Objective To discuss the characteristics,diagnosis,mechanism and the prognosis of dilated cardiomyopathy (DCM) induced by accessory pathway (AP).Methods The clinical,electrophysiological and echocardiographic characteristics in four cases,who were diagnosed as AP-induced DCM in the Department of Pediatric Cardiology of Beijing Anzhen Hospital,Capital Medical University from Mar.2011 to Aug.2012,were analyzed before and after ablation.Results The electrocardiograms of the 4 patients all indicated type B ventricular preexcitation.The locations of the APs were the right-sided anteroseptum and the free wall.Dyschronous contractions between posterior wall of left ventricle and interventricular septum were demonstrated by M-Mode echo.The basal segments of the interventricular septum turned thin and moved similar to an aneurysm,with typical bulging during end-systole,which was observed in all cases by two-dimension echo.Dyschronous left ventricular contraction was shown by speckle tracing technique.All patients received successful radio frequency current ablations.Their physical activities and growth improved greatly in the 4 cases.The echocardiographic data demonstrated that their left ventricular contraction recovered to synchrony shortly after the ablation,left ventricular ejection fraction recovered to normal and left ventricular end diastolic diameter decreased to almost normal gradually during the follow-up.Conclusions Overt right-sided APs localized in anteroseptum or free wall may have adverse effects on ventricular wall motion and left ventricular function.They can even result in DCM.Dyssynchronous ventricular contraction induced by right-sided overt accessory pathway may be the vital mechanism.AP-induced DCM is an indication for ablation with good prognosis.

BACKGROUND:Osteoarthritis animal models induced by papain are commonly used for studying osteoarthritis.
OBJECTIVE:To observe the morphology of articular cartilage surface during early osteoarthritis process in rats induced by papain and L-cysteine under scanning electron microscope.
METHODS:The right knees of Sprague-Dawley rats were given 0.15 mL mixed solution of 2%papain and 0.03 mol/L L-cysteine in the ratio of 2:1. The left knees were given injections of 0.15 mL 0.9%NaCl, as the control group. Another two rats (four knees) maintained untreated, as the normal control group. Al the rats were observed with scanning electron microscope at 2, 4, 6 weeks after injection, to explore the surface morphology of medial condyle of femur.
RESULTS AND CONCLUSION:The condyles of normal and control groups revealed numerous shal ow pits on the surface of articular cartilage. At 2 weeks after injection, the surfaces of condyles were unsmooth, presenting the shrinkage and distortion. The thinner articular cartilage and local tiny cracks were seen at 4 weeks. The deep and great cracks and cartilage defect were observed on the surface of cartilage at 6 weeks. The time of 4-6 weeks is a reference point for establishing early osteoarthritis model in rats through injections of 2%papain and 0.03 mol/L L-cysteine.

Objective:To investigate the immune effects of Clostridium difficile toxoid B (CdtB) vaccine formulated with different mucosal adjuvants through microneedle immunization, and to provide ideas for the prevention and treatment of Clostridium difficile infection. Methods:CdtB vaccine was prepared with purified Clostridium difficile toxin B(TcdB) after formaldehyde detoxification. Female BALB/c mice were immunized with different doses of vaccine alone or in combination with mucosal adjuvants. The titers of specific serum IgG and fecal IgA were detected at 0 d, 7 d, 14 d, 28 d and 42 d after immunization. The protective effects of CdtB vaccine were evaluated by cell neutralization assay and Clostridium difficile challenge infection. Results:(1) With the increase of immune dose, the mice immunized with CdtB vaccine alone by microneedle not only produced better serum specific IgG, but also had higher level of IgA in feces. (2) When the mice were immunized with CdtB vaccine containing LT or CTB adjuvant by microneedle, the trend of serum specific IgG titer in each group increased with the increase of immune dose, especially in the group containing LT adjuvant. There were significant differences in the trend of specific IgA titer in feces between the adjuvant groups and the group without adjuvant, but the adjuvant effect was not obvious. (3) No significant difference in serum IgG titer was observed between the mice immunized with 10 μg CdtB by microneedle or intraperitoneal injection, but microneedle immunization significantly increased fecal IgA level. (4) The neutralization titers of specific antibodies in mouse serum after immunization and the test results of challenge protection in mice confirmed that the use of CdtB vaccine had certain protective effects.Conclusions:CdtB vaccine had better immune effects in mice through microneedle immunization, but the adjuvant effects of LT and CTB were not significant.

OBJECTIVETo analyze the adverse effects of type B ventricular pre-excitation on ventricular wall motion and left ventricular function and its clinical characteristic.

METHODThe clinical, electrophysiological and echocardiographic characteristics of the 9 cases with type B ventricular pre-excitation before and after ablation seen between March 2011 and March 2013 were analyzed. The patients aged from 3 to 16 years. Five of them were female.

RESULTDyschronous left ventricular contraction was demonstrated by M-Mode echocardiography in all of the cases. The basal segments of the interventricular septum turned thin and moved in a manner similar to that of an aneurysm, with typical bulging during end-systole, which was observed in six cases. All patients received successful RFCAs. The locations of the accessory pathways (APs) were the right-sided anteroseptum (n = 2) and the free wall (n = 7). Their physical activities and growth improved greatly in the four cases with coexisting dilated cardiomyopathy (DCM). The echocardiographic data demonstrated that their LV contraction recovered to synchrony shortly after the ablation, LVEF recovered to normal and LVED decreased to almost normal gradually during the follow-up.

CONCLUSIONOvert right-sided APs may have adverse effects on ventricular wall motion and left ventricular function. They can even result in DCM. Dyssynchronous ventricular contraction induced by right-sided overt accessory pathway may be the vital mechanism. Such kinds of cases are indication for ablation with good prognosis.

Adolescent ; Cardiomyopathy, Dilated ; diagnostic imaging ; etiology ; physiopathology ; Catheter Ablation ; Child ; Child, Preschool ; Echocardiography ; Female ; Heart Ventricles ; physiopathology ; Humans ; Male ; Myocardial Contraction ; Ventricular Dysfunction, Left ; diagnostic imaging ; etiology ; physiopathology ; Wolff-Parkinson-White Syndrome ; complications ; physiopathology