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Qing Lu

Publications and source records attributed to Qing Lu.

At least 37 records · Page 2Linked to original sources
PubMed2006

[Effects of D-limonene on leukemia cells HL-60 and K562 in vitro].

To investigate the effects of D-limonene (D-L) on the cell growth and apoptosis in HL-60, K562 cells and to elucidate its mechanism, the influence of D-L on proliferation of HL-60 and K562 cells was determined by propidium iodide assay, the expression levels of mutant p53, bcl-2, bax gene were detected by cell morphological analysis, flow cytometry and immunohistochemistry staining, the D-L-inducing HL-60 and K562 cell apoptosis in vitro was observed systematically. The results showed that D-L inhibited HL-60 and K562 cell growth in a dose- and time-dependent manner with the IC50 of 0.75 mmol/L similarly, D-L induced apoptosis of HL-60 and K562 cells, and expression of bcl-2 gene was down regulated by D-L in a concentration-dependent manner in HL-60 cells. The bcl-2, mutant type of p53 genes were down regulated while bax gene was up regulated by D-L in a concentration-dependent manner in K562 cells. It is concluded that D-L can inhibit proliferation and induce apoptosis of HL-60 and K562 cells. The bcl-2, mutant type of p53 and bax may be involved in the gene regulation of D-L-induced apoptosis.

Apoptosis↗
PubMed2006

Cutaneous angiosarcoma of the head and neck: a case presentation and review of the literature.

Cutaneous angiosarcoma of the head and neck is a rare vascular neoplasm. When it does occur, it is most common in elderly white men. Early diagnosis and treatment are essential for local control of this aggressive tumor but recognition can be delayed because of its rarity or because of difficulty in making a pathologic diagnosis. A combined-modality treatment approach is most often advocated. We report the case of a 77-year-old black man who presented with a 1-month history of two painless, violaceous, subcentimeter nodules of the upper lip. After a diagnosis of low-grade angiosarcoma was definitively established, the lesions were locally excised with good cosmetic and functional results. The patient subsequently was found to have probable metastatic disease, but he declined further intervention. We review the literature on cutaneous angiosarcoma, and we discuss its epidemiology, presentation, tissue diagnosis, treatment, and prognosis in an effort to increase awareness of this rare malignancy.

Aged↗
PubMed2005

Effect of genotyping error in model-free linkage analysis using microsatellite or single-nucleotide polymorphism marker maps.

Errors while genotyping are inevitable and can reduce the power to detect linkage. However, does genotyping error have the same impact on linkage results for single-nucleotide polymorphism (SNP) and microsatellite (MS) marker maps? To evaluate this question we detected genotyping errors that are consistent with Mendelian inheritance using large changes in multipoint identity-by-descent sharing in neighboring markers. Only a small fraction of Mendelian consistent errors were detectable (e.g., 18% of MS and 2.4% of SNP genotyping errors). More SNP genotyping errors are Mendelian consistent compared to MS genotyping errors, so genotyping error may have a greater impact on linkage results using SNP marker maps. We also evaluated the effect of genotyping error on the power and type I error rate using simulated nuclear families with missing parents under 0, 0.14, and 2.8% genotyping error rates. In the presence of genotyping error, we found that the power to detect a true linkage signal was greater for SNP (75%) than MS (67%) marker maps, although there were also slightly more false-positive signals using SNP marker maps (5 compared with 3 for MS). Finally, we evaluated the usefulness of accounting for genotyping error in the SNP data using a likelihood-based approach, which restores some of the power that is lost when genotyping error is introduced.

Chromosome Mapping↗
PubMed2005

Comparison of microsatellites, single-nucleotide polymorphisms (SNPs) and composite markers derived from SNPs in linkage analysis.

There is growing evidence that a map of dense single-nucleotide polymorphisms (SNPs) can outperform a map of sparse microsatellites for linkage analysis. There is also argument as to whether a clustered SNP map can outperform an evenly spaced SNP map. Using Genetic Analysis Workshop 14 simulated data, we compared for linkage analysis microsatellites, SNPs, and composite markers derived from SNPs. We encoded the composite markers in a two-step approach, in which the maximum identity length contrast method was employed to allow for recombination between loci. A SNP map 2.3 times as dense as a microsatellite map (approximately 2.9 cM compared to approximately 6.7 cM apart) provided slightly less information content (approximately 0.83 compared to approximately 0.89). Most inheritance information could be extracted when the SNPs were spaced < 1 cM apart. Comparing the linkage results on using SNPs or composite markers derived from them based on both 3 cM and 0.3 cM resolution maps, we showed that the inter-SNP distance should be kept small (< 1 cM), and that for multipoint linkage analysis the original markers and the derived composite markers had similar power; but for single point linkage analysis the resulting composite markers lead to more power. Considering all factors, such as information content, flexibility of analysis method, map errors, and genotyping errors, a map of clustered SNPs can be an efficient design for a genome-wide linkage scan.

Chromosome Mapping↗
PubMed2005

Fine-mapping using the weighted average method for a case-control study.

We present a new method for fine-mapping a disease susceptibility locus using a case-control design. The new method, termed the weighted average (WA) statistic, averages the Cochran-Armitage (CA) trend test statistic and the difference between the Hardy-Weinberg disequilibrium test statistic for cases and controls (the HWD trend). The main characteristics of the WA statistic are that it improves on the weaknesses, and maintains the strengths, of both the CA trend test and the HWD trend test. Data from three different populations in the Genetic Analysis Workshop 14 (GAW14) simulated dataset (Aipotu, Karangar, and Danacaa) were first subjected to model-free linkage analysis to find regions exhibiting linkage. Then, for fine-scale mapping, 140 SNPs within the significant linkage regions were analyzed with the WA test statistic on replicates of the three populations, both separately and combined. The regions that were significant in the multipoint linkage analysis were also significant in this fine-scale mapping. The most significant regions that were obtained using the WA statistic were regions in chromosome 3 (B03T3056-B03T3058, p-value < 1 x 10(-10)) and chromosome 9 (B09T8332-B09T8334, p-value 1 x 10(-6)). Based on the results of the simulated GAW14 data, the WA test statistic showed good performance and could narrow down the region containing the susceptibility locus. However, the strength of the signal depends on both the strength of the linkage disequilibrium and the heterozygosity of the linked marker.

Case-Control Studies↗
PubMed2005

Neuroprotective effects of candesartan against cerebral ischemia in spontaneously hypertensive rats.

The cerebral protective effects of 4-week treatment with candesartan (0.3, 1, 3 mg/kg/day) and ramipril (0.5, 1.5, 5 mg/kg/day) were examined in spontaneous hypertensive rats 24 h after middle cerebral artery occlusion. We found that both candesartan and ramipril could reduce the infarct volume and neurological deficit scores compared with control. Importantly, the neuroprotective effects of candesartan (1 mg/kg/day) were abolished by PD123319 (an AT2 receptor antagonist, 10 mg/kg/day). AT1 receptor gene expression was downregulated while AT2 receptor gene expression was upregulated by candesartan. It is concluded that candesartan appears to provide beneficial effects against stroke in spontaneous hypertensive rats in three ways: AT1 receptor antagonism, downregulation of AT1 receptor expression and upregulation of AT2 receptor expression.

Animals↗
PubMed2005

4-Aryl-1,2,3-triazole: a novel template for a reversible methionine aminopeptidase 2 inhibitor, optimized to inhibit angiogenesis in vivo.

Inhibitors of human methionine aminopeptidase type 2 (hMetAP2) are of interest as potential treatments for cancer. A new class of small molecule reversible inhibitors of hMetAP2 was discovered and optimized, the 4-aryl-1,2,3-triazoles. Compound 24, a potent inhibitor of cobalt-activated hMetAP2, also inhibits human and mouse endothelial cell growth. Using a mouse matrigel model, this reversible hMetAP2 inhibitor was also shown to inhibit angiogenesis in vivo.

Aminopeptidases↗
PubMed2005

Studies on direct electron transfer and biocatalytic properties of heme proteins in lecithin film.

Myoglobin (Mb), hemoglobin (Hb) and horseradish peroxidase (HRP) were incorporated in lecithin (PC) film on glassy carbon (GC) electrode by the method of vesicle-fusion. A pair of well-defined and quasi-reversible cyclic voltammetric peaks was obtained, which reflected the direct electron transfer of heme proteins. UV-Vis and reflectance absorption infrared (RAIR) spectroscopy showed that proteins in PC films remained at their secondary structure similar to their native states. Scanning electron microscopy (SEM) demonstrated the interaction between the proteins and PC would make the morphology of protein-PC films very different from the PC films alone. The immobilized proteins retained their biocatalytic activity to the reduction of NO and hydrogen peroxide, which provide the perspective to be the third generation sensors.

Calibration↗
PubMed2005

PKCdelta regulates endothelial basal barrier function through modulation of RhoA GTPase activity.

We have shown that PKCdelta enhanced microvascular endothelial basal barrier function, correlating with elevated RhoA GTPase activity and increased focal contact formation. In the current study, we investigated signaling pathways important in PKCdelta modulation of barrier function in unstimulated endothelial cell monolayers by assessing the effects of PKCdelta inhibition in endothelial cells (EC) derived from rat pulmonary artery (PAEC) and epididymus (FPEC). Rottlerin exposure or Ad PKCdeltadn infection significantly enhanced monolayer permeability in both EC. Immunofluorescence analyses demonstrated fewer stress fibers and focal contacts in rottlerin-treated or Ad PKCdeltadn-infected EC; yet, PKCdelta inhibition caused no significant changes in microtubule structures. These changes correlated with a reduction in both focal adhesion kinase (FAK) and RhoA GTPase activities. Microfilament stabilization significantly attenuated the focal contact and barrier disruptive effects of rottlerin. FAK overexpression did not blunt the effects of rottlerin-induced barrier dysfunction or stress fiber and focal contact disruption. Conversely, GFP-linked dominant active RhoA overexpression protected EC from stress fiber and focal contact disruption induced by both rottlerin exposure and overexpression of PKCdelta dominant negative protein. Additionally, PKCdelta immunoprecipitated with p190RhoGAP and p120RasGAP, modulators of RhoA activity. Thus, PKCdelta may regulate basal endothelial barrier function by stabilizing microfilaments and focal contacts by regulating RhoA GTPase activity through upstream modulators, p190RhoGAP and p120RasGAP.

Actin Cytoskeleton↗
PubMed2005

Comparison of accuracy of mitral valve area in mitral stenosis by real-time, three-dimensional echocardiography versus two-dimensional echocardiography versus Doppler pressure half-time.

Mitral valve area (MVA) in 30 patients with mitral stenosis (MS) and 34 normal controls was calculated by real-time, 3-dimensional echocardiography (RT3DE); MVA in patients with MS correlated well with the mitral area determined by 2-dimensional echocardiography (r = 0.98) and by pressure half-time (r = 0.90). MVA in normal controls on RT3DE correlated well with MVA on 2-dimensional echocardiography (r = 0.94) and pressure half-time (r = 0.91). There were significant differences between the orifice areas in patients with MS and normal controls. RT3DE can provide not only the anatomic structure of mitral valve apparatus, but also the optimal plane of the smallest mitral valve orifice, and can thus accurately measure the MVA.

Adult↗
PubMed2005

Modulator recognition factor 1, an AT-rich interaction domain family member, is a novel corepressor for estrogen receptor alpha.

Cardiovascular tissues are important targets of estrogen action. Vascular cells express the two known estrogen receptors (ERs), ERalpha and ERbeta, ligand-activated transcription factors that regulate gene transcription through interactions with both coactivator and corepressor molecules. To isolate ERalpha coregulators in vascular cells, we performed a yeast two-hybrid screen for ERalpha-interacting proteins using a human aorta library. Here we report the identification of modulator recognition factor 1 (MRF1) as an ERalpha-interacting corepressor protein. Full-length MRF1 binds to both the N terminus and the C terminus of ERalpha. ERalpha and MRF1 coimmunoprecipitate in an estradiol-independent manner, and recombinant ERalpha binds to both full-length and COOH-terminal MRF1 in the absence of estradiol. MRF1 also interacts in a ligand-dependent manner with thyroid receptor alpha, retinoid X receptor alpha, and androgen receptor, and in a ligand-independent manner with ERbeta and the retinoic acid receptor. MRF1 RNA is highly expressed in aorta, heart, skeletal muscle, and liver. MRF1 has intrinsic repressor activity in an in vitro GAL reporter assay. Transient transfection studies show that MRF1 represses transcription by ERalpha activated by estradiol in a dose-dependent manner, as well as by the selective ER modulators 4-hydroxy-tamoxifen and raloxifene. MRF1 repression is not influenced by pharmacological inhibition of histone deacetylase. These data identify MRF1 as a repressor of ERalpha-mediated transcriptional activation and support a role for MRF1 in regulating ER-dependent gene expression in cardiovascular and other cells.

Aorta↗
PubMed2005

Solvent-assisted formation of nanostrand networks from supramolecular diblock copolymer/surfactant complexes at the air/water interface.

We describe a simple manipulation of an asymmetric diblock copolymer, polystyrene-b-poly(4-vinylpyridine), mixed with 3-pentadecylphenol that generates a dense network of interconnected nanostrands at the air/water interface. This morphology is obtained by compression of the solution immediately after spreading, contrasting with the dot-and-planar morphology obtained by the conventional method, and is attributed to the presence of the solvent that confers sufficient mobility to the system to enable reorganization in response to increased surface pressure. This procedure thus adds a facile yet effective tool for controlling pattern formation at the air/water interface.

Air↗
PubMed2005

Effect of ascorbic acid on microcirculation in patients with Type II diabetes: a randomized placebo-controlled cross-over study.

Manifestations of vascular disease, including microvascular changes, constitute the major part of the morbidity and mortality in diabetic patients. Oxidative stress has been suggested to play an important role in the vascular dysfunction of diabetic patients. Furthermore, epidemiological observations indicate a beneficial effect of an increased dietary intake of antioxidants. The present study tested the hypothesis that the antioxidant ascorbic acid influences microcirculatory function in patients with Type II diabetes. Patients with Type II diabetes were treated with 1 g of ascorbic acid three times a day for 2 weeks in a randomized placebo-controlled double-blind cross-over design. Microvascular reactivity was assessed by vital capillaroscopy and PRH (post-occlusive reactive hyperaemia). hs-CRP (high-sensitivity C-reactive protein), IL-6 (interleukin-6), IL-1ra (interleukin-1 receptor antagonist) and ox-LDL (oxidized low-density lipoprotein) were analysed. The results showed no significant change in microvascular reactivity assessed after 2 weeks of ascorbic acid treatment. TtP (time to peak) was 12.0+/-3.3 s before and 11.2+/-3.5 s after ascorbic acid (n=17). In comparison, TtP was 11.5+/-2.9 s before and 10.6+/-2.8 s after placebo (not significant). IL-1ra, IL-6, hs-CRP and ox-LDL did not change significantly after ascorbic acid, neither as absolute or relative values. In conclusion, in contrast with some studies reported previously, we could not demonstrate an effect of continuous oral treatment with ascorbic acid on microvascular reactivity assessed at the level of individual capillaries. Furthermore, we found no indication of an effect on inflammatory cytokines or ox-LDL.

Antioxidants↗
PubMed2005

Apoptosis and lung injury.

Apoptosis is important in developmental biology and in remodeling of tissues during repair. Apoptosis also plays important roles in the progression of many diseases. The cellular and molecular mechanisms of apoptosis, in general, have been extensively demonstrated. However, the causes and the roles of apoptosis of various cell types in the lung are not well understood. We have determined that adenosine/homocysteine causes lung vascular endothelial cell apoptosis by inhibition of carboxyl methylation of the small GTPase, Ras, through inhibition of isoprenylcysteine carboxyl methyltransferase(ICMT) activity, leading to inactivation of Ras and the subsequent disruption of focal adhesion complexes, resulting in cell-extracellular matrix detachment and anoikis. Apoptosis can either ameliorate or exacerbate lung injury, depending upon the cell type. Although apoptosis of polymorphonuclear leukocytes in the lung prevents inflammation and the development of acute respiratory distress syndrome during acute lung injury, Fas/FasL-mediated alveolar epithelial cell apoptosis promotes acute lung injury and pulmonary fibrosis. Lung epithelial and endothelial cell apoptosis also contributes to the development of emphysema. This article focuses on elucidating the mechanisms of adenosine/homocysteine-induced endothelial cell apoptosis. We also review the current understanding of the role of lung cell apoptosis in acute lung injury, pulmonary fibrosis and emphysema.

Animals↗
PubMed2005

[The reverse first dorsal metatarsal artery flap for the defects of the distal foot].

OBJECTIVE: To explore a new method to reconstruct the defect of the distal foot. METHODS: A distally based dorsum pedis island flap pedicled with the first dorsal metatarsal artery was designed and transferred to the defect of the distal foot. RESULTS: Five patients were treated with this flap, which ranged from 2 cm x 4 cm to 6 cm x 7 cm in size. Four flaps survived completely, one flap had marginal necrosis and healed after conservative therapy. CONCLUSIONS: The reverse first dorsal metatarsal artery flap, with good blood circulation and easy manipulation, is a good option for the defects of the distal foot.

Adolescent↗
PubMed2005

[Microvessel counts and the expressions of chemotactic factors in the pathological scar tissues].

OBJECTIVE: To explore the microvessel counts and the expressions of interleukin-8 (IL-8), monocyte chemoattractant protein-1 (MCP-1), and macrophage inflammatory protein-1 ( MIP-1) alpha mRNA in the pathological scar tissues. METHODS: Immunohistochemical method of avidin-biotin complex was used for microvessel counts on the routinely formalin-fixed and paraffin-embedded sections of specimens of hypertrophic scars, keloids, normal skin, and surgical scar, and in situ hybridization for the expressions of IL-8, MCP-1, MIP-1alpha mRNA. RESULTS: The microvessel counts as well as the positive rates and the scorings of IL-8, MCP-1, and MIP-1alpha mRNA were significantly higher in pathological scars than those in the normal skin and surgical scar (all P < 0.05). The microvessel counts were significantly higher in the positive cases of IL-8, MCP-1 and MIP-1alpha mRNA than those in the negative ones (P < 0.05). The close positive correlations were found among the microvessel counts and the expressive scorings of 3 factors (P < 0.05). The close positive correlations were also found among the expressive scorings of IL-8, MCP-1, and MIP-1alpha mRNA in pathological scars. Microvessel counts were significantly higher in hypertrophic scars with the course less than 1 year than those with the course more than 1 year. CONCLUSION: IL-8, MCP-1 and MIP-1alpha play important roles in promoting the neovascularization of pathological scars.

Adolescent↗