ABSTRACT
Abstract This study aimed to assess the feasibility of comet and cytogenetic tests as tools for evaluating genomic instability in seeds of Oryza sativa L. (rice) and Phaseolus vulgaris (beans) L. from gene banks. Rice and beans were exposed to methyl methanesulfonate (MMS) as a reference DNA damaging agent. Seeds of two accessions of rice and beans were obtained from Embrapa Rice and Beans - Brazil. Seed groups were imbibed in three concentrations of MMS for three periods of time to carry out cytogenetic tests, and for one period for the comet test. At concentrations of 10 and 15 mg/L, MMS induced cytotoxic and/or mutagenic effects in the meristematic cells of roots from all the accessions of both species. In the comet test, MMS induced genotoxic effects at all the concentrations in the evaluated accessions of rice and beans, except in one accession of beans at the lowest concentration (5 mg/L). Both species showed sensitivity to MMS. The comet test can be proposed for the measurement of genomic instability in accessions of rice and beans in gene banks, as being more sensitive than the cytogenetic tests used.
ABSTRACT
OBJECTIVE:To establish a method for determination the genotoxicity impurities (methyl methanesulfonate,ethyl methanesulfonate and isopropyl methanesulfonate) in mesylate nafamostat raw materia. METHODS:GC-MS was conducted,and the genotoxicity impurities were extracted by dichloromethane. The column was DB-5 capillary column by programmed tempera-ture,the inlet temperature was 240 ℃,column flow was 3.0 ml/min,purge flow was 6.0 ml/min,sample mode splitless injection, carrier gas was high purity helium,detector is a mass spectrometer detector,ion source temperature was 230 ℃,the interface tem-perature was 230 ℃,the delay time of solvent was 2.5 min,ionization mode was electron impact,detector voltage was respect to the tuning results,scanning(detection)method was selective ion monitoring,electron energy was 70 eV,and the injection volume was 1.0μl. RESULTS:The separation degree of 3 impurities were greater than 2.0;the linear range of 3 impurities were 0.10-20μg/ml (r≥0.999 5);RSDs of precision,stability and reproducibility tests were lower than 2%;recoveries were 97.7%-104.8%(RSD=2.8%, n=9),102.5%-110.7%(RSD=2.6%,n=9)and 103.0%-107.6%(RSD=1.6%,n=9). CONCLUSIONS:The method is simple, accurate,sensitive and rapid,and can be used for the genotoxicity impurities in mesylate nafamostat raw materia.
ABSTRACT
Objective To explore the possible effects of methyl methanesulfonate sensitive 2(MMS2)in the process of angiotensin Ⅱ inducing differentiation of neural stem cells (NSCs) into dopaminegic phenotype neurons. Methods NSCs were isolated from the brain of newborn rats and were cultured in the serum-free medium.Identification of neural precursor cells was done by Nestin immunocyt ochemical staining. Then the second generation of NSCs was divided into the following six groups: A, control; B, AⅡ; C, AT1 antagonist ZD7155; D, ZD7155+AⅡ; E, AT2 antagonist PD123319; F, PD123319+AⅡ. The detection of expression of MMS2 and TH mRNA level was done by real-time PCR. The silence of the expression of MMS2 in NSCs was brought about via the transfection of MMS2-siRNA, and then the NSCs were induced to differentiate into dopaminegic neurons. The expression of TH mRNA level in the cells of the groups after transfection was detected by real-time PCR. Results Nestin-positive cells were observed in suspended growth in the medium.Real-Time PCR revealed that the MMS2 and TH mRNA expression of group B and D were significantly higher than that of the control group(P<0.05), There was no significant difference in MMS2 and TH mRNA expression between group C, E, F and the control, respectively. Conclusion AⅡ increased the expression of MMS2 mRNA in NSCs and induced the differentiation of NSCs into DA neurons via AT2 recepter. MMS2 may play important roles in the process of angiotensin Ⅱ inducing NSCs to differentiate into dopaminergic neurons.
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55 population doubling, PD) were compared with those of the young cells(