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Iwayama H.,Yamashita Ladies Clinic
Zygote (Cambridge, England) | Year: 2011

This study was designed to investigate whether a non-invasive birefringence parameter, determined using the Oosight™ imaging system, is useful for estimating the hardness of human zona pellucida (ZP). The value for retardance (R) × thickness (T), but not R or T alone, of ZP was positively correlated (r = 0.92, p < 0.0001) with its hardness estimated by the time required for a 0.1% protease solution to solubilize ZP at 37 °C. In a model experiment to induce ZP puncture by Fluorinert™ fluid microinjection (sham-hatching), the R × T value at the punctured site was positively correlated (r = 0.78, p < 0.01) with the hardness of the ZP as estimated by the maximum expansion rate. The R × T values of ZP in in vitro fertilization-derived embryos (21.6 ± 7.5) and intracytoplasmic sperm injection-derived embryos (20.8 ± 6.3) were significantly higher than that in unfertilized metaphase II oocytes (16.6 ± 6.1; p < 0.05). The R × T value after in vitro hatching of viable blastocysts (10.8 ± 6.2) was significantly lower than that of unexpanded morulae and early blastocysts (19.0 ± 4.0; p < 0.05), while the value of expanding blastocysts (15.3 ± 4.1) was intermediate. In conclusion, hardness of human ZP can be estimated non-invasively by birefringence-based microscopic observation. Source


Iwayama H.,Yamashita Ladies Clinic | Hochi S.,Shinshu University | Yamashita M.,Yamashita Ladies Clinic
Journal of Mammalian Ova Research | Year: 2010

The fate of human oocytes with impaired stretchability of the oolemma during piezo-ICSI was investigated in vitro (development into blastocysts in 5-day culture) and in vivo (implantation 4 weeks after embryo transfer). Oolemma of metaphase-II human oocytes was penetrated either before application of a piezo-pulse at stretching of less than 75% of the diameter (category-Low), or by a piezo-pulse when the oolemma was stretched over 75% of the diameter (category-High). Following in vitro culture, oocyte survival and developmental capacity to the blastocyst stage were compared between the two categories of oolemma stretchability. Moreover, we investigated whether oolemma stretchability was independently related as a risk factor of implantation using multivariate logistic regression. The post-injection survival rate of category-Low oocytes (73.6%) was significantly (P < 0.01) lower than that of category-High oocytes (99.4%). The blastocyst yield of category-Low oocytes (36.7%; calculated from surviving oocytes) was similar to that of category-High oocytes (44.5%). The low oolemma stretchability was found to be an independent risk factor of implantation (odds ratio 4.18, 95% confidence interval 1.0416.74, P = 0.043). In conclusion, stretchability of human oolemma during piezo-ICSI affects post-injection survival, but not the developmental potential to blastocysts. Since oolemma stretchability also affects the implantation, we propose this parameter as a criterion for embryo selection in single embryo transfer. Source


Iwayama H.,Yamashita Ladies Clinic | Hochi S.,Shinshu University | Yamashita M.,Yamashita Ladies Clinic
Zygote | Year: 2010

SummaryThis study was designed to investigate whether a non-invasive birefringence parameter, determined using the Oosight™ imaging system, is useful for estimating the hardness of human zona pellucida (ZP). The value for retardance (R) × thickness (T), but not R or T alone, of ZP was positively correlated (r = 0.92, p < 0.0001) with its hardness estimated by the time required for a 0.1% protease solution to solubilize ZP at 37 °C. In a model experiment to induce ZP puncture by Fluorinert™ fluid microinjection (sham-hatching), the R × T value at the punctured site was positively correlated (r = 0.78, p < 0.01) with the hardness of the ZP as estimated by the maximum expansion rate. The R × T values of ZP in in vitro fertilization-derived embryos (21.6 ± 7.5) and intracytoplasmic sperm injection-derived embryos (20.8 ± 6.3) were significantly higher than that in unfertilized metaphase II oocytes (16.6 ± 6.1; p < 0.05). The R × T value after in vitro hatching of viable blastocysts (10.8 ± 6.2) was significantly lower than that of unexpanded morulae and early blastocysts (19.0 ± 4.0; p < 0.05), while the value of expanding blastocysts (15.3 ± 4.1) was intermediate. In conclusion, hardness of human ZP can be estimated non-invasively by birefringence-based microscopic observation. Source


Iwayama H.,Yamashita Ladies Clinic | Hochi S.,Shinshu University | Yamashita M.,Yamashita Ladies Clinic
Journal of Assisted Reproduction and Genetics | Year: 2011

Purpose: This study was designed to investigate whether artificial shrinkage, induced by a laser pulse or hyperosmotic sucrose solutions, improves in vitro survival and/or implantation of vitrified-warmed human expanded blastocysts. Methods: Before Cryotop vitrification, the blastocoelic cavity was collapsed either by a laser pulse or sucrose solutions. Non-treated blastocysts were used as control. Post-warm blastocyst survival and implantation after transfer were examined. Implantation rate outcome was retrospectively analyzed by morphological grading and developmental kinetics of post-warm blastocysts. Results: Survival rates in the three groups were high. Implantation rates in the laser-pulse group (59.7%) were comparable with those in the sucrose group (49.3%), and were significantly higher than those in the control group (34.2%). The proportion of blastocysts showing fast development tended to be higher when the blastocysts underwent artificial shrinkage treatment before vitrification. There was no clear correlation between morphology of post-warm blastocysts and implantation rate. Conclusion: Artificial shrinkage treatment before vitrification is associated with an increased probability of fast-developing embryos, resulting in higher implantation rates. © 2010 Springer Science+Business Media, LLC. Source


Ouji-Sageshima N.,Nara Medical University | Yuui K.,Nara Medical University | Nakanishi M.,Nara Medical University | Takeda N.,Fertility Clinic Tokyo | And 9 more authors.
Journal of Reproductive Immunology | Year: 2016

In the field of in vitro fertilization (IVF), useful markers for the prediction of successful implantation for oocyte or embryo selection are essential. It has been reported that sHLA-G (sHLA-G1/HLA-G5) could be detected in the supernatant of the fertilized embryo and in follicular fluid samples (FFs), and that the presence of sHLA-G was related to successful implantation. If sHLA-G could be used as a marker of oocyte selection from multiple FFs, oocytes could be selected without physical contact, thus reducing the likelihood of damage. To investigate the potential for sHLA-G as a marker of oocyte selection from multiple FFs in one patient, protein levels of total protein, sHLA-G, and sHLA-I (sHLA-A, B, and C) were examined in FFs. The variation among multiple FFs in total protein level and sHLA-G level was not related to successful pregnancy. The average sHLA-I levels did not differ in the successful implantation and unsuccessful implantation groups, indicating that sHLA-I levels were not related to successful pregnancy. Furthermore, sHLA-G in FFs was not detected by western blotting, despite being detected by ELISA, while sHLA-I was detected by both ELISA and western blot. These data suggest that sHLA-G in FF might not be a useful marker for oocyte selection as measurements of sHLA-G were inconsistent and there was no association with successful pregnancy. Further, more rigorously tested ELISA systems for detecting sHLA-G in body fluids are necessary before the utility of sHLA-G for diagnosis can be established. © 2015 Elsevier Ireland Ltd. Source

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