Spontaneous Baroreflex Sensitivity and Multifractal Hurst Analysis of Heart Rate

BACKGROUND AND OBJECTIVES: This study was designed to examine whether the multifractal Hurst exponents of heart rate can estimate activating and deactivating spontaneous baroreflex sensitivity (SBRS). SUBJECTS AND METHODS: Age and sex matched 24 healthy volunteers were placed in the supine position and head-up tilt position for 30 minutes, and the systolic blood pressure and heart rate were measured in an noninvasive manner. When the RR interval (RRI) sequence and systolic pressure sequence simultaneously increased or decreased for more than three successive beats, the slope of the linear regression line of systolic blood pressure and RR interval sequence was defined as the value of spontaneous baroreflex sensitivity (SBRS). From the RR intervals, very short-term (alpha range, or =12 heartbeats), and the multrifractal Hurst exponents were calculated to determine the linear correlation.coefficients for SBRS. RESULTS: In the supine position, the linear correlation coefficients (p) of SBRS and H-5alpha, H-4alpha, H-3alpha, H-2alpha, H-1alpha, H1alpha, H2alpha, H3alpha, H4alpha, H5alpha were -0.195 (NS), -0.207 (NS), -0.232 (NS), -0.282 (NS), -0.355 (NS), -0.621 (0.003), -0.650 (0.001), -0.677 (0.001), -0.699 (0.0006) and -0.708 (0.0005), respectively. In the tilting position, the linear correlation coefficients of SBRS and H-5beta, H-4beta, H-3beta, H-2beta, H-1beta, H1beta, H2beta, H3beta, H4beta, H5beta were 0.024 (NS), 0.020 (NS), 0.010 (NS), -0.028 (NS), -0.193 (NS), -0.627 (0.0034), -0.607 (0.0045), -0.598 (0.0053), -0.572 (0.0084) and -0.539 (0.0141), respectively. CONCLUSION: Some of the very short-term and short-term generalized Hurst exponents, such as H5alpha and H1beta, can be used for the estimation of spontaneous baroreflex sensitivity during patient placement in the supine and head-up tilt position, respectively.

Correlation between Different Chemokines Induced by Specific Allergens in Atopic Dermatitis / 소아알레르기및호흡기학회지

PURPOSE:Many patients with atopic dermatitis have shown different responses to treatment or different prognosis dependenting on the kinds of offending allergens. We attempted to evaluate the difference of mechanism in allergic inflammation between food allergens and aeroallergens by measuring chemokines, including TARC (Thymus and activation regulated chemokine), MDC (Marcrophage-derived chemokine), IL-18, CCL-28 (Chemokine receptor ligand-28) and ECP (Eosinophil cationic protein), and to investigate the correlation between the clinical severity and chemokine levels induced by food allergens and aeroallergens in atopic dermatitis. METHODS:Sixty-seven children with atopic dermatitis (39 males and 28 females) were recruited. Thirteen nonatopic children without atopic dermatitis (6 males and 7 females) were selected as controls. RESULTS:We obtained SCORAD index cut-off points that were similar to those established by clinical criteria. Comparisons between the groups of mild, moderate and severe atopic dermatitis revealed significant differences in serum total IgE and ECP levels. SCORAD index significantly correlated with total IgE, TARC, MDC and ECP levels. Serum IgE levels correlated with TARC and ECP. SCORAD index and total IgE strongly correlated to HDM. While IL-18, TARC, MDC and ECP levels strongly correlated to egg white and milk. In soybean, IgE and TARC and ECP levels significantly correlated with specific IgE levels. CONCLUSION:TARC, MDC and ECP might play a crucial role in the chronic inflammatory process of food-specific atopic dermatitis. In contrast, IgE-mediated mechanisms might have implications for HDM, when compared with food specific atopic dermatitis. These results suggest that pathogenic mechanisms of atopic dermatitis might be different according to relevant allergens.