RESUMO
Here we analyze the trends of rainfall and the frequency of rainy days over the Brazilian Cerrado between 1960 and 2021 in four distinct periods according to the seasonal patterns over the region. We also evaluated trends in evapotranspiration, atmospheric pressure, winds, and atmospheric humidity over the Cerrado to elucidate the possible reasons for the detected trends. We recorded a significant reduction in rainfall and frequency of rainy days in the northern and central Cerrado regions for all periods except at the beginning of the dry season. The most pronounced negative trends were recorded during the dry season and the beginning of the wet season, where we recorded reductions of up to 50% in total rainfall and the number of rainy days. These findings are associated with the intensification of the South Atlantic Subtropical Anticyclone, which has been shifting atmospheric circulation and raising regional subsidence. Moreover, during the dry season and the beginning of the wet season, there was a reduction in regional evapotranspiration, which also potentially contributed to the rainfall reduction. Our results suggest an expansion and intensification of the dry season in the region, potentially bringing broad environmental and social impacts that transcend the Cerrado boundaries.
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Objetivo: Describir las características clínicas y epidemiológicas de los pacientes con infecciones por Acinetobacter en Unidad de Terapia Intensiva Pediátrica. Material y Método: Estudio descriptivo y retrospectivo, en el periodo de enero de 2005 a agosto de 2007. Se incluyó a todos los pacientes cuyos cultivos fueron positivos para Acinetobacter. Resultados: De 18 pacientes, 7 de sexo femenino (39%) y 11 del masculino (61%), la edad promedio fue de 4,7 meses con rango entre 4 días a 15 años. La estancia hospitalaria promedio fue de 44 días (10 a 104 días); todos los pacientes utilizaron catéteres venosos centrales, 4 en promedio (1 a 9 catéteres). Previo al aislamiento del germen, en 16/18 pacientes se utilizó antibióticos de amplio espectro por 8,6 días y ARM (89%) con 12 días en promedio. El germen fue aislado en secreción traqueal 10/18 (55%), hemocultivo 5/18 (28%), punta de catéter 2/18 (11%) y secreción ótica 1/18 (6%). Fueron considerados en 16/18 (89%) gérmenes intrahospitalarios y en 2/18 (11%) provenientes de la comunidad. Fue utilizado como tratamiento Colistina en 7/18 (39%), otros antibióticos-ATB en 9/18 (50%) y sin tratamiento 2/18 (11%). La mortalidad relacionada con la infección fue 17% (3/18) y la no relacionada 6% (1/18). Conclusión: Los pacientes con ingreso de urgencia a UTI, con tratamiento antibiótico previo, altamente invadidos y aquellos con sepsis previa estarían más predispuestos a sufrir infecciones por Acinetobacter. La presencia de este germen en la UTI debe ser considerado motivo de preocupación por la capacidad de permanecer e infectar por largos períodos de tiempo. Se debe realizar esfuerzos para la identificación de gérmenes nosocomiales, de manera a establecer medidas rápidas de control. Son necesarios más estudios para establecer factores de riesgo en nuestra población.
Introduction: Acinetobacter is a Gram-negative coccobacillus whose importance lies in its ability to rapidly acquire resistance to broad spectrum antibiotics and cause nosocomial outbreaks. According to the WHONET analysis done by the microbiology department of the central hospital of the Institute of Social Security, the incidence of Acinetobacter in our unit has increased over the years. Acinetobacter is difficult to control because it is capable of surviving for extended periods on dry surfaces, although the most important means of transmission is on the hands of medical personnel. Objective: To describe the clinical and epidemiological characteristics of patients with Acinetobacter infections in the pediatric intensive care unit. Material and Methods: A descriptive and retrospective study done from January 2005 to August 2007. All patients with positive cultures for Acinetobacter were included. Results: Of 18 patients, 7 (39%) were female and 11 (61%) were male, while the average age was 4.7 months, with a range of from 4 days to 15 years. Average hospital stay was 44 days (10 to 104 days). Patients were catheterized with an average of 4 central venous catheters (1 to 9 catheters). Prior to isolation of the germ, 16 of 18 patients received broad-spectrum antibiotics for 8.6 days and 89% received mechanically assisted ventilation for an average of 12 days. From 10 of 18 patients the bacteria was isolated from tracheal secretions, from 5/18 (28%) from blood cultures, from 2/18 (11%) from catheters and 1/18 (6%) from ear discharge. Bacteria were considered to be hospital-acquired in 16/18 cases (89%) and community-acquired in 2/18 (11%). Treatment was with colistin in 7/18 (39%), other antibiotics in 9/18 (50%) and no treatment was received by 2/18 (11%). Infection-related mortality was 17% (3/18) and unrelated mortality 6% (1/18)...
Assuntos
Acinetobacter , Infecções por Acinetobacter , Cuidados Críticos , PediatriaRESUMO
Introducción: La presencia de fiebre en el niño representa uno de los motivos más frecuentes de consulta en la práctica pediátrica diaria, y en ocasiones se convierte en una situación de temor y angustia para los padres que consideran la fiebre como el indicador más importante de que su hijo ha adquirido alguna infección seria, lo cual puede conllevar al uso inadecuado del sistema médico de atención y en especial de los servicios de urgencias.Objetivo: Determinar conocimientos, actitudes y prácticas de cuidadores de niños ante la fiebre.Material y Método: Se realizó un trabajo prospectivo, descriptivo de corte trasversal en los meses de julio y agosto del 2006. Fueron incluidos cuidadores de niños que consultaron en el Servicio de Urgencias Pediátricas del Hospital Central de Instituto de Previsión Social, independientemente de la causa que motivara la consulta. Se les proporcionó una encuesta de 26 preguntas de opciones cerradas, donde se midió conocimientos, actitudes y prácticas.Resultados: La mayoría de los encuestados fueron las madres. El nivel instructivo fue 47% secundaria completa, 37% universitarios. 90% conocía las cifras de temperatura consideradas normales.60% usa termómetro de mercurio para medir la temperatura, 33% usa el tacto. La creencia de los padres de que la fiebre ocasiona daño en el niño es generalizada, siendo los mayores daños principalmente convulsiones en 32, 6% y daño cerebral permanente en 12,6%. Este daño podría presentarse independientemente de la edad del niño. El baño (82%) fue el método más frecuente para bajar la fiebre, seguido de uso de fármacos, solos o combinados.Conclusiones: Los conocimientos y prácticas de los padres ante la fiebre de sus hijos fueron adecuados, aunque se precisan más acciones educativas ante las creencias del daño ocasionado por la misma.
Introduction: Fever in children is one of the most common reasons for presenting in daily pediatric practice, and can at times be a source of great anxiety for the parents, who may take the fever as a primary indicator of a serious infection and which may lead to inappropriate use of the healthcare system and emergency services in particular. Objective: To determine the state of knowledge, attitudes, and common practices of childcare providers faced with a feverish child. Materials and Methods:We carried out a prospective, descriptive, cross-sectional study during July and August of 2006. We included caregivers who presented with a child at the pediatric emergency department of the central hospital of the Instituto de Previsión Social (social insurance institute, or IPS) independently of the reason for presenting. They were given a survey including 26 closed option questions measuring their knowledge, attitudes, and practices. Results: Most respondents were mothers, while 47% had completed secondary school and 37% had completed an undergraduate university degree. The temperature considered normal was known by 90%, and 60% used a mercury thermometer for measuring the child's temperature while 33% detected fever using touch. The belief that fever causes harm to children is generalized; with the most commonly cited by parents being seizures (32.6%) and permanent brain damage (12.6%). This damage can occur independently of the age of the child. The most common methods for combating fever were bathing (82%) followed by use of medications alone or in combination. Conclusions: The knowledge and practices of parents confronting fever were adequate, although more education is required concerning beliefs about the harm caused by fever.
Assuntos
Criança , Cuidadores , Febre , Conhecimentos, Atitudes e Prática em Saúde , PaisRESUMO
Pestiviruses are capable of infecting a wide range of animals within the order Artyodactila. Currently, the genus Pestivirus includes Bovine Viral Diarrhea Virus 1 (BVDV-1) and 2 (BVDV-2), Border Disease Virus (BDV), and Classical Swine Fever Virus (CSFV). BVDV-1, BVDV-2 and BDV are able to cross species barrier to infect a wide range of hosts, whereas CSFV is restricted to domestic pigs and wild boars. In Argentina, 70% of cattle are seropositive to BVDV. Although there were some serological studies in llamas, alpacas and buffaloes, no reports existed about the circulation of BVDV in sheep in Argentina. Based on these, 54 blood samples of healthy ovines were analysed by serology. The results showed that 46.3% of the analysed sheep were seropositive to BVDV-1, 13% to BVDV-2 and 20.4% for both BVDV-1 and BVDV-2. The molecular analysis confirmed the presence of BVDV-1a in some samples.
Assuntos
Vírus da Diarreia Viral Bovina/isolamento & purificação , Ovinos/sangue , Ovinos/virologia , Animais , Vírus da Diarreia Viral Bovina/genética , Filogenia , Reação em Cadeia da Polimerase/veterinária , Testes SorológicosRESUMO
Bovine viral diarrhoea virus (BVDV) is a pestivirus that infects mainly bovine cattle. Nevertheless, there are several reports about infections in other members of the Artiodactyla order including serological studies, that indicate infection of BVDV in buffaloes. The aim of this article is to study the presence of BVDV in three young water buffaloes, displaying nonspecific clinical signs, compatible with the BVDV infection. Both immunohistochemistry and RT-PCR confirmed the presence of BVDV in the animals. The sequence analysis on RT-PCR amplicons revealed high identity with reference strains of genotypes 1a and 1b. Although BVDV was unequivocally identified in the sick animals, it has not been proved it is responsible for the clinical signs. Further studies are needed to clarify the pathogenic role of BVDV infection in this animal species, and the role of buffaloes in the epidemiology of BVDV infection.
Assuntos
Antígenos Virais/isolamento & purificação , Búfalos/virologia , Vírus da Diarreia Viral Bovina/isolamento & purificação , Ácidos Nucleicos/isolamento & purificação , Infecções por Pestivirus/veterinária , Animais , Vesícula Biliar/virologia , Íleo/virologia , Imuno-Histoquímica/veterinária , Infecções por Pestivirus/virologia , FilogeniaRESUMO
Introdução: o tratamento das patologias da mão através da cirurgia de transposição tendinosa requer pro- fundo conhecimento anatômico e fisiológico do membro superior. O terapeuta de mão deve entender os princípios da cirurgia e compreender a alteração que o procedimento provoca na informação cerebral do paciente em relação à movimentação do músculo. Objetivos: apresentar protocolo de trabalho do Serviço de Microcirurgia Reconstrutiva e Terapia Ocupacional do Hospital Cristo Redentor referente à reabilitação após cirurgia de trans- posição tendinosa. Métodos: centímetros Foram tratados sete pacientes, no período de março de 2006 a janeiro de 2007, sendo seis pacientes com lesão de nervo radial e um de mediano. Todos realizaram dois meses de reabilitação pré-operatória e quatro meses de reabilitação pós-operatória. Resultados: resultados satisfatórios, com período de reabilitação mais rápido e retorno da funcionalidade da mão, permitindo aos pacientes retomarem suas atividades. Discussão: centímetros o grande diferencial deste trabalho está na educa- ção pré-operatória dos pacientes, no treino do mecanismo cirúrgico e na simulação de movimentos. No pós- operatório o ganho de tempo é enorme, pois os pacientes sabem quais comandos devem ser treinados para atingir o movimento desejado. Conclusão: a formação da equipe para realizar este trabalho é importante, per- mitindo a obtenção de bons resultados.
Introduction: the tendon transposition surgery to treat the pathologies of the hand requires a profound knowledge of upper limb anatomy and physiology. The hand therapist must understand the principles of surgery and the changes that it causes in patients cerebral information about muscle movement. Objective: introduce the work protocol of rehabilitation after tendon transposition surgery, currently in use at the Center of Reconstructive Microsurgery and Occupational Therapy of Cristo Redentor Hospital. Methods: between March 2006 and January 2007, seven patients were treated, by the same surgeon and hand therapist. Six patients had radial nerve palsy and one had median nerve palsy. All patients had two months of pre-operatory rehabilitation and four months of pos-operatory rehabilitation. Results: satisfactory results, with faster recovery time and hand function return, allowing patients to resume their daily activities. Discussion: the greatest difference about this work is the pre-operatory rehabilitation, the surgery mechanism training and simulation of movements. The reduction recovery time is impressive, because patients already know wich commands they have to exercise to achieve the desired move. Conclusions: the professionals working with this patient have to be carefully selected, so good results can be achieved.
Assuntos
Humanos , Masculino , Feminino , Terapia Ocupacional , Reabilitação , Extremidade SuperiorRESUMO
A method to amplify long genomic regions (up to approximately 12.3 kb) from pestiviruses in one RT-PCR is described. The difficulty in designing conserved Pestivirus primers for the amplification of genomes from highly divergent isolates simply by means of overlapping segments is demonstrated using new bioinformatic tools. An alternative procedure consisting of optimizing the length of the genomic cDNA fragments and their subsequent amplification by polymerase chain reaction (PCR) using a limited set of specific primers is described. The amplification of long DNA fragments from a variety of sources, including genomic, mitochondrial, and viral DNAs as well as cDNA produced by reverse transcription (RT) has been achieved using this methodology, known as long distance PCR. In the case of viruses, it is necessary to obtain viral particles from infected cells prior to RT procedures. This work provides improvements in four steps of long distance RT-PCR (L-RT-PCR): (i) preparation of a viral stock, (ii) preparation of template RNA, (iii) reverse transcription and (iv) amplification of the cDNA by LD-PCR. The usefulness of L-RT-PCR is discussed in the light of current knowledge on pestivirus diversity. The genomic sequence of Singer_Arg reference strain obtained using this method is presented and characterized.
Assuntos
Pestivirus/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Animais , Bovinos , Linhagem Celular , Primers do DNA , DNA Complementar , Dados de Sequência Molecular , Pestivirus/crescimento & desenvolvimento , RNA Viral/genética , Moldes GenéticosRESUMO
Bovine pestiviruses (Bovine Viral Diarrea Virus 1 (BVDV 1) and Bovine Viral Diarrea Virus 2 (BVDV 2)) belong to the genus Pestivirus (Flaviviridae), which is composed of positive stranded RNA viruses causing significant economic losses world-wide. We used phylogenetic and bootstrap analyses to systematically scan alignments of previously sequenced genomes in order to explore further the evolutionary mechanisms responsible for variation in the virus. Previously published data suggested that homologous crossover might be one of the mechanisms responsible for the genomic rearrangements observed in cytopathic (cp) strains of bovine pestiviruses. Nevertheless, homologous recombination involves not just homologous crossovers, but also replacement of a homologous region of the acceptor RNA. Furthermore, cytopathic strains represent dead paths in evolution, since they are isolated exclusively from the fatal cases of mucosal disease. Herein, we report evidence of homologous inter-genotype recombination in the genome of a non-cytopathic (ncp) strain of Bovine Viral Diarrea Virus 1, the type species of the genus Pestivirus. We also show that intra-genotype homologous recombination might be a common phenomenon in both species of Pestivirus. This evidence demonstrates that homologous recombination contribute to the diversification of bovine pestiviruses in nature. Implications for virus evolution, taxonomy and phylogenetics are discussed.
Assuntos
Vírus da Diarreia Viral Bovina/genética , RNA Viral/genética , Recombinação Genética , Algoritmos , Sequência de Aminoácidos , Animais , Bovinos , Vírus da Diarreia Viral Bovina/classificação , Evolução Molecular , Variação Genética , Genoma Viral , Filogenia , Homologia de Sequência de AminoácidosRESUMO
This study presents a phylogenetic analysis of 115 bovine pestiviruses. A sequence data set from the 5' untranslated genomic region was analyzed with maximum parsimony, bootstrapping and parsimony jackknifing. We tested for the proposed classifications of the group and analyzed the evolution of the symptoms associated with Pestivirus infections in bovines. Based on the historical framework provided by our phylogenetic trees, we also characterized the extent and importance of contamination caused in biologicals by the virus. Our phylogenetic analyses showed that the previously defined genotypes are monophyletic, except for genotype 1a. Based on our cladograms, we propose the existence of more than 12 monophyletic groups within the species BVDV 1. The mapping of clinical symptoms suggests that the emergence of some genotypes could have been driven by a change in the pathogenic process. Enteric Problems appear to be ancestral, while Reproductive and Respiratory Problems arise with the emergence of genotypes 1b, 1d and the herein-proposed genotype Arg 1. The distribution of contaminant strains on the cladograms shows that pestiviral contamination is a common process, and also suggests that a contaminated product might be a vehicle for virus dispersion. Implications for virus evolution, virus taxonomy, veterinary medicine and biotechnology are discussed.
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Genetic typing of 29 Bovine Viral Diarrhea Virus (BVDV) isolates from Argentina was carried out by sequencing 245 nucleotides of the RT-PCR products of the 5'-UTR region. Sequence analysis shows that these Argentinean BVDV include types 1 and 2. The majority (26/29) of the isolates are type 1, which comprises subtypes 1a and 1b, together with an additional subgroup within subtype 1a. This subgroup is close to the South African subgroup Ic of 1a viruses, and to the deer pestivirus strain "Deer". The three type 2 BVDV were isolated from fetal tissues or serum during the 7-8 years before a clinical outbreak in Argentina had been reported. Only inactivated vaccines are used in bovines of the country, thus the analysed viruses are authentic field strains. The long term circulation of type 2 BVDV (situation similar to that of North America before the epidemic of 1993), and the existence of viral populations which differ from the reference strains commonly used in vaccine elaboration should be considered by manufacturers of diagnostic reagents and vaccines.
Assuntos
Vírus da Diarreia Viral Bovina/genética , Animais , Argentina , Doença das Mucosas por Vírus da Diarreia Viral Bovina/virologia , Bovinos , Vírus da Diarreia Viral Bovina/classificação , Genótipo , FilogeniaRESUMO
Single-strand conformation polymorphism (SSCP) analysis of polymerase chain reaction (PCR) products is a genetic screening technique for rapid detection of nucleotide substitutions in PCR-amplified genomic DNA or cDNA. It is based on the observation that partially formamide-denatured double-stranded DNA migrates as 2 single-stranded DNA molecules when electrophoresed in nondenaturing polyacrylamide gels. The mobility depends on the 3-dimensional conformation of the strand under the conditions used. It is possible to discriminate between DNA strands differing in only 1 nucleotide. The method was applied to the analysis of Bovine Viral Diarrhea Virus (BVDV) isolates. Reference and Argentinian strains were assessed for variations in their 5' untranslated region (5'-UTR). The PCR products of the 5'-UTR ends were formamide denatured and compared by SSCP analysis in nondenaturing 15% polyacrylamide and 15% polyacrilamide-5% glycerol gels. The reference strains SD-1, Singer, and Oregon C24V had differences in electrophoretic patterns. Despite the high conservation among the 5'-UTR of pestiviruses, the method allowed discrimination among all 9 Argentinian isolates. The 5'-UTR of a fetal kidney-derived isolate (1R93) was PCR amplified and cloned in a plasmid vector; the SSCP analysis of 30 PCR products obtained by direct amplification over randomly selected clones produced 5 different banding patterns, indicating the existence of viral quasispecies. The results show that SSCP may be used to identify and differentiate among BVDV isolates.
Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina/diagnóstico , Vírus da Diarreia Viral Bovina/genética , Polimorfismo Conformacional de Fita Simples , Regiões 5' não Traduzidas/genética , Animais , Sequência de Bases , Doença das Mucosas por Vírus da Diarreia Viral Bovina/genética , Bovinos , Rim/patologia , Rim/virologia , Dados de Sequência Molecular , Plasmídeos , Reação em Cadeia da Polimerase/veterinária , Sensibilidade e EspecificidadeRESUMO
Fetal bovine serum (FBS) used in cell culture may be contaminated with viruses, among them bovine viral diarrhea virus (BVDV) affecting the production of biological reagents and the results of diagnosis. The filtration process used in the preparation of commercial FBS abrogates most viral agents that may be present in raw FBS, but BVDV may pass through the filters because of its small size and its pleomorphism. While detection of bovine herpes virus-1 and parainfluenza-3 (PI-3) is determined by observation of the cytopathic effect, and also by hemadsorption in the case of PI-3, the most frequently isolated BVDV is non cytopathic, and infects cells without morphological alterations, inducing problems that arise after several cell generations. Batches of raw and processed FBS were analyzed. Frequencies of BVDV detection in raw serum in Argentina were similar to those published for USA. By conventional methods for BVDV detection, only 2 of 20 commercial batches of FBS had BVDV. Using cell cultures maintained with high concentrations of the serum under study for at least 2 weeks, with detection of viral antigen by indirect immunofluorescence, the percentage of BVDV detection was 80%. This method shows that most lots of commercial FBS contain BVDV. RT-PCR allows faster detection of the viral genome, but it must be validated, as it does not show viral replication. To eliminate the problem of BVDV contamination in FBS, only gamma irradiated FBS is used in our laboratory.
Assuntos
Sangue/virologia , Vírus da Diarreia Viral Bovina/isolamento & purificação , Animais , Bovinos , Meios de CulturaRESUMO
Fetal bovine serum (FBS) used in cell culture may be contaminated with viruses, among them bovine viral diarrhea virus (BVDV) affecting the production of biological reagents and the results of diagnosis. The filtration process used in the preparation of commercial FBS abrogates most viral agents that may be present in raw FBS, but BVDV may pass through the filters because of its small size and its pleomorphism. While detection of bovine herpes virus-1 and parainfluenza-3 (PI-3) is determined by observation of the cytopathic effect, and also by hemadsorption in the case of PI-3, the most frequently isolated BVDV is non cytopathic, and infects cells without morphological alterations, inducing problems that arise after several cell generations. Batches of raw and processed FBS were analyzed. Frequencies of BVDV detection in raw serum in Argentina were similar to those published for USA. By conventional methods for BVDV detection, only 2 of 20 commercial batches of FBS had BVDV. Using cell cultures maintained with high concentrations of the serum under study for at least 2 weeks, with detection of viral antigen by indirect immunofluorescence, the percentage of BVDV detection was 80. This method shows that most lots of commercial FBS contain BVDV. RT-PCR allows faster detection of the viral genome, but it must be validated, as it does not show viral replication. To eliminate the problem of BVDV contamination in FBS, only gamma irradiated FBS is used in our laboratory.(AU)
Assuntos
Animais , Bovinos , Sangue/virologia , Vírus da Diarreia Viral Bovina/isolamento & purificação , Meios de CulturaRESUMO
Fetal bovine serum (FBS) used in cell culture may be contaminated with viruses, among them bovine viral diarrhea virus (BVDV) affecting the production of biological reagents and the results of diagnosis. The filtration process used in the preparation of commercial FBS abrogates most viral agents that may be present in raw FBS, but BVDV may pass through the filters because of its small size and its pleomorphism. While detection of bovine herpes virus-1 and parainfluenza-3 (PI-3) is determined by observation of the cytopathic effect, and also by hemadsorption in the case of PI-3, the most frequently isolated BVDV is non cytopathic, and infects cells without morphological alterations, inducing problems that arise after several cell generations. Batches of raw and processed FBS were analyzed. Frequencies of BVDV detection in raw serum in Argentina were similar to those published for USA. By conventional methods for BVDV detection, only 2 of 20 commercial batches of FBS had BVDV. Using cell cultures maintained with high concentrations of the serum under study for at least 2 weeks, with detection of viral antigen by indirect immunofluorescence, the percentage of BVDV detection was 80. This method shows that most lots of commercial FBS contain BVDV. RT-PCR allows faster detection of the viral genome, but it must be validated, as it does not show viral replication. To eliminate the problem of BVDV contamination in FBS, only gamma irradiated FBS is used in our laboratory.
Assuntos
Animais , Bovinos , Sangue , Vírus da Diarreia Viral Bovina/isolamento & purificação , Meios de CulturaRESUMO
Fetal bovine serum (FBS) used in cell culture may be contaminated with viruses, among them bovine viral diarrhea virus (BVDV) affecting the production of biological reagents and the results of diagnosis. The filtration process used in the preparation of commercial FBS abrogates most viral agents that may be present in raw FBS, but BVDV may pass through the filters because of its small size and its pleomorphism. While detection of bovine herpes virus-1 and parainfluenza-3 (PI-3) is determined by observation of the cytopathic effect, and also by hemadsorption in the case of PI-3, the most frequently isolated BVDV is non cytopathic, and infects cells without morphological alterations, inducing problems that arise after several cell generations. Batches of raw and processed FBS were analyzed. Frequencies of BVDV detection in raw serum in Argentina were similar to those published for USA. By conventional methods for BVDV detection, only 2 of 20 commercial batches of FBS had BVDV. Using cell cultures maintained with high concentrations of the serum under study for at least 2 weeks, with detection of viral antigen by indirect immunofluorescence, the percentage of BVDV detection was 80
. This method shows that most lots of commercial FBS contain BVDV. RT-PCR allows faster detection of the viral genome, but it must be validated, as it does not show viral replication. To eliminate the problem of BVDV contamination in FBS, only gamma irradiated FBS is used in our laboratory.
RESUMO
The word "prion" was created in 1982 to name the etiological agent of the transmissible spongiform encephalopathies (TSE), a group of degenerative diseases affecting central nervous system of man and animals, including bovine spongiform encephalopathy (BSE) and variant Creutzfeldt-Jakob disease (vCJD). Prions present two isoforms: PrPC, cellular or normal, which exists in all vertebrates and is sensitive to detergents and proteases, and PrPSc, disease associated, partially resistant. The molecular weight of both PrPC and PrPSc is 30-35 kD; after treatment with detergents and proteases PrPSc originates PrP27-30 (27-30 kD). PrPC is also denominated PrPsens, and PrPSc is PrPres. PrPSc and PrP27-30 cause disease. PrPC presents polymorphisms specifically associated with some TSE. The "prion hypothesis" says that PrPSc transmits its characteristic resistance to PrPC through conformational changes, and accumulation of the protein, without involvement of nucleic acids, causes disease. Most of the hypothesis has been demonstrated with transgenic mice, computer models and recombinant proteins, but the existence of strains of the TSE agents has not been explained. The description of similar mechanisms of propagation of protein conformational properties in Saccharomyces cereviseae has extended the meaning of the prion definition. Although the transmission of conformational changes between PrPC and PrPSc was experimentally shown, the pathogenesis of the TSE remains unknown. The relationship between BSE and vCJD is mentioned.(AU)
Assuntos
Animais , Humanos , Doenças Priônicas/virologia , Príons/fisiologia , Estrutura Quaternária de ProteínaRESUMO
The word "prion" was created in 1982 to name the etiological agent of the transmissible spongiform encephalopathies (TSE), a group of degenerative diseases affecting central nervous system of man and animals, including bovine spongiform encephalopathy (BSE) and variant Creutzfeldt-Jakob disease (vCJD). Prions present two isoforms: PrPC, cellular or normal, which exists in all vertebrates and is sensitive to detergents and proteases, and PrPSc, disease associated, partially resistant. The molecular weight of both PrPC and PrPSc is 30-35 kD; after treatment with detergents and proteases PrPSc originates PrP27-30 (27-30 kD). PrPC is also denominated PrPsens, and PrPSc is PrPres. PrPSc and PrP27-30 cause disease. PrPC presents polymorphisms specifically associated with some TSE. The "prion hypothesis" says that PrPSc transmits its characteristic resistance to PrPC through conformational changes, and accumulation of the protein, without involvement of nucleic acids, causes disease. Most of the hypothesis has been demonstrated with transgenic mice, computer models and recombinant proteins, but the existence of strains of the TSE agents has not been explained. The description of similar mechanisms of propagation of protein conformational properties in Saccharomyces cereviseae has extended the meaning of the prion definition. Although the transmission of conformational changes between PrPC and PrPSc was experimentally shown, the pathogenesis of the TSE remains unknown. The relationship between BSE and vCJD is mentioned.
Assuntos
Animais , Humanos , Doenças Priônicas/virologia , Príons , Estrutura Quaternária de ProteínaRESUMO
The word "prion" was created in 1982 to name the etiological agent of the transmissible spongiform encephalopathies (TSE), a group of degenerative diseases affecting central nervous system of man and animals, including bovine spongiform encephalopathy (BSE) and variant Creutzfeldt-Jakob disease (vCJD). Prions present two isoforms: PrPC, cellular or normal, which exists in all vertebrates and is sensitive to detergents and proteases, and PrPSc, disease associated, partially resistant. The molecular weight of both PrPC and PrPSc is 30-35 kD; after treatment with detergents and proteases PrPSc originates PrP27-30 (27-30 kD). PrPC is also denominated PrPsens, and PrPSc is PrPres. PrPSc and PrP27-30 cause disease. PrPC presents polymorphisms specifically associated with some TSE. The "prion hypothesis" says that PrPSc transmits its characteristic resistance to PrPC through conformational changes, and accumulation of the protein, without involvement of nucleic acids, causes disease. Most of the hypothesis has been demonstrated with transgenic mice, computer models and recombinant proteins, but the existence of strains of the TSE agents has not been explained. The description of similar mechanisms of propagation of protein conformational properties in Saccharomyces cereviseae has extended the meaning of the prion definition. Although the transmission of conformational changes between PrPC and PrPSc was experimentally shown, the pathogenesis of the TSE remains unknown. The relationship between BSE and vCJD is mentioned.
Assuntos
Doenças Priônicas/virologia , Animais , Humanos , Príons/fisiologia , Estrutura Quaternária de ProteínaRESUMO
Bovine Viral Diarrhea Virus (BVDV) is a pathogen of cattle, member of the family Flaviviridae, genus pestivirus, which also includes Classical Swine Fever Virus (CSFV, or hog cholera virus), and Border Disease Virus of sheep (BDV). It causes important economical losses associated mainly with reproductive failure. Pestiviruses are small enveloped viruses, with a diameter of about 40 nm. The nucleocapsid is probably icosahedral . The genome consists of a single stranded positive RNA, encoding approximately 430 kD of proteic product. Genetic expression consists of the synthesis of a polyprotein which is co- and post-translationally processed. According to its behavior "in vitro" two biotypes can be distinguished: non cytopathic (ncp) and cytopathic (cp), most probably derived from the ncp through mutations and/or recombination. BVDV is able to cross the placenta and infect the fetus, causing a variety of problems, from fetal death to the birth of a persistently infected (P) calf, according to the fetal age at the time of infection. PI animals are immunotolerant to the virus and shed it in all secretions. Only the ncp biotype has been isolated from PI animals. The superinfection of a PI animal with a cp strain causes mucosal disease, always fatal. Outbreaks of a severe, sometimes hemorrhagic disease, caused by ncp BVDV, have occurred in Canada and USA since 1993. Genomic and serological differences between the "traditional" strains and the viruses isolated from these outbreaks led to the division of BVDV in subtypes I and II, both including cp and ncp strains. Analyses of the non coding 5'-UTR zone of the genome of pestiviruses from different species (bovine, ovine, porcine) suggest that there are at least 3 genotypes within the genus. A new classification of these viruses, based on genomic sequence instead of species of origin, has been proposed. Genomic heterogeneity exists in the BVDV genome, which presents 3 hypervariable zones, 2 of them in the major neutralizing protein. In Argentina prevalence of BVDV antibodies in cattle population is 70%, and the prevalence of persistent infections is around 1%.
Assuntos
Vírus da Diarreia Viral Bovina , Aborto Animal/epidemiologia , Aborto Animal/virologia , Animais , Anticorpos Antivirais/sangue , Variação Antigênica , Antígenos Virais/genética , Argentina/epidemiologia , Doença das Mucosas por Vírus da Diarreia Viral Bovina/epidemiologia , Doença das Mucosas por Vírus da Diarreia Viral Bovina/prevenção & controle , Doença das Mucosas por Vírus da Diarreia Viral Bovina/virologia , Bovinos , Efeito Citopatogênico Viral , Vírus da Diarreia Viral Bovina/classificação , Vírus da Diarreia Viral Bovina/genética , Vírus da Diarreia Viral Bovina/imunologia , Vírus da Diarreia Viral Bovina/fisiologia , Vírus da Diarreia Viral Bovina/ultraestrutura , Feminino , Doenças Fetais/veterinária , Doenças Fetais/virologia , Genoma Viral , Gravidez , Complicações Infecciosas na Gravidez/veterinária , Complicações Infecciosas na Gravidez/virologia , PrevalênciaRESUMO
PIP: Bolivia is one of the poorest and least developed countries in South America. As of mid-1997, the country's population was comprised of 7.8 million individuals spread across 418,680 square miles. Bolivia's population size is growing through natural increase at the rate of 2.6% per year, with 36 births and 10 deaths per 1000 population. Bolivia's total population size is projected to reach 13.2 million by 2025. The total fertility rate is 4.8 births per woman even though the 1994 Demographic and Health Survey found that only 45% of pregnancies were wanted and the average woman has reported wanting only 2.5 children. 42% of women at risk of pregnancy use some form of contraception, with 18% using a modern method. There are 71 infant deaths per 1000 live births, child mortality is especially high between ages 1 and 3 years due to widespread child malnutrition after weaning, 650 women die for every 100,000 births, and life expectancy is 59 and 62 years for men and women, respectively. Concern over the high infant and child mortality rates has led to increased interest in family planning in recent years and the government of Bolivia now provides some support for the distribution of contraceptives.^ieng