[Contribution of Tissue Hypoxia to Corpus Luteum Formation].

Corpus luteum is a temporary endocrine organ that is formed and regressed during the female reproductive cycle.It is developed from the residual follicular tissue after ovulation,which is associated with the rapid angiogenesis.Vascular endothelial growth factor(VEGF)is the most important stimulatory factor that regulates the luteal angiogenesis and also plays a key role during corpus luteum formation.VEGF is regulated by hypoxia-inducible factor(HIF)-1,which is a heterodimeric transcription factor consistent of HIF-1α and HIF-1ß.The local hypoxia of ovary due to the ruptured follicle and the lack of new vascular networks induces HIF-1α expression and participates in the luteal formation through VEGF-dependent angiogenesis.The present article describes the functional and structural changes during the luteal formation from the local and hypoxic conditions immediately before and after ovulation,with an attempt to clarify the roles of hypoxia in luteal formation as well as ovarian physiology.

Preparation and performance of a pH-sensitive cisplatin-loaded magnetic nanomedicine that targets tumor cells via folate receptor mediation.

The present study aimed to prepare cisplatin (CDDP)-loaded magnetic nanoparticles (MNPs), which target folate receptors via a pH-sensitive release system (FA­PEG­NH­N=MNPs­CDDP). This is of interest for the development of intelligent drug delivery systems that target tumors of the head and neck. The chemical coprecipitation method was used to prepare ferroferric oxide MNPs. These were modified with aldehyde sodium alginate complexed with the chemotherapeutic agent, CDDP on the surface of the nanoparticles. Double hydrazine­poly(ethylene glycol; PEG) was also prepared by attaching the carboxyl group of hydrazine­folate on one side of the double hydrazine­PEG, obtaining folate­hydrazine­PEG­diazenyl. This binds the aldehyde group of sodium alginic acid on the MNP to enclose CDDP, in order that it is sequestered within the carrier. This method obtained a pH­sensitive, FA­modified CDDP­loaded MNP (FA­PEG­NH­N=MNPs­CDDP), which acts as an intelligent tumor targeting drug delivery system. The mean size of the MNPs was ~10.2±1.5 nm, the mean hydrodynamic diameter detected by laser particle sizing instruments was 176.6±1.1 nm, and the ζ­potential was ­20.91±1.76 mV. The CDDP content was 0.773 mg/ml, the iron content was ~1.908 mg/ml and the maximum saturation magnetization was 16.3±0.2 emu/g. The current study produced a pH­sensitive FA­modified CDDP­loaded MNP that is stable and exhibits magnetic responsiveness, which releases CDDP in a low pH environment.

[Timing of operation and therapeutic effect of endoscopic optic nerve decompression for traumatic optic neuropathy].

OBJECTIVE: To observe the optimal timing of operation and the therapeutic effect of endoscopic optic nerve decompression for traumatic optic neuropathy (TON). METHODS: The clinical records of 90 consecutive patients with TON (93 eyes) after head and/or maxillofacial trauma from April 1998 to March 2007 were reviewed and analyzed. All patients were either unresponsive or intolerant to medication before they underwent intranasal endoscopic optic nerve decompression. The time interval between the injury and operation ranged from one day to 97 days (median 5.5 days). Among the 93 eyes, there were 71 eyes with no visual acuity before operation and 22 eyes with residue visual acuity, including light perception in 1 eye, hand movement in 5 eyes, counting fingers in 13 eyes, 0.04 in 1 eye, and 0.1 in 2 eyes. Duration of follow-up ranged from 6 days to two years (median 8 days). RESULTS: After decompression, 35 patients (36/93 eyes, 38.7%) showed improvement of visual acuity, 53 patients (55 eyes, 59.1%) remained the same as before operation, while 2 patients (2 eyes, 2.2%) showed decreased visual acuity. Among patients with visual acuity beyond light perception before decompression, 68.2% of them (15/22 eyes) experienced visual improvement, whereas only 22.9% (8/35 eyes, 0.02 in two eyes) among patients who lost visual acuity immediately after injury, and 36.1% (13/36 eyes, 0.02 in five eyes) among those who lost visual acuity gradually after injury. There was a significant difference in visual improvement between group with visual acuity and group with no visual acuity (chi(2) = 11.864, P < 0.01). Among patients with no visual acuity, 41.2% of those (7/17 eyes) who underwent operation within 3 days of injury, experienced improvement in visual acuity, compared with 25.9% (14/54 eyes) for those who underwent the operation more than 3 days after injury. It was indicated that no significant difference in visual improvement between these two groups (chi(2) = 1.46, P > 0.05). When comparing different sites of fracture, the effect of surgery was the most desirable (55.6%, 10/18 eyes improved) if the fracture occurred simultaneously in both exterior and interior walls of optic canal, followed by the interior wall fracture (45.7%, 21/46 eyes). The operation was less effective if there was no fraction (20%, 4/20 eyes) or if the fracture occurred in exterior wall alone (11.1%, 1/9 eyes). CONCLUSIONS: Endoscopic optic nerve decompression is a minimally invasive procedure with no adverse cosmetic effects. Early operation is recommended for saving vision, even though visual acuity is lost immediately after injury. However, the satisfactory clinical effects of endoscopic optic nerve decompression require further study.

Estrogen mediates mammary epithelial cell proliferation in serum-free culture indirectly via mammary stroma-derived hepatocyte growth factor.

Epithelial-stromal cell interactions are important for normal development and function of the mouse mammary gland. The steroid hormone estrogen is required for epithelial cell proliferation and ductal development in vivo. Recent studies of estrogen receptor alpha knockout mice indicate that estrogen-induced proliferation is dependent upon the presence of estrogen receptor in mammary stromal cells, but not in epithelial cells. The purpose of the present study was to identify the underlying mechanism of estrogen-dependent stroma-derived effects on mammary epithelium. We have developed a minimally supplemented serum-free medium, collagen gel primary mammary coculture system to address the issue of stroma-derived, estrogen-dependent effects on epithelial cell proliferation. Conditioned medium from mammary fibroblasts or coculture with mammary fibroblasts caused increased epithelial cell proliferation and produced tubular/ductal morphology. Hepatocyte growth factor (HGF) was identified as the mediator of this effect, as the proliferative activity in fibroblast-conditioned medium was completely abolished by neutralizing antibody to HGF, whereas neutralizing antibodies to either epidermal growth factor or IGF-I had no effect. Treatment of mammary fibroblasts with estrogen increased the production of HGF. From these results we conclude that estrogen may indirectly mediate mammary epithelial cell proliferation via the regulation of HGF in mammary stromal cells and that HGF plays a crucial role in estrogen-induced proliferation in vivo.