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Biomedical subjects

T Takagi

Publications and source records attributed to T Takagi.

At least 847 records · Page 47Linked to original sources
PubMed1983

Serial plasma oxytocin levels during pregnancy and labor.

Maternal plasma oxytocin levels during pregnancy and labor were measured by a sensitive and specific radio-immunoassay. The mean plasma oxytocin concentration in maternal peripheral plasma showed a gradual rise towards term, reaching 12.5 microU/ml in term subjects without labor contractions. This level was not significantly different from the mean value in the 1st stage of normal spontaneous labor (12.6 microU/ml). Brief fluctuations in plasma oxytocin levels of considerable degree, and sometimes spurt release, were observed in labor and at term, but not in the mid-trimester, in serial samples collected at short intervals (about 10 sec). In normal spontaneous labor, no obvious relation was observed between the plasma oxytocin level and the uterine contraction period, and no significant difference was found between the mean value in uterine contraction periods (12.1 microU/ml) and that in relaxation periods (11.5 microU/ml).

Female↗
PubMed1983

Mechanism of suppressed renin-angiotensin system in spontaneously hypertensive rat (SHR).

Plasma renin concentration (PRC) of SHR decreased with the elevation of blood pressure. In addition in vitro study of basal renin release from kidney slices obtained from SHR produced similar results. However kidney renin activity and total renin content in kidney of SHR were not less than those of Wistar rats. These results indicate that the decreased renin release from kidney might be responsible for the suppression of renin-angiotensin system of SHR after the development of hypertension. Administration of fusaric acid, a dopamine-beta-hydroxylase inhibitor markedly decreased urinary excretion of catecholamine and prostaglandin E in both SHR and Wistar rat and abolished the development of hypertension in SHR. PRC of SHR which became normotensive by fusaric acid administration (normotensive SHR), increased up to the level of control Wistar rats. Therefore suppressed renin-angiotensin system was not observed in normotensive SHR. Nevertheless basal renin release from kidney slices obtained from normotensive SHR was still less than that from control Wistar rats. As urinary catecholamine and prostaglandin E excretion were decreased by fusaric acid administration, these well-known renin stimulators could not be responsible for the reversal of suppressed renin-angiotensin system in normotensive SHR. Rather decreased arterial blood pressure in normotensive SHR lowered renal perfusion pressure, and led to the stimulation of renin release up to the levels of control Wistar rats by the activation of renal arteriolar baroreceptors.

Angiotensin II↗
PubMed1983

[Phase II study with methyl-6[[[2-chloroethyl) nitrosoamino] carbonyl] amino]-6-deoxy-alpha-D-glucopyranoside (MCNU) in hematological malignancies].

A total of 117 cases with hematological malignancies were treated with MCNU at doses of 70-100 mg/m2. Following are the results obtained. 1. MCNU showed a marked depression of cells in the cases with CML, polycythemia vera and thrombocythemia. The low level of cells was maintained for 2 to 7 months. 2. A good response was observed in several cases with blastic crises of CML. 3. No response was observed in two cases with acute leukemia. 4. Although a fair response was observed in several cases with malignant lymphoma or multiple myeloma, moderate bone marrow suppression was observed in a majority of the cases.

Adult↗
PubMed1983

Serum levels of polyamines in patients with chronic renal failure.

Serum levels of total putrescine, cadaverine, spermidine and spermine were measured in 10 normal subjects, 11 nondialyzed patients with chronic renal failure, and 25 patients undergoing maintenance hemodialysis. The measurement of the serum levels of four polyamines was done with high-performance cation-exchange chromatographic separation and fluorometric detection using o-phtalaldehyde. In normal subjects, the serum levels of putrescine and spermine were 0.24 +/- 0.09 and 0.20 +/- 0.05 nmoles/ml. In patients with chronic renal failure, the levels of polyamines were obtained in the order of putrescine, cadaverine, spermidine, and spermine: 0.51 +/- 0.15; 0.05 +/- 0.01; 0.34 +/- 0.08; and 0.05 +/- 0.04 nmoles/ml. In dialyzed patients, predialysis values of polyamines in the same order as above were: 0.88 +/- 0.31; 0.12 +/- 0.10; 0.67 +/- 0.31; and 0.09 +/- 0.08 nmoles/ml. The results show that, compared to normal subjects, the serum levels of all four polyamines are significantly elevated either in nondialyzed patients with chronic renal failure or in dialyzed patients. In dialyzed patients, the postdialysis putrescine and spermidine levels are significantly low. Serum levels of putrescine and spermidine are both significantly correlated with serum urea nitrogen and serum creatinine in a combined group of normal subjects and patients with chronic renal failure. In dialyzed patients, none of the four polyamine serum levels show correlations either with serum urea nitrogen or serum creatinine; with hematocrit, only spermine exhibits a correlationship, whereas other polyamines do not.

Blood Urea Nitrogen↗
PubMed1983

[Effect of diltiazem on experimental cerebral vasospasm incomparison with effects of cinnarizine, verapamil and nifedipine].

The contractile activity of arterial muscle cells is controlled by the intercellular free Ca2+ concentration. The membrane systems of both the cell surface and internal organs, seem to be responsible for controlling the myoplasmic Ca2+ level. The mechanism of action of Ca2+ antagonists, typified by verapamil and nifedipine, has been postulated to be a blockade of transmembrane calcium influx. In this study, the vasodilating effect of diltiazem on experimental cerebral vasospasm in vivo was examined using dogs and was compared with those of cinnarizine, verapamil and nifedipine which have already been reported by us. Cerebral vasospasms were induced in adult dogs by injecting 5 ml of fresh arterial blood into the cisterna magna. 10(-6)M diltiazem was injected by one shot into the vertebral artery with cerebral vasospasm. Dilatation of the cerebral arteries were monitored by angiography after administration of diltiazem. Blood pressure, intracranial pressure and pulse rate were measured during intravenous application of the drug in normal animals. Administration of diltiazem released the vasospasm for 30 minutes comparable to the times of the other Ca2+ antagonists. Diltiazem had cerebral vasodilator actions similar to cinnarizine at doses that did not decrease systemic blood pressure, while the other drugs decreased intracranial pressure slightly and nifedipine decreased pulse rate slightly. Therefore, we consider diltiazem to be satisfactory for the treatment of experimental cerebral vasospasm.

Animals↗
PubMed1983

[Cerebral blood flow dynamics of spontaneous occlusion of the circle of Willis (Part 1)--comparison between electrophysiological findings and neuroradiological findings].

Four cases (2 children and 2 adults) of spontaneous occlusion of the circle of Willis were studied using EEG, somatosensory evoked potential (SEP), cerebral angiography and CT scan. The following results were obtained. 1) Among the above described parameters, SEP was the most useful to detect the ischemic change in the thalamus when the obstruction of the posterior part of the circle of Willis extends, even before a low density lesion of the thalamus appears on CT. 2) In child cases, a decrease in the amplitude N3 of SEP was observed after hyperventilation. It was speculated that this finding of SEP might be correlated with the mild cortical ischemia due to vasoconstriction and "rebuild up" phenomenon in EEG after hyperventilation.

Adult↗
PubMed1983

[Clinical evaluation of diagnostic methods of nodular goiter].

In 47 patients who had undergone roentgenography, ultrasonography, 201 Tl-scintigraphy, and aspiration cytology and on whom a pathological diagnosis had been made, the diagnostic value of the above-mentioned 4 examinations was evaluated. The correct diagnosis rate for aspiration cytology and 201 Tl-scintigraphy was 76.6%; for ultrasonography and roentgenography it was 70.2%. The false-negative rate of cancer for aspiration cytology was 14.9%; for the other examinations it was 10.6%. The false-negative rate upon combining 3 examinations, except roentgenography (soft tissue technique), proved to be 0% and 24 patients with thyroid cancer were preoperatively correctly diagnosed as "malignant" by means of the combination method.

Adult↗
PubMed1982

Estimation of molecular weights of membrane proteins in the presence of SDS by low-angle laser light scattering combined with high-performance porous silica gel chromatography. Confirmation of the trimer structure of porin of the E. coli outer membrane.

An assessment study was carried out to evaluate the performance of the low-angle laser light-scattering technique combined with high-performance porous silica gel chromatography in the presence of sodium dodecyl sulfate and precision differential refractometry. It was found that the combined technique is highly promising as a reliable method for determining the molecular weight of a membrane protein solubilized by the surfactant. As a test, molecular weights of porin forming the permeability channel of the outer membrane of E. coli B in an oligomeric form were measured before and after heat treatment, which is known to cause dissociation. The results obtained indicate that the porin oligomer is a trimer with stoichiometric composition.

Chromatography, High Pressure Liquid↗
PubMed1982

Interaction between the alpha 1 chain of rat tail collagen and sodium dodecyl sulfate with reference to its behaviour in SDS-polyacrylamide gel electrophoresis.

The interaction between the alpha 1 chain of rat tail collagen and sodium (SDS) was studied to provide knowledge necessary to understand the behavior of the complex between them in a molecular sieving technique such as SDS-polyacrylamide gel electrophoresis. Measured properties include binding isotherm, CD spectrum, viscosity and behavior in free boundary electrophoresis, gel electrophoresis and high-pressure silica gel chromatography. The complex differed in most respects from the complexes between SDS and polypeptides derived from water-soluble globular proteins, reflecting its peculiar amino acid composition. THe hydrodynamically effective volume of the SDS-alpha 1 chain complex was the most significantly different among the properties studied. The complex of the alpha 1 chain consisted of 1052 amino acid residues and was found to have the same effective volume as that of a standard polypeptide consisting of about 800 residues. The abnormal behaviour of the SDS-alpha 1 chain complex was interpreted on the basis of these results.

Animals↗
PubMed1982

Posterior fossa subdural hemorrhage in the newborn as a result of birth trauma.

During the past 19 years, 229 autopsies of intracranial hemmorrhages were performed at the Department of Pathology, and 23 cases of posterior fossa subdural hemorrhages were discovered (10.0%). 25 cases of posterior fossa subdural hemorrhages (2 of our own treated surgically and 23 untreated found at autopsy) are described in detail. 2 cases treated surgically responded favorably to surgical treatment. The mechanism of hemorrhage into posterior fossa subdural spaces is investigated and reconsidered following a review of the literature. The necessity for CT is emphasized for early diagnosis of posterior fossa subdural hemorrhage.

Birth Injuries↗