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Biomedical subjects

C Whalen

Publications and source records attributed to C Whalen.

At least 37 records · Page 2Linked to original sources
PubMed1997

Site of disease and opportunistic infection predict survival in HIV-associated tuberculosis.

OBJECTIVE: Infection with HIV adversely affects survival in patients with tuberculosis (TB), even when TB is effectively treated. The aim of this study was to identify the determinants of survival in HIV-associated TB. DESIGN: Retrospective cohort study. SETTING: Four US academic medical centers. PATIENTS: An inception cohort of 112 HIV-infected patients (mean age 41 years, 96% men, 46% African American) with their first episode of culture-proven TB. OUTCOMES MEASURES: Observed survival from the date of diagnosis of TB to the date of death or censoring. Independent variables included demographics, HIV-related conditions, risk behavior for HIV, absolute CD4+ counts, and site of disease with Mycobacterium tuberculosis. RESULTS: Of the 112 patients, 54 (48%) had pulmonary TB alone, 36 (32%) had both pulmonary and extra-pulmonary TB and 22 (20%) had extrapulmonary TB alone. Median CD4+ count was 95 x 10(6)/l (range, 2-767 x 10(6)/l). During follow-up, 45 patients (40%) died. Median survival was shortest in patients with both pulmonary and extrapulmonary disease (8.4 months), followed by extrapulmonary disease alone (15.6 months), then pulmonary disease (30.4 months; P < 0.001, log-rank test). Median survival was also reduced in patients with previous opportunistic infection and in those with CD4+ < 200 x 10(6)/l. In a proportional hazards regression analysis, which adjusted for CD4+ count, extrapulmonary disease and previous opportunistic infection were the only factors independently associated with shorter survival. Of the extrapulmonary sites of disease, TB meningitis was associated with the greatest risk of death. CONCLUSION: The site of culture-proven TB at presentation and the history of previous opportunistic infection are important predictors of survival in HIV-infected patients with TB.

AIDS-Related Opportunistic Infections↗
PubMed1997

Risk factors associated with permanent access-site infections in chronic hemodialysis patients.

OBJECTIVE: To determine the epidemiological risk factors associated with permanent access-site (PAS) infection in a population of chronic hemodialysis patients. DESIGN: Retrospective cohort analysis. SETTING: Hemodialysis unit of a 400-bed Department of Veterans' Affairs hospital. RESULTS: A cohort of 94 males (1,316 patient months) was studied. Fifty-one PAS infections in 31 patients were observed. Six patients had two PAS infections, four patients had three infections, and two patients had four infections. Twenty-nine of the 31 patients with PAS infections were bacteremic at least once. Univariate analysis identified seven factors significantly associated with PAS infection in this population: location of PAS other than forearm, type of vascular access (polytetrafluoroethylene [PTFE] versus endogenous arteriovenous [AV] fistula), limited ambulatory status, residence in a nursing home, bacterial infection at a distant site, number of access-site revisions, and number of hospitalizations. In a logistic regression analysis, only graft type and number of PTFE graft revisions were associated independently with PAS infection. The odds ratio for PAS infection in PTFE grafts compared to endogenous AV fistula was 7.8; the odds ratio for PAS infection with each PTFE graft revision was 1.5. CONCLUSIONS: PAS infections were associated independently with the type of graft and the number of PTFE graft surgical revisions.

Adult↗
PubMed1997

Clinical course of human immunodeficiency virus type 1 associated pulmonary tuberculosis during short-course antituberculosis therapy.

To describe the clinical response to antituberculosis therapy in HIV-1 disease, 49 HIV-1 positive Ugandan adults (mean age 29.4 years; 68% men) with active pulmonary tuberculosis (PTB) were studied in a trial of rifampicin containing short-course antituberculosisis regimens. At presentation, 18 patients were PPD non-reactors (PPD skin test induration < 2mm), ten patients (20%) had non-cavitary lung disease. The mean CD4 lymphocyte count at presentation was 339/microliters (+/- SD 275). Among patients with abnormal baseline clinical values, the median time to resolution of fever, weight gain of 10%, increase of haemoglobin to 10g/dl and of Karnofsky performance score (KPS) to 80 occurred before sputum smear and culture conversion. Short-term survival was associated with: baseline lymphocytes < 1200/microliters, (Odds ratio (OR) 17.5), CD4+ lymphocytes < 200/microliters (OR 9.8), cavitary lung disease, (OR 0.6), atypical chest radiograph, (OR 6.7), and PPD non-reactivity, (OR 13.5), PPD non-reactivity and non-cavitary disease were associated with significantly lower CD4 lymphocyte counts. Affordable serial measurements parallel the response to therapy and predict survival in HIV-associated PTB.

AIDS-Related Opportunistic Infections↗
PubMed1996

Pentoxifylline therapy in human immunodeficiency virus-seropositive persons with tuberculosis: a randomized, controlled trial.

Macrophage activation and tumor necrosis factor-alpha (TNF-alpha) production are critical in tuberculosis immunity but may result in increased human immunodeficiency virus (HIV) expression and accelerated HIV disease progression in HIV-infected persons. Pentoxifylline inhibits expression of TNF-alpha and HIV. A double-blind, placebo-controlled study of adjunctive therapy with pentoxifylline (1800 mg/day) as a timed-release formulation was done in Ugandan HIV-infected patients with pulmonary tuberculosis. Subjects had early HIV disease (mean CD4 cell count, 380/microL) and did not receive other antiretroviral drugs. Pentoxifylline resulted in decreased plasma HIV RNA and serum beta 2-microglobulin and, in a subset of moderately anemic patients, improved blood hemoglobin levels. Trends were noted toward reduced TNF-alpha production in vitro and improved performance scores, but these did not reach statistical significance. No effect was noted on body mass, CD4 cell count, or survival. Additional studies of more potent TNF-alpha inhibitors in HIV-positive subjects with tuberculosis are warranted.

Adult↗
PubMed1996

Relationship between sleepiness and general health status.

One commonly used instrument for evaluating general health and functional status is the medical outcomes survey short form 36 (MOS). Scores obtained from this instrument are known to vary with chronic diseases and depression. However, the degree to which these health dimensions may be influenced by sleep quality or sleepiness is not well understood. A cross-sectional study was performed on the association between general health status, as determined by the MOS, with sleepiness, assessed using a standardized questionnaire [the Epworth sleepiness scale (ESS)] and the multiple sleep latency test (MSLT). One hundred twenty-nine subjects (68 women), aged 25-65 years, without severe chronic medical or psychiatric illnesses, underwent an overnight sleep study, followed by an MSLT (consisting of a series of four attempts at napping at 2-hour intervals), and completed the MOS and the ESS. The mean MSLT score was 11 +/- 2 minutes, (range 2-20) and the mean ESS score was 10 +/- 5 (range 0-24). Scores for the MOS dimensions "general health perceptions", "energy/fatigue", and "role limitations due to emotional problems" were correlated significantly with ESS scores (r = -0.30, -0.41, and -0.30, respectively; p values were all < 0.001). The MSLT was also significantly correlated with "energy/fatigue" (r = -0.19; p < 0.05). After considering the effects of chronic illness and/or body mass index in a multiple hierarchical regression analysis, sleepiness, as assessed by the ESS score, explained 8% of the variance in general health perceptions, 17% of the variance in energy/fatigue, 6% of the variance in the summary measure of well-being, and 3% of the variance in the summary measure of functional status. The variation of MOS scores with sleepiness, unrelated to age or chronic disease, suggests that measures of general health status may be broadly influenced by sleepiness and sleep quality. These data suggest that 1) sleepiness has an important impact on general health and functional status, specifically influencing self-perceptions regarding energy/fatigue; 2) a more specific assessment of sleepiness in general health evaluations may help explain some of the observed variability in these measures across subjects; and 3) general health measures may be useful in the evaluations of patients with sleep disorders.

Adult↗
PubMed1996

Fear, anxiety and perceived control in children of agoraphobic parents.

Sixteen children (M = 11 years) of agoraphobic parents were compared with 16 children of parents with no history of psychopathology, matched on age, gender and socioeconomic status. The majority (68%) of children of agoraphobic parents met DSM-III-R diagnostic criteria, anxiety disorders being most common. They reported more fear and anxiety and less control over various risks than did comparison children. Group's perceptions of the prevalence and their vulnerability to these risks did not differ. Agoraphobic mothers reported more separation anxiety than did comparison mothers, and maternal separation anxiety was negatively correlated with children's perceived control. Results are related to models of anxiety transmission.

Adolescent↗
PubMed1996

Predictors of survival in human immunodeficiency virus-infected patients with pulmonary tuberculosis. The Makerere University-Case Western Reserve University Research Collaboration.

Infection with the human immunodeficiency virus (HIV) has changed both the epidemiology and natural history of tuberculosis. Despite a generally good response to effective antituberculous therapy, the prognosis remains poor. The objective of this analysis was to determine the independent predictors of survival in HIV-infected Ugandan adults with smear-positive pulmonary tuberculosis. A total of 191 HIV-infected Ugandan adults with smear-positive pulmonary tuberculosis were enrolled into a clinical trial of chemotherapy for tuberculosis. The subjects received either rifampin, isoniazid, and pyrazinamide for two months, followed by rifampin and isoniazid for six months (n = 101) or streptomycin, thiacetazone, and isoniazid for two months followed by thiacetazone and isoniazid for eight months (n = 90). After standard measurements were made at baseline, the group was followed at regular intervals for a mean of 16 months to determine survival. During the course of follow-up, 82 (43%) of the patients died, six within the first month of therapy. The one-year survival proportion was 68% with an estimated median survival of 26 months and did not differ according to treatment regimen. The hazard for death was biphasic, high early in the course of therapy, and then again after about one year. After controlling for the treatment regimen, four independent predictors of survival were found: anergy to purified protein derivative, atypical chest roentgenogram, previous HIV-related condition, and lymphopenia. In this cohort of Ugandan adults, four simple and inexpensive predictors of survival were found. These factors suggest that the degree of immunosuppression was a major determinant of survival.

AIDS-Related Opportunistic Infections↗
PubMed1995

Health insurance and utilization in Pneumocystis carinii pneumonia.

To examine the relationship between health insurance status and health services utilization among HIV-infected patients with active Pneumocystis carinii pneumonia (PCP), the discharge and outpatient databases of a large California medical facility were reviewed. Four hundred fifty records met the inclusion criteria. Logistic regression indicated that those who had publicly funded insurance were about half as likely (95% CI 0.28, 0.99) as were those who had private insurance to undergo bronchoscopy with bronchoalveolar lavage at the time of their first PCP episodes. Further research is required to identify the reasons for this difference.

AIDS-Related Opportunistic Infections↗
PubMed1995

Accelerated course of human immunodeficiency virus infection after tuberculosis.

To determine the effect of active tuberculosis on survival and the incidence of opportunistic infections in HIV-infected patients, we performed a retrospective cohort study at four U.S. medical centers to compare the survival and incidence rate of opportunistic infections in 106 HIV-infected patients with active tuberculosis (cases) with that of 106 HIV-infected patients without tuberculosis (control subjects) but with a similar level of immunosuppression (measured by the absolute CD4+ lymphocyte count) as the cases. Cases and control subjects were similar with regard to age, sex, race, previous opportunistic infection, and use of antiretroviral therapy, but they were more likely than control subjects to have a history of intravenous drug use (49 versus 19%). The mean CD4+ counts were similar for cases and control subjects (154 versus 153 cells/microliters, respectively). The incidence rate of new AIDS-defining opportunistic infections in cases was 4.0 infections per 100 person-months compared with 2.8 infections per 100 person-months in control subjects for an incidence rate ratio (RR) of 1.42 (95% confidence interval: 0.94-2.11). Cases also had a shorter overall survival than did controls subjects (p = 0.001). Active tuberculosis was associated with an increased risk for death (odds ratio = 2.17), even when controlling for age, intravenous drug use, previous opportunistic infection, baseline CD4+ count, and antiretroviral therapy. Although active tuberculosis may be an independent marker of advanced immunosuppression in HIV-infected patients, it may also act as a cofactor to accelerate the clinical course of HIV infection.

AIDS-Related Opportunistic Infections↗
PubMed1994

Randomised trial of thiacetazone and rifampicin-containing regimens for pulmonary tuberculosis in HIV-infected Ugandans. The Makerere University-Case Western University Research Collaboration.

Among HIV-positive patients who received treatment for active tuberculosis, thiacetazone has been associated with cutaneous hypersensitivity and recurrent tuberculosis. No controlled trials have investigated the safety and efficacy of thiacetazone-containing regimens compared with alternative regimens among patients with HIV. In a randomised clinical trial of 191 HIV-positive patients with active pulmonary tuberculosis, we examined the safety and short-term efficacy of isoniazid, rifampicin, and pyrazinamide for two months followed by isoniazid and rifampicin for seven months (RHZ) compared with streptomycin, thiacetazone, and isoniazid for two months followed by thiacetazone and isoniazid for ten months (STH). Between May, 1990, and September, 1991, 191 HIV-positive adult Ugandan patients with acid-fast bacilli sputum smear-positive pulmonary tuberculosis (93% confirmed by culture) received either STH or RHZ. Subjects had a standard evaluation that included Mantoux skin test, complete blood count with differential white blood cell count, and chest radiography. After starting therapy, subjects were followed-up over one year for three outcomes: complications of anti-tuberculosis therapy, early sterilisation of cultures, and survival. Of 191 eligible subjects, 90 received STH and 101 received RHZ. The overall one-year survival was similar for STH and RHZ (65% vs 72%), but when controlled for baseline differences in Mantoux reaction size and absolute lymphocyte count, the relative risk of death for STH compared with RHZ was 1.57 (95% CI 1.0-2.48). Overall, 12 adverse drug reactions occurred in the STH arm (18.2 reactions per 100 person years [PYO]) compared with one in the RHZ arm (1.6 reactions per 100 PYO) for a relative risk of 11.7 (95% CI 1.52-90.0). 10 cutaneous reactions occurred in the STH arm (15.2 events per 100 PYO) compared with one event in the RHZ arm (1.6 events per 100 PYO) for a relative risk of 9.7 (95% CI: 1.24, 75.8). A greater proportion of RHZ patients compared with STH patients had sterilised their sputum within two months (74% vs 37%, p < 0.001). In developing countries, rifampicin-containing regimens should be given, when possible, to HIV-positive patients to reduce drug toxicity and to prolong survival.

AIDS-Related Opportunistic Infections↗
PubMed1994

Assessment of the validity and utility of a sleep-symptom questionnaire.

Although questionnaires have been developed to assess symptoms of obstructive sleep apnea (OSA), their overall reliability and utility have not been established. We have evaluated the ability of a questionnaire to identify increased apnea activity (IAA) in 465 participants in an epidemiologic study of OSA. Subjects and their roommates each completed a questionnaire and underwent in-home sleep studies. Responses to 56 questions about sleep habits, sleepiness, and daytime performance were analyzed with factor analysis, logistic regression, and receiver-operator curves (ROCs). Factor analysis demonstrated that 16 questions, grouped into five factors (functional impact of sleepiness, self-reported breathing disturbances, roommate-observed breathing disturbances, driving impairment, and insomnia) explained 67% of the variance in the questionnaire data. Symptom questions demonstrated internal consistency (Cronbach correlations: 0.91 to 0.98). Moderate levels of agreement were observed between self- and roommate-reported responses for nine of ten questions asked of both the subject and his/her partner (kappa statistics: 0.34 to 0.57). Logistic regression analysis demonstrated that IAA could be best predicted by three questions about intensity of snoring, roommate-observed choking, and having fallen asleep while driving (ROC area: 0.78). Use of symptoms with data on gender and body mass index (BMI) improved predictive ability by 10% (ROC area: 0.87). Thus, questionnaire data provide a valid means of characterizing symptom distributions in population surveys of OSA. Predictive ability is not significantly improved with multiple questions or a separate roommate questionnaire, but is improved with consideration of data on BMI and gender.

Adult↗
PubMed1992

Cloning of the rat insulin-like growth factor binding protein-1 gene and analysis of its 5' promoter region.

To understand specific mechanisms involved in the regulation of insulin-like growth factor binding protein-1 (IGFBP-1), an important modulator of IGF bioactivity, we cloned the rat IGFBP-1 gene and sequenced a 1.5 kb Sph1-Sph1 fragment containing 1110 bases upstream from the translation start site. Computer analysis reveals the presence of ATA, CACCC, and CCAAT elements, and putative homeodomain, AP-1, insulin and glucocorticoid response elements in the 5' promoter. Primer extension and ribonuclease protection studies reveal a single cap site in RNA from rat hepatoma cells and both control and diabetic rat liver.

Animals↗
PubMed1986

A teratology study on vomitoxin (4-deoxynivalenol) in rabbits.

Diets containing 4-deoxynivalenol (vomitoxin) of greater than 98% purity were fed to rabbits on days 0-30 of gestation. The dietary concentrations of 4-deoxynivalenol were 0, 0.00075, 0.0015, 0.003, 0.006, 0.012 and 0.024% and the daily intakes of deoxynivalenol were 0, 0.3, 0.6, 1.0, 1.6, 2.0 and 1.8 mg/kg body weight/day, respectively. A pair-fed group was given a feed intake equivalent to that in the 1.6-mg/kg group. The only significant effects that were observed in foetuses examined at day 30 of gestation occurred only at doses that caused reductions in both the body weight and feed intake of does. The foetal effects consisted of a 100% incidence of resorption in the 1.8- and 2.0-mg/kg groups and decreased mean foetal weight in the 1.0- and 1.6-mg/kg and pair-fed groups. The doses that did not appear to be maternotoxic (0.6 and 0.3 mg/kg) did not show any adverse effects in foetuses at term. Vomitoxin given in the diet during pregnancy failed to show any evidence of teratogenic potential in rabbits.

Abnormalities, Drug-Induced↗