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Biomedical subjects

T Okada

Publications and source records attributed to T Okada.

At least 1,045 records · Page 58Linked to original sources
PubMed1984

Sex difference in cholesterol esterase activity in rats adipose tissues and changes of the activity following orchiectomy and ovariectomy.

Sex differences in cholesterol esterase activity and changes in the activity in response to orchiectomy and ovariectomy were investigated in rat adipose tissue in association with serum lipid levels. Cholesterol esterase activity in the parametrial adipose tissue was 65% higher than that in the epididymal adipose tissue, but there were no sex differences in the activity of subcutaneous and perirenal adipose tissue. Pre- and post-pubertal orchiectomy resulted in a marked enhancement of cholesterol esterase activity, whereas ovariectomy significantly reduced the activity. Serum cholesterol and triacylglycerol levels were elevated through orchiectomy but ovariectomy had no effect. These results suggest that cholesterol esterase activity in the adipose tissue around sexual organs is regulated by gonadal hormones and that the increase in serum cholesterol due to orchiectomy is unlikely to be related to the change in the enzyme activity.

Adipose Tissue↗
PubMed1984

Enhancement in cholesterol-esterase activity and lipolysis due to 17 beta-estradiol treatment in rat adipose tissue.

The effects of 17 beta-estradiol and testosterone administration on cholesterol esterase, lipoprotein lipase activities and adrenalin-induced lipolysis were examined in rat adipose tissues with the change in serum lipid level. The administration of 17 beta-estradiol (500 micrograms/kg, 2 or 4 weeks) to male rats significantly reduced the body weight, and markedly increased serum cholesterol, triacylglycerols and phospholipids. Cholesterol esterase activity was significantly enhanced in the epididymal adipose tissue from estradiol treated rats and the effect was greater with duration of the treatment. In contrast, lipoprotein lipase activity was markedly reduced. Testosterone reduced cholesterol esterase activity in the parametrial adipose tissue through the treatment with 500 micrograms/kg for 6 weeks, but it did neither influence serum lipids nor lipoprotein lipase activity. Basal lipolysis and adrenalin-induced lipolysis were also significantly enhanced in the epididymal adipose tissue from the male rat treated either with 7 mg/kg estradiol 12 h ahead or with 500 micrograms/kg estradiol for 2 weeks. These results indicate that estradiol exerts strong effects on metabolism of the adipose and these effects seems to be mediated through cyclic-AMP. An alteration of adrenergic functions by gonadal steroids might be intervened.

Adipose Tissue↗
PubMed1984

Detecting early esophageal cancers, with special reference to the intraepithelial stage.

Early-stage esophageal cancers, particularly intraepithelial cancers, are extremely difficult to detect because patients have no particular complaints and x-ray is so often useless. Only panendoscopic examination has proved highly effective in discerning lesions. Lugol-combined panendoscopic examination is not only feasible, but also effective in spotting the presence and spread of lesions.

Aged↗
PubMed1984

Plasma lipid peroxides and alpha-tocopherol in critically ill patients.

Plasma lipid peroxide measured as thiobarbituric acid reactive substances (TBARS) and alpha-tocopherol levels in 24 critically ill patients were compared with those of control subjects. The mean plasma alpha-tocopherol level was significantly lower and the mean TBARS level was significantly higher in critically ill patients. Eight ICU patients developed disseminated intravascular coagulation (DIC); the mean TBARS level during DIC was significantly above the mean pre-DIC level. These results indicate that lipid peroxidation may contribute to the development of DIC in critically ill patients.

Adolescent↗
PubMed1984

Left ventricular function and muscle mechanics in hypertrophied rabbit heart.

Ventricular contractile performance was studied in relation to wall muscle mechanics in isolated rabbit left ventricles during pressure-overloaded hypertrophy. The isovolumic pressure-volume relation of the hypertrophied ventricle (LVH) shifted to the left and upward from the normal control (NC) (P less than 0.001), but calculated wall stress at each normalized circumferential length decreased in LVH. The pressure-ejection rate relation, determined accurately by velocity control technique, could be adequately approximated by a hyperbola. In LVH, the maximum pressure (Po) was larger (154.3 +/- 17.0 mmHg), whereas the maximum ejection rate (Vej max) was smaller (13.7 +/- 4.2 ml/s, P less than 0.001) than those for NC (127.7 +/- 23.3 mmHg and 22.3 +/- 5.7 ml/s, respectively). The pressure-stiffness relation was linear in both groups, but the vertical axis intercept increased, indicating increased resting stiffness in LVH. Ventricular volume stiffness vs. the mean wall stress relationship of LVH shifted upward, whereas the normalized wall muscle stiffness vs. the mean wall stress relationship of LVH showed a smaller slope. Thus the hypertrophied ventricle can maintain its pumping ability at normal or augmented levels with depressed contractile function of the wall muscle.

Animals↗
PubMed1984

Gamma-aminobutyric acid-induced contraction of the dog basilar artery.

gamma-Aminobutyric acid (GABA) produced a biphasic action, that is, a relaxation followed by a contraction in the isolated dog basilar artery. Repeated applications of each concentration of GABA (10(-6), 10(-5), 10(-4), 10(-3) M) at regular intervals under resting conditions caused a stepwise increase in the contractile response. Marked reproducible contractile responses occurred (ED50: 1.3 X 10(-5) M), after at least 8-10 applications. The GABA-induced contraction as well as relaxation was blocked by bicuculline and picrotoxin. Pretreatment with inhibitors of prostaglandin synthesis such as aspirin (3 X 10(-6) to 3 X 10(-4) M) and indomethacin (3 X 10(-6) M) reduced the contractile response to GABA in an irreversible manner and without affecting the relaxation induced by GABA. These inhibitors increased the resting tone but reduced the tone in strips subjected to repeated applications of GABA. 15-Hydroperoxyarachidonic acid at concentrations of 1 X 10(-6) and 1 X 10(-5) M also attenuated the contractile response to GABA in a dose-dependent fashion. These observations suggest that GABA may modulate the contractile effect by inducing the production of contraction-causing prostaglandin(s) mediated through GABA receptors and/or by some as yet undefined mechanism.

Animals↗
PubMed1984

Systemic vascular lesions and prognosis in systemic lupus erythematosus.

The purpose of this paper is to show the relationship of systemic vascular lesions to the clinical manifestations and prognosis in SLE. Thirty-four autopsied cases of SLE formed the subject material for this study. Histopathological tissue studies were made on vascular lesions from almost all organs. Vascular lesions were separated into three groups according to the size of the involved vessel: 1) medium-sized artery (9 cases), 2) small artery (12 cases) and 3) (13 cases) without systemic vascular lesions. Vascular lesions were also separated into five groups (a) fibrinoid degeneration (10 cases), b) intimal thickening (6 cases), c) thrombosis (6 cases), d) sclerosis (7 cases) and e) (13 cases) without systemic vascular lesions. Patients with involvement of medium-sized arteries had a low female incidence, photosensitivity, and positive LE cell incidence, and the cause of death in these patients was cerebral vascular involvement. The cause of death in patients with vascular fibrinoid degeneration and thrombosis was mainly uremia, whereas patients with sclerosis more often died from infection. Regarding systemic vascular lesions in SLE, the prognosis for the patients with thrombosis and vascular involvement of medium-sized arteries was the most grave.

Adult↗
PubMed1984

Alterations in cardiac alpha and beta adrenoceptors during the development of spontaneous hypertension.

To study potential cardiac receptor alterations during the development of spontaneous hypertension, specific binding of [3H]-2-N(2,6-dimethoxyphenoxyethyl)amino-methyl-1,4-benzodioxane, (-)-[3H]dihydroalprenolol and (-)-[3H]quinuclidinyl benzilate in ventricles of Wistar Kyoto rats (WKY), spontaneously hypertensive rats (SHR) and stroke-prone SHR (SHRSP) at different ages was determined. The Kd and maximal binding for specific binding of [3H]-2-N(2,6-dimethoxyphenoxyethyl)amino-methyl-1,4-benzodioxane and (-)-[3H]dihydroalprenolol in ventricular homogenates of SHR and SHRSP at prehypertensive ages were similar to those of age-matched WKY. With the development of spontaneous hypertension in SHR and SHRSP, there was a significant decrease in the maximal binding for both ligands without a change in Kd. The decrease in maximal binding in SHR and SHRSP at 10 weeks of age was 29 to 38%, compared with age-matched WKY. There was no difference in ventricular (-)-[3H]quinuclidinyl benzilate binding between WKY and SHRSP. Hofstee analysis of the inhibition of ventricular (-)-[3H]dihydroalprenolol binding by practolol demonstrated a specific 51% decrease in ventricular beta-1 receptor density in 10-week-old SHRSP. In addition, the inotropic response to isoproterenol in isolated papillary muscles from SHRSP was significantly smaller than that in WKY. Thus, it is concluded that during the development of spontaneous hypertension in SHR and SHRSP, there is a specific loss in number of cardiac alpha and beta-1 adrenoceptors with a consequently reduced responsiveness of isolated papillary muscles to isoproterenol in SHRSP. These results are compatible with the reported increase in sympathetic outflow to the cardiovascular system in spontaneous hypertension.

Adrenergic alpha-Antagonists↗
PubMed1984

[A double-blind comparison between cefaclor and cephalexin in the treatment of dental infections].

A comparative clinical study of cefaclor (CCL) with cephalexin (CEX) was carried out by randomized double-blind techniques in order to contemplate the clinical efficacy, side effects and usefulness in treatment of 243 patients with dental infections. In the CEX group, CEX was orally administered 4 times a day at a daily dosage of 1,000 mg for 3 to 5 days. In the CCL group, CCL was orally administered 3 times a day at a daily dosage of 750 mg for 3 to 5 days and 1 capsule of placebo was also given every evening in order to keep the blindness of the administration. Evaluable cases for efficacy of athe drugs were 213 consisting of 108 for CCL and 105 for CEX. There were no significant differences in background of the patients and severity of the disease between 2 treatment groups. Clinical effectiveness on the 3rd day was 89.7% in CCL group and 78.6% in CEX group, showing significant difference between 2 treatment groups. Clinical effectiveness on the final day of administration was 94.4% in CCL group and 92.4% in CEX group, showing no significant difference between 2 treatment groups. Side effects were found in 10.5% of 114 patients receiving CCL and in 4.5% of 112 patients with CEX, and there was no significant difference between 2 treatment groups. The side effects were mostly gastrointestinal origin. According to the judgement by physicians in charge, no significant difference was seen in clinical usefulness between the 2 drugs.

Adult↗
PubMed1984

Nephropathy associated with Charcot-Marie-Tooth disease.

In this report, we describe a case of 14-year-old girl with Charcot-Marie-Tooth (CMT) disease and the nephropathy which was characterized by heavy proteinuria and microscopic hematuria. She progressed to renal failure with clinical duration of 4 years from the onset of disease. Renal biopsy specimens revealed the features of focal segmental glomerulosclerosis (FSGS). The patient has also a bilateral sensorineural deafness. Although the clinical features show similarities to those of the Alport syndrome, electron microscopic examination did not disclose the glomerular basement membrane changes which were characteristic of the Alport syndrome. The association of nephropathy with CMT disease is discussed, as compared with previous report.

Adolescent↗