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Biomedical subjects

J Convit

Publications and source records attributed to J Convit.

At least 145 records · Page 8Linked to original sources
PubMed1972

A test for the determination of competency in clearing bacilli in leprosy patients.

A skin test has been developed to determine the degree of competency in clearing bacilli from the tissues of patients suffering from various forms of leprosy. The test involves the intradermal injection of a suspension of killed Mycobacterium leprae. The response of leprosy patients to the injection of other mycobacterial antigens, one prepared from M. lepraemurium and another from an atypical mycobacterium from a hamster, was also investigated in order to study the isopathic phenomenon. Since lepromatous patients react negatively in tests with standard Mitsuda antigen, a concentration of 640 x 10(6)M. leprae per ml was used to produce macroscopic responses. The results of the test can be applied to determine the duration of consolidation treatment for lepromatous and indeterminate bacteriologically negative patients after regular treatment has ended. The test can also be used to indicate which Mitsuda-negative contacts should be given preventive treatment, and might be used to identify a given mycobacterium as M. leprae.

Antigens, Bacterial↗
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↗
PubMedDate not supplied

The clinical and immunological spectrum of American cutaneous leishmaniasis.

American cutaneous leishmaniasis is characterized by a spectrum of clinical manifestations. These include localized, often self-healing single lesions, intermediate forms which frequently produce mucosal lesions and often show exaggerated delayed-type hypersensitivity (DTH), and the rare diffuse cutaneous leishmaniasis in which no reaction of protective cell-mediated immunity or DTH can be demonstrated. Clinical, pathological and immunological studies have begun to unravel some of the mechanisms associated with different disease manifestations, dependent on complex interactions between the host immune response, measured in terms of indices including lymphocyte subsets and lymphokines in vitro and within active lesions, and different species of Leishmania.

Animals↗
PubMedDate not supplied

Leishmania braziliensis causing visceral leishmaniasis in a patient with human immunodeficiency virus infection, identified with the aid of the polymerase chain reaction.

This study describes a male patient with human immunodeficiency virus infection, grade IV-C (oropharyngeal moniliasis and Pneumocystis carinii pneumonia), associated with visceral involvement produced by Leishmania braziliensis which was identified by deoxyribonucleic acid hybridization after the polymerase chain reaction had been performed. The patient was treated with molgramostim in association with meglumine antimonate to enhance macrophage destruction of parasites.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

Canine visceral leishmaniasis on Margarita Island (Nueva Esparta, Venezuela).

The frequency of American visceral leishmaniasis affecting humans on Margarita Island, Venezuela, has increased in recent years, and infected dogs appear to constitute the principal source of infection. ELISA tests with Leishmania donovani promastigotes and rK39 antigen from L. chagasi in serum from 541 dogs were positive in 33.1% and 21.6% of the samples, respectively. A second blood sample taken from 50 animals after 8-10 months revealed an increase from 24% to 40% of ELISA positivity to both antigens, suggesting high susceptibility and transmission in the canine population. Among 42 serologically positive dogs, 33% of which showed clinical signs of disease, 79% were positive in polymerase chain reactions using primers specific for the L. donovani complex. Control measures including epidemiological hypersurveillance, the humane sacrifice of infected dogs, and rapid diagnosis and treatment of human cases have been initiated.

Animals↗
PubMedDate not supplied

Immunotherapy of american cutaneous leishmaniasis in Venezuela during the period 1990-99.

Of a total of 11532 Venezuelan patients with American cutaneous leishmaniasis (ACL) receiving immunotherapy with a combined vaccine containing heat-killed Leishmania promastigotes and bacille Calmette-Guerin (BCG) during the period 1990-99, we evaluated 5341 from 4 widely separated geographical states. Clinical healing varied from 91.2 to 98.7%, with an average of 95.7%. Adverse reactions were mild and limited to those associated with BCG vaccination alone. Immunotherapy failures in 143 patients included 54.5% with typical localized ulcers and 45.5% with non-mucosal intermediate cutaneous leishmaniasis (ICL). Less than 2% of the patients in this study had lesions suggestive of ICL. The disproportionately large number of immunotherapy failures in the ICL group suggests that it should not be used as monotherapy in this group. Weaker reactivity to purified protein derivative in immunotherapy failures, while not statistically significant in the small group reported here, suggests the possibility that these patients develop a relatively torpid immune response. The high percentage of clinical cures achieved with immunotherapy, associated with few secondary effects and low cost, support the use of immunotherapy in the routine treatment of localized ACL.

Animals↗
PubMedDate not supplied

Lymphocyte suppression in leprosy induced by unique M. leprae glycolipid.

Leprosy remains a significant medical and social problem in many developing countries. The varied forms of the disease form a spectrum. At one pole, tuberculoid leprosy, patients develop high levels of cell-mediated immunity which results in the killing and clearing of bacilli in the tissues. At the lepromatous pole, patients exhibit a selective immunological unresponsiveness to antigens of Mycobacterium leprae so that the organisms inexorably multiply in the skin. We have suggested that in lepromatous leprosy one or a small number of unique antigenic determinants present on M. leprae might induce specific suppressor cells that inhibit the reactivity of helper T-cell clones capable of recognizing other specific or cross reactive determinants. Although unique epitopes have been identified by monoclonal antibodies on a small number of M. leprae proteins, the only unique species of antigen present in M. leprae, and not on any other species of mycobacteria so far examined, is a phenolic glycolipid (gly-I). We show here that this unique antigen of M. leprae is capable of inducing suppression of mitogenic responses of lepromatous patients' lymphocytes in vitro and provide evidence that the suppressor T cells recognize the specific terminal trisaccharide moiety.

Antigens, Bacterial↗