The Latest Research Progress on Cell-Free DNA and Prospects of Its Forensic Application / 法医学杂志

In recent years,with the continuous progress of DNA extraction and detection technology,cell-free DNA(cfDNA)has been widely used in the life science field,and its potential application value in forensic identification is becoming more and more obvious.This paper reviews the concept,formation mechanism,and classification of cfDNA,etc.,and describes the latest research progress of cfDNA in personal identification of crime scene touch DNA samples and non-invasive prenatal pater-nity testing(NIPPT).Meanwhile,this paper summarizes the potential application of cfDNA in injury inference,and discusses the advantages and disadvantages of common cfDNA analysis methods and techniques,and its application prospects,to provide a new idea for the wide application of cfDNA in the field of forensic science.

Screening of tuberculosis among freshmen in 156 schools in Baoding City / 中国感染控制杂志

Objective To investigate the screening and prevalence of tuberculosis among freshmen in different schools in Baoding City,and provide reference for tuberculosis control in schools.Methods Screening data of tu-berculosis and tuberculin test(PPD)of freshmen from 156 schools in different regions of Baoding City from Septem-ber 2021 to March 2022 were collected.PPD screening results of students from different regions and different school stages were analyzed and compared.Results A total of 68 177 freshmen from 156 schools were investigated for suspected symptoms and close contact history of pulmonary tuberculosis.PPD screening was conducted on 63 939 students.13 821 students were PPD positive,with a positive rate of 21.62％.3 083 students were strongly posi-tive,with a strong positive rate of 4.82％.15 cases of tuberculosis were found,and the reported incidence was 23.46/100 000.PPD positive rate and strong positive rate as well as incidence of tuberculosis in students in different school stages presented statistically significant differences(all P＜0.01).Positive rate and strong positive rate in students in different school stages showed upward trends(all P＜0.01).PPD positive rate and strong positive rate of students from schools in plain and mountainous areas presented statistically significant differences([22.28％vs 17.89％];[4.85％vs 3.62％],both P＜0.01).PPD positive rate and strong positive rate between students from boarding junior school and non-boarding junior school were significantly different,respectively([23.94％vs 21.60％];[5.07％vs 3.56％],both P＜0.01).Conclusion It is necessary to strengthen tuberculosis screening and health education for freshmen,especially those from boarding schools in plain areas,screening latent Mycobac-terium tuberculosis infection as early as possible,take corresponding measures to prevent and control the spread of tuberculosis,and reduce the risk of tuberculosis.

Correlation Study Between Percutaneous Coronary Intervention Complicated Depression and Serum Levels of Brain-derived Neurotrophic Factor, Ghrelin in Coronary Artery Disease Patients / 中国循环杂志

Objective: To explore the relationship between the incidences of percutaneous coronary intervention (PCI) complicated depression and serum levels of brain-derived neurotrophic factor (BDNF), ghrelin in coronary artery disease (CAD) patients. Methods: A total of 90 CAD patients after PCI were enrolled. According to Hamilton depression (HAMD) scale, the patients were divided into 2 groups: Depression group, n=40 and Non-depression group, n=50. Serum levels of BDNF and Ghrelin were examined by ELISA and compared between 2 groups. Results: Compared with Non-depression group, Depression group had reduced serum levels of BDNF and Ghrelin, both P<0.05. As increased severity of depression, BDNF and Ghrelin were decreased accordingly; serum levels of BDNF and Ghrelin were negatively related to HAMD score (r=-0.711, P<0.05 and r=-0.711, P<0.05). Conclusion: Serum levels of BDNF and Ghrelin have an early warning effect on depression in CAD patients after PCI, it may reflect the severity of depression at certain degree in relevant patients.

Construction of HA-1-DC nucleic-acid vaccine and induction of specific cytotoxic T lymphocytes / 中国实验血液学杂志

The purpose of this study was to construct a HA-1-DC nucleic acid vaccine and to induce anti-leukemia effect after hematopoietic stem cell transplantation (HSCT). The dendritic cells (DCs) were generated from HSCT donors in vitro, and its immunologic activity was studied by using flow cytometry and mix lymphocyte reaction. HA-1 gene was electroporated into the cultured DCs to construct a DC nucleic acid vaccine. After transfecting for 48 hours, the expression of HA-1 protein was detected by Western blot. The DCs were cultured with isogenic lymphocytes to induce specific cytotoxic T lymphocytes (CTLs). The cytotoxicity of the CTLs was detected by LDH assay. The results showed that the DCs derived from peripheral blood monocytes (PBMCs) expressed the DC phenotype, and were effective in stimulating proliferation of the allogenic lymphocytes. After electroporating for 48 hours, HA-1 protein was detected by Western blot. The cytotoxity of inducing CTLs was higher than that in the control group. It is concluded that the minor histocompatibility antigen HA-1 can be considered as a target of immunotherapy against leukemia after HSCT.

Construction and expression of dendritic cell nucleic acid vaccine containing CML28 gene in human dendritic cells / 中国实验血液学杂志

This study was aimed to construct nucleic acid vaccine containing the coding region of the CML28 gene and to express it in human dendritic cells. The full length of CML28 cDNA was amplified from K562 by RT-PCR and subcloned into pGEM-T vector. The CML28 fragment was digested and subsequently inserted into the EcoRI-Xba I sites of pcDNA3.1HisA to construct the recombinant expression vector pcDNA3.1HisA-CML28, which was identified by restrition analysis and sequencing. Human dendritic cells (DC) were separated from peripheral blood mononuclear cells (PBMC) by culture with rhGM-CSF, rhIL-4 and assessed by flow cytometry. The constructed plasmid pcDNA3.1 HisA-CML28 was transfected into DC by electroporation. Western blot was used to detect the expression of fusion protein His-CML28. The results showed that recombinant plasmid pcDNA3.1HisA-CML28 contained the correct full CML28 cDNA identified by restriction analysis and sequencing, and can express the fusion protein His-CML28 in DCs. It is concluded that nucleic acid vaccine containing CML28 gene was constructed and expressed in DC successfully.

Monitoring CML28 mRNA levels in patients before and after HSCT by real-time quantitative RT-PCR / 中国实验血液学杂志

The purpose of this study was to establish a SYBR Green I real-time quantitative RT-PCR method for investigating the correlation between CML28 mRNA expression levels and relapse of leukemia after allo-hematopoietic stem cell transplantation (HSCT). pcDNA3.1HisA-CML28 plasmid had been constructed as the standard template. Serial monitoring of CML28 mRNA levels by SYBR Green I real-time quantitative RT-PCR technique was performed in 14 patients, including 10 patients with CML and 3 patients with AML, 1 patient with Ph(+) ALL. The results showed that the sensitivity of the established method was at 10(-4) (0.05 ng) level, with interassay variation and intraassay variation of standard samples both below 10%. The CML28 was highly expressed in AML and CML-BP or AP. CML28 level in newly diagnosed group was (6.58 +/- 2.34) x 10(-2), in pre-conditioning regimen group was (2.19 +/- 0.32) x 10(-2), in group that 1 month after HSCT was (1.35 +/- 1.28) x 10(-2), in group that 3 months after HSCT was (4.57 +/- 6.39) x 10(-3). CML28 can be detected 3 months after HSCT in 1 patient with CML-CP and 3 patients with CML-AP or BC. 2 of them with low level (<2 x 10(-2)) survived without relapse, the other 2 case with high level (>2 x 10(-2)) relapsed within one year, 1 case died and 1 case received the second time HSCT, CML28 level decreased rapidly after HSCT, but still higher than 2 x 10(-2) and relapse has taken place. The conclusions was made that CML28 mRNA level is obviously correlated with the development of leukemia. Serial quantification of CML28 mRNA levels are necessary for HSCT recipients, and more informative than a single detection. Using of this assay to evaluate MRD in the patients received HSCT is helpful for prediction of relapse.