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Objective: To determine the branching patterns of the inferior mesenteric artery (IMA) and to describe the clinical applicability of computed tomography (CT) angiography in the evaluation of these vessels to facilitate the planning of colorectal cancer surgery. Materials and Methods: We included 100 patients who underwent CT angiography of the abdomen and pelvis. The branching patterns of the IMA were examined and classified as type 1 (bifurcated), including 1A (sigmoid and left colic arteries arising from a common trunk), 1B (sigmoid and superior rectal arteries arising from a common trunk) and 1C (sigmoid arteries arising from both trunks); type 2 (trifurcated); and type 3 (no left colic branch). Results: Among the 100 patients evaluated, we found the variant to be type 1A in 9%, type 1B in 47%, type 1C in 24%, type 2 in 16%, and type 3 in 4%. Conclusion: Preoperative CT angiography for evaluating the IMA branching pattern could inform decisions regarding the surgical approach to colorectal cancer.
Objetivo: Determinar os padrões de ramificação da artéria mesentérica inferior (AMI) e descrever a aplicabilidade clínica da angiografia por tomografia computadorizada na avaliação desses vasos na elaboração das estratégias pré-operatórias de cirurgia de câncer colorretal. Materiais e Métodos: Foram incluídos 100 pacientes submetidos a angiografia por tomografia computadorizada abdominal e pélvica. Os padrões de ramificação da AMI foram examinados e classificados como tipo 1 (bifurcado), incluindo 1A (artérias sigmoide e cólica esquerda originando-se de um tronco comum), 1B (artérias sigmoide e retal superior originando-se de um tronco comum) e 1C (artérias sigmoide originando-se de ambos os troncos); tipo 2 (trifurcado); e tipo 3 (sem ramo cólico esquerdo). Resultados: Do total de participantes incluídos no estudo, a variante do tipo 1A foi observada em 9%, a do tipo 1B em 47%, e a do tipo 1C em 24%. Com relação à variante tipo 2, esta foi observada em 16% dos pacientes, e a do tipo 3, em 4% dos casos.Conclusão O uso da angiografia por tomografia computadorizada pré-operatória para avaliar o padrão de ramificação da AMI pode ajudar a escolher a abordagem cirúrgica no câncer colorretal.
RESUMO
Abstract Objective: To determine the branching patterns of the inferior mesenteric artery (IMA) and to describe the clinical applicability of computed tomography (CT) angiography in the evaluation of these vessels to facilitate the planning of colorectal cancer surgery. Materials and Methods: We included 100 patients who underwent CT angiography of the abdomen and pelvis. The branching patterns of the IMA were examined and classified as type 1 (bifurcated), including 1A (sigmoid and left colic arteries arising from a common trunk), 1B (sigmoid and superior rectal arteries arising from a common trunk) and 1C (sigmoid arteries arising from both trunks); type 2 (trifurcated); and type 3 (no left colic branch). Results: Among the 100 patients evaluated, we found the variant to be type 1A in 9%, type 1B in 47%, type 1C in 24%, type 2 in 16%, and type 3 in 4%. Conclusion: Preoperative CT angiography for evaluating the IMA branching pattern could inform decisions regarding the surgical approach to colorectal cancer.
Resumo Objetivo: Determinar os padrões de ramificação da artéria mesentérica inferior (AMI) e descrever a aplicabilidade clínica da angiografia por tomografia computadorizada na avaliação desses vasos na elaboração das estratégias pré-operatórias de cirurgia de câncer colorretal. Materiais e Métodos: Foram incluídos 100 pacientes submetidos a angiografia por tomografia computadorizada abdominal e pélvica. Os padrões de ramificação da AMI foram examinados e classificados como tipo 1 (bifurcado), incluindo 1A (artérias sigmoide e cólica esquerda originando-se de um tronco comum), 1B (artérias sigmoide e retal superior originando-se de um tronco comum) e 1C (artérias sigmoide originando-se de ambos os troncos); tipo 2 (trifurcado); e tipo 3 (sem ramo cólico esquerdo). Resultados: Do total de participantes incluídos no estudo, a variante do tipo 1A foi observada em 9%, a do tipo 1B em 47%, e a do tipo 1C em 24%. Com relação à variante tipo 2, esta foi observada em 16% dos pacientes, e a do tipo 3, em 4% dos casos. Conclusão O uso da angiografia por tomografia computadorizada pré-operatória para avaliar o padrão de ramificação da AMI pode ajudar a escolher a abordagem cirúrgica no câncer colorretal.
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The buoyancy of eggs and embryos is associated with successful development in pelagic fish. Buoyancy is the result of oocyte hydration, which depends on the osmotic force exerted by free amino acids (FAA) generated by yolk proteolysis, and cathepsins are the main enzymes involved in this process. Seriola lalandi is a pelagic fish whose farming has been hampered by development failure that have been partially attributed to decreased buoyancy of embryos. Therefore, the aim of this study was to compare the mRNA expression and activity of cathepsins B, D, and L, as well as the FAA content in floating and low-floating embryos at different developmental stages. The chosen stages were eggs, morula, blastula, gastrula and 24 h embryos. Complementary assessments showed that there were no differences attributed to buoyancy status in embryo and oil droplet diameters, as well as the transcriptional status at any developmental stage. Cathepsin B did not show differences in mRNA expression or activity related to buoyancy at any stage. Cathepsin D displayed higher transcript and activity levels only in low-floating eggs compared with those floating. Cathepsin L showed higher expression in floating eggs and 24 h embryos compared with that of low-floating, but the activity of this enzyme was higher in floating eggs and morula. Total FAA content constantly decreased throughout development in floating embryos, but it was always higher than low-floating embryos until gastrula stage. In 24 h embryos floating and low-floating embryos share similar quantities of FAA. In summary, differences in the expression and activity of cathepsins between floating and low-floating embryos could be revealed at specific embryonic stages, suggesting different functions of these enzymes throughout development. Besides 24 h embryos, FAA content seems to be a decisive factor for buoyancy of embryos during early development of S. lalandi. Overall, considering the main role of cathepsins and FAA in buoyancy acquisition process and therefore in both embryo quality and viability, our study identifies good marker candidates to evaluate embryo quality in the farming of this species.
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The domestic cat (Felis catus) has become a worldwide threat to wildlife. The potential impact of owned cats on wildlife in Chile has not been documented at a large scale. The purpose of this study was to investigate the number and type of prey that owned cats bring back in Chile and its relation with responsible ownership practices. An online survey was distributed to 5216 households that included questions about the type of pet, responsible ownership practices, and in the case of cats, the type of prey they brought home. Descriptive statistics as well as univariate and multivariate logistic regression analysis were applied. The results showed that 94.3% of respondents had a pet, and from these, 49.9% had at least one cat. A total of 84.1% of owners reported that their cats had brought back prey. Birds were the most common type of prey, followed by mammals and insects. Not being registered with a microchip, not having a litter box, living in a house with access to a garden, not having a hiding place for the cats, and having free access to the outdoors significantly increased the odds of cats bringing back prey. Body condition score or providing ad libitum food to cats did not have an effect on bringing prey.
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Flavobacterium psychrophilum is the etiologic agent of rainbow trout fry syndrome (RTFS). This pathogen infects a wide variety of salmonid species during freshwater stages, causing significant losses in the aquaculture industry. Rainbow trout (Oncorhynchus mykiss) infected with F. psychrophilum, presents as the main external clinical sign ulcerative lesions and necrotic myositis in skeletal muscle. We previously reported the in vitro cytotoxic activity of F. psychrophilum on rainbow trout myoblast, however little is known about the molecular mechanisms underlying the in vivo pathogenesis in skeletal muscle. In this study, we examined the transcriptomic profiles of skeletal muscle tissue of rainbow trout intraperitoneally challenged with low infection dose of F. psychrophilum. Using high-throughput RNA-seq, we found that 233 transcripts were up-regulated, mostly associated to ubiquitin mediated proteolysis and apoptosis. Conversely, 189 transcripts were down-regulated, associated to skeletal muscle contraction. This molecular signature was consistent with creatine kinase activity in plasma and oxidative damage in skeletal muscle. Moreover, the increased caspase activity suggests as a whole skeletal muscle atrophy induced by F. psychrophilum. This study offers an integrative analysis of the skeletal muscle response to F. psychrophilum infection and reveals unknown aspects of its pathogenesis in rainbow trout.
Assuntos
Doenças dos Peixes/genética , Infecções por Flavobacteriaceae/veterinária , Flavobacterium/fisiologia , Oncorhynchus mykiss/genética , Transcriptoma , Animais , Aquicultura , Doenças dos Peixes/microbiologia , Doenças dos Peixes/patologia , Infecções por Flavobacteriaceae/genética , Infecções por Flavobacteriaceae/microbiologia , Infecções por Flavobacteriaceae/patologia , Interações Hospedeiro-Patógeno , Músculo Esquelético/metabolismo , Músculo Esquelético/microbiologia , Músculo Esquelético/patologia , Oncorhynchus mykiss/microbiologiaRESUMO
The clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) system has been widely used in animals as an efficient genome editing tool. In fish cells, the technique has been difficult to implement due to the lack of proper vectors that use active promoters to drive the expression of both small guide RNA (sgRNA) and the S. pyogenes Cas9 (spCas9) protein within a single expression platform. Until now, fish cells have been modified using co-transfection of the mRNA of both the sgRNA and the spCas9. In the present study, we describe the optimization of a new vector for the expression of a CRISPR/Cas9 system, designed to edit the genome of fish cell lines, that combines a gene reporter (mCherry), sgRNA, and spCas9 in a single vector, facilitating the study of the efficiency of piscine and non-piscine promoters. A cassette containing the zebrafish U6 RNA III polymerase (U6ZF) promoter was used for the expression of the sgRNA. The new plasmid displayed the expression of spCas9, mCherry, and sgRNA in CHSE/F fish cells. The results demonstrate the functionality of the mammalian promoter and the U6ZF promoter in fish cell lines. This is the first approach aimed at developing a unified genome editing system in fish cells using bicistronic vectors, thus creating a powerful biotechnological platform to study gene function.
Assuntos
Proteína 9 Associada à CRISPR/metabolismo , Sistemas CRISPR-Cas/genética , Peixes/genética , Vetores Genéticos/metabolismo , Animais , Linhagem Celular , Genoma , Células HEK293 , Humanos , Mutação/genética , Regiões Promotoras Genéticas , RNA Guia de Cinetoplastídeos/metabolismo , Ribonuclease III/metabolismo , Peixe-ZebraRESUMO
The Flavivirus genus includes a large number of medically relevant pathogens that cycle between humans and arthropods. This host alternation imposes a selective pressure on the viral population. Here, we found that dengue virus, the most important viral human pathogen transmitted by insects, evolved a mechanism to differentially regulate the production of viral non-coding RNAs in mosquitos and humans, with a significant impact on viral fitness in each host. Flavivirus infections accumulate non-coding RNAs derived from the viral 3'UTRs (known as sfRNAs), relevant in viral pathogenesis and immune evasion. We found that dengue virus host adaptation leads to the accumulation of different species of sfRNAs in vertebrate and invertebrate cells. This process does not depend on differences in the host machinery; but it was found to be dependent on the selection of specific mutations in the viral 3'UTR. Dissecting the viral population and studying phenotypes of cloned variants, the molecular determinants for the switch in the sfRNA pattern during host change were mapped to a single RNA structure. Point mutations selected in mosquito cells were sufficient to change the pattern of sfRNAs, induce higher type I interferon responses and reduce viral fitness in human cells, explaining the rapid clearance of certain viral variants after host change. In addition, using epidemic and pre-epidemic Zika viruses, similar patterns of sfRNAs were observed in mosquito and human infected cells, but they were different from those observed during dengue virus infections, indicating that distinct selective pressures act on the 3'UTR of these closely related viruses. In summary, we present a novel mechanism by which dengue virus evolved an RNA structure that is under strong selective pressure in the two hosts, as regulator of non-coding RNA accumulation and viral fitness. This work provides new ideas about the impact of host adaptation on the variability and evolution of flavivirus 3'UTRs with possible implications in virulence and viral transmission.
Assuntos
Adaptação Biológica/genética , Culicidae/virologia , Vírus da Dengue/genética , Aptidão Genética/genética , RNA Viral/genética , Regiões 3' não Traduzidas/genética , Animais , Northern Blotting , Dengue/genética , Variação Genética , Genoma Viral , Interações Hospedeiro-Patógeno/genética , Humanos , Insetos Vetores/virologia , Filogenia , Reação em Cadeia da Polimerase , TransfecçãoRESUMO
Resumen: Objetivo Comprender la iniciación sexual en mujeres con prácticas homoeróticas en cuatro ciudades del Eje Cafetero Colombiano. Métodos . Una encuesta biográfica fue aplicada en 2012 a 308 mujeres haciendo uso de las técnicas de RDS (Respondent Driven Sampling) y bola de nieve. Resultados . El 83,7% de las mujeres manifestó sentir atracción por otra mujer antes de los 18 años; un 67.5% había tenido en su curso biográfico relaciones sexuales con hombres y con mujeres. Las mujeres mayores de 40 años tardaron más tiempo en reconocer su atracción homoerótica y presentan altos porcentajes de iniciación heterosexual (79,6%), previa a la homosexual. Conclusiones. El debut sexual entre mujeres presenta diferencias entre cohortes, notándose una aceleración del evento entre las jóvenes y una cada vez mayor iniciación sexual con personas del mismo sexo. Los hallazgos confirman que en la construcción del deseo se imbrican, de manera problemática, la homosexualidad y la heterosexualidad.
Resumo: O objetivo do estudo foi compreender a iniciação sexual em mulheres com práticas sexuais homoeróticas em quatro cidades na região cafeeira da Colômbia. Foi aplicado um levantamento biográfico, em 2012, a 308 mulheres usando técnicas RDS (Respondent Driven Sampling) e bola de neve. Para a análise das informações foram definidos coortes de nascimentos. 83,7% das mulheres relataram se sentirem atraídas por outra mulher antes dos 18 anos, 67,5% tiveram sexo com homens e mulheres no seu curso biográfico. Mulheres com mais de 40 anos de idade levaram mais tempo para reconhecer a sua atração homossexual e têm altas taxas de iniciação heterossexual (79,6%), pré-homossexual. Os resultados indicam que a iniciação sexual entre as mulheres apresenta diferenças entre coortes, observando-se uma aceleração do evento entre jovens e um crescimento na iniciação sexual com pessoas do mesmo sexo. Os resultados confirmam que na construção do desejo se sobrepõem problematicamente homossexualidade e heterossexualidade.
Abstract: Objective . The aim of the study was to understand sexual initiation in women who have sex with women in four cities of the Colombian Coffee triangle. Methods . A biographical survey was applied in 2012 to 308 women using the RDS (Respondent Driven Sampling) and snowball techniques. For information analysis birth cohorts were defined. Results . 83.7% of women said they felt attracted to another woman before the age of 18; 67.5% had had sex with men and women in their biographical course. Women over age 40 took longer to recognize their homosexual attraction and have high rates of heterosexual initiation (79.6%), before homosexual practices. Conclusions . The results indicate that sexual initiation among women are differences between cohorts, with a notable acceleration of the event among young people and a growing sexual initiation with people of the same sex. The findings confirm that the fields of homosexuality and heterosexuality overlap problematically in the construction of desire.
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Humanos , Feminino , Adulto , Comportamento Sexual/estatística & dados numéricos , Mulheres , Homossexualidade Feminina/estatística & dados numéricos , Sexualidade , Minorias Sexuais e de Gênero , Acontecimentos que Mudam a Vida , Colômbia , Sexualidade Oculta , Normas de GêneroRESUMO
El problema ético de la huelga de hambre ha dado cabida a soluciones contrapuestas, incluso en el contexto de teorías éticas que rechazan el suicidio. Algunos piensan que la sola honestidad del fin subjetivo basta para justificar la acción del huelguista. Otros, aunque son minoría, sostienen que la huelga de hambre es un acto reprobable per se, porque implica un atentado directo contra la vida o salud del sujeto. En este trabajo se defiende esta última interpretación. A juicio de los autores, la huelga de hambre es un caso de suicidio intencional. Luego, nunca es lícito, bajo ningún aspecto, llevar adelante una acción de esta naturaleza.
The ethical problem of hunger strikes has accommodated competing solutions, even in the context of ethical theories that reject suicide. Some believe the honesty of the subjective goal is enough in itself to justify the hunger striker's action. Others, although they are a minority, argue a hunger strike is a reprehensible act per se, because it implies a direct attempt on the person's life or health. This paper defends the second interpretation. According to the authors, a hunger strike is a case of intentional suicide. Therefore, it is never in any way licit to perform an act of this nature.
O problema ético da greve de fome tem proporcionado soluções contraditórias, inclusive no contexto das teorias éticas que rejeitam o suicídio. Alguns pensam que somente a honestidade do fim subjetivo basta para justificar a ação de quem faz a greve. Outros, embora sejam minoria, sustentam que a greve de fome é um ato reprovável por si porque implica um atentado direto contra a vida ou saúde do sujeito. Neste trabalho, defende-se esta última interpretação. No entender dos autores, a greve de fome é um caso de suicídio intencional. Portanto, nunca é lícito, sob nenhum aspecto, levar adiante uma ação dessa natureza.
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Humanos , Suicídio , Saúde , Jejum , Vida , JulgamentoRESUMO
Rapid and reliable detection and classification of infectious bursal disease viruses (IBDVs) is of crucial importance for disease surveillance and control. This study presents the development and validation of a real-time RT-PCR assay to detect and discriminate very virulent (vv) from non-vv (classic and variant) IBDV strains. The assay uses two fluorogenic, minor groove-binding (MGB) TaqMan probes targeted to a single nucleotide polymorphism (SNP) embedded in a highly conserved genomic region. The analytical sensitivity of the assay was determined using serial dilutions of in vitro-transcribed RNA. The assay demonstrated a wide dynamic range between 10(2) and 10(8) standard RNA copies per reaction. Good reproducibility was also detected, with intra- and inter-assay coefficients of variation ranging from 0.13% to 2.23% and 0.26% to 1.92%, respectively. The assay detected successfully all the assessed vv, classical, and variant field and vaccine strains and correctly discriminated all vvIBDV strains from non-vvIBDV strains. Other common avian RNA viruses tested negative, indicating high specificity of the assay. The high sensitivity, rapidity, reproducibility, and specificity of the real-time RT-PCR assay make this method suitable for general and genotype-specific detection and quantitation.
Assuntos
Vírus da Doença Infecciosa da Bursa/classificação , Vírus da Doença Infecciosa da Bursa/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Virologia/métodos , Animais , Infecções por Birnaviridae/virologia , Primers do DNA/genética , Vírus da Doença Infecciosa da Bursa/genética , Vírus da Doença Infecciosa da Bursa/patogenicidade , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
A hepatitis A virus (HAV) recovered in Argentina from a stool sample of a sick child in the year 2006 (HAV-Arg/06) was entirely sequenced. Phylogenetic analysis included the HAV-Arg/06 sequence in subgenotype IA, either considering the usual VP1-2A variable junction fragment or the full length nucleotide sequence. Interestingly, a recombination event with subgenotype IB, involving a portion of the 2C-3A nonstructural proteins coding region (nucleotides 4961-5140) was detected using specific software. Only subgenotype IA strains have been detected in Argentina or Uruguay, whereas subgenotype IA and IB strains have been reported to circulate in Brazil. Although recombination has been given an important role in the evolution of picornaviruses, there have been only a few reports of its involvement in the evolution of HAV, probably due to the limited number of complete HAV sequences available. This study constitutes the first report of a full-length HAV sequence in Argentina and the third in South America, after the sequence of the IA isolate HAV5 from Uruguay and the IB isolate HAF-203 from Brazil. The availability of new sequence data covering the complete HAV genome will help establish a more consistent genetic relatedness among HAV isolates and the role of recombination in its evolution.
Assuntos
Genoma Viral , Vírus da Hepatite A/genética , Vírus da Hepatite A/isolamento & purificação , Hepatite A/virologia , RNA Viral/genética , Recombinação Genética , Análise de Sequência de DNA , Argentina , Pré-Escolar , Análise por Conglomerados , Fezes/virologia , Vírus da Hepatite A/classificação , Humanos , Dados de Sequência Molecular , Filogenia , Proteínas Virais/genéticaRESUMO
A type A avian influenza (AI) virus was isolated from dead or severely ill red-winged tinamous (Rhynchotus rufescens) found in a hunting ground in April 2008 in Argentina. The subtype of A/red-winged tinamou/Argentina/MP1/2008 was determined as H1N1 by sequence analysis. The cleavage site of the viral hemagglutinin corresponded to a low pathogenic influenza virus, although the clinical presentation and pathological studies suggest that the virus was pathogenic for red-winged tinamous. Phylogenetic analysis of the viral genome suggested that while the hemagglutinin and neuraminidase genes were related to AIV from North America, the internal genes were most closely related to other South American isolates. These findings support the postulated South American phylogenetic lineage for AIV PB2, PB1, PA, M and NS genes, and suggest that the evolutionary pathways of HA and NA genes involve exchanges between the Northern and Southern hemispheres.
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Aves/virologia , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Animais , Argentina , Sequência de Bases , Testes de Inibição da Hemaglutinação , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Vírus da Influenza A Subtipo H1N1/classificação , Influenza Aviária/diagnóstico , Influenza Aviária/patologia , Dados de Sequência Molecular , Neuraminidase/genética , Filogenia , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
El cáncer gástrico es una patología de muy alta incidencia y mortalidad en Chile, razón que motivó su incorporación al programa de garantías explícitas en salud, GES, desde el 1º de julio de 2006. El propósito de este estudio es evaluar el efecto de este programa sobre el acceso al diagnóstico y tratamiento oportuno de esta neoplasia, para lo cual se analizaron datos secundarios obtenidos a partir de fichas clínicas, informes de Endoscopía Digestiva Alta y Biopsias, realizadas a 76 pacientes tratados quirúrgicamente por diagnóstico de cáncer gástrico entre el 1º de julio 2003 hasta el 30 de junio de 2007 en un hospital del SSMS. Los resultados mostraron que en contra de lo esperado, no hubo cambios significativos en el número de pacientes operados. De hecho, en comparación a años anteriores el número de gastrectomías por cáncer gástrico fue menor, realizándose sólo 12 en el período Post-Auge en comparación a las 16,33 gastrectomías/año del período precedente, lo que representa una disminución del 26,53%; sin haber cambios significativos en la proporción por sexo y la edad de los pacientes. En cuanto a las garantías explícitas, hubo incumplimiento de plazos en, al menos, 2 de los 12 pacientes con diagnóstico de cáncer gástrico e indicación de resección quirúrgica. Las razones por la cual los resultados del Auge no se tradujeron en mayor número de cirugías y en un cumplimiento total de los plazos garantizados, son múltiples y no necesariamente excluyentes entre sí, y debieran ser objeto de análisis en estudios posteriores.
Gastric cancer is a pathology with a high prevalence and mortality rate in Chile. In view of the latter, such condition was incorporated to the explicit health guarantees program (GES) from July 1st 2006. The purpose of the present study is to assess the impact of such program on the access to a timely diagnosis and treatment for such neoplasia. This was achieved through the analysis of secondary data obtained from medical records, Upper GI Endoscopy and Biopsy reports, from 76 patients having undergone surgery for gastric cancer between July 1st 2003 and June 30th 2007 at a SSMS hospital of operated patients. In fact, compared to previous years, the number of gastrectomies for Gastric Cancer was smaller, with 12 procedures carried out during the Post-AUGE period, as compared to 16,33 gastrectomies/year during the previous period. This represents a decrease in 26,53%, without significant proportional changes per patient gender and age. As for the explicit guarantees, there was non-fulfillment of the assured deadlines in at least 2 of the 12 patients with a diagnosisof gastric cancer and an indication for surgical therapy. The reasons why the AUGE outcomes did not result in a greater number of surgeries and in a total fulfillment of the guaranteed deadlines are manifold and not necessarily mutually excluding, and should be subject of analysis in further studies.
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Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso de 80 Anos ou mais , Avaliação de Programas e Projetos de Saúde , Gastrectomia/estatística & dados numéricos , Neoplasias Gástricas/cirurgia , Acessibilidade aos Serviços de Saúde , Chile , Distribuição por Idade e Sexo , Estudos Prospectivos , Neoplasias Gástricas/diagnóstico , Saúde PúblicaRESUMO
Chagas' disease is routinely diagnosed by detecting specific antibodies (Abs) using serological methods. The methodology has the drawback of potential cross-reactions with Abs raised during other infectious and autoimmune diseases (AID). Fusion of DNA sequences encoding antigenic proteins is a versatile tool to engineer proteins to be used as sensitizing elements in serological tests. A synthetic gene encoding a chimeric protein containing the C-terminal region of C29 and the N-terminal region of TcP2beta was constructed. A 236-serum panel, composed of 104 reactive and 132 nonreactive sera to Chagas' disease, was used to evaluate the performance of the chimera. Among the nonreactive sera, 65 were from patients with AID (systemic lupus erythematosus and rheumatoid arthritis) or patients infected with Leishmania brasiliensis, Brucella abortus, Streptococcus pyogenes, or Toxoplasma gondii. The diagnostic performances of the complete TcP2beta (TcP2betaFL) and its N-terminal region (TcP2betaN) were evaluated. TcP2betaFL showed unspecific recognition toward leishmaniasis (40%) and AID Abs (58%), while TcP2betaN showed no unspecific recognition. The diagnostic utility of the chimera was evaluated by analyzing reactivity and comparing the results with those obtained with TcP2betaN. The chimera reactivity was higher than that of the peptide fractions (0.874 versus 0.564 optical density, P = 0.0017). The detectability and specificity were both 100% for the whole serum panel tested. We conclude that the obtained chimera shows an improved selectivity and sensitivity compared with other ones previously reported, therefore displaying an optimized performance for Trypanosoma cruzi infection diagnosis.
Assuntos
Antígenos de Protozoários/metabolismo , Doença de Chagas/diagnóstico , Proteínas Recombinantes de Fusão/metabolismo , Animais , Antígenos de Protozoários/genética , Humanos , Dados de Sequência Molecular , Proteínas Recombinantes de Fusão/genética , Sensibilidade e Especificidade , Trypanosoma cruzi/isolamento & purificaçãoRESUMO
Infectious bursal disease (IBD) viruses detected in commercial flocks of different regions of Argentina were analyzed by reverse transcription-polymerase chain reaction-restriction fragment length polymorphism (RFLP) of a VP2 gene fragment, followed by sequence analysis. Two out of eight IBD viruses presented an SspI restriction site, typical of the very virulent phenotype. Three IBD viruses presented a SacI restriction site, typical of classic virulent strains, and one isolate presented restriction sites for both enzymes. The Argentine IBD viruses showed three different molecular patterns by RFLP with the restriction endonuclease BstNI and five different patterns with MboI. By comparison of nucleotide and deduced amino acid sequences of the hypervariable region of the VP2 protein, four Argentine viruses were found to be closely related to Brazilian subclinical strains and two isolates were found to be related to vaccine IBDV strains in use in Argentina. Strain LD9569 was genetically characterized as a very virulent strain and was found to be closely related to international and regional vvIBDV strains. This is the first report on variability of IBDV strains circulating in Argentina.