Changes in HIV treatment beliefs and sexual risk behaviors among gay and bisexual men, 1997-2005.

Objective: Beliefs about HIV treatment effectiveness and the impact of HIV treatments on HIV transmission risks were initially related to sexual risk-taking in the late 1990s when multidrug HIV treatments first became available. This study examined changes in beliefs about the effects of HIV treatment for preventing HIV transmission and their association to sexual risk behaviors between the years 1997 and 2005. Design: Anonymous surveys were administered to a convenience sample of gay and bisexual men attending a large community event in Atlanta, Georgia in 1997 (N = 498) and again at the same community event in 2005 (N = 448). Analyses were performed for men living with HIV/AIDS and for men who have not been diagnosed with HIV/AIDS. Main Outcome Measures: Rates of unprotected anal intercourse in the previous 3 months. Results: There were significant increases in high-risk sexual practices that coincided with increased beliefs that HIV treatments can reduce the chance of transmitting HIV. However, optimistic beliefs about the health benefits of HIV treatments decreased over the 8 years and were not related to risk behaviors. Conclusions: Beliefs about how HIV treatments impact HIV infectiousness remain associated with HIV transmission risk behavior and interventions targeting at-risk as well as HIV-positive men who have sex with men must directly address these beliefs and perceptions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mechanical properties of bone cements containing large doses of antibiotic powders

The addition of up to 10 g gentamicin sulfate antibiotic powder to 60 g units of Simplex-P acrylic bone cement caused gradual, proportional decreases in the bulk muchanical properties of compressive and diametral tensile strengths. Water leaching of the antibiotic from the cement did not significnatly decrease these strenghts. Scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS) showed the antibiotic to reside in the acrylic matrix as discrete particles not usually associated with internal porosity. The surface-sensitive flexural strength of a proprietary bone cement was lowered immediately by small quantities of antibiotic powder, and continued to decrease as doses of up to 10 g/unit were admixed. Water leaching caused channeling as the antibiotic was removed from the surface, but it did not create further changes in flexural strength.     

Temporal cortical projections to the olfactory tubercle in the rhesus monkey

Chickens that had been vaccinated with a lentogenic strain 2 to 9 weeks before challenge with a virulent virus remained clinically normal following challenge and circulated virus within leukocytes for as long as ten days. The virulent virus was detected by inoculating embryonating eggs with leukocytes separated from blood shortly after drawing. Freezing the leukocytes before inoculating the eggs reduced isolation 64.8%. Virus was demonstrated most readily in chickens challenged when antibody was decreasing, about 9 weeks after vaccination. The observation that virus in blood may be contained within a cellular component and be readily demonstrable only if the cells are separated and washed is significant both to an understanding of the immunological responsiveness of vaccinated chickens exposed to field challenge and to an understanding of epizootiological events.     

Effects of vaccination with a Moraxella bovis bacterin on the subsequent development of signs of corneal disease and infection with M bovis in calves under natural environmental conditions

A vaccination study was conducted for infectious bovine keratoconjunctivitis (IBK) in 440 purebred Hereford cattle (cows and their newborn calves) of the USDA Meat Animal Research Center cattle herd at Clay Center, Ne. The cattle were allotted to 4 groups: 60 calves were vaccinated with an autogenous Moraxella bovis bacterin (group 1); 60 calves that were matched with group 1 calves were designated nonvaccinated matched controls (group 2); 99 calves were peer group nonvaccinated controls (group 3); and 219 cows, the dams of the calves, were nonvaccinated consorts (group 4). The infection rates in cattle groups 1, 2, 3, and 4 during the summer were 96.6, 98.3, 100, and 79.1%, respectively, and the disease rates were 90, 93, 85, and 20%. The infection and the disease rates were significantly (P less than 0.01) different between claves and cows. The disease rate was also significantly different between older and younger cows. A larger percentage of the affected calves and cows had mild or moderate (61%) signs of IBK rather than severe (39%) signs. The rate of body weight gain was reduced in calves with severe signs of IBK. The results seemed to indicate that little would be gained by vaccinating cattle against IBK under the conditions of study.     

Life events and subsequent illness

The objective was to examine for relationships between stress, as measured by life events, and hospitalization or death during the following 6 to 12 months, using a case-control design. As part of the Community Mental Epidemiology Program, life events data for the preceding year were gathered on a random sample of the population at two sites, and health data for the interval between interviews were collected at follow-up. A case is defined as anyone becoming ill and being hospitalized or dying during the interval between interviews. Each case was individually matched by several variables to a control who had neither been sick nor hospitalized. There were no significant demographic differences between cases and control in either site or between sites. When life events were examined by various scoring methods, there were no differences between cases and controls. This finding is important since most longitudinal studies that have shown a positive relationship between life events and subsequent illness have had methodologic limitations or have been based on healthy, young, male populations who generally did not become seriously ill during the study period. The results of this study plus the lack of generalizability of previous findings and their somewhat conflicting results raise serious questions about the etiologic relationship of life events to subsequent illness.     

Approaches to the standardization of serum unsaturated iron-binding capacity

An important aspect in the development and use of serum unsaturated iron-binding capacity (UIBC) procedures is the standardization of reference serum. Spectrophotometric titration of serum transferrin is the oldest of the UIBC methods; however, the literature on this subject indicates that the technique is not being fully exploited and describes a variety of suboptimal conditions. A spectrophotometric titration protocol is described which gives excellent reproducibility with fresh, frozen, lyophilized, and stored serum samples. An indirect UIBC method utilizing differential chelation and ultrafiltration is also described. In this method Fe3+ -NTA (nitrilotriacetic acid), in excess of the anticipated UIBC, is added to a serum sample supplemented with NaHC03. The addition of EDTA (ethelenediaminetetraacetic acid) allows the mobilization of iron from nonspecific macromolecular sites. The ultrafiltrate is analyzed for iron, and the UIBC is calculated. The results were validated via an ultrafiltration titration which was compared with a spectrophotometric titration. The precision of this method is excellent.     

Oxygen-dependent circulation of sickle erythrocytes

The effects of in vivo hyperoxia and hypoxia on the intravascular survival of 51Cr-labeled human sickle erythrocytes (SS RBS's) were studied after transfusion into rats and guinea pigs. The function of these animals' reticuloendothelial and complement systems had been previously inhibited by ethyl palmitate and cobra venom factor, thus allowing extension of the survival of the heterologous human RBC's. In the blood of rats breathing ambient air the 51Cr half-life survival of RBC's from 11 patients with sickle-cell anemia (mean, 7.1 hours; range, 2.0 to 16.5 hours) was significantly shorter (p less than 0.001) than that of five control subjects (mean, 17.5 hours; range, 12.0 to 26.5 hours). When rats transfused with sickle RBC's were exposed to 100 per cent O2, a mean increment of 16.5 per cent blood 51Cr activity was observed within the first 15 to 60 minutes of hyperoxia. Subsequent oxygen deprivation (7 to 8 per cent O2) resulted in an equally rapid decrease (mean, 35.6 per cent) in blood 51Cr activity. Continuation of hypoxia for up to 17 hours did not cause further acceleration of 51Cr activity. Continuation of hypoxia for up to 17 hours did not cause further acceleration of 51 Cr RBC clearance. Under these conditions the slope of the sickle RBC survival curve was similar to that in animals kept in ambient air. After hypoxic rats were allowed to breate room air again, mean 51Cr blood activity increased by 41.7 per cent. Sickle RBC's transfused to guinea pigs exhibited similar oxygen-dependent survival characteristics. The survival of 51Cr RBC's from four adult control subjects and of unlabeled fetal RBC's from three human cord blood samples was unaffected by oxygen changes. When rats that had been transfused with sickle reticulocytes labeled in vitro with 59Fe were made hypoxic, a decrease in blood 59Fe activity was observed. The extent of this decrease was comparable to that in rats transfused with 51Cr labeled RBC's from the same patients. There was increased liver and spleen 51Cr activity in animals transfused with 51Cr SS RBC's and killed during hypoxia when compared to that of hyperoxic animals. These studies suggest that a minor population of sickle cells is removed from circulation during hypoxia and circulates again upon reoxygenation of the animals. Erythrocyte aging does not appear to be responsible for this phenomenon. The oxygen-depdendent circulation of a population of SS RBC's in this animal system is probably due to reversible sickling and trapping of sickled cells in the microcirculation.     

Alimentary-tract ganglioneuromatosis. A major component of the syndrome of multiple endocrine neoplasia, type 2b

Although the syndrome of multiple endocrine neoplasia, type 2b, is known to comprise mucosal ganglioneuromatosis, medullary thyroid carcinoma, pheochromocytoma and skeletal anomalies, we wish to document the importance of the alimentary-tract components. In nine patients with this syndrome, we found diffuse ganglioneurmatosis extending from the lips to the rectum. Alimentary symptoms, constipation or diarrhea or both were present in six of these patients. Similar symptoms were present in six of seven other affected patients from whom alimentary-tract tissue was not obtained. Five of the 16 patients had megacolon, which led to operation in four, and a sixth patient had colectomy for diverticulitis complicating diffuse diverticulosis. The alimentary manifestations warrant greater emphasis, not only because they were prominent in the patients whom we studied but also because in 14, these manifestations were present before the endocrine neoplasms were detected.