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1.
Mol Genet Metab ; 140(4): 107714, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37918171

RESUMO

Fabry disease (FD) is an X-linked lysosomal storage disease caused by pathogenic variants in the GLA gene. It has a wide range of clinical manifestations, typically related to the specific underlying GLA variant. One of the main features of FD is kidney involvement; therefore, several studies have addressed the prevalence of FD in all types of patients with chronic kidney disease. We performed a systematic review and meta-analysis of screening studies in chronic kidney disease patients, including those on dialysis, had undergone a kidney transplantation, and those who did not receive kidney replacement therapy, and assessed the prevalence of pathogenic variants in these cohorts. Fifty-five studies were included, involving a total of 84,062 individuals. Of these, 251 cases were positive for FD; a third of the reported GLA variants were of a benign phenotype (37.8%), followed by classical phenotype (31.7%), late onset (15.5%), and of uncertain significance (14.7%). The overall prevalence among dialysis patients was 0.10% (CI95%, 0.06-0.15), 0.28% (CI95%, 0.06-0.15) among patients with kidney transplantation, and 0.17% (CI95%, 0.11-0.39) among those without kidney replacement therapy. Although the overall prevalence of FD is low in patients with kidney involvement, screening, especially in patients who have not yet undergone kidney replacement therapy, is important, in order to provide timely and effective treatment interventions, including disease modifying therapies. The prevalence of kidney involvement in females with Fabry Disease is lower but this should not lead to inadequate follow up. Further research is also needed on the impact of genetic variants of uncertain significance to elucidate their role in Fabry disease.


Assuntos
Doença de Fabry , Insuficiência Renal Crônica , Feminino , Humanos , Doença de Fabry/complicações , Doença de Fabry/epidemiologia , Doença de Fabry/genética , alfa-Galactosidase/genética , Prevalência , Insuficiência Renal Crônica/epidemiologia , Insuficiência Renal Crônica/genética , Insuficiência Renal Crônica/terapia , Fenótipo , Mutação
2.
Rev. méd. (La Paz) ; 29(2): 11-20, 2023. Tab.
Artigo em Espanhol | LILACS | ID: biblio-1530239

RESUMO

OBJETIVO: Conocer la prevalencia al nacimiento de los defectos del tubo neural en recién nacidos del Hospital de la Mujer, La Paz, Bolivia, período comprendido entre el año 2008 - 2017. DISEÑO METODOLÓGICO: Observacional, descriptivo, de corte transversal, retrospectivo. LUGAR: Hospital de la Mujer, a 3650 m.s.n.m. La Paz, Bolivia. MÉTODOS: Se examinaron los expedientes clínicos de todos los recién nacidos del Hospital de la Mujer, en período ya establecido. Para la detección de anomalías congénitas, se utilizaron libros de registro de nacimientos. Se ingresaron los datos a una base Excel, se procedió al análisis de los mismos a través del uso de la estadística descriptiva. RESULTADOS: Se recurrió a registros de 58120 expedientes de recién nacidos, se presentaron 1269 casos con Anomalías Congénitas (2.2%) con una prevalencia al Nacimiento (PN) de 21.83/10.000 RN (22.57/10.000 RN vivos). De dichos 1269 casos, 69 (5.44%) correspondieron a Defectos del Tubo Neural (DTN), con una PN de 11.87/10.000 RN (12.27/10.000 RN vivos), 59.42% DTN asociados al sexo masculino. El tipo de DTN más frecuente evidenciado fue Mielomeningocele (52.17%), y los DTN mortinatos representan el 17.39%. CONCLUSIONS: La llamativa diferencia encontrada, (en relación a la predilección por el sexo masculino), podría sugerir la presencia de una carga genética cuantitativamente mayor (propia de la población estudiada) en la etiología de los DTN en nuestro medio, ya que cuando las condiciones multifactoriales como los DTN afectan al sexo menos frecuentemente descrito, se puede asumir un peso mayor de los factores genéticos en relación a factores ambientales, siguiendo conceptos de heredabilidad y la teoría del umbral para este modo de herencia, sin embargo, somos conscientes que se requiere un tamaño de muestra mayor para arribar a conclusiones más certeras, dichos factores se adicionan al subregistro y posibles sesgos de registro evidenciados durante la realización del estudio.


OBJECTIVE: To know the prevalence at birth of neural tube defects in newborns at Hospital de La Mujer, La Paz, Bolivia, 3650 m.a.s.l, period between 2008 - 2017. PLACE: Women's Hospital, La Paz, Bolivia. METHODS: Observational, descriptive, cross-sectional, retrospective. The clinical records of all newborns were examined, in an already established period. For the detection of congenital anomalies, birth registration books were used. The data were entered into an Excel database, and analyzed through the use of descriptive statistics. RESULTS: 58120 newborn records were examined, 1269 cases with Congenital Anomalies (2.2%) with a prevalence at Birth (PB) of 21.83/10.000 RN (22.57/10.000 RN alive) were presented. Of these 1269 cases, 69 (5,44%) corresponded to Neural Tube Defects (NTD), with a PB of 11.87/10,000 RN (12.27/10,000 RN alive), 59.42% DTN associated with the male sex. The most frequent type of NTD evidenced was Myelomeningocele (52.17%), and stillborn DTNs represented 17.39%. CONCLUSIONS: The distinctive difference found (predilection of NTD for the male sex), could suggest the presence of a quantitatively greater genetic load (typical of the population studied) in the etiology of NTDs in our environment, since when multifactorial conditions affect the less frequently described sex, a greater weight of genetic factors can be assumed compared to environmental factors, following concepts of heritability and the threshold theory for this mode of inheritance; however, we are aware that a larger sample size is needed to arrive at more accurate conclusions, these factors are added to the underreporting and possible recording biases evidenced during the study.

3.
Behav Res Methods ; 53(3): 1301-1307, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33037602

RESUMO

Psychophysical tests are commonly carried out using software applications running on desktop or laptop computers, but running the software on mobile handheld devices such as smartphones or tablets could have advantages in some situations. Here, we present StimuliApp, an open-source application in which the user can create psychophysical tests on the iPad and the iPhone by means of a system of menus. A wide number of templates for creating stimuli are available including patches, gradients, gratings, checkerboards, random-dots, texts, tones or auditory noise. Images, videos and audios stored in files could also be presented. The application was developed natively for iPadOS and iOS using the low-level interface Metal for accessing the graphics processing unit, which results in high timing performance.


Assuntos
Computadores de Mão , Smartphone , Humanos , Microcomputadores , Software
4.
Arq Bras Oftalmol ; 83(4): 323-328, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32756794

RESUMO

PURPOSE: To determine the frequency of ocular squamous surface neoplasia associated with pterygium in an ophthalmology reference center in Central Mexico. METHODS: We reviewed histopathological reports and slides of all patients who underwent pterygium surgery from 2014 to 2016 at the Instituto Mexicano de Oftalmologia in Queretaro (Mexico). RESULTS: We studied 177 biopsy samples; 66% were from women, and the median age was 52 years. We found ocular squamous surface neoplasias in 11.29% (n=20) of the samples. One biopsy sample revealed a poorly differentiated keratinizing and infiltrating carcinoma. CONCLUSIONS: The prevalence of ocular squamous surface neoplasia in our region appears to be high. Countrywide studies are necessary to determine the true prevalence of ocular squamous surface neoplasia in Mexico and to examine related risk factors.


Assuntos
Carcinoma de Células Escamosas , Neoplasias da Túnica Conjuntiva , Pterígio , Carcinoma de Células Escamosas/epidemiologia , Túnica Conjuntiva , Neoplasias da Túnica Conjuntiva/epidemiologia , Feminino , Humanos , México/epidemiologia , Pessoa de Meia-Idade , Pterígio/epidemiologia , Pterígio/etiologia
5.
Arq. bras. oftalmol ; 83(4): 323-328, July-Aug. 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1131616

RESUMO

ABSTRACT Purpose: To determine the frequency of ocular squamous surface neoplasia associated with pterygium in an ophthalmology reference center in Central Mexico. Methods: We reviewed histopathological reports and slides of all patients who underwent pterygium surgery from 2014 to 2016 at the Instituto Mexicano de Oftalmologia in Queretaro (Mexico). Results: We studied 177 biopsy samples; 66% were from women, and the median age was 52 years. We found ocular squamous surface neoplasias in 11.29% (n=20) of the samples. One biopsy sample revealed a poorly differentiated keratinizing and infiltrating carcinoma. Conclusions: The prevalence of ocular squamous surface neoplasia in our region appears to be high. Countrywide studies are necessary to determine the true prevalence of ocular squamous surface neoplasia in Mexico and to examine related risk factors.


RESUMO Objetivo: Determinar a frequência de neoplasia escamosa da superfície ocular associada ao pterígio com apresentação clínica, em um centro de referência em Oftalmologia da região central do México. Métodos: Revisamos os laudos histopatológicos e as lâminas de biópsia de todos os pacientes que foram submetidos à cirurgia de pterígio de 2014 a 2016 no Instituto Mexicano de Oftalmologia, na cidade de Querétaro. Resultados: Estudamos 177 amostras de biópsia; 66% eram de pacientes do sexo feminino, sendo a mediana da idade de 52 anos. Encontramos neoplasia escamosa da superfície ocular em 11,29% (n=20). Uma amostra de biópsia mostrou um carcinoma queratinizante infiltrativo pouco diferenciado. Conclusões: A prevalência da neoplasia escamosa da superfície ocular nessa região parece ser maior do que a indicada por outras pesquisas. Mais estudos de âmbito nacional são necessários para determinar a verdadeira prevalência da neoplasia escamosa da superfície ocular no México e examinar os fatores de risco relacionados.


Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Pterígio , Carcinoma de Células Escamosas , Carcinoma de Células Escamosas/epidemiologia , Túnica Conjuntiva , Neoplasias da Túnica Conjuntiva , Neoplasias da Túnica Conjuntiva/epidemiologia , Pterígio/etiologia , Pterígio/epidemiologia , México/epidemiologia
6.
Elife ; 82019 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-30916643

RESUMO

The contribution of sensory and decisional processes to perceptual decision making is still unclear, even in simple perceptual tasks. When decision makers need to select an action from a set of balanced alternatives, any tendency to choose one alternative more often-choice bias-is consistent with a bias in the sensory evidence, but also with a preference to select that alternative independently of the sensory evidence. To decouple sensory from decisional biases, here we asked humans to perform a simple perceptual discrimination task with two symmetric alternatives under two different task instructions. The instructions varied the response mapping between perception and the category of the alternatives. We found that from 32 participants, 30 exhibited sensory biases and 15 decisional biases. The decisional biases were consistent with a criterion change in a simple signal detection theory model. Perceptual decision making, thus, even in simple scenarios, is affected by sensory and decisional choice biases.


Assuntos
Viés , Tomada de Decisões , Percepção Visual , Humanos , Modelos Neurológicos
7.
Sci Rep ; 9(1): 120, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30644398

RESUMO

Putrescine and cadaverine are among the most common biogenic amines (BA) in foods, but it is advisable that their accumulation be avoided. Present knowledge about their toxicity is, however, limited; further research is needed if qualitative and quantitative risk assessments for foods are to be conducted. The present work describes a real-time analysis of the cytotoxicity of putrescine and cadaverine on intestinal cell cultures. Both BA were cytotoxic at concentrations found in BA-rich foods, although the cytotoxicity threshold for cadaverine was twice that of putrescine. Their mode of cytotoxic action was similar, with both BA causing cell necrosis; they did not induce apoptosis. The present results may help in establishing legal limits for both putrescine and cadaverine in food.


Assuntos
Aminas Biogênicas/análise , Cadaverina/análise , Análise de Alimentos/normas , Putrescina/análise , Apoptose/efeitos dos fármacos , Aminas Biogênicas/toxicidade , Cadaverina/toxicidade , Células Cultivadas , Citotoxinas/análise , Citotoxinas/farmacologia , Células HT29 , Humanos , Intestinos/citologia , Intestinos/efeitos dos fármacos , Necrose/induzido quimicamente , Putrescina/toxicidade
8.
Sci Rep ; 8(1): 16056, 2018 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-30375459

RESUMO

Motion perception of briefly displayed images has been reported to be abnormal in clinical populations afflicted with schizophrenia, major depression, autism, Alzheimer's disease and epilepsy. These abnormalities have been measured using CRT monitors connected to a computer. Given that the use of this experimental set-up in clinical environments can be difficult, we tested whether motion perception of briefly displayed images could also be measured using a tablet. For 13 participants, we found similar estimates of motion discrimination on a tablet and a CRT. This validates a tablet to measure motion perception of briefly displayed images.


Assuntos
Computadores , Processamento de Imagem Assistida por Computador/métodos , Percepção de Movimento/fisiologia , Adulto , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/fisiopatologia , Transtorno Autístico/diagnóstico por imagem , Transtorno Autístico/fisiopatologia , Transtorno Depressivo Maior/diagnóstico por imagem , Transtorno Depressivo Maior/fisiopatologia , Epilepsia/diagnóstico por imagem , Epilepsia/fisiopatologia , Feminino , Humanos , Masculino , Esquizofrenia/diagnóstico por imagem , Esquizofrenia/fisiopatologia
9.
Food Chem ; 269: 321-326, 2018 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-30100441

RESUMO

Spermine and spermidine are polyamines (PA) naturally present in all organisms, in which they have important physiological functions. However, an excess of PA has been associated with health risks. PA accumulates at quite high concentrations in some foods, but a quantitative assessment of the risk they pose has been lacking. In the present work, the cytotoxicity of spermine and spermidine was evaluated using an in vitro human intestinal cell model, and employing real-time cell analysis. Both spermine and spermidine showed a dose-dependent cytotoxic effect towards the cultured cells, with necrosis the mode of action of spermidine and perhaps also that of spermine. Spermine was more cytotoxic than spermidine, but for both PA the concentrations found to be toxic were above the maximum at which they have been found in food. The present results do not, therefore, support the idea that spermine or spermidine in food is harmful to healthy people.


Assuntos
Espermidina/toxicidade , Espermina/toxicidade , Células Cultivadas , Relação Dose-Resposta a Droga , Análise de Alimentos , Humanos , Intestinos , Poliaminas , Putrescina
10.
Front Microbiol ; 8: 846, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28572792

RESUMO

Consumer interest in healthy lifestyle and health-promoting natural products is a major driving force for the increasing global demand of biofunctional dairy foods. A number of commercial sources sell synthetic formulations of bioactive substances for use as dietary supplements. However, the bioactive-enrichment of health-oriented foods by naturally occurring microorganisms during dairy fermentation is in increased demand. While participating in milk fermentation, lactic acid bacteria can be exploited in situ as microbial sources for naturally enriching dairy products with a broad range of bioactive components that may cover different health aspects. Several of these bioactive metabolites are industrially and economically important, as they are claimed to exert diverse health-promoting activities on the consumer, such as anti-hypertensive, anti-inflammatory, and anti-diabetic, anti-oxidative, immune-modulatory, anti-cholesterolemic, or microbiome modulation. This review aims at discussing the potential of these health-supporting bacteria as starter or adjunct cultures for the elaboration of dairy foods with a broad spectrum of new functional properties and added value.

11.
Genome Announc ; 5(17)2017 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-28450504

RESUMO

Here is presented the whole-genome sequence of Streptococcus thermophilus APC151, isolated from a marine fish. This bacterium produces gamma-aminobutyric acid (GABA) in high yields and is biotechnologically suitable to produce naturally GABA-enriched biofunctional yogurt. Its complete genome comprises 2,097 genes and 1,839,134 nucleotides, with an average G+C content of 39.1%.

12.
Food Chem ; 218: 249-255, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-27719906

RESUMO

Tyramine and histamine are the biogenic amines (BA) most commonly found at high concentrations in food; they may even appear together at toxic concentrations. The present work examines, via real-time cell analysis, whether histamine and tyramine show synergistic toxicity towards intestinal cell cultures. Employing a constant equipotency ratio, their interaction was examined via the combination index (CI) method of Chou & Talalay. Co-treatment with tyramine and histamine was associated with a stronger cytotoxic effect than was treatment with either BA or on its own. Indeed, a synergistic interaction (CI<1) was observed in the range of concentrations found in foods. The results also show that histamine, at concentrations below the legal limit, increases the cytotoxicity of tyramine at concentrations frequently reached in some foods. The synergistic cytotoxicity of tyramine and histamine should be taken into account when establishing legal limits designed to ensure consumer safety.


Assuntos
Aminas Biogênicas/toxicidade , Células Epiteliais/efeitos dos fármacos , Histamina/toxicidade , Intestinos/citologia , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Análise de Alimentos , Células HT29/efeitos dos fármacos , Humanos , Intestinos/efeitos dos fármacos , Tiramina/toxicidade
13.
Front Microbiol ; 7: 1876, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27920772

RESUMO

Consumer interest in health-promoting food products is a major driving force for the increasing global demand of functional (probiotic) dairy foods. Yogurt is considered the ideal medium for delivery of beneficial functional ingredients. Gamma-amino-butyric acid has potential as a bioactive ingredient in functional foods due to its health-promoting properties as an anti-stress, anti-hypertensive, and anti-diabetic agent. Here, we report the use of a novel Streptococcus thermophilus strain, isolated from the digestive tract of fish, for production of yogurt naturally enriched with 2 mg/ml of gamma-amino-butyric acid (200 mg in a standard yogurt volume of 100 ml), a dose in the same range as that provided by some commercially available gamma-amino-butyric acid supplements. The biotechnological suitability of this strain for industrial production of yogurt was demonstrated by comparison with the reference yogurt inoculated with the commercial CH1 starter (Chr. Hansen) widely used in the dairy industry. Both yogurts showed comparable pH curves [ΔpH/Δt = 0.31-0.33 h-1], viscosity [0.49 Pa-s], water holding capacity [72-73%], and chemical composition [moisture (87-88%), protein (5.05-5.65%), fat (0.12-0.15%), sugar (4.8-5.8%), and ash (0.74-1.2%)]. Gamma-amino-butyric acid was not detected in the control yogurt. In conclusion, the S. thermophilus APC151 strain reported here provides a natural means for fortification of yogurt with gamma-amino-butyric acid.

14.
Int J Food Microbiol ; 236: 83-9, 2016 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-27454783

RESUMO

Lactococcus lactis subsp. cremoris CECT 8666 is a lactic acid bacterium that synthesizes the biogenic amine putrescine from agmatine via the agmatine deiminase (AGDI) pathway. The AGDI genes cluster includes aguR. This encodes a transmembrane protein that functions as a one-component signal transduction system, the job of which is to sense the agmatine concentration of the medium and accordingly regulate the transcription of the catabolic operon aguBDAC. The latter encodes the proteins necessary for agmatine uptake and its conversion into putrescine. This work reports the effect of extracellular pH on putrescine biosynthesis and on the genetic regulation of the AGDI pathway. Increased putrescine biosynthesis was detected at acidic pH (pH5) compared to neutral pH. Acidic pH induced the transcription of the catabolic operon via the activation of the aguBDAC promoter PaguB. However, the external pH had no significant effect on the activity of the aguR promoter PaguR, or on the transcription of the aguR gene. The transcriptional activation of the AGDI pathway was also found to require a lower agmatine concentration at pH5 than at neutral pH. Finally, the following of the AGDI pathway counteracted the acidification of the cytoplasm under acidic external conditions, suggesting it to provide protection against acid stress.


Assuntos
Proteínas de Bactérias/genética , Citosol/metabolismo , Lactococcus lactis/metabolismo , Putrescina/biossíntese , Ácidos/metabolismo , Agmatina/metabolismo , Proteínas de Bactérias/metabolismo , Citosol/química , Regulação Bacteriana da Expressão Gênica , Homeostase , Concentração de Íons de Hidrogênio , Hidrolases/genética , Hidrolases/metabolismo , Lactococcus lactis/química , Lactococcus lactis/genética , Óperon , Transcrição Gênica
15.
Microbiol Mol Biol Rev ; 80(3): 837-90, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27466284

RESUMO

Lactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and the potential relatedness of LAB virulence to their stress resilience have intensified interest in the field. Thus, a wealth of information concerning stress responses exists today for strains as diverse as starter (e.g., Lactococcus lactis), probiotic (e.g., several Lactobacillus spp.), and pathogenic (e.g., Enterococcus and Streptococcus spp.) LAB. Here we present the state of the art for LAB stress behavior. We describe the multitude of stresses that LAB are confronted with, and we present the experimental context used to study the stress responses of LAB, focusing on adaptation, habituation, and cross-protection as well as on self-induced multistress resistance in stationary phase, biofilms, and dormancy. We also consider stress responses at the population and single-cell levels. Subsequently, we concentrate on the stress defense mechanisms that have been reported to date, grouping them according to their direct participation in preserving cell energy, defending macromolecules, and protecting the cell envelope. Stress-induced responses of probiotic LAB and commensal/pathogenic LAB are highlighted separately due to the complexity of the peculiar multistress conditions to which these bacteria are subjected in their hosts. Induction of prophages under environmental stresses is then discussed. Finally, we present systems-based strategies to characterize the "stressome" of LAB and to engineer new food-related and probiotic LAB with improved stress tolerance.


Assuntos
Enterococcus/fisiologia , Lactobacillus/fisiologia , Streptococcus/fisiologia , Estresse Fisiológico/fisiologia , Biofilmes/crescimento & desenvolvimento , Metabolismo Energético/fisiologia , Fermentação/fisiologia , Microbiologia de Alimentos , Ácido Láctico/metabolismo , Pressão Osmótica/fisiologia , Probióticos/metabolismo , Transdução de Sinais/fisiologia
16.
Food Chem ; 197(Pt A): 658-63, 2016 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-26617000

RESUMO

Tyramine and histamine, the most toxic biogenic amines (BA), are often found in high concentrations in certain foods. Prompted by the limited knowledge of BA toxicity, and increasing awareness of the risks associated with high intakes of dietary BA, the in vitro cytotoxicity of tyramine and histamine was investigated. Tyramine and histamine were toxic for HT29 intestinal cell cultures at concentrations commonly found in BA-rich food, as determined by real-time cell analysis. Surprisingly, tyramine had a stronger and more rapid cytotoxic effect than histamine. Their mode of action was also different, while tyramine caused cell necrosis, histamine induced apoptosis. To avoid health risks, the BA content of foods should be reduced and legal limits established for tyramine.


Assuntos
Aminas Biogênicas/toxicidade , Histamina/toxicidade , Tiramina/toxicidade , Apoptose/efeitos dos fármacos , Aminas Biogênicas/análise , Fragmentação do DNA , Análise de Alimentos , Células HT29 , Histamina/análise , Humanos , Mucosa Intestinal/metabolismo , Intestinos/citologia , Intestinos/efeitos dos fármacos , Nível de Efeito Adverso não Observado , Tiramina/análise
17.
Bioengineered ; 7(1): 11-20, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26709457

RESUMO

The scientific evidence supporting the gut microbiome in relation to health maintenance and links with various disease states afflicting humans, from metabolic to mental health, has grown dramatically in the last few years. Strategies addressing the positive modulation of microbiome functionality associated with these disorders offer huge potential to the food and pharmaceutical industries to innovate and provide therapeutic solutions to many of the health issues affecting modern society. Such strategies may involve the use of probiotics and prebiotics as nutritional adjunct therapies. Probiotics are generally recognized to be a good form of therapy to keep harmful, intestinal microorganisms in check, aid digestion and nutrient absorption, and contribute to immune function. Probiotics are reported to improve microbial balance in the intestinal tract and promote the return to a baseline microbial community following a perturbing event (dysbiosis) such as antibiotic therapy. Prebiotics are selectively fermented ingredients that allow specific changes, both in the composition and/or activity in the gastrointestinal microflora, which confers benefits upon host well-being and health.


Assuntos
Bibliometria , Resistência à Doença/imunologia , Microbioma Gastrointestinal/imunologia , Intestinos/microbiologia , Probióticos/farmacologia , Humanos , Imunomodulação , Intestinos/imunologia , Redes e Vias Metabólicas , Prebióticos , Simbiose
18.
Genom Data ; 6: 228-30, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26697381

RESUMO

Lactococcus lactis subsp. cremoris CECT 8666 (formerly GE2-14) is a dairy strain that catabolizes agmatine (a decarboxylated derivative of arginine) into the biogenic amine putrescine by the agmatine deiminase (AGDI) pathway [1]. The AGDI cluster of L. lactis is composed by five genes aguR, aguB, aguD, aguA and aguC. The last four genes are responsible for the deamination of agmatine to putrescine and are co-transcribed as a single policistronic mRNA forming the catabolic operon aguBDAC[1]. aguR encodes a transmembrane protein that functions as a one-component signal transduction system that senses the agmatine concentration of the medium and accordingly regulates the transcription of aguBDAC[2], which is also transcriptionally regulated by carbon catabolic repression (CCR) via glucose, but not by other sugars such as lactose and galactose [1], [3]. Here we report the transcriptional profiling of the aguR gene deletion mutant (L. lactis subsp. cremoris CECT 8666 ∆aguR) [2] compared to the wild type strain, both grown in M17 medium with galactose as carbon source and supplemented with agmatine. The transcriptional profiling data of AguR-regulated genes were deposited in the Gene Expression Omnibus (GEO) database under accession no. GSE59514.

19.
Microb Cell Fact ; 14: 208, 2015 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-26715338

RESUMO

BACKGROUND: Lactococcus lactis has been safely consumed in fermented foods for millennia. This Gram-positive bacterium has now become of industrial importance as an expression host for the overproduction of lipopolysaccharide-free recombinant proteins used as food ingredients, therapeutic proteins and biotechnological enzymes. RESULTS: This paper reports an agmatine-controlled expression (ACE) system for L. lactis, comprising the lactococcal agmatine-sensor/transcriptional activator AguR and its target promoter P(aguB). The usefulness and efficiency of this system was checked via the reporter gene gfp and by producing PEP (Myxococcus xanthus prolyl-endopeptidase), an enzyme of biomedical interest able to degrade the immunotoxic peptides produced during the gastrointestinal breakdown of gluten. CONCLUSION: The ACE system developed in this work was suitable for the efficient expression of the functional recombinant proteins GFP and PEP. The expression system was tightly regulated by the agmatine concentration and allowed high protein production without leakiness.


Assuntos
Agmatina/metabolismo , Regulação Bacteriana da Expressão Gênica/genética , Lactococcus lactis/genética , Lactococcus lactis/metabolismo
20.
Appl Environ Microbiol ; 81(18): 6145-57, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26116671

RESUMO

Dairy industry fermentative processes mostly use Lactococcus lactis as a starter. However, some dairy L. lactis strains produce putrescine, a biogenic amine that raises food safety and spoilage concerns, via the agmatine deiminase (AGDI) pathway. The enzymatic activities responsible for putrescine biosynthesis in this bacterium are encoded by the AGDI gene cluster. The role of the catabolic genes aguB, aguD, aguA, and aguC has been studied, but knowledge regarding the role of aguR (the first gene in the cluster) remains limited. In the present work, aguR was found to be a very low level constitutively expressed gene that is essential for putrescine biosynthesis and is transcribed independently of the polycistronic mRNA encoding the catabolic genes (aguBDAC). In response to agmatine, AguR acts as a transcriptional activator of the aguB promoter (PaguB), which drives the transcription of the aguBDAC operon. Inverted sequences required for PaguB activity were identified by deletion analysis. Further work indicated that AguR is a transmembrane protein which might function as a one-component signal transduction system that senses the agmatine concentration of the medium and, accordingly, regulates the transcription of the aguBDAC operon through a C-terminal cytoplasmic DNA-binding domain typically found in LuxR-like proteins.


Assuntos
Agmatina/metabolismo , Lactococcus lactis/genética , Lactococcus lactis/metabolismo , Transativadores/genética , Transativadores/metabolismo , Transcrição Gênica , Vias Biossintéticas/genética , Perfilação da Expressão Gênica , Regulação Bacteriana da Expressão Gênica , Óperon , Putrescina/biossíntese
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