Developmental potential of vitrified mouse testicular tissue after ectopic transplantation

Objective: Cryopreservation of immature testicular tissue should be considered as an important factor for fertility preservation in young boys with cancer. The objective of this study is to investigate whether immature testicular tissue of mice can be successfully cryopreserved using a simple vitrification procedure to maintain testicular cell viability, proliferation, and differentiation capacity

Materials and Methods: In this experimental study, immature mice testicular tissue fragments [0.5-1 mm[2]] were vitrified-warmed in order to assess the effect of vitrification on testicular tissue cell viability. Trypan blue staining was used to evaluate developmental capacity. Vitrified tissue [n=42] and fresh [control, n=42] were ectopically transplanted into the same strain of mature mice [n=14] with normal immunity. After 4 weeks, the graft recovery rate was determined. Hematoxylin and eosin [H and E] staining was used to evaluate germ cell differentiation, immunohistochemistry staining by proliferating cell nuclear antigen [PCNA] antibody, and terminal deoxynucleotidyl transferase [TdT] dUTP Nick-End Labeling [TUNEL] assay for proliferation and apoptosis frequency

Results: Vitrification did not affect the percentage of cell viability. Vascular anastomoses was seen at the graft site. The recovery rate of the vitrified graft did not significantly differ with the fresh graft. In the vitrified graft, germ cell differentiation developed up to the secondary spermatocyte, which was similar to fresh tissue. Proliferation and apoptosis in the vitrified tissue was comparable to the fresh graft

Conclusion: Vitrification resulted in a success rates similar to fresh tissue [control] in maintaining testicular cell viability and tissue function. These data provided further evidence that vitrification could be considered an alternative for cryopreservation of immature testicular tissue

[Excitatory and inhibitory effects of nitric oxide on weight, size, and histological changes of rat cerebellum]

Nitric oxide [NO] is produced in different body organs in mammals and numerous physiological and pathological properties are attributed to this small molecule. The precursor of this substance in the body, L-arginine, is synthesized by the enzyme nitric oxide synthase [NOS], and it is catalyzed, and is inhibited by a substance called L-NG-nitroarginine methyl ester [L-NAME]. In this study we investigated the qualitative and quantitative effects of nitric oxide on cerebellar histopathology in vivo environment via increasing and decreasing its production. Forty Wister rats, weighing 200- 250 gr with a mean age of 8 weeks, were divided into 5 groups after making sure the rats were pregnant. Except the control group, the other pregnant groups, respectively received: 2 ml/kg normal saline, 200 mg/kg L-arginine, 20 mg/kg L-NAME and a mixture of the same doses of L-arginine and L-NAME on the third, fourth and fifth days of pregnancy. On day 18 of pregnancy, we anesthetized the rats, excised the cerebellum after craniotomy and fixed the organs in 10% formalin. We later prepared 5 to 6-micron in thickness tissue sections and dyed them by the routine Hematoxylin and eosin [HE] and Masson's Trichrom staining methods before studying them by light microscopy. There was a significant difference between the rats receiving L-arginine and the rats in other groups [P<0.01]. This study showed that L-NAME is capable of significantly decreasing the injury caused by nitric oxides in rat cerebellum