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1.
Nature ; 561(7722): 189-194, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30209367

RESUMO

Multidrug-resistant bacteria are spreading at alarming rates, and despite extensive efforts no new class of antibiotic with activity against Gram-negative bacteria has been approved in over fifty years. Natural products and their derivatives have a key role in combating Gram-negative pathogens. Here we report chemical optimization of the arylomycins-a class of natural products with weak activity and limited spectrum-to obtain G0775, a molecule with potent, broad-spectrum activity against Gram-negative bacteria. G0775 inhibits the essential bacterial type I signal peptidase, a new antibiotic target, through an unprecedented molecular mechanism. It circumvents existing antibiotic resistance mechanisms and retains activity against contemporary multidrug-resistant Gram-negative clinical isolates in vitro and in several in vivo infection models. These findings demonstrate that optimized arylomycin analogues such as G0775 could translate into new therapies to address the growing threat of multidrug-resistant Gram-negative infections.


Assuntos
Antibacterianos/classificação , Antibacterianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Peptídeos Cíclicos/farmacologia , Biocatálise/efeitos dos fármacos , Produtos Biológicos/classificação , Produtos Biológicos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Escherichia coli/enzimologia , Bactérias Gram-Negativas/enzimologia , Bactérias Gram-Negativas/patogenicidade , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/microbiologia , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/patogenicidade , Lisina/metabolismo , Proteínas de Membrana/antagonistas & inibidores , Testes de Sensibilidade Microbiana , Peptídeos Cíclicos/química , Porinas , Ligação Proteica , Domínios Proteicos , Serina Endopeptidases , Especificidade por Substrato
2.
Artigo em Inglês | MEDLINE | ID: mdl-38599458

RESUMO

BACKGROUND: Angiotensin receptor blockers (ARBs) are commonly prescribed antihypertensive agents that have well-known antifibrotic properties. The purpose of this study was to examine the association between ARB use and the rates of new-onset adhesive capsulitis as well as adhesive capsulitis requiring operative treatment. METHODS: Using a large national insurance database, a randomly generated cohort of patients with at least 3 continuous months of ARB use between January 2010 and December 2019 (n = 1,000,000) was compared to a separate randomly generated cohort without ARB use (n = 3,000,000). Rates of newly diagnosed adhesive capsulitis and associated manipulation under anesthesia (MUA) and/or arthroscopic capsulotomy were calculated over a 1- and 2-year period following the completion of at least 3 continuous months of ARB therapy. Rates were compared using multivariable logistic regression to control for demographics and comorbidities. Both unadjusted and adjusted odds ratios and 95% confidence intervals were calculated and reported for each comparison. Statistical significance was set at P <.05. RESULTS: The mean age in the ARB cohort was 61.8 years (standard deviation [SD] = 10.0), whereas in the control cohort, it was 54.8 years (SD = 12.3) (P < .001). The ARB cohort had significantly lower rates of newly diagnosed adhesive capsulitis compared with the control cohort at both 1 year (0.15% vs. 0.55%, P < .001) and 2 years (0.3% vs. 0.78%, P < .001). Similar findings were observed for the arthroscopic capsular release/MUA cohort associated with adhesive capsulitis. After adjusting for confounding factors, the lower rates of adhesive capsulitis and arthroscopic capsular release/MUA associated with adhesive capsulitis in the ARB cohort remained statistically significant (P < .001). CONCLUSION: Patients prescribed ARBs experienced a decreased rate of newly diagnosed adhesive capsulitis, as well as adhesive capsulitis requiring surgical intervention when compared to a control cohort. These findings suggest a potential protective effect of ARBs against the development of adhesive capsulitis. Further investigations are warranted to elucidate the underlying mechanisms and establish a causal relationship.

3.
J Pediatr Orthop ; 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38881536

RESUMO

BACKGROUND: Patients with Osgood-Schlatter disease (OSD) may be at increased risk of tibial tubercle fractures due to an underlying weakness of the tibial tubercle apophysis relative to the patellar tendon as a result of repetitive microtrauma. HYPOTHESIS/PURPOSE: The purpose of this study is to analyze the incidence of tibial tubercle fractures in patients with and without Osgood-Schlatter disease. We hypothesized that the incidence of tibial tubercle fractures would be higher in patients with Osgood-Schlatter disease. METHODS: A retrospective cohort analysis of the PearlDiver database was performed by querying all patients diagnosed with Osgood-Schlatter disease between January 2010 and October 2022. An OSD cohort of 146,672 patients was captured using International Classification of Diseases, Ninth Revision (ICD-9), Tenth Revision (ICD-10) billing codes, and age as inclusion/exclusion criteria. The Student t test and the χ2 analyses were used to compare the demographics and obesity between the OSD and control cohorts. Multivariable logistic regressions, controlling for residual differences in age, sex, and obesity, were used to compare rates of tibial tubercle fractures. RESULTS: Patients with a recent history of OSD were found to have higher rates of tibial tubercle fractures than the control group at all measured time points (P<0.001). The 1-year rate of tibial tubercle fractures was 0.62% in the OSD group. The incidence of tibial tubercle fractures in the OSD group was 627.3 cases per 100,000 person-years compared with 42.7 cases per 100,000 person-years in the control group (P<0.001). Male sex and obesity were also associated with an increased risk of sustaining a tibial tubercle fracture within these patient populations (P<0.001). CONCLUSION: We report a significantly higher incidence of tibial tubercle fractures among patients with OSD compared with controls. This increase was most significant at 1 month following OSD diagnosis, however, held true for all measured time points. In addition, male patients and those with obesity were also noted to have increased incidence of tibial tubercle fractures regardless of an OSD diagnosis.

4.
Appl Opt ; 61(14): 4215-4225, 2022 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-36256099

RESUMO

During 2019, an infrared camera, the compact thermal imager (CTI), recorded 15 million images of the Earth from the International Space Station. CTI is based on strained-layer superlattice (SLS) detector technology. The camera covered the spectral range from 3 to 11 µm in two spectral channels, 3.3-5.4 and 7.8-10.7 µm. Individual image frames were 26×21km2 projected on the ground, with 82 m pixel resolution. A frame time of 2.54 s created continuous image swaths with a 13% along-track image overlap. Upper limits determined on the ground and in flight for the electronic offset, read noise, and dark current demonstrated the stability of the SLS detector and camera over many months. Temperature calibration was established using a combination of preflight and in-flight measurements. A narrowband approximation of temperature as a function of photon counts produced an analytic relationship covering a temperature range of 0°-400°C. Examples of CTI images illustrate temperature retrievals over sea ice, urban and agricultural areas, desert, and wildfires.

5.
J Community Health ; 47(6): 949-958, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35925435

RESUMO

The Affordable Care Act includes a call for community health care workers (CHWs) to be integrated into health care delivery systems to improve health care quality. In recent years, there have been increasing calls for community-based participatory research (CBPR) and patient-centered outcomes research (PCOR), as such types of research hold much potential for identifying interventions to reduce health and health care disparities. Yet, little is known about the research training, knowledge, experience, and even interest of CHWs in these types of research or in health research in general (HR). Thus, the purposes of this study include determining if there are differences between participating CHWs (N = 202) in their levels of training, knowledge, experience, and interest in relation to CBPR, PCOR and HR. Findings suggest that certified CHWs, as compared to non-certified CHWs, have significantly higher knowledge levels across all three types of research (ß = 1.3, p = .007). Additionally, participants had significantly higher knowledge of HR compared to CBPR (ß = 0.5, p = .015), but not higher than their knowledge of PCOR (p > .5). Qualitative data analyses performed to determine research areas of interest among the participating CHWs resulted in eighteen major research interest themes. Examples of these major themes are chronic illness (n = 95), health promotion (n = 39), healthcare services and administration (n = 30), mental health (n = 29), and research evaluation and methodology (n = 26). Together, the findings suggest that though CHWs have an interest in a wide range of health research areas, they could benefit from research trainings tailored to their responsibilities and interests.


Assuntos
Agentes Comunitários de Saúde , Patient Protection and Affordable Care Act , Estados Unidos , Humanos , Agentes Comunitários de Saúde/psicologia , Atenção à Saúde , Promoção da Saúde , Pesquisa Participativa Baseada na Comunidade , Pesquisa Qualitativa
6.
Oecologia ; 195(2): 421-433, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33464386

RESUMO

The cool season rainfall at our study site should favour C3 rather than C4 grasses. There are, however, several locations where C4 grasses have become dominant, suggesting that rainfall seasonality is not a constraint on distribution. Here, we explored the limitations on C4 grass distribution in a fynbos shrubland. Using δ13C values of SOM, we determined when these grasses had established. We also looked at the role of roads as conduits for establishment and asked what impact these grasses may have on fynbos species richness. We then conducted a field experiment designed to examine the extent to which soil moisture, nutrient availability, and competition with fynbos for resources influence the establishment and growth of the grasses. Finally using aerial photography, we explored the role of changes in land use on distribution. Our results showed that the establishment is recent, that roads may be acting as conduits, and that with establishment, there is a reduction in fynbos species richness and diversity. Disturbance and removing below-ground competition for resources open the system to establishment in wetter areas. This study is the first to look at the potential for C4 grasses expanding into cool season rainfall shrublands such as in Western Australia and South Africa. What is interesting about these results is that C4 grasses can establish and dominate in a cool season rainfall regime. Rather than temperature of the growing season, it is competition for resources from fynbos that prevents these grasses from encroaching.


Assuntos
Poaceae , Solo , África do Sul , Temperatura
7.
J Dairy Sci ; 104(9): 10203-10216, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34099287

RESUMO

We investigated the single and combined effects of 2 feeding levels (normal lactation diet vs. energy-reduced diet, both fed for ad libitum intake) and 2 daily milking frequencies (twice vs. once) during 1 wk before the dry-off day (d 0), as well as an intramuscular injection of either a dopamine agonist (cabergoline; Velactis, Ceva Santé Animale; labeled for use only with abrupt dry-off, e.g., no reduction in feeding level or milking frequency before the last milking) or saline after the last milking on d 0 on the feeding motivation of clinically healthy, loose-housed, pregnant, lactating Holstein cows. From d 0, all cows were fed the same dry-cow diet for ad libitum intake. Cows were subjected to 2 feed-thwarting tests, a test in the home pen using their diets (test A: d -6, -1, and 1; during 35 min when the feed bins were filled, but locked) and another test carried out in an adjacent pen in which access to concentrate provided in a familiar plastic box was blocked by a wire-mesh lid (test B: d -5 and 2). In test A, we recorded how often cows attempted to feed per 35 min, whether cows vocalized during the 35-min period, and latency to feed within 300 s after feed bins were unlocked. In test B, we recorded latency to approach either of 2 familiar boxes (the wire-mesh box and an identical open box with a small portion of concentrate) within 600 s and how often cows directed behaviors toward the wire-mesh box (number of occurences/5 min). On d -6 (test A), no clear differences in feeding motivation among treatments were found. On d -5 and -1, cows fed the energy-reduced diet displayed a higher probability of vocalizing (test A), were more than 50% quicker to feed (test A), were approximately 5× quicker to approach a box (test B), and directed 60% more behavior toward the wire-mesh box (test B) than cows fed the normal diet. Moreover, cows fed the energy-reduced diet attempted to feed approximately 75% more on d -1 compared with d -6 (test A). On d 2 (test B), cows previously fed the normal diet directed 40% more behavior toward the wire-mesh box than cows previously fed the energy-reduced diet. Reducing feeding level, either before or on the dry-off day, resulted in consistently increased feeding motivation, interpreted as a sign of hunger. No clear effects of change in milking frequency, singly or combined with reduced diet energy density, on feeding motivation were found before d 0. Whereas, on d 2, cows previously milked twice daily were quicker to approach a box than cows previously milked once daily. Cows injected with cabergoline attempted to feed more, but showed lower probability of vocalizing compared with saline-injected cows (d 1; test A), irrespective of treatment before d 0. The effects of cabergoline on feeding motivation are not easily interpreted and warrant further investigation. From a hunger perspective, reducing milking frequency rather than diet energy density seems to be a less negative management to reduce milk production before dry-off.


Assuntos
Lactação , Leite , Ração Animal/análise , Animais , Cabergolina , Bovinos , Indústria de Laticínios , Dieta/veterinária , Feminino , Fome , Gravidez
8.
J Dairy Sci ; 103(9): 8360-8368, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32684445

RESUMO

With growing interest in provision of brushes for cattle and the implications of brush use for behavioral development and welfare, there is a need to validate methodology for quantifying grooming behavior. Our objectives were to characterize patterns of brush use, including bouts, diurnal activity, and individual variability over 24-h periods, and to validate time-sampling methodologies to characterize these traits, including instantaneous recording at various time intervals and continuous recording for subsets of the day. Data sets from previous experiments involving steers (experiment 1; n = 18) and heifers (experiment 2; n = 64), consisting of start and end times of brush use continuously recorded from video, were used to analyze brush use. We extrapolated data sets representative of a range of instantaneous recording intervals and compared daily brush duration and bout characteristics with corresponding values from continuous recording using linear regression. To assess validity of sampling subsets of the day, we selected 2-h time periods representative of different functional parts of the day and compared hourly brush rates with continuous data using Spearman's rank order correlation (rs). Brush use was variable among individuals. All steers used the brush in experiment 1, but 17% (n = 11 of 64) of heifers in experiment 2 did not. Bout analysis revealed that individuals used the brush for an average of 7 to 8 brush bouts lasting 4 to 6 min, leading to an average of 24 and 36 min/d for experiments 1 and 2, respectively. Cattle used the brush mainly during daylight hours, with peaks around sunrise, sunset, and the afternoon. Instantaneous recording at intervals less than 1 to 3 min, depending on the experiment, provided good estimates of daily brush use duration (R2 > 0.95 and slope and intercept not different from 1 and 0, respectively), but intervals >3 min were less reliable. For bout characteristics, the intercept of the modeled line differed from 0 for most recording intervals for both experiments, and the slope differed from 1 for recording intervals >30 s in experiment 1, suggesting that time sampling may have underestimated true values. Of the 2-h periods compared with 24 h of observation, 1800 to 2000 h was most highly correlated (rs = 0.84) for experiment 1, and 1800 to 2000 h and 1400 to 1600 h were the most highly correlated (rs = 0.71 and 0.74, respectively) for experiment 2 with daily values. When using time-sampling methods to characterize brush use, we suggest that the recording interval used and time of day observed should be carefully considered, as time sampling at an interval of 1 to 3 min may measure daily brush use duration, but continuous recording may be required to capture bout characteristics.


Assuntos
Comportamento Animal , Bovinos/fisiologia , Animais , Feminino , Asseio Animal , Modelos Lineares , Masculino , Fatores de Tempo , Desmame
9.
Eur Spine J ; 28(4): 719-726, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30511243

RESUMO

PURPOSE: To evaluate the radiographic and clinical outcomes of the combination of platelet-rich fibrin matrix (PRFM) with beta-tricalcium phosphate (ß-TCP) and bone marrow aspirate (BMA) as a graft alternative in posterolateral lumbar fusion procedures. METHODS: Researchers evaluated 50 consecutive patients undergoing one-level to three-level posterolateral lumbar fusion procedures, resulting in a total of 66 operated levels. The primary outcome was evidence of radiographic fusion at 1-year follow-up, assessed by three independent evaluators using the Lenke scoring system. Secondary outcomes included back and leg VAS scores, incidence of reoperations and complications, return-to-work status, and opioid use. RESULTS: At 1-year follow-up, radiographic fusion was observed in 92.4% (61/66) of operated levels. There was significant improvement in VAS scores for both back and leg pain (p < 0.05). Compared to baseline figures, the number of patients using opioid analgesics at 12-months decreased by 38%. The majority (31/50) of patients were retired, yet 68% of employed patients (n = 19) were able to return to work. No surgical site infections were noted, and no revision surgery at the operated level was required. CONCLUSIONS: This is the first report to analyze the combination of PRFM with ß-TCP and BMA for PLF procedures. Our results indicate a rate of fusion similar to those reported using iliac crest bone graft (ICBG), while avoiding donor site morbidity related to ICBG harvesting such as hematoma, pain, and infection. These slides can be retrieved under Electronic Supplementary Material.


Assuntos
Substitutos Ósseos/uso terapêutico , Fosfatos de Cálcio/uso terapêutico , Vértebras Lombares/cirurgia , Fibrina Rica em Plaquetas , Fusão Vertebral/métodos , Adulto , Idoso , Transplante de Medula Óssea/métodos , Transplante Ósseo/métodos , Terapia Combinada , Feminino , Seguimentos , Humanos , Ílio/transplante , Vértebras Lombares/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Radiografia , Reoperação/estatística & dados numéricos , Estudos Retrospectivos , Resultado do Tratamento
10.
J Dairy Sci ; 102(2): 1530-1541, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30594384

RESUMO

Muddy surfaces have negative effects on the health and welfare of dairy cattle, and if possible, cows will avoid this surface. However, it is unclear whether it is the moisture content or the contamination with manure that is aversive to the cows. This study aimed to assess the use and preference for different wood chip (0.4 m deep) surface types: (1) clean and dry (clean, dry matter content, DM: 44 ± 2.8%), (2) dirty (dirty, contaminated with manure, DM: 40 ± 3.7%), and (3) clean and wet (wet, wetted by water, DM: 23 ± 3.3%). Eighteen nonlactating, pregnant cows were tested individually (mean 24-h temperature: 9.9 ± 4.46°C, mean ± standard deviation for all preceding values). Cows were kept indoors in test pens for 18 h on wood chip without feed and 6 h on pasture to allow for daily feed intake. To ensure cows made informed choices and to measure changes in behavior and hygiene associated with each option, they were first exposed to each surface for 5 d (n = 12 cows per surface type when they were restricted on one surface; i.e., each cow was exposed to 2 treatment surfaces only). Cows on the wet surface spent the least amount of time lying when restricted to one surface for 18 h (wet: 21%, dirty: 57%, clean: 64%) and spent more time lying when on pasture for 6 h (wet: 13%, dirty: 4%, clean: 3%). The total lying times during the 5-d surface exposure were wet: 4.6 ± 1.04 h, dirty: 10.6 ± 0.25 h, and clean: 11.7 ± 0.25 h per 24 h. Cows restricted on the wet surface for 18 h had fewer bouts (no.) of lateral lying (wet: 0.9 ± 1.36, dirty: 6.3 ± 1.36, clean: 8.4 ± 1.38), spent less time lying with their heads supported (wet: 18.9 ± 7.17 min, dirty: 36.7 ± 7.17 min, clean: 39.1 ± 7.26 min), and spent less time with the front legs tucked (wet: 16 ± 4.3%, dirty: 41 ± 4.3%, clean: 50 ± 4.3% of time spent lying, mean ± standard error of the mean for all preceding values), than cows on the other surfaces. Cows on the dirty surface were less clean compared with the other treatment groups (0.6 of a score on a 5-point scale; standard error of the differences of means: 0.11 for both comparisons). They were then given a free choice between 2 known surfaces for 2 consecutive days (n = 6 per pairwise choice). Cows ranked the surfaces as clean > dirty > wet. In summary, there is compelling evidence that wet surfaces impair the welfare of dairy cattle by affecting the quantity and quality of rest. Rebound responses indicate that the motivation to rest is not fulfilled on wet surfaces. Finally, when given a choice, they show clearly that they will avoid wet and dirty surfaces. The combined results indicate that changes in affective state likely underlie these behavioral responses.


Assuntos
Comportamento Animal , Bovinos/fisiologia , Indústria de Laticínios , Abrigo para Animais , Animais , Indústria de Laticínios/métodos , Feminino , Higiene , Gravidez , Temperatura , Água , Madeira
11.
Infect Immun ; 85(8)2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28584161

RESUMO

Parasitic protozoan infections represent a major health burden in the developing world and contribute significantly to morbidity and mortality. These infections are often associated with considerable variability in clinical presentation. An emerging body of work suggests that the intestinal microbiota may help to explain some of these differences in disease expression. The objective of this minireview is to synthesize recent progress in this rapidly advancing field. Studies of humans and animals and in vitro studies of the contribution of the intestinal microbiota to infectious disease are discussed. We hope to provide an understanding of the human-protozoal pathogen-microbiome interaction and to speculate on how that might be leveraged for treatment.


Assuntos
Microbioma Gastrointestinal , Interações Hospedeiro-Parasita , Parasitos/fisiologia , Animais , Humanos , Parasitos/patogenicidade , Infecções por Protozoários/terapia
12.
Int J Equity Health ; 14: 103, 2015 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-26499852

RESUMO

INTRODUCTION: In Australia, there is little empirical research of the racial identity of Indigenous children and youth as the majority of the current literature focuses on adults. Furthermore, there are no instruments developed with cultural appropriateness when exploring the identity and self-esteem of the Australian Aboriginal population, especially children. The IRISE_C (Racial Identity and Self-Esteem of children) inventory was developed to explore the elements of racial identity and self-esteem of urban, rural and regional Aboriginal children. This paper describes the development and validation of the IRISE_C instrument with over 250 Aboriginal children aged 8 to 12 years. METHODS: A pilot of the IRISE C instrument was combined with individual interviews and was undertaken with 35 urban Aboriginal children aged 8-12 years. An exploratory factor analysis was performed to refine the survey and reduce redundant items in readiness for the main study. In the main study, the IRISE C was employed to 229 Aboriginal children aged 6-13 years across three sites (rural, regional and urban) in Western Australia. An exploratory factor analysis using Principal axis factoring was used to assess the fit of items and survey structure. A confirmatory factor analysis was then employed using LISREL (diagonally weighted least squares) to assess factor structures across domains. Internal consistency and reliability of subscales were assessed using Cronbach's co-efficient alpha. RESULTS: The pilot testing identified two key concepts - children's knowledge of issues related to their racial identity, and the importance, or salience, that they attach to these issues. In the main study, factor analyses showed two clear factors relating to: Aboriginal culture and traditions; and a sense of belonging to an Aboriginal community. Principal Axis Factoring of the Knowledge items supported a 2-factor solution, which explained 38.7% of variance. Factor One (Aboriginal culture) had a Cronbach's alpha of 0.835; Factor 2 (racial identity) had a Cronbach's alpha of 0.800, thus demonstrating high internal reliability of the scales. CONCLUSION: The IRISE_C has been shown to be a valid instrument useful of exploring the development of racial identity of Australian Aboriginal children across the 8-12 year old age range and across urban, rural and regional geographical locations.


Assuntos
Havaiano Nativo ou Outro Ilhéu do Pacífico/psicologia , Autoimagem , Identificação Social , Criança , Análise Fatorial , Feminino , Humanos , Masculino , Inquéritos e Questionários , População Urbana , Austrália Ocidental
13.
J Dairy Sci ; 98(1): 295-304, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25465636

RESUMO

The comfort of dairy cattle while standing has important implications for housing design. Research has examined how cattle respond to standing surfaces by presenting options under all 4 legs or under a single leg, but no work, to date, has compared presentation methods. This study examined behavior and muscle activity when cows stood on rough floors under all 4 legs or just 1 hind leg. Three treatments were tested: smooth concrete under all 4 legs (0-ROUGH), a rough surface under all 4 legs [2cm × 2cm × 4cm trapezoidal protrusions (4-ROUGH)], and a rough surface only under 1 hind leg, with other legs on smooth concrete (1-ROUGH). Twenty-four healthy Holstein cows stood on each surface for 1h/d in a repeated-measures design. Surface electromyograms (SEMG) were used to evaluate muscle fatigue and total activity. Muscle fatigue was measured using SEMG to evaluate (1) static contractions when cows were continuously weight bearing on each hind leg, before and after 1h of standing, and (2) dynamic contractions associated with steps during 1h of standing. Behavioral measures included steps per minute, time between each consecutive step, and the latency to lie down after testing. The number of legs affected by roughness influenced both behavioral and physiological responses to flooring. Cows on 1-ROUGH stepped twice as often with the rough-treated leg and one-half as much with the hind leg on smooth concrete compared with other surfaces. Similarly, on the 1-ROUGH surface, total muscle activity was reduced in the leg on the rough surface, and muscle activity was more sustained (3× higher) in the other hind leg, suggesting that cows avoid possible discomfort under 1 leg by using muscles in the other. In the 4-ROUGH treatment, time between steps was more variable than on the other 2 treatments (coefficient of variation, 4-ROUGH: 245; 1-ROUGH: 208; 0-ROUGH: 190±5.8%), likely because cows could not move away from this uneven flooring. Thus, the method of presentation of stimuli used to evaluate comfort while standing altered the response. Stepping rate and SEMG changed when roughness was under a single leg, whereas timing between consecutive steps was more variable with rough flooring under all 4 legs. These results have implications for the design of experiments evaluating standing comfort in the future.


Assuntos
Comportamento Animal/fisiologia , Bovinos/fisiologia , Extremidades/fisiologia , Músculo Esquelético/fisiologia , Postura/fisiologia , Animais , Estudos Cross-Over , Eletromiografia/veterinária , Feminino , Pisos e Cobertura de Pisos/normas , Membro Posterior/fisiologia , Abrigo para Animais/normas , Suporte de Carga
14.
J Dairy Sci ; 97(5): 2808-15, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24612809

RESUMO

On dairy farms, flooring is often sloped to facilitate drainage. Sloped floors have been identified as a possible risk factor for lameness, but relatively little is known about how this flooring feature affects dairy cattle. Ours is the first study to evaluate the short-term effects of floor slope on skeletal muscle activity, restless behavior (measured by number of steps), and latency to lie down after 90 min of standing. Sixteen Holstein cows were exposed to floors with a 0, 3, 6, or 9% slope in a crossover design, with a minimum of 45 h between each testing session. Electromyograms were used to evaluate the activity of middle gluteal and biceps femoris muscles. Muscle activity was evaluated in 2 contexts: (1) static muscle contractions when cows continuously transferred weight to each hind leg, before and after 90 min of standing; and (2) dynamic contractions that occurred during 90 min of treatment exposure. Median power frequency and median amplitude of both static and dynamic muscle electrical signals were calculated. Total muscle activity was calculated using the root mean square of the signals. Restless behavior, the number of steps per treatment, steps and kicks in the milking parlor, and the latency to lie down after the test sessions were also measured. It was predicted that restless behavior, muscle fatigue (as measured by median power frequency and median amplitude), total muscle activity, and latency to lie down after testing would increase with floor slope. However, no treatment differences were found. Median power frequency was significantly greater for the middle gluteal muscle [35 ± 4 Hz (mean and SE)] compared with the biceps femoris muscle (24 ± 3 Hz), indicating that the contractive properties of these muscles differ. The number of steps per minute and total muscle activity increased significantly over 90 min of standing, irrespective of floor slope. Although restless behavior and muscle function did not change with slope in our study, this work demonstrates that electromyograms can be used to measure skeletal leg muscle activity in cattle. This technology, along with restless behavior, could be useful in assessing cow comfort in other situations, such as prolonged standing.


Assuntos
Comportamento Animal , Bovinos/fisiologia , Pisos e Cobertura de Pisos , Músculo Esquelético/fisiologia , Animais , Peso Corporal , Indústria de Laticínios , Eletromiografia/veterinária , Feminino , Marcha , Abrigo para Animais , Fadiga Muscular , Postura , Fatores de Tempo
15.
J Dairy Sci ; 97(6): 3599-605, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24731637

RESUMO

Shade reduces the negative effects of heat load, but little is known about how much is required for efficient cooling in commercial settings. The effect of the amount of shade on 8 Holstein-Friesian herds was studied for 2 consecutive summers (mean temperature: 23 °C) on 6 commercial, pasture-based dairy farms. Farms varied in the amount of natural shade provided (range: 0 to 15.6m(2) shade/cow). Time spent in shade, near water, eating, ruminating, lying, and standing were recorded between 1000 and 1530 h in 31 shaded and 11 unshaded paddocks using 20-min instantaneous scan observations of 15 focal cows/herd. Respiration rate and panting score (0 to 4.5) was recorded for focal animals once per hour. The total numbers of cows in shade, near water, and with panting scores ≥ 2 were recorded every 30 min. Cows without shade spent 4% more time lying than cows with shade (standard error of the difference, SED = 1.9%). A larger proportion of the herd had panting scores ≥ 2 when no shade was available (6 vs. 2% of the herd, SED = 1.2%), and respiration rates were higher by 8 breaths/min in cows without shade (SED = 4.7 breaths/min). Under the conditions tested, the maximum proportion of the herd that was observed using the shade increased by 3.1% for every 1-m(2) increase in shade size [standard error (SE) = 1.51%], and all cows were first seen simultaneously using shade when 2m(2)/cow was provided. For every 1-m(2) increase in shade, 0.3% fewer cows had panting score ≥ 2 (SE = 0.12%). We observed no significant relationships between the amount of shade available and any other variables. Although additional work is required to make specific recommendations, these results indicate that providing more shade allowed a higher proportion of animals to use this resource and reduced respiratory signs of heat load.


Assuntos
Comportamento Animal/fisiologia , Comportamento Animal/efeitos da radiação , Lactação , Luz Solar , Animais , Bovinos , Feminino , Taxa Respiratória/fisiologia , Taxa Respiratória/efeitos da radiação , Estações do Ano , Temperatura , Água
16.
J Dairy Sci ; 97(6): 3523-30, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24657083

RESUMO

Dairy welfare assessment programs are becoming more common on US farms. Outcome-based measurements, such as locomotion, hock lesion, hygiene, and body condition scores (BCS), are included in these assessments. The objective of the current study was to investigate the proportion of cows in the pen or subsamples of pens on a farm needed to provide an accurate estimate of the previously mentioned measurements. In experiment 1, we evaluated cows in 52 high pens (50 farms) for lameness using a 1- to 5-scale locomotion scoring system (1 = normal and 5 = severely lame; 24.4 and 6% of animals were scored ≥ 3 or ≥ 4, respectively). Cows were also given a BCS using a 1- to 5-scale, where 1 = emaciated and 5 = obese; cows were rarely thin (BCS ≤ 2; 0.10% of cows) or fat (BCS ≥ 4; 0.11% of cows). Hygiene scores were assessed on a 1- to 5-scale with 1 = clean and 5 = severely dirty; 54.9% of cows had a hygiene score ≥ 3. Hock injuries were classified as 1 = no lesion, 2 = mild lesion, and 3 = severe lesion; 10.6% of cows had a score of 3. Subsets of data were created with 10 replicates of random sampling that represented 100, 90, 80, 70, 60, 50, 40, 30, 20, 15, 10, 5, and 3% of the cows measured/pen. In experiment 2, we scored the same outcome measures on all cows in lactating pens from 12 farms and evaluated using pen subsamples: high; high and fresh; high, fresh, and hospital; and high, low, and hospital. For both experiments, the association between the estimates derived from all subsamples and entire pen (experiment 1) or herd (experiment 2) prevalence was evaluated using linear regression. To be considered a good estimate, 3 criteria must be met: R(2)>0.9, slope = 1, and intercept = 0. In experiment 1, on average, recording 15% of the pen represented the percentage of clinically lame cows (score ≥ 3), whereas 30% needed to be measured to estimate severe lameness (score ≥ 4). Only 15% of the pen was needed to estimate the percentage of the herd with a hygiene score ≥ 3, whereas 30% to estimate the prevalence of severe hock lesions. Estimating very thin and fat cows required that 70 to 80% of the pen be measured. In experiment 2, none of the pen subsamples met our criteria for accurate estimates of herd prevalence. In conclusion, we found that both a higher percentage of the pen must be sampled to generate accurate values for relatively rare parameters and that the population measured plays an important role in prevalence estimates.


Assuntos
Bem-Estar do Animal , Doenças dos Bovinos/epidemiologia , Indústria de Laticínios , Abrigo para Animais , Animais , Bovinos , Feminino , Marcha , Higiene , Lactação , Coxeadura Animal/epidemiologia , Locomoção , Prevalência , Tarso Animal/anatomia & histologia , Tarso Animal/fisiopatologia
17.
Int J Sports Med ; 35(14): 1203-7, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25144432

RESUMO

Recreational runners have an estimated overuse injury incidence rate of up to 79% and 90% for marathoners. A pre-participation screening tool that can identify risk for injury may help reduce overuse injury in runners. The Functional Movement Screen (FMS(TM)) is a reliable clinical tool used with athletes to help predict injury. To date, the FMS(TM) has not been used with endurance athletes. The purpose of this article is to establish normative FMS(TM) values for distance runners. 45 healthy runners performed the FMS(TM). Descriptive statistics were calculated; independent t-tests were performed to examine the effect of gender, experience and injury on scores. A Chi-square test was used to evaluate whether significant differences in scores exist for any component of the FMS(TM). The mean FMS(TM) score was 13.13±1.8. No significant differences in FMS(TM) scores were found between novice and experienced runners (p=0.71) or runners with a history of injury and those without (p=0.20). While male and female runners did not differ significantly in their total FMS(TM) score (p=0.65), significant differences were found in the deep squat (p<0.05), trunk stability push-up (p<0.001) and active straight leg raise components (p=0.002). This study provides normative values for FMS(TM) scores when testing uninjured distance runners.


Assuntos
Teste de Esforço/métodos , Corrida/fisiologia , Adulto , Transtornos Traumáticos Cumulativos/prevenção & controle , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resistência Física/fisiologia , Valores de Referência , Fatores de Risco , Corrida/lesões , Fatores Sexuais
18.
World Neurosurg ; 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38885740

RESUMO

BACKGROUND: Lumbar degenerative disease imposes a substantial burden on global healthcare expenditures. Transforaminal lumbar interbody fusion (TLIF) utilizing either traditional trajectory (TT) pedicle screws or cortical bone trajectory (CT) pedicle screws have become increasingly common. This meta-analysis evaluates the outcomes and safety of open TLIF with TT compared to CT. METHODS: PubMed, Cochrane, and Google Scholar (pages 1-20) were explored until April 2024. The studied outcomes included complications, revision surgeries, operative room (OR) time, estimated blood loss (EBL), length of hospital stay (LOS), incision length, Visual Analog Scale (VAS), Oswestry Disability Index (ODI), and the Japanese Orthopedic Association (JOA) score. RESULTS: Five studies were included in this meta-analysis. A total of 770 patients undergoing TLIF were included, with 415 in the CT group and 355 in the TT group. No statistically significant differences were found in the rate of overall complications, including specific complications, the rate of revision surgeries, PROMS scores, OR time, and EBL. However, the CT group demonstrated shorter LOS (p=0.05), and shorter incision lengths (p<.001) compared to the TT group. CONCLUSION: Both TT and CT techniques in TLIF procedures demonstrated comparable rates of complications, reoperations, and PROMs. Despite similar OR times and EBL, the CT group exhibited shorter incision lengths, and shorter LOS compared to the TT group. Both cortical and traditional trajectory pedicle screws are safe and effective options for TLIF. There are potential benefits to CT such as shorter incision and LOS, although TT remains an essential tool for spinal instrumentation techniques.

19.
J Physiol ; 591(24): 6209-20, 2013 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-24167225

RESUMO

While glucocorticoids (GCs) are known to be present in the zebrafish embryo, little is known about their physiological roles at this stage. We hypothesised that GCs play key roles in stress response, hatching and swim activity during early development. To test this, whole embryo cortisol (WEC) and corticosteroid-related genes were measured in embryos from 6 to 120 h post fertilisation (hpf) by enzyme linked immunosorbent assay (ELISA) and quantitative real-time polymerase chain reaction (qRT-PCR). Stress response was assessed by change in WEC following stirring, hypoxia or brief electrical impulses applied to the bathing water. The impact of pharmacological and molecular GC manipulation on the stress response, spontaneous hatching and swim activity at different stages of development was also assessed. WEC levels demonstrated a biphasic pattern during development with a decrease from 0 to 36 hpf followed by a progressive increase towards 120 hpf. This was accompanied by a significant and sustained increase in the expression of genes encoding cyp11b1 (GC biosynthesis), hsd11b2 (GC metabolism) and gr (GC receptor) from 48 to 120 hpf. Metyrapone (Met), an inhibitor of 11ß-hydroxylase (encoded by cyp11b1), and cyp11b1 morpholino (Mo) knockdown significantly reduced basal and stress-induced WEC levels at 72 and 120 hpf but not at 24 hpf. Spontaneous hatching and swim activity were significantly affected by manipulation of GC action from approximately 48 hpf onwards. We have identified a number of key roles of GCs in zebrafish embryos contributing to adaptive physiological responses under adverse conditions. The ability to alter GC action in the zebrafish embryo also highlights its potential value for GC research.


Assuntos
Embrião não Mamífero/metabolismo , Hidrocortisona/metabolismo , Estresse Fisiológico , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/genética , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/metabolismo , Animais , Embrião não Mamífero/fisiologia , Locomoção , Receptores de Glucocorticoides/genética , Receptores de Glucocorticoides/metabolismo , Esteroide 11-beta-Hidroxilase/genética , Esteroide 11-beta-Hidroxilase/metabolismo , Peixe-Zebra , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
20.
J Dairy Sci ; 96(7): 4465-76, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23684030

RESUMO

Body condition score (BCS) around calving, and the typical BCS loss for up to 100 d after parturition, is associated with both production and reproductive performance of dairy cattle. In addition, there is public concern that thin cows may have impaired welfare, particularly in early lactation where feed demand exceeds pasture growth, and a lag exists between peak milk energy requirements and intake. The aim of this experiment was to determine how BCS at calving influences behavioral and physiological responses to a short-term feed restriction at 47 DIM. Body condition score (on a 10-point scale) at calving was manipulated by modifying the diets in the previous lactation of healthy dairy cattle to generate 3 treatment groups: low BCS (3.4; n=17), medium BCS (4.6; n=18), or high BCS (5.4; n=20). Cows were tested in 4 groups for 8 consecutive days; testing consisted of different levels of feed allocation (d 1 and 2: 100%; d 3 and 4: 75%; d 5: 50%; d 6 to 8: 125%), where 100% was 15kg of DM/cow per day. All BCS groups had similar and marked behavioral and physiological responses to feed restriction. For example, they increased vocalization, time spent eating silage and grazing, aggressive behavior, and fat metabolism (as measured by concentrations of ß-hydroxybutyrate and nonesterified fatty acids), and reduced milk production. Body condition affected some of these responses. Fewer cows with low BCS engaged in aggressive interactions in a feed competition test (trough filled with silage that could be consumed in 15 min) on the first day of feed restriction (low: 32%; medium: 74%; high: 64%; standard error of difference=15.4%). High BCS cows had greater concentrations of ß-hydroxybutyrate and nonesterified fatty acids throughout the experimental period, which suggests more fat mobilization; however, plasma leptin and fecal glucocorticosteroid metabolite concentrations were unaffected by BCS. Whereas cows demonstrated marked responses to feed restriction, the results suggest that a BCS of 3.4, 4.6, or 5.4 in healthy cows at calving does not overwhelmingly influence this response at 47 DIM.


Assuntos
Comportamento Animal/fisiologia , Composição Corporal/fisiologia , Bovinos/fisiologia , Privação de Alimentos/fisiologia , Lactação/fisiologia , Parto/fisiologia , Ácido 3-Hidroxibutírico/sangue , Animais , Ácidos Graxos não Esterificados/sangue , Feminino , Gravidez , Reprodução/fisiologia
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