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Biomedical subjects

H Fukumoto

Publications and source records attributed to H Fukumoto.

136 records · Page 8Linked to original sources

Detailed characterization of the biological activities of recombinant human nerve growth factor expressed in Chinese hamster ovary cells.

The biological activities of recombinant human nerve growth factor (rhNGF) produced by Chinese hamster ovary (CHO) cells that were transfected with human NGF gene were investigated in vitro and in vivo. rhNGF showed the same immunoreactivity as mouse NGF (mNGF) in a highly sensitive two-site enzyme immunoassay system employing mouse monoclonal antibody against mouse beta-NGF (MAb 27/21) for both the primary and the secondary antibodies. In PC12 cells, rhNGF promoted neurite extension and induced acetylcholinesterase (AChE) with the same potency as mNGF, showing an ED50 of 10-20 ng/mL. In fetal rat septal neurons cultured on a feeder layer of astroglial cells, rhNGF promoted survival and neurite extension as well as an increase in choline acetyltransferase (ChAT) activity and acetylcholine (ACh) content. At a maximal effective concentration of 30 ng/mL, rhNGF promoted a 1.4-, 2.8-, and 4-fold increase in surviving cell number, ACh content, and ChAT activity, respectively. rhNGF was five times more potent than mNGF for the increase in ChAT activity and ACh content showing an ED50 of 0.5 ng/mL, although the maximal response was the same for the two NGFs. Transection of the fimbria-fornix resulted in a loss of AChE-positive cells in the medial septum (MS) and vertical limb of the diagonal band of Broca (VDB). The administration of rhNGF or mNGF (3 or 30 micrograms in gel form) attenuated the loss of AChE-positive cells; rhNGF was as potent as or even more potent than mNGF. Radio frequency lesion of the basal forebrain (BF) including the nucleus basalis magnocellularis (NBM) resulted in severe impairment of memory and/or learning in passive avoidance and Morris' water maze tasks. Repeated injection of rhNGF (5 micrograms x 5 over 2 wk) into the lateral ventricle ameliorated the behavioral impairment in the water maze task but not in passive avoidance. rhNGF treatment increased ChAT activity in the frontal cortex and even in other subregions of the cerebral cortex where ChAT activity was not decreased by BF lesion. These results indicate that human NGF can be measured in an enzyme immunoassay system using monoclonal antibody against mNGF (MAb 27/21) and that rhNGF has potent biological activity, comparable to or greater than mNGF, both in vitro and in vivo.

Acetylcholine↗

Effects of changing the type of H2-blocker in the treatment of H2-blocker-resistant ulcers: comparison of roxatidine acetate hydrochloride and other H2-blockers.

The efficacy of switching from one type of H2-receptor antagonist (H2-blocker) to another, in the treatment of H2-blocker-resistant ulcers was investigated using H2-blockers with five-membered rings (five-membered-ring agents)--such as cimetidine, ranitidine and famotidine--and an H2-blocker with a six-membered ring, roxatidine. By switching from a five-membered-ring agent to roxatidine in the treatment of five-membered-ring resistant ulcers (study I), gastric ulcers were healed in nine of 19 patients (47%) and duodenal ulcers were healed in eight of nine patients (89%). By switching from roxatidine to one of the five-membered-ring agents in the treatment of roxatidine-resistant ulcers (study II), gastric ulcer was healed in six of 15 patients (40%), and duodenal ulcer was healed in 4 of 10 patients (40%). Particularly in the case of duodenal ulcers, the switch to treatment with roxatidine, which has a different chemical structure from the five-membered-ring agents, may be useful in the treatment of five-membered-ring-resistant ulcers.

Adult↗

Alteration of caspase-3 (CPP32/Yama/apopain) in wild-type MCF-7, breast cancer cells.

Caspase-3 (CPP32/Yama/apopain), one of the interleukin 1 -converting enzyme (ICE)-like proteases (caspases), is anticipated to mediate apoptotic cell death. We observed the expression of caspase-3 in various cancer cell lines and lack of normal expression of mRNA and protein in MCF-7, human breast carcinoma cell line. Sequence analysis of cDNA showed 125 nucleotides deletion in spite of no gross gene alteration of caspase-3 in MCF-7. The possible cause is altered splicing of the fragment followed by frame shift at translation level. MCF-7 cells are widely used in the research of apoptosis because of the high sensitivity to tumor necrosis factor induced cell death. However, our results suggest the existence of other apoptotic pathways independent on caspase-3 at least in MCF-7 cells.

Adenocarcinoma↗

Use of gastroepiploic and internal mammary arteries for myocardial revascularization.

Triple coronary artery bypass grafting utilizing the right gastroepiploic artery and both internal mammary arteries was performed successfully in a 37-year-old male, achieving primary myocardial revascularization. All grafts were in situ. The right gastroepiploic artery was anastomosed to the posterior descending artery. The right and left internal mammary arteries were anastomosed to the left anterior descending artery and the posterolateral branch, respectively. The postoperative angiogram showed good patency of all grafts. The patient recovered uneventfully with resolution of his angina pectoris.

Adult↗

Antitumor effects of butyrolactone I, a selective cdc2 kinase inhibitor, on human lung cancer cell lines.

Butyrolactone I, which is a naturally occurring specific inhibitor of the cdc2 kinase family, showed antitumor effects on several non-small- and small-cell-lung cancer cell lines with IC50 values the order of 50 micrograms/ml on the former. No cross-resistance of several drug-resistant cell lines, including those with the multidrug-resistant phenotype and five cisplatin-resistant cell lines to butyrolactone I was observed. The cdc2 kinase activity of PC-14 cells was inhibited by treatment with 20 micrograms/ml butyrolactone I, a concentration comparable to the IC50 value, for 2 hours. Longer exposure to butyrolactone I (> 24 hours) reduced the cdc2 kinase protein level. Butyrolactone I arrested the cells at the G2/M phase in a concentration dependent manner. These results suggest that butyrolactone I actually acts on cdc2 kinase, rather than other cdk kinases, in PC-14 cells. Inhibition of DNA synthesis, determined by measuring thymidine uptake, occurred earlier (2 hours) after initiating exposure than the decrease in the cdc2 protein level and was concentration dependent, suggesting that butyrolactone I inhibited DN4 synthesis. Cell permeabilization by digitonin enhanced DN4 synthesis inhibition by butyrolactone I, suggesting that the permeability of the membrane to this agent was the limiting factor for its growth inhibitory effect. Many anticancer agents, such as alkylating agents and cisplatin, cause cells to accumulate at the G2/M phase of the cell cycle. We investigated whether butyrolactone I had any modulatory effect on the antitumor effects of several anticancer drugs in vitro. Butyrolactone I showed no modulatory effects on vindesine, paclitaxel, or etoposide, but exposure of PC-9 and PC-14 cells to butyrolactone I together with or prior to treatment with cisplatin reduced the cytotoxicity of the latter. Thin-layer chromatographic analysis revealed that butyrolactone I bound to cisplatin, which was a possible cause of the reduced cisplatin cytotoxicity in the presence of bytyrolactone I.

4-Butyrolactone↗