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Biomedical subjects

C J Chacko

Publications and source records attributed to C J Chacko.

44 records · Page 3Linked to original sources
PubMedDate not supplied

Histological changes in the nerve, skin and nasal mucosa of patients with primary neuritic leprosy.

Primary neuritic leprosy (PNL) presents as a peripheral neuropathy with no visible skin patches and skin smears negative for acid fast bacilli. The pathogenesis of PNL is poorly understood. The aim of the study was to document the histological changes in the nerve, apparently normal skin and nasal mucosa in PNL and to study its significance to the pathogenesis of leprosy lesions. The study is based on a cohort of 208 PNL patients registered at the Schieffelin Leprosy Research and Training Centre, Karigiri. All patients had a nerve biopsy, 196 had a skin biopsy and 39 had a nasal mucosal biopsy. The findings reveal that PNL patients exhibit a spectrum of disease histologically in the nerve ranging from lepromatous to tuberculoid leprosy with a significant proportion (46%) manifesting a multibacillary leprosy histology. Findings in the apparently normal skin and nasal mucosa reveal that there are widespread changes due to leprosy in tissues such as the skin and nasal mucosa even when the disease appears clinically confined to a few nerves. PNL may be an early stage in the pathogenesis of the disease before the appearance of skin lesions. The number of nerves enlarged and lepromin status did not give any clue to the nature of underlying disease.

Adult↗
PubMedDate not supplied

Computerized mathematical model of M. leprae population dynamics during multiple drug therapy.

A computerized mathematical model of M. leprae populations during multiple drug therapy (MDT) was constructed. Relevant published information available to date was fed into it, and reasoned assumptions were made. From the model, it seems likely that MDT steadily selects bacteria resistant to the most powerful of the three drugs used: unless the individual bactericidal potencies of the drugs balance one another. If the drugs used have differing potencies, cure probably hinges on treatment being continued until all metabolically active bacteria are killed. Withdrawal of treatment before that could lead to relapse with bacteria resistant to the most powerful of the drugs used.

Drug Resistance, Microbial↗
PubMedDate not supplied

Progressive nerve lesion in a disease-arrested leprosy patient. An electron microscopic study.

An ulnar nerve biopsy from a patient with purely neural leprosy of the borderline tuberculoid group, who developed ulnar and median paralysis after 2.5 years of DDS therapy, was examined using light and electron microscopes. The nerve parenchyma was largely replaced by collagen fibrils. There were many onion bulbs similar to those seen in hypertrophic neuropathies. Bizarre fibroblasts such as those seen in hereditary sensory neuropathy were also demonstrated. A few Schwann cells contained M. leprae. It is suggested that considerable proliferation of fibrous tissue may be a reactive phenomenon in response to the continued presence of fragmented M. leprae and their products. Ischemia following a marked progressive increase of intraneural collagen is an important cause of atrophy of Schwann cells followed by segmental demyelination and necrosis of the axons in this healed leprosy patient.

Adult↗
PubMedDate not supplied

Evaluation of cell mediated immunity in the histopathologic spectrum of leprosy using lymphocyte transformation test.

Lymphocyte transformation in response to PHA, M. leprae and BCG with the use of measurements of 3H-thymidine uptake, was studied in 10 normal controls, and 71 leprosy patients of different types histologically classified according to the Ridley-Jopling scale. Lepromin and PPD tests were done in each one of them. It was found that there was a generalized depression of immune responsiveness to PHA in all forms of leprosy. The immune responsiveness of lymphocytes to M. leprae continuously and gradually increases from the lepromatous (LL) towards the tuberculoid (TT) end of the spectrum. The loss of immune response of lymphocytes from lepromatous patients to M. leprae is specific as evidenced by their capacity to respond selectively to BCG when PPD-positive, irrespective of their place in the leprosy spectrum.

Antigens, Bacterial↗