Tuberculosis and human immunodeficiency virus infection in west Burkina Faso: clinical presentation and clinical evolution.

OBJECTIVE: To study the relationship between human immunodeficiency virus (HIV) infection and tuberculosis (TB) in a West African country. DESIGN: A cohort study in TB patients at the TB centre of Bobo Dioulasso, Burkina Faso. RESULTS: HIV seroprevalence rose from 12.5% in 1987 to 24.7% in 1990. Analysis of clinical findings showed that extra-pulmonary TB was not more frequent in HIV-positive patients (18.5%) than in HIV negative patients (17.3%). Four symptoms were independently associated with HIV infection: diarrhoea, lymphadenopathy, weight loss and oral candidiasis. At the end of six months of chemotherapy for TB (2SHRZ/4HR), the mortality rate among HIV-positive TB patients was 27%, versus 10% among HIV-negative TB patients (P < 0.001). There was no difference between treatment failure rates among HIV-positive patients (3.8%) and HIV-negative patients (3.9%). At the final evaluation, 18 months after the start of chemotherapy, the relapse rate was 8% in HIV-positive patients versus 5.6% in HIV-negative patients (NS). Global mortality rate during the whole study period was significantly higher in HIV-1 (40.3%) and HIV-1 + 2 (20%) patients than in HIV-2 (11.1%) and HIV-negative (12.9%) patients. CONCLUSION: We conclude that, according to previous African studies, despite a higher mortality rate due generally to HIV disease itself, short-course chemotherapy of 6 months is as effective in HIV-positive patients as in HIV-negative patients, and must be continued.

Increased sensitivity of autoradiography and fluorography by membrane blotting.

The detection of low amounts of 3H-, 14C- or 35S-labeled compounds can be difficult with x-ray films. Here we report the benefits of blotting labeled molecules that have been electrophoretically separated to a membrane prior to autoradiographic or fluorographic detection. Blotting allows a reduction, by a factor of 5-10, in exposure times compared with dried gels. When combined with a rapid and safe alternative to the impregnation of blots with liquid scintillant, a further 3-fold to 5-fold increase in sensitivity is achieved. Bands containing as low as 1 Bq 14C or 100 to 10(3) Bq 3H could be detected after 24 hours of exposure. This enhancement in sensitivity may lead to new applications of 3H and 14C.

Destruction of genotoxic wastes mixed with radioactive products.

Before their disposal, genotoxic substances are destroyed by strong oxidizing agents. If there are molecules labelled with radionuclides in the medium which is oxidized, then this treatment may bring about the release of gaseous radioactive compounds. We have looked for evidence of such a release following the action of K permanganate and sodium hypochlorite on molecules labelled with 3H, 14C, 32P, and 125I. Among the compounds examined, only those labelled with 14C showed significant quantities of radioactive gas released, with values up to 60% of the total radioactivity. For the other products, less than 0.6% of the radioactivity appeared in a volatile form.

In vivo 14C isotopic evaluation of amino acid oxidative catabolism in the growing chick. I. Fast respiratory 14CO2 and acetyl-CoA renewal.

A single dose of [1-14C] or [U-14C]glycine or L-[1-14C] or [U-14C]valine was injected intraperitoneally into 1- and 3-week-old chicks. Continuous automatic determination of respiratory 14CO2 and determination of 14C in excreta and uric acid were carried out for 8 h. Computer-aided analysis of the kinetics of respiratory 14CO2 demonstrated two exponentially decreasing components, 'fast 14CO2' and slow 14CO2'. Fast 14CO2 production represents the immediate oxidation and/or decarboxylation of the 14C-labeled amino acid. The half-lives differed according to the nature of the 14C-labeled amino acid but not to the age of the chick. The size of the acetyl-CoA pool labeled by [14C]glycine was between 10 and 15 mmol/100 g of chick. Metabolic partition of a circulating plasma free amino acid between oxidation and retention could be quantified by an isotopic index.

In vivo 14C isotopic evaluation of amino acid oxidative catabolism in the growing chick. II. Slow respiratory 14CO2 and protein renewal.

Analysis of the respiratory 14CO2 of growing chicks injected intraperitoneally with [1-14C] or [U-14C]glycine or valine has shown the presence of a delayed 'slow 14CO2' exponential component. The half-lives, about 3 h, are independent of the nature of the amino acid and of the age (1-3 weeks) of the animal. As supported by investigations in cycloheximide-treated chicks of the oxidative catabolism of glycine, valine and acetate, slow 14CO2 is significantly associated with the degradation of short-lived proteins.

Flow measurement of blood radioactivity in animals.

In order to permit flow measurement of blood radioactivity in an animal after establishing extracorporeal circulation, counting cells were constructed of various plastic scintillator materials. The cell was placed in a liquid scintillation spectrometer replacing the sample vial. Stable and reproducible counting rates were obtained only with cells made of blue Altustipe plastic. The counting efficiency was 1.8%. Using this detection system, continuous records were produced of blood radioactivity in miniature pigs after administration of 14C-urethane and [14C]methyl-piperazinyl pyrazino benzoxazepine maleate.

[Clofoctol binding by the bacteria (author's transl)]. / Fixation du clofoctol par les bactéries.

Clofoctol is an antibacterial agent which is active only on Gram + bacteria. The clofoctol binding on bacteria is fast and the number of molecules bound is about 10(6) to 1,5 10(7) molecules per bacteria. Bacteria sensitivity towards clofoctol is the result of their ability to bind with it. Gram negative and Gram + protoplasts of bacteria bind the clofoctol. Binding of clofoctol by B. subtilis is obtained with viable cells and also with thermal inactivated cells. Binding of clofoctol by the cells is reversible and we showed that the 14C clofoctol used for the experiments and the unlabelled clofoctol have the same behaviour. ions as K+, Mg++, Ca++, Mn++, and Fe++, pH variation between 2 to 9, and urea have no influence on the binding of clofoctol by the bacteria, but, sodium lauryl sulfate is an inhibitor of the binding. These results mean that clofoctol bounds are made by hydrophobic links.