Drinking water quality assessment for manganese in rural areas of Guangxi Province during 2014-2019 / 上海预防医学

Objective To determine the content and distribution of manganese in rural drinking water in Guangxi province, and to provide scientific evidence for improving drinking water quality and safety. Methods The monitoring results of manganese in rural drinking water in Guangxi from 2014 to 2019 were evaluated according to GB 5749-2006 Sanitary Standards for Drinking Water. Results 47 637 samples were analyzed during 2014-2019.Manganese detection rate was 28.46 %, with the range from 0.05 to 2.71 mg/L, and the qualified rate was 99.46%.The difference of manganese compliance rate in different years was statistically significant (χ2=25.049, P < 0.01), and the rate increased with the increase of year (χ2 =17.498, P < 0.01).The compliance rate in dry seasons was higher than that in wet seasons(χ2=5.871, P < 0.05).The qualified rate of manganese was statistically different between the water samples collected from centralized and scattered supply sources (χ2=90.983, P < 0.01).The qualified rate of manganese in large centralized water supply was higher than that in small centralized water supply (χ2=10.294, P < 0.01).The geographic distribution of the qualified manganese rate was in the following order:center>west>north>south>east.(χ2=103.908, P < 0.01). Conclusion There are high and low concentrations of water manganese in rural areas of Guangxi.While most areas showed low manganese in drinking water, some areas dispayed a local point distribution of high water manganese.

Expression of long-chain non-coding RNA-LINC00485 in lung cancer and its effect on proliferation and migration of lung cancer cells / 临床与实验病理学杂志

Purpose To observe the expression of longchain non-coding RNA-LINC00485 (LINC00485) in lung cancer cell lines and tissues, and to investigate its effect on the proliferation and migration of lung cancer cells and its mechanism.Methods Quantitative real-time quantitative polymerase chain reaction (qRT-PCR) was used to detect differential expression of LINC00485 in four lung cancer cell lines (H1975, A549, HCC827, H1299), normal alveolar epithelial cells HPAEPIC, and in 12 cases lung cancer tissues and adjacent tissues. Bioinformatics methods were used to predict the microRNA (miRNA) that LINC00485 may bind and target gene that miRNA may bind. Small interfering RNAs (siRNAs) that target silencing LINC00485 were transfected into HCC827 cells by liposomes.The expression levels of LINK00485, miR-361-5p, and p21 activated protein kinase 2 (PAK2) mRNA were detected by qRTPCR. The expression level of PAK2 protein was detected by Western blot. The cell proliferation ability was measured by MTS assay. Cell scratch assay was used to detect cell migration. Results Compared with normal alveolar epithelium, LINC00485 was highly expressed in lung cancer cell lines (P < 0.05), and the expression level was highest in HCC827 cells. The expression of LINC00485 in lung cancer tissues was higher than that in adjacent tissues (P < 0.01). After down-regulation of LINC00485 expression in HCC827 cells, the expression of miR-361-5p was up-regulated (P < 0.01), the expression of PAK2 mRNA and protein was down-regulated (P < 0.01), the proliferative capacity of HCC827 cells was decreased (P < 0.05), and the ability of cell migration was decreased (P < 0.01).Conclusion The expression of LINC00485 is increased in lung cancer cell lines and tissues. Down-regulation of LINC00485 can inhibit the proliferation and migration of lung cancer HCC827 cells by regulating the expression of miR-361-5p and PAK2 genes.

Research Progress on Gene Alterations of Amelogenin Locus in Gender Identification / 法医学杂志

There are two kinds of amelogenin gene mutation, including mutation in primer-binding region of amelogenin gene and micro deletion of Y chromosome encompassing amelogenin gene, and the latter is more common. The mechanisms of mutation in primer-binding region of amelogenin gene is nucleotide point mutation and the mechanism of micro deletion of Y chromosome encompassing amelogenin gene maybe non-allelic homologous recombination or non-homologous end-joining. Among the population worldwide, there is a notably higher frequency of amelogenin gene mutations in Indian population, Sri Lanka population and Nepalese population which reside within the Indian subcontinent. Though amelogenin gene mutations have little impact on fertility and phenotype, they might cause incorrect result in gender identification. Using composite-amplification kit which including autosomal STR locus, amelogenin gene locus and multiple Y-STR locus, could avoid wrong gender identification caused by amelogenin gene mutation.

Identification of Vaginal Fluid Using Microbial Signatures / 法医学杂志

OBJECTIVES@#To investigate the specific microbial signatures in vaginal fluid.@*METHODS@#Vaginal fluid （16 samples）, saliva （16 samples）, feces （16 samples）, semen （8 samples）, peripheral blood （8 samples）, urine （5 samples）, and nasal secretion （4 samples） were collected respectively. The 16S rRNA genes of Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus jensenii, Lactobacillus iners, and Atopobium vaginae were amplified. PCR production was detected via a 3130xl Genetic Analyzer.@*RESULTS@#The detected number of Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus jensenii, Lactobacillus iners, and Atopobium vaginae were 15, 5, 8, 14, and 3 in all vaginal fluid samples, respectively. Lactobacillus crispatus and Lactobacillus jensenii existed specifically in vaginal fluid.@*CONCLUSIONS@#There is a potential application value to detect Lactobacillus crispatus and Lactobacillus jensenii for the identification of vaginal fluid.

Application of Ion Torrent PGM™ System in Detection of Fetal DNA in Maternal Plasma / 法医学杂志

OBJECTIVE@#To explore the feasibility of detecting of Y-STR of fetal DNA in maternal plasma using Ion Torrent PGM™ System.@*METHODS@#A total of 16 fetal DNA samples from maternal plasmas (8 cases from 38 weeks gestational age and 8 ones from 12 weeks) were prepared and a multiplex assay with 7 STR loci (DYS390, DYS391, DYS393, DYS438, DYS437, DYS456, DYS635) was designed for multiplex-PCR amplification. Using Ion Torrent PGM™ System, the results of Y-STR sequences and capillary electrophoresis were obtained and compared.@*RESULTS@#Y-STR specific alleles were detected in the maternal plasma of all the pregnant women having male babies of second and third trimester, which were higher than that detected by capillary electrophoresis. Consistent Y-STR genotypes were observed between fetal DNA from maternal plasma and genomic DNA from the newborn babies.@*CONCLUSION@#Based on Ion Torrent PGM™ System, the prenatal Y-STR detection method may provide a high-sensitive and high-throughput choice for prenatal STR detection in forensic testing.

AS-PCR assay for 20 mtDNA SNP typing and haplotype frequency / 法医学杂志

OBJECTIVE@#To develop a multiplex allele-specific PCR (AS-PCR) assay with three-color fluorescence labeling for mitochondrial DNA (mtDNA) SNP typing.@*METHODS@#Based on the principle of AS-PCR, the primer sets were designed for 20 SNP located on the coding region of mtDNA and divided into 2 groups labeled with FAM and HEX fluorescence, respectively. A primer set included two forward (reverse) allelic specific primers with different sizes and a generic reverse (forward) primer. Blood samples from 200 unrelated individuals were analyzed by AS-PCR and capillary electrophoresis. Three random samples at least for each SNP site were examined and verified by direct sequencing. The haplotype frequency was investigated.@*RESULTS@#Distinct electropherograms of 200 blood samples were obtained successfully. The typing results of direct sequencing were identical to those obtained from AS-PCR. The minimum detectable DNA concentration was 0.2 pg under the system of 10 microL. The sensitivity of the DNA concentrations ranged from 0.5 to 5 pg. The 200 individuals were assigned into 15 haplotype, and the haplotype diversity was 0.906 0.@*CONCLUSION@#AS-PCR is a simple, rapid and efficient method for mtDNA SNP typing, and can be applied to forensic practice.

Determination of the biological attribute of evidence at the scene using reverse transcription PCR and real-time fluorescent quantitative PCR / 法医学杂志

OBJECTIVE@#To explore the feasibility of biological method to identify the biological attribute of samples at crime scene.@*METHODS@#Thirty samples of ten blood stains, ten saliva stains and ten semen stains were selected, and all the samples were processed by the routine method and biomolecular method, respectively. Both RNA and DNA were isolated using DNA-RNA co-extraction technology and the mRNA was converted into cDNA using reverse transcription PCR (RT-PCR). Three pairs of specific primers were designed for blood stain, saliva stain and semen stain based on the different target genes in three specific tissues and the primers were amplified using real-time fluorescent quantitative PCR. The differences in these biological samples were evaluated by melting temperature (Tm) values and the size of the amplification fragment.@*RESULTS@#The Tm values of blood stain, saliva stain and semen stain were (84.5 +/- 0.2) degrees C, (76.9 +/- 0.3) degrees C and (88.5 +/- 0.2) degrees C, respectively. The length of PCR fragments of them was 177bp, 134bp and 294bp, respectively.@*CONCLUSION@#Compared with the routine method, RT-PCR with real-time fluorescent quantitative PCR is highly specific, sensitive and reliable to identify the biological attribute of evidence, and can be potentially applied to determine evidence attribute in forensic practice.

Research status and prospects of DNA test on difficult specimens / 法医学杂志

This paper reviews the advances of DNA detection on three types of difficult biological specimens including degraded samples, trace evidences and mixed samples. The source of different samples, processing methods and announcements were analyzed. New methods such as mitochondrial test system, changing the original experimental conditions, low-volume PCR amplification and new technologies such as whole genome amplification techniques, laser capture micro-dissection, and mini-STR technology in recent years are introduced.