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Biomedical subjects

F Nakayama

Publications and source records attributed to F Nakayama.

At least 55 records · Page 3Linked to original sources
PubMed1990

Biliary lipids and bile acid composition before and after endoscopic sphincterotomy.

The effect induced by endoscopic sphincterotomy on biliary lipids and bile acid composition was examined by following up the seven patients prior to early (1-2 week) and late (0.5-1 year) after the endoscopic sphincterotomy. The concentrations of total bile acids, phospholipid and cholesterol were essentially constant throughout the one-year observation period. Cholesterol saturation indices were not significantly altered. No bile acid concentration changed significantly. The results indicate that endoscopic sphincterotomy has little undesirable effect on the biliary lipids and bile acid compositions over an observed period.

Adult↗
PubMed1989

Assay of cholesterol 7 alpha-hydroxylase utilizing a silica cartridge column and 5 alpha-cholestane-3 beta, 7 beta-diol as an internal standard.

A simplified and accurate assay of cholesterol 7 alpha-hydroxylase activity using 5 alpha-cholestane-3 beta,7 beta-diol as an internal standard is described. Endogenous microsomal cholesterol was used as the substrate. Following incubation and addition of the internal standard, lipids extracted from the incubation mixture were applied to Bond-Elut silica cartridge columns. 7 alpha-Hydroxycholesterol, 7 beta-hydroxycholesterol, 7-ketocholesterol and the internal standard were quantitatively recovered by eluting the column with 6 ml of benzene-ethyl acetate (2:3, v/v) after removal of cholesterol with 6 ml of benzene-ethyl acetate (9:1, v/v). After trimethylsilylation, the mass of 7 alpha-hydroxycholesterol was determined by capillary gas chromatography with selected-ion monitoring. The method permits a faster, easier and more sensitive determination of the activity of cholesterol 7 alpha-hydroxylase in small samples.

Animals↗
PubMed1989

Stimulation of DNA synthesis in hepatocytes by Kupffer cells after partial hepatectomy.

The role of Kupffer cells during reparative regeneration of rat liver was investigated with an in vitro experimental model. Conditioned media from primary cultures of Kupffer cells isolated from intact and regenerating liver were added to primary cultures of hepatocytes, and [3H]thymidine incorporation into DNA was studied. Kupffer cell-conditioned media from intact liver and regenerating remnant liver significantly stimulated DNA synthesis in hepatocytes as compared with control media (p less than 0.05). Moreover, the stimulating activity of Kupffer cells prepared from regenerating liver at 6 and 12 hr after partial hepatectomy was significantly higher than that of Kupffer cells from untreated rats (p less than 0.05). The activity was found in serum-free conditioned media. This stimulating activity exponentially increased as the increase of the number of the cultured cells, indicating that the stimulating activity was released directly by cultured Kupffer cells. These results suggest that Kupffer cells stimulate DNA synthesis in hepatocytes by producing and releasing certain factor(s) at an early stage of liver regeneration after partial hepatectomy.

Animals↗
PubMed1989

The possible presence of a separate disease entity in nonfamilial polyposis of the large intestine.

Familial adenomatosis coli (FAC) traditionally has been diagnosed as the presence of more than 100 colonic adenomas, even if no familial occurrence is present. In the present communication, clinical features of FAC have been compared in detail to detect differences between familial and nonfamilial cases with regard to colonic and extracolonic lesions and to discover whether they constitute the same disease entities. No significant difference was found in the incidence of extracolonic lesions. The average number of colonic polyps in the nonfamilial cases of patients over 30 years old was 1128, the number of polyps was significantly higher in the familial cases (3154). When three patients with approximately 100 polyps were excluded, the mean number of colonic polyps in nonfamilial cases became 2608. This was similar to that of familial cases. Furthermore, the occurrence of approximately 100 polyps was extremely rare in familial patients who were over 30 years old. Therefore, most of the nonfamilial cases can be considered to be familial probands of FAC, but some, such as the three cases in the present study, may be a different disease entity, such as recessive adenomatous polyposis or multiple colonic adenomas.

Adenoma↗
PubMed1989

Bile composition after total proctocolectomy with interposed jejunal segment as neorectum.

Changes of bile composition in gallbladder bile and serum chemistries were investigated in nine dogs after proctocolectomy and ileoanal anastomosis, using an interposed jejunal segment as a neorectum. A significant decrease in cholic acid and an increase in deoxycholic acid were observed 24 weeks after the operation, although there was no significant change of total bile acid and phospholipids in the bile. Concentration of cholesterol and cholesterol saturation index in bile increased after total proctocolectomy. Although serum triglyceride levels became lower compared with the nontreated control group, concentrations of total protein, serum cholesterol, total lipids, blood sugar, and electrolytes showed no significant difference. This operative procedure apparently did not impair intestinal absorption of bile acid, but did increase the biliary cholesterol saturation index.

Anal Canal↗
PubMed1989

Lithocholate in liver tissue with obstructive jaundice.

The existence of tissue-bound lithocholate in liver tissue was first suggested by Nair et al. (Lipids 1988;12:922-929). Since lithocholate is well known to be cholestatic, we investigated whether tissue-bound lithocholate, if present, can be correlated to liver dysfunction in obstructive jaundice. Tissue-bound lithocholate in liver tissues of 7 patients with obstructive jaundice was analyzed using gas chromatography-mass spectrometry-selected ion monitoring. We found no accumulation of lithocholate, including tissue-bound form, indicating that the role of lithocholate in inducing hepatic dysfunction in obstructive jaundice is minimal, if any.

Cholestasis↗
PubMed1989

Complete ten-year postgastrectomy follow-up of early gastric cancer.

The postoperative courses of 109 patients with early gastric carcinoma treated from 1970 through 1976 were followed for 10 years. The cumulative 5-year survival rate was 96 percent and the 10-year survival rate was 92 percent. In this series, there was no significant difference in the survival rates between the mucosal cancer and submucosal invasion groups or between patients with and without lymph node metastasis. Five patients died from the recurrent cancer. The other causes of death were metachronous primary cancer in eight patients, synchronous primary cancer of sigmoid colon or rectum in two, cerebrovascular accident in six, heart disease in six, other causes in four, and unknown causes in four. Although the prognosis of early gastric cancer is remarkably good, patients should be carefully followed over a long period for late recurrence of the primary cancer and possible metachronous cancer of the other organs.

Adult↗
PubMed1989

Congenital cutis laxa.

We have encountered 2 cases (mother and son) with an autosomal dominant form of cutis laxa, which is clinically characterized by inelastic, loose, and pendulous skin without systemic organ involvement. The histopathological findings disclosed that the elastic fibers were decreased in number and had abnormalities in shape. Furthermore, electron microscopic observations showed some variations in structural abnormalities of the elastic fibers between the 2 cases. These findings may suggest that the elastic fibers seen in congenital cutis laxa give various features for elastogenesis and elastolysis in the individual cases, perhaps due to aging.

Adult↗
PubMed1989

[Cultured biliary tract epithelial cells/alkaline and neutral elution as a model for the detection of carcinogens to the biliary tract epithelium].

Alkaline and neutral elution techniques were applied to detect chemical carcinogens in biliary tract cancer using biliary tract epithelial cells in culture. Since biliary tract epithelial cells actively grow in culture, DNA breaks induced by carcinogens in the [14C] thymidine-prelabeled DNA could be detected as radioactivities in the eluted fractions. Our study demonstrated that aflatoxin B1, 20-methylcholanthrene and dimethylnitrosamine induced DNA single-strand breaks in the biliary tract epithelial cells by the use of this system. Cultured biliary tract epithelial cells/alkaline and neutral elution offers a sensitive and organ-specific model for the detection of chemical carcinogens to the biliary tract epithelium.

Aflatoxin B1↗
PubMed1989

Deoxycholate 7 alpha-hydroxylase in the hamster: substrate specificity and effect of phenobarbital.

In a recent publication, we reported that deoxycholic acid is 7 alpha-hydroxylated to yield glycocholate or taurocholate in vivo in the hamster (1987. Kuroki et al. Hepatology. 7: 229-234). In order to explore the possibility that amidation of free deoxycholic acid precedes the 7 alpha-hydroxylation, we assayed 7 alpha-hydroxylase activities of free and conjugated deoxycholates in vitro. 7 alpha-Hydroxylase activities of glycodeoxycholate and taurodeoxycholate were 720 +/- 132 and 640 +/- 160 pmol/mg.min-1, respectively. Activity of 7 alpha-hydroxylation of free deoxycholate was very low (60 +/- 20 pmol/mg.min-1). After treatment with phenobarbital in a dose of 100 mg/kg per day for 6 days, 7 alpha-hydroxylase activities of conjugated deoxycholates were decreased significantly (40%, P less than 0.01, n = 8), whereas that of free deoxycholate was not significantly changed. In the rat, 7 alpha-hydroxylase activities of conjugated deoxycholates were induced significantly (45% increase, P less than 0.05, n = 5) by phenobarbital treatment in sharp contrast to the hamster. There were significant correlations between the 7 alpha-hydroxylase activity of taurodeoxycholate and that of glycodeoxycholate both in the hamster and in the rat (hamsters: n = 16, r = 0.98, P less than 0.01; rats: n = 10, r = 0.82, P less than 0.01). These studies suggested that deoxycholic acid is 7 alpha-hydroxylated after amidation with glycine or taurine in vivo and that the same enzyme may well catalyze the 7 alpha-hydroxylation of glycodeoxycholate and taurodeoxycholate in the hamster.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Isolation and culture of bile duct epithelial cells as an useful tool for screening of biliary tract carcinogens].

A method of isolation and culture of extrahepatic bile duct epithelial cells from Holstein cows has been established for detection of carcinogens in relation to bile duct cancer. Cells were isolated by digestion with Dispase followed by scraping of the mucosa. The integrity, the epithelial character and the purity of cells isolated were confirmed by electron microscopy. By the use of this culture induction of unscheduled DNA synthesis by chemicals which are capable of developing bile duct cancers in experimental animals, were assessed autoradiographically with or without addition of S-9 mixture. MNNG and ENNG induced UDS, which was not influenced by S-9 mixture. MCA elicited UDS only if S-9 mixture was added. Regardless of the presence of S-9 mixture, DMN failed to induce UDS but AFB1 induced UDS dose-dependently. The contact routes of the carcinogens with bile duct cells were established and this culture system way be an useful tool for the detection of biliary tract carcinogens.

Animals↗
PubMed1989

Familial occurrence of anomalous pancreaticobiliary duct union associated with gallbladder neoplasms.

The authors present two cases of anomalous pancreaticobiliary duct union that occurred in a mother and her daughter; the former was associated with gallbladder adenocarcinoma, and the latter, gallbladder adenoma with high grade dysplasia. This disorder has been considered a developmental anomaly, although the true etiology has not been known. This is the first report of familial occurrence of this anomaly, and it may point to the presence of a genetic factor in its development. Another implication is the presence of histological features which suggest the possible sequence of anomalous pancreaticobiliary duct union to intestinal metaplasia to adenoma or dysplasia to cancer of the gallbladder.

Adenocarcinoma↗
PubMed1988

Cholesterol monomer activity correlates with nucleation time in model bile.

Nucleation time (Cholesterol monohydrate crystallization) in bile has been introduced to distinguish patients with cholesterol gallstone from normal human beings. To test the hypothesis that cholesterol monomer activity correlates with nucleation time, we have examined the relationship between nucleation time, apparent cholesterol monomer activity and cholesterol monomer concentration in the aqueous phase using model biles containing bile salt, phospholipid and cholesterol. Apparent cholesterol monomer activity was inversely well correlated with nucleation time in the dilution study (r = -0.98) and in the cholesterol saturation study (r = -0.88) but positively with cholesterol monomer concentration in the aqueous phase in the dilution study (r = 0.72) and in the cholesterol saturation study (r = 0.93). The results indicate that cholesterol monomer activity reflects the nucleation time in model bile system.

Bile↗
PubMed1988

Quantitative microanalysis of bile acids in biological samples. Collaborative study.

The analysis of bile acids in biological samples has always presented a problem because of their complex nature and low concentration. Recently, newer analytical procedures for bile acids have become available, including enzymatic analysis, radioimmunoassay, thin-layer chromatography (TLC), gas chromatography, high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS) with selected ion monitoring (SIM). However, they differ greatly with respect to specificity, sensitivity, accuracy and simplicity. On the other hand, the choice of analytical procedure differs according to the specific aims and the nature of biological samples to be analysed. These newer procedures have been compared in a double-blind fashion by distributing bile, plasma and urine samples to seven participating laboratories. GC-MS-SIM was found to be the most sensitive and reliable, but it requires other procedures for preliminary clean-up and fractionation steps. Enzymatic analysis is simple and gives small analytical errors but tends to over-estimate plasma bile acids. Radioimmunoassay gives variable results but is useful as a screening procedure for large numbers of plasma samples. TLC gives reliable results for biliary bile acids in experienced hands, except for differentiation between conjugated dihydroxycholanoic acids. HPLC, whether using derivatization or with fixed 3 alpha-hydroxy steroid dehydrogenase detection, is suitable for the analysis of major bile acids in normal human serum but not for the identification of unknown minor peaks.

3-Hydroxysteroid Dehydrogenases↗
PubMed1988

Simultaneous microanalysis of bile acids and cholesterol in bile by glass capillary column gas chromatography.

Simultaneous quantitative microanalysis of bile acids and cholesterol was carried out by enzymatic hydrolysis, the formation of the ethyl ester dimethylethylsilyl ether derivatives and subsequent analysis by glass capillary gas chromatography. A complete separation and satisfactory recovery of cholesterol and the five major bile acids commonly occurring in human and hamster bile were obtained. The method is applicable to individual small animal models such as hamster from which only a small amount of bile is available.

Animals↗
PubMed1988

Differences in the release of cholesterol from taurocholate versus taurochenodeoxycholate micellar solutions.

The maximal micellar solubility, distribution and apparent monomer activity of cholesterol in taurine-conjugated cholate and chenodeoxycholate micellar solutions were studied to clarify the different modulating effect of these bile salt species on cholesterol uptake in an intestinal lumen. The maximal micellar solubility was significantly greater in taurochenodeoxycholate. The intermicellar cholesterol monomer concentration was not significantly different between the two kinds of micellar solution. However, the apparent cholesterol monomer activity determined using an artificial organic phase (polyethylene disc) was significantly higher in taurocholate than that in taurochenodeoxycholate. A linear relationship between the intermicellar cholesterol concentration and the apparent cholesterol monomer activity was found, with the slope depending upon the bile salt species. It is concluded that the difference in partitioning of cholesterol from taurocholate and taurochenodeoxycholate micelles into a fixed organic phase may contribute in part to the different regulating effects of these bile salts on the uptake of cholesterol in the intraluminal phase.

Chenodeoxycholic Acid↗
PubMed1988

Ki-1+ cutaneous lymphoma. Gene rearrangement analysis of tumor cells in tissue and short-term culture of a patient.

Cutaneous malignant lymphomas developed in an 80-year-old man without any evidence of leukemic disseminations of lymphoma cells. Immunohistologic staining showed the expression of Leu-3a, Leu-4, Ki-1, Tac, and HLA-DR antigens on tumor cells in tissue and large lymphoid cells in long-term, interleukin 2-containing culture of tumor explants. DNA samples extracted from the skin tumors and cultured lymphoid cells showed a clonal rearrangement of T-cell receptor (TCR) gene C beta 1 with the molecular size of 9 kilobases. These findings suggested the T-cell origin of Ki-1+ cutaneous lymphoma cells and the occurrence of a clonal proliferation of tumor cells in culture.

Aged↗