Objective:To document any effect of environmental enrichment on nerve regeneration in a mouse model of sciatic nerve compression and explore its mechanism.Methods:A crushed sciatic nerve model was successfully established in 22 C57BL/6 mice, and they were then randomly divided into an intervention group and a control group. The mice of the intervention group were raised in a cage with an enriched environment, while those of the control group were kept in a standard cage. Two weeks later, both groups′ gait was analyzed and the compound muscle action potential (CMAP) of the sciatic nerve was measured. The proportion of myelinated sciatic nerve fibers was examined using toluidine blue staining, and the expression of myelin basic protein (MBP), growth associated protein-43 (GAP43) and p75 neurotrophin receptor (p75 NTR) was measured using immunofluorescence intensity. Results:①The latency of the CMAP [(1.05±0.04)ms] was significantly shortened in the intervention group compared with the control group and the amplitude was significantly higher. ②Gait analysis showed a significant increase in the average contact intensity, stride length and stride rate of the intervention group compared with the control group. However, the step axis angle of the intervention group was significantly smaller than in the control group on average. ③The stained nerve fibers in the intervention group were orderly and dense, and the average number of myelinated fibers was significantly greater than in the control group. ④Quantitative analysis of the immunofluorescence showed that the levels of MBP, GAP43 and p75 NTR in the sciatic nerves of the intervention group were, on average, significantly higher than in the control group. Conclusion:An enriched environmental can promote the regeneration and functional recovery of crushed sciatic nerves by promoting the proliferation and myelination of Schwann cells.

Objective:To explore the application value of artificial intelligence (AI) in image post-processing of reconstructed CTA based on CT cerebral perfusion (CTP).Methods:Clinical and radiological data of 100 patients suspected of cerebrovascular diseases in Hebei General Hospital from January to July 2020 were retrospectively selected. All patients were divided into A and B group on average according to the different examination schemes. Cerebral CTP examination was performed in group A (the temporal maximum intensity projective data set generated by the first 5 time phases in the maximum period of the difference between arteriovenous CT values selected as subgroup A1, and the corresponding original thin-layer images selected as subgroup A2), single phase CTA examination was performed in group B, manual and AI image post-processing were performed respectively. Subjective scoring of the image data was performed, and the objective bid evaluation indexes such as CT value, noise (SD), signal-to-noise ratio (SNR), contrast to noise ratio (CNR) were measured, the qualified rate of artificial and AI vascular segmentation was counted, and post-processing time were recorded. The objective evaluation indexes were compared between three groups using one-way ANOVA, and the Kruskal-Wallis H test was used to compare the difference of subjective scores.Results:Statistically significant differences were observed in subjective score and objective evaluation index of original images among group A1, group A2 and group B (all P<0.05). Among them, arterial enhancement, arteriolar detail display score, cerebral artery CT value, SNR and CNR in group A1 were higher than those in group A2 and group B (all P<0.05). In a total of 100 patients with 1 100 blood vessels, the qualified rates of AI vascular segmentation in group A1 [98.4% (541/550)] and group B [98.7% (543/550)] were higher than those of manual [82.9% (456/550), 87.1% (479/550), χ2=77.392, 56.521, P<0.001], but the qualified rate of AI vascular segmentation of group A2 [78.4% (431/550)] was lower than that of manual [85.6% (471/550), χ2=9.855, P=0.002]. The completion time of AI post-processing were reduced by 56.30%, 49.63%, 50.81%, respectively than those with manual. Conclusion:Compared with manual image post-processing, AI has certain advantages in image quality and work efficiency of reconstructed CTA post-processing based on CTP de-noising dataset, and it is worth popularizing and applying in the image post-processing of cerebrovascular disease, combined with artificial quality control.

Objective To analyze drug resistance data of Enterococcus faecalis and Enterococcus faecium,submitted by member units of Chongqing bacterial drug resistance monitoring network,and to provide the basis for our city effective application of antimicrobial agents and the reference.Methods Target bacteria identification and drug susceptibility test were performed by member units,according to the national technology scheme of bacterial drug resistance monitoring network and the results were determined according to standards published by Clinic and Laboratory Standard Institute(CLSI) in 2015.WHONET5.6 software was used to analyze drug susceptibility,and drug resistance difference was analyzed by using SPSS21.0 software.Results A total of un-repeated 1 811 strains of Enterococcus faecalis and 1 601 strains of Enterococcus faecium,accounting for 13.1% of all positive strains.The resistant rates of the two kinds of bacteria to vancomycin were 0.5% and 1.8%,to rinathiazole amine were 2.5% and 0.5% respectively.Tigecycline resistant strains were not founded.The resistant rate of Enterococcus feaclis to ouinupristin/dalfopristin was 90.1%,to tetracycline was 78.8%,to high concentration of gentamicin was 43.0%,to penicillin,ampicillin and nitrofurantoin was less than 7%.Except ouinupristin/dalfopristin and tetracycline,the resistant rate of Enterococcus faecium to the other drugs were significantly higher than Enterococcus faecalis(P<0.05).Strains isolated from children and adult patients,Intensive Care Unit(ICU) and un-ICU patients were with differences of drug resistance(P<0.05).Conclusion Most of Enterococcus infection could be caused by Enterococcus faecalis and Enterococcus faecium.Monitoring of drug resistance might be helpful for rational and effective usage of antimicrobial agents.

OBJECTIVETo establish a method for determination of fatty acid esters of chloropropanols (chloropropanols esters) in milk powder by isotope dilution-gas chromatography-mass spectrometry (GC-MS), and to acquire the pollution level of chloropropanols esters in infant formula and evaluate the dietary exposure risk of chloropropanols esters in infant formula for infants.

METHODSA total of 111 infant formula samples were collected from supermarkets in Beijing, and the infant formula with no chloropropanols esters detected was served as the blank sample. The samples were ultrasonically extracted with hexane, followed by ester-bond cleavage reaction with sodium methylate-methanol and purification by matrix solid-supported liquid-liquid extraction, then being derivatived with heptafluoro butyrylimidazol. After extracted by sodium chloride solution, the derivatives were determined by GC-MS. The concentration of chloropropanols esters were quantified using the deuterium chloropropanols esters as the internal standards. The accuracy of the method was assessed by the recoveries of the blank spiked samples, and the relative standard deviations (RSD) of the recoveries represent the precision of the method. The contamination level of chloropropanols esters and the intake amount of the infant formula of the 6-month infant were used to estimate the dietary exposure assessment, and x (95% CI) and P97.5 of the contamination level of chloropropanols esters were used to represent the average dietary exposure and the high-end dietary exposure.

RESULTSThe satisfied linear correlations in the range of 0.010-0.800 mg/L was acquired for 3-MCPD esters, 2-MCPD esters, 1,3-DCP esters and 2,3-DCP esters with coefficient correlations of 0.999 9, 0.999 8, 0.999 5 and 0.999 6, respectively. The limits of detection (LOD) and the limits of quantitation (LOQ) for 3-MCPD esters, 2-MCPD esters, 1,3-DCP esters and 2,3-DCP esters were 0.005, 0.005, 0.015, 0.015 mg/kg, and 0.015, 0.015, 0.045, 0.045 mg/kg. The average recoveries of the four chloropropanols esters spiked at 0.025, 0.050 and 0.100 mg/kg in blank matrix were in a range from 80.3% to 111.9%, with relative standard deviations (RSD) less than 11.4%. Of the 111 infant formula samples, the detection rates and the contamination levels of 3-MCPD esters and 2-MCPD esters were 77.5% (86/111), 11.7% (13/111) with the contamination levels in the range of ND-0.230 mg/kg and ND-0.039 mg/kg, respectively, and χ (95% CI) and P97.5 of 3-MCPD esters and 2-MCPD esters were 0.020 (0.003-0.113) and 0.006 (0.005-0.025) mg/kg, 0.113 and 0.025 mg/kg, respectively. 1,3-DCP esters and 2,3-DCP esters were not detected in the 111 samples. x (95% CI) and P75 of the six-month old infants to 3-MCPD esters were 0.304 (0.038-1.735) and 1.735 µg · kg⁻¹ · d⁻¹, respectively, which accounted for 15.2% and 86.7% of the PMTDI (2 µg · kg⁻¹ · d⁻¹) of 3-MCPD.

CONCLUSIONThis GC-MS method was accurate and rugged for the determination of chloropropanols esters in milk powder. Based on the exposure assessment results, the health risk of chloropropanols esters for infants caused by the intake of infant formula was acceptable.

Chlorohydrins ; Esters ; Fatty Acids ; Food Contamination ; Gas Chromatography-Mass Spectrometry ; Humans ; Infant ; Infant Formula ; alpha-Chlorohydrin

BACKGROUNDH9N2 avian influenza viruses (AIVs) have repeatedly caused infections in mammals even humans in many countries. The purpose of our study was to evaluate the acute lung injury (ALI) caused by H9N2 viral infection in mice.

METHODSSix- to eight- week-old female SPF C57BL/6 mice were infected intranasally with 1 × 10(4) MID50 of A/HONG KONG/2108/2003 [H9N2 (HK)] virus. Clinical signs, pathological changes, virus titration in tissues of mice, arterial blood gas, and cytokines in bronchoalveolar lavage fluid (BALF) and serum were observed at different time points after AIV infection.

RESULTSH9N2-AIV-infected mice exhibited severe respiratory syndrome, with a mortality rate of 50%. Lung histopathological changes in infected mice included diffuse pneumonia, alveolar damage, inflammatory cellular infiltration, interstitial and alveolar edema, and hemorrhage. In addition, H9N2 viral infection resulted in severe progressive hypoxemia, lymphopenia, and a significant increase in interleukin 1, interleukin 6, tumor necrosis factor, and interferon in BALF and serum.

CONCLUSIONSThe results suggest that H9N2 viral infection induces a typical ALI in mice that resembles the common features of ALI. Our data may facilitate the future studies of potential avian H9N2 disease in humans.

Acute Lung Injury ; blood ; etiology ; virology ; Animals ; Bronchoalveolar Lavage Fluid ; chemistry ; Female ; Influenza A Virus, H9N2 Subtype ; pathogenicity ; Interleukin-1 ; blood ; metabolism ; Interleukin-6 ; blood ; metabolism ; Mice ; Mice, Inbred C57BL ; Respiratory System ; virology ; Tumor Necrosis Factor-alpha ; blood ; metabolism

Objective To review video-assisted thoracoscopic thymectomy as a treatment for myasthenia gravis (MG),compare outcomes of thoracoscopic thymectomy for thymoma and non-thymoma MG,and assess the efficacy of Video-assisted Thoracoscopic Extended Thymectomy (VATET) combined with mediastinoscopy.Methods A retrospective review of 500 patientswith MG who underwent VATS thymectomy between 2001 and 2011 has been done.They were divided into three groups:118 cases of thymoma MG group,thoracoscopy for non-thymoma MG group 301cases,and VATET for non-thymoma MG group 81cases.Results There was no mortality.Thoracoscopic thymectomy was successfully performed for 495 cases.In the thoracoscopy group for non-thymoma MG,the operating time is (111.3 ± 31.6) min,11.0％ having post-operative myasthenic crises ; in the VATET group,the operating time is (145.0 ± 71.6) min,9.9％ having post-operative myasthenic crises ;in the thymoma MG group,the operating time is (128.5 ± 77.8)min,24.6％ having post-operative myasthenic crises.During the follow-up,CSR was 37.3％,36.5％ and 28.7％ in the groups of thoracoscopy for non-thymoma MG,VATET and thymoma MG respectively.However,the disease-free survival curve shows that CSR of the thymoma MG group became lower than other two groups 3 years after surgery,and CSR of the VATET group becoming higher than that of thoracoscopy for nou-thymoma MG group 5 years after surgery.CSRs of groups of thoracoscopy for non-thymoma MG,VATET and thymoma MG might reach 50％,60％ and 36％.Conclusion The VATET combined with mediastinoscopy has a better long-term outcome because the more thymus might be removed comparing with non-thymoma MG,thoracoscopic thymectomy for thymoma MG had a worse long-term outcome.

To retrospectively analyze the clinical data of 42 patients at our department with bulbar myasthenia gravis.They underwent video-assisted thoracoscopic extended thymectomy (VATET) from May 2003 to August 2010.Another 42 patients treated with medications alone were selected as controls.Compared with the control group (4.32 ± 0.23),postoperative dysphagia scores improved significantly in patients undergoing VATET(9.21 ±0.41).And so did the dysphagia assessment classification (P ＜0.05).Thus VATET could effectively and definitely relieve dysphagia in patients with bulbar myasthenia gravis.

Objective To develop a double-regulated replicative adenovirus carrying the Human endostatin gene(hEndo). Methods The plasmid pTPHre-hEndo was constructed by gene engineering technique, carrying human endostatin gene, in which El A gene and E1B gene were driven by human telomerase reverse transcriptase (hTERT) promoter and hypoxia response element (HRE) promoter,respectively. The pTPHre-hEndo was co-transfected with pBHGE3 in 293 cells to generate recombinant adenovirus AdTPHre-hEndo. Virus titer was measured by the TCID50 method. Virus replication assay was performed to evaluate the selective replication ability of AdTPHre-hEndo. The transgene expression of endostatin was detected by ELISA assay. Results A novel gene-viral therapeutic system AdTPHre-hEndo was constructed by gene engineering technique and its titer was 3. 25 X 1010 pfu/ml.Proliferative test revealed that AdTPHre-hEndo could proliferate selectively in telomerase positive tumors. Furthermore, in comparison with non-replicative adenovirus Ad-hEndo, the transgene expression of endostatin mediated with AdTPHre-hEndo was significantly increased (P < 0. 01).Conclusion The novel gene-viral therapeutic system AdTPHre-hEndo has the capacity to replicate in pancreatic cancer cells and expresses the endostatin efficiently, and may provide a new strategy for pancreatic cancer gene therapy.

Objective To establish human pancreatic cancer xenografts in nude mice, and to investigate the antitumor efficacy of human endostatin expressed by replication-competent adenovirus AdTPHre-hE in vivo. Methods Pancreatic cancer cells AsPC-1 were injected subcutaneously in BALB/c nude mice to establish the xenografts. Tumor growth was observed and measured after AdTPHre-hE treatment. Expression of endostatin was detected by ELISA assay. The tumors were harvested for pathologic examination and immunohistochemical staining. Results Tumors grew more slowly in the AdTPHre-hE group and their sizes were markedly smaller than those of the Ad-hE group (P＜0.01)and control group(P＜0. 01). Endostatin levels were detected in the sera of nude mice in all treated groups, and endostatin expression in AdTPHre-hE group increased with time. The endostatin level in the AdTPHre-hE treated group was much higher(P＜0. 01)and increased faster than that in the Ad-hE treated group. Immunohistochemical staining for Hexon of adenovirus capsid showed more positive tumor cells in the tumor tissues treated with AdTPHre-hE. Immunohistochemical staining for FⅧ revealed a decreased microvessel density in the tumor tissues treated with AdTPHre-hE. Conclusion The replication-competent adenovirus efficiently expressed high-level endostatin and significantly inhibited tumor growth in vivo.

Objective To explore the effect of wild type or mutant parkin gene expression on the growth of human hepatocellular carcinoma cell line Huh-7. Methods The parkin (wild type or mutant) expression vector and empty vector were transferred into Huh-7 cell lines with LipofectAMINE 2000 reagents. The positive clones that expressed parkin gene stably were chosen by G418 and checked by reverse transcription-polymerase chain reaction (RT-PCR) to check the DNA sequences. The cytobiological behaviors of those positive clones were analyzed by cell proliferation assay and tumorigenesis in nude mice. Results Huh-7 cell lines that expressed wild type or mutant parkin gene stably were successfully established. The growth of wild type parkin-expressed cells was obviously inhibited compared with the control cells transfected with empty vectors(t= 3. 875, P= 0. 031).The volume of tumor formed by wild type parkin-expressing cells in nude mice was also significantly reduced (t=8. 228,P=-0. 003). Mutant parkin gene expression had a slight effect on the growth of Huh-7 cells in vitro and in vivo (P＞0.05). Conclusion The re-expression of wild type parkin gene can favor the malignant phenotype revision of Huh-7 cells. Therefore, it might be a good candidate for tumor suppressor gene associated with HCC.