Survey on the Construction Status of Forensic Virtual Autopsy Laboratory and the Applicability of Laboratory Accreditation / 法医学杂志

OBJECTIVES@#To survey the development status and actual needs of virtual autopsy technology in China and to clarify the applicability of forensic virtual autopsy laboratory accreditation.@*METHODS@#The questionnaire was set up included three aspects：(1) the current status of virtual autopsy technology development; (2) the accreditation elements such as personnel, equipment, entrustment and acceptance, methods, environmental facilities; (3) the needs and suggestions of practicing institutions. A total of 130 forensic pathology institutions were surveyed by online participation through the Questionnaire Star platform.@*RESULTS@#Among the 130 institutions, 43.08% were familiar with the characteristics of virtual autopsy technology, 35.38% conducted or received training in virtual autopsy, and 70.77% have establishment needs (including maintenance). Relevant elements were suitable for laboratory accreditation.@*CONCLUSIONS@#Virtual autopsy identification has gained social recognition. There is a demand for accreditation of forensic virtual autopsy laboratory. After the preliminary assessment, considering the characteristics and current situation of this technology, China National Accreditation Service for Conformity Assessment (CNAS) can first carry out the accreditation pilot of virtual autopsy project at large comprehensive forensic institutions with higher identification capability, and then CNAS can popularize the accreditation in a wide range when the conditions are suitable.

Evaluation and Countermeasures of the Implementation of Forensic Clinical Identification Standards Based on the Perspective of Accreditation / 法医学杂志

The new Standardization Law, implemented in 2018, has added a standard post-implementation evaluation system, aiming to continuously improve the quality of standards through post-implementation evaluation. Standards in the forensic science field are closely related to accreditation activities. Forensic science standards are not only the criteria on which accreditation activities are carried out, but also one of the key contents of the inspection of forensic science institutions in accreditation activities. Since 2018, the certification and accreditation policies in the forensic science field have also been changed, which has brought impacts on the construction of a standard system based on accreditation.This paper analyzes the standard data from China National Accreditation Center from Conformity Assessment on forensic clinical identification accreditation assessment. It points out that the current coverage of laboratory accreditation activities is limited, the development in different provinces is unbalanced, and there is overlap and crossover in the standards in use. It is emphasized that the construction of the national forensic science standardization technical committee, the improvement of the forensic science standard system, the establishment of the standard implementation evaluation index system, and promotion of the coordination of standards, and the certifications and accreditations should be accelerated, in order to continue to promote the standardization and accreditation activities in the field of forensic science.

Isolating sperm cells by laser capture microdissection technique from mixture sample / 法医学杂志

OBJECTIVE@#To assess the application value of laser capture microdissection (LCM) technique for isolating a small number of sperm cells from mixture sample.@*METHODS@#Mixture samples were prepared with sperm cells and vaginal epithelia at different concentrations. Both LCM technique and the differential lysis method were employed to obtain sperm cells from the mixture samples, and DNA was extracted by magnetic beads method. STR genotyping was determined using Identifiler kit.@*RESULTS@#The successful STR genotype rate of sperm cells isolated from mixture samples with LCM technique was 92.86% (13/14). The rate of differential lysis method was 7.14% (1/14). The successful rates between the two methods were statistically different (P < 0.05).@*CONCLUSION@#LCM technique can effectively exclude the interference of female cell component and isolate a small number of sperm cells to obtain a single male STR genotyping. LCM technique is obviously better than the differential lysis method.

Establishment of a semi-nested PCR for identifying the sub-genotypes (Ba and Bj) of hepatitis B virus of genotype B / 中华流行病学杂志

<p><b>OBJECTIVE</b>To establish a sensitive, specific, simple and practicable method for identifying the two sub-genotypes (Ba and Bj) of genotype B isolates of hepatitis B virus (HBV) (HBV/ B).</p><p><b>METHODS</b>The entire nucleotide sequences of HBV/B and HBV/C were obtained from GenBank, compared and analyzed with DNAStar software. The specific primers for HBV/B (HB) and Ba (BA), Bj (BJ) were designed respectively. HB as HBV/B specific primer (sense) and HBAS-4V (designed by Japanese scientists Sugauchi et al) as a universal outer primer (antisense) were used in the first-round PCR. In the second-round PCR, HB was also used as sense primer while BA and BJ as inner primers (antisense) and they were added into a single tube for PCR reaction. The two sub-genotypes of HBV/B were identified according to the length of the PCR products. A total of 71 HBV DNA-positive serum samples were selected randomly from our laboratory, including 56 HBV/B samples identified by type-specified PCR method and 15 HBV/C samples identified by direct sequencing in preS and S Region (preS/S). All the 71 samples were detected with this semi-nested PCR method. A plasmid containing full length genomic DNA of HBV/Bj, was presented by Professor Kenji Abe as positive control of Bj. Then, the first-round PCR products of 15 HBV/B were randomly selected and sequenced directly, and their sequences were compared phylogenetically with the above known Ba and Bj sequences using Blast and DNAStar softwares to confirm the results of semi-nested PCR.</p><p><b>RESULTS</b>56 HBV/B samples were all identified as HBV/Ba by our semi-nested PCR method. 15 randomly selected PCR products were all sequenced as HBV/Ba. All of the 15 HBV/C samples were negative.</p><p><b>CONCLUSION</b>A simple, rapid, sensitive and specific method for identifying sub-genotypes Ba and Bj was established with might be used for large-scale clinical and epidemiological studies.</p>

Study on the distribution of sub-genotype B on hepatitis B virus in patients with chronic HBV infection from 4 cities of China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate the distribution of sub-genotype B on hepatitis B virus (HBV) in patients with HBV chronic infection from 4 cities (Beijing, Shijiazhuang, Wenzhou and Shenzhen) of China.</p><p><b>METHODS</b>A type-specific nested polymerase chain reaction(PCR) with multiplex pairs of primers was used for HBV genotyping,and Ba and Bj sub-genotypes were identified by a PCR-restriction fragment length polymorphism (PCR-RFLP) method. A total of 101 serum samples collected from patients with chronic HBV/B infection were detected. Among them, 18 were collected from Beijing, 22 from Shijiazhuang, 34 from Wenzhou and 27 from Shenzhen. Thirty from the 101 serum samples were randomly selected and analyzed by PCR product sequencing.</p><p><b>RESULTS</b>All of the 101 serum samples were identified as sub-genotype Ba,and none of them was sub-genotype Bj.</p><p><b>CONCLUSION</b>Sub-genotype Ba was a predominant strain of HBV/B in patients with chronic HBV infection from these 4 cities.</p>

Distribution of hepatitis B virus genotypes in patients with chronic hepatitis B virus infection among 12 cities in China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate the distribution of hepatitis B virus (HBV) genotypes in patients with chronic HBV infection among 11 cities of China.</p><p><b>METHODS</b>A total of 1214 serum samples from patients with chronic HBV infection were collected in 11 cities of China, including Beijing, Qingyuan, Shenzhen, Shijiazhuang, Hanchuan, Nanjing, Changchun, Liaocheng, Jinan, Ningbo and Wenzhou. Genotypes of the 1214 HBV strains were identified by PCR method with type specific primers. Parts of the results were confirmed by direct sequencing analysis of PCR products.</p><p><b>RESULTS</b>Among the 1214 patients with chronic HBV infection, 0.7% (9/1214)were genotype A, 28.4% (345/1214)genotype B, 58.4% (709/1214) genotype C, and 12.4% (151/1214) genotype B and genotype C mixed infection. No other genotypes were found. Genotype C was predominant in the northern part of China, such as Changchun, Beijing, Shijiazhuang,while genotype B was more commonly seen in south of China. 71.4% (20/28) for patients from Qingyuan and 63.6% (70/110) from Shenzhen were infected with genotype B.</p><p><b>CONCLUSION</b>HBV genotypes had distinct geographic distribution. Genotype B and C the predominant strains in patients with chronic HBV infection in China. Genotype C was predominantly identified in the northern part of China versus genotype B the south.</p>