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Biomedical subjects

H Usui

Publications and source records attributed to H Usui.

At least 109 records · Page 6Linked to original sources
PubMed1992

[Maxillary prosthesis for better QOL--early setting and faster construction of maxillary prosthesis].

The maxillofacial prosthesis (MFP) is well accepted as one of the modalities to ameliolate the postsurgical crippling in the patients with maxillary malignancy. In this report, we analyzed 55 primary cases of MFP out of 100, from July, 1981 to July, 1987 in terms of the time of start after operation, and the duration and procedure of the MFP-making. MFP-making set about within 4 weeks in 35% of patients, 8 weeks in 25%, 12 weeks in 22%, and more than 12 weeks in 18%. The completion of MFP-making averaged 10 days. As a result of simplifying of MFP-making, we shortened a period requiring MFP-making within 3 days in recent 10 cases. There were no adverse effects of early wear of MFP after operation. We believe that early wear of MFP after operation improve the quality of life of patients with maxillary malignancy and considered that wear of MFP is not the completion of treatment, but is one of the procedures of treatment for the patients undergone maxillectomy.

Adolescent↗
PubMed1991

Purification and characterization of a rat liver membrane tyrosine-protein kinase, the possible protooncogene c-yes product, p60c-yes.

A tyrosine-protein kinase was purified more than 270-fold from the rat liver plasma membrane fraction by successive column chromatographies on Sephacryl S-300, wheat germ agglutinin-agarose, casein-Sepharose, and hydroxylapatite, followed by isoelectrofocusing electrophoresis. The enzyme with pI of 6.2 was a 60-kDa single polypeptide which represented 42% of total protein. The enzyme reacted quantitatively with a monoclonal antibody to the amino-terminal sequence (Cys-3 to Ser-66) specific to the human c-yes protein, but not with antibodies to the specific amino-terminal sequences of the c-src, fyn, and lck proteins. The purified enzyme contained almost no phosphotyrosine residue but was autophosphorylated with Mg.ATP exclusively at tyrosine residues with concomitant increase in the kinase activity. The rates of autophosphorylation of the enzyme and phosphorylation of tyrosine-glutamate (1:4) copolymers, catalyzed by the enzyme were proportional to the square of enzyme concentration, suggesting that p60c-yes undergoes autophosphorylation through intermolecular catalysis, resulting in stimulation of the enzyme activity. Although the enzyme reaction showed an essential requirement for Mg2+ or Mn2+ with optimal concentrations of 20 and 3 mM, respectively, autophosphorylation significantly activated the enzyme only in the presence of Mg2+. Autophosphorylation of the enzyme reduced the Km for tyrosine-glutamate copolymers and tubulin, but not for ATP, and increased the Vmax of copolymer and tubulin phosphorylation.

Animals↗
PubMed1991

In situ hybridization histochemistry of Spot 35 protein, a calcium-binding protein, in the rat brain.

Using in situ hybridization, we analyzed the localization of mRNA for Spot 35 protein (Spot 35), a calcium-binding protein of the EF-hand type, in the rat cerebellum at various developmental stages. A cDNA fragment corresponding to part of the 3'-noncoding region was 35S-labeled and used as a hybridization probe. Autoradiographic signals for Spot 35 mRNA were detected in all the Purkinje cells, but not in any other neurons or glial cells in the adult rat cerebellum. There was no significant difference in signal intensity among individual cells. The signals were observed exclusively in Purkinje cell bodies, but not in their processes, in striking contrast to previous immunohistochemical studies in which Spot 35 protein was demonstrated in both cell bodies and processes. In the time-course study, signals for Spot 35 mRNA were detected in Purkinje cell bodies weakly at embryonic day 19, thereafter more intensely at more developed stages and most intensely at postnatal days 30 and 60 (adulthood). The signal intensities of individual cells were similar at each of these developmental stages except for the very early stages at which signals were weak and slightly variable among cells. These findings, especially that of the characteristic coordinated expression of Spot 35 mRNA at given stages, should prove useful in studies of degenerative diseases in the cerebellum in experimental animals and man. A weak expression of Spot 35 mRNA in some of non-Purkinje cells was also noted.

Animals↗
PubMed1991

Endothelium-independent and -dependent contractions induced by endothelin-1 in canine basilar arteries.

Endothelium-dependence of contractile responses to endothelin-1 was examined in isolated canine basilar arteries. Within 2 hrs after mounting tissue preparations, endothelin-1 (10(-9) M) caused a monophasic tonic contraction that developed very slowly and was sustained in intact and endothelium-removed arteries. More than 5 hrs after tissue mounting, endothelin-1 (10(-9) M) caused a biphasic contraction consisting of phasic and tonic components in intact arteries, and caused a monophasic tonic contraction in endothelium-removed arteries. This phasic component was significantly decreased by aspirin (5 x 10(-5) M,), OKY-046 (10(-5) M) (a TXA2 synthetase inhibitor) and ONO-3708 (10(-8) M) (a TXA2 antagonist). The present experiments demonstrate that endothelin-1 causes an endothelium-independent tonic contraction and an endothelium-dependent phasic contraction in canine basilar arteries, and suggest that TXA2 plays a role as an endothelium-derived contracting factor.

Animals↗
PubMed1991

Vasoinhibitory effect of NP-252, a new dihydropyridine derivative, in canine cerebral artery.

The vasoinhibitory effect of NP-252, a 1,4-dihydropyridine derivative Ca++ antagonist, was examined in canine cerebral artery, and this effect was compared with that of nifedipine. NP-252 (10(-7)M) and nifedipine (10(-6) M) nearly abolished the contraction induced by addition of Ca++ to Ca(++)-free medium containing KC1. NP-252 (10(-6)M) and nifedipine (10(-6)M) attenuated the contraction produced by thromboxane A2 agonist (STA2) in normal medium, and the resultant contractions were 22% (n = 6) and 35% (n = 6) of the control contraction, respectively. The vasoinhibitory effects of NP-252 were significantly stronger than those of nifedipine in canine cerebral artery. NP-252 (10(-7) and 10(-6) M) dose-dependently attenuated nifedipine-resistant Ca(++)-contraction in the presence of STA2 in both canine cerebral and coronary arteries. The inhibitory effect of combined treatment with NP-252 (10(-6) M) and nitroglycerin (10(-6) M) on nifedipine-resistant Ca(++)-contraction in the cerebral artery was additive. These results indicate that NP-252 possesses a stronger vasoinhibitory effect than that of nifedipine in canine cerebral artery.

Animals↗
PubMed1991

Structure and expression of rat S-100 beta subunit gene.

The gene structure for S-100 beta subunit has been elucidated. The gene spans about 8 kbp and consists of 3 exons and 2 introns. The transcription initiation site was determined by an S1 nuclease mapping. The promoter region contains TATA-box-like and CAAT-box-like sequences. To examine the activity of the promoter sequence, a transfection of pS100 beta-lacZ fused gene to the cultured cells was carried out. C6 glioma cells showed a positive expression of beta-galactosidase. Gene-deletion experiments suggested the functional importance of the DNA fragment (22 bp) containing TATA-box-like and CAAT-box-like sequences. A factor protein that binds to the 100 bp DNA fragment containing the promoter sequence was specifically detected in the rat brain nuclear extract.

Animals↗
PubMed1991

Functional reinnervation of carotid artery by implanted preganglionic trunk in the cat.

The preganglionic trunk of the superior cervical ganglion was implanted chronically into the carotid artery. A helical strip of the carotid artery with nerve was prepared, and electrical stimulation of the nerve caused a definite contraction. Part of the contraction was attenuated by phentolamine, and the remaining part of the contraction was nearly abolished by tubocurarine but not by hexamethonium and atropine. The present results clearly demonstrate that the carotid artery is reinnervated by preganglionic cholinergic fibers.

Animals↗
PubMed1991

[Simultaneous bilateral neck dissections].

From April 1985 to December 1989, 65 patients with advanced head and neck squamous cell carcinoma, underwent simultaneous bilateral neck dissection (SBND) at Saitama Cancer Center. Three and five year survival percentages were 53 and 42%, respectively. In patients without histologic involvement of cervical nodes, five year survival rate was 83%, whereas in those with nodal involvement five year survival fell to 32% (p less than 0.005). The conclusion were the following: (1) Of 38 patients diagnosed to have lymph node involvements on one side of neck before operation, 8 patients (22%) were found to have bilateral lymph node metastasis in clinicopathological study. Of 13 patients having no clinical lymph node metastasis on both sides of neck, 7 patients (54%) were found to have unilateral lymph node metastasis. Of 16 patients diagnosed to have bilateral lymph nodes involvement, 10 patients were found to have bilateral neck metastasis and 2 had unilateral neck metastasis. (2) Of 35 cases of hypopharyngeal canners, 19 cases had clinically positive lymph nodes on one side of neck. Of these 19 cases, 5 cases (26%) had histologically positive nodes on the opposite side. 14 (40%) of 35 cases had metastasis on the opposite side. In conclusion, SBND is a proper treatment for metastatic cervical cancer from a primary lesion of the head and neck, especially in hypopharyngeal cancers, because the rate of recurrence seems to be related more to the difficulty in controlling lymph node metastasis than to the failure in treatment of the primary cancer.

Aged↗
PubMed1991

[Reconstruction of hypopharynx and cervical esophagus using a free jejunal graft].

Forty-four patients with cancer in the hypopharynx and cervical esophagus underwent pharyngoesophageal reconstruction with a free jejunal graft after total removal of a tumor combined with resection of the circumferential tissues. The graft survival rate was 93.2% (41 of 44). Postoperative complications occurred in 16 patients (36.4%), which included postoperative death in one (2.3%), graft necrosis in 3 (6.8%), fistula formation in 4 (9.1%) and graft stricture in 3 (6.8%). All 3 cases of graft necrosis underwent successfully reimplantation. The mean interval time was 20.9 days until oral intake was possible. Thirty-two of 42 patients (76.2%) were able to take usual food. Esophageal speech was limited in the selected cases by this procedure. A cumulative survival rate of 5 years was 40.6% in this series. This method of reconstruction should be advocated as one of relatively safe and reliable procedures for patients with hypopharyngeal and cervical esophageal cancer.

Adult↗
PubMed1991

Endothelium-independent and endothelium-dependent contractions mediated by P2X- and P2Y-purinoceptors in canine basilar arteries.

Both alpha, beta-methylene ATP and beta, gamma-methylene ATP (P2X selective agonists) were shown to induce transient contraction in intact and endothelium-removed preparations of canine basilar arteries. 2-Methylthio ATP (a P2Y selective agonist) caused transient contraction of intact arteries and this response was nearly abolished by removal of the endothelium. In the presence of alpha, beta-methylene ATP (10(-6) M), the endothelium-independent contractions induced by alpha, beta-methylene ATP itself (10(-6) M) and by beta, gamma-methylene ATP (10(-5) M) were both abolished. The endothelium-dependent contraction induced by 2-methylthio ATP (10(-7) M) was not attenuated by alpha, beta-methylene ATP. The contraction induced by 2-methylthio ATP (10(-7) M) was attenuated markedly by reactive blue 2 (a P2Y antagonist) (3 x 10(-6) M), aspirin (5 x 10(-5) M), OKY-046 (thromboxane A2 synthetase inhibitor) (10(-5) M) and ONO-3708 (thromboxane A2 antagonist) (10(-8) M). However, these agents did not affect the endothelium-independent contraction induced by alpha, beta-methylene ATP (10(-6) M). Neither TMK-777 (a 5-lipoxygenase inhibitor) (10(-7) M) nor superoxide dismutase (100 U/ml) plus catalase (1,000 U/ml) affected either contraction. The present experiments demonstrate that P2X-purinoceptors mediate endothelium-dependent contraction in the canine basilar artery, and that the endothelium-derived contracting factor in this system is probably thromboxane A2.

Adenosine Triphosphate↗
PubMed1990

Purification of D2 dopamine receptor by photoaffinity labelling, high-performance liquid chromatography and preparative sodium dodecyl sulphate polyacrylamide gel electrophoresis.

[125I]N-azidophenethylspiperone ([125I]azido-NAPS) was used as a photoaffinity ligand for bovine D2 dopamine receptor. On photolysis, [125I]azido-NAPS was covalently incorporated into a major band of 94 kDa in bovine striatal membrane as assessed by autoradiography after sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) (10% acrylamide gel). The labelled D2 receptor protein from striatal membrane was solubilized and subjected to HPLC using gel filtration (TSK G3000SW) and hydroxyapatite gel (Pentax SH2010C), followed by two steps of preparative SDS-PAGE. The D2 receptor protein could be obtained as a single major polypeptide on SDS-PAGE by either silver staining or autoradiography.

Affinity Labels↗
PubMed1990

Syntheses of monocyclic and bicyclic 2,4(1H,3H)-pyrimidinediones and their serotonin 2 antagonist activities.

New serotonine 2 (5-HT2) antagonists with a monocyclic or bicyclic 2,4(1H,3H)-pyrimidinedione have been prepared and their activities evaluated. In a series of monocyclic compounds, 1-substituted 5-phenyl-2,4(1H,3H)-pyrimidinedione 14 showed potent in vitro activity, and the corresponding 3-substituted 5-phenyl and 6-phenyl derivatives 3, 8 and 20a also showed moderate activity. In the bicyclic compounds, 3-substituted 5,6,7,8-tetrahydro-2,4(1H,3H)-quinazolinedione 33 exhibited the most potent activity among the compounds prepared in this paper. The in vivo antagonist activity of 33 was comparable to that of ketanserin, a typical peripheral 5-HT2 antagonist.

Animals↗
PubMed1990

Effects of nitroglycerin on stable thromboxane A2 analogue-induced, nifedipine-resistant contraction in canine basilar artery.

The stable thromboxane A2 analogue, STA2, caused concentration-dependent contractions in the canine basilar artery. In Ca2(+)-free medium containing EGTA (0.1 mM) and nifedipine (10(-6) M), the addition of Ca2+ (2.5 mM) in the presence of STA2 (10(-8) M) caused a tonic contraction (nifedipine-resistant Ca2(+)-induced contraction). In the basilar artery, nitroglycerin did not significantly affect such nifedipine-resistant Ca2(+)-induced contractions, but nearly abolished the contraction in the coronary artery. The present experiments suggest that the regulatory mechanism of mobilized Ca2+ for the nifedipine-resistant Ca2(+)-induced contraction produced by STA2 in the basilar artery is different from that in the coronary artery.

Animals↗
PubMed1990

Cerebrovascular reactivities to N-methylated catecholamines in humans, monkeys and dogs.

A comparison was made of the cerebrovascular responses of humans, monkeys and dogs to noradrenaline (NAd) and dopamine (DA) as well as to their N-methylated derivatives, adrenaline (Ad) and N-methyl dopamine (methyl DA). The present experiments demonstrated that N-methylation of both NAd and DA enhanced the contractile responses of these agents in human cerebral arteries, while only N-methylation of DA enhanced the contraction of monkey cerebral arteries, and such an enhancement was not seen in dog cerebral arteries.

Adult↗