Objective:To explore the clinical value of synovial fluid calprotectin for the diagnosis of periprosthetic joint infection (PJI).Methods:Based on prospective cohort study design, a total of 82 patients suspected of PJI after hip and knee arthroplasty in the First Medical Center of the PLA General Hospital from July 2021 to June 2022 were selected. Patients were divided into infection group (PJI, n=39) and non-infection group (non-PJI, n=43) according to the diagnostic criteria proposed by the Second International Consensus Conference in 2018. The matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was used for double-blind detection of calprotectin and internal reference standard (IRS) in synovial fluid of patients. The peaks of target protein and IRS were recorded for further analysis. Mann-Whitney U test was used to compare the concentrations of S100A8 and S100A9 between the two groups, and receiver operating characteristic curve (ROC) was used to analyze the diagnostic efficacy of S100A8 and S100A9 for PJI. Results:Calprotectin was detected as monomers S100A8 and S100A9. Synovial fluid S100A8 was significantly higher in the PJI group than that in the non-PJI group [1.57 (0.48, 4.17) vs 0.00 (0.00, 0.05), Z=?7.221, P<0.05]. Synovial fluid S100A9 was also significantly higher in the PJI group than that in the non-PJI group [0.74 (0.29, 1.70) vs 0.06 (0.00, 0.10), Z=?6.255, P<0.05]. When using S100A8 and S100A9 to diagnose PJI, the sensitivity were 97.4% and 87.2%, the specificity were 86.0% and 88.4%, and the area under the ROC were 0.964 (95% CI 0.929-0.998) and 0.902 (95% CI 0.924-0.996), respectively. Conclusion:The detection of synovial fluid S100A8 and S100A9 by MALDI-TOF MS can make a satisfactory diagnosis for PJI.

Objective:A high-throughput assay for the detection of five common clinical Candidaemia pathogens was established by combining polymerase chain reaction (PCR) and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS).Method:Establishment of methodology. We selected Candida albicans, Candida parapsilosis, Candida glabrata, Candida krusei, Candida tropicalis to be the target pathogens and the internal transcribed spacer (ITS) region as the target gene. Specific single base extension primers were designed to perform single base extension reaction in the same reaction system. MALDI-TOF MS was used to detect the characteristic peaks of each target pathogen. The sensitivity and specificity of the detection system were verified by using spiked blood samples. Totally 108 blood samples from proven or suspected candidaemia patients were collected from October 2021 to September 2022 in a hospital in Beijing. The results of nucleic acid mass spectrometry were compared with those of clinical blood culture. Results:The established nucleic acid mass spectrometry detection system can simultaneously detect five common clinical Candida species. Each strain can produce specific product peaks and there is no mutual interference between the strains. The detection limit of Candida albicans was 100 CFU/ml. The detection limit of Candida parapsilosis, Candida glabrata, Candida krusei and Candida tropicalis was 10 CFU/ml. For the 108 blood samples, the sensitivity, specificity, positive predictive value and negative predictive value of nucleic acid mass spectrometry were 94.74% (36/38), 97.14% (68/70), 92.31% (36/39) and 98.55% (68/69), respectively. The McNemar χ 2 test showed no significant difference between the two methods ( P>0.05), and the Kappa consistency test showed good consistency between the two methods ( Kappa=0.9, P<0.05). Conclusion:A nucleic acid mass spectrometry detection system suitable for clinical candida detection was successfully constructed, and the method validation results were consistent with the clinical blood culture.

Objective:To establish an inductively coupled plasma mass spectrometry (ICP-MS) based immunoassay method for the quantitative detection of human chorionic gonadotropin (HCG), and evaluate the clinical applicability of this method.Methods:Sm was selected as element tags, and the HCG quantitative detection system was established by double antibody sandwich method. The dosage of biotinylated antibody and reaction time were optimized. According to EP documents of Clinical and Laboratory Standards Institute (CLSI) and related standards, the analytical performance was evaluated after the establishment of the assay, including the limit of blank (LOB), linearity, precision, recovery, cross reactivity and interference test. And 88 clinical samples were measured using the new method compared to the electrochemical immunoassay (ECLIA) method.Results:Total process completed within 30 min after optimization, and the optimal biotinylated antibody dosage was 0.5 μl. The LOB was 0.29 mIU/ml. The linearity was good within the range of 1.16-8 365.62 mIU/ml with the linear correlation coefficient greater than 0.995 ( R2=0.998 0), the recovery was 97.53%-102.01%. Both intra-and inter-assay coefficients of variation of the high-value sample and the low-value sample were less than 10%. And there was no significant cross-reaction with Luteinizing hormone (LH), follicular stimulating hormone (FSH), and thyroid-stimulating hormone (TSH). The interference bias caused by different concentrations of interference substances was less than 10%. When compared with the ECLIA method for clinical sample detection, the proposed method showed a significant correlation( R2=0.960 0). Conclusion:The proposed ICP-MS base immunoassay for HCG detection has good accuracy, high sensitivity and specificity, and the results of analytical performance verification meet the clinical requirements, which provides experimental basis for the clinical application of this method.

Objective:To study the molecular biological characteristics of isolates from the infection site and isolates colonizing in anterior nares of children with invasive Staphylococcus aureus (SA) infection, and to analyze the concordance between the two types of strains from different sources. Methods:A total of 45 strains were collected from children with invasive SA infection treated in the Pediatric Ward of Sichuan Provincial Maternal and Child Health Care Hospital from January 2019 to August 2019, and 28 colonization isolates were obtained from the anterior nares of these patients.The susceptibility test was carried out by broth dilution method.The drug resistance genes mecA and blaZ and the virulence gene panton-valentine leucocidin( pvl) were detected by PCR.The homology of infective and colonizing isolates was detected by pulsed-field gel electrophoresis(PFGE)typing technique. Results:Colonization of SA was found in the nasal vestibule of 62.2% (28/45 cases) of patients with invasive SA infection.A total of 40.0% (18/45 strains) of the infective isolates and 32.1% (9/28 strains) of the colonizing isolates were Methicillin-resistant SA (MRSA), and the difference was not statistically significant( P>0.05). The resistance of infective isolates to Clindamycin, Azithromycin and Erythromycin was stronger than that of colonizing isolates, the difference of drug resistance rate was statistically significant( χ2=7.114, 7.820, 5.359, all P<0.05). There were no differences in the carrying rates of the drug resistance gene blaZ and the virulence gene pvl between the infective and colonizing bacteria( P>0.05). Phenotypically, Methicillin-susceptible SA (MSSA)was more susceptible to concordant colonization than MRSA[16.7%(3/18 cases) vs.48.1%(13/27 cases), χ2=4.671, P<0.05]. PFGE indicated that patients with invasive MSSA infection were significantly more likely to have a concordant MSSA colonization isolate in their anterior nares, compared with patients with invasive MRSA infection[59.3%(16/27 strains) vs.27.8%(5/18 strains), χ2=4.301, P<0.05]. Conclusions:The infective and colonizing strains of invasive SA show no difference in their resistance to some anti-biotics, but they carry almost the same number of drug resistance and virulence genes.Compared with those with MRSA infection, patients with MSSA infection are more likely to have concordant colonizing isolates.It is of potential clinical significance to screen the colonizing SA strains in patients with invasive SA infection.

OBJECTIVETo explore the clinical and genetic characteristics of a case with Pallister-Killian syndrome (PKS).

METHODSChromosomal karyotype of umbilical cord blood sample derived from a 36-year-old pregnant woman was analyzed by G-banding analysis. After birth, the child was further analyzed with single nucleotide polymorphism microarray (SNP array) and fluorescence in situ hybridization (FISH) using 12pter/12qter probes.

RESULTSG-banding analysis showed that the fetus has a karyotype of 46,XY [77]/47,XY,+mar [23]. After birth, Affymetrix CytoScan 750K array analysis showed a segmental tetrasomy of arr [hg19] 12p13.33p11.1(173 786 - 34 835 641)×4 and a 34.6 Mb repeat at 12p13.33p11.1 with in the neonate. FISH analysis confirmed that 39% of cells harbored the 12p tetrasomy.

CONCLUSIONCombined clinical examination, G-banded chromosomal karyotyping, FISH and microarray analysis can delineate the origin and fragments of small supernumerary marker chromosomes and diagnose PKS with precision.

Adult ; Chromosome Banding ; Chromosome Disorders ; diagnosis ; Chromosomes, Human, Pair 12 ; Female ; Humans ; In Situ Hybridization, Fluorescence ; methods ; Karyotyping ; Oligonucleotide Array Sequence Analysis ; Polymorphism, Single Nucleotide ; Pregnancy ; Prenatal Diagnosis ; methods

Objective:To identify enolase,47 kD allergen,from Litopenaeus vannamei by Mass spectrometry. Methods: The proteins were extracted from Litopenaeus vannamei tissue with acetone precipitation method. The protein components were analyzed by SDS-PAGE and Western blot. By using Matrix-Assisted Laser Desorption/Ionization time of flight mass spectrometry ( MALDI-TOF/TOF-MS) ,the 47 kD allergen from Litopenaeus vannamei was identified as enolase. Results:By SDS-PAGE,we proved that the native protein components from Litopenaeus vannamei were completely. According to the Western blot result more than 14 components could react with the positive serum. MALDI-TOF/TOF analysis results showed that the suspected proteins were enolase. A sensitization frequency was 55%. Conclusion:Enolase was identified as a new allergen of Litopenaeus vannamei.

Objective To explore the clinical value of flow cytometry( FCM) and DNA automated cell image analyzer ( AICM) in determine the character of ascites and pleural effusion.Methods This was a cross-sectional study.203 ascites and pleural effusionsamples were random selected from PLA hospital inpatients between August 2013 to June 2014 .The DNA content of sediment cells were detectedthrough the FCM and AICM respectively benign and malignant disease were differentiated according the counts and proportion of aneuploid cells.The sensitivity, specificitywere calculated byROC curves.Results The sensitivity, specificity and accuracy of flow cytometry cell in detectingtumor cells were 78.6%,80.0% and 79.2%%, while the sensitivity, specificity and accuracy of image analyzer were 83.5%,78.6% and 81. 3%respectively.When FCM and AICMwere combined ,the sensitivity, specificity and accuracyincreased to 92.2%, 86.3% and 89.6%.Conclusions Compared toconventional cytology test, the sensitivity and specificity were significantly high when the two methods were combined .Therefore, the combination method can be used to assist in clinical identification of the nature of ascites and pleural effusion and to help the diagnosis of disease.

Objective To investigate the way of fear conditioning memory model evoked and erased by foot-shock in tree shrew. Methods First, detect the tree shrew activities regularly in light/dark box. Second, test a suitable voltage degree of foot shock on tree shrew. Third, investigate the memory formation and erasing of fear conditioning on tree shrew of trial group. Results The duration of tree shrew (n=4) stay in the dark-box was significantly lon-ger than that of in the light box (P<0. 01) in normal condition. In the same environment of two light boxes, given different voltage degrees, the durations of tree shrew (n=6) stay in the stimulating chamber gradually reduced and the durations of tree shrew stay had significant difference between stimulatus chamber and no stimulatus chamber when the stimulus voltage up to 12 V ( P<0. 05 ) , 16 V ( P<0. 01 ) and 20 V ( P<0. 01 ) . The animal of trial group ( n=4 ) could build up the fear conditioning memory of the dark box with the stimulus of 16 V foot-shock in the dark box ( P<0. 001 ) . After formation of the fear conditioning memory, the same stimulus in light box ap-peared for 4 days. The durations of tree shrew stay in trial group (n=4) decreased in light box, and there was no significant difference between the trial group and the control group. Conclusion Tree shrew prefers to stay in the dark box. The suitable voltage for foot-shock on tree shrew is 16 V. The fear conditioning memory can be evoked and erased by foot-shock.

ischemia reperfusion model .DADLE might have a protective effect on lung tissues of ALI in rats .