精子冷冻环无保护剂玻璃化冷冻方法的初步研究

目的探讨精子冷冻环无保护剂玻璃化冷冻方法的可行性。方法正常精液标本上游处理后,进行常规冷冻和冷冻环无保护剂的玻璃化冷冻,复苏后分别从活力参数及电镜下超微结构等指标比较两种冷冻方法的效果。结果两种方法冷冻后精子存活率、活动率之间差异无显著性(48%∶48%;44.5%∶43.5%,P>0.05),但均较未冷冻的89%和88.5%明显下降(P<0.001)。超微结构亦较未冷冻时发生了一定的改变,但核结构基本保持完整。结论精子冷冻环无保护剂的玻璃化冷冻是一种简单、方便而行之有效的冷冻方法。     

The application of vitrification in human blastocyst cryopreservation: Analysis of clinical outcome of 117 cycles

Objective: To summarize the clinical outcomes of 117 human vitrified blastocyst transfer cycles and to determine the impact factors.Methods: In IVF-ET cycles, supernumerary embryos were cultured to 5-Day(D5) or 6-Day(D6), blastocysts of various stages were cryopreserved by vitrification using cryoloops. Survival rate and clinical pregnancy rate were observed.Results: A total of 312 blastocysts were thawed in 117 frozen embryo transfer cycles, the survival rate was 90.7% (283/312) after thawing. After the transfer of 230 blastocysts in 115 cycles, 69.6% (80/115) of the women got clinically pregnant, and 17.5% (14/80) of them suffered from miscarriage, 39 healthy babies were born in 28 deliveries, and the other 38 pregnancies are ongoing. The implantation rate was 47.4% (109/230). In 107 transfer cycles with 2 hatched blastocysts transferred in each cycle, 72.9% (78/107) got clinically pregnant, while in 8 cycles with 1 or no hatched blastocysts in the two transferred blastocysts, the clinical pregnancy rate is 25%(2/8). The clinical pregnancy rates were not statistically different between natural (77.4%, 24/31) or artificial endometrium preparation (66.7%, 56/84) cycles. Conclusions: These findings suggest that blastocyst vitrification is effective in terms of implantation rate and pregnancy outcome. Transferring of two hatched blastocyst can achieve a higher pregnancy rate.     

小鼠扩张囊胚颗粒法玻璃化冷冻保存技术研究

在２５℃室温下,用ＥＦＳ３０玻璃化溶液,对小鼠扩张囊胚进行颗粒法玻璃化冷冻保存。结果,胚胎在ＥＦＳ３０溶液中平衡１ｍｉｎ后滴入液氮中,解冻后的胚胎发育率达１００％,囊胚孵化率达７６％。而在１０％乙二醇溶液中将胚胎预处理５ｍｉｎ,再移入ＥＦＳ３０中平衡１ｍｉｎ后冷冻保存的胚胎,解冻后的发育率和囊胚孵化率分别为９８％和６３％。上述２组的胚胎发育率与对照组无明显差异,而囊胚发育率均明显低于对照组（Ｐ＜０．０１）。上述２组胚胎解冻后植入假孕小鼠子宫后的受体妊娠率分别为９０％和８１％,产出率分别为７１％和５８％,与对照组（６１％）相比均无显著性差异（Ｐ＞０．０５）。     

RapidWarm Blast玻璃化解冻液对囊胚复苏的效果观察

目的 观察在囊胚复苏周期中,RapidWarm Blast玻璃化解冻液对囊胚的复苏效果。方法 回顾性分析2018年12月至2019年12月在安徽医科大学第一附属医院首次行囊胚复苏移植的655例患者临床资料,根据囊胚解冻液不同分A组357例及B组298例。A组采用传统Vitrification Media解冻液进行囊胚复苏,B组采用新型RapidWarm Blast解冻液复苏。比较两组囊胚复苏后整体存活率,解冻2 h后囊胚重扩张率、孵化率,囊胚种植率及临床妊娠率;同时比较两种解冻液对囊胚不同发育阶段(第5天囊胚、第6天囊胚)的重扩张率、孵化率及临床妊娠率的影响。结果 两组囊胚复苏后的存活率、重扩张率、孵化率、临床妊娠率比较,差异均无统计学意义(P>0.05);B组囊胚种植率(55.45%)高于A组(48.76%),差异有统计学意义(P<0.05)。两组中发育第5天的囊胚复苏2 h后重扩张率及孵化率均高于发育第6天的囊胚,差异均有统计学意义(P<0.05);两组间发育第5天的囊胚复苏2 h后重扩张率及孵化率比较,差异无统计学意义(P>0.05),B组发育第6天的囊胚复苏2 h后扩张率及孵化率均高于A组,差异有统计学意义(P<0.05)。结论 新型RapidWarm Blast解冻液用于囊胚玻璃化复苏,可获得与传统的Vitrification Media相似的临床结局,但新型解冻液对发育第6天囊胚的复苏效果更好,胚胎种植率更高。     

Property evolution during vitrification of dimethacrylate photopolymer networks

Objectives

This study seeks to correlate the interrelated properties of conversion, shrinkage, modulus and stress as dimethacrylate networks transition from rubbery to glassy states during photopolymerization.

Methods

An unfilled BisGMA/TEGDMA resin was photocured for various irradiation intervals (7–600 s) to provide controlled levels of immediate conversion, which was monitored continuously for 10 min. Fiber optic near-infrared spectroscopy permitted coupling of real-time conversion measurement with dynamic polymerization shrinkage (linometer), modulus (dynamic mechanical analyzer) and stress (tensometer) development profiles.

Results

The varied irradiation conditions produced final conversion ranging from 6% to more than 60%. Post-irradiation conversion (dark cure) was quite limited when photopolymerization was interrupted either at very low or very high levels of conversion while significant dark cure contributions were possible for photocuring reactions suspended within the post-gel, rubbery regime. Analysis of conversion-based property evolution during and subsequent to photocuring demonstrated that the shrinkage rate increased significantly at about 40% conversion followed by late-stage suppression in the conversion-dependent shrinkage rate that begins at about 45–50% conversion. The gradual vitrification process over this conversion range is evident based on the broad but well-defined inflection in the modulus versus conversion data. As limiting conversion is approached, modulus and, to a somewhat lesser extent, stress rise precipitously as a result of vitrification with the stress profile showing little if any late-stage suppression as seen with shrinkage.

Significance

Near the limiting conversion for this model resin, the volumetric polymerization shrinkage rate slows while an exponential rise in modulus promotes the vitrification process that appears to largely dictate stress development.     

以细胞筛为载体的玻璃化冷冻和慢速程序化冷冻保存人卵巢组织的效果比较

目的比较以细胞筛为载体的玻璃化冷冻与慢速程序化冷冻用于人卵巢组织冷冻的效果。方法人卵巢组织取皮质切块后,随机分为3组:新鲜组织对照组(F组)、慢速程序化冷冻组(S组)及以细胞筛为载体玻璃化冷冻组(V组)。卵巢组织冷冻复苏后,固定切片后行苏木素-伊红染色,观察卵泡形态;使用TdT介导的dUTP缺口末端标记技术,观察卵泡凋亡情况;部分卵巢组织体外培养,隔日采集培养液后检测雌二醇(E2)浓度。比较三组卵泡正常形态率、卵泡凋亡率及E2浓度。结果与F组原始卵泡正常形态率(91.1%)相比,V组原始卵泡正常形态率(88.1%)无显著差异(P0.05),而S组原始卵泡正常形态率(79.6%)显著下降(P0.001);V组初级卵泡正常形态率(74.2%)与S组(73.6%)相似,但两组均低于F组(89.0%)(P0.05);凋亡检测中,3组凋亡率无显著差异(P0.05);体外培养2周,各组E2浓度持续上升,F组E2浓度显著高于S组、V组(P0.001),而S组与V组E2浓度无显著差异(P0.05)。结论以细胞筛为载体的玻璃化冷冻能较好地保存人卵巢组织,复苏后组织体外培养后,还可持续分泌E2。     

Stress-Strain Measurements and Viscoelastic Response of Blood Vessels Cryopreserved by Vitrification

To gain increased insight into thermo-mechanical phenomena during cryopreservation, tensile stress relaxation experiments were conducted on vitrified blood vessels (vitreous in Latin means Glassy), and the results compared with various viscoelastic models. Using a recently presented device, isothermal stress-relaxation results were obtained for a bovine carotid artery model, permeated with the cryoprotectant cocktail VS55 and a reference solution of 7.05 M DMSO. After a rapidly applied tensile strain, experimental results display exponential decay of stress with time; the stress at a given time increases with decreasing specimen temperature. Among the viscoelastic models investigated, the Williams–Landel–Ferry model was found to best-fit the variation of the stress relaxation data with temperature, while a Maxwell–Weichert model is used to represent the exponential decay of the stress with time. Blood vessel properties were found to dominate at temperatures above roughly −100 °C, while the properties of the cryoprotectant dominate below this temperature. A suitably defined steady-state viscosity displayed a similar behavior for both cryoprotectants, when normalized with respect to the cryoprotectant glass transition temperature.     

囊胚玻璃化冷冻保存时长对复苏移植临床结局的影响

目的研究使用开放式载体玻璃化冷冻保存囊胚的时长对复苏移植妊娠结局和新生儿结局的影响,探讨胚胎经过玻璃化冷冻并进行6年以上的长期保存是否对临床结局产生负面影响。方法回顾性分析2006年3月至2018年12月期间在我院生殖中心进行囊胚玻璃化冷冻复苏移植的2 643例患者的临床资料。按照胚胎玻璃化冷冻保存时长将其分为7组:≤1年,1~2年,2~3年,3~4年,4~5年,5~6年和≥6年,比较各组患者一般情况、临床结局、活产情况和单胎新生儿出生结局之间的差异,再使用二分类Logistic回归分析女性取卵年龄、移植年龄、胚胎冷冻保存时间、囊胚冷冻日期和囊胚级别对妊娠率和活产率的影响。结果各组患者取卵年龄、移植年龄、优胚率、复苏胚胎存活率、妊娠率和活产率组间差异有统计学意义(P<0.05)。各组平均移植胚胎数、D5胚胎比例、种植率、流产率、异位妊娠率、单胎率、出生男孩率、出生缺陷率、单胎出生体重、身长和孕天数均无统计学差异(P>0.05)。Logistic回归分析显示取卵年龄、移植年龄和冷冻保存时间对妊娠率无显著影响(P>0.05),取卵年龄和冷冻保存时长对活产率无显著影响(P>0.05),而增加移植D5胚胎和优质胚胎数量可以提高妊娠率和活产率(P<0.05),移植年龄的增加会降低活产率(P<0.05)。结论使用开放性载体玻璃化冷冻保存囊胚的时长对复苏后移植的妊娠结局和新生儿结局没有明显影响。囊胚经过玻璃化冷冻并进行6年以上长期冷冻保存,临床结局未产生明显负面影响。     

大鼠卵巢组织冷冻复苏及自体异位移植研究

目的：探讨直接覆盖玻璃化冷冻(direct cover vitrification, DCV)在冷冻大鼠卵巢组织中的效果,并对自体异位移植后卵巢组织存活状况及内分泌情况进行分析。方法性成熟的 Wistar 大鼠50只随机分为 A、B、C、D 组, A 和 B 组各20只,C 和 D 组各5只。 A 组为新鲜卵巢组织移植;B 组卵巢组织经 DCV 冷冻保存2周复苏后移植;C 组为去势对照;D 组为假手术对照。自体异位移植6周后检测大鼠血清中雌二醇(E2)水平,计算卵泡密度,观察移植卵巢组织形态学及增殖细胞核抗原(proliferating cell nuclear antigen, PCNA)的表达情况。结果大鼠卵巢组织移植存活的卵巢组织周围可见血管供应,移植失败的卵巢组织呈纤维化状态,与周围组织血供不明显。 B 组卵巢组织移植存活率低于 A 组(P <0．05)。 B 组卵巢组织中卵泡密度均低于 A、D 组,且 A 组低于 D 组(P <0．05)。 A、B 组血清 E2水平高于 C 组,低于 D 组(P <0．05)。 A、B 组卵巢组织 PCNA 阳性率均低于 D 组,且 B 组低于 A 组(P <0．05)。结论大鼠卵巢组织经 DCV 法冻融自体异位移植后部分卵泡能存活并可恢复内分泌功能。