Biomedical subjects

Yan Shen

Publications and source records attributed to Yan Shen.

At least 19 recordsLinked to original sources

PubMed2026

Repeated Cross-Sectional Surveillance and ORF5-Based Molecular Epidemiology of Porcine Reproductive and Respiratory Syndrome Virus in Anhui Province, China, 2019-2024.

Porcine reproductive and respiratory syndrome virus (PRRSV) remains a major threat to swine production, and its circulation after the African swine fever outbreak requires continued surveillance. This study investigated the temporal, regional, and genetic characteristics of PRRSV in Anhui Province from September 2019 to November 2024. Ten rounds of repeated cross-sectional surveillance were conducted at 147 slaughterhouses and 21 rendering plants. Tissue samples were collected by random, cluster, or risk-based sampling, pooled in groups of five, and tested by RT-qPCR. Representative positive samples with Ct values < 25 underwent ORF5 amplification, Sanger sequencing, and phylogenetic analysis. A total of 994 site visits yielded 18,733 tissue samples. No positive samples were detected in autumn 2020 or spring 2021, whereas PRRSV was detected again from autumn 2021 and subsequently fluctuated. The highest site-level positivity was 41.18% in autumn 2023, and the highest estimated individual-level positivity was 4.66% in spring 2023. Regional differences were statistically significant, with the highest site-level positivity in northern Anhui, and pooled-sample positivity was higher in rendering plants than in slaughterhouses. All 24 ORF5 sequences belonged to PRRSV-2 and mainly clustered with NADC30-like, NADC34-like, or MLV/classical strains. These findings demonstrate temporal fluctuations and lineage coexistence, supporting continued multisource surveillance and broader genomic and antigenic evaluation.

NADC30-like↗

PubMed2026

RPN1 at the crossroads of glycosylation, tumor immunity, and disulfidptosis.

Ribophorin I (RPN1), a core component of the oligosaccharyltransferase complex, is traditionally known for its role in endoplasmic reticulum-associated N-glycosylation. Recent studies have identified RPN1 as an emerging regulator of tumor progression and immunity. Aberrant RPN1 overexpression has been reported in multiple malignancies, including glioma, hepatocellular carcinoma, sarcoma, and triple-negative breast cancer, where it is frequently associated with aggressive clinicopathological features and poor prognosis. RPN1 promotes tumor immune evasion by promoting N-glycosylation and stabilization of programmed death-ligand 1 (PD-L1), thereby enhancing immune checkpoint signaling and directly inhibiting anti-tumor T-cell responses. Consequently, elevated RPN1 expression is consistently associated with an immunosuppressive tumor microenvironment rich in M2 macrophages and poor in CD8+ T cells. More importantly, multiple omics signature analyses indicate RPN1 is integrated into several disulfidptosis-related risk models; however, direct experimental evidence confirming the causal linkage between RPN1 and disulfidptosis remains limited. Correlative database data also show potential associations between RPN1 upregulation and genomic instability and treatment resistance. Based on tiered classification of existing evidence (biochemical functional validation vs. multi-omics correlation), this review systematically summarizes the biological roles of RPN1 in cancer, its functions in tumor immunity and disulfidptosis-associated pathways and finally evaluates its potential as a therapeutic target in precision oncology.

PDL1↗

PubMed2003

Haplotype structure and evidence for positive selection at the human IL13 locus.

Interleukin-13 (IL13) is believed to play an important role in the pathogenesis of atopy and allergic asthma. To better understand genetic variation at the IL13 locus, we resequenced a 5.1-kb genomic region spanning the entire locus and identified 26 single-nucleotide polymorphisms (SNPs) in 74 individuals from three major populations-Chinese, Caucasian, and African. Our survey suggests exceptionally high and significant geographic structure at the IL13 locus between African and outside Africa populations. This unusual pattern suggests that positive selection that acts in some local populations may have played a role on the IL13 locus. In support of this suggestion, we found a significant excess of high frequency-derived SNPs in the Chinese population and Caucasian population, respectively, as expected after a recent episode of positive selection. Further, the unusual haplotype structure indicates that different scenarios of the action of positive selection on the IL13 locus in different populations may exist. In the Caucasian population, the skewed haplotype distribution dominated by one common haplotype supports the hypothesis of simple directional selection. Whereas, in the Chinese population, the two-round hitchhiking hypothesis may explain the skewed haplotype structure with three dominant ones. These findings may provide insight into the likely relative roles of selection and population history in establishing present-day variation at the IL13 locus, and, motivate further studies of this locus as an important candidate in common diseases association studies.

Asian People↗

PubMed2003

[Association of child absence epilepsy with T-STAR gene].

OBJECTIVE: To investigate the Association of child absence epilepsy with T-STAR gene. METHODS: PCR was conducted on the DNA of peripheral blood white cells from 48 children with child absence epilepsy (CAE), 47 male and 49 female, aged 2.9 approximately 14, of Han nationality in Northern China and 48 healthy children in the same area to amplify the exons of T-STAR gene The PCR products underwent sequencing to identify the possible mutations. RESULTS: No mutation was found in the exons of the T-STAR gene, however, 3 single nucleotide polymorphisms (SNPs) were found. A case-control study was carried out, using SNP1 and SNP2. There was no significant difference in genotype frequency of the 2 SNPs between the CAE group and control group (SNA1: chi(2) = 2.965, df = 1, P = 0.085; SNP2: chi(2) = 2.965, df = 1, P = 0.085). There was no significant difference in allele frequency of the 2 SNPs between the CAE group and control group too (SNA1: chi(2) = 3.185, df = 2, P = 0.203; SNP2: chi(2) = 3.185, df = 2, P = 0.203). CONCLUSION: T-STAR may not be a susceptibility gene for CAE in Chinese populations.

Adolescent↗

PubMed2003

The gene encoding GABBR1 is not associated with childhood absence epilepsy in the Chinese Han population.

Childhood absence epilepsy (CAE) is considered to be a genetic disease, but the genes responsible for it have not yet been identified. To investigate whether or not the GABBR1 gene is a susceptibility gene for CAE in the Chinese Han population, we systematically screened all the 22 exons and nearby intron regions of the gene and found 12 single nucleotide polymorphisms (SNPs). Using four SNPs as markers, we conducted a case-control study in 96 CAE patients and 96 normal controls. There were no significant discrepancies between the cases and controls in allele and phenotype frequencies of the four SNPs. There were still no significant differences in haplotype distributions between the cases and controls. We postulate that the GABBR1 gene might not be a susceptibility gene for CAE at least in the Chinese population.

Alleles↗

PubMed2003

[Infection of Coxsackievirus group B type 3 regulates the expression profile of chemokines in myocardial tissue/cells].

OBJECTIVE: To investigate the role of Coxsackievirus group B type 3 (CVB3) infection on the expression profile of chemokines (ChKs) in myocardial tissue/cells. METHODS: CVB3 was inoculated into male BALB/c intraperitoneally and primary neonatal myocardial cells of BALB/c to establish CVB3 infection models in vivo and in vitro, where the expression profile of ChKs was detected at different time points post-infection as well as under different loading of CVB3 qualitatively and quantitatively by RT-PCR. RESULTS: The expression of MIP-2 and IP-10 was induced post-infection, while SDF-1, MCP-1, MCP-2, MCP-3, MCP-5, MDC, FKN and Ltn were constitutively expressed in myocardial tissue. The expression of MCP-1, MCP-2, MCP-3, MCP-5, MDC and Ltn increased 1.8, 1.9, 3.7, 1.7, 1.3 and 1.2 folds post-infection higher than that of uninfected control (P < 0.01). There was not significant difference in the expression of SDF-1 and FKN between infected myocardial tissue and uninfected myocardial tissue (P > 0.05). The expression of Eot was not detected in infected and uninfected myocardial tissue. Every chemokine had different expression at different infection time points. For example, the expression of MIP-2 at the 4th day was 1.1 and 1.5 times than that of the 7th and 14th day (P < 0.01). IP-10 showed similar expression between the 4th and 7th days (P > 0.05), which is 2.47 and 2.54 times compared to that of the 9th day (P < 0.01). And the expression of MCP-1 at the 14th day post-infection was 1.3, 1.2 and 1.0 times comparing to that of the 4th, 7th, 9th day post-infection, which showed statistical meaning. The expression of MCP-2 at the 4th was 1.4, 1.5 and 2.2 times comparing to that of the 7th, 9th, 14th day, and moreover, the expression was lower than that of the basal expression. The expression of MCP-1 and MCP-3 was up-regulated significantly, which occurred at different time points post-infection in vitro. While the expression of MIP-2 and MCP-5 was down-regulated in vitro. The expression patterns of MCP-2, MCP-3, MCP-5 and MDC were consistent with CVB3 loading. But that of the others (FKN, SDF-1, et al) were inconsistent with CVB3 loading. There was a correlation between change patterns of MCP-3 and CVB3 loading post-infection (r = 0.881, P < 0.05) within 14 days after infection. The varied expression trend of MCP-1 and MCP-3 was similar to the titer of anti-CVB3 antibody (r = 0.913, P = 0.031), while the expression of MCP-2, MCP-5 and MDC shows contrary change. There was not a significant correlation between change patterns of other ChKs (IP-10, SDF-1, et al) and the titer of anti-CVB3 antibody. A positive correlation between anti-CVB3 antibody and MCP-1 (r = 0.976, P < 0.05) was showed. CONCLUSION: The expression level and kind of ChKs in vivo and in vitro was varied significantly in clusters after CVB3 infection. The ChKs changed in clusters consisted of the expression profiles of ChKs. There were complexity and unbalance in the change of the expression of ChKs in every expression profile. It suggested that CVB3 infection could regulate the expression of ChKs in myocardial tissue/cells likely in different ways.

Animals↗

PubMed2003

T-type calcium channel gene alpha (1G) is not associated with childhood absence epilepsy in the Chinese Han population.

We investigated whether the T-type calcium channel gene alpha (1G) is associated with childhood absence epilepsy (CAE), a form of idiopathic generalized epilepsy. We carried out direct sequencing of exons 1-37 and the exon-intron boundaries of the alpha (1G) gene in 48 Han Chinese patients with CAE and 48 normal controls. We found no mutation in the exons of alpha (1G). However, we did identify six single nucleotide polymorphisms (SNPs). Using two of these as markers, we carried out a case-control study in 192 patients with CAE and 192 normal controls. The allele and genotype distributions of all the SNPs studied were not significantly different between cases and control groups, thus the alpha (1G) gene is not an important susceptibility gene for CAE, at least in the Chinese population.

Alleles↗

PubMed2003

Unique physiological and pathogenic features of Leptospira interrogans revealed by whole-genome sequencing.

Leptospirosis is a widely spread disease of global concern. Infection causes flu-like episodes with frequent severe renal and hepatic damage, such as haemorrhage and jaundice. In more severe cases, massive pulmonary haemorrhages, including fatal sudden haemoptysis, can occur. Here we report the complete genomic sequence of a representative virulent serovar type strain (Lai) of Leptospira interrogans serogroup Icterohaemorrhagiae consisting of a 4.33-megabase large chromosome and a 359-kilobase small chromosome, with a total of 4,768 predicted genes. In terms of the genetic determinants of physiological characteristics, the facultatively parasitic L. interrogans differs extensively from two other strictly parasitic pathogenic spirochaetes, Treponema pallidum and Borrelia burgdorferi, although similarities exist in the genes that govern their unique morphological features. A comprehensive analysis of the L. interrogans genes for chemotaxis/motility and lipopolysaccharide synthesis provides a basis for in-depth studies of virulence and pathogenesis. The discovery of a series of genes possibly related to adhesion, invasion and the haematological changes that characterize leptospirosis has provided clues about how an environmental organism might evolve into an important human pathogen.

Bacterial Adhesion↗

PubMed2003

Extensive association analysis between polymorphisms of PON gene cluster with coronary heart disease in Chinese Han population.

OBJECTIVE: An extensive association analysis of PON gene cluster (PONs) with coronary heart disease (CHD) was performed in Chinese Han population. METHODS AND RESULTS: Thirty polymorphisms of PON1, PON2, and PON3 gene were identified by direct sequencing of genomic DNA derived from 48 randomly selected patients. Twelve polymorphisms were additionally investigated for association with CHD in 474 male patients and 475 controls. Univariate analyses showed the cases had significantly higher frequencies of PON1 192Q allele, 160R allele, -162A allele, and PON2 311C allele than were seen in the controls. Logistic regression analyses revealed only the PON1 R160G and -162G/A polymorphisms remained significantly associated with CHD (P=0.0054 and P=0.0002). Haplotype analyses for various polymorphism combinations additionally confirmed the results of individual polymorphism analyses. Only the frequencies of haplotypes containing -162A allele were significantly higher, whereas only the frequencies of haplotypes containing 160G allele were significantly lower in cases than in controls in various polymorphism combinations. CONCLUSIONS: This extensive association study has identified the PON1 -162G/A and R160G polymorphisms to be independently associated with CHD in Chinese Han population and warrants additional study to elucidate the biological mechanism.

Alleles↗

PubMed2003

Association between genetic variation of CACNA1H and childhood absence epilepsy.

Direct sequencing of exons 3 to 35 and the exon-intron boundaries of the CACNA1H gene was conducted in 118 childhood absence epilepsy patients of Han ethnicity recruited from North China. Sixty-eight variations have been detected in the CACNA1H gene, and, among the variations identified, 12 were missense mutations and only found in 14 of the 118 patients in a heterozygous state, but not in any of 230 unrelated controls. The identified missense mutations occurred in the highly conserved residues of the T-type calcium channel gene. Our results suggest that CACNA1H might be an important susceptibility gene involved in the pathogenesis of childhood absence epilepsy.

Age of Onset↗

PubMed2003

GenomeComp: a visualization tool for microbial genome comparison.

We have developed a software tool, GenomeComp, for summarizing, parsing and visualizing the genome sequences comparison results derived from voluminous BLAST textual output. With GenomeComp, the variation between genomes can be easily highlighted, such as repeat regions, insertions, deletions and rearrangements of genomic segments. This software provides a new visualizing tool for microbe comparative genomics.

Computational Biology↗

PubMed2003

Genome-based analysis of virulence genes in a non-biofilm-forming Staphylococcus epidermidis strain (ATCC 12228).

Staphylococcus epidermidis strains are diverse in their pathogenicity; some are invasive and cause serious nosocomial infections, whereas others are non-pathogenic commensal organisms. To analyse the implications of different virulence factors in Staphylococcus epidermidis infections, the complete genome of Staphylococcus epidermidis strain ATCC 12228, a non-biofilm forming, non-infection associated strain used for detection of residual antibiotics in food products, was sequenced. This strain showed low virulence by mouse and rat experimental infections. The genome consists of a single 2499 279 bp chromosome and six plasmids. The chromosomal G + C content is 32.1% and 2419 protein coding sequences (CDS) are predicted, among which 230 are putative novel genes. Compared to the virulence factors in Staphylococcus aureus, aside from delta-haemolysin and beta-haemolysin, other toxin genes were not found. In contrast, the majority of adhesin genes are intact in ATCC 12228. Most strikingly, the ica operon coding for the enzymes synthesizing interbacterial cellular polysaccharide is missing in ATCC 12228 and rearrangements of adjacent genes are shown. No mec genes, IS256, IS257, were found in ATCC 12228. It is suggested that the absence of the ica operon is a genetic marker in commensal Staphylococcus epidermidis strains which are less likely to become invasive.

Adhesins, Bacterial↗

PubMed2003

Linkage analysis of 2q14-q23 and 5q32 with blood pressure quantitative traits in Chinese sib pairs.

OBJECTIVES: Several genome-wide scans recently accomplished in the ethnic Chinese revealed a number of candidate loci possibly contributing to essential hypertension, and some appeared to be replicable in 2q14-q23 and 5q32. The current study aimed to examine the linkage of qualitative and blood pressure quantitative traits in essential hypertension with these genomic regions in a large sample of Chinese hypertensive families. METHODS: We performed a genetic analysis on 148 randomly ascertained families containing 328 affected sib pairs, grouped into two geographically distinct subsets. Five highly informative microsatellite markers (D2S151, D2S142, D5S2090, D5S413 and D5S2013) were genotyped, and linkage analyses were performed with different genetic models. RESULTS: We did not observe consistent evidence for excess allele sharing identity by descent in either of the qualitative or the quantitative test. However, higher LOD scores were found at D5S2013 in North Group subset with Haseman-Elston and maximum likelihood (ML) variance (no dominance variance, NDV) algorithms. With the ML (NDV) algorithm, the LOD was 1.410 for diastolic blood pressure at this locus, although this was not statistically significant. CONCLUSIONS: These findings provide no evidence to support a significant linkage of 2q14-q23 or 5q32 with essential hypertension or blood pressure quantitative traits in the ethnic Chinese, and indicate the aetiologic diversity and complexity of hypertension. Previous reports implied 2q14-q23 or beta 2- adrenergic receptor gene potentially linked to essential hypertension in the ethnic Chinese. To replicate these results and perform quantitative linkage analysis, we genotyped members of 148 hypertensive families with five highly informative microsatellite markers. We observed no evidence of excess allele sharing identity by descent in sib pairs, revealing a lack of linkage between 2q14-q23 or 5q32 (chromosome region harboring the gene encoding beta 2 adrenergic receptor) and hypertension in our study sample.

Adult↗

PubMed2003

Variation near the region of the lipoprotein lipase gene and hypertension or blood pressure levels in Chinese.

Essential hypertension (EH) is a common late-onset disease that exhibits complex genetic heterogeneity. Human lipoprotein lipase (LPL) is a rate-limiting enzyme that regulates the catabolism of triglycerides (TG) and chylomicrons (CM). Since dyslipidemia is a common finding in hypertensive patients, the LPL gene is a logical candidate gene that could contribute to the development of hypertension. Using linkage analysis in 148 Chinese hypertensive families, we identified a region of linkage with systolic blood pressure (SBP) and diastolic blood pressure (DBP) that consisted of a 10.6-cM interval defined by markers D8S1145, D8S261, and D8S282 on chromosome 8, which maps between 31 to 41.6 cM from the 8p-telomere contained LPL gene, with statistically significant p values for the marker D8S261 (p = 0.0021 for SBP, and p = 0.0395 for DBP). In the qualitative-trait linkage analysis, evidence for linkage between the marker D8S1145 and EH was found (p = 0.0286). The transmission/disequilibrium test (TDT/S-TDT) also supported a significant linkage-disequilibrium of the allele 3 of D8S261 with EH (chi2 = 8.643, p < 0.01). Furthermore, the marker neurofilament light polypeptide (NEFL) (11 cM centromeric to the LPL gene) appeared to be in linkage with SBP and DBP (p = 0.0329 for SBP; p = 0.0319 for DBP). Additionally, two flanking markers for LPL, D8S511 (9.5 cM telomeric to the LPL gene) and D8S560 (3.2 cM centromeric to the LPL gene), also showed significant linkage with EH (p = 0.0036 for D8S511; p = 0.0115 for D8S560). Previous knowledge about the physiological involvement of LPL in blood pressure regulation and the present findings of variation near the LPL gene support the proposition that a region near the LPL gene or the LPL gene itself might contribute to the individual blood pressure variation in Chinese.

Adult↗

PubMed2003

Synergistic effect of cell differential agent-II and arsenic trioxide on induction of cell cycle arrest and apoptosis in hepatoma cells.

AIM: To illustrate the possible role of cell differential agent-II (CDA-II) in the apoptosis of hepatoma cells induced by arsenic trioxide (As(2)O(3)). METHODS: Hepatoma cell lines BEL-7402 and HepG2 were treated with As(2)O(3) together with CDA-II. Cell surviving fraction was determined by MTT assay; morphological changes were observed by immunofluorescence staining of Hoechst 33,258; and cell cycle and the apoptosis index were determined by flow cytometry (FCM). RESULTS: Cytotoxicity of CDA-II was low. Nevertheless, CDA-II could strongly potentiate arsenic trioxide-induced apoptosis. At 1.0 g/L CDA-II, IC(50) of As(2)O(3) in hepatoma cell lines was reduced from 5.0 micromol/L to 1.0 micromol/L (P<0.01). The potentiation of apoptosis was dependent on the dosage of CDA-II. FCM indicated that in hepatoma, cell growth was inhibited by CDA-II at lower concentrations (<2.0 g/L) primarily by arresting at S and G(2) phase, and at higher concentrations (>2.0 g/L) apoptotic cell and cell cycle arresting at G(1) phase increased proportionally. The combination of two drugs led to much higher apoptotic rates, as compared with the either drug used alone. CONCLUSION: CDA-II can strongly potentiate As(2)O(3)-induced apoptosis in hepatoma cells, and two drugs can produce a significant synergic effect.

Apoptosis↗

PubMed2003

Protein kinase C/zeta (PRKCZ) gene is associated with type 2 diabetes in Han population of North China and analysis of its haplotypes.

AIM: To identify the susceptible gene (s) for type 2 diabetes in the previously mapped region, 1p36.33-p36.23, in Han population of North China using single nucleotide polymorphisms (SNPs) and to analyze the haplotypes of the gene (s) related to type 2 diabetes. METHODS: Twenty three SNPs located in 10 candidate genes in the mapped region were chosen from public SNP domains with bioinformatic methods, and the single base extension (SBE) method was used to genotype the loci for 192 sporadic type 2 diabetes patients and 172 normal individuals, all with Han ethical origin, to perform this case-control study. The haplotypes with significant difference in the gene (s) were further analyzed. RESULTS: Among the 23 SNPs, 8 were found to be common in Chinese Han population. Allele frequency of one SNP, rs436045 in the protein kinase C/zetagene (PRKCZ) was statistically different between the case and control groups(P<0.05). Furthermore, haplotypes at five SNP sites of PRKCZ gene were identified. CONCLUSION: PRKCZ gene may be associated with type 2 diabetes in Han population in North China. The haplotypes at five SNP sites in this gene may be responsible for this association.

Asian People↗

PubMed2003

[Ototoxic study spiral ganglion neurons in the pig guinea with ethylene oxide remained in absorbable gelatin sponge].

OBJECTIVE: To measure ethylene oxide remained in absorbable gelatin sponge, and to observe change of ultrastructure in spiral ganglion neurons after deposited in otic vesicle of pig guinea with ethylene oxide sterilized absorbable gelatin sponge. METHOD: To use comparative colour technique measuring ethylene oxide remained in absorbable gelatin sponge, by means of transmission electron microscope to observe change of ultrastructure in spiral ganglion neurons after 3 months deposited in otic vesicle of pig guinea with ethylene oxide sterilized absorbable gelatin sponge. RESULT: The mean value of ethylene oxide remained in absorbable gelatin sponge were 438.32 mg, while nation standard are less 10 mg, FDA standard(1978) less 25 mg. ultrastructural appearance showed condensed matric electron dense of spiral ganglion mitochondria and dark crista of mitochondria, vacuolated cytoplasm. Ultrastructural observation also demonstrated dissolution or necrosis of ganglion cells, satellite cells, and vacuolated myelin. These changes were near Donson reported(1997) intracochlear perfusion with aminoglycosides. CONCLUSION: The mean value of ethylene oxide remained in absorbable gelatin sponge were 40 times nation standard. Toxic changes of ethylene oxide remained in absorbable gelatin sponge in spiral ganglion neurons were similar to intracochlear perfusion with aminoglycosides.

Animals↗

PubMed2003

[Clinical analysis of different periods of liver transplantation at an organ transplantation centre].

OBJECTIVE: To summarize our clinical experience in liver transplantation while considering the background in this field in China. METHODS: Ninety-five patients who had received liver transplantation from April 1993 to March 2002 were analyzed retrospectively. Three periods were defined objectively as period I (1993 - 1997), II (1999) and III (2000 - 2002). Operative techniques, recipients, original diseases, complications and survival rates were compared among the three periods. RESULTS: Malignant liver lesions were the main cause for liver transplantation in period I and II. The ratio of number of malignant disease to total recipients decreased gradually from period I to III (100%, 53% and 35%, respectively). The 1-year survival rate in patients with benign liver disease was 85% and the total operative mortality was 5% in period III. The incidence of hepatitis B virus reactivation or reinfection was 24% twelve months after liver transplantation. Vascular complication decreased but biliary complications did not and remained a major long-standing problem. No veno-venous bypass technique was used in period III, and its advantages were obvious when comparing with those with veno-venous bypass in period I and II. CONCLUSIONS: Strict selection of recipients, fine operative technique, familiarity with various complications and correct therapeutic methods, prophylaxis of recurrence of hepatitis B and hepatocellular carcinoma are necessary to improve long-term results of liver transplantation in China.

Adult↗