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Biomedical subjects

C K Job

Publications and source records attributed to C K Job.

At least 181 records · Page 10Linked to original sources

First lesion in experimental armadillo leprosy.

Eighteen armadillos were infected intravenously with 10(8) M. leprae and 10 intracutaneously with 10(7) M. leprae. Among those which developed disseminated disease, a nodule at the site of inoculation was the first lesion noticed in 14 of the 16 infected intravenously and 4 of the 4 infected intradermally. It is possible that in human leprosy the first sign of infection is localized proliferation of M. leprae at the site of entry, and even nodule formation in lepromatous patients. It may be important to search for asymptomatic swelling or keloid-like lesions in skin or in nasal mucosa while screening a population for early leprosy.

Animals↗

Effect of repeated lepromin testing on experimental nine-banded armadillo leprosy.

Twenty-eight armadillos were lepromin tested and infected with M. leprae; 18 intravenously and 10 intradermally. The lepromin test was repeated after 3 months and at intervals of 6 months thereafter until their death or sacrifice up to 30 months. The one animal with tuberculoid lepromin was resistant and 14 of the 16 with lepromatous lepromin developed generalized disease. Of the 11 with borderline lepromin, 6 developed disseminated disease and 5 were resistant. There is a definite relationship between resistance and tuberculoid lepromin in the armadillo. Repeated lepromin testing had no effect in the rate of infection and the course of the disease in animals infected intravenously. In the intradermally infected animals the results were inconclusive. Whereas all the 20 animals with disseminated disease showed lesions in the liver, spleen and lymph nodes, only 4 animals had sciatic nerve involvement. Peripheral nerve trunk is not necessarily the preferred site in the armadillo. Lung lesions were an important cause of death in lepromatous armadillos.

Animals↗

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↗

Liver lesions in experimental lepromatoid leprosy of the armadillo. A histopathologic study.

A retrospective study of liver lesions was made in 13 armadillos infected intracutaneously with 10(7) M. leprae from the same inoculum, to evaluate the pathogenesis of the experimental disease. Survival times ranged from 13 to 55 months. In seven armadillos the liver lesions were markedly less severe than in six of these animals. The extent of the lesions was unrelated to the duration of the infection and was interpreted as reflecting individual differences in resistance. In contrast to man, leprosy bacilli were found in the liver cells of both groups of armadillos but to a lesser extent in those of the more resistant armadillos. The latter also had no obvious changes in the liver tissue except for round cell infiltration and prominent Kupffer's cells which contained M. leprae. These lesions can be compared to indeterminate leprosy in humans. The lesions in the more susceptible (lepromatoid) armadillos were initiated in Kupffer's cells. Later, large collections of bacillated macrophages infiltrated the liver lobules. The liver cells heavily loaded with M. leprae developed a pale granular cytoplasm which became foamy in the late lesions. In three of the lepromatoid livers, lesions compatible with erythema nodosum leprosum were seen.

Animals↗

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↗