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Since the advent of intracytoplasmic sperm injection (ICSI) in the early 1990s, surgical techniques to recover samples from the epididymis and testis directly have been used to benefit patients suffering from obstructive and nonobstructive azoospermia. Various studies have demonstrated comparable fertilization, ongoing pregnancy, and implantation rates when fresh and frozen-thawed epididymal sperms were used for ICSI [1]. Injection of fresh and frozen testicular sperms into mature oocytes resulted in similar fertilization rates in cases of obstructive azoospermia. However, in cases of nonobstructive azoospermia, the outcome depends upon the degree of impairment of spermatogenesis, criteria for sperm freezing, and patient selection [2].

With absolute normal semen analysis parameters it may not be necessary to shift to specialized tests early but in cases with borderline parameters or with history of fertilization failure in past it becomes necessary to do a battery of tests to evaluate different parameters of spermatozoa. Various sperm function tests are proposed and endorsed by different researchers in addition to the routine evaluation of fertility. These tests detect function of a certain part of spermatozoon and give insight on the events in fertilization of the oocyte. The sperms need to get nutrition from the seminal plasma in the form of fructose and citrate (this can be assessed by fructose qualitative and quantitative estimation, citrate estimation). They should be protected from the bad effects of pus cells and reactive oxygen species (ROS) (leukocyte detection test, ROS estimation). Their number should be in sufficient in terms of (count), structure normal to be able to fertilize eggs (semen morphology). Sperms should have intact and functioning membrane to survive harsh environment of vagina and uterine fluids (vitality and hypo-osmotic swelling test), should have good mitochondrial function to be able to provide energy (mitochondrial activity index test). They should also have satisfactory acrosome function to be able to burrow a hole in zona pellucida (acrosome intactness test, zona penetration test). Finally, they should have properly packed DNA in the nucleus to be able to transfer the male genes (nuclear chromatic decondensation test) to the oocyte during fertilization. [ABSTRACT FROM AUTHOR]

Background Cryopreservation of spermatozoa is a widely used technique to preserve the fertility of males. It can also benefit the armed forces personnel who are to be sent for long recruitments, while leaving their families behind. This study, apart from studying the effects of freezing and thawing, reveals the effect of the post thaw interval on the motility of the human spermatozoa and thus widens the insemination window period. Methods A detailed semen analysis was carried out as per the WHO guidelines for 25 samples. The samples were then washed, analysed and frozen in liquid nitrogen. The semen samples were subsequently thawed and similarly analysed after 20 min and 40 min of thawing. This was then followed by statistical analysis of the comparative motilities. Results Motility of sperms is found to decrease after cryopreservation. However, the study revealed that after thawing a significant increase in the motility of the sperms was noted with the progression of time ( p < 0.05). Conclusion By simulating conditions similar to the in vivo conditions for the post thaw semen samples, we can safely wait, confirm the parameters like motility and count, and then inseminate the samples instead of blindly inseminating them immediately after thawing. [ABSTRACT FROM AUTHOR]

Background: Human egg is enveloped by a glycoproteinaceous matrix, zona pellucida (ZP), responsible for binding of the human spermatozoa to the egg and induction of acrosomal exocytosis in the spermatozoon bound to ZP. In the present manuscript, attempts have been made to delineate the downstream signalling components employed by human ZP to induce acrosome reaction. Methods: Heat-solubilized human ZP (SIZP) was used to study the induction of acrosome reaction in capacitated human spermatozoa using tetramethylrhodamine isothiocyanate conjugated Pisum sativum agglutinin (TRITC-PSA) in absence or presence of various pharmacological inhibitors. In addition, intracellular calcium ([Ca2+]i) levels in sperm using Fluo-3 acetoxymethyl ester as fluorescent probe were also estimated in response to SIZP. Results: SIZP induces acrosomal exocytosis in capacitated human sperm in a dose dependent manner accompanied by an increase in [Ca2+]i. Human SIZP mediated induction of acrosome reaction depends on extracellular Ca2+ and involves activation of Gi protein-coupled receptor, tyrosine kinase, protein kinases A & C and phosphoinositide 3 (PI3)- kinase. In addition, T-type voltage operated calcium channels and GABA-A receptor associated chloride (Cl-) channels play an important role in SIZP mediated induction of acrosome reaction. Conclusions: Results described in the present study provide a comprehensive account of the various downstream signalling components associated with human ZP mediated acrosome reaction. [ABSTRACT FROM AUTHOR]