RESUMO
Given the importance of the management of sedation, analgesia and delirium in Intensive Care Units, and in order to update the previously published guidelines, a new clinical practice guide is presented, addressing the most relevant management and intervention aspects based on the recent literature. A group of 24 intensivists from 9 countries of the Pan-American and Iberian Federation of Societies of Critical Medicine and Intensive Therapy met to develop the guidelines. Assessment of evidence quality and recommendations was made according to the Grading of Recommendations Assessment, Development and Evaluation Working Group. A systematic search of the literature was carried out using MEDLINE, Cochrane Library databases such as the Cochrane Database of Systematic Reviews and the Cochrane Central Register of Controlled Trials (CENTRAL), the Database of Abstracts of Reviews of Effects, the National Health Service Economic Evaluation Database and the database of Latin American and Caribbean Literature in Health Sciences (LILACS). A total of 438 references were selected. After consensus, 47 strong recommendations with high and moderate quality evidence, 14 conditional recommendations with moderate quality evidence, and 65 conditional recommendations with low quality evidence were established. Finally, the importance of initial and multimodal pain management was underscored. Emphasis was placed on decreasing sedation levels and the use of deep sedation only in specific cases. The evidence and recommendations for the use of drugs such as dexmedetomidine, remifentanil, ketamine and others were incremented.
Assuntos
Analgesia/métodos , Anestesia/métodos , Estado Terminal/terapia , Delírio/terapia , Analgesia/normas , Anestesia/normas , Benzodiazepinas/administração & dosagem , Sedação Consciente/métodos , Sedação Consciente/normas , Cuidados Críticos/métodos , Cuidados Críticos/normas , Medicina Baseada em Evidências/normas , Humanos , Hipnóticos e Sedativos/administração & dosagem , Unidades de Terapia Intensiva , Midazolam/administração & dosagem , Manejo da Dor/normasRESUMO
INTRODUCTION: The risk of falls in older adults increases because of the decrease in strength, flexibility, balance and sensory changes affecting functionality and quality of life. For this reason, an integral system of evaluation of equilibrium is necessary, for preventive purposes or for early therapeutic interventions. AIM: To present the results of the transcultural translation and adaptation process of the Balance Evaluation Systems Test (BESTest) to Spanish language. SUBJECTS AND METHODS: The original version of the BESTest was translated into Spanish, following the process of retro-traduction and cultural adaptation considering the semantic, idiomatic, conceptual and experiential equivalences. Subsequently the version was reviewed by a panel of experts qualifying clarity, coherence, relevance and sufficiency. The pilot test included 32 adults between 50 and 80 years old. RESULTS: It was possible to carry out the complete translation of the instrument, the instructions for the subject and for the evaluator. Most items of the test reached the maximum score of 4.0 (100%), nine items achieved an average score of 3.9 (99%), one item got an average score of 3.8 (95%) and two items achieved an average score of 3.7 (92.5%). CONCLUSIONS: With this study the Spanish speakers community has a pertinent sufficient, coherent and clear instrument in order to identify the control postural system altered to focus treatment and to get better functional outcomes from balance evaluation in older adults.
TITLE: Adaptacion transcultural al castellano del sistema de evaluacion del equilibrio (BESTest) en adultos mayores.Introduccion. El riesgo de caidas en adultos mayores se incrementa a consecuencia de la disminucion de la fuerza, la flexibilidad, el equilibrio y los cambios sensoriales, que afectan a la funcionalidad y la calidad de vida. Por tal razon se hace necesario un sistema integral de evaluacion del equilibrio con fines preventivos o para intervenciones terapeuticas tempranas. Objetivo. Presentar los resultados del proceso de traduccion y adaptacion transcultural del sistema de evaluacion del equilibrio (BESTest) al castellano. Sujetos y metodos. Se tradujo al castellano la version original del BESTest, siguiendo el proceso de retrotraduccion y adaptacion cultural y teniendo en cuenta las equivalencias semanticas, idiomaticas, conceptual y experiencial. Posteriormente, la version fue revisada por un panel de expertos que califico la claridad, la coherencia, la pertinencia y la suficiencia. En la prueba piloto participaron 32 adultos de 50-80 años. Resultados. Se realizo la traduccion completa del instrumento y de las instrucciones para el sujeto y para el evaluador. La mayoria de items de la prueba alcanzaron la puntuacion maxima de 4 (100%), nueve items lograron una calificacion media de 3,9 (99%); un item, una calificacion media de 3,8 (95%), y dos items, una calificacion media de 3,7 (92,5%). Conclusiones. Con este estudio, la comunidad de habla hispana cuenta con un instrumento pertinente, suficiente, coherente y claro para identificar el sistema del equilibrio afectado, enfocar el tratamiento y obtener mejores resultados funcionales a partir de la evaluacion del equilibrio en adultos mayores.
Assuntos
Características Culturais , Avaliação Geriátrica/métodos , Equilíbrio Postural , Idoso , Idoso de 80 Anos ou mais , Humanos , Pessoa de Meia-Idade , Projetos Piloto , TraduçõesRESUMO
El pH es el grado de acidez de una solución. En cavidad bucal, el pH define diferentes sucesos tanto bioquímicos como microbiológicos, entre los factores que ejercen influencia en todos estos eventos intrabucales encontramos: 1) capacidad buffer salival, la saliva no estimulada es de pH ligeramente ácido, la saliva estimulada posee pH básico. 2) carbohidratos exógenos. 3) bacterias acidógenas de la biopelícula dental, las cuales coexisten en microambientes altamente organizados, pudiendo metabolizar rápidamente ciertos azúcares a glucanos y productos finales ácidos. 4) agentes químicos, tales como hidróxido de calcio, el cual libera iones hidroxilos al medio, alcalinizándolo y haciéndolo no viable para el metabolismo bacteriano; clorhexidina, antiséptico de gran sustantividad, activo en bacterias Gram positivas y Gram negativas; fluoruros, que exhiben capacidad de inhibición metabólica, mecanismo antiadherente, producción de cambios en la carga superficial del diente. 5) azúcares alcoholes edulcorantes (xilitol), presenta la propiedad de retardar el flujo metabólico de ciertas bacterias cariogénicas.
pH is the acidity of a solution. In oral cavity, pH defines different events both biochemical and microbiological, factors that influence these intraoral events are: 1) salivary buffer capacity, unstimulated saliva is slightly acidic, stimulated saliva has basic pH. 2) exogenous carbohydrates. 3) acidogenic bacteria of dental biofilm , which coexist in highly organized microenvironments , can rapidly metabolize some sugars to glucans and acidic end products . 4) chemical agents, such as calcium hydroxide , which releases hydroxyl ions to the medium, and makes it non viable for bacterial metabolism; chlorhexidine antiseptic with high substantivity , active in Gram positive and Gram negative bacteria; fluorides exhibit metabolic inhibition capacity, antiadherent mechanism, production of changes in the surface charge of the tooth. 5) Sweeteners sugar alcohols (xylitol), has the property of retarding certain metabolic flux of cariogenic bacteria.
Assuntos
Humanos , Masculino , Feminino , Biofilmes/crescimento & desenvolvimento , Boca/anatomia & histologia , Concentração de Íons de Hidrogênio , OdontologiaRESUMO
INTRODUCTION: Optimal management of sedation, analgesia and delirium offers comfort and security for the critical care patient, allows support measures to be applied more easily and enables an integral approach of medical care, at the same time that lowers the incidence of complications, wich translates in better patient outcomes. OBJECTIVE: To update the Guía de práctica clínica basada en la evidencia para el manejo de la sedoanalgesia en el paciente adulto críticamente enfermo published in Medicina Intensiva in 2007, and give recommendations for the management of sedation, analgesia, and delirium. METHODOLOGY: A group of 21 intensivists from 9 countries of the Federación Panamericana e Ibérica de Sociedades de Medicina Crítica y Terapia Intensiva, 3 of them also specialists in clinical epidemiology and methodology, gathered for the development of guidelines. Assessment of evidence quality and recommendations were made based on the Grading of Recommendations Assessment, Development and Evaluation system. Strength of recommendations was classified as 1=strong, or 2=weak, and quality of evidence as A=high, B=moderate, or C=low. Two authors searched the following databases: MEDLINE through PUBMED, The Cochrane Library and Literatura Latinoamericana y del Caribe en Ciencias de la Salud and retrieved pertinent information. Members assigned to the 11 sections of the guidelines, based on the literature review, formulated the recommendations, that were discussed in plenary sessions. Only those recommendations that achieved more than 80% of consensus were approved for the final document. The Colombian Association of Critical Medicine and Intensive Care (AMCI) supported the elaboration of this guidelines. RESULTS: Four hundred sixty-seven articles were included for review. An increase in number and quality of publications was observed. This allowed to generate 64 strong recommendations with high and moderate quality of evidence in contrast to the 28 recommendations of the previous edition. CONCLUSIONS: This Guidelines contains recommendations and suggestions based on the best evidence available for the management of sedation, analgesia and delirium of the critically ill patient, including a bundle of strategies that serves this purpose. We highlight the assessment of pain and agitation/sedation through validated scales, the use of opioids initially to apropiate analgesic control, associated with multimodal strategies in order to reduce opioide consumption; to promote the lowest level of sedation necessary avoiding over-sedation. Also, in case of the need of sedatives, choose the most appropiate for the patient needs, avoiding the use of benzodiazepines and identify risk factors for delirium, in order to prevent its occurrence, diagnose delirium and treat it with the most suitable pharmacological agent, whether it is haloperidol, atypical antipsychotics or dexmedetomidine, once again, avoiding the use of benzodiazepines and decreasing the use of opioids.
Assuntos
Analgesia , Sedação Consciente , Cuidados Críticos/normas , Estado Terminal/terapia , Sedação Profunda , Algoritmos , Procedimentos Cirúrgicos Cardíacos , Delírio/terapia , Humanos , Falência Hepática/terapia , Doenças do Sistema Nervoso/terapia , Cuidados Pós-Operatórios , Insuficiência Renal/terapia , Respiração Artificial , Síndrome de Abstinência a Substâncias/terapia , Desmame do RespiradorRESUMO
El síndrome de Boca Ardiente (SBA) se caracteriza por ardor, picor, escozor y dolor bucal sin causa orgánica que lo justifique. La boca ardiente aún es un desafío en el campo de la medicina. Su etiología es desconocida, a pesar de que diversos estudios indican que intervienen una serie de factores locales, sistémicos y psicológicos que se consideran como posibles agentes causales. La saliva puede desempeñar un papel importante en la sintomatología del ardor bucal, presenta propiedades físicas y químicas (reológicas) que determinan funciones imprescindibles para el equilibrio de la cavidad bucal. En pacientes con boca ardiente hay cambios en la composición y tasa del flujo salival relacionados con boca seca, viscosidad, ardor bucal, humedad entre otros. En esta revisión se trata de actualizar varios aspectos que relacionan las distintas causas del síndrome de boca ardiente con la saliva y sus alteraciones como uno de los factores más importantes en la etiología del ardor bucal. Estudios recientes sugieren que el ácido alfa lipoico combinado con gabapentina es un tratamiento efectivo para este síndrome
Burning mouth syndrome is characterized by burning, smarting and oral pain without any organic cause justifying it. Burning mouth is still a challenge in medical field. It has an unknown aetiology; despite many studies indicate the involvement of local, systemic and psychological factors that can be considered possible causal agents. Saliva can perform an important role in oral smarting symptomatology, shows physico-chemical properties (rheological) determining vital functions for oral cavity equilibrium. There are changes in composition and salivary flow rate of burning mouth patients, related with dry mouth, viscosity, oral smarting, and humidity, among others. This review pretends to update many aspects that relate different causes of burning mouth syndrome with saliva and its alterations as one of the most important factors in the aetiology of oral smarting. Recent studies suggest that alpha lipoic acid combined with gabapentin is an effective treatment for this syndrome
Assuntos
Feminino , Glossalgia/etiologia , Saliva/química , Síndrome da Ardência Bucal/etiologia , Doenças da BocaRESUMO
Los virus del papiloma humano (VPH), son virus ADN de doble cadena helicoidal, epiteliotrópicos que producen lesiones verrugosas en piel y mucosas. Algunas evidencias indican que ciertos tipos específicos de estos virus son necesarios pero no totalmente suficientes para ocasionar la transformación maligna, debido a que requieren algunas acciones sinérgicas de otros eventos iniciadores. Existen más de 230 tipos de VPH, 118 tipos están bien caracterizados, más de 40 tipos anogenitales, de los cuales 15 de ellos son oncogénicos; y en humanos constituyen uno de los grupos virales más frecuentes que infectan el epitelio de piel y mucosas: conjuntivas, cavidad bucal, laringe, árbol traqueobronquial, esófago, vejiga, ano y tracto genital. El examen clínico de la boca y sus anexos, constituye el paso inicial para la detección de una infección por este virus. El examen histológico revela el cambio morfológico y patognomónico más relevante de la infección por VPH, las células coilocíticas; las técnicas moleculares, como la Reacción en Cadena de la Polimerasa, la Hibridación in situ, entre otras, están basadas en la detección del genoma del virus. El VPH puede asociarse a distintos agentes físicos y químicos que promueven el desarrollo del carcinoma bucal, siendo los tipos (16, 18, 31, 32, 33 y 35) potencialmente oncogénicos. Esta revisión se propone analizar los diferentes tipos de VPH asociados con lesiones malignas de la cavidad bucal
Human papillomaviruses (HPV) are epitheliotropic and double-helix stranded DNA viruses, which produce warty lesions in mucosae and skin. A bigger amount of evidence suggests that specific types of viruses are necessary but not enough to produce the malignant transformation, also it´s necessary the synergistic action of other indicators. There are more than 230 types of HPV, 118 types are well characterized, more than 40 types anus genital, 15 of them have an oncogenic potential; in humans constitutes one of the most frequent viral groups infecting skin epithelium and mucosae: conjunctives, oral cavity, tracheo-bronchial tree, esophagus, bladder, anus and genital tract. Clinical exam of the mouth and its annexes constitutes the initial step for the detection of an infection by this virus. Histological exam reveals morphological and pathognomonic most relevant changes of HPV infection, koilocytes; molecular techniques such as Polimerase Chain Reaction, in situ hybridization, among others, are based in the detection of virus genome. HPV can act with different types of physical and chemical agents that promote the development of oral carcinoma being (16, 18, 31, 32, 33 y 35) HPV´s potentially oncogenic. This review analyzes the different types of HPV associated with malignant lesions of oral cavity
Assuntos
Humanos , Doenças Transmissíveis , Infecções por Papillomavirus/etiologia , Neoplasias Bucais/etiologia , Assistência OdontológicaRESUMO
We have developed an enzyme-linked immunosorbent assay (ELISA) that uses polyclonal or monoclonal anti-surfactant protein SP-B antibodies to quantitate purified SP-B in chloroform/methanol and in chloroform/methanol extracts of whole pulmonary surfactant at nanogram levels. This method has been used to explore the effect of the presence of different phospholipids on the immunoreactivity of SP-B. Both polyclonal and monoclonal antibodies produced reproducible ELISA calibration curves for methanolic SP-B solutions with protein concentrations in the range of 20-1000 ng/mL. At these protein concentrations, neither dipalmitoylphosphatidylcholine, dipalmitoylphosphatidylglycerol, nor phosphatidylcholine or phosphatidylglycerol from egg yolk had significant effects on the binding of antibodies to SP-B up to protein-to-lipid weight ratios of 1:20. Coating of ELISA plates with SP-B concentrations higher than 1 microg/mL produced a substantial decrease in the binding of antibodies to the protein that was prevented by the presence of negatively charged but not zwitterionic phospholipids. Characterization of the secondary structure of SP-B by far-UV circular dichroism showed that phospholipids induced pronounced changes on the conformation of SP-B when the solvent was evaporated and dry lipid-protein films were formed, a necessary step to expose protein to antibodies in ELISA. Under these conditions, negatively charged lipids, but not zwitterionic ones, induced a marked decrease on the ellipticity of SP-B that would be associated with a conformation that is significantly more exposed to antibodies.
Assuntos
Ensaio de Imunoadsorção Enzimática , Fosfolipídeos/análise , Proteolipídeos/análise , Surfactantes Pulmonares/análise , Animais , Ânions/química , Ânions/metabolismo , Anticorpos Monoclonais/imunologia , Western Blotting , Dicroísmo Circular , Soros Imunes/imunologia , Bicamadas Lipídicas , Micelas , Fosfolipídeos/química , SuínosRESUMO
Binding of polyclonal and monoclonal antibodies, quantitated by enzyme-linked immunosorbent assay, to porcine SP-B reconstituted in different phospholipid bilayers has been used to assess differences in protein structure due to lipid-protein interactions. SP-B bound significantly more antibodies when it was reconstituted in bilayers made of anionic phospholipids (phosphatidic acid, cardiolipin, phosphatidylglycerol, phosphatidylinositol or phosphatidylserine) than in zwitterionic bilayers (phosphatidylcholine, phosphatidylcholine/cholesterol, or phosphatidylethanolamine) or in fatty acid micelles (made of salts of palmitic or stearic acids). These differences in immunoreactivity can be important in the development of quantitation methods for SP-B in clinical samples based on immunological techniques.
Assuntos
Antígenos/imunologia , Antígenos/metabolismo , Bicamadas Lipídicas/química , Bicamadas Lipídicas/metabolismo , Proteolipídeos/imunologia , Proteolipídeos/metabolismo , Surfactantes Pulmonares/imunologia , Surfactantes Pulmonares/metabolismo , Animais , Ânions/química , Ânions/metabolismo , Anticorpos Monoclonais/imunologia , Ensaio de Imunoadsorção Enzimática , Soros Imunes/imunologia , Micelas , Ácido Palmítico/metabolismo , Fosfolipídeos/química , Fosfolipídeos/metabolismo , Eletricidade Estática , Ácidos Esteáricos/metabolismo , SuínosRESUMO
The nature of the initial interactions of African swine fever (ASF) virus with target cells is only partially known, and to date only the ASF virus protein p12 has been identified as a viral attachment protein. More recently, antibodies to viral proteins p54 and p30 have been shown to neutralize the virus, inhibiting virus binding and internalization, respectively. Therefore, we investigated the role of these proteins in the receptor-mediated ASF virus endocytosis in swine macrophages, the natural host cells. Proteins p54 and p30, released from ASF virus particles after treatment of virions with a nonionic detergent, bound to virus-sensitive alveolar pig macrophages. Binding of these proteins was found to be specifically inhibited by neutralizing antibodies obtained from a convalescent pig or from pigs immunized with recombinant p54 or p30 proteins. The baculovirus-expressed proteins p54 and p30 retained the same biological properties as the viral proteins, since they also bound specifically to these cells, and their binding was equally inhibited by neutralizing antibodies. Binding of 35S-labeled recombinant p54 and p30 proteins to macrophages was specifically competed by an excess of unlabeled p54 and p30, respectively. However, cross-binding inhibition was not observed, suggesting the existence of two different saturable binding sites for these proteins in the susceptible cells. In addition, protein p54 blocked the specific binding of virus particles to the macrophage, while protein p30 blocked virus internalization. Both proteins independently prevented virus infection and in a dose-dependent manner, suggesting that binding interactions mediated by both proteins are necessary to give rise to a productive infection. The relevance of blockade of virus-cell interactions mediated by p54 and p30 in the protective immune response against ASF virus was then investigated. Immunization of pigs with either recombinant p54 or p30 proteins induced neutralizing antibodies which, as expected, inhibited virus attachment or internalization, respectively. However, immunized pigs were not protected against lethal infection and the disease course was not modified in these animals. In contrast, immunization with a combination of p54 and p30 proteins simultaneously stimulated both virus neutralizing mechanisms and modified drastically the disease course, rendering a variable degree of protection ranging from a delay in the onset of the disease to complete protection against virus infection. In conclusion, the above results strongly suggest that proteins p54 and p30 mediate specific interactions between ASF virus and cellular receptors and that simultaneous interference with these two interactions has a complementary effect in antibody-mediated protection.
Assuntos
Vírus da Febre Suína Africana/imunologia , Febre Suína Africana/prevenção & controle , Fosfoproteínas/imunologia , Proteínas Virais/imunologia , Proteínas Estruturais Virais/imunologia , Vírus da Febre Suína Africana/metabolismo , Animais , Anticorpos Antivirais/imunologia , Linhagem Celular , Células Cultivadas , Macrófagos Alveolares/metabolismo , Fosfoproteínas/metabolismo , Proteínas Recombinantes de Fusão/imunologia , Suínos , Vacinação , Proteínas Virais/metabolismo , Proteínas Estruturais Virais/metabolismoRESUMO
Rabbit hemorrhagic disease is a rapidly lethal infection caused by a calicivirus, characterized by acute liver damage and disseminated intravascular coagulation (DIC). Following morphological criteria and using a specific in situ labeling technique, we have found that liver cell death induced upon infection is due to apoptosis, and that programmed cell death is a constant feature in rabbits experimentally infected with RHDV. The process affected mainly hepatocytes, but also macrophages and endothelial cells presented morphologic hallmarks of apoptosis, expressing all these cell types viral antigens as determined by immunohistochemistry. The occurrence of programmed cell death was correlated with the appearance of the RHDV induced pathology in tissues by DNA fragmentation detection in situ. Hepatocyte apoptosis produced extensive parenchymal destruction causing a lethal, acute fulminant hepatitis that is characteristic of RHD. Apoptosis of intravascular monocytes and endothelial cell was observed together with fibrin thrombi in blood vessels. Since apoptotic cells are known sites of enhanced procoagulant activity, apoptosis of these cell populations might constitute a first step in the pathogenesis of DIC and a common pathway to other viral hemorrhagic fevers. In conclusion, apoptosis in RHD may be determinant in the development of the pathogenesis of this disease.
Assuntos
Apoptose , Infecções por Caliciviridae/patologia , Vírus da Doença Hemorrágica de Coelhos/patogenicidade , Animais , Fígado/patologia , CoelhosRESUMO
At present, the eradication of African swine fever (ASF) in affected countries is based only on an efficient diagnosis program because of the absence of an available vaccine. The highly antigenic ASF virus proteins p54 and p30, encoded by genes E183L and CP204L respectively, were expressed in baculovirus for diagnostic purposes. A sequence comparison analysis of these genes from different field virus strains which are geographically diverse and isolated in different years, revealed that both genes are completely conserved among the isolates. Partially purified baculovirus-expressed proteins were used in ELISA and Western blot for ASF antibody detection in sera from experimentally inoculated pigs and field sera from ASF innaparent carriers. These comparative analyses showed that p54 presents better reactivity than p30 in Western blot. However, recombinant p30 was more efficient for antibody detection by ELISA, improving the discrimination between positive and negative sera by this technique. These data suggest the convenience of using p30 as ELISA antigen, while p54 should be the selected antigen for ASF virus antibody detection by Western blot. The combined use of both antigens for serodiagnosis of ASF disease will improve the sensitivity of innaparent carriers detection, facilitating also the interpretation of the tests, and eliminating the use of ASF virus in antigen production.
Assuntos
Vírus da Febre Suína Africana/genética , Febre Suína Africana/virologia , Fosfoproteínas/genética , Proteínas Virais/genética , Proteínas Estruturais Virais/genética , Febre Suína Africana/diagnóstico , Febre Suína Africana/imunologia , Vírus da Febre Suína Africana/imunologia , Vírus da Febre Suína Africana/isolamento & purificação , Animais , Anticorpos Antivirais/sangue , Baculoviridae , Western Blotting , Linhagem Celular , Chlorocebus aethiops , Clonagem Molecular , Ensaio de Imunoadsorção Enzimática , Vetores Genéticos , Fosfoproteínas/imunologia , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Spodoptera/citologia , Suínos , Células Vero , Proteínas Virais/imunologia , Proteínas Estruturais Virais/imunologiaRESUMO
In this study we have investigated the generation of African swine fever (ASF) virus variants resistant to neutralizing antibodies after cell culture propagation. All highly passaged ASF viruses analyzed were resistant to neutralization by antisera from convalescent pigs or antibodies generated against individual viral proteins which neutralized low-passage viruses. A molecular analysis of neutralizable and nonneutralizable virus isolates by sequencing of the genes encoding for neutralizing proteins revealed that the absence of neutralization of high-passage viruses is not due to antigenic variability of critical epitopes. A comparative analysis of phospholipid composition of viral membranes between low- and high-passage viruses revealed differences in the relative amount of phosphatidylinositol in these two groups of viruses, independent of the cells in which the viruses were grown. Further purification of low- and high-passage viruses by Percoll sedimentation showed differences in the phospholipid composition identical to those found with the partially purified viruses and confirmed the susceptibility of these viruses to neutralization. The incorporation of phosphatidylinositol into membranes of high-passage viruses rendered a similar neutralization susceptibility to low-passage viruses, in which this is a major phospholipid. In contrast, other phospholipids did not interfere with high-passage virus neutralization, suggesting that phosphatidylinositol is essential for a correct epitope presentation to neutralizing antibodies. Additionally, the removal of phosphatidylinositol form a low-passage virus by a specific lipase transformed this virus from neutralizable to nonneutralizable. These data constitute clear evidence of the importance of the lipid composition of the viral membranes for the protein recognition by antibodies and may account in part for the past difficulties in reproducibly demonstrating ASF virus-neutralizing antibodies by using high-passage viruses.
Assuntos
Vírus da Febre Suína Africana/química , Vírus da Febre Suína Africana/imunologia , Anticorpos Antivirais/imunologia , Fosfolipídeos/química , Vírus da Febre Suína Africana/isolamento & purificação , Animais , Linhagem Celular , Chlorocebus aethiops , Testes de Neutralização , Inoculações Seriadas , Suínos , Células Vero , VírionRESUMO
African swine fever virus induces in convalescent pigs antibodies that neutralized the virus before and after binding to susceptible cells, inhibiting both virus attachment and internalization. A further analysis of the neutralization mechanisms mediated by the different viral proteins showed that antibodies to proteins p72 and p54 are involved in the inhibition of a first step of the replication cycle related to virus attachment, while antibodies to protein p30 are implicated in the inhibition of virus internalization.
Assuntos
Vírus da Febre Suína Africana/imunologia , Febre Suína Africana/virologia , Anticorpos Antivirais/imunologia , Proteínas Virais/imunologia , Replicação Viral/imunologia , Vírus da Febre Suína Africana/metabolismo , Animais , Anticorpos Antivirais/farmacologia , Suínos , Replicação Viral/efeitos dos fármacosRESUMO
Antibody neutralization of African swine fever (ASF) virus measured by a plaque reduction assay presents frequent difficulties because of the absence or delay in plaque formation by many strains, especially low-passage viruses. To overcome this problem, a new ASF virus neutralization test has been developed. The new test consists of a conventional plaque reduction assay in which the viral plaques are detected by expression of marker genes. For the development of this neutralization assay 4 mutant viruses were generated by homologous recombination, containing beta-galactosidase or beta-glucuronidase reporter genes inserted into the thymidine kinase locus of the viral genome. These recombinant viruses have the following advantages with respect to parental viruses: (1) the neutralization assay takes less than a third of the time needed using non-recombinant viruses; (2) the small plaques can be detected more accurately by color contrast; and (3) the neutralization-resistant virus clones can be recovered easily post-plaque counting. Additionally, these recombinant viruses permit differentiation by chromogenic staining of individual infected pig macrophages, the natural host cell for ASF virus, facilitating neutralization assays in these primary cultures as described in cell lines.
Assuntos
Vírus da Febre Suína Africana/imunologia , Genes Reporter , Testes de Neutralização/métodos , Vírus da Febre Suína Africana/genética , Animais , Chlorocebus aethiops , Macrófagos/virologia , Mutagênese Insercional , Suínos , Células Vero , Ensaio de Placa Viral , beta-Galactosidase/genéticaRESUMO
A Western blot technique using a recombinant protein has been developed to confirm positive results obtained in African swine fever (ASF)-specific antibody detection by ELISA. The new confirmatory Western blot is based on the use of protein p54, one of the most antigenic ASF virus structural proteins, expressed in Escherichia coli fused to the N-terminus of MS2 polymerase. The recombinant Western blot assay was highly specific and equally sensitive for ASF virus-infected pigs detection as the conventional Western blot, which uses virus-induced proteins ranging in molecular weight between 23 and 35 kDa. The novel Western blot assay provides a simpler interpretation of the test, eliminates the possibility of false-positive reactions produced by cellular compounds that contaminate the antigen employed in the conventional technique, and avoids the use of live virus in antigen production.