Preparation of the first national reference standard for determination of HEK293 cell DNA content / 中国生物制品学杂志

@#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.

Transcriptomic Analysis of Wuzi Yanzongwan on Testicular Spermatogenic Function in Semi-castrated Male Mice / 中国实验方剂学杂志

ObjectiveTo screen out the transcriptomes related to the intervention of Wuzi Yanzongwan on the spermatogenic function of semi-castrated male mice， and to explore its potential mechanism in the intervention of the progress of low spermatogenic function. MethodBalb/c mice were randomly divided into sham-operated group， model group， testosterone propionate group（0.2 mg·kg-1·d-1， intramuscular injection） and Wuzi Yanzongwan group（1.56 g·kg-1·d-1， intragastric administration） according to body weight， with 12 mice in each group. The right testicle and epididymis were extracted from the model group and the drug administration group to construct the semi-castrated model of low spermatogenic function， while the fur and the right scrotum of the sham-operated group were only cut and immediately sterilized and sutured. At the end of the intervention， hematoxylin-eosin（HE） staining was used to observe the histopathology of testis， enzyme-linked immunosorbent assay（ELISA） was used to detect the levels of serum testosterone（T）， luteinizing hormone（LH） and follicle stimulating hormone（FSH）. The sperm count and motility of epididymis were measured by automatic sperm detector of small animal. Transcriptomic microarray technology was used to detect the mRNA expression level of testicular tissue in each group， the transcriptome of genes related to the regulation of Wuzi Yanzongwan was screened， and three mRNAs were selected for Real-time fluorescence quantitative polymerase chain reaction（Real-time PCR） to verify the transcriptome data. Through the annotation analysis of Gene Ontology（GO） and the signaling pathway analysis of Kyoto Encyclopedia of Genes and Genomes（KEGG）， the related functions of drugs regulating transcriptome were analyzed. ResultCompared with the sham-operated group， the testicular tissue of mice in the model group showed spermatogenic injury， contraction and vacuolization of the seminiferous tubules， reduction of spermatogenic cells at all levels， widening of the interstitial space， obstruction of spermatogonial cell development and other morphological abnormalities， and serum T significantly decreased， LH significantly increased（P<0.01）， and FSH elevated but no statistically significant difference， the count and vitality of epididymal sperm significantly decreased（P<0.01）. There were 882 differentially expressed mRNAs in the testicular tissues， of which 565 were up-regulated and 317 were down-regulated. Cluster analysis showed that these differentially expressed mRNA could effectively distinguish between the sham-operated group and the model group. Compared with the model group， the damage to testicular tissue in the Wuzi Yanzongwan group was reduced， the structure of the seminiferous tubules was intact， vacuolization was reduced， and the number of spermatogenic cells at all levels was significantly increased and arranged tightly. The serum T significantly increased， LH significantly decreased（P<0.01）， and FSH decreased but the difference was not statistically significant. The count and vitality of sperm in the epididymis were significantly increased（P<0.01）. Moreover， Wuzi Yanzongwan could regulate 159 mRNA levels in the testes of semi-castrated mice， of which 32 were up-regulated and 127 were down-regulated， and the data of the transcriptome assay was verified to be reliable by Real-time PCR. GO and KEGG analysis showed that the transcriptome functions regulated by Wuzi Yanzongwan were involved in the whole cell cycle process of sperm development such as sex hormone production of interstitial cells in testis， renewal， differentiation， metabolism， apoptosis and signal transduction of spermatogenic cells， and were closely related to the biological behaviors of signaling pathways such as spermatogenic stem cell function， endoplasmic reticulum protein processing and metabolic program. ConclusionWuzi Yanzongwan can effectively improve the low spermatogenic function of semi-castrated male mice， and its mechanism may be related to the regulation of testicular transcriptional regulatory network， the synthesis of sex hormones in testicular interstitial cells， the function of spermatogenic stem cells， the whole cell cycle process of spermatogenesis， as well as the expression of endoplasmic reticulum protein processing and metabolic program related genes transcription.

Identification and expression analysis of NHX gene family in Chinese cabbage / 生物工程学报

Na+/H+ antiporter (NHX) gene subfamily plays an important role in plant response to salt stress. In this study, we identified the NHX gene family members of Chinese cabbage and analyzed the expression patterns of BrNHXs gene in response to abiotic stresses such as high temperature, low temperature, drought and salt stress. The results showed that there were 9 members of the NHX gene family in Chinese cabbage, which were distributed on 6 chromosomes respectively. The number of amino acids was 513-1 154 aa, the relative molecular weight was 56 804.22-127 856.66 kDa, the isoelectric point was 5.35-7.68. Members of BrNHX gene family mainly existed in vacuoles, the gene structure is complete, and the number of exons is 11-22. The secondary structures of the proteins encoded by the NHX gene family in Chinese cabbage had alpha helix, beta turn and random coil, and the alpha helix occurred more frequently. Quantitative real-time PCR (qRT-PCR) analysis showed that the gene family members had different responses to high temperature, low temperature, drought and salt stress, and their expression levels differed significantly in different time periods. BrNHX02 and BrNHX09 had the most significant responses to these four stresses, and their expression levels were significantly up-regulated at 72 h after treatments, which could be used as candidate genes to further verify their functions.

Development and validation of real-time fluorescence quantitative PCR method for murine virus / 中国生物制品学杂志

@#Objective To develop and validate the real-time fluorescent quantitative PCR(Q-PCR)method for the detection of 8 murine viruses. Methods The specificity,sensitivity and precision of the Q-PCR method were verified by four laboratories,and the virus simulated contamination test and blind sample detection were carried out simultaneously,of which the detection results were compared. The Q-PCR method was used to detect 26 batches of monoclonal antibody cell lines for SARS-CoV-2 vaccine production and 15 batches of other products of murine origin. Results The Q-PCR method used for detecting 8 kinds of murine viruses had no cross reaction with the same family and genus or other murine viruses. Except the sensitivity of laboratory 2 to ectromelia virus(EctV/Mouse Pox,MPV)was 2 × 10~2copies/μL,the sensitivity of laboratory 2 to other 7 viruses and 3 other laboratories to 8 murine viruses was 2 × 10~1copies/μL. Except the inter-assay CV of the copy number of mouse adenovirus(MAdV)detected by laboratory 3 was 37. 58%,the intra-assay and inter-assay CVs of the Ct and copy number of other 7 viruses detected by laboratory 3 and those of 8 viruses detected by other 3 laboratories were all less than 25%.The sensitivity of virus simulated contamination test met the parameter requirements. The coincidence rate of blind sample detection results by 4 laboratories was 100%. All the 26 batches of monoclonal antibody cell lines for SARS-CoV-2 vaccine production and 15 batches of other murine derived products were negative for 8 murine viruses. Conclusion Q-PCR method for murine virus has good specificity,sensitivity and precision,and can be used for the detection of murine derived biological products.

Development and verification of multiplex fluorescence quantitative PCR (Taqman probe) for detection of telomerase activity / 中国生物制品学杂志

@#Objective To develop and verify a multiplex fluorescence quantitative PCR(Taqman probe) method for the detection of telomerase activity.Methods Specific reverse transcription primers,two pairs of quantitative primers and probes were designed for the CDS sequence of telomerase catalytic subunit telomerase reverse transcriptase(TERT).After optimization of the reverse transcription primers(specific reverse transcription primers and random primers) and quantitative primers(two pairs of quantitative primer probes used alone or in combination) in the reaction system,with the primer probe of internal reference gene GAPDH,multiplex fluorescence quantitative PCR was performed in a single tube.In addition,telomerase positive standard and negative standard were prepared with 293T and MRC-5 cells respectively,and the stability and precision of the method were verified.The telomerase activity in 19 normal mesenchymal cell samples and 32 breast cancer cell samples were detected by the developed method.Results The optimum reaction system was as follows:using cDNA synthesized with specific reverse transcription primers as the template,2 pairs of quantitative primer probes of TERT gene were mixed with internal reference gene GAPDH primer probes for multiplex fluorescence quantitative PCR reaction in a single tube.After optimization,the sensitivity and TERT fluorescence signal quantity of the system were greatly improved,and the ΔRn was enhanced by 3 times.The amplification curve of positive standard TERT gene was normal,and the ΔCt between TERT gene and GAPDH gene remained stable.The amplification curve of GAPDH gene in negative standard was normal,while there was no amplification curve of TERT gene.There was a little difference in ΔCt between TERT and GAPDH genes in the positive standard frozen and thawed for 3 and 5 times repeatedly and the positive standard without freezing and thawing,and the CVs of precision in intra-and inter-groups were all less than 1%.Telomerase activity was negative in 19 normal mesenchymal cell samples and positive in 32 breast cancer cell samples,and significant difference in Ct value of TERT gene between them was observed(t=4.236,P <0.001).Conclusion The developed multiplex fluorescence quantitative PCR(Taqman probe) method for the detection of telomerase activity has good stability and precision,which is expected to be used in early diagnosis and gene therapy of tumors.

Selection and validation of reference genes for quantitative real-time PCR analysis in Paeonia veitchii / 中国中药杂志

Paeonia veitchii and P. lactiflora are both original plants of the famous Chinese medicinal drug Paeoniae Radix Rubra in the Chinese Pharmacopoeia. They have important medicinal value and great potential in the flower market. The selection of stable and reliable reference genes is a necessary prerequisite for molecular research on P. veitchii. In this study, two reference genes, Actin and GAPDH, were selected as candidate genes from the transcriptome data of P. veitchii. The expression levels of the two candidate genes in different tissues(phloem, xylem, stem, leaf, petiole, and ovary) and different growth stages(bud stage, flowering stage, and dormant stage) of P. veitchii were detected using real-time fluorescence quantitative technology(qRT-PCR). Then, the stability of the expression of the two reference genes was comprehensively analyzed using geNorm, NormFinder, BestKeeper, ΔCT, and RefFinder. The results showed that the expression patterns of Actin and GAPDH were stable in different tissues and growth stages of P. veitchii. Furthermore, the expression levels of eight genes(Pv-TPS01, Pv-TPS02, Pv-CYP01, Pv-CYP02, Pv-CYP03, Pv-BAHD01, Pv-UGT01, and Pv-UGT02) in different tissues were further detected based on the transcriptome data of P. veitchii. The results showed that when Actin and GAPDH were used as reference genes, the expression trends of the eight genes in different tissues of P. veitchii were consistent, validating the reliability of Actin and GAPDH as reference genes for P. veitchii. In conclusion, this study finds that Actin and GAPDH can be used as reference genes for studying gene expression levels in different tissues and growth stages of P. veitchii.

Establishment and application of detection method for interferon stimulated genes expression in children / 中华检验医学杂志

Objective:To establish the detection method for the interferon stimulated genes(ISGs), calculate the cut-off value and test it in clinical practice.Methods:Patients with type I interferonopathies who were admitted to Peking Union Medical College Hospital from November 2017 to September 2021 were chosen as the disease group, and healthy children were included as the control group. A total of 18 children were in the disease group, including 8 males and 10 females, with a median age of 8.5 years for the first test. From them 25 blood specimens were collected. A total of 28 healthy children, aged 1 to 18 years, with a median age of 10.5 years, including 15 males and 13 females, were included in the control group. Blood samples of 34 controls and 18 interferonopathies patients were collected, then total RNA extraction and cDNA synthesis were performed. Real-time quantitative polymerase chain reaction assays were run in duplicate to measure the expression of six ISGs: interferon induced protein with tetratricopeptide repeats 1 (IFIT1), interferon α inducible protein 27 (IFI27), interferon induced protein 44 like (IFI44L), interferon stimulated genes 15 (ISG15), sialic acid binding Ig like lectin 1 (SIGLEC1), and radical S-adenosyl methionine domain containing 2 (RSAD2). The relative abundances of each target transcript was normalized to the expression level of β-Actin and OAZ. The median fold change of the six ISGs was used to create an interferon score (IS) for each individual. Samples with abnormal expressions were removed and the cDNA mix of the remaining samples was used as a calibrator to calculate the IS. We define an abnormal IS as being greater than+2 standard deviations above the mean of controls. Differences in IS between groups were compared using t-test or Mann-Whitney U-test. Results:The mean IS of controls was 1.046, standard 0.755, and the cut-off value was 2.556. A total of 25 samples from 18 interferonopathies patients were tested. The mean value was 27.010 with a 15/18 abnormality rate. Compared with the control group, IS in patients was significantly higher, t=4.247( P=0.000 1). The accuracy, precision, sensitivity, and specificity were 91.30% (42/46), 7.47%(0.084/1.124), 15/18, and 96.43% (27/28), respectively. Conclusion:This study provides a new and reliable method for clinical screening and dynamic monitoring of type Ⅰ interferonopathies by detecting ISGs expression and creating an IS.

Establishment and preliminary application of a joint detection method for transplantation-associated infection pathogens / 中国输血杂志

【Objective】 To investigate the effectiveness of multilink real-time fluorescence quantitative PCR (qPCR) in the detection of common pathogens in transplantation. 【Methods】 The primers of the qPCR detection system were designed for 24 common infectious pathogens after clinical transplantation, and the standard plasmids of each pathogen were used to verify the qPCR reaction.After the primer probe effect and concentration of each pathogen reaction system in this experiment was optimized, the sensitivity, correlation coefficient (R2) and amplification efficiency (E) of qPCR method were analyzed and confirmed.Twenty-two samples from patients, who underwent liver and kidney transplantation in transplant ICU of Sichuan Provincial People′s Hospital, were used to verify the application of the detection system.The total nucleic acid of 100 μL was extracted from each individual and divided into two aliquots, which were detected by multi-link qPCR reaction system and analyzed by high-throughput sequencing method (NGS). At the same time, samples (2 mL each) were taken from the transplanted patients for microbial culture.The results of the three detection methods were compared, and the NGS method was taken as the gold standard to analyze the positive detection rate of the multi-link qPCR method and its difference with the culture method and NGS. 【Results】 The lower limit of qPCR detection for 24 pathogens in the established qPCR detection system was 101cp/μL(R2>0.99), with the positive rate of pathogens at 59.1% (13/22), showing significant difference versus microbial culture (18.2%, 4/22)(P<0.05), but not versus NGS (63.6%, 14/22)(P>0.05). Percentage of pathogens detected was as follows: human herpetic virus type 6 (HHV-6) 30.8% (4/13), cytomegalovirus (HCMV) 23.1% (3/13), Epstein-Barr virus (EBV) 23.1% (3/13), human parvovirus B19 15.4% (2/13), Haemophilus influenzae (Hin) 15.4% (2/13), Enterococcus faecium (EFM) 15.4% (2/13), Clostridium difficile 15.4% (2/13), Escherichia coli 7.7% (1/13), Stenotrophomonas maltophilia (Sma) 7.7% (1/13), Klebsiella pneumoniae (Kpn) 7.7% (1/13), Enterococcus faecalis (Efa) 7.7% (1/13) and Streptococcus pneumoniae (Spn) 7.7% (1/13). The consistency rate of pathogens detected by the three methods was 32% (7/22), among which the consistency rate of multi-link qPCR with NGS method was 59% (13/22), and multi-link qPCR with microbial culture was 41% (9/22). 【Conclusion】 Compared with the microbial culture, the multi-link qPCR method demonstrated high sensitivity, accurate quantification, short time and low cost for the detection of common pathogens in clinical transplantation.Multi-link qPCR combined with NGS and microbial culture is helpful to quickly predict the pathogen infection status of patients after transplantation.

Validation and application of a blood screening method for SARS-CoV-2 nucleic acid / 中国输血杂志

【Objective】 To evaluate the performance and clinical application of a high-throughput nucleic acid blood screening detection system for SARS-CoV-2, so as to provide basis and technical means for its application in detection of plasma from recovered COVID-19 patients. 【Methods】 The SARS-CoV-2 nucleic acid was detected by real-time fluorescence quantitative PCR, and the sensitivity, precision, anti-interference and other parameters were evaluated. Blood donor samples collected during COVID-19 epidemic period were screened using the detection system to evaluate its applicability. 【Results】 The detection limits of gene N and ORF 1ab were 3.98 copies/mL and 9.38 copies/mL, respectively. The CV of high and low concentration samples were both less than 5%. Hemoglobin at 500 mg/dL and triglyceride at 3g/dL had little effect on the results. The detection system can effectively prevent carryover, thus avoiding false positive results. The SARS-CoV-2 nucleic acid blood screening was carried out in a total of 39 306 blood samples, and all samples were negative. 【Conclusion】 The established method can meet the needs of SARS-CoV-2 nucleic acid screening therefore ensure the safe application of plasma from recovered COVID-19 patients.

The clinical value of fluorescence quantitative assay and G6PD/6PGD ratio method in the diagnosis of glucose-6-phosphate dehydrogenase deficiency and gene mutation / 中华检验医学杂志

Objective:To investigate the diagnostic value of fluorescence quantitative method and G6PD/6PGD ratio method in glucose-6-phosphate dehydrogenase (G6PD) deficiency and the type of gene mutation.Methods:A total of 1 201 patients (711 males and 490 females) with suspected G6PD deficiency in Shanghai Children′s Hospital were collected from June 2018 to March 2021. Fluorescence quantification method, G6PD/6PGD ratio method and multicolor melting curve were used to detects enzyme activity, ratio and gene mutation type. Comparison of each index and evaluation of its diagnostic efficiency were performed.Results:Among 1 201 suspicious samples, 163 cases (135 males and 28 females) were finally diagnosed. 156 cases were diagnosed by fluorescence quantitative method with a detection rate of 95.71%, and 140 cases were diagnosed by G6PD/6PGD ratio method with a detection rate of 85.89%. enzymatic activity of G6PD and ratio of G6PD/6PGD in male were significantly lower than female, and the differences were statistically significant ( U=642.5, 734.5, P<0.001). 112 cases received G6PD gene mutation detection and 92 cases were diagnosed, 74 were hemizygous mutations, 1 were homozygous mutations, 15 were heterozygous mutations, and 2 were compound heterozygous mutations. Among 15 cases of heterozygous mutations, 11 cases were diagnosed by fluorescence quantitative method, the diagnosed rate was 73.33%, 4 cases were diagnosed by G6PD/6PGD ratio method, and the diagnosed rate was 26.67%. A total of 7 mutation sites were detected and the proportions were c.1388G>A (32.22%), c.1376G>T (30.00%), c.871G>A (13.33%), c.1024C>T (11.11%). c.95A>G (7.78%), c.487G>A (4.44%), c.392G>T (1.11%). The enzymatic activities of c.1376G>T and c.1024C>T, c.487G>A were statistically significant ( P<0.001,0.015); the G6PD/6PGD ratios of c.1024C>T and c.1388G>A, c.1376G>T were statistically significant ( P=0.017,0.002,0.011,0.013). Fluorescence quantitative method had sensitivity of 100%, specificity of 95.65%, and the area under the curve (AUC) is 0.972. The sensitivity of the G6PD/6PGD ratio method was 100%, the specificity was 94.57%, and the AUC was 0.979. The sensitivity of fluorescence quantitative method combined with G6PD/6PGD ratio was 96.7%, the specificity was 100%, and the AUC was 0.992. Conclusions:Compared with fluorescence quantification, the G6PD/6PGD ratio method might not be able to diagnose female heterozygotes effectively; The panel of G6PD fluorescence quantification and G6PD/6PGD ratio was helpful to reduce the missed diagnosis. Combined with gene mutation analysis, it could improve the diagnosis rate of G6PD deficiency in the children.

Significance of serum circRNA hsa_circ_0000437 in the auxiliary diagnosis and prognosis of gastric cancer / 中华检验医学杂志

Objective:To investigate the expression of hsa_circ_0000437 in the serum of patients with gastric cancer and its clinical value.Methods:The serum samples from 80 patients (57 males and 23 females) with pathologically confirmed gastric cancer (GC), 50 gastric benign disease (28 males and 22 females) and 80 healthy controls (46 males and 34 females) were collected from October 2018 to December 2020 in Affiliated Hospital of Nantong University.Serum samples from 35 of 80 gastric cancer patients after operation were collected. The expression of serum hsa_circ_0000437 was determined by real-time fluorescent quantitative PCR (RT-qPCR). Serum carcinoembryonic antigen (CEA), carbohydrate antigen 199 (CA 199) and carbohydrate antigen 724 (CA724) were determined by chemiluminescence method.Comparisons of serum hsa_circ_0000437 between groups were performed by Mann-Whitney U test.The correlation between serum expression of hsa_circ_0000437 in gastric cancer patients and its clinical pathological characteristics was performed by χ 2 test.Receiver operating characteristic (ROC) curve and the area under the curve of ROC (AUC) were used to evaluate their diagnosis efficiency. Kaplan-Meier survival curve analysis was used to analyze the relationship between the expression level of serum hsa_circ_0000437 and the prognosis of patients. Results:The relative expression of hsa_circ_0000437 in GC, gastric benign disease, healthy controls were 2.252 (1.235, 4.765), 1.598(1.139, 1.982) and 1.000 (0.818, 1.385) respectively.The relative expression of hsa_circ_0000437 in GC was significantly higher than that in gastric benign disease ( P<0.001) and healthy controls ( P<0.001). The difference between gastric benign disease and healthy controls was also statistically significant ( P<0.001).The differences of serum hsa_circ_0000437 expression in GC patients between T stage, N stage, and tumor differentiation were statistically significant. The AUC of hsa_circ_0000437, CEA, CA199 and CA724 in GC patients were 0.863, 0.619, 657 and 0.608 respectively compared with healthy controls. The AUC of above four-parameter panel was 0.892 and the sensitivity was up to 97.5% (78/80). Kaplan-Meier survival curve showed that the overall survival rate of patients with high serum hsa_circ_0000437 expression was significantly lower than that of patients with low expression ( P=0.008). Conclusion:Serum hsa_circ_0000437 could be a biomarker for the auxiliary diagnosis and prognosis of GC.

Expression Analysis of miRNA Profiles in Apheresis Platelets during Storage / 中国实验血液学杂志

OBJECTIVE@#To study the expression profiles changes of miRNA in apheresis platelets after 1, 3 and 5 days of storage.@*METHODS@#The apheresis platelets were collected from 20 volunteer blood donors. After mixing fully, the platelets were stored in a shaker with (22±2) ℃ horizontal oscillation. The samples were taken on the 1st, 3rd and 5th day, and used to sequence for miRNAs by DNA nanoball (DNB) sequencing technology, which were named as C_1, C_3 and C_5, respectively. The expression level of platelets miRNA was standardized by transcripts per kilobase million (TPM) algorithm. MiRNAs with P-value < 0.001 and the expression difference of more than two times were considered as significant difference between two groups. The expression of miRNAs was verified by real-time fluorescence quantitative PCR (RT-qPCR).@*RESULTS@#By DNB sequencing, there were 688, 730, and 679 platelet miRNAs expressed in C_1, C_3 and C_5 group, respectively. Cluster analysis showed that the expression profile of miRNAs changed significantly. The expression level of the first 20 high abundance miRNAs was about 4/5 of the total amounts of expressed miRNAs in each group, which the top five miRNAs were miR-21-5p, miR-26a-5p, miR-199a-3p, miR-126-3p, and let-7f-5p. The correlation of high abundance platelet miRNAs among the three groups was high (R2=0.876, R2=0.979, R2=0.937, respectively) and the differences were not statistically significant (P>0.05). Compared with the differential expression of platelet miRNAs with more than 1 000 TPM in the C_3 and C_1 group, there were 6 differentially expressed miRNAs, including 3 up-regulated (miR-146a-5p, miR-379-5p, and miR-486-5p) and 3 down-regulated (miR-652-3p, miR-142-5p, and miR-7-5p). While in the C_5 and C_1 group, there were 4 differentially expressed miRNAs, including 2 up-regulated (miR-146a-5p and let-7b-5p) and 2 down-regulated (miR-30d-5p and miR-142-5p). Compared with the differentially expression of platelet miRNAs between 1-1 000 TPM in the C_3 and C_1 group, there were 133 differentially expressed miRNAs, in which 99 were up-regulated and 34 were down-regulated. While in the C_5 and C_1 group, there were 77 differentially expressed miRNAs, in which 31 were up-regulated and 46 were down-regulated. The six selected differentially expressed miRNAs verified by RT-qPCR were consistent with those of sequencing.@*CONCLUSION@#The expression profiles of platelets miRNAs change significantly among 1, 3, and 5 d of storage in vitro.

Etiological analysis of acute respiratory tract infection in Taizhou of Zhejiang Province from 2020 to 2021 / 上海预防医学

ObjectiveWe examined the principal respiratory pathogens in patients with acute respiratory tract infection in Taizhou， Zhejiang Province during 2020‒2021 to provide evidence for prevention， diagnosis and treatment of acute respiratory tract infection. MethodsFrom September 2020 to August 2021， a total of 2 831 cases with acute respiratory tract infection were collected from two influenza sentinel surveillance hospitals in Taizhou， which had then received the examination of 22 respiratory pathogens by multiple fluorescence quantitative PCR. ResultsThe total positive rate of respiratory pathogens in 2 831 samples was 14.13%， among which enterovirus （7.77%） and respiratory syncytial virus （1.59%） were the principal pathogens. Except enterovirus， there was no significant difference in the positive rate of pathogens detected by gender（P>0.05）. Moreover， there was significant difference in pathogens by age （P<0.05）， with the highest positive rate in 0‒4 years（35.21%）. There was also significant difference in pathogens by seasons （P<0.05）， with the highest positive rate in summer（20.54%）. ConclusionThe positive rate of acute respiratory tract infection decreases significantly， compared with that before the COVID-19 epidemic. The differences in the positive rate differ significantly by age and seasons. Comprehensive consideration of diverse factors before diagnosis and the utilization of multiple fluorescent quantitative PCR can quickly and effectively determine the pathogens in the early stage of infection. Our findings may provide certain support for the diagnosis and treatment of acute respiratory infections in the context of COVID-19 in Taizhou.

Expression analysis of miRNA profiles in apheresis platelets at the end of storage / 中国输血杂志

【Objective】 To investigate the changes of platelet microRNA (miRNA) expression profiles of storage in vitro, and to explore the molecular mechanism of miRNAs involved in the regulation of platelet storage lesion (PSL). 【Methods】 20 platelet samples (5 mL / sample) were collected from apheresis platelet donors, fully mixed and stored in a shaker with (22±2) ℃ horizontal agitation, sampled on day 1 and day 5, and sequenced by DNA nanoball (DNB) sequencing technology. The miRNAs with more than 2 times expressions (P<0.01) were considered as significantly differences between d5 and d1 groups. The miRanda and TargetScan softwares were used to predict the target genes. Gene Ontology (GO) function enrichment analysis and Kyoto Encyclopedia of genes and genomes (KEGG) pathway enrichment analysis were performed on the target genes of significant differentially expressed miRNAs. The expression of miRNAs was verified by real-time fluorescence quantitative PCR (qRT-PCR). 【Results】 Compared with d1 group, 315 miRNAs with significantly different expression (P<0.01) were screened in d5 group, including 146 up-regulated miRNAs (such as miR-146a, let-7b), and 169 down-regulated miRNAs (such as mir-30d, mir-142). Among 126 known miRNAs, 43 were up-regulated and 83 were down-regulated. There are 189 new miRNA sequences. The enriched GO terms of target genes of differentially expressed miRNAs in d5 and d1 groups included cell components, organelles, cell membrane and other cell structures, molecular functions such as adhesion, catalysis and activity, and biological processes such as cell processing, metabolism, biological regulation and stress. The corresponding pathways in the top 10 of KEGG enrichment were mainly signal transduction, secretion, membrane transport, amino acid metabolism, polysaccharide metabolism, protein synthesis and environmental adaptation. The 6 randomly selected differentially expressed miRNAs verified by qRT-PCR were consistent with those of DNB sequencing. 【Conclusion】 The expression profiles of platelets miRNAs have changed significantly between the d1 and d5 of storage in vitro. Functional prediction suggested that these miRNAs might be involved in the regulation of platelet PSL.

Expression and significance of microRNA-125b in tongue squamous cell carcinoma / 华西口腔医学杂志

OBJECTIVE@#The expression of microRNA-125b in tongue squamous cell carcinoma (TSCC) was detected and analyzed for its relationship with the clinicopathological features of TSCC.@*METHODS@#Real time fluorescence-quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of microRNA-125b in 35 TSCC tissues and adjacent normal tissues from 35 TSCC cases. The relationship between the expression of microRNA-125b in TSCC tissues and the clinicopathological features of patients with TSCC was analyzed. In situ hybridization (ISH) was used to detect the expression level of microRNA-125b gene in the TSCC tissues and adjacent normal tissues.@*RESULTS@#RT-qPCR results showed that the relative expression levels of microRNA-125b in the TSCC issues was 2.32±0.69, and that of normal tissues was 0.87±0.32. The statistical results showed that the expression level of microRNA-125b was significantly higher in the TSCC tissues than in the normal tissues (P<0.001). The expression level of microRNA-125b in the TSCC tissues was not significantly correlated with age, gender, pathological grade, and lymph node metastasis but was positively correlated with TNM stage. Patients with high TNM stage had high microRNA-125b expression levels (P<0.05). The ISH results showed that the expression levels of microRNA-125b in the TSCC tissues were 0.010±0.003, and that of normal tissues was 0.004±0.001. The expression levels of microRNA-125b in the 35 TSCC tissues were significantly higher than those in the normal tissues (P<0.05).@*CONCLUSIONS@#MicroRNA-125b is highly expressed in TSCC and associated with TNM stage, suggesting that high microRNA-125b expression may be involved in the development of TSCC.

Development and Comparison of Determination of Staphylococcus aureus in Different Processed Products of Angelicae Sinensis Radix Based on Real-time PCR Technique / 中国实验方剂学杂志

Objective:To quantitatively analyze the changes of Staphylococcus aureus in different processed products of Angelicae Sinensis Radix. Method:The real-time fluorescence quantitative polymerase chain reaction method （Real-time PCR） was established to quantitatively analyze S. aureus in Angelicae Sinensis Radix decoction pieces which bought from different producing areas， different enterprises and different storage time. The fluorescence quantitative reaction system was SYBR Premix Ex Taq Ⅱ of 10 μL， each of forward primer and reverse primer （10 μmol·L-1） of 0.8 μL， template/genome DNA of 1 μL， double distilled water of 7.4 μL. The reaction conditions of the fluorescence quantitative amplification curve were pre-denaturing for 30 s at 94 ℃， denaturing for 10 s at 94 ℃， annealing for 12 s at 60 ℃， extensing for 30 s at 72 ℃， cycling 45 times， single-point detection signal at 72 ℃. The melting curve was made from 72 ℃， and the step temperature of 0.5 ℃ was kept for 15 s to collect fluorescence. According to the results of Real-time PCR， representative samples were selected from Angelicae Sinensis Radix decoction pieces for comparison between plate counting method and Real-time PCR. Result:The content of S. aureus in different processed products was sorted by rank of raw Angelicae Sinensis Radix>soil-fried Angelicae Sinensis Radix>wine-processed Angelicae Sinensis Radix. The content of S. aureus was the lowest in the samples from Weiyuan area of Gansu province by comparing with other producing areas. Compared with the retail enterprises， the content of S. aureus in raw products and wine-processed products from production and sale enterprises was lower. Different storage time had certain effect on the content of S. aureus in raw products and wine-processed products， and the content of S. aureus increased with the increase of storage time. The detection results of plate counting method were 3-4 orders of magnitude lower than that of Real-time PCR. Conclusion:The established Real-time PCR is superior to plate counting method in specificity， sensitivity， reliability and reporting period， which can provide an effective method for rapid and accurate quantitative detection of S. aureus in different processed products of Angelicae Sinensis Radix.

Development and comparative study of determination of Escherichia coli in different processed products of Angelicae Sinensis Radix based on fluorescence quantitative PCR / 中草药

Objective: To make quantitative analysis for the quantity of Escherichia coli in Angelicae Sinensis Radix (ASR) and its processed products. Methods: The fluorescence quantitative PCR method was established to quantitatively analyze E. coli in ASR from different processed products, different producing areas, different enterprises and different storage time. Results: The number of E. coli in different processed products was ranked as follows: ASR > ASR stir-frying with soil > ASR stir-frying with wine. And the number of E. coli in the three producing areas of ASR in Min County of Gansu Province was less than that in other producing areas. Compared with the retail enterprises, the number of E. coli in ASR and ASR stir-frying with wine was less in production and sale enterprises. Different storage time had certain effect on the number of E. coli in ASR and ASR stir-frying with wine. With the increase of storage time, the number of E. coli also increased. Plate counting method and fluorescence quantitative PCR method were carried out at the same time for some representative samples. The results showed that the results of the plate counting method were mostly negative, and the results of the fluorescence quantitative PCR were positive. Conclusion: The quantitative fluorescence PCR method established in this paper is superior to the plate counting method in specificity, sensitivity, reliability, and reporting cycle, which can provide an effective method for rapid and accurate quantitative detection of E.coli in different processed products of ASR.

Short-term water changes response of saponin biosynthesis process in Astragalus membranceus / 中国中药杂志

The study is aimed to explore the effect of different water on the content of total saponins,astragaloside Ⅳ and gene expression in the growth of Astragalus membranceus. In this study, one-year-old A. membranaceus was used as the experimental material, by pot culture different water treatments were simulated at herbal garden in Jilin Agricultural University. The content of astragaloside Ⅳ was determined by HPLC and the total saponins by UV spectrophotometry. With 18 S RNA as a reference gene, fluorescent quantitative PCR was applied to analyze the eight key enzymes in astragalus saponin synthesis pathway AACT,HMGS,HMGR,IDI,FPS,SS,SE,CAS expression. With the decrease of soil water, the content of astragaloside Ⅳ in the root tissue of A. membranaceus showed an increasing trend, up to 1.46 mg·g~(-1). The total saponin content tended to increase, up to 6.80 mg·g~(-1). The results of relative expression of genes showed that the eight genes showed different effects at different water. With the change of soil water content, the amount of(AACT,IDI,SS) relative expression in drought stress group firstly increased and then decreased, then increased, and then decreased. The amount of(HMGS,HMGR,FPS) relative expression in drought stress group increased firstly and then decreased. The amount of(SE,CAS) relative expression in drought stress group increased firstly and then decreased, and continued to decrease after rehydration. The expression of key enzyme genes involved in the synthesis of astragaloside was influenced by each other, and the expression of key enzyme in roots showed a correlation with the content of astragaloside. Correlation analysis showed that there was a very significant positive correlation between HMGR gene and total saponins content in drought stress group and a significant negative correlation between content of CAS and total saponins. The contents of FPS,SE,CAS and astragaloside Ⅳ were very significantly and negative correlated. The relationship between other genes and quality was positive. Therefore, HMGR, FPS, SE and CAS genes have significant effects on the regulation of saponin content under water control. On the 15 th day after water regulation, the total amount of astragaloside and total saponins reached the highest value and could be harvested.

Establishment and validation of hsa_circ_0004123 absolute quantitative PCR method / 解放军医学杂志

Objective To establish an absolute reverse transcription fluorescence quantitative PCR method (RT-qPCR) that can accurately quantify the circRNA hsa_circ_0004123, and verify the copy number of hsa_circ_0004123 in the leukemia cell line. Methods Total RNA was extracted from HMy2.CIR cell line, and reverse transcribed to cDNA. Using cDNA as template, a 236 bp characteristic segment containing the back-spliced junction of hsa_circ_0004123 transcript was cloned and inserted into the pGM-T vector, and then the recombinant plasmid was sequenced. Regarding the gradient diluted recombinant plasmid as standard substance, the standard curve of hsa_circ_0004123 was established by SYBR fluorescent staining RT-qPCR, and then the copy number of hsa_circ_0004123 in leukemia cell lines (HMy2.CIR, Jurkat, Raji, K562) were verified. Results The absolute RT-qPCR method was established that can accurately quantify the copy number of hsa_circ_0004123 with wide linear range (9.63×103–9.63×109) copies/μl, high sensitivity (4528±516) copies/μl, intra-batch coefficient of variation (CV) of 0.30%-1.86%, inter-batch CV of 1.40%-2.30%, and a single peak dissolution curve. The copy number of hsa_circ_0004123 in leukemia cell lines HMy2.CIR, Jurkat, Raji and K562 was detected respectively. The expression of hsa_circ_0004123 was significantly different (P<0.001) in the 4 kinds of leukemia cell lines. Conclusion The absolute RT-qPCR method used to detect the copy number of hsa_circ_0004123 has a wide linear range, high sensitivity and specificity, and good repeatability, and lays a technical foundation for accurate quantification of hsa_circ_0004123 in leukemia.

Expression of RIZ1 gene in myelodysplastic syndromes and its significance / 肿瘤研究与临床

Objective To explore RIZ1 mRNA expression level in different subtypes and risk classification groups of the patients with myelodysplastic syndromes (MDS) and to analyze the correlation between the clinical features and RIZ1 mRNA expression. Methods A total of 46 newly diagnosed as MDS patients and 10 healthy controls who were the donors of hematopoietic stem cell transplantation from Chuiyangliu Hospital Affiliated to Tsinghua University and the Second Hospital of Shanxi Medical University between January 2014 and December 2017 were collected. The real time fluorescence quantitative polymerase chain reaction (RT-PCR) was used to detect the expression level of RIZ1 mRNA in bone marrow cells from MDS patients and the healthy controls. Results Compared with the healthy control group, the relative expression level of RIZ1 mRNA in MDS patients was decreased [the median (P25, P75):1.003 (0.895, 1.812) vs. 0.557 (0.333, 0.815)], and the difference was statistically significant (Z= -2.991, P= 0.0003). According tothe World Health Organization (WHO) classification criteria, compared with the healthy control group, the relative expression of RIZ1 mRNA in refractory anemia/refractory anemia with ring sideroblasts/refractory cytopenia with multiple dysplasia (RA/RAS/RCMD), refractory anemia with excess blasts Ⅰ (RAEB-Ⅰ), RAEB-Ⅱand MDS transformed into acute myeloid leukemia (MDS/AML) groups had statistically significant differences (χ2= 19.500, P< 0.01). Further pairwise comparison showed that the relative expression level of RIZ1 mRNA in RAEB-Ⅰ, RAEB-Ⅱand MDS/AML groups was lower than that in the healthy control group, and the differences were statistically significant (all P < 0.05). According to the international prognostic scoring system (IPSS), compared with the healthy control group, the expression of RIZ1 mRNA in low-risk, inter-risk-1, inter-risk-2 and high-risk group had statistical differences (χ2= 19.214, P= 0.001). Further pairwise comparison showed that the relative expression of RIZ1 mRNA in inter-risk-1, inter-risk-2 and high risk group was lower than that in the healthy control group, and the differences were statistically significant (all P<0.05). And RIZ1 mRNA expression showed a decreasing trend with the increase of disease risk grade. RIZ1 mRNA expression level had no relationship with age, gender, peripheral blood white cell count, the hemoglobin, platelet count and karyotype (all P> 0.05). Conclusion RIZ1 mRNA expression level is decreased in MDS patients, and it is different in various subtypes and risk classification. RIZ1 may involve in the pathogenesis of MDS and play an important role in the progression of MDS.