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Biomedical subjects

K Okuda

Publications and source records attributed to K Okuda.

At least 847 records · Page 47Linked to original sources

Incidence of portal vein thrombosis in liver cirrhosis. An angiographic study in 708 patients.

Portal vein thrombosis was thought to be a common complication of liver cirrhosis in the past. The incidence of angiographically demonstrable portal vein thrombosis was studied in 708 consecutive patients with unequivocal cirrhosis seen in the past 10 yr in whom either transhepatic portography or superior mesenteric arterial portography clearly delineated the major portal vein system. Excluding 2 cases that were thought to be associated with past splenectomy, there were 4 cases of portal vein thrombosis related to cirrhosis, all in a decompensated stage. The calculated incidence of portal vein thrombosis was 0.573% of all cirrhotic patients without splenectomy in the past. They constituted 23.5% of the 17 cases of extrahepatic portal vein obstruction encountered during the same period. There were 78 cases of idiopathic portal hypertension similarly studied angiographically, and the incidence of portal vein thrombosis unrelated to splenectomy was 2.86%. A statistical survey based on 247,728 necropsies recorded in the Japan Autopsy Registries of 1975-1982 showed a 0.05489% incidence of portal vein thrombosis and a 6.58857% incidence of cirrhosis of all types among them, suggesting that portal vein thrombosis is not a common complication of cirrhosis in Japan in recent years.

Adult↗

Active and inactive replication of hepatitis B virus deoxyribonucleic acid in chronic liver disease.

Little is known about the replicative forms of hepatitis B virus (HBV) in the liver in chronic liver disease. We therefore analyzed HBV DNA and the changes in DNA signals after endonuclease digestion in liver tissues taken from 64 patients with hepatitis B surface antigen-positive chronic liver disease. The "active" replication pattern, which included various replicative intermediates, was seen in 36 of 38 (95%) hepatitis B e antigen-seropositive patients. This pattern was also found in 5 of 26 (19%) hepatitis B e antigen-seronegative patients who showed the highest mean serum alanine aminotransferase level (403 +/- 184 mU/ml). Most of them had advanced liver disease. Episomal viral DNA of an "inactive" type having only the supercoiled form was found in 3 patients; they showed the lowest mean serum alanine aminotransferase level (27 +/- 7 mU/ml) and only mild liver disease. As with duck HBV infection, episomal replicative forms of human HBV could be resolved by Southern blot analysis and seem to have clinical implications in human HBV infection.

Adult↗

Membranous obstruction of the portal vein. A case report.

Membranous obstruction of the portal vein has not been previously reported. This 56-yr-old Indonesian man with a history of a tropical fever 5 yr earlier presented with variceal bleeding. Transhepatic obliteration of the varices was attempted, but the catheter placed in the right portal branch would not pass beyond the porta hepatis. Another catheter was inserted into the portal trunk under ultrasound guidance. Simultaneous opacification through the two catheters demonstrated a complete membranous obstruction of the portal vein at the porta hepatis and a portal-superior mesenteric-venous axis that had lost communication with incoming veins and the left portal branch, most likely because of multiple thrombosis. Other angiographic procedures also revealed marked hepatopetal collaterals (cavernous transformation) entering the liver through the hilum. Liver biopsy showed acute posttransfusion hepatitis superimposed upon portal fibrosis. The possible mechanism for membrane formation in relation to thrombosis is discussed.

Humans↗

Association of gallbladder carcinoma and anomalous pancreaticobiliary ductal union.

A total of 96 patients with gallbladder carcinoma in whom direct cholangiography clearly opacified the pancreaticobiliary ductal union and the common channel, and 65 patients with an anomalous union of these two duct systems at a distance greater than 15 mm from the papilla of Vater (normally less than 4.6 +/- 2.2 mm, mean +/- SD) were studied. It was found that this anomalous ductal union occurred in 16.7% of the patients with gallbladder carcinoma in comparison with an incidence of 2.8% among 641 consecutive patients with various hepatobiliary and pancreatic diseases studied by endoscopic retrograde cholangiopancreatography who did not have gallbladder carcinoma. It was also found that gallbladder carcinoma occurred in 24.6% of the 65 cases of anomalous ductal union in comparison with a 1.9% incidence of this cancer among 635 consecutive patients similarly studied and found to have normal ductal union (p less than 0.001). Thus, a close etiologic association was suggested between this anomaly in the terminal segment of the biliary tract and gallbladder carcinoma. Of the 65 patients with anomalous ductal union, 50 had the so-called congenital cystic dilatation of the common bile duct and 15 did not. Five of the 50 (10%) and 11 of the 15 (73.3%) had gallbladder carcinoma (p less than 0.01), and this carcinoma seems to be related to anomalous ductal union rather than to cystic dilatation of the common bile duct. As a tumorigenic factor in this anomaly, regurgitation of pancreatic juice has been stressed.

Adult↗

Direction of splenic venous flow assessed by pulsed Doppler flowmetry in patients with a large splenorenal shunt. Relation to spontaneous hepatic encephalopathy.

We studied the direction of blood flow in the splenic vein, using a combined ultrasonic system consisting of an electronic sector scanner and a pulsed Doppler flowmeter, in 21 patients with a large spontaneous splenorenal shunt demonstrated by angiography. Pulsed Doppler flowmetry revealed hepatofugal flow in the splenic vein in all 11 patients with chronic spontaneous hepatic encephalopathy, and hepatopetal flow in 10 patients without encephalopathy. In the former, hepatofugal flow of part of the superior mesenteric venous blood into the splenorenal shunt was corroborated by the venogram obtained after superior mesenteric arteriography. In 5 patients without a history of hepatic encephalopathy, superior mesenteric arteriography demonstrated hepatofugal flow of part of the superior mesenteric venous blood into the splenorenal shunt. Pulsed Doppler flowmetry, however, revealed hepatopetal flow in all of these patients, suggesting that the angiographic finding of hepatofugal flow may have represented an artifact.

Arteriovenous Malformations↗

Assays for cholesterol 7 alpha-hydroxylase and 12 alpha-hydroxylase using high performance liquid chromatography.

Rapid and accurate assay methods for cholesterol:NADPH oxidoreductase (EC 1.14.13.17, 7 alpha-hydroxylating) and 7 alpha-hydroxy-4-cholesten-3-one 12 alpha-hydroxylase (enzyme not yet registered) are described. 7 alpha-Hydroxylase utilizes the endogenous cholesterol of liver microsomes as substrate. The reaction products were separated by high performance liquid chromatography monitored at 214 nm. Much higher activity was obtained with the method compared to literature values, which were obtained using externally added radioactive cholesterol as the substrate. The 12 alpha-hydroxylase activity was measured using non-radioactive steroid as the substrate. The reaction products were separated by the chromatography and detected at 240 nm. Comparable activities were obtained by this method compared to those that were obtained using radioactive substrate.

Animals↗

Recombinant leukocyte a interferon treatment in patients with chronic hepatitis B virus infection. Pharmacokinetics, tolerance, and biologic effects.

Large doses of recombinant leukocyte A interferon were administered to 20 patients with deoxyribonucleic acid polymerase- and hepatitis B e antigen-positive chronic hepatitis B to study the maximum tolerated dose, its pharmacokinetics, and its antiviral activity. The first group of 5 patients received a constant dose of 36 X 10(6) U/day for 28 consecutive days. When it was well tolerated, the second, third, and fourth groups (5 patients each) received 50, 72, and 100 X 10(6) U/day, respectively. All 20 patients completed the 28-day treatment. Hourly and daily profile of serum interferon level showed a dose-dependent effect with an increasing dosage, and cumulative effects during the treatment. The mean peak serum interferon concentration ranged from 93 U/ml on day 1 in the first group to 1271 U/ml on day 28 in the fourth group. Inhibition of serum deoxyribonucleic acid polymerase activity and hepatitis B virus-deoxyribonucleic acid during the treatment was compared between the groups with low doses (36 and 50 X 10(6) U) and high doses (72 and 100 X 10(6) U). Low doses of interferon suppressed deoxyribonucleic acid polymerase activity to the same extent as did the high doses. Prednisolone withdrawal was combined with interferon in 5 patients. Three patients treated with such combination became seronegative for hepatitis B e antigen during the treatment, whereas all 15 with interferon alone remained seropositive. These results suggest that a maximum antiviral effect of recombinant leukocyte A interferon is below the maximum tolerated doses.

Adult↗

Development of portal vein thrombosis complicating idiopathic portal hypertension. A case report.

A 58-yr-old woman with biopsy-proven idiopathic portal hypertension presented with ascites and pretibial pitting edema. On admission, ultrasonic Doppler flowmetry demonstrated hepatopetal flow of a markedly reduced velocity in the portal vein, hepatofugal flow in the splenic vein, and a large spontaneous splenorenal shunt. The patient spontaneously developed hepatic encephalopathy 1 mo later. Percutaneous transhepatic portography demonstrated mural thrombi at the porta hepatis after the catheter had penetrated the mural thrombi without resistance; there was also a long retention of contrast medium in the portal vein. 99mTc-Macroaggregated albumin instilled into the superior mesenteric vein was caught in the lungs, and no activity entered the liver. Measurements of ammonia and immunoreactive insulin clearly indicated that superior mesenteric venous blood was shunted through the splenic vein and the splenorenal shunt. Subsequent ultrasonic examination with Doppler flowmetry suggested further growth of the thrombi and lack of blood flow in the portal vein. Although the procedure of percutaneous transhepatic catheterization could have contributed to the growth of thrombi, it is more likely that the thrombosis in the portal vein was a sequela to idiopathic portal hypertension, and was growing at the time of catheterization. This case may be of significance in the understanding of the relationship between idiopathic portal hypertension and extrahepatic portal obstruction.

Female↗

Portal hemodynamics in chronic portal-systemic encephalopathy. Angiographic study in seven cases.

A portal hemodynamic study was made in 7 consecutive patients with chronic portal-systemic encephalopathy by percutaneous transhepatic catheterization of the portal vein and injecting contrast medium into the superior mesenteric vein or by superior mesenteric arterial portography in comparison with patients without encephalopathy studied by percutaneous catheterization of these veins. All 7 patients had a large gastro-renal or spleno-renal shunt, and a large proportion of superior mesenteric venous blood was being shunted as estimated from the diameter of the portal and the collateral vein, whereas in nonencephalopathic patients in whom part of the superior mesenteric venous blood was shunting this diversion was much less (P less than 0.001). Only one of the chronic portal-systemic encephalopathic patients had esophageal varices, insignificant in size, and the incidence of esophageal varices was significantly less compared to the 12 nonencephalopathic control patients with portal hypertension who had either a gastro-renal or spleno-renal shunt (P less than 0.05). It is suggested that chronic portal-systemic encephalopathy is a result of a large collateral route shunting a large proportion of the superior mesenteric venous blood into systemic circulation, and that development of such collaterals precludes formation of large esophageal varices.

Ammonia↗

Duck hepatitis B virus DNA in liver and serum of Chinese ducks: integration of viral DNA in a hepatocellular carcinoma.

The presence of duck hepatitis B virus (DHBV) DNA in liver and serum and its state (integrated vs. free) were studied in 23 ducks from Chi-tung county in China by spot hybridization and Southern blot hybridization, respectively. In 16 of 23 (70%), DHBV DNA was detected in serum and/or in liver tissue. These infected ducks showed a variety of pathological changes including advanced chronic disease in the liver. In contrast, none of the virus-negative ducks had advanced hepatic changes. One DHBV DNA-seropositive duck had a large hepatocellular carcinoma. Southern blot analysis demonstrated integrated DHBV DNA in neoplastic tissue and abundant episomal DHBV DNA in non-neoplastic tissue of the liver. In one noninfected duck with a small adenoma, no viral DNA was detected in tumor or non-neoplastic tissue. The detection of integrated DHBV DNA in hepatocellular carcinoma suggests that DHBV behaves like human and woodchuck hepatitis viruses in relation to chronic liver disease and hepatocarcinogenesis.

Animals↗

Analysis of hen egg white lysozyme (HEL)-specific delayed type hypersensitivity hybridomas.

Hen egg white lysozyme (HEL) specific delayed type hypersensitivity hybridomas (TDTH hybridomas) were established by fusing HEL specific C3H/HeN (H-2k haplotype) TDTH with BW5147 thymoma cells. TDTH hybridomas, which had Lyt-1+2- and Thy-1.2 antigens on their surfaces, were injected into mouse footpads with HEL antigens, and foot pad swellings were measured 24 h later. Mice with I-Ak haplotype showed strong responses, and their swellings were reduced by anti-I-Ak specific monoclonal antibodies, which suggests that the activity of the hybridomas is restricted by I-Ak. However, TDTH hybridomas did not modulate HEL specific T-cell proliferation responses.

Animals↗

Fatty acid composition and Shwartzman activity of lipopolysaccharides from oral bacteria.

The composition and the nature of the linkage of fatty acids and the Shwartzman activity of lipopolysaccharide (LPS) preparations derived from oral gram-negative bacteria including Bacteroides gingivalis, Bacteroides loesheii, Eikenella corrodens, Fusobacterium nucleatum, and Actinobacillus actinomycetemcomitans were examined. 3-Hydroxylated and nonhydroxy fatty acids of various chain lengths were found in all of the LPS preparations. All nonhydroxy fatty acids were found to be ester-bound, and part of the 3-hydroxy fatty acids in the LPS of B. gingivalis, E. corrodens, F. nucleatum, and A. actinomycetemcomitans were shown to be involved in ester linkage. It was also suggested that the hydroxy group of the ester-bound 3-hydroxy fatty acid of the LPS of F. nucleatum and A. actinomycetemcomitans is at least partly substituted by another fatty acid, but in the LPS of B. gingivalis and E. corrodens it is not. The main amide-linked fatty acid of the LPS of B. gingivalis, E. corrodens, F. nucleatum, and A. actinomycetemcomitans was 3-hydroxyheptadecanoic, 3-hydroxydodecanoic, 3-hydroxyhexadecanoic, and 3-hydroxytetradecanoic acid, respectively. The results of the Shwartzman assay showed that the E. corrodens LPS was the most active among the preparations tested, and that the Shwartzman toxicity of Bacteroides LPS is extremely low.

Actinobacillus↗

Pathogenesis of portal sclerosis in the liver with idiopathic portal hypertension. Observations of 19 autopsy cases and animal experiments.

The pathomorphological changes of intrahepatic portal veins were studied in 19 autopsy cases of idiopathic portal hypertension (IPH), and the pathogenesis of portal sclerosis was discussed by the observations on the human and experimental materials. The degree and morphological appearance of intimal lesions vary from vessel to vessel. Fibro-cellular proliferation of subendothelial tissue and incorporation of organized mural thrombi were suggested as the cause of intimal thickening in the portal veins. Animal experiment showed that injury of portal vein wall was followed by intimal hyperplasia and/or incorporation of mural thrombi, and resulted in portal sclerosis similar to that of IPH liver. The cause of portal phlebosclerosis in IPH can not be explained by passive congestion alone. There might be a certain possibility of direct injurious effect in the vessel wall in the pathogenesis of portal lesions of IPH. The following pathogenesis of portal sclerosis in IPH is postulated: phlebo-sclerotic changes of the portal veins are initiated by injury to the vessel wall due to unknown cause(s) and accelerated by secondary thrombosis and/or mechanical injury due to increased portal pressure.

Animals↗