Browsing by Subject "Congestion"

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    Atrophic hepatocytes express keratin 7 in ischemia-associated liver lesions
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2016) Delladetsima, Ioanna; Sakellariou, Stratigoula; Kokkori, Aikaterini; Tiniakos, Dina
    Aim: To investigate atrophic parenchymal changes in ischemic liver conditions. Design: We studied 18 cases of hepatic lesions with atrophic changes due to altered blood flow (hepatic venous congestion n=15 including 4 cases with additional nodular regenerative hyperplasia-NRH, NRH n=1, and antiphospholipid syndrome with patchy parenchymal atrophy n=2). Metaplastic hepatocellular changes, hepatocyte proliferation, hepatic stellate cell (HSC) activation, and sinusoidal capillarization were examined immunohistochemically with antibodies to keratins (K) 7 and 19, Ki67, αSMA and CD34, respectively. Results: K7 was positive and K19 was negative in zone 3 atrophic hepatocytes in venous congestion and in areas of plate atrophy, as well as in congested or compressed sites in NRH. Sinusoidal CD34-positivity indicating capillarization accompanied K7 immunoexpression. Masson trichrome revealed sinusoidal fibrosis to be restricted in atrophic areas, usually mild and in 7 cases focally dense. αSMA expression expanded beyond K7- positive areas. Ki67 was negative in K7-positive hepatocytes. Conclusion: Ischemic parenchymal changes are characterized by hepatocyte K7 immunoexpression, sinusoidal capillarization, HSC activation and lack of cellular proliferation, indicating an early reaction of the major liver parenchyma cellular components creating a more resistant microenvironment. These phenotypic alterations may prove valuable in the discrimination of ischemic liver lesions.
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    Nonconstant reputation effect in a dynamic tourism demand model for Spain
    (2016) Albaladejo Pina, Isabel; González Martínez, María Isabel; Martínez-García, María Pilar; Métodos Cuantitativos para la Economía y la Empresa
    Following the ideas of the Tourism Area Life Cycle (TALC) theory, we propose a dynamic econometric model for tourism demand where the reputation effect (the effect of the lagged demand on the current tourism demand) is not constant, but dependent on congestion. We test the model using panel data from Spanish regions during the period 2000-2013. Two estimations are performed depending on whether the tourists’ origin is domestic or international. The results show that the reputation effect is not constant in both estimates, supporting the idea that tourism congestion influences tourist arrivals in Spain