Fumihiko Kaneko

Past Rifampicin Dosing Determines Rifabutin Resistance of Helicobacter pylori

Background: Recently, the number of Helicobacter pylori isolates showing antibiotic resistance has been increasing. Rifabutin (RFB) is one of the possible candidates for H. pylori eradication. In the present study, the RFB minimum inhibitory concentrations (MICs) and the resistance-determining genes to RFB (rpoB) were examined to clarify the relationship between drug MICs, rpoB mutations, and past history of rifampicin (RFP) treatment. Methods: The MICs of RFB and rpoB mutations were examined for 48 strains with failure of H. pylori eradication in the University Hospital and 46 isolated from patients at a specialized hospital for chronic respiratory diseases without past H. pylori eradication. Past RFP treatment was also examined. Results: Eight of 94 strains showed high RFB MICs and 6 of the 8 strains showed rpoB point mutations. Although no strains showed high RFB MICs among 48 strains from the patients in the University Hospital, all 7 strains isolated from patients with past RFP treatment showed high RFB MICs (≥0.12 mg/l). Conclusion: Although RFB might be a potential candidate component of a new H. pylori eradication regimen following the first- or second-line failure, it should be used after examining a past history of RFP treatment.

Pentoxifylline prevents pig serum-induced rat liver fibrosis by inhibiting interleukin-6 production

Background/Aim:  Pig serum‐induced rat liver fibrosis is a model of liver fibrosis in the absence of obvious hepatocyte injury. Penoxifylline (PTX), a xanthine derivative, which is a well‐known suppressor of tumor necrosis factor‐α (TNF‐α) production from inflammatory cells, has also been shown to inhibit the growth of hepatic stellate cells and to inhibit collagen synthesis in these cells in vitro. We investigated the effect of PTX on pig serum‐induced liver fibrosis in vivo, and assessed the mechanisms of prevention of fibrogenesis by this drug.

Overexpression of apelin receptor (APJ/AGTRL1) on hepatic stellate cells and sinusoidal angiogenesis in human cirrhotic liver

BackgroundThe apelin receptor (APJ) is related to angiotensin-like-receptor 1 (AGTRL1). This study was designed to elucidate the in vivo localization and changes of APJ in cirrhotic liver, and the in vitro changes of APJ expression in cultured hepatic stellate cells (HSCs) and capillarized sinusoidal endothelial cells (SECs) activated by growth factors.MethodsIn vivo studies used control liver samples, cirrhotic liver samples from patients with Child’s A cirrhosis undergoing surgical resection (Child-A-LC), and cirrhotic liver samples from autopsied cases of decompensated Child’s C cirrhosis (Child-C-LC). Immunohistochemical (IHC), Western blot, laser-capture microdissection (LCM) coupled with reverse transcription -polymerase chain reaction (RT-PCR), and immunoelectron microscopic (IEM) studies for APJ expression were conducted. In vitro examinations used commercial human HSCs and SECs. APJ expression was examined in cultured HSCs activated by growth factors and in capillarized SECs activated by angiogenic factors.ResultsThe IHC study of liver samples revealed only slight APJ expression in hepatic sinusoids in control liver tissue. In cirrhotic liver (Child-A-LC and Child-C-LC), APJ expression was evident mainly along the sinusoids and on portal fibroblasts in fibrotic septa. Western blot analysis of whole-liver homogenate and LCM–PCR of sinusoids revealed overexpression of APJ in Child-C-LC samples. The results of IEM studies showed that APJ expression was increased significantly on HSCs, but it was sparse on SECs in Child-C-LC tissue. In vitro examination revealed that APJ was overexpressed in cultured HSCs activated by platelet-derived growth factor-β.ConclusionsEnhanced expression of APJ on HSCs in cirrhosis indicates markedly increased vascular remodeling.

Aquaporin-1 associated with hepatic arterial capillary proliferation on hepatic sinusoid in human cirrhotic liver.

Aquaporins (AQPs) are key regulators not only of water transport in the cytoplasm but also of angiogenesis. Although AQPs in the normal hepatobiliary system have been studied in mammals, little is known about the localization and changes of AQPs in the hepatic microvascular system including sinusoids in cirrhotic liver, which might contribute to portal hypertension.

Lymphatic marker podoplanin/D2-40 in human advanced cirrhotic liver- Re-evaluations of microlymphatic abnormalities

BackgroundFrom the morphological appearance, it was impossible to distinguish terminal portal venules from small lymphatic vessels in the portal tract even using histochemical microscopic techniques. Recently, D2-40 was found to be expressed at a high level in lymphatic endothelial cells (LECs). This study was undertaken to elucidate hepatic lymphatic vessels during progression of cirrhosis by examining the expression of D2-40 in LECs.MethodsSurgical wedge biopsy specimens were obtained from non-cirrhotic portions of human livers (normal control) and from cirrhotic livers (LC) (Child A-LC and Child C-LC). Immunohistochemical (IHC), Western blot, and immunoelectron microscopic studies were conducted using D2-40 as markers for lymphatic vessels, as well as CD34 for capillary blood vessels.ResultsImunostaining of D2-40 produced a strong reaction in lymphatic vessels only, especially in Child C-LC. It was possible to distinguish the portal venules from the small lymphatic vessels using D-40. Immunoelectron microscopy revealed strong D2-40 expression along the luminal and abluminal portions of the cell membrane of LECs in Child C-LC tissue.ConclusionIt is possible to distinguish portal venules from small lymphatic vessels using D2-40 as marker. D2-40- labeling in lymphatic capillary endothelial cells is related to the degree of fibrosis in cirrhotic liver.

Acute intrahepatic cholestasis accompanied with Chlamydophila pneumoniae infection

We report a case of Chlamydophila (C.) pneumoniae infection presenting with fever and rapid intrahepatic cholestasis. A 63-year-old man had a week-long history of intermittent high fever and rapidly progressive jaundice with atypical erythema. The results of liver function tests were recorded. The results of all serological tests were negative; the IgM, IgG, and IgA titers for C. pneumoniae had increased, which indicates a C. pneumoniae infection. The patient’s fever and liver dysfunction improved upon administration of minocycline. Light microscopic findings showed the presence of enlarged liver cells with clear cytoplasm, a few mitotic figures, multinucleated cells, and bile cholestasis. The electron microscopic appearance of liver biopsy showed that bile canaliculi exhibited intrahepatic forms of cholestasis. From the results of light and electron microscopy, we inferred atypical intrahepatic cholestasis, probably resulting from the C. pneumoniae infection.