In this study ,a wild type Salmonella typhimurium (S .typhimurium) strain was isolated and identified in Hong Kong (S129) ,then the asdA gene was knocked out and replaced with kanamycin resistant gene in a Salmonella typhi-murium strain S129 using the λ RED-mediated recombination method .The constructed mutant asdAΔS129 was validated by culturing in the presence or absence of 2 ,6-diaminopimelic acid (DAP) growth in vitro and evaluating its virulence in BALB/c mice challenge assay .Therefore ,this study has demonstrated that an asdA mutant Salmonella typhimurium has been success-fully constructed .

OBJECTIVE: To evaluate the association between single nucleotide polymorphisms of calcium/calmodulin-dependent kinase 4 (CAMK4) and the therapeutic effect of amlodipine in essential hypertensive patients in Chinese Han nationality.
 METHODS: A total of 108 mild-to-moderate essential hypertension patients in Chinese Han nationality were treated with amlodipine for 8 weeks at a dosage of 5 mg/d. Polymerase chain reaction-restriction fragment length polymorphism was performed to detect the genotypes (rs10491334). Blood pressure was measured and analyzed.
 RESULTS: The result of rs10491334 polymorphism of CAMK4 was consistent with Hardy-Weinberg equilibrium distribution and the frequencies of C allele and T allele were 88.89% and 11.11%, respectively. The systolic blood pressure and diastolic blood pressure before amlodipine treatment were not statistically different among different genotype carriers (P>0.05). The blood pressure was significantly reduced in all patients after amlodipine treatment (P<0.05). Systolic blood pressure was significantly decreased in patients with rs10491334 CC genotype and CT genotype compared with those patients with rs10491334 TT genotype. Total effective rates of CT and TT carriers were higher than those of the CC genotype carriers (P<0.01).
 CONCLUSION The CAMK4 gene polymorphism might be associated with the efficacy of calcium channel blocker in treating mild-to-moderate essential hypertension patients.
Alleles ; Amlodipine ; Asian Continental Ancestry Group ; Blood Pressure ; Calcium-Calmodulin-Dependent Protein Kinase Type 4 ; Calmodulin ; Essential Hypertension ; Ethnic Groups ; Gene Frequency ; Genotype ; Humans ; Hypertension ; Polymerase Chain Reaction ; Polymorphism, Single Nucleotide