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H Ohta

Publications and source records attributed to H Ohta.

At least 487 records · Page 27Linked to original sources
PubMed1992

The site of nonenzymic glycation of human extracellular-superoxide dismutase in vitro.

The secretory enzyme extracellular-superoxide dismutase (EC-SOD) has affinity for heparin and some other sulfated glycosaminoglycans and is in vivo bound to heparan sulfate proteoglycan. Nonenzymic glycation of EC-SOD, both in vivo and in vitro, is associated with a reduction in heparin affinity, whereas the enzymic activity is not affected. The glycation sites in EC-SOD are further studied in the present article. It is shown that modification of a few of the five lysyl residues of the subunits of the enzyme with trinitrobenzene sulfonic acid nearly abolishes the in vitro glycation susceptibility. From a chymotryptic digest of in vitro glycated EC-SOD, two peptides with affinity for boronate could be isolated. Amino acid sequence analysis showed that both encompassed the carboxyterminal end. epsilon-Glucitol lysine was identified in both peptides at positions 211 and 212. The primary glycation sites in EC-SOD are thus lysine-211 and lysine-212 in the putative heparin-binding domain in the carboxyterminal end.

Amino Acid Sequence↗
PubMed1992

Appearance of new lipoxygenases in soybean cotyledons after germination and evidence for expression of a major new lipoxygenase gene.

The appearance and subsequent disappearance of lipoxygenase activity at pH 6.8 in germinated cotyledons of soybean (Glycine max [L.]) was shown using a variant soybean cultivar (Kanto 101) that lacks the two lipoxygenase isozymes, L-2 and L-3, that are present in dry seeds of a normal soybean cultivar (Enrei). Three new lipoxygenases, designated lipoxygenase L-4, L-5, and L-6, were purified using anionic or cationic ion exchange chromatography. The major lipoxygenase in 5-day-old cotyledons of the variant soybean was lipoxygenase L-4. Lipoxygenases L-5 and L-6 preferentially produced 13(S)-hydroperoxy-9(Z), 11(E)-octadecadienoic acid (13S-HPOD) as a reaction product of linoleic acid, whereas lipoxygenase L-4 produced both 13S-HPOD and 9(S)-hydroperoxy-10(E), 12(Z)-octadecadienoic acid. All three isozymes have pH optima of 6.5, no activity at pH 9.0, and preferred linolenic acid to linoleic acid as a substrate. Partial amino acid sequencing of lipoxygenase L-4 showed that this isozyme shares amino acid sequence homology with lipoxygenases L-1, L-2, and L-3 but is not identical to any of them. This indicates that a new lipoxygenase, L-4, is expressed in cotyledons.

Journal Article↗
PubMed1992

Contribution of cyclic GMP formation to KRN2391-induced relaxation in coronary artery of the pig.

1. In the present study, we investigated the relationship between relaxation and guanosine 3':5'-cyclic monophosphate (cyclic GMP) formation induced by KRN2391, compared with those induced by nicorandil and nitroglycerin, in the coronary artery of the pig. 2. KRN2391 (10(-8)-3 X 10(-5) M), nicorandil (10(-8)-3 X 10(-4) M) and nitroglycerin (10(-9)-10(-5) M) antagonized the contraction caused by 25 mM KCl in a concentration-dependent manner. 3. The concentration-relaxation curves for KRN2391, nicorandil and nitroglycerin shifted rightward in the presence of methylene blue (10(-5) M). 4. KRN2391 (10(-6) M), nicorandil (10(-4) M) and nitroglycerin (10(-6) M) induced an increased in cyclic GMP. 5. The magnitude of the shift of the concentration-relaxation curve caused by methylene blue and the increase in cyclic GMP with KRN2391 were lower than those with nicorandil and nitroglycerin. 6. The adenosine 3':5'-cyclic monophosphate (cyclic AMP) level was not increased by KRN2391 even at a concentration that produced full relaxation. 7. The present results suggest that KRN2391-induced relaxation in the coronary artery of the pig is partly due to the increase in cyclic GMP formation through the stimulation of guanylate cyclase.

Animals↗
PubMed1992

Fusion regulation proteins on the cell surface: isolation and characterization of monoclonal antibodies which enhance giant polykaryocyte formation in Newcastle disease virus-infected cell lines of human origin.

Newcastle disease virus (NDV)-infected HeLa and FL cells showed small polykaryocytes at about 24 h postinfection, while the addition of anti-FL-cell rabbit, rat, or mouse serum to the NDV-infected cells gave rise to giant polykaryocytes at 15 h postinfection. We isolated three monoclonal antibodies (MAbs) (4-5-1, 6-1-13, and 7-2-1) capable of enhancing giant polykaryocyte formation in NDV-infected HeLa cells. These MAbs immunoprecipitated gp80 or gp135, which were detected mainly on the surface of HeLa cells. A functionally intact F protein was essential for antibody-enhanced cell fusion, and hemagglutinating (receptor-binding) activity of HN protein was involved in the fusion at an early stage; that is, the MAbs enhanced NDV-mediated syncytium formation. These molecules were considered to have the ability to regulate NDV-mediated cell fusion and thus were designated fusion regulation protein (FRP)-1 (gp80) and FRP-2 (gp135). Anti-FRP MAbs enhanced the susceptibility of cells to fusion activity of NDV. Anti-FRP-1 MAbs reacted with a molecule on the surface of every cell derived from humans and monkeys but showed no cross-reactivity with mouse or hamster cells. FRP-2 could be detected in limited cell lines of human origin.

Animals↗
PubMed1992

Renal effects of endogenous prostaglandin synthesis promoter ONO-3122.

The renal effects of a prostaglandin synthesis agonist, 1-iodo-3-aminomethyl-5,6,7,8-tetrahydro-2-naphthol (ONO-3122), were investigated in anesthetized rats. ONO-3122 (0.3 mg/kg + 0.3 mg.kg-1.h-1 iv) doubled the urinary excretion of the main metabolites of prostaglandin F, and induced transient increases in renal blood flow and glomerular filtration rate (GFR) with a marked, stable natriuresis. Indomethacin suppressed the natriuresis. When the diuretic fluid losses were replaced, micropuncture showed an unaltered reabsorption of sodium in the proximal tubule but reductions in the loop of Henle (86 +/- 1 vs. 76 +/- 1%) and in the more distal segments (98 +/- 1 vs. 83 +/- 3%) with comparable reductions in water reabsorption. Potassium secretion was seen in the distal and collecting tubules. Without fluid replacement, sodium reabsorption was reduced in the loop and more distal nephron but increased in the proximal tubule. Differences between proximal and distal nephron GFR were unaffected by systemic ONO-3122. Loop perfusion with ONO-3122 did not change tubuloglomerular feedback responses, which were, however, completely suppressed by furosemide. It is concluded that ONO-3122 stimulates renal prostaglandin biosynthesis, transiently dilates renal vasculature, and induces natriuresis mainly by suppressing sodium and water reabsorption in the loop of Henle and the more distal nephron. Luminal ONO-3122 does not affect the tubuloglomerular feedback.

Animals↗
PubMed1992

Stimulation of IgM production in human-human hybridoma HB4C5 cells by chitosan.

We screened for immunoglobulin production stimulating factors (IPSFs) in polysaccharides using human-human hybridoma cells, HB4C5, cultured in serum-free medium. Among polysaccharides, citrus pectin, locust bean gum, and chitosan stimulated IgM production of HB4C5 cells. Especially chitosan showed the strongest IPSF activity; 100 ng/ml of chitosan stimulated IgM production approximately 5-fold. Chitosan had several characteristics as IPSF, as follows. 1) For the IPSF activity, 70-90% deacetylation was essential. 2) Chitosan oligomers (n = 5, 6, 7) and chitin oligomers (n = 5, 6, 7) showed no IPSF activities. 3) The IPSF activity of chitosan was inhibited by glucosamine, one of the constitutive sugars of chitosan. 4) Chitosan stimulated IgM production of human lymphocytes in serum-free culture, but not IgG or IgA, nor in serum-supplemented culture.

Cell Line↗
PubMed1992

Amyotrophic lateral sclerosis associated with the syndrome of inappropriate secretion of antidiuretic hormone.

A 71-year-old female with amyotrophic lateral sclerosis (ALS) developed the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) during respiratory failure due to atrophy of the respiratory muscles. Serum sodium concentration fell to 116 mEq/l and then returned to the normal range after water restriction and respiratory care. This is considered to be the first case report of ALS associated with SIADH.

Aged↗
PubMed1992

Interstitial nephritis associated with glomerulonephritis in a patient with Hashimoto's disease and idiopathic portal hypertension.

A middle-aged women with hypothyroidism, idiopathic portal hypertension and nephrotic syndrome is presented. This unusual clinical appearance could not be explained as SLE by serological examinations. Pathohistological examinations showed "Banti's liver", Hashimoto's thyroiditis and diffuse proliferative glomerulonephritis with severe tubulo-interstitial nephritis. Immunohistochemical studies revealed IgA deposits in glomeruli. Electron microscopic study disclosed peculiar lucent areas of rarefaction with osmiophilic particles in tubular basement membranes. This tubulointerstitial nephritis was considered to be related to the immunological mechanism involving thyroid gland, liver and kidney disorders. This case thus had a clinically rare combination of these three.

Female↗
PubMed1992

[A case-control study on factors relating to discontinuation of domiciliary care for the bedridden elderly in a metropolitan area].

A case-control study was conducted to examine factors relating to discontinuation of domiciliary care for the bedridden elderly in Shinagawa-ku, Tokyo. Cases were bedridden residents aged 65 years and over who had abandoned home care and applied for admission to live in a special nursing home for the aged between April and September in 1990 after being recipients of welfare allowances for disabled elderly. Controls were bedridden residents who continued to be given home care and matched to cases by sex, age and beginning month of the receiving of allowances. Among 50 cases and 94 controls interviewed, we obtained responses from 31 cases (62%) and 60 controls (64%). The main results were as follows: 1. During the home-care period, ADL (activities of daily living) of cases, especially walking ability, deteriorated more severely than in controls. Night delirium also appeared more frequently in cases. 2. The primary caregivers of cases were older than those of controls. Remarkable differences between cases and controls were observed in the family structure, the number of family members and the number of sub-caregivers. Cases tended to live alone or live with a spouse only, and with smaller number of family members and caregivers. 3. Case lived more frequently in houses with small numbers of rooms and without rooms of their own. 4. As regards utilization of domiciliary care services, cases used dispatch of home helpers more frequently and used day services less frequently.

Aged↗
PubMed1992

[Role of p185c-erbB2 in endometrial cancer growth in vitro].

Human endometrial adenocarcinoma cells (Ishikawa line) constitutively express c-erbB2 coded oncoprotein p185erbB2 (p185) which is believed to be an orphan receptor for an unknown growth factor. Since we have shown that expression of p185 in primary lesions of endometrial cancer correlates well with high frequency of lymph node++ metastases and that the metastatic cells in the nodes strongly expressed p185, the role of the oncoprotein in processes of metastases was studied. Culturing the cells in the presence of 15% FCS and with monoclonal antibody to the extracellular domain of p185 (CB-1) inhibited cell growth and attenuated p185 expression on Western blotting, whereas no change occurred with the control antibody. Cells cultured without FCS achieved only approximately 1/3 growth compared to cells with FCS, and further suppression of growth was observed after adding CB-1. When cells were cultured on human term amnion, basement membrane invasion with p185 expression was observed. In nude mice, intraperitoneal seeding resulted in implant formation which was also associated with positive p185 as well as cyclin immunohistochemistry. In the two experiments, treatment of cells with CB-1 inhibited invasion or implant formation. The present study suggests that a signal through p185 receptor molecules acts as a trigger for early proliferation, and interaction with the host may enhance up-regulation of p185.

Adenocarcinoma↗
PubMed1992

[Seasonal variation of intraocular pressure after trabeculotomy].

The author reviewed the seasonal variation of intraocular pressure (IOP) in primary open angle glaucoma or late type developmental glaucoma to investigate possible relationships among seasonal variation of IOP, progression of visual field defects and the follow-up period between 53 eyes of 39 subjects with successful trabeculotomy (trabeculotomy group) and 45 eyes of 31 subjects with only medication (no operation group). IOPs in both groups were inclined to be low in summer and high in winter. Maximum seasonal variation of IOP and standard deviation of IOP during all follow-up periods which showed the degree of seasonal variation of IOP had no significant difference between the trabeculotomy group and the no operation group. These results showed that seasonal variation of IOP was not reduced even by successful trabeculotomy. The maximum seasonal variation of IOP and standard deviation of IOP had a tendency to be bigger in cases with progression of visual field defects than in cases with no progression of visual field defects, in both groups. Therefore, seasonal variation of IOP may be an important factor influencing the progression of visual field defects.

Follow-Up Studies↗
PubMed1992

Effects of phenothiazine on contractions induced by prostaglandin F2 alpha and 5-hydroxytryptamine in normal and spastic canine cerebral artery.

We have investigated the effect of phenothiazine, a compound known to inhibit calmodulin, on the responses of normal and spastic cerebral arteries, using the canine "two hemorrhage" model of cerebrovascular spasm. Ring preparations from control vessels or vessels removed three or seven days after injection of blood, were contracted with either 5-hydroxytryptamine (5-HT) or prostaglandin F2 alpha (PGF2 alpha) and then exposed to increasing concentrations of phenothiazine. In normal arteries, low concentrations of phenothiazine enhanced the response to PGF2 alpha, while higher concentrations caused relaxation. Responses to 5-HT were inhibited by all concentrations of phenothiazine tested. When normal arteries were compared with arteries from animals injected with blood, in the case of 5-HT, phenothiazine was a less effective antagonist at low doses, but equieffective at higher doses. Similar experiments conducted with PGF2 alpha showed that phenothiazine was a more effective antagonist in spastic vessels. We conclude that 5-HT and PGF2 alpha have significant differences in the mechanism by which they produce contraction of cerebral vessels, that phenothiazine has secondary effects on contraction independent of inhibition of calmodulin, and, finally that the effects of phenothiazine in clinical vasospasm may be insufficient to reverse the condition, despite the observation that vessels in spasm may be more sensitive to this agent.

Animals↗
PubMed1992

[Nonfunctioning paraganglioma of the posterior mediastinum].

A 23-year-old man, complaining of a discomfort in the chest, saw a physician nearby and was pointed out chest abnormal shadow in chest X-ray. He was admitted to our hospital for surgery. As a result of a close check-up at this department, a giant tumor extending from above the right diaphragm to the posterior mediastinum was found. Physical findings in the preoperative examination and general examinations showed no abnormality. The operation was performed and was diagnosed as paraganglioma. This tumor is abundant in blood vessels. Thus, preoperative angiography and securing of the field of operation in treating the blood vessels were considered indispensable for the safety of operation.

Adult↗
PubMed1992

[An adult case of anomalous origin of the left coronary artery from the pulmonary artery with the coronary artery-bronchial artery anastomosis].

A case was 33 years old man who had complained chest pain during exercise. He was diagnosed anomalous origin of the left coronary artery from the pulmonary artery by coronary angiography. At operation, left main coronary artery originated from the posterior wall of the pulmonary artery. Numerous retrograde flow was seen through left coronary artery during aortic cross clamping. The left coronary ostium was closed, because sufficient extracardial anastomosis to coronary artery should be thought. The post operative course was uneventful and the patient is asymptomatic. The selective bronchial artery angiography was performed and it demonstrated collaterals between the bronchial artery and the left circumflex artery. The Thallium scintigraphy had showed ischemia of antrolateral wall of the left ventricle before operation, but postoperatively there was no ischemic redistribution.

Adult↗
PubMed1992

Antitumor effect of thermosensitive CDDP-liposomes on human osteosarcoma cells in culture.

We have administered cis-diamminedichloroplatinum (II) (CDDP) containing thermosensitive liposome and simultaneous hyperthermia into human osteosarcoma cells (OST) and studied the antitumor effects. Experiments were conducted under the following three different culture conditions as follows, (1) drug treatment alone, (2) hyperthermia after drug treatment, and (3) simultaneous hyperthermia and drug treatment. Antitumor effects were estimated by inhibition of DNA synthesis and decrease in cell growth rates. The antitumor action of simultaneous hyperthermia and drug treatments was the most dominant and synergistic among three experimental conditions. Accumulation of cellular platinum from thermosensitive CDDP-liposomes was markedly enhanced by hyperthermia. Flow cytometric analysis of the cell cycle indicated that CDDP-liposomes only under the simultaneous application of hyperthermia released free CDDP, and evoked cell accumulation in S and G 2/M phase. The results suggested that thermosensitive CDDP-liposomes were not taken up into cells by endocytosis, and released free CDDP into culture media under hyperthermia at 42 degrees C. From these, we have concluded that administration of thermosensitive CDDP-liposomes and simultaneous local hyperthermia could be a promising method for the treatment of osteosarcoma especially in the extremities.

Cisplatin↗
PubMed1991

Molecular cloning and expression of the cDNA coding for a new member of the S100 protein family from porcine cardiac muscle.

We isolated a new calcium-binding protein from porcine cardiac muscle by calcium-dependent hydrophobic and dye-affinity chromatography. It showed an apparent molecular weight of 11,000 on SDS-PAGE. Amino acid sequence determination revealed that the protein contained two calcium-binding domains of the EF-hand motif. The cDNA gene coding for this protein was cloned from the porcine lung cDNA library. Sequence analysis of the cloned cDNA showed that the protein was composed of 99 amino acid residues and its molecular weight was estimated to be 11,179. Immunological and functional characterization showed that the recombinant S100C protein expressed in Escherichia coli was identical to the natural protein. Homologies to calpactin light chain, S100 alpha and beta protein were 41.1%, 40.9% and 37.5%, respectively. The protein was expressed at high levels in lung and kidney, and low levels in liver and brain. The tissue distribution was apparently different from those of the other S100 protein family. These results indicate that this protein represents a new member of the S100 protein family, and thus we refer to it as S100C protein.

Amino Acid Sequence↗