PubMed Health⌕ Search

Biomedical subjects

Ji He

Publications and source records attributed to Ji He.

At least 19 recordsLinked to original sources
PubMed2026

HLA-DQB1*06:02 and a critical amino acid variant in protection against occult hepatitis B virus infection.

The human leukocyte antigen (HLA) system plays a critical role in determining the outcomes of hepatitis B virus (HBV) infection, yet the genetic mechanisms underlying occult HBV infection (OBI), a form marked by detectable HBV DNA in the absence of hepatitis B surface antigen, remain poorly defined. Here, we performed high-resolution HLA genotyping and amino acid-based association analysis in a Chinese population comprising 239 OBI cases and 545 healthy controls. We identified the HLA class II allele DQB1*06:02 as a protective signal against OBI, with conditional analysis confirming its independent effect. This allele is carried on the conserved haplotype DRB1*15:01~DQA1*02:01~DQB1*06:02, which was significantly underrepresented in OBI cases. Conversely, the DRB1*09:01~DQA1*03:02~DQB1*03:03 haplotype was associated with increased OBI risk. Analysis of the HLA-DQB1 amino acid residues revealed that position 119, located in an α-helix of the peptide-binding groove, drives a substantial portion of the observed association. The phenylalanine variant at this site remained strongly protective after multiple-testing correction and is encoded by DQB1*06:02. Our study thus delineates both allele and amino acid level HLA determinants of OBI susceptibility, highlighting a key structural residue that may influence antigen presentation and immune clearance of HBV. These findings provide a refined genetic framework for understanding host and virus interactions in occult HBV persistence.

Humans↗
PubMed2006

[Formation of platelets from cord blood CD34+ cells-derived megakaryocytes induced by S-nitrosoglutathione].

To investigate the effect of S-nitrosoglutathione (GSNO), a nitric oxide donor, on platelet production from megakaryocytes differentiated from cord blood CD34(+) cells in vitro, the CD34 (+) cells from eight fresh umbilical cord blood samples by a high-gradient magnetic cell sorting (MACS) system were cultured in serum-free medium for 14 d with thrombopoietin (TPO) 50 ng/ml, IL-3 10 ng/ml, stem cell factor (SCF) 50 ng/ml and rHuGM-CSF 20 ng/ml. Then, CD61 (+) cells were purified by MACS system from these CD34 (+) cells, and were cultured in serum-free medium supplemented with TPO 50 ng/ml, IL-3 10 ng/ml and SCF 50 ng/ml in the presence (treatment group) and absence (control group) of GSNO for 30 min or 2 h. Platelet-sized particles were counted by flow cytometry; megakaryocyte structure was detected by scanning electron microscope. Aggregation of the thrombin-induced platelet particle was observed under inversion microscope. cGMP was assessed by commercial ELISA kit. The results showed that, compared with the control group, the number of platelet-sized particles significantly increased (P<0.05) in the treatment group, in which megakaryocytes presented significant pseudopod formation and extensive membrane blebbing. The platelet particle aggregation could be observed under microscope after thrombin induction. cGMP activity was significantly increased after treatment with GSNO (P<0.05). These results propose that GSNO can facilitate platelet production from megakaryocyte, and it may be partly through cGMP pathway.

Antigens, CD34↗
PubMed2006

[Sequence analysis of a novel HLA-DRB1 allele, DRB1 * 1212].

OBJECTIVE: To investigate the molecular genetics basis for HLA novel allele HLA-DRB1*1212 in Chinese population. METHODS: Genomic DNA was extracted from whole blood by salting-out method. HLA-DRB1 gene exon 2 was amplified by PCR with group-specific primers from genomic DNA. PCR products were cut back from agarose gels and purified to sequence directly. The polymerase chain reaction-sequence specific oligonucleotide probes (PCR-SSO) was performed to confirm the mutations which were detected by sequencing in this study. RESULTS: The sequencing results showed HLA-DRB1 alleles of the proband as DRB1*090102 and the novel allele. The sequences of the novel allele have been submitted to GenBank (AY899825). Through BLAST analysis, the novel allele was found to be different from DRB1*120101 at position 199A-->C in exon 2, that results in an amino acid change from Ile to Leu at codon 67. CONCLUSION: This allele is a novel and has been officially named as DRB1*1212 by the WHO Nomenclature Committee.

Alleles↗
PubMed2006

[Sequence analysis of a novel HLA-A*3308 allele].

OBJECTIVE: To investigate the molecular genetics basis for HLA novel allele HLA-A*3308 in Chinese population. METHODS: DNA was extracted from whole blood by PEL-FREEZ DNA extraction kit. The amplification of HLA-A exons 1-8 of the proband was preformed by PCR and the amplified product was cloned with TOPO cloning sequencing kit to split the two alleles apart. Both strands of exons 2, 3 and 4 of chosen clones were sequenced. The PCR-SSP was performed to confirm the mutations detected by sequencing. RESULTS: The sequencing results showed HLA-A alleles of the proband as A*0201 and the novel allele. The sequences of the novel allele have been submitted to GenBank (DQ089631, DQ089632, DQ089633). BLAST analysis showed that the novel allele got the difference from A*3303 by five nucleotides at positions 240 A>T, 256C>G, 259A>G, 261C>G and 270T>A in exon 2. This resulted in three amino acids changes from Arg to Gly at codon 62, Asn to Glu at codon 63 and Asn to Lys at codon 66. CONCLUSION: This allele is a novel allele and has been officially named A*3308 by the WHO Nomenclature Committee.

Alleles↗
PubMed2006

[Allelic polymorphism analysis of killer cell immunoglobulin-like receptor gene 3DL2 in Zhejiang Han population].

OBJECTIVE: To analyze the allelic polymorphism of killer cell immunoglobulin (Ig)-like receptor (KIR) gene 3DL2 in Zhejiang Han population. METHODS: Allelic definition within KIR3DL2 was achieved through using the PCR-sequence specific oligonucleotide probes (PCR-SSOP) method and the specific amplification of exon 3-exon 4 and exon 8-exon 9. Twenty-one digoxigenin-labelled probes were used to the SSOP analysis. RESULTS: Seven alleles of KIR3DL2 were observed, in which KIR3DL2 *002 had the highest allele frequency, 0.57. One sample could not be given the allele combination according to the probe profile. CONCLUSION: The PCR-SSOP method was reliable. There is a distinctive allele frequency of KIR3DL2 in Zhejiang Han population.

Asian People↗
PubMed2006

[Molecular basis of partial D phenotypes in Chinese].

To investigate the molecular basis of partial D phenotypes in Chinese, D variants with weak D expression was screened by using indirect anti-human globulin test (IAT) method, the polymerase chain reaction-sequence specific primer (PCR-SSP) method was employed to amplify RHD specific exons and their flanking regions. The amplification products were sequenced directly to determine the molecular basis of D variants. The results showed that ten cases of partial D phenotypes, including one case of D Va (Kou.), one case of D Va (Hus.), one case of D Va-like (YH.), and seven cases of D VI type III, were detected from 22 cases of weak D phenotype respectively. All ten cases of partial D phenotypes had one RHD allele deleted. In conclusion, the molecular basis of ten cases of partial D phenotype was confirmed, including D Va (Kou.) and D Va-like (YH.) phenotypes reported firstly in Chinese population.

Alleles↗
PubMed2006

[Effect of angiotensin II on differentiation of umbilical cord blood CD34+ cells into megakaryocytes].

This study was aimed to investigate the effect of angiotensin II on differentiation of cord blood CD34+ cells into megakaryocytes in vitro. The CD34+ cells from eight fresh umbilical cord blood samples sorted by a high-gradient magnetic cell sorting system (MACS) were cultured in serum-free culture medium containing thrombopoietin (TPO) 50 ng/ml, IL-3 10 ng/ml, stem cell factor (SCF) 50 ng/ml and different concentrations of angiotensin II (0, 50, 100, 1000 microg/ml) for 14 days. Mononuclear cells (MNC) were counted by automatic cell analyzer. Cultured CD41+ cell and platelet counts in cultured system, and cell cycle were analyzed by flow cytometry. CD41 specific monoclonal antibody staining was observed by immunofluorescence microscopy. The results showed that as compared with the control group, the number of MNC not increased significantly (P > 0.05), but the number of CD41+ cells and platelets increased significantly in treatment group (P < 0.05). Cell cycle analysis revealed that the amounts of 4N cells increased and apoptosis cells obviously existed in treatment group (P < 0.05). After fluorescence staining, more CD41+ cells of different sizes were observed by means of fluorescence microscopy in both groups. It is concluded that angiotensin II can induce the cord blood CD34+ cells to differentiate towards megakaryocyte, and enhance the function of megakaryocyte to produce platelet.

Angiotensin II↗
PubMed2005

[Composition and diversity of acaroid mite community in different environments in Huainan City].

OBJECTIVE: To investigate the composition and diversity of acaroid mite community in Huainan City. METHODS: Dust samples were collected from storage circumstances, human dwellings and working places. Acaroid mites were isolated, counted and identified. 30 sampling spots from each of the three environments were selected, and 2 samples, each with 10 g, were collected from each sampling spot. RESULTS: 26 species of acarid mites were identified from the three environments. These acarid mites belonged to 19 genera, 7 families. Diversity analysis showed that the average breeding density ranged from 15.35 +/- 6.13 to 31.27 +/- 8.34, the number of species ranged from 11 to 14, the values of the species richness index Rmargalef for the three circumstances raged from 1.99 to 4.35, the species diversity index (Shannon-Wiener index) ranged from 2.27 to 3.13, and Pielou index ranged from 0.95 to 0.96. CONCLUSION: The composition and diversity of acaroid mite community in three different circumstances are different significantly, which might be relevant to temperature, humidity and human interference.

Acaridae↗
PubMed2005

Processing and cryopreservation for 1963 units of human umbilical cord blood.

The study was aimed to establish a standard procedure for human umbilical cord blood bank. The hematopoietic nucleated cells in cord blood were processed by using sedimentation and centrifugation method. After finishing CD34(+) cell counting, hematopoietic progenitor cell assay, microbial culture, infectious disease test and HLA typing, cord blood units were stored in the liquid nitrogen for further application. The results showed that nucleated cells of cord blood were (10.94 +/- 2.74) x 10(8) per unit; recovery rate of nucleated cells was (79.82 +/- 17.76)%. CD34(+) cells in cord blood were counted as (51.62 +/- 30.53) x 10(5) per unit. Eight units of cord blood were thawed after two years of cryopreservation, the recovery rate of nucleated cells, CD34(+) cells and CFU-GM were (91.4 +/- 6.0)%, (84.6 +/- 20.0)% and (85.8 +/- 14.9)% respectively. It is suggested that the methods and procedure reported for processing and cryopreservation of hematopoietic stem/progenitor cells in the human umbilical cord blood is effective.

Antigens, CD34↗
PubMed2005

[Cloning of human RHD gene and its expression in K562 cells].

The aim of this study was to clone human RHD gene and to investigate its expression in transduced K562 cells. Total RNA was extracted from reticulocyte of cord blood. RHD and RHCE genes were amplified using RT-PCR method. The amplified products were cloned into pGEM-T plasmid by TA ligation and several clones were screened by direct sequencing method in order to obtain the RHD gene. RHD gene was subcloned into pcDNA3.1(-) expression vector, then the recombined plasmids were transduced into K562 cells with superfect transfection reagent kit. Finally transcription and expression of RHD gene in K562 cells were detected. The result showed that RHD gene has been cloned sucessfully, the inserted sequence and direction of RHD cDNA in its recombined pcDNA3.1(-) vector were identified using enzyme cutting and sequencing method. After transduced with recombined pcDNA3.1(-) vector, K562 cells could transcribe RHD mRNA in its cytoplasm and express RhD antigen on its membrane surface. In conclusion, RhD antigen can expressed in K562 cells with RHD cDNA transduction, and the expression system in vitro may be helpful to further investigate the molecular basis of RhD variants.

Base Sequence↗
PubMed2005

[Effect of GM-CSF on expansion and differentiation of CD34+ megakaryocyte progenitor cells from cord blood in vitro].

To study the effect of GM-CSF on in vitro expansion of megakaryocyte progenitor cells from cord blood, CD34(+) cells isolated by magnetic cell sorting system (MACS) were cultured in serum-free medium containing TPO, IL-3, SCF and with or without various concentrations of GM-CSF (5, 20, 100 ng/ml). The numbers of MNC, proportion of CD34(+)CD41(+) cells and CFU-MK were measured at 6, 10 and 14 days. The results showed that the expansion of MNC and proportion of CD41(+) cells was accelerated distinctly by various concentrations of GM-CSF after 14 days, while 20 and 100 ng/ml GM-CSF exhibited higher expansion effect than that of 5 ng/ml. TPO + IL-3 + SCF with 5 ng/ml or 20 ng/ml GM-CSF could stimulate the formation of CFU-MK, while TPO + IL-3 + SCF with 100 ng/ml GM-CSF could inhibit it. It is concluded that GM-CSF can accelerate the expansion of megakaryocyte progenitor cells from CD34(+) cells in cord blood in the serum-free medium containing TPO + IL-3 + SCF.

Adult↗
PubMed2005

[Determination of ABO blood group genotypes with one tube PCR reaction].

This study was aimed to establish one tube PCR reaction technique to determine ABO blood group genotypes. Salting-out method was adopted to extract genomic DNA; one tube polymerase chain reaction with GeneScan technique was used to identify ABO genotypes. The results showed that the ABO genotypes of 132 samples were in accordance with the phenotypes determined by serological technique. The frequencies of A, B and O were 0.205, 0.159 and 0.636 respectively. AA, AO, AB, BB, BO and OO genotypes were 8 (6.1%), 31 (23.5%), 7 (5.3%), 6 (4.5%), 23 (17.4%), and 57 (43.2%) respectively. It is concluded that one tube polymerase chain reaction with GeneScan technique can determine the genotypes of ABO blood group.

ABO Blood-Group System↗
PubMed2004

Modified ART 2A growing network capable of generating a fixed number of nodes.

This paper introduces the Adaptive Resonance Theory under Constraint (ART-C 2A) learning paradigm based on ART 2A, which is capable of generating a user-defined number of recognition nodes through online estimation of an appropriate vigilance threshold. Empirical experiments compare the cluster validity and the learning efficiency of ART-C 2A with those of ART 2A, as well as three closely related clustering methods, namely online K-Means, batch K-Means, and SOM, in a quantitative manner. Besides retaining the online cluster creation capability of ART 2A, ART-C 2A gives the alternative clustering solution, which allows a direct control on the number of output clusters generated by the self-organizing process.

Cluster Analysis↗