Tehran University Medical Journal

Background: Hepatitis B vaccination has been included in routine immunization of all individuals according to WHO recommendations since 1991. Despite successful coverage, 3-5% of recipients fail to mount a desirable protection level of Ab. Vaccine failure results from: emergence of mutation, immune failure of individuals, decrease in vaccine potency, and etc. The quality of Hepatitis B vaccine should be evaluated by a reliable method.

Methods: The amount of vaccine antigen was measured through the in vitro assay of Hepatitis B vaccines which consists of multiple dilutions of the reference material and samples. The preparations were evaluated by Elisa to determine the amount of HBsAg. The data were analyzed by parallel-line analysis software. The in vivo assay was performed by inoculating multiple doses of the reference and sample preparations in Balb/c mice. A control group was also inoculated with vaccine matrix. Four weeks later, the mice sera were evaluated to determine the presence of antibodies against Hepatitis B by Elisa method. The data were analyzed by Probit analysis software.

Results: Both methods were set up in our laboratory by which different batches of Hepatitis B vaccine were evaluated. It was observed that In vivo and In vitro methods provide comparable results. Therefore we can use the in vitro method for routine testing of HB vaccine quality control.
Conclusion: In vitro method can be used in place of In vivo method because of its time and cost-effectiveness. Moreover, since no animals are used in in vitro method, it complies well with the 3R concept (Reduction, Refinement, and Replacement of animal testing) and the current tendency to use alternative method.

Background: Recently, the role of inflammation and oxidative stress in the pathophysiology of atrial fibrillation (AF) after cardiac surgery has been emphasized. Vitamin C as an antioxidant important role in reducing the incidence of postoperative atrial fibrillation. This study aimed to investigate, administration of vitamin C, as a way to reduce the incidence of atrial fibrillation after coronary bypass surgery.

Methods: In this double-blind clinical study, 290 patients in Rajaee Heart Center, from March 2013 to December 2014 who underwent coronary artery bypass surgery were randomly divided into intervention and control groups to receive vitamin C and placebo. The intervention group before the surgery in the operating room received 2 grams of vitamin C intravenously then one gram per day for four days prior to surgery. After the operation, the two groups were compared in terms of the following: Atrial and ventricular arrhythmias after surgery, ICU stay and hospital stay and duration of intubation.

Results: 113 cases and 177 controls (191 men and 99 women) with a mean age of 55.40±14.40 years in both groups (vitamin C and placebo) were enrolled. The incidence of postoperative atrial fibrillation was 55% in the placebo group to 35% in the vitamin C group decreased (P= 0.001). Duration of intubation in the intervention group 11.8 and the control group was 14.14 hours (P= 0.004). The amount of drainage was lower in vitamin C group (P= 0.003). Vitamin C had no effect on the rates of hospital and ICU stay (P= 0.075). There was no significant reduction in threatening arrhythmia (VT) and VF in this period (P= 0.159).

Conclusion: Vitamin C supplements may reduce atrial fibrillation after coronary artery bypass surgery also can improve conditions such as reducing the duration of intubation. With regard to the safety, these supplements can be recommended for the prevention of atrial fibrillation before coronary artery bypass surgery.