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1.
J Biol Chem ; 292(14): 5845-5859, 2017 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-28213522

RESUMO

Type I interferons (IFN-I) are critical in antimicrobial and antitumor defense. Although IFN-I signal via the interferon-stimulated gene factor 3 (ISGF3) complex consisting of STAT1, STAT2, and IRF9, IFN-I can mediate significant biological effects via ISGF3-independent pathways. For example, the absence of STAT1, STAT2, or IRF9 exacerbates neurological disease in transgenic mice with CNS production of IFN-I. Here we determined the role of IFN-I-driven, ISGF3-independent signaling in regulating global gene expression in STAT1-, STAT2-, or IRF9-deficient murine mixed glial cell cultures (MGCs). Compared with WT, the expression of IFN-α-stimulated genes (ISGs) was reduced in number and magnitude in MGCs that lacked STAT1, STAT2, or IRF9. There were significantly fewer ISGs in the absence of STAT1 or STAT2 versus in the absence of IRF9. The majority of ISGs regulated in the STAT1-, STAT2-, or IRF9-deficient MGCs individually were shared with WT. However, only a minor number of ISGs were common to WT and STAT1-, STAT2-, and IRF9-deficient MGCs. Whereas signal pathway activation in response to IFN-α was rapid and transient in WT MGCs, this was delayed and prolonged and correlated with increased numbers of ISGs expressed at 12 h versus 4 h of IFN-α exposure in all three IFN-I signaling-deficient MGCs. In conclusion, 1) IFN-I can mediate ISG expression in MGCs via ISGF3-independent signaling pathways but with reduced efficiency, with delayed and prolonged kinetics, and is more dependent on STAT1 and STAT2 than IRF9; and 2) signaling pathways not involving STAT1, STAT2, or IRF9 play a minor role only in mediating ISG expression in MGCs.


Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , Fator Gênico 3 Estimulado por Interferon, Subunidade gama/metabolismo , Interferon-alfa/farmacologia , Neuroglia/metabolismo , Fator de Transcrição STAT1/metabolismo , Fator de Transcrição STAT2/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Fator Gênico 3 Estimulado por Interferon/genética , Fator Gênico 3 Estimulado por Interferon/metabolismo , Fator Gênico 3 Estimulado por Interferon, Subunidade gama/genética , Camundongos , Camundongos Knockout , Neuroglia/citologia , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT2/genética
2.
J Cell Physiol ; 231(8): 1671-87, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26638980

RESUMO

Long-chain fatty acid (LCFA) movement into skeletal muscle involves a highly mediated process in which lipid rafts are utilized in the cellular membrane, involving numerous putative plasma membrane-associated LCFA transport proteins. The process of LCFA uptake and oxidation is of particular metabolic significance both at rest and during light to moderate exercise. A comprehensive systematic search of electronic databases was conducted to investigate whether exercise alters protein and/or gene expression of putative LCFA transport proteins. There were 31 studies meeting all eligibility criteria, of these 13 utilized an acute exercise protocol and 18 examined chronic exercise adaptations. Seventeen involved a study design incorporating an exercise stimulus, while the remaining 14 incorporated a combined exercise and diet stimulus. Divergent data relating to acute exercise, as well as prolonged exercise training (≥3 weeks), on protein content (PC) response was identified for proteins CD36, FABPpm and CAV1. Messenger ribonucleic acid (mRNA) data did not always correspond to functional PC, supporting previous suggestions of a disconnect due to potentially limiting factors post gene expression. The large array of study designs, cohorts, and primary dependent variables within the studies included in the present review elucidate the complexity of the interaction between exercise and LCFA transport proteins. Summary of the results in the present review validate the need for further targeted investigation within this topic, and provide an important information base for such research. J. Cell. Physiol. 231: 1671-1687, 2016. © 2015 Wiley Periodicals, Inc.


Assuntos
Exercício Físico/fisiologia , Proteínas de Transporte de Ácido Graxo/metabolismo , Ácidos Graxos/metabolismo , Contração Muscular , Músculo Esquelético/metabolismo , Proteínas de Transporte de Ácido Graxo/genética , Regulação da Expressão Gênica , Humanos , RNA Mensageiro/metabolismo , Transdução de Sinais , Fatores de Tempo
3.
Glia ; 63(10): 1738-52, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25903009

RESUMO

Interleukin-6 (IL-6) participates in the host response to injury and infection in the central nervous system (CNS). We identified strawberry notch homolog 2 (Sbno2) as an IL-6-stimulated gene in murine astrocytes. Sbno2 is a mouse homolog of the sno gene in Drosophila but little is known about the regulation or function of the mammalian gene. Here we examined the regulation of the Sbno2 gene in astrocytes in vitro and in the murine CNS following systemic endotoxin administration. In murine and human cultured astrocytes, Sbno2 gene expression was significantly upregulated in a dose- and time-dependent fashion by hyper-IL-6 (IL-6 + soluble IL-6 receptor). The level of Sbno2 mRNA was also upregulated significantly in murine astrocytes by other glycoprotein130 cytokine-family members and the pro-inflammatory cytokines interleukin-1 beta and tumor necrosis factor alpha. These changes were reflected by corresponding alterations in the level of the SBNO2 protein. Inhibiting protein synthesis resulted in higher Sbno2 mRNA and did not abolish the upregulation of Sbno2 mRNA mediated by hyper-IL-6. Inhibition of transcription led to a rapid reduction in hyper-IL-6-induced Sbno2 mRNA in astrocytes suggesting that the Sbno2 mRNA is quite unstable. Following intra-peritoneal lipopolysaccharide injection in mice, Sbno2 mRNA levels in the brain were significantly increased. Cellular localization studies revealed that this increase in Sbno2 mRNA occurred predominantly in astrocytes and in the choroid plexus and in some microglia, endothelial cells, and neurons. These findings are consistent with SBNO2 functioning as an acute inflammatory response gene in astrocytes as well as other cells in the CNS.


Assuntos
Astrócitos/metabolismo , Proteínas Repressoras/metabolismo , Análise de Variância , Animais , Animais Recém-Nascidos , Astrócitos/efeitos dos fármacos , Encéfalo/citologia , Células Cultivadas , Cicloeximida/farmacologia , Relação Dose-Resposta a Droga , Humanos , Interleucina-6/farmacologia , Lipopolissacarídeos/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Inibidores da Síntese de Proteínas/farmacologia , RNA Mensageiro/metabolismo , Receptores de Citocinas/metabolismo , Proteínas Repressoras/genética , Fatores de Tempo , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética
4.
Exp Parasitol ; 133(4): 483-6, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23333590

RESUMO

A Taenia hydatigena model was used to assess the effect 0, 7, 14, 21, and 28 days of ensilation of minced potato on viability of tapeworm eggs. For infection of lambs, 2,000 T. hydatigena eggs were ensiled for 0, 7, 14, 21 and 28 days in minced potato at 22°C and fed to recently weaned lambs (29.9±0.76 kg). At slaughter, no cysticerci were recovered from lambs infected with eggs ensiled for 28 days while a mean of 5.0±5.0 cysticerci (0.25% of the initial egg dose) were recovered from lambs infected with eggs ensiled for 21 days. For lambs fed eggs ensiled for 0 days (control), 359.3±55.6 cysticerci were recovered (18.0% of the initial egg dose). Regression analysis revealed that a 99.9% reduction in viability was attained after 18.59 days of ensilation.


Assuntos
Silagem , Solanum tuberosum/metabolismo , Taenia/crescimento & desenvolvimento , Teníase/transmissão , Animais , Cães , Concentração de Íons de Hidrogênio , Modelos Lineares , Fígado/parasitologia , Omento/parasitologia , Óvulo/crescimento & desenvolvimento , Distribuição Aleatória , Ovinos , Teníase/parasitologia , Fatores de Tempo
5.
Exp Parasitol ; 133(4): 421-6, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23333617

RESUMO

Effects of heat treatments on activation and infectivity of Taenia hydatigena eggs were assessed. Eggs containing oncospheres were used for in vitro and in vivo studies to determine the response to 5min of heat treatment, ranging from room temperature (22°C) to 60°C. The study demonstrated 99.47% and 100% reduction in oncosphere activation or infectivity after 5min of heat treatment at 60°C and 57.38°C under in vitro and in vivo conditions, respectively. Similar results between the two approaches indicted the appropriateness of the in vitro methods to identify oncosphericidal treatments of practical significance. Similar heat treatments may also be effective against Taenia saginata and help to reduce occurrence of beef cysticercosis.


Assuntos
Temperatura Alta , Taenia/crescimento & desenvolvimento , Análise de Variância , Animais , Bile/fisiologia , Cysticercus/crescimento & desenvolvimento , Cães , Modelos Lineares , Fígado/parasitologia , Masculino , Omento/parasitologia , Óvulo/crescimento & desenvolvimento , Óvulo/fisiologia , Distribuição Aleatória , Ovinos , Taenia/fisiologia , Teníase/parasitologia , Teníase/prevenção & controle , Teníase/veterinária
6.
Can Vet J ; 53(10): 1119-22, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23543934

RESUMO

Factors associated with time to clearance of mycoplasma mastitis were studied in 18 dairy cattle herds. Most herds cleared mycoplasma mastitis within 1 month; < 50% of the herds culled diseased cows preferentially, yet culling was not associated with hastened clearance. Other known mastitis biosecurity and management practices were not associated with clearance time.


Délai de guérison de la mammite à mycoplasmes : effet des facteurs de gestion incluant l'hygiène lors de la traite et la réforme préférentielle. Les facteurs associés au délai de guérison de la mammite à mycoplasmes ont été étudiés dans 18 troupeaux laitiers. La plupart des troupeaux se débarrassaient de la mammite à mycoplasmes dans un délai d'un mois; < 50 % des troupeaux procédaient à une réforme préférentielle des vaches malades, pourtant la réforme n'a pas été associée à une guérison hâtive. Les autres pratiques de biosécurité et de gestion connues pour la mammite n'ont pas été associées au délai de guérison.(Traduit par Isabelle Vallières).


Assuntos
Antibacterianos/uso terapêutico , Indústria de Laticínios/métodos , Higiene , Mastite Bovina/prevenção & controle , Infecções por Mycoplasma/veterinária , Animais , Bovinos , Eutanásia Animal , Feminino , Mycoplasma/isolamento & purificação , Infecções por Mycoplasma/prevenção & controle , Fatores de Risco , Fatores de Tempo
7.
CBE Life Sci Educ ; 21(1): ar4, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34941363

RESUMO

A critical goal for science education is to design and implement learning activities that develop a deep conceptual understanding, are engaging for students, and are scalable for large classes or those with few resources. Approaches based on peer learning and online technologies show promise for scalability but often lack a grounding in cognitive learning principles relating to conceptual understanding. Here, we present a novel design for combining these elements in a principled way. The design centers on having students author multiple-choice questions for their peers using the online platform PeerWise, where beneficial forms of cognitive engagement are encouraged via a series of supporting activities. We evaluated an implementation of this design within a cohort of 632 students in an undergraduate biochemistry course. Our results show a robust relationship between the quality of question authoring and relevant learning outcomes, even after controlling for the confounding influence of prior grades. We conclude by discussing practical and theoretical implications.


Assuntos
Avaliação Educacional , Estudantes , Humanos , Aprendizagem , Motivação , Grupo Associado
8.
J Nutr ; 141(6): 1195-201, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21490290

RESUMO

The zinc transporter (ZnT; SLC30) and Zrt- and Irt-like protein (Zip, SLC39) zinc transporter families are integral to the maintenance of intracellular zinc concentrations. Few studies have examined the expression patterns of zinc transporter genes in human primary tissues. This study investigated the expression levels of a range of zinc transporter mRNA in the peripheral blood mononuclear cells of healthy men and women (n = 40) using quantitative real-time PCR. It also explored the relationships among zinc transporter expression levels, plasma zinc concentrations, and dietary zinc intake. The relative expression of the zinc transporter mRNA varied considerably, with ZnT7, ZnT1, and Zip1 being the most abundantly expressed. ZnT1 and Zip1 mRNA were highly correlated with one another (r = 0.9; P < 0.001) and with ZnT5, ZnT7, Zip3, and Zip10 (P < 0.001). When analyzed by gender, a correlation between the mRNA of ZnT7 and Zip3 (r = 0.6; P < 0.01) was demonstrated only in women. Zip10 mRNA was correlated with ZnT1 and Zip1 (r = 0.9; P < 0.001) in men only. In a regression analysis, plasma zinc variability was not significantly explained by dietary zinc intake, gender, age, or any individual or combination of zinc transporters. This study expands what is known about both the levels of zinc transporter gene transcription in humans and the extent of its variation in healthy men and women. The positive association between the mRNA of ZnT1 and Zip1, which have reciprocal roles in zinc transport across the plasma membrane, provides insight into the coordinated control of zinc homeostasis in humans.


Assuntos
Proteínas de Transporte/genética , Proteínas de Transporte de Cátions/genética , Zinco/administração & dosagem , Zinco/sangue , Adulto , Idoso , Estudos Transversais , Dieta , Feminino , Expressão Gênica , Humanos , Leucócitos Mononucleares/metabolismo , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/sangue , RNA Mensageiro/genética , Adulto Jovem
9.
J Endocr Soc ; 5(9): bvab057, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34337274

RESUMO

25-hydroxyvitamin D 1α-hydroxylase (encoded by CYP27B1), which catalyzes the synthesis of 1,25-dihydroxyvitamin D3, is subject to negative or positive modulation by extracellular Ca2+ (Ca2+ o) depending on the tissue. However, the Ca2+ sensors and underlying mechanisms are unidentified. We tested whether calcium-sensing receptors (CaSRs) mediate Ca2+ o-dependent control of 1α-hydroxylase using HEK-293 cells stably expressing the CaSR (HEK-CaSR cells). In HEK-CaSR cells, but not control HEK-293 cells, cotransfected with reporter genes for CYP27B1-Photinus pyralis (firefly) luciferase and control Renilla luciferase, an increase in Ca2+ o from 0.5mM to 3.0mM induced a 2- to 3-fold increase in firefly luciferase activity as well as mRNA and protein levels. Surprisingly, firefly luciferase was specifically suppressed at Ca2+ o ≥ 5.0mM, demonstrating biphasic Ca2+ o control. Both phases were mediated by CaSRs as revealed by positive and negative modulators. However, Ca2+ o induced simple monotonic increases in firefly luciferase and endogenous CYP27B1 mRNA levels, indicating that the inhibitory effect of high Ca2+ o was posttranscriptional. Studies with inhibitors and the CaSR C-terminal mutant T888A identified roles for protein kinase C (PKC), phosphorylation of T888, and extracellular regulated protein kinase (ERK)1/2 in high Ca2+ o-dependent suppression of firefly luciferase. Blockade of both PKC and ERK1/2 abolished Ca2+ o-stimulated firefly luciferase, demonstrating that either PKC or ERK1/2 is sufficient to stimulate the CYP27B1 promoter. A key CCAAT box (-74 bp to -68 bp), which is regulated downstream of PKC and ERK1/2, was required for both basal transcription and Ca2+ o-mediated transcriptional upregulation. The CaSR mediates Ca2+ o-dependent transcriptional upregulation of 1α-hydroxylase and an additional CaSR-mediated mechanism is identified by which Ca2+ o can promote luciferase and possibly 1α-hydroxylase breakdown.

10.
Foodborne Pathog Dis ; 7(4): 449-57, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19958100

RESUMO

The purpose of this study was to determine whether antimicrobial resistance (AMR) in foodborne pathogens (Escherichia coli O157, Salmonella, and Campylobacter) and non-type-specific E. coli obtained from fecal samples of feedlot cattle was associated with antimicrobial drug (AMD) use. A secondary objective was to determine if AMR in non-type-specific E. coli could be used as a predictor of AMR in foodborne pathogens. Fecal samples were collected from pen floors in 21 Alberta feedlots during March through December 2004, and resistance prevalence was estimated by season (Spring, Fall) and cattle type (fewest days-on-feed and closest to slaughter). AMD exposures were obtained by calculating therapeutic animal daily doses for each drug before sampling from feedlot records. Generalized linear mixed models were used to investigate the relationship between each AMR and AMD use. Non-type-specific E. coli was commonly recovered from fecal samples (88.62%), and the highest prevalence of resistance was found toward tetracycline (53%), streptomycin (28%), and sulfadiazine (48%). Campylobacter jejuni was recovered from 55.3% of the fecal samples, and resistance was generally less for the drugs that were evaluated (doxycycline 38.1%, ciprofloxacin 2.6%, nalidixic acid 1.64%, erythromycin 1.2%). E. coli O157 and Salmonella were recovered much less frequently (7% and 1% prevalence, respectively). The prevalence of recovery for the bacteria studied varied between seasons and cattle types, as did patterns of AMR. Among non-type-specific E. coli, resistance to tetracycline, streptomycin, and sulfadiazine was found to be positively associated with in-feed exposure as well as injectable tetracycline, but these differences were relatively small and of questionable practical relevance. Among C. jejuni isolates, cattle type was significantly associated with doxycycline resistance. Results suggested that resistance in non-type-specific E. coli to chloramphenicol, trimethoprim/sulfamethoxazole, and tetracycline might be used as predictors of resistance to these drugs in E. coli O157 recovered from the same fecal samples.


Assuntos
Anti-Infecciosos/administração & dosagem , Farmacorresistência Bacteriana , Enterobacteriaceae/efeitos dos fármacos , Alberta , Criação de Animais Domésticos/métodos , Criação de Animais Domésticos/estatística & dados numéricos , Animais , Campylobacter jejuni/efeitos dos fármacos , Bovinos , Enterobacteriaceae/isolamento & purificação , Enterobacteriaceae/patogenicidade , Escherichia coli/efeitos dos fármacos , Escherichia coli O157/efeitos dos fármacos , Fezes/microbiologia , Testes de Sensibilidade Microbiana , Modelos Estatísticos , Salmonella enterica/efeitos dos fármacos , Estações do Ano
11.
J Am Vet Med Assoc ; 236(12): 1338-44, 2010 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-20550450

RESUMO

OBJECTIVE: To describe geographic, farm-type, and animal-type factors associated with multiple antimicrobial resistance (MAR) in fecal Escherichia coli isolates from cattle. DESIGN: Cross-sectional field study. SAMPLE POPULATION: 1,736 fecal samples from cattle on 38 farms in California, Oregon, and Washington. PROCEDURES: Fecal samples were collected from preweaned calves (2 to 4 weeks old) and cows that recently calved on dairy and beef cow-calf farms, preweaned calves on calf ranches, and 1-year-old steers on feedlots. One fecal E coli isolate per sample was isolated, and antimicrobial susceptibility was tested. Escherichia coli isolates were initially clustered by antimicrobial resistance patterns and categorized by number of antimicrobial resistances. A generalized estimating equations cumulative logistic regression model was used to identify factors associated with an increase in MAR in fecal E coli isolates from cattle. RESULTS: MAR was higher in E coli isolates from cattle in California, compared with those from cattle in Washington or Oregon. Multiple antimicrobial resistance was highest in E coli isolates from calves on calf ranches and progressively lower in isolates from feedlot steers, dairy cattle, and beef cattle. Multiple antimicrobial resistance was higher in E coli isolates from calves than from adult cattle, in E coli isolates from cattle of conventional farms than of organic farms, and in isolates from beef cattle in intensive dairy farm regions than from beef cattle distant from dairy farm regions. CONCLUSIONS AND CLINICAL RELEVANCE: MAR in fecal E coli isolates from cattle was influenced by factors not directly associated with the use of antimicrobials, including geographic region, animal age, and purpose (beef vs dairy).


Assuntos
Antibacterianos/farmacologia , Doenças dos Bovinos/microbiologia , Farmacorresistência Bacteriana Múltipla , Escherichia coli/efeitos dos fármacos , Fezes/microbiologia , Criação de Animais Domésticos , Animais , California/epidemiologia , Bovinos , Doenças dos Bovinos/epidemiologia , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/veterinária , Oregon/epidemiologia , Washington/epidemiologia
12.
J Clin Microbiol ; 47(6): 1934-8, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19386855

RESUMO

In recent years, the proportion of Salmonella enterica infections represented by S. enterica serovar Newport has increased markedly among humans and animals. Multilocus variable-number tandem-repeat analysis (MLVA) has proven to be useful in discriminating other highly clonal Salmonella serovars. Here, we report on the development of a highly discriminatory MLVA for Salmonella serovar Newport.


Assuntos
Técnicas de Tipagem Bacteriana/métodos , Impressões Digitais de DNA/métodos , DNA Bacteriano/genética , Repetições Minissatélites , Salmonella enterica/classificação , Salmonella enterica/genética , Animais , Aves , Bovinos , Genótipo , Humanos , Infecções por Salmonella/microbiologia , Salmonelose Animal/microbiologia , Salmonella enterica/isolamento & purificação
13.
Appl Environ Microbiol ; 75(11): 3648-55, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19376926

RESUMO

Third-generation cephalosporin resistance of Salmonella and commensal Escherichia coli isolates from cattle in the United States is predominantly conferred by the cephamycinase CMY-2, which inactivates beta-lactam antimicrobial drugs used to treat a wide variety of infections, including pediatric salmonellosis. The emergence and dissemination of bla(CMY-2)(-)-bearing plasmids followed and may in part be the result of selection pressure imposed by the widespread utilization of ceftiofur, a third-generation veterinary cephalosporin. This study assessed the potential effects of ceftiofur on bla(CMY-2) transfer and dissemination by (i) an in vivo experimental study in which calves were inoculated with competent bla(CMY-2)-bearing plasmid donors and susceptible recipients and then subjected to ceftiofur selection and (ii) an observational study to determine whether ceftiofur use in dairy herds is associated with the occurrence and frequency of cephalosporin resistance in Salmonella and commensal E. coli. The first study revealed bla(CMY-2) plasmid transfer in both ceftiofur-treated and untreated calves but detected no enhancement of plasmid transfer associated with ceftiofur treatment. The second study detected no association (P = 0.22) between ceftiofur use and either the occurrence of ceftiofur-resistant salmonellosis or the frequency of cephalosporin resistance in commensal E. coli. However, herds with a history of salmonellosis (including both ceftiofur-resistant and ceftiofur-susceptible Salmonella isolates) used more ceftiofur than herds with no history of salmonellosis (P = 0.03) These findings fail to support a major role for ceftiofur use in the maintenance and dissemination of bla(CMY-2)-bearing plasmid mediated cephalosporin resistance in commensal E. coli and in pathogenic Salmonella in these dairy cattle populations.


Assuntos
Bovinos/microbiologia , Resistência às Cefalosporinas , Cefalosporinas/farmacologia , Escherichia coli/efeitos dos fármacos , Salmonella enterica/efeitos dos fármacos , Seleção Genética , beta-Lactamases/genética , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Cefalosporinas/uso terapêutico , Conjugação Genética , Escherichia coli/isolamento & purificação , Transferência Genética Horizontal , Plasmídeos , Salmonella enterica/isolamento & purificação , Estados Unidos , beta-Lactamases/biossíntese
14.
Can Vet J ; 50(2): 166-72, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19412396

RESUMO

The occurrence of generic Escherichia coli, E. coli O157, Salmonella, and Campylobacter in cattle manure, beef carcasses, catch basin water, and soils receiving manure application was determined in 21 Alberta feedlots. In cattle manure, generic E. coli (98%, 2069/2100) and Campylobacter (76%, 1590/2100) were frequently detected; E. coli O157 (7%, 143/2100) and Salmonella (1%, 20/2100) were less frequently detected. Samples from beef carcasses in the cooler following Hazard Analysis Critical Control Point interventions yielded only 1 isolate each of generic E. coli and Campylobacter (1/1653) and no Salmonella (0/1653). Catch basin water specimens were positive for generic E. coli in both the spring (62%, 13/21) and the fall (52%, 11/21). Other bacteria were detected only in the spring water specimens, including E. coli O157 (29%, 6/21), Salmonella (5%, 1/21), and Campylobacter (52%, 11/21). Generic E. coli was frequently isolated from soil specimens (30%, 27/88), but E. coli O157 was not found in soil samples obtained in the spring and was only occasionally detected in the fall samples (9%, 3/32). Salmonella were occasionally found in the soil specimens collected in the spring (3%, 2/56), but not in the fall season (0/32). Campylobacter jejuni was frequent in cattle manure (66%, 1070/1623), but rare in carcass and environmental samples. E. coli O157 and Salmonella were rarely detected in cattle or the environment. Generic E. coli and Salmonella were rarely detected on carcasses.


Assuntos
Bovinos/microbiologia , Contaminação de Alimentos/prevenção & controle , Esterco/microbiologia , Microbiologia do Solo , Microbiologia da Água , Alberta , Animais , Campylobacter/isolamento & purificação , Contagem de Colônia Microbiana/veterinária , Qualidade de Produtos para o Consumidor , Microbiologia Ambiental , Escherichia coli/isolamento & purificação , Escherichia coli O157/isolamento & purificação , Feminino , Humanos , Masculino , Prevalência , Salmonella/isolamento & purificação , Estações do Ano
15.
Nat Commun ; 10(1): 875, 2019 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-30787277

RESUMO

Cognitive abilities underpin the capacity of individuals to build models of their environment and make decisions about how to govern resources. Here, we test the functional intelligences proposition that functionally diverse cognitive abilities within a group are critical to govern common pool resources. We assess the effect of two cognitive abilities, social and general intelligence, on group performance on a resource harvesting and management game involving either a negative or a positive disturbance to the resource base. Our results indicate that under improving conditions (positive disturbance) groups with higher general intelligence perform better. However, when conditions deteriorate (negative disturbance) groups with high competency in both general and social intelligence are less likely to deplete resources and harvest more. Thus, we propose that a functional diversity of cognitive abilities improves how effectively social groups govern common pool resources, especially when conditions deteriorate and groups need to re-evaluate and change their behaviors.

16.
Cell Metab ; 29(1): 183-191.e7, 2019 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-30318338

RESUMO

Protein kinase C epsilon (PKCɛ) activation in the liver is proposed to inhibit insulin action through phosphorylation of the insulin receptor. Here, however, we demonstrated that global, but not liver-specific, deletion of PKCɛ in mice protected against diet-induced glucose intolerance and insulin resistance. Furthermore, PKCɛ-dependent alterations in insulin receptor phosphorylation were not detected. Adipose-tissue-specific knockout mice did exhibit improved glucose tolerance, but phosphoproteomics revealed no PKCɛ-dependent effect on the activation of insulin signaling pathways. Altered phosphorylation of adipocyte proteins associated with cell junctions and endosomes was associated with changes in hepatic expression of several genes linked to glucose homeostasis and lipid metabolism. The primary effect of PKCɛ on glucose homeostasis is, therefore, not exerted directly in the liver as currently posited, and PKCɛ activation in this tissue should be interpreted with caution. However, PKCɛ activity in adipose tissue modulates glucose tolerance and is involved in crosstalk with the liver.


Assuntos
Tecido Adiposo/metabolismo , Glucose/metabolismo , Insulina/metabolismo , Fígado/metabolismo , Proteína Quinase C-épsilon/fisiologia , Animais , Dieta Hiperlipídica , Técnicas de Inativação de Genes , Intolerância à Glucose , Resistência à Insulina , Metabolismo dos Lipídeos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína Quinase C-épsilon/genética
18.
Appl Environ Microbiol ; 74(23): 7447-50, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18849446

RESUMO

Escherichia coli O157:H7 genotypes in the bovine reservoir may differ in virulence. The proportion of clinical genotypes among cattle isolates was weakly (P = 0.054) related to the international incidence of E. coli O157:H7-associated hemolytic-uremic syndrome, varied among clinical isolates internationally, and also differed along the putative cattle-hamburger-clinical case transmission chain.


Assuntos
Bacteriófagos/genética , Doenças dos Bovinos/microbiologia , Microbiologia Ambiental , Infecções por Escherichia coli/veterinária , Escherichia coli O157/genética , Escherichia coli O157/isolamento & purificação , Síndrome Hemolítico-Urêmica/microbiologia , Prófagos/genética , Animais , Bovinos , Infecções por Escherichia coli/microbiologia , Escherichia coli O157/virologia , Genótipo , Humanos , Epidemiologia Molecular , Polimorfismo Genético , Toxinas Shiga/biossíntese
19.
Vet Parasitol ; 151(2-4): 203-11, 2008 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-18063313

RESUMO

Methods to determine viability of taeniid oncospheres following treatments with potential lethality have practical application in efforts to control transmission. Here we investigated several methods, in lieu of infectivity studies, to assess oncosphere viability and determine lethal temperature treatment regimens. In the first experiment, a standard treatment to exshell oncospheres with 0.5% hypochlorite was assessed for influence on oncosphere recovery of Taenia taeniaeformis eggs. Recovery of eggs and exshelled oncospheres decreased with increasing time in hypochlorite, which indicated that hypochlorite can damage eggs and oncospheres, translating into potential overestimation of lethality of experimental treatments. Losses in hypochlorite were accentuated when eggs were pretreated at 75 degrees C, but not lower temperatures, including 65 degrees C, indicating a sharp threshhold between 65 degrees C and 75 degrees C where eggs and oncospheres became hypersensitive to subsequent hypochlorite treatment. To further investigate this change in relation to temperature, non-vital (acridine orange, AO) and vital (propidium iodide, PI; trypan blue, TB) dyes were used to assess staining of oncospheres (exshelled or not) under conditions ranging from room temperature up to 95 degrees C. The behaviors of dyes as related to internal staining of oncospheres were described using non-linear regression and a sigmoid four-parametric model to determine the inflection point (T50). Each of the dyes differed significantly in T50 estimates, e.g. AO (69.22+/-0.53), PI (73.89+/-0.52) and TB (79.43+/-0.45). For these dyes, the T50 increased in relation to the increasing molecular weight of the dyes. Collectively, the results suggested that barriers to chemical permeability exist in eggs that breakdown incrementally with increasing temperatures above 65 degrees C. This staining behavior and the likelihood that the temperatures involved are above a lethal threshhold clarify a basic limitation in the use of vital dyes to assess oncosphere viability. The results may be relevant to other Taenia spp.


Assuntos
Coloração e Rotulagem/veterinária , Taenia/efeitos dos fármacos , Taenia/fisiologia , Laranja de Acridina/química , Laranja de Acridina/metabolismo , Animais , Corantes/química , Corantes/metabolismo , Temperatura Alta , Peso Molecular , Óvulo/efeitos dos fármacos , Óvulo/fisiologia , Oxidantes/farmacologia , Propídio/química , Propídio/metabolismo , Análise de Regressão , Hipoclorito de Sódio/farmacologia , Fatores de Tempo , Azul Tripano/química , Azul Tripano/metabolismo
20.
Biochem Mol Biol Educ ; 46(4): 306-317, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29528559

RESUMO

Disciplines such as Biochemistry and Molecular Biology, which involve concepts not included in the high-school curriculum, are very challenging for many first year university students. These subjects are particularly difficult for students accustomed to surface learning strategies involving memorization and recall of facts, as a deeper understanding of the relationship between concepts is needed for successful transfer to related areas and subsequent study. In this article, we explore an activity in a very large first year Molecular Biology course, in which students create multiple-choice questions related to targeted learning outcomes, and then answer and evaluate one another's questions. This activity encompasses elements of both self- and peer-assessment and the generative tasks of creating questions and producing written feedback may contribute to a deeper understanding of the material. We make use of a free online platform to facilitate all aspects of the process and analyze the effect of student engagement with the task on overall course performance. When compared to previous semester's cohorts, we observe a pronounced improvement in class performance on exam questions targeting similar concepts to the student-generated questions. In addition, those students that engage to a greater extent with the activity perform significantly better on the targeted exam questions than those who are less active, yet all students perform similarly on a set of isolated control questions appearing on the same exam. © 2018 by The International Union of Biochemistry and Molecular Biology, 46:306-317, 2018.


Assuntos
Aprendizagem Baseada em Problemas , Avaliação Educacional , Humanos , Biologia Molecular , Estudantes
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