Motofumi Yokoyama

Urinary excretion of pyridinium crosslinks of collagen in oophorectomized women as markers for bone resorption

To detect increased bone resorption in estrogen-deficient women, the urinary excretion of hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP), which are intermolecular crosslinkings of collagen fibers, were measured and their chronological changes were evaluated following oophorectomy. Seventy-five women were divided into three groups; 15 premenopausal women (mean age 44.0 years), 15 postmenopausal women (mean age 54.2 years) and 45 surgically menopausal women who had a normal menstrual cycle before surgery (mean age 42.2 years). There was a significant increase in HP and LP of the postmenopausal women (P < 0.001). In the oophorectomized women, both HP and LP were three times higher than those of premenopausal women within 1 year after oophorectomy, and decreased to the same level of the postmenopause between 2 and 3 years after surgery. In the six oophorectomized women after the administration of estrogen, HP and LP both decreased remarkably in all cases. The present study thus indicates that an increase of bone resorption which was evaluated by urinary HP and LP occurs in the early stage after oophorectomy. It may, therefore, be good to begin estrogen replacement therapy as soon as possible after oophorectomy.

Cytotoxic Cells Directed Against Placental Cells Detected In Human Habitual Abortions by an In Vitro Terminal Labeling Assay

PROBLEM: From the clinical point of view, it has been proposed that an immunological imbalance between the mother and the fetus might exist in one of the mechanisms for human habitual abortion. However, in the definition of habitual abortion, we have no distinct immunological criteria for this clinical entity at the moment.

Elevation of the phospholipase A2 activity in peritoneal fluid cells from women with endometriosis

OBJECTIVE To assess the prostaglandin (PG) production on peritoneal fluid (PF) cells, phospholipase A2 (PLA2) activity of those cells in women with endometriosis was measured and compared with that of women without endometriosis. DESIGN Prospective clinical controlled study. PATIENTS Women who underwent laparoscopy and were found either to have endometriosis (n = 15) or not (n = 9) were included in this study. Mononuclear cells obtained from the patients at laparoscopy were immediately separated by a Ficoll-Paque technique, lysed by nitrogen cavitation, and stored at -80 degrees C. INTERVENTIONS Phospholipase A2 activity was measured by Dole assay using 1-palmitoyl-2-[1-14C] palmitoyl phosphatidyl choline and assessed on a protein basis and a cell number basis. RESULTS There were at least four measurable kinds of PLA2 activity detected in the cells: two calcium-dependent pH optima 7.0 and 9.0 activities and two calcium-independent pH optima 7.5 and 8.5 activities. A calcium-dependent and pH optima 9.0 activity was the highest, and it was significantly higher in women with endometriosis when compared with those who did not have endometriosis. CONCLUSION These results indicate that the increase in the PGs in PF with endometriosis may be produced by PF cells in which PLA2 activity is elevated.

Changes in phospholipase A2 activity of the rabbit ampullary epithelium by ovarian steroids.

Phospholipase A2 (EC 3.1.1.4) activity of the ampullary epithelium from rabbit oviducts was compared in the presence of various ovarian steroids to assess how they could modulate prostaglandins (PG) biosynthesis in the oviduct. The phospholipase A2 (PLA2) activity of the cells from ovariectomized rabbits (control) was 190.8 +/- 9.8 pmol/min/mg. The PLA2 activity of the cells from progesterone-treated rabbits was 156.0 +/- 41.8 pmol/min/mg and was not significantly different from the control activity. However, the PLA2 activity of the cells from the estrogen-treated rabbits was 233.5 +/- 29.0 pmol/min/mg, which was significantly higher than the control activity (p < 0.05). On the other hand, the PLA2 activity of the cells from progesterone-treated rabbits after being primed with estrogen was 116.3 +/- 25.9 pmol/min/mg, which was significantly lower than the control activity (p < 0.01). These results suggest that the effects on PLA2 activity of ovarian steroids could regulate the local production of PG which plays a role in both smooth muscle contractility and ciliary activity.

Thymus cell migration in a prostaglandin-mediated system.

Prostaglandin (PG)-mediated T cell traffic and the nature of these emigrant T cells were analyzed by using a fluorescent activated cell sorter. Administration of indomethacin (INDO), an inhibitor of PG synthesis, increased the number of splenic T cells in normal mice but not in adult-thymectomized mice. An increase in thymus cell migrants in peripheral blood lymphocyte and splenic cell populations of mice pretreated with INDO were detected, using the method of in situ labelling of thymocytes with fluorescein diacetate. These results indicate that the increase in the T cell population in the spleen by INDO treatment results from the increase in thymus cell migration to the spleen. Such recent emigrants in the spleen were thought to have been derived from the thymus cortex, judging from the response to phytohemagglutinin and intracellular terminal deoxynucleotidyl transferase activity; however, they expressed a Thy-1 level similar to that found on peripheral T cells. These results suggested that a cortical thymocyte population was recruited from the thymus to the spleen by a PG-mediated system, but its Thy-1 level rapidly changed to that found on the peripheral T cell population.

Improvement in blastocyst hatching of mouse embryos cocultured with human placental cells

PurposeAlthough the hatching of embryos is an important phenomenon, the mechanism of hatching remains controversial. Therefore, we attempted to develop a new coculture system with human placental cells to investigate the hatching of mouse embryos.ResultsIn our new system there was no difference in development from the two-cell stage to blastocysts between embryos cultured with a T6 medium and embryos cocultured with human placental cells at 1 × 105, 5 × 105, and 1 × 106 cells/ml. However, the hatching-rate cell number increased significantly in embryos cocultured with placental cells compared to embryos cultured without placental cells. [3H]Thymidine uptake did not show any significant difference from the beginning of in vitro culture to the hatching stage between the coculture group and the control group. Nevertheless, the [3H]uridine uptake was significantly different in the two groups, measuring 2167 ± 532 cpm/10 embryos in the coculture group and 804 ± 86 cpm/10 embryos in the control group at 114 hr after human chorionic gonadotropin injection (P < 0.01).ConclusionThese results therefore seem to indicate that the hatching of blastocysts depends on the protein synthesis of the embryos and not on DNA duplications.

Regional differences of phospholipase A2 activity in the rabbit oviductal epithelium

To evaluate the biosynthesis of prostaglandins in the oviducts, phospholipase A2 (EC 3.1.1.4) activities were first measured in the epithelial cells obtained from rabbit oviducts. At least four kinds of phospholipase A2 (PLA2) activities with respect to calcium dependency and pH requirement were observed. There were two calcium-dependent, pH optima of 7.5 and 8.5 activities, and two calcium-independent, pH optima of 4.0 and 8.0 activities. One of those activities, a calcium-dependent and alkaline active PLA2 activity of the epithelial cells was then compared between the ampullary portion and the isthmic portion of the oviducts. The activity was significantly higher in the ampullary epithelium than in the isthmic epithelium (223.2 +/- 57.2 or 103.8 +/- 32.3 pmol/min/mg, p < 0.05). These results support the idea that the production of prostaglandins, which is dependent upon the activity of the arachidonate cascades, was higher in the ampullary portion of oviduct than that in the isthmic portion. The PLA2 activity of the ampullary epithelium may thus play an important role in the regulation of smooth muscle contractility and ciliary movement.

Abdominal Bleeding from Omental Trophoblastic Implants After Laparoscopic Salpingostomy

Laparoscopic salpingostomy is commonly performed to preserve fertility in cases of ectopic tubal pregnancy. However, persistent ectopic pregnancy (PEP) possibly occurs because of remaining trophoblastic tissue inside and/or outside the fallopian tube. We report an uncommon case of a woman who had severe abdominal bleeding caused by omental trophoblastic implants after laparoscopic salpingostomy. To prevent such a severe complication after initial surgery, local or systemic adjuvant therapy such as methotrexate therapy should be considered in high-risk PEP cases.