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Biomedical subjects

N Yanai

Publications and source records attributed to N Yanai.

119 records · Page 7Linked to original sources
PubMed1983

The granulopoietic effect of human urinary colony stimulating factor on normal and cyclophosphamide treated mice.

A practically endotoxin-free colony stimulating factor from human urine (CSFHU) was prepared and its granulopoietic effect on normal and cyclophosphamide treated mice was examined. When normal C57BL/6N mice were injected intraperitoneally with 2.5 X 10(6) units/kg of the CSFHU daily for a 5-day period, the numbers of progenitor cells (CFUC) in the femur and spleen were significantly increased. The CFUC in the femur and spleen reached a maximum at day 3 (270%) and day 5 (250%) after the initial injection, respectively. The increase in number of CFUC in the femur exhibited a dose-dependency with respect to the CSFHU and a significant increase was observed even at 4 X 10(5) U/kg (P less than 0.05). However, neither granulocytosis nor monocytosis occurred in normal C57BL/6N mice injected with the CSFHU. In cyclophosphamide induced leukopenic C3H/HeN mice, daily injections of the CSFHU at 2.5 X 10(6) U/kg for 5 days stimulated the restorative granulocyte production (P less than 0.05) as well as the CFUC recovery in both the femur and spleen. These findings suggested that the CSFHU might be involved in granulocyte production in vivo.

Animals↗
PubMedDate not supplied

Sonographically thick placenta: a marker for increased perinatal risk--a prospective cross-sectional study.

The aim of this study was to determine placental thickness by ultrasound examination throughout pregnancy and establish the correlation of sonographically thick placenta with perinatal mortality and morbidity. Placental thickness was determined by routine sonographic examination throughout pregnancy in 561 normal singleton pregnancies. Thick placenta was determined as placenta that was above the 90th percentile. Gravidae between 20-22 weeks' gestation (n=193) and 32-34 weeks (n=73) were then divided into two groups according to placental thickness. The study group consisted of 44 gravidae with thick placenta. The control group included 151 gravidae with placental thickness between the 10th and 90th percentile. A comparison of perinatal mortality and morbidity rates as well as the incidence of small and large for gestational age neonates was conducted.A linear increase of placental thickness was found to correlate with gestational age throughout pregnancy. No statistical differences were observed between the two groups with regard to obstetrical variables such as maternal age, parity and gestational age at delivery. No correlation was found between placental thickness and maternal age or parity. The incidence of perinatal mortality was significantly higher among gravidae with thick placentae (6.82% versus 0.66 per cent, P=0.037, 95 per cent confidence interval 1.71-70.29). Birthweight at term was found to be above 4000 g in 20.45 per cent of the thick-placenta group as compared to 5.3 per cent in the control group (P=0.001, 95 per cent CI 2.08-13.85), and birthweight of less than 2500 g was found in 15. 9 per cent of the thick-placenta group as compared to 7.3 per cent in the control group (P=0.03, 95 per cent CI 1.11-8.14). The incidence of fetal anomalies was 9.1 per cent in the thick-placenta group and 3.97 per cent in the control group (not significant). Sonographically thick placenta is associated with increased perinatal risk with increased mortality related to fetal anomalies and higher rates of both small for gestational age and large for gestational age infants at term.

Birth Weight↗
PubMedDate not supplied

Establishment of Leydig cell line, TTE1, from transgenic mice harboring temperature-sensitive simian virus 40 large T-antigen gene.

A Leydig cell line, TTE1, has been established from transgenic mice harboring a temperature-sensitive simian virus 40 (tsSV40) large T-antigen gene. The cells grew at a permissive temperature (33 degrees C), but growth was markedly prevented at a nonpermissive temperature (39 degrees C). T-antigen was expressed in the nuclei at 33 degrees C but disappeared at 39 degrees C, indicating that the cells show a temperature-sensitive growth phenotype reflected by the tsSV40 large T-antigen. TTE1 cells did not show any colony-forming activity in soft agar and form tumors in subcutaneous tissue in nude mice, indicating that the cells were not transformed. Alkaline phosphatase and 3beta-hydroxysteroid dehydrogenase (HSD) activities or expression of cytokeratin and vimentin were observed. Reverse transcription-polymerase chain reaction (RT-PCR) analysis indicated that TTE1 cells expressed mRNAs encoding 17beta-HSD types 1 and 3, and inhibin-alpha. The cells with unique characteristics, therefore, should serve useful model study the function of Leydig cell.

17-Hydroxysteroid Dehydrogenases↗
PubMedDate not supplied

Oncostatin m regulates mesenchymal cell differentiation and enhances hematopoietic supportive activity of bone marrow stromal cell lines.

Bone marrow stromal cell lines (TBR cell lines) established from temperature-sensitive Simian Virus 40 T-antigen gene transgenic mice exhibited myogenic, osteogenic, and adipogenic differentiation. The effect of oncostatin M (OSM) on such mesenchymal cell differentiation of marrow stromal cell lines was examined. One of those stromal cell lines, TBRB, differentiated into skeletal muscle, and its differentiation was stimulated by OSM, whereas differentiation of TBR10-1 into smooth muscle was inhibited by OSM. TBR31-2 is a bipotent progenitor for adipocytes and osteoblasts, and OSM stimulated osteogenic differentiation while inhibiting adipogenic differentiation. On the other hand, TBR cell lines exhibited various potentials for supporting hematopoiesis in culture. When hematopoietic progenitor cells were cocultured with OSM-stimulated stromal cell lines, TBR10-1 and TBR31-2 exhibited enhanced hematopoietic supportive activity. As responsible molecules for stromal cell dependent hematopoiesis, expression of stem cell factor (SCF) (a ligand of c-Kit), vascular cell adhesion molecule (VCAM-1) (a ligand of VLA-4), and secretion of interleukin (IL)-6 were increased by OSM. OSM affected mesenchymal cell differentiation and promoted the hematopoietic supportive activity of marrow stromal cell lines. As OSM production is induced by cytokines from hematopoietic cells, OSM may be a key factor in mutual regulation between hematopoietic cells and stromal cells in the bone marrow. OSM may play a role as a regulator in maintaining the hematopoietic microenvironment in marrow by coordinating mesenchymal differentiation.

Adipocytes↗