Qualitative analysis of the viability of autogenous fat grafts grafted in different environments of interstitial pressure. Preliminary results and description of a new experimental model in mini-pigs

Abstract Purpose: To evaluate the feasibility of an experimental model of autologous fat graft (AFG) in different interstitial pressure (IP) environments. Methods: Three mini-pigs(Minipig-BR) with age of 8 months (weight: 25-30 kg) were used. AFG were collected from the bucal fat pad, and grafted in the intramuscular pocket (biceps femoralis muscle). IP model was based on a fusiform ressection followed by primary closure "under tension". A blood pressure catheter located in the intramuscular region connected to a pressure module was applied to quantify IP. Results: The mean operative time was 236 min (210 - 272 min). All the AFG and muscular segments were removed successfully. Average interstitial pressure CP and H were 3 and 10.6 mmHg respectively. The AFG were biopsied for histopathological analysis 30 days after graft. Hematoxylin-eosin staining and immunohistochemical analyzes (TNF-alpha, CD31 and Perilipine with monoclonal antibodies) were employed. Conclusion: The data show that minipigs model could be used as a recipient site for autologous fat graft techniques and allow the development of studies to explore the AFG intake and pathophysiology response.

P16 and p27 Immunohistochemical Expression in Colorectal Cancer: Analysis of 128 Patients

P16 and p27 are inhibiting proteins of cyclin-dependent kinases (CDKIs) that act in the restriction points of the cellular cycle, and it avoids its progression to DNA verification and repair by the cellular apparatus. This way, there should be, physiologically, an inverse relation between the expression of these proteins and cellular proliferation. However, what is really observed are changeable amounts of p27 in normal and tumor tissues. P16 participation in tumorigenesis is controversial. The expression of p16 and p27 as a prognostic factor in colorectal cancer (CRC) patients is controversial. Objetive: To establish a correlation between p16 and p27 immunohistochemical expressions with clinical and anatomopathological variable from patients with CRC. Material and methods: descriptive and retrospective study, with 128 CRC patients, treated surgically between 2000 and 2004, with available material for immunohistochemical analysis through standardized methods. The association between categorical variables was done using Chi-square, Pearson or Fisher?s Exact tests, and the continuous variables were analyzed by t-Student. Global survival and disease-free period were calculated according to Kaplan-Meier method and the associations through log-rank test. Results: The average follow-up time of patients was 35 months. Positivity of p16 was detected in 100% of cases. Negativity of p27 in 6.3% (n=8) of cases, with a significant association (p30.05) between p27 negative and tumors located in right colon (62.5%, n=5) and mucinous (62.5%, n=5). The average global survival was 54.8 months, and the significant clinical and pathological variables associated to survival were: better for curative surgeries; better for early stages; better for well-differentiated tumors; worse for cases with sanguineous or vascular lymphatic invasion; worse for perineural invasion. Conclusions: p27 negative is more frequent in right colon...

Avaliação morfológica e molecular de lesões colônicas em modelo de colite experimental induzida por dextran sulfato de sódio / Morphological and molecular evaluation of colonic lesions in a mouse model of experimental colitis induced by Dextran Sulfate Sodium (DSS)

A retocolite ulcerativa (RU) é uma doença inflamatória crônica que caracteristicamente afeta o reto e o intestino grosso e cuja etiologia ainda é desconhecida. Os pacientes portadores de RU apresentam um alto risco para o desenvolvimento de câncer colorretal (CCR). O desenvolvimento e a progressão do câncer associado à RU envolvem vários eventos genéticos que parecem ser diferentes dos observados nos cânceres esporádicos... O modelo animal de colite através do uso de DSS desenvolve displasia e câncer muito similares aos observados em humanos. O estudo da carcinogênese do cólon nestes animais pode ser de grande valia para o melhor entendimento das alterações que ocorrem em humanos e pode proporcionar o descobrimento de novos marcadores ou mesmo regimes quimiopreventivos para o câncer relacionado à RU. O objetivo deste estudo é elucidar os eventos moleculares das neoplasias relacionadas à RU no modelo experimental animal de colite induzida por DSS, traçando um paralelo com os estudos moleculares realizados em humanos. Para isto, foram utilizadas duas abordagens. A primeira, relacionada com a pesquisa de alterações moleculares nas neoplasias originadas no modelo de colite pelo uso de DSS e Azoxymethane (AOM) em animais sadios, onde foram avaliados os genes Trp53, k-ras, Apc e ß-catenina. A segunda, relacionada com o uso de DSS em animais alterados geneticamente para o gene Trp53, considerado o evento inicial nos tumores associados à RU... Nos animais geneticamente alterados para o gene Trp53 a pesquisa de mutação no gene k-ras foi negativa. Estes animais demonstraram a presença de displasia e câncer, também muito similares aos humanos, sendo que os animais homozigotos (p53-/-) apresentaram uma maior incidência de lesões quando comparados aos animais heterozigotos (p53+/-) e controles p53 (+/+)...

Ulcerative Colitis (UC) is a diffuse inflammatory disease of the colorectum, which etiology is unknown. UC patients are at increased risk of developing colorectal cancer (CRC). Development and progression of UC-associated to CRC involves multiple genetic alterations that appear to be different from those of sporadic cancer. Alterations of APC gene and k-ras gene are less frequent than in sporadic colorectal neoplasia. Although, alterations of TP53 gene is a frequently observed in both UC associated tumors and sporadic tumors, this alteration is an early event in UC related tumors but it is occurs late in sporadic tumors. Dextran Sulfate Sodium (DSS) mouse colitis model develop dysplasia and cancer similar to UC in human. Studies of colon carcinogenesis in this model can be very useful to elucidate mechanisms and provide development of markers or hemoprevention approaches in the human situation. The aim of this study is to establish the molecular events in a DSS mouse colitis model associated neoplasia in parallel with the molecular alterations seen in humans. Two different approaches had been used to achieve this goal. First, investigate molecular events in neoplastic lesions developed in a mouse model of colitis using DSS in combination with Azoxymethane (AOM) in healthy animals. In this approach, it was investigate genes, such as Trp53, k-ras, ß-catenin and Apc. Second, evaluate genetic events in mice deficient in the Trp53 gene, considered an early event in RUassociated tumors. Besides k-ras evaluation, it was also evaluated the histological aspects of the colonic lesions in this model. ß-catenin mutation (codons 32 and 34) and translocation ß-catenin were observed in healthy animals using DSS/AOM. No mutation of k-ras and Apc were observed and Apc LOH was not informative. DSS induced colitis in p53 deficient mice developed dysplasia and cancer. p53-/- (homozygous) showed a higher incidence of tumors when compared with p53+/- (heterozygous) and p53+/+ (wild-type) animals. No mutation of k-ras gene was observed. Besides dysplasia and cancer, p53-/- and p53+/- animals developed colite cystica profunda and hyperplastic lesions, both observed in patients with UC. The further accumulation of data originated in studies with mouse models of colitis related-neoplasia chemically-induced should provide information for better understand UC- related colorectal neoplasia in humans (AU)

Carcinoma de pequenas células hipercalcêmico do ovário / Small cell carcinoma of the ovary with hypercalcemia

Objetivos: apresentar três casos recentes de carcinoma de pequenas células hipercalcêmico (CPCH) do ovário atendidos em nossa instituição quanto às suas características clínicas, diagnóstico e evolução pós-tratamento. Métodos: foram obtidos dados dos prontuários médicos arquivados no Serviço de Arquivo Médico e Estatística (SAME) com respeito às características epidemiológicas, clínicas e evolução, além de dados histopatológicos obtidos no Serviço de Anatomia Patológica dos três pacientes com diagnóstico de carcinoma de pequenas células hipercalcêmico do ovário. Resultados: as idades quando do diagnóstico foram de 26, 36 e 68 anos. O diâmetro tumoral variou de 8,8 a 23 cm, com média de 14 cm. Todas as pacientes apresentavam hipercalcemia, com cálcio total de 8,9, 10,8 e 16,7 mEq/dL (VN = 8,8 a 10,2) e cálcio iônico de 1,26, 1,27 e 1,21 mEq/dL (VN = 1,12 a 1,23), respectivamente. Todas as pacientes foram submetidas a cirurgia e esquemas de quimioterapia contendo platina. Duas pacientes que receberam quimioterapia adjuvante à cirurgia apresentam-se sem evidência de doença 2 e 18 meses depois. A outra paciente, que teve o diagnóstico inicial de tumor de células da granulosa, recebeu quimioterapia apenas após a recidiva e encontra-se viva com doença 32 meses após o diagnóstico. Conclusão: dentre os indicadores prognósticos de maior importância encontramos: o estádio inicial da neoplasia, a idade, a presença de hipercalcemia, tamanho tumoral, presença de grandes células, tipo de cirurgia realizada e tempo para início do tratamento. O tratamento ideal para o carcinoma de pequenas células do tipo hipercalcêmico permanece desconhecido, devido a múltiplos fatores, como: estadiamento inadequado, múltiplas abordagens e esquemas terapêuticos empregados, dificuldade no diagnóstico histológico inicial e raridade de casos.