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Biomedical subjects

M D Begg

Publications and source records attributed to M D Begg.

21 records · Page 2Linked to original sources

Oral manifestations of HIV infection in homosexual men and intravenous drug users. Study design and relationship of epidemiologic, clinical, and immunologic parameters to oral lesions.

This article describes the baseline findings from a study designed to compare the oral manifestations of HIV infection in homosexual men and intravenous drug users. Both seropositive and seronegative persons were studied. A standard examination instrument was developed to record indexes of oral disease as well as to record the presence of oral lesions. The two groups differed in terms of education, race, socioeconomic status, employment status, housing, and smoking experience. The prevalence and type of oral lesions differed in the two seropositive groups. In seropositive homosexual men, white lesions on the tongue (28.4%) predominated; whereas for the seropositive intravenous drug users, oral candidiasis (43.0%) and gingival marginal erythema (33.3%) were most often detected. We also observed that seronegative intravenous drug users displayed a greater number of oral lesions than seronegative homosexual men. For seropositive homosexual men, lesion presence was significantly associated with decreased levels of CD4; positive associations were seen with current smoking, antiviral drug use, and antibiotic use, and a negative association was observed with current employment. In contrast, only exposure to antiviral drugs was significantly correlated with lesion presence for seropositive intravenous drug users. This baseline analysis from our longitudinal study suggests clear differences in oral manifestations of HIV infection between seropositive homosexual men and intravenous drug users and between seronegative homosexual men and intravenous drug users. Among other parameters, it is apparent that lifestyle, access to health care, and the condition of the oral cavity before infection influence the development of oral lesions in persons with HIV infection.

AIDS-Related Opportunistic Infections↗

Serum prolactin levels in homosexual and bisexual men with HIV infection.

OBJECTIVE: Prolactin is a neurohormone that may be secreted in response to stress and also has regulatory effects on the immune system. Some, but not all, studies suggest that prolactin levels are higher than normal in persons with HIV infection. The authors measured prolactin levels in HIV-positive and HIV-negative homosexual and bisexual men to assess possible differences in levels and then examined relationships between prolactin level and measures of medical status, anxiety, depression, stress, and neuropsychological test performance. METHOD: Blood for prolactin level determination was obtained from 121 HIV-seropositive and 79 HIV-seronegative homosexual and bisexual men enrolled in a longitudinal study. The men also underwent a daylong assessment that included medical, immunological, psychiatric, psychosocial, psychosexual, and neuropsychological evaluations. RESULTS: There was no statistically significant difference in serum prolactin level among the seronegative men, the seropositive men with no or minimal physical symptoms, and the seropositive men with significant physical symptoms of HIV infection. Furthermore, within the HIV-seropositive group, the correlations between serum prolactin level and measures of depression, anxiety, stress, and neuropsychological test performance were all nonsignificant. CONCLUSIONS: Serum prolactin level does not seem to respond to HIV infection or to be related to stress or psychiatric symptoms in HIV-infected men. As none of the subjects had AIDS, the possibility cannot be ruled out that prolactin level increases in very late stages of HIV infection.

Adult↗

On the consequences of model misspecification in logistic regression.

Logistic regression models are commonly used to study the association between a binary response variable and an exposure variable. Besides the exposure of interest, other covariates are frequently included in the fitted model in order to control for their effects on outcome. Unfortunately, misspecification of the main exposure variable and the other covariates is not uncommon, and this can adversely affect tests of the association between the exposure and response. We allow the term "misspecification" to cover a broad range of modeling errors including measurement errors, discretizing continuous explanatory variables, and completely excluding covariates from the model. This paper reviews some recent results on the consequences of model misspecification on the large sample properties of likelihood score tests of association between exposure and response.

Animals↗