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Biomedical subjects

J M Pearson

Publications and source records attributed to J M Pearson.

At least 73 records · Page 4Linked to original sources
PubMed1976

Evidence for prevention of borderline leprosy reactions by dapsone.

68 patients were included in a prospective study of the treatment of borderline leprosy. 34 were treated with dapsone 5 mg daily, and 34 with 50 mg daily. Reversal reactions developed in 11 of those on 5 mg daily and in 3 of those on 50 mg daily. The statistically significant difference between the two treatment groups indicates that, contrary to previous teaching, dapsone given in higher dosage does not predispose patients to reversal reactions and indeed may prevent them.

Adolescent↗
PubMed1976

Does nonspecific T-lymphocyte stimulation of B lymphocytes occur during reversal reaction in borderline leprosy?

Serum immunoglobulins G, A, and M were estimated in 14 patients with border-line cases of leprosy at commencement of treatment and subsequently when they developed 'reversal reaction'. There was a significant increase in all immunoglobulin levels during the reaction, with a subsequent fall; the postreaction values for IgG and IgA were below the base-line figures. Additonal investigations in six patients indicated that the rise was a nonspecific one, not brought about by an increase in antimycobacterial antibodies. It seems likely that the rise in immunoglobulins during reaction is due to nonspecific T-lymphocyte stimulation of B lymphocytes.

Adult↗
PubMed1975

Antigenic heterogeneity in patients with reactions in borderline leprosy.

Fifteen patients with borderline leprosy who developed "reversal" reactions were studied from the inception of treatment. Thirteen showed an appreciable increase in lymphocyte transformation (LT) when preparations of Mycobacterium leprae were used as antigen. The LT responses to either "whole" or "sonicated" preparations of the bacillus in these 15 patients and in nine others also in reaction correlated with the clinical presentation. Those with skin disease predominating in the reaction showed an appreciable increase in LT when whole M leprae was used as antigen. Those with nerve disease predominating showed an increase with sonicated M leprae. In those with both skin and nerve disease there was an increase with both antigen preparations. The ratios of the LT test results (whole to sonicated M leprae) showed highly significant differences between the three groups.

Adolescent↗
PubMed1975

Sulphone resistance in leprosy. A review of one hundred proven clinical cases.

An account is given of the first hundred consecutive proven cases of sulphone resistance in leprosy, detected in Malaysia between 1963 and 1974. Proof of resistance was clinical in eighty patients and was obtained by drug-sensitivity testing in mice in ninety-six patients; 76 cases were proved both clinically and experimentally, and there was no discrepancy between the two methods. Sulphone resistance was confined to patients with lepromatous-type leprosy--i.e., patients with a large bacterial population. Clinical evidence of relapse due to drug resistance appeared 5-24 years after the start of sulphone treatment. Low dosage favoured the appearance of resistance; therefore regular treatment of lepromatous leprosy with dapsone in full dosage is recommended. The attainment of "skin smears negative for leprosy bacilli" is no test of cure of lepromatous leprosy.

Adolescent↗
PubMed1975

Depressive effect of serum from patients with leprosy on mixed lymphocyte reactions. Influence of anti-leprosy treatment.

Mixed leucocyte cultures, from two normal donors, were set up in media containing human serum from one of the following sources: (a) a pool of normal group AB donors; (b) Chinese, Malay or Indian patients with untreated leprosy; (c) the same patients after effective anti-leprosy treatment; (d) control Chinese, Malay or Indian subjects. Transformation was estimated by measuring the incorporation of tritiated thymidine in the last 24 hr of a 7-day culture period. Transformation was impaired in sera from treated lepromatous patients, but was less impaired or not impaired at all in sera from treated lepromatous patients. The loss of depressive activity after treatment was more marked in Chinese and Indian than in Malay patients. Transformation was also impaired, though to a lesser extent, in sera from patients with untreated tuberculoid leprosy; it was still impaired in sera from treated tuberculoid patients. There was no evidence of specificity in impairment of mixed lymphocyte reactivity and lymphocytotoxic antibodies appeared to play no role. The incidences of hepatitis B antigen and antibody and of anti-nuclear factor were not notably high.

Adolescent↗
PubMed1975

Leprosy--histopathologic aspects of nerve involvement.

The most striking single feature of the clinical manifestations of leprosy is the very wide range of appearances shown by the skin lesions. These include the vague, hypopigmented macules of indeterminate leprosy; the large, sharply defined hypopigmented anaesthetic lesions of tuberculoid leprosy; the nodules and diffuse infiltration of lepromatous leprosy; and a wide range of plaques and annular lesions of the intermediate (borderline or dimorphous) types of disease. From superficial appearances it would be impossible to say that these were manifestations of the same infection. Moreover, histologically there is a similar wide range of appearances, including minimal lymphocyte infiltration around the neurovascular bundles in indeterminate leprosy; epithelioid granulomata with Langhans' giant cells and virtually no bacilli to be seen in tuberculoid cases; and in lepromatous leprosy, histiocytic infiltration occupying the whole thickness of the dermis, with massive parasitisation by Mycobacterium leprae, of which there may be up to 10-9 per gram of tissue. Strain differences have been recognised, but appear not to be responsible for this remarkable range of manifestations; they are caused by variations in the soil, not in the seed. Leprosy is almost unique among infectious diseases in the importance that host factors play in its development. The different clinical appearances shown by different types of leprosy can be graded into a continuous series, forming a spectrum from the single or scanty lesions of tuberculoid leprosy to the total body involvement o lepromatous; and the patient with leprosy can indeed truly be said to wear his skin lesions like medals displaying his capacity to resist Myco. leprate. The histopathologic features of the developed disease have a similar spectrum, from an epithelioid granuloma to infiltration with histiocytes that are full of bacilli and are ultimately converted to foam cells (Virchow cells)...

Adrenal Cortex Hormones↗