Ali Nabi

Vitrification is not superior to rapid freezing of normozoospermic spermatozoa: effects on sperm parameters, DNA fragmentation and hyaluronan binding.

Human sperm vitrification is a new cryopreservation method. This study compared the effects of rapid freezing and vitrification on various sperm parameters, hyaluronan-binding assay and DNA fragmentation and assessed the impact of cryoprotectant agents (CPA) with vitrification. A total of 30 normo-ejaculates were prepared by swim up and the motile sperm fraction was divided into four: fresh (control), rapid freezing, and two vitrification groups (a, lacking CPA; b, with CPA). For rapid freezing, a cryovial of sperm suspension was held just above the liquid nitrogen surface, and for vitrification, 30μl suspension was dropped directly into liquid nitrogen. Sperm parameters, including motility, viability and morphology, declined after cryopreservation in both groups. DNA fragmentation was not significantly higher in the vitrification (15.7±4.4%) or rapid freezing (16.6±5.6%) groups when compared with controls (11.6±4.5%). The rates of hyaluronan binding were similar between the control and cryopreserved groups. Moreover, addition of CPA for vitrification had a neutral effect on rates of sperm recovery. In conclusion, vitrification has great potential for human sperm cryopreservation and does not require CPA, with its possible toxicity. However, it is not superior to rapid cryopreservation regarding sperm recovery rate in normozoospermia. Human sperm vitrification is a new cryopreservation method that has been introduced recently. This study compared the effects of rapid freezing with vitrification on rates of sperm parameters, hyaluronan-binding assay and DNA fragmentation after thawing/warming and assessed the impact of cryoprotectant agent (CPA) on vitrification. The study was performed on 30 ejaculates prepared using the swim-up technique. Each motile sperm suspension was divided into four: control (fresh); rapid freezing; and two vitrification groups (a, lacking CPA; b, with CPA). For rapid freezing, a cryovial of sperm suspension was held above the surface of liquid nitrogen. For vitrification, 30μl sperm suspension was dropped into liquid nitrogen directly. The rates of progressive motility (86.6±5.9%) and viability (95.8±3.9%) in controls declined significantly, to 40.0±13.0% and 63.2±7.7% for rapid freezing and 41.9±10.3% and 64.4±10.0% for vitrification, respectively. Normal sperm morphology was also significantly decreased after cryopreservation in all groups. DNA fragmentation was higher with rapid freezing compared with fresh controls (16.6±5.6% vs. 11.6±4.5%, P=0.01), but DNA fragmentation did not increase significantly in vitrified samples (15.7±4.4%). The rates of hyaluronan binding were similar between the control and cryopreserved groups. Moreover, addition of CPA for vitrification had a neutral effect on rates of sperm recovery. In conclusion, vitrification has great potential for human sperm cryopreservation and does not require CPA, with its possible toxicity. However, it is not superior to rapid cryopreservation regarding sperm recovery rate in normozoospermia.

Intravenous transplantation of bone marrow mesenchymal stem cells promotes neural regeneration after traumatic brain injury.

To investigate the supplement of lost nerve cells in rats with traumatic brain injury by intravenous administration of allogenic bone marrow mesenchymal stem cells, this study established a Wistar rat model of traumatic brain injury by weight drop impact acceleration method and administered 3 × 106 rat bone marrow mesenchymal stem cells via the lateral tail vein. At 14 days after cell transplantation, bone marrow mesenchymal stem cells differentiated into neurons and astrocytes in injured rat cerebral cortex and rat neurological function was improved significantly. These findings suggest that intravenously administered bone marrow mesenchymal stem cells can promote nerve cell regeneration in injured cerebral cortex, which supplement the lost nerve cells.

The quality of sperm preparation medium affects the motility, viability, and DNA integrity of human spermatozoa

Aim: The goal was to compare the effects of three different sperm preparation media on sperm motility, viability, and DNA integrity of semen samples from normozoospermic men. Methods: A total of 15 normozoospermic males were included in the study. The semen analysis (SA) was performed in accordance with the WHO guidelines (2010). After SA, each sample was divided into three aliquots, and swim-up was performed with three different sperm preparation media (Sperm Preparation Media, Origio, Denmark; Ham′s F10, Biochrome, Berlin, Germany; and VitaSperm TM , Innovative Biotech, Iran). Sperm motility, viability, and DNA fragmentation were evaluated at 0, 1, 2, and 24 h after swim-up. Results: There were no significant differences, at any time intervals, in the total sperm motility between the different sperm preparation media. However, the rate of progressive motility was significantly higher in spermatozoa prepared using the media from Origio in comparison with VitaSperm TM (P = 0.03), whereas no significant difference was found against Ham′s F10 medium. No significant differences in sperm viability were seen between the media products. However, 1 h after swim-up, the extent of sperm DNA fragmentation was lower in the medium from Origio versus VitaSperm TM (P = 0.02). Conclusions: The data showed that the quality of medium for preparation of semen samples from normozoospermic men significantly affects the performance of spermatozoa in assisted conception programs.

Evaluating the spermicidal activity of an antimicrobial peptide from the Bufo kavirensis, MaximinBk: in vitro study

Abstract Objective: The aim of this study was to evaluate the spermicidal activity of this peptide to introduce a new potent agent for prevention of sexually transmitted infections and unplanned pregnancies. Methods: The purified MaximinBk (with amino acid sequence: ILGPVLGLVGRLAGGLIKRE) was diluted with Ham’s F10 solution in 100, 200, 400, 600, 800 and 900 μg/mL. One milliliter from peptide solution with different dosage was mixed with 200 μL prepared sperm solution in microtube. Sperm motility, viability and morphology were assessed at different time intervals (0.3, 5, 10, 15 min). Eosin–Nigrosin staining and Giemsa staining methods were applied for sperm viability and morphology detection, respectively. Results: Total spermicidal activity was shown after addition of 900 μg/mL for 0.3 min without any morphological change in the sperm head, midpiece or tail. Also, Eosin–Nigrosin staining indicated MaximinBk can disturb membrane integrity of normal sperm that is in dose-dependent manner. Conclusion: MaximinBk has spermicidal activity in addition to antimicrobial activities (especially on vaginal infections such as candidal vulvovaginitis). It seems this peptide might be a potential candidate in order to use in male contraception, although, this preliminary study needs more studies to elucidate final conclusion.

Effects of in-vitro application of pentoxifylline on the morphology of human spermatozoa after vitrification in asthenozoospermic patients

Cryopreservation of human spermatozoa is widely used in many assisted reproduction units to preserve male fertility [1]. Vitrification is based on the ultrarapid freezing and is routinely assayed for cryopreservation in assisted reproductive technology. Mohamed [2] showed that cryopreservation significantly affects progressive motility, viability and mitochondrial membrane potential of spermatozoa. Pentoxifylline (PX) is a phosphodiesterase considered to be a sperm movement enhancer, hyperactivation agent, inhibitor of reactive oxygen species and acrosome reaction-improving agent. The aim of our study was to evaluate the effect of in-vitro application of PX on sperm parameters and ultrastructure after vitrification. A total of 30 asthenozoospermic semen samples were selected and divided into two groups after vitrification: control (without PX) and experimental (with PX). A significant decrease in sperm motility, morphology and viability was observed post vitrification, but sperm motility was increased significantly following application of PX. On the other hand, PX did not exert any significant effect on the ultrastructure of the acrosome, plasma membrane and tail of vitrified spermatozoa.