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1.
Chem Soc Rev ; 47(14): 5312-5337, 2018 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-29770369

RESUMEN

The applications of nanoparticles (NPs) are increasing exponentially in consumer products, biotechnology and biomedicine, and humans, as well as the environment, are increasingly being exposed to NPs. Analogously, various (pathogenic) microorganisms are present at all the major exposure and entry sites for NPs in the human body as well as in environmental habitats. However, the field has just started to explore the complex interplay between NPs and microbes and the (patho)biological consequences. Based on recent insights, herein, we critically reviewed the available knowledge about the interaction of NPs with microbes and the analytical investigations including the latest intravital imaging tools. We have commented on how the NPs' characteristics influence complex formation with microorganisms, presented the underlying physicochemical forces, and provided examples of how this knowledge can be used to rationally control the NP-microbe interaction. We concluded by discussing the role of the biomolecule corona in NP-microbe crosstalk and speculated the impact of NP-microbe complex formation on the (patho)biological outcome and fate of microbial pathogens. The presented insights will not only support the field in engineering NPs with improved anti-microbial activity but also stimulate research on the biomedical and toxicological relevance of nanomaterial-microbiome complex formation for the anthropocene in general.


Asunto(s)
Bacterias Gramnegativas/metabolismo , Bacterias Grampositivas/metabolismo , Nanopartículas/metabolismo , Esporas Fúngicas/metabolismo , Animales , Antiinfecciosos/química , Antiinfecciosos/farmacología , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Humanos , Microalgas/efectos de los fármacos , Microalgas/metabolismo , Nanopartículas/química , Nanopartículas/toxicidad , Imagen Óptica , Polen/efectos de los fármacos , Polen/metabolismo , Esporas Fúngicas/efectos de los fármacos
2.
J Dairy Sci ; 97(7): 4227-35, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24792790

RESUMEN

The prevalence and severity of multiple gross pathologic lesions and abnormalities in cull dairy and beef cows was evaluated at a commercial abattoir in the Great Lakes region of the United States; 1,461 cattle were examined at slaughter over the course of 3 production days and evaluated for the occurrence and severity of lung, liver, rumen, and carcass abnormalities and pathologies. Of the 1,461 cattle examined at slaughter, 87% were classified as Holstein cows and 13% were classified as other cows. Liver abscesses were observed in 32% of the population and over half were classified as severe (18.5% population prevalence). The frequency distribution of cattle observed with a liver abscess was not different among production days. Severe ruminal lesions and rumenitis scars were observed in 10.0% of the population, and 25.1% of cattle were observed to have short or denuded papillae. Severe bovine respiratory disease complex lesions were observed in 10.3% of cattle. The most common reason for USDA postmortem carcass condemnation was malignant lymphoma (9 of 41). Only 45.9% of carcasses were free from bruising. Results indicate that ruminal acidosis and bovine respiratory disease complex occur at a relatively high frequency in this population. Although cows are routinely culled for reproductive failure or low milk production, the underlying reason may be causally related to these relatively prevalent conditions. Further investigation is warranted to assess this relationship and to examine the use of specific health intervention strategies within this demographic of cattle.


Asunto(s)
Enfermedades de los Bovinos/epidemiología , Mataderos , Animales , Bovinos , Enfermedades de los Bovinos/patología , Femenino , Great Lakes Region/epidemiología , Medio Oeste de Estados Unidos/epidemiología , Prevalencia
3.
Int J Dent Hyg ; 10(4): 277-83, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22356661

RESUMEN

OBJECTIVE: Adherence of young adults to preventive programmes is low. The following study compares three different educational concepts to increase toothbrushing adherence in young adults. METHODS: Nine vocational school classes (157 young adults) were randomly assigned to three different 60-min approaches: (I) Education by a dentist, (II) Peer-teaching and (III) 'Adherence triangle concept' uniting dentists, teachers and participants as equal partners in intervention planning combined with peer teaching. Follow-up was 1 week for approaches I and II, and 1 week, 3 and 9 months for approach III. Adherence was defined as reported change from the childhood toothbrushing technique to adult technique. Adherence was evaluated using anonymous questionnaires and by diary analysis. RESULTS: After instruction, 90% of participants (approaches I-III) showed the desired behaviour in practice and theory. Reported adherence after 1 week with approach I was 28.5%, with approach II 39% and with approach III 95%. Prolonged follow-up of approach III yielded 76% after 3 months and 68% after 9 months. Adherence using approach III was significantly higher (P ≤ 0.001) than using approach I and II after 1 week. Adherence rates with approach III after 9 months were still higher than those of approaches I and II after 1 week. CONCLUSIONS: The 'adherence triangle' concept enhanced reported adherence significantly in comparison with previous studies and the one-dimensional concepts of approaches I and II. The tools of the adherence triangle concept seem worthwhile to be considered when planning new preventive action.


Asunto(s)
Cooperación del Paciente , Educación del Paciente como Asunto , Enseñanza/métodos , Cepillado Dental , Actitud Frente a la Salud , Asistentes Dentales , Relaciones Dentista-Paciente , Femenino , Estudios de Seguimiento , Conductas Relacionadas con la Salud , Humanos , Masculino , Registros Médicos , Motivación , Salud Bucal , Grupo de Atención al Paciente , Participación del Paciente , Grupo Paritario , Proyectos Piloto , Relaciones Profesional-Paciente , Estudios Prospectivos , Autoinforme , Clase Social , Adulto Joven
4.
J Exp Med ; 181(2): 503-13, 1995 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-7836907

RESUMEN

The nature of alloantigens seen by T lymphocytes, in particular the role of peptides in allorecognition, has been studied intensively whereas knowledge about the in vivo emergence, diversity, and the structural basis of specificity of alloreactive T cells is very limited. Here we describe human T cell clones that recognize HLA-B35 alloantigens in a peptide-dependent manner. TCR sequence analysis revealed that several of these allospecific clones utilize homologous TCR: they all express TCRAV2S3J36C1 and TCRBV4S1J2S7C2 chains with highly related CDR3 sequences. Thus peptide-specific alloreactivity is reflected in homologous CDR3 sequences in a manner similar to that described for T cells that recognize nominal peptide/self-MHC complexes. The in vivo frequency of this TCR specificity was studied in unstimulated PBL of the responding cell donor who was not sensitized against HLA-B35. The vast majority (approximately 75%) of the VA2S3J36 junctional regions obtained from two samples of PBL, isolated at a 9-yr interval, encode CDR3 identical or homologous to those of the functionally characterized HLA-B35 allospecific T cells. These data are most easily explained by a model of alloreactivity in which persistent or recurrent exposure to a foreign peptide/self-MHC complex led to the in vivo expansion and long-term maintenance of specific T cells that show fortuitous crossrecognition of an HLA-B35/peptide complex and dominate the alloresponse against HLA-B35.


Asunto(s)
Antígeno HLA-B35/inmunología , Péptidos/inmunología , Receptores de Antígenos de Linfocitos T/inmunología , Linfocitos T/inmunología , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Callithrix , Línea Celular , Amplificación de Genes , Antígenos HLA/inmunología , Humanos , Isoantígenos/inmunología , Datos de Secuencia Molecular , Oligodesoxirribonucleótidos , Receptores de Antígenos de Linfocitos T/genética , Linfocitos T/citología
5.
Ann Oncol ; 21(2): 275-282, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19633042

RESUMEN

BACKGROUND: High-level expression of epithelial cell adhesion molecule (EpCAM) is associated with unfavorable prognosis in breast cancer. This study was designed to investigate two doses of the fully human IgG1 anti-EpCAM antibody adecatumumab (MT201) in patients with metastatic breast cancer (MBC). METHODS: A total of 109 patients were stratified into high- and low-level EpCAM expression by immunohistochemical staining of primary tumors and subsequently randomly assigned to receive monotherapy with either high- (6 mg/kg every two weeks (q2w)) or low-dose adecatumumab (2 mg/kg/ q2w) until disease progression. RESULTS: No complete or partial tumor responses could be confirmed by central RECIST assessment. The probability for tumor progression was significantly lower in patients receiving high-dose adecatumumab and expressing high levels of EpCAM (hazard ratio 0.43; P = 0.0057 versus low dose and low EpCAM). Three of 18 patients with highest EpCAM expression treated with adecatumumab developed new metastases up to week 6, compared with 14 of 29 patients with low EpCAM. Most frequent treatment-related adverse events (high dose/low dose) were chills (59%/20%), nausea (55%/18%), fatigue (39%/23%) and diarrhea (43%/7%). CONCLUSIONS: Single-agent adecatumumab shows dose- and target-dependent clinical activity in EpCAM-positive MBC, albeit no objective tumor regression. Further investigation of adecatumumab in patients with EpCAM-overexpressing tumors and lower tumor burden is warranted.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Antígenos de Neoplasias/inmunología , Neoplasias de la Mama/tratamiento farmacológico , Moléculas de Adhesión Celular/inmunología , Moléculas de Adhesión Celular/uso terapéutico , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Monoclonales/efectos adversos , Anticuerpos Monoclonales Humanizados , Antineoplásicos/administración & dosificación , Antineoplásicos/efectos adversos , Antineoplásicos/uso terapéutico , Neoplasias de la Mama/patología , Moléculas de Adhesión Celular/administración & dosificación , Moléculas de Adhesión Celular/efectos adversos , Progresión de la Enfermedad , Supervivencia sin Enfermedad , Relación Dosis-Respuesta a Droga , Molécula de Adhesión Celular Epitelial , Femenino , Humanos , Persona de Mediana Edad , Metástasis de la Neoplasia , Resultado del Tratamiento
6.
Science ; 200(4348): 1343-7, 1978 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-208143

RESUMEN

The major lethal factors in uncontrolled fires are toxic gases, heat, and oxygen deficiency. The predominant toxic gas is carbon monoxide, which is readily generated from the combusion of wood and other cellulosic materials. Increasing use of a variety of synthetic polymers has stimulated interest in screening tests to evaluated the toxicity of polymeric materials when thermally decomposed. As yet, this country lacks a standardized fire toxicity test protocol.


Asunto(s)
Incendios , Gases/toxicidad , Intoxicación por Monóxido de Carbono/etiología , Intoxicación por Monóxido de Carbono/mortalidad , Predicción , Calor , Ácido Clorhídrico/toxicidad , Cianuro de Hidrógeno/toxicidad , Hipoxia/mortalidad , Esfuerzo Físico , Seguridad , Factores de Tiempo
7.
Science ; 201(4359): 928-30, 1978 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-98843

RESUMEN

The regulative behavior of cells from the imaginal wing disk of Drosophila melanogaster can be modified by interaction with cells from different disk types. Both thoracic and nonthoracic disks are able to interact, but there are major differences in the effectiveness of interaction. The finding lends experimental support to the idea that cells in different fields within the same organism use the same mechanism for specifying positional information. A similar conclusion has been reached by Wilcox and Smith based on studies of the mutation wingless.


Asunto(s)
Drosophila melanogaster/crecimiento & desarrollo , Animales , Diferenciación Celular/efectos de la radiación , Drosophila melanogaster/citología , Rayos gamma , Regeneración , Alas de Animales/citología , Alas de Animales/crecimiento & desarrollo
8.
Euro Surveill ; 14(17)2009 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-19422767

RESUMEN

Hand hygiene represents the single most effective way to prevent healthcare-associated infections. The World Health Organization, as part of its First Global Patient Safety Challenge, recommends implementation of multi-faceted strategies to increase compliance with hand hygiene. A questionnaire was sent by the European Centre for Disease Prevention and Control to 30 European countries, regarding the availability and organisation of their national hand hygiene campaigns. All countries responded. Thirteen countries had organised at least one national campaign during the period 2000-2009 and three countries were in the process of organising a national campaign. Although the remaining countries did not have a national campaign, several reported regional and local hand hygiene activities or educational resources on national websites.


Asunto(s)
Control de Enfermedades Transmisibles/métodos , Control de Enfermedades Transmisibles/estadística & datos numéricos , Desinfección de las Manos/métodos , Promoción de la Salud/organización & administración , Promoción de la Salud/estadística & datos numéricos , Higiene , Europa (Continente) , Humanos
9.
Opt Express ; 15(25): 16667-80, 2007 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-19550953

RESUMEN

Excitation, focusing and directing of surface plasmon polaritons (SPPs) with curved chains of nanoparticles located on a metal surface is investigated both experimentally and theoretically. We demonstrate that, by using a relatively narrow laser beam (at normal incidence) interacting only with a portion of a curved chain of nanoparticles, one can excite an SPP beam whose divergence and propagation direction are dictated by the incident light spot size and its position along the chain. It is also found that the SPP focusing regime is strongly influenced by the chain inter-particle distance. Extensive numerical simulations of the configuration investigated experimentally are carried out for a wide set of system parameters by making use of the Green's tensor formalism and dipole approximation. Comparison of numerical results with experimental data shows good agreement with respect to the observed features in SPP focusing and directing, providing the guidelines for a proper choice of the system parameters.

10.
Hamostaseologie ; 27(1): 55-8, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17279277

RESUMEN

Tissue factor (TF) is the major initiator of blood coagulation, and a mediator of inflammation, angiogenesis, and carcinogenesis. According to recent evidence, preformed TF and inducible expression of the protein is observed in several blood components. TF is apparently constitutively expressed on circulating microparticles, and can be exposed within minutes on the cell membrane of activated eosinophils and platelets, and, potentially, on neutrophils. Expression in monocytes and neutrophils largely requires transcriptional activation of the TF gene. Eosinophils appear to harbour the highest concentration of preformed TF among all blood components under resting conditions. TF expression in eosinophil progenitor cells is substantially higher than in precursors of other granulocyte fractions. Eosinophil TF promotes transendothelial migration, which documents that presynthesized TF in blood supports functions apart from coagulation. It is still an open question how the intravascular TF is activated to trigger initiation of coagulation. TF activation in different blood components is likely to be differentially regulated according to the (patho)physiologic context.


Asunto(s)
Tromboplastina/metabolismo , Aterosclerosis/sangre , Proteínas Sanguíneas/metabolismo , Endotelio Vascular/metabolismo , Eosinófilos/metabolismo , Humanos , Monocitos/metabolismo , Trombosis/sangre
11.
Transl Anim Sci ; 1(3): 304-310, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32704655

RESUMEN

Strip loin steaks (n = 119) were used to evaluate the association between liver abscess severity and USDA quality grade and meat tenderness and sensory attributes of steaks from finished feedlot cattle. Steaks were used in a 3 × 2 factorial treatment structure using a completely randomized design and were collected at a commercial abattoir located in northwest Texas. All cattle were sourced from a single feedlot and fed a common diet that did not include tylosin phosphate. Treatments were USDA quality grades of Select (SEL) and Low Choice (LC) and liver abscess scores of normal (NORM; healthy liver, no abscesses), mild (M; 1 abscess less than 2 cm in diameter to 4 abscesses less than 4 cm in diameter), and severe (SV; 1 abscess greater than 4 cm in diameter or greater than 4 small abscesses). All steak samples were collected on the same day, approximately 36-h post-mortem and were cut from the left side of the carcass at the 13th rib by a trained abattoir employee. Steaks were vacuum-packaged, and aged at 3 ± 1°C for 14-d post-mortem. Warner-Bratzler Shear Force (WBSF) and Slice Shear Force (SSF) analyses were conducted and cook-loss percentage was measured. A trained sensory panel analyzed samples for juiciness, tenderness, and flavor attributes. There were no differences among liver abscess scores for WBSF or SSF (P > 0.52). Warner-Bratzler Shear Force was lower for LC-SV than SEL-SV (P = 0.04). Sensory attributes of initial and sustained juiciness, and overall tenderness were all greater for LC than for SEL steaks (P < 0.04) and connective tissue amount was less for LC steaks when compared to SEL (P = 0.03). Liver abscess score had no effect on any sensory attributes (P > 0.70); however, there was an interaction between quality grade and liver score for myofibillar tenderness (P = 0.03). Within LC steaks, liver abscess score had no effect on myofibrillar tenderness (P > 0.05), however, in SEL steaks, M steaks were more tender than SV steaks (P < 0.03). These results indicate that within quality grades, meat tenderness or sensory attributes were not influenced by liver abscess score but that mild liver abscesses may affect the myofibrillar tenderness of SEL steaks.

12.
Transl Anim Sci ; 1(4): 489-497, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32704672

RESUMEN

Cattle injuries can occur during transportation due to vehicle design, transport conditions, and loading or unloading procedures and lead to carcass bruising and economic loss due to decreased carcass value. The objectives of this study were to determine whether a relationship exists between trauma incurred during unloading and prevalence of carcass bruising in finished beef cattle at commercial slaughter facilities and determine related risk factors which contribute to both trauma and carcass bruising. Breed (classified as either Holstein cattle or beef breeds), sex, distance traveled, and trailer type ("fat/feeder combination" vs. "fat" trailer) were considered risk factors which may contribute to traumatic event prevalence. When carcass bruise prevalence within each lot was used as the dependent variable, breed, sex, distance traveled, traumatic event prevalence, ribeye area, fat thickness, yield grade, and average carcass weight were considered potential risk factors. Carcass bruises were categorized by location and size, according to the Harvest Audit Program Carcass Bruise Scoring System. Traumatic events were observed while cattle exited trailers onto the unloading docks, and were categorized by location on the animal. Average traumatic event prevalence per lot was 20.4% (± 1.11%). Average carcass bruise prevalence by lot was 68.2% (± 1.15%). There was an interaction between breed and trailer type when multiple linear regression was used to explore variables contributing to traumatic events observed at unloading (P ≤ 0.05). Traumatic events were not associated with prevalence of carcass bruising, while average carcass weight and breed were associated with carcass bruising prevalence. Carcass bruising was more prevalent in Holstein cattle than in cattle which were predominantly beef breeds (P ≤ 0.01). Average carcass weight was negatively associated with carcass bruise prevalence (P ≤ 0.05). The association between traumatic events at unloading and carcass bruising is not significant when multiple variables are considered, indicating that bruising may occur at numerous other points prior to and during the transportation process, including loading and transport, and that other variables can contribute to carcass bruise prevalence. These areas should be explored to determine all potential causes of bruising in beef carcasses, and to help implement prevention practices.

13.
J Vet Cardiol ; 19(2): 153-159, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27720380

RESUMEN

INTRODUCTION: Atrial premature complexes have been reported to be the most common arrhythmia in cattle and is suspected to be secondary to systemic disease, especially gastrointestinal disease. In order to properly identify pathologic arrhythmia in cattle, the normal rhythm and arrhythmia prevalence should be defined. The objective of this study was to determine the normal heart rate, rhythm, number of ventricular premature complexes (VPCs), and atrial premature complexes (APCs) in unrestrained Angus steers. ANIMALS: Twenty-seven client owned steers with unremarkable physical examinations and serum biochemical analyses were used. MATERIALS AND METHODS: Twenty-four hour Holter monitors, attached by a custom-made harness, were retrospectively evaluated. Three lead electrocardiographic registrations of good quality and normal sinus rhythm were obtained from all steers in the study. RESULTS: The mean heart rate was 66.8 bpm ± 16.4 bpm. Ventricular premature complexes were rare (noted in 14.8% of steers), and APCs were common (noted in 85% of the steers). Simple second degree AV block was observed in 18.5% of the steers. CONCLUSION: In summary, healthy steers have rare single VPCs, although it is possible for an individual animal to have apparent more frequent VPCs. Mean heart rate varies with a diurnal pattern similar to other species. Atrial premature complexes are the most prevalent abnormality observed in feedlot steers.


Asunto(s)
Crianza de Animales Domésticos , Complejos Atriales Prematuros/veterinaria , Enfermedades de los Bovinos/fisiopatología , Bovinos/fisiología , Electrocardiografía Ambulatoria/veterinaria , Complejos Prematuros Ventriculares/veterinaria , Animales , Complejos Atriales Prematuros/fisiopatología , Enfermedades de los Bovinos/diagnóstico , Frecuencia Cardíaca , Masculino , Valores de Referencia , Estudios Retrospectivos , Complejos Prematuros Ventriculares/fisiopatología
14.
G3 (Bethesda) ; 7(7): 2185-2193, 2017 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-28546386

RESUMEN

In the framework of a gene flow assessment, we investigated the natural hybridization rate between Gossypium hirsutum (AADD genome) and G. herbaceum (AA genome). The latter species, a diploid progenitor of G. hirsutum, is spontaneously present in South Africa. Reciprocal crosses were performed without emasculation between G. herbaceum and G. hirsutum Neither examination of the morphological characteristics nor flow cytometry analysis of the 335 plants resulting from the G. hirsutum × G. herbaceum cross showed any hybrid features. Of the 148 plants produced from the G. herbaceum × G. hirsutum cross, three showed a hybrid phenotype, and their hybrid status was confirmed by SSR markers. Analysis of DNA content by flow cytometry and morphological traits clearly showed that two of these plants were triploid (AAD). The third plant had a flow cytometry DNA content slightly higher than G. hirsutum In addition, its morphological characteristics (plant architecture, presence and size of petal spots, leaf shape) led us to conclude that this plant was AAAD thus resulting from fertilization with an unreduced AA gamete of the female G. herbaceum parent. Fluorescent In Situ Hybridization (FISH) and meiotic behavior confirmed this hypothesis. To the best of our knowledge, this is the first description of such gametes in G. herbaceum, and it opens new avenues in breeding programs. Furthermore, this plant material could provide a useful tool for studying the expression of genes duplicated in the A and D cotton genome.


Asunto(s)
Quimera/genética , Diploidia , Flujo Génico , Genoma de Planta , Células Germinativas de las Plantas , Gossypium/genética , ADN de Plantas/genética , Sudáfrica
15.
J Anim Sci ; 95(5): 1977-1992, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28726982

RESUMEN

Feedlot cattle ( = 128; BW = 549 ± 60 kg) were used to evaluate the effects of ractopamine hydrochloride (RAC) on growth performance, physiological response to handling, and mobility during shipment for slaughter in a study utilizing a split-plot design with a 2 × 2 factorial arrangement of treatments: 1) diet (CON [no ß-adrenergic agonist] vs. RAC [400 mg·animal·d ractopamine hydrochloride for 28 d]) and 2) handling intensity (HI; low-stress handling [LSH; cattle moved at a walking pace with no electric prod use] vs. high-stress handling [HSH; cattle moved at a minimum of a trot and an electric prod applied while in the alley for posthandling restraint and during loading for shipment to the abattoir]). Cattle fed RAC tended to have greater ADG and G:F ( = 0.06), and had greater HCW and LM area ( = 0.04). The HI treatments were applied on the day after the 28-d growth performance period. Blood samples were collected before HI treatment (baseline), after HI treatments (POSTHAND), after transport to the abattoir (POSTTRANS), and during exsanguination at slaughter. A diet × HI interaction ( = 0.01) was observed in the change in cortisol from baseline to POSTTRANS, and there tended ( ≤ 0.07) to be diet × HI interactions for the change in epinephrine from baseline to POSTHAND and for the change in creatine kinase (CK) from baseline to POSTTRANS. Feeding RAC and HSH both increased the change from baseline to POSTHAND in norepinephrine and pH ( ≤ 0.05). The HSH cattle also had greater changes from baseline to POSTHAND in blood HCO, base excess, partial pressure of CO, lactate, cortisol, and glucose ( ≤ 0.01). Ractopamine and HSH both produced greater increases in CK concentrations from baseline to slaughter ( < 0.01). Mobility was not affected by RAC at the feedlot or following an average 6-h lairage ( ≥ 0.43). This study confirms RAC improves growth performance and suggests metabolic acidosis, a precursor to fatigued cattle syndrome, develops in cattle allowed to trot without the use of a lead rider regardless of RAC administration. Cattle fed RAC displayed altered hormonal responses to handling and transport stress, and the overall proportion of cattle with compromised mobility appears to increase later in the marketing channel. These findings warrant additional research aimed at better understanding the physiological response to stress and protect the welfare of cattle during shipment for slaughter.


Asunto(s)
Agonistas Adrenérgicos beta/farmacología , Bovinos/fisiología , Manejo Psicológico , Fenetilaminas/farmacología , Estrés Fisiológico/efectos de los fármacos , Mataderos , Alimentación Animal , Animales , Composición Corporal/efectos de los fármacos , Bovinos/crecimiento & desarrollo , Dieta/veterinaria , Femenino , Masculino , Transportes , Aumento de Peso/efectos de los fármacos
16.
J Anim Sci ; 95(5): 1963-1976, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28727025

RESUMEN

The effects of handling intensity on the physiological response and carcass characteristics of feedlot cattle fed ractopamine hydrochloride were evaluated at the time of transport to slaughter. Eighty steers (BW = 668 ± 36 kg) representing 10 lots of similar breed, frame size, and degree of finish were blocked by lot, stratified by weight, and randomly assigned to 1 of 2 handling intensities (HI) over a 1,600 m dirt alley course: 1) low-stress handling (LSH) or 2) high-stress handling (HSH). For the LSH treatment, 4 penmates were kept at a walk with the use of a lead rider. For the HSH treatment, 4 penmates were kept at a minimum of a trot and received 2 applications of an electric prod (approximately 1 s per impulse) at 2 separate instances: first in the alley before post-handling sampling, and again during loading for transportation to the abattoir. Behavioral observations and physical indicators of stress were recorded a minimum of 1 h before handling (baseline), immediately after handling (POSTHAND), and while in lairage after a 200 km transport to the abattoir. Vital parameters were recorded at baseline and POSTHAND. Venous blood samples were collected via jugular venipuncture at baseline and POSTHAND, and mixed arterial and venous blood samples were collected during exsanguination at slaughter. Muscle tremors tended to be more prevalent in HSH cattle at POSTHAND ( = 0.10). The HSH cattle tended to have greater POSTHAND heart rate ( = 0.08); however, there was no effect of HI on POSTHAND respiration rate or rectal temperature ( 0.34). The HSH cattle had greater lactate, epinephrine, norepinephrine, cortisol, and glucose concentrations at POSTHAND ( ≤ 0.02). Additionally, HSH cattle had lower POSTHAND blood pH, bicarbonate, base excess, and partial pressure carbon dioxide ( < 0.0001). Bicarbonate concentrations were greater in HSH cattle at slaughter ( = 0.05); however, there were no differences between HI treatments for the remaining blood variables ( 0.11). Concentrations of stress hormones and CK were significantly greater at slaughter relative to baseline and POSTHAND for both LSH and HSH cattle ( < 0.001). These findings suggest cattle trotted without a lead rider develop metabolic acidosis, and illustrate the importance of low-stress handling at the time of transport for slaughter. Further research is warranted to develop strategies to mitigate stress at the time of transport and ensure the welfare of beef cattle presented to abattoirs.


Asunto(s)
Acidosis/veterinaria , Agonistas Adrenérgicos beta/farmacología , Enfermedades de los Bovinos/fisiopatología , Bovinos/fisiología , Fenetilaminas/farmacología , Mataderos , Acidosis/fisiopatología , Alimentación Animal , Bienestar del Animal , Animales , Composición Corporal/efectos de los fármacos , Temperatura Corporal , Dieta/veterinaria , Epinefrina/sangre , Manejo Psicológico , Frecuencia Cardíaca , Hidrocortisona/sangre , Ácido Láctico/sangre , Masculino , Frecuencia Respiratoria , Estrés Fisiológico/efectos de los fármacos , Transportes
17.
J Anim Sci ; 94(12): 5064-5076, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28046169

RESUMEN

Feedlot cattle ( = 1,395; BW = 568 ± 43 kg) were used to evaluate the effects of shade on animal welfare, growth performance, and carcass quality during the summer of 2013 in a Kansas commercial feedlot. Seven lots of predominately black steers and heifers (4 and 3, respectively) visually determined to be approaching the final mo on feed were identified, randomly gate-sorted, and allocated to pens located across the feed alley from each other to receive 1 of 2 treatments: 1) Shade (mean shade area = 1.5 m/ animal) or 2) No shade. Shade was provided using a 13-ounce polyethylene fabric and pens were oriented northwest to southeast. The mean starting date was June 13 and the mean days on feed for lots while on the study was 38 d. Cattle were fed a 77.67% DM steam-flaked corn-based diet and had ad libitum access to water throughout the duration of the trial. Zilpaterol hydrochloride (ZIL) was included in the finishing ration at an inclusion rate of 8.3 mg/kg of DM for the last 20 d on feed with a 3 d withdrawal period. Pen floor temperatures (PFT) were measured using an infrared thermometer and prevalence of cattle open-mouth breathing (OMB) was recorded on a pen basis. In addition to shade treatment, the effect of temperature humidity index (THI) on PFT and OMB was analyzed by classifying days as either "Alert" (THI < 79) or "Danger" (THI > 79). On the day of slaughter, pens within a replicate were kept separate through all stages of the marketing channel from loading at the feedlot until stunning at the plant. Pen served as the experimental unit for all measurements. There was a THI × shade treatment interaction for PFT and OMB ( < 0.001) where days classified as "Danger" increased PFT and prevalence of OMB compared to "Alert" days in unshaded but not shaded cattle. Shaded cattle had greater DMI ( = 0.01); however, unshaded cattle had greater G:F ( = 0.05) and therefore no differences were observed in ADG ( = 0.39). Shaded cattle had greater dressing percentage ( = 0.01), although HCW, LM area, fat thickness, marbling score, and quality grade did not differ between treatments ( > 0.05). Heat stress, a significant animal welfare concern and cause of reduced performance in feedlot cattle during the final phase of the feeding period, was alleviated in shaded cattle and illustrates the importance of shade provision as 1 tool to protect the welfare and increase feed consumption in large pens of feedlot cattle during hot summer months.


Asunto(s)
Bienestar del Animal , Bovinos/fisiología , Alimentación Animal/análisis , Crianza de Animales Domésticos , Animales , Composición Corporal/efectos de los fármacos , Bovinos/crecimiento & desarrollo , Dieta/veterinaria , Conducta Alimentaria , Femenino , Respuesta al Choque Térmico , Kansas , Masculino , Distribución Aleatoria , Estaciones del Año , Luz Solar , Temperatura , Zea mays
18.
J Anim Sci ; 94(2): 581-91, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27065128

RESUMEN

Angus crossbred steers (n = 40; 563 ± 44 kg) were used to examine the effects of handling method and fat thickness on the blood chemistry and physiology of market steers. Steers were blocked by backfat (BF) thickness and were randomly assigned to treatment groups: low-stress handling (LSH) and aggressive handling (AH). Cattle were then ran¬domly assigned to one of 5 blocks containing 4 steers from the LSH and AH treatments. Steers in the LSH treatment were walked and AH cattle were run through a course of 1,540 m. Blood samples were obtained via jugular venipuncture before handling (BASE), at 770 m (LAP1), at 1,540 m (LAP2), and at1 h (1H) and 2 h (2H) after finishing the course. Blood samples were analyzed for plasma lactate (LAC), creatinine kinase (CK), base excess (BE), blood pH (pH), serum cortisol (CORT) concentrations, and venous carbon dioxide (PvCO2) and oxygen (PvO2) pressures. Heart rate (HR), respiratory rate (RR), and rectal temperature (TEMP) were measured at the same intervals. Cattle in the AH treatment had greater ( < 0.05) LAC than those in LSH at BASE (4.1 vs. 3.0 mmol/L), LAP1 (16.5 vs. 2.3 mmol/L), LAP2 (22.3 vs. 2.4 mmol/L), 1H (7.2 vs. 2.7 mmol/L), and 2H (4.0 vs. 2.5 mmol/L), respectively. Creatinine kinase and RR were not different (P > 0.14). Blood pH in AH cattle was decreased compared with that in LSH cattle ( < 0.05) at LAP1 (7.25 vs. 7.45) and LAP2 (7.19 vs. 7.48) but was not different ( > 0.13) at BASE, 1H, or 2H. Heart rate and TEMP were increased in AH cattle compared to LSH ( > 0.01). Serum cortisol was increased ( < 0.05) in AH compared to that in LSH cattle at LAP1 (87.5 vs. 58.9 nmol/L), LAP2 (144.4 vs. 93.1 nmol/L), and 1H (113.5 vs. 53.1 nmol/L). Although RR was not differ¬ent between LSH and AH, PvCO2 was decreased in AH compared to that in LSH ( < 0.05) at LAP2 (30.6 vs. 39.3 mmHg) and PvO2 was increased at LAP1 (42.7 vs. 33.5 mmHg) and at LAP2 (51.5 vs. 36.6 mmHg). Lactate was increased in AH cattle in the thicker BF group at 1H ( < 0.05), and blood pH was decreased at LAP1, LAP2, and 1H ( < 0.05) compared to the thinner BF cohorts. Four AH steers became exhausted (EXH) and did not complete the course. Increased CK, decreased PvCO2, and muscle tremors occurred in EXH steers compared to non-exhausted AH cohorts. Results of this study show that AH causes physiologic and blood chemistry changes in steers, which can be potentially detrimental to cattle, emphasizing the need for low-stress handling practices.


Asunto(s)
Agonistas Adrenérgicos beta/administración & dosificación , Bovinos/fisiología , Suplementos Dietéticos , Fatiga/veterinaria , Manejo Psicológico , Agresión/fisiología , Crianza de Animales Domésticos , Animales , Temperatura Corporal , Bovinos/sangre , Fatiga/prevención & control , Ácido Láctico/sangre , Locomoción , Masculino , Condicionamiento Físico Animal , Frecuencia Respiratoria , Estrés Fisiológico/fisiología
19.
J Anim Sci ; 94(3): 1194-202, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27065280

RESUMEN

Crossbred yearling steers ( = 360; 395 ± 33.1 kg initial BW) were used to evaluate the effects of dry-rolled corn (DRC) particle size in diets containing 20% wet distiller's grains plus solubles on feedlot performance, carcass characteristics, and starch digestibility. Steers were used in a randomized complete block design and allocated to 36 pens (9 pens/treatment, with 10 animals/pen). Treatments were coarse DRC (4,882 µm), medium DRC (3,760 µm), fine DRC (2,359 µm), and steam-flaked corn (0.35 kg/L; SFC). Final BW and ADG were not affected by treatment ( > 0.05). Dry matter intake was greater and G:F was lower ( < 0.05) for steers fed DRC vs. steers fed SFC. There was a linear decrease ( < 0.05) in DMI in the final 5 wk on feed with decreasing DRC particle size. Fecal starch decreased (linear, < 0.01) as DRC particle size decreased. In situ starch disappearance was lower for DRC vs. SFC ( < 0.05) and linearly increased ( < 0.05) with decreasing particle size at 8 and 24 h. Reducing DRC particle size did not influence growth performance but increased starch digestion and influenced DMI of cattle on finishing diets. No differences ( > 0.10) were observed among treatments for any of the carcass traits measured. Results indicate improved ruminal starch digestibility, reduced fecal starch concentration, and reduced DMI with decreasing DRC particle size in feedlot diets containing 20% wet distiller's grains on a DM basis.


Asunto(s)
Alimentación Animal/análisis , Composición Corporal/efectos de los fármacos , Bovinos/fisiología , Dieta/veterinaria , Zea mays/química , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Digestión/efectos de los fármacos , Manipulación de Alimentos , Masculino , Tamaño de la Partícula , Almidón , Vapor
20.
J Thromb Haemost ; 14(5): 1011-20, 2016 05.
Artículo en Inglés | MEDLINE | ID: mdl-26786324

RESUMEN

UNLABELLED: Essentials Cofactor-independent antiphospholipid antibodies (CI-aPL) are generally considered non-pathogenic. We analyzed the effects of human monoclonal CI-aPL in a mouse model of venous thrombosis. As shown in vitro, CI-aPL induce a procoagulant state in vivo by activation of endosomal NADPH-oxidase. Contrary to common belief, CI-aPL induce venous thrombosis in vivo. SUMMARY: Background There is general consensus that the antiphospholipid syndrome (APS) is caused by antiphospholipid antibodies (aPL) with antibodies against ß2-glycoprotein-I being the most relevant. aPL that bind phospholipids in the absence of protein cofactors are generally considered pathogenetically irrelevant. We showed that cofactor-independent human monoclonal aPL isolated from APS patients induce proinflammatory and procoagulant cellular responses by activating endosomal NADPH-oxidase 2 (NOX2). Similar aPL were detected in all IgG fractions from APS patients analyzed. Objectives We aimed to clarify if cofactor-independent aPL can be thrombogenic in vivo and, if so, whether these effects are mediated via activation of NOX2. Methods Two cofactor-independent human monoclonal aPL, HL5B and RR7F, were tested in a mouse model of venous thrombosis. Genetically modified mice and in vitro assays were used to delineate the mechanisms underlying thrombus induction. Results HL5B and RR7F dramatically accelerate thrombus formation in this mouse model. Thrombus formation depends on tissue factor activation. It cannot be induced in NOX2-deficient mice. Bone marrow chimeras of C57BL/6J mice reconstituted with NOX2-deficient bone marrow showed that leukocyte activation plays a major role in thrombus formation. Neither TLR4 signaling nor platelet activation by our aPL is required for venous thrombus formation. Conclusions Cofactor-independent aPL can induce thrombosis in vivo. This effect is mainly mediated by leukocyte activation, which depends on the previously described signal transduction via endosomal NOX2. Because most APS patients have been shown to harbor aPL with similar activity, our data are of general relevance for the APS.


Asunto(s)
Anticuerpos Antifosfolípidos/inmunología , Anticuerpos Monoclonales/inmunología , NADPH Oxidasa 2/inmunología , Trombosis de la Vena/inmunología , beta 2 Glicoproteína I/inmunología , Adulto , Animales , Modelos Animales de Enfermedad , Endosomas/metabolismo , Femenino , Regulación de la Expresión Génica , Humanos , Inmunoglobulina G/inmunología , Leucocitos/metabolismo , Ratones , Ratones Endogámicos C57BL , NADPH Oxidasa 2/genética , Tromboelastografía , Trombosis/inmunología , Vena Cava Inferior/patología , Trombosis de la Vena/tratamiento farmacológico
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