Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 76
Filtrar
1.
Poult Sci ; 102(6): 102634, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37011467

RESUMO

Broiler mortality during transport and lairage, prior to slaughter, has negative welfare and economic implications. Knowledge of the factors affecting the dead-on-arrival (DOA) rate can help identify risk-mitigating strategies. The objectives of this study were to determine the DOA rate in broiler chickens transported to slaughter in Great Britain and associated risk factors. Requested data for all loads of broilers transported to slaughter by 5 large British commercial companies on 57 randomly-selected dates in 2019 were obtained and combined with weather data extracted from the Met Office MIDAS Open database. The DOA rate was described overall and per load using summary descriptive statistics. Mixed-effects Poisson regression was used to evaluate considered flock-, journey- and weather-related risk factors. Results were reported as incidence rate ratios (IRR) and 95% confidence intervals (CI). On the selected dates, 25,476 loads transported 146,219,189 broilers to slaughter. The overall mean DOA rate was 0.08%. The median DOA rate per load was 0.06% (interquartile range 0.03-0.09%; range 0.00-17.39%). Multiple risk factors were identified including loading temperature and catch method. At relative humidity ≤80%, the DOA rate was 16.89 (95% CI 15.25-18.70, P < 0.001) times higher for loads loaded in external ambient temperatures >30.0°C compared to those loaded in temperatures between 10.1°C and 15.0°C. When relative humidity was >80%, there was a 43% increase in DOA rate for loads loaded in temperatures below freezing compared to those loaded in temperatures between 10.1°C and 15.0°C (IRR 1.43, 95% CI 1.35-1.52, P < 0.001). The DOA rate was 32% higher for loads caught mechanically compared to those caught manually (IRR 1.32, 95% CI 1.23-1.42, P < 0.001). The overall DOA rate was lower than that previously reported in Great Britain and for other European countries. Most identified risk factors had a marginal effect, however, loading temperatures >30°C substantially increased DOA rate. Internal thermal environmental conditions were not evaluated. Avoidance of loading during periods of hot weather would improve the welfare of, and reduce economic losses in, broiler chickens.


Assuntos
Matadouros , Galinhas , Animais , Temperatura , Reino Unido/epidemiologia , Meios de Transporte , Bem-Estar do Animal
2.
Vet Rec ; 183(13): 420, 2018 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-30287570
3.
Br Poult Sci ; 55(5): 592-7, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25181283

RESUMO

Heat shock proteins (HSPs) are highly conserved proteins, shown to protect organisms against physical and physiological stress. TEX-OE(®) is a patented total extract of the fruit of Opuntia ficus indica, which has been demonstrated to accelerate the development of HSPs in several animal species. One-day-old commercial broiler chicks were treated with TEX-OE(®); HSP was measured by enzyme-linked immunosorbent assay (ELISA), and a large commercial field trial investigated key performance indicators (KPIs) in treated versus untreated controls chicks. TEX-OE(®) significantly increased HSP concentrations in treated chicks versus controls. Final cumulative mortality, liveweight and percentage factory-rejects were better than in controls. The accelerated HSP response may enable chicks to cope with early stressors, which is reflected in improved KPIs.


Assuntos
Galinhas/crescimento & desenvolvimento , Galinhas/metabolismo , Proteínas de Choque Térmico/metabolismo , Opuntia/química , Extratos Vegetais/farmacologia , Animais , Animais Recém-Nascidos/crescimento & desenvolvimento , Animais Recém-Nascidos/metabolismo , Ensaio de Imunoadsorção Enzimática/veterinária , Frutas/química , Distribuição Aleatória
5.
Vet J ; 198(3): 661-5, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24206630

RESUMO

Mycoplasma gallisepticum (MG) is a bacterium that causes respiratory disease in chickens, leading to reduced egg production. A dynamic simulation model was developed that can be used to assess the costs and benefits of control using antimicrobials or vaccination in caged or free range systems. The intended users are veterinarians and egg producers. A user interface is provided for input of flock specific parameters. The economic consequence of an MG outbreak is expressed as a reduction in expected egg output. The model predicts that either vaccination or microbial treatment can approximately halve potential losses from MG in some circumstances. Sensitivity analysis is used to test assumptions about infection rate and timing of an outbreak. Feedback from veterinarians points to the value of the model as a discussion tool with producers.


Assuntos
Criação de Animais Domésticos/métodos , Técnicas de Apoio para a Decisão , Surtos de Doenças/veterinária , Infecções por Mycoplasma/veterinária , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/prevenção & controle , Criação de Animais Domésticos/economia , Animais , Antibacterianos/economia , Antibacterianos/uso terapêutico , Vacinas Bacterianas/economia , Vacinas Bacterianas/uso terapêutico , Galinhas , Modelos Biológicos , Infecções por Mycoplasma/epidemiologia , Infecções por Mycoplasma/microbiologia , Infecções por Mycoplasma/prevenção & controle , Mycoplasma gallisepticum , Óvulo/microbiologia , Doenças das Aves Domésticas/microbiologia
6.
Vet Rec ; 171(15): 372, 2012 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-22949546

RESUMO

In December 2010, infection with a H9N1 low pathogenicity avian influenza (LPAI) virus was detected in a broiler breeder flock in East Anglia. Disease suspicion was based on acute drops in egg production in two of four sheds on the premises, poor egg shell quality and evidence of diarrhoea. H9N1 LPAI virus infection was confirmed by real-time reverse transcription PCR. Sequencing revealed high nucleotide identity of 93.6 per cent and 97.9 per cent with contemporary North American H9 and Eurasian N1 genes, respectively. Attempted virus isolation in embryonated specific pathogen free (SPF) fowls' eggs was unsuccessful. Epidemiological investigations were conducted to identify the source of infection and any onward spread. These concluded that infection was restricted to the affected premises, and no contacts or movements of poultry, people or fomites could be attributed as the source of infection. However, the infection followed a period of extremely cold weather and snow which impacted on the biosecurity protocols on site, and also led to increased wild bird activity locally, including waterfowl and game birds around the farm buildings. Analysis of the N1 gene sequence suggested direct introduction from wild birds. Although H9 infection in poultry is not notifiable, H9N2 LPAI viruses have been associated with production and mortality episodes in poultry in many parts of Asia and the Middle East. In the present H9N1 outbreak, clinical signs were relatively mild in the poultry with no mortality, transient impact on egg production and no indication of zoonotic spread. However, this first reported detection of H9 LPAI virus in chickens in England was also the first H9 UK poultry case for 40 years, and vindicates the need for continued vigilance and surveillance of avian influenza viruses in poultry populations.


Assuntos
Galinhas , Vírus da Influenza A/isolamento & purificação , Influenza Aviária/diagnóstico , Animais , Surtos de Doenças/veterinária , Inglaterra , Vírus da Influenza A/classificação , Vírus da Influenza A/patogenicidade , Influenza Aviária/epidemiologia , Influenza Aviária/virologia , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Vigilância de Evento Sentinela/veterinária , Organismos Livres de Patógenos Específicos , Virulência
9.
J Insect Sci ; 9: 44, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19619032

RESUMO

The long-term fitness of individuals is examined in complex and temporally dynamic ecosystems. We call this multigeneration fitness measure "future fitness". Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) is a polyphagous insect that feeds on many wild and cultivated hosts. While four generations of H. zea occur during the cropping season in the U.S. Mid Southern agroecosysem, the latter two generations were of most interest, as corn (which has been largely nontransgenic in the Mid-South) dominates the first two generations in the cropping system. In simulations of the evolution of resistance to Bt-transgenic crops, cotton refuge areas were found to be significantly more effective than similar soybean acreages at delaying the evolution of resistance. Cotton is a suitable host for H. zea during two late summer generations, while a soybean field is suitable for only one of these generations, therefore soybean fields of other maturity groups were simulated as being attractive during the alternative generation. A hypothetical soybean variety was tested in which a single field would be attractive over both generations and it was found to be significantly more effective at delaying resistance than simulated conventional soybean varieties. Finally, the placement of individuals emerging at the start of the 3rd (first without corn) generation was simulated in either refuge cotton, conventional soybean and the hypothetical long attractive soybean and the mean number of offspring produced was measured at the end of the season. Although females in conventional and long soybean crops had the same expected fecundity, because of differences in temporal stability of the two crops, the long soybean simulations had significantly more H. zea individuals at the end of the season than the conventional soybean simulations. These simulations demonstrate that the long-term fecundity associated with an individual is dependent not only on the fecundity of that individual in its current habitat, but also the temporal stability of habitats, the ecosystem at large and the likelihood that the individual's offspring will move into different habitats.


Assuntos
Ecossistema , Resistência a Inseticidas/genética , Inseticidas/farmacologia , Psychodidae/efeitos dos fármacos , Psychodidae/fisiologia , Adaptação Fisiológica , Animais , Feminino , Reprodução/efeitos dos fármacos
10.
Int Immunopharmacol ; 1(6): 1199-210, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11407314

RESUMO

Patients with purine nucleoside phosphorylase (PNP) deficiency present a selective T-cell immunodeficiency. Inhibitors of PNP are, therefore, of interest as potential T-cell selective immunosuppressive agents. BCX-1777 is a potent inhibitor of PNP from various species including human, mouse, rat, monkey and dog, with IC50 values ranging from 0.48 to 1.57 nM. BCX-1777, in the presence of 2'-deoxyguanosine (dGuo, 3-10 microM), inhibits human lymphocyte proliferation activated by various agents such as interleukin-2 (IL-2), mixed lymphocyte reaction (MLR) and phytohemagglutinin (PHA) (IC50 values < 0.1-0.38 microM). BCX-1777 is a 10-100-fold more potent inhibitor of human lymphocyte proliferation than other known PNP inhibitors like PD141955 and BCX-34. Nucleotide analysis of human lymphocytes indicate that inhibition of proliferation by BCX-1777 correlates with dGTP levels in the cells. BCX-1777 has excellent oral bioavailability (63%) in mice. At a single dose of 10 mg/kg in mice, BCX-1777 elevates dGuo to approximately 5 microM. BCX-1777 was not effective in mouse T-cell models such as delayed type hypersensitivity (DTH) and splenomegaly because mouse T-cells do not accumulate dGTP as do human T-cells. However, in the human peripheral blood lymphocyte severe combined immunodeficiency (hu-PBL-SCID) mouse model, BCX-1777 was effective in prolonging the life span 2-fold or more. This is the first known example of a PNP inhibitor that elevates dGuo in mice similar to the levels observed in PNP-deficient patients. Furthermore, these dGuo levels are also required for in vitro T-cell inhibition by BCX-1777. Thus, BCX-1777 represents a novel class of selective immunosuppressive agents that could have therapeutic utility in various T-cell disorders.


Assuntos
Inibidores Enzimáticos/farmacologia , Imunossupressores/farmacologia , Purina-Núcleosídeo Fosforilase/antagonistas & inibidores , Pirimidinonas/farmacologia , Pirróis/farmacologia , Administração Oral , Animais , Disponibilidade Biológica , Inibidores Enzimáticos/farmacocinética , Reação Enxerto-Hospedeiro/efeitos dos fármacos , Guanosina Trifosfato/metabolismo , Indicadores e Reagentes , Injeções Intravenosas , Teste de Cultura Mista de Linfócitos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos SCID , Nucleosídeos de Purina , Pirimidinonas/farmacocinética , Pirróis/farmacocinética , Análise de Sobrevida , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia
11.
Antimicrob Agents Chemother ; 45(4): 1162-7, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11257030

RESUMO

We have recently reported an influenza virus neuraminidase inhibitor, RWJ-270201 (BCX-1812), a novel cyclopentane derivative discovered through structure-based drug design. In this paper, we compare the potency of three compounds, RWJ-270201, oseltamivir, and zanamivir, against neuraminidase enzymes from various subtypes of influenza. RWJ-270201 effectively inhibited all tested influenza A and influenza B neuraminidases in vitro, with 50% inhibitory concentrations of 0.09 to 1.4 nM for influenza A neuraminidases and 0.6 to 11 nM for influenza B neuraminidases. These values were comparable to or lower than those for oseltamivir carboxylate (GS4071) and zanamivir (GG167). RWJ-270201 demonstrated excellent selectivity (>10,000-fold) for influenza virus neuraminidase over mammalian, bacterial, or other viral neuraminidases. Oral administration of a dosage of 1 mg/kg of body weight/day of RWJ-270201 for 5 days (beginning 4 h preinfection) showed efficacy in the murine model of influenza virus infection as determined by lethality and weight loss protection. RWJ-270201 administered intranasally at 0.01 mg/kg/day in the murine influenza model demonstrated complete protection against lethality, whereas oseltamivir carboxylate and zanamivir at the same dose demonstrated only partial protection. In the delayed-treatment murine influenza model, oral administration of a 10-mg/kg/day dose of RWJ-270201 or oseltamivir (GS4104, a prodrug of GS4071) at 24 h postinfection showed significant protection against lethality (P < 0.001 versus control). However, when the treatment was delayed for 48 h, no significant protection was observed in either drug group. No drug-related toxicity was observed in mice receiving 100 mg/kg/day of RWJ-270201 for 5 days. These efficacy and safety profiles justify further consideration of RWJ-270201 for the treatment and prevention of human influenza.


Assuntos
Acetamidas/farmacologia , Antivirais/farmacologia , Ciclopentanos/farmacologia , Infecções por Orthomyxoviridae/prevenção & controle , Orthomyxoviridae/efeitos dos fármacos , Ácidos Siálicos/farmacologia , Acetamidas/administração & dosagem , Ácidos Carbocíclicos , Administração Intranasal , Administração Oral , Animais , Antivirais/administração & dosagem , Ciclopentanos/administração & dosagem , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/farmacologia , Feminino , Guanidinas , Concentração Inibidora 50 , Camundongos , Camundongos Endogâmicos BALB C , Neuraminidase/antagonistas & inibidores , Orthomyxoviridae/enzimologia , Oseltamivir , Piranos , Ácidos Siálicos/administração & dosagem , Especificidade da Espécie , Análise de Sobrevida , Fatores de Tempo , Zanamivir
13.
J Econ Entomol ; 92(4): 837-45, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10504897

RESUMO

Laboratory and field studies were conducted during 1993 and 1994 to quantify interplant movement of Heliothis virescens (F.) larvae in pure and mixed plantings of cotton, Gossypium hirsutum L., with ('Event 531') and without ('Coker 312') the expression of Cry1Ac delta-endotoxin protein of Bacillus thuringiensis Berliner. Field studies were conducted with neonate, 4-, and 7-d-old larvae placed on 3-plant experimental units and observed at 24, 48, 72, and 96 h after inoculation of larvae. Combining larval movement across observations of neonates, 4-, and 7-d-old larvae, an estimated 52% of the larvae on pure plantings of Coker 312 had moved at least 1 plant by the cumulative time required to reach the age of 10 d. More larvae placed on Event 531 cotton moved to an adjacent plant (13% of the neonates had moved at least 1 plant within 24 h) than those placed on Coker 312 (0% of the neonates had moved at least 1 plant within 24 h). When larvae were placed on Event 531 plants, an estimated 82% of the larvae had moved to an adjacent plant by cumulative age of 10 d. Collectively, these data indicate that movement of larvae from plant to plant increases with larval age and occurs more rapidly for larvae placed on Event 531 cotton than on Coker 312. Previous studies have suggested that resistance to B. thuringiensis could develop more rapidly in insects exposed to seed mixtures of plants with and without endotoxin if larvae move between plants and if an external refuge exists. These data provide evidence of larval movement between plants in seed mixtures.


Assuntos
Bacillus thuringiensis , Proteínas de Bactérias , Toxinas Bacterianas , Endotoxinas , Gossypium , Mariposas , Controle Biológico de Vetores , Animais , Toxinas de Bacillus thuringiensis , Proteínas de Bactérias/genética , Endotoxinas/genética , Proteínas Hemolisinas , Larva , Controle Biológico de Vetores/métodos , Plantas Geneticamente Modificadas
14.
J Biol Chem ; 273(32): 20644-52, 1998 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-9685423

RESUMO

The invariant chain (Ii) targets newly synthesized major histocompatibility complex class II complexes to a lysosome-like compartment. Previously, we demonstrated that both the cytoplasmic tail (CT) and transmembrane (TM) domains of Ii were sufficient for this targeting and that the CT contains two di-leucine signals, 3DQRDLI8 and 12EQLPML17 (Odorizzi, C. G., Trowbridge, I. S., Xue, L., Hopkins, C. R., Davis, C. D., and Collawn, J. F. (1994) J. Cell Biol. 126, 317-330). In the present study, we examined the relationship between signals required for endocytosis and those required for lysosomal targeting by analyzing Ii-transferrin receptor chimeras in quantitative transport assays. Analysis of the Ii CT signals indicates that although 3DQRDLI8 is necessary and sufficient for endocytosis, either di-leucine signal is sufficient for lysosomal targeting. Deletions between the two signals reduced endocytosis without affecting lysosomal targeting. Transplantation of the DQRDLI sequence in place of the EQLPML signal produced a chimera that trafficked normally, suggesting that this di-leucine sequence coded for an independent structural motif. Structure-function analysis of the Ii TM region showed that when Ii TM residues 11-19 and 20-29 were individually substituted for the corresponding regions in the wild-type transferrin receptor, lysosomal targeting was dramatically enhanced, whereas endocytosis remained unchanged. Our results therefore demonstrate that the structural requirements for Ii endocytosis and lysosomal targeting are different.


Assuntos
Antígenos de Diferenciação de Linfócitos B/química , Endocitose/fisiologia , Antígenos de Histocompatibilidade Classe II/química , Lisossomos/fisiologia , Sequência de Aminoácidos , Cloreto de Amônio/farmacologia , Animais , Embrião de Galinha , Humanos , Cinética , Proteínas de Membrana/química , Dados de Sequência Molecular , Mutação/genética , Receptores da Transferrina/química , Proteínas Recombinantes de Fusão/química , Relação Estrutura-Atividade
15.
J Biol Chem ; 273(23): 14355-62, 1998 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-9603944

RESUMO

The sorting of membrane proteins to the lysosome requires tyrosine- or dileucine-based targeting signals. Recycling receptors have similar signals, yet these proteins seldom enter the latter stages of the endocytic pathway. To determine how lysosomal and internalization signals differ, we prepared chimeric molecules consisting of the cytoplasmic tails of CD3 gamma-chain, lysosomal acid phosphatase, and lysosomal-associated membrane glycoprotein-1, each fused to the transmembrane and extracellular domains of the transferrin receptor (TR). Each chimera was expressed on the cell surface and rapidly internalized. Metabolic pulse-chase experiments showed that the CD3 gamma-chain and lysosomal acid phosphatase chimeras, unlike the lysosomal-associated membrane glycoprotein chimera, were rapidly degraded in a post-Golgi compartment following normal glycosylation. Transplantation of signals from CD3 gamma-chain and lysosomal acid phosphatase into the TR cytoplasmic tail in place of the native signal, Y20TRF23, indicated that each signal was sufficient to promote endocytosis but not lysosomal targeting of the resulting mutant. Transplantation of two CD3 signals at specific sites in the TR cytoplasmic tail or a single tyrosine-based signal in a truncated TR tail, however, was sufficient to promote lysosomal targeting. Our results therefore suggest that the relative position of the signal within the cytoplasmic tail is a critical feature that distinguishes lysosomal targeting signals from internalization signals.


Assuntos
Lisossomos/fisiologia , Receptores da Transferrina/química , Proteínas Recombinantes de Fusão/química , Fosfatase Ácida/química , Sequência de Aminoácidos , Cloreto de Amônio/farmacologia , Animais , Antígenos CD/química , Complexo CD3/química , Embrião de Galinha , Endocitose/fisiologia , Fibroblastos , Humanos , Imuno-Histoquímica , Ferro/farmacocinética , Proteínas de Membrana Lisossomal , Glicoproteínas de Membrana/química , Proteínas de Membrana/metabolismo , Dados de Sequência Molecular , Mutação/genética , Tirosina/metabolismo
16.
J Emerg Nurs ; 23(4): 351-3, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9379580
17.
Comput Nurs ; 15(1): 30-3; quiz 34-6, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9014391

RESUMO

The contractual process for the purchase of a health-care facility information system is a major endeavor for today's informatics practitioners as more facilities purchase information solution from vendors rather than producing proprietary systems. The goal of the contractual process is not simply to protect either party from future litigation but to produce a clearly understood document that outlines the duties and responsibilities of both the organization and the vendor. This document should anticipate and set forth contingencies for problems that may arise in the future. Guidelines are offered to assist nurses who are members of the acquisition team better understand the contract review process.


Assuntos
Serviços Contratados/normas , Sistemas de Informação Hospitalar/organização & administração , Negociação , Serviços Contratados/legislação & jurisprudência , Educação Continuada em Enfermagem , Software , Estados Unidos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...