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Biomedical subjects

F Nakayama

Publications and source records attributed to F Nakayama.

At least 91 records · Page 5Linked to original sources
PubMed1987

Effect of albumin on the solubility of cholesterol in bile.

Despite the fact that a considerable amount of albumin is present in bile, little is known about the effect of albumin on micellar solubility of cholesterol. The effect of albumin on solubility of cholesterol in various micellar bile salt solutions was studied using Millipore filtration after equilibration. In addition, partitioning of cholesterol from micellar solution was studied using a polyethylene disc method. Decrease of the solubility of cholesterol by the presence of albumin was observed only in unconjugated bile salt solution. The lowering effect of albumin on the cholesterol solubility was found to be proportional to the hydrophobicity of bile salt. In contrast, albumin had almost no effect on cholesterol solubility, either in conjugated bile salt solution or in micellar bile salt solution containing phosphatidylcholine. Addition of albumin enhanced the partitioning of cholesterol out of the micelles in sodium chenodeoxycholate solution as a result of decreased micellar solubility and increased the aqueous solubility of cholesterol in the presence of albumin. Therefore, conjugated bile salt and phosphatidylcholine exert a buffering action on the albumin-induced adverse effect on cholesterol solubility, thus stabilising bile against inadvertent precipitation of cholesterol.

Bile↗
PubMed1987

Bile acid metabolism in cirrhotic liver tissue--altered synthesis and impaired hepatic secretion.

Bile acid analysis of mild and severe cirrhotic liver showed that with the advancement of cirrhosis the concentration of chenodeoxycholic acid in liver tissue becomes higher, resulting in the lower ratio of cholic to chenodeoxycholic acid probably due to the progressive alteration of cholic and chenodeoxycholic acid synthesis with the advancement of liver cirrhosis. Bile acid analysis of paired liver and bile of severe cirrhosis showed that the ratio of cholic to chenodeoxycholic acid in liver was lower than that in bile or even with that in bile. This can be explained by postulating the impaired hepatic secretion of bile acids, especially chenodeoxycholic acid. The impaired secretion together with the relatively well preserved chenodeoxycholic acid synthesis results in the accumulation of chenodeoxycholic acid in liver tissue with cirrhosis.

Bile Acids and Salts↗
PubMed1987

Nonbacterial transformation of bilirubin in bile.

Bilirubin present in gallstones is mainly in the unconjugated form despite the frequent absence of bacteria in bile. The aim of the present study was to determine if nonbacterial beta-glucuronidase activity and/or nonenzymatic hydrolysis is responsible. Inflammatory cells such as polymorphonuclear leukocytes and lymphocytes appearing with the presence of brown pigment gallstones and inflammation in biliary tract was shown to effect deconjugation of bilirubin conjugates in bile and contribute to their formation in addition to that of bacterial beta-glucuronidase. Gallbladder bile (mean +/- SD, 4.0 +/- 1.6%, N = 29) contained more unconjugated bilirubin than hepatic bile (mean +/- SD, 2.7 +/- 1.1%). In vitro experiments showed the deconjugation to take place during incubation at 37 degrees C without the presence of bacteria. Therefore, transformation of conjugated to unconjugated bilirubin is likely to take place in vivo during the storage in gallbladder, and nonbacterial beta-glucuronidase activity and/or nonenzymatic hydrolysis may be responsible for such transformation.

Bacteria↗
PubMed1987

Effect of total colectomy and mucosal proctectomy on intestinal absorptive capacity in dogs.

Changes in intestinal absorptive capacity for water and electrolytes were investigated in dogs after total colectomy and mucosal proctectomy reconstructed with interposing jejunum into the anorectal area. Rate of absorption of water and sodium from the ileum increased significantly at 29 weeks postoperatively. The absorption of water, sodium, and chloride in the jejunum was significantly higher than in the neorectum. The net secretion rate of potassium increased significantly in the ileum and neorectum. The authors suggest that intestinal adaptation achieved after proctocolectomy is enhanced in the jejunum and ileum rather than in the neorectum.

Animals↗
PubMed1987

Demonstration and maintenance of mucus secretion in cultured human gallbladder epithelial cells.

The method of human gallbladder epithelial cell culture has been developed successfully with active mucus secretory function. Human gallbladder epithelial cells were dissociated by Dispase digestion from the specimens obtained by cholecystectomy for uncomplicated gallbladder stone cases. The dissociated cells formed a monolayer in Eagle's minimum essential medium supplemented with 10% fetal bovine serum within 24 h after the inoculation. These cells were maintained for at least 2 wk without fibroblastic overgrowth. Cultured cells contained periodic acid Schiff-positive material in cellular cytoplasm for 3 d. On transmission electron microscopy these materials were identified as mucous secretory granules. Mucous secretory function was determined by [3H]glucosamine incorporation. Sixty percent of the secreted glycoproteins labeled with [3H]glucosamine was eluted in excluded fractions of Sepharose 4B gel filtration, which were considered to be mucous glycoprotein, because they were found to be resistant to proteoglycan-specific enzymes such as hyaluronidase, chondroitinase ABC, heparitinase, and heparinase. The mucous glycoprotein secretion was maintained for 3 d and found to be inhibited in a dose-dependent manner by monensin (10(-7) to 10(-5) M) which is a known blocker of secretory function.

Cells, Cultured↗
PubMed1987

Bile acid metabolism in isolated rat hepatocytes: studied by gas-liquid chromatography-mass spectrometry-selected ion monitoring.

Bile acid contents in isolated rat hepatocytes were determined by gas-liquid chromatography-mass spectrometry-selected ion monitoring with the use of deuterium-labeled internal standards. This allowed us first to monitor the actual amounts of not only major but also minor bile acid components present with sufficient sensitivity and specificity and to follow the changes of individual bile acids in cultured rat hepatocytes simultaneously. In freshly isolated rat hepatocytes, cholic and beta-muricholic acids were the major components, comprising 35 and 46% of the total bile acids, respectively. These two bile acids were found to be most actively synthesized during the first 2 h of incubation and continued to increase thereafter for up to 6 h (the end of the period studied). In contrast, chenodeoxycholic and alpha-muricholic acids, which are the precursors of beta-muricholic acid, showed slight increases only in the first hour of incubation and decreased thereafter. These results suggested that the conversion to beta-muricholic acid from chenodeoxycholic acid via alpha-muricholic acid occurred rapidly in cultured rat hepatocytes. The secondary bile acids such as deoxycholic, hyodeoxycholic, and 3 alpha, 12 beta-dihydroxy-5 beta-cholanoic acids declined steadily from the start of incubation, which supported the findings that further hydroxylation of these dihydroxy bile acids occurs in rat liver.

Animals↗
PubMed1987

Analysis of 3-sulfated and nonsulfated bile acids by one-step solvolysis and high performance liquid chromatography.

A facile solvolysis procedure of 3-sulfated bile acid was devised using trifluoroacetic acid, tetrahydrofuran, and methanol. The sulfate esters were completely solvolyzed within only 2 hr by the present method. The clinical utility of the solvolysis procedure and high performance liquid chromatography using immobilized 3 alpha-hydroxysteroid dehydrogenase was demonstrated in the analysis of bile acids in serum of patients with obstructive jaundice. The quantities of 3-sulfated bile acids were calculated from the difference in the amount of bile acids before and after solvolysis. A significantly large proportion of 3-sulfated glycochenodeoxycholic acid, i.e., 21.9 to 31.3% of total glycochenodeoxycholic acid, was found in the serum of patients with obstructive jaundice. Thus, the present method permits simultaneous quantitation of 3-sulfated as well as nonsulfated bile acids in biological samples.

Bile Acids and Salts↗
PubMed1987

Altered metabolism of bile alcohol and bile acid in complete extrahepatic cholestasis: qualitative and quantitative aspects.

Urinary excretion of bile alcohols and bile acids in patients with complete extrahepatic cholestasis before and after the release by external biliary drainage was studied. Following extraction, isolation, and hydrolysis, bile alcohols were determined by capillary gas-liquid chromatography-mass spectrometry as dimethylethylsilyl derivatives. During cholestasis, 8.89 mumol/day of bile alcohol and 140.4 mumol/day of bile acid were excreted in urine. The amount of bile alcohol excreted was 6.1% of that of bile acid. Positive correlation between excretion of bile alcohols and bile acids was observed. The major bile alcohols excreted were also present in urine from healthy individuals but in much smaller amounts. After the release of extrahepatic cholestasis, urinary excretion of bile acid decreased rapidly, but that of bile alcohol decreased only gradually. The latter often increased again and remained high. The results indicate that the increased excretion of bile alcohols in complete extrahepatic cholestasis may reflect the expansion of a normally existing pathway of bile alcohol synthesis and excretion leading to the modification of bile alcohols for their efficient urinary elimination. It is also suggested that the rate of synthesis of bile alcohols is determined partly by the size of the substrate pool available.

Adult↗
PubMed1987

Electrohydraulic lithotripsy of intrahepatic stones during choledochoscopy.

In two patients, electrohydraulic lithotripsy was used under direct vision during choledochoscopy to fragment intrahepatic calculi above bile duct strictures, which were difficult to remove by ordinary choledochoscopic methods. Choledochoscopy was performed after dilation of a percutaneous transhepatic tract in one patient and after intubation of the subcutaneous blind jejunal limb of a previous Roux-en-Y intrahepatic cholangiojejunostomy in the other. Both patients were treated without any complications. Electrohydraulic lithotripsy during choledochoscopy is a safe and effective method to fragment stones and facilitate their removal.

Adult↗
PubMed1987

Anomalous junction of pancreaticobiliary duct without congenital choledochal cyst: a possible risk factor for gallbladder cancer.

Among 1586 patients subjected to endoscopic retrograde cholangiopancreatography, an anomalous junction of the pancreaticobiliary duct (AJPB) was found in 24 patients (1.5%). Eighteen of the 24 had an associated congenital choledochal cyst, and six did not. Four of these six patients (66.7%) had gallbladder cancer. A clinicopathological study was performed on these four and 43 such cases reported in the literature. The diagnosis of AJPB was made by direct cholangiography. Median age of these 47 (53.5 yr) was younger than those without AJPB. The length of the common channel ranged from 15 to 53 mm. The pancreatic-biliary type junction was present in 36 of 39 cases (92.3%). Gallstones were present in 7 of 40 (17.5%). Levels of amylase in bile were high in 10 of 11. Presence of AJPB without congenital choledochal cyst may be a high risk factor in gallbladder cancer; hence prophylactic cholecystectomy should be considered for patients with AJPB, without congenital choledochal cyst.

Adenocarcinoma↗
PubMed1986

Pigment gallstone composition in patients with hemolysis or infection/stasis.

The effect of hemolysis and infection/stasis on pigment gallstones was assessed by comparing the composition of stones from (1) U.S. patients without hemolysis or cirrhosis, (2) U.S. patients with sickle cell disease, and (3) Japanese patients with biliary infections. Gallstone composition was quantitated by infrared spectroscopy and chemical analyses. Gallstones from patients with sickle cell anemia contained more pigment, carbonate, calcium, and measured components than stones from U.S. patients without hemolysis (P less than 0.05). However, the similar types of calcium salts in black stones from patients with and without sickle cell anemia suggested that intermittent hemolysis may be a potential mechanism in the formation of black stones found in the general population. In Japanese patients with brown pigment stones, there was an absence of calcium carbonate, low levels of calcium phosphate, and the presence of calcium salts of fatty acids (P less than 0.05). Thus, the accompanying stasis and/or infection in this latter group was associated with the formation of a distinctive stone type and was not involved in the formation of the black stones. The similarly small proportion of cholesterol in each of these groups suggested that it was present due to coprecipitation rather than to cholesterol supersaturation.

Anemia, Sickle Cell↗
PubMed1986

Hepatolithiasis in East Asia. Retrospective study.

Hepatolithiasis is a major disease in Asia but differences in operative incidence between countries have not been examined. A retrospective study was conducted in Taiwan, Hong Kong, and Singapore, and the results were compared with those in Japan with the aim of defining factors involved in the etiology of the condition. In order to ensure uniformity of the data collected, the same form was used throughout the study and was completed by the same personnel after reviewing the patient's record and radiographs in each case. The years 1976-1980 were chosen for the study, since the newer methods of diagnosis such as ultrasound, endoscopic retrograde cholangiography, and percutaneous transhepatic cholangiography became available during that period. The most significant finding was the difference in the relative prevalence of hepatolithiasis as a proportion of all gallstone cases in Taiwan, Hong Kong, and Singapore, where the majority of the population consisted of patients of Chinese descent. The highest prevalence, 53.5%, was found in Taiwan, while in Hong Kong it was 3.1% and in Singapore 1.7%. Environmental rather than ethnic factors are implicated in the cause of hepatolithiasis.

Adult↗
PubMed1986

Endoscopic retrograde cholangiography with a balloon catheter: analysis of 100 consecutive cases.

One hundred patients whose standard endoscopic retrograde cholangiographic studies gave poor visualization of the biliary tract were investigated using a balloon catheter introduced into the common bile duct by duodenoscopy to block contrast material leakage. Full diagnostic visualization was obtained in 90 patients, leading to accurate diagnosis in 88. In two other patients, the diagnosis was not confirmed. In ten patients the bile ducts were not filled because of balloon size (seven), vagovagal reflex (two), and fistula (one). There were no serious clinical complications. Laboratory studies following the procedure disclosed impaired liver function (three patients), hyperamylasemia (two), and leukocytosis (two) of 41 patients tested, and positive blood culture in three of 81 patients studied. When standard retrograde cholangiography fails to visualize the biliary tract, endoscopic retrograde balloon catheter cholangiography is a useful diagnostic procedure, associated with acceptable minor complications.

Adult↗
PubMed1986

Cancer mortality among patients undergoing cholecystectomy for benign biliary diseases.

Potential risks of gastrointestinal cancers after cholecystectomy were examined among 1238 patients who had had their gallbladders extirpated for benign biliary diseases from 1951 to 1970. The observed deaths between 1953 and 1984 were compared with the expected values which were calculated from death rates in Japan. No appreciable excess mortality was found for stomach cancer, colorectal cancer or pancreas cancer in relation to cholecystectomy. Observed and expected deaths during the whole observation period were 29 vs. 31.58 for stomach cancer, 8 vs. 6.50 for colorectal cancer overall, 5 vs. 3.19 for colon cancer and 3 vs. 3.51 for pancreas cancer. The corresponding figures in the 10 years or more after cholecystectomy were 14 vs. 19.06 for stomach cancer, 5 vs. 4.66 for colorectal cancer and 3 vs. 2.38 for colon cancer. A notably increased mortality from liver cancer was observed, but it was considered to be related not to cholecystectomy itself but to blood transfusion.

Biliary Tract Diseases↗