RESUMO
Anoikis is a type of apoptosis that occurs in response to the loss of adhesion to the extracellular matrix (ECM). Anoikis resistance is a critical mechanism in cancer and contributes to tumor metastasis. Nitric oxide (NO) is frequently upregulated in the tumor area and is considered an important player in cancer metastasis. The aim of this study was to evaluate the effect of NO on adhesiveness, invasiveness, and migration of anoikis-resistant endothelial cells. Here, we report that anoikis-resistant endothelial cells overexpress endothelial nitric oxide synthase. The inhibition of NO release in anoikis-resistant endothelial cells was able to decrease adhesiveness to fibronectin, laminin, and collagen IV. This was accompanied by an increase in cell invasiveness and migration. Furthermore, anoikis-resistant cell lines displayed a decrease in fibronectin and collagen IV protein expression after L-NAME treatment. These alterations in adhesiveness and invasiveness were the consequence of MMP-2 up-regulation observed after NO release inhibition. The decrease in NO levels was able to down-regulate the activating transcription factor 3 (ATF3) protein expression. ATF3 represses MMP-2 gene expression by antagonizing p53-dependent trans-activation of the MMP-2 promoter. We speculate that the increased release of NO by anoikis-resistant endothelial cells acted as a response to restrict the MMP-2 action, interfering in MMP-2 gene expression via ATF3 regulation. The up-regulation of nitric oxide by anoikis-resistant endothelial cells is an important response to restrict tumorigenic behavior. Without this mechanism, invasiveness and migration potential would be even higher, as shown after L-NAME treatment.
Assuntos
Anoikis , Células Endoteliais , Adesividade , Linhagem Celular Tumoral , Células Endoteliais/metabolismo , Humanos , Invasividade Neoplásica , Óxido Nítrico/metabolismo , Regulação para CimaRESUMO
Anoikis is a type of apoptosis that occurs in response to the loss of adhesion to the extracellular matrix (ECM). Anoikis resistance is a critical mechanism in cancer and contributes to tumor metastasis. Nitric oxide (NO) is frequently upregulated in the tumor area and is considered an important player in cancer metastasis. The aim of this study was to evaluate the effect of NO on adhesiveness, invasiveness, and migration of anoikis-resistant endothelial cells. Here, we report that anoikis-resistant endothelial cells overexpress endothelial nitric oxide synthase. The inhibition of NO release in anoikis-resistant endothelial cells was able to decrease adhesiveness to fibronectin, laminin, and collagen IV. This was accompanied by an increase in cell invasiveness and migration. Furthermore, anoikis-resistant cell lines displayed a decrease in fibronectin and collagen IV protein expression after L-NAME treatment. These alterations in adhesiveness and invasiveness were the consequence of MMP-2 up-regulation observed after NO release inhibition. The decrease in NO levels was able to down-regulate the activating transcription factor 3 (ATF3) protein expression. ATF3 represses MMP-2 gene expression by antagonizing p53-dependent trans-activation of the MMP-2 promoter. We speculate that the increased release of NO by anoikis-resistant endothelial cells acted as a response to restrict the MMP-2 action, interfering in MMP-2 gene expression via ATF3 regulation. The up-regulation of nitric oxide by anoikis-resistant endothelial cells is an important response to restrict tumorigenic behavior. Without this mechanism, invasiveness and migration potential would be even higher, as shown after L-NAME treatment.
RESUMO
O objetivo deste experimento foi comparar três métodos analíticos para determinação de soro em leite cru refrigerado: cromatografia líquida de alta eficiência, ninidrina ácida e colorimétrico adaptado. Foram coletadas 100 amostras de leite cru refrigerado de tanques de expansão. Estas, quando submetidas à análise pelo método da ninidrina ácida, apresentaram 10 (14,7%) amostras negativas e 58 (85,3%) positivas. O teor médio de ácido siálico encontrado na técnica da ninidrina foi de 5,58(g/mL, com valor mais frequente de 2,70(g/mL. Das 68 amostras negativas pela cromatografia líquida de alta eficiência, duas foram positivas (2,94%) e 66 (97,06%) negativas, quando analisadas pelo método colorimétrico. A frequência relativa de amostras positivas foi de 32%, com a CLAE apresentando a maior média de soro (14,37%), seguida do método colorimétrico (5,28%) e o da ninidrina ácida (3,12%). A técnica de cromatografia líquida de alta eficiência diferiu dos métodos de ninidrina ácida e colorimétrico, enquanto os métodos da ninidrina e colorimétrico não diferiram entre si, podendo ambos serem utilizados como metodologias de triagem. Entre as três técnicas, a cromatografia líquida de alta eficiência foi a metodologia mais sensível na detecção e quantificação do soro em leite cru refrigerado.(AU)
The objective of this study was to compare three analytical methods to determine serum in refrigerated raw milk. High-performance liquid chromatography (HPLC), acidic and colorimetric ninhydrin methods were applied. A collection of 100 samples of raw milk from cooled expansion tanks took place. The results showed that 10 samples (14.7%) were negative and 58 (85.3%) were positive for the acidic ninhydrin method. The mean sialic acid content found in the ninhydrin technique was 5.58µg/mL, with a more frequent value of 2.70µg/mL. From all 68 HPLC negative samples, two were positive (2.94%) and 66 (97.06%) negative to the colorimetric method. The relative frequency of positive samples was 32%, HPLC had the highest mean serum levels (14.37%), followed by the colorimetric method (5.28%) and acid ninhydrin (3.12%). The high-performance liquid chromatography method was different from the acid and colorimetric ninhydrin methods. The ninhydrin and colorimetric methods were not different from each other, both of which could be used as screening methodologies. Among the three techniques, HPLC was the most sensitive methodology for the detection and quantification of serum in refrigerated raw milk.(AU)
Assuntos
Cromatografia/estatística & dados numéricos , Ninidrina/síntese química , Soro do Leite/diagnóstico por imagemRESUMO
O objetivo deste experimento foi comparar três métodos analíticos para determinação de soro em leite cru refrigerado: cromatografia líquida de alta eficiência, ninidrina ácida e colorimétrico adaptado. Foram coletadas 100 amostras de leite cru refrigerado de tanques de expansão. Estas, quando submetidas à análise pelo método da ninidrina ácida, apresentaram 10 (14,7%) amostras negativas e 58 (85,3%) positivas. O teor médio de ácido siálico encontrado na técnica da ninidrina foi de 5,58(g/mL, com valor mais frequente de 2,70(g/mL. Das 68 amostras negativas pela cromatografia líquida de alta eficiência, duas foram positivas (2,94%) e 66 (97,06%) negativas, quando analisadas pelo método colorimétrico. A frequência relativa de amostras positivas foi de 32%, com a CLAE apresentando a maior média de soro (14,37%), seguida do método colorimétrico (5,28%) e o da ninidrina ácida (3,12%). A técnica de cromatografia líquida de alta eficiência diferiu dos métodos de ninidrina ácida e colorimétrico, enquanto os métodos da ninidrina e colorimétrico não diferiram entre si, podendo ambos serem utilizados como metodologias de triagem. Entre as três técnicas, a cromatografia líquida de alta eficiência foi a metodologia mais sensível na detecção e quantificação do soro em leite cru refrigerado.(AU)
The objective of this study was to compare three analytical methods to determine serum in refrigerated raw milk. High-performance liquid chromatography (HPLC), acidic and colorimetric ninhydrin methods were applied. A collection of 100 samples of raw milk from cooled expansion tanks took place. The results showed that 10 samples (14.7%) were negative and 58 (85.3%) were positive for the acidic ninhydrin method. The mean sialic acid content found in the ninhydrin technique was 5.58µg/mL, with a more frequent value of 2.70µg/mL. From all 68 HPLC negative samples, two were positive (2.94%) and 66 (97.06%) negative to the colorimetric method. The relative frequency of positive samples was 32%, HPLC had the highest mean serum levels (14.37%), followed by the colorimetric method (5.28%) and acid ninhydrin (3.12%). The high-performance liquid chromatography method was different from the acid and colorimetric ninhydrin methods. The ninhydrin and colorimetric methods were not different from each other, both of which could be used as screening methodologies. Among the three techniques, HPLC was the most sensitive methodology for the detection and quantification of serum in refrigerated raw milk.(AU)
Assuntos
Ninidrina/síntese química , Cromatografia , Soro do LeiteRESUMO
This work reports the setting up of the X-ray diffraction and spectroscopy beamline at the Brazilian Synchrotron Light Laboratory for performing total scattering experiments to be analyzed by atomic pair distribution function (PDF) studies. The results of a PDF refinement for Al2O3 standard are presented and compared with data acquired at a beamline of the Advanced Photon Source, where it is common to perform this type of experiment. A preliminary characterization of the Pb1-xLaxZr0.40Ti0.60O3 ferroelectric system, with x = 0.11, 0.12 and 0.15, is also shown.
RESUMO
The objective of this study was to evaluate the physical and sensory characteristics of tilapia (Oreochromis niloticus) reared in freshwater and saltwater environments. The microbiological quality of the samples was evaluated by determination of the most probable number of coliform bacteria at 35C and 45C and by the detection of Staphylococcus spp. and Salmonella sp. For physical evaluation, the pH, color, texture, cooking loss, and water-retention capacity (WRC) were determined. Sensory analysis was performed by 30 trained tasters of both sexes and the following attributes were evaluated: color, flavor, odor, texture, and juiciness. There was a significant difference in pH between the two treatments (P>0.05), as well as in WRC and texture. The findings were uniform in terms of color (L*, a* and b*). The results of microbiological analysis were lower than those established by the current legislation, with the samples being adequate for consumption. No significant differences were observed in the sensory parameters, except for color. Rearing tilapia in a saltwater environment resulted in greater pH and WRC, better texture, and less cooking losses than freshwater-reared tilapia. The sensory characteristics flavor, odor, texture and juiciness are similar, but tasters prefer saltwater-reared tilapia (paired comparison).
O presente estudo teve como objetivo avaliar as características físicas e sensoriais da tilápia (Oreochromis niloticus), cultivada em ambiente de água doce e salgada. Para atestar a qualidade microbiológica das amostras foi determinado o número mais provável de coliformes a 35C e 45C, detecção de Staphylococcus spp. e Salmonella sp. Para a avaliação física, foram verificados o potencial hidrogeniônico (pH), cor, textura, perda de peso por cocção (PPC) e capacidade de retenção de água (CRA). A análise sensorial foi realizada com 30 provadores treinados, de ambos os sexos e foram avaliados os atributos de cor, sabor, odor, textura e suculência. Houve diferença significativa de pH entre os dois tratamentos (P>0,05), bem como CRA e textura. Com relação a cor (L*, a* e b*), os resultados apresentaram uniformidade. Nas análises microbiológicas, as amostras apresentaram resultados inferiores aos estabelecidos pela legislação vigente, estando próprias para o consumo. Nos parâmetros sensoriais, não houve diferenças significativas no sabor, odor, suculência e textura, diferindo apenas a cor. O cultivo da tilápia em ambiente de água salgada proporciona maior pH, capacidade de retenção de água, textura e menor peso por cocção em relação ao cultivo da tilápia em água doce...
Assuntos
Animais , Ciclídeos , Pesqueiros , Sensação , Água Doce/análise , Águas Salinas/análiseRESUMO
The objective of this study was to evaluate the physical and sensory characteristics of tilapia (Oreochromis niloticus) reared in freshwater and saltwater environments. The microbiological quality of the samples was evaluated by determination of the most probable number of coliform bacteria at 35C and 45C and by the detection of Staphylococcus spp. and Salmonella sp. For physical evaluation, the pH, color, texture, cooking loss, and water-retention capacity (WRC) were determined. Sensory analysis was performed by 30 trained tasters of both sexes and the following attributes were evaluated: color, flavor, odor, texture, and juiciness. There was a significant difference in pH between the two treatments (P>0.05), as well as in WRC and texture. The findings were uniform in terms of color (L*, a* and b*). The results of microbiological analysis were lower than those established by the current legislation, with the samples being adequate for consumption. No significant differences were observed in the sensory parameters, except for color. Rearing tilapia in a saltwater environment resulted in greater pH and WRC, better texture, and less cooking losses than freshwater-reared tilapia. The sensory characteristics flavor, odor, texture and juiciness are similar, but tasters prefer saltwater-reared tilapia (paired comparison).(AU)
O presente estudo teve como objetivo avaliar as características físicas e sensoriais da tilápia (Oreochromis niloticus), cultivada em ambiente de água doce e salgada. Para atestar a qualidade microbiológica das amostras foi determinado o número mais provável de coliformes a 35C e 45C, detecção de Staphylococcus spp. e Salmonella sp. Para a avaliação física, foram verificados o potencial hidrogeniônico (pH), cor, textura, perda de peso por cocção (PPC) e capacidade de retenção de água (CRA). A análise sensorial foi realizada com 30 provadores treinados, de ambos os sexos e foram avaliados os atributos de cor, sabor, odor, textura e suculência. Houve diferença significativa de pH entre os dois tratamentos (P>0,05), bem como CRA e textura. Com relação a cor (L*, a* e b*), os resultados apresentaram uniformidade. Nas análises microbiológicas, as amostras apresentaram resultados inferiores aos estabelecidos pela legislação vigente, estando próprias para o consumo. Nos parâmetros sensoriais, não houve diferenças significativas no sabor, odor, suculência e textura, diferindo apenas a cor. O cultivo da tilápia em ambiente de água salgada proporciona maior pH, capacidade de retenção de água, textura e menor peso por cocção em relação ao cultivo da tilápia em água doce...(AU)
Assuntos
Animais , Ciclídeos , Pesqueiros , Água Doce/análise , Águas Salinas/análise , SensaçãoRESUMO
Ceria (CeO2) is a promising dilute magnetic semiconductor. Several studies report that the intrinsic and extrinsic structural defects are responsible for room temperature ferromagnetism in undoped and transition metal doped CeO2 nanostructures; however, the nature of the kind of defect necessary to promote and stabilize the ferromagnetism in such a system is still a matter of debate. In the work presented here, nanorods from the system Ce1-xCuxO2-δ with x = 0, 0.01, 0.03, 0.05 and 0.10, with the more stable {111} surface exposed were synthesized by a microwave-assisted hydrothermal method. A very careful structure characterization confirms that the Cu in the samples assumes a majority 2+ oxidation state, occupying the Ce (Ce(4+) and Ce(3+)) sites with no secondary phases up to x = 0.05. The inclusion of the Cu(2+) in the CeO2 structure leads to the introduction of oxygen vacancies in a density proportional to the Cu(2+) content. It is supposed that the spatial distribution of the oxygen vacancies follows the Cu(2+) distribution by means of the formation of a defect complex consisting of Cu(2+) ion and an oxygen vacancy. Superconducting quantum interference device magnetometry demonstrated a diamagnetic behavior for the undoped sample and a typical paramagnetic Curie-Weiss behavior with antiferromagnetic interactions between the Cu(2+) ions for the single phase doped samples. We suggest that the presence of oxygen vacancies is not a sufficient condition to mediate ferromagnetism in the CeO2 system, and only oxygen vacancies in the surface of nanostructures would lead to such a long range magnetic order.
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
Plantas Medicinais/classificação , Ecossistema Amazônico/classificação , Rubiaceae/metabolismo , Artemia/anatomia & histologia , Rubiaceae/classificação , Citotoxinas , Antifúngicos/farmacologia , Antioxidantes/farmacologiaRESUMO
Vários aspectos relacionados à mastite bubalina precisam ser esclarecidos. Muitas condutas são adaptadas a essa espécie pelo conhecimento adquirido com a espécie bovina. Com este experimento, objetivou-se evidenciar particularidades da mastite em búfalas e vacas que tiveram uma glândula inoculada com 1,0 x 103 UFC de S. aureus. Os animais foram monitorados por cultura bacteriana do leite, California Mastitis Test (CMT), e escores para avaliação da severidade da mastite. Foram utilizados os seguintes critérios: temperatura retal, apetite, produção de leite (resposta sistêmica à inflamação), contagem de células somáticas (CCS), aparência/consistência da glândula e aparência da secreção láctea (resposta localizada à inflamação). Todos os animais desenvolveram mastite clínica superaguda. A bactéria foi recuperada de todas as glândulas desafiadas, sem diferença significativa no percentual de isolamento entre as espécies até o 11º dia pós-inoculação, porém com diferença (P<0,001) no 30º dia pós-inoculação. A CCS pelo método eletrônico e o CMT detectaram nas búfalas resposta mais intensa logo após a inoculação e diminuição mais rápida da contagem ao final do experimento, quando se comparou essa espécie com as vacas. Ambos os testes demonstraram correlação com a cultura bacteriana. Na avaliação da severidade da mastite, as médias do escore total, do escore da resposta local e do escore da resposta sistêmica foram mais elevadas na espécie bovina (P<0,05). Ao longo do período de observação, verificou-se uma capacidade superior das búfalas em recuperar o status sanitário adequado, chegando, ao final do experimento, com os parâmetros avaliados mais próximos dos fisiológicos...
Several aspects related to bubaline mastits need to be clarified. Many conducts are adapted to this species by the knowledge adquired with the bovine species. This experiment aimed to evidence particularities of mastits in buffaloes and cows submitted to one-gland inoculation with 1.0 x 103 CFU of S. aureus. The animals were monitored through bacterial culturing milk, California Mastitis Test (CMT) and scores to assess the severity of mastitis. The following criteria were used: rectal temperature, appetite, milk production (systemic response to inflammation), somatic cell count (SCC), appearance/consistency of the gland and appearance of the milk secretion (localized response to inflammation). All animals developed hyperacute clinical mastitis. The bacteria was recovered from all challenged glands, with no significant difference in the percentage of isolation between the species until day 11 after inoculation, but with a difference (p<0.001) on day 30 post inoculation. The SCC with the electronic method and CMT, detected in buffaloes a more intense response right after the inoculation and a faster decrease of counting by the end of the experiment, when compared to cows. In both tests correlation with the bacterial culture was detected. In assessing the severity of mastitis, the averages of total score, of the score of local response and the systemic response score were higher in the bovine species (P<0.05). Throughout the observation period, there was a higher capacity of buffaloes in reaching the appropriate sanitary status, coming to the end of the experiment with the parameters closer to the physiological...
Assuntos
Animais , Bovinos , Búfalos , Mastite Bovina , Índice de Gravidade de Doença , Fenômenos Fisiológicos Bacterianos , Inflamação/veterinária , Staphylococcus aureusRESUMO
Vários aspectos relacionados à mastite bubalina precisam ser esclarecidos. Muitas condutas são adaptadas a essa espécie pelo conhecimento adquirido com a espécie bovina. Com este experimento, objetivou-se evidenciar particularidades da mastite em búfalas e vacas que tiveram uma glândula inoculada com 1,0 x 103 UFC de S. aureus. Os animais foram monitorados por cultura bacteriana do leite, California Mastitis Test (CMT), e escores para avaliação da severidade da mastite. Foram utilizados os seguintes critérios: temperatura retal, apetite, produção de leite (resposta sistêmica à inflamação), contagem de células somáticas (CCS), aparência/consistência da glândula e aparência da secreção láctea (resposta localizada à inflamação). Todos os animais desenvolveram mastite clínica superaguda. A bactéria foi recuperada de todas as glândulas desafiadas, sem diferença significativa no percentual de isolamento entre as espécies até o 11º dia pós-inoculação, porém com diferença (P<0,001) no 30º dia pós-inoculação. A CCS pelo método eletrônico e o CMT detectaram nas búfalas resposta mais intensa logo após a inoculação e diminuição mais rápida da contagem ao final do experimento, quando se comparou essa espécie com as vacas. Ambos os testes demonstraram correlação com a cultura bacteriana. Na avaliação da severidade da mastite, as médias do escore total, do escore da resposta local e do escore da resposta sistêmica foram mais elevadas na espécie bovina (P<0,05). Ao longo do período de observação, verificou-se uma capacidade superior das búfalas em recuperar o status sanitário adequado, chegando, ao final do experimento, com os parâmetros avaliados mais próximos dos fisiológicos.(AU)
Several aspects related to bubaline mastits need to be clarified. Many conducts are adapted to this species by the knowledge adquired with the bovine species. This experiment aimed to evidence particularities of mastits in buffaloes and cows submitted to one-gland inoculation with 1.0 x 103 CFU of S. aureus. The animals were monitored through bacterial culturing milk, California Mastitis Test (CMT) and scores to assess the severity of mastitis. The following criteria were used: rectal temperature, appetite, milk production (systemic response to inflammation), somatic cell count (SCC), appearance/consistency of the gland and appearance of the milk secretion (localized response to inflammation). All animals developed hyperacute clinical mastitis. The bacteria was recovered from all challenged glands, with no significant difference in the percentage of isolation between the species until day 11 after inoculation, but with a difference (p<0.001) on day 30 post inoculation. The SCC with the electronic method and CMT, detected in buffaloes a more intense response right after the inoculation and a faster decrease of counting by the end of the experiment, when compared to cows. In both tests correlation with the bacterial culture was detected. In assessing the severity of mastitis, the averages of total score, of the score of local response and the systemic response score were higher in the bovine species (P<0.05). Throughout the observation period, there was a higher capacity of buffaloes in reaching the appropriate sanitary status, coming to the end of the experiment with the parameters closer to the physiological.(AU)
Assuntos
Animais , Bovinos , Mastite Bovina , Búfalos , Índice de Gravidade de Doença , Staphylococcus aureus , Inflamação/veterinária , Fenômenos Fisiológicos BacterianosRESUMO
Determinou-se o efeito da contagem de células somáticas do leite sobre o rendimento e a composição físico-química do queijo muçarela. Foram selecionadas vacas com contagem de células somáticas (CCS) <200.000 células/mL; CCS >200.000 a <400.000 células/mL; CCS >400.000 células/mL a <750.000 células/mL e CCS >750.000 células/mL e que não receberam tratamento com antimicrobianos nos dias que antecederam a obtenção do leite utilizado no processamento. Os queijos foram avaliados por meio das análises de pH, acidez, umidade, proteína, gordura, extrato seco total e desengordurado. Os queijos elaborados do leite com alta CCS >750.000 cél./mL apresentaram menor teor de proteína, maior umidade e menor rendimento industrial. Conclui-se que a elevação da CCS cursou com alterações na qualidade do queijo muçarela, o que reflete em sua composição nutricional e microbiológica, pois ocorre um incremento na atividade de água, fator intrínseco indispensável para o crescimento microbiano e consequente redução da vida de prateleira...
The effect of somatic cell count (SCC) on the yield and composition of mozzarella cheese was evaluated. Cows with different levels of SCC in their milk (<200.000 cells/mL; >200.000 to <400.000 cells/mL; >400.000 cells/mL to <750.000 cells/mL and >750.000 cells/mL) were selected. The animals had no antimicrobial treatment prior to or on milk sampling day. The mozzarella cheese quality was evaluated analyzing pH, acidity, moisture and protein content, fat, total solids and nonfat solids. The trial was replicated four times and the experimental design was analyzed through randomized blocks. The mozzarella cheese from milk with high SCC (>750.000 cells/mL) had lower protein content, higher moisture content and lower industrial yield, compared to cheese from milk with lower levels of SCC. High numbers of SCC impaired mozzarella cheese quality, which was reflected in its nutritional and microbiological composition. We observed an increase in water activity, an intrinsic and essential factor for microbial growth...
Assuntos
Animais , Feminino , Bovinos , Bovinos , Qualidade dos Alimentos , Mastite , Queijo/análise , Análise de AlimentosRESUMO
Determinou-se o efeito da contagem de células somáticas do leite sobre o rendimento e a composição físico-química do queijo muçarela. Foram selecionadas vacas com contagem de células somáticas (CCS) <200.000 células/mL; CCS >200.000 a <400.000 células/mL; CCS >400.000 células/mL a <750.000 células/mL e CCS >750.000 células/mL e que não receberam tratamento com antimicrobianos nos dias que antecederam a obtenção do leite utilizado no processamento. Os queijos foram avaliados por meio das análises de pH, acidez, umidade, proteína, gordura, extrato seco total e desengordurado. Os queijos elaborados do leite com alta CCS >750.000 cél./mL apresentaram menor teor de proteína, maior umidade e menor rendimento industrial. Conclui-se que a elevação da CCS cursou com alterações na qualidade do queijo muçarela, o que reflete em sua composição nutricional e microbiológica, pois ocorre um incremento na atividade de água, fator intrínseco indispensável para o crescimento microbiano e consequente redução da vida de prateleira.(AU)
The effect of somatic cell count (SCC) on the yield and composition of mozzarella cheese was evaluated. Cows with different levels of SCC in their milk (<200.000 cells/mL; >200.000 to <400.000 cells/mL; >400.000 cells/mL to <750.000 cells/mL and >750.000 cells/mL) were selected. The animals had no antimicrobial treatment prior to or on milk sampling day. The mozzarella cheese quality was evaluated analyzing pH, acidity, moisture and protein content, fat, total solids and nonfat solids. The trial was replicated four times and the experimental design was analyzed through randomized blocks. The mozzarella cheese from milk with high SCC (>750.000 cells/mL) had lower protein content, higher moisture content and lower industrial yield, compared to cheese from milk with lower levels of SCC. High numbers of SCC impaired mozzarella cheese quality, which was reflected in its nutritional and microbiological composition. We observed an increase in water activity, an intrinsic and essential factor for microbial growth.(AU)
Assuntos
Animais , Feminino , Bovinos , Queijo/análise , Bovinos/fisiopatologia , Mastite , Qualidade dos Alimentos , Análise de AlimentosRESUMO
The aim of this study was to evaluate the antimicrobial activity of lapachol, α-lapachone, ß-lapachone and six antimicrobials (ampicillin, amoxicillin/clavulanic acid, cefoxitin, gentamicin, ciprofloxacin and meropenem) against twelve strains of Staphylococcus aureus from which resistance phenotypes were previously determined by the disk diffusion method. Five S. aureus strains (LFBM 01, LFBM 26, LFBM 28, LFBM 31 and LFBM 33) showed resistance to all antimicrobial agents tested and were selected for the study of the interaction between ß-lapachone and antimicrobial agents, busing checkerboard method. The criteria used to evaluate the synergistic activity were defined by the Fractional Inhibitory Concentration Index (FICI). Among the naphthoquinones, ß-lapachone was the most effective against S. aureus strains. FICI values ranged from 0.07 to 0.5, suggesting a synergistic interaction against multidrug resistant S. aureus (MRSA) strains. An additive effect was observed with the combination ß-lapachone/ciprofloxacin against the LFBM 33 strain. The combination of ß-lapachone with cefoxitin showed no added benefit against LFBM 31 and LFBM 33 strains. This study demonstrated that, in general, ß-lapachone combined with beta lactams antimicrobials, fluoroquinolones and carbapenems acts synergistically inhibiting MRSA strains.
Assuntos
Antibacterianos/farmacologia , Ciprofloxacina/farmacologia , Resistência a Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Naftoquinonas/farmacologia , Infecções Estafilocócicas/microbiologia , Tabebuia/química , Combinação de Medicamentos , Sinergismo Farmacológico , Humanos , Testes de Sensibilidade MicrobianaRESUMO
BACKGROUND: Proliferation of Leishmania infantum depends on exogenous inorganic phosphate (P(i)) but little is known about energy metabolism and transport of P(i) across the plasma membrane in Leishmania sp. METHODS: We investigated the kinetics of 32P(i) transport, the influence of H+ and K+ ionophores and inhibitors, and expression of the genes for the Na+:P(i) and H+:P(i) cotransporters. RESULTS: The proton ionophore FCCP, bafilomycin A1 (vacuolar ATPase inhibitor), nigericin (K+ ionophore) and SCH28080 (an inhibitor of H+, K(+)-ATPase) all inhibited the transport of P(i). This transport showed Michaelis-Menten kinetics with K0.5 and V(max) values of 0.016 +/- 0.002 mM and 564.9 +/- 18.06 pmol x h(-1) x 10(-7) cells, respectively. These values classify the P(i) transporter of L. infantum among the high-affinity transporters, a group that includes Pho84 of Saccharomyces cerevisiae. Two sequences were identified in the L. infantum genome that code for phosphate transporters. However, transcription of the PHO84 transporter was 10-fold higher than the PHO89 transporter in this parasite. Accordingly, P(i) transport and LiPho84 gene expression were modulated by environmental P(i) variations. CONCLUSIONS: These findings confirm the presence of a P(i) transporter in L. infantum, similar to PHO84 in S. cerevisiae, that contributes to the acquisition of inorganic phosphate and could be involved in growth and survival of the promastigote forms of L. infantum. GENERAL SIGNIFICANCE: This work provides the first description of a PHO84-like P(i) transporter in a Trypanosomatide parasite of the genus Leishmania, responsible for many infections worldwide.
Assuntos
Leishmania infantum/enzimologia , Fosfatos/metabolismo , Proteínas de Protozoários/metabolismo , Sequência de Aminoácidos , Transporte Biológico , Carbonil Cianeto p-Trifluormetoxifenil Hidrazona/farmacologia , Meios de Cultura , Inibidores Enzimáticos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Imidazóis/farmacologia , Cinética , Leishmania infantum/genética , Macrolídeos/farmacologia , Dados de Sequência Molecular , Nigericina/farmacologia , Fosfatos/farmacologia , Radioisótopos de Fósforo , Filogenia , Ionóforos de Próton/farmacologia , Simportadores de Próton-Fosfato/antagonistas & inibidores , Simportadores de Próton-Fosfato/genética , Simportadores de Próton-Fosfato/metabolismo , Proteínas de Protozoários/genética , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas Cotransportadoras de Sódio-Fosfato/antagonistas & inibidores , Proteínas Cotransportadoras de Sódio-Fosfato/metabolismo , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , ATPase Trocadora de Sódio-Potássio/metabolismo , ATPases Vacuolares Próton-Translocadoras/antagonistas & inibidores , ATPases Vacuolares Próton-Translocadoras/metabolismoRESUMO
A deterioração “blown pack” é caracterizada por abundante produção de gás e odor desagradável, induzindo à completa distensão da embalagem durante o processo de estocagem sob refrigeração de cortes cárneos embalados a vácuo. Assim, o objetivo deste trabalho foi o de determinar os possíveis microrganismos envolvidos nessa deterioração através da quantificação e caracterização das populações de Enterobacteriaceae e quantificação de bactérias ácido-lácticas, além da pesquisa de Clostridium estertheticum e Clostridium gasigenes, através da PCR, em carnes próprias para o consumo e em carnes que apresentaram a deterioração “blown pack”. Foram analisadas 54 peças de carne embaladas a vácuo, sendo 27 com deterioração e 27 sem deterioração. As populações médias de enterobactérias foram de 1,7x106 UFC/mL para amostras deterioradas e de 5,5x103 UFC/mL nas não deterioradas, d
RESUMO
A deterioração blown pack é caracterizada por abundante produção de gás e odor desagradável, induzindo à completa distensão da embalagem durante o processo de estocagem sob refrigeração de cortes cárneos embalados a vácuo. Assim, o objetivo deste trabalho foi o de determinar os possíveis microrganismos envolvidos nessa deterioração através da quantificação e caracterização das populações de Enterobacteriaceae e quantificação de bactérias ácido-lácticas, além da pesquisa de Clostridium estertheticum e Clostridium gasigenes, através da PCR, em carnes próprias para o consumo e em carnes que apresentaram a deterioração blown pack. Foram analisadas 54 peças de carne embaladas a vácuo, sendo 27 com deterioração e 27 sem deterioração. As populações médias de enterobactérias foram de 1,7x106 UFC/mL para amostras deterioradas e de 5,5x103 UFC/mL nas não deterioradas, d
RESUMO
"Blown pack" spoilage is characterized by abundant production of gas and off-odor leading to swelling of the packing of vacuum-packed chilled meat cuts. The aim of this study was to determine possible microorganisms involved in this spoilage by quantifying and characterizing the population of Enterobacteriaceae, quantifying lactic-acid bacteria, as well as researching Clostridium estertheticum and Clostridium gasigenes by PCR in meat proper for consumption and meat presenting "blown pack" spoilage. Fifty-four vacuum-packed meat cuts were analyzed, of which 27 were spoiled and 27 non-spoiled. Average enterobacteria population was 1.7x10° CFU/mL and 5.5x103 CFU/mL for spoiled and non-spoiled samples, respectively. Average lactic-acid bacteria population was 5.5x10 and 1.0x10 CFU/mL for spoiled and non-spoiled samples, respectively. The most prevalent enterobacteria species was Hafnia alvei. Meat showing "blown pack" spoilage had higher frequency of positive samples for Clostridium estertheticum. No statistically significant difference was observed in the population of Clostridium gasigenes between "blown pack" spoilage and non-spoiled meat. It was concluded that the most efficient method to control "blown pack" spoilage is to prevent meat contamination by fecal material.
A deterioração "blown pack" é caracterizada por abundante produção de gás e odor desagradável, induzindo à completa distensão da embalagem durante o processo de estocagem sob refrigeração de cortes cárneos embalados a vácuo. Assim, o objetivo deste trabalho foi o de determinar os possíveis microrganismos envolvidos nessa deterioração através da quantificação e caracterização das populações de Enterobacteriaceae e quantificação de bactérias ácido-lácticas, além da pesquisa de Clostridium estertheticum e Clostridium gasigenes, através da PCR, em carnes próprias para o consumo e em carnes que apresentaram a deterioração "blown pack". Foram analisadas 54 peças de carne embaladas a vácuo, sendo 27 com deterioração e 27 sem deterioração. As populações médias de enterobactérias foram de 1,7x10° UFC/mL para amostras deterioradas e de 5,5x10³ UFC/mL nas não deterioradas, de bactérias ácido-lácticas foram, respectivamente, de 5,5x108 e 1,0x10 UFC/mL. Dentre as enterobactérias, a espécie de maior prevalência foi Hafnia alvei. A maior frequência de amostras positivas para o Clostridium estertheticum foram aquelas apresentando a deterioração "blown pack". Não houve diferença estatística significativa para a presença do Clostridium gasigenes entre amostras com deterioração "blown pack" e carnes não deterioradas. Concluiu-se que a principal forma de controle desta deterioração é a prevenção da contaminação da carne por material fecal.
Assuntos
Clostridium/isolamento & purificação , Enterobacteriaceae/isolamento & purificação , Conservação de Alimentos/métodos , Carne/microbiologia , Inspeção de Alimentos , Embalagem de AlimentosRESUMO
AIM: This study compared the bond strength durability of a feldspathic veneering ceramic to glass-infiltrated reinforced ceramics in dry and aged conditions. METHODS: Disc shaped (thickness: 4 mm, diameter: 4 mm) of glass-infiltrated alumina (In-Ceram Alumina) and glass-infiltrated alumina reinforced by zirconia (In-Ceram Zirconia) core ceramic specimens (N=48, N=12 per groups) were constructed according to the manufacturers' recommendations. Veneering ceramic (VITA VM7) was fired onto the core ceramics using a mold. The core-veneering ceramic assemblies were randomly divided into two conditions and tested either immediately after specimen preparation (Dry) or following 30000 thermocycling (5-55 ºC±1; dwell time: 30 seconds). Shear bond strength test was performed in a universal testing machine (cross-head speed: 1 mm/min). Failure modes were analyzed using optical microscope (x20). The bond strength data (MPa) were analyzed using ANOVA (α=0.05). RESULTS: Thermocycling did not decrease the bond strength results for both In-Ceram Alumina (30.6±8.2 MPa; P=0.2053) and In-Ceram zirconia (32.6±9 MPa; P=0.3987) core ceramic-feldspathic veneering ceramic combinations when compared to non-aged conditions (28.1±6.4 MPa, 29.7±7.3 MPa, respectively). There were also no significant differences between adhesion of the veneering ceramic to either In-Ceram Alumina or In-Ceram Zirconia ceramics (P=0.3289). Failure types were predominantly a mixture of adhesive failure between the veneering and the core ceramic together with cohesive fracture of the veneering ceramic. CONCLUSION: Long-term thermocycling aging conditions did not impair the adhesion of the veneering ceramic to the glass-infiltrated alumina core ceramics tested.
Assuntos
Cerâmica , Porcelana Dentária , Facetas Dentárias , Temperatura Alta , Colagem Dentária , Falha de Equipamento , Vidro , Umidade , Técnicas In Vitro , Teste de Materiais , Distribuição Aleatória , Resistência ao Cisalhamento , Fatores de TempoRESUMO
Surface composition plays an important role in carbon nanotube dispersibility in different environments. Indeed, it determines the choice of dispersion medium. In this paper the effect of oxidation on the dispersion of HiPCO single-walled carbon nanotubes (SWNTs) in N-methyl-pyrrolidinone (NMP), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA), N-dodecyl-pyrrolidinone (N12P) and cyclohexyl-pyrrolidinone (CHP) was systematically studied. During the oxidation process, similar amounts of carboxylic acid and phenolic groups were introduced to mostly already existing defects. For each solvent the dispersion limits and the absorption coefficients were estimated by optical absorption analysis over a range of SWNT concentrations. The presence of acid oxygenated groups increased SWNT dispersibility in NMP, DMF and DMA, but decreased in N12P and CHP. The absorption coefficients, however, decreased for all solvents after oxidation, reflecting the weakening of the effective transition dipole of the π-π transition with even limited extension functionalization and solvent interaction. The analysis of the results in terms of Hansen and Flory-Huggins solubility parameters evidenced the influence of dipolar interactions and hydrogen bonding on the dispersibility of oxidized SWNTs.