Five years experiences with microinjection of testicular spermatozoa into oocytes in Hungary.

The aim of the study was to summarize our five years experience (1996-2000) of testicular spermatozoa for intracytoplasmic sperm injection in Hungary. The influence of sperm count, maternal age, number of transferred embryos, and application of assisted hatching on outcome was investigated. Testicular spermatozoa were retrieved by microsurgical testicular sperm extraction. Samples were classified depending on the number of spermatozoa. Indication for testicular sperm extraction in conjunction with intracytoplasmic sperm injection was severe azoospermia or azoospermia combined with tubal origin infertility. Ovarian stimulation was carried out using an ultrashort protocol with GnRH agonist and gonadotrophin. Intracytoplasmic sperm injection was performed without PVP. Embryos were cultured for 48 or 72 h before embryo transfer. Indications for assisted hatching included elevated maternal age, increased zona thickness or at least two previous unsuccessful IVF cycles. Testicular spermatozoa were successfully retrieved in 218 out of 273 cases. Extreme low sperm count was found more frequently in cases of nonobstructive azoospermia. No significant differences were observed in fertilization rate (61.1% vs. 51.7%) or clinical pregnancy rate (29.0% vs. 26.7%) between patients with obstructive or nonobstructive azoospermia. Maternal age, number of transferred embryos and application of assisted hatching had a significant effect on outcome. A total of 55 clinical pregnancies were achieved, including 14 sets of twins, three sets of triplets and two sets of quadruplets. It is concluded that testicular sperm extraction is an efficient way of obtaining testicular spermatozoa, allowing not only successful fertilization by ICSI, but also freezing of testicular spermatozoa for use in subsequent cycles.

Formation of Rydberg atoms in an expanding ultracold neutral plasma.

We study the formation of Rydberg atoms in expanding plasmas at temperatures of 1-1000 K and densities from 10(5)-10(10) cm(-3). Up to 20% of the initially free charges recombine in about 100 micros, and the binding energy of the Rydberg atoms approximately equals the increase in the kinetic energy of the remaining free electrons. Three-body recombination is expected to dominate in this regime, yet most of our results are inconsistent with this mechanism.

Seasonal influences on in vitro fertilization and embryo transfer.

PURPOSE: The study was aimed to investigate the influence of time factors (day, week, month) on pregnancy rates and in vitro fertilization (IVF) and embryo transfer (ET) parameters. METHODS: 8,184 IVF-ET cycles, taking place in two IVF centers from 1992 to 1999, were analyzed. Multiple logistic and linear regression methods were performed as statistical analyses. RESULTS: Oocyte pickup on Tuesdays achieved a significantly higher mean number of oocytes (median: 7) and the highest pregnancy rate (PR) (33.4%) per ET There was a significant variation over the year, with the lowest PR/ET in July (25.71%) and the highest in December (35.5%). Concerning outcomes, the age factor and the number of embryos transferred had the highest significant (p < 0.0001) influence. CONCLUSIONS: The observed weekly rhythm for oocyte pick-ups is certainly due to preprogrammed ovarian stimulation used in our IVF programs. Age as well as the number of embryos transferred are the main influencing factors on a positive outcome and more predictive than seasonal aspects.

Plasma oscillations and expansion of an ultracold neutral plasma

We report the observation of plasma oscillations in an ultracold neutral plasma. With this collective mode we probe the electron density distribution and study the expansion of the plasma as a function of time. For classical plasma conditions, i.e., weak Coulomb coupling, the expansion is dominated by the pressure of the electron gas and is described by a hydrodynamic model. Discrepancies between the model and observations at low temperature and high density may be due to strong coupling of the electrons.

[Delivery following cryopreserved embryo transfer]. / Szülés mélyfagyasztva tárolt praeembriók beültetését követöen.

In this case report the authors describe the first delivery following cryopreserved preembryo transfer in Hungary. They concluded that this method may help to improve the cumulative pregnancy rate during in vitro fertilization cycles and alleviate the ethical problems associated with the destruction of viable preembryos.

Human serum and follicular fluid stimulate hyperactivation of human spermatozoa after preincubation.

OBJECTIVE: To test the effects of steroid-containing media such as follicular fluid (FF) and serum and of steroid-free but human protein-rich medium on hyperactivation (HA) of human spermatozoa with and without a preincubation period. DESIGN: Analysis of HA using a computer-aided sperm analysis system. SETTING: Academic hospital and andrologic laboratory. PATIENTS: Twenty-six sperm samples were obtained from 26 different IVF patients. INTERVENTIONS: None. RESULTS: After a preincubation period of 3 hours, FF and serum enhanced the HA after 1 hour. A human plasma protein-rich solution did not. Without preincubation, no stimulation of HA was observed. CONCLUSION: Steroids may be involved in HA, and a preincubation period may be required for an appropriate FF-induced HA.