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1.
Biol Sport ; 39(3): 563-569, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35959328

RESUMO

This study aimed to evaluate the application of a single pre-exercise bout of partial-body cryotherapy (PBC) to augment jump performance, salivary biomarkers and self-reported performance readiness. Twelve male rugby union players (age 20.7 ± 3.2 yr; body mass 93.1 ± 13.9 kg; mean ± SD) were exposed to PBC for 3 min at -140°C or control condition prior to a pre-post series of loaded countermovement jumps (CMJ), salivary biomarker samples and performance readiness questionnaires. PBC elicited a moderately greater improvement in CMJ velocity of +4.7 ± 3.5% (mean ± 90% confidence limits) from baseline to 15 min in comparison with a -1.9 ± 4.8% mean difference in the control condition. The mean change in concentration of salivary α-amylase at 15 min was substantially increased by +131 ± 109% after PBC exposure, compared to a -4.2 ± 42% decrease in the control. Salivary testosterone concentrations were unclear at all timepoints in both the PBC and control interventions. Self-reported perceptions of overall performance readiness indicated small to moderate increases in mental fatigue, mood, muscle soreness and overall questionnaire score after PBC compared to control with a higher score more favourable for performance. The application of pre-exercise PBC can elicit favourable outcomes in controlled physical performance tests and holds promise to be applied to training or competition settings.

2.
BMC Musculoskelet Disord ; 22(1): 1048, 2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34930192

RESUMO

BACKGROUND: Greater trochanteric pain syndrome (GTPS) is a musculoskeletal condition which can cause disability and reduce quality of life. However, limited evidence is available on the long-term outcomes of people with GTPS. Our aims were to determine the long-term prevalence of GTPS; to calculate the proportion of people with GTPS who had developed hip osteoarthritis (OA); and to determine the level of function and quality of life, 11-years after initial GTPS diagnosis. METHODS: A prospective 11-year natural history study. Two groups [GTPS group (n = 24), asymptomatic control (ASC) group (n = 20)] were evaluated at baseline, 12-months and 11-years. At 11-years all participants completed the modified Harris Hip Score (mHHS), Oswestry Disability Index (ODI) and Assessment of Quality-of-Life questionnaire. At 11-year follow-up 20/24 GTPS and 19/20 ASC participants were clinically assessed for GTPS and hip OA, completed the 10 metre-walk-test, timed up and go, and hip abduction and external rotation strength testing. RESULTS: At 11-year follow-up 45.0% of GTPS participants had GTPS compared to 5.3% of ASC participants (p = 0.008), OR [95% CI]: 10.19 [1.95, 104.3], and 35.0% of GTPS participants were clinically diagnosed with hip OA compared to none of the ASC participants (p = 0.002), OR [95% CI]: 21.6, [2.3, 2898.0]. GTPS participants reported more pain and disability than ASC participants via the ODI, mean difference [95% CI]: 6.1 [0.7, 11.6] but not the modified Harris Hip Score, mean difference [95% CI]: -3.3 [-10.3, 3.7]. Both groups had similar levels of quality of life and measures of function. CONCLUSIONS: GTPS is a chronic condition: people with GTPS at baseline had twice the odds of being clinically diagnosed with GTPS or hip OA than the control group at 11-years. Further, there appears to be a temporal relationship between GTPS and the development of hip OA. This finding highlights the need to identify effective treatments that address the underlying impairments associated with GTPS. Pain and function results varied depending on the assessment tools used. Between group differences in quality of life seen at baseline are not found at the 11-year follow-up. The small sample size means the results must be considered with caution. LEVEL OF EVIDENCE: Level II Natural history Study.


Assuntos
Bursite , Qualidade de Vida , Seguimentos , Humanos , Dor , Estudos Prospectivos
3.
BMC Cancer ; 20(1): 787, 2020 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-32819304

RESUMO

BACKGROUND: Cardiovascular disease (CVD) remains the largest cause of death in breast cancer survivors. The aim of this study was to explore the impact of exercise intensity on aerobic fitness and autonomic cardiac regulation (heart rate variability (HRV)) and salivary biomarkers of the stress systems (HPA-axis, cortisol; sympathetic nervous system, α-amylase) and mucosal immunity (secretory(s)-IgA), markers of increased risk of CVD in breast cancer survivors. METHODS: Participants were randomly assigned to; 1) high intensity interval training (HIIT); 2) moderate-intensity, continuous aerobic training (CMIT); or 3) a wait-list control (CON) for a 12-week (36 session) stationary cycling intervention. Cardiorespiratory fitness (VO2peak), resting HRV and salivary biomarkers were measured at baseline 2-4 d pre-intervention and 2-4 d post the last exercise session. RESULTS: Seventeen participants were included in this study (62 ± 8 years, HIIT; n = 6, CMIT; n = 5, CON; n = 6). A significant improvement (p ≤ 0.05) was observed for VO2peak in the HIIT group; 19.3% (B = 3.98, 95%CI = [1.89; 4.02]) and a non-significant increase in the CMIT group; 5.6% (B = 1.96, 95%CI = [- 0.11; 4.03]), compared with a 2.6% (B = - 0.64, 95%CI = [- 2.10; 0.82]) decrease in the CON group. Post intervention improvements in HRV markers of vagal activity (log (ln)LF/HF, LnRMSSD) and sympathetic nervous system (α-amylase waking response) occurred for individuals exhibiting outlying (> 95% CI) levels at baseline compared to general population. CONCLUSION: High intensity interval training improved cardiovascular fitness in breast cancer survivors and improved cardiac regulation, and sympathetic nervous system (stress) responses in some individuals. High-intensity interval training was safe and effective for breast cancer survivors to participate in with promising results as a time efficient intensity to improve physical health and stress, reducing CVD risk. TRIAL REGISTRATION: This pilot study was retrospectively registered through the Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12620000684921 .


Assuntos
Neoplasias da Mama/reabilitação , Sobreviventes de Câncer/estatística & dados numéricos , Terapia por Exercício/métodos , Treinamento Intervalado de Alta Intensidade/métodos , Estresse Psicológico/diagnóstico , Idoso , Austrália , Biomarcadores/sangue , Neoplasias da Mama/complicações , Neoplasias da Mama/mortalidade , Neoplasias da Mama/fisiopatologia , Sobreviventes de Câncer/psicologia , Aptidão Cardiorrespiratória/fisiologia , Doenças Cardiovasculares/fisiopatologia , Doenças Cardiovasculares/prevenção & controle , Terapia por Exercício/efeitos adversos , Feminino , Treinamento Intervalado de Alta Intensidade/efeitos adversos , Humanos , Hidrocortisona/sangue , Pessoa de Meia-Idade , Projetos Piloto , Comportamento Sedentário , Estresse Psicológico/sangue , Estresse Psicológico/fisiopatologia , Sistema Nervoso Simpático/fisiopatologia , Resultado do Tratamento , alfa-Amilases/sangue
4.
J Virol ; 92(16)2018 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-29875251

RESUMO

Global swine populations infected with influenza A viruses pose a persistent pandemic risk. With the exception of a few countries, our understanding of the genetic diversity of swine influenza viruses is limited, hampering control measures and pandemic risk assessment. Here we report the genomic characteristics and evolutionary history of influenza A viruses isolated in Australia from 2012 to 2016 from two geographically isolated swine populations in the states of Queensland and Western Australia. Phylogenetic analysis with an expansive human and swine influenza virus data set comprising >40,000 sequences sampled globally revealed evidence of the pervasive introduction and long-term establishment of gene segments derived from several human influenza viruses of past seasons, including the H1N1/1977, H1N1/1995, H3N2/1968, and H3N2/2003, and the H1N1 2009 pandemic (H1N1pdm09) influenza A viruses, and a genotype that contained gene segments derived from the past three pandemics (1968, reemerged 1977, and 2009). Of the six human-derived gene lineages, only one, comprising two viruses isolated in Queensland during 2012, was closely related to swine viruses detected from other regions, indicating a previously undetected circulation of Australian swine lineages for approximately 3 to 44 years. Although the date of introduction of these lineages into Australian swine populations could not be accurately ascertained, we found evidence of sustained transmission of two lineages in swine from 2012 to 2016. The continued detection of human-origin influenza virus lineages in swine over several decades with little or unpredictable antigenic drift indicates that isolated swine populations can act as antigenic archives of human influenza viruses, raising the risk of reemergence in humans when sufficient susceptible populations arise.IMPORTANCE We describe the evolutionary origins and antigenic properties of influenza A viruses isolated from two separate Australian swine populations from 2012 to 2016, showing that these viruses are distinct from each other and from those isolated from swine globally. Whole-genome sequencing of virus isolates revealed a high genotypic diversity that had been generated exclusively through the introduction and establishment of human influenza viruses that circulated in past seasons. We detected six reassortants with gene segments derived from human H1N1/H1N1pdm09 and various human H3N2 viruses that circulated during various periods since 1968. We also found that these swine viruses were not related to swine viruses collected elsewhere, indicating independent circulation. The detection of unique lineages and genotypes in Australia suggests that isolated swine populations that are sufficiently large can sustain influenza virus for extensive periods; we show direct evidence of a sustained transmission for at least 4 years between 2012 and 2016.


Assuntos
Variação Genética , Vírus da Influenza A/classificação , Vírus da Influenza A/isolamento & purificação , Infecções por Orthomyxoviridae/veterinária , Doenças dos Suínos/virologia , Suínos/virologia , Animais , Genótipo , Humanos , Vírus da Influenza A/genética , Epidemiologia Molecular , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/virologia , Filogenia , Queensland/epidemiologia , Doenças dos Suínos/epidemiologia , Austrália Ocidental/epidemiologia
5.
Int J Sport Nutr Exerc Metab ; 29(3): 282-288, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-29989475

RESUMO

Given the importance of body composition in maintaining optimal physical and functional capacities, the use of appropriate, field-based assessment tools should be a priority to assist in maintaining the occupational safety of firefighters and the community. For ease, body mass index has often been used to assess these changes. However, it is limited in its accuracy. The purposes of this study were twofold: (a) to compare the validity of different measures of body composition against dual-energy X-ray absorptiometry (DXA) in urban firefighters and (b) to assess these measures in their ability to provide meaningful interpretation of criteria-driven categories of adiposity. A total of 64 male firefighters (age = 44.0 ± 9.5 years) underwent full anthropometric profiling (predictor equations used to determine body fat percentage [BF%]), bioelectrical impedance analysis (BIA), and DXA assessments. Participants' body mass index was calculated, and BF% and lean mass were determined along with criteria-driven categorizations of adiposity. Anthropometric (skinfolds) predictor equations (e.g., mean bias = -4.4% for BF%) were typically closer to DXA measures, compared with BIA (9.4% for BF%). However, when determining categories of criteria-driven adiposity, BIA (42.9% overweight or obese) provided closer estimates to the DXA-determined distribution (44.6%) than anthropometric-based measures (up to 40%). Body mass index appears an inappropriate measure for accurately determining categories of adiposity with 64.1% classified as overweight or obese. Given the logistical constraints of anthropometric profiling, and the closeness of BIA to DXA in adiposity categories, BIA may be a suitable alternative to DXA for assessing body composition in professional urban firefighters.


Assuntos
Absorciometria de Fóton , Antropometria/métodos , Composição Corporal , Impedância Elétrica , Bombeiros , Adiposidade , Adulto , Índice de Massa Corporal , Humanos , Masculino , Pessoa de Meia-Idade , Dobras Cutâneas
6.
Eur Radiol ; 26(3): 874-83, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26105023

RESUMO

OBJECTIVE: To compare the performance of different types of detectors in breast cancer detection. METHODS: A mammography image set containing subtle malignant non-calcification lesions, biopsy-proven benign lesions, simulated malignant calcification clusters and normals was acquired using amorphous-selenium (a-Se) detectors. The images were adapted to simulate four types of detectors at the same radiation dose: digital radiography (DR) detectors with a-Se and caesium iodide (CsI) convertors, and computed radiography (CR) detectors with a powder phosphor (PIP) and a needle phosphor (NIP). Seven observers marked suspicious and benign lesions. Analysis was undertaken using jackknife alternative free-response receiver operating characteristics weighted figure of merit (FoM). The cancer detection fraction (CDF) was estimated for a representative image set from screening. RESULTS: No significant differences in the FoMs between the DR detectors were measured. For calcification clusters and non-calcification lesions, both CR detectors' FoMs were significantly lower than for DR detectors. The calcification cluster's FoM for CR NIP was significantly better than for CR PIP. The estimated CDFs with CR PIP and CR NIP detectors were up to 15% and 22% lower, respectively, than for DR detectors. CONCLUSION: Cancer detection is affected by detector type, and the use of CR in mammography should be reconsidered. KEY POINTS: The type of mammography detector can affect the cancer detection rates. CR detectors performed worse than DR detectors in mammography. Needle phosphor CR performed better than powder phosphor CR. Calcification clusters detection is more sensitive to detector type than other cancers.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Calcinose/diagnóstico por imagem , Mamografia/instrumentação , Idoso , Detecção Precoce de Câncer/instrumentação , Detecção Precoce de Câncer/métodos , Feminino , Humanos , Mamografia/métodos , Programas de Rastreamento/instrumentação , Programas de Rastreamento/métodos , Pessoa de Meia-Idade , Agulhas , Variações Dependentes do Observador , Curva ROC , Intensificação de Imagem Radiográfica/métodos
8.
Radiology ; 277(3): 697-706, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26176654

RESUMO

PURPOSE: To compare the diagnostic performance of two-dimensional (2D) mammography, 2D mammography plus digital breast tomosynthesis (DBT), and synthetic 2D mammography plus DBT in depicting malignant radiographic features. MATERIALS AND METHODS: In this multicenter, multireader, retrospective reading study (the TOMMY trial), after written informed consent was obtained, 8869 women (age range, 29-85 years; mean, 56 years) were recruited from July 2011 to March 2013 in an ethically approved study. From these women, a reading dataset of 7060 cases was randomly allocated for independent blinded review of (a) 2D mammography images, (b) 2D mammography plus DBT images, and (c) synthetic 2D mammography plus DBT images. Reviewers had no access to results of previous examinations. Overall sensitivities and specificities were calculated for younger women and those with dense breasts. RESULTS: Overall sensitivity was 87% for 2D mammography, 89% for 2D mammography plus DBT, and 88% for synthetic 2D mammography plus DBT. The addition of DBT was associated with a 34% increase in the odds of depicting cancer (odds ratio [OR] = 1.34, P = .06); however, this level did not achieve significance. For patients aged 50-59 years old, sensitivity was significantly higher (P = .01) for 2D mammography plus DBT than it was for 2D mammography. For those with breast density of 50% or more, sensitivity was 86% for 2D mammography compared with 93% for 2D mammography plus DBT (P = .03). Specificity was 57% for 2D mammography, 70% for 2D mammography plus DBT, and 72% for synthetic 2D mammography plusmDBT. Specificity was significantly higher than 2D mammography (P < .001in both cases) and was observed for all subgroups (P < .001 for all cases). CONCLUSION: The addition of DBT increased the sensitivity of 2D mammography in patients with dense breasts and the specificity of 2D mammography for all subgroups. The use of synthetic 2D DBT demonstrated performance similar to that of standard 2D mammography with DBT. DBT is of potential benefit to screening programs, particularly in younger women with dense breasts. (©) RSNA, 2015.


Assuntos
Neoplasias da Mama/diagnóstico , Detecção Precoce de Câncer/métodos , Imageamento Tridimensional/métodos , Mamografia/métodos , Adulto , Idoso , Erros de Diagnóstico , Feminino , Humanos , Pessoa de Meia-Idade , Curva ROC , Estudos Retrospectivos , Reino Unido
9.
J Asthma ; 52(9): 913-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25563059

RESUMO

OBJECTIVE: To investigate the reliability and the utility of spirometry generated by community pharmacists participating in two large asthma intervention trials of 892 people. METHODS: The Pharmacy Asthma Care Program (PACP) and the Pharmacy Asthma Management Service (PAMS) involved up to four visits to the pharmacy over 6 months for counseling and goal setting. Pharmacists performed spirometry according to ATS/ERS guidelines to inform management. The proportion of A-E, F quality tests, as per EasyOne QC grades, were recorded. Lung function results between visits and for participants referred/not referred to their general practitioner on the basis of spirometry were compared. RESULTS: Complete data from 2593 spirometry sessions were recorded, 68.5% of spirometry sessions achieved three acceptable tests with between-test repeatability of 150 ml or less (A or B quality), 96% of spirometry sessions included at least one test that met ATS/ERS acceptability criteria. About 39.1% of participants had FEV1/FVC values below the lower limit of normal (LNN), indicating a respiratory obstruction. As a result of the service, there was a significant increase in FEV1 and FEV1/FVC and asthma control. Lung function values were significantly poorer for participants referred to their general practitioner, compared with those not referred, on the basis of spirometry. CONCLUSIONS: Community pharmacists are able to reliably achieve spirometry results meeting ATS/ERS guidelines in people with asthma. Significant improvements in airway obstruction were demonstrated with the pharmacy services. Pharmacists interpreted lung function results to identify airway obstruction for referral, making this a useful technique for review of people with asthma in the community.


Assuntos
Asma/fisiopatologia , Serviços Comunitários de Farmácia/organização & administração , Adulto , Idoso , Serviços Comunitários de Farmácia/normas , Humanos , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Testes de Função Respiratória , Espirometria
10.
AJR Am J Roentgenol ; 203(2): 387-93, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25055275

RESUMO

OBJECTIVE. The objective of our study was to investigate the effect of image processing on the detection of cancers in digital mammography images. MATERIALS AND METHODS. Two hundred seventy pairs of breast images (both breasts, one view) were collected from eight systems using Hologic amorphous selenium detectors: 80 image pairs showed breasts containing subtle malignant masses; 30 image pairs, biopsy-proven benign lesions; 80 image pairs, simulated calcification clusters; and 80 image pairs, no cancer (normal). The 270 image pairs were processed with three types of image processing: standard (full enhancement), low contrast (intermediate enhancement), and pseudo-film-screen (no enhancement). Seven experienced observers inspected the images, locating and rating regions they suspected to be cancer for likelihood of malignancy. The results were analyzed using a jackknife-alternative free-response receiver operating characteristic (JAFROC) analysis. RESULTS. The detection of calcification clusters was significantly affected by the type of image processing: The JAFROC figure of merit (FOM) decreased from 0.65 with standard image processing to 0.63 with low-contrast image processing (p = 0.04) and from 0.65 with standard image processing to 0.61 with film-screen image processing (p = 0.0005). The detection of noncalcification cancers was not significantly different among the image-processing types investigated (p > 0.40). CONCLUSION. These results suggest that image processing has a significant impact on the detection of calcification clusters in digital mammography. For the three image-processing versions and the system investigated, standard image processing was optimal for the detection of calcification clusters. The effect on cancer detection should be considered when selecting the type of image processing in the future.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Calcinose/diagnóstico por imagem , Mamografia/métodos , Intensificação de Imagem Radiográfica/métodos , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Idoso , Biópsia , Feminino , Humanos , Pessoa de Meia-Idade , Reino Unido
11.
Ergonomics ; 57(4): 612-21, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24588283

RESUMO

Currently, there is no enforcement of physical standards within Australian fire services post-recruitment, possibly leading to inappropriate fitness and body composition. This study evaluated the impacts of ageing on physical standards of Australian firefighters. Seventy-three firefighters from three different 10-year age groups [25-34 years (n = 27), 35-44 years (n = 27), 45-54 years (n = 19)] volunteered for physical testing using dual-energy X-ray analysis and existing fitness tests used for recruitment by an Australian fire service. Older (45-54 years) participants demonstrated significantly poorer physical standards compared with younger participants including cardiovascular fitness (p < 0.05), strength (p = 0.001) and simulated operational power testing tasks (p < 0.001). Age-related body composition changes were also observed independent of body mass index. Minimum recruitment standards and fitness programs need to account for age-related declines in physical capabilities to ensure that the minimum standard is maintained regardless of age.


Assuntos
Envelhecimento/fisiologia , Composição Corporal , Bombeiros , Seleção de Pessoal/normas , Aptidão Física , Absorciometria de Fóton , Adulto , Austrália , Teste de Esforço , Força da Mão , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio , População Urbana
12.
Med Phys ; 39(6): 3202-13, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22755704

RESUMO

PURPOSE: This study aims to investigate if microcalcification detection varies significantly when mammographic images are acquired using different image qualities, including: different detectors, dose levels, and different image processing algorithms. An additional aim was to determine how the standard European method of measuring image quality using threshold gold thickness measured with a CDMAM phantom and the associated limits in current EU guidelines relate to calcification detection. METHODS: One hundred and sixty two normal breast images were acquired on an amorphous selenium direct digital (DR) system. Microcalcification clusters extracted from magnified images of slices of mastectomies were electronically inserted into half of the images. The calcification clusters had a subtle appearance. All images were adjusted using a validated mathematical method to simulate the appearance of images from a computed radiography (CR) imaging system at the same dose, from both systems at half this dose, and from the DR system at quarter this dose. The original 162 images were processed with both Hologic and Agfa (Musica-2) image processing. All other image qualities were processed with Agfa (Musica-2) image processing only. Seven experienced observers marked and rated any identified suspicious regions. Free response operating characteristic (FROC) and ROC analyses were performed on the data. The lesion sensitivity at a nonlesion localization fraction (NLF) of 0.1 was also calculated. Images of the CDMAM mammographic test phantom were acquired using the automatic setting on the DR system. These images were modified to the additional image qualities used in the observer study. The images were analyzed using automated software. In order to assess the relationship between threshold gold thickness and calcification detection a power law was fitted to the data. RESULTS: There was a significant reduction in calcification detection using CR compared with DR: the alternative FROC (AFROC) area decreased from 0.84 to 0.63 and the ROC area decreased from 0.91 to 0.79 (p < 0.0001). This corresponded to a 30% drop in lesion sensitivity at a NLF equal to 0.1. Detection was also sensitive to the dose used. There was no significant difference in detection between the two image processing algorithms used (p > 0.05). It was additionally found that lower threshold gold thickness from CDMAM analysis implied better cluster detection. The measured threshold gold thickness passed the acceptable limit set in the EU standards for all image qualities except half dose CR. However, calcification detection varied significantly between image qualities. This suggests that the current EU guidelines may need revising. CONCLUSIONS: Microcalcification detection was found to be sensitive to detector and dose used. Standard measurements of image quality were a good predictor of microcalcification cluster detection.


Assuntos
Calcinose/diagnóstico por imagem , Mamografia/métodos , Intensificação de Imagem Radiográfica/métodos , Neoplasias da Mama/complicações , Neoplasias da Mama/diagnóstico por imagem , Calcinose/complicações , Humanos , Processamento de Imagem Assistida por Computador , Imagens de Fantasmas , Controle de Qualidade , Curva ROC , Doses de Radiação
13.
Avian Pathol ; 41(2): 161-76, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22515535

RESUMO

We report the pathotyping of six Australian isolates of Marek's disease virus-1 (MDV1) isolated between 1992 and 2004 and association of virulence with meq gene polymorphism. Unvaccinated and herpesvirus of turkeys (HVT)-vaccinated specific pathogen free chickens were challenged at day 5 with 500 plaque forming units of Marek's disease virus. The isolates induced gross Marek's disease lesions in 53 to 94% of unvaccinated chickens, and HVT induced a protective index ranging from 38 to 100% by 56 days post challenge. This experiment provides evidence that current Australian isolates of MDV1 vary significantly in pathogenicity. However, there was no clear evidence that the most virulent recent isolates were more pathogenic than isolates from the 1980s or that any of the isolates belong to the highest pathotype category of very virulent plus. Evidence is presented that virulence can be predicted by measurements taken as early as 13 days post challenge. The meq gene sequences of five of the isolates used in the experiment were determined. When compared with the very virulent US isolate Md5, there was a 177 base-pair insertion and distinct point mutations in each of the five isolates. There were no individual mutations in the meq sequences that correlated with levels of virulence. However, amino acid alignment of the five Australian and 14 international isolates revealed that the number of repeat sequences of four prolines (PPPP repeats) in the meq gene (overall range 2 to 8) was strongly associated with virulence across all isolates, with the most pathogenic isolates having the fewest number of repeats. The results suggest that the presence of the 177 base-pair insertion alone is not an indicator of attenuation. Rather, the number of PPPP repeats, independent of the presence of the insertion, is a better indicator of pathogenicity.


Assuntos
Galinhas , Herpesvirus Galináceo 2/patogenicidade , Doença de Marek/virologia , Proteínas Oncogênicas Virais/genética , Polimorfismo Genético/genética , Doenças das Aves Domésticas/virologia , Sequência de Aminoácidos , Animais , Austrália , Sequência de Bases , Herpesvirus Galináceo 2/genética , Doença de Marek/mortalidade , Doença de Marek/patologia , Dados de Sequência Molecular , Doenças das Aves Domésticas/mortalidade , Doenças das Aves Domésticas/patologia , Sequências Repetitivas de Aminoácidos/genética , Alinhamento de Sequência , Análise de Sequência de DNA , Virulência
14.
Int J Sports Physiol Perform ; 17(6): 893-900, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35235905

RESUMO

PURPOSE: This study evaluated the effect of partial-body cryotherapy (PBC) exposure 1, 2, or 3 hours before maximal-effort jump performance, salivary enzyme concentration, perceived readiness, and well-being. METHODS: Male team-sport players (N = 27; 24.2 [3.6] y; 91.5 [13.2] kg) were exposed to a blinded bout of PBC (-135°C [6°C]) and control (-59°C [17°C]) either 1, 2, or 3 hours prior to countermovement jumps. Passive saliva samples were collected to determine α-amylase concentration. Self-reported performance readiness and well-being questionnaires were completed using a 1-5 Likert scale. RESULTS: Differences in the change in mean countermovement jump velocity and absolute power between PBC and control were unclear at 1 hour (+1.9% [5.3%], P = .149; +0.7% [10.6%], P = .919; mean difference [90% confidence limits]), 2 hours (+3.3% [2.7%], P = .196; +7.8% [7.4%], P = .169), and 3 hours postexposure (+3.1% [3.3%], P = .467; +0.7% [4.8%], P = .327). Salivary α-amylase concentration was elevated 15 minutes postexposure in the 1-hour (+61% [14%], P = .008) and 2-hour groups (+55% [12%], P = .013). The increase in self-reported performance readiness was higher after PBC (+2.4 [1.2] units, P = .046) in the 2-hour group and by 1.4 (1.1) units (P = .023) after 3 hours. Mental fatigue was favorably decreased 2 hours after PBC exposure (+0.5 [0.1], P = .041). CONCLUSIONS: An acute exposure of PBC elicits potentially favorable but unclear changes in countermovement jump performance. The PBC enhances salivary α-amylase concentration and perceived performance readiness, reduces mental fatigue, and could be useful in sport-specific training or competitions.


Assuntos
Desempenho Atlético , alfa-Amilases Salivares , Crioterapia , Humanos , Masculino , Fadiga Mental
15.
Int J Sports Physiol Perform ; 17(3): 415-422, 2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-34920412

RESUMO

PURPOSE: To determine whether a single acute preexercise bout of partial-body cryotherapy (PBC) enhanced maximal-effort shuttle run performance, salivary enzyme concentration, and self-reported performance readiness. METHODS: A total of 18 male rugby league players (age = 20.1 [0.5] y; mass = 91.4 [12.4] kg) were exposed to either PBC for 3 minutes at -136°C (1°C) or a control condition prior to a continuous, high-intensity 6 × 40-m shuttle run test. Passive saliva samples were collected to determine salivary alpha amylase (sAA) concentration. Perceived performance readiness and well-being questionnaires were completed using a 1-to-7 Likert scale. RESULTS: The PBC exposure did not elicit a greater improvement in 6 × 40-m shuttle run performance in comparison with the control condition (standardized difference; +0.4 [5.9%]; P = .881; mean ± 90% confidence limits). The increase in sAA concentration was moderately greater 15 minutes after PBC compared with the control group (+67 [32%], P = .012) and remained moderately higher up to 2 hours post-PBC exposure compared with the control condition (+41 [40%], P = .045). There were greater improvements in self-reported perceptions of muscle soreness (+0.6 [0.4%], P = .043; units ±90% confidence limits) and mood (+0.6 [0.7%], P = .038) after PBC compared with control. CONCLUSIONS: It appears that a single 3-minute bout of PBC does not augment maximal effort shuttle run performance in elite rugby league players. Beneficial increases in sAA concentration, coupled with improved perceptions of muscle soreness and mood, should be explored further for alternative training or precompetition practices.


Assuntos
Desempenho Atlético , Corrida , Adulto , Desempenho Atlético/fisiologia , Crioterapia , Humanos , Masculino , Mialgia/terapia , Corrida/fisiologia , Adulto Jovem
16.
Nurse Educ Today ; 100: 104857, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33714854

RESUMO

OBJECTIVES: This paper aims to investigate pre-registration nursing students' experiences and perceptions of their clinical placements in nursing homes in order to develop recommendations for nurse educators. Evidence indicates that nursing students do not view nursing home placements as favourably as acute hospital placements. Therefore, nurse educators are challenged to facilitate a change in students' perceptions towards working in the nursing home environment. DESIGN: An integrative literature review allowed for the analysis and synthesis of the data relating to students' experiences and perceptions of nursing home practice, from studies with diverse research designs. METHODS: An electronic database search of CINAHL (Ebsco), Pubmed, British Nursing Database (BND), ERIC and social service abstracts, published from 2008 to April 2020 in English was completed. Papers were included using pre-allocated criteria and 649 qualified for closer examination. After exclusion, 21 papers underwent final analysis and synthesis using NIVIO 12. RESULTS: Five main themes were derived from the literature; i) the importance of effective supervision; ii) students' experiences and perceptions of the learning environment; iii) understanding the roles of care staff, iv) comprehensive orientation to the learning environment, and v) curriculum preparation. From these five categories, two synthesised themes were developed: nursing home placement encounters and enhancing learning opportunities. CONCLUSIONS: Increasing the visibility of caring for older people in the curriculum is urgent in order to address nursing students' perceived misconceptions about placements in nursing homes. The development of standalone older people pathways, delivered by experienced and knowledgeable faculty, as well as the provision of compulsory clinical placements in settings exclusive to nursing older people and supervised by registered nurses are recommended. Failing to resolve this immediate problem will result in a further shortage of nurses who are adequately prepared to meet future nursing needs.


Assuntos
Bacharelado em Enfermagem , Estudantes de Enfermagem , Idoso , Docentes de Enfermagem , Humanos , Casas de Saúde , Percepção
17.
Sports (Basel) ; 9(10)2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34678916

RESUMO

Whole- (WBC) and partial-body cryotherapy (PBC) are commonly used sports medicine modalities for the treatment of injury and exercise recovery. Physiological and perceptual effects have the potential to be utilised in a novel application that involves pre-exercise WBC and PBC exposure to improve physical performance. A systematic literature search of multiple databases was conducted in July 2021 to identify and evaluate the effects of pre-exercise exposure of WBC or PBC on physical performance measures, and any potential translational effects. The following inclusion criteria were applied: (1) use of WBC or PBC exposure pre-exercise, (2) use of WBC or PBC in healthy and/or athletic populations, (3) control group was used in the data collection, and (4) investigated physiological, psychosocial or direct physical performance impacts of pre-exercise cryotherapy exposure. A total of 759 titles were identified, with twelve relevant studies satisfying the inclusion criteria after full-text screening. The twelve studies were categorised into three key areas: performance testing (n = 6), oxidative stress response (n = 4) and lysosomal enzyme activity (n = 2). The potential for eliciting favourable physical and physiological responses from pre-exercise WBC or PBC is currently unclear with a paucity of good quality research available. Furthermore, a lack of standardisation of cryotherapy protocols is a current challenge.

18.
Dev Biol ; 327(2): 313-26, 2009 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-19135438

RESUMO

During vertebrate development, the hindbrain is transiently segmented into 7 distinct rhombomeres (r). Hindbrain segmentation takes place within the context of the complex morphogenesis required for neurulation, which in zebrafish involves a characteristic cross-midline division that distributes progenitor cells bilaterally in the forming neural tube. The Eph receptor tyrosine kinase EphA4 and the membrane-bound Ephrin (Efn) ligand EfnB2a, which are expressed in complementary segments in the early hindbrain, are required for rhombomere boundary formation. We showed previously that EphA4 promotes cell-cell affinity within r3 and r5, and proposed that preferential adhesion within rhombomeres contributes to boundary formation. Here we show that EfnB2a is similarly required in r4 for normal cell affinity and that EphA4 and EfnB2a regulate cell affinity independently within their respective rhombomeres. Live imaging of cell sorting in mosaic embryos shows that both proteins function during cross-midline cell divisions in the hindbrain neural keel. Consistent with this, mosaic EfnB2a over-expression causes widespread cell sorting and disrupts hindbrain organization, but only if induced at or before neural keel stage. We propose a model in which Eph and Efn-dependent cell affinity within rhombomeres serve to maintain rhombomere organization during the potentially disruptive process of teleost neurulation.


Assuntos
Efrina-B2/metabolismo , Morfogênese/fisiologia , Receptor EphA4/metabolismo , Rombencéfalo , Células-Tronco/fisiologia , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra , Animais , Adesão Celular/fisiologia , Diferenciação Celular/fisiologia , Divisão Celular/fisiologia , Efrina-B2/genética , Feminino , Humanos , Masculino , Mosaicismo , Receptor EphA4/genética , Rombencéfalo/citologia , Rombencéfalo/embriologia , Fuso Acromático/metabolismo , Células-Tronco/citologia , Peixe-Zebra/anatomia & histologia , Peixe-Zebra/embriologia , Proteínas de Peixe-Zebra/genética
19.
Front Physiol ; 10: 1007, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31447697

RESUMO

The final hours of preparation before competition are important for performance. Recovery, preparation and warm up protocols are evolving continuously and include passive and active modalities often developed by "trial and error" approaches. Passive modalities, such as whole-body cryotherapy (WBC), have the potential to enhance both recovery and preparation. Whole-body cryotherapy has generally been used within a recovery setting after competition or strenuous training for athletes, and in clinical settings for the general population. However, the acute hormonal, anti-inflammatory, perceptual and psychological responses yielded by a single, or repeated, bouts of WBC indicate that this practice could enhance an athlete's competition readiness when used alongside traditional elements of active warm-ups in the hours before competition in addition to aiding recovery in the hours after. Here we summarize and evaluate the acute effects of WBC exposures on physiological, performance and perceptual responses, and examine the likelihood these responses could theoretically translate into enhanced athletic performance. The potential to enhance an athlete's performance using acute passive WBC exposure is a novel intervention that requires further investigation.

20.
Curr Biol ; 15(6): 536-42, 2005 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-15797022

RESUMO

The formation of boundaries between or within tissues is a fundamental aspect of animal development. In the developing vertebrate hindbrain, boundaries separate molecularly and neuroanatomically distinct segments called rhombomeres. Transplantation studies have suggested that rhombomere boundaries form by the local sorting out of cells with different segmental identities. This sorting-out process has been shown to involve repulsive interactions between cells expressing an Eph receptor tyrosine kinase, EphA4, and cells expressing its ephrinB ligands. Although a model for rhombomere-boundary formation based on repulsive Eph-ephrin signaling is well established in the literature, the predictions of this model have not been tested in loss-of-function experiments. Here, we eliminate EphA4 and ephrinB2a proteins in zebrafish with antisense morpholinos (MO) and find that rhombomere boundaries are disrupted in EphA4MO embryos, consistent with a requirement for Eph-ephrin signaling in boundary formation. However, in mosaic embryos, we observe that EphA4MO cells and EphA4-expressing cells sort from one another, an observation that is not predicted by the Eph-ephrin repulsion model but instead suggests that EphA4 promotes cell adhesion within the rhombomeres in which it is expressed. Differential cell adhesion is known to be an effective mechanism for cell sorting. We therefore propose that the well-known EphA4-dependent repulsion between rhombomeres operates in parallel with the EphA4-dependent adhesion within rhombomeres described here to drive the cell sorting that underlies rhombomere-boundary formation.


Assuntos
Adesão Celular/fisiologia , Diferenciação Celular/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Receptor EphA4/fisiologia , Rombencéfalo/embriologia , Transdução de Sinais , Peixe-Zebra/embriologia , Animais , Efrina-B2/metabolismo , Imuno-Histoquímica , Microscopia Confocal , Modelos Biológicos , Morfogênese , Oligonucleotídeos , Rombencéfalo/metabolismo
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