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Cephalopods are highly visual animals with camera-type eyes, large brains, and a rich repertoire of visually guided behaviors. However, the cephalopod brain evolved independently from those of other highly visual species, such as vertebrates; therefore, the neural circuits that process sensory information are profoundly different. It is largely unknown how their powerful but unique visual system functions, as there have been no direct neural measurements of visual responses in the cephalopod brain. In this study, we used two-photon calcium imaging to record visually evoked responses in the primary visual processing center of the octopus central brain, the optic lobe, to determine how basic features of the visual scene are represented and organized. We found spatially localized receptive fields for light (ON) and dark (OFF) stimuli, which were retinotopically organized across the optic lobe, demonstrating a hallmark of visual system organization shared across many species. An examination of these responses revealed transformations of the visual representation across the layers of the optic lobe, including the emergence of the OFF pathway and increased size selectivity. We also identified asymmetries in the spatial processing of ON and OFF stimuli, which suggest unique circuit mechanisms for form processing that may have evolved to suit the specific demands of processing an underwater visual scene. This study provides insight into the neural processing and functional organization of the octopus visual system, highlighting both shared and unique aspects, and lays a foundation for future studies of the neural circuits that mediate visual processing and behavior in cephalopods.
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Octopodiformes , Animais , Olho , Percepção Visual , Sistema Nervoso , Vias Visuais/fisiologiaRESUMO
Cephalopods are highly visual animals with camera-type eyes, large brains, and a rich repertoire of visually guided behaviors. However, the cephalopod brain evolved independently from that of other highly visual species, such as vertebrates, and therefore the neural circuits that process sensory information are profoundly different. It is largely unknown how their powerful but unique visual system functions, since there have been no direct neural measurements of visual responses in the cephalopod brain. In this study, we used two-photon calcium imaging to record visually evoked responses in the primary visual processing center of the octopus central brain, the optic lobe, to determine how basic features of the visual scene are represented and organized. We found spatially localized receptive fields for light (ON) and dark (OFF) stimuli, which were retinotopically organized across the optic lobe, demonstrating a hallmark of visual system organization shared across many species. Examination of these responses revealed transformations of the visual representation across the layers of the optic lobe, including the emergence of the OFF pathway and increased size selectivity. We also identified asymmetries in the spatial processing of ON and OFF stimuli, which suggest unique circuit mechanisms for form processing that may have evolved to suit the specific demands of processing an underwater visual scene. This study provides insight into the neural processing and functional organization of the octopus visual system, highlighting both shared and unique aspects, and lays a foundation for future studies of the neural circuits that mediate visual processing and behavior in cephalopods. Highlights: The functional organization and visual response properties of the cephalopod visual system are largely unknownUsing calcium imaging, we performed mapping of visual responses in the octopus optic lobeVisual responses demonstrate localized ON and OFF receptive fields with retinotopic organizationON/OFF pathways and size selectivity emerge across layers of the optic lobe and have distinct properties relative to other species.
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ABSTRACT: As part of a program to reduce numbers of the human pathogen Campylobacter on retail chickens, 22 broiler processing lines, representing more than 90% of UK production, were characterized by enumerating Campylobacter on pooled neck skins after exsanguination, scalding, defeathering, evisceration, crop removal, inside-outside washing, and air-chilling stages of processing. Sixteen of the processing lines investigated showed significant (P < 0.05) reductions in Campylobacter numbers because of carcass scalding. However, in all of these lines, the following defeathering stage caused a significant increase in Campylobacter contamination that effectively negated the reductions caused by scalding. On four processing lines, primary chilling also caused a significant reduction in numbers of Campylobacter. On three lines, there was a significant microbiological benefit from inside-outside washing. The stages where Campylobacter numbers were reduced require further investigation to determine the specific mechanisms responsible so that the observed pathogen reductions can be optimized and then more widely implemented. The transfer of up to 4 log CFU Campylobacter per g of neck skin from a colonized flock to a following uncolonized flock was observed. Cross-contamination was substantial and still detectable after 5,000 carcasses from an uncolonized flock had been processed. Numbers of Campylobacter recovered from the uncolonized flocks were highest on the first of the uncolonized birds to pass along the line, and in general, the numbers declined as more uncolonized birds were processed. Air sampling recovered low numbers at the processing stages monitored, indicating that airborne transmission was unlikely to be the primary transfer mechanism operating for cross-contamination between flocks.
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Campylobacter , Humanos , Animais , Galinhas/microbiologia , Matadouros , Microbiologia de Alimentos , Contagem de Colônia Microbiana , Reino Unido , Manipulação de Alimentos , Contaminação de Alimentos/análise , Carne/microbiologiaRESUMO
Bipedal locomotion evolved along the archosaurian lineage to birds, shifting from "hip-based" to "knee-based" mechanisms. However, the roles of individual muscles in these changes and their evolutionary timings remain obscure. Using 13 three-dimensional musculoskeletal models of the hindlimbs of bird-line archosaurs, we quantify how the moment arms (i.e., leverages) of 35 locomotor muscles evolved. Our results support two hypotheses: From early theropod dinosaurs to birds, knee flexors' moment arms decreased relative to knee extensors', and medial long-axis rotator moment arms for the hip increased (trading off with decreased hip abductor moment arms). Our results reveal how, from the Triassic Period, bipedal theropod dinosaurs gradually modified their hindlimb form and function, shifting more from hip-based to knee-based locomotion and hip-abductor to hip-rotator balancing mechanisms inherited by birds. Yet, we also discover unexpected ancestral specializations in larger Jurassic theropods, lost later in the bird-line, complicating the paradigm of gradual transformation.
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Dinossauros , Animais , Evolução Biológica , Aves/fisiologia , Dinossauros/fisiologia , Membro Posterior/fisiologia , Locomoção/fisiologia , MúsculosRESUMO
OBJECTIVE: To estimate the association between threatened preterm labour (TPTL) and perinatal outcomes of infants born at term. DESIGN: A population-based cohort study of perinatal outcomes following TPTL <37 weeks of gestation with delivery at term. SETTING: Nova Scotia, Canada. POPULATION: All non-anomalous, singleton pregnancies ≥37 weeks of gestation without antepartum haemorrhage from 1988 to 2019. METHODS: Using data from the Nova Scotia Atlee Perinatal Database, TPTL was defined as pregnancies with a hospital admission between 20 and 37 weeks of gestation, with a diagnosis code denoting TPTL with administration of antenatal corticosteroids, or with administration of any tocolysis. Poisson regression models were used to estimate the risk ratios (RR) with 95% CI of maternal and perinatal outcomes in women who had an episode of TPTL relative to those who did not. MAIN OUTCOME MEASURES: Birthweight for gestational age below the tenth centile and a composite of perinatal mortality or severe perinatal morbidity. RESULTS: Of 256 599 term deliveries meeting the inclusion criteria, 2278 (0.9%) involved TPTL. The risks of the primary outcomes were higher among those with TPTL relative to those without: birthweight for gestational age below the tenth centile (RR 1.24, 95% CI 1.11-1.39) and the composite of perinatal mortality/severe perinatal morbidity (RR 1.33, 95% CI 1.15-1.54). CONCLUSIONS: Although the prevalence of TPTL in term deliveries is low, affected pregnancies are at increased risk for adverse perinatal outcomes. Increased fetal surveillance should be considered in the management of pregnancies affected by TPTL.
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Trabalho de Parto Prematuro/epidemiologia , Estudos de Coortes , Feminino , Idade Gestacional , Glucocorticoides/uso terapêutico , Humanos , Recém-Nascido de Baixo Peso , Recém-Nascido , Nova Escócia/epidemiologia , Mortalidade Perinatal , Gravidez , Complicações na Gravidez/epidemiologia , Transtornos Puerperais/epidemiologia , Tocolíticos/uso terapêuticoRESUMO
BACKGROUND: Hospital drains may be an important reservoir for carbapenemase-producing Enterobacterales (CPE). AIM: To determine prevalence of CPE in hospital drains exposed to inpatients with CPE, relatedness of drain and patient CPE, and risk factors for drain contamination. METHODS: Sink and shower drains in patient rooms and communal shower rooms exposed to 310 inpatients with CPE colonization/infection were cultured at 10 hospitals. Using short- and long-read whole-genome sequencing, inpatient and corresponding drain CPE were compared. Risk factors for drain contamination were assessed using multi-level modelling. FINDINGS: Of 1209 exposed patient room and communal shower room drains, 53 (4%) yielded 62 CPE isolates in seven (70%) hospitals. Of 49 CPE isolates in patient room drains, four (8%) were linked to prior room occupants. Linked drain/room occupant pairs included Citrobacter freundii ST18 isolates separated by eight single nucleotide variants (SNVs), related blaKPC-containing IncN3-type plasmids (different species), related blaKPC-3-containing IncN-type plasmids (different species), and related blaOXA-48-containing IncL/M-type plasmids (different species). In one hospital, drain isolates from eight rooms on two units were Enterobacter hormaechei separated by 0-6 SNVs. Shower drains were more likely to be CPE-contaminated than hand hygiene (odds ratio: 3.45; 95% confidence interval: 1.66-7.16) or patient-use (13.0; 4.29-39.1) sink drains. Hand hygiene sink drains were more likely to be CPE-contaminated than patient-use sink drains (3.75; 1.17-12.0). CONCLUSION: Drain contamination was uncommon but widely dispersed. Drain CPE unrelated to patient exposure suggests contamination by undetected colonized patients or retrograde (drain-to-drain) contamination. Drain types had different contamination risks.
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Enterobacter/isolamento & purificação , Contaminação de Equipamentos , Hospitais , Quartos de Pacientes , Abastecimento de Água , Proteínas de Bactérias , Farmacorresistência Bacteriana , Infecções por Enterobacteriaceae/prevenção & controle , Humanos , Ontário , beta-LactamasesRESUMO
BACKGROUND: The incidence of antimicrobial-resistant Neisseria gonorrhoeae (GC) is rising in Canada; however, antimicrobial resistance (AMR) surveillance data are unavailable for infections diagnosed directly from clinical specimens by nucleic acid amplification tests (NAATs), representing over 80% of diagnoses. We developed a set of 10 improved molecular assays for surveillance of GC-AMR and prediction of susceptibilities in NAAT specimens. METHODS: Multiplex real-time PCR (RT-PCR) assays were developed to detect SNPs associated with cephalosporin (ponA, porB, mtrR -35delA, penA A311V, penA A501, N513Y, G545S), ciprofloxacin (gyrA S91, parC D86/S87/S88) and azithromycin [23S (A2059G, C2611T), mtrR meningitidis-like promoter] resistance. The assays were validated on 127 gonococcal isolates, 51 non-gonococcal isolates and 50 NAATs with matched culture isolates. SNPs determined from the assay were compared with SNPs determined from in silico analysis of WGS data. MICs were determined for culture isolates using the agar dilution method. RESULTS: SNP analysis of the 50 NAAT specimens had 96% agreement with the matched culture RT-PCR analysis. When compared with MICs, presence of penA A311V or penA A501 and two or more other SNPs correlated with decreased susceptibility and presence of three or more other SNPs correlated with intermediate susceptibility to cephalosporins; presence of any associated SNP correlated with ciprofloxacin or azithromycin resistance. NAAT-AMR predictions correlated with matched-culture cephalosporin, ciprofloxacin and azithromycin MICs at 94%, 100% and 98%, respectively. CONCLUSIONS: We expanded molecular tests for N. gonorrhoeae AMR prediction by adding new loci and multiplexing reactions to improve surveillance where culture isolates are unavailable.
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Gonorreia , Neisseria gonorrhoeae , Antibacterianos/farmacologia , Azitromicina/farmacologia , Canadá , Cefalosporinas/farmacologia , Ciprofloxacina/farmacologia , Farmacorresistência Bacteriana , Humanos , Testes de Sensibilidade Microbiana , Neisseria gonorrhoeae/genética , Reação em Cadeia da Polimerase em Tempo RealRESUMO
Adenoviruses are responsible for a spectrum of pathogenesis including viral myocarditis. The gap junction protein connexin43 (Cx43, gene name GJA1) facilitates rapid propagation of action potentials necessary for each heartbeat. Gap junctions also propagate innate and adaptive antiviral immune responses, but how viruses may target these structures is not understood. Given this immunological role of Cx43, we hypothesized that gap junctions would be targeted during adenovirus type 5 (Ad5) infection. We find reduced Cx43 protein levels due to decreased GJA1 mRNA transcripts dependent upon ß-catenin transcriptional activity during Ad5 infection, with early viral protein E4orf1 sufficient to induce ß-catenin phosphorylation. Loss of gap junction function occurs prior to reduced Cx43 protein levels with Ad5 infection rapidly inducing Cx43 phosphorylation events consistent with altered gap junction conductance. Direct Cx43 interaction with ZO-1 plays a critical role in gap junction regulation. We find loss of Cx43/ZO-1 complexing during Ad5 infection by co-immunoprecipitation and complementary studies in human induced pluripotent stem cell derived-cardiomyocytes reveal Cx43 gap junction remodeling by reduced ZO-1 complexing. These findings reveal specific targeting of gap junction function by Ad5 leading to loss of intercellular communication which would contribute to dangerous pathological states including arrhythmias in infected hearts.
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Infecções por Adenoviridae/patologia , Adenoviridae/fisiologia , Comunicação Celular , Conexina 43/metabolismo , Junções Comunicantes/patologia , Miócitos Cardíacos/patologia , Transcrição Gênica , Infecções por Adenoviridae/metabolismo , Infecções por Adenoviridae/virologia , Células Cultivadas , Conexina 43/genética , Junções Comunicantes/virologia , Regulação da Expressão Gênica , Células HEK293 , Humanos , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/virologia , FosforilaçãoRESUMO
BACKGROUND: Rural areas face health care workforce shortages. Nursing students seeking rural employment require instruction and clinical experience in using telehealth to work in health care teams. METHOD: An innovative telehealth consultation simulation paired nurse practitioner (NP) students with prelicensure baccalaureate nursing degree (BSN) students. The simulation aimed to enhance NP student proficiency and confidence in telehealth consultation skills and to foster professional role development through exposure to telehealth nursing roles for RNs and NPs. On-campus BSN students assumed the role of the RN in a rural clinic and consulted with off-campus NP students using telehealth technology in the care of a standardized patient. RESULTS: Participants demonstrated level-appropriate proficiency and reported confidence in telehealth consultation and favorable attitudes toward intraprofessional communication. CONCLUSION: An intraprofessional educational model allowing BSN and NP students to develop telehealth consultation skills successfully addressed a gap in preparing nursing students to meet rural health care workforce needs. [J Nurs Educ. 2020;59(5):274-277.].
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Currículo , Bacharelado em Enfermagem , Profissionais de Enfermagem , Equipe de Assistência ao Paciente , Consulta Remota , Serviços de Saúde Rural , Escolha da Profissão , Competência Clínica , Humanos , Modelos Educacionais , Estudantes de EnfermagemRESUMO
AIM: Following previous research on improving the cleaning of crates used to transport broiler chickens from the farm to the abattoir, a demonstration project was undertaken to investigate improvements in crate washing on a commercial scale. METHODS AND RESULTS: The soak tank of a conventional crate washing system was replaced with a high-performance washer fitted with high-volume, high-pressure nozzles. The wash water could be heated, and a greatly improved filtration system ensured that the nozzles did not lose performance or become blocked. Visual cleanliness scores and microbial counts were determined for naturally contaminated crates which had been randomly assigned to different cleaning protocols. CONCLUSIONS: When a combination of mechanical energy, heat and chemicals (i.e. detergent and disinfectant) was used, the results showed significant improvements to crate cleaning. Reductions of up to 3·6 and 3·8 log10 CFU per crate base were achieved for Campylobacter and Enterobacteriaceae, respectively, along with a marked improvement in visual cleanliness. SIGNIFICANCE AND IMPACT OF THE STUDY: Broiler transport crates may become heavily contaminated with faeces and this may contribute to the spread of disease between farms. The results of this trial may be of use in reducing the spread of zoonotic pathogens in the poultry meat supply chain.
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Galinhas/microbiologia , Desinfecção/métodos , Contaminação de Alimentos/prevenção & controle , Manipulação de Alimentos/métodos , Aves Domésticas/microbiologia , Animais , Campylobacter/efeitos dos fármacos , Campylobacter/isolamento & purificação , Desinfetantes/farmacologia , Desinfecção/instrumentação , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/isolamento & purificação , Desenho de Equipamento , Manipulação de Alimentos/instrumentação , Microbiologia de Alimentos , Reino UnidoRESUMO
BACKGROUND: Epidemiological studies indicate that gene-environment interactions play a role in atopic dermatitis (AD). OBJECTIVES: To review the evidence for gene-environment interactions in AD aetiology, focusing on filaggrin (FLG) loss-of-function mutations. METHODS: A systematic search from inception to September 2018 in Embase, MEDLINE and BIOSIS was performed. Search terms included all synonyms for AD and filaggrin/FLG; any genetic or epidemiological study design using any statistical methods were included. Quality assessment using criteria modified from guidance (ROBINS-I and Human Genome Epidemiology Network) for nonrandomized and genetic studies was completed, including consideration of power. Heterogeneity of study design and analyses precluded the use of meta-analysis. RESULTS: Of 1817 papers identified, 12 studies fulfilled the inclusion criteria required and performed formal interaction testing. There was some evidence for FLG-environment interactions in six of the studies (P-value for interaction ≤ 0·05), including early-life cat ownership, older siblings, water hardness, phthalate exposure, higher urinary phthalate metabolite levels (which all increased AD risk additional to FLG null genotype) and prolonged breastfeeding (which decreased AD risk in the context of FLG null genotype). Major limitations of published studies were the low numbers of individuals (ranging from five to 94) with AD and FLG loss-of-function mutations and exposure to specific environmental factors, and variation in exposure definitions. CONCLUSIONS: Evidence on FLG-environment interactions in AD aetiology is limited. However, many of the studies lacked large enough sample sizes to assess these interactions fully. Further research is needed with larger sample sizes and clearly defined exposure assessment. Linked Comment: Park and Seo. Br J Dermatol 2020; 183:411.
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Dermatite Atópica , Animais , Gatos , Dermatite Atópica/etiologia , Dermatite Atópica/genética , Exposição Ambiental/efeitos adversos , Proteínas Filagrinas , Predisposição Genética para Doença/genética , Genótipo , Proteínas de Filamentos Intermediários/genética , Mutação com Perda de Função , MutaçãoRESUMO
BACKGROUND: Neisseria gonorrhoeae have acquired resistance to many antimicrobials, including third generation cephalosporins and azithromycin, which are the current gonococcal combination therapy recommended by the Canadian Guidelines on Sexually Transmitted Infections. OBJECTIVE: To describe antimicrobial susceptibilities for N. gonorrhoeae circulating in Canada between 2012 and 2016. METHODS: Antimicrobial resistance profiles were determined using agar dilution of N. gonorrhoeae isolated in Canada 2012-2016 (n=10,167) following Clinical Laboratory Standards Institute guidelines. Data were analyzed by applying multidrug-resistant gonococci (MDR-GC) and extensively drug-resistant gonococci (XDR-GC) definitions. RESULTS: Between 2012 and 2016, the proportion of MDR-GC increased from 6.2% to 8.9% and a total of 19 cases of XDR-GC were identified in Canada (0.1%, 19/18,768). The proportion of isolates with decreased susceptibility to cephalosporins declined between 2012 and 2016 from 5.9% to 2.0% while azithromycin resistance increased from 0.8% to 7.2% in the same period. CONCLUSION: While XDR-GC are currently rare in Canada, MDR-GC have increased over the last five years. Azithromycin resistance in N. gonorrhoeae is established and spreading in Canada, exceeding the 5% level at which the World Health Organization states an antimicrobial should be reviewed as an appropriate treatment. Continued surveillance of antimicrobial susceptibilities of N. gonorrhoeae is necessary to inform treatment guidelines and mitigate the impact of resistant gonorrhea.
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OBJECTIVES: This review examines differences in the use of emotion regulation (ER) strategies among younger and older adults. METHOD: A systematic review using search terms related to ageing and ER identified 23 relevant studies. Narrative synthesis was adopted to analyse the findings. RESULTS: Generally, greater use of situation selection and attentional deployment was identified among older adults, although these relationships were dependent on contextual/moderator variables. While older adults employed greater levels of situation modification in response to negative stimuli, there was considerable variation in age differences across specific situation modification subtypes. Available evidence pointed to an absence of age differences in the cognitive change strategy of cognitive reappraisal. The use of relatively less-cognitively demanding cognitive change subtypes (e.g. acceptance) was, under particular circumstances, greater among older adults. Findings regarding the response modulation strategy of expressive suppression were equivocal. CONCLUSION: Adult development is not characterised by straightforward shifts in preferences for use of different ER strategies. Moderator variables appear to be of central importance in shaping the emergence of age differences in ER. Systematically examining interactions of age with individual difference variables and situational factors in samples including oldest-old adults will be important for advancing knowledge regarding developmental differences in ER.
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Cognição , Regulação Emocional , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Atenção , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Autoeficácia , Adulto JovemRESUMO
Human patellae (kneecaps) are thought to act as gears, altering the mechanical advantage of knee extensor muscles during running. Similar sesamoids have evolved in the knee extensor tendon independently in birds, but it is unknown if these also affect the mechanical advantage of knee extensors. Here, we examine the mechanics of the patellofemoral joint in the helmeted guineafowl Numida meleagris using a method based on muscle and tendon moment arms taken about the patella's rotation centre around the distal femur. Moment arms were estimated from a computer model representing hindlimb anatomy, using hip, knee and patellar kinematics acquired via marker-based biplanar fluoroscopy from a subject running at 1.6 ms-1 on a treadmill. Our results support the inference that the patella of Numida does alter knee extensor leverage during running, but with a mechanical advantage generally greater than that seen in humans, implying relatively greater extension force but relatively lesser extension velocity.
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A curated Web-based user-friendly sequence typing tool based on antimicrobial resistance determinants in Neisseria gonorrhoeae was developed and is publicly accessible (https://ngstar.canada.ca). The N. gonorrhoeae Sequence Typing for Antimicrobial Resistance (NG-STAR) molecular typing scheme uses the DNA sequences of 7 genes (penA, mtrR, porB, ponA, gyrA, parC, and 23S rRNA) associated with resistance to ß-lactam antimicrobials, macrolides, or fluoroquinolones. NG-STAR uses the entire penA sequence, combining the historical nomenclature for penA types I to XXXVIII with novel nucleotide sequence designations; the full mtrR sequence and a portion of its promoter region; portions of ponA, porB, gyrA, and parC; and 23S rRNA sequences. NG-STAR grouped 768 isolates into 139 sequence types (STs) (n = 660) consisting of 29 clonal complexes (CCs) having a maximum of a single-locus variation, and 76 NG-STAR STs (n = 109) were identified as unrelated singletons. NG-STAR had a high Simpson's diversity index value of 96.5% (95% confidence interval [CI] = 0.959 to 0.969). The most common STs were NG-STAR ST-90 (n = 100; 13.0%), ST-42 and ST-91 (n = 45; 5.9%), ST-64 (n = 44; 5.72%), and ST-139 (n = 42; 5.5%). Decreased susceptibility to azithromycin was associated with NG-STAR ST-58, ST-61, ST-64, ST-79, ST-91, and ST-139 (n = 156; 92.3%); decreased susceptibility to cephalosporins was associated with NG-STAR ST-90, ST-91, and ST-97 (n = 162; 94.2%); and ciprofloxacin resistance was associated with NG-STAR ST-26, ST-90, ST-91, ST-97, ST-150, and ST-158 (n = 196; 98.0%). All isolates of NG-STAR ST-42, ST-43, ST-63, ST-81, and ST-160 (n = 106) were susceptible to all four antimicrobials. The standardization of nomenclature associated with antimicrobial resistance determinants through an internationally available database will facilitate the monitoring of the global dissemination of antimicrobial-resistant N. gonorrhoeae strains.
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Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Tipagem de Sequências Multilocus/métodos , Neisseria gonorrhoeae/classificação , Neisseria gonorrhoeae/efeitos dos fármacos , Sequência de Aminoácidos , Azitromicina/farmacologia , Cefalosporinas/farmacologia , Fluoroquinolonas/farmacologia , Gonorreia/epidemiologia , Gonorreia/microbiologia , Humanos , Neisseria gonorrhoeae/genética , Neisseria gonorrhoeae/isolamento & purificaçãoRESUMO
REASONS FOR PERFORMING STUDY: Synthetic glucocorticoids are used to treat inflammatory conditions in horses. In other pregnant animals, glucocorticoids are given to stimulate fetal maturation with long-term metabolic consequences for the offspring if given preterm. However, their metabolic effects during equine pregnancy remain unknown. OBJECTIVE: Thus, this study investigated the metabolic effects of dexamethasone administration on pregnant pony mares and their foals after birth. STUDY DESIGN: Experimental study. METHODS: A total of 3 doses of dexamethasone (200 µg/kg bwt i.m.) were given to 6 pony mares at 48 h intervals beginning at ≈270 days of pregnancy. Control saline injections were given to 5 mares using the same protocol. After fasting overnight, pancreatic ß cell responses to exogenous glucose were measured in the mares before, during and after treatment. After birth, pancreatic ß cell responses to exogenous glucose and arginine were measured in the foals at 2 and 12 weeks. RESULTS: In mares during treatment, dexamethasone but not saline increased basal insulin concentrations and prolonged the insulin response to exogenous glucose. Basal insulin and glucose concentrations still differed significantly between the 2 groups 72 h post treatment. Dexamethasone treatment significantly reduced placental area but had little effect on foal biometry at birth or subsequently. Foal ß cell function at 2 weeks was unaffected by maternal treatment. However, by 12 weeks, pancreatic ß cell sensitivity to arginine, but not glucose, was less in foals delivered by dexamethasone- than saline-treated mares. CONCLUSIONS: Dexamethasone administration induced changes in maternal insulin-glucose dynamics, indicative of insulin resistance and had subtle longer term effects on post natal ß cell function of the foals. The programming effects of dexamethasone in horses may be mediated partially by altered maternal metabolism and placental growth.
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Animais Recém-Nascidos , Dexametasona/análogos & derivados , Cavalos/fisiologia , Células Secretoras de Insulina/efeitos dos fármacos , Animais , Dexametasona/administração & dosagem , Dexametasona/farmacologia , Feminino , Hiperinsulinismo/induzido quimicamente , Hiperinsulinismo/veterinária , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , GravidezRESUMO
In several species, adult metabolic phenotype is influenced by the intrauterine environment, often in a sex-linked manner. In horses, there is also a window of susceptibility to programming immediately after birth but whether adult glucose-insulin dynamics are altered by neonatal conditions remains unknown. Thus, this study investigated the effects of birth weight, sex and neonatal glucocorticoid overexposure on glucose-insulin dynamics of young adult horses. For the first 5 days after birth, term foals were treated with saline as a control or ACTH to raise cortisol levels to those of stressed neonates. At 1 and 2 years of age, insulin secretion and sensitivity were measured by exogenous glucose administration and hyperinsulinaemic-euglycaemic clamp, respectively. Glucose-stimulated insulin secretion was less in males than females at both ages, although there were no sex-linked differences in glucose tolerance. Insulin sensitivity was greater in females than males at 1 year but not 2 years of age. Birth weight was inversely related to the area under the glucose curve and positively correlated to insulin sensitivity at 2 years but not 1 year of age. In contrast, neonatal glucocorticoid overexposure induced by adrenocorticotropic hormone (ACTH) treatment had no effect on whole body glucose tolerance, insulin secretion or insulin sensitivity at either age, although this treatment altered insulin receptor abundance in specific skeletal muscles of the 2-year-old horses. These findings show that glucose-insulin dynamics in young adult horses are sexually dimorphic and determined by a combination of genetic and environmental factors acting during early life.
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Peso ao Nascer , Glicemia/metabolismo , Glucocorticoides/farmacologia , Insulina/metabolismo , Envelhecimento , Animais , Animais Recém-Nascidos , Feminino , Cavalos , Resistência à Insulina , Masculino , Receptor de Insulina/metabolismo , Fatores SexuaisRESUMO
As clinical laboratories transition to using culture-independent detection test (CIDT) panels for cases of acute gastroenteritis, culture of clinical specimens is becoming less common. The reduction in bacterial cultures available for public health activities is expected to hinder surveillance and outbreak response by public health laboratories at the local, provincial, national and international levels. These recommendations are intended to serve as guidelines for the implementation of CIDT panels in frontline laboratories in Canada. The United States of America has already seen a significant reduction in culture of stool specimens despite the Association of Public Health Laboratories recommendation to perform reflex culture on positive CIDT specimens. Priority public health organisms addressed in these Canadian guidelines include Shiga toxin-producing Escherichia coli, Shigella and Salmonella and, under regional circumstances, other organisms such as Campylobacter jejuni/coli and Yersinia enterocolitica. These recommendations suggest active engagement between primary diagnostic laboratories and provincial public health laboratories to determine the workflow and protocols for reflex or parallel culture. Consequently, notifiable disease definitions will also need modification, with consultation of all stakeholders. Stakeholders need to work together to enhance recovery of bacterial isolates with best practices used for stool transport and storage.
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Antimicrobial resistance profiles were determined for Neisseria gonorrhoeae strains isolated in Canada during 2010-2014. The proportion of isolates with decreased susceptibility to cephalosporins declined significantly between 2011 and 2014, whereas azithromycin resistance increased significantly during that period. Continued surveillance of antimicrobial drug susceptibilities is imperative to inform treatment guidelines.
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Antibacterianos/uso terapêutico , Azitromicina/uso terapêutico , Cefalosporinas/uso terapêutico , Farmacorresistência Bacteriana/efeitos dos fármacos , Gonorreia/tratamento farmacológico , Neisseria gonorrhoeae/efeitos dos fármacos , Canadá , Humanos , Testes de Sensibilidade Microbiana/métodosRESUMO
We developed a real-time PCR assay to detect single nucleotide polymorphisms associated with ciprofloxacin resistance in specimens submitted for nucleic acid amplification testing (NAAT). All three single nucleotide polymorphism (SNP) targets produced high sensitivity and specificity values. The presence of ≥2 SNPs was sufficient to predict ciprofloxacin resistance in an organism.