Biomedical subjects

M Tomonari

Publications and source records attributed to M Tomonari.

10 recordsLinked to original sources

PubMed2003

Gene expression of telomerase related proteins in human normal oral and ectocervical epithelial cells.

We analyzed telomerase activities and gene expressions of telomerase components: hTERT, hTR, hTEP1, telomeric repeat binding factors: TRF1, TRF2, and c-myc, Max and Mad in human normal oral and ectocervical epithelial keratinocytes, comparing with those of squamous carcinoma cells and HPV16- or SV40-immortalized cells. Significant telomerase activity and hTERT expression were detected in primary keratinocytes. However, both were dramatically down-regulated during serial passages. The down-regulation of hTERT mRNA was associated with augmented expression of TRF1. Expression of c-myc was slightly decreased, whereas Mad was expressed in parallel with that of hTERT during passages. We also detected an alternate splicing of hTERT transcript in two of four cancer cells and normal aged epithelial cells. These results suggest that the senescence of normal oral and ectocervical keratinocytes is accompanied with up-regulation of TRF1 and down-regulation of telomerase activity due to transcriptional suppression of active form of hTERT in vitro.

Alternative Splicing↗

PubMed1990

[The circadian and pulsatile secretions of prolactin during pregnancy, labour and puerperium].

The circadian and pulsatile secretions of prolactin were studied in 15 pregnant and 5 puerperal women. Blood samples were taken every 15 minutes for 3 hours during daytime and at night. Diurnal levels of prolactin and estradiol were examined in 135 pregnant women. In addition, prolactin and estradiol of 8 parturient women were measured every 15 minutes until 24 hours after delivery. Prolactin and estradiol levels increased gradually in advance of pregnancy, and a positive correlation was revealed between prolactin(Y) and gestational weeks(X): Y = 7.125X-42.997, r = 0.9955. Furthermore, a positive correlation between prolactin(Y) and estradiol(X) levels was observed: Y = 4.439X + 44.115, r = 0.7590. The circadian secretion of prolactin was observed in 15 out of 20 cases studied. The pulsatile secretion of prolactin was revealed in all 20 cases. The daytime pulse-frequency significantly decreased in the 2nd trimester and that of the nighttime also decreased in the 3rd trimester. The pulse-amplitude increased in advance of pregnancy, but amplitude/baseline value ratio was stationary 28% during the daytime and 34% during the nighttime in every trimester of pregnancy. 63.0% of coincidence in prolactin pulse with increase of immunoreactive LH-hCG was observed. The pulsatile secretion of hCG has not been yet reported. However, the pulsatile increase of immunoreactive LH-hCG was observed in 10 pregnancies, while LH was not detected in any pregnancy by highly specific LH assay. This suggested that immunoreactive hCG changed in a pulsatile manner in the blood of pregnant subjects. A highly significant decline of prolactin levels was observed from 10 hours before until 4 hours after delivery, which did not correlate with changes of estradiol levels. These results indicated that the pulsatility and circadian secretion of prolactin were preserved during pregnancy and puerperium and also suggested that prolactin secretion during pregnancy, delivery and puerperium was regulated by at least 3 factors: estradiol, dopamine and LH-hCG.

Chorionic Gonadotropin↗

PubMed1987