Average volume of mitochondrion, nucleous, heterochromatin and euchromatin in hexamethylene bisacetamide (HMBA) induced human colonic carcinoma cell line (Lovo)

Synopses of Paperspostprin

Nuclear and cell membrane surface area alteration in hexamethylene bisacetamide (HMBA) induced human colonic carcinoma cell line (LoVo)

Synopses of Paperspostprin

Stereology of the thyroid gland in Indo-Pacific bottlenose dolphin (Tursiops aduncus) in comparison with human (Homo sapiens) : quantitative and functional implications

Author name used in this publication: Kot, Brian Chin Wing.Author name used in this publication: Lau, Thomas Yue HuenVersion of RecordPublishe

Expression and functions of vasoactive substances regulated by hypoxia-inducible factor-1 in chronic hypoxemia

The aims of the present review are to summarize and to discuss the role of hypoxia-inducible factor-1 (HIF-1) and the expression and functions of vasoactive substances in chronic hypoxemia with specific focus in the liver and the carotid body. Vascular remodelling and vasoactive substances play important functional roles in the adaptive response to chronic hypoxemia for the maintenance of oxygen homeostasis in all systems in man. HIF-1 regulates the gene expression of vasoactive substances such as vascular endothelial growth factor (VEGF), endothelin-1 (ET-1) and enzymes for producing nitric oxide (NO). Recent studies have shown the effect of chronic hypoxia on the expression of HIF-1α and HIF-1-target genes in multiple organ systems including the liver and the carotid body. Results are consistent with increases in the hematocrit levels, pulmonary arterial pressure and right heart mass developed during chronic hypoxia. In addition, the carotid body is also hyperplastic and increases in organ mass with increased levels of HIF-1α and the vasoactive substances. These molecules increase the mitotic activity and modulate the excitability of the chemoreceptor. Intriguingly, the liver morphology, serum alanine aminotransferase and 8-isoprostane levels are within normal range in chronic hypoxia, suggesting the absence of significant oxidative stress. Yet, the HIF-1α is upregulated and the mRNA and protein levels of VEGF, ET-1, inducible and constitutive NO synthases are elevated in the liver during chronic hypoxia. In conclusion, the adaptive response to long-term hypoxemia involves compensatory mechanisms mediated by expressing significant levels of HIF-1α and vasoactive substances regulated by HIF-1. © 2006 Bentham Science Publishers Ltd.link_to_subscribed_fulltex

Cyclooxygenase inhibitors protect d-galactosamine/lipopolysaccharide induced acute hepatic injury in experimental mice model

We investigated the protective effects of two non-steroid anti-inflammatory drugs, indomethacin (COX-1 and COX-2 inhibitors) and nimesulide (specific COX-2 inhibitor) on the hepatic injury induced by lipopolysaccharide in d-galactosamine sensitized (Gal/LPS) mice. ICR male mice were injected with a single dose of Gal/LPS with or without pre-treatment of 3. mg/kg indomethacin or 30. mg/kg nimesulide (single i.p. injection). Sixteen hours later, blood and liver tissues of mice were collected for histological, molecular, and biochemical analyses. Our results showed marked reduction of hepatic necrosis, serum ALT, and tissue TBARS levels in both indomethacin- and nimesulide-pre-treated mice when compared with Gal/LPS-treated mice. Western blot and RT-PCR analysis showed decreased levels of iNOS mRNA, iNOS protein, and nitrotyrosine formation in both COX inhibitor pre-treated groups when compared with Gal/LPS-treated group. There was an inverse relationship between COX-1 and COX-2 expressions, as well as between COX-2 and C/EBP-α expressions in COX inhibitors groups, Gal/LPS and control groups. COX inhibitors reduced the expression of TNF-α mRNA and the activity of NF-κB which were elevated by Gal/LPS treatment. We conclude that COX inhibitors protected the liver from Gal/LPS-induced hepatotoxicity. COX inhibitors could be considered as potential agents in the prevention of acute liver failure and sepsis. © 2011 Elsevier Ltd.link_to_subscribed_fulltex

Hypoxia-inducible factor-1 (HIF-1) in hepatic adaptation to chronic hypoxia

Polymethyl methacrylate (PMMA) is a kind of typical amorphous polymer, whose main mechanical property is viscoelasticity that can be of great importance in materials characterization and nondestructive evaluation (NDE). On the other hand, ultrasonic NDE technique is one of the basic methods to characterize polymeric materials. By the measurements of the velocity and attenuation of the bulk waves as a function of frequency and temperature [1–3], the moduli of PMMA can be deduced and various relaxation phenomena can be investigated. However, as we know, the studies on the SAW attenuation of PMMA have not been reported. It is difficult for the contact ultrasonic method to do so because the effect of the electric transducers working in the contact way on the SAW field can not be avoided. Some disadvantages of using electronic ultrasonic method to characterize polymers, such as the measurement must be made in the immersion apparatus and the piezoelectric transducers with different frequencies must be used to obtain the attenuation spectra etc. have been overcome by the means of the laser ultrasonic technique [4,5]. The noncontact nature of the laser ultrasonic technique can also eliminate the effect of the contact measurement on the SAW field and make it convenient for the measurement at elevated temperatures. Therefore the laser ultrasonic technique is extremely suitable for the study on the attenuation of SAW