P A Gorin

Universidade Federal do Paraná, Curitiba, Estado do Parana, Brazil

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Publications (64)142.38 Total impact

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    ABSTRACT: Two distinct sulfonoglycolipid fractions were isolated from the basidiolichen Dictyonema glabratum by chromatography on Diethylaminoethyl (DEAE)-Sepharose, which resulted in rapid elution, followed by partition between aqueous sulfuric acid and an ethyl acetate-methanol-chloroform mixture and the content of the organic layer chromatographed of a column of silicic acid. The products were examined by nuclear magnetic resonance spectroscopy in their native rather than their acetylated forms, as in previous investigations. Each was methanolyzed to give the same methyl glycoside, Me-G. On electrospray ionization mass spectrometry (ESI-MS), it provided a pseudomolecular ion at m/z 303 in the positive-ion mode and a molecular ion at m/z 257 with a daughter ion at m/z 146 in the negative-ion mode, showing the presence of a sulfonate group S-linked to a hexosyl ring. An exclusively alpha-glucopyranosyl configuration was indicated by (1)H, (1)H correlation spectroscopy (COSY) and (1)H, (1)H total correlation spectroscopy (TOCSY). S-substitution occurred at CH(2)-6, because a high-field (13)C signal at delta 52.6 gave an inverted distortionless enhancement by polarization transfer (DEPT) signal and (1)H, (3)C heteronuclear multiple quantum coherence (HMQC) showed correlation with two H-6 signals. This 6-sulfono-alpha-quinovopyranoside group was present in the glycolipid fractions, O-alpha-D-Quip-6-sulfono-(1'<-->1)-2,3-diacyl-D-glycerol (polar fraction 1a; PF1a) and O-alpha-D-Quip-6-sulfono-(1'<-->1)-2- or -3-monoacyl-D-glycerol (polar fraction 1b; PF1b), the monoacyl derivatives not having been previously completely characterized in other systems. All components are typical of plant glycolipids. The most abundant fatty acid ester in PF1a and PF1b was C(16:0). Other esters present in PF1a were C(14:0), C(17:0), C(18:0), C(18:1) (oleic), C(20:0), C(21:0), and C(24:0), in contrast with C(14:0), C(17:0), C(18:0), and C(20:0) in PF1b. HMQC and TOCSY data can be used as fingerprints for detection of glycosylacylglycerides and sulfonoglycolipids and the positive ESI-MS ions at m/z 329 and 271 for identification of the latter.
    Glycobiology 05/2001; 11(4):345-51. · 3.54 Impact Factor
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    G L Sassaki, P A Gorin, M Iacomini
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    ABSTRACT: A mixture of two lyso isomers of a galactolipid was obtained from Dictyonema glabratum. Aqueous hydrolysis gave rise to galactose and glycerol in a 3:1 molar ratio. ESI-MS spectroscopy gave, in the positive-ion mode, a pseudomolecular ion at m/z 839 and daughter ions with m/z 677, 600, 515 and 353, suggesting three galactosyl units linked to a glycerol moiety, substituted by one O-acyl group. 1D and 2D NMR experiments were used to characterize the glycolipid, and HMQC examination showed three anomeric signals, corresponding to two alpha-Galp and one beta-Galp residue liked to glycerol. The glycolipid structure was shown to be O-alpha-D-Galp-(1-->6)-O-alpha-D-Galp-(1-->6)-O-beta-D-Galp-(1<-->1)-2- and -3-monoacyl-D-glycerol, the latter structures not having been previously found in nature. The fatty acid composition was determined by GC-MS of derived methyl esters: that of palmitic acid C(16:0) was the most abundant, although the presence of C(12:0), C(14:0), C(16:1) and C(18:0) esters was observed.
    FEMS Microbiology Letters 01/2001; 194(2):155-8. · 2.05 Impact Factor
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    ABSTRACT: Beta-D-glucans of the laminaran type were prepared from 15 Cladonia spp., Cladonia bellidiflora, Cladonia boryi, Cladonia clathrata, Cladonia connexa, Cladonia crispatula, Cladonia furcata, Cladonia gracilis, Cladonia ibitipocae, Cladonia imperialis, Cladonia miniata, Cladonia penicillata, Cladonia salmonea, Cladonia signata, Cladonia substellata and Cladonia uncialis. They were extracted with 10% aqueous KOH at 100 degrees C, giving polysaccharides with varying yields and proportions of mannose, galactose and glucose. Their aqueous solutions were freeze-thawed giving precipitates of mixed alpha-glucan (nigeran) and beta-glucans, which were isolated and suspended in aqueous 0.5% KOH at 50 degrees C, which preferentially dissolved the beta-glucan. In the case of the C. uncialis product, it was subjected to methylation analysis, which gave rise to 2,4,6-tri-O-methylglucitol acetate only, corresponding to (1-->3)-linkages. Its specific rotation (+4 degrees ) and one- and two-dimensional nuclear magnetic resonance (NMR) spectra were consistent with beta-linkages. 13C and (1)H-1 signals were observed, respectively, at delta 102.8 (C-1), 86.0 (C-3), 76.2 (C-5), 72.6 (C-2), 68.3 (C-4) and 60.7 (C-6), and 4.55 (H-1), 3.31 (H-2), 3.49 (H-3), 3.27 (H-4), 3.27 (H-5), 3.48 (H-6) and 3.72 (H-6'). Similar (13)C-NMR spectra were obtained from the glucans from the other 14 Cladonia spp. The beta-D-glucans of the laminaran type seems to be present in all Cladonia spp. being significant for chemotyping since it was observed in every species studied.
    FEMS Microbiology Letters 01/2001; 194(1):65-9. · 2.05 Impact Factor
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    ABSTRACT: The chemical structures of the glucans, galactoglucomannans and galactomannoglucans of two species of the Cladonia, section Cocciferae, Cladonia miniata and Cladonia salmonea, were determined and compared. alpha-D-Glucans of the nigeran type were isolated from both species, in common with all Cladonia spp., along with galactoglucomannans containing (1-->6)-linked main-chains of alpha-D-Manp units substituted by structurally different and typical side-chains. Isolated were previously unreported galactomannoglucans, with (1-->3)-linked main-chains of beta-D-Glcp units, substituted at O-2,6 by side-chains. These consisted of beta-D-Galf, 6-O-substituted beta-D-Galf and 2-O-, 4-O-, 6-O- and 2, 3-di-O-substituted alpha-D-Manp units. According to (13)C NMR spectroscopy, a similar galactomannoglucan was isolated from the Cladonia spp. Cladonia signata, Cladonia crispatula, Cladonia penicillata, Cladonia imperialis, Cladonia clathrata, Cladonia connexa, Cladonia substellata and Cladonia ibitipocae. Its presence could also contribute to the classic taxonomy of lichenized fungi.
    FEMS Microbiology Letters 01/2000; 181(2):313-7. · 2.05 Impact Factor
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    ABSTRACT: A natural low molecular weight heparin (8.5 kDa), with an anticoagulant activity of 95 IU/mg by the USP assay, was isolated from the shrimp Penaeus brasiliensis. The crustacean heparin was susceptible to both heparinase and heparitinase II from Flavobacterium heparinum forming tri- and di-sulfated disaccharides as the mammalian heparins. (13)C and (1)H NMR spectroscopy revealed that the shrimp heparin was enriched in both glucuronic and non-sulfated iduronic acid residues. The in vitro anticlotting activities in different steps of the coagulation cascade have shown that its anticoagulant action is mainly exerted through the inhibition of factor Xa and heparin cofactor II-mediated inhibition of thrombin. The shrimp heparin has also a potent in vivo antithrombotic activity comparable to the mammalian low molecular weight heparins.
    Biochimica et Biophysica Acta 09/1999; 1428(2-3):273-83. · 4.66 Impact Factor
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    ABSTRACT: A novel method is described for the determination of sequential side-chain structures in the complex, high-arabinose polysaccharide of the gum exudate of angico branco (Anadenanthera colubrina), using as basis the structurally similar reducing oligosaccharides present in small quantities. Of the ten detected, eight were characterized as disaccharides (2, 3, and 9), linear trisaccharides (1 and 4), branched pentasaccharides (5 and 6), and a doubly branched heptasaccharide (8). The oligosaccharides are substituents of the polysaccharide, which has a (1-->3)-linked beta-D-galactopyranosyl main chain, and with two exceptions they had 6-O-substituted galactopyranosyl reducing ends, probably corresponding to its main-chain units. Characterization was effected through their 1D and 2D NMR correlation spectra, which were better resolved and more readily interpretable than those of the polysaccharide. These spectral data were supported by monosaccharide composition and rotation values. Controlled Smith degradations and methylation analyses were carried out when it was necessary. These data were confirmed by field-desorption MS.
    Carbohydrate Research 08/1999; 320(3-4):167-75. · 2.04 Impact Factor
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    ABSTRACT: The galactoglucomannans of two species of the lichen genus Cladonia, C. substellata and C. ibitipocae, were compared. They were homogeneous on gel-filtration chromatography and structurally related, having (1-->6)-linked alpha-D-mannopyranosyl main-chains, but were substituted in different patterns by alpha- and beta-D-galacto-, beta-D-gluco- and alpha-D-mannopyranosyl groups. The C-1 portions of their 13C-NMR spectra are typical of the lichen species and indicate differences between the two polysaccharides. Partial acetolysis of the galactoglucomannan from C. substellata gave rise to oligosaccharides and three were identified, namely alpha-D-Manp-(1-->3)-alpha beta-D-Galp, alpha-D-Manp-(1-->2)-alpha beta-D-Manp and alpha-D-Manp-(1-->2)-[beta-D-Glcp-(1-->4)]-alpha beta-D-Manp, whereas only the latter two were obtained from that of C ibitipocae. Methylation and Smith degradation data confirmed these results. Whereas the mannobiose represents a common structure in lichen heteropolysaccharides, it is the first time that the other oligosaccharides have been isolated from those of lichens.
    Phytochemistry 06/1999; 51(3):395-402. · 3.35 Impact Factor
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    ABSTRACT: Three glycolipids (1-3) were isolated from the basidiolichen Dictyonema glabratum. Their carbohydrate and lipid components were structurally characterized using 1D 1H and 13C and 2D NMR spectroscopy, complemented by mass spectrometry, as were the carbohydrate moieties formed on saponification. These were O-alpha-D-Galp-(1''-->6')-O-beta-D-Galp-(1'<-->1)-2, 3-diacyl-D-glycerol (2) and two others not previously found in lichens, O-beta-D-Galp-(1'<-->1)-2,3-diacyl-D-glycerol (1) and O-alpha-D-Galp-(1'''-->6'')-O-alpha-D-Galp-(1' '-->6')-O-beta-D-Galp-(1'<-->1)-2,3-diacyl-D-glycerol (3). Each was saponified to give the free carbohydrates and its fatty acid methyl esters. The most abundant fatty acid esters in 1-3 was palmitic C16:0, but there was a wide variation of ester composition. Others present were C8:0 and C14:0 in 1, C14:0, C15:0, C17:0, C18:0, C18:1 (oleic), C18:2 (linoleic), C22:0, and C24:0 in 2, and C8:0, C14:0, C18:0, C18:1 (oleic), C18:2 (linoleic), and C18:3 (linolenic) in 3. As in ascolichens, the glycolipids appear to arise from the phycobiont.
    Journal of Natural Products 06/1999; 62(6):844-7. · 3.29 Impact Factor
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    ABSTRACT: The gum from Anadenanthera colubrina consists mainly of a complex high-arabinose heteropolysaccharide with a (1-->3)-linked beta-D-Galp main-chain and many different side-chains. These contain beta-D-Galp-[(1-->6)-beta-D-Galp]m-(1-->6)-, substituted in turn at O-3 by alpha-L-Araf-[(1-->3)-alpha-L-Araf-]0-2. Also present are (1) main-chain units substituted at O-4 and O-6 by alpha-L-Araf units, (2) side-chains of Rhap-(1-->4)-beta-D-GlcpA-(1-->6)-beta-Galp-groups, (3) alpha-L-Arap non-reducing end-units linked (1-->6) to D-Galp, and (4) beta-Araf and beta-Arap structures. For the first time, a plant gum exudate was found to contain in the natural state, reducing low M(r) carbohydrates. These were rhamnose (0.6%), arabinose (4.7%), mannose (0.1%), galactose (0.8%) and many oligosaccharides (0.6%; 11 with different RFs, with the majority containing arabinose). They were all mixtures with the exception of alpha-Rhap-(1-->4)-beta-D-GlcpA-(1-->6)-alpha beta-Gal and an incompletely identified hexasaccharide, probably having alpha-L-Araf-(1-->4)-beta-D-Galp- and -alpha-L-Araf-(1-->3)-beta-D-Galp- structures. The mono- and oligosaccharides do not appear to arise via in situ autohydrolysis of the gum.
    Phytochemistry 05/1998; 47(7):1207-14. · 3.35 Impact Factor
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    ABSTRACT: The gum exudate from the Brazilian cashew-nut tree (Anacardium occidentale) contained traces of the reducing sugars, rhamnose (0.005%), arabinose (0.03%), mannose (0.007%), galactose (0.03%), glucose (0.02%), beta-D-Galp-(1-->6)-alpha beta-D-Gal (0.05%), alpha-L-Rhap-(1-->4)-alpha beta-D-GlcA (0.008%) and alpha-L-Rhap-(1-->4)-beta-D-GlcpA-(1-->6)-beta-D-Galp-(1-->6 )-alpha beta-D-Gal (0.008%). Rhamnose, arabinose, glucose and the three oligosaccharides are components of the side-chains of the gum polysaccharide, which has a main chain of (1-->3)-linked beta-D-Galp units. The structure of this polysaccharide was determined and found to differ from that previously reported for the gum of a tree growing in India, lacking units of 4-O-methylglucuronic acid. Other new side-chain structures were characterized, particularly -alpha-D-Galp-(1-->6)-D-Galp- and alpha-L-Araf-(1-->6)-D-Galp-).
    Phytochemistry 03/1998; 47(5):715-21. · 3.35 Impact Factor
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    ABSTRACT: The most active polysaccharides which show anti-tumoral activity are (1-->3)-beta-D-glucans, branched or not at O-6. Since these structures are sometimes poorly soluble in aqueous media, alpha-D-glucans and their chemical derivatives, which are more soluble, were also studied. The present object is to observe morphological alterations in HeLa cells caused by two different polysaccharides obtained from the lichen Ramalina celastri, which are (1-->3),(1-->4)-linked alpha-D-glucan and its sulphated derivative. The cells were incubated in Eagle's medium in the absence or presence of each polysaccharide and routinely processed and analysed by light and electron microscopy. Even though the alpha-D-glucan altered the cellular volume, cytoplasmic densities, and mitosis, the resulting monolayer was similar to the control. TEM analysis showed cytoplasmic blebbing and the presence of an amorphous electron-dense material free in the cytoplasm and interior membranes. The enhanced injury caused by the sulphated derivative was apparent, altering cell adhesion and causing cell aggregation. Nuclear modifications such as fragmentation and condensation of chromatin under the nuclear envelope, which showed to be convoluted, suggested the occurrence of cell death by apoptosis.
    Journal of submicroscopic cytology and pathology 11/1997; 29(4):503-9.
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    ABSTRACT: Extraction of Evernia prunastri with hot aqueous alkali solubilized heteropolysaccharide-containing material which was purified via Fehling precipitation. Further workup of this polysaccharide with Cetavlon gave two fractions having related but different structures. Each structure consisted of a 1-->6-linked alpha-D-Man p main chain partially monosubstituted at O-2 with side chains of alpha-D-Gal p and partially disubstituted at O-2 and O-4 with alpha-D-Gal p and beta-D-Gal p, respectively. The fractions differed in that one contained much more uronic acid than the other, with corresponding predominance of side chains containing alpha-D-Glc pA-(1-->3)-D-Glc p, alpha-D-Gal p-(1-->2)-D-Glc p, and beta-D-Gal f units.
    Carbohydrate Research 12/1994; 264(1):63-71. · 2.04 Impact Factor
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    ABSTRACT: We report for the first time the detection of glycolipids in a lichen. Three glycolipids were extracted from Ramalina celastri and their carbohydrates were determined. The main component was O-alpha-D-galactopyranosyl-(1-->6)-O-beta-D-galactopyranosyl-(1-->1)-D- glyceritol, esterified with long-chain fatty acids, some of which were unsaturated.
    Brazilian Journal of Medical and Biological Research 02/1994; 27(2):523-6. · 1.14 Impact Factor
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    ABSTRACT: The lichen Parmotrema cetratum contains traces of the unusual threitol and unexpected volemitol, along with galactose (2%). Present is a complex containing a lightly branched beta-glucan containing (1-->3) and (1-->4)-linkages in a 25:47 molar ratio chemically linked to a galactomannan with structural features common in other lichens. A glucogalactomannan with a small proportion of Glc rho side chains was also characterized.
    Phytochemistry 10/1993; 34(3):715-7. · 3.35 Impact Factor
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    ABSTRACT: Antimony(Sb)-yeast mannan complexes were synthesized as a strategy to introduce Sb into macrophages infected with Leishmania amastigotes. The complexes were taken up by endocytosis after specific recognition by alpha-D-mannosyl receptors on the macrophage membrane. About 90% of the intracellular parasites were destroyed by Sb-mannan in vitro, whereas the corresponding Sb concentration used as the pentavalent antimonial drug glucantime destroyed about 60% of the amastigotes. None of the Sb complexes prepared with mannan acid or basic derivatives was as effective as the simple Sb-mannan complex in clearing macrophage infection by Leishmania (L) amazonensis. The leishmanicidal effect of Sb-mannan was also demonstrated in vivo with infected hamsters. The alternative use of Sb-mannan complex in the treatment of human leishmaniasis is envisaged on the basis of parasite-killing efficiency and the use of a low antimony dose.
    Biochemical Journal 02/1993; 289 ( Pt 1):155-60. · 4.65 Impact Factor
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    ABSTRACT: Mannose-containing polysaccharides of 18 lichen species were prepared via successive alkaline extraction, precipitation with Fehling solution and fractional precipitation with Cetavlon. Products from Fehling and Cetavlon precipitation, the latter at pH 8.5 in the presence of borax, were structurally similar, except with those of Usnea sp., U. meridionalis, Parmotrema araucaria and Evernia prunastri, which were mixtures and initially provided precipitates at pH 7 due to the presence of carboxyl groups. With one exception, glucosyl units were detected in all preparations, but possibly arose from glucan contaminants of the galactomannans. Tornabenia intricata, however, did not contain galactose, and a glucomannan was isolated. It consisted of two components with M(r)s of ca 0.85 x 10(5) and ca 1.1 x 10(5) and whose 13C NMR spectra were identical. The overall preparation contained a (1-->6)-linked alpha-D-Manp main-chain substituted at 0-2 mainly with side chains of alpha-D-Manp with smaller amounts of alpha-D-Glcp, alpha-D-Glcp-(1-->2)-[alpha-D-Manp-(1-->4)]-alpha-D-Manp, and possibly alpha-D-Manp-(1-->2)-[alpha-D-Manp-(1-->4)]-alpha-D-Manp+ ++.
    Phytochemistry 10/1992; 31(10):3467-70. · 3.35 Impact Factor
  • A M Miceno, P A Gorin, M Iacomini
    Agricultural and biological chemistry 06/1991; 55(5):1391-2.
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    ABSTRACT: Antibodies that lyse trypomastigotes in a complement-mediated reaction are believed to be the main participants in the protection against virulent Trypanosoma cruzi. Antibodies with a specificity for alpha-galactosyl-containing determinants--generally called antiGal--were studied to determine their role in the lysis of trypomastigote forms. The titers of antiGal markedly increase in Chagas's disease. In the present study we demonstrate binding of this antibody to T. cruzi and the complement-mediated lysis of trypomastigotes by antiGal. Lysis of metacyclic trypomastigotes by whole Chagasic (Ch) serum or isolated antiGal fractions was equally inhibited by alpha- but not by beta-galactosides. Most of the lytic power of the Ch antiGal as well as of the whole Ch serum was removed by absorption on Synsorb-linked Gal alpha 1, 3Gal beta 1, 4GlcNAc followed by rabbit erythrocyte absorption. The Ch antiGal had a lower affinity for melibiose bound to agarose than for the trisaccharide linked to Synsorb, and was several times more effective in the immunolysis of trypomastigotes than the corresponding antiGal from normal human serum. Lytic antibodies were partly absorbed by Serratia marcescens but not by Escherichia coli O111. A human volunteer immunized with an S. marcescens vaccine elicited a specific antiGal response that was lytic to trypomastigotes (70% lysis). We suggest that in vivo high-affinity antiGal antibody clones, as occur in Ch patients, may significantly contribute to the destruction of the parasite, whereas low-affinity antiGal clones are much less effective in the protection against T. cruzi infection.
    The Journal of Immunology 05/1991; 146(7):2394-400. · 5.52 Impact Factor
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    ABSTRACT: The lipopeptidophosphoglycan of epimastigote forms of Trypanosoma cruzi is composed of a glycan linked through a non-N-acetylated glucosamine residue to an inositol phosphorylceramide. Using conventional analysis techniques, including 1H, 13C, and 31P NMR spectroscopy and negative ion fast atom bombardment mass spectroscopy, the structure of the carbohydrate-containing part of the molecule is determined as: (Sequence: see text). There is uncertainty as to which 2-O-substituted alpha-D-Manp unit is attached the side chain or whether it is distributed between the two units. Some of the structures lack the Galf side chain. The inositol unit is linked to ceramide via a phosphodiester bridge. The major aliphatic components of the ceramide portion were lignoceric acid and sphinganine.
    Journal of Biological Chemistry 03/1990; 265(5):2518-26. · 4.65 Impact Factor
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    ABSTRACT: Fractions were prepared from the water-soluble components ofAspergillus fumigatus mycelium either by lectin-affinity chromatography or salt precipitation. While they varied considerably in their amino-acid composition, each contained a preponderance of aspartic and glutamic acids.13C-NMR spectroscopy of these fractions, compared with that of polysaccharide obtained by alkaline extraction, indicated the presence of glycoproteins, the polysaccharide components of which contained -d-Galf units that are part of structures chemically different from those obtained by alkali treatment. In two of the three fractions examined, gas-liquid chromatography-mass spectrometry showed marked differences in the contents of non-reducing end-units of -d-Manp and -d-Galf. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis of the preparations revealed an array of components, which stained to differing extents with silver stain and with Coomassie Blue and many of which were bound by lectins with specificity for different sugars.
    Glycoconjugate Journal 02/1989; 6(1):85-100. · 1.88 Impact Factor

Publication Stats

803 Citations
142.38 Total Impact Points

Institutions

  • 1987–2001
    • Universidade Federal do Paraná
      • • Departamento de Bioquímica
      • • Departamento de Farmácia
      Curitiba, Estado do Parana, Brazil
  • 1999
    • Federal University of Santa Catarina
      • Departamento de Análises Clínicas
      Florianópolis, Estado de Santa Catarina, Brazil
  • 1977–1990
    • Federal University of Rio de Janeiro
      • Departamento de Microbiologia Geral
      Rio de Janeiro, Rio de Janeiro, Brazil
  • 1986
    • For the Children Brazil
      Miami Beach, Florida, United States
  • 1985
    • National Research Council Canada
      • Plant Biotechnology Institute (PBI)
      Ottawa, Ontario, Canada