Effects of tobacco smoking on cancer and cardiovascular disease in urban black South Africans.

Demographic and lifestyle information from 9690 black patients diagnosed with cancer or cardiovascular disease was collected in an ongoing case-control study in Johannesburg, South Africa. Compared to never smokers, the odds ratio (OR) for lung cancer among current smokers was 16.3 (95% confidence interval (CI), 9.6-27.6) for men and 6.4 (95% CI, 4.0-10.4) for women. The corresponding OR for other smoking-related cancers was 4.6 (95% CI, 3.7-5.7) among men and 1.9 (95% CI, 1.6-2.2) among women, and for cardiovascular disease, 3.4 (95% CI, 2.1-5.4) among men and 1.5 (95% CI, 1.1-2.1) among women. Risks were higher among smokers than former smokers, and all risk estimates increased with increasing levels of smoking duration and intensity. Non-electric domestic fuel was associated with approximately 60% increase in the risk of smoking-related cancer, but not cardiovascular disease. Risks for cancers of cervix, oesophagus, oral cavity/pharynx, stomach, larynx, pancreas and anogenital region, as well as squamous cell carcinoma of skin were all significantly higher among current than never-smokers, with ORs ranging from 1.5 for cervix (95% CI, 1.2-1.8) to 14.7 for larynx (95% CI, 7.2-30). The risks of tobacco-related disease reported here are similar to that currently observed in Western countries, even though cigarette consumption is relatively low in this population.

Antibodies against six human herpesviruses in relation to seven cancers in black South Africans: a case control study.

BACKGROUND: Infections with certain human herpesviruses have been established as risk factors for some cancer types. For example, Epstein-Barr Virus is considered a cause of Burkitt's lymphoma and other immunosuppression related lymphomas, Hodgkin lymphoma, and nasopharyngeal cancer. Several other human herpesviruses have been linked to cancers but the totality of evidence is inconclusive. METHODS: We conducted a systematic sub-study from within an ongoing case control study of adult black South Africans to investigate the relationship between antibodies to six human herpesviruses and seven cancer groups that may be caused by infectious agents. Subjects had incident cancers of the oral cavity (n = 88), the cervix (n = 53), the prostate (n = 66), Hodgkin lymphoma (n = 83), non-Hodgkin lymphoma (n = 80), multiple myeloma (n = 94) or leukaemia (n = 203). For comparison, patients with other cancers (n = 95) or cardiovascular disease (n = 101) were randomly selected from within the study. Patients were interviewed and their blood was tested for IgG antibodies against HSV-1, HSV-2, VZV, EBV-EBNA, CMV and HHV-6 using enzyme linked immunosorbent assays. Because these viruses are highly prevalent in this population, optical density results from the assays were used as an indirect, quantitative measure of antibody level. RESULTS: There was significant variation in the mean log antibody measures for HSV-2, VZV, CMV and HHV-6 between the disease groups. However, none of the specific cancer groups had significantly higher mean log antibody measures for any of the viruses compared to either control group. In a more detailed examination of seven associations between cancers and herpesviruses for which there had been prior reports, two statistically significant associations were found: a decreasing risk of myeloid leukaemia and an increasing risk of oral cancer with increasing tertiles of antibodies against HHV-6 compared to all other patients (p-trend = 0.03 and 0.02, respectively). Odds ratios for the top tertile compared to the bottom tertile were 0.58 (95%CI 0.3-1.0) for myeloid leukaemia and 2.21 (95% CI 1.1-4.3) for oral cancer. CONCLUSION: In this population, using these tests for IgG, neither mean antibody measure nor high antibody measure against human herpesviruses 1-6 was strongly associated with any of the seven cancer groups. However, we may not have had sufficient power to detect weak associations or associations with a sub-type of cancer if they were present.

Risk factors for oesophageal, lung, oral and laryngeal cancers in black South Africans.

The authors used data collected from 1995 to 1999, from an on-going cancer case-control study in greater Johannesburg, to estimate the importance of tobacco and alcohol consumption and other suspected risk factors with respect to cancer of the oesophagus (267 men and 138 women), lung (105 men and 41 women), oral cavity (87 men and 37 women), and larynx (51 men). Cancers not associated with tobacco or alcohol consumption were used as controls (804 men and 1370 women). Tobacco smoking was found to be the major risk factor for all of these cancers with odds ratios ranging from 2.6 (95% CI 1.5-4.5) for oesophageal cancer in female ex-smokers to 50.9 (95% CI 12.6-204.6) for lung cancer in women, and 23.9 (95% CI 9.5-60.3) for lung cancer and 23.6 (95% CI 4.6-121.2) for laryngeal cancer in men who smoked 15 or more grams of tobacco a day. This is the first time an association between smoking and oral and laryngeal cancers has been shown in sub-Saharan Africa. Long-term residence in the Transkei region in the southeast of the country continues to be a risk factor for oesophageal cancer, especially in women (odds ratio=14.7, 95% CI 4.7-46.0), possibly due to nutritional factors. There was a slight increase in lung cancer (odds ratio=2.9, 95% CI 1.1-7.5) in men working in 'potentially noxious' industries. 'Frequent' alcohol consumption, on its own, caused a marginally elevated risk for oesophageal cancer (odds ratio=1.7, 95% CI 1.0-2.9, for women and odds ratio=1.8, 95% CI 1.2-2.8, for men). The risks for oesophageal cancer in relation to alcohol consumption increased significantly in male and female smokers (odds ratio=4.7, 95% CI=2.8-7.9 in males and odds ratio=4.8, 95% CI 3.2-6.1 in females). The above results are broadly in line with international findings.

Pneumocystis carinii as a cause of pneumonia in HIV-infected patients in Lusaka, Zambia.

PIP: 4 cases of Pneumocystis carinii pneumonia in HIV-infected patients studied at the University of Zambia Medical School, Lusaka, were verified by bronchoalveolar lavage. Pneumocystis is common in North American AIDS patients, but has been considered rare in Africa. One reason may be that facilities for diagnosis, bronchoscopy with bronchoalveolar lavage, are not usually available. 44 consecutive HIV seropositive patients who were unresponsive to a 10-day course of antibiotics, and whose sputum was negative for acid fast bacteria, underwent bronchoalveolar lavage from February 1990 to December 1990. HIV status was assayed with Welcozyme ELISA kits, and P. carinii was detected with toluidine blue O stain. The 1st case of confirmed P. carinii pneumonia was a 35-year old man who had a productive cough for 4 weeks, fever, and dyspnea. He was treated with co-trimoxazole and was symptom-free in 3 weeks, but developed severe Stevens-Johnson reaction. His cultures were positive for M. tuberculosis at week 8. He was lost to follow-up. The 2nd case was a 26-year old man with a 6-month history of cough and white sputum, treated without effect with antituberculous medication. He improved over 3 weeks with co-trimoxazole, but died of respiratory failure 2 months later. The 3rd case was a 30-year old woman being treated for pulmonary tuberculosis, who became progressively dyspneic 7 months later. She developed a generalized maculo-papular rash after taking co-trimoxazole, so was given dapsone 100 mg/day, prednisone 1 mg/kg/day, and trimethoprim 15 mg/kg for 1 week. She improve in 3 weeks. The 4th case was a 30-year old man with a 4-week history of dry cough and dyspnea and recent high fever. He was given co-trimoxazole, but developed generalized purpura after 5 days. His treatment was changed to Dapsone 100 mg/day, prednisone 1 mg/kg/day, and antituberculous medication. He improved after 3 weeks, and is being maintained on Fansidar 1 tablet/week. These cases are remarkable because 2 of them also had pulmonary tuberculosis, which is often the presumed diagnosis of pneumonia in African AIDS patients. Furthermore, 3 developed serious drug reactions to co-trimoxazole, also considered an uncommon occurrence.^ieng

The pattern of paediatric malignancy in Zambia (1980-1989): a hospital-based histopathological study.

The pattern of malignancies among indigenous Zambian children is described. The study, based upon an analysis of histopathology, autopsy and haematology records for a 10-year period (1980-1989), reveals a total of 525 neoplasms with a peak prevalence in the 5-9 year age group. Non-Hodgkin's lymphoma (17.5%) was the most common disorder followed by Burkitt's lymphoma (13.9%), retinoblastoma (11.4%), Kaposi's sarcoma (8.8%), Hodgkin's disease (5.9%), Wilms' tumour (5.9%), acute lymphocytic leukaemia (4%), rhabdomyosarcoma (3.4%), nasopharyngeal carcinoma (2.7%) and osteogenic sarcoma (2.1%). Kaposi's sarcoma and Hodgkin's disease revealed a significant male dominance; the former presented mainly in nodal form. Compared to an earlier report from Zambia (1968-1972), a significant increase in the incidence of Kaposi's sarcoma and nasopharyngeal carcinoma was noted in the present series.

Recombination and transfection mapping of cistron 5 of bacteriophage sp82g.

Recombination between transfecting SP82G DNA molecules has been studied in Bacillus subtilis. Recombinant progeny issuing from transfected cells show many of the features that characterize progeny production in multiplicity reactivated bacteriophage, such as: majority recombinant clones, non-reciprocity of recombinant clones and the frequent absence of input alleles. While transfection substantially lowers the linkage observed between markers in normal phage crosses, linkage is observed at small map distances in transfection either by plating transfected bacteria or the progeny phage. Maps constructed from transfection crosses are identical to those of normal phage crosses, except in magnitude.-Examination of the concentration response of two marker biparental crosses, and three marker triparental crosses using transfecting DNA leads to the conclusion that at all concentrations, transfective centers are saturated with respect to the number of molecules that can be taken up. Thus, the frequency of recombinant infective centers, or recombinant progeny is independent of concentration effects.