Objective To explore the operation timing and technique selection of floating knee injury in children.Methods According to Letts types,36 cases were divided into 5 types.The function outcome in every group was compared by Karlstrorm criterion according operation timing or technique selection respectively.Results Thirty-six cases were followed up for an average of 25 months(19 to 84 months).The rate of excellent and good results accounted for 94.12%(16/17) in one stage operation,78.95%(15/19)in stages,60%(6/10)in 2 stages,respectively.Conclusions It may be recommended to treat children with floating knee injury with open reduction intenal fixation or external fixation.The best operation time shall be urgent treatment of both femur and tibia fracture.

Objective To explore the DNA damage in peripheral blood lymphocytes of rats exposed to sodium arsenite. Methods Thirty-two Wistar rats, weighing 180 - 200 g, equal male and female, were randomly divided into 4 groups, 8 in each group. Sodium arsenite 0(control) ,0.05,0.15,0.45 mg/L were given through drinking water for 30 days. Body weight and drinking water consumption were measured every day. Blood were collected and DNA damage in peripheral blood lymphocytes was examined by single cell gel electrophoresis.Results The increase of body mass[( 121.00 ± 38.57), ( 120.62 ± 42.80), ( 125.38 ± 48.68)g]and water intake [(36.9 ± 6.2), (37.9 ± 5.8), (39.3 ± 4.2)ml/d]in 0.05,0.15,0.45 mg/L sodium arsenite groups were compared with the control group[( 119.25 ± 47.27)g, (38.4 ± 5.1 )ml/d], and the difference were not significant (F = 0.040,0.828, all P ＞ 0.05). The tail ratios[46.25%(185/400) ,57.00%(228/400),64.00%(256/400)], tail lengths [(32.89 ± 17.18), (58.74 ± 36.28), (77.55 ± 35.73 ) μm]and tail moments [(6.29 ± 3.74), ( 11.20 ± 9.64),(17.30 ± 12.60)μm]in 0.05,0.15,0.45 mg/L sodium arsenite groups were significantly higher than those of the control group[39.25%(157/400), (18.73 ± 15.83),(2.61 ± 1.05)μm, all P ＜ 0.01], and the tail ratios,tail lengths and tail moments in lymphocytes increased with increased doses of arsenic concentration. Conclusions Low doses of arsenic exposure can induce DNA damage in peripheral blood lymphocytes of rats.

Objective To established cardiac-specific transgenic mice of the cTnC D145E and cTnCG159D and compare the HCM and the DCM.Methods The cTnCD145E and cTnCG159D were generated by site-directed mutagenesis and the transgenic plasmids were constructed by insertion of the mutant genes under the control of α-MHC, which is a myocardium specific promoter.The transgenic mice were generated by microinjection and were all maintained on a C57BL/6J genetic backgroud .The cardiac structure and function of the transgenic mice were compared and analysized by echocardiographic and pathological observation at different ages .Results The cTnCD145E and cTnCG159D transgenic mice were established and developed to HCM and DCM, respectively, with aging.The left ventricular end-systolic volume (ESV) and left ventricular end-diastolic volume ( EDV) decreased and ejection fraction ( EF) and left ventricular end-systolic posterior wall thickness (ESPWT) increased in the cTnCD145E transgenic mice, while EDV and ESV increased and EF and ESPWT decreased in the cTnCG159D transgenic mice at 12 months of age.Conclusions Cardiac-specific human cTnCD145E transgenic mice showed HCM phenotypes , and cardiac-specific human cTnC G159D transgenic mice showed DCM phenotypes , which can be used as different models for comparative study of the pathogenesis of cardiomyopathy .

We applied Lempel-Ziv complexity (LZC) combined with brain electrical activity mapping (BEAM) to study the change of alertness under sleep deprivation in our research. Ten subjects were involved in 36 hours sleep deprivation (SD), during which spontaneous electroencephalogram (EEG) experiments and auditory evoked EEG experiments-Oddball were recorded once every 6 hours. Spontaneous and evoked EEG data were calculated and BEAMs were structured. Results showed that during the 36 hours of SD, alertness could be divided into three stages, i. e. the first 12 hours as the high stage, the middle 12 hours as the rapid decline stage and the last 12 hours as the low stage. During the period SD, LZC of Spontaneous EEG decreased over the whole brain to some extent, but remained consistent with the subjective scales. By BEAMs of event related potential, LZC on frontal cortex decreased, but kept consistent with the behavioral responses. Therefore, LZC can be effective to reflect the change of brain alertness. At the same time LZC could be used as a practical index to monitor real-time alertness because of its simple computation and fast calculation.
Attention ; physiology ; Brain Mapping ; Electroencephalography ; Evoked Potentials ; Humans ; Nonlinear Dynamics ; Sleep Deprivation

Objective To summarize the first 16 eases in mainland China and to discuss the cli-nical experience of robot-assisted laparoseopie radical prostateetomy(RLRP). Methods Sixteen pa-tients with localized prostate carcinoma underwent RLRP with da Vinci S surgical system (Intuitive Surgical Inc.). The age of the patients was 62-76 years, average 69 years. The preoperative t-PSA level was 0.2-79. 2. Ng/ml. The volume of prostate was 9.8-232.9 ml. Fifteen patients were with biopsy-proven prostate cancer, the average Gleason score was 7(4-9). Three were T2a. N0 M0, 4 were T2b N0 M0 and 8 were T2c N0/M0 by clinical stage. One was prostatic intraepithelial neoplasm-Ⅲ. The level of t-PSA in serum and the result of urinary continence were followed up after RLRP. Results All the operations were accomplished successfully. The mean preoperative set-up time of the da Vinci surgical system was 64(60--90)min;the mean operation time was 236(190--390)rain;the mean esti-mated blood loss was 231(50-500)m.L The patients were ambulant between the 2nd and 3rd postop-erative days. Foley catheter was sueeeasfully removed on day 10 to 14, and mean hospital stay was 13 (6-19) days. Two eases had positive surgical margins, the pathological stages were both pT3b N0 M0. The average serum t-PSA was less than 0. 1 ng/ml during a median follow-up of 9(6-12) months. By the conventional definition of urinary continence (0 to 1 pads daily), 94%(15/16) and 100% (16/16)of patients were continent at 3 and 6 months, respectively. Of the patients, 75% (12/16)and 88% (14/16)had no urinary leakage(0 pads daily). Conclusions RLRP is small incision and safe. It is the direction of minimally invasive urologic surgery.

AIM: To investigate the effect of problem - based learning ( PBL) used in the teaching of medical students'evidence-based medicine ( EBM) .
METHODS: Five classes ( total 147 students ) were randomly selected as experimental ( PBL ) group, at the same time, another 5 classes ( total 149 students ) were also randomly selected as control group, using traditional teaching method ( lecture-based learning, LBL ) in 2010 grade. The final examination scores of the experimental group were compared with control at the end of term. In addition, all students were interviewed using self -administered questionnaire to obtain their evaluation for PBL practice. SPSS13. 0 software was used for statistical analysis.
RESULTS: The homogeneity test in baseline survey showed that the basic characteristics between the two groups of students were no significant differences, and were comparable (P>0. 05). Final exam results showed that in addition to the scores of the EBM basic knowledge indicated no significant difference between two groups of students (P>0. 05), for the 5 steps of EBM procedure, namely, asking questions, finding the best evidence, evaluating the evidence, using and practicing the evidence, re - evaluating the evidence, and the total scores between the two groups, there were significant statistically differences (P<0. 05). The results to student learning evaluation showed that there was no significant difference between the two groups (P>0. 05) in aspects of better understanding classroom knowledge, improving language expression ability, and writing skill exercises. And other residual items had a significant difference ( P<0. 05), especially in aspects of improving enthusiasm for learning, self - study ability, improving learning efficiency, information analysis and utilization ability, team collaboration, and communication between teachers and students, however, there was a very significant difference (P<0. 001) between the two groups.
CONCLUSION: PBL teaching mode can effectively improve teaching effectiveness and the quality of EBM teaching, so the this teaching mode is worth further popularizing.

Objective To investigate the effect of selenium on proliferation and apoptosis of chondrocytes of articular cartilage cultured in vitro in Kaschin-Beck disease(KBD) patients and normal person, to explore the role of selenium in control of KBD, and to provide evidence for selenium's effect on the growth of normal cartilage cells. Methods The articular cartilage samples of grade Ⅱ and Ⅲ KBD patients were selected according to the national "Clinical Diagnosis of KBD" (GB 16003-1995). Chondrocytes of 5 KBD and 5 non-endemic normal accidentswere separated and cultured in vitro. KBD group and control group were given different doses of selenium (0,0.0125,0.0250,0.0500,0.1000,0.2500,0.5000,1.0000 mg/L, respectively). Methyl thiazolyl tetrazolium (MTT),flow cytometric analysis, and immunocytochemical staining were used to observe the effect of selenium on cell growth and apoptosis in KBD and normal persons. Results MTT results showed that the cell proliferation rate in each dosage group of the control group at the 6th day(0.086 ± 0.025,0.077 ± 0.012,0.073 ± 0.027,0.071 ± 0.017,0.058 ± 0.028,0.052 ± 0.028 and 0.046 ± 0.037) was significantly lower than that of 0 mg/L group(0.138 ± 0.026,all P ＜ 0.05);the average cell proliferation rate was negative( - 0.001 ± 0.001, - 0.003 ± 0.000, - 0.003 ± 0.001and - 0.004 ± 0.001 ) in 0.1000 - 1.0000 mg/L dose group, which was significantly lower than that of the 0 mg/L group(0.025 ± 0.003, all P ＜ 0.05);compared with 0 mg/L group(0. 115 ± 0.011), the KBD 0.2500 mg/L dose group promoted cell proliferation(0.128 ± 0.037, P ＜ 0.05), the KBD 1.0000 mg/L dose group inhibited cell growth (0.071 ± 0.019, P ＜ 0.05). The apoptotic rate of 0.0500 - 1.0000 mg/L dose control group [ (18.88 ± 0.02)%,(17.58 ± 0.01)%, (17.09 ± 0.04)%, (56.00 ± 0.02)%, (57.85 ± 0.03)% ] were higher than that of the 0 mg/L group[(13.51 ± 0.01)%, all P ＜ 0.05];compared with 0 mg/L group[(25.84 ± 0.02)%], the apoptotic rate in KBD 0.0250 - 0.2500 mg/L dose group [ ( 13.69 ± 0.02) %, ( 15.96 ± 0.03 ) %, ( 16.68 ± 0.03 ) %, ( 16.67 ± 0.02) % ]were lower, and the apoptotic rate in 0.5000, 1.0000 mg/L dose group [ (59.58 ± 0.03)%, (73.48 ± 0.04)% ] were significantly higher(all P ＜ 0.05). The Fas expression in KBD 0.0500 - 0.2500 mg/L dose groups[ (41.2 ± 1.5)%,(40.3 ± 2.0)%, (50.2 ± 2.5)%] were lower than those of the same dose control group with selenium intervention [(52.4 ± 1.0)%, (67.2 ± 4.0)%, (75.1 ± 5.0)%, all P ＜ 0.05], the caspase-3 expression in KBD 0.0500,0.1000 mg/L dose groups[ (40.8 ± 1.1 )%, (45.1 ± 2.1 )%] were lower than those of the same dose control group with selenium intervention[ (68.0 ± 3.0)%, (70.6 ± 3.5)%, all P ＜ 0.05 ]. Conclusions Appropriate dose of selenium supplementation (0.1000 - 0.2500 mg/L) could promote the growth of KBD chondrocyte, decrease cell apoptosis,but have a damage when the dose of selenium ＞ 0.5000 mg/L;doses of selenium that could promote the growth of KBD chondrocyte does not mean to promote the growth of normal cartilage cells in vivo.

Carboxylesterases (CESs) play important roles in the metabolism of endogenous and foreign compounds in physiological and pharmacological responses. The aim of this study was to investigate the effect of dexamethasone at different doses on the expression of CES1 and CES2. Imidapril and irinotecan hydrochloride (CPT-11) were used as special substrates for CES1 and CES2, respectively. Rat hepatocytes were cultured and treated with different concentrations of dexamethasone. The hydrolytic activity of CES1 and CES2 was tested by incubation experiment and their expression was quantitated by real-time PCR. A pharmacokinetic study was conducted in SD rats to further evaluate the effect of dexamethasone on CESs activity in vivo. Western blotting was performed to investigate the regulatory mechanism related to pregnane X receptor (PXR) and glucocorticoid receptor (GR). The results showed that exposure of cultured rat hepatocytes to nanomolar dexamethasone inhibited the imidapril hydrolase activity, which was slightly elevated by micromolar dexamethasone. For CES2, CPT-11 hydrolase activity was induced only when dexamethasone reached micromolar levels. The real-time PCR demonstrated that CES1 mRNA was markedly decreased by nanomolar dexamethasone and increased by micromolar dexamethasone, whereas CES2 mRNA was significantly increased by micromolar dexamethasone. The results of a complementary animal study showed that the concurrent administration of dexamethasone significantly increased the plasma concentration of the metabolite of imidapril while the ratio of CPT-11 to its metabolite SN-38 was significantly decreased. PXR protein was gradually increased by serial concentrations of dexamethasone. However, only nanomolar dexamethasone elevated the level of GR protein. The different concentrations of dexamethasone required suggested that suppression of CES1 may be mediated by GR whereas the induction of CES2 may result from the role of PXR. It was concluded that dexamethasone at different concentrations can differentially regulate CES1 and CES2.

Objective:To observe the changes of macular microvessels in patients with retinal vein occlusion (RVO) and macular edema (ME) after intravitreal injection of aflibercept (IVA), and analyze its correlation with best corrected visual acuity (BCVA).Methods:A retrospective case study. Thirty patients (30 eyes) with monocular RVO with ME (RVO-ME) who were diagnosed in the clinical examination of Tianjin Eye Hospital from April 2019 to February 2020 were included in the study. Among them, there were 12 males (12 eyes) and 18 females(18 eyes); the average age was 54.30±13.17 years. The average course of disease was3.43±1.97 months. Both eyes were examined by BCVA and optical coherence tomography (OCTA). The on-demand injection was adopted after the first injection in IVA treatment regimen. The macular area 6 mm×6 mm in both eyes was scanned with an OCTA instrument, and the area of the foveal avascular area (FAZ), FAZ circumference (PERIM), and out-of-roundness were measured at baseline and 1, 3, and 6 months after treatment. Index (AI), blood flow density within 300 μm width of FAZ (FD-300), foveal retinal thickness (CMT), superficial retinal capillary plexus (SCP), deep retinal capillary plexus (DCP) blood flow density. The paired t test was used to compare the quantitative parameters of the affected eye and the contralateral healthy eye at baseline; the changes of the quantitative parameters at baseline and 1, 3, and 6 months after treatment were analyzed by repeated measures analysis of variance. Pearson correlation analysis was used to analyze the correlation between BCVA, retinal perfusion, and macular blood supply parameters at 6 months after IVA treatment. Results:At baseline, compared with the contralateral healthy eye, the FAZ area ( t=-4.091), PERIM ( t=-5.098) and AI ( t=-9.093) of the RVO-ME eye were enlarged, and FD-300 ( t=7.237) and overall SCP and DCP blood flow density ( t=8.735, 9.897) decreased, the difference was statistically significant ( P<0.001). Six months after treatment, the BCVA of RVO-ME eyes was significantly increased, CMT decreased, FAZ area expanded, and AI decreased ( t=8.566, 16.739, -6.469, 9.719; P<0.001), the difference was statistically significant. There was no significant change in the blood flow density of FD-300 and overall SCP and DCP, and the difference was not statistically significant ( t=1.017, 1.197, 0.987; P>0.05). Compared with baseline, the FAZ area of RVO-ME eyes gradually expanded at 3 and 6 months after treatment, and the difference was statistically significant ( F=21.979, P<0.001). Correlation analysis results showed that BCVA at 6 months after treatment was positively correlated with the overall SCP and DCP blood flow density at baseline and 6 months after treatment ( r=-0.538, -0.484, -0.879, -0.854; P<0.05). There was a negative correlation with the area of FAZ 6 months after treatment ( r=0.544, P=0.001). The number of ME recurrences was negatively correlated with BCVA and overall SCP and DCP blood flow density 6 months after treatment ( r=0.604, -0.462, -0.528; P<0.05), it was positively correlated with FAZ area ( r=0.379, P=0.043). Conclusion:Within 6 months of IVA treatment in RVO-ME eyes, ME is significantly reduced and visual acuity is improved; SCP blood flow density decreases, and FAZ area expands.

Vigilance is defined as the ability to maintain attention for prolonged periods of time. In order to explore the variation of brain vigilance in work process, we designed addition and subtraction experiment with numbers of three digits to induce the vigilance to change, combined it with psychomotor vigilance task (PVT) to measure this process of electroencephalogram (EEG), extracted and analyzed permutation entropy (PE) of 11 cases of subjects' EEG and made a brief comparison with nonlinear parameter sample entropy (SE). The experimental results showed that: PE could well reflect the dynamic changes of EEG when vigilance decreases, and has advantages of fast arithmetic speed, high noise immunity, and low requirements for EEG length. This can be used as a measure of the brain vigilance indicators.
Attention ; Brain ; physiology ; Electroencephalography ; Entropy ; Humans ; Mathematics