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Biomedical subjects

H Ohyanagi

Publications and source records attributed to H Ohyanagi.

At least 73 records · Page 4Linked to original sources
PubMed1990

Mode of stimulatory action of deoxycholate in signal transduction system of isolated rat pancreatic acini.

Mode of stimulatory action of deoxycholate (DCA) on the secretagogue-induced amylase release and the phospholipase C reaction in isolated rat pancreatic acini was investigated using sodium fluoride (NaF), which is a direct activator of GTP-binding proteins (G proteins). DCA enhanced the amylase release induced by submaximal concentrations of NaF without affecting the maximal level of this reaction. Under the similar conditions, DCA enhanced the NaF-induced phospholipase C reaction. These stimulatory effects of DCA on the NaF-induced amylase release and phospholipase C reaction are comparable to those on the secretagogue-induced reactions reported previously. These results suggest that DCA acts on the coupling of a G protein(s) to the phospholipase C in the membrane transduction mechanism in isolated rat pancreatic acini.

Amylases↗
PubMed1990

Purification and characterization of a novel GTP-binding protein with a Mr value of 24,000 from rat liver.

About 15% of the total GTP-binding proteins (G proteins) of rat liver homogenate was found in the microsomes-Golgi complex fraction. From this fraction, we purified to near homogeneity and characterized a G protein with a Mr value of 24,000 (24K G). 24K G specifically bound guanosine 5'-(3-Q-thio) triphosphate (GTP gamma S), GTP and GDP with a Kd value for GTP gamma S of about 30 nM. 24K G bound maximally about 0.7 mol of GTP gamma S/mol of protein. 24K G hydrolyzed GTP to liberate Pi with a turnover number of about 0.008 min-1. 24K G was not copurified with the beta gamma subunit of heterotrimeric G proteins. The partial amino acid sequences of 24K G revealed that this protein was a novel small G protein.

Animals↗
PubMed1990

Characterization of an antigen defined by monoclonal antibody KMO1.

We have isolated an antigen defined by the monoclonal antibody KMO1 from tissue culture supernatant as a glycoprotein and from cancer cells as a glycolipid. The antigenic determinant was a carbohydrate. Antibody KMO1 inhibited the binding activity of 19-9 to CA19-9, but 19-9 antibody did not inhibited the binding activity of KMO1 to KMO1 antigen. The glycolipid antigen of KMO1 was a monosialoganglioside and was separated into 3 components on thin layer chromatography. The 19-9 antibody reacted with one of the components. These results suggest that the KMO1 antigen is similar to but not identical to CA19-9.

Animals↗
PubMed1990

Development of monoclonal antibodies against human gastrointestinal cancer.

We have evaluated approximately 10,000 monoclonal antibodies resulting from 14 hybridization of spleen cells from mice immunized with established cancer cell lines. They were screened by binding assays using cancer cell lines or normal fibroblast cells, followed by immunohistochemical study on tissue sections. Ninety-one monoclonal antibodies were obtained by above binding assays. One of them, named KM10 was further investigated. Isotype of KM10 was IgG1 with kappa-light chain. It was shown that KM10 has strong reactivity with tumors of colon, stomach, papilla Vater, and pancreas, while the limited reactivity displayed with normal tissues. The electron microscopic observation revealed that the antigen recognized by KM10 is expressed on the surface of cancer cells. KM10 could mediate ADCC. These results indicate that KM10 is a good candidate for a probe of diagnosis and therapy of cancer.

Antibodies, Monoclonal↗
PubMed1990

Selection of monoclonal antibodies detecting KM01 antigen.

Monoclonal antibodies (MoAbs) were selected for specific binding inhibition of KM01 to the KM01 antigen, which was detected in the serum of colorectal and other gastrointestinal carcinoma patients. Out of 91 MoAbs tested, 8 were found to have the inhibiting activity. The reactivity of these MoAbs with glycolipid antigen, which was isolated from cancer cell line, corresponded well with that of cancer patients sera. These monoclonal antibodies are thought to be useful in combination with KM01 for the construction of the second generation of the KM01 antigen-detecting system.

Antibodies, Monoclonal↗
PubMed1990

Immunohistochemical staining of pancreatic cancer with CA19-9, KM01, unabsorbed CEA, and absorbed CEA. A comparison with normal pancreas and chronic pancreatitis.

In order to test the effectiveness of CA19-9, KM01, unabsorbed CEA (carcinoembryonic antigen) and absorbed CEA by immunoperoxidase staining, we evaluated the staining distribution, intensity, and cellular localization in pancreatic cancer. The results were then compared with those of normal pancreas and chronic pancreatitis. The positive staining rate of the pancreatic cancer with any of the four tumor markers was higher than that of the normal pancreas. However, all markers except absorbed CEA showed a higher positive staining rate for chronic pancreatitis than for pancreatic cancer. There was no stromal type in normal pancreatic or chronic pancreatitis tissues with any of the four tumor markers. Our findings, therefore, indicate that absorbed CEA is useful in differentiating pancreatic cancer from normal pancreatic tissues. It is not useful in distinguishing chronic pancreatitis, however, unless a specific staining pattern is observed.

Antibodies, Monoclonal↗
PubMed1990

[Production of human monoclonal antibody reactive with gastrointestinal carcinoma].

Lymphocytes obtained from regional lymph nodes and spleen in the patients with gastrointestinal carcinoma were fused with the human B lymphoblastoid cell line GC01 and human hybridomas producing human monoclonal antibody (MoAb) were derived. Human MoAb No. 235 (IgM) derived from spleen cell of a gastric cancer patient reacted with adenocarcinoma of stomach, colon, and pancreas in the new immunohistochemical assay, modified direct immunoperoxidase method, and reacted with KATO III cells in cultured cell lines. The antigenic determinant of this antibody was suspected to be protein moiety after enzyme treatment. The competitive binding inhibition assay indicated that its epitope was different from anti-CEA monoclonal antibodies (KM10, A10, B9, AH3, JA4) and KM01. These findings suggested the possible use of human MoAb No. 235 for clinical application of targeting cancer chemotherapy in the future.

Antibodies, Monoclonal↗
PubMed1990

Extracorporeal removal of anticancer drugs in hepatic artery infusion: the effect of direct hemoperfusion combined with venovenous bypass.

The effect of a new extracorporeal system combining direct hemoperfusion (DHP) with venovenous bypass was evaluated in the elimination of anticancer drugs in hepatic artery infusion. Adriamycin (3 mg/kg) and mitomycin C (1 mg/kg) were given to mongrel dogs through the hepatic artery with three different durations of 1, 10, and 20 minutes. Plasma drug levels were determined at the inlet and outlet of DHP and right external jugular vein (systemic level). Blood flow through DHP averaged 200 ml/min. In dogs without DHP (group I; n = 4), systemic levels of adriamycin and mitomycin C increased rapidly with 1-minute infusion, reaching the peak values of 6.61 +/- 2.44 (mean +/- SD) and 2.20 +/- 1.05 micrograms/ml, respectively. With DHP under single venous bypass (group II; n = 5), the peak values were reduced to 1.25 +/- 1.02 and 0.79 +/- 0.52 microgram/ml. Moreover, the peak levels were markedly reduced by DHP under hepatic venous isolation (group III; n = 6), the values being 0.41 +/- 0.15 and 0.13 +/- 0.07 microgram/ml with 1-minute infusion. The drug-removal rates were improved substantially in group III compared with group II. The longer the duration of infusion, the higher the removal rates tended to be in group III. These results indicate that effective elimination of anticancer drugs can be accomplished by this system during intraarterial chemotherapy of the liver.

Absorption↗
PubMed1990

[A new method of intraarterial high dose chemotherapy for unresectable hepatocellular carcinoma--the effect of direct hemoperfusion under hepatic venous isolation].

We undertook hepatic artery infusion of high dose adriamycin (ADR) in three patients with unresectable hepatocellular carcinoma utilizing direct hemoperfusion (DHP) under hepatic venous isolation (HVI). 5 minutes continuous infusion of ADR at dosages of 100 and 150 mg/m2 was combined with DHP of 20 and 30 minutes, respectively. HVI was established by occlusions of suprahepatic and retrohepatic vena cava using a tourniquet tape and a cuff-cannula. During HVI, hepatic venous outflow was directed toward DHP and joined with the rest of the intra-caval blood before the centrifugal pump connected to a return cannula to the left axillary vein. Systemic levels of ADR were maintained less than 2 micrograms/ml during the treatments in three patients. The estimated drug removal rates were 72.3%, 51.2% and 31.1% respectively. Hematologic changes due to DHP were tolerable and transient. Highest values of serum transaminases were demonstrated on day 2 and rapidly recovered to the pretreatment levels within a week. Postoperative CT studies revealed also marked reduction in tumor size. We consider this method an attractive therapeutic option for patients with advanced hepatocellular carcinoma.

Aged↗
PubMed1989

Papillary hyperplasia of the pancreas.

We report the first case of surgically resected pure papillary hyperplasia of the pancreas. Interestingly, it was not associated with chronic pancreatitis or pancreatic cancer. Histologic and immunohistochemical features are described, with a review of the literature on papillary hyperplasia of the pancreas.

Humans↗