Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 81
Filtrar
1.
Eur Clin Respir J ; 8(1): 1894658, 2021 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-33763190

RESUMEN

Background: Allergen avoidance is important in allergic asthma management. Nocturnal treatment with Temperature-controlled Laminar Airflow (TLA) has been shown to provide a significant reduction in the exposure to allergens in the breathing zone, leading to a long-term reduction in airway inflammation and improvement in Quality of life (QoL). Allergic asthma patients symptomatic on Global Initiative for Asthma (GINA) step 4/5 were found to benefit the most as measured by Asthma Quality of Life Questionnaire (AQLQ). However, the effect of TLA on severe asthma exacerbations is uncertain and therefore a meta-analysis was performed. Methods: Patients with severe allergic asthma (GINA 4/5) were extracted from two 1-year randomised, double-blind, placebo-controlled trials conducted with TLA. A meta-analysis of the effect on severe exacerbations was performed by negative binomial regression in a sequential manner, defined by baseline markers of asthma control (symptoms and QoL scores). Results: The pooled dataset included 364patients. Patients with more symptoms at baseline (ACT<18 or ACQ7>3; N=179), had a significant mean 41% reduction in severe exacerbations (RR=0.59 (0.38-0.90); p=0.015) in favour of TLA. Higher ACQ7 cut-points of 3.5-4.5 resulted in significant reductions of 48-59%.More uncontrolled patients based on AQLQ total and symptom domains ≤3.0 at baseline also showed a significant reduction in severe exacerbations for TLA vs. placebo ((47% (p=0.037) and 53% (p=0.011), respectively). The meta-analysis also confirmed a significant difference in AQLQ-responders ((Minimal Clinically Important Difference)≥0.5; 74% vs. 43%, p=0.04). Conclusion: This meta-analysis of individual patient data shows a beneficial effect on severe exacerbations and quality of life for TLA over placebo in more symptomatic patients with severe allergic asthma. These outcomes support the national management recommendations for patients with symptomatic severe allergic asthma. The actual effect of TLA on severe exacerbations should be confirmed in a prospective study with larger numbers of patients.

2.
Thromb Res ; 131(2): 150-7, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23260446

RESUMEN

Histamine and tumor necrosis factor-α (TNF-α) are critical mediators of acute and chronic inflammation that are generated by mast cells and macrophages in atherosclerotic lesions or systemically during allergic attacks. Both of them induce activation of vascular endothelium and thus may play a role in thrombosis. Here we studied the interplay between histamine and TNF-α in glycoprotein (GP) Ibα-mediated platelet adhesion to cultured human vascular endothelial cells under static and shear flow conditions. The stimulation of endothelial cells with histamine or TNF-α increased the number of adherent or slow rolling GP Ibα-coated microbeads or washed human platelets. However, the application of histamine to endothelium pre-activated by TNF-α inhibited GP Ibα-mediated platelet adhesion. These effects were found to be associated with changes in the concentration of ultra large von Willebrand factor (ULVWF) strings anchored to endothelium. The results of this study indicate that histamine released during mast cell degranulation may cause or inhibit thrombosis, depending on whether it acts on resting endothelial cells or on cells pre-activated by other inflammatory stimuli.


Asunto(s)
Plaquetas/citología , Endotelio Vascular/citología , Histamina/sangre , Adhesividad Plaquetaria/fisiología , Complejo GPIb-IX de Glicoproteína Plaquetaria/metabolismo , Factor de Necrosis Tumoral alfa/sangre , Plaquetas/efectos de los fármacos , Plaquetas/metabolismo , Endotelio Vascular/efectos de los fármacos , Histamina/farmacología , Células Endoteliales de la Vena Umbilical Humana/citología , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Humanos , Adhesividad Plaquetaria/efectos de los fármacos , Complejo GPIb-IX de Glicoproteína Plaquetaria/farmacología , Factor de Necrosis Tumoral alfa/farmacología
3.
Br J Cancer ; 102(9): 1428-37, 2010 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-20424618

RESUMEN

BACKGROUND: Prioritising control measures for occupationally related cancers should be evidence based. We estimated the current burden of cancer in Britain attributable to past occupational exposures for International Agency for Research on Cancer (IARC) group 1 (established) and 2A (probable) carcinogens. METHODS: We calculated attributable fractions and numbers for cancer mortality and incidence using risk estimates from the literature and national data sources to estimate proportions exposed. RESULTS: 5.3% (8019) cancer deaths were attributable to occupation in 2005 (men, 8.2% (6362); women, 2.3% (1657)). Attributable incidence estimates are 13 679 (4.0%) cancer registrations (men, 10 063 (5.7%); women, 3616 (2.2%)). Occupational attributable fractions are over 2% for mesothelioma, sinonasal, lung, nasopharynx, breast, non-melanoma skin cancer, bladder, oesophagus, soft tissue sarcoma, larynx and stomach cancers. Asbestos, shift work, mineral oils, solar radiation, silica, diesel engine exhaust, coal tars and pitches, occupation as a painter or welder, dioxins, environmental tobacco smoke, radon, tetrachloroethylene, arsenic and strong inorganic mists each contribute 100 or more registrations. Industries and occupations with high cancer registrations include construction, metal working, personal and household services, mining, land transport, printing/publishing, retail/hotels/restaurants, public administration/defence, farming and several manufacturing sectors. 56% of cancer registrations in men are attributable to work in the construction industry (mainly mesotheliomas, lung, stomach, bladder and non-melanoma skin cancers) and 54% of cancer registrations in women are attributable to shift work (breast cancer). CONCLUSION: This project is the first to quantify in detail the burden of cancer and mortality due to occupation specifically for Britain. It highlights the impact of occupational exposures, together with the occupational circumstances and industrial areas where exposures to carcinogenic agents occurred in the past, on population cancer morbidity and mortality; this can be compared with the impact of other causes of cancer. Risk reduction strategies should focus on those workplaces where such exposures are still occurring.


Asunto(s)
Neoplasias/epidemiología , Enfermedades Profesionales/epidemiología , Exposición Profesional/efectos adversos , Ocupaciones/estadística & datos numéricos , Enfermedades de los Trabajadores Agrícolas/epidemiología , Amianto , Carcinógenos , Alquitrán/efectos adversos , Femenino , Humanos , Incidencia , Industrias , Masculino , Mesotelioma/inducido químicamente , Reino Unido/epidemiología
5.
Occup Environ Med ; 63(4): 261-6, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16556746

RESUMEN

BACKGROUND: Intervention development research is an essential prerequisite of any study that attempts to determine whether specific interventions work to prevent work related injury and illness. METHODS: Focus groups (n = 5) and direct observational studies (n = 21) of printers were used to elicit key issues that would aid the development of subsequent interventions. Transcripts from these were analysed by standard qualitative methods to identify common and related themes. RESULTS: The views of managers differed significantly from those of print workers in a number of areas, and working practices did not always follow policy. The majority of printers did not perceive dermatitis to be a major problem, although many complained of dry hands. Other key results included: the lack of skin care policy in most companies; poor understanding of the nature, causes, and treatment of dermatitis; low priority of dermatitis within health and safety concerns; little or no provision of occupational health services, particularly skin checks; variability in provision of and access to appropriate skin protection; and lack of accessible washing facilities. CONCLUSIONS: As a result it was decided to evaluate the implementation of four INTERVENTIONS: provision of (1) skin checks and treatment advice; (2) gloves of the correct type and size, and use of an after-work cream; (3) information on dermatitis within the printing industry; and (4) development of best practice skin care policy.


Asunto(s)
Dermatitis Profesional/prevención & control , Promoción de la Salud/provisión & distribución , Servicios de Salud del Trabajador/provisión & distribución , Salud Laboral , Impresión , Actitud Frente a la Salud , Consejo/métodos , Consejo/normas , Atención a la Salud/organización & administración , Atención a la Salud/normas , Dermatitis Profesional/etiología , Dermatitis Profesional/psicología , Fármacos Dermatológicos/administración & dosificación , Grupos Focales , Guantes Protectores/normas , Guantes Protectores/provisión & distribución , Desinfección de las Manos , Promoción de la Salud/organización & administración , Humanos , Servicios de Salud del Trabajador/normas , Pomadas/uso terapéutico , Administración de la Seguridad/organización & administración , Administración de la Seguridad/normas , Pruebas Cutáneas/métodos , Jabones/toxicidad , Solventes/toxicidad , Reino Unido
6.
Avian Dis ; 49(3): 352-60, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16252487

RESUMEN

Proventriculitis was studied by experimentally reproducing the disease in broiler chickens. One-day-old infectious bursal disease virus (IBDV) and infectious bronchitis virus (IBV) antibody positive commercial broilers and 1-day-old antibody negative specific-pathogen-free (SPF) broilers were orally gavaged with proventricular homogenates produced from the proventriculi of broilers with proventriculitis. At 7 and 14 days, both commercial and SPF broilers had enlargement of the proventriculus with necrosis of the glandular epithelium and lymphocytic infiltrates in the proventricular glands. SPF broilers exposed to the proventricular homogenates developed infectious bursal disease, and IBDV was detected by reverse transcriptase-polymerase chain reaction (RT-PCR). They also were positive by RT-PCR to IBV and developed nephritis. Commercial broilers developed mild nephritis but not bursal disease and were negative for IBDV and positive for IBV by RT-PCR. Both homogenate-inoculated commercial and SPF chickens were negative for reovirus and Newcastle disease virus by RT-PCR and variably positive for adenovirus by PCR. Bacteria were not identified in histologic sections, nor were they isolated from affected proventriculi. Indirect fluorescent antibody assay using convalescent sera detected intracytoplasmic staining in the proventricular glandular epithelial cells. Examination of thin sections of proventriculi using electron microscopy identified virus-like particles approximately 120 nm in diameter within the cytoplasm of these cells at 7 days after inoculation. Passage of proventricular homogenate filtrates in chicken embryos for virus isolation caused stunting, and allantoic fluid from these eggs was positive for IBV by RT-PCR.


Asunto(s)
Infecciones por Birnaviridae/veterinaria , Virus de la Enfermedad Infecciosa de la Bolsa/fisiología , Enfermedades de las Aves de Corral/transmisión , Enfermedades de las Aves de Corral/virología , Proventrículo/virología , Gastropatías/veterinaria , Gastropatías/virología , Animales , Infecciones por Birnaviridae/patología , Infecciones por Birnaviridae/transmisión , Infecciones por Birnaviridae/virología , Pollos , Virus de la Enfermedad Infecciosa de la Bolsa/genética , Virus de la Enfermedad Infecciosa de la Bolsa/aislamiento & purificación , Virus de la Enfermedad Infecciosa de la Bolsa/ultraestructura , Tamaño de los Órganos , Enfermedades de las Aves de Corral/patología , Proventrículo/patología , Organismos Libres de Patógenos Específicos , Gastropatías/patología , Aumento de Peso
7.
Occup Environ Med ; 62(7): 442-5, 2005 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15961619

RESUMEN

AIMS: To develop a job-exposure matrix (JEM) from personal and static respirable crystalline silica (RCS) measurements in UK industrial silica sand workers. METHODS: A total of 2429 personal and 583 static RCS dust samples were collected using cyclone samplers at seven UK quarries between 1978 and 2000. These data were combined, and analysis of variance using general linear models was used to evaluate the effect of quarry, job, and year on RCS concentrations, and facilitate the creation of five quarry and three time categories with similar exposure levels by comparing the least-square GM RCS concentrations. RESULTS: The overall geometric mean (GM) RCS concentration was 0.09 mg/m3 (geometric standard deviation 3.9). Silica flour and dry job categories tended to have the highest RCS exposure and 13.3% of all samples exceeded the UK maximum exposure level of 0.3 mg/m3. RCS levels generally decreased over time. CONCLUSIONS: Data have been collected and used to develop a JEM for UK industrial silica sand workers between 1978 and 2000. Although there were some limitations in the data and certain assumptions were made, the use of available data to estimate exposure quantitatively is an improvement over the use of qualitative and surrogate measures of exposure. The continual collection of dust measurements in the industry is essential to facilitate the exploration of exposure-response relations that may exist between silica and silicosis, lung cancer, and other diseases.


Asunto(s)
Contaminantes Ocupacionales del Aire/toxicidad , Exposición a Riesgos Ambientales/estadística & datos numéricos , Industrias , Enfermedades Profesionales/mortalidad , Dióxido de Silicio/toxicidad , Humanos , Exposición por Inhalación/estadística & datos numéricos , Modelos Lineales , Concentración Máxima Admisible , Exposición Profesional/estadística & datos numéricos , Ocupaciones , Reino Unido/epidemiología
8.
Occup Environ Med ; 62(7): 446-52, 2005 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15961620

RESUMEN

AIMS: To evaluate the mortality experience of a cohort of employees in the UK silica sand industry exposed to respirable crystalline silica (RCS). METHODS: A retrospective cohort mortality study followed all workers to 2001 with at least one year's employment at one of seven UK silica sand producing quarries between 1950 and 1986. Each worker was assigned a job category and cumulative exposure to RCS was estimated using a job-exposure matrix. RESULTS: A total of 764 deaths were identified in 2703 cohort members. The overall mortality rate for the cohort was lower than would be expected in the general population. Mortality from circulatory and respiratory disease was also less than expected, but death due to pneumoconiosis was slightly raised (two deaths). Mortality from all cancers was slightly decreased. Mortality was not raised in any job category. Cancer mortality was raised at one quarry due to a significant increase in lung (standardised mortality rate (SMR) 162.0, 95% CI 113.5 to 224.3) and bladder (SMR 366.5, 95% CI 167.6 to 695.7) cancers. Mortality from lung cancer and other causes did not show a trend with cumulative exposure to RCS. CONCLUSIONS: This study did not show any consistent relation between RCS exposure (in the absence of other known carcinogens) and the development of lung cancer. This contrasts with a number of studies that have shown positive findings in similar and related industries.


Asunto(s)
Industrias , Exposición por Inhalación/estadística & datos numéricos , Enfermedades Profesionales/mortalidad , Dióxido de Silicio , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Neoplasias Pulmonares/mortalidad , Masculino , Persona de Mediana Edad , Ocupaciones , Enfermedad Pulmonar Obstructiva Crónica/mortalidad , Estudios Retrospectivos , Factores de Tiempo , Reino Unido/epidemiología , Neoplasias de la Vejiga Urinaria/mortalidad
9.
Vet Pathol ; 41(6): 641-8, 2004 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-15561672

RESUMEN

Broiler chickens with transmissible proventriculitis have severe lymphocytic infiltration of the proventricular glands. The distribution of T cells and B cells in these infiltrates was studied histopathologically, and their identity was confirmed immunohistochemically (CD3, CD4, CD8, and B cells). To reproduce this disease, 1-day-old commercial boilers were orally gavaged with homogenized proventriculi from broilers with proventriculitis. Resulting lesions were examined at both acute (7 days postinoculation [i]) and chronic (14 and 21 dpi) time points. Lymphocytic infiltrates in the proventricular glands and the mucosal lamina propria were present at all time points and were most prominent and demarcated at 14 dpi. T and B lymphocytes were present during acute and chronic proventriculitis, but their distribution varied within the glands. Lymphocytic infiltrates in the proventricular glands and in the lamina propria were predominantly CD3+T cells, and most of these were also CD8+. B cells and CD4+ T cells formed aggregates in chronic proventriculitis. Thus, both cell-mediated and humoral immune responses are induced during transmissible proventriculitis, and the cell-mediated immune response is morphologically greater.


Asunto(s)
Pollos/inmunología , Gastritis/veterinaria , Enfermedades de las Aves de Corral/inmunología , Proventrículo/inmunología , Proventrículo/patología , Animales , Linfocitos B/inmunología , Gastritis/inmunología , Gastritis/patología , Enfermedades de las Aves de Corral/patología , Linfocitos T/inmunología
10.
Avian Dis ; 48(2): 300-16, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15283417

RESUMEN

Proventriculitis in broilers causes carcass condemnation when swollen proventriculi tear during evisceration. The cause of this proventriculitis is unknown, but several infectious agents have been associated with it. One such agent, infectious bursal disease virus (IBDV), has been implicated as a cause of proventriculitis, but a direct effect of this virus on the proventriculus has not been proven. The role of IBDV in proventriculitis may be indirect as a result of its ability to cause immunosuppression. The objective of this study was to understand how immunosuppression affects the incidence of proventriculitis in broiler chickens. Immunosuppression was induced in commercial and specific-pathogen-free broiler chickens using chemicals (cyclophosphamide and cyclosporin) or virus (IBDV). All groups were then exposed to a proventricular homogenate produced from diseased birds. At 7 and 14 days postinoculation, the incidence of proventriculitis in these groups was compared to that produced by homogenate exposure in immunocompetent broilers. All birds exposed to the proventricular homogenate from diseased birds developed proventriculitis. Cyclophosphamide and IBDV, both B cell suppressors, did not significantly affect the incidence or characteristics of the proventriculitis observed, although they did have an effect on the size of the proventriculus at 7 days postinoculation. Chickens immunosuppressed with cyclosporin, a T cell suppressor, developed more severe lesions and had a higher incidence of proventriculitis. These findings indicate that both B and T cells are involved in the immune response against proventriculitis, but cell-mediated immunity appears to have a more important role in controlling the disease. IBDV affects both humoral and cellular immunity in the chicken, so although under experimental conditions it didn't have a major effect on proventriculitis, it may explain why control of IBDV in the field seems to reduce the incidence of proventriculitis.


Asunto(s)
Infecciones por Birnaviridae/veterinaria , Pollos , Tolerancia Inmunológica/inmunología , Terapia de Inmunosupresión/veterinaria , Enfermedades de las Aves de Corral/inmunología , Proventrículo/inmunología , Gastropatías/veterinaria , Animales , Formación de Anticuerpos , Linfocitos B/efectos de los fármacos , Linfocitos B/inmunología , Infecciones por Birnaviridae/inmunología , Infecciones por Birnaviridae/patología , Ciclofosfamida/farmacología , Ciclosporina/farmacología , Ensayo de Inmunoadsorción Enzimática/métodos , Ensayo de Inmunoadsorción Enzimática/veterinaria , Inmunidad Celular , Inmunosupresores/farmacología , Virus de la Enfermedad Infecciosa de la Bolsa/fisiología , Enfermedades de las Aves de Corral/patología , Proventrículo/patología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria , Organismos Libres de Patógenos Específicos , Gastropatías/inmunología , Gastropatías/patología , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunología , Vacunación/veterinaria , Vacunas Virales/administración & dosificación
12.
Avian Dis ; 47(4): 1298-304, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-14708975

RESUMEN

An infectious bronchitis virus (IBV) was isolated from commercial broilers from the state of California exhibiting respiratory distress, inflamed tracheas, airsaculitis, and edematous lungs. After reverse transcriptase-polymerase chain reaction (RT-PCR), the California isolate exhibited an identical restriction fragment length polymorphism (RFLP) pattern to some isolates obtained from California, known as California 99 isolates. Commercial Mass-Conn and Mass-Ark vaccines were used to vaccinate commercial broiler chickens via eye drop once at 1 or 10 days of age or twice at 1 and 10 days of age. At 27 days of age the birds were challenged via eye drop with the isolated IBV California 99 strain. Protection was measured by failure to reisolate the challenge virus from tracheas 5 days postchallenge and complemented withthe tracheal and epithelium thickness scores. When the Mass-Ark vaccine was included in the vaccination programs, there was protection against challenge with the IBV California 99 isolate. The Mass-Conn vaccine conferred protection when used once at 1 day of age and twice at 1 and 10 days of age. However, no total protection was achieved when used as the only vaccine at 10 days of age, since one of the replicates was positive for virus isolation. Significant differences (P < 0.05) in the epithelium thickness and tracheal scores were observed between the unvaccinated-unchallenged group and the groups vaccinated once or twice with the Mass-Conn vaccine. Based on these results, all chickens were protected against the California 99 isolate when the IBV Arkansas type was used as a vaccine.


Asunto(s)
Virus de la Bronquitis Infecciosa/inmunología , Vacunas Virales/inmunología , Animales , Secuencia de Bases , Bovinos/virología , Pollos/virología , Cartilla de ADN , Pruebas de Hemaglutinación , Virus de la Bronquitis Infecciosa/genética , Virus de la Bronquitis Infecciosa/aislamiento & purificación , Tonsila Palatina/virología , Polimorfismo de Longitud del Fragmento de Restricción , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Tráquea/virología
13.
Avian Dis ; 46(3): 735-9, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12243543

RESUMEN

Several cases of elevated mortality with neurologic signs in 14-to-16-day-old broilers were presented to the Poultry Diagnostic and Research Center from one local integrated company. Suspected of "spiking mortality" associated with hypoglycemia, blood glucose levels were <150 mg/dl overall, with several birds with blood glucose levels as low as 30 mg/dl. Tissues, submitted for histopathology, revealed rickets in 50% of the birds. Virus isolation and serology for reovirus and infectious bursal disease virus were negative. After evaluation of these cases, a brief investigation was conducted to determine the effects of feed restriction on the induction of rickets and resulting hypoglycemia. One-hundred 1-day-old broilers were randomly assigned to three treatment groups of: 1) ad libitum feed, 2) 25% restriction, and 3) 50% restriction. Restriction began on the fifth day of age and continued to 21 days of age. Samples collected during the course of the study included whole blood for blood glucose measurements and proximal tibiotarsus for histopathologic examination for rickets. We were unable to reproduce the clinical signs of spiking mortality, neurologic changes, or hypoglycemia experimentally. Histopathology of the growth plates of the proximal tibiotarsus did indicate mild changes consistent with rickets, but the changes were not significant between treatment groups.


Asunto(s)
Pollos , Dieta Reductora/veterinaria , Hipoglucemia/veterinaria , Enfermedades de las Aves de Corral/mortalidad , Raquitismo/veterinaria , Alimentación Animal , Crianza de Animales Domésticos/métodos , Animales , Glucemia/análisis , Dieta Reductora/efectos adversos , Hipoglucemia/etiología , Hipoglucemia/mortalidad , Hipoglucemia/patología , Enfermedades de las Aves de Corral/etiología , Enfermedades de las Aves de Corral/patología , Distribución Aleatoria , Raquitismo/complicaciones , Raquitismo/mortalidad , Raquitismo/patología , Síndrome
14.
Vet Pathol ; 39(1): 161-4, 2002 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12102213

RESUMEN

Dilated cardiomyopathy and ascites in broiler chickens are frequently associated with rapid growth and pulmonary hypertension, but can be associated with some avian leukosis virus (ALV) infections. The novel subgroup J of ALV has a high cardiac tropism, but dilated cardiomyopathy has not been reported previously. We report a dilated cardiomyopathy incidence of 11.1% in broiler chickens congenitally infected with ALV subgroup J (ALV-J). Gross lesions included severe body weight suppression, cardiomegaly with biventricular dilation, right ventricular hypertrophy, visceral congestion, and ascites. Cardiac myocytes and Purkinje fibers contained 2- to 10-microm intracytoplasmic magenta inclusions that contained ALV-J-specific nucleic acid. Ultrastructurally, inclusions contained ribosomes and immature virions and were associated with myofibril disruption and disarray. Peracute centrilobular hepatic necrosis was present in most cases. ALV-J-associated cardiomyopathy may involve a direct viral effect on cardiac myocytes and Purkinje fibers.


Asunto(s)
Leucosis Aviar/patología , Cardiomiopatías/veterinaria , Miocardio/patología , Enfermedades de las Aves de Corral/patología , Animales , Virus de la Leucosis Aviar/clasificación , Cardiomiopatías/patología , Cardiomiopatías/virología , Pollos , Enfermedades de las Aves de Corral/virología
15.
Avian Dis ; 46(1): 64-74, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-11922350

RESUMEN

Infectious laryngotracheitis virus (ILTV) is routinely diagnosed by histopathologic examination of trachea, eyelid, and lung tissues. Lesions consistent with infectious laryngotracheitis (ILT) infection include syncytial cell formation with intranuclear inclusion bodies. These changes are present during the acute phase of infection. To increase the sensitivity of detecting ILT, a nested polymerase chain reaction (PCR) was developed for detection of ILTV DNA. Nested PCR assay was specific for the amplification of ILTV DNA and did not amplify a variety of other avian pathogens. To further validate the ability of this assay to detect ILT, nested PCR was performed in formalin-fixed, paraffin-embedded tissues from 35 cases of respiratory disease. Of the 35 cases, 12 were considered ILT suspects on the basis of initial clinical observation. Eleven of the 12 ILT-suspect cases were diagnosed as ILT, and the remaining 24 were diagnosed as nonspecific tracheitis (NST) by histopathologic examination. Histopathologically positive samples were confirmed by direct fluorescent antibody test and virus isolation. Of the 11 ILT-positive cases, 10 were positive by nested PCR. In addition, ILTV DNA was detected in 7 of the 24 samples diagnosed as NST upon histopathologic examination. Therefore, by nested PCR, ILTV DNA was detected in tissues independently of the presence of syncytial cells, intranuclear inclusions, or both. ILT nested PCR is a specific and sensitive assay capable of detecting ILT at different stages of infection and can be utilized in combination with histopathological examination to accelerate the diagnosis of ILT infection.


Asunto(s)
Pollos , Infecciones por Herpesviridae/veterinaria , Herpesvirus Gallináceo 1/aislamiento & purificación , Reacción en Cadena de la Polimerasa/veterinaria , Enfermedades de las Aves de Corral/diagnóstico , Infecciones del Sistema Respiratorio/veterinaria , Animales , Secuencia de Bases , ADN Viral/aislamiento & purificación , Técnica del Anticuerpo Fluorescente Directa/veterinaria , Infecciones por Herpesviridae/diagnóstico , Infecciones por Herpesviridae/patología , Infecciones por Herpesviridae/virología , Herpesvirus Gallináceo 1/genética , Inmunohistoquímica/veterinaria , Reacción en Cadena de la Polimerasa/métodos , Enfermedades de las Aves de Corral/patología , Enfermedades de las Aves de Corral/virología , Infecciones del Sistema Respiratorio/diagnóstico , Infecciones del Sistema Respiratorio/patología , Infecciones del Sistema Respiratorio/virología , Sensibilidad y Especificidad , Tráquea/patología , Tráquea/virología
16.
Vet Pathol ; 38(6): 649-56, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11732798

RESUMEN

The novel subgroup J of avian leukosis virus (ALV-J) has emerged as a significant cause of myeloid neoplasia and weight suppression in broiler chickens. We investigated viral tropism using RNA in situ hybridization (ISH) in naturally infected chickens. Formalin-fixed tissues were collected from 12-day-old embryos (seven infected, two control) and from 0-week-old (four infected, one control), 3-week-old (five infected, one control), 6-week-old (five infected, one control), and 9-week-old (10 infected, two control) chickens naturally infected with ALV-J in ovo. A 636-base antisense riboprobe complementary to the 3' and 5' ends of the pol and env viral genes, respectively, was constructed. Strong positive staining was present in cardiac myocytes, Purkinje fibers, vascular and pulmonary smooth muscle, renal glomeruli, distal tubules, and pituitary glands. Light staining was present in gastrointestinal smooth muscle, thyroid and adrenal glands, and follicular medullae in the cloacal bursa. Staining was not present in any hematopoietic precursors. Tissues from newly hatched chicks exhibited the strongest and most consistent staining, whereas staining in embryos was minimal. RNA ISH confirmed the presence of ALV-J-specific nucleic acid within cytoplasmic inclusions in cardiac myocytes, Purkinje fibers, pituitary glands, and renal glomeruli. Viral tropism for cardiac myocytes and Purkinje fibers may relate pathogenetically to the cardiomyopathy and congestive heart failure described in index chicken flocks infected with ALV-J. Viral tropism for endocrine organs may relate pathogenetically to the weight suppression associated with infection.


Asunto(s)
Virus de la Leucosis Aviar/genética , Leucosis Aviar/virología , Pollos/virología , Enfermedades de las Aves de Corral/virología , ARN Viral/genética , Animales , Leucosis Aviar/patología , Virus de la Leucosis Aviar/clasificación , Peso Corporal , Embrión de Pollo , Femenino , Corazón/virología , Hibridación in Situ/veterinaria , Riñón/patología , Riñón/virología , Masculino , Miocardio/patología , Adenohipófisis/patología , Adenohipófisis/virología , Enfermedades de las Aves de Corral/patología , ARN Viral/química , ARN Viral/aislamiento & purificación , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria , Glándula Tiroides/patología , Glándula Tiroides/virología
17.
J R Soc Promot Health ; 121(3): 177-84, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11688305

RESUMEN

A consultation was undertaken to investigate the views and concerns of stakeholders in the aircraft industry about the possible harmful effects on personal health, comfort and safety of aircraft cabin environments. Stakeholders were identified from a variety of sources including Government agencies, the Internet, House of Lords inquiry, and suggestions of interviewees. They represented: aircraft crews, aircraft constructors and engineers, government departments and authorities, holiday/flight companies, insurance companies, non-governmental organisations, occupational health physicians, passenger representatives, and independent researchers and consultants. Eighty-seven were contacted of which 57 were interviewed over the telephone using a semi-structured questionnaire. Their concerns were transcribed into a standard format and analysed qualitatively. Key stakeholders, along with Government officials, were invited to a workshop to discuss and prioritize the issues raised during the interviews. The main concerns expressed by the participants fell into five main areas: deep vein thrombosis, air quality, infection, cosmic radiation, and jet lag and work patterns. In addition, a number of safety concerns were raised as well as comments on the provision of appropriate advice to passengers. It was generally felt that further research was required on each of these subjects, as well as an improvement in the quality, quantity and availability of information provided for passengers prior to boarding a flight.


Asunto(s)
Contaminación del Aire Interior/efectos adversos , Aeronaves/normas , Infecciones Bacterianas/etiología , Radiación Cósmica/efectos adversos , Exposición a Riesgos Ambientales/efectos adversos , Síndrome Jet Lag/etiología , Trombosis de la Vena/etiología , Estado de Salud , Encuestas Epidemiológicas , Humanos , Salud Pública , Control de Calidad , Medición de Riesgo , Seguridad , Reino Unido
18.
Vet Pathol ; 38(5): 519-27, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11572559

RESUMEN

Avian leukosis virus subgroup J has a high tropism for myeloid lineage cells and frequently induces neoplastic transformation of myelocytes. The impact of congenital avian leukosis virus subgroup J infection on the function of circulating heterophils and susceptibility to staphylococcal infection was investigated. Six-week-old broiler chickens negative for exogenous avian leukosis viruses or congenitally infected with avian leukosis virus subgroup J were inoculated intravenously with 10(6) colony-forming units of Staphylococcus aureus, and pre- and postinoculation heterophil function was assessed. All chickens developed a leukocytosis with heterophilia after inoculation, but total leukocyte and heterophil counts were significantly higher in leukosis-negative chickens than in virus-infected chickens. Tenosynovitis was more severe in leukosis-negative chickens, and 2/10 (20%) of the virus-infected chickens had no histologic evidence of tenosynovitis. Osteomyelitis in the tibiotarsus or tarsometatarsus developed in 5/10 (50%) of the chickens in each group. S. aureus was recovered from the hock joint of 6/10 (60%) of the chickens in each group. Heterophils from all chickens exhibited similar phagocytic ability pre- and postinoculation. Heterophils from virus-infected chickens exhibited less bactericidal ability preinoculation than did heterophils from leukosis-negative chickens. However, postinoculation bactericidal ability was similar in both groups. Avian leukosis virus subgroup J provirus was present in heterophils isolated from congenitally infected chickens. Heterophils isolated from broiler chickens congenitally infected with avian leukosis virus subgroup J exhibit no significant functional deficits, and infected and uninfected chickens exhibit similar susceptibility to staphylococcal infection.


Asunto(s)
Leucosis Aviar/congénito , Pollos , Granulocitos/fisiología , Enfermedades de las Aves de Corral/congénito , Infecciones Estafilocócicas/veterinaria , Staphylococcus aureus/patogenicidad , Animales , Leucosis Aviar/inmunología , Leucosis Aviar/microbiología , Virus de la Leucosis Aviar/clasificación , Recuento de Colonia Microbiana/veterinaria , Susceptibilidad a Enfermedades/veterinaria , Femenino , Granulocitos/inmunología , Recuento de Leucocitos/veterinaria , Masculino , Osteomielitis/inmunología , Osteomielitis/microbiología , Osteomielitis/veterinaria , Fagocitosis , Enfermedades de las Aves de Corral/inmunología , Enfermedades de las Aves de Corral/microbiología , Infecciones Estafilocócicas/inmunología , Tenosinovitis/inmunología , Tenosinovitis/microbiología , Tenosinovitis/veterinaria
19.
Avian Dis ; 45(3): 598-604, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11569732

RESUMEN

Two experiments were conducted to determine the toxicity, pathology, and histopathology of purified gossypol in broiler chicks. Gossypol was added to broiler feed at 0, 100, 200, and 400 mg/kg of feed in Experiment 1 and at 0, 800, and 1600 mg/kg of feed in Experiment 2. Day-old broiler chicks were fed these diets from 1 to 21 days in Experiment 1 and from 1 to 23 days in Experiment 2. In Experiment 1, body weight and feed intake at 21 days were not significantly affected by dietary gossypol. However, chicks fed gossypol at 400 mg/kg of feed had poor feed conversion ratio compared with the other treatment. Feed conversion ratios were 1.493, 1.564, 1.471, and 1.60 for chicks fed gossypol at 0, 100, 200, and 400 mg/kg of feed, respectively (Experiment 1). Chicks fed 400 mg/kg gossypol also had mild perivascular lymphoid aggregate formations and bilary hyperplasia in the liver. In Experiment 2, gossypol at 1600 mg/kg resulted in 28.1% mortality. Gossypol at 800 and 1600 mg/kg feed resulted in significant decreases in body weight and feed intake of chicks. The average body weights of 23-day-old chicks in Experiment 2 were 676, 224, and 111 g for 0, 800, and 1600 mg/kg gossypol, respectively. Feed conversion ratios of chicks fed 800 and 1600 mg/kg gossypol were significantly higher than those of chicks fed control diets (1.383 vs. 1.564 vs. 1.745 for 0, 800, and 1600 mg/kg gossypol, respectively). Plasma iron and hematocrit values were significantly reduced by gossypol at 800 and 1600 mg/kg of feed. Enlarged gallbladder was the only gross pathology symptom associated with gossypol levels. Severe cases of perivascular lymphoid aggregate formation, biliary hyperplasia, and hepatic cholestasis were observed in chicks fed 800 and 1600 mg/kg of gossypol in feed. No gossypol-related changes were observed in kidney tissues of chicks. These results show that gossypol is toxic to broiler chicks at high levels. This study also shows that histopathologic changes in liver due to gossypol also occur at levels lower than the levels that affect body weight.


Asunto(s)
Peso Corporal/efectos de los fármacos , Pollos/crecimiento & desarrollo , Ingestión de Energía/efectos de los fármacos , Gosipol/toxicidad , Alimentación Animal , Animales , Relación Dosis-Respuesta a Droga , Vesícula Biliar/patología , Gosipol/administración & dosificación , Hematócrito/veterinaria , Hierro/sangre , Hígado/patología , Masculino , Distribución Aleatoria , Distribución Tisular
20.
Infect Immun ; 69(3): 1880-2, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11179367

RESUMEN

We challenged cats transfused with anti-Bartonella serum and kittens born to antibody-positive queens with Bartonella henselae to determine the contribution of antibodies to the control of B. henselae in cats. In both experiments, antibody-positive cats were protected from clinical disease but passive antibody to the homologous strain of B. henselae did not prevent bacteremia.


Asunto(s)
Anticuerpos Antibacterianos/uso terapéutico , Bacteriemia/prevención & control , Bartonella henselae/inmunología , Enfermedad por Rasguño de Gato/prevención & control , Inmunización Pasiva , Animales , Gatos , Femenino
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...