Objective To analyze the colistin heteroresistance in Pseudomonas aeruginosa strains and their in vitro susceptibility to antibiotics used in combination.Methods Two hundred and ninety-seven carbapenem-resistant Pseudomonas aeruginosa strains were selected for this study.Broth microdilution method was used to determine the minimum inhibitory concentrations of colistin and other antimicrobials against the Pseudomonas aeruginosa strains.The colistin heterogeneity of 20 colistin sensitive strains was analyzed by using population analysis profiles.The time-kill curves of 3 randomly selected colistin heteroresistant strains were used to determine the bacteriostatic activity of colistin.Chequer-board method was used to measure the combination efficacy of colistin with other antimicrobials including imipenem,meropenem,biapenem,ceftazidime,levofloxcin,piperacillin/tazobactam and cefoperazone/sulbactam.Results The colistin sensitive Pseudomonas aeruginosa strains accounted for 99.66％ of the 297 isolates.Population analysis profiles displayed that 35％ of the 20 isolates were colistin heteroresistant and 20％ of the 20 isolates were heterogeneous.It showed that when colistin was used in combination with other drugs,they mainly had synergistic and additive effects on heteroresistant isolates,but additive and indifferent effects on non-heterogeneous isolates.Conclusion Multidrug resistant Pseudomonas aeruginosa strains were highly susceptible to colistin,but heteroresistant and heterogeneous strains were common.The efficacy of colistin against heteroresistant isolates could be enhanced by using in combination with other drugs.

Objective To study the risk factors of post-hepatectomy hepatic decompensation (PHD) in patients with hepatocellular carcinoma.MethodWe reviewed 562 patients with Child-Pugh A classification,who underwent partial hepatectomy for hepatocellular carcinoma at Zhongshan Hospital,Fudan University between July 1st 2007 to December 31st 2007,to study the risk factors of hepatic decompensation.ResultsPreoperative high total bilirubin (TB) and low prealbumin (PA) were independent risk factors of PHD by logistic multivariate analysis ROC analysis revealed the cut-offs of preoperative PA predicting PHD were 0.14 g/L (sensitivity 41.4％; specificity 83.1％).The incidence of PHD was 16.0％ when TB≥20.4 μmol/L and PA＜0.14 g/L(OR=7.276,P=0.002).ConclusionThe Child-Pugh A patients recovered well when the preoperative liver function was as follows:TB＜20.4 μmol/L and PA≥0.14 g/L.

Objective:For severe skin defects which are deep to dermis, engineered skin with epidermis and dermis (bilayered) is required. Based on the success of engineering epidermis with GT/PCL electrospun membranes, our study was to investigate whether this membrane could be also used for engineering bilayered skin graft.Methods:From 2013 to 2019, we first prepared three GT/PCL electrospun membranes with different proportion (70∶30; 50∶50; 30∶70) in our laboratory; the biocompatibility of the membrane was evaluated in vitro by seeding fibroblasts or keratinocytes on the membranes. Then the outcome of GT/PCL membranes repairing skin defects in the nude mouse was investigated.Results:Cell attachment and proliferation were significantly improved with increase of gelatin. Histological analyses showed that bilayered skin engineered with GT/PCL (70∶30) group could form relatively better structure after 3 weeks of cultivation in vitro. Further in vivo transplantation studies revealed that scaffolds were not degraded in all three groups, indicating that these materials were not suitable for engineering bilayered skin although they had good biocompatibility.Conclusions:The higher gelatin membranes possess better biocompatibility. Further in vivo transplantation studies reveal that bilayered skin engineered with GT/PCL membranes is able to repair skin defects in the nude mouse.

Objective To explore a new method for the treatment of nasal deformity in the middle part of facial cleft.Methods Eight patients with craniofacial cleft midface depression were treated with nasal reconstruction,nasal reconstruction plus pear shaped hole week osteotomy forward,pyriform aperture osteotomy advancement by using the auxiliary week preoperative design and postoperative surgical navigation system,and the preoperative design and postoperative CT data fit was compared.Results All the 8 patients were satisfied with results of the operation.There was no significant difference in CT data between preoperative simulation design and postoperative follow-up.Conclusions The expanded forehead flap in nasal reconstruction surgery has good effect on congenital craniofacial cleft nasal defect,and surgical navigation assisted pyriform hole osteotomy advancement for correction of congenital craniofacial cleft caused by midface depression to achieve a precise osteotomy,has good application value.

Objective:To measure the changes in the orbital and nasal parameters before and after Tessier box osteotomy with primary aesthetic rhinoplasty concurrently with byotogenous costochondral graft.Methods:From 2013 to 2018, 60 hypertelorism patients were treated in our craniofacial center. Correction involved a classic Tessier box osteotomy combined with aesthetic augmentation and reconstruction of the nasal dorsum using a costochondral graft. All patients underwent photographic and tomographic documentation both before and 12 months after surgery. Patients underwent morphometric analysis to document the changes in interorbital distance (IOD) and aesthetic nasal parameters, including the nasal dorsum and alar width, the nasal dorsal height, and the index of nasal apex protrusion versus nasal length.Results:All patients were satisfied with the outcome of the combined orbital and nasal repair. Morphometric analysis indicated that the IOD and aesthetic nasal parameters all improved following surgery. The resorption rate of the costochondral graft was 16-19%, and graft warpage was nearly absent. Although complications so as infection, cerebrospinal fluid leak or hyposomia, no severe or life-threatening complications occurred.Conclusions:Tessier box osteotomy with primary aesthetic rhinoplasty using costochondral grafts has showed to be efficacious in the treatment of patients with hypertelorism.

Objective:To discuss the regulatory effect of physiological tensile stress on the differentiation of chondrocytes,and to clarify the associated signaling pathway mechanism.Methods:The ATDC5 chondrocytes were cultured in vitro and subjected to physiological tensile stress by four-point bending cell mechanical loading device.Initially,the cells were divided into control group and tensile stress group(2 000 μstrain/2 h group),and further divided into different stress magnitudes(1 000,2 000,and 3 000 μstrain)for 2 h,and 2 000 μstrain for different duration time(1,2,and 4 h)groups;the cells without tensile stress were used as control group.Real-time fluorescence quantitative PCR(RT-qPCR)method was used to detect the expression levels of type Ⅱ collagen(Col-Ⅱ),type Ⅹ collagen(Col-Ⅹ),aggregated proteoglycom(Aggrecan),sex-determining region Y-box protein 9(SOX9),vascular endothelial growth factor(VEGF),proliferating cell nuclear antigen(PCNA),Nel-like molecule tyep 1(Nell-1),Runt-related transcription factor 2(Runx2),Indian hedgehog(Ihh),patched homolog 1(Ptch-1),GLI family zinc finger protein 1(Gli-1),and hedgehog interacting protein 1(Hhip-1)mRNA in the cells in various groups;Western blotting method was used to detect the expression levels of Nell-1,Runx2,and Ihh proteins in the cells in various groups.The ATDC5 cells were divided into control group,cyclopamine group,tensile stress group,and cyclopamine + tensile stress group.RT-qPCR method was used to detect the expression levels of Nell-1,Ihh,Ptch-1,Gli-1,and Hhip-1 mRNA in the cells in various groups;Western blotting method was used to detect the expression levels of Nell-1 and Ihh proteins in the cells in various groups.Results:Compared with control group,the expression levels of Col-Ⅱ,Col-Ⅹ,Aggrecan,SOX9,VEGF,and PCNA mRNA in the cells in 2 000 μstrain/2 h group were significantly increased(P<0.01);after treated with 2 000 μstrain tensile stress for different duration time(1,2,and 4 h)or different tensile stresses(1 000,2 000,and 3 000 μstrain)for 2 h,compared with control group,the expression levels of Runx2 mRNA in the cells in other groups were increased with the prolongation of time or the increasing of tensile stress(P<0.01),and the expression levels of Nell-1,Ihh,Ptch-1,Gli-1,and Hhip-1 mRNA were gradually increased(P<0.01),the expression levels reached the peaking at 2 000 μstrain/2 h,and then decreased but remained significantly higher than that in control group(P<0.01).The Western blotting results showed that the expression levels of Nell-1,Runx2,and Ihh proteins in the cells were consistent with the change trend of mRNA expression levels.After pre-treated with cyclopamine,compared with control group,the expression levels of Ihh,Ptch-1,Gli-1,and Hhip-1 mRNA in the cells in cyclopamine group were significantly decreased(P<0.01),and the expression levels of Ihh,Ptch-1,Gli-1,and Hhip-1 mRNA in the cells in tensile stress and cyclopamine+tensile stress groups were significantly increased(P<0.01);compared with cyclopamine group,the expression levels of Nell-1,Ihh,Ptch-1,Gli-1,and Hhip-1 mRNA in the cells in cyclopamine+tensile stress group were significantly increased(P<0.01);compared with tensile stress group,the expression levels of Ihh,Ptch-1,Gli-1,and Hhip-1 mRNA in the cells in cyclopamine + tensile stress group were significantly decreased(P<0.01).Compared with control group,the expression level of Ihh protein in the cells in cyclopamine group was significantly decreased(P<0.01),but there was no significant difference in expression level of Nell-1 protein in the cells between control group and cyclopamine group(P>0.05),while the expression levels of Nell-1 and Ihh proteins in the cells in tensile stress group and cyclopamine + tensile stress group were significantly increased(P<0.01);compared with cyclopamine group,the expression levels of Nell-1 and Ihh proteins in the cells in tensile stress group and cyclopamine + tensile stress group were significantly increased(P<0.01);compared with tensile stress group,in the expression levels of Nell-1 and Ihh proteins in the cells in cyclopamine + tensile stress group had no significant differences(P>0.05).Conclusion:After stimulated with physiological tensile stress,Nell-1 can activate the Ihh signaling pathway upstream,and regulate the differentiation of the ATDC5 chondrocytes.

BACKGROUND:Based on different algorithms of machine learning,how to carry out clinical research on lumbar disc herniation with the help of various algorithmic models has become a trend and hot spot in the development of intelligent medicine at present. OBJECTIVE:To review the characteristics of different algorithmic models of machine learning in the diagnosis and treatment of lumbar disc herniation,and summarize the respective advantages and application strategies of algorithmic models for the same purpose. METHODS:The computer searched PubMed,Web of Science,EMBASE,CNKI,WanFang,VIP and China Biomedical(CBM)databases to extract the relevant articles on machine learning in the diagnosis and treatment of lumbar disc herniation.Finally,96 articles were included for analysis. RESULTS AND CONCLUSION:(1)Different algorithm models of machine learning provide intelligent and accurate application strategies for clinical diagnosis and treatment of lumbar disc herniation.(2)Traditional statistical methods and decision trees in supervised learning are simple and efficient in exploring risk factors and establishing diagnostic and prognostic models.Support vector machine is suitable for small data sets with high-dimensional features.As a nonlinear classifier,it can be applied to the recognition,segmentation and classification of normal or degenerative intervertebral discs,and to establish diagnostic and prognostic models.Ensemble learning can make up for the shortcomings of a single model.It has the ability to deal with high-dimensional data and improve the precision and accuracy of clinical prediction models.Artificial neural network improves the learning ability of the model,and can be applied to intervertebral disc recognition,classification and making clinical prediction models.On the basis of the above uses,deep learning can also optimize images and assist surgical operations.It is the most widely used model with the best performance in the diagnosis and treatment of lumbar disc herniation.The clustering algorithm in unsupervised learning is mainly used for disc segmentation and classification of different herniated segments.However,the clinical application of semi-supervised learning is relatively less.(3)At present,machine learning has certain clinical advantages in the identification and segmentation of lumbar intervertebral discs,classification and grading of the degenerative intervertebral discs,automatic clinical diagnosis and classification,construction of the clinical predictive model and auxiliary operation.(4)In recent years,the research strategy of machine learning has changed to the neural network and deep learning,and the deep learning algorithm with stronger learning ability will be the key to realizing intelligent medical treatment in the future.

OBJECTIVETo investigate the safety, feasibility, clinical value, indication, and distribution of diagnostic diseases in different age groups of colonoscopy in pediatric patients.

METHODSA retrospective analysis was performed on the data of pediatric patients receiving colonoscopy from April 2013 to June 2016 at The Sixth Affiliated Hospital of Sun Yat-sen University. Pediatric patients were divided into 0-6 years group (n=57) and 7-14 years group (n=172). Indication for colonoscopy, detective events and diagnostic diseases distribution were compared between two groups.

RESULTSA total of 229 pediatric patients (male 157 and female 72) were divided into 0-6 years group (57/229, 24.9%) and 7-14 years group(172/229, 75.1%). The main Indications for colonoscopy included abdominal pain (81/229, 35.4%), hematochezia (64/229, 27.9%), crissum abscess or fistula (40/229, 17.5%). Hematochezia was the most common complaint in 0-6 years group (40/57, 70.2%), while abdominal pain in 7-14 years group (74/172, 43.0%). Completion rate between 0-6 years group and 7-14 years group was not significantly different (87.72% vs. 85.47%, χ=0.181, P=0.671). Only one pediatric patient (1/229, 0.4%) developed transient oxygen desaturation and recovered quickly after oxygen supply and aspiration of sputum. No serious complications such as bleeding, perforation or death occurred. Including 45 pediatric patients in 0-6 years group and 102 pediatric patients in 7-14 years group, a total of 147 pediatric patients (147/229, 64.2%) were found to have colorectal lesions. Inflammatory bowel disease (57/147, 38.8%), colonic polyps (40/147, 27.2%) and other intestinal inflammation (39/147, 26.5%) were the main findings. The most frequent diagnosis in 0-6 years group was colonic polyps (28/57, 49.1%), among them, 25 pediatric patients (25/28, 89.3%) were with the complaint of hematochezia. The most frequent diagnosis in 7-14 years group was Inflammatory bowel disease (54/172, 31.4%), among them, 29 pediatric patients (29/54, 53.7%) were with the complaint of abdominal pain.

CONCLUSIONSPediatric colonoscopy is safe and effective. Hematochezia and abdominal pain are the most common complaints in 0-6 years group and 7-14 years group respectively. Colonic polyps and inflammatory bowel disease are the most frequent diagnosis in 0-6 years group and 7-14 years group respectively.