Objective To investigate the effects of Acinetobacter baumannii culture supernatants on planktonic cell growth and biofilm formation of Pseudomonas aeruginosa.Methods The standard isolates (ATCC 19606,ATCC 1195) and clinical isolates (AB23,AB39,AB53) of Acinetobacter baumannii were collected and the 6,12,16,24 and 48 hour-cultured supernatants were extracted.The effects of the culture supernatants on the biofilm formation of Pseudomonas aeruginosa PAO1 were detected on the 96-well plate combined with crystal violet staining.Two-fold concentration of LB medium was prepared to eliminate the effects of nutrition consumption of Acinetobacter baumannii during culture on Pseudomonas aeruginosa growth.The active ingredients in the supernatant of Acinetobacter baumannii culture medium were investigated by using the concentrated tube containing protein with relative molecular mass 3 000.Results The most suitable period for Acinetobacter baumannii culture supernatant extraction was between 12 to 24 hours,so the 16 hourcultured supernatant was chosen for next experiments.The 50％ culture supernatant of Acinetobacter baumannii ATCC 1195 and ATCC 19606 significantly inhibited the planktonic cell growth of Pseudomonas aeruginosa PAO1,in which the absorbance at 630 nm reduced from(0.688 ± 0.014) and(0.692 ± 0.014) to (0.431 ± 0.023) and (0.428 ± 0.020) respectively (t =16.780,P ＜ 0.05;t =18.500,P ＜ 0.05).The 50％ culture supernatant of Acinetobacter baumannii ATCC 1195 and ATCC 19606 also significantly inhibited the biofilm formation of Pseudomonas aeruginosa PAO1 with decreased absorbance at 570 nm from (2.071 ± 0.068) and (1.986 ±0.023) to (1.639 ± 0.042) and (1.525 ± 0.202) respectively (t =9.358,P ＜ 0.05;t =3.924,P ＜ 0.05).The biofilm inhibitory effect of the protein with relative molecular mass less than 3 000 was obviously observed by reducing amount of biofilm formation from (1.177 ± 0.040) to(1.056 ± 0.030) (t =4.192,P ＜ 0.05),while there was no inhibitory effect of the proteins with relative molecular mass more than 3 000 in the composition.Conclusion Acinetobacter baumannii culture supernatant could effectively inhibit the planktonic cell growth and biofilm formation of Pseudomonas aeruginosa and the relative molecular mass of active ingredients in the culture supernatant may be less than 3 000.

Objective To investigate the expressions of PTEN and MDM2 in bladder transitional cell carcinoma (BTCC) and their clinical significance.Methods The expressions of PTEN and MDM2 were detected by tissue immunohistochemistry test (SP method) in BTCC (n =80) and normal bladder tissues (n =20).The relationship between PTEN and MDM2 as well as their correlations with clinical pathological features were analyzed.Results The positive rate of PTEN in different pathological grading (G1,G2,G3)and clinical staging [superficial (Tis ～ T1),infiltration (T2 ～ T4)] was (86.20％,74.07％,37.50％ ;80.00％,46.67％),respectively,with a significant difference (x2 =15.004,P ＜ 0.01 ; x2 =9.497,P ＜0.01).The positive rate of MDM2 in different pathological grading(G1,G2,G3) and clinical staging [superficial (Tis ～ T1),infiltration (T2 ～ T4)] was (82.75％,55.55％,37.50％ ; 70.00％,43.35％),respectively,with a significant differcnce(x2 =11.543,P ＜ 0.01 ; x2 =5.556,P ＜ 0.05).The expression of PTEN was negatively correlated with that of MDM2 in BTCC (r =-0.611,P ＜ 0.05).Conclusions Expressions of PTEN and MDM2 might be involved in the BTCC pathogenesis.The combined detection of PTEN and MDM2 might be of great value in the prediction of tumor behavior and prognosis.

Objective To investigate the effects of 3 kinds of broth media,including tryptose soya broth(TSB),LB and M-H,on the biofilm formation of Staphylococcus epidermidis (S.epidermidis).Methods The effects of TSB,LB and M-H broth media on the biofilm formation of S.epidermidis were investigated by the construction of bacterial biofilm in 96-well and 6-well microplates and the crystal violet straining for the semi-quantitative analysis and microscopic observation of the bacterial biofilm.The effects of TSB,LB and M-H broth media on the expression of adhesion-related genes in S.epidermidis were determined by the extraction of bacterial total RNA,reverse transcription and real-time PCR.Results Compared with LB (0.149 ± 0.047) and M-H (0.323 ± 0.003) media,TSB medium (2.954 ± 0.287) could significantly promote the biofilm formation of S.epidermidis (TSB vs LB,t =16.706,P ＜ 0.01;TSB vs M-H,t =15.877,P ＜ 0.01).Compared with LB medium,TSB medium could significantly enhance the expression of icaA gene (t =9.667,P＜0.01) but inhibit icaR gene (t =13.283,P＜0.01).Conclusion Compared with LB and M-H broth media,TSB medium may significantly improve the biofilm formation and the expression of adhesion-related gene icaA of S.epidermidis.

Objective To investigate the application valve of real-time fluorescence quantitative polymerase chain reaction(RT-PCR) for the detection of tumor M2-pyruvate kinase(tM2-PK) DNA in patients with colorectal cancer(CRC).Methods Fragment of tM2-PK DNA(162 bp) was amplified and inserted into PGM-T vector to construct recombinant plasmid,which was used to develop RT-PCR method.Sensitivity,specificity and repeatability of RT-PCR for the detection of tM2-PK were analyzed.From Jan.2014 to Jun.2016,200 CRC patients and 100 healthy subjects were enrolled and detected for fecal and serum tM2-PK DNA by using RT-PCR,and the detected results were compared with those detected by using enzyme linked immunosorbent assay(ELISA).Results Recombinant plasmid was successfully constructed,which was certified by sequencing.The sensitivity of RT-PCR for the detection of tM2-PK DNA was 10 copy/mL,with high specificity and 0.3%-2.9% of coefficient of variation.In patients,the positive rate of fecal tM2-PK DNA,detected by RT-PCR,was 92.50%,and that of ELISA to detect tM2-PK was 80.00%.Fecal and serum levels of tM2-PK were correlated with the pathologic stages of tumour.Conclusion Self-established RT-PCR could be specificity and sensitivity for the detection of fecal tM2-PK,which could be used for the early diagnosis of CRC.

Objective To investigate the identification of staphylococcus aureus lineage ST59 using the combined detection of delta hemolysin allelic variant G10S(HldG10S) and beta hemolysin(β-toxin). Methods Perspective study.A total of 82 non-duplicate clinical staphylococcus aureus were collected from November 2017 to April 2018 in the department of Clinical laboratory, the Third Xiangya Hospital of Central South University, China.The strains were routinely identified by MALDI-TOF MS and the mass spectra were obtained. According to the m/z expression intensity of delta hemolysin(Hld), all strains were divided into three groups:HldG10S (3036±2.0)m/z, Hld (3006±2.0)m/z and ND [no (3036±2.0)m/z and no (3006±2.0)m/z]. The distribution of ST59 in the three groups was detected by MLST. Reverse synergic hemolysis test was used to determine theβ-toxin phenotype. And the sensitivity, specificity and accuracy of HldG10S,β-toxin and the combined detection of HldG10S and Hld to identify ST59 were compared. Results Among the 82 strains, 21 strains expressed HldG10S toxin, accounting for 25.6％. 39 strains expressed Hld toxin, accounting for 47.6％.22 strains did not express HldG10S and Hld toxin, accounting for 26.8％. In HldG10S group,16 strains were ST59, accounting for 76.19％(16/21).ST59 was not found in both Hld and ND groups. All 16 strains of ST59 in HldG10S group producedβ-toxin, while none of the 5 strains of non-ST59 producedβ-toxin. The specificity(100％) and accuracy(100％) of the combined detection was significantly higher than that of HldG10S andβ-toxin single detection of specificity(92.4％, 77.3％) and accuracy(80.5％, 81.7％) (χ2=19.472, P<0.001;χ2=17.792, P<0.001). Conclusion The combined detection of HldG10S andβ-toxin can preliminarily and rapidly identify ST59, which can assist the routine monitoring of the change trend of staphylococcus aureus epidemic.

Lysine specific demethylase1 (LSD1) is a flavin adenine dinucleotide (FAD)-dependent monoamine oxidase. Studies have confirmed that aberrant expression of LSD1 is closely related to tumor metastasis and proliferation, and is currently one of the important targets for tumor-targeted therapy. In addition, LSD1 is involved in the development of various conditions such as neurodegenerative diseases, cardiovascular diseases, and inflammatory responses. Currently, several inhibitors have been developed for the clinical research stage. In this paper, the structure and mechanism of action of LSD1 and the research progress of LSD1 inhibitors are briefly introduced to provide some reference for the design and development of novel LSD1 inhibitors.

Objective: To analyze the clinicopathological characteristics of papillary thyroid microcarcinoma (PTMC) and risk factors for central lymph node metastasis(CLNM) in PTMC. Methods: The data of 900 patients with PTMC initially treated in our hospital from January 2004 to December 2015 were retrospectively analyzed. Chi-square test and Logistic regression analysis were performed to determine the risk factors for CLNM. Results: CLNM affected 162 (22.9%) of 707 patients treated with central lymph node dissection. Age, maximum tumor size, multifocality, bilaterality, and extracapsular spread (ECS) were significantly correlated with CLNM (all P<0.01). Age<45 years, maximum tumor size>5 mm, multifocality, bilaterality, and extracapsular spread were independently correlated with CLNM. Conclusion A prophylactic central lymph node dissection should be considered in PTMC patients with age<45 years, maximum tumor size>5 mm, multifocality, bilaterality, and extracapsular spread.