Background Natural pyrethrins have long been widely used in the fields of environmental and household hygiene. Studies have reported that natural pyrethrins have potential liver toxicity, but their specific mechanisms are still unclear yet. Objective To explore the effect of natural pyrethrins on DNA damage in human liver cells. Methods This study used human liver cell QSG7701 as an in vitro testing model. After exposure to DMSO and a series of concentrations of natural pyrethrins (5, 10, 20, and 40 μg·mL⁻¹) for 6 and 24 h, reactive oxygen species (ROS) was detected by fluorescence microscopy using a fluorescence probe, thiobarbituric acid reactive substance (TBARS) by colorimetric method using a microplate reader, DNA damage by comet assay through observing DNA fragment migration under microscope, and phospho H2AX (γH2AX) and 8-oxoguanine (8-oxoG) by immunofluorescence assay using a laser confocal microscope. Results As the exposure concentration of natural pyrethrins increased, the fluorescence intensity of ROS significantly increased in a concentration-dependent manner. The differences in ROS between the 10 μg·mL⁻¹ and above groups and the control group were statistically significant (P<0.01), and the ROS levels in the 20 μg·mL⁻¹ and 40 μg·mL⁻¹ treatment groups were 2.17 and 3.05 times higher than that in the control group respectively. The TBARS level increased in a concentration-dependent manner in natural pyrethrins treated cells (P<0.01), and the levels in the 20 μg·mL⁻¹ and 40 μg·mL⁻¹ treatment groups were 2.46 and 3.01 times higher than that in the control group respectively. The results of comet assay showed trailing formation of cellular DNA in each dose group; as the exposure concentration of natural pyrethrins increased, indicators such as tail DNA content (TDNA%), tail length (TL), tail moment (TM), and Olive tail moment (OTM) increased in a concentration-dependent manner. Compared with the control group, the differences in the indicators between the 20 μg·mL⁻¹ and above groups and the control group were statistically significant (P<0.01), especially in the 40 μg·mL⁻¹ treatment groups, where TDNA%, TL, TM, and OTM were (46.92 ± 3.52) %, (64.67± 4.16) μm, 30.96 ± 2.94, and 22.64 ± 3.89, respectively. The cellular immunofluorescence results showed that natural pyrethrins induced the formation of γH2AX and 8-oxoG, the fluorescence intensities of γH2AX and 8-oxoG increased in a concentration-dependent manner, and the differences between the 10 μg·mL⁻¹ and above groups and the control group were statistically significant (P<0.01). Conclusion Natural pyrethrins could induce DNA damage in human liver cells, and ROS-mediated oxidative stress may play an important role in its liver cell genotoxicity.

Objective:To explore the relationship between negative evaluation fear and mobile phone addiction, and the mediating role of balanced time perspective.Methods:In April 2021, totally 1 158 secondary vocational school students were investigated by scales of fear of negative evaluation(FNE), mobile phone addiction index(MPAI)and Zimbardo time perspective inventory(ZTPI). The balanced time perspective was calculated by deviation from the balanced time perspective(DBTP). SPSS 20.0 statistical software was used for descriptive statistical analysis and correlation analysis of the data.Bootstrap method was used to test the mediating effect.Results:(1) Negative evaluation fear(37.87±7.71)was significantly positively correlated with balanced time perspective(4.50±0.75)( r= 0.379, P<0.01) and mobile phone addiction(46.11±11.92)( r=0.437, P<0.01). The balanced time perspective was significantly positively correlated with mobile phone addiction( r=0.475, P<0.01). (2) Negative evaluation fear directly and positively predicted mobile phone addiction( β=0.300, 95% CI=0.248-0.352). The balanced time perspective played a partial mediating role between negative evaluation fear and mobile phone addiction, and the mediating effect value was 0.137, accounted for 31.31%(0.137/0.437) of the total effect. Conclusion:The fear of negative evaluation can directly affect the mobile phone addiction behavior of secondary vocational students, and can also indirectly affect the mobile phone addiction by affecting the balanced time perspective.Good balanced time perspective can reduce the risk caused by the fear of negative evaluation.

ObjectiveTo compare the differences in resistance and structure of skin between acupoints and non-acupoints， and to study the difference in skin permeability characteristics of Corydalis Rhizoma total alkaloid patches （CTTP） after administration at Shenque acupoint and non-acupoint， so as to provide experimental support for its clinical acupoint application to prevent and treat chronic pain. MethodTaking corydaline （CD）， tetrahydropalmatine （THP） and corydalis L （CDL） as evaluation indexes， and the quantitative analysis was carried out by high performance liquid chromatography （HPLC）. The mobile phase was methanol-0.04 mol·L^-1 phosphoric acid aqueous solution （70∶30， pH 6.0 adjusted with triethylamine）， the detection wavelength was 281 nm. In vitro transdermal test in Franz diffusion cell and in vivo transdermal test were used to study the skin permeability characteristics of CTTP through Shenque acupoint and non-acupoint administration. At the same time， the skin resistance between Shenque acupoint and non-acupoint was measured before and after the administration， and the distribution of the drug in each layer of the skin was compared by freezing sectioning， and visual verification was performed with fluorescence inverted microscope. ResultAfter 24 h of administration， the results of in vivo and in vitro experiments showed that the cumulative permeation and retention of CD， THP and CDL at Shenque acupoint skin were higher than those at non-acupoint skin （P<0.05， P<0.01）， the skin resistance of Shenque acupoint was lower than that of non-acupoint at all time points. The fluorescence microscopic observation results showed that the drug content of each layer of the skin was all Shenque acupoint>non-acupoint， indicating that the skin of Shenque acupoint had better effect on drug penetration and storage than non-acupoint. ConclusionThe 24 h cumulative permeation and retention of CTTP in Shenque acupoint skin are higher than those in non-acupoint skin， and the mechanism may be related to the thin skin， low electrical resistance and large number of hair follicle bodies at Shenque acupoint.

Objective To investigate imaging characteristics of human skin in different sites by using 20-MHz and 50-MHz high-frequency ultrasonography,and to compare the reliability of skin thickness measurement by the above two approaches of ultrasonography.Methods A total of 39 healthy volunteers aged 18-39 years were enrolled into this study.Then,20-MHz and 50-MHz ultrasonography were separately performed to image 20 different sites on the body,and the thickness of the epidermis and dermis were measured and evaluated by 3 dermatologists independently.The ultrasonic images were analyzed,and the intraclass correlation coefficient (ICC) was used to assess and compare the reliability of skin thickness measurement by 20-MHz and 50-MHz ultrasound.Results The ICC values were less than or close to 0.7 in epidermal thickness measurement at almost all the tested sites between 20-MHz and 50-MHz ultrasonography,suggesting poor reliability.However,20-MHz and 50-MHz ultrasonography showed excellent reliability in dermal thickness measurement with the ICC greater than 0.75 at almost all the tested smooth and flat body sites.The 20-MHz ultrasound could provide clear images of the dermis and subcutaneous tissue,while 50-MHz ultrasound could only provide clearer images of the dermis in details.In some uneven sites with complex anatomical structures,20-MHz and 50-MHz ultrasound probes had their own advantages and disadvantages in imaging depth and detail resolution.Conclusions The 20-MHz and 50-MHz ultrasono-graphy both can serve as non-invasive imaging techniques to show structures of the epidermis and dermis better.In different parts of human body,ultrasound frequencies should be selected according to their imaging characteristics.

Objective To explore the value of real-time shear wave elastography in evaluating gastrocnemius muscle elasticity in patients with lumbar disc herniation.Methods One hundred patients with clinically diagnosed unilateral lumbar disc herniation were selected.Selective nerve root block combined with ozone ablation and pulsed radiofrequency therapy via the lateral crypt was performed.The real-time shear wave elastography was applied to detect the mean elastic modulus (Mean) and the maximum elastic modulus (Max) of bilateral tense gastrocnemius muslcs (kPa) before and after treatment.Statistical analysis was done.Results The EMean and EMax values of ipsilateral tension in gastrocnemius muscle before treatment were (11.28±2.60)kPa and (15.26±2.63)kPa,lower than those of contralateral (EMean:[16.284-5.25]kPa,EMax:[21.13±6.62]kPa;t=78.241,64.634,both P＜0.001).The EMean and EMax values of ipsilateral tension in gastrocnemius muscle after treatment were (13.18±2.38)kPa and (17.63± 2.73)kPa,higher than those before treatment (t=6.407,14.815,both P＜0.001).In different strength condition,EMean and EMax of gastrocnemius muscle before and after treatment were statistically significant (all P＜0.001).With the myodynamia increasing,EMean and EMax also increased before and after treatment.The differences between patients with any two different myodynamia were statistically different (all P＜0.05).Conclusion The muscle tissue recovery can be evaluated quantitatively by detecting EMean and EMax of tense gastrocnemius in patients with lumbar disc herniation using real-time shear wave elastography before and after treatment.

BACKGROUND:The whole-kidney acelular matrix scaffold in rats prepared by perfusion method is proved to have goodin vitro biocompatibility, butin vivo biocompatibility is stil unclear. OBJECTIVE:To produce a whole-kidney acelular matrix scaffold in rats by perfusion method and to evaluate the in vivo biocompatibility of the scaffold. METHODS:The whole-kidney acelular matrix scaffold in Wistar rats was prepared by perfusion method and evaluated with the folowing tests. (1) Acute toxicity test: mice were subject to intraperitoneal injection of whole-kidney acelular matrix scaffold extract liquid, normal saline and phenol. (2) Hemolytic test: Anticoagulant blood samples from New Zealand rabbits were mixed with whole-kidney acelular matrix scaffold extract liquid, normal saline and distiled water, respectively. (3) Pyrogen test: Whole-kidney acelular matrix scaffold extract liquid was injected into the ear vein of New Zealand rabbits. (4) Intracutaneous stimulation test: Whole-kidney acelular matrix scaffold extract liquid was injected subcutaneously into New Zealand rabbits for observing whether there was a skin stimulus response. (5) Subcutaneous implantation test: The whole-kidney acelular matrix scaffold was implanted subcutaneously into the back of New Zealand rabbits. RESULTS AND CONCLUSION:There was no cel residual in the whole-kidney acelular matrix scaffold preparedby perfusion method, and no acute systemic toxicity, hemolytic reaction, pyrogen response, and skin stimulus respons, indicating the scaffold has a good histocompatibility in the rabbits. These findings suggest that the whole-kidney acelular matrix scaffolds in Wistar rats prepared by perfusion method have goodin vivo biocompatibility.

Objective To study drug resistance of carbapenem-resistant Klebsiella pneumonia ( CRKP) in neonates hospitalized in the neonatal unit , and to identify the risk factors for CRKP colonization in neonates .Methods Totally 108 neonates with Klebsiella pneumonia colonization admitted in Department of Neonates , the Second Hospital of Tianjin Medical University during January 2012 and June 2014 were enrolled in the study , including 23 cases with CRKP colonization ( case group ) and 85 cases with carbapenem-sensitive Klebsiella pneumonia (CSKP) colonization (control group).Chi-square test and fisher exact test were used to compare the differences in resistance to 21 antibiotics between CRKP and CSKP . Univariate analysis and Logistic regression analysis were performed to identify the risk factors for CRKP colonization in neonates .Results All of the CRKP strains were resistant to penicillins , cephalosporins and SMZco, and 95.7% and 87.0% of the CRKP strains were resistant to meropenem and imipenem , respectively.All of the CRKP strains were susceptible to amikacin , gentamicin, ciprofloxacin and tetracycline, but were highly resistant to the rest 16 antibiotics compared with CSKP strains (all P<0.05). Univariate analysis showed that 14 factors were associated with CRKP colonization: exposure to cefoxitin (χ2 =20.053, P<0.01), sputum suction (χ2 =15.817, P<0.01), gastrointestinal decompression (χ2 =10.731, P<0.01), nasogastric feeding (χ2 =15.146, P<0.01), invasive procedure (χ2 =22.572, P<0.01), birth weight (χ2 =6.026, P<0.05), frequency of sampling for CRKP/CSKP (χ2 =18.577, P<0.01), hypertension of pregnancy (χ2 =8.698, P<0.01), premature birth (χ2 =4.904, P<0.05), prenatal hospitalization experience (χ2 =8.396, P<0.01), adequacy for gestational age (χ2 =7.295, P<0.05), gestational age (χ2 =7.294, P<0.05), rupture of membranes (χ2 =9.397, P<0.01), length of hospitalization (χ2 =14.649, P<0.01) and admission to the neonatal intensive care unit (NICU) (OR=11.050, P<0.01).Multivariate Logistic regression analysis showed that hypertension of pregnancy (OR=9.718, P<0.01), rupture of membranes ( <24 h) (OR=6.640, P<0.01) and admission to NICU ( OR=4.119, P<0.05) were independent risk factors for CRKP colonization .Conclusions CRKP strains are highly resistant to most antibiotics .Preventing hypertension of pregnancy and rupture of membranes , and monitoring bacterial resistance in NICU may help to reduce the occurrence of CRKP colonization and dissemination .

OBJECTIVE: To evaluate the effect of the vestibular diagnosis and treatment system (SRM-IV ) in diagnosis and treatment of patients with benign paroxysmal positional vertigo (BPPV). METHOD: Patients who were diagnosed as BPPV by SRM-TV in the clinic of our hospital from November 2013 to October 2014 were retrospectively analyzed in this study. RESULT: Among 425 suspected cases, 230 BPPV-positive patients were diagnosed including 131 cases of posterior SC (57.0%), 95 cases of horizontal SC (41.3%) and 4 cases of more than two SC (1.7%). The cure rate by SRM-V was 94.6% and the effective rate was 100.0%. The relapsed occurred in 10 patients (4.8%), which contained 4 men and 6 women. CONCLUSION SRM-V can realize 360° reasonable repositioning procedure while Canalish reposition procedure cannot. SRM-V can improve both the corrective rate of diagnosis and the cure rate, especially for the patients who suffered from complex BPPV.
Benign Paroxysmal Positional Vertigo ; diagnosis ; therapy ; Female ; Humans ; Male ; Patient Positioning ; Retrospective Studies ; Vestibule, Labyrinth ; physiopathology

Objective To explore the value of serum insulin-like growth factor-1(IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3)in diagnosis of children with idiopathic short stature (ISS).Methods 36 ISS and 50 normal children were collected and divided into preadolescent group and adolescent group respectively.Serum IGF-1 and IGFBP-3 were detected by chemiluminescence analysis.Results There were significant positive correlations between age and the serum levels of IGF-1 and IGFBP-3(r =0.435,r =0.718,P <0.01)in both groups.The concentrations of IGF-1 and IGFBP-3 in adolescent group were significantly higher than those in preadolescent group,and the concentrations of IGF-1 and IGFBP-3 in ISS group were significantly lower than those in the control group (P <0.01).Conclusion The detections of IGF-I and IGFBP-3 have a great value in the diagnose,growth monitoring and the treatment with GH for children with ISS.

Objective To explore the value of serum insulin-like growth factor-1(IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3)in diagnosis of children with idiopathic short stature (ISS).Methods 36 ISS and 50 normal children were collected and divided into preadolescent group and adolescent group respectively.Serum IGF-1 and IGFBP-3 were detected by chemiluminescence analysis.Results There were significant positive correlations between age and the serum levels of IGF-1 and IGFBP-3(r =0.435,r =0.718,P <0.01)in both groups.The concentrations of IGF-1 and IGFBP-3 in adolescent group were significantly higher than those in preadolescent group,and the concentrations of IGF-1 and IGFBP-3 in ISS group were significantly lower than those in the control group (P <0.01).Conclusion The detections of IGF-I and IGFBP-3 have a great value in the diagnose,growth monitoring and the treatment with GH for children with ISS.