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Biomedical subjects

C K Job

Publications and source records attributed to C K Job.

At least 19 recordsLinked to original sources

Role of inducible nitric oxide synthase in resistance to Mycobacterium leprae in mice.

The manifestation of leprosy in humans is largely determined by host immunity to Mycobacterium leprae and is a model for immunoregulation in a human disease. However, animal models available for exploration of the leprosy spectrum are inadequate. This study explored M. leprae infection in mice deficient in inducible nitric oxide synthase, and this report describes elements resembling borderline tuberculoid leprosy in humans.

Animals↗

Comparative study of Mitsuda reaction to nude mouse and armadillo lepromin preparations using nine-banded armadillos.

In 14 nine-banded armadillos the Mitsuda response to nude mouse-derived lepromin (lepromin-nu/nu) was compared to that of armadillo-derived lepromin (lepromin-A) by injecting the reagents intradermally into either side of the abdomen of the animal and examining the biopsies from the sites after 12 days. The histopathologic responses to both antigens were found to be similar, whether the animal was Mitsuda-negative (lepromatous) or Mitsuda-positive (tuberculoid). It is pointed out that armadillos are good experimental models for leprosy, and their use can replace humans in experimental studies.

Animals↗

Epithelioid granuloma in the iris of a lepromatous leprosy patient; an unusual finding.

This case report depicts a case of histopathologically confirmed polar lepromatous (LL) leprosy with a bacterial index of 4+. He experienced recurrent episodes of erythema nodosum leprosum (ENL) in the first 5 years after diagnosis. Skin smears became negative after 6 years of dapsone monotherapy and have remained negative since that time. At 23 years after diagnosis, the patient had developed cataracts and underwent intracapsular cataract extractions with broad-based iridectomies. In one of the iris specimens, histopathologic examination revealed a focal granuloma composed of epithelioid cells. Subsequently a lepromin skin test showed a positive Mitsuda reaction with a borderline tuberculoid histopathology. This clearly illustrates the immunological upgrading of a polar lepromatous patient, perceived first in the iris tissue.

Adult↗

Role of S-100 staining in differentiating leprosy from other granulomatous diseases of the skin.

Since Mycobacterium leprae are rarely demonstrable in the tuberculoid spectrum of leprosy, a confirmatory diagnosis of leprosy can be made on the basis of finding active destruction of cutaneous nerves by granulomatous inflammation in a skin biopsy. Immunoperoxidase staining for S-100 protein, which is a marker for Schwann cells, was used to delineate nerves in lesional skin biopsies of 25 patients with tuberculoid and borderline tuberculoid leprosy as well as 15 controls with nonleprous granulomatous inflammation. Four different patterns of nerve damage were observed: infiltrated, fragmented, absent, and intact. All of the nonleprous granulomatous dermatoses showed only intact nerves, either inside or outside the granuloma, and so S-100 staining can be used to rule out leprosy.

Diagnosis, Differential↗

Nasal mucosa and skin of smear-positive leprosy patients after 24 months of fixed duration MDT: histopathological and microbiological study.

The skin and nasal mucosa of 10 lepromatous leprosy patients who had completed 24 doses of fixed duration multidrug therapy (MDT) but who continued to be skin-smear positive for acid-fast bacilli (AFB) were examined histopathologically. The nasal mucosa showed granuloma fractions that exceeded those seen in the skin specimens, signifying that activity in this region subsides much more gradually than the activity in the skin. Mouse foot pad studies done using T900r mice with an inoculum from the nasal mucosa biopsy specimens of these patients did not demonstrate any growth of Mycobacterium leprae, indicating that these bacilli were not viable. A skin specimen from one patient grew significant amounts of bacteria in the T900r mouse foot pad. These results show that 2 years of treatment with MDT would prevent dissemination of M. leprae from the nasal mucosa and, therefore, should preclude further transmission of the disease. It also indicates that viable bacteria might persist in the skin of patients, especially those with an initial bacterial index of > or = 4+ who have completed 24 doses of regular MDT. Therefore, a more cautious approach to administering only 12 doses of MDT to highly positive multibacillary patients is suggested.

Adult↗

Histopathological activity in paucibacillary leprosy patients after ROM therapy.

Histopathological activity was assessed in the skin tissue of 13 skin-smear negative, borderline tuberculoid leprosy patients after administration of a single dose of ROM (rifampin 600 mg, ofloxacin 400 mg and minocycline 100 mg) therapy. Biopsies taken just before therapy showed Mycobacterium leprae to be present in eight cases. After 6 months, only three showed granulomatous lesions and others showed only resolving or inactive lesions. Acid-fast bacilli (AFB) persisted in the nerves of three cases. At the end of 12 months, granulomas persisted in 2 out of 13 (15%) patients. No bacilli, however, were detected in any of them at the end of 12 months. This study demonstrated that 12 months after a single dose of ROM granuloma cleared in 85% of the patients and AFB were absent in all of them.

Adolescent↗

Mycobacterium leprae binds to a 25-kDa phosphorylated glycoprotein of human peripheral nerve.

Mycobacterium leprae, the causative agent of leprosy, specifically invades and destroys the peripheral nerve, which results in the main clinical manifestation of the disease. Little is known about the bacteria-nerve protein interaction. We show in the present work that M leprae binds to a 25 kDa glycoprotein from human peripheral nerve. This protein is phosphorylatable and it binds to lectins which have alpha-mannose specificity. This M leprae-protein interaction could be of importance in the pathogenesis of leprosy.

Autoradiography↗

Histopathological features of lepromatous iridocyclitis; a case report.

A peripheral iridectomy specimen which included a portion of the ciliary body from an advanced lepromatous leprosy patient was studied histopathologically. The lepromatous granuloma in the iris was similar in content and appearance to that of skin lesions. It appeared that even in this advanced lepromatous patient the dilator muscles of the iris were preserved. This study agrees with the earlier observation that the dysfunction of the iris in lepromatous disease is most probably the result of autonomic nerve destruction. Further, it is possible that the lepromatous involvement of the iris may reflect the histopathological changes in the ciliary body.

Aged↗

Epidemiological significance of first skin lesion in leprosy.

The epidemiological significance of monolesions in leprosy and the possible inferences on the mode of entry by Mycobacterium leprae into the body are presented based on data from the clinical records of the Leprosy Control Programme of Gudiyatham Taluk in India; 660 children with monolesions (335 males, 305 females) younger than 15 years of age and detected during the period 1990-1995 were included in the study. Detailed investigations on the location of monolesions were carried out and compared with a random sample of 669 normal rural children matched for age and sex. A large majority of the leprosy monolesions were in the uncovered parts of the body, with special predilection for the posterior aspects of the upper extremities and the anterior aspects of the lower extremities. Based on observation of normal children, these happen to be precisely the sites vulnerable for trauma since they are exposed to the environment where M. Leprae could enter through abraded skin and manifest as a patch. The need for further studies is emphasized.

Adolescent↗

Pathology of iris in leprosy.

AIM: The histopathological features of the iris in leprosy were studied by light microscopy. METHOD: Formalin fixed and paraffin embedded iris tissue excised during cataract surgery from 20 leprosy patients were sectioned and studied with haematoxylin and eosin stain and modified Fite Faraco's stain for acid fast bacilli (AFB). RESULTS: Chronic inflammatory reactions were seen in the iris of 11 patients, seven of whom did not have any clinically demonstrable evidence of iridocyclitis. Smooth muscle disruption and destruction were seen in two specimens. AFB were found in the iris tissue of a polar lepromatous patient whose skin smears were negative for AFB and who had completed the WHO recommended antileprosy multidrug therapy (MDT). CONCLUSION: Histopathology discloses far more silent chronic iridocyclitis in leprosy patients than are diagnosed clinically. AFB can persist in the iris tissue even after completion of MDT. Smooth muscle disruption and destruction, a cause of the miotic pupil in leprosy has been conclusively demonstrated histopathologically.

Adult↗