[Show abstract][Hide abstract]ABSTRACT: When human blastocysts hatch through the zona pellucida, gaining the ability to adhere to the endometrium, crosstalk between the embryo and the uterus may represent a successful outcome of their synchronized development and differentiation. CD26/dipeptidyl peptidase IV is known as a marker molecule of the implantation phase endometrium. To study the role of CD26 in implantation, 35 human hatched blastocysts were prepared by enzymatic treatment of expanded blastocysts that had been grown on schedule from frozen-thawed surplus embryos at the 2- or 4-cell stage. The blastocysts were placed on CD26-overexpressing or mock-transfected control monolayer cell cultures. The CD26-overexpression caused significantly higher blastocyst adhesion rate (53.3% versus 25.0%, P < 0.05) and significantly larger outgrowth area of trophectoderm (1.7-fold, P < 0.05). The second part of the present study was to show the expression of fibronectin, a CD26 ligand, in human preimplantation embryos, using the same donated resources. Fibronectin mRNA was detected by RT-PCR from the single hatched blastocyst (2/2) and from the single early blastocyst (3/6) but not from the single morula (0/5) samples. An indirect immunofluorescence technique verified the localization of fibronectin on the surface of the blastocyst. These results indicate that the adhesion mechanism by endometrial CD26 and embryonal fibronectin may be involved in human blastocyst implantation.
Full-text · Article · Sep 2006 · Molecular Human Reproduction
[Show abstract][Hide abstract]ABSTRACT: Ovarian hyperstimulation syndrome (OHSS) is an important and dangerous aspect of assisted reproduction techniques. Although elective cryopreservation of all embryos can prevent pregnancy-induced late OHSS, it cannot prevent early OHSS, which is induced by hCG administration.
We undertook this trial to assess the efficacy with which the combined oral administration of angiotensin-converting enzyme inhibitor (ACEI) and angiotensin II receptor blocker (ARB) could prevent early OHSS in IVF patients at very high risk for this syndrome. Four women, who had serum estradiol concentration > or =8000 pg/ml on the day of hCG injection, were treated with the combination of the ACEI alacepril and the ARB candesartan cilexetil for 8 days starting the day after oocyte retrieval. Embryos were cryopreserved and embryo transfer was postponed until later cycles.
Despite the extremely enlarged ovaries, no ascites was accumulated in any of the cases. Haematocrit (34.1 +/- 1.0) and serum albumin concentration (4.1 +/- 0.2 g/dl) were normal throughout the treatment period. These patients showed elevated plasma renin and angiotensin II concentration before the treatment.
The dual renin-angiotensin blockade therapy used here would be worth exploring further in a study with more patients and a prospective, randomized design.
Full-text · Article · Jul 2003 · Human Reproduction
[Show abstract][Hide abstract]ABSTRACT: The mechanism of monozygotic multifetal pregnancy and its association with assisted reproductive technology are uncertain. This report presents two cases of dizygotic triplet pregnancy after the transfer of three embryos in utero. The incidence of monozygotic twinning following assisted conception procedures is higher than in the general population. Zonal manipulation may be a major factor in the increased incidence of monozygotic twinning. As both cases followed the conventional in vitro fertilization (IVF), the reason for these monozygotic twinnings might be because of the changes in the zona pellucida in in vitro conditions. In one case, fetuses developed into severe twin-to-twin transfusion syndrome (TTTS), resulting in one intrauterine fetal death at 26 weeks gestation. (Reprod Med Biol 2003; 2: 41–44)
No preview · Article · Mar 2003 · Reproductive Medicine and Biology
[Show abstract][Hide abstract]ABSTRACT: To clarify the role of hepatocyte growth factor (HGF) in embryonic lung development, organoids from fetal rat lung were cultured in collagen gels with or without HGF antisense oligonucleotides. Cyst-like structures formed within 24 h in organoids isolated from fetuses after 14 days' gestation, but this was abolished by the oligonucleotide addition, apparently by interference with the endogenous expression of HGF. Electron microscopy revealed two types of structure: an alveolar type characterized by osmiophilic lamellar bodies in the cytoplasm and lumen, and a bronchial type consisting of epithelial cells bearing microvilli on their apical surfaces. HGF mRNA was detectable from day 14 in fetal lung by RT-PCR. Our results suggest that HGF plays, coordinately with its expression, a crucial role in the morphogenesis of both alveolar and bronchial epithelia in the rat fetal lung.
Full-text · Article · Jan 1998 · Biochemical and Biophysical Research Communications
[Show abstract][Hide abstract]ABSTRACT: The purpose of this study was to elucidate the possible relationship between hepatocyte growth factor (HGF) expression and the pathogenesis of preeclampsia. The concentration of immunoreactive HGF was measured and the expression of HGF messenger ribonucleic acid (mRNA) assessed in human placentas obtained from two groups: uncomplicated and preeclamptic pregnancies at various gestational weeks. In addition, the localization of HGF mRNA and c-met protein was analyzed using in situ hybridization and immunohistochemical staining, respectively. The expression of HGF mRNA and the concentration of immunoreactive HGF were highest in second trimester and were significantly decreased in preeclamptic placentas compared with the uncomplicated cases in third trimester. HGF mRNA was localized to placental mesenchymal cells, whereas c-met protein was demonstrated on cytotrophoblast. These results provide evidence of an abnormality of HGF expression in the preeclamptic placentas. Such placentas exhibit the abnormally shallow trophoblast invasion of the uterus, and reduced expression of HGF could well account for this morphometric change.
[Show abstract][Hide abstract]ABSTRACT: To find out if hepatocyte growth factor (HGF) in amniotic fluid (HGF-AF) has a direct effect on fetal lung development, we investigated the effects of AF as well as recombinant human HGF (rhHGF) on proliferation, migration, and morphogenesis of fetal alveolar type II cells in vitro.
Amniotic fluid samples were obtained from 37 women at various gestational ages. Mitogenic, motogenic, and morphogenic activity was investigated by 5-bromo-2'-deoxyuridine incorporation, Boyden chamber assay, and culture in collagen-gels, respectively.
The motility of AK-D cells was stimulated by AF from 14 to 31 weeks' gestation in proportion to the concentration of HGF-AF, and this effect was comparable to that observed with rhHGF. Furthermore, this activity was neutralized by anti-human HGF antibody. However, AF samples subsequent to 32 weeks had no motogenic influence despite the continued presence of immunoreactive HGF-AF. Neither increased DNA synthesis nor morphogenesis in response to AF was identified under the conditions used.
The present study suggests that AF stimulates alveolar type II cell migration by way of HGF-AF in vitro.
No preview · Article · Jun 1997 · Obstetrics and Gynecology
[Show abstract][Hide abstract]ABSTRACT: Lipid peroxides and their related free radicals have been implicated in the pathogenesis of placental dysfunction in preeclampsia. Recent studies suggest that the placenta is a source of the increased lipid peroxides in the maternal circulation of women with preeclampsia. We examined intracellular localization of 4-hydroxy-2-nonenal (HNE: a major aldehydic product of lipid peroxidation)-modified proteins in human placentas by immunohistochemistry, and immunoblotting. The trophoblast layer of the chorionic villi showed intense immunoreactivity for HNE-modified proteins in 4 of 12 preeclamptic placentas, whereas no staining was observed in 12 normal placentas. Immunoblotting revealed that three immunoreactive proteins with apparent molecular mass of 110 kDa, 75 kDa, and 70 kDa were localized in the mitochondrial fraction. The present results indicate that the damage to mitochondrial proteins by lipid peroxidation by products and subsequent dysfunction of trophoblasts contribute to the pathophysiology of preeclampsia.
Preview · Article · May 1997 · Biochemistry and molecular biology international
[Show abstract][Hide abstract]ABSTRACT: Fetal behavior in monozygotic twins, one being anencephalic, was serially recorded from 20 to 35 weeks of gestation and analyzed. The commencement of breathing movement was concluded to reflect the development of the medulla oblongata of the fetus.
No preview · Article · Feb 1996 · Gynecologic and Obstetric Investigation