Objective To investigate the value of mesenteric vascular CTA in the diagnosis of small intestinal neoplasms.Methods A retrospective analysis of mesenteric CTA from January 2008 to April 2013 was conducted in 51 patients with pathologically proven small intestinal neoplasms.Features of intestinal neoplasms CTA signs including neoplasm feeding artery,draining vein,mesangial side vasa recta and the formed neoplasm vessels,were observed.Two radiologists individually used two methods,namely intestinal tumor feeding artery positioning method and Cole fractionation method,for diagnosis and localization diagnosis of tumor,and also for comparing the results with those of surgical pathology.McNemar Chi-square test was adopted to evaluate the diagnosis differences between the two physicians and between the two methods by the same physician.Kappa value was used to assess the consistency of the results.Results Features of intestinal tumors CTA signs:12 cases of enlarged neoplasm feeding artery,9 cases of early displayed draining vein,22 cases of enlarged mesangial side vasa recta,and 11 cases of vessels formed inside and around the neoplasm,single lesion for all and the largest lesion diameter≥ 5 cm for 37 cases.The accuracy of Cole fractionation method positioning and the feeding artery positioning were 84.31％(43/51) and 98.03％(50/51) respectively.Moderate consistency(Kappa=0.49,P＜0.01) was seen with Cole fractionation method by the two physicians and high consistency(Kappa=1.00,P＜0.01) with feeding artery positioning method.McNemar Chi-square test showed no significant difference between the two methods by the same physician and the consistency of the results from the two methods was passable(P were 0.062 and 0.125).Conclusion Mesenteric CTA can display the intestinal tumor feeding arteries and draining veins,and is helpful in identification of the relationship between the tumor and its surrounding blood vessels,which can improve the accuracy of pre-operative localization and qualitative diagnosis for small intestinal tumor.

ObjectiveTo study the toxin genes and pandemic group distribution as well as the genetic correlation between the major serotypes( O3:K6,O1:Kut,O4:K8 ) of Vibrio parahaemolyticus (VP) isolated from the outbreaks of Guangdong province.MethodsThe tdh and trh genes,GS-PCR and orf8 gene were detected on the 62 isolates sourced from patient and seafood occurred in the 23 outbreaks during 2008-2010.44 isolates of which were analyzed on PFGE digested by Not Ⅰ enzyme.ResultsToxin genes distributions suggested that 96.8% (60/62)isolates were tdh+,trh-.Three tdh+ isolates sourced from seafood were found.Pandemic group distribution suggested that 97.2% (35/36) O3:K6,5.88% (1/17) O4:K8,66.7% (8/9)O1:Kut serotype was GS-PCR+ and/or orf8+,respectively.PFGE analysis suggested that 44 isolates were separated into 3 clusters,of which the similarity of PFGE profile was 80.5% in the pandemic group cluster constructed by 28 isolates,the similarity between pandemic group and non-pandemic group was 59.5%.Pandemic group of O3:K6,O1:Kut as well as 04:K8 isolated on some outbreaks were processing the same PFGE profiles.ConclusionThe characteristic of toxin genes of major serotypes VP isolated in the outbreaks of Guangdong province form 2008-2010 was tdh- present and trh- absent.Within the pandemic group,O3:K6 and O1:Kut were the major serotypes.In single outbreak,isolates belongs to pandemic group but with different serotype seem to be close correlations.

Objective To develop a rapid and sensitive DNA microarray for Listeria monocytogenes detection.Methods A DNA microarray was developed using gyrB,ISR,16S rRNA,23S rRNA,hlyA,iap and prfA as the target genes and tested against 18 different species of known reference for repeatability,sensitivity,and specificity to verify the effectiveness of the chip.Results After testing of samples by the LM array,results show that the 70 mer Oligos synthesized by IDT are superior to the Oligos synthesized by Sagon with respect to both probe spotting or samples detection.The comparison of 3 spotting probe concentrations of 10 μmol/L,40 μmol/L and 80 μmol/L demonstrated that the 10 pmol/L probes result in good detection signals equivalent to the 40 μmol/L and 80 μmol/L probes.The repeatability and sensitivity evaluated by sample testing on the LM array revealed that the chips developed in this study have good repeatability and the lower limit of sample detection is 0.9 ng DNA.The LM array can distinguish clearly and definitively between Listeria and non-Listeria bacteria in the sample.Conclusion The microarray is able to rapidly detect and identify Listeria monocytogenes.

Objective To prepare simulated stool specimens for proficiency testing ( PT) by mix-ing lentils with Salmonella, Shigella and Escherichia coli strains and to establish an assessment scheme for the detection of Salmonella and Shigella in clinical samples. Methods Salmonella, Shigella and Escherich-ia coli strains were respectively spiked to lentils in Cary-Blair transport medium to create simulated stool specimens. Various ratios of Escherichia coli to Salmonella strains were spiked to lentils to prepare mixed simulated stool specimens. The accuracy and stability of prepared stool samples for PT were tested in-house. Results of sample detection were collected from participating laboratories for further external quality assess-ment. Results The Escherichia coli and Salmonella strains mixed at ratios of 100 ∶ 1 to 106 ∶ 1 could be ef-ficiently isolated from the media. Enrichment was needed in order to effectively isolate Salmonella strains from the media when the ratios of Escherichia coli to Salmonella strains were 104 ∶ 1 to 106 ∶ 1. Of the16 participating laboratories, 14 laboratories (87. 5%) received a grade of“satisfactory” and the other 2 labo-ratories (12. 5%) received a grade of “mainly satisfactory”. Conclusion The simulated stool specimens and the PT procedures designed in this study were suitable for proficiency testing program on the detection of Salmonella, Shigella and other similar microbes.

Objective To analyze the serotype distribution and antibiotic resistance characteristics of Salmonella strains isolated in Guangdong province for better understanding the condition of Salmonella infection in patients with diarrhea.Methods Fecal samples collected from patients with diarrhea in Guangdong province were used to isolate Salmonella strains.Biochemical analysis was performed to identify these isolated strains.Serotyping and antimicrobial susceptibility testing were carried out for further analysis of the isolated Salmonella strains.Results The rate of Salmonella infection was 7.64％in 2015, and the male to female patient ratio was 1.52∶1.A total of 2 377 patients of all age groups were positive for Salmonella infection and the patients aged 0-6 years accounted for 81.74％.The isolation rate of Salmonella strains in the summer and autumn was higher than that in the winter and spring (10.73％ vs 4.24％;X2=463.77, P<0.01).The Salmonella isolation rates in different areas were as follows: 16.82％ in Zhuhai, 15.85％ in Heyuan, 11.81％ in Yangjiang, 10.68％ in Jiangmen, 8.49％ in Zhongshan, 8.07％ in Maoming, 8.05％ in Jieyang, 7.35％ in Shaoguan, 6.97％ in Foshan, 6.03％ in Dongguan, 5.48％ in Guangzhou and 0.00％ in Zhanjiang.And the differences between different regions were statistically significant (X2=367.67, P<0.01).The 2 377 isolated Salmonella strains were classified into 108 serotypes except for oneSalmonella strain that could not be classified.The top four predominant serotypes were 4,5,12:i:-, Salmonella enteritidis,Salmonella stanley and Salmonella typhimurium.Most Salmonella strains were sensitive to imipenem, azithromycin, ceftazidime, cefotaxime and trimethoprim/sulfamethoxazole, but multidrug resistance was common among those strains.Conclusion Salmonella serotypes of 4,5,12:i:-and Salmonella enteritidis are the predominant pathogens causing human Salmonella infections in Guangdong province.Ceftazidime and cefotaximeare are preferred in the treatment of Salmonella infections.Surveillance for drug resistance in Salmonella should be strengthened as multidrug resistant strains have become a serious problem in Guangdong province.

Objective To investigate the diagnostic value of dual-energy CT virtual non-contrast (VNC) technology for osteoporosis(OP). Methods Dual-energy CT images of 50 patients with lumbar traumas were collected prospectively.Patients who suffer from vertebral bodies fractures between lumbar 1 to 4, have internal metal fixations or underwent percutaneous vertebroplasty, or presented tumors or compromised bone metabolism induced by diseases or medications were excluded.The scanning range was from the upper edge of the 12th thoracic vertebral body to the lower edge of the first sacral vertebral body. The voltages of tubes A and B were 90 kV and Sn 150 kV,and the reference tubes currents were 220 mAs and 138 mAs. Image reconstruction was performed using Advanced Modeled Iterative Reconstruction (ADMIRE)with iterative strength of 3 and convolution kernel of Qr 40.The default parameters of the virtual non-contrast software were corrected by the standard recommended by the Bone Marrow software of the post-processing platform Syngo.via,and the CT value of calcium(contrast media CM),the CT value of mixed energy images(regular CT value,rCT),the calcium density(CaD)and the fat fraction(Fat)were measured. The bone mineral density (BMD) and T score of each lumbar vertebra from lumbar 1 to lumbar 4 were measured by dual energy X-ray absorptiometry(DXA).With T score less than or equal to the 2.5 standard deviation as the gold standard for the diagnosis of OP,correlations between CT measurements and vertebral BMDs were analyzed using Pearson correlation analysis and linear regression and the diagnostic values of different CT measurements for OP were compared using receiver operating characteristic curve. Results Each of the vertebral bodies was analyzed as a single unit.Fifty of them were osteoporotic and the rest 116 were non-osteoporotic.Except for Fat,the CT measurement parameters of the osteoporotic vertebral bodies were lower than those of the ones without osteoporosis, and the difference was statistically significant (P<0.01).CM,rCT and CaD were significantly correlated with BMD(r were 0.75,0.65,0.71,all P<0.01)and there was a linear relationship(F were 209.91,120.24,167.69,all P<0.01).Meanwhile,CM,rCT,CaD and T score were also significantly correlated (r were 0.74, 0.65, 0.70, all P<0.01) with a linear relationship (F were 195.04,120.29,156.37,all P<0.01).CM,rCT and CaD had relatively high concordance rates against the OP diagnosis gold standard (respectively 81.9%, 62.2% and 81.9%). CM and CaD had higher concordance rates than rCT,the difference being statistically significant(P<0.01),and by the CM less than 239.5 HU or CaD less than 10.9 mg/cm3standard, their sensitivities of diagnosing osteoporosis were respectively 86.0% and 84.0%,while the specificities,80.2% and 81.0%.After superimposing CM and CaD, the results did not improve the diagnosis efficiency of OP (pre-superposition diagnostic performance better than post-superposition (P<0.05). Conclusion The VNC technology on DECT can do both vertebral fractures diagnosis and osteoporosis assessment at the same time, thus optimizing the clinical examination process.

Objective To understand the effect ofserotyping on Salmonella isolates,by use of Microsphere-based Liquid Array method,among diarrhea patients,in Guangdong.Methods Salmonella isolated from humans in Guangdong province were serotyped on the Microsphere-based Liquid Array platform with SSA kit.Results A total of 4 942 Salmonella strains with 189 serotypes,were identified in Guangdong province in 2010-2014.The top 100 serotypes accounted for 98.08％ (4 847/4 942) of all the strains.98％ of the top 100 species serotypes could completely be serotyped with SSA kit.In order to detect O antigen among 198 isolates with SSA kit,181 strains were carrying the O antigen,with the coincidence rate as 100％.However,under the SSA,98.32％ (528/537) of the H antigen could be detected and were consistent with the traditional serum agglutination test.The coincidence rate of fljB gene was 93.09％ (175/188),with false negative rate and false positive rate of fljB gene as 7.35％ (9/134) and 7.41％ (4/54) respectively.The coincidence rate of sdf gene and Vi gene were 100％.11 out of the 12 Salmonella strains could not be serotyped under the traditional methods but were successfully serotyped by the molecular serotyping method.Conclusions Using the SSA kit,more than 96％ of the anthropogenic Salmonella strains could be serotyped in Guangdong province.Comparing with the traditional methods,the coincidence rate of serotyping appeared over 98％.Under the Microsphere-based Liquid Array techniques,the molecular serotyping method appeared faster and more accurate on Salmonella serotyping than those traditional methods.

Objective To analyze the feasibility and efficacy of a deep convolutional neural network(DCNN)model based on chest CT images to evaluate bone mineral density(BMD).Methods A total of 1 048 health check subjects'2 096 central level images of lumbar 1 and 2 vertebral bodies were used for experiments and analysis in this retrospective study.According to the results of quanti-tative computed tomography(QCT)BMD measurement,the subjects were divided into three categories:normal,osteopenia,osteopo-rosis(OP).Herein,a DCNN segmentation model was constructed based on chest CT images[training set(n=1 096),tuning set(n=200),and test set(n=800)],the segmentation performance was evaluated using the Dice similarity coefficient(DSC)to com-pare the consistency with the manually sketched region of vertebral body.Then,the DCNN classification models 1(fusion feature construction of lumbar 1 and 2 vertebral bodies)and model 2(image feature construction of lumbar 1 alone)was developed based on the training set(n=530).Model performance was compared in a test set(n=418)by the receiver operating characteristic(ROC)curve analysis.Results When the number of images in the training set(n=300)was adopted,the DSC value was 0.950 in the test set.The results showed that the sensitivity,specificity and area under the curve(AUC)of model 1 and model 2 in diagno-sing osteopenia and OP were 0.716,0.960,0.952;0.941,0.948,0.980;0.638,0.954,0.940;0.843,0.959,0.978,respectively.The AUC value of normal model 1 was higher than that of model 2(0.990 vs 0.983,P=0.033),while there was no significant difference in AUC values between osteopenia and OP(P=0.210,0.546).Conclusion A DCNN may have the potential to evaluate bone mass based on chest CT images,which is expected to become an effective tool for OP screening.