Biomedical subjects

Xia Luo

Publications and source records attributed to Xia Luo.

13 recordsLinked to original sources

PubMed2026

Description and genomic characterization of Aquipuribacter aurantiacus sp. nov., isolated from saline lake sediment.

Strains MA13-6T and MA13-13, two Gram-stain-positive, aerobic, short rod-shaped actinobacteria, were isolated from a saline lake in Ngari Prefecture, Xizang Autonomous Region, China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that these two strains belonged to the genus Aquipuribacter, with the closest relationship to Aquipuribacter hungaricus IV-75T (98.47% sequence similarity) and Aquipuribacter nitratireducens AMV4T (97.36% sequence similarity). Phylogenetic analysis based on genomes further confirmed their classification as a distinct cluster within the genus Aquipuribacter. The average nucleotide identity and digtal DNA-DNA hybridization values between these two strains and their closest relative Aquipuribacter hungaricus IV-75T, were 82.44-82.49% and 23.00%, respectively, clearly indicating that strains MA13-6T and MA13-13 represent a novel species. The 16S rRNA gene sequence similarity, average nucleotide identity and digital DNA-DNA hybridization values between these two strains were 99.79%, 99.97% and 99.40%, respectively, unequivocally confirming their classification within the same species. However, DNA fingerprinting analysis distinguished them as non-clonal variants. The polar lipids comprised phosphatidylglycerol, two unidentified phospholipids, two unidentified glycolipids, and two unidentified lipids. The predominant respiratory quinone was MK-10 (H4). The major fatty acids were anteiso-C15:0, C18:1ω9c, isoC16:0 and anteiso-C17:0. The cell wall diagnostic diamino acid was meso-diaminopimelic acid. Based on phylogenetic analyses combined with phenotypic and chemotaxonomic characterization, strains MA13-6T and MA13-13 represent a novel species of the genus Aquipuribacter, for which the name Aquipuribacter aurantiacus sp. nov. is proposed. The type strain is MA13-6T (=MCCC 1K10045T = KCTC 59572T).

Phylogeny↗

PubMed2026

Tracing and characterization of a family outbreak of subtype B2 botulism linked to homemade pickled eggs in Jinan, China.

Foodborne botulism (FB) results from the ingestion of food contaminated with botulinum neurotoxin. Here, we report a family outbreak of foodborne botulism caused by Clostridium botulinum subtype B2 linked to homemade pickled eggs. On August 13, 2024, the Jinan Center for Disease Control and Prevention and the Shanghe County Center for Disease Control and Prevention collaborated to investigate an outbreak of botulism poisoning related to a family gathering in Shanghe County, Jinan City. A total of 4 people attended the family gathering, three of whom developed clinical symptoms of botulism after consuming pickled eggs. The diagnosis of botulism was suspected through collaborative efforts by the Qilu Medical Prevention and Control Innovation Integration Mechanism and multidisciplinary consultations across multiple hospitals. We detected the bont gene using real-time quantitative PCR (qPCR) in Jinan CDC, determined the toxin serotype by mouse bioassay (MBA) in China CDC and performed whole-genome sequencing of bacterial strains isolated from patient feces, the homemade pickled eggs and soil in both laboratories. It was shown that the toxin type and bont gene were subtype B2, belonging to the ha gene cluster. The Clostridium botulinum strains isolated from two patients were closely related to the strains from the homemade pickled eggs through whole-genome single nucleotide polymorphism analysis. We also found that Clostridium botulinum strains from soil clustered into one branch with those from patients and food, suggesting that the source of Clostridium botulinum contamination may be from soil, although the contamination pathway was not clear. Importantly, our findings provided a basis for clinical antitoxin treatment, in which one patient successfully gave birth after recovery. These results underscore the importance of strengthening public education about the health risks associated with consuming homemade fermented or preserved foods and enhancing the laboratory detection capabilities.

Botulism↗

PubMed2006

Streptococcus suis sequence type 7 outbreak, Sichuan, China.

An outbreak of Streptococcus suis serotype 2 emerged in the summer of 2005 in Sichuan Province, and sporadic infections occurred in 4 additional provinces of China. In total, 99 S. suis strains were isolated and analyzed in this study: 88 isolates from human patients and 11 from diseased pigs. We defined 98 of 99 isolates as pulse type I by using pulsed-field gel electrophoresis analysis of SmaI-digested chromosomal DNA. Furthermore, multilocus sequence typing classified 97 of 98 members of the pulse type I in the same sequence type (ST), ST-7. Isolates of ST-7 were more toxic to peripheral blood mononuclear cells than ST-1 strains. S. suis ST-7, the causative agent, was a single-locus variant of ST-1 with increased virulence. These findings strongly suggest that ST-7 is an emerging, highly virulent S. suis clone that caused the largest S. suis outbreak ever described.

Animals↗

PubMed2004

TL1A synergizes with IL-12 and IL-18 to enhance IFN-gamma production in human T cells and NK cells.

TL1A, a recently described TNF-like cytokine that interacts with DR3, costimulates T cells and augments anti-CD3 plus anti-CD28 IFN-gamma production. In the current study we show that TL1A or an agonistic anti-DR3 mAb synergize with IL-12/IL-18 to augment IFN-gamma production in human peripheral blood T cells and NK cells. TL1A also enhanced IFN-gamma production by IL-12/IL-18 stimulated CD56(+) T cells. When expressed as fold change, the synergistic effect of TL1A on cytokine-induced IFN-gamma production was more pronounced on CD4(+) and CD8(+) T cells than on CD56(+) T cells or NK cells. Intracellular cytokine staining showed that TL1A significantly enhanced both the percentage and the mean fluorescence intensity of IFN-gamma-producing T cells in response to IL-12/IL-18. The combination of IL-12 and IL-18 markedly up-regulated DR3 expression in NK cells, whereas it had minimal effect in T cells. Our data suggest that TL1A/DR3 pathway plays an important role in the augmentation of cytokine-induced IFN-gamma production in T cells and that DR3 expression is differentially regulated by IL-12/IL-18 in T cells and NK cells.

CD56 Antigen↗

PubMed2004

Potential role for TL1A, the new TNF-family member and potent costimulator of IFN-gamma, in mucosal inflammation.

TNF can potentiate IFN-gamma production by activated T cells and other members of the TNF-superfamily play key roles in this effect. A newly discovered TNF-superfamily cytokine (TL1A) could also be involved in initiating or promoting the Th1 response by enhancing IFN-gamma production. The purpose of this study was to assess the role of recombinant TL1A on IFN-gamma production by cultured PBMC and lamina propria LPMC and to determine whether TL1A expression is altered in inflammatory bowel disease. IFN-gamma, but not IL-4 or IL-10 production by PBMC and LPL, was dose-dependently augmented by TL1A (or by activation of its receptor, death domain receptor 3 [DR3], with specific mAb) independently of, but in synergy with, IL-12 and IL-18. T cell activating stimuli induced expression of TL1A on the cell membrane (mb-TL1A) in a fraction of peripheral blood (PB) T cells. In the intestinal mucosa, a fraction of lamina propria (LP) T cells, especially CD4+ cells, constitutively expressed mb-TL1A, and the fraction increased in mucosal inflammation. A higher fraction of cells also express the TL1A receptor DR3 in ulcerative colitis and Crohn's disease. TL1A transcript was several times more abundant in RNA from mucosal biopsies taken from inflamed Crohn's disease lesions than in those taken from uninvolved areas. Expression of TL1A and its receptor DR3 by lamina propria mononuclear cells (LPMC) could have significant influence on the severity of mucosal inflammation.

Biopsy↗

PubMed2004

[The influence of Bazhen decoction on hematopoietic modulator in anaemic mice].

This study was designed to evaluate the effect of Bazhen decoction on bone marrow depression induced by cyclophosphamide (CY) in mice. An experimental model of mouse bone marrow injury was established through cyclophosphamide induced and the following phenomena were observed. The techniques of culture of hematopoietic progenitor cell and hematopoietic growth factor assay were used. Bazhen decoction could obviously promote the proliferation of bone marrow cells of anaemic mice. The culture media of spleen cell, macrophage, lung and skeletal muscle treated with Bazhen decoction had much stronger stimulating effects on hematopoietic cells. The bone marrow cells of the anaemic mice could yield TNF through Bazhen decoction treatment. It was suggested that Bazhen decoction is clinically a hopeful drug used to cure bone marrow depression and attenuate the side effects of CY.

Anemia↗

PubMed2004

[Effect of Spatholobus suberectus on the bone marrow cells and related cytokines of mice].

OBJECTIVE: To study the effect of Spatholobus suberectus on proliferation and the hematonic mechanism. METHOD: The techniques of culture of hematopoietic cell and hematopoietic growth factor (HGF) assay were used. RESULT: Spatholobus suberectus could obviously promote the proliferation of bone marrow cells in healthy and anaemic mice. The culture media of spleen cell, macrophage, lung and skeletal muscle treated with S. suberectus had much stronger stimulating effects on hematopoietic cells. CONCLUSION: S. suberectus may enhance hematopoiesis by directly or indirectly stimulating stroma cell in hematopoietic inductive microenvironment and muscle tissue to secrete some HGF (Epo, GM-CSF, IL, and MK-CSF). This is one of the biological mechanisms for hematonic effect of S. suberectus.

Anemia↗

PubMed2003

TL1A-induced NF-kappaB activation and c-IAP2 production prevent DR3-mediated apoptosis in TF-1 cells.

We recently identified TL1A, an endothelium-derived T cell costimulator and a ligand for tumor necrosis factor receptor superfamily members DR3 and decoy receptor 3. To elucidate the signaling events triggered by TL1A-DR3 interaction and to understand the molecular mechanisms regulating DR3-mediated apoptosis, we have studied the effect of TL1A and an agonistic DR3 monoclonal antibody in human erythroleukemic TF-1 cells, which express DR3 endogenously. TL1A induced the formation of a DR3 signaling complex containing TRADD, TRAF2, and RIP and activated the NF-kappaB and the ERK, JNK, and p38 mitogen-activated protein kinase pathways. However, TL1A or an agonistic DR3 monoclonal antibody did not induce apoptosis in these cells nor were there detectable levels of FADD or procaspase-8 seen in the signaling complex. Interestingly, DR3-mediated apoptosis was induced in TF-1 cells in the presence of a NF-kappaB pathway-specific inhibitor but not in the presence of mitogen-activated protein kinase inhibitors, either alone or in combination, suggesting that DR3-induced NF-kappaB activation was responsible for resistance to apoptosis in these cells. Consistent with this, we found that TL1A significantly increased the production of c-IAP2, a known NF-kappaB-dependent anti-apoptotic protein, and that the NF-kappaB inhibitor or cycloheximide prevented its synthesis. Furthermore, inhibition of c-IAP2 production by RNA interference significantly sensitized TF-1 cells to TL1A-induced apoptosis. Our study identifies a molecular mechanism by which TL1A and DR3 regulate cell fate in TF-1 cells.

Antibodies, Monoclonal↗

PubMed2003

[Effects of long-term installation of intrauterine devices on intrauterine microenvironment].

OBJECTIVES: To study the effect of long-term installation of intrauterine devices (IUD) on the intrauterine microenvironment. METHODS: Eighty-nine healthy 26 - 50-year-old women undergoing physical examination or having their IUD removed were recruited. Among them 62 had used IUDs, including 32 inert IUD (I-IUD) and 30 copper releasing IUD (T-IUD), for 5 - 20 years, and 27 women without installation of IUD were used as controls. In the 3rd to 13th day of menstrual cycle, 3 ml of irrigation of intrauterine cavity were collected to examine the concentrations of tumor necrosis factor-alpha (TNF-alpha), interleukin 2 (IL-2) and secretary IgA (SIgA) by radioimmunoassay (RIA). Hysteroscopy was used to obtain 3 pieces of endometrium at the place where the IUD was attached for each subject. Three pieces of endometrium were curretted from each control during the proliferative stage. Thirty specimens of endometrium, including 10 cases with I-IUD, 10 cases with T-IUD, and 10 control cases were used to examine the distribution of T cell subset by immunohistochemistry. Fifteen specimens of endometrium, including 6 cases with I-IUD, 6 cases with T-IUD, and 3 control cases, were used to examine the endometrial ultrastructure by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Twenty-five specimens of endometrium, including 10 cases with I-IUD, 10 cases with T-IUD, and 5 control cases, were used to detect the expression and mutation of P16, P53 and K-ras by PCR-SSCP technique. RESULTS: There was no significant difference in TNF-alpha level in the irrigation among the three groups (P > 0.05). IL-2 and SIgA levels (0.39 +/- 0.18) microg/L and (2000 +/- 1224) microg/L respectively) in the T-IUD group were significantly lower than those in the control group (0.96 +/- 0.15) microg/L and (3377 +/- 1906) microg/L respectively, both (P < 0.05). There was a significant difference in the population of T lymphocytes (CD(8)(+) and CD(4)(+) lymphocytes) between the T-IUD group and control group (P < 0.05). SEM and TEM showed no necrosis and atypia in the endometrial cells of I-IUD group and T-IUD group. There was no positive expression of gene p16, p53 and K-ras in the endometrium of the three groups. CONCLUSION: It is safe and effective using I-IUD or T-IUD for a long time, however, T-IUD has some effects on intrauterine local immune function.

Adult↗

PubMed2003

[Study on the association between maternal-infantile vertical transmission of hepatitis B virus and human leukocyte antigen DR gene domain].

OBJECTIVE: To study on the association between maternal-infantile vertical transmission of hepatitis B virus and human leukocyte antigen (HLA)-DR gene domain. METHODS: HLA-DR3, HLA-DR4, HLA-DR13, HLA-DR15 were detected by the technique of polymerase chain reaction-sequence specific primers (PCR-SSP) in maternal and neonatal blood of study group (78 cases) and control group (40 cases). RESULTS: (1) In the pregnant women of study group, the gene frequency of HLA-DR3 was significantly higher than that in control group (P < 0.05), but the frequency of HLA-DR13 was significantly lower than those in control group (P < 0.05), while the frequencies of HLA-DR4 and HLA-DR15 had no significant difference between the two groups (P > 0.05). (2) The pregnant women with high replication condition of HBV had significantly higher frequency of HLA-DR3 than those with low replication of HBV (P < 0.05). There was no significant difference of other phenotype between the two conditions. (3) The frequency of HLA-DR3 of pregnant women in intrauterine infection group was significantly higher than that of intrauterine non-infection group (P < 0.05). There had no significant difference of the frequencies of HLA-DR4, HLA-DR13, HLA-DR15 between the two groups (P > 0.05). The gene frequencies of HLA-DR3, HLA-DR4, HLA-DR13, HLA-DR15 were found no significant difference between the neonates of the study group and the control group (P > 0.05). Although the gene frequency of HLA-DR3 (30.0%) in neonates of intrauterine infection group was higher than that of intrauterine non-infection group (7.4%), but no statistical difference was found between the two group (P > 0.05). CONCLUSIONS: HLA-DR3 is positively correlated with chronic HBV carrying and high replication conditions of pregnant women. HLA-DR13 correlated negatively with chronic HBV carrying of the pregnant women. HLA-DR3 carriers of pregnant women and their fetuses have a susceptibility of HBV infection.

Adult↗

PubMed2003

[Molecular mechanism of wendan tang in prevention of lipid metabolism disorder in adult rats].

OBJECTIVE: To elucidate the molecular mechanism of Wendan Tang in prevention of lipid metabolism disorder in adult rats. METHOD: On the basis of hyperlipidemia rat models, triglycerides (TG), total cholesterol (TC) in serum, activities of lipase (LA), lipoprotein lipase (LPL), hepatic lipase (HL) in liver, parts of hemogram and hepatic LDLR mRNA levels were investigated 21 days after the feeding of atherogenic diet. RESULT: Wendan Tang significantly reduced the serum TG, TC and increased the activity of LPL and LA, but caused no chang in HL. The result of RT-PCR test showed that high fat and high cholesterol feeding could significantly induce the reduction of LDLR mRNA levels, while Wendan Tang could increase hepatic LDLR density. CONCLUSION: Wendan Tang can prevent disorder of lipid metabolism by regulating TC, TG, LDL-c through upregaulation of LDLR transcription level and improving antioxidant ability.

Animals↗

PubMed2002

TL1A is a TNF-like ligand for DR3 and TR6/DcR3 and functions as a T cell costimulator.

DR3 is a death domain-containing receptor that is upregulated during T cell activation and whose overexpression induces apoptosis and NF-kappaB activation in cell lines. Here we show that an endothelial cell-derived TNF-like factor, TL1A, is a ligand for DR3 and decoy receptor TR6/DcR3 and that its expression is inducible by TNF and IL-1alpha. TL1A induces NF-kappaB activation and apoptosis in DR3-expressing cell lines, while TR6-Fc protein antagonizes these signaling events. Interestingly, in T cells, TL1A acts as a costimulator that increases IL-2 responsiveness and secretion of proinflammatory cytokines both in vitro and in vivo. Our data suggest that interaction of TL1A with DR3 promotes T cell expansion during an immune response, whereas TR6 has an opposing effect.

Amino Acid Sequence↗

PubMed2002

[Study on the effects of various dosage of dexamethasone in accelerating fetal lung maturation and the accompanied side effects in rats].

OBJECTIVE: To compare the effect of various dosage of dexamethasone (Dex) in accelerating fetal lung maturation and the accompanied side effects. METHOD: Sixty time-bred Wistar rats were randomly assigned to one of the four groups (15 rats each group). They were given normal saline 0.8 ml (group A); Dex 0.2 mg (group B); Dex 0.4 mg (group C); Dex 0.8 mg (group D) IH, separated for 4 times on gestational day 15, 16. ten rats in each group were killed and hysterectomy were made immediately on day 17. The neonate breathing scale and their lung were observed and scored; the amniotic lamellar bodies (LB) were counted to assess the preterm fetal lung maturation. The remaining 5 rats in each group delivered naturally. The mother rats' condition in perinatal period, the birth weight of their neonates, and the structure of the livers and adrenal glands of the neonates were recorded to assess the side effects of the drug. RESULTS: The scores of neonatal breathing scale in group A to D were: 1.4 +/- 0.5, 3.6 +/- 0.7, 4.2 +/- 0.5, 4.5 +/- 0.5; their lung histologic maturation degree: 1.4 +/- 0.6, 3.9 +/- 0.9, 4.2 +/- 0.7, 4.4 +/- 0.6; and the account of their amniotic LB were: (8.6 +/- 3.0), (30.2 +/- 4.2), (33.0 +/- 3.4), (35.8 +/- 2.7) x 10(9)/ml respectively. All the indexes in the three Dex groups were higher than group A, and there were no statistical difference among in the three Dex groups except the neonatal breathing scale scores, which were higher in the high dose group D than the low dose group B. When high dose Dex was used, there was a reductive tendency in mother rats weight and its ability to resist infectious disease; meanwhile, the birth weight of their neonates reduced, the number of stillbirth and neonate liver necrosis increased. CONCLUSION: By the preterm gravid rat model, low dosage of antenatal dexamethasone administration accelerate fetal lung maturation to the extent equally to the middle even high doses of the drug. When high dosage of Dex was administered, the increasing side effects on the mother rats and their fetuses were accompanied.

Animals↗