Histology and histopathology Vol.24, nº2 (2009)
Ir a Estadísticas
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- PublicationOpen AccessAberrant nuclear beta-catenin expression in the spindle or corded cells in so-called corded and hyalinized endometrioid carcinomas. Another critical role of the unique morphological feature(Murcia : F. Hernández, 2009) Wani, Yoji; Saegusa, Makoto; Notohara, KenjiCorded and hyalinized endometrioid carcinoma (CHEC), showing spindle and/or corded (SPICO) cells often in the background of hyalinized stroma, is a rare variant of uterine endometrioid carcinomas. The aim of our study was to explore the status of cell-adhesion molecules (beta-catenin, Ecadherin) in CHECs and to survey whether immunostains for beta-catenin and p53 can help to distinguish CHECs from their morphological mimics: malignant mixed mullerian tumors (MMMTs) and uterine tumors resembling ovarian sex-cord tumors (UTROSCTs). Immunohistochemistry was performed and scored for each element as follows: 0: negative, 1+: <10% positive cells, 2+: 10-30%, 3+: >30%. The SPICO patterns were classified as spindle/fusiform; 3, corded; 1, and both; 2. SPICO components consisted of <10%: 4, 10-30%: 1, >30%: 1. Five contained squamous components. In SPICO elements of all CHECs, nuclear beta-catenin expression (score: 1+; 1, 2+; 2, 3+; 3) and complete loss of membranous expression of E-cadherin was observed. In contrast, comparable components (sarcomatous ones for eight MMMTs or sex-cord-like ones for six UTROSCTs) showed no nuclear positivity for beta-catenin. p53 expression was observed in SPICO (64.7%), sarcomatous (87.5%), and sex-cord-like (50%) components, and sarcomatous areas of most MMMTs notably showed diffuse and intense staining. Sequence analysis of PCR amplification products of exon 3 of the beta-catenin gene revealed mutation in all cases, except two lacking SPICO components represented on microdissected areas. Our results suggest that alterations in beta-catenin/E-cadherin complex play a critical role in SPICO features. Immunostain for beta-catenin and p53 is a promising approach for distinguishing CHECs from MMMTs and UTROSCTs
- PublicationOpen AccessIntracellular signalling pathways regulating the adaptation of skeletal muscle to exercise and nutritional changes(Murcia : F. Hernández, 2009) Matsakas, Antonios; Patel, KetanThe focus of the present review is to assimilate current knowledge concerning the differing signalling transduction cascades that control muscle mass development and affect skeletal muscle phenotype following exercise or nutritional uptake. Effects of mechanical loading on protein synthesis are discussed. Muscle growth control is regulated by the interplay of growth promoting and growth suppressing factors, which act in concert. Much emphasis has been placed on understanding how increases in the rate of protein synthesis are induced in skeletal muscle during the adaptive process. One key point to emerge is that protein synthesis following resistance exercise or increased nutrient availability is mediated through changes in signal transduction involving the phosphorylation of mTOR and sequential activation of downstream targets. On the other hand, AMPK activation plays an important role in the inhibition of protein synthesis by suppressing the function of multiple translation regulators of the mTOR signalling pathway in response to cellular energy depletion and low metabolic conditions. The effects of exercise and/or nutritional uptake on the activation of signalling molecules that regulate protein synthesis are highlighted, providing a better understanding of the molecular changes in the cell.
- PublicationOpen AccessDistribution of cytoskeletal and adhesion proteins in adult zebrafish skeletal muscle(Murcia : F. Hernández, 2009) Câmara-Pereira, E.S.; Campos, L.M.; Vannier-Santos, M.A.; Mermelstein, C.S.; Costa, M.L.The organization of cytoskeletal and adhesion proteins in skeletal muscle is critical for its contractile function. Zebrafish has become a paramount model for studies of vertebrate biology, including muscle. However, only a few studies have been published using immunolabeling to specifically localize proteins in adult zebrafish muscle. To fully appreciate the distribution of cytoskeletal and adhesion proteins, and therefore to better correlate the adult muscle with its myogenesis, we used indirect immunofluorescence microscopy of frozen adult zebrafish skeletal muscle sections. Here we describe the fish muscle cytoskeletal architecture and location of the major myofibrillar proteins desmin, alpha-actinin, myosin, titin, troponin, tropomyosin and nebulin, the adhesion proteins vinculin and paxillin, and the extracellular matrix proteins laminin and fibronectin. Electron microscopical analysis in ultra-thin sections of adult zebrafish skeletal muscle showed bundles of collagen fibers and fibroblastic cells in the extracellular space of the myosepta.
- PublicationOpen AccessCritical role of IkB kinase alpha in embryonic skin development and skin carcinogenesis(Murcia : F. Hernández, 2009) Zhu, Feng; Park, Eunmi; Liu, Bigang; Xia, Xiaojun; Fischer, Susan M.; Hu, YinlingIκB kinase alpha (IKKα), IKKß, and IKKγ/NEMO form the IKK complex, which is essential for NF-κB activation. However, genetic studies have shown that the role of IKKα is distinct from that of IKKß or IKKγ in the development of the mouse embryonic skin. Loss of IKKα has been shown to cause epidermal hyperplasia, prevent keratinocyte terminal differentiation, and impair the formation of the skin, resulting in the deaths of IKKα-deficient (Ikkα -/-) mice soon after birth. Recent experimental data from several laboratories have revealed that IKKα functions as a tumor suppressor in human squamous cell carcinomas (SCCs) of skin, lungs, and head and neck. Chemical carcinogenesis studies using mice have shown that reduction in IKKα expression increases the number and size of Ras-initiated skin tumors and promotes their progression, indicating that reduced IKKα expression provides a selective growth advantage that cooperates with Ras activity to promote skin carcinogenesis. In this review, we will summarize these findings from our and other studies on the role that IKKα plays in development of the mouse embryonic skin and skin carcinogenesis
- PublicationOpen AccessTracing the accumulation and effects of mercury uptake in the previtellogenic ovary of crucian carp Carassius auratus gibelio by autometallography and caspase-3 immunohistochemistry(Murcia : F. Hernández, 2009) Zarnescu, OtiliaThe aims of the present study were to apply the AMG technique for localization of mercury at the light and electron microscopic level in the ovary of crucian carp after exposure to mercuric chloride and to find out if this heavy metal induces expression of caspase-3. Depending on the stage of ovarian follicle development, two patterns of mercury accumulation have been found in previtellogenic ovary of crucian carp. The first mercury accumulation pattern has been found in the early previtellogenic oocyte without zona radiata. In these oocytes, mercury accumulates into an ooplasmic region that seems to correspond to the Balbiani body (32-65 μm oocyte diameter), throughout the cytoplasm (84-116 μm oocyte diameter) and in the cortical cytoplasm (~180 μm oocyte diameter). The second mercury accumulation pattern has been found in the late previtellogenic oocyte with cortical alveoli (229- 330 μm oocyte diameter). Ultrastructural observations have shown grains of silver-enhanced mercury inside coated vesicles, the cortical lysosome-like bodies or multivesicular bodies and cortical alveoli. Immunohistochemistry reaction for caspase-3 was positive in nuclei of the early previtellogenic oocyte and Balbiani body.
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