RESUMEN
Non-thermal food processing and replacement of chemical additives by natural antimicrobials are promising trends in the food industry. The objective of the present work was to evaluate the effect of a process which combines mild high hydrostatic pressure - HHP (200 and 300â¯MPa, 5â¯min, 10⯰C), phage Listex™ P100 and the bacteriocin pediocin PA-1 as a new non-thermal process for destruction of Listeria monocytogenes (104â¯CFUâ¯mL-1 or 107â¯CFUâ¯mL-1) in milk. For inoculum levels of 104â¯CFUâ¯mL-1, HHP combined with phage P100 eliminated L. monocytogenes immediately after pressurization. When L. monocytogenes was inoculated at levels of 107â¯CFUâ¯mL-1, a synergistic effect between phage P100, pediocin PA-1 and HHP (300â¯MPa) on the inactivation of L. monocytogenes was observed during storage of milk at 4⯰C. For non-pressure treated samples inoculated with phage or pediocin or both, L. monocytogenes counts decreased immediately after biocontrol application, but regrowth was observed in a few samples during storage. Phage particles were stable during refrigerated storage for seven days while pediocin PA-1 remained stable only during three days. Further studies will have to be performed to validate the findings of this work in specific applications (e.g. production of raw milk cheese).
Asunto(s)
Bacteriófagos/fisiología , Conservación de Alimentos/métodos , Conservantes de Alimentos/farmacología , Listeria monocytogenes/efectos de los fármacos , Listeria monocytogenes/virología , Leche/microbiología , Pediocinas/farmacología , Animales , Bovinos , Recuento de Colonia Microbiana , Conservación de Alimentos/instrumentación , Presión Hidrostática , Listeria monocytogenes/química , Listeria monocytogenes/crecimiento & desarrolloRESUMEN
The application of lytic phages as biocontrol agents is emerging as a promising strategy towards elimination or reduction of foodborne pathogens in a variety of food products. This technology is particularly advantageous for minimally processed and ready-to-eat (RTE) foods. In this study, the potential use of Listex™ P100 combined with high hydrostatic pressure (HPP), to enhance the control of Listeria monocytogenes in food was evaluated. For that, the effect of three pressures (200, 300 or 400â¯MPa; 5â¯min, 10⯰C) on phage P100 stability was tested when inoculated in six different matrices: phosphate buffered saline (PBS, pH 7.4); apple juice (pH 3.41); orange/carrot nectar (pH 3.54); UHT whole milk (pH 6.73); and, two traditional Portuguese fermented products, "Serra da Estrela" cheese (pH 5.66) and "Alheira", a meat sausage (pH 6.07). The results showed that treatment at 400â¯MPa reduced phage titres to below the detection level in all matrices, whereas at milder pressures the survival of the phage was matrix dependent. "Alheira", "Serra da Estrela" cheese and UHT whole milk were shown to be baroprotective matrices that support phage P100 application in HHP up to 300â¯MPa; however, an accentuated phage inactivation was observed in apple and orange/carrot nectar, which may be related to the acidic pH values of these matrices. The initial phage load did not affect the inactivation rate during HHP processing (300â¯MPa, 5â¯min, 10⯰C) in PBS, cheese, sausage or milk matrices, and the phage titres were stable in these matrices during storage at 4⯰C for 28 days for milk and 60 days for "Alheira" and "Serra da Estrela" cheese. In addition, a baroprotective effect on phage stability was observed when PBS was supplemented with reducing sugars, dextrin, casein, and tween 80. In conclusion, at mild HHP treatment, phage P100 remained active in specific matrices and seems to present potential to be added in non-thermal inactivation of L. monocytogenes.
Asunto(s)
Bacteriófagos/fisiología , Queso/microbiología , Comida Rápida/microbiología , Conservación de Alimentos/métodos , Jugos de Frutas y Vegetales/microbiología , Listeria monocytogenes/virología , Productos de la Carne/microbiología , Leche/microbiología , Animales , Contaminación de Alimentos/prevención & control , Conservación de Alimentos/instrumentación , Presión Hidrostática , Listeria monocytogenes/fisiologíaRESUMEN
The regulation of protein kinase C (PKC) isoforms by ceramide is still controversial. In this work, the yeast Saccharomyces cerevisiae was used as a model to elucidate the effect of ceramide on the activity of mammalian PKC isoforms. For that, isc1Δ cells, with a deletion in the pathway for ceramide production by hydrolysis of complex sphingolipids, individually expressing mammalian PKCα, δ and ζ were used. Contrary to PKCα and ζ, expression of PKCδ in isc1Δ cells exhibited a similar phenotype to that observed with wild-type yeast cells expressing PKCδ treated with a PKC activator, as phorbol 12-myristate 13-acetate (PMA), specifically a growth inhibition associated with a G2/M cell cycle arrest. Interestingly, in isc1Δ yeast cells expressing PKCδ this phenotype was completely abrogated in the presence of exogenous ceramide. Moreover, using a yeast-based assay previously developed for the screening of PKC inhibitors, it was also shown that, like the known PKC inhibitor NPC 15437, ceramide reduced the PMA-induced growth inhibition, supporting an inhibitory effect of ceramide on PKCδ. Altogether, these results may indicate that ceramide distinctly interfere with the activity of PKCα, δ and ζ. Most importantly, they showed that ceramide is an inhibitor of PKCδ.
Asunto(s)
Ceramidas/metabolismo , Proteína Quinasa C/metabolismo , Saccharomyces cerevisiae/enzimología , Saccharomyces cerevisiae/fisiología , Ciclo Celular/efectos de los fármacos , Inhibidores Enzimáticos/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteína Quinasa C/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Saccharomyces cerevisiae/genéticaRESUMEN
The hitherto implemented Listeria monocytogenes detection techniques are cumbersome or require expensive non-portable instrumentation, hindering their transposition into on-time surveillance systems. The current work proposes a novel integrated system resorting to loop-mediated isothermal amplification (LAMP), assisted by a bacteriophage P100-magnetic platform, coupled to an endpoint electrochemical technique, towards L. monocytogenes expeditious detection. Molybdophosphate-based optimization of the bacterial phagomagnetic separation protocol allowed the determination of the optimal parameters for its execution (pH 7, 25 °C, 32 µg of magnetic particles; 60.6% of specific capture efficiency). The novel LAMP method targeting prfA was highly specific, accomplishing 100% inclusivity (for 61 L. monocytogenes strains) and 100% exclusivity (towards 42 non-target Gram-positive and Gram-negative bacteria). As a proof-of-concept, the developed scheme was successfully validated in pasteurized milk spiked with L. monocytogenes. The phagomagnetic-based approach succeeded in the selective bacterial capture and ensuing lysis, triggering Listeria DNA leakage, which was efficiently LAMP amplified. Methylene blue-based electrochemical detection of LAMP amplicons was accomplished in 20 min with remarkable analytical sensitivity (1 CFU mL-1). Hence, the combined system presented an outstanding performance and robustness, providing a 2.5 h-swift, portable, cost-efficient detection scheme for decentralized on-field application.
Asunto(s)
Listeria monocytogenes , Listeria monocytogenes/genética , Técnicas de Amplificación de Ácido Nucleico/métodos , Antibacterianos , Bacterias Gramnegativas/genética , Bacterias Grampositivas/genética , ADN , Sensibilidad y Especificidad , Microbiología de AlimentosRESUMEN
Traditional foods are increasingly valued by consumers, whose attention and purchase willingness are highly influenced by other claims such as 'natural', 'sustainable', and 'clean label'. The purpose of the present study was to evaluate the impact of a novel non-thermal food processing method (i.e., HPP-assisted biocontrol combining mild high hydrostatic pressure, listeriophage Listex, and pediocin PA-1 producing Pediococcus acidilactici) on the succession of bacterial communities and quality of a fermented sausage model. A comparative analysis of instrumental color, texture, and lipid peroxidation revealed no significant differences (p > 0.05) in these quality parameters between non- and minimally processed fermented sausages throughout 60-day refrigerated storage (4 °C). The microbiota dynamics of biotreated and untreated fermented sausages were assessed by 16S rRNA next-generation sequencing, and the alpha and beta diversity analyses revealed no dissimilarity in the structure and composition of the bacterial communities over the analyzed period. The innovative multi-hurdle technology proposed herein holds valuable potential for the manufacture of traditional fermented sausages while preserving their unique intrinsic characteristics.
RESUMEN
Lactic acid bacteria (LAB) have been documented as potential vitamin B12 producers and may constitute an exogenous source of cobalamin for the microalga Chlorella vulgaris, which has been described as being able to perform vitamin uptake. Hence, there is an interest in discovering novel B12-producing probiotic LAB. Therefore, the purpose of the current work was to perform a phenotype-genotype analysis of the vitamin B12 biosynthesis capacity of LAB isolated from C. vulgaris bioreactors, and investigate their probiotic potential. Among the selected strains, Lactococcus lactis E32, Levilactobacillus brevis G31, and Pediococcus pentosaceus L51 demonstrated vitamin B12 biosynthesis capacity, with the latter producing the highest (28.19 ± 2.27 pg mL-1). The genomic analysis confirmed the presence of pivotal genes involved in different steps of the biosynthetic pathway (hemL, cbiT, cobC, and cobD). Notably, P. pentosaceus L51 was the only strain harboring cobA, pduU, and pduV genes, which may provide evidence for the presence of the cobalamin operon. All strains demonstrated the capability to withstand harsh gastrointestinal conditions, although P. pentosaceus L51 was more resilient. The potential for de novo cobalamin biosynthesis and remarkable probiotic features highlighted that P. pentosaceus L51 may be considered the most promising candidate strain for developing high-content vitamin B12 formulations.
RESUMEN
Consumers' quest for healthier, locally produced foods, renders the demand for these products increasingly prominent. The purpose of the present work was to evaluate the impact of a non-thermal multi-hurdle approach, which associated mild high hydrostatic pressure (HHP, 300 MPa), the bacteriophage Listex™ P100, and the pediocin PA-1 producing Pediococcus acidilactici HA 6111-2, as a novel minimal processing towards Listeria monocytogenes eradication in Alheira (a traditional fermented meat sausage from Northern Portugal). The combination of the three hurdles achieved the USDA-FSIS 5 log reduction (in accordance with the standard guidelines for ready-to-eat foods), being the only treatment to elicit the absence of L. monocytogenes immediately following processing (p < 0.05). The pair association of HHP with Listex™ P100 was unable to eliminate L. monocytogenes, whilst in the HHP-pediocin PA-1 producing P. acidilactici treated samples the eradication was delayed when compared to the three hurdles combination. In addition to the listericidal effect of the HHP-phage-lactic acid bacterium treatment, no significant differences (p > 0.05) in the pH values were observed, and the semi-quantification of the in situ biosynthesized pediocin PA-1 was documented for the first time in a fermented meat sausage model.
Asunto(s)
Bacteriófagos , Listeria monocytogenes , Productos de la Carne , Pediococcus acidilactici , CarneRESUMEN
Alcohol withdrawal syndrome is an acute condition secondary to total or partial reduction of alcohol consumption, characterized by self limited signs and symptoms and different degrees of severity. It can be complicated by several clinical and/or other psychiatric related problems. The objective of this article is to review the most important psychiatric complications to alcohol withdrawal syndrome as well as other psychiatric disorders associated with alcohol dependence as Wernicke Korsakoff and Marchiava Bignami syndromes. We aim to promote early diagnosis and treatment of these conditions, minimizing morbidity and mortality associated with them.
Asunto(s)
Delirio por Abstinencia Alcohólica/psicología , Trastornos Mentales/etiología , Humanos , Síndrome de Korsakoff/psicologíaRESUMEN
Yeast has proven to be an efficient model system for functional and pharmacological studies of the p53 tumour suppressor protein. In this work, the human p53-MDMX regulatory pathway was reconstituted in yeast. Additionally, by using the known inhibitor of p53-MDMX interaction, SJ-172550, the efficacy of a simplified yeast-based screening assay to search for inhibitors of p53-MDMX interaction is demonstrated for the first time. Moreover, further insights on p53 transcriptional activity in yeast are provided. In particular, it is shown that the reported wild-type (wt) p53-induced yeast growth inhibition and cell cycle arrest is associated with actin depolarization and with an increase of actin mRNA and protein expression levels. The increase of actin protein levels was not observed with the p53 R273H mutant (a loss of function p53 mutation hotspot) and was further intensified with the toxic p53 V122A mutant (reported to exhibit higher transcriptional activity than wt p53 for selected p53 target sequences). Moreover, it is shown that the wt p53-induced actin protein levels are modulated by natural (MDM2 and MDMX) and chemical (pifithrin-α, nutlin-3a and SJ-172550) regulators of p53 activity. Furthermore, wt p53 could stimulate transcription from a minimal promoter containing a fragment of the ACT1 upstream sequence. Thus, ACT1 is proposed as a putative endogenous p53 target gene. This finding may open the way for the development of simpler yeast p53 transactivation assays, not based on artificial reporter constructs, for the analysis of the impact of mutants, cofactors and small molecules on p53 transcriptional activity.
Asunto(s)
Actinas/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Ensayos Analíticos de Alto Rendimiento , Proteínas Nucleares/metabolismo , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Acetatos/farmacología , Actinas/genética , Western Blotting , Proteínas de Ciclo Celular , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Humanos , Luciferasas/metabolismo , Mutación/genética , Proteínas Nucleares/antagonistas & inhibidores , Proteínas Nucleares/genética , Regiones Promotoras Genéticas/genética , Proteínas Proto-Oncogénicas/antagonistas & inhibidores , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas c-mdm2/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-mdm2/genética , Pirazoles/farmacología , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crecimiento & desarrollo , Proteína p53 Supresora de Tumor/antagonistas & inhibidores , Proteína p53 Supresora de Tumor/genéticaRESUMEN
A síndrome de abstinência alcoólica é um quadro agudo, caracterizado por um conjunto de sinais e sintomas autolimitados, com gravidade variada, secundário à interrupcão total ou parcial do consumo de álcool, podendo ser associado a inúmeros problemas clínicos e/ou outros transtornos psiquiátricos. O objetivo deste artigo é rever as principais complicacões psiquiátricas secundárias à síndrome de abstinência alcoólica, como convulsões e delirium tremens, bem como algumas outras condicões psiquiátricas associadas à dependência de álcool, como as síndromes de Wernicke Korsakoff e de Marchiava Bignami. Pretende-se, com isso, auxiliar no diagnóstico precoce e tratamento adequado, minimizando assim a morbidade e a mortalidade associadas a tais complicacões.
Asunto(s)
Humanos , Delirio por Abstinencia Alcohólica/complicaciones , Trastornos Mentales/etiología , Delirio por Abstinencia Alcohólica/psicología , Síndrome de Korsakoff/complicaciones , Síndrome de Korsakoff/psicologíaRESUMEN
O presente estudo visa encontrar e analisar o perfil cognitivo de pacientes com esquizofrenia e posterior correlacao com os achados psicopatologicos, na busca de criterios clinicos mais abrangentes e esclarecedores para o diagnostico. A partir de entrevista com SCID-DSM-IV selecionou-se 53 pacientes esquizofrenicos. Inicialmente estes foram classificados segundo os achados psicopatologicos como positivos, negativos e desorganizados, porem de acordo com a gravidade destas dimensoes no curso do transtorno. Foram submetidos a testagem neuropsicologica, sendo selecionados parametros visando o enfoque sobre os circuitos subcortico-frontais, temporais (limbicos) e difencas entre processamento verbal e visual. A exploracao da amostra foi feita com rede neural artificial ART, metodo de analise nao-parametrica e nao-linear, visando a busca de agrupamentos segundo padroes completos dos achados. A rede neural foi capaz de identificar um grupo (I) que se mostrou coeso, mesmo a imposicao da variacao do numero de agrupamentos a rede neural. Este grupo apresentou ao exame neuropsicologico evidencias de disfuncao dos circuitos subcortico-frontais difusamente e predominio de sintomas negativos e desorganizados, que nao foram separados com os parametros utilizados. Outro grupo formado (II) mostrou-se menos coeso, reagrupando-se segundo variacoes do numero de agrupamentos impostas a rede neural, sugerindo uma dimensao de achados. Nestes pacientes houve tambem evidencia de disfuncao de circuitos subcortico-frontais, porem verificou-se tendencia a lateralizacao dos achados, com superioridade do processamento de material visual sobre o verbal. Correlacionando-se a psicopatologia observou-se que a dimensao de sintomas positivos era pedominante com relacao aos sintomas negativos e desorganizados. Considerando-se que os achados neuropsicologicos, a diferenca dos psicopatologicos, se mostram estaveis no curso do transtorno, permitem determinar tendencias evolutivas e padroes neuropsicologicos, uteis para programar realbilitacao cognitiva.
Asunto(s)
Neuropsicología , Esquizofrenia , Psicopatología , Neuropsicología , Esquizofrenia , PsicopatologíaRESUMEN
O presente estudo visa encontrar e analisar o perfil cognitivo de pacientes com esuizofrenia e posterior correlaçäo com os achados psicopatológicos, na busca de critérios clínicos mais abrangentes e esclarecedores para o diagnóstico. A partir de entrevista com SCID-DSM-IV selecionou-se 53 pacientes esquizofrênicos. Inicialmente estes foram classificados segundo os achados psicopatológicos como positivos, negativos e desorganizados, porém de acordo com a gravidade destas dimensöes no curso do transtorno. Foram submetidos a testagem neuropsicológica, sendo selecionados parâmetros visando o enfoque sobre os circuitos subcórtico-frontais, temporais (límbicos) e diferenças entre procedimento verbal e visual. A exploraçäo da amostra foi feita com rede neural artificial ART, método de análise näo-paramétrica e näo-linear, visando a busca de agrupamentos segundo padröes completos dos achados. A rede neural foi capaz de identificar um grupo (I) que se mostrou coeso, mesmo à imposiçäo da variaçäo do número de agrupamentos à rede neural. Este grupo apresentou ao exame neuropsicológico evidências de disfunçäo dos circuitos subcórtico-frontais difusamente e predomínio de sintomas negativos e desorganizados, que näo foram separados com os parâmetros utilizados. Outro grupo formado (II) mostrou-se menos coeso, reagrupando-se segundo variaçöes do número de agrupamentos impostas à rede neural, sugerindo uma dimensäo de achados. Nestes pacientes houve também evidência de disfunçäo de circuitos subcórtico-frontais, porém verificou-se tendências à lateralizaçäo dos achados, com superioridade do processamento de material visual sobre o verbal. Correlacionando-se à psicopatologia observou-se que a dimensäo de sintomas positivos era predominante com relaçäo aos sintomas negativos e desorganizados. Considerando-se que os achados neuropsicológicos, à diferença dos psicopatológicos, se mostram estáveis no curso do transtorno, permitem determinar tendências evolutivas e padröes neuropsicológicos, úteis para programar reabilitaçäo cognitiva
Asunto(s)
Humanos , Red Nerviosa , Neuropsicología , Psicopatología , EsquizofreniaRESUMEN
The plant Maytenus ilicifolia (populary called "Espinheira Santa") is used in Brazilian folk medicine to combat gastroduodenal affections. Experimental evidence has sugested that the plant has anti-ulcer activity although its mechanism of action is still unknown. To determine a possible effect of the plant on Helicobacter pulori (HP0, the major agent involved in gastroduodenal ulcer, 10 patients with duodenal ulcer and infected with HP were studied. The diagnosis of the presence of HP and the quatitative evaluation of a possible anti-urease activity or the supressor and/or eradicating action of a dry extract of the plant on HP were performed by the (14)C-urea breath test (UBT). All patients were submitted to four UBT: the first upon admission to the study the second 20 min after the ingestion of a capsule containing 300 mg of a dry extract at 8-h intervals for one week, and the fourth one month after discontinuation of the preparation. One patient presented suppression of urease activity at the third UBT, but the activity had returned to basal values on the occasion of the fourth examination. We conclude that at the doses and formulation employed, Maytemus ilicifolia has no significant action against HP.
Asunto(s)
Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Ratas , Extractos Vegetales/uso terapéutico , Úlcera Péptica/tratamiento farmacológico , Brasil , Pruebas Respiratorias , Helicobacter pylori , Plantas MedicinalesRESUMEN
A Estratégia Saúde da Família é um Programa que teve início em meados de 1993, sendo regulamentado de fato em 1994, pelo Ministério da Saúde de forma que pudesse modificar a forma tradicional de prestação de assistência médica às comunidades mais carentes, visando estimular a implantação de um novo modelo de Atenção Primária que resolvesse em grande parte os problemas de saúde dessa população. O programa é realizado por profissionais da saúde, dentre os quais o enfermeiro, que foi construindo suas práticas entrelaçadas aos modelos de atenção à saúde, aos modos de organização dos serviços e ao processo de trabalho em saúde, vinculada aos contextos históricos e sociais. Em sua relação com o paciente hipertenso, a Estratégia Saúde da Família com a contribuição da enfermagem vem construindo e modificando seu trabalho, ampliando e diversificando suas atividades, de acordo com as transformações ocorridas pelos modelos de atenção à saúde das pessoas. Para compreender melhor sobre esta temática, este estudo descritivo, de revisão de literatura objetivou apreender sobre o trabalho do(a) enfermeiro(a) que atua, nos dias atuais, no Programa Estratégia Saúde da Família, em postos de saúde e sua contribuição quanto ao uso de propostas de intervenção e recuperação da saúde do hipertenso. Os referenciais teóricos foram retirados de autores como Gil (1994), Goleman (1995), Lima (1994), Silva (1989), Paixão (1979), além de pesquisa na Biblioteca Virtual de Saúde, utilizando como descritores estratégia saúde da família, enfermagem, perfil profissional, hipertenso. Nesta fundamentação, emergiram temas como: Enfermagem: do empirismo à ciência moderna, o Programa Estratégia Saúde da Família, a importância do(a) enfermeiro(a) no contexto do Programa e sua participação na prevenção da saúde e responsabilidade na vida do hipertenso. Com base neste estudo, a discussão indica que o ofício do(a) enfermeiro(a) é hoje, não apenas cuidador, pelo cuidado direto e a gerência deste cuidado, mas apresenta destaque no predomínio de um profissional ético, afetivo e que deve estar constantemente se atualizando, seja pelo uso amplo de tecnologias disponíveis, que potencializam as relações singulares de cuidar, ou pelo saber generalista, necessário para exercer esse trabalho. Espera-se que este trabalho seja uma contribuição aos profissionais da enfermagem, pela subjetividade de seu ofício como um saber e um fazer em relações, com responsabilidade e compromisso, e pelas formas de dominação e resistência às relações desiguais que toda e qualquer profissão recebe.