Biomedical subjects
Publications and source records attributed to B Kumar.
Swiss albino mice were inoculated with Mycobacterium leprae obtained from untreated lepromatous patients. Histopathological study of sciatic nerves showed no abnormality. However a few free acid fast bacilli (AFB) were detected in the sciatic nerves taken from the inoculated limbs during the early stages of infection, suggesting the nerve-fibre route of travel as seen in humans in experimental leprosy, too.
Normal and immunosuppressed mice were inoculated with Mycobacterium leprae obtained from untreated lepromatous patients. Besides monitoring the AFB counts in the footpads at 3,6 and 9 months post inoculation, antibody dependent cellular cytotoxicity (ADCC) function was studied. The ADCC function seen to be largely unaltered in the M. leprae infected animals, comparable to the observation made in human leprosy.
Mycobacterium leprae infection was produced through the footpads in normal and immunosuppressed mice. Circulating immune complexes were detected by specific binding test and by conglutinin binding assay for specific and total immune complexes respectively in the sera of these mice during different periods of infection. Out of the total 30 samples tested from the infected groups, 3 were positive by specific binding test and 5 by conglutinin binding ELISA. The implications of the findings in relation to human leprosy are discussed.
25 cases of bacillary positive leprosy patients and 25 age and sex matched controls were investigated for assessment of cochleo-vestibular status. Impaired hearing was complained of by 4 patients. None had tinnitus, dizziness or vertigo. On testing 44% patients were found to have unilateral or bilateral perceptive deafness. Specialised tests of hearing indicated that the deafness was of cochlear type. The vestibular functions were not affected. Leprosy seems to selectively involve the cochlea.
Local and systemic side effects of clofazimine in 514 Leprosy and 26 vitiligo patients who had taken the drug in different doses (100 mg to 300 mg daily) for variable periods of time. The commonest side effect noted was reddish brown pigmentation of skin in 77.8% patients. In an equal number of patients, ichthyotic changes on the peripheral parts of the body were noticed. GIT symptoms occurred only in 0.04% patients in the form of abdominal pain, epigastric distress, mild transient nausea and anorexia. Other minor side effects noted were reddish coloration of sweat, urine and tears. Schilling's, d-xylose tests and faecal fat excretion were near normal in the 21 patients in whom these parameters were done. No abnormality in the Jejunal mucosal biopsy was observed after therapy. No abnormality in the EKG or serum biochemistry occurred even after prolonged therapy. We found the drug to be very safe in the usual doses.
Fifteen patients of lepromatous leprosy having type 2 lepra reaction were treated with colchicine. Seven had moderate, five mild and three had severe E.N.L., colchicine was found effective in all mild, six moderate and one case of pustular E.N.L.
35 lepromatous leprosy patients with recurrent trophic ulcers were analysed for tetanus antitoxin levels by passive haemagglutination test (PHA). 42.85% patients and 32% controls had protective levels of antitoxin in their serum (greater than or equal to 0.1). All the patients (100%) demonstrated measurable antitoxin levels. The findings indicate immunological protection from tetanus and support the clinical impression of it's rarity in leprosy patients.
The data of thirty patients who completed two years of multi-drug therapy (MDT) is analysed in regard to clinical improvement, occurrence of reactions, bacteriological response and compliance to therapy.
Normal uninfected (N) and M. leprae infected mice (NI) were given levamisole in the dose of 2.5 mg/kg body weight. The animals were observed over a period of nine months for bacillary load, T and B cell counts and blast transformation with PHA. Significant increase in B cell counts was observed in the levamisole treated normal (NL) compared to normal control (N) group. T cell counts and blast transformation, however, remained unaffected. However, T-cell counts and blast transformation improved significantly in the infected and levamisole treated (NIL) as compared to the infected group (NI) not given levamisole. Bacillary loads remained unaltered in both, the infected (NI) and levamisole treated (NIL) group.
20 carefully selected untreated patients of bacilliferous leprosy were investigated for primary dapsone resistance by foot pad inoculation. Mice were fed on 0.001 g% and 0.01 g% of dapsone during the period of study. Mice in the control group were given normal rodent feed only. Animals were sacrificed from 6 month onwards at 6 week intervals upto 9 months. In two animals the growth of M. leprae was not inhibited by 0.001 g% concentration of dapsone in diet, but was completely inhibited by 0.01 g% of dapsone.
Normal and immunosuppressed mice were infected with Mycobacterium leprae and the bacillary counts were made from the footpads at 3, 6 and 9 months post inoculation. A decrease in the serum C3 level was observed in the infected groups of animals compared to controls.
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Twenty one patients of leprosy were studied for gastrointestinal symptoms and submitted to detailed intestinal absorption tests and jejunal biopsy before and after the institution of Clofazimine therapy. Fifteen patients were administered 100 mg orally daily for 3 months, while six patients with ENL received 300 mg of the drug for 6 weeks initially and then 100 mg daily. Mild diarrhoea and abdominal symptoms occurred in four patients, fecal fat excretion increased in one patient but Schilling's and d-Xylose tests did not alter. No significant changes were produced by Clofazimine therapy in jejunal mucosa. Clofazimine crystals were seen in the lamina properia of one patient, the overlying mucosa was normal. No correlation was found between the abnormality in mucosal pattern, crystal deposition, absorption parameters or symptomatology and doses of drug taken.
Lymph node aspiration was performed from the inguinal group of lymph nodes in 16 patients having lepromatous or borderline leprosy. In the same group of patients impression smears of excised lymph node and slit smears of the skin were also studied. This study made it obvious that the aspiration biopsy technic gave similar information regarding the Bacteriologic (BI) and Morphologic Indices (MI) as the impression smears of excised lymph nodes. The technic of aspiration being simple and nontraumatic is recommended for the follow-up of patients on antileprosy drugs and in reactional phases.
Responses to various tests of cardiovascular reflexes were studied in 15 patients with leprosy. Heart rate was continuously monitored by electrocardiogram and blood pressure was recorded simultaneously. Three patients showed evidence of cardiac dysautonomia, showing involvement of both the sympathetic and parasympathetic systems. These three patients belonged to the bacilliferous group.
Skin slit smears from fingers and ear lobules and lymph node aspiration smears stained with Ziehl-Neelsen stain were studied in 43 patients of LL or BL disease. All the patients had taken dapsone monotherapy for 3-7 years. None of the patients had clinical evidence of dapsone resistance. Small number of bacilli were detected in 16 patients. Lymph node aspirate was positive in 5 cases, whereas ear lobule and fingers yielded bacilli in 12 and 13 cases respectively. It is recommended that in addition to the traditional ear lobe it is imperative to study other sites as well. Study from fingers is recommended for the sake of simplicity. Where facilities are available sampling of the lymph node may also be attempted to advantage.
Closely bred Swiss albino normal mice (Lecca Strain) were inoculated in the footpad with M. leprae, at room temperature. The animals were harvested at 3, 6 and 9 months post inoculation, and bacillary counts were made. Trophic changes were observed in the tail-tips, ears, footpads and forepaws 12-14 months post inoculation in a group which was allowed to survive. The histopathological changes and bacillary infiltration was found in many tissues/organs. The possibility of studying this normal strain of mice as an experimental model for human leprosy has been discussed.
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