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K Tsuchida

Publications and source records attributed to K Tsuchida.

At least 181 records · Page 10Linked to original sources
PubMed1989

Molecular characterization of a functional cDNA for rat substance P receptor.

This paper describes the amino acid sequence of the rat substance P receptor and its comparison with that of the rat substance K receptor on the basis of molecular cloning and sequence analysis. From a rat brain cDNA library constructed with an RNA expression vector, we identified a cDNA mixture containing a functional substance P receptor cDNA by examining electrophysiologically a receptor expression following injection of the mRNAs synthesized in vitro into Xenopus oocytes. A receptor cDNA clone was then isolated by cross-hybridization with the bovine substance K receptor cDNA. The clone was confirmed by selective binding of substance P to the cloned receptor expressed in mammalian COS cells. The deduced amino acid sequence (407 amino acid residues) possesses seven putative membrane spanning domains and shows a sequence similarity to the members of G-protein-coupled receptors. The rat substance P and substance K receptors are very similar in both size and amino acid sequences, particularly in the putative transmembrane regions and the first and second cytoplasmic loops. This similarity is in marked contrast to the sequence divergence in the amino- and carboxyl-terminal regions and the third cytoplasmic loop. The observed sequence similarity and divergence would thus contribute to the expression of similar but pharmacologically distinguishable activities of the two tachykinin receptors.

Amino Acid Sequence↗
PubMed1989

Electrophysiological actions of A23187 and X-537A in spontaneously beating and in voltage-clamped rabbit sino-atrial node preparations.

Electrophysiological effects of calcium ionophores, A23187 and X-537A, on spontaneously beating and voltage-clamped rabbit sino-atrial node preparations were examined, using the voltage-clamp technique with two microelectrodes. (1) A23187 (administered cumulatively) increased the cycle length significantly at 3 x 10(-6) and 10(-5) mol/l, and X-537 only at 10(-5) mol/l. Other action potential parameters were unaffected in the presence of these concentrations of either agent. At 2 x 10(-5) mol/l, either agent prolonged the cycle length significantly, but increased the amplitude and the duration of the action potentials and the maximum diastolic potential not to any significant extent. Both X-537A and A23187, at 2 x 10(-5)mol/l, induced a dysrhythmia, which in the former was probably due to delayed afterdepolarizations. (2) In voltage-clamped sino-atrial node cells, the holding current was shifted outwardly, to a greater extent in the presence of X-537A than A23187 at the same concentration (2 x 10(-5) mol/l). The ionophores initially increased the slow inward current and then decreased it. The steady outward current was inhibited, and its activation curve was shifted to a more negative voltage range. X-537A caused a transient inward current and an inward tail current on repolarization to the holding potential. (3) At concentrations of 10 and 18 mmol/l [Ca2+]o or in the presence of isoprenaline 10(-7) mol/l, these ionophores induced a more severe dysrhythmia. Conversely in the nominal absence of [Ca2+]o the regular rhythm was resumed.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗
PubMed1989

Relative influence of plaque control, scaling and root planing on occlusal sounds.

Nine periodontally affected subjects and eight healthy subjects were selected in order to examine the effect of initial periodontal treatment on occlusal sounds. Gingival Index, probing depth, tooth mobility and occlusal sound duration via an occlusal sound analyser were recorded at the baseline. The nine periodontal patients were then treated by plaque control, root planing with general scaling and were re-examined at 1 month and 3 months post-operatively. The following results were obtained: (i) The normal duration of an occlusal sound is less than 10 ms. (ii) Occlusal sounds of periodontal patients were of longer duration compared with values in healthy subjects, but decreased and approached the normal value after treatment.

Adult↗
PubMed1989

Treatment by pacemaker in familial amyloid polyneuropathy.

Amyloid deposits often involve the heart and cause disturbances in conduction and impulse formation in patients with familial amyloid polyneuropathy (FAP). Seven patients with FAP required pacemaker treatment during eight years. The most frequent bradyarrhythmias requiring pacing were sinus node dysfunction with junctional failure. Our seven patients had attacks and symptoms of bradyarrhythmias. A pacemaker relieved symptoms of bradycardias with recurrence of dislocation of electrode, exit block, and relatively high threshold. However, pacing did not improve the ultimate prognosis of FAP, because of progressive inanition of FAP. In our series, pacing should have been started earlier before advanced stage according to the ECG findings as in other diseases with bradycardias.

Adult↗
PubMed1989

[Surgery of aortic disease with coronary heart disease].

From 1978 through 1989, 1200 patients underwent attempted coronary surgery. Seventy-six CABG-patients were recognized aorto-vascular disease. Thirty-one CABG-patients were operated with vascular surgery. Operative mortality of CABG was 0% (0/76). Operative mortality of vascular surgery was 3.2% (1/31). Total operative mortality was 1.1% (1/91).

Aortic Aneurysm↗
PubMed1989

[Two cases reports of neurologic complications after aortic aneurysm operation].

Two cases with dissecting aortic aneurysm of DeBakey type IIIb were treated by graft replacement of the descending thoracic aorta under temporary bypass (Heparinized Hydrophilic Polymer shunt tube) with concurrent somatosensory evoked potential (SEP) monitoring. The SEP was unchanged during operation in both cases, and three sets of intercostal or lumbar arteries were reattached in case 2. In case 1 anterior spinal artery syndrome occurred below the fourth thoracic level (T-4) and right side hemiplegia immediately after the operation. Case 2 had normal neurological function initially after recovering from anesthesia but showed Brown-Séquard syndrome below the first lumbar level (L-1) two days later. In both cases, neurologic disturbance gradually recovered, 19 months postoperatively, case 1 can walk with assistance, and case 2 is able to resume his former activity. The probability of the prevention of neurologic deficits is discussed.

Aortic Dissection↗
PubMed1989

[Intracardiac repair in anatomically corrected malposition of the great arteries (SDL): report on 2 successful repair].

Two cases of anatomically corrected malposition of the great arteries (SDL) with aorto-mitral fibrous continuity and pulmonary-tricuspid discontinuity are presented. Case 1 was a 24-year-old male with an associated ventricular septal defect (VSD) and pulmonary stenosis. Case 2 was a 1-year-old boy also with VSD. Both cases successfully underwent total correction. The aorto-mitral fibrous continuity was verified in both cases through right ventriculotomy during the operation. The postoperative course was uneventful in both cases and they have remained asymptomatic 5 years after operation. We believe this report to be the first one of anatomically corrected malposition of the great arteries with aorto-mitral fibrous continuity.

Adult↗
PubMed1988

ESR studies on the ripple phase in multilamellar phospholipid bilayers.

The structure of the ripple phase in multilamellar DPPC liposomes was studied by measuring electron spin resonance (ESR) spectra of the stearic acid spin probe (16-SASL). The spectrum observed in the P beta' phase is explained in terms of the superposition of ordered- and disordered-type spectra. This fact suggests the existence of a nonhomogeneous structure in the P beta' phase, i.e., the coexistence of the ordered region present in the L beta' phase and the disordered region present in the L alpha phase. The fluidity of acyl chains in both regions and the intensity ratio of the disordered-type spectra to the total intensity were estimated from the ESR spectra at various temperatures. The fluidity of both regions did not exhibit remarkable temperature dependence. On the other hand, the intensity ratio showed almost similar temperature dependence of the partitioning of the TEMPO observed by ESR measurement and of the enthalpy curve by DSC measurement, that is, the intensity ratio value increases slowly near the pretransition temperature, is almost constant in the P beta' phase, and increases abruptly at the main transition temperature with temperature. The proportion of the disordered region is estimated to be about one-fifth to the total region in the P beta' phase. Based upon the above results, a model for the ripple structure is proposed.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1988

[Behavioral dental science. Part VIII. The dentist's rating and adolescents' perceptions of oral health].

The purpose of this study was twofold. The first objective was to measure the periodontal status and perceptions of oral health in adolescents. The second objective was to determine the effects that a program of dental health education would have on their periodontal status and perceptions of oral health. The dental health education with a 90-minute lecture had been given to eleventh-grade students (352) in the previous year. The dental health education program was not carried out in tenth-grade students (442) yet. The oral examination was performed by a dentist for both grades. The examination time was about ten seconds per person. The students' periodontal status was scored as "excellent (+2)," "good (+1)," "questionable (0)," "poor (-1)," or "very poor (-2)" according to the criteria of an Oral Rating Index (ORI) System proposed by the present authors. The level of students' perceptions was assessed by the cognition score of our dental health test (10 items concerning dental attitudes and behavior). Main results were as follows: 1. Only 6% of the 10-th grade students were judged as having "excellent (+2)" oral health. Thirty-six percent were "very poor (-2)" or "poor (-1)" periodontal status. 2. The mean cognition score and the mean ORI score of the 11-th grade students were significantly greater for each sex group than those of the 10-th grade students. 3. The cognition score showed a clear relationship to the ORI score in each grade and in all. The behavioral component of the cognition score was more closely related to the ORI score. These findings suggest that the dental health education contributes to the improvement of periodontal status as well as that of perceptions. Furthermore, the ORI may be utilized for a screening system to evaluate adolescents' periodontal status quickly and effectively.

Adolescent↗
PubMed1987

Dynamics of appearance and disappearance of the ripple structure in multilamellar liposomes of dipalmitoylphosphatidylcholine.

The physical properties of the pretransition (P beta'----L beta') of dipalmitoylphosphatidylcholine liposomes were investigated using freeze-fracture electron microscopy. The kinetics of pretransition examined in the previous paper using TEMPO spin probe (Tsuchida, K., et al. (1985) Biochim. Biophys. Acta 812, 249-254) was extensively studied by observing the ripple structures in the freeze-fractured surfaces at different time intervals. When the temperature is decreased from 38 degrees C to 30 degrees C, the ripple structure disappears in the following steps. The intervals between ripples begin to expand with the decrease of ripple density upon the temperature shift, and this process continues for several tens minutes. Then, each ripple disappears gradually and changes into a completely smooth surface at 3 h after the temperature shift. The comparison of relaxation times between the previous ESR measurement and the present experiment suggests that the fast relaxation observed in the previous study corresponds to the expansion of the intervals between ripples. On the other hand, the ripple structure of regular intervals appears rapidly in some places and then spreads over the whole area of fractured surface when the temperature is increased from 23 degrees C to 35 degrees C. The results obtained in this work and the previous ESR work strongly suggest that the formation and disappearance of ripple structure is closely related to the relaxation processes near the pretransition temperature.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1987

Intraatrial conduit repair in Scimitar syndrome.

A 26-year-old woman with partial anomalous pulmonary venous drainage into the right atrium (Scimitar syndrome) was successfully operated upon by incorporating an intra-atrial conduit. The single right pulmonary vein present was connected to the right atrial inferior vena cava junction. The atrial septum was extremely deviated to the left, and the left atrium was located entirely on the left of the spine. A small patent foramen ovale was found. The distance between the orifice of the right pulmonary vein and the enlarged atrial septal defect was too great to use an intracardiac patch, so a 14 mm woven Dacron graft, 6 cm long, was interposed between them. The patient is doing well 21 months following the operation.

Adult↗
PubMed1987

Effects of midodrine on experimentally induced postural hypotension and venous pooling in dogs.

Effects of (+/-)-2-amino-N-2,5-(dimethoxyphenyl-beta-hydroxyphenyl) acetamide hydrochloride (midodrine) on experimental postural hypotension and venous pooling were examined in the anesthetized dog treated with hexamethonium (20 mg/kg s.c.). A 30 degree-tilt caused a significant decrease in blood pressure. Midodrine, at 0.1 mg/kg, significantly attenuated the decrease in blood pressure induced by the tilt 10, 20 and 30 min after its administration. The heart rate was not affected by the tilt. Cardiac output decreased significantly following the tilt. Midodrine significantly increased the basal rate of cardiac output and attenuated the decrease in cardiac output induced by the tilt. Venous pooling was produced by the occlusion of the circulation of the dog foot, and the increase of limb girth by the cuff inflating was measured as an indicator of venous pooling. Midodrine, at 0.1 mg/kg, significantly attenuated the increase of limb girth, indicating that the drug reduced venous pooling. These results suggest that midodrine (0.1 mg/kg i.v.) constricts the venous bed, resulting in the increase in cardiac output in the anesthetized dog with experimental postural hypotension.

Animals↗
PubMed1987

Effects of the new calcium antagonist 2-nitratopropyl-3-nitratopropyl-2,6-dimethyl-4-(3-nitrophe nyl)- 1,4-dihydropyridine-3,5-dicarboxylate on cerebral circulation in dogs.

2-Nitratopropyl-3-nitratopropyl-2,6-dimethyl-4-(3-nitropheny l)- 1,4-dihydropyridine-3,5-dicarboxylate (CD-349), nimodipine and nicardipine (0.3-3 micrograms/kg i.v.) increased vertebral blood flow (VBF) in the anesthetized dog, the effect of CD-349 being the strongest, and they also decreased blood pressure. All these drugs slightly increased femoral blood flow. CD-349, nimodipine and nicardipine (1-10 micrograms/kg i.v.) increased cerebral tissue blood flow (CBF) in the anesthetized dog, CD-349 producing the most sustained and pronounced effect. CD-349 (3 micrograms/kg i.v.) restored the decrease of CBF induced by the application of 0.5 ml of serotonin (5-HT, 10(-5) mol/l), KCl (30 mmol/l) and prostaglandin F2 alpha (PGF2 alpha, 10(-4) mol/l) to the surface of the cerebrum of the anesthetized dog. In isolated canine basilar arteries. K-contraction was completely inhibited, but the relaxation of 5-HT- and PGF2 alpha-contractions by these drugs was incomplete. CD-349 had a more potent effect than nicardipine and nimodipine on basilar arteries. These results indicate that CD-349 is a potent cerebrovasodilator.

Animals↗
PubMed1986

Effects of propranolol on tissue necrosis in experimental myocardial infarction in dogs.

We studied the effects of propranolol on degradation of cardiac structural proteins resulting from ischemia induced by 24 h ligation of the coronary artery in dogs. Degradation of myocardial myosin heavy chain, alpha-actinin and troponin-I was used as an indicator of degradation of cardiac structural proteins. In dogs with left circumflex coronary artery ligation, propranolol, given orally in the dose of 10 or 30 mg/kg, significantly reduced degradation of cardiac structural proteins. This can be supported by the facts that treatment with propranolol, 10 or 30 mg/kg, reduced release of cathepsins B, L and D from lysosome to cytosol in the ischemic tissue and that the reduced acidity of the ischemic tissue was improved by treatment with propranolol, 30 mg/kg. In conclusion, propranlol delays the necrotic development of the severely ischemic myocardial tissue as shown by reduced protein degradation.

Animals↗