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Biomedical subjects

H Oka

Publications and source records attributed to H Oka.

At least 397 records · Page 22Linked to original sources
PubMed1987

Enzyme-linked immunosorbent assay of serum pepsinogen I.

A hybridoma monoclonal antibody against human pepsinogen I was used to develop an enzyme-linked immunosorbent assay for pepsinogen I in serum. In the two-step competitive procedure using antimouse immunoglobulin F(ab')2 fragment coupled to alkaline phosphatase, the measurable assay range was 8-256 micrograms/l. No cross-reactivity with rat pepsinogen 1, human pepsinogen II, gastrin I, bombesin, somatostatin and peptide YY was shown. However, there was slight cross-reactivity (0.09%) with porcine pepsinogen. The coefficients of variation within and between series were 7.6% and 13.0%. This enzyme-linked immunosorbent assay for serum pepsinogen I correlated positively with radioimmunoassay (r = 0.87, n = 92). The concentration range of serum pepsinogen I in 354 healthy controls was 15-100 micrograms/l with a lognormal distribution. Serum pepsinogen I levels were significantly higher in the subjects who developed active duodenal ulcer or active gastric ulcer, but significantly lower in those who had gastric cancer, than in control subjects.

Adult↗
PubMed1987

Serum pepsinogens as a screening test of extensive chronic gastritis.

The serum level of pepsinogen I (PG I) and pepsinogen II (PG II), and the PG I/PG II ratio were compared with the surface area of the fundic mucosa, as determined endoscopically by the Congo red staining method. Reduction in the area of the fundic mucosa due to gastritis was associated with stepwise reduction in the PG I levels and the PG I/PG II ratios. Reduction in the area of the fundic mucosa was also associated with decreases in the basal acid output, maximal acid output (MAO), the basal pepsin output and the stimulated pepsin output. The best sensitivity and specificity levels for the diagnosis of normal mucosa and severe gastritis were obtained with the PG I/PG II ratio and the MAO. A retrospective study of 58 patients with gastric cancer and 162 cancer-free patients showed that a PG I/PG II ratio identified 86.2% of all carcinomas and 87.5% of early carcinomas. Although this test gave a positive rate of 36% among the cancer-susceptible age group controls, its use would lower the cost of mass screening by targeting a smaller test population.

Chronic Disease↗
PubMed1987

Effects of calmodulin antagonists on secretion of bile and bile acid.

In the isolated perfused rat liver, the effects of calmodulin (CaM) antagonists, chlorpromazine (CPZ), trifluoperazine (TFP), W-7 and W-5, on secretion of bile and bile acid were compared. Without addition of taurocholic acid to the perfusate, TFP (200 microM or higher), CPZ (200 microM) and W-7 (400 microM) decreased the bile flow transiently. In contrast, W-5 did not decrease the bile flow. Taking into consideration the binding of TFP and CPZ to bovine serum albumin in the perfusate, they diminished the bile flow by inhibiting CaM function. This was also supported by the difference between the effects of W-7 and W-5. These findings suggested that CaM was involved in the secretion of bile. Under the constant infusion of taurocholic acid into the perfusate, CaM antagonists decreased the secretion of bile acid. However this might be due to the inhibition of bile acid uptake, because these agents inhibited the uptake into isolated rat hepatocytes. The concentrations required for inhibition of the uptake were near to those which decreased the viability, suggesting that the inhibition was due to their non-specific cytotoxic effect. Future studies must be carried out to determine whether CaM is involved in the secretion of bile acid.

Animals↗
PubMed1987

A diagnostic marker of autoimmune chronic active hepatitis: liver plasma membrane antibody in the serum absorbed with particulate fraction of kidney homogenate.

The sera absorbed with the particulate fraction of rabbit kidney homogenate (RK) were tested for the antibody against liver plasma membrane (LPM-Ab) by the radiometric assay method. After incubation of the isolated rabbit liver plasma membrane (RLPM) with appropriately diluted serum, IgG bound to RLPM (IgG-RLPM) was determined using 125I-labelled Staphylococcal protein A. IgG-RLPM in each subject tested was expressed in arbitrary units, that is, the multiple of the mean radioactivity associated with RLPM in 35 control subjects. Thus IgG-RLPM was 1.00 (mean) +/- 0.23 (SD) in the control subjects, 1.13 +/- 0.30 in 9 patients with chronic persistent hepatitis (CPH), 1.13 +/- 0.52 in 15 with chronic active hepatitis (CAH), 1.34 +/- 0.38 in 23 with liver cirrhosis (LC) and 3.45 +/- 0.73 in 5 with autoimmune CAH. F(ab')2 fragments from a patient with autoimmune CAH and a control subject decreased IgG-RLPM by 86.4 +/- 6.35 and -5.2 +/- 14.9%, respectively, in four patients with autoimmune CAH. LPM-Ab was detected in 0, 20.0 and 17.4% in the patients with CPH, CAH and LC, respectively. All of the patients with autoimmune CAH were positive for LPM-Ab. The absorption of the sera positive for LPM-Ab with RK decreased IgG-RLPM in various extents. In two of five patients with autoimmune CAH and two of seven patients with CAH or LC, the majority of LPM-Ab was cross-reactive with RK.

Animals↗
PubMed1987

Poliovirus infection of established human blood cell lines: relationship between the differentiation stage and susceptibility of cell killing.

The replication of type 1 poliovirus in 13 established human blood cell lines differing in the differentiation stage and cell lineage was investigated. Three T (CCRF-CEM, CCRF-HSB-2, and Molt-3) and three B (Raji, CCRF-SB, and RPMI 8226) cell lines showed no cytopathic effects (CPE) or virus production. CPE associated with virus production were detected in the other seven cell lines: HL-60, ML-1, and KG-1 (granulocytic lineage), U-937 and THP-1 (monocytic lineage), K-562 (erythroid lineage), and Molt-4 (T cell lineage). These susceptible cell lines greatly differed in the speed at which the CPE progressed. The progression of CPE was faster in relatively well-differentiated cell lines such as HL-60 and U-937, independently of the multiplicity of infection, than in less differentiated cell lines such as K-562, KG-1, and THP-1. Thus, for the same lineage, the speed at which CPE progressed became proportionally higher with subsequent differentiation stages. In the K-562 cell culture, CPE were not observed until at least 5 days postinfection (p.i.), while more than 80% of HL-60 cells were killed within 3 days p.i. There were no significant differences between infected HL-60 and K-562 cells in the efficiency of infection determined at 8 hr p.i. by the indirect immunofluorescent technique, the rate of virus growth, or the amount of viral capsid protein synthesized. This indicated that there were similar viral replication cycles in the two cell lines. These observations suggest that the killing function of the virus is expressed more slowly in K-562 cells than in HL-60 cells.

Blood Cells↗
PubMed1987

Role of cell-surface modulator of DNA synthesis in liver regeneration.

A cell-surface modulator of DNA synthesis by cultured rat hepatocytes was studied in relation to the liver regeneration process. When rat hepatocytes isolated 24 h after partial hepatectomy were cultured, the first burst of DNA synthesis peaked at 5-8 h and declined until 24 h, followed by the second burst. Rat liver plasma membranes added 2 h after plating inhibited only the second burst, while in the case of the normal hepatocytes where the DNA synthesis began to increase after 5 h, this inhibition was observed at 16 h but not at 8 h. The inhibition did not differ when the membranes obtained from regenerating livers 12 h after partial hepatectomy were used. Epidermal growth factor binding to the cultured hepatocytes was not hindered by the membranes. These results suggest that the modulator inhibits hepatocyte proliferation at the early G1-phase of the cell cycle and that its action might be controlled by other factors in the process of liver regeneration.

Animals↗
PubMed1987

Effect of dietary cholesterol on production of lipoproteins and apolipoproteins by perfused livers from Japanese monkeys (Macaca fuscata).

Isolated livers from Japanese monkeys were perfused for the purpose of characterizing low density lipoprotein (LDL) secreted directly by the liver, and for determining whether cholesterol feeding affects the hepatic production of LDL. Perfusate containing [3H]leucine was recirculated for 60 min, followed by perfusion with fresh perfusate for two additional 2-h periods. Radiolabelled lipoproteins, which are isolated by ultracentrifugation as very low density lipoprotein (VLDL), LDL, and high density lipoprotein were 0.87 +/- 0.74, 1.83 +/- 1.47, and 0.44 +/- 0.33%, respectively, of total radiolabelled protein in the medium of the last 2-h period. Subfractionation of perfusate LDL by high performance liquid chromatography, and by concanavalin A sepharose chromatography, revealed that the newly synthesized LDL were secreted as apo E-rich particles. Cholesterol feeding resulted in a four-fold increase in hepatic secretion of newly synthesized VLDL, but not of the LDL. The distribution of radioactivity among VLDL apolipoproteins was not affected by cholesterol feeding. Incorporation of radioactivity into apo B100 of LDL decreased significantly, but that into apo E did not change. These results suggested that (i) the elevation of serum LDL in cholesterol-fed monkeys is not due to enhanced hepatic production of LDL, but probably results from intravascular metabolism of VLDL, which is of hepatic origin, and (ii) cholesterol feeding affects the hepatic apo B100 synthesis and/or release but not apo E.

Animals↗
PubMed1987

A first case of complete remission of beta-interferon sensitive adult T-cell leukemia.

A case of complete remission of adult T-cell leukemia (ATL) induced by beta-interferon is reported. A 46-year-old male was diagnosed as ATL because of the increased number of ATL cells with deeply indented and lobulated nuclei in the peripheral blood, accompanied by elevated values of the lactic dehydrogenase, the alkaline phosphatase, and the calcium in the serum. The result of the cell surface marker analysis of peripheral blood lymphocytes was compatible with ATL and anti-ATL associated antibody (ATLA) was positive. The integration of proviral deoxyribonucleic acid (DNA) of human T-cell leukemia virus type I(HTLV-I) was proved in the peripheral blood lymphocytes using Southern blot hybridization. Since an ordinal chemotherapy was not so effective for this patient, he was treated with 1.8 X 10(7) units of recombinant beta-interferon (beta-IFN) per day for 7 days as one course. After 5 courses of treatment, a markedly favorable response was recognized, and he achieved complete remission. A lower dose of beta-IFN (9 X 10(6) units per day for 3 days as one course, one or two courses per month) has been continued and he has still been in a complete remission state for 10 months. It is concluded that beta-IFN should be used to treat ATL.

Blood Cells↗
PubMed1987

L-methionine enhances the contractile response to norepinephrine of rat vas deferens.

Under Ca-depleted conditions, the contractile responses of rat vas deferens in the presence of norepinephrine were not elicited until the addition of CaCl2. L-Methionine enhanced the contractile response of vas deferens in the presence of methylation blockers under these conditions. The enhancing effect of L-methionine on some other smooth muscles could not be determined because under Ca-depleted conditions, these muscles showed 60-80% of the maximal contractile response on addition of CaCl2 alone. These findings suggested that L-methionine has an enhancing effect on contraction of the rat vas deferens as it does on rat uterine muscle.

Animals↗
PubMed1987

Phosphoinositides turnover and insulin secretion in pancreatic islets.

The relationship between glucose-induced insulin secretion and metabolism of inositol phospholipid was investigated by means of an islet perifusion method and direct measuring of inositol phosphates after sonicating the islets. The results showed that the time course of inositol phospholipid breakdown is coincident with the first phase of glucose-induced insulin secretion. Analysis of the effluent perifusate as well as the water soluble inositol-containing substance after sonication of stimulated islets revealed that most of the metabolite of inositol phospholipid is inositol-triphosphate, the hydrolysis product of phosphatidylinositol-4,5-bisphosphate. On the other hand, perifusion of islets with exogenous inositol-triphosphate showed a monophasic and dose-dependent response of insulin secretion. Thus, the initial process of glucose stimulation is accompanied with the formation of inositol-triphosphate, which is a possible candidate for the triggering of first phase insulin secretion.

Aminoquinolines↗
PubMed1987

Loss of echoes from the gallbladder wall in diagnosis of fatty infiltration of the liver.

Ultrasonograms taken within 24 h before liver biopsy were evaluated retrospectively for fatty infiltration of the liver in 155 non-ascitic patients with liver diseases. Relatively high amplitude echoes of the liver as compared with the kidney were observed in all of 33 patients whose fatty infiltration of the liver occupied more than 10% of each lobule or pseudolobule irrespective of etiology. Among such patients, loss of echoes from the gallbladder wall was additionally found in 18 of 19 cases uncomplicated by hepatic fibrosis, but only in 3 of 14 cases with this complication. We conclude that fatty infiltration without fibrosis in the liver may be differentiated from that with fibrosis by ultrasonic examination.

Adult↗
PubMed1987

Biosynthesis and secretion of the third component of complement by human endothelial cells in vitro.

The third component of complement (C3) is synthesized and released by cultured human capillary endothelial cells. After the incubation of cells in a methionine-free medium containing 35S-methionine for 48 hr, culture supernatants were immunoprecipitated with anti-human C3 serum. SDS solubilization and 2-ME reduction of the immunoprecipitates, followed by separation with SDS-polyacrylamide gel electrophoresis and autoradiography, revealed two major bands comparable to those of the alpha and beta chains of human C3. The content of C3 in the culture medium harvested at different time-intervals was determined by ELISA. The C3 secretion rate was about 250 ng/10(6) cells/5 days in the primary culture medium and 75 ng/10(6) cells/5 days after seven passages. The capillary endothelial cells described here have factor VIIIRAg specific for endothelial cells, and exhibit ring formation resembling capillary lumina, but they lack Weibel-Palade bodies.

Antigens↗