Biomedical subjects

M C de Albornoz

Publications and source records attributed to M C de Albornoz.

6 recordsLinked to original sources

PubMed1999

[Isolation, identification and serotyping of yeasts obtained from the vaginal fluid in patients with clinical vaginitis].

A study was carried out to determine the presence of Candida in 105 patients with clinical vaginitis who consulted in the Infectious Disease Unit of the Vargas Hospital after referral from Gynecology Service. Yeasts were detected in 23 cases (24%), and identified as C. albicans (12), C. tropicalis (5), C. guilliermondii (3), C. glabrata (2) and C. parapsilosis (1). The presence of hyphae was observed in 50% of the direct examinations, in which the isolated species was C. albicans. These structures were not observed in infections with other species of Candida. In this study, there was relatively little difference between the percentages of serotypes A and B, 58 % and 42, respectively. This is in contrast with previous studies reported in clinical material from Venezuela and other countries, in which serotype A presented a greater incidence than serotype B. Our observations suggest an increase in serotype B C. albicans in vaginal candidiasis.

Adolescent↗

PubMed1995

Comparative ultrastructure and immunolabeling of MHC-II antigens of alveolar macrophages obtained from patients with paracoccidioidomycosis and other lung diseases.

Samples of alveolar macrophages (AM) obtained by bronchoalveolar lavage from patients with either paracoccidioidomycosis, silicosis, sarcoidosis, or allergic alveolitis were investigated by electron microscopy and immunocytochemistry to compare cellular ultrastructure and expression of MHC-II antigens in the AM cell surface. All samples of AM obtained from patients with these pathologies showed heterogeneous structural features. Although, this morphological diversity is also present in AM of healthy donors, our observations seem to indicate that in the diseases studied this morphofunctional diversity is associated with additional ultrastructural characteristics inherent to each disease. In paracoccidioidomycosis the proportion of vacuolated macrophages is significantly lower than in other diseases; this might indicate that in paracoccidioidomycosis the proportion of activated AM is smaller. We observed significant differences in the expression of MHC-II antigens. Silicosis, sarcoidosis, and allergic alveolitis do not differ significantly in the quantity of immunolabeled AM or in the distribution of the label. The percentage of AM from paracoccidioidomycosis that exhibit the MHC-II molecule is very low with poor immunolabeling. In this disease the low expression of the MHC-II molecule could be related to a decrease of the antigen presenting function by AM.

Alveolitis, Extrinsic Allergic↗

PubMed1992

[Serotyping of 48 isolates of Candida albicans: predominance of serotype A over B in Venezuela].

The study of serotyping of isolates of Candida albicans of clinical material obtained from different geographic areas of Venezuela suggest that serotype A is predominant over type B. These results are in relation with results obtained in other countries. Type A serotype is predominant in 57 to 100% in the areas studied. Only in 2 cities serotype B was isolated. Both serotypes of Candida albicans were observed in intertriginous, mucosal, inguinal and lung forms. These studies have allowed us to have information about the predominance of serotypes in certain areas of the country.

Agglutination Tests↗

PubMed1985

A novel method for estimating killing ability and digestion of Paracoccidioides brasiliensis by phagocytic cells in vitro.

We describe a novel method by which phagocytosis, digestion and killing of Paracoccidioides brasiliensis yeast cells by polymorphonuclear leukocytes or other phagocytic cells may be estimated simultaneously. Suspensions of P. brasiliensis (yeast-like phase) were sonicated, counted and incubated at 37 degrees C with known numbers of phagocytes. Control preparations contained no phagocytic cells. At given intervals samples were incorporated into gelatin nutrient medium and droplets of the mixtures were incubated at room temperature. Live yeast-like P. brasiliensis germinate in vitro and produce filaments. After incubation, droplets may be melted and examined under phase contrast optics, or the cells may be washed and stained by a variation of Papanicolaou's method. Digested P. brasiliensis, intact but non-germinating yeasts and filamented (viable) yeasts may be identified and counted. Killing and digestive abilities of phagocytes may be estimated by the difference between values obtained from phagocyte-containing and control preparations.

Cells, Cultured↗

PubMed1980

Defect of in vitro digestive ability of polymorphonuclear leukocytes in paracoccidioidomycosis.

Selected functions of polymorphonuclear leukocytes were studied in patients with paracoccidioidomycosis (South American blastomycosis), in healthy control individuals, and in patients with diseases unrelated to paracoccidioidomycosis. Patients with paracoccidioidomycosis were also evaluated by standard immunological techniques. Phagocytosis and digestion of Paracoccidioides brasiliensis yeastlike cells in vitro was estimated by an original method. It was based on the appearance of phagocytosed P. brasiliensis in preparations stained by a modification of the Papanicolaou method and examined with phase-contrast optics. Interpretation of such findings was confirmed by electron microscopy. Two strains of P. brasiliensis were used. Strain 8506 was freshly isolated from a patient. Strain Pb9 was known to be nonpathogenic and to have a peculiar cell wall composition. Yeastlike cells of the Pb9 strain were digested significantly better than those of strain 8506. A higher number of leukocytes per fungus cells led to a higher proportion of digested P. brasiliensis. Leukocytes from patients with paracoccidioidomycosis phagocytosed the fungus in a normal way, but had a significant lower ability to digest it in vitro. When individual cases were analyzed, there was an excellent correlation between clinical evolution and digestive ability of polymorphonuclear leukocytes. There was good correlation between both of these and immunological parameters. Leukocytes from all groups behaved comparably in tests of general leukocyte function and in their abilities to kill and digest Candida albicans. Our results indicate that, as a group, polymorphonuclear leukocytes from patients with paracoccidioidomycosis had a significant, rather specific, defect in their in vitro digestive capacity against phagocytosed P. brasiliensis. There was also an inverse correlation between strain pathogenicity and its susceptibility to in vitro digestion by polymorphonuclear leukocytes. Our findings are concordant with and relevant to clinical reality.

Candida albicans↗

PubMed1980

Demonstration and quantification oomycosis.

Using a radioimmunoassay technique, we have determined the total IgE concentration and specific IgE antibody level against Paracoccidioides brasiliensis in the sera of patients with mycologically confirmed active paracoccidioidcosis. Patients with aspergilloma, or individuals with antibodies against Cadida albicans, and sera of apparently healthy individuals from the endemic area were also examined. The level of total IgE was significantly elevated in 9 out of 10 cases of paracoccidioidomycosis. The mean level of specific IgE against P. brasiliensis was significantly higher in the serum of the patients in comparison with control individuals. The percentage of specific IgE relative to the total varied from 0.38 to 2.28%. The differences between IgE levels in pare other mycoses were statistically significant. Our results suggest a possible involvement of specific IgE antibodies against P. brasiliensis in the immune response of patients with paracoccidioidomycosis. The hyperimmunoglobulinemia E may be related to the T-cell defect that characterizes the severe forms of the disease.

Adolescent↗