ABSTRACT
The double replica device was used to obtain freeze-fracture replicas of gently pressed cells, allowing the visualization of a large number of longitudinally fractured epimastigote and trypomastigote forms of Trypanosoma cruzi. This technique revealed large areas of the plasma membrane, the region of attachment of the flagellum to the cell body and the branched mitochondria.
Subject(s)
Freeze Fracturing/methods , Trypanosoma cruzi/ultrastructure , Animals , Cell Membrane/ultrastructure , Freeze Fracturing/instrumentation , Microscopy, ElectronABSTRACT
The double replica device was used to obtain freeze-fracture replicas of gently pressed cells, allowing the visualization of a large number of longitudinally fractured epimastigote and trypomastigote forms of Trypanosoma cruzi. This technique revealed large areas of the plasma membrane, the region of attachment of the flagellum to the cell body and the branched mitochondria.
Subject(s)
Animals , Freeze Fracturing/methods , Trypanosoma cruzi , Cell Membrane , Microscopy, Electron , Freeze Fracturing/instrumentationABSTRACT
The double replica device was used to obtain freeze-fracture replicas of gently pressed cells, allowing the visualization of a large number of longitudinally fractured epimastigote and trypomastigote forms of Trypanosoma cruzi. This technique revealed large areas of the plasma membrane, the region of attachment of the flagellum to the cell body and the branched mitochondria.(AU)
Subject(s)
Animals , RESEARCH SUPPORT, NON-U.S. GOVT , Freeze Fracturing/methods , Trypanosoma cruzi/ultrastructure , Cell Membrane/ultrastructure , Freeze Fracturing/instrumentation , Microscopy, ElectronABSTRACT
The replica staining label fracture technique was used to analyse the distribution of cruzipain and Ssp4 in Trypanosoma cruzi. Intense labeling for the two proteins was seen on the E fracture face of amastigote forms. Gold particles did not co-localize with the intramembranous particles. Labeling was abolished by previous treatment of the parasites with phospholipase C from Trypanosoma brucei, which removes glycosylphosphatidyl inositol (GPI) anchored proteins. These observations suggest that cruzipain and Ssp4 are attached to the parasite surface via a GPI anchor.
Subject(s)
Cysteine Endopeptidases/analysis , Protozoan Proteins/analysis , Trypanosoma cruzi/chemistry , Animals , Antibodies, Protozoan , Antibody Specificity , Concanavalin A , Cysteine Endopeptidases/immunology , Freeze Fracturing , Glycoproteins/analysis , Glycoproteins/immunology , Gold , Membrane Proteins/analysis , Membrane Proteins/immunology , Protozoan Proteins/immunology , Trypanosoma cruzi/growth & developmentABSTRACT
The effects of sodium dodecyl sulfate on extracellular lipase produced by Candida lipolytica have been studied. The microorganism was grown in culture medium containing different sodium dodecyl sulfate concentrations added to the culture at different intervals of growth. The extracellular lipase activity was not detected when the treated culture supernatants were directly tested in Yeast Mold Agar-Triolein-Rhodamine plates, regardless of surfactant addition time and concentrations. However, after ammonium sulfate precipitation and dialysis, the extracellular lipase activity could be recovered. Therefore, the surfactant, under the experimental conditions used here, does not seem to be able to inhibit lipase production, but it does inhibit the enzyme activity because of its presence in the mixture of the reaction.
Subject(s)
Candida/drug effects , Lipase/metabolism , Sodium Dodecyl Sulfate/pharmacology , Candida/cytology , Candida/enzymology , Cell Division/drug effects , Colony Count, Microbial , Culture Media , Dialysis , Lipase/drug effects , Surface-Active Agents/chemistryABSTRACT
The need for a reliable method for the immunological diagnosis of kala-azar is imperative. Leishmania donovani donovani and L. donovani chagasi culture promastigotes were compared as antigens in a direct agglutination test (DAT) for the diagnosis of visceral leishmaniasis in Brazil. Both antigens were successfully employed for the DAT, showing 100% sensitivity and greater than 98% specificity when used to test sera from Brazilian and African kala-azar, Chagas' disease, malaria, filaria and syphilis patients, and on sera from Brazilian controls. Cross-reactions were sometimes observed when cutaneous and mucocutaneous leishmaniasis patient sera were tested. The cross-reactions were completely abolished by the addition of 0.78% 2-mercaptoethanol to the serum diluent. These data show that this improved DAT can be used for the diagnosis of visceral leishmaniasis in Brazil.
Subject(s)
Agglutination Tests , Antigens, Protozoan/analysis , Leishmania donovani/immunology , Leishmaniasis, Visceral/diagnosis , Animals , HumansABSTRACT
The need for a reliable method for the immunological diagnosis of Kala-azar is imperative. Leishmania donovani donovani and L. donovani chagasi culture promastigotes were compared as antigens in a direct agglutination test (DAT) for the diagnosis of visceral leishmaniasis in Brazil. Both antigens were successfully employed for the DAT, Showing 100½ sensitivity and > 98% specificity when used to test sera from Brasilian and African Kala-azar, Chagas'disease, malaria, filaria and symphilis patients, and on sera from Brazilian controls. Cross-reactions were sometimes observed when cutaneous and cucocutaneous leishmaniasis patient sera were teste. The vross-reactions were completely abolished by the addition of 0.78% 2-mercaptoethanol to the serum diluent. These data show data that this improved Dat can be used for the diagnosis of visceral leishmaniasis in Brazil
