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Biomedical subjects

C J Chacko

Publications and source records attributed to C J Chacko.

At least 37 records · Page 2Linked to original sources
PubMed1981

Histology of the Fernandez reaction. An appraisal.

The early lepromin reaction was studied clinically and histologically in 38 leprosy patients. There was a quantitative and a qualitative difference in the character of the early inflammatory response to lepromin in the different groups of leprosy patients. In tuberculoid patients, the extent and degree of inflammation and the density of lymphocytic infiltration were maximal. In the polar lepromatous group, the inflammatory reaction was far less intense, and lymphocytes were scarce or absent. An intermediate histology was noted in the borderline and indeterminate groups of patients. In 11 patients with negative clinical reactions, the histology showed moderately dense lymphocytic infiltrations. The paucity of the clinical reaction could be due to the injection and localization of the antigen in the mid- and deep dermis. The correlation between early and late lepromin reactivity, both clinically and histologically, in the polar tuberculoid group and the polar lepromatous group was good. In the borderline and indeterminate groups, only the correlation between the early and late histological reactions to lepromin was good. The relationships between the early and late clinical reactions to lepromin showed marked variation. It is suggested that the early reaction is as good an indicator of lepromin reactivity as the late reaction in all forms of leprosy but only if it is assessed histologically.

Adolescent↗
PubMed1980

HLA-A, B and C antigens in South Indian families with leprosy.

Seventy-two families, selected for having at least two children affected with leprosy, were HLA typed for 57 A, B and C locus antigens recognized by the WHO Nomenclature Committee. In addition, 20 possible new "splits" were investigated. The distribution of A, B and C locus antigens in affected and unaffected family members was similar, irrespective of the type of leprosy in the family. Gene frequencies (derived by direct gene counting from 253 haplotypes), haplotype frequencies and delta values were calculated. There is evidence for heterogeneity of B5, B15, B17, Bw16 and Bw35 and for the existence of at least one A locus and one B locus antigen not previously detected. The value of the HLA system for detecting expaternal children in a highly inbred population and the effect of inbreeding on the HLA system is discussed.

Chromosome Mapping↗
PubMed1980

T-cell depletion of spleen in patients with longstanding lepromatous leprosy.

In 8 autopsied lepromatous patients the spleen was examined histopathologically and their differential cell population was counted in subcapsular area, red pulp and white pulp. There was considerable reduction of lymphocytes and well marked increase in macrophages and plasma cells in the thymus dependent white pulp. In the subcapsular area and the red pulp, although there was an increase in plasma cells and macrophages no significant reduction of lymphocytes was recorded. Therefore, it is suggested that in lepromatous leprosy there is a selective reduction in the number of T lymphocytes.

Adult↗
PubMed1980

Segmental necrotizing granulomatous neuritis of leprosy.

In leprosy, the occurrence of necrotizing nodular lesions in peripheral nerves is a relatively uncommon complication. Despite clinical and gross similarities, there are microscopical differences among groups of such cases, indicating that in all probability different pathogenetic mechanisms are operative. Furthermore, the vast majority of such cases are not true abscesses but are characterized by caseous necrosis and granulomatous inflammation. The traditional collective name "nerve abscess" is therefore inappropriate. Presented herein is an analytic study of 30 cases of the commonest variant, which we suggest should be called segmental necrotizing granulomatous neuritis of leprosy (SNGN). This lesion commonly affects the right ulnar nerve just above the elbow and occurs most often in those with the borderline tuberculoid form of leprosy. It appears to represent the result of a hypersensitivity phenomenon marked by a preponderance of epithelioid cells rather than a reaction of immunity in which lymphocytes predominate. Acid fast bacilli were demonstrable in the lesion in 77% of cases.

Adolescent↗
PubMed1980

Skin adnexa in leprosy and their role in the dissemination of M. leprae.

Skin biopsies from twenty patients each of tuberculoid, border-line and lepromatous leprosy were studied with a view to find out the presence of bacilli in sweat glands, sebaceous glands, hair follicles and arrector pili muscles and also the pattern of destruction of these tissues by leprous granuloma. M. leprae are found in large numbers in sweat glands, sweat ducts, sebaceous glands, hair follicles and arrector pili muscles. Further in lepromatous leprosy the granulomas mainly surround the skin adnexa which atrophy due to pressure by the granuloma. However in tuberculoid leprosy the inflammatory cells infiltrate the adnexal tissues and destroy them. This study confirms that M. leprae are discharged and disseminated through sweat and sebaceous secretions and therefore infection through skin to skin contact can be one of the common modes of transmission of the disease.

Hair↗
PubMed1980

Prevalence of secondary dapsone resistance in Gudiyattam Taluk, the leprosy control area of the Schieffelin Leprosy Research and Training Centre, Karigiri. 1. Preliminary report.

A preliminary study of the prevalence rate of secondary dapsone resistance among leprosy patients in Gudiyattam Taluk, Tamil Nadu, was undertaken. During the period March 1978 to February 1979, there were 1580 lepromatous and borderline lepromatous patients considered to be at risk of developing secondary resistance. Of them, 1431 were examined clinically, and reactivation and/or relapse was found in 114 patients. Of these, 46 had a bacteriological index of 2,000 and more. Skin biopsies were taken from 26 patients for mouse foot pad studies. Resistance to dapsone at the highest drug concentration was found in 22 and partial resistance in two patients. The organisms from two patients were sensitive to dapsone. Twenty patients were not biopsied because they had been absent from treatment for significant periods of time. These patients are now under observation. Prior to this study, nine patients had been confirmed to have dapsone resistance in the control area, and during the present study 24 additional patients with secondary resistance have so far been detected. Thus 33 patients with dapsone resistance among the 1431 patients examined yields a crude prevalence rate of 2.3% in Gudiyattam Taluk.

Dapsone↗
PubMed1979

HLA-linked genes and leprosy: a family study in Karigiri, South India.

The evidence for a genetic determination of susceptibility to leprosy is reviewed. To test the hypothesis that an HLA (histocompatibility leukocyte antigen)-linked gene is associated with such susceptibility, the association between the distribution of leprosy within a family and the segregation of HLA haplotypes was investigated among 72 families who lived in Karigiri, Tamil Nadu State, South India. A statistically significant association was found for families in which siblings had tuberculoid leprosy and in which neither parent had leprosy. The findings from the data of this study agree with those of two previous studies carried out among smaller populations is Surinam and Wardha, Maharashtra State, India. Such an agreement suggests that a genetic determinant which is linked to the major HLA locus on chromosome 6 and which is probably recessive affects susceptibility to tuberculoid leprosy in humans.

Alleles↗
PubMed1979

The significance of changes in the nasal mucosa in indeterminate, tuberculoid and borderline leprosy.

A study of nasal biopsies from 137 leprosy patients classified on the basis of clinical, microbiological and skin biopsy as Indeterminate, Tuberculoid, Borderline-tuberculoid and Borderline-leproma was undertaken. Changes suggestive of leprosy viz., nerve and smooth muscle inflammation with a few acid fast bacilli in a proportion of the biopsies were seen in all groups of patients examined. This suggests, that even in Indeterminate and Tuberculoid leprosy the disease becomes generalised by the time clinical manifestations appear in skin. Tuberculoid granuloma was seen in two nasal biopsies from Borderline-tuberculoid leprosy patients, one of which was located in the wall of a vein, suggesting the possibility of intravascular dissemination of the disease even in non-lepromatous leprosy. 33 of the patients were children 15 years and below and they also showed changes such as nerve and smooth muscle inflammation but bacilli were seen only in the Borderline group. These findings suggest involvement of the nasal mucosa early in the course of the disease as 70% of the children had the skin lesion for less than one year. The nasal mucosa offers favourable conditions for the growth of the organisms and is readily accessible to infection by droplets, and therefore, it could be one of the primary sites of involvement in leprosy.

Adolescent↗
PubMed1977

Electromicroscopic study of histoid leprosy with special reference to its histogenesis.

Biopsies from 2 patients clinically diagnosed and confirmed by histopathological studies as histoid leprosy were examined using and electronmicroscope. The cells that form the nodule are found to contain far more solid bacilli and much less electron transparent substance than those in lepromatous lesions. They have the characteristics of both macrophages and fibroblasts. It is reasonable to conclude that they are histiocytes produced by local multiplication in response to stimulation by rapidly proliferating M. leprae rather than from accumulation of blood monocytes at the site of inflammation as lepromatous lesions.

Humans↗
PubMed1977

Tuberculoid leprosy and tuberculosis skin: a comparative histopathological study.

Since it has been found hard to differentiate histopathologically tuberculoid leprosy from tuberculosis of the skin, a study of 20 biopsies from each of those conditions was undertaken to identify if possible some of their characteristic features. In tuberculoid leprosy along with tuberculoid granulomata there is always selective involvement and destruction of nerves, lack of fibrosis, absence of caseous necrosis and often epidermal atrophy. In cutaneous tuberculosis, on the other hand, in addition to tuberculous granuloma, there is often a proliferation reaction of the epidermis, areas of ulceration, absence of nerve destruction, marked increase in the reticulin, significant fibrosis and occasionally caseous necrosis.

Biopsy↗
PubMed1976

An evaluation of the self administration of DDS in Gudiyatham Taluk.

This study using the dapsone/creatinine (D/C) ratio was undertaken to find out how many of the patients attending the Village Clinics were actually taking the DDS tablets. The Urine D/C ratio was estimated in 35 patients who were receiving a supervised daily dosage of either 50 or 100 mgs of DDS. The D/C ratio was also estimated in 100 out patients who were on either 50 or 100 mgs of dapsone. It was determined that 72% of this group had taken DDS in the previous 24 hours. It was also seen that the 55 patients who were receiving 100 mgs of DDS had taken 79.3% of their dapsone dosage, and the 45 patients receiving 50 mgs of DDS had taken 96% of their dosage.

Adult↗