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Biomedical subjects

I Moriyama

Publications and source records attributed to I Moriyama.

At least 91 records · Page 5Linked to original sources
PubMed1985

[Studies on the mechanism of placental transport of L-glutamate (the effect of K+ in microvillous vesicles on L-glutamate uptake)].

The effect of potassium ion and membrane potential on the uptake of L-glutamate in microvilli (brush border) vesicles prepared from human term placenta was studied using a rapid filtration technique. The uptake of L-glutamate into microvilli vesicles is Na+ electrochemical gradient dependent and pre-equilibration of the vesicles with K+ stimulates L-glutamic acid uptake. Imposition of a K+ gradient (K+ in greater than K+ out) enhances Na+-dependent L-glutamate uptake. Changes in membrane potential due to the imposition of anion replacement markedly affect Na+ dependent L-glutamate uptake only in the presence of K+. However, this effect is not significant when changes in membrane potential incur following the imposition of valinomycin induced by K+ diffusion potential. The data indicate that Na+-dependent L-glutamate transport can be additionally energized by a K+ gradient. Furthermore K+ renders Na+-dependent L-glutamate transport sensitive to changes in the transmembrane potential difference.

Cell Membrane Permeability↗
PubMed1985

[Study on the mechanism of placental transport of phosphate (using human placental microvillous (brush border) membrane vesicles)].

Using the rapid filtration technique, the uptake of phosphate into microvillous (brush border) membrane vesicles isolated from human placental trophoblast was investigated. The microvillous membrane vesicles exhibit the uptake of phosphate into an osmotically reactive intravesicular space and preincubation with the phosphate increased the uptake of phosphate into the vesicles. These findings indicate that the uptake of phosphate by placental trophoblast microvillous membranes represents transport into membrane vesicles. In the presence of sodium electrochemical gradient (extravesicular greater than intravesicular) the uptake of phosphate by vesicles shows an overshoot phenomenon. Sodium-dependent phosphate uptake is about two times higher at pH 6.0 as in the uptake observed at pH 8.0. The initial rate of sodium-dependent phosphate transport exhibited saturation kinetics with respect to phosphate concentration: An apparent Km of 0.28 mM and Vmax of 330 pmol/mg protein in 20 seconds were calculated. These results indicate that the transport of phosphate across the microvillous membranes is carrier mediated. Experiments with different anions (SCN-, Cl-, gluconate-) and ionophore (valinomycin) showed that at pH 7.4 phosphate transport in the presence of a Na+ gradient is almost independent of electrical potential across the vesicle membranes. It was concluded that placental trophoblast microvillous membranes contain an electroneutral Na+/phosphate co-transport system.

Anions↗
PubMed1984

[Clinical studies on sulbactam/cefoperazone in the field of obstetrics and gynecology].

Sulbactam/cefoperazone (SBT/CPZ), a new developed antibiotic, was clinically studied. The following results were obtained. Total of 5 cases comprising 1 with endometritis, 3 with Bartholin's abscess, 1 with pyometra (due to corpus cancer) were treated with SBT/CPZ at a dose of 1 g twice daily for 4-5 days by intravenous injection or intravenous drip infusion. The clinical response was good in all cases. A case with pyometra did not respond to the therapy in bacteriologically. Side effects and abnormal laboratory findings due to the drug were not noted.

Adult↗
PubMed1984

[Fundamental and clinical study on ceftriaxone in the field of obstetrics and gynecology].

It is reported that ceftriaxone (Ro 13-9904, CTRX) has a half-life time of 7 to 8 hours. In the present study, the serum level 18 hours after intravenous injection with 1 g CTRX was as high as 9.3 micrograms/ml while obviously a higher tissue concentration was maintained compared with other drugs. These facts suggest that CTRX is effective against infections and that the dosage and frequency of administration could be reduced. The global evaluation revealed that CTRX was clinically effective in all the 4 cases with infections. As the adverse reaction, light leukopenia was observed only in 1 case out of the present 4 cases and 20 others administered with CTRX.

Aged↗
PubMed1984

[Nephritogenic glycoprotein isolated from human placenta--purification and isolation by sonication].

Previously, we reported that we succeeded in isolating from human placenta a substance comparable to human renal nephritogenic glycoprotein prepared from glomerular basement membrane (GBM). This time we purified a sample isolated from human placental trophoblast basement membrane (TrBM) with the methods for purifying renal nephritogenic glycoprotein and clarified its chemical composition. To purify the sample prepared from human placental TrBM, we fractionated the sample by Zone Electrophoresis, Concanavalin A(Con A) affinity column chromatography and Bio Gel P200 column chromatography. As the active fraction of the sample purified from human placental TrBM bound specifically with Con A, it proved to be a glycoprotein. The monosaccharide composition of this glycoprotein was rich in glucose (glucose, galactose and mannose were in the ratio of 1.00:0.30:0.33) and the amino acid composition of this glycoprotein contained no collagenous components. Ouchterlony gel diffusion demonstrated the existence of a common precipitin line between antiserum to human renal nephritogenic glycoprotein prepared from GBM and human renal nephritogenic glycoprotein prepared from GBM, purified human placental glycoprotein, the sample prepared from human placental TrBM by sonication and nephritogenic glycoprotein prepared from urine of S.L.E. patient.

Amino Acids↗
PubMed1983

[Nephritogenic glycoprotein isolated from human placenta (methods of isolation from placenta].

In our experiments, we succeeded in obtaining from human placenta a substance comparable to human renal nephritogenic glycoprotein prepared from GBM (glomerular basement membrane). The procedure was quite similar to that for preparation from the kidney. At first, placental terminal villi were isolated by the successive use of three metal sieves. Then trophoblast basement membranes (TrBM) were isolated from placental terminal villi by ultrasonic disruption. Finally TrBM were made soluble by trypsin digestion, after which they were further digested by pronase. Ouchterlony gel diffusion demonstrated the existence of a common precipitin line between antiserum to human renal nephritogenic glycoprotein prepared from GBM and antiserum to the sample prepared from human placental TrBM, and human renal nephritogenic glycoprotein prepared from GBM and the sample prepared from human placental TrBM. The monosaccharide composition of the sample prepared from human placental TrBM was rich in glucose (glucose, galactose and mannoside in the ratio of 1.00 : 0.74 : 1.00), and the amino acid composition of the sample contained no collagenous components. As a result of fractionation of the sample prepared from human placental TrBM by Bio Gel P200 column chromatography, the activity of renal nephritogenic glycoprotein was found within the void fraction.

Basement Membrane↗
PubMed1982

[A study on the constitutional change of taurine and other free amino acids during the fetal development (author's transl)].

In human pregnancy, maternal and umbilical blood of the 22nd week of pregnancy and of the parturition were submitted to the analysis of total free amino acids (FAA) by amino acids analyzer. In addition, the neonatal blood was also submitted until 9 days after birth. The content of FAA in umbilical vein was higher than that of the maternal blood and it decreased at the parturition. However, the content of taurine (T) kept extremely higher level than other amino acids until term and it decreased to the normal level at 9 days after birth. In pregnant rats on day 17, 18 and 19 of gestation, the content of FAA in umbilical vein and fetal artery were 5800-7000 micrograms/dl and 5700-6250 micrograms/dl, respectively. They were two fold higher than that of maternal value. In amniotic fluid, FAA was 4100 micrograms/dl on day 18 and 8850 micrograms/dl on day 20. On the contrary, the content of T in maternal blood on day 18 was the highest value (360 micrograms /dl), and decreased to the half of the value on day 20. T in carotid artery on the same day was 1150 micrograms/dl, but it decreased to 280 micrograms/dl on day 20. In amniotic fluid, it was almost constant in the range of 380-400 micrograms/dl. When the pregnant rat was stressed by starvation, FAA was increased in both umbilical and fetal blood but it was almost constant in amniotic fluid. T was increased both in maternal and fetal blood. When the degree of starvation, T value also increased in fetal blood. From these data, we discussed on the possible mechanism of the production of T during pregnancy and after birth.

Amino Acids↗