Zhun Xiao

Novel needle immersed vitrification: a practical and convenient method with potential advantages in mouse and human ovarian tissue cryopreservation

BACKGROUND Ovarian tissue cryopreservation may be a potential method of preserving fertility in women who have experienced gonadotoxic treatments. To improve the efficiency of existing cryopreservation, we developed a practical and convenient vitrification method named needle immersed vitrification (NIV), which required a less concentrated and minimum volume of vitrification solution. METHODS Mouse ovaries and human ovarian cortex fragments were vitrified using the NIV method, the slow-freezing method or the dropping vitrification method. Their morphology, ultrastructure and viability were analyzed and compared with fresh group. RESULTS Primordial follicles in human and mouse ovarian tissues vitrified by NIV were well preserved. In mice, the percentages of normal morphological primary and secondary follicles were greater in the NIV group than that in the slow-freezing group or dropping vitrification group (P < 0.001). Ultrastructure of the stromal cells was preserved better in the NIV group than the slow-freezing or the dropping vitrification group in both human (P = 0.039, P = 0.023, respectively) and mouse (both P < 0.001) models. The viability assessment on frozen-thawed human ovarian tissue strips revealed that the follicles and the stroma had a satisfactory viability in the NIV group. In mouse model, the ovarian functional restoration in the NIV group was the best among three freezing groups, which was demonstrated by follicle counting in grafts after transplantation (P = 0.009 and P = 0.010 versus slow freezing and dropping vitrification, respectively). The cleavage rate of oocytes from grafts of the NIV group was most similar to that observed in the fresh group. CONCLUSIONS The NIV method could facilitate vitrification process, maximize the cooling rate and reduce the toxicity of the vitrification solution with a minimal volume of less concentrated cryoprotectants. NIV was practical and convenient for cryopreservation of ovarian tissues.

Needle immersed vitrification can lower the concentration of cryoprotectant in human ovarian tissue cryopreservation

OBJECTIVE To investigate whether needle immersed vitrification (NIV) can further lower the concentration of cryoprotective agent (CPA). DESIGN Experimental cross-sectional controlled in vitro study. SETTING University teaching hospital. PATIENT(S) Human ovarian biopsy tissues were obtained from ten women undergoing gynecology operations. INTERVENTION(S) Ovarian cortical tissues were cryopreserved using slow freezing or vitrification. The vitrification solutions used were as follows: group A: 2.69 mol/L ethylene glycol (EG)+2.11 mol/L dimethylsulfoxide (DMSO)+0.5 mol/L sucrose; group B: 2.42 mol/L EG+1.90 mol/L DMSO+0.5 mol/L sucrose; group C: 2.15 mol/L EG+1.69 mol/L DMSO+0.5 mol/L sucrose; and group D: 1.88 mol/L EG+1.48 mol/L DMSO+0.5 mol/L sucrose. MAIN OUTCOME MEASURE(S) Histologic evaluations were performed using light and electron microscopy. Apoptosis was assessed by TUNEL staining. Tissue damage after cryopreservation was measured by the levels of lactate dehydrogenase (LDH) in culture. RESULT(S) The proportion of normal ultrastructure of granulosa cells and stromal cells in groups B and C was higher than that in group A. The proportion of TUNEL-positive primordial follicles and stromal cells in the NIV groups decreased with reduction of concentration. Additionally, LDH levels in groups B and C were lower than in group A. CONCLUSION(S) The NIV method could further lower the concentration of CPA. Therefore, we can use the CPA of group C as an optimal concentration for NIV.

Gonadotropin-releasing hormone for preservation of ovarian function during chemotherapy in lymphoma patients of reproductive age: a summary based on 434 patients.

Background Gonadotropin-releasing hormone agonists (GnRHa) might play a role in preserving ovarian function in lymphoma patients by inhibiting chemotherapy-induced ovarian follicular damage. However, studies of its clinical efficacy have reported conflicting results. Method We conducted a meta-analysis to determine the effect of the preservation of ovarian function by administering GnRHa in young patients with lymphoma undergoing chemotherapy. Seven studies were identified that met inclusion criteria and comprised 434 patients assigned to GnRHa combined chemotherapy or chemotherapy alone. Results The incidence of women with premature ovarian failure (POF) demonstrated a statistically significant difference in favor of the use of GnRHa (OR=0.32, 95% CI 0.13-0.77). In addition, the final level of FSH in the GnRH group was significantly lower than control group. (MD= -11.73, 95% CI,-22.25- -1.20), and the final level of AMH in the GnRH group was significantly higher than control group (MD=0.80; 95% CI, 0.61–0.98). However, there was no statistically significant difference between treatment and the control groups in the incidence of a spontaneous pregnancy (OR=1.11; 95% CI, 0.55–2.26). Conclusion This meta-analysis suggests that GnRHa may be effective in protecting ovarian function during chemotherapy in lymphoma patients. More well-designed prospective studies are needed to carry out for further understanding of this topic.

ASSOCIATION BETWEEN INTERLEUKIN-10 PROMOTER POLYMORPHISMS AND ENDOMETRIOSIS: A META-ANALYSIS

To investigate the influence of the interleukin-10 gene promoter polymorphisms on the susceptibility of endometriosis, we examined the association by performing a meta-analysis. The PubMed, Embase, HuGE Navigator and CNKI were searched to identify eligible studies. We then conducted a meta-analysis to examine the association between interleukin-10 gene promoter polymorphisms and endometriosis. Eight case-control studies which examined the association between the IL-10 gene promoter polymorphisms and the susceptibility to endometriosis were finally included in the meta-analysis. Meta-analysis of the IL-10 -592 A/C polymorphisms showed a significant increased risk of endometriosis in the overall and Asian population in all genetic models and allele contrast. However, meta-analysis of the IL-10 -1082 A/G and IL-10 -819 T/C polymorphisms showed no association with endometriosis in all genetic models and allele contrast in the overall and Asian population samples. In addition, there was not a significant association between the IL-10 -592 A/C gene promoter polymorphisms with the severity of endometriosis. In conclusion, this meta-analysis suggests that the IL-10 -592 A/C polymorphisms conferred susceptibility to endometriosis. However, no associations were found between the IL-10 -1082 A/G and -819 T/C polymorphisms and susceptibility to endometriosis. Further studies are required to elucidate these associations more clearly.

Influence of the Wenchuan earthquake on self-reported irregular menstrual cycles in surviving women

Objective. To explore the influence of stress induced by the Wenchuan earthquake on the menstrual cycles of surviving women. Methods. Self-reports of the menstrual cycles of 473 women that survived the Wenchuan earthquake were analyzed. Menstrual regularity was defined as menses between 21 and 35 days long. The death of a child or the loss of property and social resources was verified for all surviving women. The severity of these losses was assessed and graded as high, little, and none. Results. About 21% of the study participants reported that their menstrual cycles became irregular after the Wenchuan earthquake, and this percentage was significantly higher than before the earthquake (6%, p < 0.05). About 30% of the surviving women with a high degree of loss in the earthquake reported menstrual irregularity after the earthquake. Association analyses showed that some stressors of the Wenchuan earthquake were strongly associated with self-reports of menstrual irregularity, including the loss of children (RR: 1.58; 95% CI: 1.09, 2.28), large amounts of property (RR: 1.49; 95% CI: 1.03, 2.15), social resources (RR: 1.34; 95% CI: 1.00, 1.80) and the hormonal contraception use (RR: 1.62; 95% CI: 1.21, 1.83). Conclusions. Self-reported menstrual irregularity is common in women that survived the Wenchuan earthquake, especially in those who lost children, large amounts of property and social resources.

Cryopreservation of human ovarian tissue using the silver closed vitrification system

PurposeThe aim of this study is to evaluate the feasibility of using a hand-made silver container for the cryopreservation of human ovarian cortex.MethodsHuman ovarian cortex tissues were vitrified using an open vitrification system (OVS) of needle immersed vitrification (NIV) and two closed vitrification systems (CVS) of a plastic vial (plastic CVS) and a silver container (silver CVS). Outcomes of vitrification were evaluated morphologically and histologically by in vitro culture and xenotransplantation. The apoptosis of primordial follicles was assessed by TUNEL staining. The production of E2 and P4 was examined by a chemiluminescent immunoassay. Blood vessels were visualized with CD31 staining.ResultsCompared with the fresh ovarian cortex tissue, ovarian cortex tissues that were vitrified using the three different carriers and then warmed showed significantly reduced percentages of normal primordial follicles, viability of primordial follicles, E2 and P4 levels during in vitro culture and decreased amounts of blood vessels. However, much better outcomes were obtained with NIV and silver CVS than with plastic CVS, based on the better morphology and viability of primordial follicles, higher E2 and P4 production during an in vitro culture, and greater numbers of blood vessels after xenografting. Importantly, the outcomes of ovarian cortex cryopreservation with silver CVS were similar and comparable to those with NIV.ConclusionsThe hand-made silver container as a CVS is a promising carrier for the cryopreservation of the human ovarian cortex.