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Biomedical subjects

G Kosaki

Publications and source records attributed to G Kosaki.

At least 55 records · Page 3Linked to original sources
PubMed1986

Complete amino acid sequence of the large subunit of the low-Ca2+-requiring form of human Ca2+-activated neutral protease (muCANP) deduced from its cDNA sequence.

The complete amino acid sequence of the large subunit (catalytic subunit) of human low-Ca2+-requiring-calcium-activated neutral protease (muCANP) was deduced from its cDNA base sequence. It is composed of 714 amino acid residues and its sequence is highly homologous to the chicken CANP sequence determined previously. Human muCANP, like chicken CANP, has a clear 4-domain structure, and their fundamental structures are essentially the same, although their Ca2+ sensitivities are significantly different. The role of each domain in the Ca2+ sensitivity and protease activity of CANP is discussed on the basis of sequence comparison.

Amino Acid Sequence↗
PubMed1986

Cleavage site of calcium-dependent protease in human platelet membrane glycoprotein Ib.

Chicken muscle-derived m-type calcium-dependent protease cleaved purified glycoprotein Ib alpha-chain (GPIb alpha, Mr 130,000) from human platelets into two fragments (Mr 100,000 and Mr 38,000) in the presence of 5 mM calcium. With partially purified glycoprotein Ib (alpha beta-dimer), an appearance of a fragment of Mr 100,000 was also demonstrated after treatment with both the m-type and human platelet-derived mu-type protease. These processes in glycoprotein Ib were inhibited by inhibitors of calcium-dependent proteases, 50 muM E-64-C or 0.2 mM leupeptin and by the chelation of calcium. Using two-dimensional gel electrophoresis system, release of glycocalicin in addition to 100 kDa fragment was demonstrated by calcium-dependent proteases. Then surface-labeled platelets were stimulated with A23187 in the presence of 5mM calcium. Under this condition, endogenous calcium-dependent protease is activated. Of the labeled glycoproteins, glycocalicin and glycoprotein V but not 100 kDa fragment were released from the platelet membrane. The released glycocalicin was further digested into a fragment of Mr 100,000 by the addition of m-type calcium-dependent protease. These results showed (i) that GPIb alpha was hydrolyzed by exogenous calcium-dependent proteases in two points and glycocalicin and 100 kDa fragment were produced and (ii) that endogenous protease cleaved GPIb alpha at one point and released glycocalicin.

Animals↗
PubMed1986

Localization of a thrombin-binding site on human platelet membrane glycoprotein Ib determined by a monoclonal antibody.

To determine a thrombin-binding site on GPIb alpha on platelet membrane, we have examined the binding activities of tryptic or chymotryptic fragments of purified GPIb alpha to a monoclonal antibody against GPIb (TM60) and thrombin using (immuno)affinity chromatography. When purified GPIb alpha was digested with trypsin, two fragments (94-kDa, and 43-kDa) were obtained. The 43-kDa fragment was shown to bind to both affinity columns of TM60- and thrombin-Affi-Gel, while the 94-kDa fragment did not bind to either Affi-Gel columns. When trypsin fragments were incubated with TM60 and then applied to the column of thrombin-Affi-Gel, neither fragments were bound to the column. When the same experiment was performed using chymotrypsin, three fragments (94-kDa, 45-kDa and 39-kDa) were observed. On TM60- and thrombin-Affi-Gel columns, the smaller fragments (45-kDa and 39-kDa) were bound to the column. After incubation of these fragments with TM60, neither bound to the thrombin column. These results indicate (i) that the epitope for TM60 is located near, or on the thrombin-binding site of GPIb alpha, and (ii) that the thrombin-binding site is located on the tail portion of GPIb alpha, especially on a chymotrypsin cleavage site.

Antibodies, Monoclonal↗
PubMed1986

Immunohistochemical localization of pancreatic secretory trypsin inhibitor in fetal and adult pancreatic and extrapancreatic tissues.

Pancreatic secretory trypsin inhibitor (PSTI) has been thought to be only a secretory trypsin inhibitor of human pancreas, but the serum content of immunoreactive PSTI is elevated without pancreatic disease. Using the peroxidase-antiperoxidase method, immunoreactive cells for PSTI were found in human pancreas, stomach, duodenum, appendix, colon and urinary tract of both fetus and adult, adult gall bladder, and fetal lung. PSTI-immunoreactive cells were identified in fetal pancreas at the tenth gestational week, and in extrapancreatic tissues at the sixteenth (gastrointestinal and urinary tract) and twentieth weeks (lung). PSTI-immunoreactive cells of fetal lung were present in neuroepithelial bodies. Strongly positive cells in fetal duodenum were argyrophilic and resembled endocrine cells. Immunohistochemical study was also performed on tissues associated with inflammatory diseases of gastrointestinal tract. The distribution pattern of immunoreactive cells in the stomach varied in accordance with chronic gastritis. Immunoreactive cells were also found in endocrine micro-nests and in a carcinoid tumor associated with fundic gastritis. These results suggest that PSTI may play some physiological role other than secretory trypsin inhibition of the pancreas.

Adult↗
PubMed1986

[Evaluation of postoperative immunochemotherapy in lung cancer].

A study of postoperative adjuvant chemotherapy according to cell type, combined with immunotherapy using PSK and OK-432 was conducted in 178 lung cancer patients who had undergone resection. BRM (PSK or OK-432) was selected by randomization. Chemotherapy was mainly performed with VCR, MMC, and MTX except for small cell carcinoma. Of the total number of lung cancer cases, 113 were evaluable. Four-year survival rates were 36.7% for the OK-432 group, 55.9% for the PSK group and 34.7% for the control group, with significant differences among these three groups. Survival rates for stage III showed significant differences between immunochemotherapy groups, (OK-432 group, PSK group) and the chemotherapy group. Postoperative administration of immunomodulators is therefore considered to contribute to the improved survival of patients in lung cancer.

Adenocarcinoma↗
PubMed1986

[Intra-aortic infusion therapy with sequential methotrexate (MTX) and 5-FU in advanced gastric carcinoma].

Fifteen patients with advanced gastric carcinoma were treated by intraaortic infusion therapy with sequential MTX and 5-FU. Intraaortic bolus injection with 50-100 mg/body MTX was followed 3 hours later with 500-750 mg/body 5-FU and 24 hours later with 30 mg/body leucovorin. Treatment was repeated weekly. Of these 15 patients who were evaluated, 4 had PR and 3 had MR. Response rate was 27%. Two patients had WBC nadir of less than 3,000 cells/mm and other two had a platelet count nadir of less than 10/mm. Gastrointestinal symptoms such as nausea and vomiting were mild. Three patients had diarrhea and 3 had mucositis. No other toxicity was seen. This regimen has been well tolerated for long periods.

Adult↗
PubMed1985

Hemostatic defects in experimental obstructive jaundice.

To elucidate the etiology of hemostatic abnormalities in cases of obstructive jaundice, we occluded the bile duct of rats for one week and found that the moderately jaundiced rats exhibited a marked reduction in the value of Hepaplastin test and Thrombotest with minimum histological changes in liver. All other coagulation and fibrinolysis profiles were within normal limits. These findings exclude the occurrence of a hypercoagulable state or hypofibrinolytic state in the jaundiced rats due to bile duct occlusion. Similar results were obtained in rats with tube choledochostomy. The abnormalities were almost completely prevented by the daily parenteral administration of vitamin K. These observations suggest that malabsorption of vitamin K may be the sole etiologic factor producing hemostatic defects in case of uncomplicated obstructive jaundice.

Animals↗
PubMed1985

Effects of protease inhibitors and calmodulin inhibitors on Ca2+ influx and catecholamine secretion in isolated bovine adrenal medullary cells.

Acetylcholine (ACh) (10(-4) M) induced Ca2+ influx (21.2 nmol/mg cell protein/3 min) and catecholamine (CA) secretion (11.5% of total CA content) in isolated bovine adrenal medullary cells. Both excess K+ (56 mM KCl) and a calcium ionophore (A-23187: 10(-5) M) also induced CA secretion (9.7 and 7.5%, respectively, of total CA content). Protease inhibitors [gabexate mesilate (FOY), TLCK], a synthetic substrate of protease (TAME) and calmodulin inhibitors (W-7, trifluoperazine, promethazine, chlorpromazine) inhibited Ca2+ influx and CA secretion induced by ACh. Protease inhibitors and a substrate of protease had no effect on CA secretion induced by excess K+, and a high concentration of calmodulin inhibitors was required to inhibit excess K+-induced CA secretion. CA secretion induced by A-23187 was not inhibited by these inhibitors and the substrate.

Adrenal Medulla↗
PubMed1985

[Automated autoradiographic grain counting of DNA repair in cultured human fibroblasts after ultraviolet irradiation].

Measurement of autoradiographic grains produced by the decay of incorporated radioisotopes is often used for a quantitative assay of the rate of DNA replication and DNA repair in cells or tissues. However, visual grain counting by microscopic observation is time-consuming and tedious process. Recently, Kraemer et al. reported that automated measurement of grains in cultured human cells may be facilitated by using appropriate grain counting instruments. Under their experimental conditions using Kodak NTB-3 emulsion, instrument-determined grain number per nucleus was proportional to visual counts up to 30 grains, and then leveled off at much larger visual counts. The saturation phenomenon was due to counting-loss by the instrument caused by overlapping of neighboring grains. To prevent the counting-loss, we have used in the present study Japanese Sakura NR-M2 emulsion which is less sensitive to radiation exposure than Kodak NTB-3, thereby yielding smaller size of grains per radioactive decay. Samples were prepared from cultured skin fibroblasts derived from normal individuals and xeroderma pigmentosum (XP) patients defective in DNA repair. These cells were irradiated with 254 nm UV incubated for 3 h with culture medium containing 3H-thymidine, and autoradiograms were made by dipping in Sakura NR-M2 emulsion. The number of grains as well as grain surface area per nucleus was measured by using ARTEK CYTO TALLY MODEL 900 counting instrument, and compared with visual counts. The results showed that, under our optimum condition, the instrument-determined number of grains was directly proportional to visual counts, at least up to 150 grains per nucleus, with a correlation coefficient of 0.971.(ABSTRACT TRUNCATED AT 250 WORDS)

Autoradiography↗
PubMed1985

[Multitherapy of advanced esophageal carcinoma with special reference to pre- and post-operative administration of cis-platinum].

We discussed the results of multitherapy after pre- and post-operative administration of cis-platinum (CDDP) in resected cases of advanced esophageal carcinoma. The patients were, pre-operatively, dosed in the following ways; 1) CDDP (50 mg, 1/week) X 2-3, 2) CDDP (50 mg, 1-week) +BLM (15 mg, 1/week) X 2-3 or +MTX (30mg, 1/week) X 2-3. The patients under went surgery 1 to 2 weeks later. Post-operative administration of CDDP + MTX, or CDDP + BLM was performed 3-4 times about 3 weeks after surgery. Intra-operative and/or post-operative irradiation was also performed. CDDP was administered pre-operatively in 11 cases who ranged in age 45 to 71. Regarding stage, 2 were stIII and 9 were stIV; and curabilities where cIII in 2 cases, c I in 5 and c 0 in 4. With regard to surgery, the right thoracic and abdominal approach was adopted in 7 cases and the left thoracic and abdominal approach adopted in 3. Blunt dissection was performed in 1 case. We have never experienced post-operative complication of histological effects noticed in resected specimens, Ef1 was evaluated in 3/11 and Ef2 was noticed in 2/11. Patients who achieved an Ef2-1 effect due to the administration of CDDP as part of the multitherapy made satisfactory progress. On the other hand, patients who did not react to CDDP and who had marked vascular invasion died after a short period.

Aged↗
PubMed1985

[Comparative studies of estrogen receptor determinations by enzyme immuno-assay using the monoclonal antibody, dextran-coated charcoal, and sucrose density gradient methods].

Estrogen receptor (ER) determination in human mammary tumors was performed by enzyme immunoassay (EIA) using monoclonal antibody, and the results were compared with those obtained using the dextran-coated charcoal (DCC) and sucrose density gradient (SDG) method. Twenty ER-positive tumors by the DCC method were all ER-positive by EIA, when determined in the same cytosol fraction. Three out of 21 ER-negative tumors by the DCC method were ER-positive by EIA. Estrogen receptors of 8S, 8S + 4S, and 4S determined by the SDG method were all shown to be ER-positive using EIA. Between the values of estrogen receptors determined by the DCC method and by EIA, a high correlation was observed (r = 0.868). Values of ER less than 13.5 fmol/mg protein were considered as negative ER.

Antibodies, Monoclonal↗
PubMed1985

[Phase II study of 5'-DFUR in gastrointestinal and breast cancer].

Clinical effects of daily oral administration of 5'-DFUR were studied in patients with advanced or recurrent gastrointestinal cancer and breast cancer. Cases included 5 gastric cancer, 18 colorectal cancer, 27 breast cancer and 1 malignant melanoma. Out of 38 cases who completed the treatment, CR was observed in 2 and PR in 7, the response rate being 23.7%. Out of 23 cases with breast cancer who completed the treatment, CR was observed in 2 and PR in 6, the response rate being 34.8%. Safety was evaluated in 42 cases and diarrhea was found in 17.1% of cases; however, it was easily reduced by decreasing the dosage or discontinuing administration of the drug.

Administration, Oral↗
PubMed1985

Effective sequential administration of tamoxifen and medroxyprogesterone acetate for 7,12-dimethylbenz[a-anthracene-induced rat mammary tumors in relation to hormone receptors.

The effects of two hormonal agents with different mechanisms of action, medroxyprogesterone acetate (MPA) and tamoxifen (TAM), on the tumor growth and hormone receptor status were evaluated in rat mammary tumors induced by 7,12-dimethylbenz[alpha]anthracene (DMBA). All estrogen receptor-positive (ER(+)) tumors became ER-negative (ER(-)), and 3 out of 4 progesterone receptor-negative (PgR(-)) and ER(+) tumors became PgR-positive (PgR(+)) after daily, oral administration of TAM for 2 weeks. In contrast, ER and PgR remained unchanged after daily administration of MPA for 2 to 4 weeks. All the ER(+) and PgR(-) tumors were transformed into PgR(+) after daily treatment with MPA for 2 weeks and then with TAM for another 2 weeks, but tumor regression was modest and none disappeared completely. In contrast, complete remission was achieved in all ER(+) tumors in the group treated with TAM for 2 weeks and then with MPA for another 2 weeks. The results suggest that the antitumor activity of the latter treatment regimen was significantly higher than that of the former. The possible mechanisms of antitumor activity of two hormonal agents are discussed.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1985

[Preliminary report of adjuvant chemo-endocrine therapy for breast cancer].

Preliminary analysis of adjuvant chemo-endocrine therapy for 193 breast cancer patients was performed. The patients consisted of 38 cases of Stage I, 124 cases of Stage II and 31 cases of Stage III. Therapeutic regimen was randomly divided into three groups; (1) Tamoxifen (TAM), (2) TAM + ftorafur (FT-E) and (3) TAM + FT-E + Adriamycin. Side effects among the three therapeutic groups were comparatively studied. Anorexia and nausea were observed in 1.4%, 17.1% and 60% of the patients, respectively. Leucopenia of less than 3,000 and alopecia were remarkably seen in the patients treated with regimen 3. Liver dysfunction was observed in 10.9% of group 1, 29.5% of group 2 and 13.3% of group 3, respectively. Gastrointestinal symptoms and liver dysfunction were important side effects.

Adult↗
PubMed1985

Amplification and enhanced expression of cellular oncogene c-Ki-ras-2 in a human epidermoid carcinoma of the lung.

The level of c-Ki-ras-2-specific mRNA was found to be markedly enhanced (10- to 20-fold) in a human epidermoid lung carcinoma transplanted into nude mice, compared with that in other lung carcinomas. Analysis of DNA revealed that c-Ki-ras-2 gene was amplified approximately 10-fold in this carcinoma, while c-Ha-ras, c-myc and c-sis were not amplified. Chromosome abnormalities were also observed in this carcinoma.

Aged↗
PubMed1985

[Intra-arterial infusion therapy with angiotensin II in gastric carcinoma].

This report describes the clinical use of MMC localized intra-arterial infusion therapy in combination with Angiotensin II for advanced gastric carcinoma which is not surgically treatable, along with some basic considerations. Since blood vessels regenerated within a tumor no longer have automatic adjustment of blood flow, there is no vascular contraction mechanism operation even when Angiotensin II is administered. The blood flow within the tumor shows a relative increase so the amount of the carcinostatic substance reaching the tumor is considered to increase. Using MMC intra-arterial infusion together with Angiotensin II, the authors were able to increase the antitumorigenic effect of the carcinostatic agent in patients with advanced gastric carcinoma. In an experiment using VX2 tumor transplanted into domesticated rabbits, the group treated with angiotensin II showed a marked reduction in the tumor. At the clinical level, differentiated gastric carcinoma patients with liver metastases very often evidenced favorable effects when treated with Angiotensin II in combination with the MMC intra-arterial infusion method. A randomized clinical study of 30 patients using either Angiotensin II together or without intraarterial infusion revealed that in 4 advanced gastric carcinoma patients could PR be obtained by the combination therapy, the non-combination treated group showed no favorable effects. In Borrmann type IV gastric carcinoma, the present combination therapy displayed no effect, while a switch to MTX-5FU sequential therapy yielded very often good results. Since the ability of the agent to reach the tumor is markedly enhanced in the Angiotensin II-intraarterial infusion approach to chemotherapy, progress in the latter science is anticipated.

Aged↗
PubMed1985

[Correlation between anti-tumor effect and delayed hypersensitivity induced by topically applied OK-432 with histological findings].

Delayed hypersensitivity (DH) against OK-432 was induced in BALB/c mice by injecting 2 KE of OK-432 with Freund's incomplete adjuvant into foot pads. One week after presensitization with OK-432, 2 X 10(5) cells of Meth A tumor were implanted subcutaneously in all mice, followed by intratumoral injection of 1 KE of OK-432 five times every other day starting at 7th day in experimental group. Tumor growth was significantly inhibited in the OK-432 presensitized group comparing to non-sensitized group. In experimental groups marked inhibition was observed in mice which were injected with OK-432 intratumorally 2 to 3 weeks after presensitization. This effect correlated well with delayed hypersensitivity against OK-432. Histological changes after intratumoral injection of OK-432 were examined in order to analyse the mechanism of this effect. The main finding of OK-432 injected specimen by H.E. staining were degeneration of tumor cells and infiltration of inflammatory cells. These changes were stronger in OK-432 presensitized mice. By beta-D-galactosidase staining accumulation of macrophages was found both inside the tumor and the surrounding tissue, and these macrophages increased in OK-432 presensitized mice. Immunoperoxidase staining with antiasialo GM1 anti-serum was also performed. Greater number of activate macrophages were observed to accumulate in the specimen of OK-432 presensitized mice than that of control mice. Some T cells were observed only around tumor tissues and not in the tumor of both presensitized and unsensitized mice. These results suggest that the activated macrophages play a major role in the augmentation of antitumor effect by presensitization with OK-432.

Animals↗