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1.
Mol Neurobiol ; 59(3): 1970-1991, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35040041

RESUMO

Neonatal hypoxia-ischemia (HI) is a major cause of mortality and morbidity in newborns and, despite recent advances in neonatal intensive care, there is no definitive treatment for this pathology. Once preclinical studies have shown that environmental enrichment (EE) seems to be a promising therapy for children with HI, the present study conducts a systematic review and meta-analysis of articles with EE in HI rodent models focusing on neurodevelopmental reflexes, motor and cognitive function as well as brain damage. The protocol was registered a priori at PROSPERO. The search was conducted in PubMed, Embase and PsycINFO databases, resulting in the inclusion of 22 articles. Interestingly, EE showed a beneficial impact on neurodevelopmental reflexes (SMD= -0.73, CI= [-0.98; -0.47], p< 0.001, I2= 0.0%), motor function (SMD= -0.55, CI= [-0.81; -0.28], p< 0.001, I2= 62.6%), cognitive function (SMD= -0.93, CI= [-1.14; -0.72], p< 0.001, I2= 27.8%) and brain damage (SMD= -0.80, CI= [-1.03; -0.58], p< 0.001, I2= 10.7%). The main factors that potentiate EE positive effects were enhanced study quality, earlier age at injury as well as earlier start and longer duration of EE exposure. Overall, EE was able to counteract the behavioral and histological damage induced by the lesion, being a promising therapeutic strategy for HI.


Assuntos
Hipóxia-Isquemia Encefálica , Animais , Animais Recém-Nascidos , Modelos Animais de Doenças , Meio Ambiente , Hipóxia-Isquemia Encefálica/patologia , Isquemia , Ratos , Ratos Wistar , Roedores
2.
Braz J Med Biol Res ; 52(2): e8001, 2019 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-30652826

RESUMO

There is no definite recommendation for testing platelet aggregation (PA) in acute coronary syndromes (ACS) due to inconclusive evidence on the usefulness of platelet function tests to guide therapy and improve clinical outcomes. The evaluation of PA with multiple electrode impedance platelet aggregometry (MEA) may be useful to manage antiplatelet therapy and possibly influence patient outcome. The primary aim of this study was to measure PA with MEA in Brazilian patients with ACS and evaluate the association between PA and adverse clinical outcomes. Forty-seven consecutive patients admitted with ACS to a Brazilian tertiary-care public hospital were studied and PA was evaluated using MEA. Patients were followed for six months for the occurrence of all-cause death, acute myocardial infarction, or stroke. Suboptimal inhibition of PA was found in 7 patients (14.9%); 5 (10.6%) in response to ASA (acetylsalicylic acid), 2 (5.0%) to clopidogrel, and none to ticagrelor. Inadequate PA inhibition in response to ASA was significantly associated with the composite end point, but there was no significant association for insufficient PA inhibition in response to clopidogrel. This study suggested that the evaluation of PA in ACS using MEA may identify non-responders to ASA. Larger studies are necessary to define, in a public health scenario, the value of MEA in the management of ACS.


Assuntos
Síndrome Coronariana Aguda/sangue , Impedância Elétrica/uso terapêutico , Agregação Plaquetária , Síndrome Coronariana Aguda/tratamento farmacológico , Adenosina/uso terapêutico , Aspirina/uso terapêutico , Feminino , Hospitais Públicos , Humanos , Masculino , Projetos Piloto , Agregação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/uso terapêutico , Contagem de Plaquetas , Testes de Função Plaquetária , Estudos Prospectivos , Receptores Purinérgicos P2Y12/sangue , Centros de Atenção Terciária
3.
Braz. j. med. biol. res ; 52(2): e8001, 2019. tab
Artigo em Inglês | LILACS | ID: biblio-974279

RESUMO

There is no definite recommendation for testing platelet aggregation (PA) in acute coronary syndromes (ACS) due to inconclusive evidence on the usefulness of platelet function tests to guide therapy and improve clinical outcomes. The evaluation of PA with multiple electrode impedance platelet aggregometry (MEA) may be useful to manage antiplatelet therapy and possibly influence patient outcome. The primary aim of this study was to measure PA with MEA in Brazilian patients with ACS and evaluate the association between PA and adverse clinical outcomes. Forty-seven consecutive patients admitted with ACS to a Brazilian tertiary-care public hospital were studied and PA was evaluated using MEA. Patients were followed for six months for the occurrence of all-cause death, acute myocardial infarction, or stroke. Suboptimal inhibition of PA was found in 7 patients (14.9%); 5 (10.6%) in response to ASA (acetylsalicylic acid), 2 (5.0%) to clopidogrel, and none to ticagrelor. Inadequate PA inhibition in response to ASA was significantly associated with the composite end point, but there was no significant association for insufficient PA inhibition in response to clopidogrel. This study suggested that the evaluation of PA in ACS using MEA may identify non-responders to ASA. Larger studies are necessary to define, in a public health scenario, the value of MEA in the management of ACS.


Assuntos
Agregação Plaquetária/efeitos dos fármacos , Impedância Elétrica/uso terapêutico , Síndrome Coronariana Aguda/sangue , Contagem de Plaquetas , Testes de Função Plaquetária , Inibidores da Agregação Plaquetária/uso terapêutico , Adenosina/uso terapêutico , Projetos Piloto , Aspirina/uso terapêutico , Estudos Prospectivos , Síndrome Coronariana Aguda/tratamento farmacológico , Receptores Purinérgicos P2Y12/sangue , Centros de Atenção Terciária , Hospitais Públicos
4.
Genet Mol Res ; 16(3)2017 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-28829905

RESUMO

Down syndrome (DS) individuals present impaired adaptive immune system. However, the etiology of the immunological deficiency in these individuals is not completely understood. This study investigated the frequency of interleukin 6 polymorphisms (rs1800795, rs1800796, and rs1800797) in individuals with DS and individuals without the syndrome. The study included 282 individuals, 94 with DS attended at the General Genetics Outpatient Service of Hospital de Base, São José do Rio Preto, SP, Brazil, and 188 individuals without DS attended at the Pediatric Service of Hospital de Base de São José do Rio Preto, SP, Brazil. Genotyping was performed by allelic discrimination technique by real-time polymerase chain reaction using TaqMan SNP Genotyping Assays (Applied Biosystems). There was no difference in the genotype frequency between individuals with and without DS for the evaluated polymorphisms (P > 0.05). The frequency of interleukin 6 polymorphisms did not differ significantly between individuals with and without DS in the casuistic analyzed.


Assuntos
Síndrome de Down/genética , Interleucina-6/genética , Polimorfismo de Nucleotídeo Único , Adolescente , Adulto , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino
5.
Int Urol Nephrol ; 48(12): 2095-2099, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27671906

RESUMO

PURPOSE: To determine the association between arterial systolic blood pressure values at the beginning and at the end of a hemodialysis (HD) session in intradialytic hypertension patients. METHODS: This study evaluated the arterial systolic blood pressure patterns in 154 chronic kidney failure patients; among these patients, 18 were identified as having intradialytic hypertension. In the patients with intradialytic hypertension, four consecutive HD sessions were analyzed in which the systolic, diastolic, mean, and pulse blood pressures were automatically determined every 30 min. RESULTS: A linear relationship was revealed between the systolic blood pressure levels measured after 30 min and those obtained after 240 min of HD (r = 0.3894, p = 0.001). This association became stronger after 90 min (r = 0.5471; p < 0.001), indicating that for intradialytic hypertension patients, systolic blood pressure values at the beginning of HD were correlated with systolic blood pressure values at the end of the session. CONCLUSIONS: For intradialytic hypertension patients, values obtained at the end of HD are correlated with the initial values. This information could facilitate planning and earlier treatment.


Assuntos
Determinação da Pressão Arterial/métodos , Hipertensão , Falência Renal Crônica/terapia , Diálise Renal , Adulto , Idoso , Benzopiranos , Intervenção Médica Precoce , Feminino , Humanos , Hipertensão/diagnóstico , Hipertensão/etiologia , Indenos , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica/métodos , Planejamento de Assistência ao Paciente , Diálise Renal/efeitos adversos , Diálise Renal/métodos , Estatística como Assunto , Fatores de Tempo
6.
Folia Morphol (Warsz) ; 74(4): 503-7, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26620513

RESUMO

Although bodypainting has been reported as a great resource for teaching surface anatomy of humans, its use in veterinary anatomy has not been scientifically reported. In the present study, bodypainting was performed on 4 horses for anatomy teaching purposes of the equine locomotor apparatus. We aimed to use the bodypainting method as an additional tool to classic teaching and to test the relevance of our purpose. Twenty one Brazilian veterinary students were given a 90-min session, which included a presentation of painted horses, with opportunities for the students to ask questions and to palpate anatomic locations on the horses. Based on a questionnaire, there was unanimous student satisfaction with this technique. Furthermore, student scores on practical tests to evaluate the attention retain given immediately before and 1 h after the session were 33.9 ± 19.8% and 69.0 ± 18.4%, respectively (p < 0.001). We concluded that bodypainting has great potential for support the classic lectures of the equine locomotor apparatus.

7.
mBio ; 6(6): e01693-15, 2015 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-26556275

RESUMO

UNLABELLED: Due to the spread of resistance, antibiotic exposure receives increasing attention. Ecological consequences for the different niches of individual microbiomes are, however, largely ignored. Here, we report the effects of widely used antibiotics (clindamycin, ciprofloxacin, amoxicillin, and minocycline) with different modes of action on the ecology of both the gut and the oral microbiomes in 66 healthy adults from the United Kingdom and Sweden in a two-center randomized placebo-controlled clinical trial. Feces and saliva were collected at baseline, immediately after exposure, and 1, 2, 4, and 12 months after administration of antibiotics or placebo. Sequences of 16S rRNA gene amplicons from all samples and metagenomic shotgun sequences from selected baseline and post-antibiotic-treatment sample pairs were analyzed. Additionally, metagenomic predictions based on 16S rRNA gene amplicon data were performed using PICRUSt. The salivary microbiome was found to be significantly more robust, whereas the antibiotics negatively affected the fecal microbiome: in particular, health-associated butyrate-producing species became strongly underrepresented. Additionally, exposure to different antibiotics enriched genes associated with antibiotic resistance. In conclusion, healthy individuals, exposed to a single antibiotic treatment, undergo considerable microbial shifts and enrichment in antibiotic resistance in their feces, while their salivary microbiome composition remains unexpectedly stable. The health-related consequences for the gut microbiome should increase the awareness of the individual risks involved with antibiotic use, especially in a (diseased) population with an already dysregulated microbiome. On the other hand, understanding the mechanisms behind the resilience of the oral microbiome toward ecological collapse might prove useful in combating microbial dysbiosis elsewhere in the body. IMPORTANCE: Many health care professionals use antibiotic prophylaxis strategies to prevent infection after surgery. This practice is under debate since it enhances the spread of antibiotic resistance. Another important reason to avoid nonessential use of antibiotics, the impact on our microbiome, has hardly received attention. In this study, we assessed the impact of antibiotics on the human microbial ecology at two niches. We followed the oral and gut microbiomes in 66 individuals from before, immediately after, and up to 12 months after exposure to different antibiotic classes. The salivary microbiome recovered quickly and was surprisingly robust toward antibiotic-induced disturbance. The fecal microbiome was severely affected by most antibiotics: for months, health-associated butyrate-producing species became strongly underrepresented. Additionally, there was an enrichment of genes associated with antibiotic resistance. Clearly, even a single antibiotic treatment in healthy individuals contributes to the risk of resistance development and leads to long-lasting detrimental shifts in the gut microbiome.


Assuntos
Antibacterianos/administração & dosagem , Fezes/microbiologia , Microbiota/efeitos dos fármacos , Saliva/microbiologia , Antibacterianos/farmacologia , DNA Ribossômico/química , DNA Ribossômico/genética , Voluntários Saudáveis , Humanos , Placebos/administração & dosagem , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Suécia , Fatores de Tempo , Reino Unido
8.
Eur J Clin Microbiol Infect Dis ; 34(3): 497-509, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25311987

RESUMO

Methicillin-resistant Staphylococcus aureus (MRSA) isolates genetically related to the CA-MRSA clone MW2/USA400 (ST1-SCCmecIV lineage) from the United States have emerged in hospitals in Rio de Janeiro and are associated with nosocomial bloodstream infections. To understand the virulence mechanisms involved in the adaptability of ST1 isolates as a hospital pathogen in Rio de Janeiro, we compared the virulence traits and fitness properties of the Brazilian isolates with those displayed by the CA-MRSA isolates from the United States. Similar to the USA400 from the United States, all the Brazilian isolates tested carried the genes encoding SEH and LukDE. In contrast, none of the Brazilian isolates carried the lukSF PVL, sea, sec, and sek genes. Competition experiments in mice demonstrated a significant increase in the fitness for the CA-MRSA isolates MW2 and USA400-0051 from the United States compared to other isolates. In the foreign body animal model, 83 % more North-American bacterial cells were recovered compared to the Brazilian ST1 isolates. Differences in gene expression of important virulence factors were detected. Transcription of rnaIII and psmα3 was increased about two-fold in the isolates from the United States, and sasG about two-fold in the Brazilian isolates. Thus, it is possible that the virulence attenuation observed among the Brazilian hospital isolates, associated with the acquisition of multiple resistant determinants, are consequences of microevolutionary events that contributed to the necessary fitness adjustment of this lineage, allowing a typically community-acquired MRSA (MW2/USA400) to emerge as a successful hospital pathogen (Brazilian ST1-SCCmecIV).


Assuntos
Infecções Comunitárias Adquiridas/microbiologia , Infecção Hospitalar/microbiologia , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/fisiologia , Infecções Estafilocócicas/microbiologia , Fatores de Virulência/genética , Animais , Evolução Biológica , Brasil , Modelos Animais de Doenças , Feminino , Perfilação da Expressão Gênica , Genes Bacterianos , Genótipo , Humanos , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Camundongos , Estados Unidos , Virulência
9.
PLoS One ; 9(9): e107640, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25268772

RESUMO

For adaptation between anaerobic, micro-aerobic and aerobic conditions Escherichia coli's metabolism and in particular its electron transport chain (ETC) is highly regulated. Although it is known that the global transcriptional regulators FNR and ArcA are involved in oxygen response it is unclear how they interplay in the regulation of ETC enzymes under micro-aerobic chemostat conditions. Also, there are diverse results which and how quinones (oxidised/reduced, ubiquinone/other quinones) are controlling the ArcBA two-component system. In the following a mathematical model of the E. coli ETC linked to basic modules for substrate uptake, fermentation product excretion and biomass formation is introduced. The kinetic modelling focusses on regulatory principles of the ETC for varying oxygen conditions in glucose-limited continuous cultures. The model is based on the balance of electron donation (glucose) and acceptance (oxygen or other acceptors). Also, it is able to account for different chemostat conditions due to changed substrate concentrations and dilution rates. The parameter identification process is divided into an estimation and a validation step based on previously published and new experimental data. The model shows that experimentally observed, qualitatively different behaviour of the ubiquinone redox state and the ArcA activity profile in the micro-aerobic range for different experimental conditions can emerge from a single network structure. The network structure features a strong feed-forward effect from the FNR regulatory system to the ArcBA regulatory system via a common control of the dehydrogenases of the ETC. The model supports the hypothesis that ubiquinone but not ubiquinol plays a key role in determining the activity of ArcBA in a glucose-limited chemostat at micro-aerobic conditions.


Assuntos
Proteínas da Membrana Bacteriana Externa/metabolismo , Complexo de Proteínas da Cadeia de Transporte de Elétrons/metabolismo , Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Aerobiose , Anaerobiose , Proteínas da Membrana Bacteriana Externa/genética , Transporte de Elétrons , Complexo de Proteínas da Cadeia de Transporte de Elétrons/genética , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Fermentação , Cinética , Modelos Biológicos , Oxigênio/fisiologia
10.
Theriogenology ; 82(5): 715-9, 2014 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-25037750

RESUMO

Recent work with P-36 demonstrates that the replacement of the last two doses of Follicle-Stimulating Hormone (FSH) with equine chorionic gonadotropin (eCG) increases embryo yields. However, it is unclear if the positive effect of eCG is related to its FSH-like activity, LH-like activity, or both. This study aimed to verify the replacement of eCG with pLH on the last day of superstimulatory treatment. Twenty-five Nelore cows were allocated to four groups: P-36 (control), P-36/eCG, P-36/LH2, and P-36/LH4. All animals underwent four treatments in a crossover design. The control group cows were superstimulated with decreasing doses of porcine Follicle-Stimulating Hormone (pFSH, 133 mg, im). In the P-36/eCG, P-36/LH2, and P-36/LH4 groups, the last two doses of pFSH were replaced in the former group by two doses of eCG (200 IU each dose, im) and in the latter two groups by two doses of pLH (1 and 2 mg each dose, im), respectively. Donors received fixed-time artificial insemination 12 and 24 hours after pLH. Embryo flushing was performed on D16. Data were analyzed by ANOVA (Proc Mixed, SAS). There was a trend of decreasing ovulation rate when comparing groups LH2 and eCG (P = 0.06). However, there was no significant difference in the mean number of viable embryos among groups P-36 (3.3 ± 0.7), P-36/eCG (4.5 ± 0.5), P-36/LH2 (3.7 ± 0.8), and P-36/LH4 (4.2 ± 1.0). It is concluded that the replacement of eCG by pLH on the last day of superstimulatory treatment can be performed with no significant variation in the production of viable embryos.


Assuntos
Bovinos/fisiologia , Gonadotropina Coriônica/farmacologia , Hormônio Luteinizante/farmacologia , Superovulação/efeitos dos fármacos , Animais , Gonadotropina Coriônica/administração & dosagem , Cloprostenol/administração & dosagem , Cloprostenol/farmacologia , Estradiol/administração & dosagem , Estradiol/farmacologia , Sincronização do Estro/efeitos dos fármacos , Sincronização do Estro/métodos , Feminino , Hormônio Foliculoestimulante/administração & dosagem , Hormônio Foliculoestimulante/farmacologia , Inseminação Artificial/veterinária , Hormônio Luteinizante/administração & dosagem , Progesterona/administração & dosagem , Progesterona/farmacologia
11.
Appl Environ Microbiol ; 80(19): 5918-26, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25038097

RESUMO

Sorbic acid and acetic acid are among the weak organic acid preservatives most commonly used to improve the microbiological stability of foods. They have similar pKa values, but sorbic acid is a far more potent preservative. Weak organic acids are most effective at low pH. Under these circumstances, they are assumed to diffuse across the membrane as neutral undissociated acids. We show here that the level of initial intracellular acidification depends on the concentration of undissociated acid and less on the nature of the acid. Recovery of the internal pH depends on the presence of an energy source, but acidification of the cytosol causes a decrease in glucose flux. Furthermore, sorbic acid is a more potent uncoupler of the membrane potential than acetic acid. Together these effects may also slow the rate of ATP synthesis significantly and may thus (partially) explain sorbic acid's effectiveness.


Assuntos
Ácido Acético/farmacologia , Bacillus subtilis/efeitos dos fármacos , Conservantes de Alimentos/farmacologia , Ácido Sórbico/farmacologia , Trifosfato de Adenosina/metabolismo , Bacillus subtilis/metabolismo , Bacillus subtilis/fisiologia , Citosol/metabolismo , Eletrofisiologia , Glucose/metabolismo , Concentração de Íons de Hidrogênio
12.
Clin Exp Immunol ; 177(3): 679-86, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24773586

RESUMO

An exacerbated type 1 response to leishmanial antigens is the basis of tissue destruction observed in mucosal leishmaniasis (ML). After therapy, a persistent production of high levels of inflammatory cytokines can confer a poor prognosis. Herein we investigated whether the clinical conditions defined during the active phase of ML affect the magnitude of long-term anti-Leishmania immune response. Twenty clinically cured ML cases were studied. Peripheral blood mononuclear cells (PBMC) were cultured with L. braziliensis antigens (Lb-Ag), Toxoplasma gondii antigens (Tg-Ag), concanavalin-A (Con-A) or medium alone, and the lymphocyte proliferative response and cytokine secretion were quantified. Medical records were reviewed for Montenegro skin test (MST) during diagnosis, duration of ML disease or time elapsed after clinical cure. The duration of disease was correlated positively with MST (r = 0·61). Lb-Ag induced interferon (IFN)-γ was correlated positively with duration of illness (r = 0·69) as well as the frequency of secreting cells [enzyme-linked immunospot (ELISPOT)] assay. No association was observed for Tg-Ag or Con-A. Disease duration was correlated negatively with interleukin (IL)-10 production (r = -0·76). Moreover, a negative correlation between length of time after clinical cure and TNF levels (r = -0·94) or the IFN-γ : IL-10 ratio (r = -0·89) were also seen. We suggest that the magnitude of the IFN-γ inflammatory response triggered by ML can be driven by the time of leishmanial antigens exposition during the active phase of the disease. This pattern could persist even long-term after cure. However, despite IFN-γ levels, the decrease of the TNF and IFN-γ : IL-10 ratio reflects the control of proinflammatory responses achieved by cure of ML, possibly preventing disease relapses.


Assuntos
Antígenos de Protozoários/imunologia , Interferon gama/biossíntese , Interleucina-10/biossíntese , Leishmaniose Mucocutânea/imunologia , Leishmaniose Mucocutânea/metabolismo , Adulto , Idoso , Citocinas/biossíntese , Feminino , Humanos , Hipersensibilidade Tardia/imunologia , Hipersensibilidade Tardia/metabolismo , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Masculino , Pessoa de Meia-Idade , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo
13.
Front Microbiol ; 5: 124, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24723921

RESUMO

The efficient redesign of bacteria for biotechnological purposes, such as biofuel production, waste disposal or specific biocatalytic functions, requires a quantitative systems-level understanding of energy supply, carbon, and redox metabolism. The measurement of transcript levels, metabolite concentrations and metabolic fluxes per se gives an incomplete picture. An appreciation of the interdependencies between the different measurement values is essential for systems-level understanding. Mathematical modeling has the potential to provide a coherent and quantitative description of the interplay between gene expression, metabolite concentrations, and metabolic fluxes. Escherichia coli undergoes major adaptations in central metabolism when the availability of oxygen changes. Thus, an integrated description of the oxygen response provides a benchmark of our understanding of carbon, energy, and redox metabolism. We present the first comprehensive model of the central metabolism of E. coli that describes steady-state metabolism at different levels of oxygen availability. Variables of the model are metabolite concentrations, gene expression levels, transcription factor activities, metabolic fluxes, and biomass concentration. We analyze the model with respect to the production capabilities of central metabolism of E. coli. In particular, we predict how precursor and biomass concentration are affected by product formation.

14.
FEBS J ; 281(3): 825-41, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24616920

RESUMO

In this article, we aim to find an explanation for the surprisingly thin line, with regard to temperature, between cell growth, growth arrest and ultimately loss of cell viability. To this end, we used an integrative approach including both experimental and modelling work. We measured the short- and long-term effects of increases in growth temperature from 28 °C to 37, 39, 41, 42 or 43 °C on the central metabolism of Saccharomyces cerevisiae. Based on the experimental data, we developed a kinetic mathematical model that describes the metabolic and energetic changes in growing bakers' yeast when exposed to a specific temperature upshift. The model includes the temperature dependence of core energy-conserving pathways, trehalose synthesis, protein synthesis and proteolysis. Because our model focuses on protein synthesis and degradation, the net result of which is important in determining the cell's capacity to grow, the model includes growth, i.e. glucose is consumed and biomass and adenosine nucleotide cofactors are produced. The model reproduces both the observed initial metabolic response and the subsequent relaxation into a new steady-state, compatible with the new ambient temperature. In addition, it shows that the energy consumption for proteome reprofiling may be a major determinant of heat-induced growth arrest and subsequent recovery or cell death.


Assuntos
Adaptação Fisiológica , Regulação Fúngica da Expressão Gênica , Modelos Biológicos , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/fisiologia , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Técnicas de Cultura Celular por Lotes , Morte Celular , Proliferação de Células , Metabolismo Energético , Perfilação da Expressão Gênica , Temperatura Alta/efeitos adversos , Cinética , Viabilidade Microbiana , Fosforilação Oxidativa , Biossíntese de Proteínas , Estabilidade Proteica , Proteólise , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/crescimento & desenvolvimento , Proteínas de Saccharomyces cerevisiae/biossíntese , Trealose/biossíntese
15.
Appl Environ Microbiol ; 80(7): 2229-39, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24487531

RESUMO

Hydrogen peroxide production is a well-known trait of many bacterial species associated with the human body. In the presence of oxygen, the probiotic lactic acid bacterium Lactobacillus johnsonii NCC 533 excretes up to 1 mM H(2)O(2), inducing growth stagnation and cell death. Disruption of genes commonly assumed to be involved in H(2)O(2) production (e.g., pyruvate oxidase, NADH oxidase, and lactate oxidase) did not affect this. Here we describe the purification of a novel NADH-dependent flavin reductase encoded by two highly similar genes (LJ_0548 and LJ_0549) that are conserved in lactobacilli belonging to the Lactobacillus acidophilus group. The genes are predicted to encode two 20-kDa proteins containing flavin mononucleotide (FMN) reductase conserved domains. Reductase activity requires FMN, flavin adenine dinucleotide (FAD), or riboflavin and is specific for NADH and not NADPH. The Km for FMN is 30 ± 8 µM, in accordance with its proposed in vivo role in H(2)O(2) production. Deletion of the encoding genes in L. johnsonii led to a 40-fold reduction of hydrogen peroxide formation. H(2)O(2) production in this mutant could only be restored by in trans complementation of both genes. Our work identifies a novel, conserved NADH-dependent flavin reductase that is prominently involved in H(2)O(2) production in L. johnsonii.


Assuntos
Coenzimas/metabolismo , FMN Redutase/metabolismo , Peróxido de Hidrogênio/metabolismo , Lactobacillus/metabolismo , NAD/metabolismo , FMN Redutase/química , FMN Redutase/isolamento & purificação , Deleção de Genes , Teste de Complementação Genética , Cinética , Peso Molecular
16.
PLoS One ; 8(2): e57235, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23468944

RESUMO

Oxygen relieves the CO2 and acetate dependency of Lactobacillus johnsonii NCC 533. The probiotic Lactobacillus johnsonii NCC 533 is relatively sensitive to oxidative stress; the presence of oxygen causes a lower biomass yield due to early growth stagnation. We show however that oxygen can also be beneficial to this organism as it relieves the requirement for acetate and CO2 during growth. Both on agar- and liquid-media, anaerobic growth of L. johnsonii NCC 533 requires CO2 supplementation of the gas phase. Switching off the CO2 supply induces growth arrest and cell death. The presence of molecular oxygen overcomes the CO2 dependency. Analogously, L. johnsonii NCC 533 strictly requires media with acetate to sustain anaerobic growth, although supplementation at a level that is 100-fold lower (120 microM) than the concentration in regular growth medium for lactobacilli already suffices for normal growth. Analogous to the CO2 requirement, oxygen supply relieves this acetate-dependency for growth. The L. johnsonii NCC 533 genome indicates that this organism lacks genes coding for pyruvate formate lyase (PFL) and pyruvate dehydrogenase (PDH), both CO2 and acetyl-CoA producing systems. Therefore, C1- and C2- compound production is predicted to largely depend on pyruvate oxidase activity (POX). This proposed role of POX in C2/C1-generation is corroborated by the observation that in a POX deficient mutant of L. johnsonii NCC 533, oxygen is not able to overcome acetate dependency nor does it relieve the CO2 dependency.


Assuntos
Acetatos/metabolismo , Dióxido de Carbono/metabolismo , Lactobacillus/metabolismo , Oxigênio/metabolismo , Probióticos , Aerobiose , Anaerobiose , Sequência de Bases , Cromatografia Líquida de Alta Pressão , Primers do DNA , Lactobacillus/genética , Lactobacillus/crescimento & desenvolvimento
17.
Arq. bras. med. vet. zootec ; 63(6): 1605-1608, dez. 2011. tab
Artigo em Português | LILACS | ID: lil-608992

RESUMO

This survey was carried out in slaughter plants in the southern of the Espírito Santo State in order to study the causes and the percentages of liver condemnation during post mortem examination from 2008 to 2010. The main reasons for the condemnation of cattle livers in routine meat inspection of the State Inspection Service were fasciolosis (62.2 percent), telangiectatic (12.2 percent), bleeding (5.9 percent), abscess (5.2 percent), cysticercosis (4.0 percent), adherence (3.7 percent), infection (1.9 percent) and tuberculosis (1.1 percent). The hepatic fascioliasis was responsible for most of the lover condemnations, constituting a major challenge to livestock health in the south of the Espírito Santo.

18.
Microbiology (Reading) ; 157(Pt 12): 3500-3511, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21964735

RESUMO

To adapt to changes in the environment, cells have to dynamically alter their phenotype in response to, for instance, temperature and oxygen availability. Interestingly, mitochondrial function in Saccharomyces cerevisiae is inherently temperature sensitive; above 37 °C, yeast cells cannot grow on respiratory carbon sources. To investigate this phenomenon, we studied the effect of cultivation temperature on the efficiency (production of ATP per atom of oxygen consumed, or P/O) of the yeast respiratory chain in glucose-limited chemostats. We determined that even though the specific oxygen consumption rate did not change with temperature, oxygen consumption no longer contributed to mitochondrial ATP generation at temperatures higher than 37 °C. Remarkably, between 30 and 37 °C, we observed a linear increase in respiratory efficiency with growth temperature, up to a P/O of 1.4, close to the theoretical maximum that can be reached in vivo. The temperature-dependent increase in efficiency required the presence of the mitochondrial glycerol-3-phosphate dehydrogenase GUT2. Respiratory chain efficiency was also altered in response to changes in oxygen availibility. Our data show that, even in the absence of alternative oxidases or uncoupling proteins, yeast has retained the ability to dynamically regulate the efficiency of coupling of oxygen consumption to proton translocation in the respiratory chain in response to changes in the environment.


Assuntos
Transporte de Elétrons , Regulação Fúngica da Expressão Gênica , Mitocôndrias/enzimologia , Mitocôndrias/metabolismo , Oxirredutases/metabolismo , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/fisiologia , Trifosfato de Adenosina/metabolismo , Oxigênio/metabolismo , Temperatura
19.
Environ Sci Technol ; 45(14): 6117-23, 2011 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-21682287

RESUMO

Cultured meat (i.e., meat produced in vitro using tissue engineering techniques) is being developed as a potentially healthier and more efficient alternative to conventional meat. Life cycle assessment (LCA) research method was used for assessing environmental impacts of large-scale cultured meat production. Cyanobacteria hydrolysate was assumed to be used as the nutrient and energy source for muscle cell growth. The results showed that production of 1000 kg cultured meat requires 26-33 GJ energy, 367-521 m(3) water, 190-230 m(2) land, and emits 1900-2240 kg CO(2)-eq GHG emissions. In comparison to conventionally produced European meat, cultured meat involves approximately 7-45% lower energy use (only poultry has lower energy use), 78-96% lower GHG emissions, 99% lower land use, and 82-96% lower water use depending on the product compared. Despite high uncertainty, it is concluded that the overall environmental impacts of cultured meat production are substantially lower than those of conventionally produced meat.


Assuntos
Meio Ambiente , Manipulação de Alimentos/normas , Tecnologia de Alimentos/tendências , Carne , Engenharia Tecidual/métodos , California , Dióxido de Carbono/análise , Conservação de Recursos Energéticos/estatística & dados numéricos , Cianobactérias/metabolismo , Hidrolisados de Proteína , Espanha , Temperatura , Tailândia , Abastecimento de Água/análise
20.
Anim Reprod Sci ; 125(1-4): 119-23, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21470801

RESUMO

The aim of this study was to evaluate the superovulatory (SOV) response of Sindhi (Bos indicus) donors submitted to an ovarian follicular superstimulatory protocol replacing the last two doses of pFSH by eCG. Forty-eight SOV treatments were performed in a crossover design in 19 nulliparous and primiparous females that were randomly divided into two groups: FSH (n=24), which consisted of eight pFSH injections, or FSH/eCG (n=24), which consisted of six pFSH injections followed by two eCG injections. Each female underwent two or three SOV treatments that consisted of an i.m. injection of 2mg estradiol benzoate and the insertion of an intravaginal progesterone-releasing device on Day 0. On Day 4, superstimulatory treatments were initiated and 100mg pFSH was divided into twice daily decreasing doses over a 4-day period. In the FSH/eCG group, the last two doses of pFSH were replaced by two doses of eCG (150 IU eCG each). At the time of the fifth and sixth injections of FSH, 0.150 mg PGF(2α) was injected i.m. The intravaginal progesterone-releasing device was removed at the time of the last FSH or eCG injection and ovulation was induced with 0.2 mg GnRH 18 h later. All females were artificially inseminated with frozen-thawed semen from the same bull 6 and 18 h after GnRH treatment. Seven days after GnRH treatment, embryos/ova were recovered and classified. Follicular superstimulatory (number of follicles ≥6mm at the time of the last FSH or eCG injection) and SOV (CL number) responses were determined by transrectal ultrasonography. Data were analyzed using generalized linear models and results were presented as least squares means±standard error. The FSH/eCG group had higher superstimulatory (33.8±3.9 compared to 23.8±2.6 follicles; P=0.03) and SOV (16.8±2.9 compared to 10.8±2.1 CL; P=0.10) responses. Although the number of total ova/embryos was not different between groups (8.2±1.8 compared to 5.9±1.4 for FSH/eCG and FSH groups, respectively; P=0.25), the number (5.8±1.3 compared to 2.6±0.7; P=0.02) and percentage (75.6±5.7 compared to 53.2±9.7%; P=0.05) of transferable embryos was greater for the FSH/eCG females. Therefore, there was improvement in follicular superstimulatory and SOV responses and embryo quality in FSH/eCG-treated females.


Assuntos
Bovinos/fisiologia , Hormônio Foliculoestimulante/administração & dosagem , Gonadotropinas Equinas/administração & dosagem , Folículo Ovariano/efeitos dos fármacos , Indução da Ovulação/veterinária , Superovulação/efeitos dos fármacos , Animais , Brasil , Estudos Cross-Over , Feminino , Inseminação Artificial/veterinária , Análise dos Mínimos Quadrados , Masculino , Folículo Ovariano/diagnóstico por imagem , Folículo Ovariano/fisiologia , Indução da Ovulação/métodos , Gravidez , Distribuição Aleatória , Superovulação/fisiologia , Ultrassonografia
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