Efficiency of heart rate and heart rate difference at different time points during head-up tilt test in the diagnosis of postural tachycardia syndrome in children and adolescents / 中国当代儿科杂志

OBJECTIVE@#To study the efficiency of heart rate (HR) and heart rate difference (HRD) at different time points during head-up tilt test (HUTT) in the diagnosis of postural tachycardia syndrome (POTS) in children and adolescents.@*METHODS@#A total of 217 children and adolescents, aged 6-16 years, who were diagnosed with POTS were enrolled as the POTS group, and 73 healthy children and adolescents, matched for sex and age, were enrolled as the control group. The POTS group was further divided into ≤12 years old group with 127 children/adolescents and >12 years old group with 90 children/adolescents. The two groups were compared in terms of HR at baseline and at 5 and 10 minutes of HUTT (HR0, HR5, and HR10 respectively), difference between HR5/HR10 and HR0 (HRD5 and HRD10 respectively). The efficiency of HR5, HR10, HRD5 and HRD10 in the diagnosis of POTS was assessed.@*RESULTS@#Compared with the control group, the POTS group had significant increases in HR5, HR10, HRD5, and HRD10 (P12 years old subgroup (P<0.05), while the coincidence rate of HRD for the diagnosis of POTS was higher in the ≤12 years old subgroup (P<0.05). The combination of HR5, HR10, HRD5, and HRD10 for the diagnosis of POTS had a greater area under the curve (0.974; 95%CI: 0.949-0.989) than HR5, HR10, HRD5, or HRD10 alone, with a sensitivity of 87.80% and a specificity of 95.83%. The diagnostic efficacy of HRD for POTS was higher than that of HR (P<0.05).@*CONCLUSIONS@#HR and HRD at different time points during HUTT have a good value in the diagnosis of POTS in children and adolescents, and the accuracy of diagnosis varies with age and gender.

The impact of air pollution on children’s respiratory diseases in Tianjin: a case-over study / 中华疾病控制杂志

Objective To explore the effect of air pollution on children’s respiratory diseases in Tianjin, so as to provide reference for the prevention and control of diseases. Methods Conditional Logistic regression model of single pollutant and multiple pollutants was used to estimate the relationships between air pollutants concentration and children’s respiratory system diseases. Results Conditional Logistic regression model of single pollutant conditions showed that the excess risk (ER) effects and 95% CI of NO2, PM2.5, PM10 and CO appeared were 2.823%(2.581-3.065), 0.476%(0.382-0.569), 0.437%(0.368-0.506), 22.263%(15.449-29.478), respectively. Logistic regression analysis of multiple pollutants conditions showed that NO2 exposure had the greatest effect on children’s respiratory diseases in cold season, and the excess risk (ER) was 7.395%(6.595-8.202). Conclusion The elevated daily average concentration of NO2, PM10, PM2.5, and CO can increase the risk of children’s respiratory diseases.

Change in P wave on electrocardiogram and its diagnostic value in children and adolescents with cardioinhibitory vasovagal syncope / 中国当代儿科杂志

OBJECTIVE@#To study the change in P wave on electrocardiogram and its diagnostic value in children and adolescents with cardioinhibitory vasovagal syncope (VVS-CI).@*METHODS@#A total of 43 children and adolescents who were diagnosed with VVS-CI were enrolled as the VVS-CI group, and 43 healthy children and adolescents were enrolled as the control group. P wave duration and P wave voltage were measured by 12-lead electrocardiography in a basal state, and the changes were analyzed.@*RESULTS@#Compared with the control group, the VVS-CI group had a significantly lower heart rate (P<0.05) and significantly longer P wave duration (Pwd), P wave maximum duration (Pmax), and corrected P wave maximum duration (Pcmax), as well as significantly higher P wave dispersion (Pd) and corrected P wave dispersion (Pcd) (P<0.05). Pwd, Pmax, Pd, Pcmax and Pcd had a certain diagnostic value in children and adolescents with VVS-CI (P<0.05): Pwd had a sensitivity of 69.77% and a specificity of 83.72% at the optimal cut-off value of 78.49 ms; Pmax had a sensitivity of 76.74% and a specificity of 90.70% at the optimal cut-off value of 93.39 ms; Pd had a sensitivity of 95.35% and a specificity of 69.77% at the optimal cut-off value of 27.42 ms; Pcmax had a sensitivity of 46.51% and a specificity of 88.37% at the optimal cut-off value of 120.90 ms; Pcd had a sensitivity of 83.72% and a specificity of 72.09% at the optimal cut-off value of 36.37 ms.@*CONCLUSIONS@#Children and adolescents with VVS-CI have significantly increased Pwd, Pmax, Pd, Pcmax, and Pcd, which may indicate abnormal atrial electrical activity. The cut-off value of P wave has a certain diagnostic value in VVS-CI.

HNO increases myofilament sensitivity to calcium in cardiac muscle through targeting thiol / 中国药学杂志

OBJECTIVE: To test the effect of 1-nitrosocyclohexyl acetate (NCA), a newly developed nitroxyl (HNO) donor, on myofilaments and its action mechanism for the thiol in tropomyosin. METHODS: Trabeculae were dissected from the right ventricule of rat heart and mounted between a force transducer and a motor arm. The muscles were superfused with K-H solution (pH 7.4) at room temperature. Fura-2 salt was loaded into the trabeculae via electrophoresis, and the sarcomere length was set at 2.2-2.3 μm. Western blotting tested the change of tropomyosin. RESULTS: Twitch force increased in a dose dependent manner in the presence of NCA in the range of 20-100 μmol·L-1. Force increased (P0.05) with different frequencies (0.5-3.0 Hz) with NCA of 20 μmol·L-1 and Ca2+ of 0.5 μmol·L-1. Skinned force increased as compared to the control (P<0.05). The effect of NCA had characteristics of structure uniqueness. A cross-linking band in tropomyosin was seen by Western blotting under non-reducing condition. The thiol reducing agent dithiothreitol (DTT) both prevented and reversed HNO action. CONCLUSION: The donor of HNO, NCA, represents a new class of agents capable of directly sensitizing cardiac myofilaments to Ca2+. Post-translational thiol modification of the key regulatory myofilament protein (i.e. tropomyosin) may underlie the effect of NCA.

Study of genotoxicity and oxidative stress induced by copper oxide nanoparticles in mice / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the genotoxicity and oxidative stress induced by copper oxide nanoparticles in mice.</p><p><b>METHODS</b>Thirty mice were randomly divided into control group and low- and high-dose exposure groups. The low- and high-dose exposure groups were given copper oxide nanoparticles (50 and 150 mg/kg) by a single intraperitoneal injection, while the control group was given an equal volume of normal saline containing 0.05%Tween 80. The micronucleus rate of reticulocytes in peripheral blood from the caudal vein and urinary 8-hydroxy-deoxyguanosine (8-OH-dG) level were measured before and at 24, 48, and 72 h after exposure. All the mice were sacrificed at 72 h after exposure, the liver, kidney, and femoral marrow were taken for DNA extraction, and 8-OH-dG in DNA was quantified.</p><p><b>RESULTS</b>The micronucleus rates of peripheral blood reticulocytes in low-dose exposure group at 48 h (3.11±1.46‰ and in high-dose exposure group at 24 and 48 h (4.25±0.43) and 5.42±0.76‰) were significantly increased compared with those before exposure (1.55±0.39‰ and 1.11±0.19‰) and those in control group (1.55±0.28‰ and 1.00±0.67‰) (P < 0.05 or P < 0.01). The urinary 8-OH-dG levels (ng/mg creatinine) in low- and high-dose exposure groups at all time points were significantly increased compared with those before exposure and those in control group (P < 0.05 or P < 0.01). The low- and high-dose exposure groups had significantly higher content of 8-OH-dG in liver DNA than the control group (4.53±1.27 and 7.69±2.78 vs 0.85±0.14, P < 0.01).</p><p><b>CONCLUSION</b>Copper oxide nanoparticles cause genotoxicity and increase oxidative stress in mice.</p>

Simultaneous determination of three active constituents in cortex moutan by RP-HPLC / 中国中药杂志

<p><b>OBJECTIVE</b>To establish a RP-HPLC method for the simultaneous determination of gallic acid, paeoniflorin and paeonol in Cortex Moutan.</p><p><b>METHOD</b>The analysis was carried out on a column of YMC-C18 (4. 6 mm x 250 mm, 5 microm), and gradient elution was used for the baseline separation of these three constituents with the different detection wavelength.</p><p><b>RESULT</b>The linear ranges for gallic acid, paeoniflorin and paeonol were 0.0130-0.267, 0.0880-1.76 and 0.164-3.28 microg, respectively. Their average recoveries were 104.3%, 101.7% and 99.5%, respectively.</p><p><b>CONCLUSION</b>The method was successfully applied to the determination of gallic acid, paeoniflorin and paeonol in Cortex Moutan from the different drugstores. It was shown in this study that the proposed method could be used to evaluate the quality of the medicinal plants or herbal preparations containing gallic acid, paeoniflorin and paeonol.</p>

A fiber optic chemical sensor system for on-line monitoring the drug dissolution of rifampicin / 药学学报

<p><b>AIM</b>To study a continuous, on-line and automatic monitoring method for dissolution of drugs.</p><p><b>METHODS</b>A new fiber optical chemical sensor prepared by sol-gel immobilization of molecular probe was reported. Based on multiple quenching of flurescence, an instrument and software system was designed to on-line monitor the drug dissolution of rifampicin.</p><p><b>RESULTS</b>The concentration of rifampicin was linear with ln(F0/F) when concentration was in the range of 10-170 micrograms/mL-1. The relative coefficient was 0.9993. The procession of dissolution can be on-line monitored. Parameters were obtained directly from the dissolution curve. There is no distinctly difference when compared with the method of the Pharmacopoeia of People's Republic of China (P > 0.05).</p><p><b>CONCLUSION</b>This procession analysis can reflect the real dissolution of drug and obtain the total information.</p>