Biomedical subjects

Bin Li

Publications and source records attributed to Bin Li.

At least 145 records · Page 8Linked to original sources

PubMed2005

Effects of Atorvastatin on Th polarization in patients with acute myocardial infarction.

BACKGROUND: The development of heart failure after acute myocardial infarction (AMI) has been shown to be associated with inflammation, which is positively and negatively regulated by T helper (Th) 1 and Th2 lymphocytes, respectively. Several studies have indicated that statins can improve heart function after AMI. AIMS: To study the effects of atorvastatin on Th polarization in patients with AMI. METHODS: Peripheral blood mononuclear cells were collected from 20 patients with AMI treated with oral atorvastatin (10 mg/d, group AMI-A) and 18 patients with AMI (group AMI-C) who did not receive treatment with statins. Cytokine-producing Th lymphocytes were quantified by 3-color flow cytometry. After in vitro culturing in the presence or absence of atorvastatin (0, 0.3, 1 and 3 micromol/L) for 6 days, cytokine-producing Th lymphocytes were quantified again in AMI-C group. RESULTS: The ratio of IFN-gamma-producing T cells was significantly higher in AMI-C group (17.8% +/- 6.4%) than in the AMI patients treated with oral atorvastatin (AMI-A, 13.1% +/- 4.6%). In vitro culturing with atorvastatin significantly reduced Th1 development in the AMI-C group. There was no significant difference on the frequencies of interleukin (IL)-4-producing T cells between each group. CONCLUSIONS: Atorvastatin can reduce Th1 development but has no effect on Th2 cell-functions in AMI patients. Our findings suggest that atorvastatin can regulate the polarization of Th1/Th2, this may be one of the mechanisms through which atorvastatin improves heart function after AMI.

Atorvastatin↗

PubMed2005

An effective and simple expansion system for megakaryocyte progenitor cells using a combination of heparin with thrombopoietin and interleukin-11.

Transfusion of ex vivo expanded megakaryocyte (MK) progenitor cells has been suggested to shorten the time of platelet recovery in the thrombocytopenia induced by radiotherapy or chemotherapy. Here, we report an effective and simple expansion system of MK progenitor cells from cord blood (CB) CD34(+) cells using a combination of thrombopoietin (TPO), interleukin (IL)-11, and heparin. When the CB CD34(+) cells were cultured in a liquid expansion system in the presence of TPO + recombination human (rh)IL-11 + heparin for 7 days, the number of CB CD34(+)/CD41a(+) cells was significantly increased compared to control groups (p < 0.05). When the suspension cells collected from 7-day liquid culture were replated in semisolid cultures, increased large MK colonies were observed in the culture with combination of TPO + IL-11 + heparin compared to those of control groups. In vivo, transfusion of CD34(+) cells expanded with TPO + IL-11 + heparin into irradiated nonobese diabetic/severe combined immunodeficient mice significantly accelerated platelet recovery. These data indicate that heparin as effective cofactor for TPO and IL-11 promotes expansion of MK progenitor cells from CB CD34(+) cells. This expansion system is simple and effective and could be used for the treatment of thrombocytopenia after radiotherapy or chemotherapy.

Animals↗

PubMed2005

LZ complexity distance of DNA sequences and its application in phylogenetic tree reconstruction.

DNA sequences can be treated as finite-length symbol strings over a four-letter alphabet (A, C, T, G). As a universal and computable complexity measure, LZ complexity is valid to describe the complexity of DNA sequences. In this study, a concept of conditional LZ complexity between two sequences is proposed according to the principle of LZ complexity measure. An LZ complexity distance metric between two nonnull sequences is defined by utilizing conditional LZ complexity. Based on LZ complexity distance, a phylogenetic tree of 26 species of placental mammals (Eutheria) with three outgroup species was reconstructed from their complete mitochondrial genomes. On the debate that which two of the three main groups of placental mammals, namely Primates, Ferungulates, and Rodents, are more closely related, the phylogenetic tree reconstructed based on LZ complexity distance supports the suggestion that Primates and Ferungulates are more closely related.

Animals↗

PubMed2005

Studies in macaques on cross-clade T cell responses elicited by a DNA/MVA AIDS vaccine, better conservation of CD8 than CD4 T cell responses.

One of the unknowns faced by an HIV/AIDS vaccine is the ability of a single clade vaccine to protect against the multiple genetic subtypes and recombinant forms of HIV-1 present in the current pandemic. Here, we use a macaque model to investigate the ability of our clade B vaccine that consists of DNA priming and modified vaccinia Ankara (MVA) virus boosting to elicit T cell responses that recognize an A/G recombinant of HIV-1. To test for cross-reactive T cells, intracellular cytokine staining was conducted using five pools of Gag and six pools of Env peptides representing B or A/G sequences. Studies using the peptide pools revealed essentially complete conservation of the CD8 response but only approximately 50% conservation of the CD4 response. Thus, the ability of an HIV vaccine for one clade to protect against other clades may be more limited by the ability to provide CD4 T cell help than the ability to elicit CD8 effector functions.

AIDS Vaccines↗

PubMed2005

Calcium supplementation and bone mineral density in females from childhood to young adulthood: a randomized controlled trial.

BACKGROUND: Short-term studies established that calcium influences bone accretion during growth. Whether long-term supplementation influences bone accretion in young adults is not known. OBJECTIVE: This study evaluated the long-term effects of calcium supplementation on bone accretion among females from childhood to young adulthood. DESIGN: A 4-y randomized clinical trial recruited 354 females in pubertal stage 2 and optionally was extended for an additional 3 y. The mean dietary calcium intake of the participants over 7 y was approximately 830 mg/d; calcium-supplemented persons received an additional approximately 670 mg/d. Primary outcome variables were distal and proximal radius bone mineral density (BMD), total-body BMD (TBBMD), and metacarpal cortical indexes. RESULTS: Multivariate analyses of the primary outcomes indicated that calcium-supplementation effects vary over time. Follow-up univariate analyses indicated that all primary outcomes were significantly larger in the supplemented group than in the placebo group at the year 4 endpoint. However, at the year 7 endpoint, this effect vanished for TBBMD and distal radius BMD. Longitudinal models for TBBMD and proximal radius BMD, according to the time since menarche, showed a highly significant effect of supplementation during the pubertal growth spurt and a diminishing effect thereafter. Post hoc stratifications by compliance-adjusted total calcium intake and by final stature or metacarpal total cross-sectional area showed that calcium effects depend on compliance and body frame. CONCLUSIONS: Calcium supplementation significantly influenced bone accretion in young females during the pubertal growth spurt. By young adulthood, significant effects remained at metacarpals and at the forearm of tall persons, which indicated that the calcium requirement for growth is associated with skeletal size. These results may be important for both primary prevention of osteoporosis and prevention of bone fragility fractures during growth.

Adolescent↗

PubMed2005

Integrating software into PRA: a test-based approach.

Probabilistic risk assessment (PRA) is a methodology to assess the probability of failure or success of a system's operation. PRA has been proved to be a systematic, logical, and comprehensive technique for risk assessment. Software plays an increasing role in modern safety critical systems. A significant number of failures can be attributed to software failures. Unfortunately, current probabilistic risk assessment concentrates on representing the behavior of hardware systems, humans, and their contributions (to a limited extent) to risk but neglects the contributions of software due to a lack of understanding of software failure phenomena. It is thus imperative to consider and model the impact of software to reflect the risk in current and future systems. The objective of our research is to develop a methodology to account for the impact of software on system failure that can be used in the classical PRA analysis process. A test-based approach for integrating software into PRA is discussed in this article. This approach includes identification of software functions to be modeled in the PRA, modeling of the software contributions in the ESD, and fault tree. The approach also introduces the concepts of input tree and output tree and proposes a quantification strategy that uses a software safety testing technique. The method is applied to an example system, PACS.

Journal Article↗

PubMed2005

Reduction of false positives by internal features for polyp detection in CT-based virtual colonoscopy.

In this paper, we present a computer-aided detection (CAD) method to extract and use internal features to reduce false positive (FP) rate generated by surface-based measures on the inner colon wall in computed tomographic (CT) colonography. Firstly, a new shape description global curvature, which can provide an overall shape description of the colon wall, is introduced to improve the detection of suspicious patches on the colon wall whose geometrical features are similar to that of the colonic polyps. By a ray-driven edge finder, the volume of each detected patch is extracted as a fitted ellipsoid model. Within the ellipsoid model, CT image density distribution is analyzed. Three types of (geometrical, morphological, and textural) internal features are extracted and applied to eliminate the FPs from the detected patches. The presented CAD method was tested by a total of 153 patient datasets in which 45 patients were found with 61 polyps of sizes 4-30 mm by optical colonoscopy. For a 100% detection sensitivity (on polyps), the presented CAD method had an average FPs of 2.68 per patient dataset and eliminated 93.1% of FPs generated by the surface-based measures. The presented CAD method was also evaluated by different polyp sizes. For polyp sizes of 10-30 mm, the method achieved mean number of FPs per dataset of 2.0 with 100% sensitivity. For polyp sizes of 4-10 mm, the method achieved 3.44 FP per dataset with 100% sensitivity.

Biophysical Phenomena↗

PubMed2005

Full-breadth analysis of CD8+ T-cell responses in acute hepatitis C virus infection and early therapy.

Multispecific CD8(+) T-cell responses are thought to be important for the control of acute hepatitis C virus (HCV) infection, but to date little information is actually available on the breadth of responses at early time points. Additionally, the influence of early therapy on these responses and their relationships to outcome are controversial. To investigate this issue, we performed comprehensive analysis of the breadth and frequencies of virus-specific CD8(+) T-cell responses on the single epitope level in eight acutely infected individuals who were all started on early therapy. During the acute phase, responses against up to five peptides were identified. During therapy, CD8(+) T-cell responses decreased rather than increased as virus was controlled, and no new specificities emerged. A sustained virological response following completion of treatment was independent of CD8(+) T-cell responses, as well as CD4(+) T-cell responses. Rapid recrudescence also occurred despite broad CD8(+) T-cell responses. Importantly, in vivo suppression of CD3(+) T cells using OKT3 in one subject did not result in recurrence of viremia. These data suggest that broad CD8(+) T-cell responses alone may be insufficient to contain HCV replication, and also that early therapy is effective independent of such responses.

Acute Disease↗

PubMed2005

The association of XRCC1 haplotypes and chromosomal damage levels in peripheral blood lymphocyte among coke-oven workers.

Theoretically, a haplotype has a higher level of heterozygosity than individual single nucleotide polymorphism (SNP) and the association study based on the haplotype may have an increased power for detecting disease associations compared with SNP-based analysis. In this study, we investigated the effects of four haplotype-tagging SNPs (htSNP) and the inferred haplotype pairs of the X-ray cross-complementing group 1 (XRCC1) gene on chromosome damage detected by the cytokinesis-block micronucleus assay. The study included 141 coke-oven workers with exposure to a high level of polycyclic aromatic hydrocarbons and 66 nonexposed controls. The frequencies of total MN and MNed cells were borderline associated with the Arg(194)Trp polymorphism (P = 0.053 and P = 0.050, respectively) but not associated with the Arg(280)His, Arg(399)Gln and Gln(632)Gln polymorphisms among coke-oven workers. Five haplotypes, including CGGG, TGGG, CAGG, CGAG, and CGGA, were inferred based on the four htSNPs of XRCC1 gene. The haplotype CGGG was associated with the decreased frequencies of total MN and MNed cells, and the haplotypes TGGG and CGAG were associated with the increased frequencies of total MN and MNed cells with adjustment for covariates among coke-oven workers. This study showed that the haplotypes derived from htSNPs in the XRCC1 gene were more likely than single SNPs to correlate with the polycyclic aromatic hydrocarbon-induced chromosome damage among coke-oven workers.

Adult↗

PubMed2005

Analysis of cytochrome P450 genes in silkworm genome (Bombyx mori).

We have searched the Bombyx mori genome for members of the major enzyme family, the Cytochrome P450s, which carry out multiple reactions to enable organisms to rid themselves of foreign compounds. As a result, 86 putative P450s were discovered in silkworm genome, which are thought to belong to 32 subfamilies. A comparative genomic analysis with Drosophila melanogaster reveals that the two insects have some similar P450 distribution patterns but still have some obvious differences. Especially, the diverse distribution exists in 7 p450 subfamilies, which are CYP4A, CYP4C, CYP4D, CYP6A, CYP6AE, CYP6B and CYP9A. Furthermore, we collected expression sequence tag (EST) evidence for 49 putative P450s genes, which are expressed at the transcriptional level and more likely to be true P450s.

Animals↗

PubMed2005

Differentiation of xanthomonads causing the bacterial leaf spot of poinsettia in China from the pathotype strain of Xanthomonas axonopodis pv. poinsettiicola.

In October 2003, a new bacterial disease with symptoms similar to those caused by Xanthomonas axonopodis pv. poinsettiicola was observed on poinsettia leaves at a flower nursery in Zhejiang Province of China. Three Xanthomonas strains were isolated from infected plants and classified as X. axonopodis. They were differentiated from the pathotype strain LMG849 of X. axonopodis pv. poinsettiicola causing bacterial leaf spot of poinsettia by comparison of pathogenicity, substrate utilization and BOX-PCR genomic fingerprints.

Cell Differentiation↗

PubMed2005

Suppression of Meloidogyne javanica by antagonistic and plant growth-promoting rhizobacteria.

Four rhizobacteria selected out of over 500 isolates from rhizosphere of the vegetables in China were further studied for suppression of the root-knot nematode and soil-borne fungal pathogens in laboratory and greenhouse in Belgium. They were identified as Brevibacillus brevis or Bacillus subtilis by Biolog test and partial 16s rDNA sequence comparison. They not only inhibited the radial growth of the root-infecting fungi Rhizoctonia solani SX-6, Pythium aphanidermatum ZJP-1 and Fusarium oxysporum f.sp. cucumerinum ZJF-2 in vitro, but also exhibited strong nematicidal activity by killing the second stage larvae of Meloidogyne javanica to varying degrees in the greenhouse. The toxic principles of bacterium B7 that showed the highest juvenile mortality were partially characterized. The active factors were heat stability and resistance to extreme pH values. B7 used either as seed dressing or soil drench significantly reduced the nematode populations in the rhizosphere and enhanced the growth of mungbean plants over the controls in the presence or absence of R. solani.

Alphaproteobacteria↗

PubMed2005

[Effects of Shengji Huayu Recipe and its decomposed formulas on synthesis of collagen types I and III in granulation tissue of rats in early wound healing].

OBJECTIVE: To study the effects of Shengji Huayu Recipe (a traditional Chinese medicine compound recipe for resolving stagnation and promoting granulation) and its decomposed formulas (Huayu Recipe for resolving stagnation and Shengji Recipe for promoting granulation) on the synthesis of collagen types I and III in granulation tissue of rats in early wound healing. METHODS: Twenty-four male Sprague-Dawley (SD) rats with full-thickness skin lesion were randomized into 4 groups: Shengji Huayu Recipe-treated group, Shengji Recipe-treated group, Huayu Recipe-treated group and untreated group. Collagen types I and III in granulation tissue of the rats were tested with immunohistochemical methods and image analysis. RESULTS: On the third day of wound healing, collagen I of the rats in both Shengji Huayu Recipe-treated group and Shengji Recipe-treated group was higher than that in the untreated group, and collagen I of the rats in Huayu Recipe-treated group was lower than that in the untreated group (P<0.05). Collagen III of the rats in the three treated groups were lower than that in the untreated group (P<0.05). On the seventh day of wound healing, Collagen I of the rats in both Shengji Huayu Recipe-treated group and Shengji Recipe-treated group was higher than that in the untreated group (P<0.05), and collagen III of the rats in both Shengji Recipe-treated group and Huayu Recipe-treated group was higher than that in the untreated group (P<0.05). CONCLUSION: Resolving stagnation and promoting granulation therapy can promote the wound healing in rats.

Animals↗

PubMed2005

[Method for segmenting medical image based on anatomical model].

OBJECTIVE: To improve the automatization and reliability of medical image segmentation. METHOD: An anatomical model was built and used to guide the low-level segmentation process. The system architecture was made up of an anatomical model, image processing routines and an inference engine, the interaction of which are governed by a blackboard. RESULT: The result of application of the segmentation for chest CT image was satisfactory and needs less operator intensive. CONCLUSION: This method improves automatization and reliability of the medical image segmentation. Because of the good expansibility, it may serve as a template for knowledge-based processing of medical image.

Computer Simulation↗

PubMed2005

[Effects of early treatment with metoprolol on myocardial inflammatory cytokine expression and heart function in rats with acute myocardial infarction].

OBJECTIVE: The aim of study was to explore the effects of early beta-adrenergic blockade-metoprolol treatment on myocardial inflammatory cytokine expression and heart function in rats after acute myocardial infarction (AMI). METHODS: The therapeutic effects of metoprolol on myocardial inflammation and heart function up to 4 weeks (according to the protocol of CCS-2) were studied by the rat model of AMI. Myocardial inflammation was examined by taking account of the number of lymphocytes infiltrated in the myocardium and analyzing the myocardial cytokine production including the pro-inflammatory cytokines: interleukin (IL)-1beta, 6 and tumor necrosis factor (TNF)-alpha and the anti-inflammatory cytokine: IL-10. Echocardiography was used to evaluate heart function. RESULTS: The levels of TNF-alpha, IL-1beta, IL-6 and IL-10 in AMI group were markedly elevated compared to sham rats (P < 0.01) and the cytokines principally excreted by cardiac myocytes. After 4 weeks therapy, metoprolol reduced the production of TNF-alpha and IL-1beta and increased IL-10 levels (P < 0.05) in cardiac myocytes, but had no effect on the number of lymphocytes infiltrated in myocardium. Echocardiography showed that metoprolol markedly improved left heart function (P < 0.05). CONCLUSION: Early metoprolol treatment can improve heart function and myocardial inflammatory cytokine expression after AMI. One immunopharmacologic mechanism underlying the beneficial effects of beta-adrenergic blockade may involve the attenuation of pro-inflammatory cytokines and the increase of anti-inflammatory cytokine levels in cardiac myocytes.

Adrenergic beta-Antagonists↗

PubMed2005

[Association of XRCC1 polymorphisms and chromosomal damage levels in coke-oven workers].

OBJECTIVE: To investigate the association of XRCC1 polymorphisms and chromosomal damage levels in peripheral blood lymphocyte in coke-oven workers. METHODS: The study included 141 coke-oven workers who exposed to a high level of polycyclic aromahaplotpetic hydrocarbon and 66 non-exposed controls. Urinary 1-hydroxypyrene and chromosome damage in peripheral lymphocyte were measured. Four -tagging single nucleotide polymorphisms in XRCC1 gene, including C26304T, G27466A, G28152A and G36189A, were detected and the XRCC1 haplotypes were estimated by using an extension of Clark algorithm. The associations between haplotype pairs and micronuclei data were assessed by analysis of covariance in the exposed and non-exposed groups. RESULTS: The geometric means of urinary 1-hydroxypyrene levels in coke-oven workers and the controls were 12.0 and 0.7 micromol/mol Cr respectively (P < 0.01). The cytokinesis-block micronucleus cytokinesis-block micronucleus frequencies (number of micronucleus per 1 000 binucleated lymphocytes) was significantly higher in coke-oven workers (0.95 +/- 0.66)% than in the controls (0.40 +/- 0.36)%, P < 0.01. The haplotype CGGG was associated with the decreased frequencies of total micronucleus, and the haplotypes TGGG (P = 0.01) and CGAG (P < 0.05) were associated with the increased frequencies of total micronucleus in the multivariate analysis with adjustment for covariates among coke-oven workers. CONCLUSIONS: The genetic polymorphisms of XRCC1 gene could influence the chromosome damage levels in coke-oven workers.

Adult↗

PubMed2005

[Association of metabolic and DNA repair enzyme gene polymorphisms and DNA damage in coke-oven workers].

OBJECTIVE: To investigate the association of polymorphisms of metabolic and DNA repair enzyme genes and DNA damage in peripheral blood lymphocytes in coke-oven workers. METHODS: One hundred and forty-four coke-oven workers and 50 controls were recruited in this study. Urinary 1-hydroxypyrene (1-OHP) levels were measured as the internal dose of polycyclic aromatic hydrocarbons exposure. DNA damage was detected by alkaline comet assay, and the value of 1.74 was used as the cut-off value to determine whether the individual's DNA damage was positive. The genotypes of CYP1A1, CYP2E1, GSTP1, NQO1, mEH and XRCC1 were determined by PCR-based methods. With adjustment for urinary 1-OHP, age, sex, multiple analysis of covariance was used to study the association between genotypes and the ln-transformed olive TM and multiple logistic regression was used to calculate the adjusted OR and the 95% CI for the risk of DNA damage. RESULTS: In 144 coke-oven workers, with adjustment for urinary 1-OHP, coking history and sex, the olive TM was significantly higher with XRCC1 280His allele than those with Arg allele (5.6 vs. 2.8, P < 0.01). The subjects with XRCC1 280His allele also have significantly higher risk for DNA damage than subjects with Arg allele (adjusted OR = 2.66, 95% CI = 1.00-7.14, P = 0.05) and the subjects with GSTP1 104Val allele have higher risk for DNA damage than subjects with Ile allele (adjusted OR = 1.90, 95% CI = 0.94-3.85, P = 0.07). CONCLUSION: XRCC1 and GSTP1 polymorphisms might influence the susceptibility of DNA damage in occupational PAH-exposed coke-oven workers.

Adult↗

PubMed2005

[The dynamic analysis and the clinical significance of vascular endothelial cell markers and hemolysis parameters in thrombotic thrombocytopenic purpura].

OBJECTIVE: To monitor the changes of hemolysis parameters and endothelial cell markers in thrombotic thrombocytopenic purpura (TTP) and reveal the clinical significance of these changes. METHODS: vWF-cleaving protease (vWF-CP) activity in 3 cases of TTP was detected by Western blot. The percentages of fragmented red cells (FRC) were counted throughout the entire clinical course. Levels of plasma thrombomodulin were detected by Western blot combined with density screening in TTP and healthy individuals (n = 3). Concentration of plasma VEGF was measured by enzyme-linked immunosorbent assay in TTP and healthy individuals (n = 9). Fundus fluorescein angiography was performed to search the evidence of microvascular thrombosis in one TTP patient with impaired visual acuity. RESULTS: The lower vWF-CP activity was observed in TTP patients; the percentages of FRC in 3 cases of TTP were 1.65%, 2.50%, 3.32% respectively with an average of 2.49% at the onset of and decreased with the improvement of the disease. The levels of plasma TM and VEGF were significantly elevated in TTP than those in healthy individuals, and related to the severity of TTP. Fundus photography in one TTP patient with impaired visual acuity revealed vascular occlusion in fundus arteriole and venulae. CONCLUSIONS: A decreased vWF-CP activity is in favour of TTP diagnosis. Dynamic monitoring of plasma TM and VEGF as well as percentages of FRC are useful indexes for reflecting the severity and evaluating therapeutic response of TTP. Selective fundus fluorescein angiography is useful for the judgement of microvascular thrombosis in TTP.

ADAM Proteins↗