Mostafa M. El-Naggar

Isolated pancreatic islets of the rat: an ultrastructural study.

Pancreatic islets from adult Wistar rats were isolated by an improved collagenase digestion technique. Examination of the preparations showed that they contained B cells possessing secretory granules, each having an eccentric electron-dense core surrounded by an electron-lucent halo; the Golgi bodies with their characteristic features were located in a juxtanuclear position. Roughly surfaced endoplasmic reticulum and mitochondria were present and were mostly normal in appearance. The cell possessed all the ultrastructural attributes indicating that they were fully functional and structurally intact.

Using the balance between proliferation and apoptosis to assess the cryopreservation and thawing protocol in mouse 4-cell embryos

Aims: the criteria used to assess the optimal conditions for cryopreservation of the embryos in the in vitro fertilization (IVF) protocols are still a matter of discussion. this study aimed at evaluating the use of cell proliferation and apoptosis to assess the optimal conditions for cryopreservation/thawing of the 4-cell embryos. Methods: Fertilized ova were collected from mated female MF1 mice 24 hours after hcG injection. they were cultured in KsOM medium and kept in cO2 incubator at 37°c and 5% cO2 up to the stage of the 4-cells. two methods of cryopreservation were used; the step-rate and the ultra-rapid vitrification. slow and fast thawing was done. slides were prepared from samples of the embryos, and stained immunohistochemically for proliferative and apoptotic cells. the proliferative capacity was measured by labeling with bromodeoxyuridine (brdU) and the apoptotic ability was measured with tUNEL technique. results: Vitrification with fast thawing of the 4-cell embryos gave Mostafa M. El-Naggar1, Hassan Nasrat2, Hassan Jamal2, Samar Al-Saggaf3, Mohamed H. Badawod3 Affiliations: 1Professor, Department of Anatomy, Faculty of Medicine, Jazan University, Jazan, Saudi Arabia; 2Professor, Department of Obstetrics and Gynecology, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia; 3Professor, Department of Anatomy, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia. Corresponding Author: Dr. Mostafa M. El-Naggar, Faculty of Medicine, Jazan University, P.O. Box 114, Jazan, Kingdom of Saudi Arabia; Ph:+ (966) 506570529; Email: mmnaggar@hotmail.com Received: 26 February 2015 Accepted: 23 April 2015 Published: 25 May 2015 better morphology, higher proliferative capacity, and lower apoptotic ability. Following step-rate cryopreservation with slow or fast thawing, cell labeling index for brdU was 0% and 17%, respectively and was 66% and 83%, respectively following vitrification. the incidence of apoptosis following step rate cryopreservation with slow or fast thawing was 96% and 89%, respectively and was 42% and 13%, respectively following vitrification. conclusion: It is concluded that cell proliferation and apoptosis could be used to assess the cryopreservation/thawing protocol for early embryos.

Effect of the Developmental Stage and Thawing Temperature on the Survival and Development of the Vitrified Embryos

Abstract Objectives The best developmental stage and the best thawing protocol suitable for cryopreservation of the early embryos are not well documented. The present study aimed at evaluating the effect of the ultra rapid cryopreservation (vitrification) technique, followed by slow or fast thawing protocol, on the fertilized ova, 4-cell embryos and morula. Methods The vitrification method included equilibrating the ova in the vitrification solution (EFS40; consisted of 40% ethylene glycol, 30% Ficoll, 0.5 M sucrose in D-PBS) for 2 minutes before immersion in liquid nitrogen. Slow and fast thawing were done and the cryoprotectants were withdrawn by a hyperosmolar sucrose solution, which was then gradually diluted and replaced by culture medium. Results The best results were obtained with vitrification of the 4-cell embryos both with slow and fast thawing, which gave survival rate of 86% and 94%, and in vitro development rate of 74% and 80%, respectively. Fast thawing showed better survival rates (80%, 94%, 77%) and better in vitro development rates (60%, 80%, 63%) than those of slow thawing, following vitrification of the fertilized ova, 4-cell embryos and morula, respectively. Conclusion These criteria of vitrification/ thawing could be inferred to the human 4-cell embryos in the IVF protocol.