准分子激光上皮瓣下角膜磨镶术治疗近视临床观察

目的探讨准分子激光上皮瓣下角膜磨镶术（LASEK）治疗近视的临床效果。方法将符合入选标准的病例按屈光度分为2组：组Ⅰ74只眼（等效球镜-2.375～-6 D）及组Ⅱ65只眼（等效球镜-6.25 D～-11.75 D）,术前及术后6个月应用日本NIDEK公司ARK-10000对患者行角膜地形图检查,结合综合验光结果、眼压等进行统计学分析。结果 LASEK术后6个月裸眼视力≥0.8者占99.28%,裸眼视力≥1.0者占95.62%。组Ⅰ和组Ⅱ中分别有4只眼（5.4%）、6只眼（9.2%）的术后裸眼视力（UCVA）较术前最佳矫正视力（BCVA）下降1行,而组Ⅱ中仅有1只眼（1.5%）下降2行,组Ⅰ和组Ⅱ视力改善无显著差异（χ2=1.37,P〉0.05）。LASEK术后眼压稳定,而模拟角膜镜读数（S im K）、角膜表面规则性指数（SR I）及角膜表面非对称性指数（SAI）均较术前变化显著（P〈0.05）。结论 LASEK是手术治疗近视的一种安全、有效、稳定的方法。     

The effect of long zona dissection using ICSI pipettes for mechanical assisted hatching in vitrified-thawed blastocyst transfers

Objective

To investigate the effect of long zona dissection (LZD) compared with partial zona dissection (PZD) using ICSI pipettes for mechanical assisted hatching (AH) in vitrified-thawed blastocyst transfers.

Design

Prospective study.

Setting

University IVF clinic.

Patient(s)

A total of 120 women ≦ 38 years old undergone vitrified-thawed blastocyst transfers with LZD or PZD.

Intervention(s)

The culture of all pronucleate embryos to the blastocyst stage and the selection of blastocysts ≧ grade 3BB (Gardner and Schoolcraft score), followed by vitrified-thawed blastocyst transfers with LZD (n = 60) or with PZD (n = 60)

Main outcome measure(s)

Complete hatching rates, implantation rates, pregnancy rates.

Result(s)

At 5 h after thawing, complete hatching rates of blastocysts were significantly higher in LZD group compared with PZD group, 52.4 % vs. 31.8 % (P = 0.001). Implantation and clinical pregnancy rates were significantly higher in LZD group compared with PZD group, 40.9 % vs. 25.7 % and 63.0 % vs. 40.0 %, respectively (P = 0.010, P = 0.011).

Conclusion(s)

LZD using ICSI pipettes for mechanical AH improves significantly complete hatching, implantation and pregnancy rates in vitrified-thawed blastocyst transfers.     

Localization of parathyroid hormone-related protein in the preimplantation mouse embryo is associated with events of blastocyst hatching

Purpose

To determine the pattern of expression of parathyroid hormone-related protein (PTHrP) and its receptor, parathyroid hormone receptor 1 (PTHR1), in mouse embryos in different stages of preimplantation development.

Methods

Embryos were cultured from the pronuclear zygote stage and harvested as 2-cell, 4-cell and 8-cell embryos, morulae and blastocysts. RT-PCR was carried out on mRNAs of these and of trophoblast outgrowths for detection of PTHrP and PTHR1. Whole mounted embryos intact or stripped of zonae pellucidae were immunofluorescently stained for PTHrP and PTH receptor and observed with confocal microscopy.

Results

PTHrP mRNA was present in the pronuclear zygote, not present in 2-cell, 4-cell and uncompacted 8-cell embryos, present in the 8-cell compacting embryo, and not detected in 16-cell morulae or blastocysts. The mRNA was present in trophoblasts growing on fibronectin beds. mRNA for PTHR1 was detected in the pronuclear zygote, then undetected until the compacted 8-cell stage and thereafter. PTH receptor protein was observed in 2-cell embryos, morulae and in the inner cell mass and trophectoderm of blastocysts. PTHrP was observed dispersed in the cytoplasm of 2-cell, 4-cell and uncompacted 8-cell embryos, and in distinct foci near the nuclei of morulae. In blastocysts, PTHrP appeared on the apical surface of only trophoblast cells which had extruded from the zona pellucida. Fully hatched blastocysts expressed the protein on the apical side of all trophoblasts. When morulae were prematurely stripped of their zonae, PTHrP was observed on the embryos’ outer surface.

Conclusions

PTHrP protein is expressed throughout early embryo development, and its receptor PTHR1 is expressed from the morula stage. Embryo hatching is associated with translocation of PTHrP to the apical plasma membrane of trophoblasts. PTHrP may thus have autocrine effects on the developing blastocyst.     

Effect of steroid and antibiotic treatment during assisted hatching on IVF outcomes

There are limited data on the use of steroids and antibiotics in assisted reproductive technology (ART). Our aim was to evaluate the impact of these treatments on the outcome of IVF cycles in which Assisted Hatching (AH) was performed. We studied a retrospective cohort in a large university-affiliated infertility centre. Data from 1126 AH cycles performed between 2007 and 2009 were reviewed. Cycles were categorized as “treatment” (n = 640) and “no treatment” (n = 486), depending on whether they received steroids and antibiotics. The primary outcome was live birth. Secondary outcomes included implantation, spontaneous abortion, biochemical, clinical and ectopic pregnancy. Logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (CI). OR were adjusted (AOR) for age, BMI, baseline FSH, peak estradiol, cycle number, number of oocytes retrieved, number of embryos that underwent AH, number of high-implantation potential embryos, number of embryos transferred and physician in charge. The AOR (95% CI) of live birth was 1.91 (1.08–3.38), of clinical pregnancy, 1.75 (1.08–2.83) and of biochemical pregnancy, 0.24 (0.07–0.85). Our study suggests that treatment with steroids and antibiotics during AH cycles significantly increases the odds of live birth.     

Developmental competence of mouse embryos following zona drilling using a non-contact holmium: yttrium scandian gallium garnet (Ho: YSGG) laser system

The purpose of this study was to assess the efficacy of theholmium: yttrium scandian gallium garnet (Ho:YSGG) laser, operatingin a pipette-free, non-contact mode, to assist hatching andsustain normal embryonic development. Two-cell mouse embryoswere recovered and assigned to laser-assisted hatching (LAH)treatment or control human tubal fluid (HTF) culture with orwithout serum (HTF-s, HTF-o) or with late serum supplementation(HTF-o/s). The basic experimental apparatus for LAH consistedof a stationary 2.1 µm Ho: YSGG laser beam directed througha mechanical shutter into an input port of a Zeiss Axiomat invertedmicroscope. Fewer (P < 0.05) embryos developed to the blastocyststage in the HTF-s group (81%) than in the LAH (90%), HTF-o(94%) and HTF-o/s (92%) groups. The level of hatching was significantlyincreased (P < 0.01) after the LAH treatment (57%) comparedto HTF-o/s (32%), HTF-s (18%) or HTF-o (5%). Implantation rateswere not significantly impaired following the LAH treatment(21%). These data demonstrate that LAH using the Ho: YSGG laseris a simple, accurate and effective procedure for assisted hatching.     

Assisted hatching of human embryos

There are benefits as well as drawbacks of zona pellucida breaching. Narrow gaps in the zona may cause disintegration of the hatching trophectoderm, when embryos are cultured in vitro. An increase in the formation of monozygotic twins following micromanipulation may also occur, due to the forced separation of the inner cell mass during blastocyst expulsion in utero. Mouse studies indicate that one or several narrow zona openings (<5 m) are detrimental. Such embryos may become trapped during hatching but may be rescued by drilling an additional larger gap elsewhere on the zona. The use of acidic Tyrode's solution for clinical assisted hatching of eight-cell embryos is currently under investigation. The findings suggest that large holes are efficient for promoting hatching (at least one-fourth of the embryos implanted thus far) and that embryos with unthinned zonae (those (with normally the poorest prognosis) benefit mostly from assisted hatching. Results also indicate that embryos with the best zona morphology should be replaced without micromanipulation.     

Optimizing tubal epithelial cell growth promotes mouse embryo hatching in coculture

Purpose: This study investigates the relationship between human tubal epithelial cell growth characteristics and mouse embryonic development to determine which cellular requirements should be preferentially provided in a coculture system. Methods: Cell growth and viability were assessed for 5 days in -minimal essential medium or human tubal fluid supplemented with 10% human serum or 10% synthetic serum. Two-cell mouse embryo development to blastocyst and hatching blastocyst stages was also assessed with or without coculture. Results: Both epithelial cell growth and embryo development were dependent on serum supplementation with better cell viability and growth rates in human serum and better blastocyst development in synthetic serum. The highest proportion of hatching blastocysts was found in -minimal essential medium and human serum with coculture. Conclusions: Culture conditions which improve tubal epithelial cell growth also improve the hatching rate of mouse embryos in coculture. This indicates that by meeting the metabolic and nutritional demands for epithelial cell growth, the beneficial effects of coculture on embryo development may be optimized.     

Infertility: Beneficial aspects of co-culture with assisted hatching when applied to multiple-failure in-vitro fertilization patients

A study was conducted on patients who had attempted and failedprevious in-vitro fertilization (IVF) procedures an averageof 3.8 times following the application of assisted hatchingwith conventional culture systems. The aim of this investigationwas to determine if addition of co-culture methodologies couldreduce embryonic abnormalities and thus improve the prognosisfor pregnancy. The study population consisted of 123 patients,subdivided into three patient categories. Previous IVF resultsfrom conventional culture were used to evaluate any potentialbenefits derived from the present co-culture application. Followingco-culture, the rate of blastomere development was increasedand the rate of fragmentation decreased. An increased rate ofblastomere development was most noticeable in the patients aged39 years with no male factor as well as the intracytoplasmicsperm injection (ICSI) subgroup. Similarly, the rate of fragmentationwas significantly reduced in the aforementioned subgroups. Themost pronounced impact of co-culture was on pregnancy and implantationrates. The overall clinical and ongoing pregnancy rates were38% (47/123) and 36% (44/123) respectively. The correspondingimplantation rate was 17% (72/412) as shown by embryonic cardiacactivity. The ongoing pregnancy rates in the 39 years no malefactor, 40 years no male factor and ICSI no age limit patientsubgroups were 41% (21/51), 30% (8/27) and 33% (15/45) respectively.The results indicate that addition of co-culture to the IVFprocedure for poor-prognosis patients may be advisable.