RESUMO
Schistosoma haematobium plays a central role in the development of bladder cancer in Burkina Faso. The objective of this study was to determine the presence of S. haematobium in the bladder cancer and in vector snails. For the first time, formalin-fixed tissues embedded in paraffin were analyzed by immunohistochemistry and PCR. Molecular detection has resulted in 7/7 positive bladder cancer. Finally, as the snail vectors were positive. We suggest the use of molecular methods in the snail vectors for the detection of cysts and in cancerous tissues in larger studies.
Assuntos
Carcinoma de Células Escamosas/etiologia , Carcinoma de Células Escamosas/parasitologia , Oocistos/patologia , Schistosoma haematobium/isolamento & purificação , Esquistossomose Urinária/complicações , Caramujos/parasitologia , Neoplasias da Bexiga Urinária/etiologia , Neoplasias da Bexiga Urinária/parasitologia , Animais , Burkina Faso , Vetores de Doenças , Ovos , Humanos , Schistosoma haematobium/genética , Schistosoma haematobium/metabolismo , Esquistossomose Urinária/parasitologiaRESUMO
Fixation is a critical step in the preparation of tissues for histopathology. The objective of this study was to investigate the effects of different fixatives vs formalin on proteins and DNA, and to evaluate alternative fixation for morphological diagnosis and nucleic acid preservation for molecular methods. Forty tissues were fixed for 24 h with six different fixatives: the gold standard fixative formalin, the historical fixatives Bouin and Hollande, and the alternative fixatives Greenfix, UPM and CyMol. Tissues were stained (Haematoxylin-Eosin, Periodic Acid Schiff, Trichromic, Alcian-blue, High Iron Diamine), and their antigenicity was determined by immunohistochemistry (performed with PAN-CK, CD31, Ki-67, S100, CD68, AML antibodies). DNA extraction, KRAS sequencing, FISH for CEP-17, and flow cytometry analysis of nuclear DNA content were applied. For cell morphology the alternative fixatives (Greenfix, UPM, CyMol) were equivalent to formalin. As expected, Hollande proved the best fixative for morphology. The morphology obtained with Bouin was comparable to that with formalin. Hollande was the best fixative for histochemistry. Bouin proved equivalent to formalin. The alternative fixatives were equivalent to formalin, although with greater variability in haematoxylin-eosin staining. It proved possible to obtain immunohistochemical staining largely equivalent to that following formalin-fixation with the following fixatives: Greenfix, Hollande, UPM and CyMol. The tissues fixed in Bouin did not provide results comparable to those obtained with formalin. The DNA extracted from samples fixed with alternative fixatives was found to be suitable for molecular analysis.
Assuntos
Alendronato/farmacologia , Conservadores da Densidade Óssea/farmacologia , Fixadores/farmacologia , Histocitoquímica/métodos , Côndilo Mandibular/ultraestrutura , Microscopia Eletrônica de Transmissão/métodos , Animais , Matriz Extracelular , Proteínas da Matriz Extracelular/metabolismo , Feminino , Formaldeído/farmacologia , Masculino , Côndilo Mandibular/metabolismo , Proteoglicanas/metabolismo , Ratos , Ratos WistarRESUMO
Defects in energy metabolism and oxidative stress play an important role in the pathogenesis of Alzheimer's Disease (AD). In sporadic AD cases, presenilin 2 (PS2) mRNA levels are decreased in brain areas affected by the disease. The aim of the present study was to investigate whether mitochondrial dysfunction might influence PS2 gene expression. We demonstrated that the inhibition of energy metabolism by sodium azide down-regulates PS2 gene expression through modification of promoter activity. No one of the analyzed transcription factors, sensitive to redox status of the cell, could explain this effect. Azide effect on PS2 expression was completely inhibited by the addition of an antioxidant suggesting that the imbalance of the cellular redox homeostasis modulates the expression of this gene.
