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Biomedical subjects

S Takagi

Publications and source records attributed to S Takagi.

At least 649 records · Page 36Linked to original sources
PubMed1979

The 5'-terminal structure of poly(A)-containing RNA of soybean seeds.

Poly(A)-containing RNA from soybean seeds was isolated by affinity chromatography on poly(U)-Sepharose. Translation of poly(A)-containing RNA was inhibited by the addition of m7GMP. Treatment of the poly(A)-containing RNA with periodate followed by aniline (a chemical removal of 5'-terminal m7G) resulted in a marked reduction of mRNA activity. mRNA activity of the treated RNA was partially restored when S-adenosyl methionine (SAM) was included the wheat germ cell-free system. End groups of the poly(A)-containing RNA were labeled by oxidation with periodate and reduction with [3H]borohydride. Analysis of nuclease digests of 3H-labeled poly(A)-containing RNA showed the existence of materials with a charge between --2 and--3 and/or between --3 and--4 which contain pyrophosphate linkages. These results imply the presence of 5'-terminal capped structures, m7G(5')PPp(5')N and m7G(5')PPP(5')Nm, in soybean poly(A)-containing RNA.

Poly A↗
PubMed1978

Microsphere analysis of local cerebral and extracerebral blood flow after complete ischemia of the cat brain for one hour.

In normothermic anesthetized cats complete cerebral circulatory arrest for one h was produced and followed by blood recirculation of the brain for 30 min to 4 h. Total and local blood flow of the brain, kidney, heart and liver were measured before and after ischemia using radioactive labelled microspheres. Before ischemia blood flow of the brain was 39.1 +/- 2.3 ml/100 g/min, of the kidney 307.2 +/- 28.3 ml/100 g/min, of the heart 241.1 +/- 32.5 ml/100 g/mmin and of the liver 87.8 +/- 25.6 ml/100 g/min (means +/- SEM). Regional flow rates within the brain varied between 35 and 51 ml/100 g/min. Reactive hyperemia was present in the brain 30 min after the beginning of recirculation following ischemia for 1 h. Local cerebral flow rates increased three to five times above the control flow, depending on the respective region. Mean cerebral blood flow returned to or slightly below normal, 2 to 4 h after ischemia, but there was considerable redistribution of flow rates within the brain. The filter capacity of the brain for microspheres of 15 mu and 50 mu diameter did not change after ischemia indicating that postischemic blood recirculation was not accompanied by an opening of arteriovenous shunts.

Animals↗
PubMed1978

[The determination of plasma and urinary estetrol (E4) for assessing fetal and neonatal prognosis (author's transl)].

As estetrol (E4) is believed to be the steroid most likely to wholly dependent on fetal origin, we developed a radiommunoassay for unconjugated and conjugated E4 (E4-U and E4-G) and investigated plasma and urinary levels serially throughout the second half of pregnancy to establish their validity by means of monitoring or screening tests to assess fetal well-being. E4 exhibits a remarkable increase during the latter half of pregnancy. At term, the mean E4-U level in maternal peripheral plasma was 0.67 +/- 0.33 ng/ml, a five fold increase from that at 28 weeks; E4-G was 4.57 +/- 2.84 ng/ml, showing a four fold increase; and E4-G levels in maternal urine were 1.68 +/- 0.96 mg/day, showing a three fold increase from that at 28 weeks. E4-U and E4-G levels showed no diurnal change. The coefficient of the correlation between plasma E4-U and E4-G was 0.699, which is satisfactory, but no correlation was found between urinary and plasma E4 levels. A significant correlation was shown between maternal and umbilical E4-U (r=0.820) and E4-G (r=0.608). No relationships between E4 levels and birth weight were detected. Pre-eclampsia, Rh-isoimmunization and diabetes mellitus are common complications of pregnancy which may cause latent fetal distress. Prenatal fetal assessment was performed by serial daily evaluations of these E4 values. In pre-eclampsia resulting in a small full term baby, E4 levels were mostly below normal mean values or failed to show an increased pattern. In addition, the E4 levels decreased in one case of neonatal death. In Rh-isoimmunization, plasma E4-G levels were lower in the group affected severely by the hemolytic desease. In a patient with diabetes mellitus delivered of a healthy baby, E4 levels were within the range of a normal pregnancy. In order to evaluate fetal and placental reserve capacities as well as feto-placental function, the dehydroepiandrosterone sulfate (DHA-S) loading test was performed by loading selected subjects with 50 mg of DHA-S, then serially measuring the E4 in the maternal plasma and urine. Intravenous infusion of 50 mg of DHA-S was completed in 60 minutes. A rapid and sharp increase of plasma E4 was observed, reaching maximal concentrations at 120 minutes in normal pregnancies. However, urinary levels showed patterns similar to those reported for estriol (E3). In some abnormal pregnancies, no increased or delayed patterns were observed in plasma E4-G levels, while the serial levels remained within the normal range. This possibly suggests that in these pregnancies, fetal functions had been inhibited or had reached their limit. It is concluded that the simultaneous determinations of serial E4 levels accompanied by the DHA-S loading test may be of value in assessing fetal well-being and reserve capacity and may therefore improve fetal and neonatal prognosis in abnormal pregnancies.

Dehydroepiandrosterone↗
PubMed1978

Chemical control of cerebral circulation. Modification by a new vasodilator (YC-93).

This study was undertaken to investigate influences of a new vasodilator, YC-93, a derivative of 1,4-dihydropyridine, on cerebral circulation and cerebrovascular CO2 reactivity. Cerebrocortical PO2, cerebrocortical PCO2, cerebrocortical blood flow and arterial blood pressure were continuously recorded by means of a PO2 electrode, a PCO2 electrode and a plate-type crossed thermocouple flowmeter placed on an exposed pial surface of the cat brain. The changes in each parameter induced by YC-93 were compared with those induced by papaverine hydrochloride. The effects of 5% CO2 inhalation were compared before and after the intravenous injection of YC-93. YC-93 (0.01 mg/kg) showed a more marked and longer-lasting hypotensive effect that papaverine (1 mg/kg) and yet produced a significant increase in cerebrocortical PO2. After the administration of YC-93, the degree of the increase in cerebrocortical PO2 during 5% CO2 inhalation was reduced significantly in comparison with that before the administration. The above data indicates that YC-93 has a vasodilating effect on cerebral blood vessels and that the drug causes a decrease in cerebrovascular CO2 reactivity.

Animals↗
PubMed1978

Termination of early pregnancy by ONO-802 suppositories (16,16-dimethyl-trans-delta2-PGE1 methyl ester).

ONO-802 was used in the form of vaginal suppositories for the termination of early pregnancy in 63 healthy volunteers. Fifty-four (86%) of the 63 cases had complete abortions and remaining 9 (14%) had incomplete abortions. One (1.6%) of the 63 cases complained of nausea and vomiting, and 3 (4.8%) complained of headaches. No other side effects were observed. These results suggest that ONO-802 is acceptable in the form of vaginal suppositories for the termination of early pregnancy.

Abortifacient Agents↗
PubMed1978

Occurrence of mRNA for storage protein in dry soybean seeds.

Poly(A)-containing RNA has been isolated from the cotyledons of soybean seeds by adsorption on a poly(U)-Sepharose column. Approximately 0.15% of the total soybean RNA applied bound to the column. The bound RNA (poly(A)-containing RNA) was shown to be mRNA by its ability to serve as template in a cell-free system derived from wheat germ. Poly(A)-containing RNA was polydisperse, migrating from approximately 50,000 to 700,000 daltons with a mean of 150,000 daltons in polyacrylamide gel electrophoresis. The size of the poly(A) portion of this RNA was in the range of 55 to 290 nucleotides. The adenylic acid content of the presumed poly(A) fragment was about 95%. The radioactive products of translation directed by the poly(A)-containing RNA in the wheat germ cell-free system were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and by immunoprecipitation using antisera against beta-conglycinin and glycinin. The results of this investigation show that mRNAs for the subunit proteins of the major components of a soybean storage protein exist in the poly(A)-containing RNA preparation obtained from the cotyledons of dry soybean seeds.

Cell-Free System↗
PubMed1978

A radioimmunoassay of plasma 18-hydroxy-11-deoxycorticosterone.

A radioimmunoassay for the measurement of plasma 18-hydroxy-11-deoxycorticosterone (18-OH-DOC) has been developed. The antiserum for 18-OH-DOC was produced in rabbits immunized with 18-OH-DOC-3-(0-carboxymethyl) oxime-bovine serum albumin. This antiserum was used at a final dilution of 1:40,000 and the main cross reactants were aldosterone at 29.4%, 18-hydroxy-corticosterone at 4.9% and 11-deoxycorticosterone at 3.6%. Silica gel column chromatography (7 X 30 mm, toluene saturated with propylene glycol: dichloromethane, 95:5) and Sephadex LH-20 column chromatography (7 X 60 mm, benzene: methanol, 85:15) were employed for the separation of these cross reactants. The sensitivity was 10pg and the method blank was consistently negligible. The intra- and inter-assay precision was 11.3% and 14.8%, respectively.

18-Hydroxydesoxycorticosterone↗