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Biomedical subjects

N Li

Publications and source records attributed to N Li.

At least 19 recordsLinked to original sources
PubMed2006

Human papillomavirus infection in Shenyang City, People's Republic of China: A population-based study.

To investigate the prevalence of, and risk factors for, cervical infection with human papillomavirus (HPV) in Shenyang City, People's Republic of China, we interviewed and obtained cervical cell samples from 685 women aged 15-59 years enumerated from local population lists. Human papillomavirus DNA was detected in cervical cell samples using a GP5+/6+-based PCR assay for 44 HPV types. Human papillomavirus prevalence was 16.8% overall and 13.6% among women without cervical abnormalities (16.6% and 12.4%, respectively, age-standardised to the world standard population), with no significant trends in HPV prevalence by age group. Of the 32 types identified, high-risk HPV types predominated in all age groups, HPV16 being the most common (3.4% of all women), followed by HPV52 (2.5%) and 58 (1.9%). Multiple-type infections accounted for 31.3% of all infected women. Not being married, reporting multiple sexual partners and husband's extramarital sexual relationships were all significantly associated with being HPV-positive. The disclosure of a relatively high HPV prevalence in Shenyang, in comparison with other worldwide populations, raises important questions concerning the prevention of cervical cancer in China, especially given the promising efficacy of prophylactic HPV vaccines.

Adolescent↗
PubMed2006

Sustained benefit in rheumatoid arthritis following one course of rituximab: improvements in physical function over 2 years.

OBJECTIVES: To evaluate the long-term impact on physical function of a single course of rituximab in rheumatoid factor, seropositive patients with active rheumatoid arthritis (RA) despite ongoing methotrexate treatment. METHODS: A randomized, controlled trial comparing rituximab alone [1,000 mg intravenously (iv) on days 1 and 15, n= 40], or in combination with cyclophosphamide (750 mg iv on days 3 and 7, n= 41) or oral methotrexate (> or =10 mg/week, n= 40) with placebo + methotrexate (> or =10 mg/week, n= 40), resulted in significant reductions in disease activity at weeks 24 and 48. Sustained improvements in physical function and standard effect sizes (SES) for changes in components of ACR and EULAR criteria were evaluated over 2 yrs. RESULTS: More patients receiving rituximab + methotrexate completed a 2-yr follow-up without further treatment than those receiving placebo + methotrexate (45% vs 15%, respectively), rituximab alone (10%) or rituximab + cyclophosphamide (22%). This reflected a higher percentage of patients receiving rituximab + methotrexate reporting improvements in Health Assessment Questionnaire Disability Index > or = minimum clinically important difference at 1 and 2 yrs (68% and 30%, respectively) compared with placebo + methotrexate (28% and 15%), rituximab monotherapy (43% and 10%) or rituximab + cyclophosphamide (39% and 12%). SES were high in all rituximab groups and revealed differing patterns of response over time. CONCLUSION: A single course of rituximab with continuing methotrexate in patients with active RA provided clinically meaningful improvements in physical function over 2 yrs, with lower discontinuation rates and larger SES for improvements in ACR and EULAR criteria components.

Adult↗
PubMed2006

Human papillomavirus infection in Shanxi Province, People's Republic of China: a population-based study.

To investigate the prevalence of, and risk factors for, cervical infection with human papillomavirus (HPV) in the rural province of Shanxi, People's Republic of China, which has relatively high cervical cancer mortality rates, we interviewed and obtained cervical cell samples from 662 women aged 15-59 years. A total of 24 different HPV types were identified using a GP5+/6+-based PCR assay able to detect 44 different HPV types. Human papillomavirus prevalence was 14.8% overall and 9.6% among women without cervical abnormalities (14.2 and 8.9%, respectively, age standardised to the world standard population). Multiple-type infections accounted for 30.6% of all infections. By far the most commonly found type was HPV16 (5.7% of all women and 38.8% of HPV-positive women), followed by HPV 58, 52, 33 and 18. Unlike most previous studies published, HPV prevalence was lower among women younger than 35 years (8.7%) than those older than 35 years (17.8%). High-risk HPV types predominated in all age groups. Although low-risk HPV types were rare in young women, they became more common with increasing age. 92.3% of women with cervical intraepithelial neoplasia grade 3 were infected with high-risk HPV types, but none with low-risk types only. No significant difference in HPV positivity was observed by educational level, sexual habits, reproductive history or use of contraceptive methods in this rural low-income Chinese population.

Adolescent↗
PubMed2006

Inhibition of ceramide-redox signaling pathway blocks glomerular injury in hyperhomocysteinemic rats.

Ceramide-activated NAD(P)H oxidase has been reported to participate in homocysteine (Hcys)-induced abnormal metabolism of the extracellular matrix (ECM) in rat glomerular mesangial cells. However, it remains unknown whether this ceramide-redox signaling pathway contributes to glomerular injury induced by hyperhomocysteinemia (hHcys) in vivo. The present study was designed to address this question, defining the role of ceramide and activated NAD(P)H oxidase in the development of hHcys-induced glomerular injury. Uninephrectomized Sprague-Dawley rats were fed a folate-free diet for 8 weeks to produce hHcys and the de novo ceramide synthesis inhibitor myriocin or the NAD(P)H oxidase inhibitor apocynin was administrated. Rats with folate-free diet significantly increased plasma Hcys levels, renal ceramide levels, and NAD(P)H oxidase activity accompanied by marked glomerular injury. Treatment of rats with myriocin significantly reduced ceramide levels and improved glomerular injury, as shown by decreased urinary albumin excretion and reduced glomerular damage index. ECM components changed towards to normal levels with decreased tissue inhibitor of metalloproteinase-1 and increased matrix metalloproteinase-1 activity. NAD(P)H oxidase activity and Rac GTPase activity were reduced by 69 and 66%, respectively. In rats treated with apocynin, similar beneficial effects in protecting glomeruli from hHcys-induced injury were observed. These results support the view that de novo ceramide production is involved in Hcys-induced NAD(P)H oxidase activity in the kidney of hHcys rats and indicate the important role of ceramide-mediated redox signaling in hHcys-induced glomerular injury in rats.

Acetophenones↗
PubMed2006

TA-p63-gamma regulates expression of DeltaN-p63 in a manner that is sensitive to p53.

Genetic analysis indicates that TP63 is required for establishment and preservation of self-renewing progenitors within the basal layer of several epithelial structures, however, the specific contributions of transactivating (TA-p63) and dominant-negative (DeltaN-p63) isoforms remain largely undefined. Recent studies have suggested a model in which TA-p63 plays an important role in the establishment of progenitor populations in which expression of DeltaN-p63 contributes to the preservation of self-renewing capacity. Our previous studies indicate that DeltaN-p63 is a transcriptional target of p53, however, the absence of overt epithelial deficiencies in p53-/- mice and reports of increased expression of DeltaN-p63 in p53-/- mice suggest p53-independent mechanisms also contribute to expression of DeltaN-p63. Here, we present data indicating that, prolonged loss of p53 leads to the activation of a p53-independent mechanism for transcriptional regulation of DeltaN-p63. This p53-independent mechanism is sensitive to ectopic p53 but not to a p53 mutant that lacks the transactivation domain. We further show that in cells in which p53 is expressed TA-p63-gamma protein is destabilized in a manner that is p53 dependent and sensitive to pharmacologic inhibition of the 26S proteosome. Consistent with this observation, we demonstrate that loss of p53 leads to the stabilization of TA-p63-gamma that is reversible by ectopic p53. Finally, we present evidence that disruption of TA-p63-gamma expression leads to decreased expression of DeltaN-p63 and that overexpression of TA-p63-gamma was sufficient to enhance the activity of the DeltaN-p63 promoter. Taken together, our studies indicate that TA-p63-gamma is capable of activating expression of DeltaN-p63 and that this mechanism may account for p53-independent expression of DeltaN-p63.

Breast↗
PubMed2006

Immunological advantage on small bowel graft induced by simultaneously transplanted liver in porcine auxiliary liver/small bowel transplantation.

BACKGROUND: We developed a new porcine model for auxiliary liver/small bowel transplantation (LSBT). The possible immunological advantage on small bowel graft induced by simultaneously transplanted liver in the large animal was assessed. METHODS: Thirty outbreed long-white pigs were randomized into two groups. Group A animals received LSBT without immunosuppressive treatment (n = 10). Group B animals had segmental small bowel allotransplantation without immunosuppressive treatment (n = 10). The postoperative survival time, initial acute rejection time, and pathological rejection scores were analyzed. RESULTS: There was no remarkable difference in survival time between groups A and B (10.33 days vs 12.89 days, P > .05), but the initial time of acute rejection in intestinal grafts in group A was obviously delayed when compared to group B (8.22 days vs 4.33 days, P < .05), and the rejection scores in group A were remarkably lower than those of group B (0 vs 0.44 on postoperative day (POD) 3, P < .05; 0.22 vs 1.78 on POD 5, P < .05; 1.11 vs 2.56 on POD 7, P < .05). CONCLUSIONS: An immunological advantage on intestinal graft can be induced by simultaneously transplanted liver in auxiliary LSBT. Compared to isolated segmental small bowel allotransplantation, the intestinal graft in LSBT has a delayed initial time of acute rejection and lower acute rejection scores. The liver graft may reduce the risk of intestinal rejection and thus protect the bowel graft.

Acute Disease↗
PubMed2006

A new sesquiterpene ester inhibiting no production from the fruits of Celastrus orbiculatus.

A new beta-dihydroagarofuran sesquiterpene ester, 1beta,2beta,6alpha, 13-tetraacetoxy-9alpha-cinnamoyloxy-beta-dihydroagarofuran (1), and the known compound 1beta,6alpha,13-triacetoxy-9alpha-benzoyloxy-beta-dihydroagarofuran (2), have been isolated from the fruits of Celastrus orbiculatus Thunb. Their structures have been elucidated on the basis of spectroscopic methods. Compound 1 shows moderate activity of inhibiting LPS-induced nitric oxide production in murine macrophage RAW264.7 cells, with an IC50 of 55.4 microM.

Animals↗
PubMed2006

Triterpenoids from the husks of Xanthoceras sorbifolia Bunge.

A new triterpenoid saponin, 3-O-[(3-O-alpha-l-arabinofuranosyl-2-O-beta-d-galactopyranosyl)-beta-d-glucuronopyranosyl]-21,22-di-O-angeloyl-R1-barrigenol (1), together with four known triterpenoids, have been isolated from the husks of Xanthoceras sorbifolia Bunge. Their structures were elucidated based on chemical and spectral analysis. Among them, 1 was found to have activity of inhibiting the proliferation of six human tumour cell lines (IC50 10-40 mug/ml).

Antineoplastic Agents, Phytogenic↗
PubMed2006

Flavonoids from Pyrrosia petiolosa (Christ) Ching.

A new kaempferol glycoside, kaempferol-3-O-beta-D-glucopyranoside-7-O-alpha-L-arabinofuranoside (1), was isolated from the EtOH extract of Pyrrosiapetiolosa together with six known flavonoids already reported from the same plant. Structural elucidation was performed by means of physico-chemical methods including MS, and 1D and 2D NMR spectroscopy.

China↗
PubMed2006

Human umbilical vein endothelial cells increase ex vivo expansion of human CD34(+) PBPC through IL-6 secretion.

BACKGROUND: Ex vivo expansion of hematopoietic stem cells (HSC) can help reduce cytopenia following transplantation, especially in NHL patients whose BM is deficient because of extensive chemotherapy. We have previously reported that human umbilical vein endothelial cells (HUVEC) can contribute to improved PBPC expansion when used in co-culture with CD34(+) cells. METHODS: We evaluated the roles of direct HUVEC CD34(+) contact and HUVEC-produced soluble factors. We cultured CD34(+) PBPC harvested from NHL patients in four different conditions: (1) liquid culture without HUVEC; (2) co-culture in contact with HUVEC; (3) co-culture with HUVEC but without direct contact; (4) liquid culture with HUVEC-conditioned medium (CM). Thrombopoietin (Tpo), Flk2Flt3 ligand (FL) and c-kit ligand (KL) with or without rhIL-6 were added to these four culture conditions. RESULTS AND DISCUSSION: Our results showed that HUVEC co-culture or addition of HUVEC-CM to Tpo, FL and KL (TFK) improved CD34(+) PBPC expansion compared with liquid culture, as determined by total viable nucleated cells (TNC), colony-forming cell assay (CFC) and week-6 cobblestone area-forming cells (Wk-6 CAFC) expansions. Non-contact culture led to similar PBPC expansion as contact co-culture; moreover, HUVEC-CM improved PBPC expansion. However, when rhIL-6 was added to HUVEC-CM with TFK, no significant difference was observed. Finally, high quantities of IL-6 were detected in HUVEC-CM and addition of anti-IL-6 Ab inhibited the positive effect of HUVEC on PBPC expansion. Our results thus suggest that HUVEC may improve PBPC expansion, at least through IL-6 secretion.

Antigens, CD34↗
PubMed2006

Association of polymorphisms in the promoter region of chicken prolactin with egg production.

Chicken prolactin (PRL) is a physiological candidate gene for egg production. The objective of the current research was to investigate the association of polymorphisms in the chicken PRL promoter region with egg production. Genotyping of 177 individuals from White Leghorn, Yangshan, Taihe Silkies, White Rock, and Nongdahe breeds for 6 single nucleotide polymorphisms (C-2402T, C-2161G, T-2101G, C-2062G, T-2054A, and G-2040A) and 1 24-bp indel (insertion-deletion) at the site of -358 of the chicken PRL gene revealed large breed differences in allelic frequencies for all but the T-2101G and T-2054A polymorphisms. An F2 population produced from Nongdahe x Taihe Silkies chickens consisted of 374 hens, which were recorded for egg production traits and genotyped for the above 7 polymorphisms. Marker-trait association analysis indicated that the 24-bp indel was associated with egg production (P < 0.01) and that H3 (C C T C T G) was the most advantageous haplotype for egg production.

Alleles↗
PubMed2006

Tissue expression and association with fatness traits of liver fatty acid-binding protein gene in chicken.

Fatty acid-binding proteins belong to a superfamily of lipid-binding proteins that exhibit a high affinity for long-chain fatty acids and appear to function in metabolism and intracellular transportation of lipids. The current study was designed to investigate expression characterization and association with growth and composition traits of the liver fatty acid-binding protein (L-FABP) gene in the chicken. Northern blot analysis indicated that the gene, similar to the mammal L-FABP gene, was expressed only in liver and intestinal tissues. The mRNA levels of the chicken L-FABP gene in liver and intestine had significant differences between the broilers and Baier layers. The China Agricultural University F(2) population was used in the present study. Body weight and body composition traits were measured in the populations. Primers for the coding region and 5' upstream region of the L-FABP gene were designed according to chicken genomic and cDNA sequence. Polymorphisms were detected by DNA sequencing, and the PCR single-strand conformation polymorphisms method was developed to genotype the F(2) population. The results indicated that the L-FABP gene polymorphisms were associated with abdominal fat weight and percentage of abdominal fat, and the L-FABP gene could be a candidate locus or linked to a major gene(s) that affects fatness traits in the chicken. The results of the current study provided basic molecular information for studying the role of the L-FABP gene in the regulation of lipid metabolism in avian species.

Abdominal Fat↗
PubMed2006

A potential molecular marker for selection against abdominal fatness in chickens.

The peroxisome proliferators-activated receptor-gamma coactivator-1alpha (PGC-1alpha) was investigated as a candidate gene for growth and fatness traits in chicken because of its prominent role in muscle fiber specialization and adipogenesis. A single nucleotide polymorphism (SNP) from G to A at position 646 of the open reading frame of chicken PGC-1alpha gene causing an Asp216Asn amino acid substitution was identified. The frequencies of alleles and genotypes were significantly different among 6 chicken breeds (P < 0.01). The White Plymouth Rock had the highest frequency (0.67) of allele G, whereas the White Leghorn had the lowest (0.18). The associations of the SNP with the growth and fatness traits were evaluated in 332 F(2) birds from an experimental cross of White Plymouth Rock x Silkies. No association was found between the SNP and growth-related traits. However, abdominal fat weight at 12 wk of age for birds with genotype GG was 34.26 and 28.71% higher than those with genotypes AA and AG, respectively (P < 0.01), indicating that the Asp216Asn polymorphism of the PGC-1alpha gene could be used as a novel potential molecular marker for selection against abdominal fatness without interfering in regular breeding for growth rate of chickens.

Abdominal Fat↗
PubMed2006

Identification of single nucleotide polymorphism of adipocyte fatty acid-binding protein gene and its association with fatness traits in the chicken.

Fatty acid-binding proteins (FABP) belong to a superfamily of lipid binding proteins that exhibit a high affinity for long chain fatty acids and appear to function in metabolism and intracellular transportation of lipids. The current study was designed to investigate the effects of the adipocyte (A)-FABP gene on chicken growth and body composition traits. Two F2 resource populations were used in the current study. Body weight and body composition traits were measured in the populations. Primers for the coding region of the A-FABP gene were designed from chicken genomic and cDNA sequences. Polymorphism between parental lines was detected by DNA sequencing, and the PCR-RFLP method was developed to genotype the F2 populations. The results indicated that an A-FABP gene polymorphism was associated with abdominal fat weight and percentage of abdominal fat, and the A-FABP gene could be a candidate locus or linked to a major gene(s) that affects abdominal fat content in the chicken.

Animals↗
PubMed2006

A genome scan for quantitative trait loci associated with body weight at different developmental stages in chickens.

A genome scan to detect quantitative trait loci (QTL) affecting body weight in chickens was conducted on 238 F(2) chickens from a reciprocal cross of Silky Fowl and White Plymouth Rock using 125 microsatellite markers covering 23 autosomes and the Z chromosome. Two types of QTL were considered: static QTL (SQ) and developmental QTL (DQ). Static QTL affected the body weight from hatch to time t, and DQ affected the body weight from time t-1 to time t. Six SQ and nine DQ were detected. Of these QTL, four reached a genome-wide significance of 5% or better, with SQ1 and DQ1 being the most significant QTL. Static QTL1 was on chromosome 1 between GCT0006 and MCW0106 and explained 4.05-9.80% of the phenotypic variation in body weights from 3 to 12 weeks of age. At 9, 10 and 11 weeks, the genome-wide significance thresholds of SQ1 were <1%. Developmental QTL1 was located on chromosome 1 between MCW0168 and GCT0006, and explained 2.75% of the phenotypic variation for body weight from week 7 to 8 with a genome-wide significance level <1%. The results suggest that body weight from hatch to time t and developmental growth from time t-1 to time t may involve two different sets of genes or gene actions.

Animals↗