology     

Age-related slowing and the time course of semantic priming in visual word identification.

Investigated, in 4 experiments, the time course of semantic priming effects during 2 forms of visual word identification, lexical decision and pronunciation. On each trial, a target letter string was preceded by a single-word priming context. The effects of varying the stimulus onset asynchrony between the prime and the target indicated that the time course of semantic priming was equivalent for young and older adults. There were no consistent differences between lexical decision and pronunciation in the time course of semantic priming. The age differences associated with response selection were greater than would be predicted by generalized age-related slowing. The semantic priming effects were also inconsistent with a generalized slowing model, but the reliability of these effects was substantially lower than the reliability of the other task-related variables. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Non-contact measurement of the mechanical properties of materials using an all-optical technique

Describes an optically-based measurement mechanism which realizes a totally noncontact assessment of the most important mechanical properties of structural materials - namely effective stiffness and Poisson ratio. These parameters are sensitive indicators of material integrity. The technique uses laser generated broadband ultrasound as a probe and interferometric optical detection as the detector again exploiting the broadband capability of optics in both space and time. Both detection and excitation systems are most conveniently realized in practical systems through optical fiber linkages. Observing the coupled waveforms between source and detector as a function of source: detector separation after a space : time Fourier transform yields a set of dispersion curves for the ultrasonic (typically Lamb wave) transfer function of the sample. This, in turn, can be inverted using curve fitting routines to obtain effective values of modulus and stiffness. An initial assessment of this inversion process is presented and demonstrates that the effective modulus can be extracted with a confidence level of better than a few percent with slightly larger errors in the Poisson ratio.     

The core symptoms of schizophrenia

We have compared light chain immunohistochemistry in reactive lymphoid tissue and a series of paraffin-embedded B-cell lymphomas using standard trypsin digestion with a heat mediated epitope retrieval method. Fifty-seven B-cell lymphomas (18 high grade, 29 low grade and 10 cases of nodular lymphocyte predominance Hodgkin's disease), two reactive lymph nodes and eight tonsils fixed for known times between 12 h and 2 years were studied. Paraffin-embedded tissue was stained with polyclonal anti-kappa and anti-lambda antibodies. For each antibody staining was performed on two sections, one treated with trypsin digestion and one with microwave heating. Sections were scored from 0 to + + + with 0 representing poor staining and + + + excellent staining. A score of ++ was considered satisfactory. Light chain restriction was recorded if present. Satisfactory staining was obtained in 34/59 cases using trypsin digestion and 56/59 cases using heat retrieval. Light chain restriction was demonstrated in 32/57 (56%) B-cell lymphomas using trypsin digestion and 52/57 (91%) using heat retrieval. Satisfactory staining was obtained in tonsils fixed for up to 48 h using trypsin digestion and up to 2 years using heat retrieval. We have shown that for light chain immunostaining a heat mediated epitope retrieval method produces more consistent and satisfactory results and is effective over a greater range of fixation times than traditional trypsin digestion.     

Meshlaparostomy--a comparison between polypropylene mesh and indigenous nylon net

Polypropylene mesh, the routinely used material for mesh laparostomies is expensive. A economical and easily available substitute-nylon net was compared with polypropylene mesh with regard to efficacy and wound complications in a retrospective study. 51 patients, 25 in the polypropylene mesh group and 26 in the nylon net group were studied. The groups were matched with respect to age, sex, indication for surgery and mortality. The mean hospital stay (65 vs 54 days), fate of the wound, incidence of mesh extrusion (26% vs 20%), bowel perforation (1 vs none) and incisional hernia formation (21% vs 20%) in those with polypropylene mesh and nylon net respectively was similar. In conclusion, nylon net is an effective and inexpensive indigenous substitute for polypropylene mesh for mesh laparostomies.