Estudo comparativo da análise citológica e histopatológica de massas cutâneas e subcutâneas em cães e gatos

Dissertação de Mestrado Integrado em Medicina VeterináriaA análise citológica consiste num exame complementar que pode ser fonte de informação diagnóstica relevante para qualquer clínico de pequenos animais. De baixo custo e de relativa facilidade de execução, a análise citológica pode facilmente ser integrada nos exames de diagnóstico proporcionados por qualquer centro veterinário. A avaliação microscópica das amostras citológicas pode ser feita diretamente pelo clínico, sendo requerida alguma dedicação e prática, ou serem enviadas para laboratórios externos onde são avaliadas por profissionais experientes. Por outro lado, a análise histopatológica é considerada análise de eleição para o diagnóstico de massas tumorais, incluindo as cutâneas e subcutâneas. Embora a análise histopatológica consiga na grande maioria dos casos identificar claramente a origem celular da neoplasia, fornecendo informações indispensáveis para o correto seguimento clínico, tratamento e prognóstico, trata-se de um exame que necessita de uma colheita de material realizada de forma mais invasiva e de um maior processamento da amostra. No caso da citologia a colheita e a visualização da lâmina são muito rápidos. O objetivo deste estudo retrospetivo foi então compreender a correlação entre as análises citológica e histopatológica, comparando os diversos diagnósticos alcançados através das duas análises. A amostra consiste num total de 65 lesões, provenientes de 41 (89,4%) cães e 5 (10,6%) gatos, recolhidas entre 2009 e 2013. Destas 65 lesões apenas 60 (92,3%) foram incluídas no estudo, já que 5 (7,7%) foram consideradas inconclusivas e sem valor de diagnóstico. Todas as amostras depois de colhidas por punção aspirativa por agulha fina, foram depois avaliadas no Hospital Veterinário do Oeste. Já as análises histopatológicas foram enviadas para os laboratórios INNO® e Segalab® após exérese cirúrgica das massas. Os resultados foram depois analisados, concluindo que as neoplasias mais diagnosticadas foram as de células redondas, com destaque para os mastocitomas, neoplasia mais comumente diagnosticada, representado cerca de 33,3% do total de lesões analisadas. A neoplasia benigna mais comumente diagnosticada foi o adenoma das glândulas perianais com 25,0% do total de de neoplasias. Na verificação dos diagnósticos obtidos, a concordância entre as duas análises ficou provada em 84,6% dos casos.ABSTRACT - Comparative Study of the Cytologic and Hystopatologic Analyses of Cutaneous and Subcutaneuos Masses from Cats and Dogs - The cytologic analysis is a diagnostic procedure that can be a valuable source of information for Veterinarians. This analysis can easily be done in every veterinary center due to its low cost and moderate difficulty. With some dedication and technique the cytologic specimens can be microscopicly evaluated by the veterinarian or sent to an external laboratory to be evaluated by experienced professionals. Despite its numerous advantages (easiness of sample collection, rapidity of results and low cost), to achieve a definitive diagnosis, the cytologic analysis is not the most reliable of the complementary exams. Thus, for cutaneous and subcutaneous masses, the histopathology is considered the golden method to achieve a definitive diagnosis. Although the histopathologic exam can, in most of the cases, identify the cellular origin of the mass and provide crucial information for a correct clinical follow-up, treatment and prognostic, the sample collection is more aggressive and requires a longer processing time. As far as the cytologic examination is concerned, the collection and evaluation of samples is almost immediate. This retrospective study aimed to evaluate the correlation between cytologic and histopathologic analysis.The study was based in 65 lesions (41 from dogs (89,4%) and 5 from cats (10,6%)) collected between 2009 and 2013. However, only 60 lesions (92,3%) were taken in consideration as the remaining 5 (7,7%) were unsatisfactory and therefore excluded from the study. After proceeding with the fine-needle aspiration biopsy the samples were sent to and processed in the laboratory of the Hospital Veterinario do Oeste. After surgical excision, the histopathologic samples were sent to external laboratories: INNO® and Segalab®. The round cell tumors were the most diagnosed ones with 36,4%, where mastocitomas represented 33,3% of all lesions. The perianal gland tumor was the most beningn neoplasia diagnosed, representing 25% of all lesions. The correlation of both analyses was proven in 84,6% of the cases studied

The genome of Peronospora belbahrii reveals high heterozygosity, a low number of canonical effectors and CT-rich promoters

Along with Plasmopara destructor, Peronosopora belbahrii has arguably been the economically most important newly emerging downy mildew pathogen of the past two decades. Originating from Africa, it has started devastating basil production throughout the world, most likely due to the distribution of infested seed material. Here we present the genome of this pathogen and results from comparisons of its genomic features to other oomycetes. The assembly of the nuclear genome was ca. 35.4 Mbp in length, with an N50 scaffold length of ca. 248 kbp and an L50 scaffold count of 46. The circular mitochondrial genome consisted of ca. 40.1 kbp. From the repeat-masked genome 9049 protein-coding genes were predicted, out of which 335 were predicted to have extracellular functions, representing the smallest secretome so far found in peronosporalean oomycetes. About 16 % of the genome consists of repetitive sequences, and based on simple sequence repeat regions, we provide a set of microsatellites that could be used for population genetic studies of Pe. belbahrii. Peronospora belbahrii has undergone a high degree of convergent evolution, reflecting its obligate biotrophic lifestyle. Features of its secretome, signalling networks, and promoters are presented, and some patterns are hypothesised to reflect the high degree of host specificity in Peronospora species. In addition, we suggest the presence of additional virulence factors apart from classical effector classes that are promising candidates for future functional studies

Comparative genomics including the basal pathogen Peronospora belbahrii reveal common evolutionary patterns and the monophyly of downy mildews in a paraphyletic Phytophthora

The obligate biotrophic downy mildew constitute the most species rich group of oomycetes. So far only handful of genomes of this group of pathogens has been sequenced. Most likely due to low taxon sampling, until now phylogenomic studies with few taxa were in stark contrast to multigene phylogenies with a large number of accessions with respect to the relationships of downy mildews and Phytophthora species. In the current study, we sequenced the whole genome of the economically important basil pathogen Peronospora belbahrii, and performed in-depth comparative genomics and phylogenomics towards clarifying some aspects of downy mildew and Phytophthora evolution

Gene expression profiling during asexual development of the late blight pathogen Phytophthora infestans reveals a highly dynamic transcriptome

Much of the pathogenic success of Phytophthora infestans, the potato and tomato late blight agent, relies on its ability to generate from mycelia large amounts of sporangia, which release zoospores that encyst and form infection structures. To better understand these stages, Affymetrix GeneChips based on 15,650 unigenes were designed and used to profile the life cycle. Approximately half of P. infestans genes were found to exhibit significant differential expression between developmental transitions, with approximately (1)/(10) being stage-specific and most changes occurring during zoosporogenesis. Quantitative reverse-transcription polymerase chain reaction assays confirmed the robustness of the array results and showed that similar patterns of differential expression were obtained regardless of whether hyphae were from laboratory media or infected tomato. Differentially expressed genes encode potential cellular regulators, especially protein kinases; metabolic enzymes such as those involved in glycolysis, gluconeogenesis, or the biosynthesis of amino acids or lipids; regulators of DNA synthesis; structural proteins, including predicted flagellar proteins; and pathogenicity factors, including cell-wall-degrading enzymes, RXLR effector proteins, and enzymes protecting against plant defense responses. Curiously, some stage-specific transcripts do not appear to encode functional proteins. These findings reveal many new aspects of oomycete biology, as well as potential targets for crop protection chemicals

Large-scale gene discovery in the oomycete Phytophthora infestans reveals likely components of phytopathogenicity shared with true fungi

o overview the gene content of the important pathogen Phytophthora infestans, large-scale cDNA and genomic sequencing was performed. A set of 75,757 high-quality expressed sequence tags (ESTs) from P. infestans was obtained from 20 cDNA libraries representing a broad range of growth conditions, stress responses, and developmental stages. These included libraries from P. infestans¿potato and ¿tomato interactions, from which 963 pathogen ESTs were identified. To complement the ESTs, onefold coverage of the P. infestans genome was obtained and regions of coding potential identified. A unigene set of 18,256 sequences was derived from the EST and genomic data and characterized for potential functions, stage-specific patterns of expression, and codon bias. Cluster analysis of ESTs revealed major differences between the expressed gene content of mycelial and spore-related stages, and affinities between some growth conditions. Comparisons with databases of fungal pathogenicity genes revealed conserved elements of pathogenicity, such as class III pectate lyases, despite the considerable evolutionary distance between oomycetes and fungi. Thirty-seven genes encoding components of flagella also were identified. Several genes not anticipated to occur in oomycetes were detected, including chitin synthases, phosphagen kinases, and a bacterial-type FtsZ cell-division protein. The sequence data described are available in a searchable public database

Inheritance of molecular markers and sex in the Australian freshwater crayfish, Cherax destructor Clark

Inheritance of three kinds of molecular genetic markers (mtDNA, random-amplified polymorphic DNAs (RAPDs) and allozymes) and sex were investigated in crossbreeding experiments between three populations of the Australian freshwater crayfish Cherax destructor. Crossbreeding did not disrupt the ively maternally inherited, and allozyme and RAPD markers were transmitted following expected Mendelian principles for co-dominant and dominant traits respectively. Unlike these three markers, sex ratios were found to be distorted by crossbreeding in some families. Two crossbred families produced only females. The implications of these findings for freshwater crayfish population genetics, taxonomy and aquaculture are discussed.<br /