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.

Acetylcysteine↗

PubMed1998

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.

Animals↗

PubMed1998

Severe respiratory distress following sodium oleate ingestion.

CASE REPORT: Oleic acid and oleate are pulmonary toxins used to create laboratory models of acute respiratory distress syndrome, but there is little information on human toxicity. We report the intentional ingestion of 50 mL sodium oleate 20% by a 22-year-old woman with no symptoms for the first 2 days after ingestion. Her respiratory status deteriorated rapidly on day 3 progressing to acute respiratory distress syndrome (PaO2/FIO2 < 100 mm Hg) on day 4. Treatment with high-dose steroids and intensive respiratory support including high-frequency jet ventilation were associated with gradual but complete recovery by day 39. The delayed onset of symptoms suggested that the lung injury was due to the systemic circulation of oleate to the lungs rather than to direct aspiration. In oral poisoning by sodium oleate, the lung is the first and most lethally affected target organ in humans. This case demonstrates that ingestion of a relatively small amount of sodium oleate can cause delayed, progressively severe, lung injury.

Adult↗

PubMed1997

Selective inhibition of vascular cell adhesion molecule-1 expression by verapamil in human vascular endothelial cells.

Up-regulated expression of adhesion molecules on vascular endothelial cells (ECs) is an initial event in leukocyte adhesion to ECs, which is a crucial step in the process of inflammatory or immune reaction leading to organ transplant rejection. Verapamil and other calcium channel blockers have been reported to improve transplantation outcome and seem to possess immunosuppressive functions. Therefore, we tested the effect of verapamil on adhesion molecule expression of ECs and adherence of leukocytes to ECs. Verapamil was added to replicate human umbilical vein EC cultures, before adding cytokines. Protein and mRNA expression of E-selectin, vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 were measured by cell-ELISA and by Northern blot analysis after stimulation of ECs. Adherence of leukocytes to ECs was analyzed after stimulation of ECs by tumor necrosis factor-alpha, with pretreatment of verapamil. Verapamil selectively inhibited cytokine-induced protein and mRNA levels of VCAM-1, and suppressed cell adherence between tumor necrosis factor-alpha-stimulated ECs and mononuclear leukocytes or Molt-4 cells. These results suggest that verapamil may suppress immune response partly via inhibition of VCAM-1 expression on ECs and a certain subset of lymphocytes adherent to ECs.

Calcium Channel Blockers↗

PubMed1997

Study of needlestick accidents and hepatitis C virus infection in healthcare workers by molecular evolutionary analysis.

In the five-year period between 1989 and 1993, 87 needlestick accidents occurred among healthcare workers at our hospital. Thirty-seven (43%) of these needlestick accidents involved blood contaminated with hepatitis C virus (HCV), and two of them (5.4%) led to the occurrence of hepatitis C infection. Case 1 was a 43-year-old nurse who was accidentally injured by a needle contaminated with blood from a patient who had cirrhosis and hepatocellular carcinoma due to hepatitis C. Acute hepatitis C occurred after five weeks and HCV RNA was positive after eight weeks. Case 2 was a 33-year-old nurse who was injured by a needle contaminated with blood from a patient who had chronic hepatitis C. Liver function was normal at 11 days after the accident. However, hepatitis C was diagnosed 21 months later after she had successfully given birth to her baby. The nucleotide sequence of the HCV E2/NS1 region was determined in the two patients and the needlestick victims, and phylogenetic trees were constructed by molecular evolutionary analysis. On the basis of these trees, transmission of HCV could be confirmed in both cases. This method of analysis may be useful for confirming the transmission of HCV even long after the event.

Adult↗

PubMed1997

The effects of N-acetylcysteine and anti-intercellular adhesion molecule-1 monoclonal antibody against ischemia-reperfusion injury of the rat steatotic liver produced by a choline-methionine-deficient diet.

Abundant fat in the liver has been implicated in poor outcome after liver transplantation or liver surgery, but the reasons for this association are still unclear. The aim of the present study was to examine mechanisms that may be involved in hepatic dysfunction after ischemia-reperfusion (I/R) of the steatotic rat liver. Steatosis was produced by a choline-methionine-deficient (CMDD) diet. In the first experiment, isolated perfused rat livers, subjected to 24-hour cold storage followed by 120-minute reperfusion, were used to investigate hypothermic I/R injury of the steatotic rat liver. In the second experiment, livers were subjected to 60-minute partial left lobar vascular clamping to allow study of normothermic I/R injury. In the first experiment, compared with normal nonsteatotic liver, steatotic livers showed significantly greater injury, as assessed by amounts of hepatic enzymes released into the perfusate, bile production, the concentrations of reduced glutathione (GSH) in the perfusate, as well as in the livers themselves, and electron microscopic findings of sinusoidal microcirculatory injury. The addition of N-acetylcysteine (NAC), a precursor of glutathione, to the liver before cold storage significantly improved these parameters in steatotic livers. The second experiment showed that, compared with nonsteatotic livers, steatotic livers had lower concentrations of GSH and impaired rates of bile production. There was also evidence of increased oxidative stress in polymorphonuclear leukocytes (PMNLs) in liver or peripheral blood of rats with fatty livers. An anti-rat intercellular adhesion molecule-1 (ICAM-1) monoclonal antibody inhibited neutrophil infiltration into pericentral sinusoids and improved these parameters in the steatotic rats. We conclude that sinusoidal microcirculatory injury is involved in hypothermic I/R injury, that oxidative stress produced by PMNLs is involved in normothermic I/R injury, and that NAC and anti-rat ICAM-1 monoclonal antibody restore liver integrity in I/R injury.

Acetylcysteine↗

PubMed1997

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.

Alanine Transaminase↗

PubMed1997

Allopurinol reduced hepatic ischemia-reperfusion injury exacerbated by inhalation of high-concentration oxygen in rats.

Exposure to high-concentration oxygen (O2) increases lipid peroxidation of the cellular membrane, leading to tissue injury which may involve hepatic ischemia-reperfusion (I/R) injury. We examined the effects of inhaling high-concentration O2 on hepatic I/R injury with allopurinol, which is a xanthine oxidase inhibitor. Partial hepatic ischemia was performed in rats with or without allopurinol under 21 or 100% O2 inhalation. Levels of lipid peroxide, serum liver enzymes, and hepatocellular oxidative stress in the 100% O2 group were significantly higher than in the 21% O2. Administration of allopurinol significantly inhibited those changes in the 100% O2 group. Severe degeneration of mitochondria were noted in the 100% O2 group, but appeared to be reduced by allopurinol. Results suggest that inhalation of high-concentration O2 during liver surgery may increase lipid peroxidation and exacerbate hepatic I/R injury, but those changes may be prevented by allopurinol.

Alanine Transaminase↗

PubMed1997

Effect of sairei-to on prostaglandin E2-induced phosphatidylinositol breakdown in aminonucleoside nephrotic rat.

We describe the effects of Sairei-to, a Chinese herbal medicine, on aminonucleoside-induced nephrotic rats (ANNR), and analyze the urinary excretion of protein and phosphatidylinositol (PI) turnover via prostaglandin E2 (PGE2) receptors in isolated glomeruli. Sairei-to suppressed urinary excretion of protein and PGE2 in ANNR, and inhibited acceleration of PI turnover in isolated nephrotic glomeruli. The affected responsiveness of the PI turnover system to PGE2 in a nephrotic state was presumed to be normalized by Sairei-to. These findings suggest that Sairei-to restores abnormal changes in the PI turnover system in ANNR kidneys, and thereby inhibit excretion of protein into the urine.

Animals↗

PubMed1997

Distinct subunit functions and cell cycle regulated phosphorylation of 20S APC/cyclosome required for anaphase in fission yeast.

We show here that the fission yeast gene products Cut9 and Nuc2 are the subunits of the 20S complex, the putative APC (anaphase promoting complex)/cyclosome which contains ubiquitin ligase activity required for cyclin and Cut2 destruction. The assembly of Cut9 into the 20S complex requires functional Nuc2, and vice versa. The size of fission yeast APC/cyclosome is similar to that of higher eukaryotes, but differs greatly from that (36S) of budding yeast. The 20S complex is present in cells arrested at different stages of the cell cycle, and becomes slightly heavier in mitosis than interphase. Cut9 in the 20S complex is hyperphosphorylated specifically at the time of metaphase. The truncated forms of Cut9 block entry into mitosis, however. The 20S assembly impaired in the cut9 mutant can be restored by elevating the level of a novel gene product Hcnl, similar to budding yeast Cdc26. Furthermore, deletion of protein kinase PKA (Pkal) suppresses the phenotype of the cut9 mutation and reduces phosphorylation of Cut9. In contrast, PP1 (Dis2) phosphatase mutation shows the reverse effect on the phenotype of cut9. The Cut9 subunit is likely to be a target for regulating APC/ cyclosome function through protein-protein interactions and phosphorylation.

Amino Acid Sequence↗

PubMed1997

Zinostatin stimalamer-transcatheter arterial embolization for hepatocellular carcinoma: a comparison with lipiodol-transcatheter arterial embolization.

Twenty patients with unresectable hepatocellular carcinoma were treated by zinostatin stimalamer-transcatheter arterial embolization (SMANCS-TAE). After administration of SMANCS, a superselective catheterization technique was used to inject gelatin sponge particles into the artery or artery branch supplying the cancer-bearing segment. We compared the results of SMANCS-TAE with Lipiodol (Yamanouchi, Tokyo, Japan)-TAE performed during the same period. In 18 of 20 patients (90%), a tumor necrosis rate of 100% (grade 4) was obtained after one or two courses of SMANCS-TAE. The SMANCS group was superior to the Lipiodol-TAE group in terms of the tumor reduction rate, alpha-fetoprotein reduction rate, and cumulative 1.5-year survival rate, but not significantly. No severe side effects were noted after SMANCS-TAE. SMANCS-TAE appears to have potential as a new treatment for hepatocellularcarcinoma, and patients treated with this technique will be monitored to elucidate the long-term effects.

Aged↗

PubMed1997

Prediction of postoperative decompensated liver function by technetium-99m galactosyl-human serum albumin liver scintigraphy in patients with hepatocellular carcinoma complicating chronic liver disease.

BACKGROUND: Preoperative technetium-99m galactosyl-human serum albumin (Tc-GSA) liver scintigraphy may predict postoperative decompensated liver function and its value has been investigated in patients having resection of hepatocellular carcinoma (HCC). METHODS: Hepatic uptake ratio of Tc-GSA (LHL15) was measured before operation in 30 patients. Postoperative complications were analysed retrospectively and compared with LHL15 values and other indicators evaluating hepatic function. RESULTS: The LHL15 of 22 patients without complications was 0.91 or more, compared with 0.90 or less in the eight patients who had complications. Multifactorial analyses showed that LHL15 and Child-Pugh grade significantly predicted postoperative complications (P < 0.0001 and P = 0.0111 respectively). LHL15 was a significant predictor of complications in patients with Child-Pugh grade B disease (n = 15, P = 0.0011). CONCLUSION: LHL15 was a reliable preoperative indicator of the risk of major postoperative complications in patients who had resection for HCC.

Aged↗

PubMed1996

Fission yeast Cut1 and Cut2 are essential for sister chromatid separation, concentrate along the metaphase spindle and form large complexes.

Fission yeast Schizosaccharomyces pombe temperature-sensitive (ts) cut1 mutants fail to separate sister chromatids in anaphase but the cells continue to divide, leading to bisection of the undivided nucleus (the cut phenotype). If cytokinesis is blocked, replication continues, forming a giant nucleus with polyploid chromosomes. We show here that the phenotype of ts cut2-364 is highly similar to that of cut1 and that the functions of the gene products of cut1+ and cut2+ are closely interrelated. The cut1+ and cut2+ genes are essential for viability and interact genetically. Cut1 protein concentrates along the short spindle in metaphase as does Cut2. Cut1 (approximately 200 kDa) and Cut2 (42 kDa) associate, as shown by immunoprecipitation, and co-sediment as large complexes (30 and 40S) in sucrose gradient centrifugation. Their behavior in the cell cycle is strikingly different, however: Cut2 is degraded in anaphase by the same proteolytic machinery used for the destruction of cyclin B, whereas Cut1 exists throughout the cell cycle. The essential function of the Cut1-Cut2 complex which ensures sister chromatid separation may be regulated by Cut2 proteolysis. The C-terminal region of Cut1 is evolutionarily conserved and similar to that of budding yeast Esp1, filamentous fungi BimB and a human protein.

Amino Acid Sequence↗