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Biomedical subjects

H Takei

Publications and source records attributed to H Takei.

At least 127 records · Page 7Linked to original sources
PubMed1991

Protein structure and cDNA nucleotide sequence of the Japanese quail alpha A globin.

The primary structure of the alpha polypeptide chain (alpha A) of the major component (QII) of Japanese quail hemoglobin was determined by protein and cDNA sequence analysis. The amino-acid sequences of all the soluble tryptic peptides were determined by the conventional protein sequencing technology. The sequence of the remaining portion, which contained an insoluble "core region", was determined through determination of the cDNA nucleotide sequence. The cDNA clones coding for the alpha A globin were isolated from the quail reticulocyte cDNA library, mapped by restriction enzyme digestion, and the nucleotide sequence was determined completely. The primary structure of quail alpha A globin shows a close similarity to that of chicken alpha A globin.

Amino Acid Sequence↗
PubMed1991

[Morphological changes in the lower incisor of suckling rats induced by large dose of aspirin].

Large doses of aspirin (200 mg/kg or 400 mg/kg, s.c) caused marked hypocalcemia in suckling rats, two hours after administration. The hypocalcemic effect was more evident in two week old rats than in one week old ones. Although the mechanism of aspirin-induced hypocalcemia is not clear at this moment, the drug can be a useful tool for inducing experimental hypocalcemia in suckling rats, besides hormonal and/or nutritional controls. In this report, large doses of aspirin were administrated to new born rats, once at one week after birth, or twice at one and two weeks after birth. The morphological changes of the lower incisor were examined using computer programs which have been developed for the analysis of plane curves such as the traces of the side view of the incisor. Aspirin administration shortened the length of the lower incisor and its labial trace. The width of the incisor, especially in the middle, was also diminished by aspirin administration. These observations suggest that the drug not only induced hypocalcemia in suckling rats but also to some extent suppressed the activity of odontoblasts which produce the dentin of the incisor. Analysis of curvature variance, calculated with the labial trace of the lower incisor, also suggested that large doses of aspirin had two effects. It suppressed mineralization of the teeth through its hypocalcemic effect, and it inhibited synthesis of the collagenous matrix. The computer programs applied in this study have proved useful in determining and analyzing morphological changes of bio-materials which are difficult to measure directly.

Analysis of Variance↗
PubMed1991

[A successful case report of ruptured abdominal aortic aneurysm with isolated left-sided inferior vena cava].

A 68-year-old man was admitted to our hospital because of shock. CT scan revealed ruptured abdominal aortic aneurysm (AAA) with isolated left-sided inferior vena cava (L-IVC). After emergent laparotomy, maintaining blood pressure stable, we clamped the aorta at the level of the supra-celiac region. An AAA (8.5cm in diameter) leaking from the posterior wall with a retroperitoneal hematoma was found, and L-IVC pressed by AAA was identified. The AAA was dissected with caution so as not to injure L-IVC and replaced with a woven Dacron bifurcated graft. The postoperative course was uneventful. The embryonic development and clinical significance of this rare anomaly are discussed. This is the first successful case in the Japanese literature by our survey.

Aged↗
PubMed1991

[Changes in high-energy phosphates in the myocardium before and after ischemia].

Assessment of the level of high-energy phosphates in the myocardium before, during and after ischemia was performed in 19 consecutive patients who underwent cardiac operation. The following results were obtained. 1) The levels of total nucleotides (ATP, ADP, AMP, CP) determined before, during and after aortic cross clamp were 14.94 +/- 4.12, 5.59 +/- 2.16 and 3.58 +/- 1.14 micrograms/mg. protein in the right atrial appendage. Those in the left ventricular myocardium were 18.22 +/- 4.90, 6.99 +/- 1.52 and 4.35 +/- 1.06 micrograms/mg. protein. The latter levels were higher than the former. 2) Rapidly decreasing after aortic cross clamp, the nucleotides dropped to 37-38% of preischemic level during aortic cross clamp and to 23% of preischemic level 30 minutes after reperfusion. At the termination of extracorporeal circulation, when circulatory dynamics stabilized, the nucleotides were only recovered to 50-53% of preischemic level. 3) Negative correlation was observed between the length of aortic cross clamp time and the content of nucleotides in the atrial muscle. (p less than 0.05) 4) Fluctuations in the nucleotide level indicated that the current method of myocardial protection using GIK solution produced unsatisfactory recover from ischemic damage and reperfusion injury.

Adenine Nucleotides↗
PubMed1990

Diffuse low-density areas in white matter on CT scans after intracarotid ACNU infusion--report of three cases.

Since 1984, we have treated 11 malignant glioma patients with intracarotid infusion of ACNU [1-(4-amino-2-methyl-5-pyrimidinyl)-methyl-3-(2-chloroethyl)- 3-nitrosourea hydrochloride] in addition to surgical removal and irradiation. We experienced three patients, who showed clinical manifestation of leukoencephalopathy and computed tomographic (CT) findings of diffuse low-density areas in the white matter on the side of ACNU infusion. Two of the three patients showed an additional CT finding of ring enhancement in the temporo-occipital region. The histological diagnosis of the first case was radiation necrosis, while that of the others was recurrent tumor with coagulation necrosis in the surrounding brain. Our experience suggests that intracarotid ACNU infusion increases the hazard of radiation necrosis, and the optimum dose and effective mode of administration should be evaluated.

Brain↗
PubMed1990

[A case report of coronary artery bypass grafting with the left internal mammary, the right gastroepiploic, and the inferior epigastric arteries].

We performed coronary artery bypass grafting with the left internal mammary artery, right gastroepiploic artery, and inferior epigastric artery on a 60-year-old male. The inferior epigastric artery used as a free graft was placed between the in situ left internal mammary graft proximally and the obtuse marginal branch distally. Both the left internal mammary graft to the left anterior descending artery and the right gastroepiploic artery to the right coronary artery were used as an in situ graft. All grafts were patent two weeks after the operation and the patient was free from angina at three months follow-up period.

Abdominal Muscles↗
PubMed1990

[Effects of 1,25-dihydroxyvitamin D3 on mineralization of incisor dentin in parathyroidectomized rats].

Male Wistar rats (8 weeks old) were parathyroidectomized (PTX) and given daily subcutaneous injections of different doses (0, 25, 50 or 100 ng/kg) of 1,25 (OH)2D3 for 13 days. Changes in plasma calcium and phosphorus levels were monitored at 3 day intervals. An appositional rate of dentin was estimated by a time marking method; that is, the distance of two lead lines deposited in a transverse section of the incisor dentin on the 9th and 12th days of the experimental period was measured. The plasma calcium levels that had been lowered by PTX were elevated dose-dependently following injections of the drug, but the plasma phosphorus levels that had been elevated by PTX were lowered. The body weight was not affected by the administration of the drug. However, the values for the dry weight and ash weight, and the calcium and phosphorus contents of the upper incisors increased dose-dependently. The mineralization of the dentin, that had been suppressed by PTX, also recovered dose-dependently. Apposition rates of the dentin in groups of rats given various doses of the drug (25, 50 and 100 ng/kg/day) averaged 46, 61 and 69 microns/3 days respectively. There was a significant correlation between the apposition rate of the dentin and the plasma calcium level. The correlation coefficients were estimated to be 0.956 (y = 17.2 + 4.6 chi, p less than 0.001) on the lingual aspect and 0.941 (y = 11.4 + 5.3 chi, p less than 0.001) on the labial aspect. However, the values for the mineralization of incisor dentin were inversely proportional to the plasma phosphorus levels. These results indicate that the stimulating effect of 1,25 (OH)2D3 on the mineralization of the dentin in PTX rats is primarily dependent upon the increase in plasma calcium levels by the hormone. The direct effect of 1,25 (OH)2D3 on the mineralization of dentin could not be demonstrated in this experiment.

Animals↗
PubMed1990

Accelerated transmural gradients of energy compound metabolism resulting from left ventricular hypertrophy.

Eighteen dogs underwent transmural left ventricular biopsies for adenosine triphosphate and suturing of the noncoronary cusp, creating valvular aortic stenosis. Three months after aortic stenosis and the subsequent development of left ventricular hypertrophy, animals underwent repeat transmural left ventricular biopsies followed by total myocardial ischemia at 37 degrees C. Left ventricular tissue samples for adenosine triphosphate and lactate levels were determined at 15-minute intervals and compared with 15 control animals. No significant difference between subendocardial and subepicardial adenosine triphosphate levels was found between left ventricular samples taken before left ventricular hypertrophy and 3 months after left ventricular hypertrophy. Significant differences in adenosine triphosphate utilization occurred between subendocardial and subepicardial layers in control and left ventricular hypertrophy myocardium, however. The gradient between the subendocardium and the subepicardium was significantly increased by left ventricular hypertrophy (p less than 0.05). Significant differences also occurred within the same layer when left ventricular hypertrophy and control groups were compared. During total ischemia, lactate concentration was significantly greater within the subendocardium than within the subepicardium in left ventricular hypertrophy. The onset of ischemic contracture was 48.2 +/- 2.1 minutes in left ventricular hypertrophy versus 62.3 +/- 1.8 minutes in control hearts (p less than 0.01). Subendocardial intramyocardial pressure increased significantly earlier than subepicardial in both left ventricular hypertrophy and control hearts. Adenosine triphosphate was used, and lactate accumulated more rapidly in animals with a more pronounced hemodynamic gradient. These data show that after left ventricular hypertrophy, adenosine triphosphate stores in the subendocardium and the subepicardium are unchanged from control values, yet the rates of adenosine triphosphate utilization and lactate accumulation during total ischemia are significantly increased. Furthermore, the subendocardial to subepicardial gradient of adenosine triphosphate utilization during ischemia found in normal hearts is markedly increased by left ventricular hypertrophy.

Adenosine Triphosphate↗
PubMed1990

[Measurement of myocardial temperature with infrared radio-thermometer in cardiovascular surgery].

We used an infrared radio-thermometer for measurement of myocardial temperature in cardiovascular surgery and a high correlation was observed when it was compared with a contact thermometer. This thermometer is characterized by the fact that it can be used in a non-contact remote-control manner either in a moving body or in a dark location. It is expected that this thermometer will be increasingly used in the clinical area in the future.

Body Temperature↗
PubMed1989

[Comparisons of bioavailability of various calcium salts. Utilization incisor dentin in parathyroidectomized rats].

In the present study, we compared the bioavailability of various calcium salts in the diet such as calcium lactate, calcium carbonate and calcium phosphate by examining the effects of these calcium salts on serum calcium concentration and on the mineralization of incisor dentin in parathyroidectomized (PTXed) rats. Each rat was given daily 12 g of a low calcium (0.1% Ca) diet beginning from 3 days before the operation and continuing for 11 days after. Then the diet was changed to those containing various calcium salts (1.5% Ca). The serum calcium and phosphorous concentrations were examined every three days, just before feeding time and 6 hours after. The degree and site of the mineralization of incisor dentin were examined histologically by a time marking method using lead acetate. In the PTXed rats maintained on a low calcium diet, the serum calcium concentration decreased to about 4.5 mg/dl and the mineralization of incisor dentin was inhibited. On the 11th day, just before feeding on diets containing various calcium salts, the serum calcium concentrations were very similar for each group, but at 6 hours after feeding, concentration was 7.6 mg/dl in the calcium lactate group, 6.2 mg/dl in the calcium carbonate group and 4.8 mg/dl in the calcium phosphate group. On the 17th day following administration of the high calcium diets, the serum calcium concentrations were 9.8 mg/dl in the calcium lactate group, 8.4 mg/dl in the calcium carbonate group and 4.4 mg/dl in the calcium phosphate group. Mineralization of the incisor dentin was best in the calcium lactate group, moderate in the calcium carbonate group and poor in the calcium phosphate group. We also examined the effects of dietary phosphorus contents on serum calcium concentrations and on the mineralization of incisor dentin using PTXed rats. On the 17th day following the administration of diets (1.5% Ca, with calcium lactate) containing various amounts of phosphorus, the serum calcium concentrations in the calcium lactate group were 8.8 mg/dl (0.4% P), 6.9 mg/dl (0.8% P) and 4.2 mg/dl (1.6% P) respectively. Mineralization of incisor dentin was also inhibited in rats fed a high phosphorus diet. These results suggest that in PTXed rats, absorption of calcium from the intestines and mineralization of the incisor dentin is best by the administration of calcium lactate, moderate by calcium carbonate and poor by calcium phosphate, and that phosphorus in the diet inhibits calcium absorption from the intestines.

Animals↗