Objective:To explore the feasibility of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in assessing the microcirculatory perfusion of skeletal muscle in rabbit limbs in the early stage after high-voltage electric burns.Methods:This study was an experimental study. Thirty-two male big ear white rabbits aged 6-8 months were assigned into electric burn group of 20 rabbits with high-voltage electric burns in the right lower limb and control group of 12 rabbits with sham injury in the right lower limb using the random number table method. At 0.5, 24.0, 48.0, and 72.0 h post injury, the lower limbs of rabbits in the two groups underwent axial fast spin echo T1-weighted imaging, fast spin echo T2-weighted imaging, and DCE-MRI examination. A reference region-based hemodynamic model was applied to obtain the blood perfusion parameters of skeletal muscle in the injured limbs, including the volume transfer constant K trans value and rate constant K ep value. The skeletal muscle tissue from the electric burn group of rabbits at 0.5, 24.0, 48.0, and 72.0 h post injury and the control group of rabbits at 0.5 h post injury was harvested for immunohistochemical staining to observe the microvascular changes and calculate the microvascular density (MVD). The correlation between the K trans and K ep values and the MVD of skeletal muscle tissue in electric burn group of rabbits at 0.5-72.0 h post injury was analyzed. The number of samples was 5 in the electric burn group, and the number of samples was 3 in the control burn group. Results:From 0.5-72.0 h post injury, the K trans and K ep values in skeletal muscle tissue of electric burn group of rabbits exhibited the trends of increase first and decrease then, both of which reached peak values at 24.0 h post injury. The K trans values at 0.5, 24.0, 48.0, and 72.0 h post injury (with t values of -15.77, -14.91, -40.35, and -40.25, respectively, P<0.05) and the K ep values at 0.5, 24.0, and 48.0 h post injury (with t values of -5.39, -6.82, and -6.83, respectively, P<0.05) in skeletal muscle tissue in electric burn group of rabbits were significantly higher than those in control group. The MVD in skeletal muscle tissue in control group of rabbits at 0.5 h post injury and in electric burn group of rabbits at 0.5, 24.0, 48.0, and 72.0 h post injury was (24.7±3.5), (21.8±2.2), (40.8±9.1), (16.4±2.4), and (9.8±0.8) per mm2, respectively. The MVD in skeletal muscle tissue in electric burn group of rabbits at 24.0 h post injury was significantly higher than that in control group at 0.5 h post injury ( t=2.89, P<0.05), and the MVD in skeletal muscle tissue at 48.0 and 72.0 h post injury was significantly lower than that in control group at 0.5 h post injury (with t values of 4.01 and 9.52, respectively, P<0.05). The K trans and K ep values of skeletal muscle tissue in rabbits in electric burn group were significantly positively correlated with microvascular density at 0.5 to 72.0 h post injury (with both r values of 0.95, P<0.05). Conclusions:The quantitative perfusion parameters K trans and K ep values of DCE-MRI can effectively reflect the microcirculatory perfusion changes of skeletal muscle in rabbit limbs in the early stage after high-voltage electric burns.

Objective:To explore the feasibility of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in assessing the microcirculatory perfusion of skeletal muscle in rabbit limbs in the early stage after high-voltage electric burns.Methods:This study was an experimental study. Thirty-two male big ear white rabbits aged 6-8 months were assigned into electric burn group of 20 rabbits with high-voltage electric burns in the right lower limb and control group of 12 rabbits with sham injury in the right lower limb using the random number table method. At 0.5, 24.0, 48.0, and 72.0 h post injury, the lower limbs of rabbits in the two groups underwent axial fast spin echo T1-weighted imaging, fast spin echo T2-weighted imaging, and DCE-MRI examination. A reference region-based hemodynamic model was applied to obtain the blood perfusion parameters of skeletal muscle in the injured limbs, including the volume transfer constant K trans value and rate constant K ep value. The skeletal muscle tissue from the electric burn group of rabbits at 0.5, 24.0, 48.0, and 72.0 h post injury and the control group of rabbits at 0.5 h post injury was harvested for immunohistochemical staining to observe the microvascular changes and calculate the microvascular density (MVD). The correlation between the K trans and K ep values and the MVD of skeletal muscle tissue in electric burn group of rabbits at 0.5-72.0 h post injury was analyzed. The number of samples was 5 in the electric burn group, and the number of samples was 3 in the control burn group. Results:From 0.5-72.0 h post injury, the K trans and K ep values in skeletal muscle tissue of electric burn group of rabbits exhibited the trends of increase first and decrease then, both of which reached peak values at 24.0 h post injury. The K trans values at 0.5, 24.0, 48.0, and 72.0 h post injury (with t values of -15.77, -14.91, -40.35, and -40.25, respectively, P<0.05) and the K ep values at 0.5, 24.0, and 48.0 h post injury (with t values of -5.39, -6.82, and -6.83, respectively, P<0.05) in skeletal muscle tissue in electric burn group of rabbits were significantly higher than those in control group. The MVD in skeletal muscle tissue in control group of rabbits at 0.5 h post injury and in electric burn group of rabbits at 0.5, 24.0, 48.0, and 72.0 h post injury was (24.7±3.5), (21.8±2.2), (40.8±9.1), (16.4±2.4), and (9.8±0.8) per mm2, respectively. The MVD in skeletal muscle tissue in electric burn group of rabbits at 24.0 h post injury was significantly higher than that in control group at 0.5 h post injury ( t=2.89, P<0.05), and the MVD in skeletal muscle tissue at 48.0 and 72.0 h post injury was significantly lower than that in control group at 0.5 h post injury (with t values of 4.01 and 9.52, respectively, P<0.05). The K trans and K ep values of skeletal muscle tissue in rabbits in electric burn group were significantly positively correlated with microvascular density at 0.5 to 72.0 h post injury (with both r values of 0.95, P<0.05). Conclusions:The quantitative perfusion parameters K trans and K ep values of DCE-MRI can effectively reflect the microcirculatory perfusion changes of skeletal muscle in rabbit limbs in the early stage after high-voltage electric burns.

Objective To observe the value of apparent diffusion coefficient(ADC)for quantitatively evaluating progressive muscle injury of rabbit limbs in early stage of high-voltage electrical burn.Methods Twenty healthy adult rabbits were selected to establish limb high-voltage electrical burn models,which were randomly divided into 0.5,24,48 and 72 h groups(each n=5).MR diffusion weighted imaging(DWI)was collected for each group at 0.5,24,48 and 72 h after modeling,and the injured core muscles of the right hind limb and the normal muscles of the contralateral limb were taken for HE staining.The muscle's ADC,muscle fiber density(MFD)and muscle fiber diameter(D)values at the injured core of current entry and exit were compared,and those of normal muscle were also analyzed.The correlations of ADC values in injured core muscle and MFD or D values were investigated.Results There were significant differences of ADC values of injured core muscle at both the entry and exit and normal muscle,also of ADC values of injured core muscle at the entry and exit within each group(all P＜0.05).ADC values of injured core muscle at the entry and exit decreased with time going(all P＜0.05),but ADC values of normal muscle were not significantly different among different time points(P＞0.05).MFD values of injured core muscle at the entry and exit decreased with time going(all P＜0.05),while MFD values of the normal muscle,D values of the injured core muscle at the entry and exit and normal muscle were not significantly different among time points(all P＞0.05).ADC value of the injured core muscle was positively correlated with MFD value and negatively correlated with D value(rs=0.846,r=-0.507,both P＜0.05).Conclusion ADC could quantitatively evaluate the progressive muscle injury of rabbit limbs in early stage of high-voltage electrical burn.

Objective: To explore the effect of nursing intervention on the biofeedback effect of functional constipation in children. Methods: A total of 112 children (4-16 years old) who were diagnosed with functional constipation in the Department of Pediatric Surgery of the First Affiliated Hospital of Zhengzhou University were randomly divided into the experimental group (54 cases) and the control group (53 cases). Children in the experimental group were treated with biofeedback training and personalized nursing intervention for functional constipation in children. The control group used biofeedback combined with traditional nursing intervention to treat functional constipation in children. The WHO-5 (World Health Organization′s five physical and mental health) scales were used to compare the effects of the two groups and were followed up for 3-6 months. Results: A total of 107 children completed the study, 54 in the experimental group and 53 in the control group. There were no significant differences in the scores of the WHO-5 scale and clinical symptoms between the two groups before the intervention (P>0.05). After intervention, the total score of WHO-5 in the experimental group was (21.69± 2.28), the total score of clinical symptoms was (6.56±1.16), the total score of WHO-5 in the control group was (17.85±3.189), and the total score of clinical symptoms was (9.04±2.121). The difference was significant (t=-7.146, t=7.491, P<0.01). Conclusion Personalized nursing intervention can enhance the effect of biofeedback training on children and adolescents with functional constipation and improve their quality of life.