01541nas a2200289   4500000000100000008004100001260001700042653001200059653001800071653001400089653001100103653001200114653002500126653001800151653002500169653003100194653001300225653002100238653000900259100001400268700001500282245011000297300001000407490000800417520081200425022001401237       1982                            d  c1982 Jul-Aug10aCalcium10aCell Membrane10aFixatives10aHumans10aleprosy10aMicroscopy, Electron10aMycobacterium10aMycobacterium leprae10aMycobacterium tuberculosis10aNocardia10aOsmium Tetroxide10aSkin1 aSilva M T1 aMacedo P M00aUltrastructure of Mycobacterium leprae and other acid-fast bacteria as influenced by fixation conditions.  a59-730 v1333 a<p>A procedure using aldehydes, OsO4, Ca++ and uranyl acetate was selected for study of the fixation of Mycobacterium leprae in skin biopsies of leprosy patients. The ultrastructural pattern of recognized normal M. leprae cells fixed by the above procedure was characterized, and was found to be similar to that of other acid-fast bacteria fixed by the same procedure, except for the geometry of the membrane profile. Under such fixation conditions, this profile is always asymmetric in in vitro-cultured normal Nocardia asteroides, M. aurum and M. tuberculosis, whereas in skin biopsies no M. leprae cells with asymmetric membranes have been found so far. The implications of this observation for the interpretation of the ultrastructure of damaged M. leprae cells found in skin biopsies are discussed.</p>  a0300-5410