Hideaki Nagasaki

Efficacy of preconditioning with N-acetylcysteine against reperfusion injury after prolonged cold ischaemia in rats liver in which glutathione had been reduced by buthionine sulphoximine

OBJECTIVE To investigate the ability of N-acetylcysteine (NAC) to prevent cold ischaemic-reperfusion injury and improve hepatic integrity in a glutathione-depleted condition. DESIGN Open laboratory study. SETTING University hospitals, Japan and France. MATERIALS 40 male Wistar rats. INTERVENTIONS To produce a glutathione-depleted liver, buthionine sulphoximine (BSO) was injected intraperitoneally 2 hours before either NAC or 5% dextrose was infused 15 minutes before the liver was harvested. We used an isolated perfused rat liver model that had undergone prolonged hypothermic ischaemia, cold-storage for 48 hours and reperfusion for 120 minutes. MAIN OUTCOME MEASURES Concentrations of hepatic enzymes released into samples of perfusate, concentration of adenosine triphosphate in liver tissue, concentrations of reduced and oxidized glutathione in perfusate, and bile production. RESULTS The concentrations of the hepatocellular enzymes and oxidised glutathione in the perfusate samples were significantly reduced in the NAC group compared with the 5% dextrose group. Bile production improved significantly in the NAC group compared with the 5% dextrose group. The concentration of reduced glutathione in liver tissue was not increased by NAC. CONCLUSION In a glutathione-depleted liver NAC prevented hepatic injury and improved liver integrity after a cold ischaemic-reperfusion injury, by acting not as a substrate for glutathione synthesis but as a direct free radical scavenger.

Feasibility of a novel weekday-on/weekend-off oral UFT schedule as postoperative adjuvant chemotherapy for colorectal cancer

Purpose: When oral anticancer agents are used for adjuvant chemotherapy of colorectal cancer, compliance and feasibility become issues because of the long treatment time. Appropriate studies of these issues are lacking. We investigated compliance and feasibility during a weekday-on/weekend-off schedule of oral UFT (uracil-tegafur) over a period of 1 year administered as adjuvant chemotherapy to patients with colorectal cancer. Patients and methods: A UFT dose of 600 mg/day was prescribed according to a weekday-on/weekend-off schedule to 87 patients after potentially curative resection. Compliance was investigated in three ways: physician interview, patient self-report, and chemical analysis of urine. The results were compared with the dose prescribed. Feasibility was evaluated on the basis of two indices: relative performance (RP), which was the ratio of the actual total dose taken to the total dose planned, and individual dose intensity (IDI), which was the ratio of the actual dose taken to the dose planned during a given period. Results: The compliance assessed by physician interview and by patient self-report conformed well with the prescribed dose, the rate of agreement among the three compliance measures being more than 94%. Chemical analysis of urine in 38 of the patients revealed that they were actually taking the drug. The RP was 0.72, and the IDI was 0.8. Conclusion: From these results, the feasibility of the weekday-on/weekend-off schedule was judged to be good. It is suggested that the feasibility would be even better if the dose of UFT was set according to body surface area.

A monoclonal antibody against ICAM-1 suppresses hepatic ischemia-reperfusion injury in rats

Since intercellular adhesion molecule-1 (ICAM-1) has been reported to play a major role in reperfusion injury after ischemia, we estimated the effects of an anti-rat ICAM-1 monoclonal antibody (1A29) on hepatic ischemia-reperfusion injury in rats. Partial liver ischemia was achieved by clamping hepatic hilar vessels supplying the cephalad three lobes of the liver for 90 min. An intraportal injection of 1A29 was given 5 min after revascularization (n = 28), and saline was injected in control rats (n = 28). Changes in the proportion of liver necrosis, hepatic tissue blood flow, serum liver enzymes and liver neutrophil sequestration were analyzed at 6, 24, 48 and 72 h after revascularization. The intraportal injection of 1A29 significantly reduced the hepatocellular necrosis, restored the hepatic tissue blood flow at 24, 48 and 72 h of reperfusion (p < 0.05 or p < 0.01), and significantly suppressed the levels of serum liver enzymes at all time points during reperfusion (p < 0.01, respectively). The 1A29 treatment significantly reduced the number of neutrophils at the pericentral area, while those at the periportal area were similar in the two groups. The results suggested that ICAM-1 plays an important role in the development of hepatic ischemia-reperfusion injury, and that 1A29 reduced the injury possibly caused by cytotoxic inflammatory responses, based on neutrophil adherence to pericentral sinusoids.

Amelioration of hepatocellular integrity and inhibition of sinusoidal oxidative stress by N-acetylcysteine pretreatment in cold ischemia-reperfusion injury of rat liver.

Further improvements of donor liver preservation are still required in liver transplantation. In the present study, we investigated whether intraportal injection of N-acetylcysteine (NAC) 15 min before flush-out of UW solution (NAC pretreatment) improves liver dysfunction after cold preservation or has a protective effect on sinusoidal oxidative stress. The effect of NAC pretreatment was examined using an isolated perfused rat liver model. The NAC pretreatment significantly reduced sinusoidal oxidative stress relative to a control dextrose 5% injection. Under a glutathione-depleted condition produced by L-buthionine-[S-R]-sulfoximine, the NAC pretreatment also significantly reduced hepatocellular as well as sinusoidal oxidative stress, resulting in improvement of hepatocelllar integrity relative to a control dextrose 5% injection.

Augmentation of Mitochondrial Reduced Glutathione by S-Adenosyl-L-Methionine Administration in Ischemia-Reperfusion Injury of the Rat Steatotic Liver Induced by Choline-Methionine-Deficient Diet

We examined whether warm ischemia-reperfusion (I/R) damage of the rat steatotic liver can be reduced by administration of S-adenosyl-L-methionine (SAMe). We examined the effect of SAMe on the mitochondrial reduced-glutathione (GSH) pool. Sixty minutes of partial left lobar vascular clamping followed by 2 h of reperfusion were employed for a model of hepatic warm ischemia. Either 5% dextrose or SAMe was injected intraperitoneally 2 h before I/R in steatotic rats (S-D5% or S-SAMe group). Serum liver enzyme concentrations 2 h after reperfusion were significantly lower in the S-SAMe group than in the S-D5% group. The cytosolic and mitochondrial GSH concentrations after I/R were significantly higher in the S-SAMe group than in the S-D5% group (p < 0.05). The cytosolic and mitochondrial oxidized-glutathione/GSH ratios after I/R were significantly greater in the S-D5% group than in the S-SAMe group (p < 0.01). The adenosine triphosphate concentration was higher in the S-SAMe group than in the S-D5% group (p = 0.0515). These results show that hepatocellular and mitochondrial oxidative stress after I/R in the steatotic liver can be reduced by administration of SAMe. The results also show that mitochondrial function and hepatocellular integrity can be restored by administration of SAMe in steatotic rats.

Liver function assessed by increased rate of Portal venous blood flow after oral intake of glucose

OBJECTIVE To find out whether an increased rate of portal venous blood flow after oral intake of glucose could be used to estimate liver function. DESIGN Prospective study. SETTING University hospital, Japan. SUBJECTS Sixty patients, of whom 23 had hepatocellular carcinoma and liver cirrhosis, 21 had tumours metastatic to normal liver, and 16 had obstructive jaundice treated with percutaneous transhepatic biliary drainage (PTBD). INTERVENTION Portal flow was measured after oral intake of glucose 75 g using pulsed-Doppler ultrasonography. RESULTS The ratio of portal flow 30 minutes after glucose intake to that before intake (PVFR30) was significantly lower in cirrhotic patients than in those with metastases and a normal liver. A PVFR30 of less than 1.5 indicated impaired hepatic function assessed by the Child-Pugh scores, indocyanine green clearance test, prothrombin time, and hepaplastin test. It also indicated less reduction in total bilirubin concentrations in the first week after PTBD. CONCLUSIONS Results suggest that PVFR30 can be used to estimate liver function and predict outcome after PTBD.

Prognostic evaluation of curatively resected locally advanced gastric cancer patients with preoperative downstaging chemotherapy assessed by histochemical and pharmacologic means.

The aim of the present study was to investigate whether the rate of thymidylate synthetase inhibition (TSIR) and the rate of proliferating cell nuclear antigen expression (PCNA-R) in gastric cancer tissues, which can be obtained within a short period after surgery, were predictive and quantitative prognostic factors for locally advanced gastric cancer patients with preoperative down-staging chemotherapy. Curatively resected 30 locally advanced gastric cancer patients with preoperative chemotherapies were studied. Three-year survival analysis showed that the higher TSIR and the lower PCNA-R significantly predicted better prognosis (p < 0.01 and p < 0.05, respectively). Multiple regression test showed that the TSIR was a significantly predictive variable for 1-year survival (p < 0.05). The TSIR and PCNA-R could be predictive and quantitative prognostic factors in advanced gastric cancer patients who received preoperative downstaging chemotherapy.