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A síndrome respiratória aguda grave (SRAG) é caracterizada por sintomas de febre alta, tosse e dispneia, e, na maioria dos casos, relacionada a uma quantidade reduzida de agentes infecciosos. O objetivo foi avaliar a prevalência dos vírus respiratórios Influenza A (FluA), vírus sincicial respiratório (RSV) e do novo coronavírus (SARS-CoV-2) em pacientes com internação hospitalar por SRAG. Estudo transversal, com pacientes em internação hospitalar com SRAG entre novembro de 2021 e maio de 2022. Dados sociodemográficos e clínicos e amostras da nasofaringe foram coletados/as, as quais foram submetidas à extração de RNA e testadas quanto à positividade para Influenza A, RSV e SARS-CoV-2 por meio da técnica de PCR em tempo real pelo método SYBR Green. Foram incluídos 42 pacientes, sendo 59,5% do sexo feminino, 57,1% idosos, 54,8% com ensino fundamental. A maior parte dos pacientes reportou hábito tabagista prévio ou atual (54,8%), não etilista (73,8%) e 83,3% deles apresentavam alguma comorbidade, sendo hipertensão arterial sistêmica e diabetes mellitus tipo 2 as mais prevalentes. Um total de 10,5% dos pacientes testou positivo para FluA, nenhuma amostra positiva para RSV e 76,3% positivos para SARS-CoV-2. Na população estudada, SRAG com agravo hospitalar foi observado em maior proporção, em mulheres, idosos e pessoas com comorbidades, embora sem significância estatística, sendo o novo coronavírus o agente etiológico mais relacionado, o que evidencia a patogenicidade desse agente e suas consequências ainda são evidentes após quase 2 anos de período pandêmico.
Severe acute respiratory syndrome (SARS) is characterized by symptoms of high fever, cough and dyspnea, and is in most cases related to a reduced amount of infectious agents. The objective was to assess the prevalence of respiratory viruses Influenza A (FluA), respiratory syncytial virus (RSV) and the new coronavirus (SARS-CoV-2) in patients hospitalized for SARS. Cross-sectional study, with patients hospitalized with SARS between November 2021 and May 2022. Sociodemographic and clinical data and nasopharyngeal samples were collected, which were subjected to RNA extraction and tested for positivity for Influenza A, RSV and SARS-CoV-2 using the real-time PCR technique using the SYBR Green method. 42 patients were included, 59.5% female, 57.1% elderly, 54.8% with primary education. Most patients reported previous or current smoking habits (54.8%), non-drinkers (73.8) and 83.3% of them had some comorbidity, with systemic arterial hypertension and type 2 diabetes mellitus being the most prevalent. A total of 10.5% of patients tested positive for FluA, no samples positive for RSV, and 76.3% positive for SARS-CoV-2. In the studied population, SARS with hospital injury was observed more frequently in women and the elderly, with associated comorbidities, with the new coronavirus being the most related etiological agent, which shows, although not statistically significant, that the pathogenicity of this agent and its consequences are still evident after almost 2 years of period pandemic.
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Humans , Male , Female , Adult , Middle AgedABSTRACT
Background@#The Panbio™ COVID-19 Ag Rapid Test is a Food and Drug Administration (FDA)-approved point-of-care test (POCT) used for SARS-CoV-2 detection which has met minimum sensitivity and specificity requirements by the World Health Organization (WHO).@*Objective@#The study aimed to compare the clinical performance of a commercial lateral flow assay (LFA) to reverse transcriptase polymerase reaction (RT-PCR) in SARS-CoV-2 infection diagnosis@*Methodology@#Clinical data and simultaneous LFA and RT-PCR samples collected from June 2021 to June 2022 were obtained to analyze the diagnostic accuracy of LFA compared to RT-PCR.@*Results@#A total of 265 samples was obtained. 34.45% of RT-PCR positive samples were reliably detected by LFA. COVID-19 was reliably ruled out by LFA in 99.32% RT-PCR negative samples. LFA sensitivity among symptomatic patients with ≤7 days of illness was 51.61%, slightly higher than those with >7 days of illness (18.92%), and significantly higher than asymptomatic patients (16.67%). Asymptomatic subjects have a varied range of Ct-values, indicating different stages of infection or viral loads. Individuals with symptoms for more than 7 days have higher Ct-values, suggesting they are in later stages of infection or have lower viral loads. The probability of a positive LFA result decreases significantly when the Ct-value is beyond 28-30.@*Conclusion@#The LFA evaluated in this study did not show significant sensitivity and specificity during the early disease course wherein viral loads are suggestively high. However, its utility to accurately rule out COVID-19 is quite reliable in subjects with symptoms that are >7 days since Ct-values are suggestively beyond 28-30 which implies a significantly decreased probability of a positive LFA result.
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COVID-19 , SARS-CoV-2ABSTRACT
@#Objective To explore a method for detecting the integrity of target nucleic acid in recombinant adeno-associated virus(rAAV),and establish a preliminary analysis algorithm.Methods The free DNA fragment of rAAV was digested,and the virus genome was extracted.Five pairs of overlapping primers were designed,using the orthogonal array method,which were detected by digital PCR respectively,with conventional conditions:20 μL reaction system with EveGreen and4 μL template,and digital PCR conditions:95 ℃ 5 min;95 ℃ 15 s,55 ℃ 30 s,72 ℃ 90 s for 45 cycles.The enhancement condition of ultra-long nucleic acid fragment was 25 μL reaction system with Mix B-2 000 bp and 2 μL template,and the quantitative analysis was performed by using the software attached to the instrument.Using the least square method,the number of full-length fragments was fitted and analyzed,and then the integrity distribution of target nucleic acid was interpreted.Results The fragments with the distance between primers of no more than 1 200 nt were amplified effectively,and a series of effective copies of fragments with a length of about 1 000 nt were obtained by systematic analysis.The copy number of common fragments was fitted and analyzed by the least square method.It was estimated that the full-length fragments in the sample were no more than 1 234 copies/μL,and there was a signficant difference(P < 0.05)between this value and the maximum measured value of 1 443 copies/μL,with the difference of approximately 16.9%.Conclusion A preliminary detection method for the integrity of target nucleic acid in rAAV has been developed,and a certain amount of incomplete target nucleic acids were analyzed in the test sample,laying a foundation for further in-depth research.
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@#Objective To develop,verify and preliminarily apply a fluorescence quantitative PCR(qPCR)method for detection of the virus titer of recombinant measles virus vector severe acute respiratory symptom coronavirus 2(SARS-CoV-2)vaccine.Methods SARS-CoV-2 S gene was amplified using recombinant plasmid pUC57-S351 as the template,and the primer concentration was optimized to develop the qPCR detection method.The specificity and repeatability of the method were verified,and the linear range and limit of detection were determined.The copy number of recombinant virus S gene was detected by the developed qPCR method 1～12 d after continuous culture in bioreactor.Results The qPCR method was developed with the primer concentration of 0.20 μmol/L,which specifically detected the copy number of SARS-CoV-2 S gene.The linear relationship was good(R2= 0.995)at the template concentration ranged from 2 × 10~2 to 2 × 10~8 copies/μL,and the limit of detection was 2 × 10~2 copies/μL;The coefficient of variation(CV)value of 6 repeated detections of copy number of recombinant virus S gene was 2.64%.The copy number of recombinant virus S gene was monitored by the developed qPCR method 1 ～ 12 d after continuous culture in bioreactor,and the results were basically consistent with those detected by cytopathic method.Conclusion The developed qPCR method has good specificity and repeatability,which can be used for virus titer detection of recombinant measles virus vector SARS-CoV-2 vaccine.
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Objective @#To construct myeloid specific Spi1 gene knockout mice and analyze their genotypes , so as to provide animal model basis for the study of pathological mechanism of diseases and drug targets .@*Methods @#According to the principle of CRISPR/Cas9 technology and C re/LoxP system , sgRNA and Donor vectors were de signed and constructed . The transcript of Exon 2 ( Exon 2) was used as the knockout region , and Loxp elements were placed on both sides of Exon 2 . Cas9 protein , sgRNA and Donor vector were mixed and microinj ected into the fertilized eggs of C57BL/6J mice , the fertilized eggs were transplanted into the uterus of C57BL/6J pregnant female mice , and F0 generation was obtained after 19 ~ 20 days . Positive F0 mice were mated with C57BL/6J mice to ob tain stable F1 Spi1 flox/ + mice . Spi1 flox/ + mice of F1 generation were selfed to obtain Spi1 flox/flox mice . Spi1 flox/flox mated with Lyz2-Cre + mice to obtain Spi1 flox/ + /Lyz2-Cre + mice , and then mated with Spi1 flox/flox , the Spi1 flox/flox/Lyz2-Cre + mice were myeloid specific Spi1 gene knockout ( KO) mice . Spi1 flox/flox/Lyz2-cre - mice were used as wild type (WT) mice . DNA of WT and KO mice was extracted , and the genotypes were identified by agarose gel electro phoresis after PCR amplification . Western blot was used to detect the expression of spleen focus forming virus proviral integration oncogene , Spi - 1 /purine rich box - 1(PU . 1) in immune cells of WT and KO mice .@*Results@#The results of PCR identification showed that the genotype of mice with only 220 bp amplified by flox primer was Spi1 flox/flox homozygote , and the genotype of mice with 700 bp amplified by Lyz2-Cre primer was Lyz2-Cre + . Western blot showed that compared with WT group , the protein PU . 1 was not expressed in bone marrow derived macropha ges (BMDMs ) and peritoneal macrophages (PM) in KO group (P < 0.01) . There was no significant difference of statistics in the expression level of PU . 1 in T cells between KO mice and WT mice . The results of PCR and West ern blot showed that myeloid specific Spi1 KO mice were successfully constructed . @*Conclusion @#The myeloid spe cific Spi1 gene KO mice are successfully constructed and identified , which provides animal model basis for further revealing the potential mechanism of PU . 1 inimmune regulation .
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ObjectiveBody fluid stains left at crime scenes are frequently trace amounts, while the identification of body fluids through real time fluorogenic quantitative technique often necessitates the repeated detection within the limited sample, as multiple miRNA markers are the basis for the identification. Based on the goal of both the throughput and efficiency improvement of miRNA analysis in trace samples, a duplex real time fluorogenic quantitative PCR assay system was designed to accurately quantify two miRNAs simultaneously, and the system should be further verified by actual sample for the body fluid identification. MethodsThe duplex real time fluorogenic quantitative PCR system of miR-451a to miR-21-5p was established with specially designed primers and probes, and the concentrations of the primers and probes were both optimized. The specificity, sensitivity and reproducibility of the system were validated, while its capability for body fluid identification was assessed using the miR-451a to miR-21-5p ratio. ResultsThe optimized assay system exhibited excellent specificity and repeatability, with coefficients of variation consistently below 8% for both intra- and inter-batch variability. The amplification efficiency of miR-451a and miR-21-5p reached 71.77% and 74.81%, respectively, with high and relatively consistent results. By utilizing this duplex real time fluorogenic quantitative PCR assay system, a total of 58 body fluid samples were analyzed, exhibiting a discrimination rate of 100% between blood and non-blood samples, as well as between peripheral blood and menstrual blood samples. Moreover, the results, obtained from single real time fluorogenic quantitative PCR assay system and duplex real time fluorogenic quantitative PCR assay system, showed no statistically significant difference with randomly selected blood samples (n=20). Compared to previous single real time fluorogenic quantitative PCR assay system, the sensitivity of duplex real time fluorogenic quantitative PCR assay system exhibited remarkable improvement. A minimum input of only 0.1 ng total RNA was sufficient for accurate detection of peripheral blood and menstrual blood samples, while saliva, semen, and vaginal secretion required only 1 ng total RNA for precise identification purposes. Additionally, the duplex real time fluorogenic quantitative PCR assay system successfully differentiated between different types of body fluids in simulated samples under natural outdoor conditions. ConclusionThe duplex real time fluorogenic quantitative PCR assay system effectively reduced both the time and material costs by half compared to the single system, especially suitable for the examination of body fluid stains left at crime scenes, solving the contradiction between the trace amount and the multiple sample volumes demand of repeated real time fluorogenic quantitative PCR. The duplex real time fluorogenic quantitative PCR assay successfully distinguished blood and other body fluid, as well as peripheral blood and menstrual blood samples, which maintains an equivalent capability for body fluid identification with half sample, time and reagent consumption. This system provides an efficient tool for identifying suspicious body fluids, as well as a foundation for more multiplexed real time fluorogenic quantitative PCR assay system research.
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@#Objective To investigate the feasibility of using quantitative PCR(qPCR)technology to detect large fragments of host cell residual DNA(HCD)in recombinant adeno-associated virus(rAAV)gene therapy products.Methods Four different serotypes of rAAV were extracted for the nucleic acids,two fragment sequences of 244 bp and 562 bp within the long terminal repeat sequence(LTR)in the genome of host cells HEK293 were specifically quantified by qPCR,and the proportion of HCD in the total nucleic acids was calculated.Results Large fragments of HCD in qPCR quantifiable range were detected in four different serotype rAAV products,with the abundance ranging from 0. 3% to 5. 4%. As the length of the detected fragment increased,the abundance of HCD fragments showed a decreasing trend.Conclusion qPCR technology can be used to determine the presence of large fragments of HCD in rAAV products.
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【Objective】 To establish a method for qualitative detection of the presence or absence of all KIR genes by quantitative polymerase chain reaction(Q-PCR). 【Methods】 Based on the polymorphism of high-resolution level KIR alleles in Chinese population and the IPD-KIR database, KIR gene-specific primers were designed to amplify all the 16 KIR genes and 2DS4-Normal and 2DS4-Deleted subtypes by Q-PCR. Meanwhile, one negative control and one positive control specific amplifying human growth hormone (HGH) gene fragment were set to monitor the false positive and false negative results in PCR amplification, respectively. A total of 302 samples with known KIR genotype previously identified by KIR PCR-SSP commercial kit were randomly selected for blind inspection to verify the reliability of KIR Q-PCR method established by authors. 【Results】 The results of 300 samples detected by our KIR Q-PCR method were consistent with the known results, but two samples showed inconsistent results. One sample was negative for 2DS5 by Q-PCR but positive by PCR-SSP, another sample was positive for 2DS1 by Q-PCR but negative by PCR-SSP. The two doubtful samples were genotyped by sequencing-based typing (PCR-SBT) for 2DS5 and 2DS1, respectively. PCR-SBT results confirmed that the results of Q-PCR test was correct. 【Conclusion】 The KIR Q-PCR method established in this paper can provide accurate and reliable results for testing the presence or absence of KIR genes.
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【Objective】 To explore the distribution of serological markers related to samples whose serological test results were inconsistent with HBV DNA test results among voluntary blood donors in Xi′an. 【Methods】 A total of 71 HBsAg ELISA positive and NAT non-reactive (ELISA+ /NAT-)blood samples were collected from Shaanxi Blood Center from November 1, 2022 to April 30, 2023. The serological markers of hepatitis B were detected by electrochemiluminescence method, and the HBV S region and C region gene fragments were amplified by nested-PCR. 【Results】 The positive rate of nested-PCR in double ELISA+ /NAT- group(n=30) was statistically higher than that of ELISA+ /NAT- group(n=41)(60% vs 24.4%, P<0.05). Donors in double ELISA+ /NAT- group were all first-time blood donors, with the positive rate of anti-HBc in serum of 100%, and the serological pattern was mainly positive for items 1, 4 and 5 items(80%). Among the ELISA+ /NAT- group, 31.7% were repeat blood donors, with the positive rate of anti-HBc in serum of only 19.51%, and the serological patterns were mainly single anti-HBs positive (43.90%) and all negative (36.58%). 【Conclusion】 There are false positives in the test results of ELISA+ /NAT- group, which leads to unnecessary blood discarding. Meanwhile, the samples with negative NAT may have low levels of HBV DNA, which may lead to missed detection. It is suggested that multiple systems and methods should be applied to trace the blood donors who are HBsAg positive and NAT non-reactive, so as to improve the accuracy of HBV screening of blood donors and reduce blood waste.
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The detection principle of microfluidic microfluidic technology was introduced.The current research status of microfluidic platform-based SARS-CoV-2 nucleic acid detection technologies were reviewed such as reverse transcription quantitative real-time polymerase chain reaction(RT-qPCR),digital PCR,isothermal amplification and clustered regularly interspaced palindromic repeats/CRISPR-associated protein.The deficiencies of microfluidic platform-based SARS-CoV-2 nucleic acid detection were analyzed.It's pointed out microfluidic platform-based SARS-CoV-2 nucleic acid detection had to be optimized and validated clinically in specialty,sensitivity,detection limit,reproducibility,informatization,quality control and reagent cost.[Chinese Medical Equipment Journal,2024,45(1):101-107]
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Objective To explore the value of droplet digital polymerase chain reaction(ddPCR)in the etiological diagnosis of severe acute pancreatitis(SAP)patients with suspected bloodstream infection(BSI).Methods SAP patients admitted to the department of critical care medicine in a hospital July to September 2022 were enrolled.When BSI was suspected,venous blood was collected for both ddPCR detection and blood culture(BC)with antimi-crobial susceptibility testing(AST)simultaneously.The time required for two detection methods was recorded,and the detection results of ddPCR and BC were compared.The etiological diagnostic efficacy of ddPCR was calculated,and the correlation between the value of pathogen load detected by ddPCR and the level of infection parameters was explored.Results A total of 22 patients were included in the analysis,and 52 venous blood specimens were collec-ted for detection.BC revealed 17 positive specimens(32.7％)and 29 pathogenic strains,while ddPCR showed 41 positive specimens(78.8％)and 73 pathogenic strains.Detection time required for ddPCR was significantly lower than that of BC([0.16±0.03]days vs[5.92±1.20]days,P＜0.001).Within the detection range of ddPCR and taking BC results as the gold standard,the sensitivity and specificity of ddPCR were 80.0％and 28.6％,respective-ly.With the combined assessment of BSI based on non-blood specimen microbial evidence within a week,the sensi-tivity and specificity of ddPCR detection increased to 91.9％and 76.9％,respectively.ddPCR detected resistance genes of blaKPC,blaNDM/IMP,VanA/VanM,and mecA from 19,9,6,and 5 specimens,respectively.Correlation analysis showed a positive correlation between pathogen load and levels of C-reactive protein as well as procalcitonin(r=0.347,0.414,P＜0.05).Conclusion As a supplementary detection method for BC in BSI diagnosis,ddPCR has the advantages of higher sensitivity and shorter detection time,and is worthy of further exploration in clinical application.
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【Objective】 To establish a highly sensitive detection method of platelet HPA-3 and HPA-15 genotyping by droplet digital PCR (ddPCR), and to explore the feasibility of applying it to the detection of human platelet antigen (HPA) compatibility in maternal peripheral blood fetal free DNA. 【Methods】 For SNP mutation sites of HPA-3 and HPA-15, specific primers and MGB probes were designed, and amplification conditions such as annealing temperature and primer concentration of ddPCR were optimized to establish the optimal reaction system and clarify the test procedures. The methodological performance of the assay was evaluated, including specificity, sensitivity, repeatability and stability. ddPCR was used to detect 67 clinical blood samples, and the allele typing results were compared with the gene sequencing results. The fetal free DNA HPA antigen of 52 maternal peripheral blood samples was detected. 【Results】 The ddPCR method for detecting platelet HPA-3 and HPA-15 showed good specificity of primers and probes. The optimal annealing temperatures for HPA-3 and HPA-15 were 61.6℃ and 60.2℃, respectively. The optimal concentrations of primers were 900 nM and 700 nM respectively. The final concentration of the probe was 250 nM. The quantitative detection range of copy number was 2 to 20 000 copies, with lower limit of detection of 0.1 copies/μL, and the linearity is good. In low copy number samples, the intra - and inter batch coefficient of variation (CV) of actual detection values for HPA-3 and HPA-15 were both lower than 5%. The detection results of HPA-3 and HPA-15 genotypes of 67 blood samples were consistent with the gene sequencing results, and its application in fetomaternal platelet HPA-3, HPA-15 genotype detection met expectations. 【Conclusion】 The HPA-3 and HPA-15 ddPCR detection system constructed in this study has high accuracy, good repeatability, stability and sensitivity, and can be applied to the establishment of platelet HPA-3 and HPA-15 genotype donor pool, gene matching and fetomaternal platelet compatibility detection.
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【Objective】 To establish and verify a new nucleic acid extraction method for OBI detection with large volume and high sensitivity, and apply it in the quantitative determination of OBI samples with low viral load. 【Methods】 The method for nucleic acid extraction with large volume was established based on the method of Roche nucleic acid detection kit. HBV standards were configured into 10 000 IU/mL, 1 000 IU/mL, 100 IU/mL, 10 IU/mL and 1 IU/mL respectively, and nucleic acid was extracted from the 10 mL standards by magnetic beads. CT values of each concentration were detected by fluorescence quantitative PCR and each concentration gradient was detected in parallel duplicates. The logarithm of virus concentration was taken as the X-axis and the average CT values of two tests were taken as the Y-axis to construct the fluorescence quantitative standard curve and regression equation. Three repeated experiments were conducted to verify the stability of the method. This method was used to extract nucleic acid from OBI samples with low viral load, and fluorescence quantification was performed. 【Results】 The amplification efficiency of fluorescence quantitative standard curves ranged from 90% to 105%, and the regression equation was greater than 0.99. The variation coefficients of variation of CT values were 0.63%, 0.78%, 1.52%, 1.36% and 0.78%, respectively. This method can extract nucleic acid from OBI samples with viral load of 1 IU/mL for quantification. 【Conclusion】 The detection limit of HBV nucleic acid quantitative detection system can reach 1 IU/mL, and it has strong stability and high sensitivity, which can be used for the quantitative detection of OBI with low viral load.
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ObjectiveTo prepare a rat model of heart failure after myocardial infarction by ligation of the anterior descending branch of the left coronary artery， and to observe the effect of Shenfu Yixin granules on the mitochondrial dynamics of rats with heart failure. MethodFifty SD male rats were randomly taken ten as the sham operation group and the rest as modeling group. The rat model of heart failure after myocardial infarction was prepared by ligation of anterior descending branch of left coronary artery. According to the left ventricular ejection fraction（LVEF） on the 28th day after operation， the model rats were randomly divided into the model group， Shenfu Yixin granule low-dose and high-dose groups（3.011， 15.055 g·kg-1） and sacubitril valsartan sodium group（20.83 mg·kg-1）. Each administration group was gavaged daily with the corresponding dose of drug solution， while the sham operation group and model group were given the same amount of normal saline once a day for 28 days， with 6 rats in each group. Ultrasound was used to detect the cardiac function parameters， rat heart mass and body mass were weighed to calculate the cardiac mass index， enzyme linked immunosorbent assay（ELISA） was used to detect serum brain natriuretic peptide（BNP） and soluble growth stimulation expressed gene 2 protein（sST2） levels. Hematoxylin-eosin（HE） staining was used to observe the pathological morphology of the myocardium. Real-time fluorescence quantitative polymerase chain reaction（Real-time PCR） and Western blot were used to detect the mRNA and protein expression of mitochondrial fusion protein 1/2（Mfn1/2）， optic atrophy protein 1（Opa1）， dynamin-related protein 1（Drp1） and fission protein 1（Fis1）. ResultCompared with the sham operation group， the mRNA and protein expression of LVEF， Mfn1， Mfn2， Opal in the model group decreased（P<0.05）， while BNP， sST2， cardiac mass index， Drp1， Fis1 mRNA and protein levels increased（P<0.05）. Compared with the model group， the expression of LVEF， Mfn1， Mfn2， Opal mRNA and protein increased in Shenfu Yixin granule high-dose and sacubitril valsartan sodium groups（P<0.05）， while BNP， sST2， cardiac mass index， Drp1， Fis1 mRNA and protein levels decreased（P<0.05）. Pathological observation showed that compared with the sham operation group， the model group had disordered arrangement of myocardial cells， inflammatory cell infiltration and myocardial fibrosis. Compared with the model group， the degree of inflammatory cell infiltration， myocardial or interstitial fibrosis was improved and alleviated in all administered groups. ConclusionShenfu Yixin granules can resist heart failure， reduce cardiac mass index， decrease BNP and sST2 contents， and improve cardiac function. Its mechanism may be related to the adjustment of mitochondrial dynamics.
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@#Objective To prepare a national reference standard for the quantification of HEK293 cell DNA content,so as to provide a support for the determination of residual DNA in HEK293 cells in the industry.Methods HEK293 cell DNA prepared using Genomic-tip 500/G and genomic DNA purification reagents was used as source materials,and the purity and content were assessed using ultraviolet spectrophotometry and agarose gel electrophoresis.After dilution to approximately 100 ng/μL,the DNA was aliquoted at 160 μL/tube.Five different laboratories were organized for collaborative calibration by using ultraviolet spectrophotometry, and the stability and applicability were evaluated.Results The HEK293 cell DNA national reference standard exhibited A_(260)/A_(280) ratios between 1.8 and 2.0 and displayed a single band on electrophoresis,meeting the specified criteria.Collaborative calibration across five laboratories yielded 78 valid data points with an average content of 104.8 ng/μL,a relative standard deviation(RSD) of 4.2%.The 95% confidence interval for the mean was 103.8—105.8 ng/μL,and the 95% reference range for single measurements was 96.0—113.6 ng/μL.The average confidence limit rate was 1.0%,and the recommended storage condition was-80 ℃.Applicability studies were conducted using two different models of fluorescence quantitative PCR instruments.The reference standard exhibited good applicability within the range of 0.3—3 000 pg/reaction,with amplification efficiencies of 101% and 95%,and R~2 values of 0.999 2 and 0.999 5 for the standard curves,respectively.Conclusion This batch of HEK293 cell DNA national reference standard meets all required specifications and can be utilized as a national reference standard for fluorescence quantitative PCR detection,with a certified content of 104.8 ng/μL,assigned batch number 270039-202301.
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@#Objective To develop and verify a multiplex fluorescent quantitative PCR method for detection of common bacterial and fungal contaminants in cell culture medium.Methods According to NUC gene of Staphylococcus aureus,COLA gene of Clostridium spore,ITS-2 segment sequence of Candida albicans,a set of primers and probes were designed for each respectively,and using UBI3 gene of capsicum introduced as external standard gene,a triple reaction system of Staphylococcus aureus,Clostridium spore and external standard gene and a double reaction system of Candida albicans and external standard gene were established.The primer specificity,linear range,limit of detection,specificity,anti-interference performance and precision of the method were verified.Finally,100 samples of 293T cell culture medium were detected by using the developed method,which was compared with the common PCR method.Results Three pairs of primers all amplified about 100 bp specific gene bands corresponding to the three strains at different annealing temperatures(56,57,58 and59 ℃),and the size was consistent with the expected.In the range of 5.80 × 10~6 — 5.80 × 10~2 copies/μL,the standard plasmids of the three strains showed a good linear relationship with the Ct values.The standard curve equations were:Y=-3.373 X+37.48,Y=-3.557X+36.59 and Y=-3.536 X+39.78,each R~2> 0.99,respectively,and the amplification efficiency was in the range of 90%—110%.All the limits of detection of the three strains were 10~1 CFU/mL.The primers and probes of the three strains showed no specific amplification on the genomic DNA of six kinds of cells that were prone to cross-reaction.The genomic DNA of 293T cells,Yeast,Escherichia coli and Mycoplasma sp.had no effect on the detection.The CVs of repeatability and intermediate precision verification were both less than 15%.Among 100 cell culture medium samples,14 positive and 86 negative samples were detected,and the results of common PCR method for three positive and two negative samples randomly selected were consistent with the developed method.Conclusion The multiplex fluorescent quantitative PCR method developed in this study for the detection of bacteria and fungi in cell culture medium has good specificity,anti-interference performance and precision,and is simple to operate with low cost and high sensitivity,which can quickly detect the contaminants during cell culture.
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Objective To investigate the effect of microglia activation regulated by C-X3-C motif chemokine ligand 1(CX3CL1)-C-X3-C motif chemokine receptor 1(CX3CR1)pathway on memory function in hemorrhagic shock/resuscitation rats.Methods The experiment was divided into two parts.In the first part,the rats were randomly divided into sham group,model-0.5 hour group,model-1.5 hour group,model-3 hour group,10 rats in each group.There were differences in the time of hemorrhagic shock among each group.In the second part,rats were randomly divided into control group and CX3CL1 group,10 rats in each group.The rats in CX3CL1 group were treated with CX3CL1 protein factor(intraventricular injection),and the rats in control group were treated with saline.All rats were trained in Morris water maze experiments before model construction,and tests of Morris water maze experiments were carried out after 4 days of model construction.After completion,the whole brains were taken for HE staining and immunohistochemical staining.Cerebrospinal fluid was taken for detection of inflammatory cytokines,and hippocampus tissues were taken for Real-time PCR detection and Western blotting detection.Results Compared with the sham group,the escape latency of rats in model group increased,the number of platform crossings and the resident time in the third quadrant decreased.The neuronal state was impaired in HE staining in model group.In addition,compared with the sham group,the expression of ionized calcium binding adaptor molecule-1(Iba1)in the brain of the rats in model group increased,the contents of tumor necrosis factor-α(TNF-α)and interleukin(IL)-6 in the cerebrospinal fluid increased,and the M1-type microglia markers CD16,TNF-α,IL-1β and inducible nitric oxide synthase(iNOS)mRNA content increased.At the same time,compared with the sham group,the expressions of CX3CL1 and CX3CR1 in the brain of model group decreased,and the expressions of phosphorylated nuclear factor-κB(p-NF-κB)and nucleotide binding oligomerization domain(NOD)-like receptor protein 3(NLRP3)increased.However,compared with the control group,rats in CX3CL1 group had reduced escape latency,increased platform crossing times and quadrantⅢresident time,and recovered neuronal states.In addition,the expression of Iba1 in the brain of CX3CL1 group decreased,the contents of TNF-α and IL-6 in the cerebrospinal fluid decreased,the mRNA contents of M1-type microglia markers like CD16,TNF-α,IL-1β and iNOS decreased,and the mRNA contents of markers of M2-type microglia glial like CD206,transforming growth factor-β(TGF-β),arginase-1(Arg1),Chitinase 3-like protein 1(Ym 1)increased.Conclusion CX3CL1 can help inhibit the excessive activation of microglia,induce the polarization of microglia to M2 type,inhibit the polarization of M1 type,reduce the release of inflammatory cytokines,and alleviate the memory function damage induced by hemorrhagic shock/resuscitation.
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Objective To investigate the efeects of microRNA(miR)-103a-3p regulates tumor protein 53-regulated inhibitor of apoptosis 1(TRIAP1)on osteoblast differentiation and bone mass in ovariectomized mice.Methods MC3T3-E1 cells were divided into normal group,miR-103a-3p-NC group,miR-103a-3p mimic group,miR-103a-3p mimic+TRIAP1-NC group,miR-103a-3p mimic+TRIAP1 mimic group.mRNA expression of miR-103a-3p,TRIAP1,P53 were detected by Real-time PCR;Cell proliferation and apoptosis were detected by MTT test and flow cytometry;cytoskeleton and mineralization of cells were detected by F-actin immunofluorescence staining and alizarin staining;alkaline phosphatase(ALP)activity was detected by ELISA.24 female mice were divided into sham group,osteoporosis(OP)group,miR-103a-3p antagonist-NC group,miR-103a-3p antagonist group(six in each group),extract bilateral ovaries to establish an OP model,sham group mice only isolated fat around ovarian tissue.mRNA expression of miR-103a-3p,TRIAP1,P53,ALP,osteocalcin(OCN),osteopontin(OPN)of bone tissue were detected;microCT detect bone mineral density(BMD),bone mineral content(BMC);haematoxylin eosin staining was used to observe pathological changes of bone tissue.Results After miR-103a-3p mimic was transfected into cells,the miR-103a-3p and P53 expression increased,TRIAP1 expression decreased,cell proliferation decreased,apoptosis increased,F-actin expression decreased,the number of calcium nodules decreased,and ALP enzyme activity decreased(P<0.01);however,after TRIAP1 mimic was additionally transfected into cells,the above result caused by miR-103a-3p mimics were significantly reversed(P<0.01).In OP group,the miR-103a-3p and P53 expression in bone tissue increased,the TRIAP1,ALP,OCN and OPN expression decreased,BMD and BMC were decreased,and bone tissue construct was damaged(P<0.05);in miR-103a-3p antagonist group,the miR-103a-3p and P53 expression in bone tissue decreased,TRIAP1,ALP,OCN,OPN expression increased,BMD and BMC increased,and bone tissue construct was improved(P<0.05).Conclusion MiRNA-103a-3p mediate TRIAP1/P53 to inhibit proliferation and mineralization of osteoblast,while miR-103a-3p antagonistic treatment reduce bone loss in OP mice.
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Objective To investigate the association of 13 single nucleotide polymorphism(SNP)sites in 6 phalange-bone development related genes[fibroblast growth factor receptor 2(FGFR2),indian hedgehog signaling molecule(IHH),Msh homeobox 1(MSX1),Runx family transcription factor 2(RUNX2),SRY-box transcription factor 9(SOX9),Wnt family member 5A(WNT5A)]with human index-ring finger length ratio(2D∶4D).Methods Digital cameras were used to take frontal photographs of the hands of 731 college students(358 males and 373 females)in Ningxia,and image analysis software was used to mark anatomical points and measure finger lengths of index(2th)and ring(4th);genotyping of 13 SNP sites(rs1047057,rs755793,rs41258305,rs3731881,rs3100776,rs12532,rs3821949,rs45585135,rs3749863,rs1042667,rs12601701,rs1829556,rs3732750)for 6 genes by multiplex PCR;One-Way ANOVA or independent sample t-test indirectly assessed the association between 2D∶4D and 13 SNP sites.Results Both left and right hand 2D∶4D were significantly higher in females than males in Ningxia college students(all P<0.01);no statistically significant differences in genotype and allele frequencies of the 13 SNP sites among different sexes(all P>0.05);among different sexes,male left hand 2D∶4D was significantly associated with the genotype of SOX9 gene rs12601701 site(P<0.05)and right hand 2D∶4D was significantly associated with the genotype of WNT5A gene rs1829556 site(P<0.05);the female right hand 2D∶4D was significantly associated with the MSX1 gene rs12532(P<0.01)and rs3821949(P<0.05)sites genotypes.Conclusion SOX9(rs12601701),WNT5A(rs1829556)and MSX1(rs12532 and rs3821949)gene polymorphisms may be associated with the formation of 2D∶4D in Ningxia population.
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Purpose To analyze the expression of FOXA3 in colorectal cancer(CRC)and its correlation with clinicopatho-logical features.Methods FOXA3 mRNA expression in 31 CRC cancer tissues and their matched normal tissues was detec-ted by real-time quantitative PCR(RT-qPCR).The protein ex-pression of FOXA3 in 120 CRC cancer tissues was detected by immunohistochemical EnVision two-step method,and the clini-copathologic features such as lymph node metastasis and immu-nohistochemical expression were analyzed.Results The mRNA expression level of FOXA3 in colorectal cancer tissues was sig-nificantly higher than that in paired paracancer tissues(t=2.952,P=0.006 1).FOXA3 protein expression level in color-ectal cancer tissues was not significantly correlated with gender,age,site and size of patients,but significantly correlated with the degree of tissue differentiation(P=0.006)and lymph node metastasis(P=0.002).The degree of differentiation was nega-tively correlated with FOXA3 expression,while lymph node me-tastasis was positively correlated with FOXA3 expression.Sur-vival analysis showed that higher FOXA3 expression was associ-ated with worse overall survival(P＜0.000 1),and FOXA3 was an independent risk factor for prognosis in patients with colorectal cancer.Conclusion This study suggests that FOXA3 may play a promoting role in the occurrence and development of colorectal cancer,and FOXA3 may be a molecular marker for the diagnosis,metastasis and prognosis of colorectal cancer.