Toshiaki Nakashima

Measurements of pO2 in Vivo, Including Human Subjects, by Electron Paramagnetic Resonance

The purpose of this paper is to provide an illustrative description of the current state of development of the use of electron paramagnetic resonance (EPR, or completely equivalently, electron spin resonance or ESR) to measure the partial pressure of oxygen (pO2) in tissues in vivo under physiological conditions. This summary is based on published and unpublished results from our laboratory (1–7) and does not attempt to describe the results of other laboratories which also are working along related lines (8–10). The pertinent features of our technique are illustrated. We also consider the current limitations of the technique and likely developments in the near future. Our evaluation is that: this technique now is suitable for immediate use in small animals; within a short period of time instruments will be available facilitating its use in larger animals; and preliminary studies are imminent in human subjects (7).

Nuclear size measurement is a simple method for the assessment of hepatocellular aging in non-alcoholic fatty liver disease: Comparison with telomere-specific quantitative FISH and p21 immunohistochemistry

Telomere‐specific quantitative fluorescent in situ hybridization (Q‐FISH) accurately evaluates hepatocellular aging on histological sections, but it requires appropriate tissue processing. To establish a more simple method for the assessment of hepatocellular aging, the usefulness of nuclear size measurement was clarified using biopsy liver samples from 64 patients with non‐alcoholic fatty liver disease (NAFLD), a model for oxidative stress‐associated hepatocellular aging, and 11 control individuals. Relative telomere intensity (RTI) was measured on Q‐FISH, and the relative nuclear size (RNS) was calculated as the average nuclear size of the hepatocytes divided by that of lymphocytes. In normal individuals and NAFLD patients, the RTI and RNS were negatively correlated. The degree of nuclear enlargement in NAFLD patients was larger than that in normal individuals with the same telomere length, possibly reflecting telomere‐independent senescence. In NAFLD patients with RNS >2.0, the regenerative responses, indicated by the ratio of Ki‐67‐positive index to serum alanine aminotransferase level, were significantly reduced. The RNS positively correlated with the p21 expression, another marker of senescence. This all indicates that nuclear enlargement progresses in parallel with reduced regenerative responses, telomere shortening, and p21 upregulation. Nuclear size measurement is an effective method for estimation of hepatocellular aging.

Influence of Helicobacter pylori infection on iron accumulation in hepatitis C

Abstract: Goal: Iron may play a role in the pathogenesis of chronic hepatitis C. Helicobacter pylori (Hp) infection was recently associated with iron‐deficiency anemia. We examined the influence of Hp infection on hepatic iron accumulation in hepatitis C.

Greater age and hepatocellular aging are independent risk factors for hepatocellular carcinoma arising from non-B non-C non-alcoholic chronic liver disease

We previously reported that hepatocellular aging can be assessed by measuring the nuclear size of hepatocytes. We attempted to elucidate whether this method is useful to identify the high risk group of hepatocellular carcinoma (HCC) in the patients with non‐B non‐C non‐alcoholic liver injury. Fourteen patients with HCC and 78 without HCC, both of whom presented with non‐B non‐C non‐alcoholic chronic liver injury and underwent liver biopsy, were selected. Twelve histologically normal liver tissues were selected as controls. The relative nuclear size (RNS) was calculated as the average nuclear size of the hepatocytes divided by that of lymphocytes. Multiple clinicopathological parameters were studied. The RNS values of normal livers ranged from 1.32 to 2.10, showing a gradual increase in an age‐dependent manner. The RNS values of the injured livers without HCC increased after middle age. Univariate analysis identified greater age, existence of diabetes and RNS, as significantly positive contributors and ALT value and the degree of steatosis as negative contributors for the occurrence of HCC. Only age and RNS retained significance in multivariate analysis. All of the HCC patients were older than 50 and showed RNS values higher than 2.00. Therefore, such patients are classified as a high risk group of HCC.

Differences in the efficacy of ursodeoxycholic acid and bile acid metabolism between viral liver diseases and primary biliary cirrhosis

Aim and Methods: The effects of ursodeoxycholic acid (UDCA, 600 mg/day) on liver function test values, and serum and urinary bile acids levels in hepatitis C virus‐related chronic hepatitis (CH, n = 39) and liver cirrhosis (LC, n = 25), and in primary biliary cirrhosis (PBC, n = 25) were compared.

Serum thioredoxin as an indicator of iron-induced oxidative stress in chronic viral hepatitis

Aim: Thioredoxin (TRX), a thiol-containing protein, is induced by various oxidative stresses. The aim of the present study is to evaluate the clinical significance of serum TRX levels in patients with chronic viral hepatitis. Methods: TRX levels and other laboratory parameters, including ironmarkers, were measured in the sera of patients with chronic hepatitis type C (CH-C, n= 163) and type B (CH-B, n=35) as well as in healthy controls (n=17). Forty-five of the CH-C patients underwent a liver biopsy. Fifteen of the CH-C patients received biweekly phlebotomies in which 400 ml of blood were drawn. Serum TRX levels were determined using a recently established sandwich ELISA kit (Fujirebio Inc., Japan). Results: I) Serum TRX levels (ng/ml, mean:tSD) were significantly higher in CH-C patients (39.1±21.2) than in CH-B patients (30.9± 16.5)(p<.05) or in controls (20.6± 12.5)(p<.001). No significant differences in TRX levels were found between CH-B patients and controls. 2) TRX levels did not correlate with ALT levels or virus titers in either CH-C or CH-B patients. Serum iron, ferritin, and transferrin saturation values were significantly higher in the CH-C patients than in the CH-B patients (p<.05). Serum TRX levels were significantly correlated with these iron-markers in CH-C patients, but not in CH-B patients. 3) In CH-C patients, significant correlations were observed between TRX levels and the levels of serum markers for hepatic fibrosis, such as hyaluronic acid, IV collagen, and P-III-P. Histological examination also demonstrated that TRX levels were significantly correlated with the degree of hepatic fibrosis (r=0.333, p<.05), but not with that of hepatic activity. Serum ferritin levels tended to increase with the progression of fibrosis. 4) The removal of excess iron by phlebotomy resulted in a reduction of TRX and ferritin serum levels in CH-C patients. Conclusions: The present findings suggest that serum TRX levels may be a useful indicator of oxidative stress in hepatitis patients. The positive correlations between serum TRX levels and the value of iron-markers as well as the histological stages of hepatic fibrosis and the good response of CH-C patients to phlebotomy indicate that iron-induced oxidative stress may contribute to the pathological mechanism of hepatitis C. No significant increases in serum TRX levels were found in CH-B patients, suggesting that hepatitis B may not be influenced by oxidative stress.