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Biomedical subjects

J O Pobee

Publications and source records attributed to J O Pobee.

At least 19 recordsLinked to original sources
PubMed1997

Neopterin, beta 2-microglobulin, and acute phase proteins in HIV-1-seropositive and -seronegative Zambian patients with tuberculosis.

Neopterin is a biochemical marker for the activation of the cell-mediated immune system. We measured neopterin, beta 2-microglobulin, and acute phase proteins in 31 HIV-seropositive and -seronegative Zambian patients with tuberculosis, using stored sera that had been obtained at the beginning and at end of antituberculosis treatment. In both HIV-seropositive and -seronegative patients neopterin and acute phase proteins were elevated when tuberculosis was initially diagnosed and fell during treatment. In contrast, the mean beta 2-microglobulin level increased during antituberculous therapy in the HIV-seropositive group. Serum neopterin levels at diagnosis were correlated with other parameters of disease activity (fever, anemia, and weight loss). In both groups, patients with persistently elevated neopterin levels at the end of treatment were more likely to suffer relapse of tuberculosis or other adverse health events in the subsequent follow-up period. Neopterin can be used to monitor the response to antituberculous therapy in both HIV-seropositive and -seronegative patients and may have a prognostic value for the patients' wellbeing in the follow-up period.

AIDS-Related Opportunistic Infections↗
PubMed1997

Radiological features of pulmonary tuberculosis in 963 HIV-infected adults at three Central African Hospitals.

Tuberculosis is one of the most important infectious complications in human immunodeficiency virus (HIV)-infected individuals in sub-Saharan Africa. In this radiological study, we detail the chest radiographic findings of Zairean and Zambian adults with a diagnosis of AIDS and tuberculosis as seen at three Central African Hospitals. Between 1992 and 1995, consecutive chest radiographs of 963 HIV-infected adults aged between 16 years and 56 years with microbiologically confirmed tuberculosis (TB) were reviewed: (1) 362 adults from Sendwe General Hospital, Lubumbashi, Zaire, (2) 175 from Mama Yemo Hospital, Kinshasa, Zaire, and (3) 426 adults from The University Teaching Hospital (UTH), Lusaka, Zambia. During the same period consecutive chest radiographs from 1000 age-matched HIV-negative adults with tuberculosis were collected for comparative purposes. Comparison of the two groups showed that the HIV-infected group of patients with tuberculosis had a significantly higher proportion of lymphadenopathy (26% vs 13%; P = 0.001), pleural effusions (16% vs 6.8%; P = 0.001), miliary shadowing (9.8% vs 5%; P = 0.001), an interstitial pattern (12% vs 7%; P = 0.01) and consolidation (10% vs 3%; P = 0.001). There was significantly less cavitation (33% vs 78%; P = 0.001) and atelectasis (12% vs 24%; P = 0.001) seen in the HIV-positive group compared to the HIV-negative group of patients. These patterns of radiographic changes were consistently seen across all three hospital sites. The radiographic appearances in HIV-infected individuals with TB is discussed.

AIDS-Related Opportunistic Infections↗
PubMed1997

Enteropathy in Zambians with HIV related diarrhoea: regression modelling of potential determinants of mucosal damage.

BACKGROUND: AIDS is characterised by small intestinal mucosal damage, but its aetiopathogenesis is poorly understood. Enteric infections in Africa differ from those in northern countries, where protozoan infections have been associated with severe enteropathy in AIDS patients. AIMS: To characterise enteropathy in Zambian AIDS patients compared with local controls, and to assess relative contributions of enteric infection, nutritional impairment, and immune dysfunction. METHODS: Computer aided mucosal morphometry of small intestinal biopsy specimens from 56 HIV infected Zambians with persistent diarrhoea and 26 diarrhoea free controls, followed by regression modelling. RESULTS: Patients with HIV related diarrhoea had reduced villous height and increased crypt depth compared with controls. There was no difference between HIV positive and negative controls. In regression models applied to AIDS mucosal measurements, villous height and crypt depth were related to nutritional parameters and to serum soluble tumour necrosis factor receptor p55 concentration. Crypt depth was also related to lamina propria plasma cell count. Intestinal infection was found in 79%, which consisted predominantly of microsporidia in 34%, Isospora belli in 24%, and Cryptosporidium parvum in 21%, but detection of these enteropathogens was not related to severity of enteropathy. CONCLUSIONS: Nutritional and immune disturbances were associated with enteropathy, accounting for over one third of the variation in mucosal morphometric parameters.

Adolescent↗
PubMed1996

Systemic immune activation as a potential determinant of wasting in Zambians with HIV-related diarrhoea.

Wasting in African AIDS patients is severe, and its aetiology is probably multifactorial: persistent diarrhoea, poverty and tuberculosis may all contribute. We report a cross-sectional study of body composition measured anthropometrically in 75 adult patients with HIV-related persistent diarrhoea in Lusaka, and its relationship to gastrointestinal infection and systemic immune activation assessed using serum neopterin and soluble tumour necrosis factor receptor (sTNF-R55) concentrations. Patients as a group were generally severely wasted (mean body mass index (BMI) 15.8 kg/m2, range 11-22), but the severity of wasting was related neither to oesophageal candidiasis nor to intestinal infection. In men but not women, all measures of nutritional status were negatively related to serum sTNF-R55 concentration (fat-free mass in men, r = -0.64; 95% CI: -0.80, -0.41; p < 0.0001). Some wasted patients had cutaneous features of malnutrition, again associated with higher sTNF55 concentrations, and two had peripheral oedema. The diarrhoea-wasting syndrome in this part of Africa seems to be associated with evidence of high cytokine activity in men, rather than oesophageal candidiasis or any particular intestinal opportunistic infection. This immune activation requires further investigation in the context of the sex difference we have observed.

Adolescent↗
PubMed1995

The impact of human immunodeficiency virus on response to treatment and recurrence rate in patients treated for tuberculosis: two-year follow-up of a cohort in Lusaka, Zambia.

To examine the effect of HIV on response to treatment and recurrence rate in patients with tuberculosis (TB), we have followed 239 previously untreated, adult, TB patients in a prospective cohort study in Lusaka, Zambia. One hundred and seventy-four (73%) were HIV-1 antibody positive. Patients with sputum smear positive, miliary, or meningeal TB were prescribed 2 months daily streptomycin, thiacetazone, isoniazid, rifampicin, pyrazinamide followed by 6 months thiacetazone and isoniazid; others, 2 months streptomycin, thiacetazone and isoniazid followed by 10 months thiacetazone and isoniazid. Thirty-five per cent of HIV-positive (HIV+ve) and 9% of HIV-negative (HIV-ve) patients were known to have died before the scheduled end of treatment. Surviving HIV+ve patients showed weight gain and improvement in symptoms and laboratory and radiological findings similar to HIV-ve patients. The risk of cutaneous drug reaction was 17% (95% CI: 12-25%) in HIV+ve, and 4% (1-13%) in HIV-ve patients. Severe rashes were attributed to thiacetazone. Recurrence of active TB was examined among 64 HIV+ve and 37 HIV-ve patients who successfully completed treatment, with mean follow-up after the end of treatment of 13.5 and 16.8 months, respectively. The rate of recurrence was 22/100 person years (pyr) for HIV+ve patients and 6/100 pyr for HIV-ve patients, giving a recurrence rate ratio of 4.0 (95% CI 1.2-13.8, P = 0.03).

AIDS-Related Opportunistic Infections↗
PubMed1994

Serum lipids and lipoprotein in adult Ghanaians.

OBJECTIVES: To date, no measurement of serum lipid levels in healthy adult Ghanaians have been carried out. This study was undertaken with the objective of providing reference values for serum lipid levels in the Ghanaian population. DESIGN/SETTING: Fasting serum lipid levels were measured in 79 adult Ghanaians living in an urban setting. Volunteers were randomly selected from the work force of the University of Ghana in Accra. There were 54 males and 25 females in the study population. RESULTS: The mean serum cholesterol (SC) for Ghanaian males was 4.27 +/- 1.00 mmol L-1. A value of 4.34 +/- 1.12 mmol L-1 was obtained for the females in this study. High-density lipoprotein cholesterol (HDL-C) in Ghanaian males averaged 1.37 +/- 0.44 mmol L-1 and 1.47 +/- 0.50 mmol L-1 in females. There was no statistically significant difference in low-density-lipoprotein cholesterol (LDL-C) and very-low-density-lipoprotein cholesterol (VLDL-C) levels between the females and males in this study. CONCLUSIONS: Compared to other studies, our results show that populations in Europe and North America have higher levels of total cholesterol and LDL cholesterol than Ghanaians. The levels of HDL cholesterol as well as VLDL cholesterol are higher in Ghanaians than in Europeans and Americans. Further work needs to be done to compare lipid levels in urban and rural Ghanaians as well as in those with cardiovascular disorders.

Adult↗
PubMed1993

Negative sputum smear results in HIV-positive patients with pulmonary tuberculosis in Lusaka, Zambia.

During recruitment to a prospective study of tuberculosis patients in Lusaka, Zambia, 109 had pulmonary disease proven by sputum culture for Mycobacterium tuberculosis, of whom 72 were HIV-1 antibody-positive and 37 were HIV-negative. Among these culture-proven cases, 43% of the HIV-positive patients had a negative sputum smear, compared with 24% of the HIV-negative cases. There was a strong trend towards lower grade or negative sputum smear in the HIV-positive group (P = 0.003). HIV-positive cases also had lower colony counts on culture and colonies took longer to appear. The findings imply that cases of HIV-associated pulmonary tuberculosis may frequently be missed and emphasise the need for new diagnostic methods.

AIDS-Related Opportunistic Infections↗
PubMed1993

The impact of HIV on infectiousness of pulmonary tuberculosis: a community study in Zambia.

OBJECTIVE: To examine the impact of HIV on infectiousness of pulmonary tuberculosis (TB). DESIGN: A cross-sectional tuberculin survey carried out among household contacts of HIV-1-positive and negative patients with bacteriologically confirmed pulmonary TB. Contacts were also examined for active TB. SETTING: Index cases were recruited from patients attending the University Teaching Hospital in Lusaka, Zambia and household contacts were examined during visits to their homes within Lusaka. PATIENTS, PARTICIPANTS: A total of 207 contacts of 43 HIV-positive patients, and 141 contacts of 28 HIV-negative patients with pulmonary TB were examined. MAIN OUTCOME MEASURES: Proportion of contacts of HIV-positive and negative index cases with a positive tuberculin response (diameter of induration > or = 5 mm to a dose of 2 tuberculin units). RESULTS: Fifty-two per cent of contacts of HIV-positive pulmonary TB patients had a positive tuberculin response compared with 71% of contacts of HIV-negative patients (odds ratio, 0.43; 95% CI, 0.26-0.72; P < 0.001). This difference persisted after allowing for between-household variations in the tuberculin response. Tuberculin response in the contact was related to age of contact, intimacy with the index case and crowding in the household. However, the effect of HIV status of the index case was not confounded by these variables. Tuberculin response in the contact was also related to the number of bacilli seen in the sputum smear of the index case which partially explained the effect of HIV status of the index case. Active TB was diagnosed in 4% of contacts of HIV-positive and 3% of contacts of HIV-negative cases, respectively (P = 0.8). CONCLUSIONS: HIV-positive patients with pulmonary TB may be less infectious than their HIV-negative counterparts and this may partly be explained by lower bacillary load in the sputum.

Adolescent↗
PubMed1993

Community-based high blood pressure programs in sub-Saharan Africa.

We studied residents of urban and rural areas of Ghana from 1972 through 1987 to evaluate the health burden of cardiovascular diseases, especially high blood pressure, in these African communities. Among urban adults, the prevalence of hypertension was 8% to 13%, compared to only 4.5% among rural adults. Overall, rates were higher among men than among women. However, the rate of hypertension was the same for men and women over 40 years old. The prevalence of hypertension was 29% for persons aged 35 and older, compared to 3.9% for persons under 35 years of age. Of the 24% of the study participants who were aware of their hypertension status, only a third were undergoing treatment, and only half of those were receiving adequate treatment. The determinants of hypertension include age, family history, body mass index, parity, and alcohol use. On a continent where over 80% of the health budget is spent on communicable diseases such as malaria, this study represents one of the few early attempts to understand the magnitude of the health burden of noncommunicable diseases in Africa.

Adolescent↗
PubMed1993

The impact of human immunodeficiency virus on presentation and diagnosis of tuberculosis in a cohort study in Zambia.

Two hundred and forty-nine patients with tuberculosis were recruited to a cohort study to investigate the interaction between tuberculosis and HIV in Lusaka, Zambia; findings at presentation are presented here. One hundred and eighty-two (73%; 95% confidence interval 67-79%) of the cases were HIV-1 antibody positive. The diagnosis of tuberculosis was confirmed by microscopy for acid-alcohol fast bacilli, culture of Mycobacterium tuberculosis, or histology in 74% of all cases. HIV negative and positive cases differed in site of disease: among HIV negative patients 72% had pulmonary disease alone, 16% extrapulmonary disease alone and 12% had both, whereas among HIV positive patients 40% had pulmonary disease alone, 34% extrapulmonary disease alone and 26% both (P < 0.001). HIV negative and positive cases were compared with regard to outcome of diagnostic procedures: 55% of HIV negative cases could be diagnosed at enrollment by sputum smear, but only 35% of HIV positive cases (P < 0.01). Among pulmonary cases confirmed by sputum culture, 76% of HIV negative patients had a positive sputum smear, compared with 57% of HIV positive patients (P = 0.09). Pleural and pericardial disease were difficult to confirm, but culture of pleural fluid was positive in 12/46 HIV positive patients, compared with 0/11 HIV negative patients. Lymph node disease was readily confirmed by biopsy. The tuberculin test was positive in only 30/110 (27%) of HIV positive cases, but in 21/38 (55%) of HIV negative cases (P < 0.01). Mycobacterium tuberculosis was cultured in 57% of HIV negative cases and 54% of HIV positive cases; no atypical mycobacteria were isolated. Initial resistance to isoniazid was present in isolates from 5% of cases with a positive culture.

Adolescent↗
PubMed1979

The Mamprobi Survey--a screening survey for cardiovascular disease and risk factors in Africa: methodology and validity.

The Mamprobi Survey is a cardiovascular disease prevalence sample survey in an African community in Ghana. This preliminary paper describes its methodology and validity. Response rate corrected for migration from the area was 73%. Subsequent sampling of non-respondents revealed only trivial reasons for non-attendance and only minor differences in health status, suggesting that estimates of disease prevalence by the survey were likely to be accurate.

Adolescent↗