Search PubMed⌕ Search

Biomedical subjects

Y Sameshima

Publications and source records attributed to Y Sameshima.

At least 55 records · Page 3Linked to original sources
PubMed1989

Validity of MR imaging for monitoring effects of percutaneous ethanol injection for HCC.

Magnetic resonance (MR) images of 44 hepato-cellular carcinoma (HCC) patients who had undergone percutaneous ethanol injection therapy (PEIT) were analyzed during and after the treatment. Using a long TE/TR spin-echo technique, the initial high intensity of the tumor decreased during treatment in all patients. Decrease in tumor intensity corresponded well with decrease of serum alpha-fetoprotein level and histopathological changes of the necrosis. During the long-term follow-up of three patients, the reappearance of a highly intense area was readily detected by MR imaging, and hence the recurrence of the tumor, as determined clinically or histopathologically, was confirmed. The long TE/TR spin-echo technique proves most helpful in monitoring the effectiveness of PEIT for HCC, as well as for its recurrence.

Carcinoma, Hepatocellular↗
PubMed1988

Mechanisms involved in the cellular uptake of hematoporphyrin by rat hepatoma cells.

To clarify the mechanisms involved in the specific uptake of hematoporphyrin by cancer cells, we investigated the interaction of the heme- and/or hematoporphyrin-hemopexin complexes with rat hepatoma dRLh-84 cells. Hemopexin bound to the cells in a saturable, time- and temperature-dependent manner. The cells exhibited 0.55 nmol of binding sites/mg of protein for the heme-hemopexin complex and 0.38 nmol for the hematoporphyrin-hemopexin complex. The dissociation constants (Kd) for the heme-hemopexin and hematoporphyrin-hemopexin complexes were 0.57 and 0.54 microM, respectively. Specific binding of the labeled hemopexin was inhibited by the unlabeled heme- and hematoporphyrin-hemopexin complexes but was unaffected by albumin or neoglycoprotein. Hematoporphyrin bound to hemopexin was incorporated into the cells at 37 degrees C, but not at 4 degrees C. These results indicate that hematoporphyrin bound hemopexin was taken up by dRLh-84 cells, via the hemopexin receptors. When the hematoporphyrin-albumin complex was incubated with the cells, the hematoporphyrin-[125I]albumin complex bound to the cells in a time and temperature-dependent manner. Here the binding was not saturated up to 100 micrograms/ml of albumin. The binding of hematoporphyrin-[125I]albumin was partially inhibited by unlabeled albumin and hemopexin. Hematoporphyrin bound to albumin was taken up by the cells at 37 degrees C. Thus, the albumin-dependent uptake of hematoporphyrin by rat hepatoma dRL-84 cells could be differentiated from the hemopexin-mediated uptake of hematoporphyrin.

Albumins↗
PubMed1988

A case of bile duct cancer treated by laser via percutaneous transhepatic choledochoscopy.

Palliative treatment of bile duct cancer with Nd: YAG laser irradiation via percutaneous transhepatic choledochoscopy (PTCS) was performed in an 86-year-old man. The obstructed lumen of the lower common bile duct, 3 cm in length, was adequately reopened, and a further endoprosthesis insertion was not required. Symptomatic and subjective improvements were achieved with no complications, and there is no sign of recurrence after 9 months at the time of writing. This method of treatment is recommended for bile duct cancers to obtain long-term and adequate bile flow without catheter insertion.

Adenocarcinoma, Papillary↗
PubMed1987

Coexistent carcinoma in congenital dilatation of the bile duct and anomalous arrangement of the pancreatico-bile duct. Carcinogenesis of coexistent gall bladder carcinoma.

From 1972 to 1985, 40 cases of congenital dilatation of the bile duct (CDBD) were experienced in the department of the authors. Those consisted of 19 cases of anomalous arrangement of the pancreatico-bile duct (P-B anomaly), five of bile duct carcinoma, and two of gall bladder carcinoma. In addition, four patients who showed no dilatation of the bile duct in spite of the presence of a P-B anomaly were experienced, and coexistent gall bladder carcinoma was present in three of four cases. The incidence of bile duct carcinoma associated with CDBD is very high. However, coexistent gall bladder carcinoma in CDBD is a new topic, and coexistent intrahepatic bile duct carcinoma in CDBD is extremely rare. This report presents interesting and rare cases of coexistent carcinomas in these anomalies and investigates their carcinogenesis, particularly that of gall bladder carcinoma.

Adenocarcinoma, Papillary↗
PubMed1987

Properties and localization of phospholipase A2 activity in rat stomach.

In the glandular stomach of rat, phospholipase A2 activity was detected and characterized by the use of sonicated 1-acyl-2-[1-14C]oleoyl-sn-glycero-3-phosphocholine (1 mM in 200 mM glycylglycine buffer/2 mM CaCl2) as substrate. The specific activity was 4.9 X 10(-2) mumol/min per mg protein in the whole glandular stomach homogenate (n = 8). It showed individual variation among rats. The optimal pH was 8.0. The activity was relatively heat-resistant and calcium-dependent. More than 90% of phospholipase A2 activity was located in the corpus and less than 10% was in the antrum. In the corpus wall, which consists of mucosa, submucosa, muscularis externa and serosa, the mucosal part (mucosa and submucosa) contained 80-90% of total activity. The effect of some clinical agents (ulcerogenic and anti-ulcer agents) on the phospholipase A2 activity was examined. The activity in the corpus was inhibited by cimetidine (50% inhibition at 5 X 10(-3) M) and stimulated by indomethacin (50% stimulation at 5 X 10(-5) M). Cetraxate hydrochloride (10(-6)-10(-3) M), 16,16-dimethylprostaglandin E2 (10(-7)-10(-4) M) and dexamethasone (10(-7)-10(-3) M) had no effect.

Acyltransferases↗
PubMed1987

Effect of malotilate (diisopropyl 1,3-dithiol-2-ylidenemalonate) on drug metabolizing activity in rat liver microsomes.

The effect of malotilate (diisopropyl 1,3-dithiol-2-ylidenemalonate) on drug metabolizing activity in rat liver microsomes was examined. Malotilate (500 mg/kg/day) was administered orally to rats for 3 days. The contents of cytochrome P-450 (P-450) and cytochrome b5 (b5), the activity of NADPH-cytochrome c reductase, and the metabolization of aniline, aminopyrine, benzo(a)pyrene (B(a)P) and 7-ethoxycoumarin (7-EC) in the microsomal fraction were examined 24 hr after the final administration of malotilate. The content of b5 and the activity of NADPH-cytochrome c reductase were increased by the malotilate treatment, but the content of P-450 was not significantly affected. 7-EC O-deethylation was markedly and aminopyrine N-demethylation was moderately enhanced; in contrast, aniline hydroxylation was significantly and B(a)P hydroxylation was slightly reduced. Such different effects of malotilate among the four substrate-metabolizing activities may be due mainly to the increase in the content of b5, which participates in the transport of the second electron required for P-450 function to various extents. It is also possible that malotilate affects the population of P-450 subtypes, each having a different substrate specificity and a different affinity for b5.

Aminopyrine↗
PubMed1987

Changes in plasma amino acids during the oral glucose tolerance test in hepatic diseases.

We have measured the plasma concentration of neutral amino acids before and after an oral glucose tolerance test (100 g) in patients with liver cirrhosis (LC), chronic active hepatitis (CAH), chronic persistent hepatitis (CPH), acute hepatitis in the acute stage (AHa) and acute hepatitis in the convalescent stage (AHc) and normal controls. The ratio of the concentration of an amino acid to the sum of those of the other neutral amino acids that compete during transport through the blood brain barrier (BBB), which was reported to correlate well with the brain level of the amino acid, was compared in patients with various liver diseases. The ratios of Trp (Trp/Tyr + Phe + Ile + Leu + Val), Tyr, Phe, and Val increased after glucose loading in all subjects, except Tyr in normal controls, which slightly decreased. On the other hand, Ile and Leu ratios decreased (Trp; tryptophan, Tyr; tyrosine, Phe; phenylalanine, Ile; isoleucine, Leu; leucine, Val; valine). LC showed a characteristic pattern; the ratios of Trp and Tyr were highest among all diseases at 3 hours after glucose loading, and those of Ile, Leu and Val were lowest. We assumed that delta an amino acid ratio = the amino acid ratio at 3 hrs after glucose loading minus the amino acid ratio at 0 hr. In LC, delta Trp ratio and delta Tyr ratio were highest, while delta Val ratio was lowest. The delta Phe ratios in AHa and AHc were significantly higher than those in healthy controls. From these results, the uptake of Trp and Tyr might be supposed to be highest and that of Val was lowest in LC, after glucose loading.

Adult↗
PubMed1986

Drug metabolizing activity in rats with chronic liver injury induced by carbon tetrachloride: relationship with the content of hydroxyproline in the liver.

The drug metabolizing activity of rat liver during long-term administration of carbon tetrachloride (CCl4), and its relationship with the content of hydroxyproline (Hyp) in the liver were examined. The contents of cytochrome P-450 (P-450) and cytochrome b5 (b5) and the metabolization of aniline, aminopyrine, 7-ethoxycoumarin (7-EC) and benzo(a)pyrene (B(a)P) in the microsomal fraction were examined five days after the final administration of CCl4. The contents of P-450 and b5 and the activity to metabolize the four substrates were gradually reduced as the Hyp content in the liver increased. However, aminopyrine N-demethylation and B(a)P hydroxylation, particularly the latter, was more reduced than aniline hydroxylation and 7-EC O-deethylation in the early stage of hepatic fibrosis. Such differences may be due mainly to the different P-450 subtypes affected by CCl4.

Animals↗
PubMed1986

Effect of H2-receptor antagonists on acetaminophen-induced hepatic injury.

The effects of H2-antagonists on acetaminophen-induced hepatic injury were examined. Rats were administered acetaminophen at the dose of 800 mg/kg body, 60 hr after injection of 3-methylcholanthrene. As an H2-antagonist, cimetidine (200 mg/kg), ranitidine (50 mg or 100 mg/kg), or famotidine (20 mg or 40 mg/kg) was administered before and after acetaminophen injection. The group administered only acetaminophen had been severely damaged as evaluated by changes in serum transaminase, P-450 content, aminopyrine demethylation, glutathione content and histological study, but administration of 200 mg cimetidine together with acetaminophen significantly reduced the hepatic injury to nearly the control level. Ranitidine had no protective effect against hepatic injury at the dose of 50 mg, which appears to have the same antacid effect as 200 mg cimetidine, whereas it had a slight but significant protective effect as evaluated by the transaminase level, glutathione content and histological study at the dose of 100 mg. Famotidine had no effect against acetaminophen induced hepatic injury. Because famotidine had no effect, the protection by H2-antagonist against acetaminophen-induced hepatic injury cannot be explained by the decrease in hepatic blood flow alone. Therefore, inhibition of P-450 activity seems to be more important for reducing the generation of the reactive metabolites of acetaminophen than hepatic blood flow decrease.

Acetaminophen↗
PubMed1986

A case of Behçet's syndrome with rupture of a pulmonary aneurysm: autopsy findings and a literature review.

A 34 year old man suffering from oral and genital ulceration with uveitis (the complete type of Behçet's syndrome) developed fluctuating radiological opacities in the right lung and showed recurrent hemoptysis. Pulmonary angiography showed multiple aneurysms and obstruction of the pulmonary arteries. After he was treated with prednisolone, the symptoms and pulmonary manifestation improved temporarily. However, he died suddenly from a massive hemoptysis. An autopsy revealed the aneurysmal rupture of right basilar branch of pulmonary artery into the right B6 bronchus. Histopathological findings in the lung showed multiple organized thrombi, inflammatory infiltration and vascular wall destruction of pulmonary arteries of various sizes. Only 47 previously reported cases of Behçet's syndrome which showed pulmonary involvements were revealed by a search of the published literature.

Adult↗