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Biomedical subjects

T Hashimoto

Publications and source records attributed to T Hashimoto.

At least 91 records · Page 5Linked to original sources
PubMed1992

Contractile activity of porcine neuromedin U-25 and various neuromedin U-related peptide fragments on isolated chicken crop smooth muscle.

Contractile activity of porcine neuromedin U-25 (p-NMU-25) and various neuromedin U (NMU) peptide fragment amides was examined on chicken crop smooth muscle preparation. The relative activity (expressed as RA value) of p-NMU-25 to porcine neuromedin U-8 (p-NMU-8) was 5.51 +/- 0.09, and p-NMU-25 (15-25) was the most potent fragment with an RA value of 7.78 +/- 0.05. All C-terminal 11-peptide amides of rat, rabbit, and frog NMU peptides retained activity about three-fold higher than the corresponding C-terminal 8-peptide amides. The peptide segment Asn15-Arg-Arg17 of p-NMU-25, as well as the corresponding positions of various NMU peptides: Ser13-Gly-Gly15 of rat NMU and Ser15-Arg-Gly17 of rabbit and frog NMUs, appeared to be involved in the structural requirements for increased contractile activity in the assay system.

Amino Acid Sequence↗
PubMed1992

The beta-adrenergic receptor/adenylate cyclase system in the cardiac ventricles of a hypertrophic cardiomyopathy rat model.

The WKY/NCrj rat strain is considered to be a good animal model for hypertrophic cardiomyopathy (HCM). The purpose of this study was to examine the beta-adrenergic receptor/adenylate cyclase system in the cardiac ventricles of these rats. beta-adrenergic receptor density (Bmax) in the right ventricle (RV) was higher in WKY/NCrj than in Wistar rats. In contrast, Bmax in the interventricular septum (IVS) was lower in WKY/NCrj than in Wistar rats. Isoproterenol-stimulated adenylate cyclase activity in cardiac ventricular slices showed that changes corresponded to the changes of Bmax in every type of studied cardiac ventricle. The intracellular adenylate cyclase pathway (GTP gamma S-, NaF- and forskolin-stimulated adenylate cyclase activity in cardiac ventricular particulate fraction) did not differ between WKY/NCrj and Wistar rats in any region of the cardiac ventricles. Catecholamine levels tended to be low in the RV and to increase in the IVS of WKY/NCrj rats. Our results suggest that the activity of the beta-adrenergic receptor/adenylate cyclase system varies in different cardiac ventricles of the WKY/NCrj rat model for HCM.

Adenylyl Cyclases↗
PubMed1992

High-energy phosphate metabolism of the myocardium in normal subjects and patients with various cardiomyopathies--the study using ECG gated MR spectroscopy with a localization technique.

Nuclear magnetic resonance spectroscopy (MRS) is a new technique for the evaluation of myocardial metabolism. Recently, localized MRS has been clinically available to measure by a non-invasive method the relative concentrations of the high-energy phosphate metabolites in the myocardium. We performed ECG gated P-31 MRS using ISIS (image-selected in vivo spectroscopy) in 15 normal volunteers, 12 patients with hypertrophic cardiomyopathy, 12 with left ventricular hypertrophy, 6 with dilated cardiomyopathy and 11 with specific heart muscle disease. Myocardial peak height ratios of PCr/gamma-ATP, Pi/gamma-ATP and PCr/Pi were measured. Myocardial P-31 MRS demonstrated a significant decrease in the ratio PCr/ATP in patients with hypertrophic cardiomyopathy and specific heart muscle disease as compared with normal subjects, indicating myocardial metabolic disturbance in these patients. The ratio of PCr/ATP in patients with dilated cardiomyopathy did not differ significantly from that of normal subjects. However, exercise MRS revealed a marked decrease of PCr peak in an asymptomatic patient with dilated cardiomyopathy, which may indicate a latent metabolic disturbance in the myocardium of dilated cardiomyopathy.

Adenosine Triphosphate↗
PubMed1992

The influence of advancing age on the electrophysiological changes of the atrial muscle induced by programmed atrial stimulation.

The influence of advancing age on the electrophysiological changes of the atrial muscle induced by programmed atrial stimulation, such as fragmented atrial activity (FAA), interatrial conduction delay (ICD), and repetitive atrial firing (RAF), was investigated in 42 patients with neither documented episodes of paroxysmal atrial fibrillation nor sick sinus syndrome. The induction rates of FAA, ICD, and RAF were not affected by age. The zones of FAA, ICD and RAF, did not show any correlation with age. However, the longest coupling interval giving rise to FAA (longest CI-FAA) or ICD (longest CI-ICD) showed a significant correlation with age (longest CI-FAA; r = 0.428, p less than 0.01, longest CI-ICD; r = 0.398, p less than 0.01). Although the longest coupling interval giving rise to RAF did not show a direct correlation with age (r = 0.267), it was significantly longer in patients over 60 years of age than in those under 60 (p less than 0.05). These results suggest that aging affects the electrophysiological properties of the atrial muscle, which can help to explain why atrial fibrillation is seem more frequently in the elderly.

Adult↗
PubMed1992

[Characteristics of medical institutions visited by 30 intractable disease patients receiving financial aid for treatment].

In order to determine the characteristics of medical institutions which patients with 30 intractable diseases visited, we analyzed data of a nationwide survey conducted by the Epidemiology of Intractable Diseases Research Committee in 1989. Each of 47 prefectural governments in Japan reported information of all patients with 30 intractable diseases who received financial aid for the diseases between April 1988 and March 1989. Information collected about each patient consisted of identification numbers, which included the disease code, sex, age, the code of the municipality where the patient lived, the medical institution which treated the patient, etc. Out of 173,637 patients whose information was reported by prefectural governments, we used data of 159,910 patients whose medical institutions were reported completely. The results can be summarized as follow: 1) Of the 159,910 patients, 8.6 percent visited medical institutions outside of the prefectures where the patients lived. Many patients living in prefectures located close to large cities, such as Tokyo, visited medical institutions in large cities. 2) The proportion of patients who visited hospitals of medical schools was 27.9 percent. 3) Patients who were affected by diseases causing physical disabilities such as SMON and malignant rheumatoid arthritis tended to visit medical institutions located in their neighborhoods and were treated in small hospitals or clinics. Old patients had the same tendency as patients with such diseases. 4) Although the number of patients receiving aid in 1988, whose data we analyzed in the current study, was larger than that in 1984, the proportion of patients visiting medical institutions outside of the prefecture where the patients lived, and the proportion of patients visiting hospitals of medical schools were nearly equal to those in 1984.

Adolescent↗
PubMed1992

Effect of glucose on Na, K-ATPase activity in cultured bovine aortic endothelial cells.

The effect of high concentrations of glucose on Na, K-ATPase activity and the polyol pathway was studied using cultured bovine aortic endothelial cells. Na, K-ATPase activity was expressed as ouabain-sensitive K+ uptake. A significant decrease in Na, K-ATPase activity with an intracellular accumulation of sorbitol was found in confluent endothelial cells incubated with 400 mg/dl glucose for 96 h. However, there was no significant change in the Na, K-ATPase activity or sorbitol content of the cells incubated with 100 mg/dl glucose plus 300 mg/dl mannitol. The decrease in Na, K-ATPase induced by the high glucose concentration was restored by the simultaneous addition of 10(-4) M ponalrestat (ICI 128,436; Statil), an aldose reductase inhibitor. The addition of this agent also significantly reduced the increase in sorbitol induced by high glucose levels. These results suggest that the decrease in Na, K-ATPase activity induced in cultured aortic endothelial cells by high concentrations of glucose may be caused in part by the accumulation of sorbitol.

Aldehyde Reductase↗
PubMed1992

Relationship between inhibitor of extrathyroidal 5'-deiodinase activity and serum free fatty acid in children with nonthyroidal illness and acute ketosis.

To clarify whether serum free fatty acid (FFA) is an inhibitor of extrathyroidal conversion (IEC) of thyroxine (T4) to thyronine (T3), we measured the concentration of FFA, IEC activity and thyroid hormones in normal subjects, acute ketotic children and children with low T3 syndrome due to nonthyroidal illness (NTI). Iodothyronine (I) 5'-deiodinase activity was assayed with reverse triiodothyronine (rT3) as substrate and liberated 125I-was measured. The IEC was determined by the inhibition of I 5'-deiodination by ether extract of sera or standard oleate solution. IEC values were represented as mM oleate. The serum concentration of FFA was 0.470 +/- 0.117 (SD) mM in 11 normal subjects, and it was significantly higher (1.242 +/- 0.248 mM; P < 0.01) in 10 acute ketotic children and in 7 samples from 6 NTI children (0.904 +/- 0.530 mM; P < 0.05). In contrast, there was no difference in IEC among three groups (normal subject, 0.451 +/- 0.069 mM; acute ketosis, 0.437 +/- 0.040 mM; NTI, 0.465 +/- 0.224 mM). No correlations were found between IEC activity and the serum FFA concentration or thyroid hormones in 28 samples from three groups. The sequential changes in serum thyroid hormones, FFA and IEC in 3 of 6 NTI children revealed no consistent relationship. Furthermore, one NTI child had significantly high IEC (> 1.000 mM) but its serum FFA (1.182 mM) was below the mean value for the acute ketotic group. These results indicate that 1) many NTI patients may bear no relation to IEC and 2) IEC may not be caused by serum FFA only but includes several factors.

Acute Disease↗
PubMed1992

Twenty-four year spironolactone therapy in an aged patient with aldosterone-producing adenoma.

A case of primary aldosteronism treated with spironolactone therapy has been followed up for 24 years. This is probably the longest case of spironolactone therapy for primary aldosteronism that has ever been reported. Long-term treatment with spironolactone controlled the hypertension and prevented hypokalemic alkalosis in this patient, without any deleterious effects on steroid biosynthesis. Based on data obtained during dose reduction and subsequent withdrawal of spironolactone, it is suggested that the suppressed plasma renin activity associated with adenoma-induced aldosteronism develops prior to hypokalemia and hypertension.

Adenoma↗
PubMed1992

Further analysis of mutant thiolase protein in fibroblasts from a Japanese boy with 3-ketothiolase deficiency.

We examined the mutant protein of mitochondrial acetoacetyl-CoA thiolase (mutant T2) in fibroblasts from a Japanese boy with 3-ketothiolase deficiency. The molecular size of the mutant T2 protein, determined by pulse labeling and SDS/PAGE, was intermediate between the mature subunit and the precursor of T2. To characterize the mutant T2 protein, pulse-labeling and rhodamine 6G inhibition of mitochondrial transport in fibroblasts, cell-free translation experiments, and family studies by thiolase assay, immunoblotting, and pulse-labeling were carried out. The mutant T2 was detectable as early as a 10-min pulse. The probable precursor of the mutant T2 was not detectable in either the rhodamine 6G inhibition or cell-free translation experiments. In the parents, the K+ ion dependency of acetoacetyl-CoA thiolase activity was low and the T2 bands in immunoblots were faint. It would thus appear that the parents are heterozygotes of this disease. In pulse-labeling, only a band for the mutant T2 was detected in the patient and a single band for the normal mature subunit of T2 in the father; both bands were detected in the mother. These findings suggested that the mutant T2 in the patient was inherited from the mother, and that the expression of another mutant allele of the father may be either abolished or scanty.

Acetyl-CoA C-Acetyltransferase↗
PubMed1992

Spontaneous disappearance of arteriovenous fistula between the vertebral artery and deep cervical vein--case report.

A 58-year-old female was readmitted with pulsatile tinnitus in the right ear 8 months after subtemporo-occipital transtentorial clipping of a peripheral superior cerebellar artery aneurysm. On examination, she was normal except for pulsatile bruit over the right mastoid region. Angiography showed a fistulous communication between the muscular branches of the right vertebral artery and the deep cervical vein. The incision of the aneurysm surgery was supratentorial, so the only possible cause of the upper cervical arteriovenous (AV) fistula was fine gold acupuncture needles implanted for bronchial asthma 18 years before. The AV fistula disappeared spontaneously after 1 month, possibly because of thrombosis of the affected veins.

Arteriovenous Fistula↗
PubMed1992

[An examination of self-monitoring as a determinant of compliant conforming behaviour].

The present study investigated the determinant of compliant conforming behaviour from the view-point of the self-monitoring. Subjects, who were classified into High Self-Monitors (HSM) and Low Self-Monitors (LSM), participated in the experiment in which they had a task to distinguish the size of two circles. About the half of subjects performed the task with confederates. In eight of 13 trials, confederates had mistaken distinctions intentionally. The results showed HSM were more conformable to confederates than LSM for male subjects. HSM seemed to conform themselves to confederates easily, because their behaviour was guided by external cues. By contrast, LSM would conform themselves with difficulty, because their behaviour was guided by their internal states. But there were no significant differences for female subjects, and the ability of self-monitoring was considered as the less explanatory determinant for conformity in this experiment.

Adult↗
PubMed1992

[Clinical results of prophylactic intravesical chemotherapy on superficial bladder cancer using the dye exclusion assay].

A chemosensitivity test was carried out on superficial bladder cancer using the dye exclusion assay for the purpose of screening chemosensitive drugs for prophylactic intravesical chemotherapy. Bladder cancer cells of each patients were incubated, in vitro, in the presence of adriamycin, (2"R)-4'-0-tetrahydropyranyladriamycin, mitomycin C, pepleomycin and 4'-epi-adriamycin (500 micrograms/ml) at 5%, CO2, 37 degrees C for 2 hours. The cytotoxic effect of the drugs was evaluated by the ratio of stained cells by trypan-blue. The most effective drug was instilled postoperatively into the bladder 3 times for the first week, and every 2 weeks during the following 14 weeks. In 18 patients followed more than 4 months the prophylactic effect was evaluated. Fifteen of the 18 patients completed the protocol, but the remaining 3 patients failed to complete to the instillation because of severe irritability of the bladder. Tumor recurrence was demonstrated in two patients. Non-recurrence rates of tumors at 12 and 24 months were 93.8% and 82.0%, respectively. These results suggested that this rapid and handy assay was useful for the purpose of screening chemosensitive drugs for the intravesical chemotherapy.

Administration, Intravesical↗
PubMed1992

[Effect of tazanolast on platelet activating factor-induced airway hyperresponsiveness in guinea pigs].

To determine whether tazanolast inhibits airway hyperresponsiveness, we studied the effect of this drug on platelet activating factor (PAF)-induced airway hyperresponsiveness in guinea pigs. Inhalation of PAF (1 microgram/ml) caused significant airway hyperresponsiveness to acetylcholine (p < 0.01) or histamine (p < 0.05). Pretreatment with tazanolast (30-300 mg/kg) produced a dose-dependent inhibition of airway hyperresponsiveness induced by PAF inhalation, and significant inhibition (p < 0.05) was obtained with the drug (300 mg/kg). Aspirin also inhibited PAF-induced airway hyperresponsiveness, while tranilast produced hardly any inhibition. From these results, it is suggested that tazanolast is effective in inhibiting airway hyperresponsiveness.

Animals↗
PubMed1992

[A case of thalamo-subthalamic hemorrhage presenting monoballism in the contralateral lower extremity].

We report a 62-year-old man with ballism confined to the right leg, so-called monoballism. He was admitted to our hospital complaining of gait disturbance due to violent involuntary movements in the right lower extremity which had developed seven days before. He had a ten-years' history of hypertension and at age 57 had been diagnosed as having asymptomatic multiple cerebral infarcts. Until admission, he was taking antiplatelet drugs for the purpose of preventing thrombotic stroke. On neurological examination, he showed mild impairment of higher brain function, Horner's sign in the left eye, and typical ballism in the right lower extremity. Involuntary movements were never observed in the face and the other extremities. Surface electromyography also showed reciprocal burst discharges at about 1 Hz related to the ballistic movements in the right lower extremity. CT scan revealed a high density lesion surrounded by a low density in the left subthalamic area. MRI examination demonstrated a dumbbell shaped hemorrhage extending from the left subthalamic nucleus to the dorsomedial nucleus of the ipsilateral thalamus. Adding to the hemorrhage, many ischemic lesions were observed in the bilateral basal ganglia and thalamus including the left pallidum. The causal end of the hemorrhage apparently located in the anterior dorsomedial portion of the subthalamic nucleus. There were few reports concerning monoballism, especially monoballism limited to the lower extremity. Recent researches indicate that a subthalamic lesion reduces the excitatory control from the subthalamus to the internal segment of the globus pallidus, which leads to a disinhibition of the thalamus and gives rise to ballism.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral Hemorrhage↗
PubMed1992

[A case of cerebral infarction presenting as retrosplenial amnesia].

We report a 73-year-old right-handed female who presented with an acute amnesic syndrome. On November 18, 1991, she was admitted to a local hospital complaining of sudden-onset vertigo and nausea, but immediately after the admission she developed an amnesic syndrome. On November 27, she was transferred to our hospital for further assessment of her memory disturbance. Neurologically she was normal except for mild right hemianopsia and increased deep tendon reflexes in the extremities. Neuropsychological assessments were performed over 3 weeks. She was always alert, attentive, and cooperative. She had no confabulation. On the Wechsler Adult Intelligence Scale revised (WAIS-R), her total IQ was 110. Frontal, verbal, and perceptual functions and motor performance were normal. She had no signs of a callosal disconnection. Despite these preserved functions, her memory function was obviously disturbed. Several memory betteries showed that her recent memory for both verbal and visual modalities was impaired, while her immediate memory such as digit span was preserved. For remote memory her retrograde episodic memory concerning both personal and public events was almost intact, although she had a profound anterograde amnesia. In particular she recalled her personal information about just-premorbid events in detail. On the other hand, her semantic memory, for example understanding of proverbs, geography, and scientific law, was preserved. Taken together, her procedural memory on learning tasks, such as "Tower of Hanoi" and mirror drawing, was intact. Computed tomography demonstrated a low-density area medial to the trigon of the left ventricle.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗