[Magnetic-activated cell sorting (MACS) versus density gradient centrifugation (DGC) for the selection of human sperm in assisted reproductive techniques]

Objective: To investigate whether the assisted reproductive techniques (ART) outcomes can be improved by using magnetic-activated cell sorting combined isolate density gradient centrifugation (MACS-DGC), and to compare the results with the conventional isolate density gradient centrifugation (DGC) method. Methods: In the period from January to December 2014, patients who attended the andrology laboratory for sperm DNA fragmentation analysis and underwent the in vitro fertilization and embryo transfer (IVF-ET) treatment were divided into 3 groups, and each group has two subgroups according to the way of fertilization : in vitro fertilization (IVF) as subgroup 1 and intracytoplasmic sperm injection (ICSI) as subgroup 2. Group A (A1, A2 ): DNA fragmentation index(DFI)≥20 and using MACs; Group B (B1, B2): DFI≥20 and using isolate method; Group C (C1, C2): DFI<20 and using isolate method. The fertilization rate, good-quality embryos, implantation rate, pregnancy rate and live-birth rate of each group were analyzed. Results: Similar results were obtained among groups for all the parameters compared: On IVF cycles no significant difference was observed in fertilization rate, percentage of good-quality embryos on day 3, implantation rate, positive beta-hCG tests, and live-birth rate among the three subgroups (A1 vs B1 vs C1). Between the subgroups of ICSI cycles (A2 vs B2 vs C2) the percentage of high-quality embryos, pregnancy rate, implantation rate and live-birth rate were all significantly higher in the MACS-DGC (A2) group compared to DGC alone (B2). Conclusion: Based on the results, MACS as a part of sperm preparation technique will not improve sperm fertilizing potential, embryos quality, implantation rate, pregnancy rate or live-birth rate of IVF, but it may help select the most fertile sperm and to improve clinical outcomes of ICSI.

Comparison of high-intensity focused ultrasound therapy under nasal endoscopy guidance versus first-line drug treatment in patients with persistent allergic rhinitis

The aim of this study was to determine whether high-intensity focused ultrasound (HIFU) therapy under nasal endoscopy guidance could provide better efficacy and safety in patients with persistent allergic rhinitis (PAR) than the first-line drugs recommended by the World Health Organization. A total of 120 adult patients with PAR were randomly divided into 2 groups (N = 60 each). One group underwent HIFU therapy under nasal endoscopy guidance using an ultrasound rhinitis therapeutic machine. The other group served as the control group and was treated with corticosteroid nasal spray and oral cetirizine hydrochloride. All patients underwent follow-up treatment for 1 year, after which the efficacy and safety were evaluated. There was no significant difference between the two groups (P > 0.05) in the total effective rate. Moreover, no complications such as nasal adhesion, septal perforation, mucosal atrophy, and hyposmia were observed, indicating that HIFU was as effective as the first-line drug treatments recommended by the World Health Organization for symptom relief in PAR patients. The treatment efficacy, repeatability, safety, economical aspects, ease of performance, and few complications of HIFU therapy strongly suggest that HIFU should be routinely incorporated into clinical practice.

[Optimization of trypsin digestion intensity to obtain high-purity in vitro cultured astrocytes]

The aim of the present study was to observe the effect of trypsin digestion on the purity of in vitro cultured astrocytes and optimize the culture methods. The cerebral cortical tissue from newborn Sprague Dawley (SD) rats was isolated and digested with 0.25% trypsin for 20, 30, or 40 min. The obtained single cell suspension was then cultured. Once reaching confluence, the cells were shaken at a constant temperature. Then, each of 20 and 30 min groups was subdivided into two groups, the control group with normal digestion and two-time-digestion group, and the cells were passaged and purified. Through inverted phase contrast microscope and MTT assay, cell growth and proliferation were observed, respectively. Immunofluorescence for glial fibrillary acidic protein (GFAP) was used to observe the morphology of astrocytes and to assess their purity in different stages. Flow cytometric analysis was used to detect the apoptotic rates of purified astrocytes. The results showed that, the cells being digested for 20 min usually reached confluence at 9 d after seeding. When the digestion time was extended to 30 min, the cells grew faster and reached confluence at 7 d after seeding, meanwhile the morphology of astrocytes was normal, GFAP positive rate (70.2 ± 4.0)% being much higher than that of the 20 min group (P < 0.05). Compared with 20 min group, 40 min group showed higher GFAP positive rate, whereas the cell proliferation was slower, and cell injury was more obvious. After shaking at constant temperature, two times of trypsin digestion could decrease the number of contaminated cells after passage. The GFAP positive rates of two-time-digestion groups in passage 1 (P1) were higher than those of corresponding control groups, and the GFAP positive rate of 30 min + two-time-digestion group in P1 reached (98.1 ± 1.7)%, which was equivalent to that of the 20 min + control group in P3. However, the apoptotic rate showed no significant difference between these two groups. Based on above mentioned results, we conclude that 30 min + two-time of trypsin digestion effectively improves the purity of astrocytes and shortens the time of primary culture and purification, suggesting that it is a rapid and effective method to obtain astrocytes with high purity in vitro.

Vasoactive intestinal peptide increases VEGF expression to promote proliferation of brain vascular endothelial cells via the cAMP/PKA pathway after ischemic insult in vitro

Vasoactive intestinal peptide (VIP) enhances angiogenesis in rats with focal cerebral ischemia. In the present study, we investigated the molecular mechanism of the proangiogenic action of VIP using an in vitro ischemic model, in which rat brain microvascular endothelial cells (RBMECs) are subjected to oxygen and glucose deprivation (OGD). Western blotting and immunocytochemistry were carried out to examine the expression of VIP receptors and vascular endothelial growth factor (VEGF) in cultured RBMECs. The cell proliferation was assessed by the MTT assay. Cyclic adenosine monophosphate (cAMP) and VEGF levels were measured by using the enzyme-linked immunosorbent assay. The cultured RBMECs expressed VPAC1, VPAC2 and PAC1 receptors. Treatment with VIP significantly promoted the proliferation of RBMECs and increased OGD-induced expression of VEGF, and this effect was antagonized by the VPAC receptor antagonist VIP6-28 and VEGF antibody. VIP significantly increased contents of cAMP in RBMECs and VEGF in the culture medium. The VIP-induced VEGF production was blocked by H89, a protein kinase A (PKA) inhibitor. These data suggest that treatment with VIP promotes VEGF-mediated endothelial cell proliferation after ischemic insult in vitro, and this effect appears to be initiated by the VPAC receptors leading to activation of the cAMP/PKA pathway.

Shifting bright spatial solitons in LiNbO3

We observe spatial bright solitons in a transversely shifting LiNbO3 crystal. In this scheme, the photovoltaic nonlinearity in LiNbO3 can be switched from self-defocusing to self-focusing by continuous shifting of the beam. Moreover, the shifting velocity has a strong influence on the wave shape of the bright spatial solitons.

[Effect of puerarin on PC12 cells apoptosis induced by Abeta25-35 in vitro]

OBJECTIVE

To establish a nerve cell injury model by incubating PC12 cell line in the presence of Abeta25-35 to study the effect of puerarin on apoptosis of nerve cells.

METHODS

PC12 cells were incubated with Abeta25-35 and puerarin. Cell viability was detected by MTT. The cellular morphology was observed with electron microscopy. FITC-labeled Annexin V and propidium iodide were adopted to evaluate the rate of cell apoptosis in different groups by means of flow cytometry.

RESULTS

Following incubation Abeta25-35, the cells were induced to undergo apoptosis. The viability of PC12 cells decreased in a time-dependent manner. Morphological evidences for apoptosis nuclear condensation were observed in PC12 cells. Cells incubated in the presence of Abeta25-35 showed increasing apoptotic rates, but cells treated with puerarin and Abeta25-35 revealed decreasing apoptotic rates, it demonstrated that puerarin had a significant protective action against Abeta25-35 evoked apoptosis.

CONCLUSION

Puerarin can resist the adverse effects of Abeta25-35 on increasing apoptotic rates, and it has the protective function towards nerve cells.

Specific suppression of beta-secretase gene expression by short interfering RNA in SK-N-SH cells

OBJECTIVE

To test the effect of short interfering RNAs (siRNAs) of beta-site APP cleaving enzyme (BACE) on inhibiting the expression of BACE in mammalian cells.

METHODS

The gene of EGFP, U6 promoter and beta-secretase targeting siRNA were cloned by PCR. The PCR products were inserted into the retrovirus plasmid pLXSN. The interfering vector was identified as pLXSN/ EGFP-U6-siBACE. The SK-N-SH cell line was produced, which can highly expressed BACE. The inhibitive effect of BACE siRNA on BACE expression was examined by fluoroscopy and immunohistochemistry tests.

RESULTS

The interfering vector, pLXSN/EGFP-U6-siBACE, was constructed successfully. The BACE siRNA inhibited the expression of BACE in the SK-N-SH cell and reduced the production of Abeta.

CONCLUSION

BACE siRNA inhibits the expression of BACE gene of mammalian, which has implications for RNA interference of Alzheimer's disease.