A new method for noninvasive prenatal diagnosis of fetal sex was developed by using single-cell PEP-PCR techniques. Micromamipulation techniques were used to obtain single fetal cells from 273 maternal blood samples. The genome of single cells was preamplified by PEP and SRY genes were analyzed by PCR method. The SRY genes of 149 samples were detected by the new method among 153 samples carrying male fetus, while 119 out of 120 samples carrying female fetus were proved negative for SRY genes. The sensitivity and specificity of the new method were 97.39% and 99.17% respectively and the correct rate was 98.17%. The new method has the advantage of high sensitivity and specificity in noninvasive prenatal diagnosis of fetal sex and provides the basis of other researches such as sex-linked inherited diseases.
Chromosomes, Human, Y ; Erythroblasts/chemistry ; Fetus/*cytology ; Genes, sry/genetics ; Genetic Diseases, Inborn/diagnosis ; Maternal-Fetal Exchange/genetics ; Polymerase Chain Reaction/methods ; Pregnancy/*blood ; Prenatal Diagnosis/*methods ; *Sex Determination (Genetics)

A new method for noninvasive prenatal diagnosis of fetal sex was developed by using single-cell PEP-PCR techniques. Micromamipulation techniques were used to obtain single fetal cells from 273 maternal blood samples. The genome of single cells was preamplified by PEP and SRY genes were analyzed by PCR method. The SRY genes of 149 samples were detected by the new method among 153 samples carrying male fetus, while 119 out of 120 samples carrying female fetus were proved negative for SRY genes. The sensitivity and specificity of the new method were 97.39% and 99.17% respectively and the correct rate was 98.17%. The new method has the advantage of high sensitivity and specificity in noninvasive prenatal diagnosis of fetal sex and provides the basis of other researches such as sex-linked inherited diseases.
Adult ; Chromosomes, Human, Y ; Erythroblasts ; chemistry ; Female ; Fetus ; cytology ; Genes, sry ; genetics ; Genetic Diseases, Inborn ; diagnosis ; Humans ; Male ; Maternal-Fetal Exchange ; genetics ; Polymerase Chain Reaction ; methods ; Pregnancy ; blood ; Prenatal Diagnosis ; methods ; Sex Determination Processes

The single cell isolation technique was used to detect fetal nucleated erythroblasts (FNRBCs) at a single cell level from the peripheral blood of pregnant women in order to investigate the feasibility of this method for noninvasive prenatal diagnosis. Single fetal nucleated erythroblasts were isolated from the peripheral blood samples from 51 pregnant women (14 to 26 weeks of gestation) by micromanipulation techniques after density gradient centrifugation. Nested polymerase chain reaction method was used to amplify the SRY gene. It was found that the concordance rate of amplification results with real fetal sex was 82.61 %. The sensitivity and specificity were 80 % and 87.50 % respectively. It was suggested that it is feasible and promising in non invasive prenatal diagnosis to detect fetal nucleated erythroblasts at a single cell level by using micromanipulation techniques.

The single cell isolation technique was used to detect fetal nucleated erythroblasts (FNRBCs) at a single cell level from the peripheral blood of pregnant women in order to investigate the feasibility of this method for noninvasive prenatal diagnosis. Single fetal nucleated erythroblasts were isolated from the peripheral blood samples from 51 pregnant women (14 to 26 weeks of gestation) by micromanipulation techniques after density gradient centrifugation. Nested polymerase chain reaction method was used to amplify the SRY gene. It was found that the concordance rate of amplification results with real fetal sex was 82.61 %. The sensitivity and specificity were 80 % and 87.50 % respectively. It was suggested that it is feasible and promising in non invasive prenatal diagnosis to detect fetal nucleated erythroblasts at a single cell level by using micromanipulation techniques.

Objective: To investigate the first family cluster of COVID-19 in Lanzhou, so as to provide basis for improving the COVID-19 outbreak prevention capacity. Methods : On January 23, the First Hospital of Lanzhou University reported two suspected cases of COVID-19.According to the COVID-19 Epidemiological Investigation Plan ( second edition ) , general information, disease diagnosis and treatment, clinical symptoms, laboratory test results, household environment, exposure history and close contacts were collected to figure out the source of infection and routes of transmission. Results: This family cluster lasted 29 days, from January 23 to February 21, reporting nine confirmed cases ( one death ) and one asymptomatic case. There were three imported cases from Wuhan, who were the source of the cluster; and seven secondary cases, who all had close contact with the imported cases during daily life or through having dinners. The secondary attack rate was 41.18% ( 7/17 ) . Among 9 confirmed cases, the incubation period ranged from four to ten days, with a median of nine days. Except for seven secondary cases, 24 close contacts were found and detected negative in the nucleic acid tests. Conclusions The first family cluster of COVID-19 in Lanzhou is caused by the imported cases from Wuhan. All the secondary cases have had dinners and/or had contact with the imported cases, thus they are infected through respiratory droplets and close contact.

Objective: To explore the effects of temperature on the daily cases of varicella. Methods: The data of daily cases of varicella was collected during 2008 to 2016 in Lanzhou from National Notifiable Disease Report System, and the meteorological data at the same period was integrated from Gansu Meteorological Administration. Distributed lag nonlinear model was fitted to reveal the relationship between the daily mean temperature and the daily cases of varicella and susceptible population. The minimum morbidity temperature was defined as the reference for the estimation of RRs in different temperature level (-5.2 ℃, 1.7 ℃, 20.1 ℃ and 25.4 ℃). Results: The total of 21 254 cases were reported from 2008 to 2016, of which the ratio of male to female was 1.28 (11 951/9 303) and people aged 6-14 years accounted for 52.87%. The relationship between the daily mean temperature and the daily cases of varicella was M type. For all subjects, the accumulative effects of temperature had statistical significance from lag 0-14 d when temperatures was at -5.2 ℃, 1.7 ℃ and 20.1 ℃,while the RRs (95%CI) were 1.87 (1.64-2.12) , 1.33 (1.10-1.62) ,1.60 (1.38-1.86) ,while from lag 0-7 d when temperatures was at 25.4 ℃,and the RR (95%CI) was 2.51 (1.93-3.27) . The RR value of accumulative effects was 6.23(95%CI: 4.38-8.86) on lag 7 d when temperatures was at -5.2 ℃, which was the highest value at different temperature during lag days. The cumulative effects trends of different temperatures were similar for different gender population or different age subjects. However, the cumulative effects of was highest for children aged 6-14 years among all subjects, and the value of RR was 6.12 (95%CI:3.71-10.10) on lag 5d when temperatures was at -5.2 ℃. Conclusion We conclude that the increasing risk of varicella is associative with low and high temperature in Lanzhou. The effects of low temperature are stronger than those of high temperature. The children aged 6-14 years belong to the high-risk population of varicella.

Objective:To screen the HIV standard strains with typical biological characteristics of HIV strains circulating in China through the isolation, culture, genotype and phenotype identification of HIV from the whole blood samples of HIV-infected persons, confirm genetic characteristics, traceability, and in line with the Standard Strains of Pathogenic Microorganism-technical Specifications for Establishment of HIV Strains (T/CPMA 027—2023).Methods:Whole blood samples were collected from 48 HIV infected patients. Peripheral blood mononuclear cells (PBMCs) were isolated from the samples and co-cultured with PBMCs isolated from healthy persons′ whole blood samples to isolate and culture HIV from infected persons. We determined concentration of p24 antigen and the virus titer in the culture supernatant. The viral RNA was extracted from the successfully isolated strains, and the gag, pol genes and env C2V3 fragments of the viral genome were amplified and sequenced. The genotype, gene recombination and drug resistance sites were determined according to the viral gene sequences. Virus infection and replication were monitored by inoculating the virus culture supernatant into Ghost cells expressing CCR5 or CXCR4 to determine the viral tropism.The formation of syncytium was observed by inoculating the virus culture supernatant into MT-2 cells to determine whether was a syncytium-induced phenotype. Results:Fourteen strains with p24 antigen concentration > 1 ng/ml in culture supernatant were isolated and cultured from 48 fresh EDTA anticoagulated whole blood samples of HIV infected persons. Of the 14 strains, only one strain with a titer≥10 5 TCID 50/ml, 8 strains with titers ≥10 4 TCID 50/ml, and the other 5 strains with titers≥10 3 TCID 50/ml. Phylogenetic analysis showed that the genotypes of the strains were 9 strains of subtype B, 3 strains of CRF01_AE and 2 strains of CRF07_BC recombinant. Genotypic resistance analysis showed that 11 strains contained drug resistance sites. Ghost cells were used to verify the tropism of the strains, and it was found that 8 strains were CCR5 tropism, 6 strains were CXCR4 & CCR5 dual tropism. Only 2 of the 14 strains could induce MT-2 cytopathic effect, which was syncytium-inducing phenotype. Conclusions:Fourteen HIV strains with typical biological and genetic characteristics were isolated to screen the standard HIV strains. Among which, 1 strain was evaluated as a standard HIV strain that meets the Standard Strains of Pathogenic Microorganism-technical Specifications for Establishment of HIV Strains (T/CPMA 027—2023). This study can also provide technical guidance for the screening of the HIV standard strains. Next step is to complete the application and reserve database construction according to the sharing mechanism of the HIV standard strains, to provide resources for the researches of HIV vaccines and drugs.

Objective: Investigate osteogenic differentiation of canine periodontal ligament stem cells ( cPDLSCs) via over-expression ephrinB2 in cPDLSCs． Methods : cPDLSCs were isolated from the premolars and molars of Beagle．After transfected with EfnB2-GFP-Bsd and GFP-Bsd empty Vector，cPDLSCs were induced to osteogenic differentiation．Western blot was used to invest the expression of ephrinB2 protein．The effect of osteogenic differentiation of EfnB2-cPDLSCs and Vector-cPDLSCs were analyzed by RT-PCR , CCK-8，Alizarin-red S staining and ALP. Results: There was no significant difference in cell proliferation between EfnB2-cPDLSCs and Vector-cPDLSCs．While EfnB2-cPDLSCs displayed an enhanced ALP activity and more prominent mineralized nodules compared with Vector-cPDLSCs．The odonto-/ osteogenic genes in EfnB2-cPDLSCs were also highly enhanced． Conclusion The results of our study indicated that ephrinB2 gene-transfected cPDLSCs showed enhanced osteogenic differentiation.