Yuki Kanda

Rapid changes of flow-mediated dilatation after surgical menopause

OBJECTIVES Estrogen acts directly on endothelial nitric oxide synthase through a non-genomic mechanism, resulting in rapid dilatation of blood vessels. In this study, we examined the change of endothelial function after surgical menopause. METHODS In 20 subjects who underwent gynecological operations (ovariectomy (OVX) 12, sham (SHAM) operation 8), postoperative changes of flow-mediated dilatation (FMD) of the brachial artery were examined using ultrasonography. Postoperative changes of the response to nitroglycerin (NTG) were also studied in these patients. RESULTS In the OVX group, significant decreases of FMD were observed 1 week after the operation, although no changes were observed in the response to NTG. In the SHAM group, no remarkable changes of FMD or the response to NTG were observed after the operation. CONCLUSIONS OVX influences endothelium-dependent vasodilatation within as little as 1 week. Therefore, it may be important to address the rapid changes of circulation after surgical menopause in order to prevent cardiovascular disease.

Pituitary folliculo-stellate-like cell line produces a cytokine-induced neutrophil chemoattractant.

In previous studies, we reported that cytokine-induced neutrophil chemoattractant (CINC) was produced in the pituitary gland. Here we investigated the possibility of detection of CINC immunoreactivity in the pituitary folliculo-stellate (FS)-like cell line (TtT/GF). Intense immunoreactivity was observed by immunocytochemistry in the cytoplasm and cell processes of TtT/GF cells. CINC immunoreactivity was detected by an enzyme-linked immunosorbent assay in as little as 3 h after conditioning the medium with TtT/GF cells, and it increased significantly in a time-dependent manner during the first 24 h of the culture. This immunoreactivity could be induced by lipopolysaccharide and tumor necrosis factor-alpha in a time- and dose-dependent manner. We also observed the expression of CINC mRNA in TtT/GF cells and LPS increased CINC mRNA accumulation in TtT/GF cells. These findings indicate that CINC produced by FS cells may play a role as a paracrine factor of the anterior pituitary gland, and TtT/GF will provide a useful model system for studying the regulation of CINC secretion by FS cells.

GRO‐alpha in Human Serum: Differences Related to Age and Sex

PROBLEM: Human GRO‐alpha (GRO‐α) is a new member of the chemokine family that is supposed to play an important role in inflammatory and immune reactions. We established a sandwich enzyme‐linked immunoassay (ELISA) system with polyclonal antibodies against human GRO‐α and investigated the serum level of healthy donors to establish normal ranges for this chemokine in adults.

Long-term hospitalization during pregnancy is a risk factor for vitamin D deficiency in neonates

Abstract. In order to examine the effects of long-term hospitalization during pregnancy on vitamin D metabolism in pregnant women and neonates, we measured the serum 25-hydroxyvitamin D (25OHD) levels in pregnant women, as well as measuring 25OHD levels in cord blood and breast milk. In pregnant women hospitalized for longer than 1 month, the serum 25OHD levels were decreased at delivery compared with those in control subjects (10.9 ± 2.6 ng/l vs 19.5 ± 4.9 ng/l; P < 0.01). Although the levels of 25OHD in the cord blood were not significantly different between the long-term hospitalized and control pregnant women in this study (9.36 ± 1.7 ng/l vs 11.1 ± 3.0 ng/l), the 25OHD concentrations in the cord blood were significantly lower than the maternal levels in both groups; the ratios of the levels in cord blood to sera in the long-term hospitalized women and control subjects were 82.1% and 60.3%, respectively. Long maternal hospitalization does not always cause neonatal vitamin D deficiency, but could be one of its major risk factors. Therefore, sufficient sunlight exposure and intake of sufficient vitamin D are considered to be important to prevent vitamin D deficiency in long-term hospitalized pregrant women as well as their babies.

The pituitary folliculo-stellate cell line TtT/GF augments basal and trhinduced prolactin secretion by GH3 cell

Numerous functions have been ascribed to anterior pituitary folliculo-stellate (FS) cells. Recently, we established a pituitary FS-like cell line (TtT/GF) from an isologously transplantable pituitary thyrotropic tumor. Here we investigated the effect of FS cells on prolactin (PRL) secretion by using a co-culture system between TtT/GF cells and GH3 cells. We observed that co-culture with TtT/GF cells significantly increased basal PRL secretion without affecting the growth rate of GH3 cells. Further, addition of anti-cytokine-induced neutrophil chemoattractant (CINC) antibody partially reduced PRL secretion in co-culture of GH3 cells with 10% TtT/GF cells. Co-culture with 5% TtT/GF cells also markedly enhanced the PRL response to thyrotropin-releasing hormone (TRH) by GH3 cells, while addition of anti-CINC antibody had no effects on the enhanced PRL response to TRH. These results suggest that FS cells augment basal PRL secretion and enhance the secretory response of PRL to TRH by a paracrine mechanism.