Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 59
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Artículo en Inglés | MEDLINE | ID: mdl-26777257

RESUMEN

We aimed to investigate the levels of anxiety, depression, satisfaction with information provision and cancer-related knowledge in partners of head and neck cancer (HNC) patients receiving a Multimode Comprehensive Tailored Information Package (MCTIP). A non-randomised, controlled trial was conducted with partners of HNC patients recruited at two academic hospitals in Montreal. The Test participants received the MCTIP, while the Control participants received information in an ad hoc manner. All participants were evaluated using the Hospital Anxiety and Depression Scale (HADS), Satisfaction with Cancer Information Profile and a cancer knowledge questionnaire at baseline, and 3 and 6 months later. Data were analysed using descriptive statistics, t-test and chi-square test, and mixed model analysis to test the impact of the intervention. A total of 31 partners of HNC patients participated in this study and completed all the evaluations. The partners in the Test group experienced significantly lower levels of anxiety (P = 0.001) and depression (P = 0.003) symptoms and were more satisfied (P = 0.002) with cancer information provided than partners in the Control group. Providing tailored information seems to have positive outcomes regarding anxiety, depression, and satisfaction in partners of HNC patients. Larger randomised studies are warranted to validate these effects.


Asunto(s)
Neoplasias de Cabeza y Cuello/psicología , Multimedia , Parejas Sexuales/psicología , Ansiedad/etiología , Depresión/psicología , Femenino , Educación en Salud , Conocimientos, Actitudes y Práctica en Salud , Humanos , Masculino , Persona de Mediana Edad , Satisfacción Personal , Calidad de Vida
2.
Disabil Health J ; 17(3): 101626, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38641454

RESUMEN

BACKGROUND: People with disabilities (PWD) commonly experience difficulties in accessing their environments, which can lead to restricted participation in outdoor leisure-time physical activity. Participating in outdoor leisure-time physical activity (OLTPA) provides health and social benefits to PWD and benefits to the communities in which they live. OBJECTIVE: The aim of the study was to identify features existing in digital platforms that facilitate access to OLTPA for PWD. METHODS: A scoping review was conducted in four library databases and in Google advance search to identify relevant scientific and grey literature, and websites. Each step of the review was independently conducted by two co-authors who confirmed consensus of results. Descriptive data analyses were performed. RESULTS: Seven scientific studies and ten websites were included in the scoping review. Seven presented mobile apps, nine presented a website and one presented an online database. Sources reported five main obstacles to using digital platforms that support access to physical activities (e.g., lack of digital literacy, technical issues, unintuitive design), and 10 facilitators (e.g., possibility to personalize your online space, accessibility features of the navigation). Among these sources, a trend emerged in the most important factors and features to consider for the visuals and navigation of the platforms. CONCLUSION: The features of digital platforms that facilitate access to OLTPA include intuitive design compliant with accessibility guidelines and supported by navigation tools, personalization of the online space, and features for social interactions.


Asunto(s)
Personas con Discapacidad , Ejercicio Físico , Promoción de la Salud , Internet , Aplicaciones Móviles , Humanos , Actividades Recreativas
3.
Med Vet Entomol ; 26(1): 92-102, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21781141

RESUMEN

We characterized the effects of subolesin and heat shock protein (HSP) expression on Ixodes scapularis Say (Acari: Ixodidae) stress responses to heat shock and feeding, questing behaviour and Anaplasma phagocytophilum (Rickettsiales: Anaplasmataceae) infection. Ticks and cultured tick cells were analysed before and after subolesin, hsp20 and hsp70 gene knock-down by RNA interference. The results of these studies confirm that HSPs are involved in the tick cell response to heat stress and that subolesin and HSPs are both involved in the tick response to blood-feeding stress and A. phagocytophilum infection. Subolesin and hsp20 are involved in the tick protective response to A. phagocytophilum infection and hsp70 expression may be manipulated by the pathogen to increase infectivity. Importantly, these results demonstrate that subolesin, hsp20 and hsp70 expression also affect tick questing behaviour. Overall, this research demonstrates a relationship between hsp and subolesin expression and tick stress responses to heat shock and blood feeding, A. phagocytophilum infection and questing behaviour, thereby extending our understanding of the tick-host-pathogen interface.


Asunto(s)
Anaplasma phagocytophilum/fisiología , Antígenos/metabolismo , Proteínas de Artrópodos/metabolismo , Regulación de la Expresión Génica/fisiología , Proteínas de Choque Térmico/metabolismo , Ixodes/fisiología , Estrés Fisiológico/fisiología , Animales , Antígenos/genética , Proteínas de Artrópodos/genética , Conducta Animal/fisiología , Línea Celular , Femenino , Proteínas de Choque Térmico/genética , Calor , Ixodes/citología , Masculino , Interferencia de ARN
4.
J Exp Med ; 193(9): 1035-44, 2001 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-11342588

RESUMEN

The adenylate cyclase toxin (CyaA) of Bordetella pertussis is a major virulence factor required for the early phases of lung colonization. It can invade eukaryotic cells where, upon activation by endogenous calmodulin, it catalyzes the formation of unregulated cAMP levels. CyaA intoxication leads to evident toxic effects on macrophages and neutrophils. Here, we demonstrate that CyaA uses the alpha(M)beta(2) integrin (CD11b/CD18) as a cell receptor. Indeed, the saturable binding of CyaA to the surface of various hematopoietic cell lines correlated with the presence of the alpha(M)beta(2) integrin on these cells. Moreover, binding of CyaA to various murine cell lines and human neutrophils was specifically blocked by anti-CD11b monoclonal antibodies. The increase of intracellular cAMP level and cell death triggered by CyaA intoxication was also specifically blocked by anti-CD11b monoclonal antibodies. In addition, CyaA bound efficiently and triggered intracellular cAMP increase and cell death in Chinese hamster ovary cells transfected with alpha(M)beta(2) (CD11b/CD18) but not in cells transfected with the vector alone or with the alpha(X)beta(2) (CD11c/CD18) integrin. Thus, the cellular distribution of CD11b, mostly on neutrophils, macrophages, and dendritic and natural killer cells, supports a role for CyaA in disrupting the early, innate antibacterial immune response.


Asunto(s)
Adenilil Ciclasas/metabolismo , Proteínas Bacterianas/metabolismo , Bordetella pertussis/metabolismo , Antígenos CD18/metabolismo , Antígeno de Macrófago-1/metabolismo , Precursores de Proteínas/metabolismo , Toxina de Adenilato Ciclasa , Animales , Anticuerpos Monoclonales/metabolismo , Antígenos CD18/genética , Células CHO , Calcio , Cationes Bivalentes , Línea Celular , Cricetinae , AMP Cíclico/metabolismo , Humanos , Antígeno de Macrófago-1/genética , Magnesio , Ratones , Ratas
5.
Vet Microbiol ; 134(3-4): 254-60, 2009 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-18823724

RESUMEN

The cattle rickettsia Anaplasma marginale is distributed worldwide and is transmitted by about 20 tick species, but only Rhipicephalus simus, a strictly African tick species, has been shown to transmit the vaccine strain of A. centrale. The aim of the present study was to examine transmission of field strains of A. marginale and of the vaccine strain of A. centrale by three tick species -Hyalomma excavatum, Rhipicephalus sanguineus and Rhipicephalus (Boophilus) annulatus - to susceptible calves. Two genetically distinct Israeli field strains of A. marginale, tailed and non-tailed (AmIsT and AmIsNT, respectively), were efficiently transmitted by R. sanguineus, whereas H. excavatum transmitted only the tailed isolate, and R. (Boophilus) annulatus did not transmit A. marginale. None of the three tick species transmitted A. centrale. By means of msp1a primers in PCR assays, amplicons of similar sizes were obtained from either A. marginale-infected calves that were used for acquisition feeding, from R. sanguineus fed on the infected calves, or from calves to which anaplasmosis had been successfully transmitted by these ticks. Although an A. centrale-specific fragment was amplified from salivary glands of R. sanguineus, no transmission to susceptible cattle occurred during 3 months of observation, and anaplasmosis was not induced in splenectomized calves that were subinoculated with blood from calves on which R. sanguineus had fed.


Asunto(s)
Anaplasma centrale/inmunología , Anaplasma marginale/inmunología , Anaplasmosis/inmunología , Vacunas Bacterianas/inmunología , Garrapatas , Animales , Bovinos , Femenino , Masculino , Esplenectomía
6.
Vet Parasitol ; 161(1-2): 150-3, 2009 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-19150177

RESUMEN

Anaplasma marginale is a tick-borne pathogen of cattle responsible for the disease anaplasmosis. Data suggest that Rhipicephalus (Boophilus) microplus and R. annulatus may be the major tick vectors of A. marginale in tropical and subtropical regions of the world. In this work we demonstrated the first infection and propagation of a Brazilian isolate of A. marginale (UFMG1) in the BME26 cell line derived originally from embryos of R. (Boophilus) microplus. The establishment of A. marginale infection in a cell line derived from R. (Boophilus) microplus is relevant for studying the A. marginale/tick interface.


Asunto(s)
Anaplasma marginale/fisiología , Rhipicephalus/citología , Animales , Brasil , Técnicas de Cultivo de Célula , Línea Celular
7.
Ann Dermatol Venereol ; 135(1): 27-33, 2008 Jan.
Artículo en Francés | MEDLINE | ID: mdl-18342070

RESUMEN

BACKGROUND: Acne in adult women is a common reason for dermatological consultation. Dermatologists are occasionally confronted with the problem of treating acne in women who are either pregnant or seeking to become pregnant, or in breast-feeding women, in whom zinc salts are the only form of systemic treatment that may be envisaged. PATIENTS AND METHODS: The purpose of our study was to provide an overview of existing data concerning the use of the zinc salts in pregnant and breast-feeding women based on a literature review, a survey of prescription of zinc gluconate by French dermatologists, and finally, analysis of French pharmacovigilance data. RESULTS: There are many studies involving the use of zinc supplements during pregnancy. In these studies, more than 2500 pregnant women were given zinc at different doses. None of these studies described any abnormalities, congenital malformation, harmful effects or risk for the foetus associated with the use of zinc during pregnancy at doses below 75 mg/day. Although there are fewer studies of the use of zinc supplements in breast-feeding women, no abnormalities associated with use of zinc during breast-feeding have been reported. According to the results of the prescription survey, around 10,000 pregnant women and 2000 breast-feeding women are treated each year for acne using zinc gluconate, with only four serious adverse events involving zinc being reported since the initial introduction of the product, and with zinc having a doubtful causal relationship. DISCUSSION: Zinc plays a key role in our body's physiology, since it is involved in the activities of many enzymes. In addition, zinc requirements increase during pregnancy, mainly because of its utilisation during embryogenesis and fetal development. This literature review shows that use of zinc salts in pregnant women is beneficial in those with zinc deficiency but that it has no harmful effects in those without zinc deficiency.


Asunto(s)
Acné Vulgar/tratamiento farmacológico , Fármacos Dermatológicos/uso terapéutico , Gluconatos/uso terapéutico , Lactancia Materna , Femenino , Humanos , Embarazo
8.
Oxid Med Cell Longev ; 2018: 5895439, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29682159

RESUMEN

Few studies have focused on the protective role of selenium (Se) against skin aging and photoaging even though selenoproteins are essential for keratinocyte function and skin development. To the best of our knowledge, the impact of Se supplementation on skin cells from elderly and young donors has not been reported. Therefore, the main objective of our study was to evaluate the effects of Se supplementation on skin keratinocytes at baseline and after exposure to ultraviolet A (UVA) irradiation. Low doses of Se (30 nM) were very potently protective against UVA-induced cytotoxicity in young keratinocytes, whereas the protection efficiency of Se in old keratinocytes required higher concentrations (240 nM). Additionally, the DNA repair ability of the old keratinocytes drastically decreased compared with that of the young keratinocytes at baseline and after the UVA exposure. The Se supplementation significantly enhanced the DNA repair of 8-oxoguanine (8oxoG) only in the keratinocytes isolated from young donors. Therefore, aged keratinocytes have an increased vulnerability to oxidative DNA damage, and the Se needs in the elderly should be considered. Strengthening DNA repair activities with Se supplementation may represent a new strategy to combat aging and skin photoaging.


Asunto(s)
Queratinocitos/efectos de los fármacos , Queratinocitos/metabolismo , Selenio/uso terapéutico , Rayos Ultravioleta , Adulto , Factores de Edad , Anciano , Células Cultivadas , Reparación del ADN/efectos de los fármacos , Reparación del ADN/genética , Humanos , Queratinocitos/efectos de la radiación , Persona de Mediana Edad , Adulto Joven
9.
Vet Res Commun ; 31 Suppl 1: 85-90, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17682852

RESUMEN

Ticks transmit pathogens that cause diseases which greatly impact both human and animal health. Vaccines developed against Boophilus spp. using Bm86 and Bm95 tick gut antigens demonstrated the feasibility of using vaccines for control of tick infestations. These vaccines also reduced transmission of tick-borne pathogens by decreasing exposure of susceptible hosts to ticks. The recently discovered tick antigens, 64P putative cement protein and subolesin involved in the regulation of tick feeding and reproduction, were also shown to reduce tick infestations. These antigens, together with the TROSPA receptor for Burrelia burgdorferi OspA were effective against tick-borne pathogens by reducing the infection levels in ticks and/or the transmission of the pathogen. Development of a vaccine targeted at both the tick vector and pathogen would contribute greatly to the control of tick infestations and the transmission of tick-borne diseases. These results have demonstrated that tick vaccines can be developed for control tick infestations and show promise for the prevention of the transmission of tick-borne pathogens.


Asunto(s)
Infestaciones por Garrapatas/prevención & control , Enfermedades por Picaduras de Garrapatas/transmisión , Garrapatas/microbiología , Vacunas/inmunología , Animales , Enfermedades por Picaduras de Garrapatas/prevención & control
10.
Vet Res Commun ; 31 Suppl 1: 91-6, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17682853

RESUMEN

Bovine anaplasmosis is a tick-borne hemolytic disease of cattle that occurs worldwide caused by the intraerythrocytic rickettsiae Anaplasma marginale. Control measures, including use of acaricides, administration of antibiotics and vaccines, have varied with geographic location. Our research is focused on the tick-pathogen interface for development of new vaccine strategies with the goal of reducing anaplasmosis, tick infestations and the vectorial capacity of ticks. Toward this approach, we have targeted (1) development of an A. marginale cell culture system to provide a non-bovine antigen source, (2) characterization of an A. marginale adhesion protein, and (3) identification of key tick protective antigens for reduction of tick infestations. A cell culture system for propagation of A. marginale was developed and provided a non-bovine source of A. marginale vaccine antigen. The A. marginale adhesion protein, MSP1a, was characterized and use of recombinant MSP1a in vaccine formulations reduced clinical anaplasmosis and infection levels in ticks that acquired infection on immunized cattle. Most recently, we identified a tick-protective antigen, subolesin, that reduced tick infestations, as well as the vectorial capacity of ticks for acquisition and transmission of A marginale. This integrated approach to vaccine development shows promise for developing new strategies for control of bovine anaplasmosis.


Asunto(s)
Anaplasmosis/prevención & control , Vacunas Bacterianas/inmunología , Ixodes/microbiología , Animales , Antígenos Bacterianos/inmunología , Proteínas Bacterianas/inmunología , Bovinos , Enfermedades de los Bovinos/prevención & control , Línea Celular , Ixodes/citología , Proteínas de la Membrana/inmunología
11.
Ann Dermatol Venereol ; 134(4 Pt 1): 347-51, 2007 Apr.
Artículo en Francés | MEDLINE | ID: mdl-17483754

RESUMEN

Seborrheic dermatitis is a chronic from of inflammatory dermatitis characterized by erythema and desquamation with predominant localization on the face (nasolabial folds, eyebrows, hair-line and ears). It appears to be caused by proliferation of Malassezia yeasts. Lithium gluconate 8% gel (Lithioderm 8% gel) is the only drug containing topical lithium salt commercially available in France for the treatment of seborrheic dermatitis. The mechanism of action of topical lithium is not well known; it may act through anti-inflammatory and antifungal action. Efficacy and safety were assessed in 2 clinical studies, one versus placebo and the other versus ketoconazole 2% foaming gel using the same principal criterion defined as the rate of patients showing complete remission after 2 months of treatment (complete disappearance of both erythema and desquamation). Lithium gluconate 8% was significantly more effective than placebo and than ketoconazole 2% foaming gel and was well tolerated. Adverse events observed were cutaneous (burning sensation, erythema and pruritus), for the most part of mild severity. No cutaneous side effects contributed to those reported with the use of systemic lithium in psychiatric disorders were noted. Pharmacokinetic studies have shown that systemic absorption after topical application is low. Lithioderm 8% gel is applied twice daily over a recommended period of 2 months. It constitutes a new alternative in the treatment of facial seborrheic dermatitis, regardless of severity.


Asunto(s)
Dermatitis Seborreica/tratamiento farmacológico , Gluconatos/uso terapéutico , Compuestos de Litio/uso terapéutico , Administración Tópica , Gluconatos/administración & dosificación , Humanos , Inflamación/fisiopatología , Cetoconazol/uso terapéutico , Compuestos de Litio/administración & dosificación , Pomadas
12.
Onderstepoort J Vet Res ; 73(4): 251-5, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17283724

RESUMEN

This paper describes the first successful in vitro cultivation of a South African isolate of an Anaplasma sp., initially thought to be Anaplasma marginale, in the continuous tick cell line IDE8. Blood from a bovine naturally infected with A. marginale kept on the farm Kaalplaas (28 degrees 08' E, 25 degrees 38' S) was collected, frozen, thawed and used as inoculum on confluent IDE8 cell cultures. Twenty days after culture initiation small intracellular colonies were detected in a Cytospin smear prepared from culture supernatant. Cultures were passaged on Day 34. Attempts to infect IRE/CTVM18 cell cultures with the Kaalplaas isolate derived from IDE8 cultures failed, whereas a reference stock of A. marginale from Israel infected IRE/CTVM18 tick cell cultures. Attempts to infect various mammalian cell lines (BA 886, SBE 189, Vero, L 929, MDBK) and bovine erythrocytes, kept under various atmospheric conditions, with tick cell-derived Anaplasma sp. or the Israeli strain of A. marginale failed. Molecular characterization revealed that the blood inoculum used to initiate the culture contained both A. marginale and Anaplasma sp. (Omatienne) whereas the organisms from established cultures were only Anaplasma sp. (Omatjenne).


Asunto(s)
Anaplasma/crecimiento & desarrollo , Eritrocitos/microbiología , Ixodes/microbiología , Anaplasma/clasificación , Anaplasma/aislamiento & purificación , Animales , Bovinos , Células Cultivadas , ADN Bacteriano/química , Eritrocitos/ultraestructura , Ixodes/citología , Microscopía Electrónica/veterinaria , Filogenia , Reacción en Cadena de la Polimerasa/métodos , Reacción en Cadena de la Polimerasa/veterinaria
13.
Int J Parasitol ; 31(2): 145-53, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11239934

RESUMEN

Anaplasma marginale is a tick-borne ehrlichial pathogen of cattle for which six major surface proteins (MSPs) have been described. The MSP1 complex, a heterodimer composed of MSP1a and MSP1b, was shown to induce a protective immune response in cattle and both proteins have been identified as putative adhesins for bovine erythrocytes. In this study the role of MSP1a and MSP1b as adhesins for bovine erythrocytes and tick cells was defined. msp1alpha and msp1beta1 genes from the Oklahoma isolate of A. marginale were cloned and expressed in Escherichia coli K-12 under the control of endogenous and tac promoters for both low and high level protein expression. Expression of the recombinant polypeptides was confirmed and localised on the surface of transformed E. coli. The adhesion properties of MSP1a and MSP1b were determined by allowing recombinant E. coli expressing these surface polypetides to react with bovine erythrocytes, Dermacentor variabilis gut cells and cultured tick cells derived from embryonic Ixodes scapularis. Adhesion of the recombinant E. coli to the three cell types was determined using recovery adhesion and microtiter haemagglutination assays, and by light and electron microscopy. MSP1a was shown by all methods tested to be an adhesin for bovine erythrocytes and both native and cultured tick cells. In contrast, recombinant E. coli expressing MSP1b adhered only to bovine erythrocytes and not to tick cells. When low expression vectors were used, single E. coli expressing MSP1a was seen adhered to individual tick cells while reaction of tick cells with the E. coli/MSP1a/high expression vector resulted in adhesion of multiple bacteria per cell. With electron microscopy, fusion of E. coli cell membranes expressing MSP1a or MSP1b with erythrocyte membranes was observed, as well as fusion of tick cell membranes with E. coli membranes expressing MSP1a. These studies demonstrated differential adhesion for MSP1a and MSP1b for which MSP1a is an A. marginale adhesin for both bovine erythrocytes and tick cells while MSP1b is an adhesin only for bovine erythrocytes. The role of the MSP1 complex, therefore, appears to vary among vertebrate and invertebrate hosts.


Asunto(s)
Adhesinas Bacterianas/metabolismo , Anaplasma/fisiología , Adhesión Bacteriana , Eritrocitos/microbiología , Garrapatas/microbiología , Adhesinas Bacterianas/genética , Anaplasma/crecimiento & desarrollo , Anaplasmosis/microbiología , Animales , Bovinos , Enfermedades de los Bovinos/microbiología , Células Cultivadas , Dermacentor/microbiología , Sistema Digestivo/microbiología , Eritrocitos/metabolismo , Escherichia coli/genética , Escherichia coli/fisiología , Hemaglutinación , Ixodes/citología , Ixodes/microbiología , Microscopía Electrónica , Proteínas Recombinantes/metabolismo , Garrapatas/citología , Garrapatas/metabolismo
14.
Int J Parasitol ; 31(14): 1705-14, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11730800

RESUMEN

Anaplasma marginale, an ehrlichial pathogen of cattle and wild ruminants, is transmitted biologically by ticks. A developmental cycle of A. marginale occurs in a tick that begins in gut cells followed by infection of salivary glands, which are the site of transmission to cattle. Geographic isolates of A. marginale vary in their ability to be transmitted by ticks. In these experiments we studied transmission of two recent field isolates of A. marginale, an Oklahoma isolate from Wetumka, OK, and a Florida isolate from Okeechobee, FL, by two populations of Dermacentor variabilis males obtained from the same regions. The Florida and Oklahoma tick populations transmitted the Oklahoma isolate, while both tick populations failed to transmit the Florida isolate. Gut and salivary gland infections of A. marginale, as determined by quantitative PCR and microscopy, were detected in ticks exposed to the Oklahoma isolate, while these tissues were not infected in ticks exposed to the Florida isolate. An adhesion-recovery assay was used to study adhesion of the A. marginale major surface protein (MSP) 1a to gut cells from both tick populations and cultured tick cells. We demonstrated that recombinant Escherichia coli expressing Oklahoma MSP1a adhered to cultured and native D. variabilis gut cells, while recombinant E. coli expressing the Florida MSP1a were not adherent to either tick cell population. The MSP1a of the Florida isolate of A. marginale, therefore, was unable to mediate attachment to tick gut cells, thus inhibiting salivary gland infection and transmission to cattle. This is the first report of MSP1a being responsible for effecting infection and transmission of A. marginale by Dermacentor spp. ticks. The mechanism of tick infection and transmission of A. marginale is important in formulating control strategies and development of improved vaccines for anaplasmosis.


Asunto(s)
Anaplasma/crecimiento & desarrollo , Anaplasmosis/transmisión , Proteínas de la Membrana Bacteriana Externa/fisiología , Enfermedades de los Bovinos/transmisión , Dermacentor/microbiología , Infestaciones por Garrapatas/veterinaria , Anaplasma/genética , Anaplasma/ultraestructura , Anaplasmosis/parasitología , Animales , Adhesión Bacteriana/genética , Proteínas de la Membrana Bacteriana Externa/genética , Western Blotting/veterinaria , Bovinos , Enfermedades de los Bovinos/parasitología , ADN Bacteriano/genética , ADN Ribosómico/genética , Vectores de Enfermedades , Electroforesis en Gel de Poliacrilamida/veterinaria , Escherichia coli/genética , Femenino , Florida , Masculino , Oklahoma , Reacción en Cadena de la Polimerasa/veterinaria , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/genética , Glándulas Salivales/parasitología , Infestaciones por Garrapatas/microbiología , Infestaciones por Garrapatas/parasitología
15.
Ann N Y Acad Sci ; 916: 501-9, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11193665

RESUMEN

Control methods for anaplasmosis have not changed markedly during the past 50 years and include arthropod control, chemoprophylaxsis, vaccination, and maintenance of an Anaplasma-free herd. Control measures implemented vary with geographic location, and depend on availability, cost, and the feasibility of application. Vaccination has been an effective means of preventing outbreaks of anaplasmosis, but these vaccines, both live and inactivated, are dependent on bovine blood as the source of infection or antigen. Blood-derived vaccines are difficult to standardize and bear the risk of transmitting other bovine pathogens inapparent at the time of blood collection. Extensive purification is required to remove bovine cell membranes, which may cause side effects. Most importantly, geographic isolates of A. marginale are often not cross-protective. Development of a tick cell culture system for A. marginale shows promise as a source of antigen for development of an improved inactivated vaccine in the near future that is free from bovine pathogens. Development of an antigenically defined molecular vaccine appears to be a realistic goal, although further research is required to determine epitopes involved in both humoral and cellular immunity, to define antigenic variation during cyclic rickettsemia, and to develop effective delivery systems for optimization of the immune response.


Asunto(s)
Anaplasmosis/prevención & control , Vacunas Bacterianas , Anaplasma/aislamiento & purificación , Anaplasmosis/epidemiología , Anaplasmosis/inmunología , Animales , Artrópodos , Bovinos , Brotes de Enfermedades/prevención & control , Brotes de Enfermedades/veterinaria , Geografía , Control de Plagas , Vacunas Atenuadas , Vacunas Sintéticas
16.
Ann N Y Acad Sci ; 791: 157-65, 1996 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-8784497

RESUMEN

Anaplasma marginale is a rickettsia transmitted by ticks that invades and multiplies in bovine erythrocytes causing the disease anaplasmosis. A complex developmental cycle occurs within ticks that begins in midgut cells, with subsequent infection in gut muscle cells. Final development occurs in salivary glands from where the rickettsia is transmitted to the vertebrate host. At each site of development, A. marginale multiplies within membrane-bound inclusions. Attempts to control anaplasmosis have focused on cattle and have included immunization and prophylactic treatment with tetracyclines. New strategies for control of anaplasmosis are being focused on the tick vector. Development of vaccines against hemoparasites in ticks may be feasible because vertebrate host immunoglobulins appear to cross the midgut epithelium of invertebrates and enter the hemolymph without breakdown. We tested the effect of A. marginale antibodies ingested by ticks with the bloodmeal on infections in ticks. Cattle were immunized with purified outer membrane proteins of erythrocytic-derived parasites. Infections in ticks exposed to the immunized cattle were determined using an Anaplasma-specific DNA probe, light and electron microscopy, and tick transmission studies. Vaccine-derived antibodies did not appear to affect the development and transmission of A. marginale in ticks. Further studies are needed to determine if bovine antibodies remain intact within ticks and whether the tick stage of A. marginale has unique surface antigens from the erythrocytic stage.


Asunto(s)
Anaplasma/crecimiento & desarrollo , Anaplasmosis/prevención & control , Anticuerpos Antibacterianos , Vacunas Bacterianas , Enfermedades de los Bovinos , Enfermedades por Picaduras de Garrapatas/veterinaria , Garrapatas/microbiología , Anaplasma/inmunología , Anaplasmosis/inmunología , Anaplasmosis/transmisión , Animales , Profilaxis Antibiótica , Bovinos , Eritrocitos/parasitología , Femenino , Masculino , Glándulas Salivales/microbiología , Glándulas Salivales/parasitología , Tetraciclinas/uso terapéutico , Enfermedades por Picaduras de Garrapatas/prevención & control
17.
Ann N Y Acad Sci ; 849: 137-45, 1998 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-9668458

RESUMEN

A non-radioactive DNA probe was developed for detection of Anaplasma marginale in ticks and cattle. The probe was labeled with digoxigenin 11-dUTP by polymerase chain reaction. The probe was tested on bovine blood and was found to be a sensitive and specific detection method for A. marginale in cattle. The DNA probe was then adapted for in situ hybridization (ISH) of A. marginale in Dermacentor andersoni and D. variabilis ticks infected either as nymphs or adults. One-half of each tick was studied with ISH while the other half was examined with light and electron microscopy. In male ticks infected as adults, tick gut cells first became infected with A. marginale while ticks fed on an infected calf, and they remained infected as they transmission fed on a second, susceptible calf. At the onset of transmission feeding, salivary glands became infected with A. marginale. During transmission feeding infection was also observed in interstitial, reproductive, skeletal muscle, fat body and Malpighian tubule tissue, resulting in a generalized A. marginale infection. When adult ticks that acquired infection as nymphs were examined with ISH and microscopy, gut tissues of both D. andersoni and D. variabilis became infected with A. marginale. However, salivary gland infection was seen only in D. variabilis, even though both species of ticks transmitted A. marginale to susceptible calves. A. marginale was not seen with ISH or microscopy in hemocytes collected from both species of ticks and, thus, hemocytes do not appear to play a role in the development of A. marginale in ticks.


Asunto(s)
Anaplasma/aislamiento & purificación , Bovinos/microbiología , Garrapatas/microbiología , Anaplasma/genética , Animales , Sondas de ADN , Dermacentor/microbiología , Hibridación in Situ , Hibridación Fluorescente in Situ/métodos , Masculino , Reacción en Cadena de la Polimerasa/métodos
18.
Ann N Y Acad Sci ; 849: 253-8, 1998 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-9668472

RESUMEN

Anaplasma marginale has been propagated and continuously passaged in an Ixodes scapularis cell line. Anaplasma development was characterized and cultures with a high density of rickettsiae were harvested at a predictable rate. Culture-derived A. marginale (CAM) remained infective for cattle and was used effectively as antigen in diagnostic tests with the sensitivity to identify bovine carriers of A. marginale. This study presents results of an initial trial using the CAM as an immunogen for cattle. CAM was mechanically disrupted, frozen at -70 degrees C, and inactivated with beta-propiolactone. Two intact yearling cattle were immunized with CAM and Freund's adjuvant, receiving 4 subcutaneous injections at 3-4 week intervals. Two control yearling cattle received adjuvant and PBS. Serum samples were evaluated by competitive ELISA (C-ELISA) using CAM as antigen and the standard complement fixation test (CFT). All cattle were subsequently challenged with A. marginale-infected blood from a carrier cow. An additional intact calf was inoculated with live CAM from the same passage and screened by C-ELISA and CFT. Sera collected from immunized cattle were negative or suspicious by CFT throughout the immunization study. The same sera were strongly positive by C-ELISA two weeks after the first injection and throughout the study. All cattle became infected following challenge-exposure with blood, but immunized cattle exhibited longer prepatent periods as well as lower parasitemias and percent reduction of packed cell volumes as compared with the controls. The calf receiving live CAM became infected and underwent a mild clinical reaction with positive C-ELISA and CFT results and did not become clinically ill following blood challenge. This preliminary study suggests that the CAM antigen is highly immunogenic in cattle. Furthermore, the CFT did not identify immunized animals whereas the C-ELISA (using CAM) was highly sensitive for detection of both immunized and infected animals.


Asunto(s)
Anaplasma/inmunología , Anaplasmosis/inmunología , Vacunas Bacterianas , Ixodes/microbiología , Anaplasma/aislamiento & purificación , Anaplasma/patogenicidad , Anaplasmosis/prevención & control , Animales , Anticuerpos Antibacterianos/sangre , Portador Sano/microbiología , Bovinos , Células Cultivadas , Pruebas de Fijación del Complemento , Ensayo de Inmunoadsorción Enzimática , Virulencia
19.
Ann N Y Acad Sci ; 849: 273-81, 1998 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-9668475

RESUMEN

Anaplasma marginale was propagated in a continuous tick cell line and detergent-solubilized infected cells were used as antigen in a competitive ELISA (C-ELISA) for detection of Anaplasma-specific antibody in bovine sera. Positive control sera competed well (> or = 35% inhibition) with an A. marginale-specific monoclonal antibody for binding to this antigen, while negative sera failed to compete (< 35% inhibition). The C-ELISA was compared to the standard complement-fixation test (CFT) using 2,208 bovine sera. Overall, C-ELISA was more sensitive than CFT (24.9% versus 9.4%), mainly because CFT yielded "suspicious" or "anti-complementary" results in 10.5% of the sera and also failed to identify several vaccinated and carrier cattle that were C-ELISA-positive. The apparent agreement between CFT and C-ELISA was 89.6% and the kappa value was 0.6. These results show that this C-ELISA would be a suitable replacement of the CFT as the standard test for detection of A. marginale antibody.


Asunto(s)
Anaplasma/inmunología , Anaplasmosis/diagnóstico , Anaplasma/aislamiento & purificación , Anaplasmosis/inmunología , Animales , Anticuerpos Monoclonales , Especificidad de Anticuerpos , Bovinos , Línea Celular , Pruebas de Fijación del Complemento , Reacciones Cruzadas , Ensayo de Inmunoadsorción Enzimática/métodos , Eritrocitos/microbiología , Ixodes/microbiología , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Pruebas Serológicas/métodos
20.
Ann N Y Acad Sci ; 849: 282-92, 1998 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-9668476

RESUMEN

Serologic diagnosis of anaplasmosis is currently done by the complement-fixation, ELISA, and card agglutination tests. These tests have utilized A. marginale harvested from bovine erythrocytes as antigen which is often contaminated with erythrocyte stroma. We are currently testing A. marginale propagated in a Ixodes scapularis cell line as antigen for serologic tests. In this study, we report the use of the cell culture-derived A. marginale as antigen for development of a rapid, semi-automated latex agglutination test. Diluted serum and latex (polystyrene microspheres), sensitized with cell culture-derived A. marginale proteins, were dispensed into 96-well microtiter plates. An initial reading of light transmission was recorded by a computer-interfaced scanning autoreader. After 30 minutes, the plates were mixed and read a second time, recording the delta % light transmittance. The sensitized latex microspheres (latex) agglutinated in the presence of A. marginale antibodies, thus producing an increase in light transmittance. In preliminary tests, 724/977 of the sera were positive for A. marginale antibodies with an apparent agreement of 83.3% when compared with the complement-fixation test. Sensitization and sera dilution buffers were shown to have a marked effect on the sensitivity and specificity of this assay. Results will be presented on the optimization of buffers and the testing of sera from experimentally and field-infected cattle.


Asunto(s)
Anaplasma/inmunología , Anaplasmosis/diagnóstico , Pruebas de Fijación de Látex/métodos , Anaplasma/aislamiento & purificación , Animales , Anticuerpos Antibacterianos/sangre , Reacciones Antígeno-Anticuerpo , Automatización , Bovinos , Células Cultivadas , Ensayo de Inmunoadsorción Enzimática , Eritrocitos/microbiología , Pruebas de Fijación de Látex/instrumentación , Reproducibilidad de los Resultados
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA