Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Trop Med Int Health ; 25(3): 328-337, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31733130

RESUMEN

OBJECTIVE: To assess maternal health care service utilisation and associated factors in Somali pastoral communities of eastern Ethiopia. METHODS: Community-based cross-sectional study complemented by qualitative assessments in Adadle district, Somali region, eastern Ethiopia, among 450 women in six kebeles from August to September 2016. Logistic regression was used to assess factors associated with antenatal care use and skilled delivery care use, controlling for confounders. RESULTS: About 27% [95%CI 22.8-31.2%] of women used antenatal care, and 22.6% [95%CI 18.7-26.5%] received skilled delivery service. None of the respondents reported post-natal care. About 43% reported that they had no knowledge of antenatal care, and 46% did not perceive delivery at a health facility as important. Pastoral lifestyle, husband's educational status, women's attitude towards health care service and financial support from the husband were significantly associated with antenatal care utilisation. Health professionals' attitudes, perceptions of institutional delivery, antenatal care utilisation and information about exemptions from maternal health care fees were associated with skilled delivery service utilisation. CONCLUSION: Improving community awareness of antenatal care, employing female health professionals and culturally adapted guidelines could improve skilled delivery utilisation. In a patriarchal society, involving male partners in all maternal health issues is essential to increase use of maternal health services and to decrease maternal mortality.


OBJECTIF: Evaluer l'utilisation des services de soins de santé maternelle et les facteurs associés dans les communautés pastorales somaliennes dans l'est de l'Ethiopie. MÉTHODES: Etude transversale basée sur la communauté complétée par des évaluations qualitatives dans le district d'Adadle, région somalienne, dans l'est de l'Ethiopie, portant sur 450 femmes dans six kebeles d'août à septembre 2016. Une régression logistique a été utilisée pour évaluer les facteurs associés à l'utilisation des soins prénatals et à l'accouchement sous soins qualifiés, en ajustant pour les facteurs confusionnels. RÉSULTATS: 27% [IC95%: 22.8-31.2%] des femmes ont utilisé des soins prénatals et 22,6% [IC95%: 18.7-26.5%] ont reçu des services d'accouchement qualifiés. Aucune des répondantes n'a signalé des soins postnatals. 43% ont déclaré qu'elles n'avaient aucune connaissance des soins prénatals et 46% ne percevaient pas l'accouchement dans un établissement de santé comme important. Le mode de vie pastoral, le niveau d'éducation du mari, l'attitude des femmes à l'égard des services de santé et le soutien financier du mari étaient significativement associés à l'utilisation des soins prénatals. Les attitudes des professionnels de la santé, les perceptions de l'accouchement en établissement, l'utilisation des soins prénatals et les informations sur les exemptions des frais de soins de santé maternelle ont été associées à l'utilisation des services d'accouchement qualifiés. CONCLUSION: Améliorer la sensibilisation de la communauté aux soins prénatals, employer des professionnels de la santé féminins et des directives culturellement adaptées pourrait améliorer l'utilisation de l'accouchement qualifié. Dans une société patriarcale, la participation des partenaires masculins à toutes les questions de santé maternelle est essentielle pour accroître l'utilisation des services de santé maternelle et réduire la mortalité maternelle.


Asunto(s)
Parto Obstétrico/estadística & datos numéricos , Aceptación de la Atención de Salud , Atención Prenatal , Adolescente , Adulto , Anciano , Estudios Transversales , Características Culturales , Etiopía , Femenino , Accesibilidad a los Servicios de Salud , Humanos , Masculino , Servicios de Salud Materna , Persona de Mediana Edad , Embarazo , Factores Socioeconómicos , Somalia/etnología , Población Urbana , Adulto Joven
2.
Rev Sci Tech ; 37(2): 331-340, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30747144

RESUMEN

While major progress has been made in the control of rabies in the Western Hemisphere, large parts of Europe and some parts of Asia, the disease continues to kill tens of thousands of people every year. Its highest burden is in resourcelimited countries in Asia and Africa, disproportionately affecting children and poor rural communities. Today, domesticated dogs are responsible for the vast majority of human rabies cases. In late 2015, rabies experts from around the world gathered at the Rabies Global Conference in Geneva, Switzerland, and launched the ambitious initiative to end deaths from dog-mediated human rabies by 2030. The most cost-effective and sustainable approach to achieve this goal is to eliminate the disease at source through mass dog vaccination. In this article, the role of and challenges faced by Veterinary Services in resourcelimited settings in implementing the dog vaccination strategy to reduce the human rabies burden are discussed, together with the role of wildlife in disease control and why the 'One Health' approach is indispensable on the path towards a dograbies- free future.


Malgré les progrès considérables accomplis en matière de lutte contre la rage dans l'hémisphère occidental, dans une grande partie de l'Europe et en certains endroits d'Asie, la maladie continue à faire plusieurs dizaines de milliers de victimes chaque année dans le monde. Ce sont les pays à faibles ressources d'Asie et d'Afrique qui sont les plus touchés, avec une majorité écrasante de victimes parmi les enfants et dans les communautés rurales pauvres. Aujourd'hui, les chiens domestiques sont de loin la principale cause des cas de rage humaine. En décembre 2015, des experts du monde entier réunis à Genève (Suisse) à l'occasion de la Conférence mondiale sur la rage intitulée « Élimination mondiale de la rage humaine transmise par les chiens : agissons maintenant ! ¼ ont lancé une initiative ambitieuse visant à mettre fin aux décès humains dus à la rage transmise par les chiens d'ici 2030. La méthode la plus efficace et durable pour atteindre cet objectif consiste à éliminer la maladie à sa source au moyen de la vaccination massive des chiens. Les auteurs examinent le rôle des Services vétérinaires et les difficultés auxquelles ceux-ci sont confrontés lorsqu'ils entreprennent d'appliquer une stratégie de vaccination des chiens destinée à réduire le fardeau de la rage humaine dans un contexte de ressources limitées. Ils évoquent également l'importance de prendre en compte la faune sauvage dans le cadre du contrôle de la rage et expliquent en quoi l'approche « Une seule santé ¼ est incontournable pour avancer vers l'objectif d'un monde indemne de rage canine.


Aunque la lucha antirrábica ha conocido avances muy sustanciales en el hemisferio occidental, grandes partes de Europa y ciertas zonas de Asia, la enfermedad sigue matando a decenas de miles de personas al año. La carga más elevada de rabia se da en países con escasos recursos de Asia y África, donde la enfermedad afecta desproporcionadamente a los niños y a las comunidades rurales pobres. A día de hoy, los perros domésticos son responsables de la inmensa mayoría de los casos de rabia humana. A finales de 2015, especialistas del mundo entero se dieron cita en Ginebra (Suiza) para celebrar la conferencia mundial titulada «Eliminación mundial de la rabia humana transmitida por perros. ¡Actuemos ahora!¼ y poner en marcha la ambiciosa iniciativa de acabar con las muertes por rabia transmitida por perros como muy tarde en 2030. Para cumplir este objetivo, el método más sostenible y más eficaz en relación con el costo consiste en eliminar la enfermedad en su foco de origen, procediendo para ello a vacunaciones masivas de perros. Los autores exponen la función de los Servicios Veterinarios y las dificultades que afrontan en situaciones de escasez de recursos a la hora de aplicar la estrategia de vacunación canina para reducir la carga de rabia humana, así como el papel de la fauna silvestre en el control de la enfermedad y la razón por la cual es indispensable aplicar los planteamientos de «Una sola salud¼ para avanzar hacia un futuro libre de rabia.


Asunto(s)
Animales Salvajes , Enfermedades de los Perros/virología , Ganado , Rabia/veterinaria , Medicina Veterinaria , Animales , Perros , Salud Global/economía , Administración Masiva de Medicamentos , Rabia/economía , Rabia/prevención & control , Vacunas Antirrábicas/inmunología
3.
Rev Sci Tech ; 35(2): 673-681, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27917989

RESUMEN

Animal diseases and zoonoses abound among pastoralist livestock, which is composed of cattle, sheep, goats, yak, camels, llamas, reindeer, horses and donkeys. There is endemic and, periodically, epidemic transmission of highly contagious viral and bacterial diseases in Africa, Asia and Latin America. Pastoralist livestock is often multiparasitised with endo- and ectoparasites, as well as being affected by vectorborne viral and protozoal diseases. Pastoral livestock can be a reservoir of such diseases and can also, conversely, be at risk from exposure to wildlife reservoirs. Public and private animal health services currently underperform in almost all pastoral areas due to structural reforms and lack of income, as indicated in assessments of national Veterinary Services by the World Organisation for Animal Health. Control of infectious disease in industrialised countries has been achieved through large-scale public funding of control measures and compensation for culled stock. Such means are not available in pastoralist areas of most low- and middle-income countries (LMICs). While the cost-effectiveness and profitability of the control of animal diseases and zoonoses is less of a consideration for industrialised countries, in the experience of the authors, understanding the economic implications of a control programme is a prerequisite for successful attempts to improve animal health in LMICs. The incremental costs of animal disease control can potentially be shared using crosssector assessments, integrated control, and regional coordination efforts to mitigate transboundary disease risks. In this paper, the authors discuss cost-effective animal disease and zoonoses control in LMICs. It illustrates frameworks and examples of integrated control and cross-sector economics, showing conditions under which these diseases could be controlled in a cost-effective way.


D'abondantes maladies animales et zoonoses affectent le cheptel pastoral, qui est composé de bovins, d'ovins, de caprins, de yaks, de chameaux, de lamas, de rennes, de chevaux et d'ânes. Il existe une transmission endémique (prenant périodiquement une dimension épidémique) des maladies virales et bactériennes hautement contagieuses en Afrique, en Asie et en Amérique latine. Le polyparasitisme à endoparasites et ectoparasites est fréquent dans les troupeaux pastoraux, ainsi que les maladies virales à transmission vectorielle et les maladies dues à des protozoaires. Les animaux élevés par les pasteurs font également office de réservoirs potentiels pour ces maladies et sont à leur tour exposés aux réservoirs sauvages. Les services de santé animale tant publics que privés sont actuellement sous-efficients dans pratiquement toutes les zones pastorales en raison des réformes structurelles et du manque de moyens, comme l'ont révélé les évaluations des Services vétérinaires nationaux réalisées par l'Organisation mondiale de la santé animale. Dans les pays industrialisés, les maladies infectieuses ont pu être maîtrisées grâce à un financement public massif des mesures de contrôle et à l'indemnisation des éleveurs dont le bétail avait été sacrifié. Ces moyens ne sont pas disponibles dans les zones pastorales de la plupart des pays à revenus faibles et moyens. Alors que les pays industrialisés n'ont pas tellement à prendre en compte les questions de rentabilité et d'efficience au regard des coûts lorsqu'ils ont à lutter contre des maladies animales ou des zoonoses, il n'en va pas de même dans les pays à revenus faibles et moyens, où, d'après l'expérience des auteurs, la prise en compte des conséquences économiques d'un programme de lutte est une étape préalable de toute tentative fructueuse d'amélioration de la santé animale. L'augmentation progressive des coûts de la lutte contre les maladies animales peut être prise en charge de manière partagée grâce aux évaluations intersectorielles, à une stratégie de lutte intégrée et aux efforts de concertation à l'échelle régionale pour atténuer les risques de maladies transfrontalières. Les auteurs de cet article examinent les méthodes efficientes au regard de leur coût déployées par les pays à revenus faibles et moyens pour lutter contre les maladies animales et les zoonoses. Ils présentent quelques cadres et exemples de lutte intégrée et d'approches économiques intersectorielles, en faisant ressortir les conditions qui permettent de contrôler ces maladies de manière efficace et à moindre coût.


Las enfermedades animales y las zoonosis son muy comunes en el ganado pastoral, formado por ganado vacuno, ovino y caprino, yaks, camellos, llamas, renos, caballos y asnos. En África, Asia y América Latina hay transmisión endémica (y periódicamente epidémica) de enfermedades víricas y bacterianas sumamente contagiosas. El ganado pastoral suele estar infestado por múltiples endo y ectoparásitos y padecer enfermedades víricas y protozoarias transmitidas por vectores. A veces ejerce de reservorio de esas enfermedades y también puede, a la inversa, verse expuesto al contacto con reservorios salvajes. Actualmente, en casi todas las zonas de pastoreo, los servicios zoosanitarios públicos y privados presentan un funcionamiento deficiente debido a las reformas estructurales y a la falta de ingresos, como se desprende de las evaluaciones de los Servicios Veterinarios nacionales realizadas por la Organización Mundial de Sanidad Animal. En los países industrializados, el control de las enfermedades infecciosas ha sido posible gracias a la financiación por el sector público de vastas y onerosas medidas de lucha y de indemnización por los animales sacrificados. Pero en las zonas de pastoreo de la mayoría de los países de ingresos bajos o medianos no existe la posibilidad de instrumentar tales medios. Mientras que los países industrializados prestan menos atención a la relación costoeficacia y la rentabilidad de las medidas de control de enfermedades animales y zoonosis, en los países de ingresos bajos o medianos, a tenor de la experiencia de los autores, el éxito de toda tentativa de mejorar la sanidad animal pasa necesariamente por tener en cuenta la dimensión económica de los programas de lucha. Existe la posibilidad de compartir los costos adicionales de la lucha zoosanitaria recurriendo a evaluaciones transectoriales, a medidas integradas de control y a actividades coordinadas a escala regional para reducir el riesgo de enfermedades transfronterizas. Los autores examinan aquí sistemas eficaces en relación con el costo para combatir las enfermedades animales y zoonosis en los países de ingresos bajos o medianos, exponiendo principios de referencia y ejemplos de lucha integrada y de economía transectorial que demuestran en qué condiciones sería posible controlar esas enfermedades de manera eficaz en relación con el costo.


Asunto(s)
Enfermedades de los Animales/prevención & control , Crianza de Animales Domésticos/métodos , Ganado , Zoonosis/prevención & control , Enfermedades de los Animales/economía , Crianza de Animales Domésticos/economía , Crianza de Animales Domésticos/educación , Animales , Análisis Costo-Beneficio , Humanos , Zoonosis/economía
4.
Epidemiol Infect ; 141(7): 1342-56, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23587372

RESUMEN

Infection of wild animals by bovine tuberculosis (bTB) is raising concern worldwide. This article reviews the current epidemiological situation, risk of emergence and control options at the wildlife­livestock­human interface in sub-Saharan Africa. In livestock, bTB has been confirmed in the majority of countries from all parts of the continent. Wildlife infection is confirmed in seven countries from southern and eastern Africa, apparently spreading in the southern Africa region. Mycobacterium bovis has been isolated from 17 wild mammal species, although only four are suspected to play a role as maintenance host. Zoonotic risks are a concern, but no direct spillover from wildlife to humans has been documented, and no case of bTB spillback from wildlife to livestock has been confirmed. In this paper we assess the main risk factors of bTB spillover at the wildlife­livestock­human interface and suggest several research themes which could improve the control of the disease in the African context.


Asunto(s)
Animales Salvajes , Mycobacterium bovis , Tuberculosis/veterinaria , Zoonosis/epidemiología , África del Sur del Sahara/epidemiología , Animales , Bovinos , Reservorios de Enfermedades/veterinaria , Fenómenos Ecológicos y Ambientales , Humanos , Tuberculosis/epidemiología , Tuberculosis/prevención & control , Tuberculosis/transmisión , Tuberculosis Bovina/epidemiología , Tuberculosis Bovina/prevención & control , Tuberculosis Bovina/transmisión , Zoonosis/transmisión
5.
J Wildl Dis ; 46(3): 753-62, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20688681

RESUMEN

Bovine tuberculosis (BTB) is endemic in Ethiopian cattle. However, the status of the disease in wildlife populations that often share habitat with livestock is unknown. We screened for BTB in wildlife in five regions in Ethiopia. Blood and tissue samples from 133 mammals of 28 species were collected from 2006 to 2008. We used a rapid serology test (RT) based on lateral flow technology, and performed culture of lymph node specimens inoculated onto Lowenstein-Jensen and Middlebrook 7H11 media. Acid-fast colonies were further analyzed by molecular typing. Sera from 20 of 87 animals (23%) were positive for BTB by RT; acid-fast bacilli were cultured from 29 of 89 animals (32.5%). None of the positive cultures yielded mycobacteria from the Mycobacterium tuberculosis complex but many environmental mycobacteria were isolated. Among these, Mycobacterium terrae was the most common. We demonstrated a high prevalence of environmental mycobacteria in wildlife, the role of which is unknown. Flagship rare endemic species such as the mountain nyala (Tragelaphus buxtoni) and the Ethiopian wolf (Canis simensis) may be at risk for BTB. We also assessed the utility of RT for field purposes.


Asunto(s)
Animales Salvajes/microbiología , Tuberculosis Bovina/epidemiología , Tuberculosis Bovina/transmisión , Animales , Animales Domésticos/microbiología , Bovinos , Etiopía/epidemiología , Femenino , Masculino , Especificidad de la Especie
6.
Vet Rec ; 167(7): 250-6, 2010 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-20710033

RESUMEN

Representative repeated cross-sectional skin testing for bovine tuberculosis (TB) was conducted over a period of three years in a total of 5377 cattle in three randomly selected woredas (districts) in Ethiopia (Meskan, Woldia and Bako-Gazer) that had never previously been tested for TB. Almost all (99 per cent) of the animals included local zebus kept in traditional husbandry systems. The comparative intradermal tuberculin test with two diagnostic thresholds were used to define positive test results, one according to the World Organisation for Animal Health (OIE) recommended cut-off of more than 4 mm, and the other with a cut-off of >2 mm. Data analysis was performed using a logistic regression model with a random effect at the village level. Applying the OIE definition, the overall representative apparent prevalence of bovine TB in skin test-positive local zebus was 0.9 per cent (95 per cent confidence interval [CI] 0.6 to 1.3 per cent). Using a cut-off of more than 2 mm the overall representative prevalence increased to 4 per cent (95 per cent CI 2.4 to 4.8 per cent). Due to the low apparent prevalence, the true prevalence could be calculated only in Meskan (4.5 per cent) and Bako-Gazer (2.4 per cent) for the more than 2 mm cut-off. With the exception of Meskan, prevalence by woreda did not change significantly over the years. Mycobacterium avium reactor animals were found at all study sites, but there were significant geographical variations. Overall, bulls and oxen were more at risk of being positive reactors (odds ratio [OR] 1.6, 95 per cent CI 1.1 to 2.3; OR 2, 95 per cent CI 1.4 to 2.6, respectively), as were animals in good body condition (OR 2, 95 per cent CI 1.5 to 2.9). Similar results were found at woreda level with the exception of Woldia, where none of the analysed variables was significantly associated with a positive test result.


Asunto(s)
Mycobacterium avium/aislamiento & purificación , Prueba de Tuberculina/veterinaria , Tuberculosis Bovina/diagnóstico , Crianza de Animales Domésticos/métodos , Animales , Bovinos , Estudios Transversales , Etiopía/epidemiología , Femenino , Modelos Logísticos , Masculino , Prevalencia , Factores de Riesgo , Tuberculosis Bovina/epidemiología
7.
Vet Rec ; 157(1): 13-8, 2005 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-15995237

RESUMEN

Five outbreaks of infectious keratoconjunctivitis (ikc) affecting alpine chamois and ibex in the western and central Swiss Alps were recorded in 2001 to 2003. Mycoplasma conjunctivae was identified from conjunctival swabs by means of a nested pcr in 27 of the 28 chamois tested. The outbreaks occurred in an area covering 1590 km(2). Deep valleys acted as a barrier to the spread of the disease. A total of 409 chamois and 33 ibex with clinical signs of ikc were reported. Most of the chamois were shot, primarily because they were blind or in poor general body condition. Almost a quarter were observed alive, and 16.9 per cent died as a result of ikc. Many of the affected animals were juveniles, and more females than males died of ikc. The disease was more common during the summer and autumn. The chamois affected by ikc were found at altitudes between 550 and 3200 m. The estimated overall mortality was less than 5 per cent, but more than 20 per cent may have died locally. Ibex affected by ikc were recorded in only two outbreaks. In six places, ibex with clinical signs of ikc were found before the first affected chamois appeared in the same area.


Asunto(s)
Brotes de Enfermedades/veterinaria , Cabras , Queratoconjuntivitis Infecciosa/epidemiología , Animales , Femenino , Queratoconjuntivitis Infecciosa/fisiopatología , Masculino , Estaciones del Año , Suiza/epidemiología
8.
Schweiz Arch Tierheilkd ; 143(9): 461-7, 2001 Sep.
Artículo en Alemán | MEDLINE | ID: mdl-11593902

RESUMEN

To establish the role of Mycoplasma bovis as an agent of respiratory disease in fattening calves, an epidemiologic study was undertaken. A recently validated commercially available ELISA was used to diagnose M. bovis infection by seroconversion in paired sera obtained for each animal at entry in the fattening herd and at follow-up seven weeks later. Management data as well as relevant clinical and epidemiological variables were prospectively recorded. The overall seroconversion rate observed among the 415 calves in 23 fattening herds on 13 farms was 54.7%. Significant risk factors for seroconversion were the mixing of fattening herds of different age groups (risk ratio RR 1.70, 95% confidence interval (CI) 1.48 to 1.96), and the presence of at least one seropositive animal in the fattening herd (RR: 2.02; CI: 1.69 to 2.40). The proportion of clinical episodes of respiratory disease attributable to M. bovis infection was 50.3%. The average weight gain during the observation period was reduced by 7.6% in seroconverting calves and these animals had about 2 times more antibiotics prescribed by a veterinarian than calves remaining negative for M. bovis throughout follow-up (RR 1.83). Maternal antibodies against M. bovis were detected in 39% of newborn calves born from seronegative cows and had a half-life of 20 days, potentially limiting the usefulness of vaccines against M. bovis in this age group.


Asunto(s)
Enfermedades de los Bovinos/epidemiología , Infecciones por Mycoplasma/veterinaria , Enfermedades Respiratorias/veterinaria , Factores de Edad , Animales , Anticuerpos Antibacterianos/sangre , Bovinos , Enfermedades de los Bovinos/sangre , Enfermedades de los Bovinos/diagnóstico , Ensayo de Inmunoadsorción Enzimática/veterinaria , Femenino , Masculino , Mycoplasma/inmunología , Infecciones por Mycoplasma/diagnóstico , Infecciones por Mycoplasma/epidemiología , Estudios Prospectivos , Enfermedades Respiratorias/diagnóstico , Enfermedades Respiratorias/epidemiología , Factores de Riesgo , Estudios Seroepidemiológicos
9.
Virology ; 216(2): 338-46, 1996 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-8607263

RESUMEN

The Bel-1 protein of human foamy virus (HFV) is a transactivator acting on the U3 region of the long terminal repeat and on an internal promoter (IP) immediately upstream of the bel genes. An HFV transgene called delta gpe, containing both promoters and all bel genes, is expressed in the central nervous system and induces neurodegeneration in mice. To dissect the role of individual promoters and bel genes on transgene expression and neurotoxicity we generated transgenic mice with a construct termed pL-bel1, which lacks the IP and the ancillary genes except bel-1. L-bel1 mice transcribed the HFV transgene in more tissues than delta gpe mice, suggesting that CNS specificity is dictated by cis-acting elements not present in the pLbel-1 construct. Unlike delta gpe mice, L-bel1 mice did not develop neurodegenerative changes and did not show induction of nitric oxide synthase expression, although both strains expressed Bel-1 in the brain. Therefore, Bel-1 expression is not sufficient for neurotoxicity. Our results suggest that Bet, a fusion protein between bel-1 and bel-2 which is highly expressed in delta gpe but not in L-bel1 mice, is a candidate for neurotoxicity.


Asunto(s)
Encefalopatías/virología , Proteínas de Unión al ADN/genética , Regiones Promotoras Genéticas , Infecciones por Retroviridae/virología , Proteínas de los Retroviridae/genética , Spumavirus/genética , Transactivadores/genética , Animales , Secuencia de Bases , Northern Blotting , Encéfalo/enzimología , Encéfalo/virología , Encefalopatías/enzimología , Encefalopatías/patología , Línea Celular , Cricetinae , Proteínas de Unión al ADN/metabolismo , Modelos Animales de Enfermedad , Regulación Viral de la Expresión Génica , Genes Virales , Humanos , Immunoblotting , Ratones , Ratones Transgénicos , Datos de Secuencia Molecular , Degeneración Nerviosa , Óxido Nítrico Sintasa/biosíntesis , Fenotipo , ARN/genética , Secuencias Repetitivas de Ácidos Nucleicos , Infecciones por Retroviridae/patología , Proteínas de los Retroviridae/metabolismo , Spumavirus/metabolismo , Spumavirus/patogenicidad , Transactivadores/metabolismo , Regulación hacia Arriba
12.
AIDS Res Hum Retroviruses ; 9(6): 553-63, 1993 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8102239

RESUMEN

One of the difficulties in understanding the complex pathology of human immunodeficiency virus (HIV) infection is to explain the progressive depletion of the CD4 helper T cell population and consequently the destruction of the immune system. Although cytopathic effects of HIV are observed in vitro, they cannot in vivo account for CD4 T cell depletion because relatively few cells are productively infected. Thus immunological mechanisms must be envisaged. We have found that peripheral blood lymphocytes (PBLs) from asymptomatic HIV-infected individuals are primed for a suicide process known as apoptosis or programmed cell death (PCD). DNA fragmentation characteristic of apoptosis was enhanced by stimulation of lymphocytes with ionomycin, a known inducer of apoptosis in suitably primed cells. Identification of the T cell subpopulations programmed for apoptosis indicated that both CD4+ and CD8+ cells died when cultured without stimulation or when polyclonally stimulated with ionomycin. Activation-induced cell death was also observed after stimulation with self-MHC class II-dependent superantigens, namely bacterial toxins from Staphylococcus (SEB), Streptococcus (ETA), and Myocoplasma (MAM) and under these conditions the CD4+ T cells were preferentially affected. To explore whether new macromolecular synthesis were required for apoptosis, various known inhibitors of apoptosis such as cycloheximide, cyclosporin A, Zn2+, or EGTA were tested. Activation-induced apoptosis was found sensitive to these inhibitors, indicating an active mechanism, but apoptosis observed in nonstimulated cultures was not, suggesting that these cells already contained the complete machinery for death. Prevention of apoptosis could be obtained in the presence of a mixture of cytokines and the minimal signal necessary for this prevention was IL-1 alpha and IL-2. Finally, a correlation between PCD and AIDS-pathogenesis was suggested by the comparison of lymphocytes from lentivirus-infected primates suceptible (SIV-infected macaques) and resistant (HIV-infected chimpanzees) to AIDS. Altogether our results suggest that, during HIV or SIV infection, PCD may contribute in vivo to the deletion of reactive T cells after antigenic stimulation.


Asunto(s)
Apoptosis/inmunología , Proteínas Bacterianas , Infecciones por VIH/inmunología , Infecciones por VIH/patología , Proteínas de la Membrana , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/patología , Linfocitos T/inmunología , Animales , Apoptosis/efectos de los fármacos , Linfocitos T CD4-Positivos/efectos de los fármacos , Linfocitos T CD4-Positivos/inmunología , Antígenos CD8/inmunología , Citocinas/farmacología , Daño del ADN , Enterotoxinas/inmunología , Exotoxinas/inmunología , Humanos , Ionomicina/farmacología , Macaca , Mitógenos/inmunología , Pan troglodytes , Linfocitos T/efectos de los fármacos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...