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Ovarian hyperstimulation syndrome (OHSS) is a severe complication arising from controlled ovarian stimulation treatment. This iatrogenic condition is potentially lethal and occurs in 0.3-5% of stimulated ovarian cycles. hCG exacerbates OHSS. The pathophysiology of OHSS is still unknown; therefore, treatment regimens are aimed at ameliorating symptoms. Prominent features of OHSS are an elevated risk of thromboembolism due to enhanced production of von Willebrand factor by endothelial cells and ascites, or pulmonary edema due to increased vascular permeability followed by third space fluid accumulation. Both of these sequelae can be evoked by vascular endothelial growth factor (VEGF), also known as vascular permeability factor (VPF). High concentrations of VEGF/VPF have been demonstrated in ascitic fluid from patients with OHSS, but the source of VEGF/VPF in these patients remained unidentified. Here we report that the messenger ribonucleic acid expression of VEGF/VPF in human luteinized granulosa cells (GCs) is dose and time dependently enhanced by hCG in vitro. Furthermore, VEGF/VPF proteins are produced by GCs. Our results suggest that the effects of hCG on the development and course of OHSS may be mediated by the production of VEGF/VPF by GCs.

Vascularization is a prerequisit for corpus luteum formation. Angiogenesis is supposed to be regulated by vascular growth factors. Vascular endothelial growth factor (VEGF) induces specifically endothelial cell proliferation as well as angiogenesis and increases capillary permeability. With this study we demonstrate for the first time the presence of VEGF-mRNA in human luteinized granulosa cells by Northern blot technique. Granulosa cells were obtained from 11 individual patients undergoing ovarian stimulation for in vitro fertilization procedure. Two transcripts of VEGF-mRNA at 3.9Kb and at 4.3Kb could be detected in each case. Specific transcripts were expressed in different amounts. These results indicate that VEGF may promote at least in part vascularization of the human corpus luteum.

Polylactide (PLA) microcellular foams with well-defined cell morphology were successfully fabricated from poly­(l-lactide) (PLLA) and poly­(d-lactide) (PDLA) blends through a supercritical carbon dioxide (CO2) foaming method. The gaps between the melting temperature of homocrystallites (T m(HC)) and stereocomplex crystallites (T m(SC)) were utilized to improve PLA’s melt foaming behaviors (i.e., cell nucleation and cell morphology) owing to the existence of exclusive SC crystallites when the foaming temperature fell in between T m(HC) and T m(SC). Thanks to the enhanced melt strength, which resulted from the introduction of SC crystallites, the cell morphology transformed from elliptical to nearly circular and the cell collapse and coalescence reduced when foamed at high temperatures and pressures. The wider foaming processing window is favorable for actual industrial manufacture such as the continuous extrusion foaming process. In addition, PLA foams possessing more SC crystallites exhibit higher heat resistance, which further broadens their applications in high-temperature conditions.

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