PubMed Health⌕ Search

Biomedical subjects

K Okuda

Publications and source records attributed to K Okuda.

At least 775 records · Page 43Linked to original sources
PubMed1987

[Hypergonadotropic ovarian failure in three patients with pituitary hyperplasia].

Three patients with ovulatory disturbances associated with increased production of gonadotropins and normal excretion of estrogen were endocrinologically examined. Patient A was 25 years old and had irregular menstruation of 13 years' duration. Patients B and C were 32 and 36 years old, the former with secondary amenorrhea of 19 years' duration and the latter with one of 2 months. Endocrinological analyses revealed a markedly increased plasma concentration of both LH (greater than 117 mIU/ml) and FSH (greater than 113 mIU/ml) in all three patients. The plasma concentration of estradiol was over 56 pg/ml in A and C before medication, and in the other patient (case B) the plasma estradiol level rose to 53 pg/ml after the administration of clomiphene. There was excessive LH and FSH response in the LH-RH stimulation test. Episodic gonadotropin secretions were observed and two weeks' administration of estrogen plasma concentrations of LH and FSH were suppressed. Computerized tomography revealed a high density area about 9-11 mm in diameter in the sella turcica of all three patients. Patient A underwent surgery via the transsphenoidal approach. Histology shows pituitary hyperplasia. After operation, the elevated LH and FSH concentration decreased to below 30 mIU/ml and the plasma concentration of estradiol and progesterone was increased to 260 pg/ml and 2 ng/ml, respectively.

Adult↗
PubMed1987

Effects of esophageal transection combined with splenectomy on portal hemodynamics.

Portal hemodynamics were studied in 69 patients with cirrhosis and 29 patients with idiopathic portal hypertension to investigate the effects of an operative procedure for varices that consists of transabdominal esophageal mucosal transection, paraesophagogastric devascularization, pyloroplasty, and splenectomy. Portal venous flow measured by the pulsed Doppler flowmeter in 14 patients with cirrhosis and nine patients with idiopathic portal hypertension, who underwent operation 2-5 yr earlier, was significantly reduced compared with that in unoperated 49 patients with cirrhosis and 17 patients with idiopathic portal hypertension who had esophageal varices (410 +/- 158 versus 660 +/- 263 ml/min in cirrhosis; 443 +/- 185 versus 912 +/- 189 ml/min in idiopathic portal hypertension). In nine patients (six cirrhosis, three idiopathic portal hypertension), portal venous flow and portal vein pressure were measured before and after operation. In patients with cirrhosis, portal vein pressure did not change significantly postoperatively even though portal venous flow was reduced. In contrast, portal vein pressure decreased in two patients with idiopathic portal hypertension in whom portal venous flow was reduced. Portal vein pressure was elevated in one patient with idiopathic portal hypertension in whom portal venous flow was increased postoperatively as a result of resection of a large gastro- and splenorenal shunt conducted additionally.

Aged↗
PubMed1986

Hepatitis B virus RNA transcripts and DNA in chronic liver disease.

To study the relation between gene expression of hepatitis B virus (HBV) and liver disease, we studied HBV RNA transcripts and DNA in liver-biopsy specimens from 30 patients with chronic liver disease (17 seropositive for hepatitis B surface antigen and 13 seronegative). HBV-specific RNA was found in all the seropositive patients and in none of the seronegative patients. Two major RNAs, sizes 29S (long) and 21S (short), were found in nine seropositive patients, of whom seven had free HBV DNA and eight were seropositive for hepatitis B e antigen. Six of the nine patients had hepatitis B core antigen in hepatocytes and active liver disease. In contrast, inactive liver disease was noted in the remaining eight seropositive patients, who had only one (21S) RNA. None of these patients had free HBV DNA (five of eight had integrated DNA) or hepatitis B core antigen in hepatocytes. Hybridization analysis suggested that 29S and 21S RNAs are messenger RNAs of hepatitis B core antigen and hepatitis B surface antigen, respectively. These data indicate that the free DNA and its products are causally related to the activity of liver disease and that once HBV DNA has been integrated, the disease will become quiescent. None of the determinants were identified in patients seronegative for hepatitis B surface antigen.

Adult↗
PubMed1986

Integration of hepatitis B virus DNA in hepatocellular carcinoma.

Integration of hepatitis B virus (HBV) DNA into genomic DNA was investigated in 34 livers bearing hepatocellular carcinoma (HCC) by Southern blot hybridization using 32P-labeled, cloned and purified HBV DNA as a probe. Rehybridization of nitrocellulose paper with a probe containing only the cloning vector was performed after dehybridization to avoid possible false-positive results. Integrated HBV DNA was detected in all 9 hepatitis B surface antigen (HBsAg)-seropositive cases and 3 out of 25 (12%) HBsAg seronegative cases. The hybridization patterns of viral DNA were the same among several cancer nodules in two HCC cases with multiple liver tumors, indicating unicentric hepatocarcinogenesis in these two cases. These results, obtained with avoidance of false-positive results, showed that only a minority of HBsAg-seronegative HCC cases in Japan had demonstrable HBV DNA in the tumors studied by the Southern blot hybridization technique.

Carcinoma, Hepatocellular↗
PubMed1986

Appearance of viral RNA transcripts in the early stage of duck hepatitis B virus infection.

Sequential analysis of duck hepatitis B virus (DHBV) DNA and RNA transcripts in the liver of the early stage of infection was carried out using 1-day-old ducklings inoculated with DHBV-positive serum. Using Southern blot analysis, a band of supercoiled DHBV DNA was detectable at 6 hr, when DHBV-specific poly[A]+RNA was also observed by Northern blot analysis as a faint smear below 3-kb. Bands of RNA at 3.5, 2.7, and 2.5 kb were detected at 12 hr, just before single-stranded viral DNA was detected. A prominent increase in the amount of viral RNA was demonstrated (between 12 hr and 3 days) prior to the increase of DHBV DNA (between 3 and 6 days). Our results suggest that 3.5-kb DHBV-specific RNA synthesized from supercoiled DNA may act as a template of reverse transcription, and that all steps of the replication pathway proposed by Summers and Mason (1982, Cell, 29, 403-415) are completed during 3 days.

Animal Diseases↗
PubMed1986

Identification of 7 alpha,12 alpha-dihydroxy-5 beta-cholestan-3-one 3 alpha-hydroxysteroid dehydrogenase.

A reductase catalyzing the reduction of the 3-ketone group of 7 alpha,12 alpha-dihydroxy-5 beta-cholestan-3-one and 7 alpha-hydroxy-5 beta-cholestan-3-one, which are the intermediates in the conversion of cholesterol to cholic acid and chenodeoxycholic acid, respectively, into the 3 alpha-hydroxyl group, was purified about 250-fold as judged by the activity from the 100,000 X g supernatant of rat liver homogenate. The purified enzyme was electrophoretically homogeneous, and its molecular weight determined by sodium dodecyl sulfate-polyacrylamide gel electrophoretography was 32,000. The absorption spectrum of the purified enzyme showed only a peak at 280 nm due to aromatic amino acids, precluding the presence of a chromophoric prosthetic group in the molecule. The enzyme showed activity toward a variety of substrates, including 3-oxo-5 beta-cholanoic acid, androsterone, 9,10-phenanthrenquinone, p-nitrobenzaldehyde, but not toward glucuronic acid, DL-glyceraldehyde, and glycolaldehyde. The optimal pH for the reduction of 7 alpha-hydroxy-5 beta-cholestan-3-one was 7.4, and the cofactor required was either NADPH or NADH, though the former gave the higher activity. Judging from the chromatography behavior as well as substrate specificity, the enzyme was identified as 3 alpha-hydroxysteroid dehydrogenase (3 alpha-hydroxysteroid:NAD(P)+ oxidoreductase, EC 1.1.1.50).

3-Hydroxysteroid Dehydrogenases↗
PubMed1986

Establishment of monoclonal antibodies which possess the same characteristics as the naturally occurring thymocytotoxic autoantibodies (NTA).

Autoantibody-secreting hybrid cell lines were obtained by fusion of spleen cells from unimmunized (NZB X NZW) F1 mice with the HAT-sensitive mouse myeloma cell line SP2/0-Ag14. Eight hybridoma cell lines producing autoantibodies to mouse thymocytes were cloned and the resultant antibodies were partially characterized. All eight monoclonal antibodies lysed mouse thymocytes in the presence of rabbit complement. The anti-thymocyte cytotoxic antibody activities were absorbed with thymocytes, lymph node cells, unfractionated spleen cells, and splenic T cells; but not with bone marrow cells, splenic B cells, or homogenates of mouse kidney, liver, or striated muscle cells. In addition, the cytotoxic activities of culture supernatants from seven of the eight hybrid clones were absorbed with mouse brain tissue homogenates. Isotyping of the monoclonal antibodies revealed that five were IgM and three were IgG2a. Mouse thymocytes sensitized with each of the eight monoclonal antibodies in vitro became highly susceptible to phagocytosis by syngeneic macrophages. The monoclonal antithymocyte antibodies, thus, appear to be similar to the naturally occurring, (NZB X NZW) F1 thymocytotoxic autoantibodies (NTA) described by Shirai et al.

Animals↗
PubMed1986

Delayed-type hypersensitivity to allogeneic mouse epidermal cell antigens. I. Lyt-1+2- T cells are important for DTH.

Footpad swelling response was used to measure the alloantigenicity of epidermal cells (ECs) in delayed-type hypersensitivity (DTH). Strong footpad swelling was observed 3 h after the challenge, and it continued for 48 h after the challenge. Genetical incompatibility between the recipients and the ECs was required to induce significant footpad swelling. H-2 or non-H-2 incompatibility between mice and ECs in the sensitization phase sufficed to develop significant footpad swelling. Incompatibility caused by point mutation in the A region induced strong responses when B6.C-H-2bm12 mice were immunized with B6/J ECs, but the disparity in immunoglobulin h (Igh) allotype genes was insufficient. H-Y antigen on ECs could also elicit the DTH response. Semiallogeneic F1-derived ECs sensitized the parental recipients. The responses were successfully transferred by immune lymph node cells, but not by immune sera. Treatment of these immune lymph node cells with monoclonal antibodies plus complement revealed that the cells responsible for DTH transfer were Lyt-1+2-, Ia- T cells.

Animals↗
PubMed1986

Primary liver cancer. Quadrennial review lecture.

Primary liver cancer, particularly HCC, is increasing in certain countries, notably Japan. Although hepatitis B virus has been etiologically linked to hepatocarcinogenesis and integration of its DNA into hepatocyte chromosomal DNA has been emphasized, other etiologic factors seem to have an interplay with virus infection. Histopathology of HCC has geographic variations. An expanding encapsulated HCC is most common in Japan, whereas it is nearly nonexistent in the West; such regional differences can only be explained by differences in the major etiologic factors. Early detection of HCC is now possible with ultrasound examination combined with AFP measurement, and this strategy has been executed with success in the Far East where HCC is endemic among cirrhotics. The speed of tumor growth can be measured with accuracy by ultrasound examination. Preneoplastic or early lesions of HCC in a cirrhotic liver seem to be adenomatous hyperplastic nodules or foci, and the conventional histological criteria for malignant liver cells do not seem applicable to such lesions. Although advanced cirrhosis is a real deterrent for hepatic surgery, hepatic resection affords a better survival compared with any nonsurgical therapeutic modality. Transcatheter arterial embolization is one of the current preferences of the hepatologist for inoperable patients. Lastly, a new staging scheme has been proposed for the assessment of prognosis and for comparison of efficacy of various therapeutic modalities.

Animals↗
PubMed1986

A case of Venoplant-induced hepatic injury.

The first case of hepatic injury induced by Venoplant, extracts of Aesculus Hippocastanum, having antiinflammatory activities, was described. A 37 yr-old man was admitted for treatment of pathological fracture of the left brachial bone. He had been received 65 mg Venoplant at another hospital several hours before admission. 17 days later, a liver function test showed mild abnormality and 60 days after injection, he complained of pruritus and jaundice. Laboratory studies revealed moderate elevation of total bilirubin, ALP, gamma-GTP and mild eosinophilia. CT studies and ERC showed no signs of extrahepatic obstructive jaundice. The lymphocyte stimulation test was positive. The liver biopsy demonstrated marked cholestasis with zonal necrosis in the centrilobular areas but showed little or no changes in the portal tracts. These features are consistent with drug-induced hepatic injury.

Adult↗
PubMed1986

An improved method for assay of cholesterol 7 alpha-hydroxylase activity.

An improved assay method for cholesterol 7 alpha-hydroxylase which is accurate, sensitive, and yet still simple is described. The method consists of two parts: the first part is cholesterol 7 alpha-hydroxylation in liver microsomes utilizing cholesterol in situ as the substrate, and the second part is conversion of the product, 7 alpha-hydroxycholesterol, into 7 alpha-hydroxy-4-cholesten-3-one having an intense absorption at 240 nm by the action of cholesterol oxidase. The converted sterol is then analyzed by high-performance liquid chromatography. During the second enzyme reaction, the first enzyme reaction is halted and further metabolism of the product is prevented. In consequence, the method had more than 10-fold increase in the sensitivity than the previous one.

Animals↗
PubMed1986

Sterol composition and biosynthesis in mouse salivary glands.

Sterol components of mouse submandibular, sublingual and parotid glands were studied by thin-layer and gas-liquid chromatography. The major sterol was cholesterol (5-cholesten-3 beta-ol; 26.7, 28.0, 18.8 micrograms/mg protein respectively), with minor amounts of squalene, lathosterol (5 alpha-cholest-7-en-3 beta-ol), desmosterol (cholesta-5,24-dien-3 beta-ol), lanosterol (4,4',14-trimethyl-5 alpha-cholesta-8,24-dien-3 beta-ol), dihydrolanosterol (4,4',14-trimethyl-5 alpha-cholest-8-en-3 beta-ol) and methylstenol. Chromatograms of salivary sterols were similar to those of liver, and different from those of skin in which the amount of lathosterol was much higher. Administration of the anticholesterolaemic agent, 20,25-diazacholesterol, resulted in accumulation of desmosterol in all tissues tested, and additional sterols also accumulated in skin. The gas-liquid chromatographic profiles of salivary sterols from the treated animals were similar to those of liver, but different from those of skin. Thus sterols were synthesized in salivary glands and the biosynthetic pathway was via C24-unsaturated side-chain intermediates, as in liver. This was verified by showing that [2-14C]-mevalonate was incorporated into sterols in vitro when it was incubated with homogenates of these glands.

Animals↗