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1.
Braz. j. biol ; 83: e242830, 2023. tab, graf
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1278540

RESUMO

Abstract Pesticide residues that contaminate the environment circulate within the hydrological cycle can accumulate within the food chain and cause problems to both environmental and human health. Microbes, however, are well known for their metabolic versatility and the ability to degrade chemically stable substances, including recalcitrant xenobiotics. The current study focused on bio-prospecting within Amazonian rainforest soils to find novel strains fungi capable of efficiently degrading the agriculturally and environmentally ubiquitous herbicide, glyphosate. Of 50 fungal strains isolated (using culture media supplemented with glyphosate as the sole carbon-substrate), the majority were Penicillium strains (60%) and the others were Aspergillus and Trichoderma strains (26 and 8%, respectively). All 50 fungal isolates could use glyphosate as a phosphorous source. Eight of these isolates grew better on glyphosate-supplemented media than on regular Czapek Dox medium. LC-MS revealed that glyphosate degradation by Penicillium 4A21 resulted in sarcosine and aminomethylphosphonic acid.


Resumo Resíduos de agrotóxicos que contaminam o meio ambiente circulam no ciclo hidrológico, podendo se acumular na cadeia alimentar e causar problemas tanto à saúde ambiental quanto humana. Por sua vez, microrganismos são bem conhecidos por sua versatilidade metabólica e capacidade de degradar substâncias quimicamente estáveis, incluindo xenobióticos recalcitrantes. O estudo atual se concentrou na bioprospecção nos solos da floresta amazônica para encontrar novas linhagens de fungos capazes de degradar com eficiência o herbicida onipresente na agricultura e no meio ambiente, o glifosato. Entre os 50 fungos isolados (usando meio de cultura suplementado com glifosato como única fonte de carbono), a maioria eram isolados do gênero Penicillium (60%) e os outros eram isolados de Aspergillus e Trichoderma (26 e 8%, respectivamente). Todos os 50 isolados de fungos foram capazes de usar glifosato como fonte de fósforo. Oito desses isolados cresceram melhor em meio suplementado com glifosato do que em meio Czapek Dox regular. LC-MS revelou que a degradação do glifosato por Penicillium 4A21 resultou nos metabólitos sarcosina e ácido aminometilfosfônico.

2.
Braz. j. biol ; 82: e241863, 2022. tab, graf
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1278488

RESUMO

Abstract Since the classic studies of Alexander Flemming, Penicillium strains have been known as a rich source of antimicrobial substances. Recent studies have identified novel metabolites produced by Penicillium sclerotiorum that have antibacterial, antifouling and pharmaceutical activities. Here, we report the isolation of a P. sclerotiorum (LM 5679) from Amazonian soil and carry out a culture-based study to determine whether it can produce any novel secondary metabolite(s) that are not thus-far reported for this genus. Using a submerged culture system, secondary metabolites were recovered by solvent extract followed by thin-layer chromatography, nuclear magnetic resonance, and mass spectroscopy. One novel secondary metabolite was isolated from P. sclerotiorum (LM 5679); the phenolic compound 5-pentadecyl resorcinol widely known as an antifungal, that is produced by diverse plant species. This metabolite was not reported previously in any Penicillium species and was only found once before in fungi (that time, in a Fusarium). Here, we discuss the known activities of 5-pentadecyl resorcinol in the context of its mode-of-action as a hydrophobic (chaotropicity-mediated) stressor.


Resumo Desde os estudos clássicos de Alexander Flemming, as cepas de Penicillium são conhecidas como uma fonte rica em substâncias antimicrobianas. Estudos recentes identificaram novos metabólitos produzidos pela espécie Penicillium sclerotiorum com atividades antibacteriana, anti-incrustante e farmacêutica. Aqui, relatamos o isolamento de uma colônia de P. sclerotiorum (LM 5679) do solo amazônico e relatamos também o estudo baseado em cultura para determinar se ele pode produzir qualquer novo metabólito (s) secundário (s) que não foram relatados até agora para este gênero. Usando um sistema de cultura submerso, os metabólitos secundários foram recuperados por extrato de solvente seguido por cromatografia em camada delgada, ressonância magnética nuclear e espectroscopia de massa. Um novo metabólito secundário foi isolado de P. sclerotiorum (LM 5679); o composto fenólico 5-pentadecil resorcinol que é amplamente conhecido como um antifúngico que é produzido por diversas espécies de plantas. Este metabólito não foi relatado anteriormente em nenhuma espécie de Penicillium, e foi encontrado apenas uma vez em fungos (Fusarium). Aqui, discutimos as atividades conhecidas do 5-pentadecil resorcinol no contexto de seu modo de ação como um estressor hidrofóbico (mediado pela caotropicidade).

3.
Braz J Biol ; 83: e242830, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34161455

RESUMO

Pesticide residues that contaminate the environment circulate within the hydrological cycle can accumulate within the food chain and cause problems to both environmental and human health. Microbes, however, are well known for their metabolic versatility and the ability to degrade chemically stable substances, including recalcitrant xenobiotics. The current study focused on bio-prospecting within Amazonian rainforest soils to find novel strains fungi capable of efficiently degrading the agriculturally and environmentally ubiquitous herbicide, glyphosate. Of 50 fungal strains isolated (using culture media supplemented with glyphosate as the sole carbon-substrate), the majority were Penicillium strains (60%) and the others were Aspergillus and Trichoderma strains (26 and 8%, respectively). All 50 fungal isolates could use glyphosate as a phosphorous source. Eight of these isolates grew better on glyphosate-supplemented media than on regular Czapek Dox medium. LC-MS revealed that glyphosate degradation by Penicillium 4A21 resulted in sarcosine and aminomethylphosphonic acid.


Assuntos
Herbicidas , Penicillium , Trichoderma , Aspergillus , Biodegradação Ambiental , Fungos , Glicina/análogos & derivados , Herbicidas/toxicidade , Humanos , Organofosfonatos , Solo , Microbiologia do Solo
4.
Braz J Biol ; 82: e241863, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34133562

RESUMO

Since the classic studies of Alexander Flemming, Penicillium strains have been known as a rich source of antimicrobial substances. Recent studies have identified novel metabolites produced by Penicillium sclerotiorum that have antibacterial, antifouling and pharmaceutical activities. Here, we report the isolation of a P. sclerotiorum (LM 5679) from Amazonian soil and carry out a culture-based study to determine whether it can produce any novel secondary metabolite(s) that are not thus-far reported for this genus. Using a submerged culture system, secondary metabolites were recovered by solvent extract followed by thin-layer chromatography, nuclear magnetic resonance, and mass spectroscopy. One novel secondary metabolite was isolated from P. sclerotiorum (LM 5679); the phenolic compound 5-pentadecyl resorcinol widely known as an antifungal, that is produced by diverse plant species. This metabolite was not reported previously in any Penicillium species and was only found once before in fungi (that time, in a Fusarium). Here, we discuss the known activities of 5-pentadecyl resorcinol in the context of its mode-of-action as a hydrophobic (chaotropicity-mediated) stressor.


Assuntos
Penicillium , Antibacterianos , Antifúngicos , Resorcinóis
5.
J Econ Entomol ; 109(2): 898-906, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26662735

RESUMO

Pentatomids (stink bugs) are major pests of soybean, Glycine max (L.) Merril. These pests reach high levels of infestation, cause severe damage to seeds by feeding, are linked to leaf retention, and are difficult to control. Host plant resistance is considered to be a valuable tool in integrated pest management and can assist in reducing the damage caused by stink bugs. This research evaluated the resistance of soybean genotypes in Brazil to the stink bug complex, the Neotropical brown stink bug, Euschistus heros (F.), redbanded stink bug, Piezodorus guildinii (Westwood), southern green stink bug, Nezara viridula (L.), green belly stink bug, Dichelops melacanthus (Dallas), and Edessa meditabunda (F.), by assessing infestation assay, yield reduction, seed damage, and leaf retention. Certain genotypes expressed different categories of resistance: least infested, low yield reduction, low levels of damage in seeds, and low levels of leaf retention. PI lines and IAC 78-2318 showed antixenotic resistance, and 'IAC 100' showed tolerance for the stink bug complex. This is the first study to evaluate several parameters of yield and seed quality using different soybean maturity groups under relatively high infestation by the three stink bugs species. The promising genotypes might be used in regions with a high incidence of stink bugs to manage their populations in combination with other integrated pest management practices.


Assuntos
Herbivoria , Heterópteros , Soja/genética , Animais , Genótipo
6.
Rev. bras. plantas med ; 17(4): 604-613, out.-dez. 2015. tab, graf
Artigo em Português | LILACS | ID: lil-763223

RESUMO

RESUMORubiaceae é uma família botânica com grande potencial químico e biológico Neste trabalho realizou-se a prospecção fitoquímica e avaliou-se as atividades citotóxica, antioxidante e antifúngica dos extratos diclorometânicos e metanólicos das folhas de Duroia saccifera, Ferdinandusa goudotiana, F. hirsuta, F. paraensis, Ferdinandusa sp., Palicourea corymbifera e P. guianensis. A avaliação da citotoxicidade foi realizada empregando-se o ensaio de toxicidade sobre Artemia salina. A atividade antifúngica foi determinada pelo método de difusão em ágar utilizando-se os fungos: Epidermophyton floccosum, Microsporum canis 32905, M. gipseum 29/00, Trichophyton mentagrophytes ATCC 9533/03, T. rubrum ATCC 28189, T. tonsurans 21/97, Cladosporium cladosporioides, C. sphaerospermum, FusariumU. 662/06, Scytalidium U. 661/06, Candida albicans ATCC 3632 e C. albicans U. 5/99. A atividade antioxidante foi determinada através dos ensaios de redução do radical livre 1,1-difenil-2-picrilhidrazila (DPPH) e de descoloração do cátion radical ácido-6-sulfônico-2,2-azinobis-3-etilbenzotiazolina (ABTS). Para o ensaio de toxicidade sobre A. salina observou-se maior toxicidade no extrato metanólico de F. goudotiana, que se mostrou tóxico até a concentração de 5 µg mL-1. A presença de princípios antifúngicos foi observada em F. hirsuta e F. paraensiscontra quatro dos fungos testados. Na avaliação da atividade antioxidante os extratos metanólicos mostraram maior atividade que os extratos diclorometânicos, sendo coincidente o resultado obtido através de ambos os métodos (redução do DPPH e descoloração do ABTS). Os resultados criam possibilidades para futuras investigações relacionadas à estrutura e atividade dos componentes de cada extrato ativo.


ABSTRACTRubiaceae is a plant family with great chemical and biological potential. In this work a phytochemical prospection was performed and it was assessed the cytotoxic, antioxidant and antifungal activities of dichloromethanic and methanolic extracts of the leaves of Duroia saccifera, Ferdinandusagoudotiana, F. hirsuta, F. paraensis, Ferdinandusa sp., Palicourea corymbifera and P. guianensis. The cytotoxicity evaluation was carried out using the test toxicity on Artemia salina. The antifungal activity was determined by agar diffusion method using fungi: Epidermophyton floccosum, Microsporum canis 32905, M. gipseum 29/00, Trichophyton mentagrophytes ATCC 9533/03, T.rubrum ATCC 28189, T. tonsurans 21/97 , Cladosporium cladosporioides, C. sphaerospermum, FusariumU. 662/06, Scytalidium U. 661/06, Candida albicans ATCC 3632 and C. albicans U. 5/99. The antioxidant activity was determined by testing the amount of free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) and the discoloration of the radical cation 6-sulfonic acid-2 ,2-azinobis-3-ethylbenzothiazoline (ABTS). For the toxicity test on A. salina greater toxicity in the methanol extract of F. goudotiana was observed, which proved to be toxic up to a concentration of 5 µg mL-1. The presence of antifungal principles was observed in the F. hirsuta and F. paraensis against four tested fungi. In the evaluation of the antioxidant activity, the methanol extracts showed greater activity than the dichloromethanic ones, being similar the obtained result through both methods (reduction of DDPH and ABTS decolorization) . The results create possibilities for future researches related to the structure and activity of the components of each active extract.


Assuntos
Ecossistema Amazônico/classificação , Plantas Medicinais/classificação , Rubiaceae/metabolismo , Antifúngicos/farmacologia , Antioxidantes/farmacologia , Artemia/anatomia & histologia , Citotoxinas , Rubiaceae/classificação
7.
Genet Mol Res ; 14(4): 13889-93, 2015 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-26535704

RESUMO

Cavernicola pilosa is a triatomine species that lives in caves and feeds on bat blood. This vector has a wide geographical distribution, and is found in Brazil, Colombia, Panama, Peru, and Venezuela. Little is known about the reproductive biology of this species, because most previous studies have only characterized its morphology, morphometry, ecology, and epidemiology. Therefore, this study aimed to obtain preliminary data related to spermatogenesis in C. pilosa by conducting cytogenetic analysis. Analysis of the heterochromatic pattern of C. pilosa during the initial prophases revealed that heterochromatic blocks are only present in the sex chromosomes. Based on the analyses of the meiotic metaphase and prophases, we found that the sex determination system of C. pilosa is XY and the chromosomes are holocentric. C. pilosa spermatids are filamentous and have long flagella. It was not possible to detect corpuscle or filament heteropycnosis in spermatids of this species. The initial cytogenetic data presented in this study are important in characterizing the spermatogenesis and heterochromatic patterns of C. pilosa. Our results suggest that adaptation to troglodytism did not result in differences in spermatogenesis in this vector.


Assuntos
Análise Citogenética , Triatominae/genética , Animais , Heterocromatina , Metáfase , Poliploidia , Espermatogênese , Triatominae/crescimento & desenvolvimento
8.
Arq. bras. med. vet. zootec ; 64(6): 1673-1681, Dec. 2012. tab
Artigo em Português | LILACS | ID: lil-660239

RESUMO

Avaliou-se a suplementação enzimática em rações contendo milheto ou sorgo sobre a microbiota intestinal e o desempenho de frangos. Foram alojados 420 pintos - ensaio de microbiota - e 1.200 pintos - ensaio de desempenho -, submetidos aos tratamentos com sorgo ou milheto suplementados ou não com complexo enzimático. O delineamento utilizado foi inteiramente ao acaso, com sete repetições de 15 aves cada, para o ensaio de microbiota, e em blocos ao acaso, com cinco repetições e 60 aves por parcela para desempenho. Foram realizadas pesquisas de bactérias Gram-negativas e contagem do número total de microrganismos aeróbios do intestino delgado. A suplementação enzimática não afetou a microbiota intestinal de frangos aos 14 e 28 dias de idade. Houve efeito da suplementação enzimática nas dietas com sorgo para conversão alimentar na fase pré-inicial. Nas dietas com milheto, a suplementação melhorou o ganho de peso no período de um a 35 dias de idade. No período total de criação, de um a 42 dias, não foi observado efeito da suplementação para milheto ou sorgo. Conclui-se que a utilização da suplementação de enzimas em rações com sorgo ou milheto pode melhorar os resultados de desempenho, dependendo da fase de crescimento de frangos de corte.


Two experiments were conducted to examine the supplementation enzyme in broilers fed with sorghum or pearl millet. The intestinal microflora and broiler performance was conducted with 420 and 1.200 broiler chickens, respectively. The treatments consisted of sorghum or pearl millet diet with enzymatic complex. The microflora assay consisted of 15 birds per experimental unit in completed randomized delineament, with seven replicates, and the performance study consisted of 60 birds per experimetal unit in a randomized block design, with five replicates. A study of bacteria negative-gram and total number bacteria aerobic in the small intestine was carried out. The averages were compared by contrasts (performance) and the Kruskal-Wallis (bacteria) tests applied for the research. The enzyme supplementation did not affect the broiler intestinal microflora at the age of 14 and 28 days. Feed conversion in the pearl millet diets supplemented with enzymes was better in the initial phase. The body weight was better to treat enzymatic complex in diets pearl millet (at age of 1- 35 days), however, at the age of 1 to 42 days there was no effect of supplementation for millet or sorghum. The results showed that the sorghum or pearl millet diets supplemented with enzymes are a viable strategy to improve the nutritional value of the diets and performance results depending on the age of the broilers.


Assuntos
Animais , Ração Animal , Pennisetum , Aves Domésticas , Sorghum , Intestino Delgado/microbiologia , Suplementos Nutricionais/análise
9.
J Fluoresc ; 22(4): 1151-8, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22488046

RESUMO

Cellular membranes have relevant roles in processes related to proteases like human kallikreins and cathepsins. As enzyme and substrate may interact with cell membranes and associated co-factors, it is important to take into account the behavior of peptide substrates in the lipid environment. In this paper we report an study based on energy transfer in two bradykinin derived peptides labeled with the donor-acceptor pair Abz/Eddnp (ortho-aminobenzoic acid/N-[2,4-dinitrophenyl]-ethylenediamine). Time-resolved fluorescence experiments were performed in phosphate buffer and in the presence of large unilamelar vesicles of phospholipids, and of micelles of sodium dodecyl sulphate (SDS). The decay kinetics were analyzed using the program CONTIN to obtain end-to-end distance distribution functions f(r). Despite of the large difference in the number of residues the end-to-end distance of the longer peptide (9 amino acid residues) is only 20 % larger than the values obtained for the shorter peptide (5 amino acid residues). The proline residue, in position 4 of the bradykinin sequence promotes a turn in the longer peptide chain, shortening its end-to-end distance. The surfactant SDS has a strong disorganizing effect, substantially broadening the distance distributions, while temperature increase has mild effects in the flexibility of the chains, causing small increase in the distribution width. The interaction with phospholipid vesicles stabilizes more compact conformations, decreasing end-to-end distances in the peptides. Anisotropy experiments showed that rotational diffusion was not severely affected by the interaction with the vesicles, suggesting a location for the peptides in the surface region of the bilayer, a result consistent with small effect of lipid phase transition on the peptides conformations.


Assuntos
Bradicinina/química , Corantes Fluorescentes/química , Corantes Fluorescentes/metabolismo , Oligopeptídeos/química , Oligopeptídeos/metabolismo , Fosfolipídeos/metabolismo , Lipossomas Unilamelares/metabolismo , Sequência de Aminoácidos , Dimiristoilfosfatidilcolina/metabolismo , Cinética , Micelas , Fosfatidilgliceróis/metabolismo , Ligação Proteica , Espectrometria de Fluorescência , Água/química
10.
Curr Med Chem ; 18(22): 3351-60, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21728966

RESUMO

Thiazolidinediones (TZDs) are a class of drugs used for treatment of type 2 diabetes. However, the therapy with currently available TDZs (e.g. rosiglitazone) is associated with important side effects, such as edema and weight gain, suggesting that the investigation of alternative TZDs with better pharmacological properties is warranted. In this study, we investigated both anti-inflammatory and antioxidant properties of a new chemically modified TZD, the arylidene-thiazolidinedione 5-(4-methanesulfonyl-benzylidene)-3-(4-nitrobenzyl)-thiazolidine-2,4-dione (SF23), and compared the results to those obtained with rosiglitazone. We found that our SF23 displays a weaker affinity for PPARγ, up-regulating in a lower magnitude the expression of both PPARγ and CD36 compared to rosiglitazone. In lipopolysaccharide (LPS)-stimulated macrophages, SF23 decreased nitrite production and attenuated the mRNA expression of both iNOS and COX-2. These anti-inflammatory effects were comparable to those obtained with rosiglitazone. Interestingly, SF23, but not rosiglitazone, prevented LPS-induced mitochondrial membrane hyperpolarization, apoptosis, reactive oxygen species (ROS) generation, and the expression of NADPH oxidase subunits, Nox1 and Nox2. In addition, in macrophages from Nrf2⁻/⁻ mice, SF23 protected against LPSinduced cellular death and ROS production, whereas rosiglitazone was only able to protect normal Nrf2⁺/⁺ cells against oxidative injury, suggesting that, unlike rosiglitazone, the antioxidant activity of SF23 might be Nrf2-independent. Finally, in macrophages exposed to high concentrations of glucose, SF23 induced significant increases in the mRNA expression of glucose transporters, insulin receptor substrate and mitoNEET. Altogether, our data indicate that our new chemically modified TDZ displays similar anti-inflammatory properties, but superior antioxidant effects on the LPS-stimulated macrophages compared to rosiglitazone.


Assuntos
Anti-Inflamatórios/química , Antioxidantes/química , Macrófagos/efeitos dos fármacos , Tiazolidinedionas/farmacologia , Animais , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/química , Lipopolissacarídeos/farmacologia , Ativação de Macrófagos , Macrófagos/metabolismo , Macrófagos/patologia , Camundongos , Rosiglitazona , Tiazolidinedionas/química , Tiazolidinedionas/uso terapêutico
11.
Braz. j. med. biol. res ; 43(8): 712-716, Aug. 2010. ilus
Artigo em Inglês | LILACS | ID: lil-554953

RESUMO

Prompt and specific identification of fungemia agents is important in order to define clinical treatment. However, in most cases conventional culture identification can be considered to be time-consuming and not without errors. The aim of the present study was to identify the following fungemia agents: Candida albicans, Candida parapsilosis, Candida tropicalis, Candida glabrata, Cryptococcus neoformans, Cryptococcus gattii, and Histoplasma capsulatum using the polymerase chain reaction and restriction fragment length polymorphism analysis (PCR/RFLP). More specifically: a) to evaluate 3 different amplification regions, b) to investigate 3 different restriction enzymes, and c) to use the best PCR/RFLP procedure to indentify 60 fungemia agents from a culture collection. All 3 pairs of primers (ITS1/ITS4, NL4/ITS5 and Primer1/Primer2) were able to amplify DNA from the reference strains. However, the size of these PCR products did not permit the identification of all the species studied. Three restriction enzymes were used to digest the PCR products: HaeIII, Ddel and Bfal. Among the combinations of pairs of primers and restriction enzymes, only one (primer pair NL4/ITS5 and restriction enzyme Ddel) produced a specific RFLP pattern for each microorganism studied. Sixty cultures of fungemia agents (selected from the culture collection of Fundação de Medicina Tropical do Amazonas - FMTAM) were correctly identified by PCR/RFLP using the prime pair NL4/ITS5 and Ddel. We conclude that the method proved to be both simple and reproducible, and may offer potential advantages over phenotyping methods.


Assuntos
Humanos , Candida/classificação , Cryptococcus/classificação , Fungemia/microbiologia , Histoplasma/classificação , Infecções Oportunistas Relacionadas com a AIDS/microbiologia , Candida/genética , Cryptococcus/genética , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Histoplasma/genética , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição
12.
Braz J Med Biol Res ; 43(8): 712-6, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20640387

RESUMO

Prompt and specific identification of fungemia agents is important in order to define clinical treatment. However, in most cases conventional culture identification can be considered to be time-consuming and not without errors. The aim of the present study was to identify the following fungemia agents: Candida albicans, Candida parapsilosis, Candida tropicalis, Candida glabrata, Cryptococcus neoformans, Cryptococcus gattii, and Histoplasma capsulatum using the polymerase chain reaction and restriction fragment length polymorphism analysis (PCR/RFLP). More specifically: a) to evaluate 3 different amplification regions, b) to investigate 3 different restriction enzymes, and c) to use the best PCR/RFLP procedure to indentify 60 fungemia agents from a culture collection. All 3 pairs of primers (ITS1/ITS4, NL4/ITS5 and Primer1/Primer2) were able to amplify DNA from the reference strains. However, the size of these PCR products did not permit the identification of all the species studied. Three restriction enzymes were used to digest the PCR products: HaeIII, Ddel and Bfal. Among the combinations of pairs of primers and restriction enzymes, only one (primer pair NL4/ITS5 and restriction enzyme Ddel) produced a specific RFLP pattern for each microorganism studied. Sixty cultures of fungemia agents (selected from the culture collection of Fundação de Medicina Tropical do Amazonas--FMTAM) were correctly identified by PCR/RFLP using the prime pair NL4/ITS5 and Ddel. We conclude that the method proved to be both simple and reproducible, and may offer potential advantages over phenotyping methods.


Assuntos
Candida/classificação , Cryptococcus/classificação , Fungemia/microbiologia , Histoplasma/classificação , Infecções Oportunistas Relacionadas com a AIDS/microbiologia , Candida/genética , Cryptococcus/genética , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Histoplasma/genética , Humanos , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição
13.
Transplant Proc ; 42(2): 451-3, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20304162

RESUMO

To study whether treatment with the beta-blocker atenolol (AT) attenuates intestinal dysfunction caused by ischemia (I) and reperfusion (R), rabbits were treated with AT (1 mg.kg(-1), introvenously) or saline solution (SS) prior to I (60 minutes), which was produced by occlusion of the superior mesenteric artery, and/or R (120 minutes). After I or I/R, 2-cm jejunal segments were mounted in an organ bath to study neurogenic contractions stimulated by electrical pulses or KCl using a digital recording system. Thin jejunal slices were stained hematoxylin and eosin for analysis by optical microscopy. Compared to the sham group, the jejunal contractions were similar in the I + AT and the I/R + AT groups, but reduced in the I + SS and the I/R + SS groups. The jejunal enteric nerves were damaged in the I + SS and the I/R + SS groups, but not in the I + AT and the I/R + AT. These results suggest that AT may attenuate intestinal dysfunction caused by I and I/R.


Assuntos
Atenolol/uso terapêutico , Enteropatias/tratamento farmacológico , Intestinos/irrigação sanguínea , Jejuno/fisiologia , Traumatismo por Reperfusão/tratamento farmacológico , Animais , Circulação Sanguínea , Estimulação Elétrica , Enteropatias/etiologia , Jejuno/irrigação sanguínea , Jejuno/efeitos dos fármacos , Masculino , Artéria Mesentérica Superior/fisiologia , Contração Muscular/efeitos dos fármacos , Contração Muscular/fisiologia , Cloreto de Potássio/farmacologia , Coelhos
14.
Biophys J ; 81(2): 1180-9, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11463659

RESUMO

The native hormone alpha-melanocyte-stimulating hormone (alpha-MSH) and its more potent analog [Nle(4),D-Phe(7)]alpha-MSH (NDP-alpha MSH), labeled at the amino terminal with the fluorescent aminobenzoic acid (Abz) isomers, were examined by fluorescence methods. We observed energy transfer between the tryptophan(9) residue acting as donor and Abz as acceptor, the transfer being more pronounced to the ortho-form of the acceptor. Within the hypothesis that different peptide conformations coexist in equilibrium during the fluorescence decay, we supposed that the intensity decay was modulated by an acceptor-donor distance distribution function f(r). From the time-resolved fluorescence experimental data, we recovered the distance distribution between Abz and Trp(9), using the CONTIN program, within the framework of the Förster resonance energy transfer model. The methodology proved to be useful to provide quantitative information about conformational dynamics of melanotropins and its dependency on the solvent. In aqueous medium, alpha-MSH has a broad Abz-Trp(9) distance distribution, reflecting the structural flexibility of the peptide. Three different distance populations could be identified in the labeled analog NDP-alpha MSH in water, indicating distinct conformational states for the synthetic peptide, compared with the native hormone. Measurements in trifluoroethanol resulted in the recovery of two Abz-Trp(9) distance populations, both for the native and the analog hormones, reflecting the decrease, induced by the solvent, of the conformational states available to the peptides.


Assuntos
Ácido 4-Aminobenzoico/metabolismo , Hormônios Estimuladores de Melanócitos/química , Hormônios Estimuladores de Melanócitos/metabolismo , Tampões (Química) , Transferência de Energia , Fluorescência , Conformação Proteica , Rotação , Espectrometria de Fluorescência , Fatores de Tempo
15.
Biochim Biophys Acta ; 1474(2): 251-61, 2000 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-10742606

RESUMO

Förster resonance energy transfer (FRET) was used to study the conformational dynamics of bradykinin related peptides. The fluorescent probe aminobenzoic acid (Abz) bound to the amino terminal of bradykinin maintained its fluorescence characteristics, like high quantum yield and excited state decay dominated by a lifetime of 8.3 ns. The binding of the acceptor group N-[2, 4-dinitrophenyl]-ethylenediamine (EDDnp) to the carboxy terminal of Abz labeled bradykinin resulted in a drastic decrease of the fluorescence intensity and in a fastening of the excited state decay. The change of the decay kinetics to an heterogeneous process, precludes the use of energy transfer models based on a single fixed distance between donor and acceptor. The computational package CONTIN was employed to the analysis of time-resolved fluorescence data, allowing the recovery of a distance distribution between donor and acceptor corresponding to the end-to-end distance of the labeled peptide. The distance distribution reflects the occurrence of distinct conformations for the peptide, that coexist in equilibrium during the fluorescence lifetime. We observed three distance populations for bradykinin in water, that merged to two populations when the solvent was trifluoroethanol (TFE). The results were consistent with those obtained from circular dichroism spectroscopy, that showed structural flexibility in water and the presence of more defined secondary structure in TFE. We also studied several peptides related to bradykinin, and the results emphasized the formation of turns involving the proline residues and the decrease of conformational flexibility induced by using TFE as the solvent.


Assuntos
Bradicinina/química , Sequência de Aminoácidos , Dicroísmo Circular , Transferência de Energia , Polarização de Fluorescência , Corantes Fluorescentes
16.
Arq Neuropsiquiatr ; 44(4): 383-90, 1986 Dec.
Artigo em Português | MEDLINE | ID: mdl-3606431

RESUMO

The authors report a case of right midbrain and high pons haemorrhage with complete external ophthalmoplegia, except bilateral convergence, voluntary and automatic-reflex abduction of the left eye and adduction of this eye with vestibulo-ocular reflex ("one-and-a-half syndrome"). There is voluntary-automatic dissociation of the eyelids motricity and the vertical gaze. Still, there is sensitive-motor hemiplegia at left and asterixis.


Assuntos
Hemorragia Cerebral/complicações , Mesencéfalo/irrigação sanguínea , Oftalmoplegia/etiologia , Ponte/irrigação sanguínea , Hemorragia Cerebral/diagnóstico por imagem , Movimentos Oculares , Feminino , Humanos , Pessoa de Meia-Idade , Oftalmoplegia/fisiopatologia , Reflexo Vestíbulo-Ocular , Tomografia Computadorizada por Raios X
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