Performance of a commercial, type-specific enzyme-linked immunosorbent assay for detection of herpes simplex virus type 2-specific antibodies in Ugandans

Two hundred forty-eight human immunodeficiency virus (HIV)-positive and 496 HIV-negative subjects in Uganda were tested by HerpeSelect herpes simplex virus type 2 enzyme-linked immunosorbent assay (ELISA) and Western blotting to optimize the ELISA for use in this population. A higher index cutoff value was required for optimal sensitivity and specificity, and overall performance of the assay was not affected by HIV status.     

The Distribution of Attention Across Auditory Input Channels: An Assessment Using the Human Evoked Potential

In order to determine the extent to which distraction disrupts performance when attention is divided, the distribution of attention across five auditory input channels was assessed using the N1 component of the human auditory evoked potential. In addition, the possibility that methylphenidate (Ritalin) affects the distribution of attention across input channels was tested. Sixteen subjects performed a tone discrimination task under conditions of focused attention and divided attention, both with and without the presence of stimuli interposed between the points to be attended. The subjects performed in two sessions during which they received either methylphenidate (10 mg) or a placebo in a double-blind design. The results showed that the interposed stimuli were receiving some attention resulting in a disruption of performance. Methylphenidate did not affect the distribution of attention as reflected in the N1 wave. The data are interpreted as showing that: 1) distraction plays a major role in producing performance deficits observed with divided attention; and 2) methylphenidate does not appreciably affect the distribution of attention across input channels.     

Transient aphagia produced following bilateral destruction of the lateral hypothalamic area and quinto-frontal tract of chicks

Six groups of broiler chicks, Gallus domesticus, sustained bilateral lesions to specific neural structures residing in the lateral hypothalamic and thalamic areas. In contrast to past data reported for the albino rat, the pigeon, Columba livia and barbary dove, Streptopelia risoria, bilateral destruction of the chick lateral hypothalamic area (LHy), quinto-frontal tract (QF), and stratum cellulare externum (SCE) resulted in transient aphagia and rapid recovery of lost body weight. Similarly, bilateral destruction of the nucleus reticularis superior (RS) and nucleus intercalatus (ICT) resulted in a temporary 1–3 day period of aphagia with body weight returning to pre-operative levels in approximately 4 days. Bilateral destruction of the ansa lenticularis (AL) resulted in a more prolonged period of aphagia (4 days) and an average 8-day period to recover lost body weight. Additional data suggest that more persistent aphagia can be induced following lesions to the posterior hypothalamus and midbrain. Specifically, bilateral lesions which destroyed the following combination of neural structures resulted in prolonged aphagia: AL, QF and posterior LHy; AL and posterior nucleus of the AL (ALp); and AL, ALp and QF. It is suggested that the AL and ALp contain neurons which are part of a more complex system that modulates or controls motor activity and feeding behavior in birds.     

Changes in thymic export of γδ and αβ T cells during fetal and postnatal development

The thymus plays an essential role in the generation and selection of T cells and exports approximately 0.5–1% of thymocytes per day in young animals and considerably fewer in older animals. To date there have been no studies directly examining fetal thymic export in any species. Using the technique of intrathymic injection of fluorescein isothiocyanate, followed by an assay for green fluorescent cells in the periphery and for the expression of cell surface antigens on these cells, we have compared directly the export of T cells from the fetal and postnatal ovine thymus. While the thymus exports both αβ and γδ T cells, our results demonstrate that the proportion of thymic γδ T cells that are exported per day is much higher than that of thymic αβ T cells. Moreover, the export rate of γδ T cells increased from approximately 1 in every 60 γδ thymocytes per day emigrating from the fetal thymus to 1 in every 20 from the postnatal thymus. In addition, we identify a population of CD5⁺CD4^?CD8^?γδ^? T cells emigrating from the fetal thymus but greatly reduced among thymic emigrants after birth. These findings have several implications regarding the mechanisms and control of selection of both γδ and αβ T cells.     

A human recessive neurosensory nonsyndromic hearing impairment locus is a potential homologue of the murine deafness (dn) locus

A locus for recessive neurosensory nonsyndromic hearing impairmentmaps to chromosome 9q13–q21 in two regionally separateconsanguineous families from India. Each family demonstratesa LOD score greater than 4.5 to this region. D9S15, tightlylinked to the Friedreich's ataxia locus, a region that has beendefined with over 1 Mb of YAC contig information and severalexpressed sequences, is one of the flanking markers. In mice,the deafness (dn) locus maps to mouse chromosome 19 and flankingloci are syntenic to human chromosome 9q11–q21. The dnmouse is a potential model for the hearing impairment foundin both these families.     

Curing efficiency and ocular hazards of dental photopolymerization sources

The spectral distributions of a range of dental photocuring sources were measured at the exit window and at a distance of 10 cm. The former enabled the evaluation of a newly proposed photocuring efficiency index which correlates well with the depth of cure of the photopolymerized resins, thus providing a basis for the comparison of different photocuring sources. The spectral irradiante of the sources obeyed the inversesquare law, allowing a comparison with the ACGIH threshold limit values. According to these criteria, no ocular hazard is posed to the patient or clinician by u.v.-A or u.v.-B radiation nor to the patient by the visible light when momentarily exposed to the sources. Similarly the ACGIH criterion indicates that the clinician does not risk chorioretinal injury provided the exposure is restricted to less than 140 s in a 3 h period.     

Phosphorylation of a C-SRC-related protein in macrophages activated in vitro with lymphokine

Treatment of proteose peptone elicited peritoneal macrophages from C3H/HeN mice or the macrophage cell line B6MP102 with a T-cell lymphokine preparation induces cytotoxicity for SV3T3 tumor cells. The Triton X-100 (TX-100) insoluble fractions from activated macrophages possessed kinase activity for an endogenous 53 kDa phosphoprotein (pp53) which was markedly greater than extracts from untreated macrophages. Addition of the tyrosine phosphatase inhibitor, Na₃,VO₄ to the cytotoxicity assay also enhanced tumor cell lysis and Na₃VO₄ treated macrophages showed increased phosphorylation of pp53. Moreover, addition of Na₃VO₄ to the cytoskeleton kinase assay enhanced the phosphorylation of pp53 in a dose dependent manner. Pp53 was immunoprecipitated from the in vitro phosphorylated TX-100 insoluble fraction with monoclonal antibody to pp60^v-src. Anti-pp60^v-src also precipitated a 53 and a 60 kDa phosphoprotein from whole cell extracts and from TX-100 cytoskeleton extracts of macrophages phosphorylated as viable intact cells. Addition of a known tyrosine kinase inhibitor, quercetin, to the macrophage cytoskeleton kinase assay inhibited phosphorylation of pp53, and the in vitro phosphorylated pp53 was resistant to 1 N NaOH hydrolysis, indicating phosphorylation of tyrosine residues. Immune complex kinase assays of anti-pp60^c-src precipitated TX-100 insoluble macrophage fractions revealed strong phosphorylation for α-casein which was inhibited by quercetin. These data suggest that macrophage pp53 is a c-src-related gene product that is inducible by stimuli that activate macrophages to cytotoxicity.     

Effects of exercise on vasodilatory capacity in endurance- and resistance-trained men

To determine vasodilatory responsiveness we measured forearm blood flow (FBF) following reactive hyperemia (RH), prior to and following a bout of maximal aerobic exercise in endurance- (n=14) and resistance-trained men (n=10). Both groups were similar in height, body mass, and percentage body fat. Using strain-gauge plethysmography, resting FBF was higher in the resistance-trained group [4.82 (0.84) vs 3.33 (1.17) ml min⁻¹ 100 ml⁻¹ of tissue; P<0.05]. However, the resistance-trained group had a 17%–29% lower pre-exercise FBF response to RH for the first 45 s (P<0.05). Following the maximal exercise bout there were no group differences in FBF. Post-exercise FBF was higher compared to pre-exercise values in both the endurance- (P<0.001) and resistance- (P<0.01) trained groups. Endurance-trained men appear to have a greater peak vasodilatory capacity compared to resistance-trained men, and acute maximal exercise increased the vasodilatory capacity in both groups. Acute exercise also equalized the peak vasodilatory response between the endurance- and resistance-trained groups, suggesting the potential for flow-mediated vasodilatation was similar for both groups. Electronic Publication     

Coping strategies,hostility, and depressive symptoms: A path model

Previous studies of coping, hostility, and depressive symptoms have highlighted the significant relations between all possible pairs of these 3 variables. To more completely explore the nature of depressive symptoms, we link them all together in this study by testing a coping→hostility→depressive symptoms path model. One hundred forty participants completed psychological questionnaires measuring coping strategies, hostility, and depressive symptoms. While controlling age and social class as covariates, SPSS stepwise regression analyses were used to examine relations among these 3 constructs. Results suggest that coping has a direct relation with depressive symptoms as well as an indirect relation mediated by hostility. Passive coping may lead to increased hostility, resulting in depressive symptoms. Active coping may have the opposite effect. These findings suggest that the inclusion of measures of both coping strategies and hostility yields a more thorough understanding of concomitants of depressive symptoms. From a clinical perspective, knowing what coping strategies a person uses and how much anger they experience and express may be useful in guiding the management of depressive symptoms.