Immunopathology of glomerulonephritis associated with chronic woodchuck hepatitis virus infection in woodchucks (Marmota monax).

Retrospective analysis of necropsy findings of 705 woodchucks was performed to determine the prevalence and morphology of immune-mediated glomerulonephritis, its relationship to woodchuck hepatitis virus (WHV) infection, and the presence of major WHV antigens. Twenty-six woodchucks had glomerular lesions. Renal tissue of the 26 animals was evaluated histologically and immunohistochemically for immune-mediated glomerulonephritis. Of these 26 animals, immune-mediated glomerulonephritis was diagnosed in six, all of which were chronic WHV carriers. Membranous glomerulonephritis was identified in three animals, two of which also had mesangial proliferation. Host immunoglobulin was present within the mesangium and along capillary loops in all three. Woodchuck hepatitis virus core antigen (WHcAg) was present along capillary loops of two of these animals, one membranous and one mixed, and in the mesangium of all three. Woodchuck hepatitis virus surface antigen (WHsAg) deposition was similar to WHcAg deposition but was only present along capillaries in those animals with mixed nephritis. The remaining three animals had mesangial proliferation. WHsAg and host immunoglobulin deposition were predominately mesangial; WHcAg was not detected. Transmission electron microscopy showed thickening of the capillary loop basement membranes and subepithelial electron-dense deposits in animal one, and deposits in the mesangium in animal six.     

Ageing of intravenous glucose solutions

The pH and acid content of 63 glucose-based solutions was measured up to eight years after their expiry. The pH ranged from 2.27 to 4.33. Newly manufactured solutions with 5 per cent or less of glucose which were packaged in plastic bags contained in the order of 0.01 mEq/L of acid per gram of glucose. Solutions with higher glucose concentrations had lower pH and greater acid. As solutions in bags became older, pH decreased and acid increased. In contrast, 25 per cent and 50 per cent glucose solutions in glass containers were much less acid and showed only slight changes with age in pH or acid. The greater rate of acid increase in glucose solutions in plastic bags may be due to the bags being permeable to oxygen and thus allowing slow oxidation of the glucose.     

Assessing hearing problems within a community survey.

Community surveys are increasingly being used as a method of collecting health and lifestyle data. This report describes the use of a simple question on hearing difficulties within such a survey. A systematic sample of 2.5% of the electoral register of the four Parliamentary constituencies of Cardiff, Wales, was drawn. Of the 5145 individuals in the sample, 83% responded. Age and social class explained much of the variability in reported hearing difficulties. A recent fall and cigarette consumption were associated with hearing problems, but the contribution of alcohol consumption while potentially important did not reach statistical significance. This self-administered community survey provided hearing data which are consistent with other specialized studies and is a viable route for the assessment of community needs.     

Comparison of the treadmill exercise score and single-photon emission computed tomographic thallium imaging in risk assessment

Background  

This study compared the prognostic value of exercise single-photon emission computed tomographic (SPECT) thallium imaging with that of treadmill exercise score in medically treated patients with coronary artery disease (CAD)     

C-terminal tail of β-adrenergic receptors: immunocytochemical localization within astrocytes and their relation to catecholaminergic neurons in N. tractus solitarii and area postrema

β-Adrenergic receptors (βAR) in the medial nuclei of tractus solitarii (m-NTS) and area postrema (AP) may bind to catecholamines released from neurons, whereas only the AP has fenestrated capillaries allowing access to circulating catecholamines. Since varied autonomic responses are seen following βAR activation of the dorsal vagal complex, including the m-NTS and AP, we hypothesized that there might be a cellular basis for varied responses to βAR stimulation that depends pn the differential access to circulating catecholamines. Therefore, we comparatively examined the ultrastructural localization of the βAR in relation to catecholaminergic neurons in these regions. An antibody directed against the C-terminal tail (amino acids 404–418) of hamster β-adrenergic receptor (βAR404) was used in this study. The localization of βAR404 was achieved by the avidin-biotin peroxidase complex (ABC) technique in combination with a pre-embed immunogold labeling method to localize tyrosine hydroxylase (TH), the catecholamine-synthesizing enzyme. Within m-NTS and at subpostremal border, labeling for βAR404 was evident along the intracellular surface of plasma membranes of small, apparently distal, astrocytic processes. Astrocytic processes with βAR404-immunoreactivity formed multiple, thin lamellae around TH-labeled and non-TH neuronal cell bodies and dendrites. βAR404-immunoreactive astrocytes also extended end-feet around blood vessels and surrounded groups of axon terminals that were directly juxtaposed to each other. Some, but not all, of these axons demonstrated TH-immunoreactivity. Fewer βAR404-immunoreactive astrocytes were detected in AP, regardless of their proximity to catecholaminergic processes or blood vessels. The present astrocytic localization of βAR404, together with the earlier, neuronal localization of βAR's third intracellular loop, suggest that the βAR may be substantially different between neurons and astrocytes. The regional difference in the prevalence of βAR404-immunoreactive astrocytes suggests that these receptive sites may either: (i) be preferentially activated by catecholamines released from terminals rather than circulating catecholamines; or (ii) be down-regulated in AP due to blood-born substances, such as catecholamines. The extensive localization of βAR in the border between m-NTS and AP also suggests that catecholaminergic activation of these astrocytes may dictate the degree of diffusion of catecholamines which are of neuronal or vascular origin. The specific localization of βAR404-immunoreactivity to the more distal portions of astrocytes suggests the possibility that astrocytes have restrictive distributions of βAR and that the β-adrenergic activation lead to morphological or chemical changes that are also localized to the distal portions of astrocytes. Additionally, the detection of βAR404 in astrocytes contacting non-TH-immunoreactive neurons suggests the possibility for catecholaminergic modulation of non-catecholaminergic neurons via the activation of astrocytes.     

The MEE/PEE ratio as a predictor of excess weight loss for up to 1 year after vertical banded gastroplasty.

Thirteen morbidly obese individuals were studied prospectively for 1 year after vertical banded gastroplasty (VBG) to determine the relationships between energy balance equation parameters and excess weight loss. The measured energy expenditure (MEE), as determined by indirect calorimetry, was not correlated with weight loss. However, when this parameter was expressed as a ratio to the predicted energy expenditure (PEE), the ratio was significantly correlated with the postoperative excess weight loss at 2, 6, and 12 months. The mean daily energy intake after the VBG was 2715 +/- 865 kJ. The postoperative energy intake was not correlated with the excess weight loss. Diet-induced thermogenesis was studied in eight patients. The mean diet-induced thermogenesis was 10.31% +/- 13.92%. The diet-induced thermogenesis was not correlated with the postoperative excess weight loss. The preliminary findings of this trial suggest that the MEE/PEE ratio is useful in predicting excess weight loss after VBG.