ABSTRACT
       Background and Objectives: Hippocampus is the main structure involved in spatial learning and memory consolidation. Formation of spatial memory can be strongly influenced by medications, hormones and different substances. Due to importance of new pharmacotherapy on drug administration in pregnancy, the aim of this study was to investigate the effect of letrozole-therapy during pregnancy on memory and learning in offspring rats.
       Methods: In this study, 24 pregnant rats were divided into a control and three experimental groups (N=6). The subjects received low dose (0.25 mg/Kg), average dose (0.5 mg/Kg) and high dose (1 mg/Kg) of letrozole orally during 16-19 days of gestation. After maturating, learning and memory of the offspring were assessed by passive avoidance learning apparatus. Data were analyzed by SPSS 20 using one-way analysis of variance and the Tukey's test. P-values less than 0.05 were considered statistically significant.
         Results: Weights of the offspring who received letrozole decreased significantly compared with the control. There was no significant difference in the step-through latency between the experimental groups. However, the step-through latency and time spent in the dark compartment decreased significantly in the experimental groups compared with control group (P<0.05).
          Conclusion: The results of this study show that letrozole can influence learning and memory of offspring rats.
          Keywords: Letrozole, Gestation, Memory, Learning, Offspring, Rats.

ABSTRACT
              Background and Objectives: Current medications used for the treatment of burn wounds have some side effects and disadvantages. Oral or topical administration of probiotic bacteria is thought to be useful for treatment of skin disorders. The aim of this study was to evaluate effects of spray-dried Streptococcus thermophilus on healing of second-degree burn wounds.
              Methods: After induction of second-degree burn on back of 80 male Wistar rats, the animals were randomly allocated to negative control (no treatment), first vehicle control (treatment with Eucerin), second vehicle control (treatment with skim milk) and experimental (treatment with bacterial ointment) groups. Wound healing rate (percent) and histopathological parameters of wound samples were evaluated on post-burn days 1, 3, 7 and 14.
              Results: On days 3 and 7, macroscopic results showed that the healing rate was significantly higher in the experimental group compared to the control groups. Histopathological analysis of wound samples showed increased fibroblastic migration, collagen formation and re-epithelialization in the wounds treated with probiotic bacteria compared with the wounds of control groups.
              Conclusion: Our results indicate that the topical use of spray-dried S. thermophilus could be useful for the treatment of burn wounds.
              Keywords: Streptococcus thermophilus; Probiotics; Burns; Wound Healing; Rats.