[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.

[Cochlear implantation and rehabilitation in prelingually deafened adolescents and young adults].

OBJECTIVE: To investigate the outcomes of prelingually deafened adolescents and young adults receiving cochlear implantation (CI). METHODS: Thirty-three patients with prelingual deafness aged 7-33 years at the time of CI were followed up for 4 years. The Speech Discrimination Score (SDS) was tested using disyllabic words and short sentences with close-set and open-set, respectively. RESULTS: After appropriate mapping, sound field audiometry with warble tone showed that the warble tone threshold average (WTA) of the patients reached 25-41 dBHL, with a mean threshold of 28.62∓2.37 dBHL. At 1 year after the operation, the mean value of SDS was 70.03% in close-set word list with lip-reading and 61.18% without lip-reading, and was improved to 82.12% and 72.67% at 4 years, respectively. In open-set word list, the mean value of SDS was 77.94% with lip-reading and 67.85% without lip-reading. The safety and the benefits-cost evaluation of CI for prelingually deafened school age children and adolescents had been recognized by 90.9% of the families involved. CONCLUSION: These patients can obtain appropriate speech discrimination scores with improved quality of life after CI.

[Cochlear implant in patients with congenital malformation of the inner ear].

OBJECTIVE: To summarize the clinical experience with multi-channel cochlear implantation in patients with inner ear malformations and evaluate and the outcomes of speech rehabilitation. METHODS: A retrospective study was conducted in 295 patients receiving cochlear implantation from 1998 to 2007, including 25 patients with large vestibular aqueduct syndrome (LVAS), 9 with Modini malformation, and 5 with common cavity deformity. All the patients received the Nucleus24 cochlear implants. In LVAS cases, 4 had Nucleus 24R (ST) implants, 8 had Contuor implants, 10 had Contuor Advance, and the remaining cases used Nucleus24(M) straight-electrode implants. RESULTS: Severe gusher appeared in 3 cases of LVAS, and perilymph fluctuation were seen in other 15 cases. Four patients with Mondini malformation and 2 with common cavity malformation also experienced severe gusher, but the electrodes were inserted smoothly in all the patients without postoperative facial paralysis or cerebrospinal fluid leakage. The hearing threshold in these patients was similar to that in patients with normal cochlear structure. After speech rehabilitation for over 6 months, the abilities of speech discrimination and spoken language improved in all the cases in comparison with the preoperative lingual functions. CONCLUSION: Multi-channel cochlear implantation can be performed in patients with inner ear malformation, but should not be attempted in patients with poor cochlear and cochlear nerve development. A comprehensive pre-operative radiographic and audiological evaluation is essential.

[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.

[Targeted distribution of cis-platin magnetic nanoparticles in mice].

OBJECTIVE: To evaluate the targeted distribution of cis-platin magnetic nanoparticles (CDDP-MNP) in normal mice. METHODS: Thirty-two normal mice were randomly assigned into 4 equal groups. External magnetic field of 4100-4200 Gs was established in the unilateral kidney area of each mouse, and CDDP-MNP was administered via the tail vein, with the external magnetic field maintained in groups A, B, C, and D for 30 min and 1, 2 and 4 h after the injection, respectively. A flame atomic absorption spectrometer (AAS) was used to detect CDDP concentration in the mouse kidney tissues. Magnetic resonance imaging (MRI), Prussian blue staining, and transmission electron microscopy (TEM) were used to detect the distribution of the magnetic nanoparticles in vivo. RESULTS: In groups A, B and C, the concentrations of CDDP in the targeted kidney tissues increased significantly in comparison with those in non-targeted kidney. The signal intensity of the targeted kidney tissue was lower than that of the non-targeted kidney on T2-weighted MR images. TEM and Prussian blue staining demonstrated MNP distribution in the lumens and endothelial cells of the blood capillary in the kidney tissue. CONCLUSION: CDDP-MNP allows targeted distribution induced by external magnetic field in normal mice after intravenous injection.

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.