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Biomedical subjects

T Takeuchi

Publications and source records attributed to T Takeuchi.

At least 1,225 records · Page 68Linked to original sources
PubMed1990

Possible role of thyroid hormone in decreased somatomedin-C levels in diabetic and starved rats.

To elucidate the possible role of thyroid hormone in somatomedin-C (SmC)/insulin-like growth factor I regulation in diabetes mellitus and starvation, plasma SmC, liver SmC, and kidney SmC concentrations were measured in streptozotocin-induced (60 mg/kg) diabetic and starved (for 72 h) rats. Triiodothyronine (T3, 5.0 micrograms/kg every 24 h) was subcutaneously injected into diabetic rats for 7 days and into starved rats at 12, 36, and 60 h after starvation. Plasma T3, plasma SmC, liver SmC, and kidney SmC concentrations were significantly decreased in diabetic and starved rats. T3 administration restored plasma T3 levels to the normal value in diabetic and starved rats. Plasma SmC and kidney SmC concentrations were significantly increased in T3-treated starved rats, while they were not increased in T3-treated diabetic rats. These results suggest that thyroid hormone may have some role in SmC regulation during starvation, but may have no role in diabetes mellitus in the rat.

Animals↗
PubMed1990

Cloning of canine gastrin cDNA's encoding variant amino acid sequences.

We have isolated 2 clones encoding gastrin from a canine antral mucosa cDNA library. The clones differed in nucleotide sequence at 2 sites in the coding region. One of the clones confirmed the amino acid sequence of dog gastrin obtained by peptide purification and analysis. An A-G substitution in the other clone resulted in a Thr-Ala substitution in the region encoding the biologically active carboxyl-terminal portion of gastrin. The source of the observed heterogeneity in cDNA sequences is not known but its location may have implications with regard to the physiology of gastrin in dogs.

Amino Acid Sequence↗
PubMed1990

Molecular mechanism of growth hormone (GH) deficiency in the spontaneous dwarf rat: detection of abnormal splicing of GH messenger ribonucleic acid by the polymerase chain reaction.

The spontaneous dwarf rat (SDR) is an experimental model for pituitary dwarfism with an autosomal recessive mode of inheritance. In the pituitary of the SDR, neither GH cells nor GH protein were detected by immunological methods, but SDR pituitary has a very small amount of GH mRNA. In the present study the effects of GH-releasing factor and an analog of its second messenger, (Bu)2cAMP, on the total accumulation and secretion of GH were studied in primary cultures from SDR pituitaries. GH-releasing factor and (Bu)2cAMP increased the amount of GH mRNA, but neither accumulation nor secretion of immunoreactive GH was detected. These results suggested that the mutation is not manifest during transcription, but at a later stage. The GH gene of SDR was cloned, and its sequence was determined. A point substitution was found in the consensus sequence of the 3' splice site of the third intron. Judging from this point mutation, one would predict an abnormal splicing and a 1-base deletion in the GH mRNA. Therefore, the fragment of SDR GH cDNA in which the deletion was predicted was amplified by the polymerase chain reaction. Its sequence analysis confirmed that the SDR GH mRNA had 1 base deletion which must cause a premature translational termination of GH mRNA. These results demonstrate that GH deficiency in SDR is caused by a point mutation in the GH gene producing an abnormal splicing of GH mRNA.

Animals↗
PubMed1990

Melanization in albino mice transformed by introducing cloned mouse tyrosinase gene.

We introduced a mouse tyrosinase minigene, mg-Tyrs-J, in which the authentic genomic 5' non-coding flanking sequence was fused to a mouse tyrosinase cDNA, into fertilized egges of albino mice. Of the 25 animals that developed from the injected eggs, four mice exhibited pigmented hair and eyes. Histological analysis of the transgenic mice revealed that the melanogenesis was restricted to hair bulbs and eyes. These results suggest that this minigene encodes active tyrosinase protein and that its 5' flanking region contains the sequences regulating expression of mouse tyrosinase gene. This is the first report of a successful expression of tyrosinase gene and of pigment production in transgenic mice.

Albinism↗
PubMed1990

Increased gamma-aminobutyrate aminotransferase activity in brain of patients with Alzheimer's disease.

In order to search for more proximal factors in the pathogenesis of Alzheimer's disease, we studied the activities of various enzyme in the brains of patients, as well as control cases, by postmortem autopsy. In addition to the findings already known, such as the increase in prolyl endopeptidase (post-proline cleaving enzyme, PPCE) activity and the decrease in kallikrein activity, we found, anew, an increase in aminobutyrate aminotransferase (GABA-T) activity in the Alzheimer brain. This may be an important impetus for the reduction of gamma-aminobutyric acid (GABA) in the brain, one of the neurotransmitters. It has to be determined whether the former two abnormalities offer a background for such an abnormality of the neurotransmitter.

4-Aminobutyrate Transaminase↗
PubMed1990

Increase in aminobutyrate aminotransferase and cholineacetyltransferase in cerebrum of aged rats.

We previously reported an increase in aminobutyrate aminotransferase (GABA-T) activity in the cerebrum of Alzheimer patients. In the present study, we investigated whether such findings are common in the usual aging process as well. We examined the activity of various enzymes, which were examined in the previous study, in the cerebrum of Wistar-Kyoto rats and spontaneously hypertensive rats. In the two strains, we compared the enzyme activities between the two groups of animals, 5 weeks and 13 weeks of age. In both strains, the older animals had significantly higher activities of GABA-T and choline acetyltransferase (ChAc-T). In spite of other enzymatic changes coexisting, the above two enzymes were suggested by discriminant function analysis to be playing a major role in the multiple enzymatic changes in the cerebrum of the animals.

4-Aminobutyrate Transaminase↗
PubMed1990

Cooperation of ATP and norepinephrine in inducing contractile responses in guinea pig vas deferens.

Stimulation of the hypogastric nerve to the guinea pig vas deferens induced biphasic contraction consisting of a rapid transient phase (mediated by ATP) and a delayed tonic phase (mediated by norepinephrine, NE), whereas stimulations in the presence of selective antagonists caused each contractile phase separately. Stimulation in the absence of antagonist induced a larger rapid transient contraction than that induced by stimulation in the presence of alpha 1-antagonist. Results obtained in separate or simultaneous additions of exogenous ATP and NE showed synergism in the rapid transient contraction. These findings indicate that NE assisted ATP in inducing the hypogastric nerve-mediated contractile response in guinea pig vas deferens, but not vice versa.

Adenosine Triphosphate↗
PubMed1990

Electroencephalogram of Japanese Black calves affected with cerebrocortical necrosis.

Electroencephalogram (EEG) examinations were carried out on three Japanese Black calves (1, 2 and 14 week old) affected with cerebrocortical necrosis (CCN) in order to investigate the relationship between EEG abnormalities and encephalic lesions. Some neurologic signs such as circling, astasia, convulsion and opisthotonus appeared in two of the calves (case 1 and 3). The other calf (case 2), however, showed no neurologic signs. The EEGs obtained from the two calves (case 1 and 2), in the awake state, showed constant high amplitude (50-160 microV) and slow (1-4 Hz) activity (HASA). One of these (case 1) had necrosis mainly in the right hemisphere and showed a markedly asymmetric sharp wave. On the other hand, in case 3, the EEG showed diffuse lowered activity, and almost flat in some leads. A decrease in fast activity observed in common with all three animals. These findings suggest that one of the characteristic EEG patterns of CCN patient may be HASA and decreased fast activity. Histopathologic diagnoses of the calves were CCN in various degrees. The degrees of abnormality of the EEGs seemed to accord with the seriousness of the lesions. Because the EEG obtained from the calf having no obvious neurologic signs showed an abnormal pattern, it was considered that EEG examinations in the early stages of disorders are valuable to diagnose CCN.

Age Factors↗
PubMed1990

[How to discriminate between vibration syndrome and local fatigue of motorcyclists].

Motorcyclists who work in some offices sometimes complained of coldness, pain and numbness of upper limbs. We studied how to discriminate between vibration syndrome and local fatigue of the motorcyclists. Subjects are 42 motorcyclists of an office in Aichi prefecture. 25 of them held several letters in their left hand when they delivered the letters. They complained of coldness, pain and numbness in the left upper limbs more than in the right limbs (p less than 0.01). We think that it is the local fatigue rather than the disorder of vibration syndrome that causes such symptoms. So it is very important to recognize the existence of local fatigue in order to know how to discriminate between vibration syndrome and local fatigue of the motorcyclists.

Adult↗
PubMed1990

Compensatory adjustment in blood flow of the rabbit cerebral cortex during graded cerebral ischemia.

The role of the bilateral internal carotid and vertebral arteries in supplying cerebral cortex tissue blood flow (CTF) and the compensatory adjustment in CTF during graded cerebral ischemia were studied to determine the relationship to the increase in systemic arterial pressure (SAP) in anesthetized rabbits. CTF was recorded continuously by using Peltier stacks placed on both sides of the surface of the cerebral parietal cortex. Occlusion of the bilateral internal carotid arteries caused a decrease in CTF to 81.9% of the control value for the right hemisphere, and 83.5% of that for the left. Occlusion of the bilateral vertebral arteries produced no appreciable change in CTF. Compensatory adjustment in CTF was incomplete, i.e., CTF was reduced to a lower level, in the range of internal carotid flow (ICF) from 2 to 6 ml/min, and was severely reduced at 1 and 0 ml/min. The relationships between ICF and SAP, and ICF and CTF formed rectangular hyperbolic curves. No significant difference was observed between the decreases in CTF obtained before and after bilateral sectioning of the cervical sympathetic trunks. The relationship between SAP and CTF was described by a linear regression equation. These results indicate that the internal carotid arteries play a much more important role in supplying CTF than the vertebral arteries, that SAP rises in inverse proportion to the decrease in CTF, and that the cervical sympathetic trunks do not influence the compensatory adjustment in CTF caused by cerebral ischemia.

Animals↗
PubMed1990

[Microbiological study in clinically characterized rapidly progressive periodontal disease].

Samples of subgingival bacteria were collected from two sites of offanteriors with greater than or equal to 6 mm deep pockets in each ten patients in a clinically characterized rapidly progressive periodontal disease. The purpose of this investigation was to study the predominant cultivable microflora at pre- and post-periodontal treatment stages, in order to monitor the clinical effects of periodontal treatment and possibly to determine the presence or absence of active disease. "Non effective site" was defined as little elimination of periodontal pocket. Some patients responded remarkably well to root curettage. However the subgingival flora of effective sites, which had been successfully treated and maintained over a period of three weeks, was still significantly different from the subgingival floras of people with healthy gingiva. The predominant cultivable microflora of diseased lesions at the pre-treatment stage, in which a similar proportion of microbiota were detected on both sites in each patient, were significantly increased proportions of Bacteroides sp., B. intermedius and B. gingivalis. Although B. gingivalis has been implicated as the etiologic agent of the disease, to which marked antibody response has been found in periodontal pockets, there were decreased proportions of B. intermedius and B. gingivalis after treatment, compared to pre-treatment stage. The results showed that non-effective lesions were associated with subgingival microflora which were populated by higher proportions of B. intermedius and E. corrodens. H. actinomycetemcomitans were detectable during the experimental periods in all sites. It was possible to indicate progressing periodontitis by examining these microflora at the pre-treatment stage. However active or progressing disease in young adults might represent not only an overgrowth of existing organisms but also an abnormality in host resistance.

Aggregatibacter actinomycetemcomitans↗
PubMed1990

Effect of intestinal osmolality on insulin secretion to subsequent intravenous glucose or arginine in the rat.

To elucidate the effect of intestinal osmolality on insulin secretion, we investigated insulin response to a subsequent intravenous infusion of glucose or arginine after intragastric or intraduodenal mannitol or NaCl instillation in the rat. After anesthesia with intraperitoneal pentobarbital sodium, mannitol solution (10% or 20%) or 2.7% NaCl was instillated into the stomach or duodenum for 5 min at a flow rate of 0.5 ml/min, and 20% glucose (0.5 g/kg) or 10% L-arginine (0.5 g/kg) was infused bolus into the femoral vein 45 min after intestinal instillation. Insulin response to intravenous glucose was significantly higher in the rat with intragastric or intraduodenal mannitol or NaCl infusion than in control rats with intragastric or intraduodenal instillation of distilled water. Insulin response to intravenous arginine was almost the same in all groups. Subcutaneous preadministration of propranolol (0.4 mg/kg), atropine (1.2 mg/kg), or phentolamine (0.8 mg/kg) did not alter the present phenomenon. These results suggest that intestinal osmolality may enhance insulin release to intravenous glucose, but not to arginine in the rat.

Animals↗
PubMed1990

[Study on nucleolar organizer regions in bladder neoplasm].

Quantification of the argyrophilic nucleolar organizer regions (AgNORs), using a one-step silver colloid method, was made in proliferative urothelial lesions including neoplasm of the rat urinary bladder induced by 0.05% N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) and of the human urinary bladder. The mean numbers of AgNORs in various experimental lesions in rats given BBN for 5-30 weeks in drinking water were: nontreated urothelium (n = 6), 1.26 +/- 0.09; urothelium outside focal lesions (n = 10), 1.75 +/- 0.10; simple hyperplasia (n = 10), 2.01 +/- 0.15; papillary or nodular (PN) hyperplasia (n = 10), 2.15 +/- 0.19; papilloma (n = 5), 2.37 +/- 0.12; and transitional cell carcinoma (TCC) (n = 5), 3.52 +/- 0.23. There was a significant difference in the mean number of AgNORs between any two groups (p less than 0.05), except for simple hyperplasia vs PN hyperplasia (p = 0.085). In various proliferative lesions of human biopsy and resected samples, the mean numbers of AgNORs were normal urothelium (n = 8), 1.71 +/- 0.08; proliferative cystitis (n = 14), 1.79 +/- 0.18; hyperplasia (n = 8), 1.76 +/- 0.23; mild dysplasia (n = 5), 2.15 +/- 0.36; moderate dysplasia (n = 13), 2.61 +/- 0.27; severe dysplasia (n = 6), 3.46 +/- 0.57; G0 of TCC (n = 9), 1.95 +/- 0.17; G1 of TCC (n = 16), 2.39 +/- 0.20; G2 of TCC (n = 21), 3.33 +/- 0.31; G3 of TCC (n = 15), 4.68 +/- 0.51; and carcinoma in situ of TCC (n = 10), 3.61 +/- 0.52.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

[Endoscopic and fluoroscopic pyeloureterotomy for ureteropelvic junction obstruction and ureteral stricture].

Endoscopic or fluoroscopic pyeloureterotomy was performed in a total of 32 patients (34 ureters) with ureteropelvic junction obstruction (UPJO) or ureteral stricture from March 1985. Cold incision was performed, using a flexible knife over a guidewire, endoscopically on 23 ureters and fluoroscopically on 11 ureters. The mean operation time was 98.9 +/- 48.3 minutes. Twenty-five (74%) of the 34 ureters showed relief of subjective symptoms, normalized urinalysis and radiographical improvement of hydronephrosis with a mean follow-up period of 11.7 +/- 10.0 months (range: 3-43). The clinical results by etiology were as follows: primary UPJO, 13/16 (81%); secondary UPJO, 4/4 (100%); ureteral stricture, 6/7 (85%); obliteration of ureteral implantation, 2/7 (29%). No major complication was noted with this endourological technique. This endourological technique might be clinically useful for the treatment of UPJO and ureteral strictures.

Adolescent↗
PubMed1990

Probestin, a new inhibitor of aminopeptidase M, produced by Streptomyces azureus MH663-2F6. I. Taxonomy, production, isolation, physico-chemical properties and biological activities.

Probestin has been isolated as part of a program designed to find microorganism-produced inhibitors of aminopeptidase M from Streptomyces azureus MH663-2F6. It was purified by use of column chromatography of Amberlite XAD-4, silica gel, YMC-gel, Toyopearl HW-40, YMC D-ODS-5 (HPLC) and then isolated as colorless powders. Probestin is competitive with the substrate, and the inhibition constant (Ki) of it was 1.9 x 10(-8) M.

Aminopeptidases↗