Yukio Yokoi

Immunoreactivity to M2 proteins in antimitochondrial antibody-negative patients with primary biliary cirrhosis.

Abstract Although antimitochondrial auto‐antibodies are characteristically present in the serum of patients with primary biliary cirrhosis (PBC), there is a discrepancy between the positivity for antimitochondrial antibody (AMA) and that for anti‐M2 auto‐antibody. In an attempt to explain the discrepancy, this study investigates the relationship between the AMA titre, determined by indirect immunofluorescence, and immunoreactivity to four inner mitochondrial membrance proteins (M2 proteins) with molecular weights of 70, 50, 47, and 40 kDa in 129 patients with PBC. Antimitochondrial antibody positivity was identified in 114 (88%) of 129 patients with clinically and histologically confirmed PBC. There were no significant differences between the AMA‐negative and AMA‐positive groups in clinical characteristics or histologically determined disease stage. Immunoblot analysis showed that all patients had anti‐M2 auto‐antibodies to one or more of the four M2 proteins. Nine (60%) of the 15 AMA‐negative patients had antibodies to only one M2 protein (either 70 or 47 kDa). In contrast, 34 (53%) of the 64 patients with high AMA titres ( 1: 320) had antibodies to all four M2 proteins. There was a significant rank correlation between the AMA titre and the number of antibodies to M2 proteins (P < 0.01). These findings indicate that the AMA titre is not influenced by the immunogenicity of M2 protein but by the number of M2 proteins that elicit an antibody response and that decreased immunoreactivity to M2 proteins may induce AMA negativity in PBC serum samples.

Hepatic stellate cell contraction is inhibited by lipo-prostaglandin E1 in vitro

Prostaglandin E1 (PGE1) has been reported to have, experimentally and clinically, a protective effect against liver damage. This effect may result from the relaxation of hepatic stellate cells, whose contraction induces vasoconstriction of hepatic sinusoids. However, prostaglandins are unstable and a new drug delivery system is necessary to administer a sufficient amount of prostaglandin to achieve a protective effect in the liver. The aim of the study is to investigate the effects of lipo‐prostaglandin E1 (lipo‐PGE1) which has a novel drug delivery system on the stellate cell contraction induced by endothelin‐1 in vitro. Lipo‐PGE1 inhibited endothelin‐1‐induced stellate cell contraction in concentrations of 10, 30 and 50 ng/mL. Therefore, lipo‐PGE1 may show a cytoprotective effect in the liver through the relaxation of stellate cells and an increase in the hepatic sinusoidal blood flow.

Oesophageal hiatal hernia‐induced hydropneumothorax

The patient presented with acute and constant abdominal pain. He had had a lobectomy of the left lung three months before. On the 4th day in hospital the pain increased and he went into temporary shock. The next day a hydropneumothorax and incarcerated stomach were revealed by chest X‐ray and computed tomography. He was transferred to the University Hospital immediately and underwent an operation. The diagnosis was an incarcerated para‐oesophageal hernia with hydropneumothorax and perforation of the stomach. As a para‐oesophageal hernia may be fatal, is important to diagnose and treat it early.

Marked retention of indocyanine green and sulfobromophthalein with chronic persistent hepatitis.

A hepatitis B virus (HBV) carrier with marked retention of indocyanine green (ICG) and sulfobromophthalein (BSP) was admitted to our hospital for assessment of liver function. On admission, he was asymptomatic and blood chemistry tests showed normal values for transaminases and bilirubin. Serum hepatitis B surface antigen (HBsAg) and antibody to hepatitis B e antigen (anti‐HBe) were positive. A history of drug abuse or alcoholism was denied. Dye excretion tests revealed marked retention of ICG (R15= 70%) and BSP (R45= 23%). Histopathological examination of a liver biopsy specimen obtained during laparoscopic observation showed chronic persistent hepatitis (CPH). Familial research of the patient failed to prove the existence of dye excretory defect in his siblings. Usual cases of CPH due to continuous HBV infection do not show such severe disturbance of organic anion transport.