Search PubMed⌕ Search

Biomedical subjects

S Takagi

Publications and source records attributed to S Takagi.

At least 631 records · Page 35Linked to original sources
PubMed1980

Expression of neuronal specificities in "transdifferentiating" cultures of neural retina.

Cells dissociated from the neural retina of embryonic chick differentiate into lens and pigment cells, when cultured in vitro. Using 3.5-day-old and 8.5-day-old chick embryos, we examined whether neuronal specificities would be expressed in such transdifferentiating cultures of neural retinal cells. The synthesis of acetylcholine and gamma-aminobutyric acid (GABA) and the activity of choline acetyl transferase (CAT) was searched for in these cultures. The synthesis of an appreciable amount of these two putative neurotransmitters was detected in cultures of 3.5-day-old embryonic retinas by about 15 days. The activity of CAT was maximum in 7-day cultures of the 3.5-day-old materials and in 2-day cultures of the 8.5-day-old materials, and then decreased. Concomitant with the decrease of CAT-activity, delta-crystallin became detectable and increased thereafter. CAT-activity changed in parallel with the increase in the number of small neuroblast-like cells in cultures. The results demonstrate that the neuronal specificity identified by the appearance of acetylcholine and GABA and of the enzyme for the synthesis of acetylcholine is expressed in the early period of transdifferentiating cultures, which would later differentiate into lens and pigment cells. The possible mechanisms of the transition from neuronal to non-neuroretinal specificities of the transdifferentiating cultures are discussed.

Acetylcholine↗
PubMed1980

Studies of maternal and fetal 11-deoxycorticosterone, corticosterone,18-hydroxycorticosterone and aldosterone in normal and toxemic pregnancy.

Simultaneous determination of maternal and fetal plasma 11-deoxycorticosterone (DOC), corticosterone (B), 18-hydroxycorticosterone (18OH-B) and aldosterone (ALDO) in normal and toxemic pregnancies was performed by utilizing a newly developed radioimmunoassay. The mean levels of plasma DOC and ALDO in normal term pregnancy were significantly higher than those of nonpregnant women. Comparing the mean levels of umbilical arterial plasma to those in maternal plasma at delivery, DOC and ALDO were consistently higher in the former, while B was higher in the latter, and 18OH-B was largely unchanged. However, no umbilical arteriovenous gradient was found in any corticosteroid measured. In toxemia of pregnancy, the corticosteroid levels in the maternal plasma were lower than those in normal pregnancies, and in umbilical arterial plasma, B was significantly higher and 18OH-B and ALDO remained almost the same as those in normal pregnancy. Thus, it appears that ALDO synthesis in mother in normal term pregnancy was enhanced but in toxemia of pregnancy it was suppressed, while in the fetus, it was enhanced not only in normal pregnancy but also in toxemia of pregnancy.

18-Hydroxycorticosterone↗
PubMed1980

[Subdural abscess in infant and child (author's transl].

Two cases of subdural abscess in infant and child treated with irrigation via burr holes were reported. The first case was a 1.4-year-old boy with right hemiparesis and mental retardation since severe head trauma at 9 months old. The patient with manifested with an acute onset of high fever followed by disturbance of consciousness and convulsive seizures 2.5 months prior to admission to our department. During admission in the other hospital, the diagnosis of septicemia caused by E. coli was made by blood cultures when CT scan demonstrated a huge lentiform low density area over the right hemisphere and contralateral crescent low density area. The low density area on the right side was well circumscribed by high density rim which was enhanced by contrast medium. Under the diagnosis of bilateral subdural abscess secondary to septicemia caused by E. coli, irrigation of the purulent cavity was carried out. The contralateral low density area was found to be chronic subdural effusion. The second case of 3-month-old infant who complained of high fever, neck stiffness, unconsciousness and right hemiconvulsions 8 days prior to admission. CT scan showed bilateral crescent low density areas indicating subdural effusion. Subdural punctures performed via the fontanelle revealed pus in the left subdural space and xanthocromic fluid in the right side. The low density area on CT scan was changed to the lentiform high density area circumscribed smooth high density rim during the course of the patient. The subdural abscess was treated with irrigation via burr holes. In this report, the etiology of the subdural abscess and route of infection in addition to follow up study of CT findings were presented with the literature.

Brain Abscess↗
PubMed1979

Plasma levels of 16 alpha-hydroxypregnenolone, 16 alpha-hydroxyprogesterone and 16 alpha-hydroxydehydroepiandrosterone in the fetus and neonates.

Simultaneous determination of unconjugated 16 alpha-hydroxypregnenolone (16 alphaOH-Preg), 16 alpha-hydroxyprogesterone (16 alphaOH-Prog) and 16 alpha-hydroxydehydroepiandrosterone (16 alphaOH-DHEA) in fetal and neonatal plasma was performed utilizing a newly developed radioimmunoassay. In all neonates, the three 16 alpha-hydroxysteroid levels were consistently higher in umbilical cord plasma than in the maternal peripheral circulation. 16 alpha-OH-Preg in the umbilical arterial plasma increased from 11.2 +/- 3.1 at 24 weeks to 29.7 +/- 12.0 ng/ml at term, 16 alphaOH-Prog from 15.5 +/- 3.2 to 34.3 +/- 11.0 ng/ml and 16 alphaOH-DHEA from 5.1 +/- 1.2 to 5.9 +/- 1.0 ng/ml. In the anencephalic neonates, only 16 alphaOH-Preg showed an increase pattern under ACTH priming. 16 alpha-OH-Preg levels for normal full term neonates remain relatively constant at the first 24 hr and show a slight decrease at 3 days post partum. In small full term neonates, 16 alphaOH-Preg levels in umbilical arterial plasma are considerably higher than in normal neonates and remain at roughly equivalent levels for the first 5 days post partum. 16 alphaOH-Prog and 16 alphaOH-DHEA levels in umbilical arterial plasma in normal and small full term neonates are almost equal and both groups show a rapid decrease during the first 24 hr. Comparison with findings of the three 16 alpha-hydroxysteroids in fetal and neonatal plasma is discussed.

17-alpha-Hydroxypregnenolone↗
PubMed1979

Study of oxytocin receptor in human myometrium using highly specific 3H-labeled oxytocin.

A highly specific tritium labeled oxytocin (3H-OT) was synthesized utilizing the method of catalytic substitution of halogen for hydrogen. The specific activity of 3H-OT was 19 Ci/mM and the biologic activity was 350 U/mg, which was sufficient for the OT radioreceptor assay. The maximum % uptake of 3H-OT in the human myometrium was observed in 20,000 X g pellets under the optimal conditions of pH 7.4, at 20 degrees C and the incubation time of 90 min and it was augmented in the presence of Mn++. It was observed from the Scatchard plot, that the binding site of OT in the human myometrial specimens was a single type within the range of OT concentration of 0.4 nM to 1.6 nM. The dissociation constants (Kd) and the number of binding sites (NBS) showed a relative increase as gestation advance. The apparent Kd of term pregnancies was 1.25 X 10(-9) M regardless of the presence or absence of labor pains, while the NBS of term pregnancies with and without labor pain was 1.2 X 10(-12) and 4.7 X 10(-12) moles/mg, protein, respectively.

Female↗
PubMed1979

[A case of cerebral tuberculoma (author's transl)].

A 27-year-old woman was admitted to other hospital for acute pleuritis in May 1977. She suddenly had a focal epileptic seizure in the face with loss of consciousness on July 10, 1977. The same episodes of seizure occurred on Aug. 8, on Oct. 26, on Nov. 22, 1977. She was admitted to our hospital on Dec. 12, 1977. Neurological examinations showed no abnormality. Chest X-ray film showed bilateral severe thickening of the pleura. Plain skull films showed normal findings. Enhanced CT scanning showed a homogenous irregular contour of high density area surrounded by low density area in the right frontal region. The lateral ventricle was slightly shifted to the left side. 99mTc brain scan also detected a spherical abnormal uptake in this area. Right carotid angiography showed no abnormal vessels and increased vascularities. On Nov. 22, 1977, a craniotomy was made over the right fronto-temporal bone, and a walnut sized tumor in the frontal subcortex was totally removed successfully. Histologically, the tumor was diagnosed as brain tuberculoma. The antituberculous therapy (AB-PC, INAH, Rifampicin), high doses of gammabenin, and steroid were given. About four months later, she was in good health without neurologic deficits and returned to her work. The literature was reviewed, and the value of CT scan and RI scan in the diagnosis of cerebral tuberculoma was emphasized.

Adult↗