A comparison of the reinforcing efficacy of PCP, the PCP derivatives TCP and BTCP, and cocaine using a progressive ratio schedule in the rat

This study was designed to compare the reinforcing efficacy of PCP (phencyclidine:phenylcyclohexyl-piperidine) and the PCP-derivatives BTCP (N-[1-(2-benzo(b)thiophenyl) cyclohexyl]piperidine) and TCP (N-[1-(2-thienyl)cyclohexyl]-piperidine) to that of cocaine, using a progressive ratio schedule of reinforcement (PR). On the PR schedule the number of responses required to obtain an i.v. infusion of drug was escalated with each injection until a breaking point was reached when the animal stopped responding. Since BTCP has an affinity for the DA uptake site comparable to that of cocaine, it was hypothesized that BTCP and cocaine would show similar patterns of self-administration and comparable breaking points. In contrast, the high affinity of TCP and PCP for the NMDA-ion channel complex suggested that these two compounds would also support comparable self-administration behaviors. Rats were trained to self-administer i.v. cocaine during daily 5h sessions under a fixed-ratio-1 (FR1) schedule. Once consistent lever-pressing behavior was established, BTCP, PCP or TCP was substituted for cocaine. Under the FRI schedule, BTCP elicited a regular pattern of lever pressing, unlike PCP and TCP. However, under the PR schedule BTCP elicited breaking points comparable to those produced by equivalent doses of cocaine, whereas TCP and PCP produced considerably lower breaking points. These results suggest that BTCP has comparable rewarding properties to that of cocaine, and that like those of cocaine they are most probably mediated through a site of action at the DA transporter. In contrast, the relatively weak reinforcing efficacy of PCP and TCP would correlate better with their primary site of action on the PCP binding site within the NMDA-ion channel complex.     

Is moderate alcohol use related to wages? Evidence from four worksites

Moderate alcohol users (approximately two drinks per day on average) have recently been shown to have a lower risk of coronary heart disease relative to abstainers and heavy drinkers. Conversely, a few studies have found that alcoholism is associated with greater unemployment and lower earnings. But, little research has examined the differential effects of drinking levels on job compensation. We utilize a newly created database on employees at four worksites to test for a nonlinear relationship between alcohol use and wages. We also examine whether alcohol use affects wages indirectly through educational achievement, marital status, and poor health. Our findings suggest an inverse U-shaped relationship between alcohol consumption and wages with a peak at approximately 1.5 to 2.5 drinks per day on average. Thus, controlling for other variables and conditional on working, moderate alcohol users have higher wages than abstainers and heavy drinkers at these worksites. We also find evidence that alcohol use is related to wages through human capital variables.     

Trichomonas vaginalis: diagnosis and clinical characteristics in pregnancy

Objective: The objectives of this study were to 1) determine the prevalance and characterize the symptomatology of Trichomonas vaginalis (TV) infection in pregnant women on entry into prenatal care in an inner-city population; 2) compare conventional microscopic methods vs. culture techniques in diagnosing TV in both symptomatic and asymptomatic pregnant patients; and 3) correlate wet mount microscopic and microbiologic characteristics of varying manifestations of trichomoniasis.Methods: One thousand two hundred sixty patients in an inner-city population were tested at entry into prenatal care for TV by saline wet mount and culture techniques. Other tests for lower genital tract infection were also performed. Vaginal symptoms were ascertained through standardized questioning prior to examination. Standard microscopic and microbiologic data were also obtained for analysis. Wet mounts were systematically examined and considered negative if no TV was identified in 10 high powerfields (HPFs). Cultures were inspected from days 4 to 7 or until positive results were obtained. Results were analyzed using McNemar's test for correlated proportions, chi-squared test, or Fisher exact test where appropriate.Results: Culture and wet mount results were available in 1,175 patients. TV infection was documented by one or both techniques in 110/1,175 (9.4%). Culture methods detected 105/110 (94.5%) of all patients while wet mount detected 90/110 (73%) (P <0.001). Vaginal symptoms were present in only 20/110 patents (18.2%). Among asymptomatic patients, culture detected 94% while wet mount detected 70% (P < 0.001). Among symptomatic patients, wet mount and culture were both effective and diagnosed 85% and 95% of infections, respectively (P = not significant). Patients with TV were more likely to have increased vaginal fluid wlaite blood cells (WBCs) and more severe vaginal flora disruption than uninfected controls. Subgroup analysis revealed wet mount-positive/culture-positive patients were more likely to have vaginal flora disruption, as evidenced by decreased lactobacilli and elevated vaginal pH, than wet mount-negative/culture-positive subjects. Coexistent infection rates were similar regardless of wet mount status. Elevated vaginal fluid WBCs were more common among patients with symptoms.Conclusions: 1) Screening pregnant women for TV based solely on symptomatology is ineffective in this population; 2) culture techniques detected more infections than conventional microscopic evaluation; and 3) significant increases in vaginal fluid WBCs and altered vaginal flora are found in both symptomatic and asymptomatic TV, suggesting that both infestations have the potential to adversely affect pregnancy outcome. Studies on the influence of TV on pregnancy outcomes are ongoing.     

Mistreatment due to weight: prevalence and sources of perceived mistreatment in women and men

OBJECTIVE: Previous research has documented prejudicial attitudes and discrimination against overweight people. Yet the extent to which overweight people themselves perceive that they have been mistreated because of their weight has not been carefully studied. The purpose of this study was to examine the prevalence of perceived mistreatment due to weight and sources of perceived mistreatment. METHODS AND PROCEDURES: A non-clinical sample of healthy adults (187 men and 800 women) enrolled in a weight gain prevention program comprised the study population. A self-administered questionnaire was used to measure perceived mistreatment due to weight. RESULTS: Overall, 22% of women and 17% of men reported weight-related mistreatment. The most commonly reported sources of mistreatment among women were strangers (12.5%) and a spouse or loved one (11.9%). Men were most likely to report mistreatment by a spouse or loved one (10.2%) and friends (7.5%). Somewhat surprisingly, sex differences in perceived weight-related mistreatment were significant only for stranger as the source. Perceived weight-related mistreatment was positively associated with body mass index (BMI) (r = 0.39, p<0.0001). Reported mistreatment was nearly ten times as pervalent among individuals in the highest quartile of the BMI distribution (42.5%) than among those in the lowest BMI quartile (5.7%), but was significantly greater than zero in all but the very lean. DISCUSSION: Perceived mistreatment due to weight is a common experience and is not restricted to the morbidly obese. Results are discussed in light of the sociocultural value for thinness.     

Antiretroviral therapy. Immune restoration disease in HIV-infected patients on HAART

Inflammatory diseases related to a preexistent or subclinical infection with an opportunistic pathogen in patients with HIV infection who respond to HAART may be caused by the restoration of an immune response against the pathogen. One danger can be misinterpreting the patient's condition as evidence of treatment failure and then stopping the drug regimen. Instead, measurement of pathogen-specific immune responses may help in the diagnosis of immune restoration diseases. The next step may be to continue HAART and therapy for the related infection and add anti-inflammatory drugs, such as corticosteroids. Generally, antiretroviral therapy should only be stopped, even temporarily, if that approach fails.     

Immunologic and clinical stages in HIV-1-infected Ugandan adults are comparable and provide no evidence of rapid progression but poor survival with advanced disease

Clear understanding of the natural history of HIV-1 disease is critical for planning and developing appropriate therapeutic strategies for HIV-1-infected populations in the developing world. Present knowledge about Africa is based on very limited data that largely use clinical staging as the prognostic marker; this approach has not been prospectively validated. Our objectives were to compare clinical staging and CD4+ T-cell counts as prognostic tools and to describe survival and cause of death in seroprevalent HIV-1-infected Ugandan adults by means of a prospective cohort study. Consecutive HIV-1-infected adults registering with a community HIV/AIDS clinic in Entebbe, Uganda were enrolled between October 1994 to January 1995 and observed during follow-up until the end of December 1997. Baseline CD4+ T-cell count distribution showed clear and appropriate associations with clinical stage in the 201 participants. Both provided equivalent prognostic information: median survival with CD4+ T-cell count <200 cells/microl was 9 months (95% confidence interval [CI], 7-15 months) compared with 19 and 7 months (95% CI, 10-28 and 0-8 months, respectively) in clinical stages 3 and 4, respectively; survival at 3 years with CD4+ T-cell count > or =200 cells/microl was 68% and for clinical stage 1 and 2, 80% and 60%, respectively. Clinical stage 3 and 4 were 76% sensitive and 65% specific for predicting a CD4+ T-cell count <200 cells/microl, positive predictive value of 56%, negative predictive value 78%. In all, 82 participants died (41%; mortality rate 216 of 1000 person-years) and was strongly associated with low CD4+ T-cell counts. In conclusion, clinical staging is valid and comparable with staging by CD4 T-cell counts for epidemiologic measurements. Mortality with early disease in Entebbe appears equivalent to that found in the developed world but there is poor survival with advanced disease.     

Hemispheric asymmetries in arousal affect outcome of the intracarotid amobarbital test.

OBJECTIVE: To evaluate changes in arousal and their impact on memory performance during the intracarotid amobarbital test (IAT). METHODS: Along with memory measures, level of arousal was evaluated through clinical ratings and nonverbal self-ratings in epilepsy patients undergoing IAT before anterior temporal lobectomy. RESULTS: Irrespective of seizure focus, left-sided amobarbital injection resulted in decreased objective and subjective arousal more often than right-side injection. Impaired objective arousal was greater when the left hemisphere was injected second, because of the presumed additive effects of systemic amobarbital residual from the first injection. Decreased objective arousal was related to poorer performance on memory testing following left-hemisphere injection. CONCLUSIONS: The IAT, as practiced in most centers, is biased, so patients with right temporal lobe seizure focus are more likely to "pass" the test, whereas patients with left seizure focus are more likely to "fail" the test. The significant impact of changes in arousal on memory testing needs to be considered when using IAT results to select patients for temporal lobectomy.