Dynamic analysis based on the relapse rate of drug epidemic model

In this paper,we study a drug epidemic model based on epidemiology by dividing thehuman population into four classes at time t:susceptibles(S),drug users(1),drugusers who are treated in isolation and temporarily quit drugs(Q_(T))and drug users whoare treated in isolation and permanently quit drugs(Qp).We obtain the basic repro-duction number Ro of the model and perform its sensitivity analysis.We show that if R_(0)<β1A/μ(μ+δ1)<1,then the drug-free equilibrium is globally asymptotically stable,and if R_(0)>1,there exists an drug-abuse equilibrium and it is locally asymptoticallystable.The proposed model may possess forward and backward bifurcations.Moreover,three different control strategies and numerical results are presented.Through differentadjustments to obtain graphical results,we obtain the best strategy to control the drugepidemic.

Efficacy of early treatment with infliximab in pediatric Crohn’s disease

AIM: To investigate the effectiveness of early infliximab use for induction and maintenance therapy in pediatric Crohn’s disease. METHODS: We performed a retrospective chart review of 36 patients with Crohn’s disease. Ten patients (group A) were treated with mesalamine after induction therapy with oral prednisolone, and 13 patients (group B) were treated with azathioprine after induction therapy with oral prednisolone. Thirteen patients (group C) received infliximab and azathioprine for induction and maintenance therapy for the first year, and were treated with azathioprine after 1 year. All patients were followed for at least 24 mo. Efficacy was determined by the relapse rate using the pediatric Crohn’s disease activity index score in each group at 12 and 24 mo. RESULTS: At the 1 year follow-up, the relapse ratee, Mi Jin Kim, Hae Jeong Lee, Yon Ho Choe (23.1%, 3 of 13 patients) in group C was lower than that (61.5%, 8 of 13 patients) in group B (P = 0.047). At the 2 years follow-up, the relapse rate (38.5%, 5 of 13 patients) in group C was lower than that (76.9%, 10 of 13 patients) in group B (P = 0.047). Adverse events in group C were fewer than in groups A and B. CONCLUSION: Early induction with infliximab at diagnosis, known as "top-down" therapy, was effective for reducing the relapse rate compared to conventional therapies for at least 2 years.