Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 561
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Gen Comp Endocrinol ; 291: 113436, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32057910

RESUMO

Baleen whales are vulnerable to environmental impacts due to low fecundity, capital breeding strategies, and their reliance on a large amount of prey resources over large spatial scales. There has been growing interest in monitoring health and physiological stress in these species but, to date, few measures have been validated. The purpose of this study was to examine whether blubber cortisol could be used as a measure of physiological stress in humpback whales. Cortisol concentrations were initially compared between live, presumably 'healthy' whales (n = 187) and deceased whales (n = 35), which had died after stranding or entanglement, or washed ashore as a carcass. Deceased whales were found to have significantly higher cortisol levels (mean ± SD; 5.47 ± 4.52 ng/g) than live whales (0.51 ± 0.14 ng/g; p < 0.001), particularly for those animals that had experienced prolonged trauma (e.g. stranding) prior to death. Blubber cortisol levels in live whales were then examined for evidence of life history-related, seasonal, or sampling-related effects. Life history group and sampling-related factors, such as encounter time and the number of biopsy sampling attempts per animal, were found to be poor predictors of blubber cortisol levels in live whales. In contrast, blubber cortisol levels varied seasonally, with whales migrating north towards the breeding grounds in winter having significantly higher levels (0.54 ± 0.21 ng/g, p = 0.016) than those migrating south towards the feeding grounds in spring (0.48 ± 1.23 ng/g). These differences could be due to additional socio-physiological stress experienced by whales during peaks in breeding activity. Overall, blubber cortisol appears to be a suitable measure of chronic physiological stress in humpback whales.


Assuntos
Estruturas Animais/metabolismo , Jubarte/anatomia & histologia , Hidrocortisona/metabolismo , Estresse Fisiológico , Tecido Adiposo/metabolismo , Animais , Feminino , Geografia , Jubarte/fisiologia , Masculino , Progesterona/metabolismo , Queensland , Estações do Ano
2.
Public Health ; 166: 53-56, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30448692

RESUMO

OBJECTIVES: This analysis explored the level of psychological distress among primary school teachers in the South West of England as compared with clinical and general population samples. STUDY DESIGN: Secondary analysis of data from the Supporting Teachers and Children in Schools (STARS) trial completed by up to 90 teachers at baseline, 9, 18 and 30 months of follow-up. METHODS: We used the Everyday Feelings Questionnaire (EFQ) as a measure of psychological distress. Baseline data on teachers were compared with a population sample of professionals and a clinical sample of patients attending a depression clinic. RESULTS: Our teacher cohort experienced higher levels of psychological distress than comparable professionals from the general population, which were sustained over 30 months of follow-up. Levels of psychological distress were lower than those found in the clinical sample. Using a cut-point indicative of moderate depression, our data suggest that between 19% and 29% of teachers experienced clinically significant distress at each time-point. CONCLUSIONS: We detected high and sustained levels of psychological distress among primary school teachers, which suggests an urgent need for intervention. Effective support for teachers' mental health is particularly important given the potential impact of poor teacher mental health on pupil well-being, pupil attainment and teacher-pupil relationships.


Assuntos
Professores Escolares/psicologia , Instituições Acadêmicas , Estresse Psicológico/epidemiologia , Adulto , Estudos de Coortes , Inglaterra/epidemiologia , Feminino , Humanos , Masculino , Professores Escolares/estatística & dados numéricos , Inquéritos e Questionários
3.
Phys Rev Lett ; 120(26): 263602, 2018 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-30004721

RESUMO

Thermal noise of highly reflective mirror coatings is a major limit to the sensitivity of many precision laser experiments with strict requirements such as low optical absorption. Here, we investigate amorphous silicon and silicon nitride as an alternative to the currently used combination of coating materials, silica, and tantala. We demonstrate an improvement by a factor of ≈55 with respect to the lowest so far reported optical absorption of amorphous silicon at near-infrared wavelengths. This reduction was achieved via a combination of heat treatment, final operation at low temperature, and a wavelength of 2 µm instead of the more commonly used 1550 nm. Our silicon-based coating offers a factor of 12 thermal noise reduction compared to the performance possible with silica and tantala at 20 K. In gravitational-wave detectors, a noise reduction by a factor of 12 corresponds to an increase in the average detection rate by three orders of magnitude (≈12^{3}).

4.
Transfus Med ; 28(6): 451-456, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28833743

RESUMO

Paroxysmal nocturnal haemoglobinuria (PNH) is a rare stem cell disorder causing, in untreated patients, symptoms that include renal damage, thrombosis and increased mortality. When correctly diagnosed and treated, patients have reduced symptoms and normal life expectancies. Historically PNH testing resided within blood transfusion laboratories using techniques that were insensitive, for example, the Ham test. However, technology has evolved and flow cytometry is now regarded as the gold standard methodology. Given the clinical importance of diagnosing PNH correctly, we undertook a study to examine PNH testing procedures in blood transfusion laboratories within the UK and Ireland to determine implementation of best practices. An online survey was issued to 386 blood transfusion laboratories in the UK and Ireland requesting details of their current PNH testing practices and procedures. There were 143 responses, representing a 37% response rate. Of these, we identified seven laboratories undertaking PNH testing using obsolete methodologies. Furthermore, multiple centres did not refer samples for confirmatory testing by national PNH reference centres and inclusion on the national PNH disease registry. Staff handling requests for PNH testing should ensure that all samples are tested in accordance with current best practices using only flow cytometry.


Assuntos
Transfusão de Sangue , Citometria de Fluxo , Hemoglobinúria Paroxística/sangue , Hemoglobinúria Paroxística/diagnóstico , Laboratórios Hospitalares , Irlanda , Reino Unido
5.
J Tissue Viability ; 26(2): 103-107, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28049612

RESUMO

BACKGROUND: Surgical wounds healing by secondary intention (SWHSI) are often difficult and costly to treat. There is a dearth of clinical and research information regarding SWHSI. The aim of this survey was to estimate the prevalence of SWHSI and to characterise the aetiology, duration and management of these wounds. METHODS: Anonymised data were collected from patients with SWHSI receiving treatment in primary, secondary and community settings. Over a two weeks period, data were collected on the patients, their SWHSI, clinical and treatment details. RESULTS: Data were collected from 187 patients with a median age of 58.0 (95% CI = 55 to 61) years. The prevalence of SWHSI was 0.41 (95% CI = 0.35 to 0.47) per 1000 population. More patients with SWHSI were being treated in community (109/187, 58.3%) than in secondary (56/187, 29.9%) care settings. Most patients (164/187, 87.7%) had one SWHSI and the median duration of wounds was 28.0 (95% CI = 21 to 35) days. The most common surgical specialities associated with SWHSI were colorectal (80/187, 42.8%), plastics (24/187, 12.8%) and vascular (22/187, 11.8%) surgery. Nearly half of SWHSI were planned to heal by secondary intention (90/187, 48.1%) and 77/187 (41.2%) were wounds that had dehisced. Dressings were the most common single treatment for SWHSI, received by 169/181 (93.4%) patients. Eleven (6.1%) patients were receiving negative pressure wound therapy. CONCLUSIONS: This survey provides a previously unknown insight into the occurrence, duration, treatment and types of surgery that lead to SWHSI. This information will be of value to patients, health care providers and researchers.


Assuntos
Ferida Cirúrgica/terapia , Cicatrização , Bandagens/estatística & dados numéricos , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tratamento de Ferimentos com Pressão Negativa/estatística & dados numéricos , Prevalência , Fatores de Risco , Ferida Cirúrgica/classificação , Ferida Cirúrgica/epidemiologia , Infecção da Ferida Cirúrgica/terapia , Inquéritos e Questionários , Fatores de Tempo
6.
Clin Infect Dis ; 62(2): 250-257, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26349551

RESUMO

BACKGROUND: CD8 T-cell counts remain elevated in human immunodeficiency virus (HIV) infection even after long-term antiretroviral therapy (ART), which is associated with an increased risk of non-AIDS-related events. We assessed the impact of ART initiation in early versus chronic HIV infection on trajectories of CD8 cell counts over time. METHODS: Of 280 individuals enrolled during primary HIV infection (PHI), 251 were followed up for 24 months; 84 started ART before 6 months of infection (eART), 49 started between 6 and 24 months, and 118 remained untreated. Plasma HIV viral load (VL), CD4 and CD8 cell counts were assessed at each study visit. CD8 counts were also examined in 182 age-matched HIV-infected individuals who started ART during chronic infection and maintained undetectable plasma VL for ≥5 years. RESULTS: At PHI baseline, higher CD8 cell counts were associated with more recent infection (P = .02), higher CD4 cell counts (P < .001), and higher VL (P < .001). The CD8 count in the eART group decreased from 797 to 588 cells/µL over 24 months (P < .001), to a level lower than that in untreated PHI (834 cells/µL; P = .004) or in long-term-treated patients with chronic HIV infection (743 cells/µL; P = .047). More prominent CD4 T-cell recovery was observed in the eART group than in the delayed ART group. CONCLUSIONS: ART initiated in early HIV infection is associated with improved resolution of CD8 T-cell elevation compared with long-term ART initiated in chronic infection. Early ART may help reduce the risk of non-AIDS-related events by alleviating this elevation.


Assuntos
Antirretrovirais/administração & dosagem , Linfócitos T CD8-Positivos/imunologia , Infecções por HIV/tratamento farmacológico , Infecções por HIV/patologia , Prevenção Secundária , Adulto , Feminino , Seguimentos , Humanos , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , RNA Viral/sangue , Resultado do Tratamento , Carga Viral
7.
AIDS Behav ; 19(8): 1388-97, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25234251

RESUMO

Most studies of psychosocial predictors of disease progression in HIV have not considered norepinephrine (NE), a neurohormone related to emotion and stress, even though NE has been related to accelerated viral replication in vitro and impaired response to antiretroviral therapy (ART). We therefore examined NE, cortisol, depression, hopelessness, coping, and life event stress as predictors of HIV progression in a diverse sample. Participants (n = 177) completed psychological assessment, blood draws [CD4, viral load (VL)], and a 15 h urine sample (NE, cortisol) every 6 months over 4 years. Hierarchical linear modeling (HLM) was used to model slope in CD4 and VL controlling for ART at every time point, gender, age, race, SES, and initial disease status. NE (as well as depression, hopelessness, and avoidant coping) significantly predicted a greater rate of decrease in CD4 and increase in VL. Cortisol was not significantly related to CD4, but predicted VL increase. To our knowledge, this is the first study relating NE, in vivo, to accelerated disease progression over an extended time. It also extends our previous 2 year study by relating depressed mood and coping to accelerated disease progression over 4 years.


Assuntos
Adaptação Psicológica , Contagem de Linfócito CD4 , Infecções por HIV/psicologia , Hidrocortisona/urina , Norepinefrina/urina , Apoio Social , Estresse Psicológico/sangue , Estresse Psicológico/urina , Carga Viral , Adulto , Antirretrovirais/farmacologia , Antirretrovirais/uso terapêutico , Aprendizagem da Esquiva , Biomarcadores/sangue , Depressão/psicologia , Transtorno Depressivo/diagnóstico , Transtorno Depressivo/psicologia , Progressão da Doença , Feminino , Seguimentos , Infecções por HIV/sangue , Infecções por HIV/tratamento farmacológico , Infecções por HIV/urina , Infecções por HIV/virologia , Humanos , Acontecimentos que Mudam a Vida , Masculino , Adesão à Medicação , Pessoa de Meia-Idade , Estudos Prospectivos , Estresse Psicológico/psicologia
8.
Eur J Clin Microbiol Infect Dis ; 33(6): 879-910, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24563274

RESUMO

This review evaluates the serotype epidemiology of complicated pneumococcal pneumonia (CPP) during the period 1990-2012. PubMed and EMBASE were searched using the terms "empyema", "complicated pneumonia", "pleural infection", "necrotizing pneumonia", "pleural effusion", "parapneumonic effusion", "pneumatocele", or "lung abscess"; "pneumococcal" or "Streptococcus pneumoniae"; and "serotype" for studies on the epidemiology of complicated pneumonias published from January 1, 1990 to October 1, 2013. Studies with data on incidence and serotypes were included; reviews, case reports, and conference abstracts were excluded. Of 152 papers, 84 fitted the inclusion criteria. A few pneumococcal serotypes were predominant causes of CPP, particularly serotypes 1, 19A, 3, 14, and 7F. CPP was a more common manifestation of pneumococcal disease among older (>2 years old) than younger children. The data support increases in both reported incidence rates and proportions of CPP in children and adults during the period 1990-2012; specific increases varied by geographic region. The proportions of serotype 3 and, particularly in Asia, serotype 19A CPP have increased, whereas most studies show declines in serotype 14. Serotype 1 has been a predominant cause of CPP since 1990, while antibiotic resistance was infrequent among serotype 1 isolates. The reported incidence and proportions of CPP among pneumonia cases steadily increased from 1990 to 2012. Several factors might account for these increases, including enhanced disease detection due to a higher index of suspicion, more sophisticated diagnostic assays, and changes in the prevalence of serotypes with capacity to invade the pleural space that were not targeted by the 7-valent pneumococcal conjugate vaccine (PCV7).


Assuntos
Empiema/epidemiologia , Pneumonia Pneumocócica/complicações , Pneumonia Pneumocócica/epidemiologia , Streptococcus pneumoniae/isolamento & purificação , Saúde Global , Humanos , Incidência , Prevalência , Sorotipagem , Streptococcus pneumoniae/classificação
9.
Bull Entomol Res ; 104(2): 117-36, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24280006

RESUMO

Many hemipteroids are major pests and vectors of microbial pathogens, infecting crops. Saliva of the hemipteroids is critical in enabling them to be voracious feeders on plants, including the economically important ones. A plethora of hemipteroid salivary enzymes is known to inflict stress in plants, either by degrading the plant tissue or by affecting their normal metabolism. Hemipteroids utilize one of the following three strategies of feeding behaviour: salivary sheath feeding, osmotic-pump feeding and cell-rupture feeding. The last strategy also includes several different tactics such as lacerate-and-flush, lacerate-and-sip and macerate-and-flush. Understanding hemipteroid feeding mechanisms is critical, since feeding behaviour directs salivary composition. Saliva of the Heteroptera that are specialized as fruit and seed feeders, includes cell-degrading enzymes, auchenorrhynchan salivary composition also predominantly consists of cell-degrading enzymes such as amylase and protease, whereas that of the Sternorhyncha includes a variety of allelochemical-detoxifying enzymes. Little is known about the salivary composition of the Thysanoptera. Cell-degrading proteins such as amylase, pectinase, cellulase and pectinesterase enable stylet entry into the plant tissue. In contrast, enzymes such as glutathione peroxidase, laccase and trehalase detoxify plant chemicals, enabling the circumvention of plant-defence mechanisms. Salivary enzymes such as M1-zinc metalloprotease and CLIP-domain serine protease as in Acyrthosiphon pisum (Aphididae), and non-enzymatic proteins such as apolipophorin, ficolin-3-like protein and 'lava-lamp' protein as in Diuraphis noxia (Aphididae) have the capacity to alter host-plant-defence mechanisms. A majority of the hemipteroids feed on phloem, hence Ca++-binding proteins such as C002 protein, calreticulin-like isoform 1 and calmodulin (critical for preventing sieve-plate occlusion) are increasingly being recognized in hemipteroid-plant interactions. Determination of a staggering variety of proteins shows the complexity of hemipteroid saliva: effector proteins localized in hemipteran saliva suggest a similarity to the physiology of pathogen-plant interactions.


Assuntos
Hemípteros/enzimologia , Proteínas e Peptídeos Salivares/metabolismo , Animais , Comportamento Alimentar
10.
PLoS One ; 18(2): e0281535, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36780533

RESUMO

Bird species that are restricted to tidal marshes during one or all of their life stages are under increasing pressure from sea-level rise. To date, most of the research focused on this group has been conducted during the breeding season despite the fact that more than half of the annual cycle is spent on wintering grounds and the high likelihood that the winter period is the most critical time for adult survival. We used a double-pass rope-drag technique to estimate the winter abundance of sharp-tailed sparrows (Ammospiza nelson and A. caudacutus collectively), seaside sparrows (A. maritimus) and marsh wrens (Cistothorus palustris) within tidal marshes of Virginia along 102 60X250 m transects between January and March, 2014. We used the first pass to remove birds from the transect and the second pass was used to estimate detection probabilities. The technique was highly effective producing detection rates of 98% for sharp-tailed sparrows, 95% for seaside sparrows, and 91% for marsh wrens. We conducted three rounds of surveys and found that species-specific detection rates were comparable when we restricted our analyses to two survey rounds. Availability and abundance estimates deviated to a greater degree than detection rates when restricting data to that collected during only two rounds but confidence intervals overlapped for all three taxa, regardless of which two survey periods were used for the comparison. However, results were less precise when we restricted our analyses to two of three rounds with confidence intervals averaging 13%, 45%, and 14% larger for detection, availability, and abundance respectively. The double-pass rope-drag technique provides an effective, unbiased sampling technique to estimate winter songbird abundance in saltmarsh habitat provided that at least two rounds are used and increasing the number of survey rounds will result in more precise estimates.


Assuntos
Mercúrio , Aves Canoras , Pardais , Animais , Áreas Alagadas , Estações do Ano , Mercúrio/análise , Ecossistema
11.
Sci Rep ; 13(1): 11138, 2023 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-37429880

RESUMO

Red Knots use the Southeast United States as a stopover during north and southbound migration and during the winter. We examined northbound red knot migration routes and timing using an automated telemetry network. Our primary goal was to evaluate the relative use of an Atlantic migratory route through Delaware Bay versus an inland route through the Great Lakes en route to Arctic breeding grounds and to identify areas of apparent stopovers. Secondarily, we explored the association of red knot routes and ground speeds with prevailing atmospheric conditions. Most Red Knots migrating north from the Southeast United States skipped or likely skipped Delaware Bay (73%) while 27% of the knots stopped in Delaware Bay for at least 1 day. A few knots used an Atlantic Coast strategy that did not include Delaware Bay, relying instead on the areas around Chesapeake Bay or New York Bay for stopovers. Nearly 80% of migratory trajectories were associated with tailwinds at departure. Most knots tracked in our study traveled north through the eastern Great Lake Basin, without stopping, thus making the Southeast United States the last terminal stopover for some knots before reaching boreal or Arctic stopover sites.


Assuntos
Charadriiformes , Clima , Animais , Estações do Ano , New York , Telemetria
12.
Tijdschr Diergeneeskd ; 137(8): 522-31, 2012 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-22930983

RESUMO

This study investigated the prophylactic action of the chemical combination zeta-cypermethrin and piperonyl butoxide, administered by means of slow-release insecticide-impregnated ear tags, against biting midges (Culicoides spp) attacking sheep and against midges, horn flies (Haematobia irritant), stable flies (Stomoxys calcitrans), and houseflies (Musca domestica) attacking cattle. Treated sheep and cattle were protected 100 percent against blood-feeding midges for two months and there was a clear reduction in the number of midges collected from treated animals. Three days after the ear tags were attached to cattle, the number of horn flies on the cattle was reduced to practically zero and remained at a low level until the end of the trial (day 85). There was also a strong reduction in the numbers of stable flies and houseflies counted.


Assuntos
Doenças dos Bovinos/prevenção & controle , Ceratopogonidae/efeitos dos fármacos , Inseticidas/farmacologia , Butóxido de Piperonila/farmacologia , Piretrinas/farmacologia , Doenças dos Ovinos/prevenção & controle , Animais , Bluetongue/prevenção & controle , Bluetongue/transmissão , Bovinos , Doenças dos Bovinos/transmissão , Dípteros/efeitos dos fármacos , Orelha , Comportamento Alimentar/efeitos dos fármacos , Moscas Domésticas/efeitos dos fármacos , Insetos Vetores/efeitos dos fármacos , Insetos Vetores/virologia , Inseticidas/administração & dosagem , Muscidae/efeitos dos fármacos , Butóxido de Piperonila/administração & dosagem , Piretrinas/administração & dosagem , Ovinos , Doenças dos Ovinos/transmissão , Especificidade da Espécie
13.
Infect Dis Now ; 52(5): 243-251, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35483633

RESUMO

Leprosy is one of the oldest infectious diseases, reported for more than 2000years. Leprosy elimination goal as a public health problem set by the World Health Organization, aiming for a global prevalence rate<1 patient in a population of 10,000, was achieved in 2000 mainly thanks to the worldwide use of leprosy drugs starting in the 1980s and their access at no cost for patients since 1995. However, around 200,000 new cases are still reported each year, particularly in India, Brazil, and Indonesia. As with other bacteria of medical interest, antimicrobial resistance is observed in Mycobacterium leprae strains in several parts of the world, despite multidrug therapy being the recommended standard leprosy treatment to avoid resistance selection since 1982. Therefore, identifying and monitoring resistance is necessary. We provide an overview of the historical facts that led to the current drug resistance situation, the antibiotics effective against M. leprae, their mechanisms of action and resistance, and resistance detection methods. We also discuss therapeutic management of the resistant cases, new genes with potential roles in drug resistance and bacterial adaptation, new drugs under investigation, and the risk for resistance selection with the chemoprophylaxis measures.


Assuntos
Hansenostáticos , Hanseníase , Resistência a Medicamentos , Quimioterapia Combinada , Humanos , Hansenostáticos/farmacologia , Hansenostáticos/uso terapêutico , Hanseníase/diagnóstico , Hanseníase/tratamento farmacológico , Hanseníase/epidemiologia , Mycobacterium leprae/genética
14.
Animal ; 16 Suppl 3: 100551, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35688653

RESUMO

The difficulty in selecting cattle for higher feed and nitrogen use efficiency (NUE) is an important factor contributing to poor growth and reproductive performance in dry-tropics rangelands. Therefore, the objectives were to examine the cattle variation in retaining nitrogen in a protein-deficient diet and the natural abundance of stable isotopes in body tissues as a practical alternative for the detection of more efficient cattle. In experiment 1, feed efficiency parameters were determined in 89 Brahman steers fed a protein-limiting diet for 70 days, followed by 7 days in metabolism crates for total collection of urine and faeces and calculation of nitrogen retention and NUE. The diet-animal fractionation of nitrogen isotopes (Δ15N) was quantified in tail hair and plasma proteins using isotope-ratio MS. There was a large variation in growth performance, feed efficiency and nitrogen losses among steers. Quantifying Δ15N in tail hair (Δ15Ntail hair) resulted in stronger correlations with feed efficiency and nitrogen metabolism parameters than when quantified in plasma proteins. Δ15Ntail hair was positively correlated with nitrogen losses in urine (r = 0.31, P < 0.01) and faeces (r = 0.25, P = 0.04), leading to a negative correlation with NUE (r = -0.40, P < 0.01). The group of steers with lower Δ15Ntail hair had greater feed efficiency, lower nitrogen losses, and greater NUE. In experiment 2, for evaluation of isotope fraction as a predictor of reproductive performance, 630 Brahman-crossed cows were classified for reproductive performance for 2 years. From this group, 25 cows with poor reproductive performance and 25 cows with good reproductive performance were selected. Tail hair representing 7 months of growth were segmented and analysed for carbon (δ13C) and nitrogen (δ15N) isotope enrichment. Reproductive performance was not associated with diet selection, as there was no difference in tail hair δ13C between groups. However, more productive cows had lower (P < 0.05) tail hair δ15N during the dry season, indicating differences in N metabolism and possibly lower N losses. In addition, cows with better reproductive performance and, therefore, greater nutrient demands, had similar body condition scores and a tendency (P = 0.09) for higher live weight at the end of the trial. In conclusion, the findings of the present study confirm that nitrogen isotope fractionation in tail hair can be used as a predictor of nitrogen losses, NUE, and reproductive performance of Brahman cattle on low-protein diets.


Assuntos
Ração Animal , Dieta , Ração Animal/análise , Animais , Proteínas Sanguíneas , Bovinos , Dieta/veterinária , Feminino , Nitrogênio/metabolismo , Isótopos de Nitrogênio
15.
Ecotoxicology ; 20(8): 1773-9, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21698442

RESUMO

Nelson's and saltmarsh sparrows (Ammodramus nelsoni and A. caudacutus) have recently been recognized as separate species, and because of their limited distributions and the susceptibility of their wetland habitats to climate change, these two new species are of conservation concern. Both species are known to bioaccumulate mercury at breeding sites in New England, USA where their ranges overlap, with the saltmarsh sparrow reported to have twice the concentration of blood total mercury. In this study we sampled both species on their shared wintering grounds, and documented that mercury exposure is lower than that reported for the breeding range, with saltmarsh sparrow blood mercury 2.6 times higher than in Nelson's sparrow. Feather mercury, which is incorporated on the breeding grounds, confirmed that saltmarsh sparrows had incorporated 2.3 times more mercury than Nelson's sparrows during the previous breeding season. A comparison of stable isotopes of nitrogen and carbon suggests that the higher exposure of saltmarsh sparrows may be not due to feeding at a higher trophic level, as previously hypothesized, but rather could be related to a difference in the carbon source at the base of each species' food chain. This study, along with recently published data from both species on additional breeding and wintering grounds, provides a more complete picture of relative mercury exposure. Saltmarsh sparrows are exposed to mercury levels that warrant concern, with the highest exposure being during the breeding season. Areas set aside for the long-term conservation of this species should be carefully assessed for mercury bioaccumulation.


Assuntos
Ecossistema , Poluentes Ambientais/metabolismo , Mercúrio/sangue , Pardais/metabolismo , Fenômenos Fisiológicos da Nutrição Animal , Animais , Isótopos de Carbono , Exposição Ambiental , Poluentes Ambientais/sangue , Plumas/química , Cadeia Alimentar , Isótopos de Nitrogênio , Estações do Ano , Pardais/sangue , Especificidade da Espécie , Virginia
16.
J Hosp Infect ; 108: 146-157, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33176175

RESUMO

Hospital-acquired pneumonia (HAP) is often more severe and life-threatening than community-acquired pneumonia (CAP). The role of Streptococcus pneumoniae in CAP is well-understood, but its role in HAP is unclear. The objective of this study was to summarize the available literature on the prevalence of S. pneumoniae in HAP episodes. We searched MEDLINE for peer-reviewed articles on the microbiology of HAP in individuals aged ≥18 years, published between 2008 and 2018. We calculated pooled estimates of the prevalence of S. pneumoniae in episodes of HAP using a random-effects, inverse-variance-weighted meta-analysis. Forty-seven of 1908 articles met the inclusion criteria. Bacterial specimen isolation techniques for microbiologically defined HAP episodes included bronchoalveolar lavage, protective specimen brush, tracheobronchial aspirate and sputum, as well as blood culture. Culture was performed in all studies; five studies also used urine antigen detection (5/47; 10.6%). S. pneumoniae was identified in 5.1% (95% confidence interval (CI): 3.8-6.6%) of microbiologically defined HAP episodes (N = 20), with 5.4% (95% CI: 4.3-6.7%, N = 29) in ventilator-associated HAP and 6.0% (95% CI: 4.1-8.8%, N = 6) in non-ventilator-associated HAP. S. pneumoniae was identified in 5.3% (95% CI: 4.5-6.3%) of HAP occurring in the intensive care unit (ICU, N = 41) and in 5.6% (95% CI: 3.3-9.5%, N = 5) outside the ICU. A higher proportion of early-onset HAP (10.3%; 95% CI: 8.3-12.8%, N = 16) identified S. pneumoniae as compared with late-onset HAP (3.3%; 95% CI: 2.5-4.4%, N = 16). In conclusion, S. pneumoniae was identified by culture in 5.1% of microbiologically defined HAP episodes. The importance of HAP as part of the disease burden caused by S. pneumoniae merits further research.


Assuntos
Pneumonia Associada à Ventilação Mecânica/microbiologia , Streptococcus pneumoniae/isolamento & purificação , Adulto , Hospitais , Humanos , Unidades de Terapia Intensiva
17.
Sci Rep ; 11(1): 12919, 2021 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-34155292

RESUMO

Each year hundreds of millions of birds cross the Atlantic Ocean during the peak of tropical cyclone activity. The extent and consequences of migrant-storm interactions remain unknown. We tracked whimbrels from two populations (Mackenzie Delta; Hudson Bay) to examine overlap between migration routes and storm activity and both the frequency and consequence of storm encounters. Here we show that Mackenzie Delta and Hudson Bay whimbrels follow different routes across the ocean and experience dramatically different rates of storm encounters. Mackenzie Delta whimbrels departed North America from Atlantic Canada, made long ([Formula: see text] = 5440 ± 120.3 km) nonstop flights far out to sea that took several days ([Formula: see text] = 6.1 ± 0.18) to complete and encountered storms during 3 of 22 crossings. Hudson Bay whimbrels departed North America from the south Atlantic Coast, made shorter ([Formula: see text] = 3643 ± 196.2 km) nonstop flights across the Caribbean Basin that took less time ([Formula: see text] = 4.5 ± 0.29) to complete and encountered storms during 13 of 18 crossings. More than half of Hudson Bay storm encounters resulted in groundings on Caribbean islands. Grounded birds required longer ([Formula: see text] = 30.4 ± 5.32 days) to complete trans-Atlantic crossings and three were lost including 2 to hunters and 1 to a predator. One of the Mackenzie Delta whimbrels was lost at sea while crossing the Intertropical Convergence Zone. Whimbrels use two contrasting strategies to cross the Atlantic including (1) a long nonstop flight around the core of storm activity with a low likelihood of encountering storms but no safety net and (2) a shorter flight through the heart of Hurricane Alley with a high likelihood of encountering storms and a safety network of islands to use in the event of an encounter. Demographic consequences of storm encounters will likely play a role in the ongoing evolution of trans-Atlantic migration pathways as global temperatures continue to rise.

18.
PLoS One ; 16(12): e0260339, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34972114

RESUMO

Many long-distance migratory birds use habitats that are scattered across continents and confront hazards throughout the annual cycle that may be population-limiting. Identifying where and when populations spend their time is fundamental to effective management. We tracked 34 adult whimbrels (Numenius phaeopus) from two breeding populations (Mackenzie Delta and Hudson Bay) with satellite transmitters to document the structure of their annual cycles. The two populations differed in their use of migratory pathways and their seasonal schedules. Mackenzie Delta whimbrels made long (22,800 km) loop migrations with different autumn and spring routes. Hudson Bay whimbrels made shorter (17,500 km) and more direct migrations along the same route during autumn and spring. The two populations overlap on the winter grounds and within one spring staging area. Mackenzie Delta whimbrels left the breeding ground, arrived on winter grounds, left winter grounds and arrived on spring staging areas earlier compared to whimbrels from Hudson Bay. For both populations, migration speed was significantly higher during spring compared to autumn migration. Faster migration was achieved by having fewer and shorter stopovers en route. We identified five migratory staging areas including four that were used during autumn and two that were used during spring. Whimbrels tracked for multiple years had high (98%) fidelity to staging areas. We documented dozens of locations where birds stopped for short periods along nearly all migration routes. The consistent use of very few staging areas suggests that these areas are integral to the annual cycle of both populations and have high conservation value.


Assuntos
Migração Animal/fisiologia , Charadriiformes/fisiologia , Animais , Canadá , Geografia , Comunicações Via Satélite , Estações do Ano , Estados Unidos
19.
J Exp Med ; 175(4): 951-60, 1992 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-1372649

RESUMO

CD28 is an adhesion receptor expressed as a 44-kD dimer on the surface of a major subset of human T cells. The CD28 receptor regulates the production of multiple lymphokines, including interleukin 2 (IL-2), by activation of a signal transduction pathway that is poorly understood. Here we show that ligation of CD28 by a monoclonal antibody (mAb) or by a natural ligand, B7/BB1, induces protein tyrosine phosphorylation that is distinct from T cell receptor (TCR)-induced tyrosine phosphorylation. CD28-induced protein tyrosine phosphorylation was greatly enhanced in cells that had been preactivated by ligation of the TCR, or by pretreatment with phorbol esters. Rapid and prolonged tyrosine phosphorylation of a single substrate, pp100, was induced in T cells after interaction with B7/BB1 presented on transfected Chinese hamster ovary (CHO) cells. Anti-B7 mAb inhibited B7/BB1 receptor-induced tyrosine phosphorylation, indicating that B7-CD28 interaction was required. CD28-induced tyrosine phosphorylation was independent of the TCR because it occurred in a variant of the Jurkat T cell line that does not express the TCR. Herbimycin A, a protein tyrosine kinase inhibitor, could prevent CD28-induced tyrosine phosphorylation and CD28-induced IL-2 production in normal T cells. The simultaneous crosslinking of CD28 and CD45, a tyrosine phosphatase, could prevent tyrosine phosphorylation of pp100. These results suggest that specific tyrosine phosphorylation, particularly of pp100, occurs directly as a result of CD28 ligand binding and is involved in transducing the signal delivered through CD28 by accessory cells that express the B7/BB1 receptor. Thus, this particular form of signal transduction may be relevant to lymphokine production and, potentially may provide a means to study the induction of self-tolerance, given the putative role of the costimulatory signal in the induction of T cell activation or anergy.


Assuntos
Antígenos CD/metabolismo , Antígenos de Diferenciação de Linfócitos T/metabolismo , Receptores de Superfície Celular/metabolismo , Linfócitos T/metabolismo , Anticorpos Monoclonais/imunologia , Antígenos CD/fisiologia , Benzoquinonas , Antígenos CD28 , Antígenos de Histocompatibilidade/fisiologia , Humanos , Técnicas In Vitro , Interleucina-2/farmacologia , Lactamas Macrocíclicas , Antígenos Comuns de Leucócito , Peso Molecular , Fosfoproteínas/metabolismo , Fosforilação , Fosfotirosina , Quinonas/farmacologia , Agregação de Receptores , Rifabutina/análogos & derivados , Transdução de Sinais , Acetato de Tetradecanoilforbol/farmacologia , Fatores de Tempo , Células Tumorais Cultivadas , Tirosina/análogos & derivados , Tirosina/metabolismo
20.
Ann Rheum Dis ; 69(2): 413-6, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19587388

RESUMO

OBJECTIVES: To determine the efficacy of CP-690,550 in improving pain, function and health status in patients with moderate to severe active rheumatoid arthritis (RA) and an inadequate response to methotrexate or a tumour necrosis factor alpha inhibitor. METHODS: Patients were randomised equally to placebo, CP-690,550 5, 15 or 30 mg twice daily for 6 weeks, with 6 weeks' follow-up. The patient's assessment of arthritis pain (pain), patient's assessment of disease activity, Health Assessment Questionnaire-Disability Index (HAQ-DI) and Short Form-36 (SF-36) were recorded. RESULTS: At week 6, significantly more patients in the CP-690,550 5, 15 and 30 mg twice-daily groups experienced a 50% improvement in pain compared with placebo (44%, 66%, 78% and 14%, respectively), clinically meaningful reductions in HAQ-DI (> or =0.3 units) (57%, 75%, 76% and 36%, respectively) and clinically meaningful improvements in SF-36 domains and physical and mental components. CONCLUSIONS: CP-690,550 was efficacious in improving the pain, function and health status of patients with RA, from week 1 to week 6.


Assuntos
Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Janus Quinase 3/antagonistas & inibidores , Inibidores de Proteínas Quinases/uso terapêutico , Pirimidinas/uso terapêutico , Pirróis/uso terapêutico , Antirreumáticos/administração & dosagem , Artrite Reumatoide/complicações , Artrite Reumatoide/fisiopatologia , Relação Dose-Resposta a Droga , Métodos Epidemiológicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dor/tratamento farmacológico , Dor/etiologia , Medição da Dor , Piperidinas , Inibidores de Proteínas Quinases/administração & dosagem , Pirimidinas/administração & dosagem , Pirróis/administração & dosagem , Recuperação de Função Fisiológica , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA