Search PubMed⌕ Search

Biomedical subjects

T Yaginuma

Publications and source records attributed to T Yaginuma.

At least 19 recordsLinked to original sources
PubMed1992

Trehalase from male accessory gland of an insect, Tenebrio molitor. cDNA sequencing and developmental profile of the gene expression.

A cDNA of alpha alpha-trehalase (EC 3.2.1.28) from a cDNA library of male bean-shaped accessory gland of the mealworm beetle, Tenebrio molitor, has been isolated by the homology screening approach. Sequence analysis of the cDNA (1830 bp) revealed that the cDNA encoded a protein of 555 amino acids with a calculated M(r) of 64457. The deduced amino acid sequence had significant similarities to rabbit small intestine and Escherichia coli trehalases. Northern blotting and semi-quantitative PCR analyses revealed that a trehalase transcript with about 2.0 kb was abundant in bean-shaped accessory glands. In the glands, the amount of trehalase transcript increased from 1 to 2 days after adult ecdysis. These tissue- and stage-specific gene expressions of trehalase corresponded to the tissue- and stage-specificity of trehalase activity.

Amino Acid Sequence↗
PubMed1992

Biosynthesis of NAD-sorbitol dehydrogenase is induced by acclimation at 5 degrees C in diapause eggs of the silkworm, Bombyx mori.

1. In diapausing eggs of the silkworm, Bombyx mori, activity of NAD-sorbitol dehydrogenase (EC 1.1.1.14, SDH) is almost negligible, but is increased by acclimation at 5 degrees C (Yaginuma et al., 1990, J. comp. Physiol. B160, 277-285). To elucidate the mechanism regulating SDH activity, the following experiments were conducted. Anti-SDH serum was made in a mouse using purified sheep liver SDH. 2. This antiserum reacted with Bombyx egg SDH purified partially by Blue Sepharose CL-6B and Sephacryl S-300 column chromatographies. 3. SDS-PAGE and immunoblotting analyses using the antiserum showed that SDH activity was correlated with the amount of the enzyme protein. 4. These results indicate that biosynthesis of SDH is induced by acclimation at 5 degrees C in diapause eggs of B. mori.

Acclimatization↗
PubMed1992

[A case of Candida albicans endocarditis with impaired lung function].

A 53-year-old male was admitted to the hospital because of Candida albicans endocarditis. He had had a thoracoplasty due to pulmonary tuberculosis and showed severe restructive lung function. In 1987 and '89, trachiostomy was made because of respiratory failure. The patient was well until nine months earlier, when he consulted a physician because of fever. The investigations failed in finding the cause of the fever. He was administered antituberculosis agents and antiinflammatory drugs but had a fever every day. Two months before admission, a cardiac ultrasonographic study showed evident vegetations with mitral regurgitation. From the above course and examinations, a diagnosis of Candida albicans endocarditis was made. Infusions of CEZ, TOB, PIPC and miconazole for more than one month was ineffective. In November, 1990, he was referred to our medical center for the purpose of operation. A blood culture proved Candida albicans infection. An intravenous administration of fluconazole 400 mg/day was begun. However, there was pulmonary bleeding probably due to heparin used for prevention of atrial thrombosis and he developed fever, hypoexemia, ventricular tachycardia, and hyponatremia. He underwent mitral-valve replacement with a SJM valve. Culture of the vegetated mitral valve again proved Candida albicans. After operation, hypoexemia, ventricular tachycardia, hyponatremia were improved gradually. However he had an eosinophilia, eruption, and dyspnea. We suspected a drug eruption of fluconazole. Lymphocyte stimulating test of fluconazole proved positive. After the episode, he had no symptoms and was discharged.

Candidiasis↗
PubMed1992

[A case of adult pulmonary supravalvular membranous stenosis which was successfully treated by percutaneous transluminal balloon dilatation].

We report a case of adult pulmonary supravalvular stenosis which was successfully treated with percutaneous transluminal balloon dilatation (PTBD). A 42-year-old man was admitted for a heart murmur and abnormal findings in the screening chest roentgenogram. Having no symptoms on admission, his physical activity was evaluated as Class I according to the classification of the New York Heart Association. A systolic murmur (Levine III/VI) with split second sound was audible at the left sternal border in the 3rd intercostal space. Chest roentgenogram revealed 57% of the cardio-thoracic ratio and no signs of increased pulmonary vascular markings. ECG showed incomplete right bundle branch block. Echocardiography and right ventriculography visualized the supravalvular membranous structured stenosed pulmonary artery 1cm above the pulmonic valve. Systolic pressure gradient between the right ventricle and the distal main pulmonary trunk was 54mmHg. The patient was diagnosed as having pulmonary supravalvular membranous stenosis. PTBD was applied using Inoue balloon catheter, where inflation was initiated from approximately 120% of pulmonary arterial diameter and terminated at 150%. This procedure decreased systolic pressure gradient from 54mmHg to 36mmHg without complication. After PTBD right ventriculography demonstrated that a part of the membranous structure had become floppy and movable. Pulmonary arterial diameter was unchanged. We considered that PTBD tore the membranous structure, which consequently resulted in the decrease of systolic pressure gradient. Systolic murmur diminished to Levine II/VI. Six months later, cardiac catheterization showed no change in systolic pressure gradient compared with that immediately after PTBD. This is the first report on pulmonary supravalvular membranous stenosis successfully treated with PTBD.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Vascular smooth muscle cells from genetically hyperlipidemic rabbit (WHHL rabbit) exhibit decreased growth response.

The Watanabe Heritable Hyperlipidemic (WHHL) rabbit is a widely studied animal model for the human genetic disorder familial hypercholesterolemia, and spontaneously develops atherosclerotic disease. We studied the growth characteristics of cultured vascular smooth muscle cells (VSMC) from WHHL rabbits compared with VSMC from Japanese white rabbits. We measured cell proliferation, DNA synthesis, and c-myc proto-oncogene expression, in response to growth stimuli such as fetal bovine serum (FBS) and platelet-derived growth factor (PDGF). VSMC from Japanese white rabbits exhibited a 4-fold increase in cell numbers during a 5-day incubation period compared with those from WHHL rabbits. FBS and PDGF stimulated DNA synthesis, as measured by thymidine incorporation into VSMC, in both Japanese white rabbits and WHHL rabbits, however the response was significantly higher in the former strain. The intracellular pH value of VSMC determined using the pH-sensitive fluorescence dye 2',7'-bis-carboxyethyl-carboxyfluorescein was significantly higher in WHHL rabbits than in Japanese white rabbits. Proto-oncogene c-myc was induced by exposure of VSMC to FBS, however there was no significant difference in c-myc mRNA levels between the two strains. These results suggest that VSMC from WHHL rabbits are not genetically growth accelerated, but show decreased growth response to growth stimuli.

Animals↗
PubMed1991

cDNA cloning, sequencing and temporal expression of the protease responsible for vitellin degradation in the silkworm, Bombyx mori.

1. We have cloned the cDNA encoding the vitellin (Vtn)-degrading protease (30 k Vtn protease and 24 k Vtn protease) of the silkworm, Bombyx mori, and determined the primary structure by sequencing the cDNA along with mRNA. 2. The deduced amino acid sequence comprised 264 amino acid residues and had high homology to the trypsin-like proteases of vertebrates and invertebrates. 3. Northern blot analysis using the cDNA as a probe revealed that the transcription of the Vtn protease gene occurred at the restricted stage of embryogenesis when the protease activity appeared. 4. The in vitro translation experiment demonstrated that a 32 kDa polypeptide was the primary translation product and the translation activity changed according to transcriptional activity. 5. By Western blotting using the antiserum against each Vtn protease, two enzymes were shown to share the common antigenicity, and the titer of both enzyme proteins changed closely related with activity of proteases. 6. These results led us to conclude that the biosynthesis of Vtn protease is regulated at the level of transcription.

Amino Acid Sequence↗
PubMed1991

Effect of paeoniflorin, glycyrrhizin and glycyrrhetic acid on ovarian androgen production.

We have shown that traditional herbal medicine, Shakuyaku-Kanzo-To consisted of Shakuyaku and Kanzo decreased serum testosterone levels in woman and rat. Therefore, paeoniflorin and glycyrrhizin, a main component of Shakuyaku and Kanzo, respectively, and glycyrrhetic acid, a metabolite of glycyrrhizin in vivo, were investigated for the steroid production in the rat ovary on the morning of proestrus. The homogenized tissues of one ovary were incubated in the Dulbecco's modified Eagle medium (pH 7.5) with 100 micrograms/ml of paeoniflorin, glycyrrhetic acid and glycyrrhizin and the medium only (the control) at 37 degrees C for 270 min. After the centrifugation, the concentrations of delta 4-androstenedione, testosterone and estradiol in the supernatants were determined by RIA. The production of the hormones expressed by [concentration x supernatant volume/weight of the ovary] was compared to the control. Paeoniflorin, glycyrrhetic acid and glycyrrhizin decreased significantly the testosterone production but did not change that of delta 4-androstenedione and estradiol. Testosterone/delta 4-androstenedione production ratio was lowered significantly by paeoniflorin, glycyrrhetic acid and glycyrrhizin. Estradiol/testosterone production ratio was increased significantly by glycyrrhetic acid and not changed by paeoniflorin and glycyrrhizin. These results suggest that paeoniflorin, glycyrrhetic acid and glycyrrhizin affect the conversion between delta 4-androstenedione and testosterone to inhibit testosterone synthesis and stimulate the aromatase activity to promote estradiol synthesis by the direct action on the rat proestrous ovary.

Androgens↗
PubMed1991

Alpha 1-adrenergic stimulation is coupled to cardiac myocyte hypertrophy.

We have investigated whether alpha 1-adrenergic stimulation is coupled to myocardial hypertrophy in adult rat ventricular cells (ARVC) in culture. Exposure of ARVC to norepinephrine (NE) caused a significant increase in [3H]-leucine incorporation and total protein content in ARVC. Prazosin totally inhibited the NE-stimulated leucine uptake by ARVC. Inhibition of spontaneous contraction of ARVC with KCl or verapamil did not prevent the stimulation of hypertrophy by NE. Protooncogene c-myc expression in ARVC was induced at 1 h after exposure to NE. Above results support the premise that activation of the alpha 1-adrenergic receptors by NE induces hypertrophy of ARVC, independent of changes in contractile activity.

Animals↗
PubMed1991

Reduced calcium sensitivity of dihydropyridine binding to calcium channels in spontaneously hypertensive rats.

To explore the role of calcium channels in hypertension, dihydropyridine ([3H]PN200-110) binding to heart, brain, and skeletal muscle microsomes of 4-, 8- and 15-week-old spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats was measured. At a constant Ca2+ ion concentration (pCa 3.0), maximal binding (Bmax) of dihydropyridine binding to heart and brain microsomes was significantly enhanced in 8- and 15-week-old SHR compared with WKY rats (p less than 0.01), whereas this phenomenon was not observed in 4-week-old SHR and WKY rats. Bmax and dissociation constant (Kd) values for skeletal muscle microsomes from SHR showed no difference compared with WKY rats irrespective of age. Dihydropyridine binding to heart microsomes, brain microsomes, and solubilized skeletal muscle microsomes exhibited strong calcium dependence. The Ca2(+)-dependent dihydropyridine binding curves for heart showed a Hill slope, and pK 0.5 values for 15-week-old SHR and WKY rats were 0.70 +/- 0.12 and 4.66 +/- 0.12 versus 0.72 +/- 0.12 and 5.66 +/- 0.08 (n = 4, mean +/- SD), respectively, indicating that 15-week-old SHR require 10-fold higher calcium concentration than WKY rats to promote dihydropyridine binding. The pK 0.5 values of calcium for brain and solubilized skeletal muscle calcium channels in 15-week-old SHR were also significantly lower than in WKY rats. This difference first became apparent in SHR and WKY rats as early as 4 and 8 weeks after birth. These results suggest that enhancement of calcium channel density might occur in the heart and brain of SHR in response to elevated blood pressure and that reduced calcium sensitivity of dihydropyridine binding to calcium channels might be a primary characteristic of this rat strain.

Animals↗
PubMed1991

Complete atrioventricular block induced during left heart catheterization.

Complete atrioventricular block (CAVB) during cardiac catheterization is a rare complication. We describe a patient with preexisting complete right bundle branch block who developed CAVB during left-sided cardiac catheterization. CAVB was induced when a left-sided catheter was passed through the aortic valve. We speculate that the patient's His bundle was injured by mechanical compression. Physicians should always pay attention to the possibility of the development of CAVB during cardiac catheterization, particularly in patients with preexisting heart block.

Animals↗
PubMed1991

Stenotic lesions and the bifurcation angle of coronary arteries in the young.

To determine the genesis of the high incidence of stenotic lesions of the left anterior descending artery (LAD) in the young, we have investigated the anatomical characteristics of coronary arteries in the following 3 groups; young (less than or equal to 40 yr) myocardial infarction (MI) patients with LAD lesions, young (less than or equal to 40 yr) patients without coronary stenosis and aged (greater than or equal to 60 yr) MI patients. The angle between the left main coronary artery (LMT) and the LAD in the young MI patient group (146.7 +/- 7.4 degrees) was significantly wider than those of the young normal (126.0 +/- 13.4 degrees) or the aged MI patient groups (127.1 +/- 18.6 degrees) (p less than 0.01, p less than 0.02, respectively). The angle between the LMT and the left circumflex artery (LCX), and the angle between the LAD and the LCX were not significantly different among the 3 groups. The LMT length in the young MI patient group was 18.3 +/- 4.7 mm, which was not significantly longer than those of the young normal (12.7 +/- 6.9 mm) or the aged patient groups (14.8 +/- 6.0 mm). The internal diameter ratio of the LAD and LCX was also not significantly different among the 3 groups. These results suggest that the angle between the LMT and LAD was significantly wider in young MI patients, and should be regarded as an inherited characteristic influencing the development of coronary atherosclerosis of the LAD, particularly in young MI patients.

Adult↗
PubMed1990

Urinary surge of human luteinizing hormone in infertile women.

An improved semiquantitative immunoassay method allows human luteinizing hormone (hLH) in urine to be detected from 2.5 to 640 mIU/ml has developed. With this method, the hLH surges in every 3 h urine samples while awake were measured in 8 normal and 12 infertile women. The result was that the urinary hLH surge in infertility was insufficient regardless of the high urinary E2 value. This result may play, at least in part, an etiologic role in infertility.

Adult↗
PubMed1990

Mitogenic action of interleukin-1 alpha on vascular smooth muscle cells mediated by PDGF.

We have investigated the effect of interleukin-1 (IL-1) on the growth of vascular smooth muscle cells (VSMC) isolated from rat aortae. Murine recombinant IL-1 alpha increased tritiated leucine incorporation into VSMC. IL-1 also stimulated tritiated thymidine uptake by VSMC in a dose-dependent manner. On the other hand, Ca2(+)-channel blocker, verapamil, inhibited the IL-1-induced thymidine uptake by VSMC with an IC50 of 10(-8) M. Antibody specific for platelet-derived growth factor (PDGF) also totally inhibited the IL-1-induced thymidine uptake. IL-1 showed no effects on the intracellular Ca2+ level in VSMC. Above results support the premise that IL-1 promotes the growth of VSMC via induction of endogenous PDGF production and might thus participate in the abnormal proliferation of VSMC that occurs early in atherogenesis.

Animals↗
PubMed1990

Ventricular cells in culture from adult spontaneously hypertensive rats exhibit decreased growth.

We have investigated the growth characteristics of adult rat ventricular cells (ARVC) in culture from 8-week-old spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). Protein synthesis in ARVC estimated from tritiated leucine uptake was augmented in both strains after exposure of cells to either norepinephrine or fetal bovine serum (FBS), but the response was significantly smaller in SHR than in WKY. A relative increase in the protein content of ARVC incubated with norepinephrine or FBS was also smaller in SHR than in WKY. These results demonstrate that SHR cardiac myocytes are not genetically growth-accelerated and show a decreased growth response to growth stimuli such as norepinephrine and serum during the adult period.

Aging↗
PubMed1990

The relevance of psychosocial factors in acute ischemic heart disease. A case-control study of a Japanese population.

We investigated, by case-control study, the relevance of psychosocial factors on the prevalence of acute ischemic heart disease (IHD) in middle aged Japanese men. We questioned 109 acute IHD patients and 80 individuals in an age-adjusted sampled control group. Multiple logistic regression analysis showed the following statistically significant factors: hypertension (odds ratio 4.01, p less than 0.001), Type A behavior pattern (2.25, p less than 0.05) and high job demand (2.23, p less than 0.02). No direct influence of family function or social support to the prevalence of acute IHD was apparent. These results suggest that, among men in Japan, Type A behavior pattern and high job demand represent psychosocial risk factors of IHD. Due to the case-control protocol, causal relationships cannot be decided. The limitation of the study design is discussed within that context.

Coronary Disease↗