Objective To analyze the epidemiological characteristics of mobile colistin resistance(mcr)genes in global Klebsiella pneumoniae(K.pneumoniae).Methods The genomes of K.pneumoniae were downloaded from the NCBI genome database by the As-pera software.After quality filtering using the CheckM v1.1.3 and Quest 5.0.2 software,the genomes were annotated using the Prokka v1.13.All the mcr gene sequences were downloaded from the NCBI website and a database was built using the makeblastdb command.Then,a self-made Perl script program was used to extract the nucleotide sequences of all genes from the annotation file as Query,and the local BLASTN analysis was performed to obtain mcr-positive strains.The gene sequence files and Profiles files of 7 housekeeping genes of K.pneumoniae were downloaded from the PubMLST website as the database,and the nucleotide sequences of the genes were extracted as Query using a self-made Perl script program.The local BLASTN analysis was implemented to determine the sequence type(ST)of each genome.Meta information of each strain,including isolation source,sample type,country,and date,were extracted in batch from the GenBank file of the downloaded K.pneumoniae genomes using a self-written Perl program to analyze the distribution characteristics of mcr-positive strains.The distribution differences of the mcr between different ST types were compared by the Chi-square test.Results Among the 11 429 global K.pneumoniae genomes included in this study,229 mcr genes were detected from 207 strains.Six variants of mcr were identified,mainly mcr-1(87/229,38.0％),mcr-8(59/229,25.8％),and mcr-9(59/229,25.8％).76 STs were identified from 207 strains,with ST15(21/207,10.1％),ST43(17/207,8.2％),ST11(16/207,7.7％),and ST 147(16/207,7.7％)being the predominant.Among 87 mcr-1 positive strains,31 STs were found,with ST43(17/87,19.5％)and ST15(10/87,11.5％)being the main ones.Among 59 mcr-8 positive strains,17 STs were identified,with ST43(17/59,28.8％)and ST11(9/59,15.3％)being the predominant.Among 59 mcr-9 positive strains,27 STs were detected,with ST147(11/59,18.6％)and ST274(11/59,18.6％)being the main ones.There were statistical differences in the variants of mcr genes carried by different ST types.The mcr-positive K.pneumoniae came from 28 countries across five continents worldwide,led by China(68/207,32.9％)and Thailand(45/207,21.7％),which were mainly from the human body(100/207,48.3％)and had a concentrated outbreak time from 2015 to 2018.Conclusion Among the global K.pneumoniae,the prevalence of mcr is mainly domina-ted by mcr-1,mcr-8,and mcr-9.The dominant clones of mcr-1 are mainly ST15 and ST43,while those of mcr-8 are mainly ST11 and ST43.The popularity of mcr-9 is mainly based on ST147 and ST274.Strengthening the monitoring of such bacteria may play an impor-tant role in preventing and controlling nosocomial infections.

Enzyme-driven micro/nanomotors consuming in situ chemical fuels have attracted lots of attention for biomedical applications. However, motor systems composed by organism-derived organics that maximize the therapeutic efficacy of enzymatic products remain challenging. Herein, swimming proteomotors based on biocompatible urease and human serum albumin are constructed for enhanced antitumor therapy via active motion and ammonia amplification. By decomposing urea into carbon dioxide and ammonia, the designed proteomotors are endowed with self-propulsive capability, which leads to improved internalization and enhanced penetration in vitro. As a glutamine synthetase inhibitor, the loaded l-methionine sulfoximine further prevents the conversion of toxic ammonia into non-toxic glutamine in both tumor and stromal cells, resulting in local ammonia amplification. After intravesical instillation, the proteomotors achieve longer bladder retention and thus significantly inhibit the growth of orthotopic bladder tumor in vivo without adverse effects. We envision that the as-developed swimming proteomotors with amplification of the product toxicity may be a potential platform for active cancer treatment.

Objective:To evaluate the clinical efficacy of microneedle radiofrequency in the treatment of moderate acne vulgaris.Methods:From August 2018 to August 2020, 393 patients (192 males and 201 females, aged 15-38 years) with moderate acne were enrolled in the Department of Dermatology, the First Affiliated Hospital of Shantou University Medical College and Shantou Chaonan Minsheng Hospital, including 201 patients in experimental group and 192 patients in control group. In the experimental group, microneedle radiofrequency therapy was used once every 2 weeks for 3 times in total. The control group adopted the fire needle, once every 2 weeks, a total of 3 times. The efficacy of both groups was evaluated at week 8.Results:A total of 378 patients were actually completed: 196 patients in the experimental group, and 182 patients in the control group. At the eighth week of follow-up, the total effective rate was 81.12% in the experimental group and 70.43% in the control group. The efficacy of the two groups was statistically different (χ 2=4.42, P<0.05). Conclusions:The efficacy of microneedle radiofrequency therapy in the treatment of moderate acne vulgaris is better than that of fire needle, with good tolerance, short recovery period, few adverse reactions and high compliance, which has clinical promotion value.

Excessive theta (θ) frequency oscillation and synchronization in the basal ganglia (BG) has been reported in elderly parkinsonian patients and animal models of levodopa (L-dopa)-induced dyskinesia (LID), particularly the θ oscillation recorded during periods when L-dopa is withdrawn (the off L-dopa state). To gain insight into processes underlying this activity, we explored the relationship between primary motor cortex (M1) oscillatory activity and BG output in LID. We recorded local field potentials in the substantia nigra pars reticulata (SNr) and M1 of awake, inattentive resting rats before and after L-dopa priming in Sham control, Parkinson disease model, and LID model groups. We found that chronic L-dopa increased θ synchronization and information flow between the SNr and M1 in off L-dopa state LID rats, with a SNr-to-M1 flow directionality. Compared with the on state, θ oscillational activity (θ synchronization and information flow) during the off state were more closely associated with abnormal involuntary movements. Our findings indicate that θ oscillation in M1 may be consequent to abnormal synchronous discharges in the BG and support the notion that M1 θ oscillation may participate in the induction of dyskinesia.

Objective: To determine the relationship between dengue virus load and clinical characteristics, so as to provide basis for dengue fever prevention and treatment. Methods : The dengue viral load and typing of 120 patients in Gongshu District of Hangzhou from June to November 2017 were detected by real-time fluorescent quantitative RT-PCR;the clinical indicators of these dengue patients were collected and their correlation with the viral load was analyzed. Results: The DNA detection of dengue virus in 120 patients showed that they were all typeⅡ. The median dengue virus load was 3.91×104 copies/mL. All the patients had fever, the average peak temperature was（38.96 ± 0.69）℃. There were 102（85.00%）cases with asthenia;116（96.67%）cases with white blood cell count（WBC）less than 4× 109/L;119（99.17%）cases with platelet count（PLT）less than 100×109/L;114（95.00%）cases with glutamic oxaloacetate transaminase（GOT）more than 40 U/L;81（67.50%）cases with glutamic pyruvate transaminase（GPT）more than 52 U/L;58（48.33%）cases with creatine kinase（CK）more than 210 U/L. There was no significant correlation of dengue virus load with length of hospitalization, peak temperature,duration of fever, WBC,PLT, GOT, GPT and CK（P>0.05）. There were 75（62.50%）severe patients, and their median viral load was 9.29×104copies/mL, which was higher than 5.33×103copies/mL in non-severe patients（P<0.05）. Conclusion The dengue virus load is not related with length of hospitalization,peak temperature,WBC,PLT,GOT,GPT and CK,but with the severity of the disease.

Objective To investigate the mechanism of improvement of gait behavior in PD rat models by low frequency electrical stimulation of pedunculopontine tegmental nucleus (PPTN) by optogenetics method. Methods (1) Twenty-four healthy adult male SD rats were randomly divided into a sham-operated group 1, a lesion group 1 and a photoactivation group (n=8); normal saline was injected into the right medial frontal tract (MFB) of the sham-operated group 1; 6-hydroxydopamine (6-OHDA) was injected into the lesion group 1 and photoactivation group to induce PD models; two weeks after modeling, injection of adeno-associated virus hsynapsin-ChR2-mcherry into the right PPTN of the three groups was performed, and the photoactivation group received blue-ray stimulation by implanting optical fibers into the PPTN at the same time. (2) Twenty-four healthy adult male SD rats were randomly divided into a sham-operated group 2, a lesion group 2 and a photoinhibition group (n=8);normal saline was injected into right MFB of the sham-operated group 2; 6-OHDA was injected into the lesion group 2 and photoinhibition group to induce PD models; two weeks after modeling, injection of adeno-associated virus hsynapsin-NpHR-mcherry into the right PPTN of the three groups was performed, and the photoinhibition group received yellow-ray stimulation by implanting optical fibers into the PPTN at the same time. (3) Three weeks after injection of adeno-associated virus, Catwalk gait analysis was used to assess the behavioral ability of rats in each group. Results (1) As compared with the sham-operated group 1, lesion group 1 had significantly increased front claw spacing and back front claw spacing, and significantly decreased stride length and pressure of damaged lateral and contralateral limbs, and significantly decreased swing speed of contralateral limb (P<0.05); as compared with those in the lesion group 1, the front claw spacing and back claw spacing were significantly shortened, and stride length and pressure of damaged lateral and contralateral limbs were statistically increased in the photoactivation group (P<0.05). (2) As compared with the sham-operated group 2, lesion group 2 had significantly increased front claw spacing and back front claw spacing, significantly decreased stride length of damaged lateral limb, and significantly decreased pressure and swing speed of damaged lateral and contralateral limbs (P<0.05); no significant differences were noted on the front claw spacing and back front claw spacing, pressure and swing speed of damaged lateral and contralateral limbs between lesion group 2 and photoinhibition group (P>0.05). Conclusion The mechanism of low frequency electrical stimulation of PPTN improving gait behavior of PD rat models is related to activation of PPTN neurons.

Objective To explore the mechanism of microRNA (miRNA, miR)-155 in the rejection after liver transplantation in rats. Methods The rats were divided into two groups. In the xenograft model group (rejection group, n=10),the donors were male Lewis rats and the recipients were male BN rats.In the allograft model group(control group, n=10),both the donors and recipients were male Lewis rats.The rat models with orthotopic liver transplantation were established by two-cuff technique in two groups. At postoperative 7 d, the animals were sacrificed for the collection of blood and liver tissue samples. The serum levels of alanine aminotransferase (ALT), total bilirubin (TB), and cytokines of interleukin (IL)-2, IL-4, interferon (IFN)-γ were quantitatively measured. The pathological changes of liver tissues were observed under light microscope. In each group, three liver tissue samples were prepared and subject to high-throughput sequencing. The miRNAs related to rejection were identified for bioinformatics analysis to predict and analyze relevant signaling pathways and genes. Results In the rejection group, the serum levels of ALT and TB were significantly higher than those in the control group (both P<0.01). Compared with the control group, the levels of IL-2 and IFN-γ were considerably up-regulated (both P<0.01), whereas the level of IL-4 was dramatically down-regulated (P<0.01). Pathological examination demonstrated that more evident rejections were observed in the rejection group than the control group. High-throughput sequencing revealed that the expression level of miR-155 was significantly up-regulated in the rejection group, which was 5.89 times of that in the control group. Bioinformatics analysis demonstrated that up-regulation of miR-155 was associated with the mammalian target of rapamycin (mTOR), mitogen-activated protein kinase (MAPK) and T cell receptor signaling pathways. The genes which were probably responsible for regulation included the yeast autophagy related gene 1(ATG1) and its homologous gene ULK2, insulin-like growth factor-1 (Igf-1) and G protein-coupled receptor regulatory gene(Arrb1),etc.Conclusions miR-155 might promote the incidence and progression of rejection after liver transplantation in rats. The involved signaling pathways probably include the mTOR, MAPK signaling pathway and T cell receptor signaling pathway.ATG1,ULK2,Igf-1,and Arrb1 genes may participate in this process.

Objective To establish male rat models for fertility following liver transplantation. Methods Male Sprague-Dawley (SD) rats were used as the donors and recipients of liver transplantation. The donor liver was transplanted with two-cuff technique. Liver transplantation was performed in 15 male SD rats. At 3 weeks after liver transplantation, 5 rats were randomly sacrificed for detection of sperm deformity rate. The remaining male rats were mixed bred and mated with healthy female SD rats at a ratio of 1︰2. General conditions of the rats undergoing liver transplantation were recorded. Liver function parameters were detected after liver transplantation. Postoperative sperm deformity rate was observed. The pregnant status of female rats and health situation of their offsprings was monitored. Results All 15 rats (100%) underwent liver transplantation successfully. Nine rats (9/10) survived longer than 8 weeks. Liver function parameters were normal in male rats following liver transplantation. The sperm deformity rate was ranged from 0.5% to 1.3%. Ten male rats undergoing liver transplantation were mixed bred with female rats at a ratio of 1︰2 for 1 week. All female rats were successfully mated and delivered their offsprings after 3 weeks. The offsprings had no evident physiological deformity. Conclusions Male rat models for fertility are successfully established after liver transplantation, which serve as an animal model to evaluate the fertility performance in male patients undergoing liver transplantation.

Objective To investigate the prevalence and characteristics of non-nucleoside reverse transcriptase inhibitors (NNRTIs)resistance-related gene mutations among the AIDS patients with virological suppression failure in Guangdong Province 2015.Methods Plasma samples from AIDS patients receiving highly active antiretroviral therapy for more than one year with viral loads > 1000 copies/mL from Guangdong province (except Shenzhen)were collected from January to December 2015.Total 612 HIV-1 gene fragments were amplified from plasma samples using self-developed lab method.Sub-genotypes were determined by phylogenetic tree according to the sequences,NNRTIs resistance-related mutations were determined in Stanford University HIV-1 Drug Resistance Database. The NNRTIs-resistance, the relationships of NNRTIs resistance-related mutations with baseline CD4 +T lymphocyte counts,transmission routes,antiviral regimens and HIV-1 genotypes were analyzed.SPSS 17.0 software was used to analyze the data.Results In 612 patients with virological suppression failure,the main NNRTIs resistance-related mutations were K103 (26.80%),Y181 (14.71 %),V179 (13.73%),G190 (11 .44%) and V106 (10.62%).The susceptibility rate of 310 patients (50.65%)to NNRTIs had changed,the highly resistant rate to nevirapine was 49.51 %,which was higher than that of efavirenz (43.14%),etravirine (5.56%) and rilpivirine (12.25%),respectively,and the differences were statistically significant (χ2 =5.00,296.3 and 198.0,all P <0.05).The incidence rate of drug resistance in patients with baseline CD4 +T lymphocyte counts >200 cells/μL was lower than that in those with baseline CD4 +T lymphocyte counts <200 cells/μL (χ2 =17.93,P <0.01 );the incidence rate of drug resistance was lower in intravenous drug abusers than that of sexually transmitted patients (χ2 =44.21 ,P <0.01 );while the incidence of drug resistance in patients receiving NVP-containing regimens was higher than that in those receiving EFV-containing regimens (χ2 =8.93,P <0.01 ),and the incidence rate was higher in patients with CRF01 _AE than that in those with CRF07_BC and CRF08 _BC (χ2 =8.46 and 8.47,P <0.01 ).Conclusions The results suggest that compliance education and follow-up should be strengthened in patients with high baseline CD4 +T lymphocyte counts and intravenous drug users,and patients with liver diseases should avoid using drugs containing NVP regimens.

Objective To investigate the BRAF-V600E mutation in pediatric patients with Langerhans cell histiocytosis and its clinical features. Methods A retrospective study was conducted among 27 children who were diagnosed in our hospital between August 2009 and June 2015 ,including 17 males and 10 females. BRAF-V600E was amplified from tissue samples of the 27 children with LCH by PCR and the relationship was analysed between the mutation and clinical features ,outcome. Results BRAF-V600E mutation was found in 9 cases within all 27 tested cases(33.3%). Significant difference was not found in age ,gender ,system involvement ,6-week reaction ,3-year overall survival and event-free survival between BRAF-V600E positive and negative groups. Conclusions BRAF-V600E mutation was found in Chinese pediatric LCH patients with positive rate of 33.3%, that indicates LCH might be a neoplastic disease. However ,its definite role on disease onset ,system involvement and disease progression remains unknown.