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Search Results: 1 - 10 of 6519 matches for " Alane Beatriz Vermelho "
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Sialoglycoconjugates in Trypanosoma cruzi-host cell interaction: possible biological model - a review
Vermelho, Alane Beatriz;Meirelles, Maria Nazareth Leal;
Memórias do Instituto Oswaldo Cruz , 1994, DOI: 10.1590/S0074-02761994000100013
Abstract: a number of glycoconjugates, including glycolipids and glycoproteins, participate in the process of host-cell invasion by trypanosoma cruzi and one of the most important carbohydrates involved on this interaction is sialic acid. it is known that parasite trans-sialidase participates with sialic acid in a coordinated fashion in the initial stages of invasion. given the importance of these sialogycoconjugates, this review sets out various possible biological models for the interaction between the parasite and mammalian cells that possess a sialylated receptor/ligand system.
Microbial Enzyme: Applications in Industry and in Bioremediation
Alane Beatriz Vermelho,Claudiu T. Supuran,Jose M. Guisan
Enzyme Research , 2012, DOI: 10.1155/2012/980681
Microbial Enzyme: Applications in Industry and in Bioremediation
Alane Beatriz Vermelho,Claudiu T. Supuran,Jose M. Guisan
Enzyme Research , 2012, DOI: 10.1155/2012/980681
Extracellular serine-proteinases isolated from Streptomyces alboniger: Partial characterization and effect of aprotinin on cellular structure
Lopes, Andréa;Coelho, Rosalie RR;Meirelles, Maria Nazareth L;Branquinha, Marta Helena;Vermelho, Alane Beatriz;
Memórias do Instituto Oswaldo Cruz , 1999, DOI: 10.1590/S0074-02761999000600010
Abstract: streptomyces alboniger atcc 12461 grown in brain heart infusion (bhi) medium produced two extracellular serine-proteinases, denoted sp i and sp ii, which were purified by ammonium sulfate precipitation and aprotinin-agarose affinity chromatography. sp i was purified 88,9-fold and sp ii 66,7- fold, with 33.4% and 10.4% yield, respectively. the optimum ph for the proteinases activity, using a-n-p-tosyl-l-arginine-methyl ester (tame) as substrate, was 9-10 and the optimum temperature was 37oc. the proteolytic activity of sp i and sp ii was inhibited by aprotinin and sp i was partially inhibited by leupeptin, both serine-proteinase inhibitors. s. alboniger growth in bhi-liquid medium decreased when 5 mg/ml, 10 mg/ml of aprotinin was used, being completely inhibited with 20 mg/ml and 40 mg/ml. at the ultrastructural level, aprotinin-treated s. alboniger cells showed swelling of the bacterial body and condensation of the genetic material, probably related to the inhibition of its growth.
Keratinase Production by Three Bacillus spp. Using Feather Meal and Whole Feather as Substrate in a Submerged Fermentation
Ana Maria Mazotto,Rosalie Reed Rodrigues Coelho,Sabrina Martins Lage Cedrola,Marcos Fábio de Lima,Sonia Couri,Edilma Paraguai de Souza,Alane Beatriz Vermelho
Enzyme Research , 2011, DOI: 10.4061/2011/523780
Abstract: Three Bacillus species (B. subtilis LFB-FIOCRUZ 1270, B. subtilis LFB-FIOCRUZ 1273, and B. licheniformis LFB-FIOCRUZ 1274), isolated from the poultry industry, were evaluated for keratinase production using feathers or feather meal as the sole carbon and nitrogen sources in a submerged fermentation. The three Bacillus spp. produced extracellular keratinases and peptidases after 7 days. Feather meal was the best substrate for keratinase and peptidase production in B. subtilis 1273, with 412?U/mL and 463?U/ml. The three strains were able to degrade feather meal (62–75%) and feather (40–95%) producing 3.9–4.4?mg/ml of soluble protein in feather meal medium and 1.9–3.3?mg/ml when feather medium was used. The three strains produced serine peptidases with keratinase and gelatinase activity. B. subtilis 1273 was the strain which exhibited the highest enzymatic activity. 1. Introduction Feather waste is a byproduct of the domestic poultry industry and is 90% keratin [1, 2]. However, the use of feather waste as a dietary protein supplement for animal feedstuffs is only carried out on a limited basis, due to its poor digestibility [3]. Keratin is an insoluble protein and is resistant to degradation by common peptidases, such as trypsin, pepsin, and papain [4, 5]. This resistance is due to the constituent amino acid composition and configuration that provide structural rigidity. The mechanical stability of keratin and its resistance to biochemical degradation depend on the tightly packed protein chains in α-helix (α-keratin) and β-sheet (β-keratin) structures. In addition, these structures are cross-linking by disulfide bridges in cystines residues [3, 4, 6]. A current value-added use for feathers is the conversion to feather meal using physical and chemical treatments. However these methods can destroy certain heat-sensitive amino acids, such as methionine, lysine, and tryptophan, generating other nonnutritive amino acids, for instance, lanthionine and lysinoalanine [7]. An alternative and attractive method for improving the digestibility of feathers or feather meal is biodegradation by keratinolytic microorganisms [8, 9]. A number of keratinolytic microorganisms can produce keratinases (E.C., peptidases which are capable of degrading keratin. Various authors have reported that, among the keratinolytic microorganisms, some species of Bacillus [10–12], actinomycetes [9, 13, 14], and fungi [15–17] are able to produce these keratinases and peptidases. Biodegradation of poultry waste by keratinases is an environment friendly biotechnological process, which
Detection of extracellular proteases from microorganisms on agar plates
Vermelho, Alane Beatriz;Meirelles, Maria Nazareth Leal;Lopes, Andréa;Petinate, Simone Dias Gon?alves;Chaia, André Adriano;Branquinha, Marta Helena;
Memórias do Instituto Oswaldo Cruz , 1996, DOI: 10.1590/S0074-02761996000600020
Abstract: we present herein an improved assay for detecting the presence of extracellular proteases from microorganisms on agar plates. using different substrates (gelatin, bsa, hemoglobin) incorporated into the agar and varying the culture medium composition, we were able to detect proteolytic activities from pseudomonas aeruginosa, micrococcus luteus and serratia marcescens as well as the influence that these components displayed in the expression of these enzymes. for all microorganisms tested we found that in agar-bhi or yeast extract medium containing gelatin the sensitivity of proteinase detection was considerably greater than in bsa-agar or hemoglobin-agar. however, when bsa or hemoglobin were added to the culture medium, there was an increase in growth along with a marked reduction in the amount of proteinase production. in the case of m. luteus the incorporation of glycerol in bhi or yeast extract gelatin-agar induced protease liberation. our results indicate that the technique described here is of value for detecting extracellular proteases directly in the culture medium, by means of a qualitative assay, simple, inexpensive, straight forward method to assess the presence of the proteolytic activity of a given microorganism colony with great freedom in substrate selection.
Identification and properties of two extracellular proteases from Brevundimonas diminuta
Chaia, André Adriano;Giovanni-De-Simone, Salvatore;Petinate, Simone Dias Gon?alves;Lima, Ana Paula Cabral de Araújo;Branquinha, Marta Helena;Vermelho, Alane Beatriz;
Brazilian Journal of Microbiology , 2000, DOI: 10.1590/S1517-83822000000100007
Abstract: extracellular proteases from brevundimonas diminuta (syn. pseudomonas diminuta) were studied in sodium dodecyl sulfate polyacrylamide gel electrophoresis (sds-page) containing a copolymerized substrate. two proteases were detected migrating at 67 kda and 50 kda: both of them hydrolysed preferentially gelatin, but casein was also degraded and a slight hydrolysis was observed with hemoglobin. no detectable extracellular proteolytic activity was found in bovine serum albumin-containing gels. the optima temperature and ph for proteolytic activity were between 40oc and 50oc in a ph ranging from 7.0 to 11.0, respectively. these enzymes were isolated by analytical high performance liquid chromatography (hplc). protease assays with the synthetic substrate z-phe-arg-mca and the inhibitors egta, edta and 1, 10 phenanthroline point out that these enzymes are metalloproteases.
Trypanosoma cruzi-cardiomyocytes: new contributions regarding a better understanding of this interaction
Meirelles, Maria de Nazareth Leal de;Pereira, Mirian Claudia S;Singer, Robert H;Soeiro, Maria de Nazaré C;Garzoni, Luciana R;Silva, Dayse T;Barbosa, Helene S;Araujo-Jorge, Tania C;Masuda, Masako O;Capella, Marcia AM;Lopes, Anibal Gil;Vermelho, Alane B;
Memórias do Instituto Oswaldo Cruz , 1999, DOI: 10.1590/S0074-02761999000700017
Abstract: the present paper summarizes new approaches regarding the progress done to the understanding of the interaction of trypanosoma cruzi-cardiomyocytes. mannose receptors localized at the surface of heart muscle cell are involved in binding and uptake of the parasite. one of the most striking events in the parasite-heart muscle cells interaction is the disruption of the actin cytoskeleton. we have investigated the regulation of the actin mrna during the cytopathology induced in myocardial cells by the parasite. t. cruzi invasion increases calcium resting levels in cardiomyocytes. we have previously shown that ca2+ atpase of the sarcoplasmic reticulum (serca) is involved in the invasion of t. cruzi in cardiomyocytes. treating the cells with thapsigargin, a drug that binds to all serca atpases and causes depletion of intracellular calcium stores, we found a 75% inhibition in the t. cruzi-cardiomyocytes invasion.
The improved Clinical Global Impression Scale (iCGI): development and validation in depression
Alane Kadouri, Emmanuelle Corruble, Bruno Falissard
BMC Psychiatry , 2007, DOI: 10.1186/1471-244x-7-7
Abstract: Thirty patients hospitalised for a major depressive episode were filmed at T1 (first week in hospital) and at T2 (2 weeks later) during a 5' specific interview. The Hamilton Depressive Rating Scale and the Symptom Check List were also rated. Eleven psychiatrists rated these videos using either the usual CGI response format or an improved response format, with or without a Delphi procedure.The new response format slightly improved (but not significantly) the interrater agreement, the Delphi procedure did not. The best results were obtained when ratings by 4 independent raters were averaged. In this situation, intraclass correlation coefficients were about 0.9.The Clinical Global Impression is a useful approach in psychiatry since it apprehends patients in their entirety. This study shows that it is possible to quantify such impressions with a high level of interrater agreement.The overall impression during an interview is a main element of psychiatric evaluation, but it is vague and difficult to operationalise. The Clinical Global Impression scale (CGI) is a classic instrument for making global assessments [1]. This scale yields three different measures: 1. Severity of illness (assessment of patient's current symptom severity, referred to here as CGIs), 2. Global improvement (comparison of patient's baseline condition with his/her current condition, referred to here as CGIi), 3. Efficacy index (comparison of patient's baseline condition with a ratio of current therapeutic benefit to severity of side effects). The CGI has been widely used in clinical research and especially in clinical trials concerning psychotropic treatments, for bipolar-disorder [2], anxiety [3] or schizophrenia [4]. Most often, the CGI scale is used with the same format or wording whatever the pathology under study. The CGI has nevertheless been more specifically adapted for bipolar disorder [2] and schizophrenia [4]. To our knowledge, there is, to date, no adaptation for depressive disorders.The
Perdas extremas em mercados de risco
Arraes, Ronaldo A;Rocha, Alane S;
Revista Contabilidade & Finan?as , 2006, DOI: 10.1590/S1519-70772006000300003
Abstract: this paper aims to infer about the distribution of extremes values of a continuous random variable, represented as the severe daily losses in financial markets investments. the extreme value theory (evt) plays a fundamental role in modeling rare events associated with great losses and very small probabilities of occurrence. one of the great concerns in risk management is to develop analytic techniques to foresee those exceptions. in that way, the tails of the rare losses' probability density function (pdf) are of great importance in evaluating that kind of risk, turning evt into a valuable tool for an accurate evaluation of high loss risks. the estimations of expected maximum losses in financial series are investigated by means of: i) traditional methods, which used all sample data in fitting the random variable pdf; ii) the extreme value methodology, particularly the generalized extreme value distribution (gev), which only used a set of maximum values detected in the sample data in estimating the pdf of expected maximum losses. the findings indicate, firstly, an important underestimation of extreme losses with the traditional methods, mainly in the pdf lower tail limits, and, secondly, that the gev distribution proved to be more efficient in forecasting extreme losses in the analyzed series: ibovespa, merval, dow jones.
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