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Aim: Transient elastography is known as a rapid, objective, and highly reliable technique for staging hepatic fibrosis caused by hepatitis C virus infection; however, the relationship between degree of fibrosis and the collagen deposition or the accumulation of myofibroblasts in non-alcoholic fatty liver disease (NAFLD) remains to be further elucidated. Methods: The subjects were 36 patients with NAFLD who received liver biopsy and liver stiffness measurement using transient elastography. Their clinical data and laboratory values were collected. Morphometric analyses of liver fibrosis indicated by collagen deposition and the relative numbers of myofibroblasts were performed. Results: Liver stiffness measured by transient elastography correlated with histopathological fibrosis staging of NAFLD determined by Brunt's scoring system ( P = 0.000149). The fibrosis staging correlated with the ratios of the Sirius red-positive area ( P = 0.000032) and α-smooth muscle actin-positive area ( P = 0.000898). Finally, liver stiffness significantly correlated with the ratios of the Sirius red-positive area ( r = 0.390, P = 0.0184) and α-smooth muscle actin-positive area ( r = 0.333, P = 0.0471). Conclusions: Liver stiffness measurement by transient elastography is valuable for evaluating fibrotic progression in NAFLD. [ABSTRACT FROM AUTHOR]

Endocytosis plays an important role in cell function and the activation and propagation of signaling pathways. Signaling occurs on endocytic pathways and signaling endosomes, and endocytosis is subjected to high-order regulation by cellular signaling mechanisms. Marginal cells showed active endocytosis of microperoxidase (MPO) via the clathrin-independent pathway. We examined the signaling pathway that regulates MPO endocytosis in marginal cells using specific inhibitors and activators of signaling molecules. The results showed that pertussis toxin - which inhibits the ribosylation of G-protein-coupled receptor - did not affect MPO endocytosis, but Clostridium botulinum C3 toxin - which induces RhoA inactivation resulting in extracellular-signal-related kinase inactivation - inhibited MPO endocytosis. The main endocytotic pathway of MPO did not depend on the Rho-associated protein kinase molecular switch or actin/myosin motor system, but was mainly regulated by the RhoA signaling cascade. Copyright © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Aim: The usefulness of transient elastography remains to be validated in chronic hepatitis B, particularly as a tool for monitoring the degree of liver fibrosis during treatment. Methods: The subjects were 50 patients with chronic hepatitis B virus infection. Liver biopsy was performed in 38 patients, and in 12 patients with platelet counts of 50 × 109/L or less, cirrhosis was clinically diagnosed on the basis of specific signs of portal hypertension. Liver stiffness was measured by transient elastography at baseline and after 12 months of treatment in 20 nucleos(t)ide-naïve patients who started entecavir within 3 months after study entry. Results: Twenty (40%) patients were classified as F1, 10 (20%) as F2, 5 (10%) as F3, and 15 (30%) as F4 (cirrhosis). Median liver stiffness (interquartile range) was 7.0 kPa (5.6–9.4), 9.8 kPa (5.6–14.7), 9.8 kPa (7.6–12.9), and 17.3 kPa (8.2–27.6) in fibrosis stages F1 to F4, respectively. Liver stiffness significantly correlated with fibrosis stage ( r = 0.46; P = 0.0014). Of the patients who started entecavir, median liver stiffness significantly decreased from 11.2 kPa (7.0–15.2) to 7.8 kPa (5.1–11.9; P = 0.0090) during 12 months of treatment. Median levels of amino-terminal peptide of type III procollagen and type IV collagen 7S domain in serum significantly decreased from 0.9 (0.6–1.3) to 0.6 (0.5–0.7) U/mL ( P = 0.0010) and from 5.0 (4.4–6.7) to 3.9 (3.2–4.4) ng/mL ( P = 0.015), respectively. Conclusion: Liver stiffness measurement can be useful for monitoring regression of liver fibrosis during entecavir treatment in patients with chronic hepatitis B virus infection. [ABSTRACT FROM AUTHOR]

AbstractEndocytosis of marginal cells plays a key role in maintaining the homeostasis of endocytosis and function of the organ of Corti. How the signaling cascade is involved in the regulation of endocytosis is an important issue at present. To investigate the regulation of endocytosis in marginal cells of the stria vascularis by the signaling network, we perfused MPO, an endocytosis tracer, with PMA, OA, staurosporin, PAO, PD98059, SB20580 or wortmannin into the cochlear duct. After 30 min endolymphatic perfusion, the tissues were fixed and the distribution of MPO was examined by electron microscopy. We explored the functions of PKC, RTK, PI3-K, PTP, and PP1/2A in MPO endocytosis and defined the MPO endocytic route. MPO endocytosis was strongly dependent on PKC, ERK, PTP, PP1/2A and PI3-K signaling networks, but not on PKA and MEK signaling networks. The MPO endocytic pathways are clathrin-, GPI-AP-, and caveolae-independent.Copyright © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Conclusion. Since many water channels and pumps, such as aquaporin (AQP) 1-4, AQP6-9, vasopressin type 2 receptor (V2-R), Na+-K+-Cl- cotransporter (NKCC) 1, and NKCC2 were expressed in the rat endolymphatic sac, it should play an important role in the physiological function of acid-based metabolism and water balance in endolymphatic fluid homeostasis. Objective: To evaluate the expression and immunolocalization of AQP1-9, V2-R, NKCC1, and NKCC2 in the rat endolymphatic sac. Materials and methods. Wistar rats were used. Expression of AQP1-9, V2-R, NKCC1, and NKCC2 mRNA in the rat endolymphatic sac was investigated using the reverse transcription-polymerase chain reaction (RT-PCR) method, and detailed immunolocalization of AQP1-9, V2-R, NKCC1, and NKCC2 was investigated using immunohistochemical methods, including immunofluorescence microscopy. Results. mRNAs and proteins of AQP1-4, AQP6-9, V2-R, NKCC1, and NKCC2 were expressed, but AQP5 was not expressed in the rat endolymphatic sac. [ABSTRACT FROM AUTHOR]

Conclusion. Our findings suggest that edaravone prevented the production of reactive oxygen species (ROS). Edaravone also delayed the formation of endolymphatic hydrops in guinea pigs, but had no effect on endolymphatic hydrops. Objective. To analyse the protective effect of a free radical scavenger, edaravone, on endolymphatic hydrops. Materials and methods. Guinea pigs were subjected to surgical obliteration of the endolymphatic duct (ED). For the detection of ROS, group 1 received intraperitoneal injections of edaravone (3 mg/kg/day) for 2 days, group 2 received edaravone for 2 weeks, group 3 saline for 2 days, and group 4 saline for 2 weeks. ROS production by the organ of Corti and stria vascularis was examined by using dihydrotetramethylrosamine. For the morphological analysis, guinea pigs were divided into five groups, i.e. 2 or 4 weeks after ED obliteration, 2 weeks with edaravone, first or last 2 weeks with edaravone and sacrificed 4 weeks after ED obliteration. Increases in the ratios of the cross-sectional area of scala media were analysed quantitatively to assess the degree of endolymphatic hydrops among the above-mentioned five groups of the hydropic cochlea. Results. ROS was detected both in the organ of Corti and in the lateral wall of cochleae 2 days after ED obliteration. Edaravone prevented the production of ROS and also attenuated the formation of endolymphatic hydrops in the acute hydrops group. [ABSTRACT FROM AUTHOR]

Volumetric changes of the scala media were histologically investigated in normal guinea pigs to see whether glycerol-induced volumetric change of the scala media followed a biphasic course similar to the auditory threshold in the glycerol test. Glycerol was administered orally in a 12 ml/kg dose. The volume of the scala media was assessed by examining the cross-sectional area of the scala media in the mid-modiolar sections of the cochlea. Histological study revealed that the time-course of the change in the volume of the scala media after glycerol intake showed biphasic changes. Specifically, the early phase of the glycerol effect is a decrease in endolymph volume. The volume of the scala media significantly decreased by 11.4±2.9% 2 h after glycerol intake. Thereafter, the volume began to increase, and reached its peak 6-12 h after intake. In addition, the volume of the scala media significantly increased by 17.6±1.1% after 6 h. The present study indicated that the secondary increase in the volume of the scala media following glycerol intake played an important role in the rebound phenomenon in the glycerol test, although the mechanism underlying the hearing loss with the endolymphatic hydrops remains to be elucidated. [ABSTRACT FROM AUTHOR]