Tubercle最新文献

Bacteriostatic and bactericidal activity of thiacetazone was determined for 68 M. avium clinical isolates and 14 wild drug-susceptible M. tuberculosis strains. The drug had equally low bactericidal activity against both mycobacterial species. The inhibitory activity against most of the M. avium strains was greater than it was against M. tuberculosis. The broth determined MICs for 65 of 68 M. avium strains were between 0.02 and 0.15 μg/ml, while the MICs for M. tuberculosis ranged from 0.08 to 1.2 μg/ml.

Drug resistance in Mycobacterium tuberculosis fell from 15.2% in 1980–1984 to 6.5% in 1985–1989 in the Indian subcontinent (ISC) ethnic group and remained low in the white ethnic group. Resistance to isoniazid, which is of particular clinical significance, fell from 6.1% in 1980–1984 to 2.7% in 1985–1989 in the ISC group. Factors which may affect this trend to reduction are discussed.

Glucose tolerance was assessed, according to WHO diagnostic criteria, in 506 consecutive African patients admitted with sputum-positive pulmonary tuberculosis to the tuberculosis wards of Muhimbili Medical Centre, Dar es Salaam. Nine (1.8%) patients were known to have diabetes. Following a 75 g oral glucose tolerance test (OGTT) diabetes was diagnosed in a further 25 (4.9%) patients giving an overall crude diabetes prevalence rate of 6.7%. Impaired glucose tolerance (IGT) was present in 82 (16.2%) subjects. A repeat OGTT was carried out in the 25 patients found to have diabetic values after the first test. Eight (28%) of the 25 patients reverted to normal glucose tolerance after the second test, 6 (24%) to IGT, and 11 (48%) remained with blood glucose values in the diabetic range, giving a crude diabetes prevalence rate of 4%. In a survey of glucose tolerance, using similar methodology, in 693 members of an urban community in Dar es Salaam the prevalence rates of diabetes and IGT were 0.9% and 8.8% respectively. Diabetes was therefore at least four times as common in the tuberculosis patients (p <0.001), and IGT twice as frequent (p <0.0001). This study confirms the relationship between diabetes and tuberculosis. Those caring for patients with tuberculosis should be aware of the increased prevalence of diabetes in their patients, since failure to diagnose the problem may adversely affect prognosis.

The tuberculostatic activity of the herb henna (Lawsonia inermis Linn.) was tested in vitro and in vivo. On Lowenstein Jensen medium, the growth of tubercle bacilli from sputum and of Mycobacterium tuberculosis H₃₇Rv was inhibited by 6 μg/ml of the herb. In vivo studies on guinea pigs and mice showed that the herb at a dose of 5 mg/kg body weight led to significant resolution of experimental tuberculosis following infection with M. tuberculosis H₃₇Rv.

Adrenocortical function was studied in patients with pulmonary tuberculosis and the findings compared with those in healthy subjects. Plasma cortisol levels in newly diagnosed patients were appreciably higher than in the healthy subjects (P< 0.001). A normal (positive) response to ACTH (tetracosactrin) stimulation was observed in 35 (97%) of 36 healthy subjects, 15 (56%) of 27 newly diagnosed patients with tuberculosis and 5 (42%) of 12 chronic cases (i.e. those who had had the disease for more than 3 years); the difference between the healthy subjects and the two groups of tuberculosis patients was highly significant (P<0.001). Dexamethasone caused an appreciable decrease in the plasma cortisol levels of tuberculosis patients. Considering the diurnal variation of cortisol secretion, there was a steady decline in the cortisol levels between 08:00 and 20:00 in the healthy subjects (P=0.02); in the tuberculosis patients, however, there was a decrease upto 16:00 followed by a significant increase (P=0.05), and the mean value at 20:00 was similar to that at 08:00.

We previously demonstrated that a single intradermal injection of 10⁹ irradiation-killed M. vaccae, given 1 month after starting chemotherapy, caused significant changes in responses to mycobacterial antigens. Amongst 38 patients with pulmonary tuberculosis, 29% had lymphocytes responding to common mycobacterial antigens after the injection, compared with only 11 % of 49 similar patients after an injection of saline (p < 0.03).

To increase the proportion of responders to these antigens, six modifications of the potentially immunotherapeutic injection, randomized with injections of saline, have been assessed by biochemical, clinical, haematological, immunological and radiological criteria.

Subsequent lymphocyte proliferation to mycobacterial antigens enabled the modifications to be ranked in order of efficacy. Tuberculin plus murabutide plus 10⁹ irradiated M. vaccae (36% of 25), an autoclaved preparation of 10⁹M. vaccae (45% of 22), and 2 x 10⁹ irradiated M. vaccae (75% of 12) were the most effective. Antibody responses in several IgG subclasses to mycobacteria, but not streptococci, were also significantly increased by the most effective modifications over the 8 weeks following injection.

Detailed radiological study showed that use of the autoclaved bacilli was followed by a delay in clearing of consolidation, but by better closing of cavities than was found in the control group, suggesting enhanced, or altered, immunological activity around the lesions.