Long-term efficacy of infliximab maintenance therapy for perianal Crohn’s disease

AIM:To assess the long-term efficacy of seton drainage with infliximab maintenance therapy in treatment of stricture for perianal Crohn’s disease(CD). METHODS:Sixty-two patients with perianal CD who required surgical treatment with or without infliximab between September 2000 and April 2010 were identified from our clinic’s database.The activities of the perianal lesions were evaluated using the modified perianal CD activity index(mPDAI)score.The primary endpoint was a clinical response at 12-15 wk after surgery as a shortterm efficacy.Secondary endpoints were recurrence as reflected in the mPDAI score,defined as increased points in every major element.The clinical responses were classified as completely healed(mPDAI=0),partially improved(mPDAI score decreased more than 4 points),and failure or recurrence(mPDAI score increased or decreased less than 3 points). RESULTS:There were 43 males and 19 females,of whom 26 were consecutively treated with infliximab after surgery as maintenance therapy.Complete healing was not seen.Failure was seen in 10/36(27.8%) patients without infliximab and 4/26(15.4%)patients with infliximab(P=0.25).Partial improvement was seen in 26/36(72.2%)patients without infliximab and 22/26(88.5%)patients with infliximab(P=0.25). Short-term improvement was achieved in 48/62(77.4%) patients.Although the mPDAI score improved significantly with surgery regardless of infliximab,it decreased more from baseline in patients with infliximab(50.0%) than in those without infliximab(28.6%),(P=0.003). In the long-term,recurrence rates were low regardless of infliximab in patients without anorectal stricture.In patients with anorectal stricture,cumulative recurrence incidences increased gradually and exceeded 40%at 5 years regardless of infliximab.No efficacy of infliximab treatment was found(P=0.97).Although the cumulative rate of ostomy creation was also low in patients without stricture and high in patients with stricture,no protective efficacy was found with infliximab treatment(P =0.6 without stricture,P=0.22 with stricture). CONCLUSION:Infliximab treatment was demonstrated to have short-term efficacy for perianal lesions.Longterm benefit with infliximab was not proven,at least in patients with anorectal stricture.

Acoustic Absorption Characteristics of Perforated Thin Plate with Air Jets and Cavity

The present paper focuses on the effect of air jets through a perforated thin plate on the characteristics of an acoustic absorption coefficient. We measured the flow rate, internal pressure, acoustic pressure, and transfer function by using an improved acoustic impedance tube. The normal incidence absorption coefficient was calculated from the measured transfer function using transfer function methods. As a result, the frequency characteristics of the acoustic absorption coefficient against the frequency showed a maximum value at the local frequency. The peak frequency of the acoustic absorption coefficient depended on the thickness of the background air space and the thickness of the perforated plate. As the flow rate increased through the micropores, the peak level of the acoustic absorption coefficient also increased until a flow rate of 80?l /min. As the flow rate further increased, the peak level of the acoustic absorption coefficient decreased and that of the high frequency band increased.