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Biomedical subjects

B Kumar

Publications and source records attributed to B Kumar.

At least 55 records · Page 3Linked to original sources

Subtrochanteric fractures of the femur--an analysis of the results of operative and non-operative management.

In this retrospective study, 38 subtrochanteric fractures of the femur, managed by operative and non-operative methods were analysed and the results compared. Excluding three pathological fractures, 12 fractures were internally fixed and 23 were treated in traction. In 83.3 per cent of fractures treated operatively and 82.6 per cent treated non-operatively, excellent or good results were obtained. Poor results in traction were due to associated head injury and failure to comply with the position required to maintain alignment. Poor results in the operative group were in the Seinsheimer Type 3A with poor medial buttress. We conclude that both operative and non-operative management give acceptable results in subtrochanteric fractures of the femur but the latter is indicated in Seinsheimer Type 3A fractures.

Adult

Enhancement of learning and memory in mice by a benzodiazepine antagonist.

Benzodiazepines, a class of drugs widely employed as anxiolytics and anticonvulsants, can induce impairments of learning and memory. The purpose of the present investigation was to determine if a benzodiazepine receptor antagonist, flumazenil (Ro 15-1788), could enhance learning and memory. Pretraining injection of flumazenil (2.5 to 40.0 mg/kg) was found to enhance both learning and memory in a test requiring young mice to discriminate the correct arm of a T-maze to escape mild electric shock. In a second test, which required mice to passively avoid a dark chamber after shock, flumazenil pretreatment prevented the occurrence of amnesia induced by the cholinergic receptor antagonist scopolamine. It is hypothesized that flumazenil may facilitate learning or memory processes by reversing a negative modulatory influence of endogenous diazepam-like ligands for benzodiazepine receptors.

Animals

Survival of Staphylococcus epidermidis on the skin of patients of lepromatous leprosy.

The effect of hydration on Staphylococcus epidermidis, the predominant resident bacterial flora, was studied on skin affected by leprosy and known to have impaired sweating. Normal areas served as control. Significantly higher bacterial counts were observed in affected areas compared with normal-looking skin in 16/19 of the patients. Artificial application of Staph. epidermidis on leprosy-affected and unaffected areas, however, showed equivocal results, as in only 50% of the patients were higher counts obtained in affected compared with unaffected sites. The possible responsible factors for the present observation are discussed.

Bacterial Adhesion

Involvement of palate and cheek in leprosy.

22 Cases of bacillary positive leprosy with no apparent lesion in the oral cavity, soft or hard palate were studied for any evidence of pathological involvement. Granulomata were present in 11 (65%) out of 17 cheek biopsies studied. M. leprae were identified in four specimens only. 9 specimens (64%) out of 14 palate biopsies showed definite granulomata. M. leprae were seen in six specimens.

Adolescent

Effect of in vitro formed immune complexes on macrophage functions of Mycobacterium leprae infected mice.

Nonspecific macrophage functions were studied in Mycobacterium leprae infected and preformed immune complex (IC) administered normal (NI) and thymectomized/irradiated (TRI) mice at different time periods. Uninfected controls given IC were also included. Significant decrease in the chemotaxis, phagocytosis and bactericidal activities of macrophages obtained from infected groups compared to their controls were observed. Phagocytic and chemotactic activities of macrophages were normal but intracellular killing was seen to be depressed in studies conducted in normal and thymectomized immunosuppressed groups (Vaishnavi et al., 1985, Kumar et al, 1987) which were not administered with preformed IC.

Animals

Plasma dapsone and its metabolite monoacetyldapsone levels in leprotic patients.

Dapsone (DDS) is a drug of choice in the treatment of leprosy. The DDS and MADDS levels and different pharmacokinetic parameters after a single dose of dapsone and at steady state in leprotic patients have been studied. At steady state, all the patients showed plasma DDS and MADDS levels above 0.5 micrograms/ml throughout the 24-h duration. There was no significant difference in the elimination half-lives of DDS and MADDS after a single dose as compared to at steady state, but AUC0-alpha for both DDS and MADDS were significantly increased at steady state. From these results, it could be concluded that 100 mg daily dose is sufficient to maintain plasma therapeutic concentration in leprotic patients in Indian population.

Adult

Pharmacokinetics of aspirin and chloramphenicol in normal and leprotic patients before and after dapsone therapy.

Pharmacokinetics of aspirin and chloramphenicol was studied in 16 normal and 16 patients suffering from leprosy. A significant increase (p less than 0.05) in the elimination half-life of chloramphenicol was observed before and after dapsone treatment in leprotic patients as compared with the normal volunteers, while no significant difference was observed in any of the pharmacokinetic parameters with aspirin.

Adult

Phrenic nerve conduction in leprosy.

Phrenic nerve conduction was performed bilaterally in 22 multibacillary (BL-LL) and 18 paucibacillary (BT-TT) leprosy patients and 25 control subjects. Prolonged phrenic nerve conduction time and/or reduced amplitude of diaphragm muscle action potential beyond 2.5 standard deviations of control mean values was observed in 9 BL-LL patients (4 bilateral) and 6 BT-TT patients (all unilateral). Out of the nine BL-LL patients with phrenic nerve involvement, median motor and/or sensory nerve conduction was also abnormal in seven patients. On fluoroscopy, diaphragm movements were normal in all patients. The study documents subclinical phrenic nerve involvement in leprosy--a fact not previously recognized.

Adolescent

Evaluation of epidural needles.

Eight different epidural needles (Tuohy Everett, Pitkin, Braun Perifix and Portex in 16-gauge, and Becton Dickinson Crawford, Becton Dickinson B-D, Monoject and Portex in 18-gauge) were evaluated using a scanning electron microscope and spectral x-ray analysis. Differences were noted in the metal composition, between disposable and reusable needles with respect to molybdenum content. The inner surface of the 18-gauge Crawford needle was found to be the smoothest and it also had the best clearance between the needle and stilette. The Portex 16-gauge had the best needle/stilette fit at its bevel. The hardness of the metal was found to be satisfactory in all the needles.

Anesthesia, Epidural