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Biomedical subjects

Y Muto

Publications and source records attributed to Y Muto.

At least 109 records · Page 6Linked to original sources
PubMed1998

Perforation due to metastatic tumors of the ileocecal region.

We reviewed our department's medical records between April 1986 and April 1994 to identify patients who showed acute abdominal symptoms requiring surgical treatment due to metastatic tumors of the small intestine. In group A, seven patients (30%) were treated for acute peritonitis, and all were found to have an intestinal perforation due to hematogenous metastases (group A). In group B, 16 patients (70%) were treated for an intestinal obstruction, and all were found to have disseminated tumors of the small intestine (group B). In group A all tumors were isolated and located exclusively in the ileocecal region, whereas all tumors in group B showed peritoneal dissemination, with no predominant anatomic localization. In general, the intestinal tumors in group A originated from cancers of the upper aerodigestive tract, whereas those in group B originated from advanced cancers in the abdominal cavity. The tumors were significantly smaller and the period between the onset of symptoms from the original malignancy and the onset of abdominal symptoms (perforation or obstruction) was significantly shorter in group A. In conclusion, intestinal metastases located in the ileocecal region have unique clinicopathologic features and so should be recognized as a distinct disease entity. Therefore when patients with a known upper aerodigestive malignancy exhibit acute abdominal symptoms, intestinal metastasis to the ileocecal region, necrotic changes, and perforation should be considered in the differential diagnosis.

Abdominal Neoplasms↗
PubMed1998

Combined hepatocellular and cholangiocellular carcinoma in a non-cirrhotic liver.

Combined hepatocellular (HCC) and cholangiocellular carcinoma (CCC) (mixed carcinoma) is a rare subtype of primary hepatic carcinoma. We report a case of mixed carcinoma that developed in a non-cirrhotic liver, in a patient who was serologically negative for both hepatitis B and C viruses. A 65-year-old Japanese woman with a 25-year history of chronic rheumatoid arthritis had been treated with steroids and anti-inflammatory drugs, and was diagnosed by ultrasonography with an asymptomatic solitary tumor in the right lobe of the liver. On computed tomography scan and hepatic arteriography, the tumor was well enhanced by contrast medium in the early phase. Based on the findings of elevated serum alpha-feto protein (AFP, 245 ng/ml) and normal carcino-embryonic antigen (CEA, 2.6 ng/ml) levels, a preoperative diagnosis of hepatocellular carcinoma was made. Right lobectomy of the liver was performed on January 7, 1997. Histological examination showed that the resected tumor consisted of combined CCC cells and HCC cells in an intermingled form, with CCC being far more dominant than HCC. The tumor was therefore determined to be a combined carcinoma, subclassified as intermingled type. This case appears to indicate that mixed type carcinoma developed in a non-cirrhotic liver, with CCC being dominant; such a finding is extremely unusual, based on previously published reports.

Aged↗
PubMed1998

Abdominal surgery for patients on maintenance hemodialysis.

Despite the growing number of major surgical procedures being performed for patients on maintenance hemodialysis, few reports focus on the management and outcome of such patients, especially those undergoing major abdominal surgery. We conducted a retrospective review of 30 patients on maintenance hemodialysis who underwent abdominal surgery, 20 of whom underwent an elective operation and 10, an emergency operation. The indications of elective surgery included gastrointestinal cancer, biliary tract disease, and abdominal aortic aneurysm, while those for emergency surgery mainly involved gastrointestinal perforation or bleeding. There were no statistically significant differences between the elective group and the emergency group regarding either the mean time on hemodialysis or the preoperative clinical data. The morbidity and mortality rates were 15% and 10%, respectively, for the patients who underwent elective surgery and 50% and 70%, respectively, for those who underwent emergency surgery (P < 0.01 and P < 0.05, respectively). Those patients with more than a 2-year history of hemodialysis had a significantly higher mortality rate following abdominal surgery than those with less than a 2-year history (P < 0.01). Thus, the morbidity and mortality rates of patients on maintenance hemodialysis who require major abdominal surgery are significantly high, which reinforces the need to further improve the intensive perioperative management of such patients.

Abdomen↗
PubMed1998

Oral supplementation with branched-chain amino acids improves survival rate of rats with carbon tetrachloride-induced liver cirrhosis.

We investigated whether supplementation with branched-chain amino acids (BCAA) improves survival of rats with carbon tetrachloride (CCl4) -induced cirrhosis. Liver cirrhosis was induced in 40 male Sprague-Dawley rats by administering CCl4 for 15 weeks. Twenty rats each were then assigned to the control and BCAA group and fed a casein diet or a BCAA-supplemented casein diet, respectively, for an additional 17 weeks with repeated injections of CCl4. No significant difference occurred in either mean energy or nitrogen intake or in body or liver weight between the two groups. BCAA-supplementation significantly preserved plasma albumin concentrations (P < 0.05) and inhibited significantly the occurrence of ascites and hyperammonemia (P < 0.05). The survival rate was significantly higher in the BCAA group (P=0.03), while no significant difference was found in liver histology between the groups. These results suggest that BCAA improved survival of rats with CCl4-induced cirrhosis by preventing hypoalbuminemia and hyperammonemia without directly reducing hepatic necrosis and fibrosis.

Administration, Oral↗
PubMed1998

Suppressive effect of low amounts of safflower and perilla oils on diethylnitrosamine-induced hepatocarcinogenesis in male F344 rats.

We have investigated the modulating effects of low amounts of dietary oils rich in polyunsaturated fatty acids (PUFA) on diethylnitrosamine (DEN)-induced hepatocarcinogenesis in male F344 rats. A total of 112 animals were divided into eight groups. Groups 1-4 were given drinking water containing 40 ppm DEN for five weeks. Groups 5-8 served as controls without DEN treatment. Groups 1 and 5 were fed a basal diet containing 5% beef tallow, Groups 2 and 6 were fed a 5% olive oil diet, Groups 3 and 7 were fed a 5% safflower oil diet, and Groups 4 and 8 were fed a 5% perilla oil diet for 21 weeks, starting 1 week before DEN exposure. Beef tallow, olive oil, safflower oil, and perilla oil are rich in saturated fatty acids, a monounsaturated fatty acid, n-6 PUFA, and n-3 PUFA, respectively. All rats were killed 20 weeks after the start of the experiment. Incidences of hepatocellular adenoma and carcinoma were 100% in DEN-treated groups, irrespective of dietary oils. Multiplicities of adenomas in Groups 3 and 4 were significantly (p < 0.05) lower than in Groups 1 and 2. Multiplicity of carcinoma in Group 3 was significantly (p < 0.05) lower than in Group 1. Mean volumes of placental glutathione S-transferase-positive foci per liver and the number of argyrophilic nucleolar organizer region proteins per nucleus in the liver tumors were significantly (p < 0.05) lower in Groups 3 and 4 than in Groups 1 and 2. ras mRNA expression in liver neoplasms was also suppressed significantly (p < 0.05) in Groups 3 and 4 compared with Groups 1 and 2. Significantly (p < 0.05) higher levels of n-6 and n-3 PUFA in the phospholipid fraction of the liver were found in Groups 3 and 4, respectively, than in the other groups. In contrast, a significantly (p < 0.05) decrease in monounsaturated fatty acid was observed in Groups 3 and 4 compared with Groups 1 and 2. These results suggest that safflower oil and perilla oil, rich in n-6 and n-3 PUFA, respectively, alter the membrane fatty acid composition of the liver and suppress the development of liver cell carcinoma in rats.

Animals↗
PubMed1998

Antiproliferative effect of carotenoids on human colon cancer cells without conversion to retinoic acid.

The present study employed two human colon cancer cell lines, DLD-1 and Colo 320DM, to investigate whether the provitamin A activity of carotenoids is necessary for their antitumor effect on colon cancer. Carotenoids, including alpha- and beta-carotene and canthaxanthin, significantly suppressed cell viability [measured by tetrazolium (MTT) assay], DNA synthesis (measured by [3H]thymidine uptake), and cell proliferation (measured by cell counting) and thus showed growth-inhibitory effects on both cancer cell lines. Because canthaxanthin does not have provitamin A activity, these results suggest that the carotenoid directly inhibited the cell growth. Moreover, the effective dose of retinoic acid, an active metabolite of vitamin A, was much higher than that of alpha- or beta-carotene. A retinoic acid-inducible gene, retinoic acid receptor-beta, was not enhanced in either type of cancer cell by treatment with alpha- or beta-carotene. Therefore, like canthaxanthin, alpha- and beta-carotene might also exert their tumor-suppressing effects without being converted to retinoids. These results suggest that a certain antitumor activity of carotenoids may not necessarily require their provitamin A activity.

Carotenoids↗
PubMed1998

Removal of endotoxin and cytokines by plasma exchange in patients with acute hepatic failure.

OBJECTIVES: To compare the circulating concentrations of endotoxin and cytokines in patients with fulminant hepatitis and patients with the severe form of acute hepatitis, and to assess the effects of plasma exchange on the circulating concentrations of these inflammatory mediators in patients with acute hepatic failure. DESIGN: Prospective, consecutive entry study of patients meeting fulminant hepatitis criteria and the severe form of acute hepatitis criteria. SETTING: University hospital, intensive care unit. PATIENTS: Five patients with fulminant hepatitis, eight patients with the severe form of acute hepatitis, two patients with acute-on-chronic hepatic failure, and one patient with postoperative hepatic failure. INTERVENTIONS: Plasma endotoxin, serum tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and IL-6 were determined on admission in five patients with fulminant hepatitis and eight patients with the severe form of acute hepatitis. Circulating concentrations of the inflammatory mediators were measured before and after a single course of plasma exchange in eight patients with acute liver failure, including five patients with fulminant hepatitis, two patients with acute-on-chronic hepatic failure, and one patient with postoperative hepatic failure. MEASUREMENTS AND MAIN RESULTS: TNF-alpha and IL-6 in patients with fulminant hepatitis were significantly higher than in patients with the severe form of acute hepatitis, whereas endotoxin concentrations did not differ between patients with fulminant hepatitis or the severe form of acute hepatitis. IL-1beta was not detectable in patients with either fulminant hepatitis or the severe form of acute hepatitis. Plasma endotoxin concentrations decreased immediately after plasma exchange. Serum concentrations of TNF-alpha and IL-6 were significantly lower after plasma exchange than before plasma exchange. CONCLUSION: TNF-alpha and IL-6 may be important in the pathogenesis of the clinical symptoms that differentiate fulminant hepatitis from the severe form of acute hepatitis, and plasma exchange removes these inflammatory mediators from the circulation of patients with severe liver disease.

Adolescent↗