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Biomedical subjects

L M Bechelli

Publications and source records attributed to L M Bechelli.

At least 55 records · Page 3Linked to original sources
PubMed1970

BCG vaccination of children against leprosy. Preliminary findings of the WHO-controlled trial in Burma.

The use of BCG vaccine in the prevention of leprosy has been one of the most important subjects of investigation in the field of leprology in the last 25 years. The action of the vaccine was for many years investigated by determining its effect on the lepromin reaction. Field studies were later considered essential to determine whether BCG vaccination would be useful to leprosy contacts, to the child population probably exposed to infection, or to persons persistently lepromin-negative.The interest of the World Health Organization in this matter began in 1952 and, following the recommendations of certain advisory committees, it was decided to institute a field trial in Singu township in Burma. The main purpose of the investigation was to observe, in a highly endemic area, the protective effect, if any, of BCG vaccine against leprosy in the child population not exposed to Mycobacterium leprae at home but possibly exposed to the infection elsewhere.Field operations began at the end of August 1964 and the preliminary findings obtained up to the end of June 1968 relate to 3 annual re-examinations. So far, from the material studied, it appears that, under the conditions prevailing in Singu township, no significant effect of BCG vaccine can be seen within a period of 3 years. When children in both trial groups are followed-up for much longer periods, mainly children aged 0-4 years at intake, it is possible that a significant difference may emerge. However, to be operationally desirable, a merely significant difference is not enough; the protective effect of BCG should be substantial to warrant its large-scale use as an immunization procedure against leprosy.

Adolescent↗
PubMed1970

Therapy of leprosy.

The latest developments and ideas in the therapy of leprosy are discussed, the need for long-term studies being stressed. The therapeutic efficacy and effective dosages of some sulfones (especially diaphenylsulfone), thiambutosine and long-acting sulfonamides such as sulfamethoxine and sulfalene, are considered. The possibilities for two newer drugs, 4,4'-diacetyldiaminodiphenylsulfone and clofazimine (B-663), both still in the early stages of evaluation, are also described and the potential value of thalidomide in treatment of the lepra reaction is discussed. The authors make a number of recommendations for controlled trials and lines of investigation and, in particular, favour a biochemical approach to the correction of defective host defences. Diaphenylsulfone is still considered the drug of choice for use in the therapy of leprosy.

Aniline Compounds↗
PubMed1970

Studies towards the standardization of lepromin. Progress and prospects.

Because of the wide range of concentrations of Mycobacterium leprae in existing lepromins the authors studied methods of producing a standardizable lepromin containing 160 million bacilli/ml. The effects of using different dilutions of lepromin on the incidence of false-positive reactions were also studied.Progress reported includes a convenient method for preparing large batches of non-sedimenting lepromin, which is directly suitable for microscopic counting of Myco. leprae cells; and a validation of current methods for microscopic enumeration of Myco. leprae. Skin tests with diluted lepromins have demonstrated that dilutions up to 1:16 increase progressively the ability to distinguish between lepromatous and tuberculoid leprosy. This work has provided further evidence that 20 million bacilli/ml (a 1:8 dilution of the initial lepromin) should produce adequate Mitsuda reactions in general populations, provided that 3-mm reactions are taken as the criterion for 1+ positivity. The net effect of these findings is equivalent to expanding the world supply of lepromin by 8 times.Recommendations for further research are proposed.

Antigens↗
PubMed1970

Some recent laboratory findings on Mycobacterium leprae. Implications for the therapy, epidemiology and control of leprosy.

From changes in the morphology and viability of Mycobacterium leprae in infected mice, some authors have concluded that the majority of smear-positive human lepromatous patients become non-infectious within 3-4 months of the beginning of regular treatment with sulfones, even at dosages equivalent to only one-hundredth of the conventional daily dose-namely, 1 mg daily. These very low dosages have, however, not been advocated because of the risk that resistant strains of Myco. leprae might develop. The laboratory findings have already been applied to human leprosy by some leprologists; if they were more widely adopted, leprosy programmes could be seriously affected and the consequences could be serious in endemic areas. Contrary to the results of laboratory tests, the shortcomings of clinical sulfone therapy are evident all over the world from the long times required for lepromatous cases to become bacteriologically negative, from the high proportion of relapses and from chemoprophylaxis trials in child contacts. Final proof of the relationship between the morphological index, i.e., the proportion of solidly staining bacilli present, and contagiousness can come only from prolonged and well-planned epidemiological studies. It appears that leprosy may develop in appreciable numbers of child contacts exposed to index cases already bacteriologically negative, with or without prophylactic dapsone treatment.The results of controlled BCG trials now in progress are not consistent although laboratory trials in mice have indicated that BCG vaccination confers a high degree of protection. However, the results that have been obtained in the mouse, an unnatural host, may not be obtainable in man.It is considered premature to apply laboratory findings to human leprosy before clinical and epidemiological studies have been made in man.

Animals↗
PubMed1966

The leprosy problem in the world.

There is at present a lack of accurate data on the prevalence of leprosy in the different countries of the world, primarily because case-finding has not reached the desired level in many of them. The authors have attempted to provide more realistic figures, using information obtained from several sources and various criteria for calculating estimated prevalence rates.In all there are 2 831 775 registered patients and 10 786 000 estimated cases; the latter figure may well be an underestimate. The number of treated patients is about 1 928 000, some 68% of the registered cases and 18% of the estimated. About 2097 million people live in areas with prevalence rates of 0.5 per 1000 or higher; in these areas nearly one million new cases of leprosy can be expected within the next five years.The estimated number of disabled patients is 3 872 000, of whom 1 961 000 are in disability grades 2-5 (excluding anaesthesia to pain).The data represent an attempt, made with many reservations, to give an indication of the magnitude of the leprosy problem throughout the world.

Female↗