Anat Stein

Assisted hatching by partial zona dissection of human pre-embryos in patients with recurrent implantation failure after in vitro fertilization*

OBJECTIVE To examine the potential of the partial zona dissection technique to promote successful implantation by assisting embryo hatching after IVF. DESIGN The study and the control group included 72 and 82 patients, respectively, each had undergone at least three failed IVF-ET attempts. Assisted hatching was performed on four- to six-cell stage embryos by creating a slit in the zona pellucida using the partial zona dissection technique. After 90 minutes incubation (5% CO2, 37 degrees C), the embryos were transferred to the uterus. SETTING Infertility and IVF Unit of an academic tertiary referral medical center. RESULTS In the assisted hatching group, 230 micromanipulated embryos were replaced (3 or 4 treated embryos per patient) compared with 295 nonmanipulated embryos in the control group. Clinical pregnancy rates (PRs) were similar in the assisted hatching and control groups (n = 15; 20.8% and n = 12; 14.6%, respectively). However, the contribution of assisted hatching by partial zona dissection to successful implantation was related to the patientss age: patients older than 38 years showed a markedly higher PR after assisted hatching: 23.9% in the study group compared with only 7% of the controls. CONCLUSIONS These results demonstrate that assisted hatching by partial zona dissection is a quick and efficient method that does not induce any visible damage to the embryos replaced. In a selected group of patients (aged over 38 years, who have failed to conceive in at least three previous IVF attempts) it significantly increases the chances for pregnancy after ET.

Treatment variables in relation to oocyte maturation: lessons from a clinical micromanipulation-assisted in vitro fertilization program.

Objective: In an effort to understand the mechanism underlying the improved pregnancy rate observed in IVF cycles when gonadotropin-releasing hormone analogues (GnRH-a) are applied, we investigated a possible relationship between treatment variables and oocyte-nuclear maturity.Design: Nuclear maturity was retrospectively assessed in cumulus-free, denuded oocytes, obtained from women undergoing micromanipulation-assisted IVF treatment following controlled ovarian hyperstimulation with GnRH-a and menotropins.Setting: The setting was the infertility and IVF unit of a tertiary academic medical center.Participants: Two hundred twenty-one patients underwent 435 treatment cycles.Main Outcome Measure: This was the proportion of germinal vesicle-intact immature (GVII) oocytes.Results: One hundred fifty-four of the 3520 oocytes studied (4.4%) were in the GVII stage. These oocytes were found in 66 of the treatment cycles (15.2%) and in 54 of the patients (24.4%). Cycles in which GVII oocytes were detected did not differ from those in which all the aspirated oocytes were mature in the following respects: patient age, type and duration of infertility, controlled ovarian hyperstimulation protocol and time of ovum pickup. However, the GVII group was characterized by a significantly higher peak estradiol level, as well as a higher number of mature follicles visualized sonographically (diameter, >14 mm) and oocytes retrieved.Conclusions: Comparing the present findings with previously published data, it appears that the inclusion of GnRH-a in the stimulation regimen is associated with a lower proportion of immature oocytes. A higher occurrence of oocyte-nuclear immaturity is apparently associated with a significantly better ovarian response to stimulation. The high incidence of immature oocytes observed in patients with normospermic partners and low fertilization rates in previous cycles may suggest that the fertilization failure in some of these cases is due to oocyte, rather than sperm, dysfunction.

Successful use of the Cryolock device for cryopreservation of scarce human ejaculate and testicular spermatozoa

The existing methods for cryopreservation of very low count sperm samples are complex and sub‐optimal for individual spermatozoa. Our purpose is to establish an effective simple method for cryoprotecting individual spermatozoa. Samples from patients with OTA were mixed with TYB or HEPES‐buffered salt solution with glycerol + glucose and placed on a Cryolock that was plunged directly into liquid nitrogen or exposed to its vapors. Thawing was performed by direct immersion into a drop of warmed medium. The favorable method was tested on diluted samples (10–50 cells) and leftover TESE specimens from patients with azoospermia. Cryopreservation was considered successful if >30 spermatozoa, (>3 motile), or >5 spermatozoa (>1 motile) in diluted and TESE samples, were detected post‐thawing. A significantly higher survival rate of seminal spermatozoa was obtained when using the Cryolock with TYB and freezing with liquid nitrogen vapor, compared to HEPES glycerol‐glucose (95 vs. 35% respectively). Plunging the Cryolock into liquid nitrogen was detrimental. Cryolock combined with TYB cryoprotection and liquid nitrogen vapor freezing was highly effective for cryopreservation of individual spermatozoa in diluted and TESE samples. The Cryolock may serve for freezing very low‐count sperm samples and individual spermatozoa. This method offers simplicity, efficacy, use of available materials, without requiring micromanipulation equipment or skills.

Enhancement of bony in-growth to metal implants by combining controlled hydroxyapatite coating and heat treatment.

The rate of bony in-growth to heat-treated and controlled hydroxyapatite metal implants made of either titanium alloy (Ti-6Al-4V) or stainless steel (SS) 316L inserted to the medullar canal of the femur in rats was investigated. It was found that while partial coverage of hydroxyapatite (HA) did not cause a significant elevation of their bonding strength when compared with nonheated implants, HA, and heat treatment caused a significant (p < 0.01) elevation of 3.1-fold in the bonding strength of the implants to the host bone. A similar phenomenon to that found for the titanium alloy implants was found to be true for the SS implants as well. It is concluded that the novel approach presented in this article, that is, to heat treat implants as well as controlled partial coating of them by HA, prior to their insertion to host bone, produce an enhancement of bone growth to metal implants greater than utilization of each method alone. Our findings may be used to further enhance bony in-growth to metal implants in several clinical settings, producing avid implants with superior integration capabilities.

Paraoxonase 1 (PON1) attenuates sperm hyperactivity and spontaneous acrosome reaction

Sperm capacitation is essential for proper fertilization and is associated with increased sperm hyperactivity (HA) and acrosome reaction (AR). For successful fertilization, AR timing is critical; accordingly, early spontaneous AR may not facilitate fertilization. Paraoxonase 1 (PON1) possesses antioxidant properties which affect sperm capacitation. The association between PON1, semen parameters, and capacitation is not fully understood.

Effect of low-energy laser (He-Ne) irradiation on embryo implantation rate in the rat

Attempts to date to increase the rate of embryo implantation, for example by assisting embryo hatching from the zona pellucida, have failed. Recently, several studies have suggested the biostimulating effect of low power laser irradiation. The objective of this study was therefore to examine the potential of low power laser irradiation of the uterus to enhance embryo implantation rate in the rat. Rat potential of low power laser irradiation of the uterus to enhance embryo implantation rate in the rat. Rat blastocysts were flushed from the uterus on day 5 of gestation. They were transferred to the uteri of pseudopregnant recipients on day 4 or 5 of pseudopregnancy. One cornu of the recipient uterus was irradiated; the other was used as control. On day 5 of pregnancy, irradiation did not change implantation rate after 10 or 30 sec of irradiation while 120 sec. of irradiation significantly decreased embryonic implantation. On the other hand, on day 4 of pregnancy, 120 sec. of radiation allowed embryonic implantation to a level similar to that seen after synchronized transfer. Conclusion: He-Ne laser irradiation of the exposed rat uterus can attenuate embryo implantation rate.