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1.
J Appl Microbiol ; 128(5): 1448-1459, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31883415

RESUMO

AIMS: Quality evaluation of fresh whitemouth croaker (Micropogonias furnieri) by histamine determination using the HPLC-DAD method and quantification of histamine-forming bacteria using NGS and qPCR. METHODS AND RESULTS: The histamine content of fresh whitemouth croaker was detected by high performance liquid chromatography with diode array detector with a concentration ranging from 258·52 to 604·62 mg kg-1 being observed. The number of histidine decarboxylase (hdc gene) copies from Gram-negative bacteria and the bacteria Morganella morganii and Enterobacter aerogenes were quantified by quantitative polymerase chain reaction. All samples were positive, with copy numbers of the hdc gene ranging from 4·67 to 12·01 log10 per g. The microbial community was determined by sequencing the V4 region of the 16S rRNA gene using the Ion Torrent platform. The bioinformatics data generated by frog software showed that the phylum Proteobacteria was the most abundant, with the family Moraxellaceae being more prevalent in samples collected in the summer, whereas the Pseudomonadaceae was more present in the winter. CONCLUSIONS: All fish muscle samples analysed in this study presented histamine values higher than those allowed by CODEX Alimentarius. Additionally, a wide variety of spoilage micro-organisms capable of expressing the enzyme histidine decarboxylase were detected. Thus, improvements in handling and processing are required to minimize the prevalence of histamine-producing bacteria in fish. SIGNIFICANCE AND IMPACT OF THE STUDY: Global fish production in 2016 was 171 million tons, with the largest consumer being China, followed by Indonesia and the USA. In Brazil, 1·3 million tons of fish are consumed per year, with whitemouth croaker being the main fish landed. Notably, cases associated with histamine poisoning are quite common. According to the European Food Safety Authority and European Centre for Disease Prevention and Control, a total of 599 HFP outbreaks were identified in the European Union during the period 2010-2017. In the USA, there were 333 outbreaks with 1383 people involved between 1998 and 2008.


Assuntos
Qualidade dos Alimentos , Histamina/análise , Perciformes/microbiologia , RNA Ribossômico 16S/genética , Alimentos Marinhos/microbiologia , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Brasil , Histamina/biossíntese , Histidina Descarboxilase/genética , Histidina Descarboxilase/metabolismo , Microbiota/genética
2.
Food Microbiol ; 90: 103449, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32336370

RESUMO

The objective of this work was to assess the efficacy of sodium hypochlorite and peracetic acid for sanitization of Brazil nuts. To evaluate the natural microbiota of the nuts, the total bacteria and fungi as well as the Aspergillus section Flavi were counted. The moisture, water activity and the presence of aflatoxins was quantified. The response surface method was used to determine the influence of exposure time and sanitizers concentration on the reduction of Aspergillus nomius inoculated on the nuts. Microbiological, sensory and quantification analyzes of aflatoxins were performed under optimum conditions The evaluation of the initial contamination of the nuts, despite presenting high microbiological contamination, humidity and water activity, was not detected aflatoxins in any samples. In artificially inoculated samples, the response surface and the desirability function were obtained to determine the optimal point of use for each sanitizer. The nuts had high microbiological contamination, moisture content and water activity. Aflatoxins were not detected in any samples. The response surface and desirability function indicated the optimal sanitization conditions were 250 mg/L and 8.5 min and 140 mg/L and 15 min for sodium hypochlorite and peracetic acid, respectively. Reductions greater than 2 log CFU/g were obtained with sodium hypochlorite and of 1 log CFU/g for peracetic acid. In the tests performed with new Brazil nuts samples under the optimized conditions, reductions of less than 2 log CFU/g were obtained. Aflatoxin B1 was detected in one untreated sample (1.51 µg/kg), one sample treated with sodium hypochlorite (0.60 µg/kg) and two samples treated with peracetic acid (0.64 and 0.72 µg/kg). Demonstrating that the sanitizers in the concentrations used had no action on aflatoxins, despite being efficient for fungal control. The treatments did not cause an unacceptable sensorial impact on the samples.


Assuntos
Aspergillus/efeitos dos fármacos , Bertholletia/microbiologia , Desinfetantes/farmacologia , Contaminação de Alimentos/prevenção & controle , Ácido Peracético/farmacologia , Hipoclorito de Sódio/farmacologia , Aflatoxinas/análise , Microbiologia de Alimentos
3.
Water Sci Technol ; 78(5-6): 1312-1323, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30388088

RESUMO

Two bioreactors were investigated as an alternative to post-treatment of effluent from an upflow anaerobic sludge blanket (UASB) reactor treating domestic sewage, with an aim of oxidizing sulfide into elemental sulfur, and removal of solid and organic material. The bioreactors were operated at different hydraulic retention times (HRTs) (6, 4, and 2 h) and in the presence or absence (control) of packing material (polypropylene rings). Greater sulfide removal efficiencies - 75% (control reactor) and 92% (packed reactor) - were achieved in both reactors for an HRT of 6 h. Higher organic matter (COD) and solid (TSS) removal levels were observed in the packed reactor, which produced effluent with low COD (100 mg CODL-1) and TSS concentrations (30 mg TSSL-1). Denaturing gradient gel electrophoresis results revealed that a metabolically diverse bacterial community was present in both bioreactors, with sequences related to heterotrophic bacteria, sulfur bacteria (Thiocapsa, Sulfurimonas sp., Chlorobaculum sp., Chromatiales and Sulfuricellales), phototrophic purple non-sulfur bacteria (Rhodopseudomonas, Rhodocyclus sp.) and cyanobacteria. The packed reactor presented higher extracellular sulfur formation and potential for elemental sulfur recovery was seen. Higher efficiencies related to the packed reactor were attributed to the presence of packing material and higher cell retention time. The studied bioreactors seemed to be a simple and low-cost alternative for the post-treatment of anaerobic effluent.


Assuntos
Chlorobi , Esgotos , Anaerobiose , Bactérias , Reatores Biológicos , Sulfetos , Eliminação de Resíduos Líquidos
4.
J Appl Microbiol ; 121(4): 1038-51, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27374976

RESUMO

AIMS: In order to improve the quality and to create a biological basis for obtainment of the protected denomination of origin (PDO), indigenous yeast were isolated and characterized for use in Salinas city (the Brazilian region of quality cachaça production). MATERIAL AND METHODS: Seven thousand and two hundred yeast colonies from 15 Salinas city distilleries were screened based on their fermentative behaviour and the physicochemical composition of cachaça. Molecular polymorphic analyses were performed to characterize these isolates. RESULTS: Two Saccharomyces cerevisiae strains (nos. 678 and 680) showed appropriate characteristics to use in the cachaça production: low levels of acetaldehyde and methanol, and high ethyl lactate/ethyl acetate ratio respectively. They also presented polymorphic characteristics more closely related between themselves even when compared to other strains from Salinas. CONCLUSIONS: The application of selected yeast to cachaça production can contribute for the improvement of the quality product as well as be used as a natural marker for PDO. SIGNIFICANCE AND IMPACT OF THE STUDY: This study suggests that the use of selected yeast strains could contribute to obtain a cachaça similar to those produced traditionally, while getting wide acceptation in the market, yet presenting more homogeneous organoleptic characteristics, and thus contributing to the PDO implementation.


Assuntos
Bebidas Alcoólicas/microbiologia , Saccharomyces cerevisiae/metabolismo , Acetaldeído/análise , Acetaldeído/metabolismo , Bebidas Alcoólicas/análise , Brasil , Fermentação , Metanol/análise , Metanol/metabolismo , Melhoria de Qualidade , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/isolamento & purificação
5.
World J Microbiol Biotechnol ; 30(7): 1977-83, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24504708

RESUMO

Kluyveromyces lactis strains are able to assimilate lactose. They have been used industrially to eliminate this sugar from cheese whey and in other industrial products. In this study, we investigated specific features and the kinetic parameters of the lactose transport system in K. lactis JA6. In lactose grown cells, lactose was transported by a system transport with a half-saturation constant (K s) of 1.49 ± 0.38 mM and a maximum velocity (V max) of 0.96 ± 0.12 mmol. (g dry weight)(-1) h(-1) for lactose. The transport system was constitutive and energy-dependent. Results obtained by different approaches showed that the lactose transport system was regulated by glucose at the transcriptional level and by glucose and other sugars at a post-translational level. In K. lactis JA6, galactose metabolization was under glucose control. These findings indicated that the regulation of lactose-galactose regulon in K. lactis was similar to the regulation of galactose regulon in Saccharomyces cerevisiae.


Assuntos
Kluyveromyces/metabolismo , Lactose/metabolismo , Transporte Biológico/fisiologia , Regulação Fúngica da Expressão Gênica , Cinética
6.
Genet Mol Res ; 12(4): 5124-33, 2013 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-24301772

RESUMO

Ancestry-informative markers (AIMs) are powerful tools for inferring the genetic composition of admixed populations. In this study, we determined the genetic ancestry of the Ouro Preto (Brazil) population and evaluated the association between ancestry and self-reported skin color. The genetic ancestry of 189 children and adolescents was estimated by genotyping 15 AIMs. The estimate of population admixture was determined using the Bayesian Markov Chain Monte Carlo (MCMC) method implemented in two different programs (STRUCTURE and ADMIXMAP). Volunteers self-reported their skin colors. The European ancestry contribution ranged from 0.503 to 0.539, the African contribution ranged from 0.333 to 0.425, and the Amerindian component ranged from 0.04 to 0.164. The relative contributions of African (P < 0.016) and European (P < 0.011) ancestry differed significantly among skin color groups, except between black and dark-brown groups. The population of Ouro Preto has a higher contribution of African ancestry compared to the mean for the southeast region of Brazil. Therefore, extrapolating the African ancestry contribution for southeastern Brazil to the Ouro Preto population would underestimate the actual value for this city. We also showed that self-reported skin color could be appropriate for describing the genetic structure of this particular population.


Assuntos
Etnicidade/genética , Genética Populacional , Alelos , Brasil , Criança , Evolução Molecular , Feminino , Frequência do Gene , Marcadores Genéticos , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Característica Quantitativa Herdável
7.
Environ Technol ; 44(4): 431-445, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34463202

RESUMO

This study aimed at evaluating the microaeration as an alternative for hydrogen sulfide removal from biogas of UASB reactors treating sewage. The set-up consisted of two pilot-scale UASB reactors, including a conventional anaerobic and a modified UASB reactor, operated under microaerated conditions. Air was supplied in the digestion zone, at 1 and 3 m from the bottom of the reactor, and three different air flows were investigated: 10, 20, and 30 mL.min-1, corresponding to 0.003, 0.005 and 0.005 LO2/Linfluent, respectively. The main results showed that the microaeration provided a substantial decrease in hydrogen sulfide concentrations when compared to the concentrations observed in the biogas of the anaerobic UASB reactor. Hydrogen sulfide concentrations remained below 70 ppmv throughout the experimental period, corresponding to an average removal efficiency of 98%. Although a decrease in methane concentrations in biogas was observed, the feasibility of energy use would not be affected. The effect of microaeration on the overall performance of the reactor was evaluated, however, no significant differences were observed. The feasibility of limiting aeration conditions in the reactor digestion zone as an efficient alternative for hydrogen sulfide removal from biogas was demonstrated.


Assuntos
Sulfeto de Hidrogênio , Anaerobiose , Biocombustíveis , Reatores Biológicos , Esgotos , Metano , Digestão , Eliminação de Resíduos Líquidos/métodos
8.
Poult Sci ; 100(4): 100969, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33684651

RESUMO

The objective of this study was to characterize differences in the cecal microbiota of chickens vaccinated for coccidiosis or receiving salinomycin in the diet. In this study, 140 male 1-day-old broiler chickens were divided in 2 groups: vaccine group (live vaccine) vaccinated at the first day and salinomycin group (125 ppm/kg since the first day until 35 d of age). Each treatment was composed for 7 replicates of 10 birds per pen. At 28 d, the cecal content of one bird per replicate was collected for microbiota analysis. The genetic sequencing was conducted by the Miseq Illumina platform. Vaccine group showed lower body weight, weight gain, and poorer feed conversion in the total period (P < 0.05). Bacterial 16S rRNA genes were classified as 3 major phyla (Bacteroidetes, Firmicutes, and Proteobacteria), accounting for more than 98% of the total bacterial community. The microbiota complexity in the cecal was estimated based on the α-diversity indices. The vaccine did not reduce species richness and diversity (P > 0.05). The richness distribution in the salinomycin group was larger and more uniform than the vaccinated birds. Salinomycin group was related to the enrichment of Bacteroidetes, whereas Firmicutes and Proteobacteria phyla were in greater proportions in the vaccine group. The last phylum includes a wide variety of pathogenic bacteria. The vaccine did not decrease the species richness but decreased the percentage of Bacteroidetes, a phylum composed by genera that produce short-chain fatty acids improving intestinal health. Vaccine group also had higher Proteobacteria phylum, which may help explain its poorer performance.


Assuntos
Coccidiose , Microbioma Gastrointestinal , Microbiota , Ração Animal/análise , Animais , Ceco , Galinhas , Coccidiose/prevenção & controle , Coccidiose/veterinária , Dieta/veterinária , Masculino , Piranos , RNA Ribossômico 16S/genética
10.
Peptides ; 29(9): 1505-13, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18554751

RESUMO

Here, we described the expression and characterization of the recombinant toxin LTx2, which was previously isolated from the venomous cDNA library of a Brazilian spider, Lasiodora sp. (Mygalomorphae, Theraphosidae). The recombinant toxin found in the soluble and insoluble fractions was purified by reverse phase high-performance liquid chromatography (HPLC). Ca2+ imaging analysis revealed that the recombinant LTx2 acts on calcium channels of BC3H1 cells, blocking L-type calcium channels.


Assuntos
Neurotoxinas/biossíntese , Neurotoxinas/farmacologia , Venenos de Aranha/química , Venenos de Aranha/farmacologia , Animais , Cálcio/fisiologia , Canais de Cálcio/efeitos dos fármacos , Canais de Cálcio/fisiologia , Linhagem Celular , Clonagem Molecular , Receptores de Inositol 1,4,5-Trifosfato/biossíntese , Camundongos , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Canal de Liberação de Cálcio do Receptor de Rianodina/biossíntese , Venenos de Aranha/biossíntese , Aranhas/química
12.
Biochim Biophys Acta ; 1136(1): 57-67, 1992 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-1322708

RESUMO

Addition of glucose-related fermentable sugars or protonophores to derepressed cells of the yeast Saccharomyces cerevisiae causes a 3- to 4-fold activation of the plasma membrane H(+)-ATPase within a few minutes. These conditions are known to cause rapid increases in the cAMP level. In yeast strains carrying temperature-sensitive mutations in genes required for cAMP synthesis, incubation at the restrictive temperature reduced the extent of H(+)-ATPase activation. Incubation of non-temperature-sensitive strains, however, at such temperatures also caused reduction of H(+)-ATPase activation. Yeast strains which are specifically deficient in the glucose-induced cAMP increase (and not in basal cAMP synthesis) still showed plasma membrane H(+)-ATPase activation. Yeast mutants with widely divergent activity levels of cAMP-dependent protein kinase displayed very similar levels of activation of the plasma membrane H(+)-ATPase. This was also true for a yeast mutant carrying a deletion in the CDC25 gene. These results show that the cAMP-protein kinase A signaling pathway is not required for glucose activation of the H(+)-ATPase. They also contradict the specific requirement of the CDC25 gene product. Experiments with yeast strains carrying point or deletion mutations in the genes coding for the sugar phosphorylating enzymes hexokinase PI and PII and glucokinase showed that activation of the H(+)-ATPase with glucose or fructose was completely dependent on the presence of a kinase able to phosphorylate the sugar. These and other data concerning the role of initial sugar metabolism in triggering activation are consistent with the idea that the glucose-induced activation pathways of cAMP-synthesis and H(+)-ATPase have a common initiation point.


Assuntos
AMP Cíclico/metabolismo , Glucose/fisiologia , Glicólise/genética , ATPases Translocadoras de Prótons/metabolismo , Saccharomyces cerevisiae/enzimologia , Membrana Celular/enzimologia , Ativação Enzimática , Frutose/fisiologia , Proteínas Fúngicas/metabolismo , Cinética , Mutação , Fosforilação , Reprodutibilidade dos Testes , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Temperatura
13.
Braz J Med Biol Res ; 48(7): 595-602, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25923461

RESUMO

Association studies of genetic variants and obesity and/or obesity-related risk factors have yielded contradictory results. The aim of the present study was to determine the possible association of five single-nucleotide polymorphisms (SNPs) located in the IGF2, LEPR, POMC, PPARG, and PPARGC1 genes with obesity or obesity-related risk phenotypes. This case-control study assessed overweight (n=192) and normal-weight (n=211) children and adolescents. The SNPs were analyzed using minisequencing assays, and variables and genotype distributions between the groups were compared using one-way analysis of variance and Pearson's chi-square or Fisher's exact tests. Logistic regression analysis adjusted for age and gender was used to calculate the odds ratios (ORs) for selected phenotype risks in each group. No difference in SNP distribution was observed between groups. In children, POMC rs28932472(C) was associated with lower diastolic blood pressure (P=0.001), higher low-density lipoprotein (LDL) cholesterol (P=0.014), and higher risk in overweight children of altered total cholesterol (OR=7.35, P=0.006). In adolescents, IGF2 rs680(A) was associated with higher glucose (P=0.012) and higher risk in overweight adolescents for altered insulin (OR=10.08, P=0.005) and homeostasis model of insulin resistance (HOMA-IR) (OR=6.34, P=0.010). PPARG rs1801282(G) conferred a higher risk of altered insulin (OR=12.31, P=0.003), and HOMA-IR (OR=7.47, P=0.005) in overweight adolescents. PARGC1 rs8192678(A) was associated with higher triacylglycerols (P=0.005), and LEPR rs1137101(A) was marginally associated with higher LDL cholesterol (P=0.017). LEPR rs1137101(A) conferred higher risk for altered insulin, and HOMA-IR in overweight adolescents. The associations observed in this population suggested increased risk for cardiovascular diseases and/or type 2 diabetes later in life for individuals carrying these alleles.


Assuntos
Obesidade/genética , Fenótipo , Polimorfismo de Nucleotídeo Único/genética , Adolescente , Análise de Variância , Antropometria , Brasil , Doenças Cardiovasculares/genética , Estudos de Casos e Controles , Criança , Colesterol/sangue , Diabetes Mellitus Tipo 2/genética , Feminino , Frequência do Gene , Humanos , Fator de Crescimento Insulin-Like II/genética , Masculino , Obesidade/complicações , Obesidade/etnologia , Sobrepeso/genética , PPAR gama/genética , Reação em Cadeia da Polimerase , Pró-Opiomelanocortina/genética , Receptores para Leptina/genética , Fatores de Risco , Fatores de Transcrição/genética
14.
FEBS Lett ; 532(3): 324-32, 2002 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-12482587

RESUMO

The PKC1 gene in the yeast Saccharomyces cerevisiae encodes for protein kinase C which is known to control a MAP kinase cascade consisting of different kinases: Bck1, Mkk1 and Mkk2, and Mpk1. This cascade affects the cell wall integrity but the phenotype of pkc1Delta mutants suggests additional targets that have not yet been identified [Heinisch et al., Mol. Microbiol. 32 (1999) 671-680]. The pkc1Delta mutant, as opposed to other mutants in the MAP kinase cascade, displays defects in the control of carbon metabolism. One of them occurs in the derepression of SUC2 gene after exhaustion of glucose from the medium, suggesting an involvement of Pkc1p in the derepression process that is not shared by the downstream MAP kinase cascade. In this work, we demonstrate that Pkc1p is required for the increase of the activity of enzymatic systems during the derepression process. We observed that Pkc1p is involved in the derepression of invertase and alcohol dehydrogenase activities. On the other hand, it seems not to be necessary for the derepression of the enzymes of the GAL system. Our results suggest that Pkc1p is acting through the main glucose repression pathway, since introduction of an additional mutation in the PKC1 gene in yeast strains already presenting mutations in the HXKII or MIG1 genes does not interfere with the typical derepressed phenotype observed in these single mutants. Moreover, our data indicate that Pkc1p participates in this process through the control of the cellular localization of the Mig1 transcriptional factor.


Assuntos
Proteína Quinase C/metabolismo , Saccharomyces cerevisiae/enzimologia , Ágar/farmacologia , Álcool Desidrogenase/metabolismo , Northern Blotting , Western Blotting , Divisão Celular , Proteínas de Ligação a DNA/metabolismo , Relação Dose-Resposta a Droga , Epitopos , Glucose/metabolismo , Glicosídeo Hidrolases/metabolismo , Proteínas de Fluorescência Verde , Proteínas Luminescentes/metabolismo , Mutação , Fenótipo , Ligação Proteica , Proteína Quinase C/genética , RNA/metabolismo , Proteínas Repressoras/metabolismo , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae , Fatores de Tempo , Transcrição Gênica , beta-Frutofuranosidase
15.
Toxicon ; 44(8): 949-52, 2004 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-15530979

RESUMO

The present work describes the identification of toxins expressed by the venom gland of the spider Lasiodora sp. The toxins LTx1, LTx2 and LTx3 were identified by the screening of a cDNA library. These toxins showed significant similarity at the amino acid level with spider toxins from Lasiodora parahybana, Eurypelma californicum, Brachypelma smithii, Selenocosmia huwena.


Assuntos
Venenos de Aranha/química , Aranhas/química , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , Expressão Gênica , Dados de Sequência Molecular , Alinhamento de Sequência , Especificidade da Espécie
16.
Am J Clin Oncol ; 23(5): 521-5, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11039516

RESUMO

Synchronous ovarian primaries are infrequently found in patients with endometrial cancer. Although numerous investigators have examined the characteristics of these women, most include patients with tumors of similar histology, which may simply represent ovarian metastases. To overcome this problem, we present here patients found to have tumors of dissimilar histology. Of 499 patients with endometrial cancer undergoing primary surgery between 1980 and 1997, 18 (3.6%) were found to have endometrial and ovarian primaries of dissimilar histology. The median age was 64.2 years. Most had stage I, grades I and II, minimally invasive endometrial adenocarcinomas and stage IA mucinous or serous ovarian cystadenocarcinomas. Most ovarian tumors were either borderline or grades I and II. The 5-year actuarial disease-free (DFS) and cause-specific survivals of the entire group were 81.2% and 89.5%, respectively. Those with both stage I ovarian and endometrial primaries had a trend to a better DFS (100 versus 68.6%, p = 0.07) than did women with higher stage disease. Our data demonstrate that synchronous ovarian primaries of dissimilar histology are infrequently found in women undergoing surgery for endometrial cancer. These women seek treatment at a relatively advanced age, and have early-stage, low grade disease in both sites. Their outcome is favorable, particularly those with stage I disease in both sites.


Assuntos
Neoplasias do Endométrio , Neoplasias Primárias Múltiplas , Neoplasias Ovarianas , Adulto , Idoso , Neoplasias do Endométrio/mortalidade , Neoplasias do Endométrio/patologia , Neoplasias do Endométrio/terapia , Feminino , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Primárias Múltiplas/mortalidade , Neoplasias Primárias Múltiplas/patologia , Neoplasias Primárias Múltiplas/terapia , Neoplasias Ovarianas/mortalidade , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/terapia , Estudos Retrospectivos , Análise de Sobrevida
17.
Braz J Med Biol Res ; 29(8): 949-55, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9181075

RESUMO

Glycine was transported in Fusarium oxysporum cells, grown on glycine as the sole source of carbon and nitrogen, by a facilitated diffusion transport system with a half-saturation constant (Ks) of 11 mM and a maximum velocity (Vmax) of 1.2 mM (g dry weight)-1 h-1 at pH 5.0 and 26 degrees C. Under conditions of nitrogen starvation, the same system was present together with a high-affinity one (Ks) of about 47 microM and Vmax of about 60 microM (g dry weight)-1 h-1). The low-affinity system was more specific than the high-affinity system. Cells grown on gelatine showed the same behavior. In cells grown on glucose-gelatine medium, the low-affinity system was poorly expressed even after carbon and nitrogen starvation. Moreover, addition of glucose to cells grown on glycine and resuspended in mineral medium caused an increase of the glycine transport probably due to a boost in protein synthesis. This stimulation did not affect the Ks of the low-affinity system. These results demonstrate that, as is the case for other eukaryotic systems, F. oxysporum glycine transport is under control of nitrogen sources but its regulation by carbon sources appears to be more complex.


Assuntos
Fusarium/metabolismo , Glicina/metabolismo , Transporte Biológico/fisiologia
18.
J Med Microbiol ; 61(Pt 9): 1194-1207, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22580913

RESUMO

Recently, much attention has been given to the use of probiotics as an adjuvant for the prevention or treatment of gastrointestinal pathology. The great advantage of therapy with probiotics is that they have few side effects such as selection of resistant bacteria or disturbance of the intestinal microbiota, which occur when antibiotics are used. Adhesion of pathogenic bacteria onto the surface of probiotics instead of onto intestinal receptors could explain part of the probiotic effect. Thus, this study evaluated the adhesion of pathogenic bacteria onto the cell wall of Saccharomyces boulardii and Saccharomyces cerevisiae strains UFMG 905, W303 and BY4741. To understand the mechanism of adhesion of pathogens to yeast, cell-wall mutants of the parental strain of Saccharomyces cerevisiae BY4741 were used because of the difficulty of mutating polyploid yeast, as is the case for Saccharomyces cerevisiae and Saccharomyces boulardii. The tests of adhesion showed that, among 11 enteropathogenic bacteria tested, only Escherichia coli, Salmonella Typhimurium and Salmonella Typhi adhered to the surface of Saccharomyces boulardii, Saccharomyces cerevisiae UFMG 905 and Saccharomyces cerevisiae BY4741. The presence of mannose, and to some extent bile salts, inhibited this adhesion, which was not dependent on yeast viability. Among 44 cell-wall mutants of Saccharomyces cerevisiae BY4741, five lost the ability to fix the bacteria. Electron microscopy showed that the phenomenon of yeast-bacteria adhesion occurred both in vitro and in vivo (in the digestive tract of dixenic mice). In conclusion, some pathogenic bacteria were captured on the surface of Saccharomyces boulardii, Saccharomyces cerevisiae UFMG 905 and Saccharomyces cerevisiae BY4741, thus preventing their adhesion to specific receptors on the intestinal epithelium and their subsequent invasion of the host.


Assuntos
Aderência Bacteriana/fisiologia , Parede Celular/microbiologia , Escherichia coli/fisiologia , Probióticos/metabolismo , Saccharomyces/fisiologia , Salmonella typhimurium/fisiologia , Animais , Humanos , Intestinos/microbiologia , Camundongos , Camundongos Endogâmicos NOD , Saccharomyces/classificação
19.
Cell Calcium ; 51(1): 72-81, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22153127

RESUMO

Previous work from our laboratories demonstrated that the sugar-induced activation of plasma membrane H(+)-ATPase in Saccharomyces cerevisiae is dependent on calcium metabolism with the contribution of calcium influx from external medium. Our results demonstrate that a glucose-induced calcium (GIC) transporter, a new and still unidentified calcium carrier, sensitive to nifedipine and gadolinium and activated by glucose addition, seems to be partially involved in the glucose-induced activation of the plasma membrane H(+)-ATPase. On the other hand, the importance of calcium carriers that can release calcium from internal stores was analyzed in glucose-induced calcium signaling and activation of plasma membrane H(+)-ATPase, in experimental conditions presenting very low external calcium concentrations. Therefore the aim was also to investigate how the vacuole, through the participation of both Ca(2+)-ATPase Pmc1 and the TRP homologue calcium channel Yvc1 (respectively, encoded by the genes PMC1 and YVC1) contributes to control the intracellular calcium availability and the plasma membrane H(+)-ATPase activation in response to glucose. In strains presenting a single deletion in YVC1 gene or a double deletion in YVC1 and PMC1 genes, both glucose-induced calcium signaling and activation of the H(+)-ATPase are nearly abolished. These results suggest that Yvc1 calcium channel is an important component of this signal transduction pathway activated in response to glucose addition. We also found that by a still undefined mechanism Yvc1 activation seems to correlate with the changes in the intracellular level of IP(3). Taken together, these data demonstrate that glucose addition to yeast cells exposed to low external calcium concentrations affects calcium uptake and the activity of the vacuolar calcium channel Yvc1, contributing to the occurrence of calcium signaling connected to plasma membrane H(+)-ATPase activation.


Assuntos
Sinalização do Cálcio/efeitos dos fármacos , Membrana Celular/enzimologia , Glucose/farmacologia , ATPases Translocadoras de Prótons/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/enzimologia , Vacúolos/metabolismo , Compostos de Boro/farmacologia , Cálcio/metabolismo , Membrana Celular/efeitos dos fármacos , Ácido Egtázico/farmacologia , Ativação Enzimática/efeitos dos fármacos , Espaço Extracelular/efeitos dos fármacos , Espaço Extracelular/metabolismo , Inositol 1,4,5-Trifosfato/metabolismo , Modelos Biológicos , Mutação/genética , Nifedipino/farmacologia , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/efeitos dos fármacos , Canais de Cátion TRPC/metabolismo , Vacúolos/efeitos dos fármacos
20.
Braz. j. med. biol. res ; 48(7): 595-602, 07/2015. tab
Artigo em Inglês | LILACS | ID: lil-751340

RESUMO

Association studies of genetic variants and obesity and/or obesity-related risk factors have yielded contradictory results. The aim of the present study was to determine the possible association of five single-nucleotide polymorphisms (SNPs) located in the IGF2, LEPR, POMC, PPARG, and PPARGC1 genes with obesity or obesity-related risk phenotypes. This case-control study assessed overweight (n=192) and normal-weight (n=211) children and adolescents. The SNPs were analyzed using minisequencing assays, and variables and genotype distributions between the groups were compared using one-way analysis of variance and Pearson's chi-square or Fisher's exact tests. Logistic regression analysis adjusted for age and gender was used to calculate the odds ratios (ORs) for selected phenotype risks in each group. No difference in SNP distribution was observed between groups. In children, POMC rs28932472(C) was associated with lower diastolic blood pressure (P=0.001), higher low-density lipoprotein (LDL) cholesterol (P=0.014), and higher risk in overweight children of altered total cholesterol (OR=7.35, P=0.006). In adolescents, IGF2 rs680(A) was associated with higher glucose (P=0.012) and higher risk in overweight adolescents for altered insulin (OR=10.08, P=0.005) and homeostasis model of insulin resistance (HOMA-IR) (OR=6.34, P=0.010). PPARG rs1801282(G) conferred a higher risk of altered insulin (OR=12.31, P=0.003), and HOMA-IR (OR=7.47, P=0.005) in overweight adolescents. PARGC1 rs8192678(A) was associated with higher triacylglycerols (P=0.005), and LEPR rs1137101(A) was marginally associated with higher LDL cholesterol (P=0.017). LEPR rs1137101(A) conferred higher risk for altered insulin, and HOMA-IR in overweight adolescents. The associations observed in this population suggested increased risk for cardiovascular diseases and/or type 2 diabetes later in life for individuals carrying these alleles.


Assuntos
Humanos , Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Produtos Biológicos/uso terapêutico , Antirreumáticos/administração & dosagem , Produtos Biológicos/administração & dosagem , Esquema de Medicação , Quimioterapia Combinada , Medicina Baseada em Evidências/métodos , Metotrexato/uso terapêutico , Guias de Prática Clínica como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
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