ABSTRACT
Aim: The effect of acetylsalicylic acid (ASA) on thiol levels was studied in a rat model of azaserine carcinogenesis. Materials and Methods: ASA and azaserine were applied to the animals to research changes in cellular sulfhydryl (–SH) content and variations in free and protein-bound molecules containing the –SH group. Such effects in rats injected with azaserine were investigated at low (200 ppm) and high (400 ppm) concentrations of ASA over a relatively short (6 months) and a relatively long (12 months) period. Results: Changes in the hepatic, pancreatic, and renal –SH contents were also determined. Conclusion: Compared to the other tissues studied, the liver contained the highest levels of both free and protein-bound –SH
ABSTRACT
Objective To study the safety and effect of the umbilical cord blood(UCB)-derived mesenchymal stem cells(MSCs)on apoptosis of human cardiomyocytes(HCM). MethodsUCB was collected at the time of delivery with informed consent obtained from 10donors.The UCB-derived MSCs were treated with 5-azaserube(5-AZA)and were further induced to differentiate into cardiomyocytes.Telomerase activity,G-banding patterns of chromosomal karyotypes,tumor formation in nude mice,RT-PCR,and the effect of inhibiting apoptosis of HCM were investigated. ResultsMSCs derived from UCB were differentiated into cardiomyocytes in vitro,which possessed telomerase activity after 5-AZA induction,and no abnormal chromosomal karyotypes were observed.Expression of p53,cyclin A,cdk2,β-actin,C-fos,h-TERT and c-myc were similar in MSCs before and after 5-AZA treatment.There was no tumor formation in nude mice after injection of UCB-derived MSCs.UCB-derived MSCs significantly inhibited apoptosis of HCM. ConclusionUCB-derived MSCs are a valuable,safe and effective source of cell-transplantation treatment.
ABSTRACT
Objective: To set up the animal model of precancerous lesion of rats' pancreatic acinar cellular cancer,and to learn estrogen's effect on this lesion's biological feature and K-ras gene mutation. Methods: male Wistar rats were injected Azaser-ine 30mg/kg(ip). Some rats received Estradiol-17 P Valerate(0.18mg/100g/2weeks, im) .4 months later, rats'pancreas were autopsied and K-ras gene mutation were detected by PCR-SSCP method. Results : The incidence of AACN were very high. The incidence of K-ras gene mutation was 42.1% in rats without estrogen and 25.6% with estrogen. Conclusion: Azaserine could induce precancerous lesion of rats' pancreatic acinar cancer successfully, K-ras gene mutation was early change during this process Estrogen could inhibit this precancerous lesion's happen and development to some degree.