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Biomedical subjects

M Goihman-Yahr

Publications and source records attributed to M Goihman-Yahr.

At least 37 records · Page 2Linked to original sources
PubMed1991

Leukocyte immunophenotypes in bronchoalveolar lavage fluid and peripheral blood of paracoccidioidomycosis, sarcoidosis and silicosis.

Leukocyte subsets in bronchoalveolar lavage (BAL) fluid and peripheral blood of patients with paraccoccidioidomycosis, sarcoidosis and silicosis were characterized using monoclonal antibodies and an immunoperoxidase technique. In paraccocidioidomycosis, the number of T-helper/inducer CD4-positive lymphocytes was lower in peripheral blood than in BAL fluid. Additional analysis showed that the expression of HLA-DR was very similar in alveolar macrophages, lung and blood T-cells. In sarcoidosis and silicosis there were higher proportions of T-helper/inducer cells in peripheral blood than in BAL fluid. The alterations in the T-helper/inducer/T-suppressor/cytoxic CD4/CD8 ratio in sarcoidosis and silicosis were more appreciable in peripheral blood than in BAL fluid, contrasting with the results in paracoccidioidomycosis. The expression of HLA-DR by alveolar macrophages in sarcoidosis was the highest of all the disease studied. No statistically significant differences were observed between chronic multifocal and chronic unifocal paracoccidioidomycosis disease, stage II and stage III sarcoidosis, and chronic and accelerated silicosis. The three granulomatous diseases analyzed had a few alveolar macrophages expressing the CD4 molecule on their surface. These findings and the technique of analyzing both peripheral blood and BAL leukocyte subsets may help to understand the pathogenesis of interstitial lung diseases.

Bronchoalveolar Lavage Fluid↗
PubMed1990

Adenosine triphosphatase in yeast phase Paracoccidioides brasiliensis.

We have previously detected various enzymatic activities in P. brasiliensis. In the present study we have examined Adenosine Triphosphatase (ATPase) activity in yeast phase cultures of P. brasiliensis of increasing age. We employed Wachstein and Meisel's method and electron microscopy and found specific electron-dense deposits indicating ATPase activity to be present in the cytoplasm around vacuoles. Their distribution varied according to age. Deposits decreased or became absent in old cultures. We assume that in P. brasiliensis, ATPase is involved (as in other systems) with transport of Na+ and K+.

Adenosine Triphosphatases↗
PubMed1990

Influence of serum on in vitro digestion of Paracoccidioides brasiliensis by neutrophils.

Serum from patients with paracoccidioidomycosis (PARA) did not block digestive abilities of neutrophils (PMNs) from healthy individuals against Paracoccidioides brasiliensis. Conversely, serum from healthy donors did not enhance digestive capacities of PMNs from patients with PARA vis á vis the causative organism. We conclude that the specific digestive defect present in PMNs from patients with PARA is not mediated by serum factors.

Adult↗
PubMed1989

Digestion of killed Paracoccidioides brasiliensis by neutrophils.

We previously described an in vitro assay showing that neutrophils (PMNs) from patients with paracoccidioidomycosis (PARA) have a specific digestive deficiency against suspensions of live Paracoccidioides brasiliensis. We now report that this defect is equally detectable against autoclaved, but not Amphotericin B-killed P. brasiliensis. The use of autoclaved suspensions facilitates the use of our in vitro assay. It might allow the development of an in vitro intradermal test for digestion of fungi. Differential digestive ability of phagocytes against live (or autoclaved) and Amphotericin-B killed fungi is of conceptual interest. It may be relevant in understanding therapeutic effect of Amphotericin B.

Amphotericin B↗
PubMed1989

Functions of polymorphonuclear leukocytes and individuality of Jorge Lobo's disease: absence of the specific leukocyte digestive defect against Paracoccidioides brasiliensis.

Peripheral blood neutrophils (PMNs) from a patient with Jorge Lobo's disease (JLD) digested well phagocytosed Paracoccidioides brasiliensis. We found no circulating antibodies against P. brasiliensis in the patient's serum. Such neutrophils showed myeloperoxidase activity and also digested normally phagocytosed Candida albicans. We had previously reported the presence of a specific digestive deficiency of PMNs from patients with paracoccidioidomycosis (PARA) vis à vis P. brasiliensis. Current findings provide new information about leukocyte functions in JLD and bolster the view that JLD, PARA and their respective causative microorganisms are distinct.

Antibodies, Fungal↗
PubMed1988

Polymorphonuclear leukocyte functions in psoriasis.

Circulating polymorphonuclear leukocyte (CPMN) functions were studied in patients with widespread psoriasis as well as in persons with chronic alcoholic liver disease (CALD), paracoccidioidomycosis, diverse granulomatous diseases, and normal individuals. We were unable to find stimulation or increase in CPMN functions in patients with psoriasis compared to normal individuals. Leukocytes from individuals with CALD had a lowering of their metabolic activation, chemotaxis, random movement, and adherence. CPMNs from patients with paracoccidioidomycosis showed a significant deficiency in their ability to digest Paracoccidioides brasiliensis. Our results are against the concept that functions of circulating PMNs are stimulated in psoriatics.

Adolescent↗
PubMed1985

Chédiak-Higashi syndrome in a Venezuelan black child.

One case of Chédiak-Higashi syndrome (CHS) in a black male child, born to a consanguineous couple from a rural village in the State of Falcón, is described. At birth the child had marked skin depigmentation and ash-gray hair. A few months later he developed an almost normal black skin color. The diagnosis of CHS was established by the presence of large peroxidase-positive granules in his leukocytes. Neutrophils showed decreased chemotaxis and lack of digestive capacity against Candida albicans. Unusual features included extreme rarity of CHS in blacks, progressive repigmentation of the skin, and an early benign evolution. A high consanguinity index in the village from which this patient originated raised the possibility of the presence of a new cluster of this disease in Venezuela.

Black or African American↗
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↗
PubMed1984

Functions of neutrophils in endemic Chediak-Higashi syndrome.

Endemic Chediak-Higashi Syndrome occurs in a restricted geographic area (Pregonero, State of Táchira, Venezuela). Neutrophils from these patients were unable to digest Candida albicans in vitro, but showed normal or increased metabolic activities. This finding supports the view that the endemic syndrome is bona fide Chediak-Higashi Syndrome.

Chediak-Higashi Syndrome↗
PubMed1982

Leprosy, an overview.

Leprosy is both a public health problem and a model for host-parasite relationship. There is much progress in many areas, and in most, hurdles are not only scientific but also social and financial. The following are goals to reach: 1) progress of growth of M. leprae in animals (to be able to breed armadillos in captivity or to substitute them with other animals); 2) to develop methods for in vitro culture of M. leprae; 3) to obtain antigens from M. leprae and characterize them immunologically; 4) to achieve techniques for objective diagnosis of infection with M. leprae and of leprosy (these techniques will most likely be serologic); 5) to develop methods to direct and manipulate immune response. This should include a better definition of immunologically active cells, their characterization by reliable methods, and an understanding of their functions. Immune control mechanisms and ways to channel them should also be understood; and 6) to have better methods of treatment including flexible adaptable schedules. It will be clear that "solving" the problem of leprosy requires "solving" the social problems in developing countries, as well as unraveling the mystery of the precise control of immune response. As I pointed out, the problems that we face are basically similar to those of autoimmune disorders and of cancer immunology. Research in autoimmune diseases or cancer might provide answers to questions posed by leprosy. It may also be that research in leprosy could supply answers to questions concerning cancer and autoimmunity.

Animals↗
PubMed1981

Wart regression.

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Dinitrochlorobenzene↗
PubMed1980

Studies on plating efficiency and estimation of viability of suspensions of Paracoccidioides brasiliensis yeast cells.

Mild sonication was used to obtain single cell suspensions of Paracoccidioides brasiliensis. These cells were intact by microscopic criteria. Direct cell counts in a given inoculum and colony formation on various media were used to determine plating efficiency. Sonicated and nonsonicated cell suspensions were used to study plating efficiency and to estimated viability by means of vital dyes. Methylene blue Erythrosin B, and Janus green were unreliable when used with P. brasiliensis, but vital dyes were accurate when tested with Candida albicans. Acridine orange gave more meaningful results of viability. Estimates of viability, however, changed significantly as a result of relatively minor alterations in the composition of the suspending medium. In initial experiments, the plating efficiency of P. brasiliensis was dismally low. It descended abruptly with increasing dilution of inoculum. Efficiency was much improved if horse serum was added to brain heart infusion plates or if glucose glycine yeast extract (GGY) plates were incubated at room temperature and mycelial colonies were counted. With the technique we report, current plating efficiency of sonicated suspensions is of the order of 25%. Our results and procedures have an important bearing upon those studies concerned with in vitro killing of P. brasiliensis in suspensions or with isolating this fungus from clinical or environmental specimens.

Acridine Orange↗
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↗