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Biomedical subjects

S Okuda

Publications and source records attributed to S Okuda.

At least 289 records · Page 16Linked to original sources
PubMed1985

Early adenocarcinoma of the gastric cardia.

The relationships of gross and histologic types of early gastric cancer in the upper portion of the stomach, the extent of the normal oxyntic gland area and the grade of intestinal metaplasia in the mucosa surrounding the tumor, to the distance of the tumor from the squamocolumnar junction were examined in 29 specimens obtained at total gastrectomy. There were significant correlations between gross type of early cancer, extent of the normal oxyntic gland areas or the grade of intestinal metaplasia in the surrounding mucosa, and the distance of the tumor from the squamocolumnar junction. Cancers located within 2 cm from the squamocolumnar junction were more frequently polypoid, more frequently associated with a large oxyntic gland area, and less commonly surrounded by profuse intestinal metaplasia. The above differences suggest that cancers located within 2 cm from the squamocolumnar junction differ from those in other regions of the upper portion of the stomach.

Adenocarcinoma↗
PubMed1985

Value of heparinized fine-needle aspiration biopsy in liver malignancy.

The accuracy of diagnosis of hepatic malignancy by percutaneous aspiration biopsy was compared using heparinized and nonheparinized 22-gauge needles. When a heparinized instrument was used, it was able to accurately diagnose malignancy and cytologic types of exfoliative cells. Heparinization also made it possible to recover small tissue fragments and make ultrathin sections for histologic examination. In this way, material suitable for cytologic and histologic examination was obtained from 100% and 95%, respectively, of 59 patients suspected of having hepatic malignancy. A correct diagnosis was made cytologically in 92.5% of patients with hepatic malignancy and in 89.5% of those from whom histologic material was obtained. From a combination of histologic and cytologic results, the overall diagnostic rate for hepatic malignancy was increased to 95%. This procedure proved to be a reliable method for diagnosis of hepatic malignancy.

Biopsy, Needle↗
PubMed1985

Lactoquinomycin, a novel anticancer antibiotic. II. Physico-chemical properties and structure assignment.

Lactoquinomycin, a new antibiotic, C24H27NO8, mp 151 approximately 159 degrees C (dec), FAB-MS: m/z 458 (MH+), is a basic substance, showing UV lambda MeOHmax (epsilon) 215 (37,600), 254 (10,700) and 432 nm (4,760), and IR nu CHCl3max 1790 (gamma-lactone), 1665 and 1650 (quinone) cm-1. The structure of lactoquinomycin has been elucidated by 1H NMR and ORD in comparison with those of kalafungin.

Antibiotics, Antineoplastic↗
PubMed1985

Effect of glucagon on gastric motility examined by the acetaminophen absorption method and the endoscopic procedure.

The effects of glucagon and butropium bromide on gastric motility were compared by the acetaminophen absorption method and the endoscopic procedure. Intramuscular administration of 1 USP unit of glucagon and 4 mg of butropium bromide caused a significant decrease in the serum acetaminophen level 30 min after digestion of a test meal. Results indicated that glucagon significantly delayed gastric emptying, and that its inhibitory effect was similar to that of butropium bromide. Moreover, endoscopic examinations showed that glucagon and butropium bromide had similar inhibitory effects on gastric peristalsis. However, butropium bromide caused side effects more frequently than glucagon. Therefore, premedication with glucagon is superior to that with butropium bromide for upper gastrointestinal endoscopy.

Acetaminophen↗
PubMed1984

Cytohistologic diagnosis of neoplasms of the liver by ultrasonically guided fine-needle aspiration biopsy.

A procedure was developed for obtaining both cytologic and histologic specimens from patients suspected of having hepatic malignancy at the time of ultrasonically guided liver aspiration biopsy using a 22-gauge needle of 0.4 mm inner diameter. The fine needle and the syringe used were heparinized before use to avoid blood coagulation in the materials obtained. With heparinized needle and syringe it was possible to centrifuge the materials obtained and make good smears containing abundant tumor cells, and to obtain small tissue specimens. Histologic specimens obtained with the heparinized needle were fixed in 2.5% glutaraldehyde, postfixed in 1.0% osmium tetroxide, and embedded in epoxy Epon resin. Ultrathin sections were made and usually stained with Azan-Mallory stain. In 41 patients suspected of having hepatic malignancy, a correct diagnosis was made by a combination of these examinations. The sensitivity of this procedure for hepatic malignancy was 100%, and the specificity was 95.7%. Therefore, this procedure is a very reliable method for diagnosis of hepatic malignancy.

Aged↗
PubMed1984

An autoradiographic study on the labeling index of biopsy specimens from gastric cancers.

With the aim of examining proliferative activity of gastric cancers of various histologic types, H3-thymidine labeling indices of biopsy specimens from 48 patients were examined using an in vitro labeling technique. The results indicated that the indices were greatly variable (1.4-40.8%) from case to case and from area to area, and could not be well correlated with either gross findings, histologic types, or the degree of tumor invasion. However, the distribution of the labeled cells within the tumor was somewhat characteristic to each histologic type. In adenocarcinomas, DNA-synthesizing cells were scattered at random over the entire tumor tissue. In signet-ring cell carcinomas, small tumor cells with dark-staining cytoplasm were preferentially labeled. In contrast, typical signet-ring cells had practically zero labeling index, suggesting that they are out-of-cycle cells and are functionally differentiated.

Adenocarcinoma↗
PubMed1984

Destruction of implanted gastric tumors in rats by acridine orange photoactivation with an argon laser.

The phototoxicity of acridine orange and argon laser irradiation on Walker carcinosarcoma 256 stomach tumors was studied. Wistar strain rats bearing stomach tumors 4-6 mm in diameter 5-10 days after their implantation were injected intraperitoneally with 40 mg/kg of acridine orange 2 hr before irradiation. Then the forestomach was opened and the tumors were exposed to the argon laser at 488 nm at an intensity of 15 mW/cm2 for 20 min. Tumors in rats treated with acridine orange were brightly fluorescent during irradiation. No marked temperature rise was detected during irradiation. Argon irradiation significantly prolonged the survival of rats treated with acridine orange. Histologically, complete or partial tumor necrosis was observed, with sparing of surrounding mucosa, in rats treated by the combination therapy. Phase-contrast and electron microscopy showed that cytotoxicity was mediated by changes in the cell, nuclear and lysosomal membranes. Neither the dye nor laser alone had any effect.

Acridine Orange↗
PubMed1984

Diagnosis of early gastric cancers in the upper part of the stomach by the endoscopic Congo red-methylene blue test.

The clinicopathological features of the early gastric cancers in the upper part of the stomach, and the accuracy of their diagnosis by routine endoscopic examination were examined, and the accuracy of diagnosis of minute and flat cancers in the upper portion of the stomach by routine endoscopic examination and by the endoscopic Congo red-methylene blue test developed in our clinic were compared. Early cancers in the upper part of the stomach occurred in the elderly patient, and grossly elevated types were frequent. Endoscopically they were most difficult to diagnose by a single routine endoscopic examination, because they were frequently overlooked, and adequate biopsy was difficult in some cases. A correct diagnosis of minute and flat cancers in the upper part of the stomach by routine examination was made in only 27.3% and 25.0% of the cases, respectively. But with the Congo red-methylene blue test the diagnostic rate was raised significantly to 75.0% and 83.3%, respectively. In this test, Congo red and methylene blue sprayed on the surface of the tumor were bleached white 2 to 5 minutes after application, in sharp contrast to the unaffected mucosa.

Adenocarcinoma↗
PubMed1984

Studies on the metabolism of unsaturated fatty acids. XIII. Properties of 2,4-dienoyl-CoA reductase from beef liver.

It is demonstrated that 3-alkenoyl-CoA is the product of the enzymic reduction catalyzed by 2,4-dienoyl-CoA reductase with the highly purified enzyme preparation from beef liver mitochondria. Incorporation of deuterium atoms from deuterium-labeled NADPH and 2H2O during the reaction catalyzed by 2,4-dienoyl-CoA reductase from beef liver was investigated. When trans-2, trans-4-decadienoyl-CoA was incubated with the reductase in the presence of 4R-[4-2H1]NADPH and H2O, no deuterium was detected in the reaction product by gas chromatography-mass spectrometry after derivatization to pyrrolidine amides of fatty acids. When the substrate was incubated with the enzyme in the presence of 4S-[4-2H1]NADPH and H2O, one deuterium atom was incorporated into the product, 3-decenoate, at the C-5 position. In the case of 3-decenoate enzymatically prepared in the presence of NADPH and 2H2O, two deuterium atoms were incorporated into the product at the C-2 position. These results indicate that the reaction catalyzed by 2,4-dienoyl-CoA reductase from beef liver is a unique example of 1,4-addition of hydrogen to a 1,3-diene system conjugated with a carbonyl group of a thioester in biochemical fields. Chain length specificity of the reductase, isotope effects on reaction rates and competitive inhibitors are also discussed.

Animals↗
PubMed1984

Turn-over of phospholipids in Selenomonas ruminantium.

The particulate enzyme prepared from Selenomonas ruminantium subsp. lactilytica catalyzed the formation of phosphatidylserine (PS) from CDP-diglyceride and serine, and phosphatidylethanolamine (PE) from PS. This indicates that PS and PE in this organism are synthesized through a similar pathway to that in Escherichia coli. In turn-over experiments with [32P]orthophosphate and [14C]caproate, a rapid turn-over of PE was observed, while ethanolamine plasmalogen was relatively stable. The decrease of 14C-radioactivity in PE side-chains was accompanied by an increase of 14C-radioactivity in side-chains of ethanolamine plasmalogen. In pulse label-chase experiments with [32P]orthophosphate, significant amounts of 32P-radioactivities were incorporated into plasmalogens at the beginning of the chase and a precursor product relationship was observed between serine plasmalogen and ethanolamine plasmalogen. On the contrary, in pulse-label-chase experiments using [14C]caproate and [3H]glycerol, no significant radioactivity was incorporated into plasmalogens at the beginning of the chase and radioactivities in plasmalogens slowly increased during the chase. These results indicate that 1-O-alk-1'-enyl-2-acyl-glycerol moieties of plasmalogens are derived from a large precursor pool, but the phosphorous moiety is not. This concept was supported by the fact that synthesis of plasmalogens occurred in the absence of fatty acid synthesis. We wish to propose the possibility that 1-O-alk-1'-enyl-2-acyl-glycerol moieties of plasmalogens are derived from the diglyceride moieties of diacyl phospholipids.

CDPdiacylglycerol-Serine O-Phosphatidyltransferase↗
PubMed1984

Cerulenin resistance in a cerulenin-producing fungus. II. Characterization of fatty acid synthetase from Cephalosporium caerulens.

Cerulenin, an antifungal antibiotic isolated from a culture filtrate of Cephalosporium caerulens, is a potent inhibitor of fatty acid synthetase systems of various microorganisms and animal tissues. This antibiotic specifically blocks the activity of beta-ketoacyl thioester synthetase (condensing enzyme) by binding to the functional cysteine-SH in the active center of the condensing enzyme domain (the peripheral SH-group). However, fatty acid synthetase from C. caerulens is much less sensitive to cerulenin than fatty acid synthetases from other sources. The properties of C. caerulens synthetase were investigated and compared to those of Saccharomyces cerevisiae synthetase, which is sensitive to the antibiotic. The molecular weight of the enzymically active form of C. caerulens synthetase was 2.53 X 10(6). The enzyme consisted of two multifunctional proteins, alpha and beta, which are arranged in a complex, alpha 6 beta 6. The synthetase was inactivated by iodoacetamide. At 0 degrees C and pH 7.15, the second-order rate constant of k = 15.6 M-1 X s-1 was obtained for the inactivation by iodoacetamide. This value was about 15 times greater than that for S. cerevisiae synthetase. Treatment of C. caerulens synthetase with iodoacetamide, while impairing the synthetase activity, induced malonyl-CoA decarboxylase activity. When S. cerevisiae synthetase was preincubated with cerulenin, malonyl-CoA decarboxylase activity could not be detected even after treatment of the enzyme with iodoacetamide (Kawaguchi, A., Tomoda, H., Nozoe, S., Omura, S., & Okuda, S. (1982) J. Biochem. 92, 7-12). In the case of C. caerulens synthetase, on the other hand, malonyl-CoA decarboxylase activity was induced by iodoacetamide even after the preincubation of the enzyme with cerulenin.(ABSTRACT TRUNCATED AT 250 WORDS)

Acremonium↗
PubMed1984

Values of serum carcinoembryonic antigen and elastase 1 in diagnosis of pancreatic carcinoma.

Carcinoembryonic antigen (CEA) and elastase 1 in the serum were determined by enzyme immunoassay and radioimmunoassay, respectively, in 224 healthy subjects, 49 patients with pancreatitis, 53 patients with pancreatic carcinoma and 129 patients with cancer in other organs. The CEA concentrations in the serum were significantly higher in patients with pancreatic carcinoma than in those with pancreatitis, but this concentration was not a satisfactory indicator of pancreatic carcinoma localised to allow irradication by resection as it was raised in only 47% of the patients. High CEA concentrations were also slightly, but not significantly, more frequent in patients with cancer of the pancreatic body or tail, and unresectable cancer or cancer of more than 6.0 cm in longest diameter than in those with cancer of the pancreatic head, resectable cancer or cancer of less than 6.0 cm diameter. Serum elastase 1 was raised in only 42% of the patients with pancreatic carcinoma and could not be used to distinguish patients with pancreatic carcinoma from those with pancreatitis. In contrast with CEA, however, its concentration was abnormally high significantly more frequently in patients with cancer of less than 6.0 cm in longest diameter than in those with larger tumours. It was also raised slightly, but not significantly, more frequently in those with cancer of the pancreatic head and in patients with resectable cancer than in those with unresectable cancer. A combination of these two tests raised the diagnostic rate of pancreatic carcinoma to 77% without a remarkable decrease in the specificity for pancreatic carcinoma. In particular, it raised the diagnostic rates of cases of cancer of the pancreatic head, resectable cancer and cancers of less than 3.0 cm and 3.0-6.0 cm in longest diameter. Therefore, a combination of measurements of CEA and elastase 1 in the serum is very useful for early detection of pancreatic carcinoma.

Adult↗
PubMed1984

Autologous immune complex nephritis in streptozotocin-induced diabetic rats.

In order to investigate the influence of diabetes mellitus on immune complex-mediated nephritis , we produced Heymann nephritis in streptozotocin-induced diabetic rats (DM-HN group) in which the clinical course for 24 weeks and histological changes were examined. Nondiabetic rats with Heymann nephritis (HN group) and diabetic rats (DM group) were also examined as controls. The degree of proteinuria, hypoproteinemia, hyperlipidemia and anemia were more pronounced and the mortality rate was higher in the DM-HN group than in the HN group or in the DM group. Histologically, larger and more subepithelial or intramembranous electron-dense deposits as well as a more markedly thickened glomerular basement membrane (GBM) were observed in the DM-HN group than in the HN group. In conclusion, the nephrotic manifestations and histological changes in the GBM in Heymann nephritis were augmented by the association with diabetes mellitus.

Animals↗
PubMed1984

Studies on macrocyclic lactone antibiotics. VII. Structure of a phytotoxin "rhizoxin" produced by Rhizopus chinensis.

A new 16-membered macrolide designated as rhizoxin was isolated as a toxin produced by Rhizopus chinensis, the causal agent of rice seedling blight . The skeletal structure was determined by detailed NMR spectroscopic investigation of this compound and of its derivatives. Rhizoxin induced at a concentration of 10 ng/ml abnormal swelling of rice seedling roots, which is one of the characteristic symptoms of this disease. This compound also exhibited potent antifungal activity but little effect against bacteria.

Anthraquinones↗
PubMed1984

Photodynamic effects of exposure to hematoporphyrin derivatives and dye-laser radiation on human gastric adenocarcinoma cells.

The phototoxicity of hematoporphyrin derivatives (HPD) and dye-laser radiation on adenocarcinoma cells of the human stomach was examined by light and electron microscopy. Adenocarcinoma cells were obtained from human stomach tissue by endoscopic biopsy. The cells were incubated for 5 minutes in the patient's own serum that contained 0.6 mg HPD/ml and then were exposed to dye-laser radiation at 630 nm at an irradiance of 15 mW/cm2. Electron microscopy showed that cytotoxicity was mediated by mitochondrial damage, dilatation of the rough endoplasmic reticulum, and alterations of the nuclear membrane. The degenerative changes were greater and more frequent in poorly differentiated adenocarcinoma cells than in well-differentiated ones. No marked temperature rise was detected during irradiation. Neither the dye alone nor light alone had any effect. A singlet oxygen-trapping agent, 1,3-diphenylisobenzofuran, prevented adenocarcinoma cell degeneration that otherwise would result from exposure to HPD and dye-laser radiation. Thus singlet oxygen may be the cytotoxic agent in this system.

Adenocarcinoma↗