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J Convit

Publications and source records attributed to J Convit.

At least 127 records · Page 7Linked to original sources

The histochemistry of armadillo skin.

The histochemistry of armadillo skin has been studied. The dendritic cells are extremely large, very sharply outlined by methods for alkaline phosphatase and alpha-naphthyl-acetate esterase, and they are dopa-negative. The mastocytes, however, are dopa-oxidase-positive, probably due to peroxidase rather than tyrosinase activity. The giant cells of the granulomas normally seen in the dermis of the armadillo are strongly beta-glucuronidase-positive. These giant cells are evidently foreign body cells reacting to the crystals always present in the dermis of the armadillo. The centre of these crystals, which are cholesterol and fat-negative, is alkaline phosphatase-positive. Further study of the mastocytes and dendritic cells is necessary to elucidate their nature.

Acetylcholinesterase↗

Preliminary taxonomic studies on the leprosy bacillus.

Antigens extracted from leprosy bacilli obtained from infected human and armadillo tissues have been examined by immunodiffusion analysis with serum samples from lepromatous patients and with immune sera raised in rabbits. Using the best combinations of serum and antigen extracts, 12 antigenic constituents were found in the leprosy bacilli. Six of these were antigens common to all mycobacteria and nocardiae, 4 were specific to the leprosy bacillus and the position of 2 could not be determined. Groups ii and iii antigens (i.e. those associated with the slow growing and fast growing subgenera of mycobacteria) were not found in theleprosy bacillus, suggesting some relationship with M. vaccae and similar strains, in which these antigens are also missing. Lymphocyte transformation tests performed on lymph node cells of mice infected or immunized with leprosy bacilli also showed the leprosy bacillus to have a closer relationship with M. vaccae than with other mycobacteria.

Animals↗

Leprosy: confirmation in the armadillo.

Bacteria isolated from lesions of lepromatoid leprosy in the armadillo were studied in comparison with Mycobacterium leprae isolated directly from human lepromatous leprosy lesions. Three methods were used to show that the bacteria from the lesions of the armadillo were identical to those of the human lesions: (i) extraction of the bacteria with pyridine and subsequent staining with various techniques, (ii) the competence in clearing bacilli (CCB) test, and (iii) the Mitsuda test.

Animals↗

Mycolic acids from "noncultivable" mycobacteria.

Chromatographic analysis, coupled to mass spectrometry with a high-resolution mass spectrometer, of materials isolated from skin lesions of patients with lepromatous leprosy allows the recognition of characteristic mycobacterial products, mycolic acids. This finding indicates that the "noncultivable" bacteria responsible for leprosy are mycobacteria.

Acetone↗