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.     

Course of depressive symptoms and medication adherence after acute coronary syndromes: an electronic medication monitoring study.

OBJECTIVES: We tested whether improvements in depressive symptoms precede improved adherence to aspirin in patients with acute coronary syndromes (ACS). BACKGROUND: Depression is associated with medication nonadherence in patients with ACS, but it is unclear whether changes in depression impact on adherence. METHODS: Electronic medication monitoring was used to measure adherence to aspirin during a 3-month period in a consecutive cohort of 172 patients (25 to 85 years) recruited within 1 week of hospitalization for ACS. Depressive symptom severity was assessed using the Beck Depression Inventory (BDI) during hospitalization and at 1 and 3 months after hospitalization. Adherence was defined as the percentage of days aspirin was taken as prescribed. RESULTS: Depression severity in hospital was associated with nonadherence in a gradient fashion: 15% of non-depressed patients (BDI score 0 to 4), 29% of mildly depressed patients (BDI score 10 to 16), and 37% of patients with moderately-to-severely depressive symptoms (BDI score >16) took aspirin less than 80% of the time (p = 0.03). A cross-lagged path analytic model revealed that improvements in depressive symptoms in the first month after the ACS were associated with improvements in adherence rates in the subsequent 2 months (standardized direct effect -0.32, p = 0.016). CONCLUSIONS: Diagnosis and treatment of depressive symptoms may improve medication adherence in patients after ACS.     

Direct evidence for the link between monoaminergic descending pathways and motor activity:: II. A study with microdialysis probes implanted in the ventral horn of the spinal cord

In order to define precisely the relation between descending monoaminergic systems and the motor system, we measured in the ventral horn of spinal cord of adult rats the variations of extracellular concentrations of 5-HT, 5-HIAA, DA and MHPG. Measurements were performed during rest, endurance running on a treadmill, and a post-exercise period, with microdialysis probes implanted permanently for 45 days. We found a slight decrease in both 5-HT and 5-HIAA during locomotion with a more marked decrease during the post-exercise period compared to the mean of rest values. In contrast, the concentration of DA and MHPG increased slightly during the exercise and decreased thereafter. These results, when compared with those of a previous study, which measured monoamines in the spinal cord white matter [C. Gerin, D. Bécquet, A. Privat, Direct evidence for the link between monoaminergic descending pathways and motor activity: I. A study with microdialysis probes implanted in the ventral funiculus of the spinal cord, Brain Res. 704 (1995) 191–201], highlight the complex regulation of the release of monoamines that occurs in the ventral horn.     

Effects of racist provocation and social support on cardiovascular reactivity in african american women

It has been speculated that exposure to the chronic stress of racism contributes to the high rates of hypertension among African Americans. Social support may buffer the effects of stress on cardiovascular (CV) health by attenuating stress-induced CV responses that have been linked to hypertension. In this study we investigated the effects of racism and social support on CV reactivity in African American women. Participants showed greater increases in CV and emotional responses while responding and listening to racist provocation. Augmented blood pressure (BP) persisted through recovery following racial stress. Participants receiving no support showed the greatest increases in anger during racist provocation. No significant effects were seen for support on CV reactivity. These results provide some of the first evidence that interactive confrontation with racism elicits significant increases in CV reactivity and emotional distress. Furthermore, individuals receiving less support may be at greater risk for the potentially health-damaging effects of racial stress. These findings may have significant implications for the health of African Americans.     

Characterization of hepatitis B virus (Dane particle)

Hepatitis B virions (Dane particles) were purified from the sera of chronic HBsAg carriers by consecutive rate-zonal and isopycnic centrifugations in sucrose gradients using HBsAg, HBcAg and endogenous DNA polymerase activities as specific markers. Purified Dane particles, radiolabelled with Na ¹²⁵I by the chloramine-T procedure, had a higher buoyant density in CsCl (1.28 g/cm³) than unlabelled particles (1.26 g/cm³) and an estimated sedimentation coefficient of 280 s. ¹²⁵I-Dane particles were fully precipitated by anti-HBs and not by anti-HBc sera. Heavy and light density core particles were purified from heavy and light density populations of Dane particles and radioiodinated. The iodinated polypeptides of Dane particles and HBcAg were compared with those of the iodinated 22-nm form of HBsAg by SDS-PAGE. Iodinated Dane particles contained seven polypeptides with molecular weights of 18,000, 23,000, 26,000, 34,000, 43,000, 48,000 and 115,000. Heavy and light core particles contained three polypeptides with molecular weights of 18,000, 25,000 and 37,000.     

Kinetics of viremia and acute liver injury in relation to outcome of neonatal woodchuck hepatitis virus infection

The kinetics of serum viral responses and acute liver injury were studied during neonatal woodchuck hepatitis virus (WHV) infection in relation to the chronic or resolved outcome. The mean concentrations of serum WHV DNA and surface antigen were significantly higher by week 10 post infection in chronic infections compared to resolving infections, and diverged even further by the time of peak viral load development in serum (week 12). After week 12, these viral markers were detected less frequently with time and at lower concentrations in the resolved outcome. In both outcomes, mean serum activities of hepatic enzymes became increased significantly above baseline by weeks 10-12, peaked at week 14, and normalized by weeks 20-22, thus indicating transient acute liver injury. The increasing liver injury responses were comparable between outcomes at week 12, when serum viral load was markedly higher in the developing chronic infections. This suggested a deficiency in early non-cytolytic control of infection in the chronic outcome. At week 14, liver injury was significantly greater in the resolved outcome and associated with higher mean Fas ligand (FasL) and perforin messenger RNAs (mRNAs) in liver compared to the chronic outcome. This indicated greater immune-mediated killing of infected hepatocytes during resolution. Thus, chronicity as an outcome of neonatal WHV infection develops relatively early during the acute phase of infection due to reduced immune-mediated clearance of infected hepatocytes by both cytolytic and non-cytolytic processes.     

Systemic distribution of woodchuck hepatitis virus in the tissues of experimentally infected woodchucks

To better assess the extent of the tissue tropism of mammalian hepadnaviruses, 10 tissues from each of six woodchucks were examined for the presence and state of woodchuck hepatitis virus (WHV) nucleic acids 15 months after experimental WHV infection. The tissues examined were peripheral blood lymphocytes, lymph node, spleen, bone marrow, thymus, pancreas, kidney, ovary, testis, and liver. Tissue samples from three chronically infected animals and three animals with serologic patterns of recovery (serum: WHsAg-, anti-WHs+, anti-WHs+, WHV DNA-) from acute WHV infection were analyzed in parallel by in situ hybridization and Southern and Northern blot techniques. WHV nucleic acids were detected in several individual tissues from each animal examined, although not all tissues in every animal contained WHV. Substantial differences were observed among the various tissues and animals with respect to the frequency, level, and intratissue distribution of WHV nucleic acids, as well as the presence of different viral genomic forms. Active WHV DNA replication was present only in the liver and spleen of the chronically infected animals. No evidence of ongoing WHV DNA replication was found in any of the tissues from the recovered animals. WHV DNA was homogeneously distributed among all hepatocytes in the livers of the chronic carriers. By contrast, WHV DNA in all the extrahepatic tissues, and in the livers of the recovered animals, was detected only in scattered foci of cells.     

Buoyant density in cesium chloride of the human reoviruslike agent of infantile gastroenteritis by ultracentrifugation,electron microscopy,and complement fixation

The buoyant density in cesium chloride of the human reoviruslike (HRVL) agent of infantile gastroenteritis was studied utilizing electron microscopy and complement fixation (CF) for the detection of reoviruslike particles in fractions of the density gradient. Three virus positive stool filtrates were studied. “Full” reoviruslike particles had a density of 1.35–1.37 g/cm³, whereas “empty” particles had a density of 1.29 g/cm³. Peak CF activity coincided with the peak fraction of both the “full” and “empty” reoviruslike particles. In addition, by differential centrifugation, CF activity was also associated with the virion and not a “soluble” antigen.     

Proteoglycan metabolism in isolated chondrocytes from human cartilage. Influence of niflumic acid

Summary The effect of niflumic acid on hyaluronic acid and proteoglycan metabolism of human cartilage cells was investigated in vitro. Cartilage cells were obtained from five different donors. Niflumic acid levels used in the test systems ranged from 0 to 22 gr/ml and were comparable to serum concentrations in humans after oral intake. Niflumic acid increased the synthesis rates of proteoglycan in some batches of isolated and monolayer-cultured chondrocytes. The effect on hyaluronate synthesis was less pronounced. The fact that this increase in the synthesis of proteoglycan was restricted to some of the donors whereas isolated cells or tissue samples from other individuals remained unaffected illustrates the heterogeneity of different human donors. Depression of proteoglycan synthesis in the presence of the drug was never observed.     

The impact of anticipation of job loss on psychological distress and worksite blood pressure.

The impact of occupational stressful life events on psychological distress and blood pressure was examined among employees of a major New York City brokerage firm undergoing massive layoffs. One hundred thirty-nine employees of the firm, who had participated in a blood pressure screening in 1986, were rescreened during the period of layoffs within their company in 1989. About two-thirds of the 139 employees reported being "somewhat" or "very" anxious or upset in 1989 during the period of layoffs, and psychological distress was significantly elevated among those employees reporting possible or definite layoff or job change and/or difficulty in obtaining a comparable job. However, we found no increase in overall blood pressure level, and no effect of anticipation of job loss on 1989 blood pressure when controlling for 1986 blood pressure level, age, body mass index, work hours, and other demographic variables. On the other hand, employment in a department sold to another employer on the day of screening, as well as employment in a clerical job title, were both associated with significant increases in diastolic blood pressure of about 5 mm Hg.