The influence of adipocyte-derived stem cells (ASCs) on the ischemic epigastric flap survival in diabetic rats

PURPOSE: To assess the effects of adipocyte-derived stem cell (ASC)-injection on the survival of surgical flaps under ischemia in diabetic rats. METHODS: Diabetes was induced in 30 male Wistar rats using streptozotocin (55 mg/kg). After eight weeks, epigastric flap (EF) surgery was performed. The animals were divided into control (CG), medium-solution (MG), and ASC groups. The outcomes were: the survival area (SA), the survival/total area rate (S/TR), and expression levels (EL) of genes: C5ar1, Icam1, Nos2, Vegf-a. RESULTS: In the ASC group, compared to CG, we observed improved flap SA (CG-420 mm(2) vs. ASC-720 mm(2); p=0.003) was observed. The S/TR analysis was larger in the ASC group (78%) than the CG (45%). This study showed an increase in the Vegf-a EL in the ASC group (2.3) vs. CG (0.93, p=0.0008). The Nos2 EL increased four-fold in the ASC group compared to CG, and C5ar1 EL decreased almost two-fold in the ASC group vs. the CG (p=0.02). There was no difference among the groups regarding Icam1 EL. Compared to the MG, the ASC group had a bigger flap SA (720 mm(2) vs. 301 mm(2), respectively), a bigger S/TR (78% vs. 32%, p=0.06, respectively) and increased EL of Vegf-a (2.3 vs. 1.3, respectively). No difference between ASC-group and MG was seen regarding Nos2 (p=0.08) and C5ar1 (p=0.05). CONCLUSIONS: This study suggests that ASCs increase the survival of EF under IR in diabetic rats

Effect of antileukotriene treatment on capsular contracture: an experimental study

Introduction: 40% of patients undergoing radiotherapy after breast reconstruction by silicone prosthesis implant may develop prosthesis encapsulation. Several strategies have already been tested to prevent capsule contracture with unsatisfactory results. This study analyzed the effect of topical antileukotriene (AL) on capsular contracture formation in rats with silicone implants associated with irradiation. Methods: Silicone blocks were implanted in the dorsal region in 20 female rats Wistar with weights ranging from 200-250g. The animals were divided into two groups: control (injection of 0.9% saline solution into the tissue around the implant) and intervention group (injection of 10mg of AL into the tissue around the implant). Immediately after surgery, the animals were irradiated with a single dose of 10Gy. After two months, we collected capsule samples for histological analysis and gene expression analysis of the following biomarkers: iNOS, VEGF-a and MMP-9. Results: Vascular density was lower in the AL group when compared to the control group (55.4±30.0 vs. 81.8±26.7, p=0.05, respectively). Similarly, VEGF-a had the same behavior (control group - 0.34±0.1 vs. group Al - 0.02±0.001, p=0.04). Conclusion: This study suggested that treatment with AL decreases angiogenesis in animals submitted to silicone implants and underwent radiotherapy

HOXB7 mRNA is overexpressed in pancreatic ductal adenocarcinomas and its knockdown induces cell cycle arrest and apoptosis

Background\ud Human homeobox genes encode nuclear proteins that act as transcription factors involved in the control of differentiation and proliferation. Currently, the role of these genes in development and tumor progression has been extensively studied. Recently, increased expression of HOXB7 homeobox gene (HOXB7) in pancreatic ductal adenocarcinomas (PDAC) was shown to correlate with an invasive phenotype, lymph node metastasis and worse survival outcomes, but no influence on cell proliferation or viability was detected. In the present study, the effects arising from the knockdown of HOXB7 in PDAC cell lines was investigated.\ud \ud Methods\ud Real time quantitative PCR (qRT-PCR) (Taqman) was employed to assess HOXB7 mRNA expression in 29 PDAC, 6 metastatic tissues, 24 peritumoral tissues and two PDAC cell lines. siRNA was used to knockdown HOXB7 mRNA in the cell lines and its consequences on apoptosis rate and cell proliferation were measured by flow cytometry and MTT assay respectively.\ud \ud Results\ud Overexpression of HOXB7 mRNA was observed in the tumoral tissues and in the cell lines MIA PaCa-2 and Capan-1. HOXB7 knockdown elicited (1) an increase in the expression of the pro-apoptotic proteins BAX and BAD in both cell lines; (2) a decrease in the expression of the anti-apoptotic protein BCL-2 and in cyclin D1 and an increase in the number of apoptotic cells in the MIA PaCa-2 cell line; (3) accumulation of cell in sub-G1 phase in both cell lines; (4) the modulation of several biological processes, especially in MIA PaCa-2, such as proteasomal ubiquitin-dependent catabolic process and cell cycle.\ud \ud Conclusion\ud The present study confirms the overexpression of HOXB7 mRNA expression in PDAC and demonstrates that decreasing its protein level by siRNA could significantly increase apoptosis and modulate several biological processes. HOXB7 might be a promising target for future therapies.This study was supported in part by a FAPESP grant 2010/01421-1

Identification of differentially expressed genes in NASH-related cirrhosis

A doença hepática gordurosa não alcoólica (DHGNA) compreende um amplo espectro morfológico de doenças com potencial de progressão em pacientes sem história de etilismo. Pode evoluir para esteatohepatite não alcoólica (EHNA), fibrose, cirrose e carcinoma hepatocelular. Com intuito de investigar as diferenças genéticas entre tecido hepático normal e cirrose secundária a EHNA, utilizamos microarranjos de oligonucleotídeos (CodeLink Uniset Human Whole Genome Bioarray System GE Healthcare - Bio-Sciences, Chalfont St. Giles, UK) para caracterizar os perfis de expressão nas duas condições. Analisamos 3 amostras de cirrose secundária a EHNA e 3 amostras de fígado normal provenientes de doadores durante o transplante hepático. Para a análise dos dados utilizamos o programa GenesifterTM analysis (VizX Labs LLC, Seattle, WA, USA; http://www.genesifter.net) para identificar os genes diferencialmente expressos e também as vias biológicas moduladas de acordo com a ontologia gênica. Posteriormente, para avaliarmos a expressão imunohistoquímica utilizamos a técnica de microarranjo tecidual em amostras de fígado normal (n=12), cirrose secundária a EHNA (n=10) e cirroses de outras etiologias (n=37). Identificamos 244 genes significativamente alterados em pelo menos 2 vezes. Destes, 138 genes apresentavam-se com expressão aumentada e 106 genes com expressão diminuída na cirrose secundária a EHNA comparados ao fígado normal. Foram selecionadas 9 vias metabólicas significativamente desreguladas. Dentre estas vias identificadas na cirrose secundária a EHNA, selecionamos a via de sinalização do mTOR e seu efetor 4EBP-1 para a análise da expressão protéica. Houve aumento significativo na expressão de 4EBP-1 no fígado normal comparado às outras cirroses, assim como na cirrose secundária a EHNA versus outras cirroses. Quanto à forma fosforilada houve apenas diferença na expressão entre fígado normal e cirroses de outras etiologias. A expressão de mTOR mostrou aumento significativo entre cirroses de outras etiologias quando comparadas ao fígado normal e cirrose secundária a EHNA. A expressão de mTOR fosforilado foi maior na cirrose secundária a EHNA quando comparada às cirroses de outras etiologias e fígado normal. Estudos recentes têm sugerido o papel do mTOR na DHGNA e o presente estudo corrobora a participação desta via também na cirrose secundária a EHNA. A avaliação imunohistoquímica de 4EBP-1 e mTOR fosforilado pode ser útil clinicamente para o diagnóstico diferencial entre cirrose secundária a EHNA versus cirroses de outras etiologias, quando a etiologia é desconhecidaNon-alcoholic fatty liver disease (NAFLD) encompasses the whole spectrum of steatosis, non-alcoholic steatohepatitis (NASH), and NASH-related cirrhosis (NASH/Cir). NASH/Cir can progress to hepatocellular carcinoma and reoccur post transplantation. Although molecular advances have been made in this field, the patogenesis of NAFLD is not completely understood. In an effort to investigate genetic differences between normal liver and NASH/Cir, first we used cDNA microarray (CodeLink Uniset Human Whole Genome Bioarray System GE Healthcare - Bio-Sciences, Chalfont St. Giles, UK) in normal liver from donor liver wedge biopsies taken at transplantation (n=3) and confirmed NASH/Cir tissues (n=3) and GenesifterTM analysis (VizX Labs LLC, Seattle, WA, USA; http://www.genesifter.net) to identify differentially expressed genes and biological pathways according to gene ontology (GO). Second, tissue microarray was used to determine immunohistochemical expression in normal liver samples (n=12), NASH/Cir (n=10) and in cirrhosis of other etiologies (n=37). Analysis of microarray data resulted in 244 genes changed in at least 2-fold with statistically significant ratio: 138 and 106 genes were, respectively, up and downregulated in NASH/Cir in comparison to normal liver. GO analysis by GeneSifterTM software identified nine statistically significant pathways containing differentially expressed genes. Among the 9 pathways identified as significantly modulated in NASH/Cir, we selected mTOR pathway and its downstream effector for immunohistochemical analysis. There was a significant increase in the expression of 4EBP-1 in normal liver compared to the other cirrhosis, as well as to NASH/Cir versus other cirrhosis. The phosphorylated 4EBP-1 showed only difference in expression between normal liver and cirrhosis of other etiologies. The expression of mTOR showed a significant increase in other cirrhosis when compared with normal liver and NASH/Cir. The expression of phosphorylated mTOR was higher in NASH/Cir when compared to other cirrhosis and normal liver. Recent findings have suggested a role for the cellular nutrient sensor mTOR in NAFLD and the present study corroborates the participation of this pathway in NASH/Cir. 4EBP-1 and phospho-mTOR evaluation might be of clinical utility as differential diagnostic of NASH/Cir from other cirrhosis, without knowing etiolog

Biocompatibilidade do polímero da mamona comparada ao implante de titânio para corações artificiais: estudo experimental em cobaias Biocompatibility of Ricinus comunnis polymer compared to titanium implant used in artificial hearts: experimental study in guinea pigs

OBJETIVO: Determinar se a reação tecidual do implante retroperitoneal do polímero de óleo de mamona (Pm) é significativa ou não por meio de análise histopatológica, tendo como controle o implante de titânio (Ti). MÉTODOS: Estudo experimental, intervencionista e randomizado com 32 cobaias. Os animais foram divididos em quatro grupos iguais e eutanasiados com 7, 20, 30 e 40 dias após o ato cirúrgico. Foram confeccionadas lâminas em hematoxilina-eosina e em tricrômio de Masson. Na comparação dos tipos de material em relação a variáveis quantitativas, foi considerado o teste não-paramétrico de Wilcoxon. Em relação a essas variáveis, os grupos definidos pelo dia do sacrifício foram comparados usando-se o teste não-paramétrico de Kruskal-Wallis. Os resultados obtidos no estudo da fibrose foram expressos por frequ��ncias e percentuais. Para a comparação entre os grupos definidos pelo dia do sacrifício, em relação a variáveis qualitativas dicotômicas da fibrose, foi considerado o teste exato de Fisher. Para avaliar a diferença entre os materiais titânio e polímero em cada grupo, ainda em se tratando da fibrose, foi considerado o teste binomial. Valores de P<0,05 indicaram significância estatística. RESULTADOS: A análise das variáveis quantitativas não demonstrou diferença nas reações teciduais entre os materiais (P>0,05). A análise da variável qualitativa também não demonstrou diferença entre as reações teciduais dos materiais (P>0,05). CONCLUSÃO: Não foi encontrada significância estatística entre a reação tecidual do Pm e do Ti.<br>OBJECTIVE: The aim of the present investigation is to determine if the tissue reaction to the Riccinus communis (mamona) polymer has significant statistical difference compared to the tissue reaction provoked by the titanium implant. METHODS: Thirty two Cavia porcellus were divided into four groups containing eight animals each one. We implanted the two types of materials in the retroperitoneal space of all the animals. They were sacrificed at 7, 20, 30 and 40 days after surgery and the samples were submitted to histological study. RESULTS: The quantitative analysis did not show difference between the tissue reaction of the two materials (P>0.05). The analysis of the qualitative variable also did not show difference between the tissue reaction of the materials (P>0.05). CONCLUSION: Macroscopic and microscopic results showed that the castor oil polymer implant has no significant statistical difference compared to the titanium implant tissue reaction