R P Mendes

São Paulo State University, São Paulo, Estado de Sao Paulo, Brazil

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Publications (46)58.99 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: To report nine additional well-defined cases with infiltrative myelopathy by paracoccidioidomycosis (PCM), to describe the specific lesions and infection-related stromal abnormalities, to review the literature on this type of involvement and to introduce a new cause of granulomatous lesions of bone marrow. Different bone marrow specimens were studied (aspirated smears, aspirated clots, biopsy imprints and biopsies) from nine patients with acute or subacute forms of PCM known to have PCM infiltrative myelopathy. The biopsy specimens were the best for demonstrating bone marrow involvement by PCM. The lesions varied from compact and focal granulomas with few fungal cells to numerous disseminated fungal cells within a loose granulomatous inflammatory reaction, with a continuum between these extremes suggesting a spectrum of immune response to the fungi. Other findings such as bone marrow fibrosis, parenchymal coagulative necrosis and bone necrosis were also observed in the affected areas.
    Histopathology 04/2006; 48(4):377-86. · 2.86 Impact Factor
  • Microbes and Infection 01/2003; 5(5). · 2.92 Impact Factor
  • Microbes and Infection 01/2003; 5(2). · 2.92 Impact Factor
  • R Poncio Mendes, R Negroni, A Bonifaz, D Pappagianis
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    ABSTRACT: The treatment of mycetomas varies according to their etiological agents and the clinical state of the patient. For the treatment of eumycetomas, the azole derivatives are the drugs of choice, with itraconazole rendering better results than ketoconazole and presenting better tolerance. Actinomycetomas are treated according to different therapeutic schemes: dapsone plus sulfamethoxazol-trimethoprim (SMT), and streptomycin or amikacin or amoxicillin plus clavulanic acid. The first therapeutic scheme is very useful in the treatment of Nocardia mycetoma, while the association of amikacin plus SMT is the best treatment for those cases produced by Actinomadura madurae. Ciprofloxacin is a very useful drug for the treatment of actinomycotic mycetomas with bone lesions. Although there are several criteria for evaluating clinical outcome there is no accepted criterion of cure. During the 1990s, there was a remarkable increase in the incidence of coccidioidomycosis in California, USA. An almost ten-fold increase in the number of cases was registered during 1992 and 1993 over the usual incidence. A gradual reduction in coccidioidomycosis cases was observed in the late 1990s. This particular coccidioidomycosis outbreak took place in areas of low endemicity, as well as in those of usual high endemicity. Among the factors believed to have influenced this phenomenon were a drought followed by abundant winter/spring rainfall, increased immigration of susceptible individuals, increase in excavation/construction work and a better diagnosis of the infection, particularly in the last part of the decade. The majority of patients presented the usual clinical manifestations of symptomatic primary infection but an unusual number of cases with acute respiratory failure were observed.
    Medical Mycology 02/2000; 38 Suppl 1:237-41. · 1.98 Impact Factor
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    ABSTRACT: Despite advances in diagnosis and treatment, the epidemiological status of the human immunodeficiency virus (HIV) infection is far from under control in most of the developing world. Sub-Saharan Africa, Southeast Asia and India show increased rates of new infections. In Latin America and the Caribbean there were 1.6 million estimated cases of HIV-infected patients at the end of 1997. Fungal diseases have been one of the most relevant diagnoses in relation to the acquired immunodeficiency syndrome (AIDS). Infections due to Candida species and Cryptococcus neoformans var. neoformans are common worldwide. Histoplasma capsulatum, Coccidioides immitis and Penicillium marneffei are important causes of disease in endemic areas. Infection due to Sporothrix schenckii, Blastomyces dermatitidis and Paracoccidioides brasiliensis are uncommon even where they are endemic. Phaeohyphomycetes, hyalohyphomycetes and zygomycetes are still rare as a cause of disease among AIDS patients. However, agents pertaining to these groups, such as Aspergillus spp., have an increasing incidence. Superficial mycoses due to dermatophytes have special features from epidemiological, clinical and therapeutic points of view.
    Medical Mycology 02/2000; 38 Suppl 1:269-79. · 1.98 Impact Factor
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    ABSTRACT: Isolates of Paracoccidioides brasiliensis may vary in virulence according to time of in vitro subcultivation. The present study compared the morphology and pathogenicity to hamsters of two P. brasiliensis isolates: one obtained from human lesions and maintained in the laboratory for several years (Pb-18) and the other isolate recovered from hamsters inoculated with organ homogenates from armadillos (Pb-T). The microscopic morphology of Pb-18 and Pb-T showed yeast cells with similar diameter. However, Pb-T produced a significantly higher number of buds per mother cell than Pb-18. Besides, the mycelial form of Pb-T developed abundant sporulation during 8 weeks of culture which was absent in the Pb-18 isolate. Virulence studies demonstrated that mortality rates, antibody levels, fungal load and extent of lesions in the organs were significantly higher in animals infected with Pb-T. The results demonstrated that Pb-T recently isolated from an animal was more virulent than Pb-18. These differences between the two P. brasiliensis isolates may be indicators of virulence attenuation in this fungal species.
    Mycopathologia 01/2000; 148(3):123-30. · 1.49 Impact Factor
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    ABSTRACT: Metabolites produced by pathogenic fungi may be involved in the pathogenesis of fungal infections consequently altering the defence mechanisms of the host. In this study the levels of Paracoccidioides brasiliensis antigens detected in the plasma of patients with paracoccidioidomycosis correlated with the suppression index detected by the low mitogenic response of peripheral blood mononuclear cells (PBMC) to phytohaemaglutinin (PHA). This inhibitory effect on lymphoproliferation was observed in the plasma of 58% of the patients, suggesting the presence of inhibitory factors. Plasma samples from paracoccidioidomycosis patients having or not having inhibitory factors showed no significant effect on chromosomes of lymphocytes from healthy individuals. However, these plasmas had a suppressive activity on the blastogenic response of these lymphocytes stimulated with PHA, that was independent of a cytotoxic effect. P. brasiliensis antigens added to the proliferative response of PBMC from healthy individuals stimulated or not stimulated with PHA showed a dose-dependent suppressor effect, reproducing the inhibitory effect of patients' plasma. We suggest that the antigens of P. brasiliensis present in the plasma of patients, even at low concentrations, can play an important role in the reduction of the cellular immune response and in the genesis of the immunoregulatory disturbances observed in paracoccidioidomycosis.
    Medical Mycology 09/1999; 37(4):277-84. · 1.98 Impact Factor
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    ABSTRACT: A group of 10 patients, nine of them seriously infected with Paracoccidioides brasiliensis (G1), received glucan (beta-1,3 polyglucose) as an immunostimulant intravenously once a week for one month, followed by monthly doses (10 mg) over an 11-month period, together with a specific anti-fungal agent as an immunostimulant. A second group of eight moderately infected patients (G2) was treated with only the anti-fungal agent. Among the patients in G1, there was only one case of relapse compared with five in G2. Values for the erythrocyte sedimentation rate (ESR) showed a significant difference (P < 0.001) post-treatment in G1 patients, when compared with the pretreatment levels. There was also a significant reduction (P < 0.001) in the level of serum antibodies to P. brasiliensis in the G1 patients in post-treatment examinations. The phytohemagglutinin (PHA) skin test showed a positive reaction among the patients in G1 (P < 0.01) post-treatment and there was a tendency towards an increase in the number of CD4+ T lymphocytes in both groups after treatment. The serum level of tumor necrosis factor (TNF) proved to be significantly higher (P < 0.02) in the G1 patients during treatment. In the G1 patients, the correlation between ESR and TNF tended to be negative whereas that between ESR and serum antibodies was positive. The present results indicate that the patients who received glucan, in spite of being more seriously ill, had a stronger and more favorable response to therapy.
    The American journal of tropical medicine and hygiene 11/1996; 55(5):496-503. · 2.53 Impact Factor
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    ABSTRACT: We studied 6 patients and 2 dogs that have been bitten by South American rattlesnake Crotalus durissus terrificus and one rabbit inoculated with crotalid venom. We analyzed sensory and motor peripheral nerve conduction, repetitive stimulation for studying neuromuscular transmission and electromyographies. Muscle biopsies were processed by histochemistry. All patients had peripheral mononeuropathy of the closest sensitive nerve to the area of snakebite. The neuromuscular transmission alterations were minimal. Muscle histochemistry of 4 patients, 2 dogs and 1 rabbit showed findings of mitochondrial myopathy. The majority of authors admit that crotalid venom causes myastenic syndrome. Our findings suggest that palpebral ptosis, myastenic facies and muscular weakness observed after crotalid poisoning are, probably, due to transient and reversible mitochondrial myopathy. As far as we know, this is the first report on the ability of the venom of this rattlesnake to cause local sensitive mononeuropathy and the first muscle histochemistry showing mitochondrial myopathy in humans poisoned by crotalid venom.
    Arquivos de Neuro-Psiquiatria 04/1996; 54(1):1-11. · 0.83 Impact Factor
  • Toxicon 01/1996; 34(1):13-13. · 2.92 Impact Factor
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    ABSTRACT: In an attempt to isolate Paracoccidioides brasiliensis from nature 887 samples of soil from Botucatu, SP, Brazil, were collected cultured in brain heart infusion agar supplemented with dextrose, in potato dextrose agar and in yeast extract starch dextrose agar, all with antibiotics, at 25 degrees and 37 degrees C. Five thermo-dependent dimorphic fungi morphologically resembling P. brasiliensis were isolated; two from armadillo holes; further studies of the biology, antigenicity and genetic features of the five dimorphic fungi are necessary to clarify their taxonomy and their possible relation to P. brasiliensis. In addition, 98 dematiaceous fungi and 581 different species of Aspergillus spp. were also isolated. Our findings emphasize that armadillos and their environment are associated with thermo-dimorphic fungi and confirm the ubiquity of pathogenic dematiaceous fungi and Aspergillus spp.
    Memórias do Instituto Oswaldo Cruz 01/1996; 91(6):665-70. · 1.36 Impact Factor
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    ABSTRACT: The exoantigen of Paracoccidioides brasiliensis standardized by Camargo et al. (AgR) was used to evaluate the in vivo and in vitro cell immune response of experimental animals and of patients with paracoccidioidomycosis (PBM). Fava Netto antigen (AgF) was tested in parallel as a control antigen. The study was conducted with mice and guinea pigs infected with P. brasiliensis or immunized with its fungal antigens, on patients with PBM and on their respective control groups. The cell immune response was analysed by skin tests, and by the macrophage and leucocyte migration inhibition tests (MMIT and LMIT) in the animals and in the patients, respectively. The skin test with AgR as paracoccidioidin was positive in infected or immunized mice and guinea pigs and negative in control animals. The skin tests with AgR (24 h) showed 96.7% positivity in patients with PBM and were negative in control individuals. Histopathological study of the in vivo tests in the different experimental models was consistent with a delayed hypersensitivity response (DHR). Immunohistochemical study of the skin tests of PBM patients demonstrated a predominance of T lymphocytes, confirming the nature of a DHR to the fungal antigens. The in vitro cell immune response showed variable results for the various experimental models, i.e. significant rates of MMIT in immunized mice, a tendency to positivity in infected guinea pigs, and the absence of migration inhibition in PBM patients. Taken together, the data indicate that the AgR is efficient as paracoccidioidin in the evaluation of DHR in PBM, with an optimum time of reading the test of 24 h.
    Journal of medical and veterinary mycology: bi-monthly publication of the International Society for Human and Animal Mycology 01/1996; 34(4):265-72.
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    ABSTRACT: The pathogenicity and immunogenicity of six recently isolated Paracoccidioides brasiliensis samples derived from patients presenting distinct and well defined clinical forms of paracoccidioidomycosis (PCM) were compared as to their virulence, tropism to different organs and ability to induce specific cellular and humoral immune response in susceptible (B10.A) inbred mice. Isolates Pb44 and Pb47 were obtained from acute cases, Pb50 from a chronic severe form, Pb45 from a chronic moderate case and both Pb56 and Pb57 from chronic mild forms of PCM. Pathogenicity and tropism of each fungal sample were evaluated by LD50% estimation, examination of gross lesions on various organs at 2, 4, 12 and 16 weeks post-infection, and by colony-forming unit (CFU) counts in the lungs at week 16 post-infection of mice. Fungal tropism in human PCM and in B10.A mice was always dissociated. A well defined relationship between virulence of the fungal sample and the clinical findings of the correspondent patient was not evident, although a tendency to higher LD50% and less intense paracoccidioidic lesions was observed in mice infected with Pb56 and Pb57. The specific DTH response patterns varied according to the infectant sample, but positive DTH reactions at the beginning of the infection and a tendency to anergy or low DTH responses at week 12 and/or week 16 post-infection were always observed. A correspondence between the DTH response in humans and in mice was noticeable only when the isolates from the most benign cases (Pb56 and Pb57) were considered. The specific antibody patterns in mice and in the correspondent patients were also not analogous. Collectively, these results indicate that an association between the fungal pathogenicity and immunogenicity in the human disease and in susceptible mice was discernible only when isolates obtained from very mild cases (Pb56 and Pb57) were considered.
    Clinical & Experimental Immunology 08/1994; 97(1):113-9. · 3.41 Impact Factor
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    ABSTRACT: The pathogenicity and immunogenicity of six recently isolated Paracoccidioides brasiliensis samples derived from patients presenting distinct and well defined clinical forms of paracoccidioidomycosis (PCM) were compared as to their virulence, tropism to different organs and ability to induce specific cellular and humoral immune response in susceptible (B10.A) inbred mice. Isolates Pb44 and Pb47 were obtained from acute cases, Pb50 from a chronic severe form, Pb45 from a chronic moderate ease and both Pb56 and Pb57 from chronic mild forms of PCM. Pathogenicity and tropism of each fungal sample were evaluated by LD50% estimation, examination of gross lesions on various organs at 2, 4, 12 and 16 weeks post-in feet ion, and by colony-forming unit (CFU) counts in the lungs at week 16 post-infection of mice. Fungal tropism in human PCM and in B10. A mice was always dissociated. A well defined relationship between virulence of the fungal sample and the clinical findings of the correspondent patient was not evident, although a tendency to higher LD50% and less intense paracoccidioidic lesions was observed in mice infected with Pb56 and Pb57. The specific DTH response patterns varied according to the infectant sample, but positive DTH reactions at the beginning of the infection and a tendency to anergy or low DTH responses at week 12 and/or week 16 post-infection were always observed. A correspondence between the DTH response in humans and in mice was noticeable only when the isolates from the most benign cases (Pb56 and Pb57) were considered. The specific antibody patterns in mice and in the correspondent patients were also not analogous. Collectively, these results indicate that an association between the fungal pathogenicity and immunogenicity in the human disease and in susceptible mice was discernible only when isolates obtained from very mild eases (Pb56 and Pb57) were considered.
    Clinical & Experimental Immunology 06/1994; 97(1):113 - 119. · 3.41 Impact Factor
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    ABSTRACT: Blood cell lymphocyte chromosomes from untreated (UT) and clinically-cured (CC) patients with paracoccidioidomycosis and from healthy (control) people (CO) were studied. The frequency of aneuploid cells in the UT patients was higher than in the CC and CO individuals. The frequency of metaphase cells with premature centromere division was significantly higher in the UT than in the CC and CO group. No structural aberration and no statistically significant difference in the frequency of polyploidy was observed in the three groups studied. Our findings are indicative of an aneugenic (aneuploidy-inducing) action of infection by Paracoccidioides brasiliensis.
    Journal of medical and veterinary mycology: bi-monthly publication of the International Society for Human and Animal Mycology 02/1994; 32(3):199-203.
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    ABSTRACT: Primary intrahepatic lithiasis is an entity defined by intrahepatic stones exclusively located in the IH ducts above the emergence of the common bile duct. The disease is classified in two types: Eastern type (stones formed primarily in intrahepatic ducts; frequent in Japan) and Western type (stones formed in the extrahepatic bile system, usually in gallbladder, which migrate up to the intra-hepatic ducts). The mechanisms of lithogenesis in the entity are as yet not fully understood; multiple factors seem to operate synergistically: anatomical changes of the intrahepatic ducts, metabolic disorders, infections, idiopathic alteration. All these factors may facilitate biliary stasis leading ultimately to stone formation. We report on a case of and review the literature on primary intrahepatic lithiasis, which is a rare occurrence in the West and a disease of difficult surgical approach and high mortality.
    Arquivos de Gastroenterologia 01/1994; 31(2):63-8.
  • Current topics in medical mycology 02/1993; 5:115-49.
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    ABSTRACT: The presence of Paracoccidioides brasiliensis was determined in sputum samples from 50 patients with paracoccidioidomycosis using four different techniques: (a) cell-block preparations stained with silver methenamine, (b) direct microbiologic examination, (c) smears stained with Shorr, and (d) smears stained with silver methenamine. Overall, cell-block preparations and smears stained with silver methenamine proved to be the most sensitive techniques, followed by smears stained with Shorr and direct microbiologic examination in decreasing order of sensitivity. Sputum cytology tended to be less positive in patients with interstitial pulmonary lesions as determined by chest X-ray than in patients with alveolar lesions. In addition to its high sensitivity, cell-block preparation technique allows storage of blocks and slides for further studies.
    Mycopathologia 07/1991; 114(3):187-91. · 1.49 Impact Factor
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    ABSTRACT: The authors evaluated the isoniazid acetylating phenotype and measured hematocrit, hemoglobin, glucose-6-phosphate dehydrogenase and glutathione reductase activities plus serum sulfadoxin levels in 39 patients with paracoccidioidomycosis (33 males and 6 females) aged 17 to 58 years. Twenty one (53.84%) of the patients presented a slow acetylating phenotype and 18(46.16%) a fast acetylating phenotype. Glucose-6-phosphate-dehydrogenase (G6PD) activity was decreased in 5(23.80%) slow acetylators and in 4(22.22%) fast acetylators. Glutathione reductase activity was decreased in 14(66.66%) slow acetylators and in 12(66.66%) fast acetylators. Serum levels of free and total sulfadoxin were higher in slow acetylator (p less than 0.02). Analysis of the results permitted us to conclude that serum sulfadoxin levels are related to the acetylator phenotype. Furthermore, sulfadoxin levels were always above 50 micrograms/ml, a value considered therapeutic. Glutathione reductase deficiency observed in 66% of patients may be related to the intestinal malabsorption of nutrients, among them riboflavin, a FAD precursor vitamin, in patients with paracoceidioidomycosis.
    Revista da Sociedade Brasileira de Medicina Tropical 06/1991; 24(2):111-4. · 0.93 Impact Factor
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    ABSTRACT: The number and activity of natural killer (NK) cells were studied in 34 untreated patients with paracoccidioidomycosis, 20 with the chronic form of the disease and 14 with the acute form. NK cells were detected with monoclonal antibody Leu-11c and the cytotoxic activity was measured using a single cell assay against K562 target cells. Both groups of patients had an increased number of circulating NK cells, their cytotoxic activity being significantly lower than in the healthy controls. These findings may be of importance in the immunological disturbances associated with paracoccidioidomycosis since NK cells exert important immune effector functions and may play a role in resistance against Paracoccidiodes brasiliensis.
    Journal of medical and veterinary mycology: bi-monthly publication of the International Society for Human and Animal Mycology 02/1991; 29(6):373-80.

Publication Stats

596 Citations
58.99 Total Impact Points

Institutions

  • 1989–2000
    • São Paulo State University
      • Departamento de Patologia
      São Paulo, Estado de Sao Paulo, Brazil
  • 1993–1994
    • University of São Paulo
      • Faculty of Medicine (FM)
      San Paulo, São Paulo, Brazil