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Objective:To provide normal reference thresholds for clinical dynamic monitoring of the risk of microthrombus during pregnancy, we aimed to establish reference intervals of D-dimer in healthy pregnant women during different periods of gestation in Xi′an.Method:From December 2020 to March 2022, a total of 1502 healthy pregnant women and healthy non-pregnant women (healthy non-pregnant control group) who received routine prenatal examination in Northwest Women and Children′s Hospital were recruited in the study by questionnaire, including 1236 healthy pregnant women and 266 healthy non-pregnant control group. Plasma D-dimer concentration was detected by STA-R Evolution automatic blood coagulation analyzer and the concentration levels of D-dimer in different pregnancies and age groups were calculated using Graph Prism 9.0 software. In addition, 20 samples were collected in each pregnancy to verify the established reference interval.Results:There was no significant difference in plasma D-dimer levels between<30 years old and ≥30 years old at different gestational weeks. Plasma D-dimer level in healthy pregnant women group was significantly higher than that in healthy non-pregnant women group of the same age (P<0.05). With the increase of gestational week, plasma D-dimer level in pregnant women increased significantly, and plasma D-dimer level at different gestational weeks ≤13 weeks, 13+ 1-20 weeks, 20+ 1-27 weeks, 27+ 1-35 weeks, ≥35 +1 week were 0.33 (0.26, 0.47) μg/ml, 0.41 (0.30, 0.51) μg/ml, 0.71 (0.48, 0.94) μg/ml, 0.91 (0.70, 1.27) μg/ml, 1.30 (0.96, 1.72) μg/mlrespectively. Unilateral reference interval acuities were≤0.89 μg/ml, ≤1.53 μg/ml, ≤2.44 μg/ml, ≤2.74 μg/ml, ≤3.82 μg/ml respectively. The reference range established in this study was verified by 20 independent samples from each of the 5 gestational age groups, and the results were acceptable. Conclusion:This study preliminarily established the reference interval of plasma D-dimer in healthy pregnant women at different gestational weeks in Xi ′an area, which is helpful for the auxiliary diagnosis of thrombotic diseases during pregnancy.
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Objective To analyze the effect of the identification and evaluation of Escherichia (E.) coli and Shigella,based on the upstream flanking sequences of CRISPR1.Methods Both CRISPR and cas sequences were obtained through the BLAST with repeating sequences against the publicly complete genome in GenBank that related to E.coli and Shigella.Clustal X was used to perform multi-sequences alignment of the flanking sequences.PCR method was used to amplify the upstream flanking sequences of CRISPR1 in order to appraise the effect of identification and evaluation of upstream flanking sequences on E.coli and Shigella,which were based on the upstream flanking sequences of CRISPR1.Results The results showed that 73.4％ of the strains containing the I-E CRISPR/Cas that belonged to the phylogroups A,B1,D while 8.4％ strains carried the I-F CRISPR/Cas.Another 17.2％ of the strains owned CRISPR3-4 (non-CRISPR/Cas) only belonged to the phylogroups B2.All the Shigella strains carried I-E CRISPR/Cas.More than 99％ of similarity the CRISPR1 upstream-flanking sequences was seen in E.coli (except B2) and Shigella and E.coli (B2).Both sensitivity and specificity were greater than 91％ after PCR amplification in the region to identify the E.coli and Shigella.Conclusion The upstream of CRISPR1 could achieve a preliminary identification effect on E.coli and Shigella.
ABSTRACT
Objective To analyze the effect of the identification and evaluation of Escherichia (E.) coli and Shigella,based on the upstream flanking sequences of CRISPR1.Methods Both CRISPR and cas sequences were obtained through the BLAST with repeating sequences against the publicly complete genome in GenBank that related to E.coli and Shigella.Clustal X was used to perform multi-sequences alignment of the flanking sequences.PCR method was used to amplify the upstream flanking sequences of CRISPR1 in order to appraise the effect of identification and evaluation of upstream flanking sequences on E.coli and Shigella,which were based on the upstream flanking sequences of CRISPR1.Results The results showed that 73.4％ of the strains containing the I-E CRISPR/Cas that belonged to the phylogroups A,B1,D while 8.4％ strains carried the I-F CRISPR/Cas.Another 17.2％ of the strains owned CRISPR3-4 (non-CRISPR/Cas) only belonged to the phylogroups B2.All the Shigella strains carried I-E CRISPR/Cas.More than 99％ of similarity the CRISPR1 upstream-flanking sequences was seen in E.coli (except B2) and Shigella and E.coli (B2).Both sensitivity and specificity were greater than 91％ after PCR amplification in the region to identify the E.coli and Shigella.Conclusion The upstream of CRISPR1 could achieve a preliminary identification effect on E.coli and Shigella.
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Objective To investigate the association between phage-mediated shiga toxin and molecular distribution of CRISPR in Escherichia (E.) coli O26:H11 or NM.Methods A total of 135 E.coli O26:H11 or NM strains were collected from NCBI database.Software CRT and CRISPR Finder were used to extract CRISPR and Excel was used to assign the spacer of unique number and type CRISPR.And the relationship between CRISPR and stx phage was analyzed.Results All the 135 E.coli O26:H11 or NM strains had the CRISPR.For CRISPRI,CRISPR2.1,CRISPR2.2 and CRISPR3-4,19,22,1 and 1 subtypes were found,respectively.According to the four CRISPR sites,the strains could be divided into 40 subtypes.Stx-phage was only observed in the group C of CRISPR.Compared with E.coli of stx-phage negative,E.coli with stx-phage harbored more spacers.Conclusions CRISPR loci was extensively existed in E.coli O26:H11 or NM,and many subtypes were found in these strains.The presence of stx-phage was related to the molecular distribution of CRISPR in E.coli O26:H11 or NM.CRISPR might be a valuable biomarker to identify strains with high virulent potential.
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Objective To explore the stability of resistant phenotypes and changes of clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) gene system on four Shigella strains in the absence of antibiotics.Methods Four clinical isolated Shigella strains that resistant to different antibiotics were consecutive passaged for 90 times without antibiotics.Agar dilution method was used to determine the minimum inhibitory concentration of Shigella strains.After sequence analysis with PCR,CRISPR Finder and Clustal X 2.1 were applied to identify the changes of CRISPR loci in the Shigella strains.Results After the consecutive transfer of 90 generations,sensitivity to certain antibiotics of four Shigella strains with different drug resistant spectrums increased.Mel-sf1998024/zz resistance to ampicillin,cephalexin,cefotaxime,chloramphenicol decreased,mel-s2014026/sx resistance to norfloxacin,trimethoprim decreased,mel-sf2004004/sx drug resistance to ampicillin,cefuroxime,cefotaxime,chloramphenicol,trimethoprim decreased and mel-sf2013004/bj resistance to chloramphenicol decreased.The spacer of which matched gene codes Cas and its upstream repeat in 3'end of CRISPR3 got lost in mel-sf1998024/zz and mel-sf2013004/bj.Conclusions Shigella strains could reduce or lose their resistance to some antibiotics after consecutive transfers,without the interference of antibiotics.CRISPR3 locus had dynamic spacers in Shigella strains while CRISPR3 locus and cas genes might have been co-evolved.
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Objective To investigate the association between phage-mediated shiga toxin and molecular distribution of CRISPR in Escherichia (E.) coli O26:H11 or NM.Methods A total of 135 E.coli O26:H11 or NM strains were collected from NCBI database.Software CRT and CRISPR Finder were used to extract CRISPR and Excel was used to assign the spacer of unique number and type CRISPR.And the relationship between CRISPR and stx phage was analyzed.Results All the 135 E.coli O26:H11 or NM strains had the CRISPR.For CRISPRI,CRISPR2.1,CRISPR2.2 and CRISPR3-4,19,22,1 and 1 subtypes were found,respectively.According to the four CRISPR sites,the strains could be divided into 40 subtypes.Stx-phage was only observed in the group C of CRISPR.Compared with E.coli of stx-phage negative,E.coli with stx-phage harbored more spacers.Conclusions CRISPR loci was extensively existed in E.coli O26:H11 or NM,and many subtypes were found in these strains.The presence of stx-phage was related to the molecular distribution of CRISPR in E.coli O26:H11 or NM.CRISPR might be a valuable biomarker to identify strains with high virulent potential.
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Objective To explore the stability of resistant phenotypes and changes of clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) gene system on four Shigella strains in the absence of antibiotics.Methods Four clinical isolated Shigella strains that resistant to different antibiotics were consecutive passaged for 90 times without antibiotics.Agar dilution method was used to determine the minimum inhibitory concentration of Shigella strains.After sequence analysis with PCR,CRISPR Finder and Clustal X 2.1 were applied to identify the changes of CRISPR loci in the Shigella strains.Results After the consecutive transfer of 90 generations,sensitivity to certain antibiotics of four Shigella strains with different drug resistant spectrums increased.Mel-sf1998024/zz resistance to ampicillin,cephalexin,cefotaxime,chloramphenicol decreased,mel-s2014026/sx resistance to norfloxacin,trimethoprim decreased,mel-sf2004004/sx drug resistance to ampicillin,cefuroxime,cefotaxime,chloramphenicol,trimethoprim decreased and mel-sf2013004/bj resistance to chloramphenicol decreased.The spacer of which matched gene codes Cas and its upstream repeat in 3'end of CRISPR3 got lost in mel-sf1998024/zz and mel-sf2013004/bj.Conclusions Shigella strains could reduce or lose their resistance to some antibiotics after consecutive transfers,without the interference of antibiotics.CRISPR3 locus had dynamic spacers in Shigella strains while CRISPR3 locus and cas genes might have been co-evolved.
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Objective To explore the regulative or mediating effect of perceived social support on the relationship between alexithymia and negative psychology of nurses.Methods A total of 503 nurses were surveyed by Toronto Alexithymia Scale-20 ( TAS-20),Perceived Social Support Scale ( PSSS ) and Genera Health Questionnaire-20 (GHQ-20).Results The scores of alexithymia,perceived social support and negative psychology of nurses were(54.82 ± 8.43 ),( 61.9 ± 9.78 ) and ( 3.70 ± 2.61 ),respectively.Alexithymia was significant positive correlated with negative psychology ( r =0.49,P ＜ 0.01 ),perceived social support was significant negative correlated with negative psychology ( r =-0.32,P＜ 0.01 ),alexithymia was significant negative correlated with perceived social support( r=-0.36,P＜0.01 ).In the test of Perceived social support's regulative effect between alexithymia and negative psychology,R12 was 0.259 and R22 was 0.257,R22 did not significantly improve,and in the second layer,t=-0.538,P＞ 0.05.The model fit indexes of perceived social support's partial mediating effect on the relationship between alexithymia and negative psychology were x2/df =1.645,RMSEA =0.036,CFI =0.995,IFI =0.995,RFI =0.960,TLI =0.984,NFI =0.987,GFI =0.993,AGFI =0.973.The model was proved well.Conclusion Perceived social support partially mediates the relationship between alexithymia and negative psychology,instand of regulating it.