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Sample records for plasma vegf determination

  1. Determination of vascular endothelial growth factor (VEGF) in circulating blood: significance of VEGF in various leucocytes and platelets

    DEFF Research Database (Denmark)

    Werther, K; Christensen, Ib Jarle; Nielsen, Hans Jørgen

    2002-01-01

    . In corresponding blood samples, automated complete blood count was performed, and the number of each cell type was correlated to VEGF concentrations in plasma, serum and lysed whole blood. Finally, the impact of increasing clotting time on the release of VEGF to serum was analysed. RESULTS: Isolated neutrophils......AIM: The sources of increased vascular endothelial growth factor (VEGF) concentrations in peripheral blood from cancer patients are not known in detail. The aim of the present study was to evaluate correlations between the VEGF content in isolated leucocyte subpopulations and VEGF concentrations...... in plasma, serum and lysed whole blood. METHODS: In 51 colorectal cancer (CRC) patients, circulating T-lymphocytes, B-lymphocytes, monocytes, and granulocytes were isolated by means of immunomagnetic separation. Subsequently, the isolated cells were lysed and VEGF contents in the lysates were determined...

  2. Biological variations in plasma VEGF and VEGFR-1 may compromise their biomarker value in colorectal cancer

    DEFF Research Database (Denmark)

    Svendsen, Mads N.; Brunner, Nils; Christensen, Ib Jarle

    2010-01-01

    Vascular Endothelial Growth Factor (VEGF) plays a prominent role in tumor angiogenesis and plasma VEGF concentration may carry prognostic information in colorectal cancer. The VEGF receptor 1 (VEGFR-1) is a regulatory receptor which is shredded into plasma of patients with colorectal cancer. For ....... For both molecules, large biological variation and lack of standardization of assay procedures are major challenges....

  3. The angiogenic growth factors HGF and VEGF in serum and plasma from neuroblastoma patients.

    Science.gov (United States)

    Sköldenberg, Erik G; Larsson, Anders; Jakobson, Ake; Hedborg, Fredrik; Kogner, Per; Christofferson, Rolf H; Azarbayjani, Faranak

    2009-08-01

    To determine whether concentrations of the angiogenic growth factors hepatocyte growth factor (HGF) and vascular endothelial growth factor A (VEGF-A) correlate with clinical and genetic markers in samples taken at diagnosis in children with neuroblastoma (NB). Heparin plasma (P-) and serum (S-) samples of healthy controls (n=73, mean age +/- SD 3.5+/-2.1; females/males: 23/50) and patients with NB (n=62; 2.2+/-1.8; 26/36) were collected between 1988 and 1999. Clinical data included age at diagnosis, gender, stage, outcome, amplification of the oncogene MYCN, loss of heterozygosity at the short arm of chromosome 1 (1p LOH) and ploidy. HGF and S-VEGF-A were elevated in NB as compared to controls (38/62 patients, p<0.0001 and p<0.05, Mann-Whitney U test). HGF concentrations were higher in high-stage (stage 3-4) as compared to low-stage (stage 1-2) disease (p<0.01). P-HGF was elevated in patients with 1p LOH (p<0.01), MYCN amplification (p<0.001) and di- or tetraploidy (p<0.001). S-HGF concentration was elevated in patients MYCN-amplified tumors only. Plasma and S-HGF concentrations were higher in the deceased group (p<0.05), but not P or S-VEGF-A. This study showed that concentrations of HGF and S-VEGF-A are elevated in patients with NB. Furthermore, HGF and S-VEGF-A concentrations correlate to higher stage disease and HGF correlates to genetic markers known to indicate a poor outcome. These observations imply that HGF and VEGF-A have biological roles in NB and suggest the possibility of interference with HGF or VEGF-A signaling as a therapeutic strategy.

  4. Changes in plasma IL-6, plasma VEGF and serum YKL-40 during Treatment with Etanercept and Methotrexate or Etanercept alone in Patients with Active Rheumatoid Arthritis Despite Methotrexate Therapy

    DEFF Research Database (Denmark)

    Knudsen, Lene Surland; Hetland, Merete Lund; Johansen, Julia Sidenius

    2009-01-01

    Changes in plasma IL-6, plasma VEGF and serum YKL-40 were determined in rheumatoid arthritis (RA) patients during treatment with etanercept alone or in combination with methotrexate. Twenty-five patients with active RA (DAS28 >/= 3.2) were randomized to receive etanercept (25 mg sc. biweekly) plus...... methotrexate (n = 12) or etanercept alone (n = 13). Plasma IL-6, plasma VEGF and serum YKL-40 were determined by ELISA. The 3 biomarkers and DAS28 scores were evaluated at baseline and after 4, 8, 12 and 16 weeks of treatment. At inclusion all patients had significantly (p plasma IL-6, plasma...... VEGF and serum YKL-40 compared to healthy subjects. Eighteen patients responded to treatment (pooled data from both treatment groups), and they had significant (p plasma IL-6, plasma VEGF, serum YKL-40, ESR and DAS28 after 4 weeks of treatment and throughout the study...

  5. [Measurement and correlation analysis of plasma VEGF level in the patients of hyperthyroidism].

    Science.gov (United States)

    Zhao, Xiaoni; Wang, Guangrong; You, Jinhui

    2013-04-01

    Vascular endothelial growth factor (VEGF) is a glycoprotein that promotes endothelial regeneration, stimulates formation of collateral blood vessels and increases vascular permeability. The purpose of this study was to measure the peripheral blood plasma level of VEGF and FT3, FT4, TSH and to analyze the correlation of the level of VEGF and TSH, FT3, FT4, age and gender in the patients of hyperthyroidism. The relationship between hyperthyroidism and VEGF was investigated as well. The plasma level of VEGF in 45 hyperthyroidism patients and 27 healthy persons were measured by enzyme-linked immunosorbent assay (ELISA), while plasma FT3, FT4, TSH were detected by chemiluminescence. The result showed that the plasma level of VEGF in hyperthyroidism patients [(92.53 +/- 62.38) pg/mL] was significantly lower than that in the control group [(158.28 +/- 77.15) pg/mL] (P hyperthyroidism patients (P > 0.05). These results suggested that the peripheral blood plasma level of VEGF in hyperthyroidism patients was significantly lower than that in the control group. Further experimental investigations are needed to estimate the relationship between VEGF and hyperthyroidism.

  6. Increased plasma levels of soluble vascular endothelial growth factor (VEGF) receptor 1 (sFlt-1) in women by moderate exercise and increased plasma levels of VEGF in overweight/obese women

    Science.gov (United States)

    Makey, Kristina L.; Patterson, Sharla G.; Robinson, James; Loftin, Mark; Waddell, Dwight E.; Miele, Lucio; Chinchar, Edmund; Huang, Min; Smith, Andrew D.; Weber, Mark; Gu, Jian-Wei

    2012-01-01

    The incidence of breast cancer is increasing worldwide, and this seems to be related to an increase in lifestyle risk factors, including physical inactivity, and overweight/obesity. We previously reported that exercise induced a circulating angiostatic phenotype characterized by increased sFlt-1 and endostatin and decreased unbound-VEGF in men. However, there is no data on women. The present study determines the following: 1) whether moderate exercise increased sFlt-1 and endostatin and decreased unbound-VEGF in the circulation of adult female volunteers; 2) whether overweight/obese women have a higher plasma level of unbound-VEGF than lean women. 72 African American and Caucasian adult women volunteers aged from 18–44 were enrolled into the exercise study. All the participants walked on a treadmill for 30 minutes at a moderate intensity (55–59% heart rate reserve), and oxygen consumption (VO2) was quantified by utilizing a metabolic cart. We had the blood samples before and immediately after exercise from 63 participants. ELISA assays (R&D Systems) showed that plasma levels of sFlt-1 were 67.8±3.7 pg/ml immediately after exercise (30 minutes), significantly higher than basal levels, 54.5±3.3 pg/ml, before exercise (P < 0.01; n=63). There was no significant difference in the % increase of sFlt-1 levels after exercise between African American and Caucasian (P=0.533) or between lean and overweight/obese women (P=0.892). There was no significant difference in plasma levels of unbound VEGF (35.28±5.47 vs. 35.23±4.96 pg/ml; P=0.99) or endostatin (111.12±5.48 vs. 115.45±7.15 ng/ml; P=0.63) before and after exercise. Basal plasma levels of unbound-VEGF in overweight/obese women were 52.26±9.6 pg/ml, significantly higher than basal levels of unbound-VEGF in lean women, 27.34±4.99 pg/ml (P < 0.05). The results support our hypothesis that exercise-induced plasma levels of sFlt-1 could be an important clinical biomarker to explore the mechanisms of exercise

  7. Covalent immobilisation of VEGF on plasma-coated electrospun scaffolds for tissue engineering applications.

    Science.gov (United States)

    Guex, A G; Hegemann, D; Giraud, M N; Tevaearai, H T; Popa, A M; Rossi, R M; Fortunato, G

    2014-11-01

    Recent findings in the field of biomaterials and tissue engineering provide evidence that surface immobilised growth factors display enhanced stability and induce prolonged function. Cell response can be regulated by material properties and at the site of interest. To this end, we developed scaffolds with covalently bound vascular endothelial growth factor (VEGF) and evaluated their mitogenic effect on endothelial cells in vitro. Nano- (254±133 nm) or micro-fibrous (4.0±0.4 μm) poly(ɛ-caprolactone) (PCL) non-wovens were produced by electrospinning and coated in a radio frequency (RF) plasma process to induce an oxygen functional hydrocarbon layer. Implemented carboxylic acid groups were converted into amine-reactive esters and covalently coupled to VEGF by forming stable amide bonds (standard EDC/NHS chemistry). Substrates were analysed by X-ray photoelectron spectroscopy (XPS), enzyme-linked immuno-assays (ELISA) and immunohistochemistry (anti-VEGF antibody and VEGF-R2 binding). Depending on the reaction conditions, immobilised VEGF was present at 127±47 ng to 941±199 ng per substrate (6mm diameter; concentrations of 4.5 ng mm(-2) or 33.3 ng mm(-2), respectively). Immunohistochemistry provided evidence for biological integrity of immobilised VEGF. Endothelial cell number of primary endothelial cells or immortalised endothelial cells were significantly enhanced on VEGF-functionalised scaffolds compared to native PCL scaffolds. This indicates a sustained activity of immobilised VEGF over a culture period of nine days. We present a versatile method for the fabrication of growth factor-loaded scaffolds at specific concentrations.

  8. Thicker carotid intima-media thickness and increased plasma VEGF levels suffered by post-acute thrombotic stroke patients

    Directory of Open Access Journals (Sweden)

    Yueniwati Y

    2016-12-01

    Full Text Available Yuyun Yueniwati,1 Ni Komang Darmiastini,1 Eko Arisetijono2 1Radiology Department, Faculty of Medicine, Brawijaya University, Malang, Indonesia; 2Neurology Department, Faculty of Medicine, Brawijaya University, Malang, Indonesia Background and objectives: Atherosclerosis causes reduction of the oxygen supply to structures in the far arterial wall, provoking the release of factors that drive angiogenesis of vasa vasorum, including VEGF. Other studies have revealed the inflammatory response in atherosclerosis and the role of platelet factor 4 (PF4 as an anti-angiogenic chemokine through the inhibition of VEGF. This cross-sectional study aims at measuring the effect of atherosclerosis assessed through carotid intima-media thickness (CIMT against plasma VEGF levels in patients with post-acute thrombotic stroke. Materials and methods: CIMT was assessed sonographically using GE Logiq S6 with 13 MHz frequency linear probe. VEGF-A plasma levels were measured using enzyme-linked immunosorbent assay (ELISA method. Differences among variables were compared statistically. The data were analyzed using Pearson correlation. Results: A total of 25 patients with post-acute thrombotic stroke were identified in days 7 to 90. CIMT thickening was indicated in 88% of patients (1.202 ± 0.312 mm, while an increase in plasma VEGF was identified in all patients (178.28 ± 93.96 ng/mL. There was no significant correlation between CIMT and plasma VEGF levels in patients with post-acute thrombotic stroke (p=0.741. A significant correlation was recognized between CIMT and total cholesterol (p=0.029 and low-density lipoprotein (p=0.018. Conclusion: There were no significant correlations between CIMT and plasma VEGF levels in patients with post-acute thrombotic stroke. However, plasma VEGF increased in patients with thrombotic stroke. CIMT measurement is a promising noninvasive modality to assess the vascular condition of patients with stroke and diabetes, while plasma VEGF

  9. Doxycycline reduces plasma VEGF-C/sVEGFR-3 and improves pathology in lymphatic filariasis.

    Science.gov (United States)

    Debrah, Alexander Yaw; Mand, Sabine; Specht, Sabine; Marfo-Debrekyei, Yeboah; Batsa, Linda; Pfarr, Kenneth; Larbi, John; Lawson, Bernard; Taylor, Mark; Adjei, Ohene; Hoerauf, Achim

    2006-09-01

    Lymphatic filariasis is a disease of considerable socioeconomic burden in the tropics. Presently used antifilarial drugs are able to strongly reduce transmission and will thus ultimately lower the burden of morbidity associated with the infection, however, a chemotherapeutic principle that directly induces a halt or improvement in the progression of the morbidity in already infected individuals would constitute a major lead. In search of such a more-effective drug to complement the existing ones, in an area endemic for bancroftian filariasis in Ghana, 33 microfilaremic and 18 lymphedema patients took part in a double-blind, placebo-controlled trial of a 6-wk regimen of 200 mg/day doxycycline. Four months after doxycycline treatment, all patients received 150-200 microg/kg ivermectin and 400 mg albendazole. Patients were monitored for Wolbachia and microfilaria loads, antigenemia, filarial dance sign (FDS), dilation of supratesticular lymphatic vessels, and plasma levels of lymphangiogenic factors (vascular endothelial growth factor-C [VEGF-C] and soluble vascular endothelial growth factor receptor-3 [(s)VEGFR-3]). Lymphedema patients were additionally monitored for stage (grade) of lymphedema and the circumferences of affected legs. Wolbachia load, microfilaremia, antigenemia, and frequency of FDS were significantly reduced in microfilaremic patients up to 24 mo in the doxycycline group compared to the placebo group. The mean dilation of supratesticular lymphatic vessels in doxycycline-treated patients was reduced significantly at 24 mo, whereas there was no improvement in the placebo group. Preceding clinical improvement, at 12 mo, the mean plasma levels of VEGF-C and sVEGFR-3 decreased significantly in the doxycycline-treated patients to a level close to that of endemic normal values, whereas there was no significant reduction in the placebo patients. The extent of disease in lymphedema patients significantly improved following doxycycline, with the mean stage of

  10. Doxycycline reduces plasma VEGF-C/sVEGFR-3 and improves pathology in lymphatic filariasis.

    Directory of Open Access Journals (Sweden)

    Alexander Yaw Debrah

    2006-09-01

    Full Text Available Lymphatic filariasis is a disease of considerable socioeconomic burden in the tropics. Presently used antifilarial drugs are able to strongly reduce transmission and will thus ultimately lower the burden of morbidity associated with the infection, however, a chemotherapeutic principle that directly induces a halt or improvement in the progression of the morbidity in already infected individuals would constitute a major lead. In search of such a more-effective drug to complement the existing ones, in an area endemic for bancroftian filariasis in Ghana, 33 microfilaremic and 18 lymphedema patients took part in a double-blind, placebo-controlled trial of a 6-wk regimen of 200 mg/day doxycycline. Four months after doxycycline treatment, all patients received 150-200 microg/kg ivermectin and 400 mg albendazole. Patients were monitored for Wolbachia and microfilaria loads, antigenemia, filarial dance sign (FDS, dilation of supratesticular lymphatic vessels, and plasma levels of lymphangiogenic factors (vascular endothelial growth factor-C [VEGF-C] and soluble vascular endothelial growth factor receptor-3 [(sVEGFR-3]. Lymphedema patients were additionally monitored for stage (grade of lymphedema and the circumferences of affected legs. Wolbachia load, microfilaremia, antigenemia, and frequency of FDS were significantly reduced in microfilaremic patients up to 24 mo in the doxycycline group compared to the placebo group. The mean dilation of supratesticular lymphatic vessels in doxycycline-treated patients was reduced significantly at 24 mo, whereas there was no improvement in the placebo group. Preceding clinical improvement, at 12 mo, the mean plasma levels of VEGF-C and sVEGFR-3 decreased significantly in the doxycycline-treated patients to a level close to that of endemic normal values, whereas there was no significant reduction in the placebo patients. The extent of disease in lymphedema patients significantly improved following doxycycline, with

  11. 果糖及血管内皮生长因子引起仓鼠颊囊血浆外渗%Fructose diet and VEGF-induced plasma extravasation in hamster cheek pouch

    Institute of Scientific and Technical Information of China (English)

    Michel FELETOU; Michelle BOULANGER; Joanna STACZEK; Olivier BROUX; Jacques DUHAULT

    2003-01-01

    AIM: To determine in the hamster cheek pouch whether or not the changes in plasma extravasation induced byvascular endothelial growth factor (VEGF) could be affected by fructose diet. METHODS: Hamsters were sub-jected to control drinking water or to water containing fructose (10 %) for 18 weeks. RESULTS: The fructose dietinduced a small but significant increase in glycemia (0.80±0.11 and 1.09±0.15, n= 8 and 9 for control and fructose-treated animals, respectively, P<0.05). Bradykinin-induced plasma extravasation was not affected by the fructosediet while the effects of VEGF were markedly increased (maximal number of leakage sites: 76±20 and 126±55, n =8 and 9 for control and fructose-treated animals, respectively, P<0.01). CONCLUSION: Even moderate changesin glycemic levels can produce profound alteration in the VEGF response.

  12. Relationship between Expression of beta-catenin and VEGFs(VEGFA,VEGF-C),VEGF Receptors-2(VEGFR-2)in Medulloblastoma

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong-mei; ZHANG Xiong; LI Yu; MI Can

    2008-01-01

    Objective:To investigate the expression of beta-catenin and VEGFs(VEGF-A,VEGF-C)and VEGF receptor-2(VEGFR-2)protein in medulloblastoma.Methods:Immunohistochemical staining with SP method Was conducted to determine the expression of beta-eatenin and VEGFs(VEGF-A,VEGF-C)and VEGFR-2 in 33 cases of medulloblastoma and 10 normal cerebellar tissues. Results:The expression rate of beta-catenin,and VEGFs (VEGF-A,VEGF-C)and VEGFR-2 in medulloblastoma were significantly higher than that in normal tissue.A significant positive correlation was found between beta-catenin and VEGFs(VEGF-A,VEGF-C)and VEGFR-2 protein in medulloblastoma. Conclusion:There was a correlation between beta-catenin and VEGFs(VEGF-A,VEGF-C)and VEGFR-2 in medulloblastoma,which may play a role in the pathogenesis and development of medulloblastoma.

  13. Development of a robust reporter-based assay for the bioactivity determination of anti-VEGF therapeutic antibodies.

    Science.gov (United States)

    Wang, Lan; Xu, Gang-Ling; Gao, Kai; Wilkinson, Jennifer; Zhang, Feng; Yu, Lei; Liu, Chun-Yu; Yu, Chuan-Fei; Wang, Wen-Bo; Li, Meng; Chen, Wei; Fan, Frank; Cong, Mei; Wang, Jun-Zhi

    2016-06-05

    Development of anti-VEGF based biologic agents has been a focus in cancer treatment for the past decades, and several anti-VEGF pharmaceuticals have been already approved for treatment of various medical indications especially in cancer. The first anti-angiogenic agent approved by FDA was bevacizumab (BVZ, trade name Avastin, Genentech/Roche), a humanized anti-VEGF monoclonal antibody. Accurate determination of bioactivity is crucial for the safety and efficacy of therapeutic antibodies. The current method widely used in the lot release and stability test for clinical trial batches of BVZ is anti-proliferation assay using primary human umbilical vein endothelial cells (HUVEC), which is tedious with high assay variations. We describe here the development and preliminary validation of a reporter gene assay (RGA) that is based on an HEK293 cell line stably expressing vascular endothelial growth factor receptor 2 (VEGFR-2), and a luciferase reporter under the control of nuclear factor activated T cell (NFAT) response elements. Our study shows this assay not only to be superior on precision, sensitivity and assay simplicity compared with HUVEC assay, but also applicable to other VEGF-targeted biotherapeutics. These results show for the first time that this new reporter assay, based on the VEGF-VEGFR-NFAT pathway, can be a viable supplement to the HUVEC assay and employed in potency determination of BVZ and other kinds of anti-VEGF antibody-based biotherapeutics. Copyright © 2016. Published by Elsevier B.V.

  14. AlphaB-crystallin is involved in oxidative stress protection determined by VEGF in skeletal myoblasts.

    Science.gov (United States)

    Mercatelli, Neri; Dimauro, Ivan; Ciafré, Silvia Anna; Farace, Maria Giulia; Caporossi, Daniela

    2010-08-01

    Recent studies suggest that the effects of VEGF-A, the prototype VEGF ligand, may extend to a variety of cell types other than endothelial cells. The expression of VEGF-A and its main receptors, Flt-1/VEGFR-1 and KDR/Flk-1/VEGFR-2, was indeed detected in several cell types, including cardiac myocytes and regenerating myotubes. In addition to its proangiogenic activity, evidence indicates that VEGF-A can sustain skeletal muscle regeneration by enhancing the survival and migration of myogenic cells and by promoting the growth of myogenic fibers. In this study, our aim was to investigate whether VEGF could protect skeletal muscle satellite cells from apoptotic cell death triggered by reactive oxygen species and to identify the main molecular mechanisms. C2C12 mouse myoblasts, cultured in vitro in the presence of exogenous VEGF or stably transfected with a plasmid vector expressing VEGF-A, were subjected to oxidative stress and analyzed for cell growth and survival, induction of apoptosis, and molecular signaling. The results of our study demonstrated that VEGF protects C2C12 myoblasts from apoptosis induced by oxidative or hypoxic-like stress. This protection did not correlate with the modulation of the expression of VEGF receptors, but is clearly linked to the phosphorylation of the KDR/Flk-1 receptor, the activation of NF-kappaB, and/or the overexpression of the antiapoptotic protein alphaB-crystallin. Copyright 2010 Elsevier Inc. All rights reserved.

  15. Clinical value ofSerumTSH combined with 3 kinds ofVEGF determination in the early diagnosis of papillary thyroid carcinoma

    Institute of Scientific and Technical Information of China (English)

    Ming Zeng

    2015-01-01

    Objective:To discuss the clinical value of Serum TSH combined with 3 kinds of VEGF (VEGF-C, VEGF-D and VEGFR-3) determination in the early diagnosis of papillary thyroid carcinoma (PTC). Method:Selected 37 cases of patients with thyroid benign tumor (Benign group) and 37 cases of patients with PTC (PTC group), then collected the serum of these both groups, to determine the TSH, VEGF-C, VEGF-D and VEGFR-3 levels of all cases by chemiluminescence immunoassay and enzyme linked immunosorbent assay respectively. Through Logistic model, to calculate the curve area of TSH combined with 3 kinds of VEGF.Results:PTC group: VEGF-C, VEGFR-3 and TSH levels were obviously higher than that in Benign group (P<0.05); and VEGF-C, VEGFR-3 and TSH levels inⅢ-Ⅳ period patients were obviously higher than that in I-Ⅱ period patients (P<0.05); AUC area of VEGF-C, VEGFR-3 and TSH were respectively 0.805, 0.736 and 0.710, reached to significance level (P<0.05); AUC area of combined diagnosis was 0.859.Conclusion:VEGF-C, VEGFR-3 and TSH between papillary thyroid carcinoma and thyroid benign tumor had significant difference. Combined determination could improve the early diagnose rate of PTC, and could be regarded as one of the important auxiliary index of PTC early diagnosis.

  16. Platelet Activation Determines Angiopoietin-1 and VEGF Levels in Malaria : Implications for Their Use as Biomarkers

    NARCIS (Netherlands)

    Brouwers, Judith; Noviyanti, Rintis; Fijnheer, Rob; de Groot, Philip G.; Trianty, Leily; Mudaliana, Siti; Roest, Mark; Syafruddin, Din; van der Ven, Andre; de Mast, Quirijn

    2013-01-01

    Introduction: The angiogenic proteins angiopoietin (Ang)-1, Ang-2 and vascular endothelial growth factor (VEGF) are regulators of endothelial inflammation and integrity. Since platelets store large amounts of Ang-1 and VEGF, measurement of circulation levels of these proteins is sensitive to platele

  17. Quantitative determination of VEGF165 in cell culture medium by aptamer sandwich based chemiluminescence assay.

    Science.gov (United States)

    Shan, Siwen; He, Ziyi; Mao, Sifeng; Jie, Mingsha; Yi, Linglu; Lin, Jin-Ming

    2017-08-15

    In this work, we have developed a sensitive and selective chemiluminescence (CL) assay for vascular endothelial growth factor (VEGF165) quantitative detection based on two specific VEGF165 binding aptamers (Apt). VEGF is a predominant biomarker in cancer angiogenesis, and sensitive detection method of VEGF are highly demanded for both academic study and clinical diagnosis of multiple cancers. In our experiment, VEGF165 was captured in a sandwich structure assembled by two binding aptamers, one capture aptamer was immobilized on streptavidin-coated magnetic beads (MBs) and another VEGF-binding aptamer was labeled by biotin for further phosphatase conjunction. After Apt-VEGF-Apt sandwich was formed on MBs surface, alkaline phosphatase (ALP) was modified to the second aptamer to catalyze CL reaction. By applying 4-methoxy-4-(3-phosphatephenyl)-spiro-(1,2-dioxetane-3,2-adamantane) (AMPPD) as CL substrate, strong signal intensity was achieved. VEGF165 content as low as 1ng/mL was detected in standard spiked samples by our assay, and linear range of working curve was confirmed from 1 to 20ng/mL. Then our method was successfully applied for cell culture medium analysis and on-chip hypoxic HepG2-HUVEC co-culture model study with excellent accuracy equal to ELISA Kit. Our developed assay demonstrated an outstanding performance in VEGF165 quantification and may be further extended to clinical testing of important biomarkers as well as probing microchip cell culture model. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Genetic determinants of plasma triglycerides

    Science.gov (United States)

    Johansen, Christopher T.; Kathiresan, Sekar; Hegele, Robert A.

    2011-01-01

    Plasma triglyceride (TG) concentration is reemerging as an important cardiovascular disease risk factor. More complete understanding of the genes and variants that modulate plasma TG should enable development of markers for risk prediction, diagnosis, prognosis, and response to therapies and might help specify new directions for therapeutic interventions. Recent genome-wide association studies (GWAS) have identified both known and novel loci associated with plasma TG concentration. However, genetic variation at these loci explains only ∼10% of overall TG variation within the population. As the GWAS approach may be reaching its limit for discovering genetic determinants of TG, alternative genetic strategies, such as rare variant sequencing studies and evaluation of animal models, may provide complementary information to flesh out knowledge of clinically and biologically important pathways in TG metabolism. Herein, we review genes recently implicated in TG metabolism and describe how some of these genes likely modulate plasma TG concentration. We also discuss lessons regarding plasma TG metabolism learned from various genomic and genetic experimental approaches. Treatment of patients with moderate to severe hypertriglyceridemia with existing therapies is often challenging; thus, gene products and pathways found in recent genetic research studies provide hope for development of more effective clinical strategies. PMID:21041806

  19. Increased plasma VEGF levels following ischemic preconditioning are associated with downregulation of miRNA-762 and miR-3072-5p

    Science.gov (United States)

    Ueno, Koji; Samura, Makoto; Nakamura, Tamami; Tanaka, Yuya; Takeuchi, Yuriko; Kawamura, Daichi; Takahashi, Masaya; Hosoyama, Tohru; Morikage, Noriyasu; Hamano, Kimikazu

    2016-01-01

    Ischemic preconditioning (IPC) has protective effects against ischemia-perfusion injury of organs. In the present study, we investigated the associated mechanisms after performing remote IPC (rIPC) of lower limbs by clamping abdominal aorta in mice. Subsequent experiments showed decreased damage and paralysis of lower limbs following spinal cord injury (SCI). Concomitantly, plasma vascular endothelial growth factor (VEGF) levels were increased 24 h after rIPC compared with those in sham-operated animals. In subsequent microRNA analyses, thirteen microRNAs were downregulated in exosomes 24 h after rIPC. Further studies of femoral CD34-positive bone marrow (BM) cells confirmed downregulation of these seven microRNAs 24 h after rIPC compared with those in sham-operated controls. Subsequent algorithm-based database searches suggested that two of the seven microRNAs bind to the 3′ UTR of VEGF mRNA, and following transfection into CD34-positive BM cells, anti-miR-762, and anti-miR-3072-5p inhibitors led to increased VEGF concentrations. The present data suggest that rIPC transiently increases plasma VEGF levels by downregulating miR-762 and miR-3072-5p in CD34-positive BM cells, leading to protection against organ ischemia. PMID:27905554

  20. Prognostic impact of matched preoperative plasma and serum VEGF in patients with primary colorectal carcinoma

    DEFF Research Database (Denmark)

    Werther, K; Christensen, Ib Jarle; Nielsen, Hans Jørgen

    2002-01-01

    . The present study analyzed the prognostic value of matched preoperative serum and plasma vascular endothelial growth factor concentrations in patients with colorectal cancer. To establish the reference range among healthy people, vascular endothelial growth factor was analyzed in 50 matched EDTA......)) and healthy blood donors (220 pg ml(-1)). The preoperative vascular endothelial growth factor concentrations were dichotomized by the 95th percentile of the healthy blood donors (plasma=112 pg ml(-1), serum=533 pg ml(-1)). In univariate survival analyses, both high plasma vascular endothelial growth factor...... (>112 pg ml(-1)) and high serum vascular endothelial growth factor (>533 pg ml(-1)) predicted a reduced survival. In multivariate survival analyses, high serum vascular endothelial growth factor (>533 pg ml(-1)) independently predicted a reduced survival (HR=1.65, P=0.015), while high plasma vascular...

  1. Circulating VEGF as a biological marker in patients with rheumatoid arthritis? Preanalytical and biological variability in healthy persons and in patients

    DEFF Research Database (Denmark)

    Hetland, Merete Lund; Christensen, Ib Jarle; Lottenburger, Tine

    2008-01-01

    and contamination of plasma with cellular elements lead to significant increases in VEGF levels, whereas storage for up to 2 years at -80 degrees C or up to 10 freeze/thaw cycles did not affect VEGF levels. Serum VEGF levels were 7-10 fold higher than plasma VEGF levels. Reference intervals for VEGF (plasma: 45 pg...

  2. Circulating VEGF as a biological marker in patients with rheumatoid arthritis? Preanalytical and biological variability in healthy persons and in patients

    DEFF Research Database (Denmark)

    Hetland, Merete Lund; Christensen, Ib Jarle; Lottenburger, Tine

    2008-01-01

    and contamination of plasma with cellular elements lead to significant increases in VEGF levels, whereas storage for up to 2 years at -80 degrees C or up to 10 freeze/thaw cycles did not affect VEGF levels. Serum VEGF levels were 7-10 fold higher than plasma VEGF levels. Reference intervals for VEGF (plasma: 45 pg...

  3. Antiangiogenic VEGF Isoform in Inflammatory Myopathies

    Directory of Open Access Journals (Sweden)

    Nila Volpi

    2013-01-01

    Full Text Available Objective. To investigate expression of vascular endothelial growth factor (VEGF antiangiogenic isoform A-165b on human muscle in idiopathic inflammatory myopathies (IIM and to compare distribution of angiogenic/antiangiogenic VEGFs, as isoforms shifts are described in other autoimmune disorders. Subjects and Methods. We analyzed VEGF-A165b and VEGF-A by western blot and immunohistochemistry on skeletal muscle biopsies from 21 patients affected with IIM (polymyositis, dermatomyositis, and inclusion body myositis and 6 control muscle samples. TGF-β, a prominent VEGF inductor, was analogously evaluated. Intergroup differences of western blot bands density were statistically examined. Endomysial vascularization, inflammatory score, and muscle regeneration, as pathological parameters of IIM, were quantitatively determined and their levels were confronted with VEGF expression. Results. VEGF-A165b was significantly upregulated in IIM, as well as TGF-β. VEGF-A was diffusely expressed on unaffected myofibers, whereas regenerating/atrophic myofibres strongly reacted for both VEGF-A isoforms. Most inflammatory cells and endomysial vessels expressed both isoforms. VEGF-A165b levels were in positive correlation to inflammatory score, endomysial vascularization, and TGF-β. Conclusions. Our findings indicate skeletal muscle expression of antiangiogenic VEGF-A165b and preferential upregulation in IIM, suggesting that modulation of VEGF-A isoforms may occur in myositides.

  4. 下肢慢性缺血患者的超重和肥胖对血浆中VEGF-A、VEGFR-1和VEGFR-2浓度的影响%Overweight and obesity versus concentrations of VEGF-A, sVEGFR-1, and sVEGFR-2 in plasma of patients with lower limb chronic ischemia

    Institute of Scientific and Technical Information of China (English)

    Radosaw WIECZR; Anna Maria WIECZR; Grayna GADOMSKA; Katarzyna STANKOWSKA; Jacek FABISIAK; Karol SUPPAN; Grzegorz PULKOWSKI; Jacek BUDZYSKI; Danuta RO

    2016-01-01

    Objective:Being overweight or obese comprises a significant risk factor for atherosclerosis. Fat tissue also generates factors stimulating angiogenesis, the process by which new blood vessels form. The purpose of this paper is to assess concentrations of the vascular endothelial growth factor A (VEGF-A) and its soluble type-1 and type-2 re-ceptors (sVEGFR-1 and sVEGFR-2) in plasma of patients with peripheral arterial disease (PAD) depending on the level of nutrition according to body mass index (BMI). Methods: The study group included patients suffering from symptomatic PAD (n=46) in Fontaine classes IIa–IV without any history of neoplastic disease and who have a normal BMI (n=15), are overweight (n=21) or are obese (n=10). The control group (n=30) consisted of healthy non-smoking volunteers who were neither overweight nor obese. Venous blood plasma samples were col ected from both groups at rest in the morning to determine plasma concentrations of VEGF-A, sVEGFR-1, and sVEGFR-2 using the enzyme-linked immunosorbent assay (ELISA) method. Results:The group of patients with PAD co-existent with being over-weight or obese tended to have higher mean concentration levels of VEGF-A and sVEGFR-2 when compared with patients suffering from PAD with normal BMI. A statistical y significant positive correlation was obtained between BMI and average plasma concentrations of sVEGFR-2 (R=0.37, P=0.0103). However, no significant correlation was no-ticed between BMI and VEGF-A or sVEGFR-1 concentrations. Conclusions: A positive correlation determined be-tween the level of antiangiogenic factor and BMI value may be indicative of the linearly growing prevalence of some antiangiogenic factors in patients with metabolic disorders, which may be one of numerous factors contributing to incomplete efficiency of collateral circulation development in patients with PAD.%目的:研究外周动脉疾病(PAD)患者血浆中血管内皮生长因子 A(VEGF-A)和它的可溶性1型和2

  5. Effective electrophoretic mobilities and charges of anti-VEGF proteins determined by capillary zone electrophoresis.

    Science.gov (United States)

    Li, S Kevin; Liddell, Mark R; Wen, He

    2011-06-01

    Macromolecules such as therapeutic proteins currently serve an important role in the treatment of eye diseases such as wet age-related macular degeneration and diabetic retinopathy. Particularly, bevacizumab and ranibizumab have been shown to be effective in the treatment of these diseases. Iontophoresis can be employed to enhance ocular delivery of these macromolecules, but the lack of information on the properties of these macromolecules has hindered its development. The objectives of the present study were to determine the effective electrophoretic mobilities and charges of bevacizumab, ranibizumab, and model compound polystyrene sulfonate (PSS) using capillary zone electrophoresis. Salicylate, lidocaine, and bovine serum albumin (BSA), which have known electrophoretic mobilities in the literature, were also studied to validate the present technique. The hydrodynamic radii and diffusion coefficients of BSA, bevacizumab, ranibizumab, and PSS were measured by dynamic light scattering. The effective charges were calculated using the Einstein relation between diffusion coefficient and electrophoretic mobility and the Henry equation. The results show that bevacizumab and ranibizumab have low electrophoretic mobilities and are net negatively charged in phosphate buffered saline (PBS) of pH 7.4 and 0.16M ionic strength. PSS has high negative charge but the electrophoretic mobility in PBS is lower than that expected from the polymer structure. The present study demonstrated that capillary electrophoresis could be used to characterize the mobility and charge properties of drug candidates in the development of iontophoretic drug delivery.

  6. Miniaturizing VEGF: Peptides mimicking the discontinuous VEGF receptor-binding site modulate the angiogenic response.

    Science.gov (United States)

    De Rosa, Lucia; Finetti, Federica; Diana, Donatella; Di Stasi, Rossella; Auriemma, Sara; Romanelli, Alessandra; Fattorusso, Roberto; Ziche, Marina; Morbidelli, Lucia; D'Andrea, Luca Domenico

    2016-08-08

    The angiogenic properties of VEGF are mediated through the binding of VEGF to its receptor VEGFR2. The VEGF/VEGFR interface is constituted by a discontinuous binding region distributed on both VEGF monomers. We attempted to reproduce this discontinuous binding site by covalently linking into a single molecular entity two VEGF segments involved in receptor recognition. We designed and synthesized by chemical ligation a set of peptides differing in length and flexibility of the molecular linker joining the two VEGF segments. The biological activity of the peptides was characterized in vitro and in vivo showing a VEGF-like activity. The most biologically active mini-VEGF was further analyzed by NMR to determine the atomic details of its interaction with the receptor.

  7. VEGF regulates TRPC6 channels in podocytes

    DEFF Research Database (Denmark)

    Thilo, Florian; Liu, Ying; Loddenkemper, Christoph;

    2012-01-01

    BACKGROUND: Both, increased plasma concentrations of vascular endothelial growth factor (VEGF) and increased expression of transient receptor potential canonical type 6 (TRPC6) channels in podocytes have been associated with proteinuric kidney diseases. Now, we investigated the hypothesis that VE...

  8. Gas chromatographic determination of xanthinol in plasma

    NARCIS (Netherlands)

    Roseboom, H.; Wiese, G.

    1979-01-01

    The determination of xanthinol in plasma is described. After extraction of the drug, together with the internal standard (papaverine hydrochloride), the extract is evaporated to dryness and the drug is derivatized with acetic anhydride for chromatography. The method is linear for 2–100μg ml-1 ; the

  9. 2型糖尿病肾病患者治疗前后VEGF水平检测的临床意义%Clinical Significance of Determination of Changes of Plasma Vascular Endothelial Growth Factor(VEGF) Contents after Treatment in Diabetic Patients with Nephropathy Type-2 Diabetes

    Institute of Scientific and Technical Information of China (English)

    彭湘鹤

    2014-01-01

    目的探讨2型糖尿病肾病患者血管内皮生长因子的水平。方法应用酶联双抗体夹心法测定84例2型糖尿病肾病患者血管内皮生长因子的含量,与正常对照组76例进行比较。结果2型糖尿病肾病患者在治疗前后血中血管内皮生长因子水平与正常对照组有显著性差异(<0.01)。结论2型糖尿病肾病的发生、发展与血管内皮生长因子水平密切相关。%Objective To investigate Type 2 diabetic nephropathy patients with vascular endothelial growth factor levels. Methods Application of enzyme-linked double antibody clamp method to determination of 84 cases of type 2 diabetic nephropathy patients with vascular endothelial growth factor levels, compared with 76 cases of normal control group. Results In type 2 diabetic nephropathy patients before and after treatment the blood level of vascular endothelial growth factor and normal control group with significant dif erence ( <0.01). Conclusion The occurrence and development of type 2 diabetic nephropathy and vascular endothelial growth factor levels are closely related.

  10. Determination and distribution of human plasma selenoproteins

    Energy Technology Data Exchange (ETDEWEB)

    Plecko, T.; Nordmann, S.; Ruekgauer, M.; Kruse-Jarres, J.D. [Institute for Clinical Chemistry and Laboratory Medicine, Stuttgart (Germany)

    1999-03-01

    Major portions of plasma-selenium are incorporated in the proteins glutathione peroxidase (GSH-Px), selenoprotein P (Sel P) and albumin. A chromatographic method, adapted from a procedure by Harrison et al. [6], uses heparin- and blue-sepharose to separate the three protein fractions. The determination of selenium was carried out by electrothermal atomic absorption spectroscopy (ETAAS) using the Zeeman effect. The selenium distribution of 17 healthy subjects was 68 {+-} 7% of the total plasma selenium associated to Sel P, 25 {+-} 4% associated to p-GSH-Px and 7{+-}4% associated to albumin. The recovery of selenium was 99 {+-} 4%. For precision measurements a plasma pool has been separated seven times. The selectivity of this method was monitored by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and GSH-Px activity measurements. A fast method, adapted for clinical applications, is described which allows to determine the human plasma selenium distribution in about an hour. (orig.) With 2 tabs., 8 refs.

  11. Myc regulates VEGF production in B cells by stimulating initiation of VEGF mRNA translation.

    Science.gov (United States)

    Mezquita, Pau; Parghi, Sean S; Brandvold, Kimberly A; Ruddell, Alanna

    2005-01-27

    Deregulated c-myc gene expression is associated with many human and animal cancers. Myc overexpression promotes the growth of blood and lymphatic vessels, which is due in part to induction of growth factors including vascular endothelial growth factor (VEGF). We determined that the P493-6 human B-cell line increases VEGF production 10-fold upon Myc overexpression. Myc overexpression in avian B cells similarly resulted in high level VEGF production. Real-time RT-PCR analyses showed that Myc did not alter the VEGF mRNA content of these cell lines, indicating that a post-transcriptional mechanism regulates VEGF production. VEGF mRNA translation was examined by RT-PCR analysis of monosome and polysome sucrose gradient fractions from Myc-on and Myc-off P493-6 cells. Myc increased VEGF mRNA translation initiation, as VEGF mRNA loading onto polysomes increased 14-fold in Myc-on cells, and the number of ribosomes loaded per VEGF mRNA increased threefold. This translational regulation is specific to VEGF mRNA, as total polysomes show the same sucrose gradient profile in Myc-on and Myc-off cells, with no change in the percent ribosomes in polysomes, or in the number of ribosomes per polysomal mRNA. Myc stimulates VEGF production by a rapamycin- and LY294002-sensitive pathway, which does not involve alteration of eIF4E activity.

  12. HPLC determination of tolperisone in human plasma.

    Science.gov (United States)

    Bae, Jung-Woo; Park, Young-Seo; Sohn, Uy-Dong; Myung, Chang-Sun; Ryu, Byung-Kwon; Jang, Choon-Gon; Lee, Seok-Yong

    2006-04-01

    A simple high performance liquid chromatographic (HPLC) method was developed for the determination of tolperisone in human plasma. Tolperisone and internal standard (chlorphenesin) were isolated from 1 mL of plasma using 8 mL of dichlormethane. The organic phase was collected and evaporated under nitrogen gas. The residue was then reconstituted with 300 mL aliquot of mobile phase and a 100 mL aliquot was injected onto the C18 reverse-phased column. The mobile phase, 45% methanol containing 1% glacial acetic acid and 0.05% 1-hexanesulfonic acid was run at a flow rate of 1 mL/min. The column effluent was monitored using UV detector at 260 nm. The retention times for tolperisone and the internal standard were approximately 7.1 and 8.4 min, respectively. The standard curve was linear with minimal intra-day and inter-day variability. The quantification limit of tolperisone in human plasma was 10 ng/ mL. The proposed method has been applied to the determination of pharmacokinetic profile of tolperisone in Koreans. The Tmax of tolperisone in Koreans (0.94 +/- 0.42 h) was not significantly differ from that reported in Europeans (0.5-1 h), but the mean half-life in Koreans (1.14 +/- 0.27 h) was shorter than that in Europeans (2.56 +/- 0.2 h). The proposed HPLC method is simple, accurate, reproducible and suitable for pharmacokinetic study of tolperisone.

  13. VEGF and prostatic cancer: a systematic review.

    Science.gov (United States)

    Botelho, Francisco; Pina, Francisco; Lunet, Nuno

    2010-09-01

    Elevated vascular endothelial growth factor (VEGF) blood concentration reflects its prostatic production, making this a potentially interesting tumour marker to support the decision of submitting a patient for prostatic biopsy. The objective was to review systematically the evidence on the role of VEGF blood concentration in prostate cancer detection. Published studies addressing the relation between serum or plasma VEGF levels and prostate cancer were identified by searching Pubmed, ISI Web of Knowledge, SCOPUS and LILACS up to January 2010, and reviewed following a standardized protocol. Three studies reported higher plasma VEGF (pg/ml) in patients with localized prostate cancer than in healthy controls (7.0 vs. 0.0, 9.9 vs. 2.2, and 210 vs. 26.5, Pprostate cancer patients than in patients with benign prostate hypertrophy (518.9 vs. 267.9, Pbenign prostate hypertrophy, localized or metastatic prostate cancer. The three studies that used controls with previous suspicion of prostatic cancer but a negative biopsy reported non-statistically significant difference in VEGF serum levels (pg/ml) between controls and localized prostate cancer patients (241 vs. 206; 69.5 vs. 55; 215.2 vs. 266.4). Higher VEGF plasma levels are observed in prostatic cancer patients compared with healthy controls, but serum levels do not appear to be useful in differentiating benign from malignant prostatic disease using, as controls, individuals with high risk of prostate cancer and negative biopsy.

  14. Angiogenesis related genes NOS3, CD14, MMP3 and IL4R are associated to VEGF gene expression and circulating levels in healthy adults.

    Science.gov (United States)

    Saleh, Abdelsalam; Stathopoulou, Maria G; Dadé, Sébastien; Ndiaye, Ndeye Coumba; Azimi-Nezhad, Mohsen; Murray, Helena; Masson, Christine; Lamont, John; Fitzgerald, Peter; Visvikis-Siest, Sophie

    2015-10-05

    Vascular endothelial growth factor (VEGF) plays a key role in angiogenesis. The aim was to assess the genetic connections between the angiogenesis-related NOS3, CD14, MMP3, IL4R, IL4 genes and VEGF expression and plasma levels. The associations between VEGF plasma levels with the polymorphisms of NOS3, CD14, MMP3, IL4R, and IL4 were assessed in 403 healthy unrelated adults. The epistatic and environmental interactions were explored, including four VEGF-related polymorphisms previously identified. The VEGF expression in peripheral blood mononuclear cells was quantified (n = 65) for the VEGF121, VEGF145, VEGF165, and VEGF189 isoforms. The polymorphism rs1799983 of NOS3 was associated with the sum of all VEGF isoforms mRNA levels (P = 0.032) and VEGF145 (P = 0.033). Rs1800779 of NOS3 interacted with rs3918226 of the same gene and with the rs2569190 of CD14 (P = 0.022, P = 0.042, respectively) for VEGF plasma levels. Other epistatic interactions included the rs1801275 of IL4R with the rs6921438 (VEGF-related variant) and rs3025058 of MMP3 (P = 0.042, P = 0.010 respectively) and the rs2569190 of CD14 with the rs3025058 of MMP3 (P = 0.0119). We also identified an interaction of rs1800779 with obesity, high-density lipoprotein cholesterol and triglycerides (P = 0.018, P = 0.005, P = 0.043, respectively) as well as the interaction of rs6921438 with hypertension (P = 0.028). Our findings indicated that genetic variants of NOS3, CD14, MMP3 and IL4R are implicated in the determination of VEGF expression and plasma levels. Thus, they support the hypothesis that in physiological conditions there are complex biological relationships between pathways (such as angiogenesis and inflammation), which are involved in the development of chronic diseases.

  15. Anemia and elevated systemic levels of vascular endothelial growth factor (VEGF)

    Energy Technology Data Exchange (ETDEWEB)

    Dunst, J.; Becker, A.; Lautenschlaeger, C.; Markau, S.; Becker, H.; Fischer, K.; Haensgen, G. [Martin-Luther Univ. Halle-Wittenberg (Germany)

    2002-08-01

    Background: Tissue hypoxia is a major stimulus for the up-regulation of vascular endothelial growth factor (VEGF). Anemia might theoretically impact on angiogenesis via impairment of tissue oxygenation. We have investigated this hypothesis in patients with solid cancers and benign diseases. Patients and methods: 49 patients with untreated locoregionally confined solid cancers of the head and neck, cervix, rectum and lung and 59 additional patients with non-malignant diseases (36 normemic patients without serious diseases and 23 patients with renal anemia) were enrolled and the impact of anemia on plasma VEGF levels were determined. VEGF was measured with a commercially available sandwich enzyme immunoassay technique. Results: Plasma levels of VEGF were 16.2{+-}12.7 pg/ml in 36 normemic patients without malignant disease, 49,2{+-}34.5 pg/ml in 49 patients with cancers (p<0.001), and 89.9{+-}67.8 pg/ml in 23 patients with renal anemia (p=0.001). VEGF levels in cancer patients were significantly correlated with hemoglobin (hb) levels and platelet counts (each p=0.001), but not with type of tumor, stage, histology or age. Patients with cancers had higher plasma levels of VEGF than patients with non-malignant diseases in case of hb{>=}12 g/dl (33.1{+-}17.5 vs. 16.6{+-}13.0 pg/ml, p<0.001) and in case of hb between 11.0 and 11.9 g/dl (56.1{+-}26.4 vs 18.5{+-}14.5 pg/ml, p=0.038). In case of a hb<11 g/dl, plasma VEGF levels were significantly elevated in patients with and without cancers (67.0{+-}47.5 vs 88.9{+-}68.8 pg/ml, n.s.). In a multivariate model, a significant association between low hb levels and increased plasma levels of VEGF was confirmed. In 16 patients with renal anemia, changes in hb under erythropoietin treatment were inversely correlated with changes in plasma VEGF levels with decreasing VEGF after increase in hb (p=0.01). Conclusions: Anemic patients have elevated levels of VEGF. The data suggest that anemia might impact on the progression of

  16. The effects of adenosine A2B receptor inhibition on VEGF and nitric oxide axis-mediated renal function in diabetic nephropathy.

    Science.gov (United States)

    Patel, Leena; Thaker, Aswin

    2014-07-01

    Diabetic nephropathy (DN) is the most common cause of end-stage renal disease worldwide. The pathophysiologic mechanisms of diabetic nephropathy are incompletely understood but include overproduction of various growth factors and cytokines. Upregulation of vascular endothelial growth factor (VEGF) is a pathogenic event occurring in most forms of podocytopathy; however, the mechanisms that regulate this growth factor induction are not clearly identified. A2B receptors have been found to regulate VEGF expression under hypoxic environment in different tissues. One proposed hypothesis in mediating diabetic nephropathy is the modulation of VEGF-NO balance in renal tissue. We determined the role of adenosine A2B receptor in mediating VEGF overproduction and nitrite in diabetic nephropathy. The renal content of A2B receptors and VEGF was increased after 8 weeks of diabetes induction. The renal and plasma nitrite levels were also reduced in these animals. In vivo administration of A2B adenosine receptor antagonist (MRS1754) inhibited the renal over expression of VEGF and adverse renal function parameters. The antagonist administration also improved the kidney tissue nitrite levels. In conclusion, we demonstrated that VEGF induction via adenosine signaling might be the critical event in regulating VEGF-NO axis in diabetic nephropathy.

  17. Determination of benzocaine in rainbow trout plasma

    Science.gov (United States)

    Bernardy, Jeffery A.; Coleman, K.S.; Stehly, G.R.; Gingerich, William H.

    1996-01-01

    A liquid chromatographic method is described for analysis of benzocaine (BZ), a proposed fish anesthetic, in rainbow trout plasma, Mean recoveries of BZ from plasma samples fortified at 44-10 100 ng/mL were 96-100%. The method detection limit is 10 ng/mL, and the limit of quantitation is 37 ng/mL. Acetylation of BZ occurs in whole blood after storage at room temperature (i.e., 21 degrees C) for 10 min. However, no acetylation of BZ was detected in plasma samples held at room temperature for 4 h, Mean method precision for plasma samples with incurred BZ residue is similar to that for fortified samples in the same concentration range (relative standard deviations of 0.9 and 1.2%, respectively).

  18. Autocrine VEGF isoforms differentially regulate endothelial cell behavior

    Directory of Open Access Journals (Sweden)

    Hideki Yamamoto

    2016-09-01

    Full Text Available Vascular endothelial growth factor A (VEGF is involved in all the essential biology of endothelial cells, from proliferation to vessel function, by mediating intercellular interactions and monolayer integrity. It is expressed as three major alternative spliced variants. In mice, these are VEGF120, VEGF164, and VEGF188, each with different affinities for extracellular matrices and cell surfaces, depending on the inclusion of heparin-binding sites, encoded by exons 6 and 7. To determine the role of each VEGF isoform in endothelial homeostasis, we compared phenotypes of primary endothelial cells isolated from lungs of mice expressing single VEGF isoforms in normoxic and hypoxic conditions. The differential expression and distribution of VEGF isoforms affect endothelial cell functions, such as proliferation, adhesion, migration and integrity, which are dependent on the stability of and affinity to VEGF receptor 2 (VEGFR2. We found a correlation between autocrine VEGF164 and VEGFR2 stability, which is also associated with increased expression of proteins involved in cell adhesion. Endothelial cells expressing only VEGF188, which localizes to extracellular matrices or cell surfaces, presented a mesenchymal morphology and weakened monolayer integrity. Cells expressing only VEGF120 lacked stable VEGFR2 and dysfunctional downstream processes, rendering the cells unviable. Endothelial cells expressing these different isoforms in isolation also had differing rates of apoptosis, proliferation, and signaling via nitric oxide (NO synthesis. These data indicate that autocrine signaling of each VEGF isoform has unique functions on endothelial homeostasis and response to hypoxia, due to both distinct VEGF distribution and VEGFR2 stability, which appears to be, at least partly, affected by differential NO production. This study demonstrates that each autocrine VEGF isoform has a distinct effect on downstream functions, namely VEGFR2-regulated endothelial cell

  19. VEGF 936C > T Polymorphism and Association of BI-RADS Score in Women with Suspected Breast Cancer

    Directory of Open Access Journals (Sweden)

    M. Wehrschuetz

    2009-10-01

    Full Text Available Purpose: Vascular endothelial growth factor (VEGF is a potent regulator of angiogenesis and thereby involved in the development and progression of solid tumors. A 936C> T polymorphism in the VEGF gene has been associated with reduced VEGF plasma levels. Purpose of the present study was to analyze the potential association between VEGF genotype and radiological appearance of breast lesions by mammography. Materials and Methods: Fifty two women with 54 suspected breast lesions were analyzed by the use of mammography with the standard breast imaging reporting and data systems (BI-RADS. Germline VEGF genotype was determined in all subjects by allele-specific digestion of amplification products. An open biopsy was performed on all lesions. Results: VEGF CC, CT and TT genotypes were found in 41 (79%, 9 (17% and 2 (4% patients. By mammography 26, 16 and 12 suspected breast lesions were classified as BI-RADS scores 3, 4 and 5, respectively. Both carriers of the TT genotype were classified as BI-RADS 5, whereas among CT or CC carriers, BI-RADS scores 3, 4 and 5 were found in 26, 16 and 10 subjects (P T polymorphism seems to be associated with a high BI-RADS score in women with suspicious breast lesions.

  20. Hcy及 VEGF与妊娠高血压疾病的关系%Relationship between plasma Hcy and VEGF levels and HDP

    Institute of Scientific and Technical Information of China (English)

    邹跃玲; 吴礼锋; 冯维良

    2014-01-01

    Objective To investigate the clinical significance of homocysteine (Hcy) and vascular endothelial growth factor (VEGF) and their relationship with hypertensive disorders in pregnancy ( HDP).Methods From January 2012 to December 2013 800 cases of HDP (375 cases of HDP, 305 cases of mild preeclampsia and 120 cases of severe preeclampsia) were admitted in People’s Hospital of Ruian City, and they were selected in HDP group .Another 800 cases of normal pregnant women at third trimester were selected in control group . The serum levels of Hcy and VEGF of two groups were detected with Enzymatic Cycling Assays Method and enzyme immunoassay .Results Hcy level of the HDP group was higher than the control group , but VEGF level was lower .The differences between two groups were significant (t value was 4.265 and 5.426, respectively, both P<0.05).Hcy level of the severe preeclampsia group was significantly higher than that of the HDP group and mild preeclampsia group (t value was 34.575 and 15.855, respectively, both P<0.05), but VEGF level was significantly lower (t value was 9.512 and 6.906, respectively, both P<0.05).Compared with the patients with good prognosis, the patients with poor prognosis had higher Hcy level and lower VEGF level , and the differences were significant ( t value was 5.448 and 6.325, respectively, both P<0.05).Conclusion Increased level of Hcy and decreased level of VEGF are closely related with the occurrence , progression and prognosis of HDP .Hcy and VEGF can be considered as evaluating indicators for prognosis of HDP .%目的:探讨同型半胱氨酸( Hcy)、血管内皮生长因子( VEGF)与妊娠高血压疾病( HDP)的关系及其临床意义。方法选取浙江省瑞安市人民医院2012年1月至2013年12月收治的800例HDP患者为研究对象,其中妊娠高血压375例,轻度子痫305例,重度子痫120例,另选取同期正常孕晚期妇女800例为对照组,分别采用循环酶法及酶类免疫法测定

  1. Hypoxia promotes adipose-derived stem cell proliferation via VEGF

    Directory of Open Access Journals (Sweden)

    Phuc Van Pham

    2016-01-01

    Full Text Available Adipose-derived stem cells (ADSCs are a promising mesenchymal stem cell source with therapeutic applications. Recent studies have shown that ADSCs could be expanded in vitro without phenotype changes. This study aimed to evaluate the effect of hypoxia on ADSC proliferation in vitro and to determine the role of vascular endothelial growth factor (VEGF in ADSC proliferation. ADSCs were selectively cultured from the stromal vascular fraction obtained from adipose tissue in DMEM/F12 medium supplemented with 10% fetal bovine serum and 1% antibiotic-antimycotic. ADSCs were cultured under two conditions: hypoxia (5% O2 and normal oxygen (21% O2. The effects of the oxygen concentration on cell proliferation were examined by cell cycle and doubling time. The expression of VEGF was evaluated by the ELISA assay. The role of VEGF in ADSC proliferation was studied by neutralizing VEGF with anti-VEGF monoclonal antibodies. We found that the ADSC proliferation rate was significantly higher under hypoxia compared with normoxia. In hypoxia, ADSCs also triggered VEGF expression. However, neutralizing VEGF with anti-VEGF monoclonal antibodies significantly reduced the proliferation rate. These results suggest that hypoxia stimulated ADSC proliferation in association with VEGF production. [Biomed Res Ther 2016; 3(1.000: 476-482

  2. Clinical Significance of Measurement on the Changes of Plasma Leptin and Serum VEGF, HGF Levels After Hemodialysis in Patients with Chronic Renal Failure%慢性肾功能衰竭患者血透前后血浆leptin和血清VEGF、HGF检测的临床意义

    Institute of Scientific and Technical Information of China (English)

    顾涛

    2012-01-01

    Objective To explor the clinical significance of changes on plasma leptin and serum VEGF,HGF levels after hemodi-alysis in patients with chronic renal failure. Methods Plasma leptin (with RIA) , serum VEGF, HGF(with ELISA) levels were measured in 32 patients with chronic renal failure both before and after hemodialysis as well as in 35 normal healthy controls. Results Before hemodialysis plasma leptin and serum VEGF,HGF levels were significantiy higher in the patients than those in controls (P < 0.05). Conclusion The levels of leptin, VEGF and HGF were significantly increased in patients with chronic renal failure. Hemodialysis could increase the clearance rate of leptin, VEGF and HGF and might be useful for clinical assessment.%目的:探讨了慢性肾功能衰竭(CRF)患者血透前后血浆leptin和血清VEGF、HGF水平的变化及意义.方法:应用放射免疫分析和酶联法对32例CRF患者进行了血透前后血浆leptin和血清VEGF、HGF检测,并与35名正常健康人作比较.结果:CRF在血透前血浆leptin和血清VEGF、HGF水平非常显著地高于正常人组(P<0.01).结论:CRF患者存在高leptin、VEGF、HGF血症.血透可增加leptin、VEGF和HGF的清除率,具有重要的临床价值.

  3. Determination of molecular species of lecithin from erythrocytes and plasma

    NARCIS (Netherlands)

    Golde, L.M.G. van; Tomasi, V.; Deenen, L.L.M. van

    The molecular species of lecithin from erythrocyte and plasma of man and rabbit were determined after conversion of the lecithins into diglycerides by means of hydrolysis with phospholipase C. The resultant diglycerides were separated by thin-layer chromatography on silica impregnated with silver

  4. Determination of molecular species of lecithin from erythrocytes and plasma

    NARCIS (Netherlands)

    Golde, L.M.G. van; Tomasi, V.; Deenen, L.L.M. van

    1967-01-01

    The molecular species of lecithin from erythrocyte and plasma of man and rabbit were determined after conversion of the lecithins into diglycerides by means of hydrolysis with phospholipase C. The resultant diglycerides were separated by thin-layer chromatography on silica impregnated with silver ni

  5. VEGF121b and VEGF165b are weakly angiogenic isoforms of VEGF-A

    Directory of Open Access Journals (Sweden)

    Pio Ruben

    2010-12-01

    Full Text Available Abstract Background Different isoforms of VEGF-A (mainly VEGF121, VEGF165 and VEGF189 have been shown to display particular angiogenic properties in the generation of a functional tumor vasculature. Recently, a novel class of VEGF-A isoforms, designated as VEGFxxxb, generated through alternative splicing, have been described. Previous studies have suggested that these isoforms may inhibit angiogenesis. In the present work we have produced recombinant VEGF121/165b proteins in the yeast Pichia pastoris and constructed vectors to overexpress these isoforms and assess their angiogenic potential. Results Recombinant VEGF121/165b proteins generated either in yeasts or mammalian cells activated VEGFR2 and its downstream effector ERK1/2, although to a lesser extent than VEGF165. Furthermore, treatment of endothelial cells with VEGF121/165b increased cell proliferation compared to untreated cells, although such stimulation was lower than that induced by VEGF165. Moreover, in vivo angiogenesis assays confirmed angiogenesis stimulation by VEGF121/165b isoforms. A549 and PC-3 cells overexpressing VEGF121b or VEGF165b (or carrying the PCDNA3.1 empty vector, as control and xenotransplanted into nude mice showed increased tumor volume and angiogenesis compared to controls. To assess whether the VEGFxxxb isoforms are differentially expressed in tumors compared to healthy tissues, immunohistochemical analysis was conducted on a breast cancer tissue microarray. A significant increase (p xxxb and total VEGF-A protein expression in infiltrating ductal carcinomas compared to normal breasts was observed. A positive significant correlation (r = 0.404, p = 0.033 between VEGFxxxb and total VEGF-A was found. Conclusions Our results demonstrate that VEGF121/165b are not anti-angiogenic, but weakly angiogenic isoforms of VEGF-A. In addition, VEGFxxxb isoforms are up-regulated in breast cancer in comparison with non malignant breast tissues. These results are to be taken

  6. An experimental study of VEGF induced changes in vasoactivity in pig retinal arterioles and the influence of an anti-VEGF agent

    Directory of Open Access Journals (Sweden)

    Su Er-Ning

    2012-07-01

    Full Text Available Abstract Background Vascular endothelial growth factor (VEGF plays an important role in ocular physiology. Anti-VEGF agents are now used for treatment of common retinal diseases. This study characterises the vasoactive properties of VEGF in isolated perfused pig retinal arterioles under normal tone or endothelin-1 (ET-1 pre-contracted conditions and determines the influence of an anti VEGF agent on VEGF induced vasoactivity. Methods An isolated perfused retinal arteriole preparation was used. The outer diameter of retinal vessels was monitored at 2 second intervals in response to VEGF and the anti VEGF agent, bevacizumab. The effect of intraluminal delivery of VEGF was determined over a wide concentration range (10-16 to 10-7 M both with and without pre-contraction with ET-1 (3 x 10-9 M. Bevacizumab (0.35 mg mL-1 was applied extraluminally to determine the influence of bevacizumab on VEGF induced vasoactive changes on ET-1 pre-contracted vessels. Results In retinal arterioles with normal tone, VEGF induced a concentration dependent contraction at low concentrations, reaching 93.5% at 10-11 M and then contraction was reduced at higher concentrations, recovering to 98.1% at 10-7 M. VEGF produced a potent concentration dependent vasodilatation in arterioles pre-contracted with ET-1. VEGF induced vasodilatation in arterioles pre-contracted with ET-1 was significantly inhibited by bevacizumab. Conclusions VEGF induced vasoactive changes in pig retinal arterioles are dependent on concentration and vascular tone. Bevacizumab inhibits VEGF-induced vasodilatation in pre-contracted arterioles.

  7. VEGF Inhibitors for Cancer Therapy

    OpenAIRE

    Prakash S. Sukhramani; Maulik P. Suthar

    2010-01-01

    Despite significant advances in systemic therapies, radiation oncology, and surgical techniques, many patients with cancer are still incurable. A novel therapeutic approach has been to target the vascular endothelial growth factors (VEGFs) which are often mutated and/or over-expressed in many tumors. The ligands and receptors of VEGF family are well established as key regulators of angiogenesis and vasculogenesis processes. VEGF is a homodimeric, basic, 45 kDa glycoprotein specific for vascul...

  8. Spectrophotometric and Refractometric Determination of Total Protein in Avian Plasma

    Directory of Open Access Journals (Sweden)

    Rodica Căpriță

    2013-10-01

    Full Text Available The aim of this study was to compare the total protein values obtained in heparin plasma of chickens by a spectrophotometric technique (biuret method, and the values obtained on the same day in the same samples by refractometry. The results obtained by refractometry (average value 2.638±0.153g% were higher than those obtained by the spectrophotometric method (average value 2.441±0.181g%. There was a low correlation (r = 0.6709 between the total protein values, determined with both methods. Protein is the major determinant of plasma refractive index, but glucose contributes too. The refractometric method is not recommended in chickens for the determination of total protein, because avian blood glucose concentration averages about twice than in mammalian blood.

  9. DNA methylation regulates expression of VEGF-C, and S-adenosylmethionine is effective for VEGF-C methylation and for inhibiting cancer growth

    Energy Technology Data Exchange (ETDEWEB)

    Da, M.X. [Department of Surgical Oncology, Gansu Provincial Hospital, Lanzhou (China); Zhang, Y.B. [Department of Surgery, Ningxia Medical University, Yinchuan (China); Yao, J.B. [Department of Surgical Oncology, Gansu Provincial Hospital, Lanzhou (China); Duan, Y.X. [Department of Surgery, Ningxia Medical University, Yinchuan (China)

    2014-09-30

    DNA hypomethylation may activate oncogene transcription, thus promoting carcinogenesis and tumor development. S-adenosylmethionine (SAM) is a methyl donor in numerous methylation reactions and acts as an inhibitor of intracellular demethylase activity, which results in hypermethylation of DNA. The main objectives of this study were to determine whether DNA hypomethylation correlated with vascular endothelial growth factor-C (VEGF-C) expression, and the effect of SAM on VEGF-C methylation and gastric cancer growth inhibition. VEGF-C expression was assayed by Western blotting and RT-qPCR in gastric cancer cells, and by immunohistochemistry in tumor xenografts. VEGF-C methylation was assayed by bisulfite DNA sequencing. The effect of SAM on cell apoptosis was assayed by flow cytometry analyses and its effect on cancer growth was assessed in nude mice. The VEGF-C promoters of MGC-803, BGC-823, and SGC-7901 gastric cancer cells, which normally express VEGF-C, were nearly unmethylated. After SAM treatment, the VEGF-C promoters in these cells were highly methylated and VEGF-C expression was downregulated. SAM also significantly inhibited tumor growth in vitro and in vivo. DNA methylation regulates expression of VEGF-C. SAM can effectively induce VEGF-C methylation, reduce the expression of VEGF-C, and inhibit tumor growth. SAM has potential as a drug therapy to silence oncogenes and block the progression of gastric cancer.

  10. Determination of actarit from human plasma for bioequivalence studies.

    Science.gov (United States)

    Loya, P; Saraf, M N

    2010-11-01

    An analytical method based on high-performance liquid chromatography with ultraviolet detection (245 nm) was developed for the determination of actarit in human plasma. Coumarin was used as an internal standard. Chromatographic separation was achieved with a C8 column using a mobile phase of methanol: 1% acetic acid (50-50, v/v) with a flow rate of 1.0 ml/min. The calibration curve was linear over the range of 0.1-4.0 μg/ml (r(2) > 0.99) and the lower limit of quantification was 0.1 μg/ml. The method was validated for sensitivity, accuracy, precision, recovery and stability. The method was used to determine the concentration-time profiles of actarit in the plasma following oral administration of 100 mg actarit tablets.

  11. Expression of VEGF(xxx)b, the inhibitory isoforms of VEGF, in malignant melanoma.

    Science.gov (United States)

    Pritchard-Jones, R O; Dunn, D B A; Qiu, Y; Varey, A H R; Orlando, A; Rigby, H; Harper, S J; Bates, D O

    2007-07-16

    Malignant melanoma is the most lethal of the skin cancers and the UK incidence is rising faster than that of any other cancer. Angiogenesis - the growth of new vessels from preexisting vasculature - is an absolute requirement for tumour survival and progression beyond a few hundred microns in diameter. We previously described a class of anti-angiogenic isoforms of VEGF, VEGF(xxx)b, that inhibit tumour growth in animal models, and are downregulated in some cancers, but have not been investigated in melanoma. To determine whether VEGF(xxx)b expression was altered in melanoma, PCR and immunohistochemistry of archived human tumour samples were used. In normal epidermis and in a proportion of melanoma samples, VEGF(xxx)b staining was seen. Some melanomas had much weaker staining. Subsequent examination revealed that expression was significantly reduced in primary melanoma samples (both horizontal and vertical growth phases) from patients who subsequently developed tumour metastasis compared with those who did not (analysis of variance (ANOVA) Pxxx)b expression appears to predict metastatic spread in patients with primary melanoma. These results suggest that there is a switch in splicing as part of the metastatic process, from anti-angiogenic to pro-angiogenic VEGF isoforms. This may form part of a wider metastatic splicing phenotype.

  12. New validated method for piracetam HPLC determination in human plasma.

    Science.gov (United States)

    Curticapean, Augustin; Imre, Silvia

    2007-01-10

    The new method for HPLC determination of piracetam in human plasma was developed and validated by a new approach. The simple determination by UV detection was performed on supernatant, obtained from plasma, after proteins precipitation with perchloric acid. The chromatographic separation of piracetam under a gradient elution was achieved at room temperature with a RP-18 LiChroSpher 100 column and aqueous mobile phase containing acetonitrile and methanol. The quantitative determination of piracetam was performed at 200 nm with a lower limit of quantification LLQ=2 microg/ml. For this limit, the calculated values of the coefficient of variation and difference between mean and the nominal concentration are CV%=9.7 and bias%=0.9 for the intra-day assay, and CV%=19.1 and bias%=-7.45 for the between-days assay. For precision, the range was CV%=1.8/11.6 in the intra-day and between-days assay, and for accuracy, the range was bias%=2.3/14.9 in the intra-day and between-days assay. In addition, the stability of piracetam in different conditions was verified. Piracetam proved to be stable in plasma during 4 weeks at -20 degrees C and for 36 h at 20 degrees C in the supernatant after protein precipitation. The new proposed method was used for a bioequivalence study of two medicines containing 800 mg piracetam.

  13. Spectrofluorimetric determination of amlodipine in human plasma without derivatization

    Directory of Open Access Journals (Sweden)

    Yucel Kadioglu

    2012-12-01

    Full Text Available A rapid and sensitive spectrofluorimetric method was developed for the determination of amlodipine (AD, a calcium channel blocker, in the plasma. The type of solvent, the wavelength range, and the range of AD concentration were selected to optimize the experimental conditions. The calibration curves were linear (r² >0.997 in the concentration range of 0.1-12.5 ppm of AD. The limit of quantitation and limit of detection values for the method for plasma samples were 0.1 ppm and 0.07 ppm, respectively. The precision calculated as the relative standard deviation was less than 3.5%, and the accuracy (relative error was better than 5.5% (n=6. The method developed in this study can be directly and easily applied for the determination of AD in the plasma without derivatization in plasma.Método espectrofluorometrico rápido e sensível é descrito para a determinação de anlodipina (AD, um bloqueador de canais de cálcio, em amostras de plasma. O tipo de solvente, a faixa de comprimento de onda e a faixa de concentração foram escolhidas a fim de otimizar as condições experimentais. As curvas de calibração foram lineares (r > 0,997 na faixa de concentração de 0,1-12,5 ppm de AD. Os valores LoQ e LoD do método para amostras de plasma foram 0,1 ppm e 0,07 ppm, respectivamente. A precisão calculada como desvio padrão relativo (RSD foi menor do que 3,5% e a precisão (erro relativo foi melhor do que 5,5% (n=6. O método desenvolvido neste estudo pode ser fácil e diretamente aplicado para a determinação de AD sem derivatização no plasma.

  14. Circulating VEGF as a biological marker in patients with rheumatoid arthritis? Preanalytical and biological variability in healthy persons and in patients

    DEFF Research Database (Denmark)

    Hetland, Merete Lund; Christensen, Ib Jarle; Lottenburger, Tine

    2008-01-01

    -analytical factors were investigated. A reference interval for VEGF was established in serum and plasma from 306 healthy persons. Diurnal, day-to-day, week-to-week, long-term variability, and impact of exercise were evaluated. RESULTS: Delayed processing time, room temperature, low centrifugal force...... and contamination of plasma with cellular elements lead to significant increases in VEGF levels, whereas storage for up to 2 years at -80 degrees C or up to 10 freeze/thaw cycles did not affect VEGF levels. Serum VEGF levels were 7-10 fold higher than plasma VEGF levels. Reference intervals for VEGF (plasma: 45 pg....../ml (range: non-detectable to 352); serum: 328 pg/ml (53-1791)) were independent of gender and age. Short- and long-term biologic variability included diurnal variation (sampling should take place after 7 AM) and impact of exercise (increased VEGF immediately after bicycling normalised within 1 hour...

  15. Use of refractometry for determination of psittacine plasma protein concentration.

    Science.gov (United States)

    Cray, Carolyn; Rodriguez, Marilyn; Arheart, Kristopher L

    2008-12-01

    Previous studies have demonstrated both poor and good correlation of total protein concentrations in various avian species using refractometry and biuret methodologies. The purpose of the current study was to compare these 2 techniques of total protein determination using plasma samples from several psittacine species and to determine the effect of cholesterol and other solutes on refractometry results. Total protein concentration in heparinized plasma samples without visible lipemia was analyzed by refractometry and an automated biuret method on a dry reagent analyzer (Ortho 250). Cholesterol, glucose, and uric acid concentrations were measured using the same analyzer. Results were compared using Deming regression analysis, Bland-Altman bias plots, and Spearman's rank correlation. Correlation coefficients (r) for total protein results by refractometry and biuret methods were 0.49 in African grey parrots (n=28), 0.77 in Amazon parrots (20), 0.57 in cockatiels (20), 0.73 in cockatoos (36), 0.86 in conures (20), and 0.93 in macaws (38) (Prefractometry in Amazon parrots, conures, and macaws (n=25 each, PRefractometry can be used to accurately measure total protein concentration in nonlipemic plasma samples from some psittacine species. Method and species-specific reference intervals should be used in the interpretation of total protein values.

  16. Steroid determination in fish plasma using capillary electrophoresis

    Science.gov (United States)

    Bykova, L.; Archer-Hartmann, S. A.; Holland, L.A.; Iwanowicz, L.R.; Blazer, V.S.

    2010-01-01

    A capillary separation method that incorporates pH-mediated stacking is employed for the simultaneous determination of circulating steroid hormones in plasma from Perca flavescens (yellow perch) collected from natural aquatic environments. The method can be applied to separate eight steroid standards: progesterone, 17α,20β-dihydroxypregn-4-en-3-one, 17α-hydroxyprogesterone, testosterone, estrone, 11-ketotestosterone, ethynyl estradiol, and 17β-estradiol. Based on screening of plasma, the performance of the analytical method was determined for 17α,20β-dihydroxypregn-4-en-3-one, testosterone, 11-ketotestosterone, and 17β-estradiol. The within-day reproducibility in migration time for these four steroids in aqueous samples was ≤2%. Steroid quantification was accomplished using a calibration curve obtained with external standards. Plasma samples from fish collected from the Choptank and Severn Rivers, Maryland, USA, stored for up to one year were extracted with ethyl acetate and then further processed with anion exchange and hydrophobic solid phase extraction cartridges. The recovery of testosterone and 17β-estradiol from yellow perch plasma was 84 and 85%, respectively. Endogenous levels of testosterone ranged from 0.9 to 44 ng/ml, and when detected 17α,20β-dihydroxypregn-4-en-3-one ranged from 5 to 34 ng/ml. The reported values for testosterone correlated well with the immunoassay technique. Endogenous concentrations of 17β-estradiol were ≤1.7 ng/ml. 11-Ketotestosterone was not quantified because of a suspected interferant. Higher levels of 17α,20β-dihydroxypregn-4-en-3-one were found in male and female fish in which 17β-estradiol was not detected. Monitoring multiple steroids can provide insight into hormonal fluctuations in fish.

  17. Serum/plasma methylmercury determination by isotope dilution gas chromatography-inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, Douglas C., E-mail: douglas.baxter@alsglobal.com [ALS Scandinavia AB, Aurorum 10, 977 75 Lulea (Sweden); Faarinen, Mikko [ALS Scandinavia AB, Aurorum 10, 977 75 Lulea (Sweden); Osterlund, Helene; Rodushkin, Ilia [ALS Scandinavia AB, Aurorum 10, 977 75 Lulea (Sweden); Division of Geosciences, Lulea University of Technology, 977 87 Lulea (Sweden); Christensen, Morten [ALS Scandinavia AB, Maskinvaegen 2, 183 53 Taeby (Sweden)

    2011-09-09

    Highlights: {center_dot} We determine methylmercury in serum and plasma using isotope dilution calibration. {center_dot} Separation by gas chromatography and detection by inductively coupled plasma mass spectrometry. {center_dot} Data for 50 specimens provides first reference range for methylmercury in serum. {center_dot} Serum samples shown to be stable for 11 months in refrigerator. - Abstract: A method for the determination of methylmercury in plasma and serum samples was developed. The method uses isotope dilution with {sup 198}Hg-labeled methylmercury, extraction into dichloromethane, back-extraction into water, aqueous-phase ethylation, purge and trap collection, thermal desorption, separation by gas chromatography, and mercury isotope specific detection by inductively coupled plasma mass spectrometry. By spiking 2 mL sample with 1.2 ng tracer, measurements in a concentration interval of (0.007-2.9) {mu}g L{sup -1} could be performed with uncertainty amplification factors <2. A limit of quantification of 0.03 {mu}g L{sup -1} was estimated at 10 times the standard deviation of concentrations measured in preparation blanks. Within- and between-run relative standard deviations were <10% at added concentration levels of 0.14 {mu}g L{sup -1}, 0.35 {mu}g L{sup -1} and 2.8 {mu}g L{sup -1}, with recoveries in the range 82-110%. Application of the method to 50 plasma/serum samples yielded a median (mean; range) concentration of methylmercury of 0.081 (0.091; <0.03-0.19) {mu}g L{sup -1}. This is the first time methylmercury has been directly measured in this kind of specimen, and is therefore the first estimate of a reference range.

  18. Spectrophotometric and Refractometric Determination of Total Protein in Avian Plasma

    OpenAIRE

    2013-01-01

    The aim of this study was to compare the total protein values obtained in heparin plasma of chickens by a spectrophotometric technique (biuret method), and the values obtained on the same day in the same samples by refractometry. The results obtained by refractometry (average value 2.638±0.153g%) were higher than those obtained by the spectrophotometric method (average value 2.441±0.181g%). There was a low correlation (r = 0.6709) between the total protein values, determined with both methods...

  19. Injectable Mussel-Inspired Immobilization of Platelet-Rich Plasma on Microspheres Bridging Adipose Micro-Tissues to Improve Autologous Fat Transplantation by Controlling Release of PDGF and VEGF, Angiogenesis, Stem Cell Migration.

    Science.gov (United States)

    Zhou, Shaolong; Chang, Qiang; Lu, Feng; Xing, Malcolm

    2017-09-07

    Platelets-rich plasma (PRP) can produce growth factors (GFs) to improve angiogenesis. However, direct injection of PRP does not lead to highly localized GFs. The current study employs a mussel-inspired polydopamine to immobilize PRP on gelatin microspheres (GMs) with the purpose of bridging adipose micro-tissues to help implanted fat survive (GM-pDA-PRP). Enhanced PRP adhesion leads to a prolonged and localized production of GFs, which is verified by platelet counting and by ELISA of vascular endothelial growth factors (VEGFs) and of platelet derived growth factors (PDGFs). The GM-pDA-PRP "hatches" a microenvironment for the proliferation of adipose-derived stem cells. After the adipose micro-tissue has bridged with GM-pDA-PRP after 16 weeks, triple-fluorescence staining reveals that the mature adipocytes, blood vessels, and capillaries are arranged like in normal adipose tissue. The survival fat increases significantly compared to that in control, PRP, and GM-PRP groups (84.8 ± 11.4% versus 47.8 ± 8.9%, 56.9 ± 9.7%, and 60.2 ± 10.5%, respectively). Both histological assessments and CD31 immunofluorescence indicate that the improvement of angiogenesis in GM-pDA-PRP is higher than in the fat graft group (6.4-fold in quantitative CD31 positive cells). The CD34 positive cells in the GM-pDA-PRP group are around 3.5-fold the amount in the fat graft group, which suggests that more stem cells migrate to the implant area. Cell proliferation staining shows that the number of Ki67 positive cells is around five times as high as that in the fat graft group. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Serum/plasma methylmercury determination by isotope dilution gas chromatography-inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Baxter, Douglas C; Faarinen, Mikko; Österlund, Heléne; Rodushkin, Ilia; Christensen, Morten

    2011-09-01

    A method for the determination of methylmercury in plasma and serum samples was developed. The method uses isotope dilution with (198)Hg-labeled methylmercury, extraction into dichloromethane, back-extraction into water, aqueous-phase ethylation, purge and trap collection, thermal desorption, separation by gas chromatography, and mercury isotope specific detection by inductively coupled plasma mass spectrometry. By spiking 2 mL sample with 1.2 ng tracer, measurements in a concentration interval of (0.007-2.9) μg L(-1) could be performed with uncertainty amplification factors levels of 0.14 μg L(-1), 0.35 μg L(-1) and 2.8 μg L(-1), with recoveries in the range 82-110%. Application of the method to 50 plasma/serum samples yielded a median (mean; range) concentration of methylmercury of 0.081 (0.091; methylmercury has been directly measured in this kind of specimen, and is therefore the first estimate of a reference range.

  1. Ionosphere Plasma State Determination in Low Earth Orbit from International Space Station Plasma Monitor

    Science.gov (United States)

    Kramer, Leonard

    2014-01-01

    A plasma diagnostic package is deployed on the International Space Station (ISS). The system - a Floating Potential Measurement Unit (FPMU) - is used by NASA to monitor the electrical floating potential of the vehicle to assure astronaut safety during extravehicular activity. However, data from the unit also reflects the ionosphere state and seems to represent an unutilized scientific resource in the form of an archive of scientific plasma state data. The unit comprises a Floating Potential probe and two Langmuir probes. There is also an unused but active plasma impedance probe. The data, at one second cadence, are collected, typically for a two week period surrounding extravehicular activity events. Data is also collected any time a visiting vehicle docks with ISS and also when any large solar events occur. The telemetry system is unusual because the package is mounted on a television camera stanchion and its data is impressed on a video signal that is transmitted to the ground and streamed by internet to two off center laboratory locations. The data quality has in the past been challenged by weaknesses in the integrated ground station and distribution systems. These issues, since mid-2010, have been largely resolved and the ground stations have been upgraded. Downstream data reduction has been developed using physics based modeling of the electron and ion collecting character in the plasma. Recursive algorithms determine plasma density and temperature from the raw Langmuir probe current voltage sweeps and this is made available in real time for situational awareness. The purpose of this paper is to describe and record the algorithm for data reduction and to show that the Floating probe and Langmuir probes are capable of providing long term plasma state measurement in the ionosphere. Geophysical features such as the Appleton anomaly and high latitude modulation at the edge of the Auroral zones are regularly observed in the nearly circular, 51 deg inclined, 400 km

  2. [Determination of plasma protein binding rate of arctiin and arctigenin with ultrafiltration].

    Science.gov (United States)

    Han, Xue-Ying; Wang, Wei; Tan, Ri-Qiu; Dou, De-Qiang

    2013-02-01

    To determine the plasma protein binding rate of arctiin and arctigenin. The ultrafiltration combined with HPLC was employed to determine the plasma protein binding rate of arctiin and arctigenin as well as rat plasma and healthy human plasma proteins. The plasma protein binding rate of arctiin with rat plasma at the concentrations of 64. 29, 32.14, 16.07 mg x L(-1) were (71.2 +/- 2.0)%, (73.4 +/- 0.61)%, (78.2 +/- 1.9)%, respectively; while the plasma protein binding rate of arctiin with healthy human plasma at the above concentrations were (64.8 +/- 3.1)%, (64.5 +/- 2.5)%, (77.5 +/- 1.7)%, respectively. The plasma protein binding rate of arctigenin with rat plasma at the concentrations of 77.42, 38.71, 19.36 mg x L(-1) were (96.7 +/- 0.41)%, (96.8 +/- 1.6)%, (97.3 +/- 0.46)%, respectively; while the plasma protein binding rate of arctigenin with normal human plasma at the above concentrations were (94.7 +/- 3.1)%, (96.8 +/- 1.6)%, (97.9 +/- 1.3)%, respectively. The binding rate of arctiin with rat plasma protein was moderate, which is slightly higher than the binding rate of arctiin with healthy human plasma protein. The plasma protein binding rates of arctigenin with both rat plasma and healthy human plasma are very high.

  3. Cancer associated proteins in blood plasma: Determining normal variation.

    Science.gov (United States)

    Stenemo, Markus; Teleman, Johan; Sjöström, Martin; Grubb, Gabriel; Malmström, Erik; Malmström, Johan; Niméus, Emma

    2016-07-01

    Protein biomarkers have the potential to improve diagnosis, stratification of patients into treatment cohorts, follow disease progression and treatment response. One distinct group of potential biomarkers comprises proteins which have been linked to cancer, known as cancer associated proteins (CAPs). We determined the normal variation of 86 CAPs in 72 individual plasma samples collected from ten individuals using SRM mass spectrometry. Samples were collected weekly during 5 weeks from ten volunteers and over one day at nine fixed time points from three volunteers. We determined the degree of the normal variation depending on interpersonal variation, variation due to time of day, and variation over weeks and observed that the variation dependent on the time of day appeared to be the most important. Subdivision of the proteins resulted in two predominant protein groups containing 21 proteins with relatively high variation in all three factors (day, week and individual), and 22 proteins with relatively low variation in all factors. We present a strategy for prioritizing biomarker candidates for future studies based on stratification over their normal variation and have made all data publicly available. Our findings can be used to improve selection of biomarker candidates in future studies and to determine which proteins are most suitable depending on study design.

  4. CXCL7-Mediated Stimulation of Lymphangiogenic Factors VEGF-C, VEGF-D in Human Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Minghuan Yu

    2010-01-01

    Full Text Available Increased expression of lymphangiogenesis factors VEGF-C/D and heparanase has been correlated with the invasion of cancer. Furthermore, chemokines may modify matrix to facilitate metastasis, and they are associated with VEGF-C and heparanase. The chemokine CXCL7 binds heparin and the G-protein-linked receptor CXCR2. We investigated the effect of CXCR2 blockade on the expression of VEGF-C/D, heparanase, and on invasion. CXCL7 siRNA and a specific antagonist of CXCR2 (SB225002 were used to treat CXCL7 stably transfected MCF10AT cells. Matrigel invasion assays were performed. VEGF-C/D expression and secretion were determined by real-time PCR and ELISA assay, and heparanase activity was quantified by ELISA. SB225002 blocked VEGF-C/D expression and secretion (P<.01. CXCL7 siRNA knockdown decreased heparanase (P<.01. Both SB225002 and CXCL7 siRNA reduced the Matrigel invasion (P<.01. The MAP kinase signaling pathway was not involved. The CXCL7/CXCR2 axis is important for cell invasion and the expression of VEGF-C/D and heparanase, all linked to invasion.

  5. The significance of VEGF expression in stage II carcinoma of uterine cervix treated with definitive radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Park, Won; Choi, Yoon La; Huh, Seung Jae; Yoon, Sang Min; Park, Young Je; Nam, Hee Rim; Ahn, Yong Chan; Lim, Do Hoon; Park, Hee Chul [Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2006-03-15

    We wanted to determine the clinical characteristics and prognosis according to the VEGF expression in stage II cervical carcinoma patients treated with definitive radiotherapy. We enrolled 31 patients who were diagnosed with cervical cancer from 1995 to 2003 at Samsumg Medical Center and their paraffin block tissue samples were available for study. The median age of the patients was 65 years. The mean tumor size was 4.1 cm (range: 1.2 {approx}8.2 cm). Seven patients (22.6%) were suspected of having pelvic lymph node metastasis. An external beam irradiation dose of 45-56.4 Gy was administered to the whole pelvis with a 15 MV linear accelerator, and an additional 24 Gy was given to point A by HDR intracavitary brachytherapy. VEGF staining was defined as positive when more than 10% of the tumor cells were stained. The median follow-up duration was 58 months. A positive VEGF expression was observed in 21 patients (67.7%). There was no significant correlation between the VEGF expression and pelvic lymph node metastasis, tumor size and the response of radiotherapy. During follow-up, 7 patients had recurrence. The complete response rate was not significant between the VEGF (-) and VEGF(+) tumors. However, the VEGF(+) tumors showed a significantly higher recurrence rate in comparison with the VEGF(-) tumors ({rho} = 0.040). The three year disease-free survival rates were 100% and 66.7%, respectively, for patients with VEGF(-) or VEGF(+) tumor ({rho} = 0.047). The VEGF expression was a significant factor for recurrence and disease-free survival. However, the significance of the VEGF expression is still controversial because of the various definitions of VEGF expression and the mismatches of the clinical data in the previous studies.

  6. VEGF incorporated into calcium phosphate ceramics promotes vascularisation and bone formation in vivo

    Directory of Open Access Journals (Sweden)

    E Wernike

    2010-02-01

    Full Text Available Bone formation and osseointegration of biomaterials are dependent on angiogenesis and vascularization. Angiogenic growth factors such as vascular endothelial growth factor (VEGF were shown to promote biomaterial vascularization and enhance bone formation. However, high local concentrations of VEGF induce the formation of malformed, nonfunctional vessels. We hypothesized that a continuous delivery of low concentrations of VEGF from calcium phosphate ceramics may increase the efficacy of VEGF administration.VEGF was co-precipitated onto biphasic calcium phosphate (BCP ceramics to achieve a sustained release of the growth factor. The co-precipitation efficacy and the release kinetics of the protein were investigated in vitro. For in vivo investigations BCP ceramics were implanted into critical size cranial defects in Balb/c mice. Angiogenesis and microvascularization were investigated over 28 days by means of intravital microscopy. The formation of new bone was determined histomorphometrically. Co-precipitation reduced the burst release of VEGF. Furthermore, a sustained, cell-mediated release of low concentrations of VEGF from BCP ceramics was mediated by resorbing osteoclasts. In vivo, sustained delivery of VEGF achieved by protein co-precipitation promoted biomaterial vascularization, osseointegration, and bone formation. Short-term release of VEGF following superficial adsorption resulted in a temporally restricted promotion of angiogenesis and did not enhance bone formation. The release kinetics of VEGF appears to be an important factor in the promotion of biomaterial vascularization and bone formation. Sustained release of VEGF increased the efficacy of VEGF delivery demonstrating that a prolonged bioavailability of low concentrations of VEGF is beneficial for bone regeneration.

  7. Use of a probing pulsed magnetic field for determining plasma parameters

    Science.gov (United States)

    Rousskikh, A. G.; Oreshkin, V. I.; Zhigalin, A. S.; Yushkov, G. Yu.

    2016-11-01

    A novel, simple, and readily usable method is proposed for measuring the electrical conductivity and temperature of a plasma. The method is based on the interaction of the test plasma with a pulsed magnetic field. The electric signals induced by the magnetic field in the circuits of two probes (miniature solenoids), one immersed in the test plasma and the other placed outside the plasma, provide data for estimating the plasma parameters. The method was verified experimentally by determining the parameters of the plasma flows generated in the cathode spots high-current pulsed vacuum arcs that were used to form cylindrical shells of bismuth Z-pinch plasma.

  8. Reduced plasma total homocysteine concentrations in Type 1 diabetes mellitus is determined by increased renal clearance.

    NARCIS (Netherlands)

    Veldman, B.A.J.; Vervoort, G.M.M.; Blom, H.J.; Smits, P.

    2005-01-01

    INTRODUCTION: Elevated plasma levels of total homocysteine are related to the development of vascular complications. Patients with diabetes mellitus are particularly at risk for the development of these complications. Several factors determine plasma total homocysteine including renal function.

  9. 99mTc-albumin can replace 125I-albumin to determine plasma volume repeatedly

    DEFF Research Database (Denmark)

    Bonfils, Peter K; Damgaard, Morten; Stokholm, Knud H

    2012-01-01

    OBJECTIVE: Plasma volume assessment may be of importance in several disorders. The purpose of the present study was to compare the reliability of plasma volume measurements by technetium-labeled human serum albumin ((99m)Tc-HSA) with a simultaneously performed plasma volume determination with iod......OBJECTIVE: Plasma volume assessment may be of importance in several disorders. The purpose of the present study was to compare the reliability of plasma volume measurements by technetium-labeled human serum albumin ((99m)Tc-HSA) with a simultaneously performed plasma volume determination...

  10. Determining the resistance of X-pinch plasma

    Institute of Scientific and Technical Information of China (English)

    Zhao Shen; Xue Chuang; Zhu Xin-Lei; Zhang Ran; Luo Hai-Yun; Zou Xiao-Bing; Wang Xin-Xin

    2013-01-01

    The current and the voltage of an X-pinch were measured.The inductance of the X-pinch was assumed to be a constant and estimated by the calculation of the magnetic field based on the well-known Biot-Savart's Law.The voltage of the inductance was calculated with L.di/dt and subtracted from the measured voltage of the X-pinch.Then,the resistance of the X-pinch was determined and the following results were obtained.At the start of the current flow the resistance of the exploding wires is several tens of Ohms,one order of magnitude,higher than the metallic resistance of the wires at room temperature,and then it falls quickly to about 1 Ω,which reflects the physical processes occurring in the electrically exploding wires,i.e.,a current transition from the highly resistive wire core to the highly conductive plasma.It was shown that the inductive contribution to the voltage of the X-pinch is less than the resistive contribution.For the wires we used,the wires' material and diameter have no strong influence on the resistance of the X-pinch,which may be explained by the fact that the current flows through the plasma rather than through the metallic wire itself.As a result,the current is almost equally divided between two parallel X-pinches even though the diameter and material of the wires used for these two X-pinches are significantly different.

  11. Effective noninvasive zygosity determination by maternal plasma target region sequencing.

    Directory of Open Access Journals (Sweden)

    Jing Zheng

    Full Text Available BACKGROUND: Currently very few noninvasive molecular genetic approaches are available to determine zygosity for twin pregnancies in clinical laboratories. This study aimed to develop a novel method to determine zygosity by using maternal plasma target region sequencing. METHODS: We constructed a statistic model to calculate the possibility of each zygosity type using likelihood ratios ( Li and empirical dynamic thresholds targeting at 4,524 single nucleotide polymorphisms (SNPs loci on 22 autosomes. Then two dizygotic (DZ twin pregnancies,two monozygotic (MZ twin pregnancies and two singletons were recruited to evaluate the performance of our novel method. Finally we estimated the sensitivity and specificity of the model in silico under different cell-free fetal DNA (cff-DNA concentration and sequence depth. RESULTS/CONCLUSIONS: We obtained 8.90 Gbp sequencing data on average for six clinical samples. Two samples were classified as DZ with L values of 1.891 and 1.554, higher than the dynamic DZ cut-off values of 1.162 and 1.172, respectively. Another two samples were judged as MZ with 0.763 and 0.784 of L values, lower than the MZ cut-off values of 0.903 and 0.918. And the rest two singleton samples were regarded as MZ twins, with L values of 0.639 and 0.757, lower than the MZ cut-off values of 0.921 and 0.799. In silico, the estimated sensitivity of our noninvasive zygosity determination was 99.90% under 10% total cff-DNA concentration with 2 Gbp sequence data. As the cff-DNA concentration increased to 15%, the specificity was as high as 97% with 3.50 Gbp sequence data, much higher than 80% with 10% cff-DNA concentration. SIGNIFICANCE: This study presents the feasibility to noninvasively determine zygosity of twin pregnancy using target region sequencing, and illustrates the sensitivity and specificity under various detecting condition. Our method can act as an alternative approach for zygosity determination of twin pregnancies in clinical

  12. Experimental determination of gap scaling in a plasma opening switch

    Science.gov (United States)

    Black, D. C.; Commisso, R. J.; Ottinger, P. F.; Swanekamp, S. B.; Weber, B. V.

    2000-09-01

    Experiments were performed to investigate the coupling between a ˜0.5 μs conduction-time, ˜0.5 MA conduction-current plasma opening switch (POS), and an electron-beam (e-beam) diode. Electrical diagnostics provided measurements of the voltage at the oil-vacuum insulator and at the diode as well as anode and cathode currents on the generator and load sides of the POS. These measurements were combined with a flow impedance model to determine the POS gap over a range of conduction times and e-beam diode impedances, and for two POS-to-load distances. A comparison of the inferred POS gap at peak power with the critical gap for magnetic insulation indicates that the POS gap is always saturated in both switch-limited and load-limited regimes. This POS gap-size scaling with load impedance is consistent with an opening mechanism dominated by erosion and not J×B forces.

  13. Association of CT perfusion imaging to plasma levels of pigment epithelial-derived factor (PEDF) and vas-cular endothelial growth (VEGF) in patients with NSCLC%非小细胞肺癌CT灌注成像与血浆PEDF及VEGF水平的相关性研究

    Institute of Scientific and Technical Information of China (English)

    魏英

    2015-01-01

    目的:探讨非小细胞肺癌CT灌注成像参数与患者血浆色素上皮衍生因子( pigment epithelial-derived factor, PEDF)及血管内皮生长因子( vascular endothelial growth, VEGF)水平的相关性。方法92例非小细胞肺癌患者和80例肺部良性病变患者均行CT灌注扫描,灌注软件分析获得病灶感兴趣区域( region of interest, ROI)的灌注参数血流量( blood flow, BF)、血容量( blood volume, BV)、平均通过时间( mean transit time, MTT)、达峰值时间(time to peal, TTP)及表面通透性(permeability surface, PS)5个灌注参数数值。采用酶联免疫吸附法( ELISA法)检测两组血浆PEDF与VEGF水平。 Pearson相关分析血浆PEDF及VEGF水平与CT灌注扫描各参数的关系。结果非小细胞肺癌患者CT灌注成像BF、BV、MTT、TTP、PS及血浆VEGF水平较肺部良性病变者均明显增高(P均<0.05),而PEDF水平则显著降低(P<0.01);同时CT灌注成像各参数及PEDF、VEGF水平在非小细胞肺癌不同分期亦存在明显差异性。 Pearson相关分析结果显示:血浆PEDF水平与CT灌注成像参数BF、BV及MTT呈负相关,与TTP呈正相关(P均<0.05),与PS无明显相关性;血浆VEGF水平与CT灌注成像参数BF、BV及MTT呈正相关,与TTP呈负相关( P均<0.05),仍与PS无明显相关性。结论非小细胞肺癌肺癌CT灌注成像与患者血浆PEDF、VEGF及其生物学特性密切相关,是定量检测肿瘤血流灌注方便、有效的检查手段。%Objective To observe the association of CT perfusion parameters to plasma levels of pigment ep-ithelial-derived factor ( PEDF) and vascular endothelial growth ( VEGF) in patients with non-small-cell lung cancer ( NSCLC) . Methods 92 patients with NSCLC and 80 patients with benign lesion were given CT perfusion imaging to obtain blood flow ( BF) , blood volume ( BV) , mean transit time ( MTT) , time to peal ( TTP) and permeability sur-face ( PS) through CT perfusion software. The plasma

  14. VEGF concentrations in tumour arteries and veins from patients with rectal cancer

    DEFF Research Database (Denmark)

    Werther, Kim; Bülow, Steffen; Hesselfeldt, Peter;

    2002-01-01

    , automated complete white cell and platelet counts were performed. In serum and EDTA plasma, no significant differences in VEGF concentrations were observed (p = 0.1 and p = 0.5), respectively) between tumour arteries and tumour veins. However, in supernatants from lysed blood, VEGF concentrations were......This pilot study investigated the hypothesis that the tumour itself is the source of the elevated vascular endothelial growth factor (VEGF) concentrations which are often observed in peripheral blood from patients with rectal cancer. Twenty-four consecutive patients with primary rectal cancer were...... included. Blood samples were drawn preoperatively from peripheral veins (I) and intraoperatively from peripheral veins (II), tumour arteries (III), and tumour veins (IV). In the four compartments, VEGF concentrations were measured in serum, EDTA plasma, and supernatants from lysed whole blood. Additionally...

  15. EXPERIMENTAL STUDY ON THE GENE THERAPY OF MALIGNANT GLIOMA WITH ANTISENSE VEGF RNA

    Institute of Scientific and Technical Information of China (English)

    浦佩玉; 王建桢; 黄强; 张敬; 张云亭

    2003-01-01

    Objective: To study the effect of antisense VEGF RNA on rat C6 gliomas in vivo and find out the feasibility of antiangiogenesis therapy with antisense VEGF RNA for malignant gliomas. Methods: Parental rat C6 glioma cells and C6 cells transfected with antisense VEGF cDNA were implanted intracerebrally and subcutaneously into SD rats as control and transfected group. Rats bearing cerebral and subcutaneous C6 gliomas were treated with antisense VEGF cDNA as treated group and sense VEGF cDNA and empty vector as control of treated group. The general manifestation, survival time, MRI and histopathological changes of all rats were observed. The volume of subcutaneously implanted tumors was determined regularly. In situ hybridization and immunohistochemical staining were used for detection of VEGF gene expression of gliomas while PCNA immunostaining and TUNEL method for examination of proliferation activity and apoptosis of gliomas, respectively. Results: The survival of the rats in transfected and treated group was prolonged. There were two rats surviving over 90 d in the treated group and their tumors disappeared. The VEGF gene expression, the number of microvessels and the proliferation activity were decreased and a large amount of apoptotic cells could be found in cerebral and subcutaneous gliomas in treated and transfected groups. Conclusion: VEGF is one of the candidate genes for gene therapy of malignant gliomas. Antisense VEGF RNA combined with other therapies should be studied further for enhancing the therapeutic effect of malignant gliomas.

  16. VEGF-A gene promoter polymorphisms and microvascular complications in patients with essential hypertension.

    Science.gov (United States)

    Palmirotta, Raffaele; Ferroni, Patrizia; Ludovici, Giorgia; Martini, Francesca; Savonarola, Annalisa; D'Alessandro, Roberta; Raparelli, Valeria; Proietti, Marco; Scarno, Antongiulio; Riondino, Silvia; Basili, Stefania; Guadagni, Fiorella

    2010-09-01

    We investigated the possible involvement of vascular endothelial growth factor (VEGF-A) gene promoter polymorphisms in essential hypertension (EH). 1225bp of the VEGF-A gene promoter were screened for polymorphisms using PCR amplification and direct DNA sequence analysis in 62 EH and 62 normotensive (HS) individuals. Circulating VEGF-A levels were determined by immunoassay. -152G/A (p=0.009) and -116G/A (p=0.016) polymorphisms were correlated to hypertension (p<0.05). Median platelet VEGF-A load in EH was 2.10fg/plt. Patients with microvascular complications (MC) had higher platelet VEGF-A load than those without (p=0.005). Multivariate analyses showed that -116 A allele was an independent predictor of microalbuminuria (p=0.014) and increased platelet VEGF-A load (p=0.009) in EH. Platelet VEGF-A load independently predicted MC (p=0.049) in addition to -116G/A polymorphism (p=0.035). Abnormal regulation of VEGF-A due to polymorphism at position -116 might represent a genetic factor for increased VEGF-A production and MC in EH. Copyright (c) 2010 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  17. Modified VEGF targets the ischemic myocardium and promotes functional recovery after myocardial infarction.

    Science.gov (United States)

    Yang, Yun; Shi, Chunying; Hou, Xianglin; Zhao, Yannan; Chen, Bing; Tan, Bo; Deng, Zongwu; Li, Qingguo; Liu, Jianzhou; Xiao, Zhifeng; Miao, Qi; Dai, Jianwu

    2015-09-10

    Vascular endothelial growth factor (VEGF) promotes angiogenesis and improves cardiac function after myocardial infarction (MI). However, the non-targeted delivery of VEGF decreases its therapeutic efficacy due to an insufficient local concentration in the ischemic myocardium. In this study, we used a specific peptide to modify VEGF and determined that this modified VEGF (IMT-VEGF) localized to the ischemic myocardium through intravenous injection by interacting with cardiac troponin I (cTnI). When IMT-VEGF was used to mediate cardiac repair in a rat model of ischemia-reperfusion (I-R) injury, we observed a decreased scar size, enhanced angiogenesis and improved cardiac function. Moreover, an alternative treatment using the repeated administration of a low-dose IMT-VEGF also promoted angiogenesis and functional recovery. The therapeutic effects of IMT-VEGF were further confirmed in a pig model of MI as the result of the conserved properties of its interacting protein, cTnI. These results suggest a promising therapeutic strategy for MI based on the targeted delivery of IMT-VEGF. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Relationship between the Expression of VEGF, FIk-1 and Fit-1 Proteins and Clinicopcrthology in Hepatocellular Carcinoma

    Institute of Scientific and Technical Information of China (English)

    JihuiHao; HuikaiLi; YuQin; QiangLi; DianchangWang; XishanHao

    2004-01-01

    OBJECTIVE To study the relationship between the expression of VEGF, FIk-1 and Fit-1 proteins and clinical pathology in hepatocellular carcinoma.METHODS The expression of VEGF, FIk-1 and Fit-1 proteins in hepatocellular carcinomas from 60 patients was determined by immunohistochemistry (ABC method) and VEGF expression in relation to the clinicopathology evaluated.RESULTS The positive rates of VEGF, FIk-1 and Fit-1 protein expression were 81.3%, 88.3%, 80.0% in tumor tissues, respectively, rates which were significantly higher than those in normal liver tissue (P<0.05). The expression of VEGF protein was correlated with the histologic grade and metastases of the tumors.CONCLUSION The results showed that, in hepatocellular carcinoma, a higher expression of VEGF protein was associated with a higher degree of malignancy and a greater tendency for metastases. VEGF, FIk-1 and Fit-1 play an important role in tumourgenesis.

  19. The LC resonance probe for determining local plasma density

    Energy Technology Data Exchange (ETDEWEB)

    Boris, D R; Fernsler, R F; Walton, S G, E-mail: david.boris.ctr@nrl.navy.mi [Naval Research Laboratory, Charge Particle Physics Branch-Code 6752, Plasma Physics Division, 4555 Overlook Ave. SW, Washington, DC 20375 (United States)

    2011-04-15

    We present a novel plasma diagnostic for measuring local plasma density in reactive-gas plasmas, and depositing plasmas. The diagnostic uses a network analyzer to measure the LC resonance (LCR) frequency of a parallel plate capacitor with inductive leads. The location of the LCR ({omega}{sub R}) in frequency space is then used as a measure of the plasma dielectric constant bold varepsilon{sub p} between the plates. By properly constructing the LCR probe, {omega}{sub R} can be tuned such that {omega}{sub R} >> {omega}{sub ce}, where {omega}{sub ce} is the electron-cyclotron frequency. Thus, the probe can be used in plasmas with varying degrees of magnetization while avoiding complications introduced to bold varepsilon{sub p} when {omega} is comparable to {omega}{sub ce}. Density measurements from the LCR probe are compared with Langmuir probe measurements in an electron-beam generated plasma in which density varied from 10{sup 9} to 10{sup 11} cm{sup -3}. An axial magnetic field, typically used to confine the electron beam, was varied between 0 to 300 G. The LCR probe showed good agreement with a Langmuir probe across the entire range of magnetic fields.

  20. Effects of beraprost sodium on plasma VEGF and ET-1 in elderly patients with type 2 diabetic nephropathy%贝前列素钠对老年2型糖尿病肾病患者血浆血管内皮生长因子及内皮素-1的影响

    Institute of Scientific and Technical Information of China (English)

    黄娟; 黄云芳; 陈文莉

    2013-01-01

    目的 观察贝前列素钠对老年2型糖尿病肾病(diabetic nephropathy,DN)患者的临床疗效,并观察患者血浆血管内皮生长因子(vascular endothelial growth factor,VEGF)及内皮素-1(endothelin-1,ET-1)水平的变化.方法 将48例老年2型糖尿病肾病患者按随机数字分类法分为常规治疗组和贝前列素钠治疗组2组,另外27例2型老年糖尿病无肾病患者为对照组,测定各组治疗前后VEGF及ET-1水平的变化,探讨血浆VEGF及ET-1水平变化在糖尿病肾病发病中的可能作用.结果 2型糖尿病肾病患者较2型糖尿病无肾病患者血浆VEGF及ET-1水平明显升高[VEGF为(4.68 ±0.97) pg/L,ET-1为(138±9) ng/L] (P <0.01),差异有统计学意义,与常规治疗组比较应用贝前列素钠可使糖尿病肾病患者血浆VEGF及ET-1水平明显降低[VEGF为(2.82 ±0.14) pg/L,ET-1为(72±4)ng/L](均P<0.05),差异有统计学意义,尿白蛋白排泄率(urinary albumin excretion rates,UAER)明显降低[UAER(89±27) mg/24 h](P<0.05),差异有统计学意义.结论 VEGF及ET-1水平升高在糖尿病肾病的发病中发挥重要作用.贝前列素钠治疗可纠正糖尿病肾病患者血浆VEGF和ET-1平衡失调,改善糖尿病肾病内皮功能,降低尿蛋白,对糖尿病肾病有保护作用.%Objective To observe the effect of beraprost sodium on elderly patients with type 2 diabetic nephropathy (DN) and to observe the change of the plasma vascular endothelial growth factor(VEGF) and endothelin(ET-1) level.Methods The levels of plasma VEGF and ET-1 in the 27 cases of type 2 diabetes without nephropathy and 48 cases with type 2 diabetic nephropathy were measured.The possible role of VEGF and ET-1 in diabetic nephropathy was explored.48 cases of type 2 diabetic nephropathy patients were randomly divided into 2 groups:the conventional treatment group and beraprost sodium treatment group.The changes of VEGF and ET-1 level in the 2 groups before and after the treatment were measured

  1. Monitoring PAI-1 and VEGF Levels in 6 Human Squamous Cell Carcinoma Xenografts During Fractionated Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Bayer, Christine, E-mail: christine.bayer@yahoo.com [Department of Radiation Oncology, Klinikum rechts der Isar der Technischen Universitaet Muenchen, Munich (Germany); Kielow, Achim [Department of Radiation Oncology, Klinikum rechts der Isar der Technischen Universitaet Muenchen, Munich (Germany); Schilling, Daniela [Department of Radiation Oncology, Klinikum rechts der Isar der Technischen Universitaet Muenchen, Munich (Germany); HelmholtzZentrum Muenchen, German Research Center for Environmental Health, Department of Radiation Oncology, University Hospital and Medical Faculty Carl Gustav Carus University of Technology, Dresden (Germany); Maftei, Constantin-Alin [Department of Radiation Oncology, Klinikum rechts der Isar der Technischen Universitaet Muenchen, Munich (Germany); Zips, Daniel; Yaromina, Ala; Baumann, Michael [OncoRay Center for Radiation Research, Department of Radiation Oncology, University Hospital and Medical Faculty Carl Gustav Carus University of Technology, Dresden (Germany); Molls, Michael [Department of Radiation Oncology, Klinikum rechts der Isar der Technischen Universitaet Muenchen, Munich (Germany); Multhoff, Gabriele [Department of Radiation Oncology, Klinikum rechts der Isar der Technischen Universitaet Muenchen, Munich (Germany); HelmholtzZentrum Muenchen, German Research Center for Environmental Health, Department of Radiation Oncology, University Hospital and Medical Faculty Carl Gustav Carus University of Technology, Dresden (Germany)

    2012-11-01

    Purpose: Previous studies have shown that the plasminogen activator inhibitor type-1 (PAI-1) and vascular endothelial growth factor (VEGF) are regulated by hypoxia and irradiation and are involved in neoangiogenesis. The aim of this study was to determine in vivo whether changes in PAI-1 and VEGF during fractionated irradiation could predict for radiation resistance. Methods and Materials: Six xenografted tumor lines from human squamous cell carcinomas (HSCC) of the head and neck were irradiated with 0, 3, 5, 10, and 15 daily fractions of 2 Gy. The PAI-1 and VEGF antigen levels in tumor lysates were determined by enzyme-linked immunosorbent assay kits. The amounts of PAI-1 and VEGF were compared with the dose to cure 50% of tumors (TCD{sub 50}). Colocalization of PAI-1, pimonidazole (hypoxia), CD31 (endothelium), and Hoechst 33342 (perfusion) was examined by immunofluorescence. Results: Human PAI-1 and VEGF (hVEGF) expression levels were induced by fractionated irradiation in UT-SCC-15, UT-SCC-14, and UT-SCC-5 tumors, and mouse VEGF (msVEGF) was induced only in UT-SCC-5 tumors. High hVEGF levels were significantly associated with radiation sensitivity after 5 fractions (P=.021), and high msVEGF levels were significantly associated with radiation resistance after 10 fractions (P=.007). PAI-1 staining was observed in the extracellular matrix, the cytoplasm of fibroblast-like stroma cells, and individual tumor cells at all doses of irradiation. Colocalization studies showed PAI-1 staining close to microvessels. Conclusions: These results indicate that the concentration of tumor-specific and host-specific VEGF during fractionated irradiation could provide considerably divergent information for the outcome of radiation therapy.

  2. The determination of phenazone in blood plasma for obtained sistem suitable test of monitoring drug level

    OpenAIRE

    Mochamad Lazuardi

    2007-01-01

    The determining of Phenazone to human blood plasma from healthy man after separated by solid phase extraction (SPE) and spectroscopic measurements has been investigated. The objective of that research was to obtain system suitable test for determine the Phenazone level in biological fluids (human blood plasma), for new performed dosage regimented in clinical dentistry. The method can be divided into the following four steps. 1. Centrifugation the blood sample, 2. Extraction from blood plasma ...

  3. Angiogenesis related genes NOS3, CD14, MMP3 and IL4R are associated to VEGF gene expression and circulating levels in healthy adults

    OpenAIRE

    Saleh, Abdelsalam; Stathopoulou, Maria G.; Dadé, Sébastien; Ndiaye, Ndeye Coumba; Azimi-Nezhad, Mohsen; Murray, Helena; Masson, Christine; Lamont, John; Fitzgerald, Peter; Visvikis-Siest, Sophie

    2015-01-01

    Background Vascular endothelial growth factor (VEGF) plays a key role in angiogenesis. The aim was to assess the genetic connections between the angiogenesis-related NOS3, CD14, MMP3, IL4R, IL4 genes and VEGF expression and plasma levels. Methods The associations between VEGF plasma levels with the polymorphisms of NOS3, CD14, MMP3, IL4R, and IL4 were assessed in 403 healthy unrelated adults. The epistatic and environmental interactions were explored, including four VEGF-related polymorphisms...

  4. Relationship between pregnancy associated plasma protein A,VEGF and hypertension during pregnancy%妊娠相关血浆蛋白A、VEGF与妊高症关系

    Institute of Scientific and Technical Information of China (English)

    李巧红; 侯爱琴

    2015-01-01

    Objective: To investigate the relationship between PAPP-A and VEGF in pregnancy induced hypertension syndrome.Methods:50 cases of PIH pregnant women as the study group, while 50 healthy pregnant women as control group. The patients with hypertension were divided into three groups according to the severity of the disease, in which the contents of VEGF and PAPP-A were compared.Results: PAPP-A was signiifcantly higher in the patients with pregnancy induced hypertension than in the control group, the difference was statistically signiifcant, with the increase of the degree of pregnancy induced hypertension, PAPP-A was also increased. VEGF was significantly higher in the patients with pregnancy induced hypertension than in the control group, the difference was statistically signiifcant, but there was no signiifcant difference between the groups in the three groups, no signiifcant change trend.Conclusion: The contents of PAPP-A and VEGF in pregnant women with pregnancy induced hypertension, and PAPP-A was positively correlated with the severity of hypertension. VEGF and PAPP-A were used as the indexes for the monitoring of pregnancy induced hypertension.%目的:探讨妊娠相关血浆蛋白A(PAPP-A)、VEGF对妊娠高血压综合症关系诊断价值。方法:选择50例妊高症孕妇为研究组,另选50例正常孕妇为对照组。妊高症组按照严重程度分为轻、中、重三组,比较各组PAPP-A、VEGF含量。结果:妊高症组PAPP-A显著高于对照组,组间比较差异有统计学意义,随妊高症程度升高,PAPP-A亦呈增高趋势。妊高症组VEGF显著高于对照组,组间比较差异有统计学意义,但轻中重三组VEGF组间比较差异无统计学意义,无明显变化趋势。结论:妊娠高血压综合症孕妇其PAPP-A、VEGF含量升高,且PAPP-A与妊高症严重程度呈正相关,PAPP-A、VEGF含量可以作为妊高症监测指标。

  5. Construction and characterization of replication-deficient adenoviral vector containing the cDNA for human VEGF165 in an antisense orientation%反义VEGF165腺病毒重组体的构建及鉴定

    Institute of Scientific and Technical Information of China (English)

    王家宁; 黄永章; 王俊峰; 王卫民; 李瑞明; 张群林

    2001-01-01

    objective To construct the recombinant adenovirus vectorcontaining the cDNA for hVEGF165 in an antisense orientation for future study of tumor treatment by antisense hVEGF165 RNA strategy.Methods The VEGF165 cDNA has been extracted from pUCCAGGS/hVEGF165 with EcoRI and then inserted in an antisense orientation into the E1-deleted expression plasmid pHCMVsp1A shuttle vector, called pAd-ahVEGF165. pAd-ahVEGF165 was cotransfected with the plasmid pJM17 into the transformed human embryonic kidney cell line 293 cells by liposome-mediated method. Homologous recombination of the pAd-ahVEGF165 and pJM17 in 293 cells replaced the E1 region with the expression cassette from pAd-ahVEGF165. Ad-ahVEGF165 was confirmed by PCR.Ad-ahVEGF165 was propagated in 293 cells and then underwent CsCl density purification. subsequently, the preparations were didalyzed in dialysis buffer. The titer of each viral stock was determined by measuring the absorbance at 260nm. Results VEGF165 cDNA was successfully inserted into the shuttle vector pHCMVSPIA. pAd-ahVEGF165 was confirmed by NcoI and XhoI digestion. Ad-ahVEGF165 was characterized by PCR coamplification. The virus titer was 5.6×1011pfu/ml. Conclusions Ad-ahVEGF165 containing the antisense VEGF165 sequence was successfully constructd.This investigation provides the basis for future study of tumor treatment based on antisense VEGF RNA strategy.%目的:构建含人反义血管内皮生长因子165(VEGF165)基因的重组腺病毒载体,为采用反义VEGF165RNA防治肿瘤的研究奠定基础。方法:将人VEGF165 cDNA反向插入到穿梭质粒pHCMVSP1A的CMV启动子之下,即pAd-ahVEGF165。后者与pJM17通过脂质体共转染293细胞,经同源重组获得含人反义VEGF165基因的重组腺病毒Ad-ahVEGF165。通过PCR共扩增法鉴别Ad-ahVEGF165的正确与否。根据260nm的紫外光吸收值计算病毒滴度。结果:VEGF165 cDNA成功地反向插入了pHCMVSP1A载体,以重组病毒基因组DNA

  6. Determination of Glimepiride in Human Plasma by Liquid Chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ho Hyun; Lee, Hee Joo [Seoul Clinical Laboratories, Seoul (Korea, Republic of); Chang, Kyu Young [Korean Biochip Society, Seoul (Korea, Republic of); Han, Sang Beom [ChungAng University, Seoul (Korea, Republic of)

    2004-01-15

    A sensitive method for quantitation of glimepiride in human plasma has been established using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI/MS/MS). Glipizide was used as an internal standard. Glimepiride and internal standard in plasma sample was extracted using diethyl etherethyl acetate (1 : 1). A centrifuged upper layer was then evaporated and reconstituted with the mobile phase of acetonitrile-5 mM ammonium acetate (60:40, pH 3.0). The reconstituted samples were injected into a C{sub 18} reversed-phase column. Using MS/MS in the multiple reaction monitoring (MRM) mode, glimepiride and glipizide were detected without severe interference from human plasma matrix. Glimepiride produced a protonated precursor ion ([M+H]{sup +}) at m/z 491 and a corresponding product ion at m/z 352. And the internal standard produced a protonated precursor ion ([M+H]{sup +}) at m/z 446 and a corresponding product ion at m/z 321. Detection of glimepiride in human plasma by the LC-ESI/MS/MS method was accurate and precise with a quantitation limit of 0.1 ng/mL. The validation, reproducibility, stability, and recovery of the method were evaluated. The method has been successfully applied to pharmacokinetic studies of glimepiride in human plasma

  7. Reinstate the Damaged VEGF Signaling Pathway with VEGF-activating Transcription Factor

    Institute of Scientific and Technical Information of China (English)

    Yao-guo Yang; Heng Guan; Chang-wei Liu; Yong-jun Li

    2009-01-01

    Objective To investigate the role of vascular endothelial growth factor-activating transcriptional factor(VEGF-ATF)on the VEGF signaling pathway in diabetes mellitus.Methods Totally,20 C57BL/6 mice fed with high fat diet was induced into diabetes mellitus.Ten diabetes mellitus mice received a lower limb muscle injection with VEGF-ATF plasmid,and another ten were as control.VEGF-ATF is an engineered transcription factor designed to increase VEGF expression.Three days later,mice were sacrificed and the injected gastrocnemius was used for analysis.VEGF mRNA and protein expressions were examined by real-time PCR and ELISA respectively.VEGF receptor 2 mRNA expression was tested with RT-PCR.Phosphorylated Akt,Akt,endothelial nitric oxide synthase(eNOS),and phosphorylated eNOS were assessed by western blot.Results At 3 days post-injection,in mice with diabetes mellitus,VEGF gene transfer increased VEGF mRNA copies and VEGF protein expression in injected muscles compared with control;and reinstated the impaired VEGF signaling pathway with increasing the ratios of phosphorylated Akt/Akt and phosphorylated eNOS/eNOS.However,it did not affect the expression of VEGF receptor 2 mRNA.Conclusion Gene transfer with VEGF-ATF is able to reinstate the impaired VEGF downstream pathway,and potentially promote therapeutic angiogenesis in mice with diabetes mcllitus.

  8. The relationship of VEGF polymorphisms with serum VEGF levels and progression-free survival in patients with epithelial ovarian cancer

    DEFF Research Database (Denmark)

    Steffensen, K D; Waldstrøm, M; Brandslund, Ivan

    2010-01-01

    -linked immunosorbent assay (ELISA). VEGF gene polymorphisms (-2578 C/A, -1154 G/A, -460 T/C, +405 G/C and +936C/T) were determined by real time PCR using genomic DNA extracted from whole blood samples. RESULTS: VEGF serum levels were significantly higher in carriers of the 2578C, 460T and 405C, alleles compared to non......-carriers (p=0.003, p=0.003 and p=0.001, respectively). There was no significant correlation between VEGF SNP genotypes and progression-free survival. In haplotype analysis, the multivariate survival analysis showed that progression-free survival (PFS) for the patients with the AGCGC haplotype...

  9. Detection of VEGF-A(xxx)b isoforms in human tissues.

    Science.gov (United States)

    Bates, David O; Mavrou, Athina; Qiu, Yan; Carter, James G; Hamdollah-Zadeh, Maryam; Barratt, Shaney; Gammons, Melissa V; Millar, Ann B; Salmon, Andrew H J; Oltean, Sebastian; Harper, Steven J

    2013-01-01

    Vascular Endothelial Growth Factor-A (VEGF-A) can be generated as multiple isoforms by alternative splicing. Two families of isoforms have been described in humans, pro-angiogenic isoforms typified by VEGF-A165a, and anti-angiogenic isoforms typified by VEGF-A165b. The practical determination of expression levels of alternative isoforms of the same gene may be complicated by experimental protocols that favour one isoform over another, and the use of specific positive and negative controls is essential for the interpretation of findings on expression of the isoforms. Here we address some of the difficulties in experimental design when investigating alternative splicing of VEGF isoforms, and discuss the use of appropriate control paradigms. We demonstrate why use of specific control experiments can prevent assumptions that VEGF-A165b is not present, when in fact it is. We reiterate, and confirm previously published experimental design protocols that demonstrate the importance of using positive controls. These include using known target sequences to show that the experimental conditions are suitable for PCR amplification of VEGF-A165b mRNA for both q-PCR and RT-PCR and to ensure that mispriming does not occur. We also provide evidence that demonstrates that detection of VEGF-A165b protein in mice needs to be tightly controlled to prevent detection of mouse IgG by a secondary antibody. We also show that human VEGF165b protein can be immunoprecipitated from cultured human cells and that immunoprecipitating VEGF-A results in protein that is detected by VEGF-A165b antibody. These findings support the conclusion that more information on the biology of VEGF-A165b isoforms is required, and confirm the importance of the experimental design in such investigations, including the use of specific positive and negative controls.

  10. 51Cr-EDTA plasma clearance in severe renal failure determined by one plasma sample

    DEFF Research Database (Denmark)

    Kamper, A L; Nielsen, S L

    1989-01-01

    at zero-time was derived from injected dose and body surface area. This method might provide values 1.5 ml/min below or 0.8 ml/min above the established method of 51Cr-EDTA plasma clearance, which would be acceptable for clinical purposes. It is concluded that exact plasma clearance of 51Cr-EDTA in severe......Two hundred and thirty-four measurements of standard 51Cr-EDTA plasma clearance were made in 50 patients with severe chronic renal failure. Based on these data two calculation methods were attempted using one plasma sample drawn 24 h after injection of 51Cr-EDTA. One of the methods used the 'one...... sample clearance' formulas disregarding exact time of plasma sampling. This method might provide values 3.1 ml/min below or 2.9 ml/min above the established method of total 51Cr-EDTA plasma clearance, and would thus provide insufficient agreement. In the other method an estimate of plasma activity...

  11. Determination of activated plasma fibronectin using radioactive labelled collagen I

    DEFF Research Database (Denmark)

    Fenger, M

    1984-01-01

    The plasma concentration of biological active fibronectin was assayed by a protein binding assay using 125I-collagen I as ligand and heparin as activator. The standard curve is linear for a fibronectin range of 1.1-11 pmol (0.5-5.0 micrograms) and the coefficient of variation was less than 10%. T...

  12. Determination of activated plasma fibronectin using radioactive labelled collagen I

    DEFF Research Database (Denmark)

    Fenger, M

    1984-01-01

    The plasma concentration of biological active fibronectin was assayed by a protein binding assay using 125I-collagen I as ligand and heparin as activator. The standard curve is linear for a fibronectin range of 1.1-11 pmol (0.5-5.0 micrograms) and the coefficient of variation was less than 10...

  13. Micro determination of plasma and erythrocyte copper by atomic absorption spectrophotometry

    Science.gov (United States)

    Blomfield, Jeanette; Macmahon, R. A.

    1969-01-01

    The free and total plasma copper and total erythrocyte copper levels have been determined by simple, yet sensitive and highly specific methods, using atomic absorption spectrophotometry. For total copper determination, the copper was split from its protein combination in plasma or red cells by the action of hydrochloric acid at room temperature. The liberated copper was chelated by ammonium pyrrolidine dithiocarbamate and extracted into n-butyl acetate by shaking and the organic extract was aspirated into the atomic absorption spectrophotometer flame. The entire procedure was carried out in polypropylene centrifuge tubes, capped during shaking. For the free plasma copper measurement the hydrochloric acid step was omitted. Removal of the plasma or erythrocyte proteins was found to be unnecessary, and, in addition, the presence of trichloracetic acid caused an appreciable lowering of absorption. Using a double-beam atomic absorption spectrophotometer and scale expansion × 10, micro methods have been derived for determining the total copper of plasma or erythrocytes with 0·1 ml of sample, and the free copper of plasma with 0·5 ml. The macro plasma copper method requires 2 ml of plasma and is suitable for use with single-beam atomic absorption spectrophotometers. With blood from 50 blood donors, normal ranges of plasma and erythrocyte copper have been determined. PMID:5776543

  14. 子痫前期疾病患者母血中肾上腺髓质素及血管内皮生长因子的表达及意义%The ADM and VEGF Expression and Significance of Blood Plasma in Patients with Preeclampsia

    Institute of Scientific and Technical Information of China (English)

    顾梅桂; 陆晓媛

    2015-01-01

    Objective: to investigate the expression of adrenomedullin(adM) and vascular endothelial growth factor(VeGf) in preeclampsia(Pe) and their correlation.Methods: the plasma adM and VeGf levels were detected by enzyme-linked immunoadsordent assayin patents with normal pregnant women.Methods select the delivery of pregnant women who were mild and severe preeclampsia both all of 30 cases for the case group,normal pregnancy childbirth pregnant women of 30 cases for the control group.the plasma adM and VeGf levels were detected by enzyme-linked immunoadsordent assayin patents with normal pregnant women, mild and severe preeclampsia. Results:(1)the blood plasma level of adM of cases of mild preeclampsia, severe preeclampsia and the control group were(1.01±0.19),(2.99±0.38) and (0.18±0.27)ng/ml,comprared with control group,the adM of plasma concentration in preeclampsia groups is signiifcantly increased.there arestatistical signiifcance difference among normal pregnant women and preeclampsia patients.it was positively correlated with the severity of disease .(2)the blood plasma level of VeGf of cases of mild preeclampsia, severe preeclampsia and the control group were(288.66±51.96)、(241.84±53.12) and (295.51±69.49)ng/l.comprared with control group,the plasma VeGf concentration of patiences in preeclampsia groups is signiifcantly decreased.there arestatistical signiifcance difference among normal pregnant women and preeclampsia patients(P<0.05).it was negative correlated with the severity of disease .(3)the results of Pearson correlation analysis showed that positive correlation between adM and VeGf in blood plasma of patients with preeclampsia(r=-0.549,P<0.01).(4)the birth weight level ofmild preeclampsia, severe preeclampsia and the control group were (3277.33±301.78)、(2545.67±703.82) and (3506.67±4189.48)g,in preeclampsia patients with fetal growth restriction was positively correlated with disease severity,neonatal weight lower than that of control group

  15. Pulmonary Large Cell Carcinoma Displays High Expression of EMMPRIN and VEGF

    Institute of Scientific and Technical Information of China (English)

    Yushuang Zheng; Miao Yu; Huachuan Zheng; Yifu Guan; Yasuo Takano

    2008-01-01

    OBJECTIVE To investigate the expression of extracellular matrix metalloproteinase inducer (EMMPRIN) and vascular endothelial growth factor (VEGF) in lung carcinomas,and to clarify their roles in carcinoma progression.METHODS Expression of EMMPRIN and VEGF was examined with tissue microarrays (TMAs) of lung carcinomas (n = 181),and their suppression in adjacent normal lung samples (n = 40) were determined by immunohistochemistry.The results were compared with clinicopathological findings for the same tumors.RESULTS Both EMMPRIN and VEGF were occasionally expressed in pseudostratified columnar epithelium and frequently in lung carcinomas.Histologically,EMMPRIN and VEGF displayed higher levels in large (LCC) cell carcinomas than adenocarcinoma (AD),squamous (SQ) and small cell carcinomas (SCC) (P < 0.05).EMMPRIN was more highly expressed in SQ as compared with AD (P < 0.05),while the converse was true for VEGF (P < 0.05).Binding was generally more intense for EMMPRIN in samples from male compared to female patients (P < 0.05),whereas the latter tended to exhibit more VEGF expression (P < 0.05).Positive associations of VEGF expression with the TNM stage and amounts of EMMPRIN were noted in the lung carcinomas (P < 0.05).CONCLUSION EMMPRIN and VEGF possibly contribute to physiological repair of normal lung and histogenesis of lung carcinoma.Both proteins might be involved in the molecular basis for differences in the incidence of lung carcinoma between men and women.

  16. Quantitative assessment of first-pass perfusion using a low-dose method at multidetector CT in oesophageal squamous cell carcinoma: Correlation with VEGF expression

    Energy Technology Data Exchange (ETDEWEB)

    Chen, T.-W. [Department of Radiology, West China Hospital of Sichuan University, 37 Guo Xue Xiang, Chengdu, Sichuan 610041 (China) and Sichuan Province Key Laboratory of Medical Imaging and Department of Radiology, Affiliated Hospital of North Sichuan Medical College, 63 Wen Hua Lu, Nanchong, Sichuan 637000 (China); Yang, Z.-G., E-mail: yangzg1117@yahoo.com.cn [Department of Radiology, West China Hospital of Sichuan University, 37 Guo Xue Xiang, Chengdu, Sichuan 610041 (China); State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, 37 Guo Xue Xiang, Chengdu, Sichuan 610041 (China); Chen, H.-J. [Department of Pathology, West China Hospital of Sichuan University, 37 Guo Xue Xiang, Chengdu, Sichuan 610041 (China); Li, Y.; Tang, S.-S.; Yao, J.; Dong, Z.-H. [Department of Radiology, West China Hospital of Sichuan University, 37 Guo Xue Xiang, Chengdu, Sichuan 610041 (China); He, D. [Department of Pathology, West China Hospital of Sichuan University, 37 Guo Xue Xiang, Chengdu, Sichuan 610041 (China)

    2012-08-15

    Aim: To investigate the correlation between vascular endothelial cell growth factor (VEGF) expression and first-pass perfusion parameters at multidetector computed tomography (MDCT) using a low-dose technique, and to determine how to discriminate VEGF positivity from VEGF negativity by perfusion CT in oesophageal squamous cell carcinomas. Materials and methods: Thirty-two patients with oesophageal squamous cell carcinomas underwent first-pass perfusion with 64-section MDCT at 50 mAs. Perfusion parameters, including perfusion, peak enhanced density (PED), time to peak (TTP), and blood volume (BV), were measured. Postoperative specimens were assessed for VEGF expression. Correlation tests were performed to determine the associations between each CT perfusion parameter and VEGF expression. The cut-off values of perfusion parameters were obtained statistically to discriminate VEGF positivity from VEGF negativity. Results: Mean perfusion, PED, TTP, and BV were 38.47 {+-} 30.26 ml/min/ml, 24.68 {+-} 9.65 HU, 28.35 {+-} 9.03 s, and 11.82 {+-} 6.06 ml/100 g, respectively. PED or BV were significantly higher in the VEGF-positive group than in the VEGF-negative group (all p < 0.05), but no significant difference in perfusion or TTP was found between the VEGF-positive and VEGF-negative groups (all p > 0.05). In VEGF positivity, PED and BV were correlated with VEGF expression (r = 0.576 and 0.765, respectively; all p < 0.05), whereas perfusion and TTP were not (r = 0.361 and 0.239, respectively; all p > 0.05). A threshold of BV (10.23 ml/100 g) achieved a sensitivity of 94.4%, and a specificity of 92.9% for discriminating VEGF positivity from VEGF negativity. Conclusion: BV could reflect tumour VEGF expression, and could be an indicator for evaluating angiogenesis in oesophageal tumours.

  17. Electrochemical determination of methylglyoxal as a biomarker in human plasma.

    Science.gov (United States)

    Chatterjee, Sanghamitra; Wen, Jiali; Chen, Aicheng

    2013-04-15

    A novel electrochemical approach for the quantitative analysis of methylglyoxal as a biomarker in human plasma has been developed. An electrochemical sensor employing a single walled carbon nanotube modified glassy carbon electrode for the sensitive detection of methylglyoxal is delineated for the first time using square wave voltammetry. This modified electrode exhibits potent and sustained electron-mediating behavior and a well-defined reduction peak in response to methylglyoxal was observed. Under optimized experimental conditions, a wide linear dynamic range, from 0.1 to 100 μM, and high sensitivity of 76.3 nA μM⁻¹ were achieved for the detection of methylglyoxal. The interfering effect of common coexisting metabolites in human whole blood has also been investigated. The developed assay was shown to be specific and sensitive for the analysis of plasma levels of methylglyoxal in healthy volunteer and diabetic patients.

  18. Determination of Some Biochemical Parameters in the Seminal Plasma of German Shepherd Dogs

    OpenAIRE

    GÜNAY, Ülgen

    2003-01-01

    In this study, we aimed to determine the levels of some biochemical parameters in the seminal plasma of German Shepherd dogs. Seven German Shepherd dogs were used as materials. A total of 35 ejaculates, five from each dog, were collected. The seminal plasma of each ejaculate was separated by centrifugation at 5000 rpm for 10 min. Biochemical analyses of the seminal plasma were performed. In conclusion, the average concentrations of total protein, calcium, phosphorus, magnesium, sodium and pot...

  19. Evidence for Pro-angiogenic Functions of VEGF-Ax.

    Science.gov (United States)

    Xin, Hong; Zhong, Cuiling; Nudleman, Eric; Ferrara, Napoleone

    2016-09-22

    The VEGF-A isoforms play a crucial role in vascular development, and the VEGF signaling pathway is a clinically validated therapeutic target for several pathological conditions. Alternative mRNA splicing leads to the generation of multiple VEGF-A isoforms, including VEGF165. A recent study reported the presence of another isoform, VEGF-Ax, arising from programmed readthrough translation. Compared to VEGF165, VEGF-Ax has a 22-amino-acid extension in the COOH terminus and has been reported to function as a negative regulator of VEGF signaling in endothelial cells, with potent anti-angiogenic effects. Here, we show that, contrary to the earlier report, VEGF-Ax stimulates endothelial cell mitogenesis, angiogenesis, as well as vascular permeability. Accordingly, VEGF-Ax induces phosphorylation of key tyrosine residues in VEGFR-2. Notably, VEGF-Ax was less potent than VEGF165, consistent with its impaired binding to the VEGF co-receptor neuropilin-1.

  20. Determination of rafoxanide and closantel in ovine plasma by high performance liquid chromatography.

    Science.gov (United States)

    Benchaoui, H A; McKellar, Q A

    1993-01-01

    A high performance liquid chromatographic method has been developed for the determination of rafoxanide and closantel in ovine plasma. Acetonitrile and chloroform were used for the extraction. The mean recoveries were 78.69% and 80.59% for rafoxanide and closantel, respectively. This method was applied to the characterization of rafoxanide plasma kinetics following oral administration of therapeutic doses to sheep.

  1. Thermographic determination of the sheath heat transmission coefficient in a high density plasma

    NARCIS (Netherlands)

    van den Berg, M. A.; Bystrov, K.; Pasquet, R.; Zielinski, J. J.; De Temmerman, G.

    2013-01-01

    Experiments were performed in the Pilot-PSI linear plasma device, to determine the sheath heat transmission coefficients in a high recycling regime under various conditions of density (1–20 × 1020 m−3) and plasma composition (H2, Ar, N2) relevant for the

  2. Thermographic determination of the sheath heat transmission coefficient in a high density plasma

    NARCIS (Netherlands)

    van den Berg, M. A.; Bystrov, K.; Pasquet, R.; Zielinski, J. J.; De Temmerman, G.

    2013-01-01

    Experiments were performed in the Pilot-PSI linear plasma device, to determine the sheath heat transmission coefficients in a high recycling regime under various conditions of density (1–20 × 1020 m−3) and plasma composition (H2, Ar, N2) relevant for the

  3. Determination of the electron energy distribution function of a low temperature plasma from optical emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Dodt, Dirk Hilar

    2009-01-05

    The experimental determination of the electron energy distribution of a low pressure glow discharge in neon from emission spectroscopic data has been demonstrated. The spectral data were obtained with a simple overview spectrometer and analyzed using a strict probabilistic, Bayesian data analysis. It is this Integrated Data Analysis (IDA) approach, which allows the significant extraction of non-thermal properties of the electron energy distribution function (EEDF). The results bear potential as a non-invasive alternative to probe measurements. This allows the investigation of spatially inhomogeneous plasmas (gradient length smaller than typical probe sheath dimensions) and plasmas with reactive constituents. The diagnostic of reactive plasmas is an important practical application, needed e.g. for the monitoring and control of process plasmas. Moreover, the experimental validation of probe theories for magnetized plasmas as a long-standing topic in plasma diagnostics could be addressed by the spectroscopic method. (orig.)

  4. VEGF-A immunohistochemical and mRNA expression in tissues and its serum levels in potentially malignant oral lesions and oral squamous cell carcinomas.

    Science.gov (United States)

    Nayak, Seema; Goel, Madhu Mati; Chandra, Saumya; Bhatia, Vikram; Mehrotra, Divya; Kumar, Sandeep; Makker, Annu; Rath, S K; Agarwal, S P

    2012-03-01

    The aim of the study was to investigate whether the estimation of circulating Vascular endothelial growth factor-A (VEGF-A) levels by ELISA could be used as surrogate of VEGF-A expression in tissues of pre-malignant oral lesions (PMOLs) and oral squamous cell carcinoma (OSCC) as compared to that in healthy controls. The study samples comprised of tissue and blood samples from 60 PMOLs, 60 OSCC, and 20 healthy controls. Serum VEGF-A levels were determined by an ELISA based assay (Quantikine human VEGF; R & D System, Minneapolis USA). Tissue VEGF-A expression and microvessel density (MVD) were assessed by immunohistochemistry (IHC) using antibodies against VEGF-A and CD-34 on formalin fixed paraffin embedded (FFPE) tissue sections. VEGF-A mRNA expression was analyzed by real-time PCR in snap frozen tissues. Serum VEGF-A levels and immunohistochemical VEGF-A expression were significantly high in PMOLs and OSCC in comparison with controls. VEGF mRNA gene expression showed more than 50-fold increase in PMOLs and OSCC. VEGF-A levels in serum correlated in a linear fashion with the tissue expression in oral pre-malignant and malignant lesions, suggesting that the serum levels may serve as surrogate material for tissue expression of VEGF-A.

  5. The relationship between plasma levels of pigment epithelial derived factor and vascular endothelial growth factor in the patients with hepatocellular carcinoma and prognosis%肝癌患者血浆 PEDF 和 VEGF 表达水平及其与预后关系的探讨

    Institute of Scientific and Technical Information of China (English)

    朱莉丽; 杨凯; 刘亚

    2014-01-01

    目的:观察肝癌患者血浆色素上皮衍生因子(PEDF)及血管内皮生长因子(VEGF)表达水平并探讨其与预后的关系。方法采用ELISA法检测肝癌患者43例(肝癌组)、肝脏良性疾病患者20例(良性肝病组)及健康对照者20例(健康对照组)血浆PEDF和VEGF水平;肝癌患者平均随访(12 W.02±0.23)个月,记录短期主要不良终点事件(SMAE)发生情况。结果血浆PEDF水平肝癌组较良性肝病组及健康对照组明显降低( P <0.01),VEGF水平明显升高( P <0.01),而良性肝病组与健康对照组比较差异无统计学意义( P >0.05)。肝癌患者随访结束后,高PEDF/VEGF比值(≥3)亚组22例发生SMAE 3例(13.64%),低PEDF/VEGF比值(<3)亚组21例发生SMAE 7例(33.33%),Kaplan-Meier生存曲线显示2组差异有统计学意义( P =0.039)。另外,与未发生SMAE的肝癌患者(33例)比较,发生SMAE者(10例)有更低的PEDF/VEGF比值(2.14±0.76 vs.3.49±1.12, P <0.01)。结论 PEDF和VEGF参与肝癌的病理生理过程,低表达的PEDF及高表达的VEGF反映肝癌发生、发展及转移情况,两者比值可能成为预测肝癌转移及预后的有效指标。%Objective To observe the expression of pigment epithelium derived factor ( PEDF) and vascular endothe-lial growth factor ( VEGF) in liver cancer patients , and to explore its relationship with the prognosis .Methods ELISA was used to detect 43 cases of patients with hepatocellular carcinoma (HCC group), 20 patients with benign liver disease (benign liver disease group ) and 20 cases of healthy controls'( healthy control group ) levels of plasma PEDF and VEGF levels , pa-tients with hepatocellular carcinoma with average follow-up (12.02 ±0.23) months, the main short recording adverse events ( SMAE) occurrence were recorded .Results The levels of plasma PEDF of liver cancer group

  6. [Plasma cholesterol determination in birds--a diagnostic tool for detection of organophosphate and carbamate intoxication].

    Science.gov (United States)

    Kiesau, B; Kummerfeld, N

    1998-07-01

    An investigation was done on the clinical usefulness of the dry chemistry analyzer Vitros DT 60 II for determination of avian plasma cholinesterase. The analytical reliability of the method, evaluated by precision and accuracy, proved to be high for plasma of numerous pet and wild birds. Values of normal plasma-cholinesterase activity were established for different psittacine and European wild birds. Significant differences in physiologic plasma-cholinesterase activity were noted between closely related species as well as between juvenile and adult birds. These findings emphasize the necessity to use control values of the same species and age group for comparison. Dry chemistry plasma-cholinesterase determination can be used as a diagnostic tool for detection of organophosphate and carbamate poisonings in the majority of investigated birds.

  7. Opiate receptor blockade on human granulosa cells inhibits VEGF release.

    Science.gov (United States)

    Lunger, Fabian; Vehmas, Anni P; Fürnrohr, Barbara G; Sopper, Sieghart; Wildt, Ludwig; Seeber, Beata

    2016-03-01

    The objectives of this study were to determine whether the main opioid receptor (OPRM1) is present on human granulosa cells and if exogenous opiates and their antagonists can influence granulosa cell vascular endothelial growth factor (VEGF) production via OPRM1. Granulosa cells were isolated from women undergoing oocyte retrieval for IVF. Complementary to the primary cells, experiments were conducted using COV434, a well-characterized human granulosa cell line. Identification and localization of opiate receptor subtypes was carried out using Western blot and flow cytometry. The effect of opiate antagonist on granulosa cell VEGF secretion was assessed by enzyme-linked immunosorbent assay. For the first time, the presence of OPRM1 on human granulosa cells is reported. Blocking of opiate signalling using naloxone, a specific OPRM1 antagonist, significantly reduced granulosa cell-derived VEGF levels in both COV434 and granulosa-luteal cells (P opiate receptors and opiate signalling in granulosa cells suggest a possible role in VEGF production. Targeting this signalling pathway could prove promising as a new clinical option in the prevention and treatment of ovarian hyperstimulation syndrome.

  8. Improved LC method to determine ivermectin in plasma.

    Science.gov (United States)

    Prieto, J G; Merino, G; Pulido, M M; Estevez, E; Molina, A J; Vila, L; Alvarez, A I

    2003-03-26

    A simple, rapid and sensitive high-performance liquid chromatographic (HPLC) method has been developed to quantify Ivermectin (IVM) in plasma using an isocratic system with fluorescence detection. The method included a fast liquid phase extraction using cold methanol. HPLC separation was carried out by reversed phase chromatography with a mobile phase composed of methanol:acetonitrile:water with 0.2% acetic acid (45:50:5 v/v/v), pumped at flow rate of 2 ml min(-1). Fluorescence detection was performed at 365 nm (excitation) and 475 nm (emission). The calibration curve for IVM was linear from 0.25 to 100 ng ml(-1). The validation method yielded good results regarding linearity, precision, accuracy, specificity and recoveries. The values of the limit of detection (LOD) and limit of quantification (LOQ) were 0.032 and 0.167 ng ml(-1), respectively.

  9. (-)-Epigallocatechin-3-gallate inhibits VEGF expression induced by IL-6 via Stat3 in gastric cancer

    Institute of Scientific and Technical Information of China (English)

    Bao-He Zhu; Hua-Yun Chen; Wen-Hua Zhan; Cheng-You Wang; Shi-Rong Cai; Zhao Wang; Chang-Hua Zhang; Yu-Long He

    2011-01-01

    AIM: To demonstrate that (-)-Epigallocatechin-3-gallate (EGCG) inhibits vascular endothelial growth factor (VEGF) expression and angiogenesis induced by interleukin-6 (IL-6) via suppressing signal transducer and activator of transcription 3 (Stat3) activity in gastric cancer.METHODS: Human gastric cancer (AGS) cells were treated with IL-6 (50 ng/mL) and EGCG at different concentrations. VEGF, total Stat3 and activated Stat3 protein levels in the cell lyses were examined by Western blotting, VEGF protein level in the conditioned medium was measured by enzyme-linked immunosorbent assay, and the level of VEGF mRNA was evaluated by reverse transcription polymerase chain reaction (RTPCR).Stat3 nuclear translocation was determined by Western blotting with nuclear extract, and Stat3-DNA binding activity was examined with Chromatin immunoprecipitation (ChIP) assay. IL-6 induced endothelial cell proliferation was measured with 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazoliumbromide assay, in vitro angiogenesis was determined with endothelial cell tube formation assay in Matrigel, and IL-6-induced angiogenesis in vitro was measured with Matrigel plug assay.RESULTS: There was a basal expression and secretion of VEGF in AGS cells. After stimulation with IL-6, VEGF expression was apparently up-regulated and a 2.4-fold increase was observed. VEGF secretion in the conditioned medium was also increased by 2.8 folds. When treated with EGCG, VEGF expression and secretion were dose-dependently decreased. IL-6 also increased VEGF mRNA expression by 3.1 folds. EGCG treatment suppressed VEGF mRNA expression in a dose-dependent manner. EGCG dose-dependently inhibited Stat3 activation induced by IL-6, but did not change the total Stat3 expression. When treated with EGCG or AG490,VEGF expressions were reduced to the level or an even lower level in the tumor cells not stimulated with IL-6. However, PD98059 and LY294002 did not change VEGF expression induced by IL-6. EGCG inhibited

  10. A new method for high-performance liquid chromatographic determination of drotaverine in plasma.

    Science.gov (United States)

    Mezei, J; Küttel, S; Szentmiklósi, P; Marton, S; Rácz, I

    1984-10-01

    A sensitive, specific high-performance liquid chromatographic procedure was developed for the determination of plasma drotaverine levels. Basic plasma samples were adjusted to pH 1.5 and extracted with chloroform. HPLC [n-heptane-dichloromethane-diethylamine (50:25:2)] on a microporous silica column, with a variable-wavelength UV detector set at 302 nm allowed the measurement of drotaverine at the 50-ng/mL level. The utility of this method for determination of drotaverine in dog and rat plasma was demonstrated.

  11. VEGF internalization is not required for VEGFR-2 phosphorylation in bioengineered surfaces with covalently linked VEGF

    Science.gov (United States)

    Anderson, Sean M.; Shergill, Bhupinder; Barry, Zachary T.; Manousiouthakis, Eleana; Chen, Tom T.; Botvinick, Elliot; Platt, Manu O.; Iruela-Arispe, M. Luisa; Segura, Tatiana

    2011-01-01

    Vascular endothelial growth factor (VEGF) is known to activate proliferation, migration, and survival pathways in endothelial cells through phosphorylation of VEGF receptor-2 (VEGFR-2). VEGF has been incorporated into biomaterials through encapsulation, electrostatic sequestration, and covalent attachment, but the effect of these immobilization strategies on VEGF signaling has not been thoroughly investigated. Further, although growth factor internalization along with the receptor generally occurs in a physiological setting, whether this internalization is needed for receptor phosphorylation is not entirely clear. Here we show that VEGF covalently bound through a modified heparin molecule elicits an extended response of pVEGFR-2 in human umbilical vein endothelial cells (HUVECs) and that the covalent linkage reduces internalization of the growth factor during receptor endocytosis. Optical tweezer measurements show that the rupture force required to disrupt the heparin-VEGF-VEGFR-2 interaction increases from 3–8 pN to 6–12 pN when a covalent bond is introduced between VEGF and heparin. Importantly, by covalently binding VEGF to a heparin substrate, the stability (half-life) of VEGF is extended over three-fold. Here, mathematical models support the biological conclusions, further suggesting that VEGF internalization is significantly reduced when covalently bound, and indicating that VEGF is available for repeated phosphorylation events. PMID:21826315

  12. Determination of self generated magnetic field and the plasma density using Cotton Mouton polarimetry with two color probes

    Directory of Open Access Journals (Sweden)

    Joshi A.S.

    2013-11-01

    Full Text Available Self generated magnetic fields (SGMF in laser produced plasmas are conventionally determined by measuring the Faraday rotation angle of a linearly polarized laser probe beam passing through the plasma along with the interferogram for obtaining plasma density. In this paper, we propose a new method to obtain the plasma density and the SGMF distribution from two simultaneous measurements of Cotton Mouton polarimetry of two linearly polarized probe beams of different colors that pass through plasma in a direction normal to the planar target. It is shown that this technique allows us to determine the distribution of SGMF and the plasma density without doing interferometry of laser produced plasmas.

  13. Small satellite attitude determination during plasma brake deorbiting experiment

    Science.gov (United States)

    Khurshid, Osama; Selkäinaho, Jorma; Soken, Halil Ersin; Kallio, Esa; Visala, Arto

    2016-12-01

    This paper presents a study on attitude estimation during the Plasma Brake Experiment (PBE) onboard a small satellite. The PBE demands that the satellite be spun at a very high angular velocity, up to 200 deg/s, to deploy the tether using centrifugal force. The spin controller, based on purely magnetic actuation, and the PBE demands accurate attitude estimation for the successful execution of the experiment. The biases are important to be estimated onboard small satellites due to the closely integrated systems and relatively higher interference experienced by the sensors. However, bias estimation is even more important for PBE due to the presence of a high voltage unit, onboard the satellite, that is used to charge the tether and can be the source of interference. The attitude and the biases, when estimated simultaneously, results in an augmented state vector that poses a challenge to the proper tuning of process noise. The adaptation of process noise covariance has, therefore, been studied and analysed for the challenging PBE. It has been observed that adapting the process noise covariance improves the estimation accuracy during the spin-up phase. Therefore, it is very important to use adaptive process noise covariance estimation.

  14. Residual stresses determination in textured substrates for plasma sprayed coatings

    Science.gov (United States)

    Capek, J.; Pala, Z.; Kovarik, O.

    2015-04-01

    In this contribution, we have striven to respond to the desire of obtaining the residual stress tensor in the both cold-rolled and hot-rolled substrates designated for deposition of thermal coatings by plasma spraying. Residual stresses play an important role in the coating adhesion to the substrate and, as such, it is a good practice to analyse them. Prior to spraying, the substrate is often being grit blasted. Residual stresses and texture were quantitatively assessed in both virgin and grit blasted sample employing three attitudes. Firstly without taking preferred orientation into account, secondly from measurements of interplanar lattice spacings of planes with high Miller indices using MoKα radiation. And eventually, by calculating anisotropic elastic constants as a weighted average between single-crystal and X-ray elastic constants with weighting being done according to the amount of textured and isotropic material in the irradiated volume. In the ensuing verification analyses, it was established that the latter approach is suitable for materials with either very strong or very weak presence of texture.

  15. 孕早期外周血VEGF165b降低对预测子痫前期的作用研究%Effects of low VEGF165b on predicting increased risk of pre-eclampsia

    Institute of Scientific and Technical Information of China (English)

    武寿荣; 钱雷; 陈玮; 吴凤会

    2012-01-01

    Objective:To evaluate the signification of vascular endothelial growth factor165 b ( VEGF165 b ) for predicting increased risk of pre- eclampsia ( PE) , and to detect the expression of VEGF165 b in plasma of PE patients. Methods; Forty-seven patients with PE,42 normotensive pregnant women and 40 nonpregnant women were recruited in this study. The concentration of VEGF165b and VEGF in plasma of all women were analyzed with the methods of ELISA and cEIA respectively. Results; At 12 weeks of gestation, the VEGF165b concentration was significantly up- regulated in plasma from normotensive group [ ( 4. 49 ± 1. 57 ) ng·Ml 1 ] compared with non-pregnant women [ (0. 42 ± 0. 18) ng·Ml , P < 0. 01 ] . In contrast, in patients who later developed pre-eclampsia, VEGF165b levels [(1. 19 ±0. 50)ng-ml ] were significantly lower than in the normotensive group, but were greater than nonpregnant women. The serum concentrations of total VEGF were increased in the patients with PE compared to the women with normotensive group [ ( 35. 6 ± 5. 7 ) vs ( 29. 3 ± 4. 7 ) ng·Ml 1 , P < 0. 01 ]. ROC curve indicate that low VEGF165b in first trimester plasma may sensitively predict the risk of pre-eclampsia. Conclusion; Plasma VEGF165b levels may be a clinically useful first trimester plasma marker for increased risk of pre-eclampsia.%目的:分析血管内皮生长因子165b(VEGF165b)在子痫前期(PE)患者血清中的表达,探讨孕早期外周血VEGF165b作为预测PE发生的生物学指标的临床意义.方法:酶联免疫吸附试验(ELISA)和竞争性酶免疫分析(cEIA)分别检测47例PE患者和42例无高血压正常孕妇、40例未怀孕正常妇女血清中VEGF165b、VEGF的含量.ROC曲线分析孕12周VEGF165b预测PE发生的灵敏度.结果:孕12周,正常孕妇组血清VEGF165b含量[(4.49±1.57) ng·ml-1]与未怀孕组[(0.42±0.18) ng·ml-1]相比显著升高(P<0.01),发展成PE患者的外周血VEGF165b含量[(1.19±0.50) ng·ml-1]与正常

  16. The protective effect of the RAS inhibitor on diabetic patients with nephropathy in the context of VEGF suppression

    Institute of Scientific and Technical Information of China (English)

    Haibing CHEN; Junxi LU; Qing LI; Yuqian BAO; Junling TANG; Huijuan LU; Kunsan XIANG; Weiping JIA

    2009-01-01

    Aim:The aim of the present study was to explore whether renin angiotensin system (RAS) inhibitor can reduce the produc-tion of vascular endothelium growth factor (VEGF).Further,we sought to elucidate the correlation between VEGF level and certain clinical parameters,such as albumin excretion rate (AER),before and after treatment with angiotensin type 1 receptor blocker.Methods: We recruited 166 type 2 diabetic patients at various stages of diabetic nephropathy (DN) and 46 healthy control subjects for a cross-sectional study.We recruited another 42 hypertensive type 2 diabetic patients with microalbuminuria for a longitudinal study involving a 6-month irbesartan treatment protocol.Urinary VEGF (uVEGF) levels were determined using ELISA.Results: In the cross-sectional study,hypertensive type 2 diabetic patients who received RAS inhibitor presented lower uVEGF levels than those who did not receive the RAS inhibitor.Statistical analysis indicated that uVEGF level was independently correlated with the AER.In the longitudinal study involving the 6-month irbesartan treatment,we demonstrated that uVEGF levels decreased significantly in patients who achieved a 50% AER reduction (remission group,n=32).In contrast,uVEGF levels remained unchanged in patients who did not exhibit a 50% AER reduction (nonremission group,n=10).Furthermore,the change in uVEGF was significantly correlated with the change in AER (r=0.65,P<0.01) before and after 6 months of irbesartan treatment.This result held true even after we had adjusted for the decrease in average blood pressure.Conclusion: The protective effect of the RAS inhibitor in DN patients is associated with the suppression of VEGF.Accordingly,it may be possible to use uVEGF as a marker of DN progression.We suggest that uVEGF may be an important target for therapeutic intervention in the context of DN.

  17. Clinical significance of co-expression of VEGF-C and VEGFR-3 in non-small cell lung cancer

    Institute of Scientific and Technical Information of China (English)

    李庆昌; 董昕; 顾伟; 邱雪杉; 王恩华

    2003-01-01

    Objective To investigate the relationship between vascular endothelial growth factor C (VEGF-C) expression, VEGFR-3 expression, lymphangiogenesis and angiogenesis in human non-small cell lung cancer (NSCLC).Methods Seventy-six NSCLC samples were stained for VEGF-C, VEGFR-3 and CD34 with immunohistochemical methods. Assessment of lymphatic vessel density (LVD) and microvessel density (MVD) was performed. The expressions of VEGF-C in 24 fresh NSCLC samples were determined with Western blot assay.Results Of the 76 NSCLC cases, 55 were VEGF-C positive and 40 were VEGFR-3 positive in cancer cells. A significant positive correlation was found between VEGF-C expression and VEGFR-3 expression in cancer cells (P<0.05). VEGF-C expression was negatively associated with differentiation of tumor cells (P<0.05). VEGF-C expression and VEGFR-3 expression were positively associated with lymph node metastasis and lymphatic invasion (P<0.05). LVD was positively related to VEGF-C expression, lymph node metastasis, lymphatic invasion and clinical stage (P<0.05). There was a significant correlation between LVD and MVD (R=0.732, P<0.05). Patients with positive VEGF-C expression had worse outcomes than those with negative VEGF-C expression (P<0.001).Conclusions In NSCLC, VEGF-C and VEGFR-3 are related to the lymphangiogenesis, angiogenesis, and occurrence and development of lung cancers. VEGF-C expression could be a useful predictor of poor prognosis in NSCLC.

  18. 2-Deoxy Glucose Modulates Expression and Biological Activity of VEGF in a SIRT-1 Dependent Mechanism.

    Science.gov (United States)

    Kunhiraman, Haritha; Edatt, Lincy; Thekkeveedu, Sruthi; Poyyakkara, Aswini; Raveendran, Viji; Kiran, Manikantan Syamala; Sudhakaran, Perumana; Kumar, Sameer V B

    2017-02-01

    Reprogramming of energy metabolism particularly switching over of cells to aerobic glycolysis leading to accumulation of lactate is a hallmark of cancer. Lactate can induce angiogenesis, an important process underlying tumor growth and metastasis. VEGF is one of the most important cytokines which regulate this process and the present study was designed to examine if blocking glycolytic pathway in tumor cells can affect its angiogenic potency with respect to VEGF. For this, the expression and biological activity of VEGF synthesized and secreted by tumor derived cell lines in the presence or absence of 2-deoxy glucose (2-DG), an inhibitor of glycolysis was determined. The results suggested that inhibition of glycolysis using sub-lethal doses of 2-DG down-regulated the expression of VEGF and also significantly reduced its biological activity. Further mechanistic studies revealed that the down regulation of VEGF gene expression by 2-DG was due to an increase in SIRT-1 activity and the reduced biological activity was found to be due to an increase in the PAR modification of VEGF. Activity of SIRT-1 and PAR modification of VEGF in turn, was found to be correlated to the cellular NAD(+) levels. The results presented here therefore suggest that treatment of cancer cells with 2-DG can significantly reduce its overall angiogenic potency through transcriptional and post-translational mechanisms. J. Cell. Biochem. 118: 252-262, 2017. © 2016 Wiley Periodicals, Inc.

  19. Influence of anti-VEGF about cardiovascular biomarkers in age related macular degeneration.

    Science.gov (United States)

    Manresa, N; Mulero, J; Losada, M; Zafrilla, P

    2015-02-01

    Systemic VEGF inhibition disrupts endothelial homeostasis and accelerates the atherogenesis, suggesting that these events contribute to the clinical cardiovascular adverse events of VEGF-inhibiting therapies. The objective of the current study was to analyze the effect of anti-VEGF therapy on cardiovascular risk factors in patients with exudative age related macular degeneration. A total of 73 patients with exudative age related macular degeneration (without previous anti-VEGF therapy) were treated with two anti-VEGF: Ranibizumab and Pegaptanib sodium. The follow up was 6 months. The following parameters were determined before and after treatment: homocysteine, lipids (total cholesterol, triglycerides, HDL-c, LDL-c), C-Reactive Protein and fibrinogen. There were not statistically significant differences in parameters studied before and after treatment with both Pegaptanib sodium and Ranibizumab, except C-Reactive Protein. Of all patients analyzed, only 3 of them have initially C-Reactive Protein levels above normal levels and after antiangiogenic therapy, there was a significant increase in C-Reactive Protein. We have not found results in our study who to suspect that treatment with anti-VEGF in the patients with exudative age related macular degeneration increases cardiovascular risk predictors. However, after therapy was increased the CRP and fibrinogen may mean that anti-VEGF contribute an alteration of endothelial homeostasis in exudative AMD.

  20. High-Performance Liquid Chromatographic Method for Determination of Germacrone in Rat Plasma

    Institute of Scientific and Technical Information of China (English)

    HEHai-bing; TANGXing; CUIFu-de

    2004-01-01

    Aim A reliable high-performance liquid chromatographic (HPLC) method was developed for determination of gennacrone in rat. plasma. Methods The plasma samples were treated with acetonitrile and analyzed by HPLC with UV detection at 244 nm. Results The limit of detection was 100 ng·mL-1 for germacrone in plasma and the linear range was0.1004-15.06μg· mL-1 in plasma. The RSD of intra-day and inter-day assay was 1.87%-4.29% and 1.29%-5.15%, respectively. The recoveries of germacrone were over 95%. The endogenous substances in plasma did not show any interference in the analysis. Conclusion The method is accurate and convenient, and suitable for pharmacokinetic studies of gennacrone in rats.

  1. A flexible software design to determine the plasma boundary in Damavand tokamak

    Science.gov (United States)

    Ghadiri, Rasoul; Sadeghi, Yahya; Esteki, Mohammad Hossein

    2014-06-01

    A plasma boundary reconstruction code has been designed by using current filament method to calculate the magnetic flux and consequently plasma boundary in Damavand tokamak. Hence, a computer-based code "The Plasma Boundary Reconstruction Code in Tokamak (PBRCT)" was developed to make a graphical user interface and to speed up the plasma boundary estimation algorithm. All required tools as the plasma boundary and magnetic surface display (MSD), error display, primary conditions and modeling panel as well as a search motor to determine a good position and number of the current filaments to find a precise model have been considered. The core is a 3000 lines Matlab code and the graphical user interface is 10,000 lines in C# language.

  2. Methodology for determination of plasma cortisol in fish using Competitive Enzyme-Linked Immunosorbent Assay (ELISA)

    DEFF Research Database (Denmark)

    Velasco-Santamaría, Yohana M.; Cruz-Casallas, Pablo E.

    2007-01-01

    Objective. To determine plasma cortisol procedure in fish using competitive enzymelinked immunosorbent assay (ELISA). Materials and methods. Two plasma samples of juveniles rainbow trout Oncorhynchus mykiss were analized by using ELISA human kit for cortisol assay. For standard curve calibration...... seven standard solutions of cortisol in human plasma (0, 20, 50, 100, 200, 400 and 800 ng.ml-1) were used. For the recovery test 50, 100 and 200 ng.ml-1 standard solutions of cortisol were used; for the linearity test four dilutions of the fish plasma samples (1/2, 1/4, 1/8 and 1/16) were prepared....... To each well fish plasma samples and standard solutions were added and its content were conjugated to peroxidase and subsequently enzyme substrate was added. The enzymatic reaction was stopped by addition of phosphoric acid 0.5 M and the absorbance was read at 450 nm. The accuracy of the pipetting...

  3. VEGF-dependent mechanism of anti-angiogenic action of diamond nanoparticles in Glioblastoma Multiforme tumor

    DEFF Research Database (Denmark)

    Grodzik, M.; Sawosz, E.; Wierzbicki, M.

    2012-01-01

    of diamond nanoparticles on the growth of brain tumor (cultured on CAM membrane) and the development of its blood vessels. We hypothesize that diamond nanoparticles can bind VEGF or their receptors and this way influence of signal transduction between cells. The aim of our study was to evaluate the influence...... of diamond nanoparticle on VEGF level and inhibition of the brain tumor angiogenesis. We evaluated interaction of VEGF-A and VEGF-receptor proteins with diamond nanoparticles (TEM), visualized lower the permeability of blood vessels after diamond nanoparticles treatment and determined localization......Malignant gliomas are highly lethal cancers dependent on angiogenesis. The concept of treating tumors by inhibiting tumor angiogenesis was first articulated almost 30 years ago. Inhibition of tumor angiogenesis suppresses both tumor growth and metastasis. We determined the inhibition effect...

  4. Accuracy of plasma turbidity measurement for determining fat intolerance during total parenteral nutrition.

    Science.gov (United States)

    Nordenström, J; Thörne, A; Lindholm, M

    1990-06-01

    The accuracy of plasma turbidity measurements in predicting ability to metabolise intravenous fat emulsions during total parenteral nutrition was studied in 35 adult surgical patients. Plasma turbidity, expressed as a light scattering index (LSI), was determined by nephelometry and compared with measured triglyceride (TG) concentrations. A poor coefficient of correlation was found between LSI and TG (r = 0.52). The sensitivity and specificity of LSI in predicting TG concentration were 19% and 96% respectively. This indicates that the measurement of LSI is more useful in ruling out hypertriglyceridaemia than in detecting it. Consequently, clinical tolerance of intravenous fat emulsion cannot be monitored by measuring plasma turbidity. In order to avoid metabolic complications which may occasionally occur during intravenous nutritional therapy including fat emulsion, determination of plasma TG levels at timed intervals are recommended.

  5. [Determination of cyclohexanone concentration in the plasma separator by gas chromatography].

    Science.gov (United States)

    Huang, Min-Ju; Yan, Lin; He, Yan-Ying; Lin, Wei-Cong

    2009-09-01

    This essay is to determine the cyclohexanone concentration of the plasma separator. The compound was introduced into the GC analytical system by the carrier gas. The determination was performed by the measurement of their peak area and by the external standard method.

  6. Evaluation of the refractometric method for the determination of total protein in avian plasma or serum.

    Science.gov (United States)

    Lumeij, J T; de Bruijne, J J

    1985-07-01

    Serum total protein concentrations in pigeon blood determined with the biuret method (TPB-se) were compared with total protein concentrations in plasma (TPR-pl) and serum (TPR-se) obtained by estimation from refractive index. The refractometric method consistently yielded higher values (Prefractometric method for determination of TP in pigeon blood is not recommended.

  7. Sensitive determination of 4-O-methylhonokiol in rabbit plasma by high performance liquid chromatography and application

    Institute of Scientific and Technical Information of China (English)

    Ming-Yue Li; Yu-Hai Tang; Xia Liu; Hai-Yan Lu; Xi-Yan Shi

    2011-01-01

    A novel high performance liquid chromatographic method was developed for the determination of 4-O- methylhonokiol in rabbit plasma and was applied to its pharmacokinetic investigation. Plasma samples were treated by one-fold volume of methanol and acetoni

  8. Proteomic-Biostatistic Integrated Approach for Finding the Underlying Molecular Determinants of Hypertension in Human Plasma.

    Science.gov (United States)

    Gajjala, Prathibha R; Jankowski, Vera; Heinze, Georg; Bilo, Grzegorz; Zanchetti, Alberto; Noels, Heidi; Liehn, Elisa; Perco, Paul; Schulz, Anna; Delles, Christian; Kork, Felix; Biessen, Erik; Narkiewicz, Krzysztof; Kawecka-Jaszcz, Kalina; Floege, Juergen; Soranna, Davide; Zidek, Walter; Jankowski, Joachim

    2017-08-01

    Despite advancements in lowering blood pressure, the best approach to lower it remains controversial because of the lack of information on the molecular basis of hypertension. We, therefore, performed plasma proteomics of plasma from patients with hypertension to identify molecular determinants detectable in these subjects but not in controls and vice versa. Plasma samples from hypertensive subjects (cases; n=118) and controls (n=85) from the InGenious HyperCare cohort were used for this study and performed mass spectrometric analysis. Using biostatistical methods, plasma peptides specific for hypertension were identified, and a model was developed using least absolute shrinkage and selection operator logistic regression. The underlying peptides were identified and sequenced off-line using matrix-assisted laser desorption ionization orbitrap mass spectrometry. By comparison of the molecular composition of the plasma samples, 27 molecular determinants were identified differently expressed in cases from controls. Seventy percent of the molecular determinants selected were found to occur less likely in hypertensive patients. In cross-validation, the overall R(2) was 0.434, and the area under the curve was 0.891 with 95% confidence interval 0.8482 to 0.9349, Phypertensive patients were found to be -2.007±0.3568 and 3.383±0.2643, respectively, Phypertensives and normotensives. The identified molecular determinants may be the starting point for further studies to clarify the molecular causes of hypertension. © 2017 American Heart Association, Inc.

  9. Determining Concentrations and Temperatures in Semiconductor Manufacturing Plasmas via Submillimeter Absorption Spectroscopy

    Science.gov (United States)

    Helal, Yaser H.; Neese, Christopher F.; De Lucia, Frank C.; Ewing, Paul R.; Agarwal, Ankur; Craver, Barry; Stout, Phillip J.; Armacost, Michael D.

    2016-06-01

    Plasmas used in the manufacturing processes of semiconductors are similar in pressure and temperature to plasmas used in studying the spectroscopy of astrophysical species. Likewise, the developed technology in submillimeter absorption spectroscopy can be used for the study of industrial plasmas and for monitoring manufacturing processes. An advantage of submillimeter absorption spectroscopy is that it can be used to determine absolute concentrations and temperatures of plasma species without the need for intrusive probes. A continuous wave, 500 - 750 GHz absorption spectrometer was developed for the purpose of being used as a remote sensor of gas and plasma species. An important part of this work was the optical design to match the geometry of existing plasma reactors in the manufacturing industry. A software fitting routine was developed to simultaneously fit for the background and absorption signal, solving for concentration, rotational temperature, and translational temperature. Examples of measurements made on inductively coupled plasmas will be demonstrated. We would like to thank the Texas Analog Center of Excellence/Semiconductor Research Corporation (TxACE/SRC) and Applied Materials for their support of this work.

  10. Structure of the Full-length VEGFR-1 Extracellular Domain in Complex with VEGF-A.

    Science.gov (United States)

    Markovic-Mueller, Sandra; Stuttfeld, Edward; Asthana, Mayanka; Weinert, Tobias; Bliven, Spencer; Goldie, Kenneth N; Kisko, Kaisa; Capitani, Guido; Ballmer-Hofer, Kurt

    2017-02-07

    Vascular endothelial growth factors (VEGFs) regulate blood and lymph vessel development upon activation of three receptor tyrosine kinases: VEGFR-1, -2, and -3. Partial structures of VEGFR/VEGF complexes based on single-particle electron microscopy, small-angle X-ray scattering, and X-ray crystallography revealed the location of VEGF binding and domain arrangement of individual receptor subdomains. Here, we describe the structure of the full-length VEGFR-1 extracellular domain in complex with VEGF-A at 4 Å resolution. We combined X-ray crystallography, single-particle electron microscopy, and molecular modeling for structure determination and validation. The structure reveals the molecular details of ligand-induced receptor dimerization, in particular of homotypic receptor interactions in immunoglobulin homology domains 4, 5, and 7. Functional analyses of ligand binding and receptor activation confirm the relevance of these homotypic contacts and identify them as potential therapeutic sites to allosterically inhibit VEGFR-1 activity.

  11. Apolipoprotein A5, a crucial determinant of plasma triglyceridelevels, is highlyresponsive to PPARalpha activators

    Energy Technology Data Exchange (ETDEWEB)

    Vu-Dac, Ngoc; Gervois, Philippe; Jakel, Heidi; Nowak, Maxine; Bauge, Eric; Dehondt, Helene; Staels, Bart; Pennacchio, Len A.; Fruchart-Najib, Jamila; Fruchart, Jean-Charles

    2003-03-30

    The recently discovered APOA5 gene has been shown in humans and mice to be important in determining plasma triglycerides (TG) levels, a major cardiovascular disease risk factor. APOAV represents the first described apolipoprotein where over-expression lowers triglyceride levels. Since fibrates represent a commonly used therapy for lowering plasma triglycerides in humans, we investigated their ability to modulate APOA5 gene expression and consequently influence plasma TG levels. Human primary hepatocytes treated with Wy 14,643 or fenofibrate displayed a strong induction of APOA5 mRNA. Deletion and mutagenesis analyses of the proximal APOA5 promoter firmly demonstrate the presence of a functional PPAR response element. These findings demonstrate that APOA5 is a highly responsive PPARa target gene and support its role as a major mediator for how fibrates reduce plasma triglycerides in humans.

  12. Determination of tolperisone enantiomers in plasma and their disposition in rats.

    Science.gov (United States)

    Yokoyama, T; Fukuda, K; Mori, S; Ogawa, M; Nagasawa, K

    1992-01-01

    A stereoselective assay for the determination of tolperisone enantiomers in plasma by high performance liquid chromatography was developed. Calibration curves obtained for the enantiomers were linear over plasma concentrations of 0.1-3.0 micrograms/ml with a detection limit of 20 ng/ml. Following intravenous bolus administration of 10 mg/kg of racemic tolperisone to rats, stereoselective disposition of tolperisone enantiomers was observed, and plasma concentrations were significantly higher for l-tolperisone than for d-tolperisone at 5, 15 and 30 min after administration. When either enantiomer was administered alone to rats, both enantiomers were found in plasma, indicating that a mutual chiral inversion occurs in the body.

  13. High-performance liquid chromatographic method for the determination of drotaverine in human plasma and urine.

    Science.gov (United States)

    Bolaji, O O; Onyeji, C O; Ogungbamila, F O; Ogunbona, F A; Ogunlana, E O

    1993-12-08

    A simple and sensitive HPLC method for the determination of drotaverine in human plasma and urine has been developed. Alkalinized plasma or urine was extracted with organic solvent and the basic components in the organic phase were back-extracted into 0.1 M HCl. An aliquot of the aqueous layer was injected onto the column and the eluent was monitored at 254 nm. Separation was performed on a C18-column with 0.02 M sodium dihydrogen phosphate-methanol (30:70, v/v) containing perchlorate ion at pH 3.2 as mobile phase. Drotaverine was well resolved from the plasma constituents and internal standard. An excellent linearity was observed between peak-height ratios and plasma concentrations and the intra- and inter-assay coefficients of variation were always drotaverine in humans as well as in animal models.

  14. Quantitative gas chromatographic determination of perfluorooctanoic acid as the benzyl ester in plasma and urine

    Energy Technology Data Exchange (ETDEWEB)

    Ylinen, M.; Hanhijaervi, H.; Peura, P.; Raemoe, O.

    1985-11-01

    A method is presented for the quantitative determination of perfluorooctanoic acid in plasma and urine of dogs. The acid was esterified by an extractive alkylation method using tetrabutylammonium ion as the counter ion and benzyl bromide as the alkylating agent. Quantitation was made by gas chromatography. Typical values for precision obtained in the determination of 5 ..mu..g/ml of perfluorooctanoic acid in plasma and urine were 3.3% (S.D. N = 6) and 3.0% (S.D. N = 6), respectively. The limit of detection was 1 ng (2.4 pmol).

  15. Defining response to anti-VEGF therapies in neovascular AMD.

    Science.gov (United States)

    Amoaku, W M; Chakravarthy, U; Gale, R; Gavin, M; Ghanchi, F; Gibson, J; Harding, S; Johnston, R L; Kelly, S P; Kelly, S; Lotery, A; Mahmood, S; Menon, G; Sivaprasad, S; Talks, J; Tufail, A; Yang, Y

    2015-06-01

    The introduction of anti-vascular endothelial growth factor (anti-VEGF) has made significant impact on the reduction of the visual loss due to neovascular age-related macular degeneration (n-AMD). There are significant inter-individual differences in response to an anti-VEGF agent, made more complex by the availability of multiple anti-VEGF agents with different molecular configurations. The response to anti-VEGF therapy have been found to be dependent on a variety of factors including patient's age, lesion characteristics, lesion duration, baseline visual acuity (VA) and the presence of particular genotype risk alleles. Furthermore, a proportion of eyes with n-AMD show a decline in acuity or morphology, despite therapy or require very frequent re-treatment. There is currently no consensus as to how to classify optimal response, or lack of it, with these therapies. There is, in particular, confusion over terms such as 'responder status' after treatment for n-AMD, 'tachyphylaxis' and 'recalcitrant' n-AMD. This document aims to provide a consensus on definition/categorisation of the response of n-AMD to anti-VEGF therapies and on the time points at which response to treatment should be determined. Primary response is best determined at 1 month following the last initiation dose, while maintained treatment (secondary) response is determined any time after the 4th visit. In a particular eye, secondary responses do not mirror and cannot be predicted from that in the primary phase. Morphological and functional responses to anti-VEGF treatments, do not necessarily correlate, and may be dissociated in an individual eye. Furthermore, there is a ceiling effect that can negate the currently used functional metrics such as >5 letters improvement when the baseline VA is good (ETDRS>70 letters). It is therefore important to use a combination of both the parameters in determining the response.The following are proposed definitions: optimal (good) response is defined as when there

  16. Expression of vascular endothelial growth factor (VEGF) and VEGF-C in serum and tissue of Wilms tumor

    Institute of Scientific and Technical Information of China (English)

    WANG Lei; ZHANG Da; CHEN Xin-rang; FAN Yu-xia; WANG Jia-xiang

    2011-01-01

    Background Angiogenesis and lymphogenesis which were promoted by vascular endothelial growth factor (VEGF)and VEGF-C are important in the growth and metastasis of solid tumors.The high level of VEGF and VEGF-C were distributed in numerous types of cancers,but their distribution and expression in Wilms tumor,the most common pediatric tumor of the kidney,was unclear.Methods To learn about the distribution,mass spectroscopy and immunohistochemistry were used to measure the level of VEGF and VEGF-C in serum and tissue of Wilms tumor.Results The expression level of VEGF in serum of Wilms tumor was the same as in pre-surgery and control,so it was the same case of VEGF-C.Both of these factors were chiefly located in Wilms tumor tissue,but not in borderline and normal.In addition,the higher clinical staging and histopathologic grading were important elements in high expression of VEGF and VEGF-C.Gender,age and the size of tumor have not certainly been implicated in expression level of VEGF and VEGF-C.Conclusions The lymph node metastasis and growth of tumors resulted from angiogenesis and lymphogenesis which were promoted by VEGF and VEGF-C in Wilms tumor.The autocrine and paracrine process of VEGF and VEGF-C were the principal contributor to specific tissues of Wilms tumor but not to the entire body.

  17. The determination of micro-arc plasma composition and properties of nanoparticles formed during cathodic plasma electrolysis of 304 stainless steel

    Science.gov (United States)

    Jovović, Jovica; Stojadinović, Stevan; Vasilić, Rastko; Tadić, Nenad; Šišović, Nikola M.

    2017-05-01

    This paper presents the research focused on the determination of micro-arc plasma composition during cathodic plasma electrolysis of AISI304 stainless steel in water solution of sodium hydroxide. The complex line shape of several Fe I spectral lines was observed and, by means of a dedicated fitting procedure based on the spectral line broadening theory and H2O thermal decomposition data, the mole fraction of micro-arc plasma constituents (H2, Fe, O, H, H2O, and OH) was determined. Subsequent characterization of the cathodic plasma electrolysis product formed during the process revealed that it consists of Fe-nanoparticles with median diameter of approximately 60 nm.

  18. VEGF: a potential target for hydrocephalus.

    Science.gov (United States)

    Shim, Joon W; Sandlund, Johanna; Madsen, Joseph R

    2014-12-01

    Growth factors are primarily responsible for the genesis, differentiation and proliferation of cells and maintenance of tissues. Given the central role of growth factors in signaling between cells in health and in disease, it is understandable that disruption of growth factor-mediated molecular signaling can cause diverse phenotypic consequences including cancer and neurological conditions. This review will focus on the specific questions of enlarged cerebral ventricles and hydrocephalus. It is also well known that angiogenic factors, such as vascular endothelial growth factor (VEGF), affect tissue permeability through activation of receptors and adhesion molecules; hence, recent studies showing elevations of this factor in pediatric hydrocephalus led to the demonstration that VEGF can induce ventriculomegaly and altered ependyma when infused in animals. In this review, we discuss recent findings implicating the involvement of biochemical and biophysical factors that can induce a VEGF-mimicking effect in communicating hydrocephalus and pay particular attention to the role of the VEGF system as a potential pharmacological target in the treatment of some cases of hydrocephalus. The source of VEGF secretion in the cerebral ventricles, in periventricular regions and during pathologic events including hydrocephalus following hypoxia and hemorrhage is sought. The review is concluded with a summary of potential non-surgical treatments in preclinical studies suggesting several molecular targets including VEGF for hydrocephalus and related neurological disorders.

  19. Determination of carbocysteine in human plasma by liquid chromatography/tandem mass spectrometry employing precolumn derivatization.

    Science.gov (United States)

    Chen, Xiaoyan; Zhong, Dafang; Han, Ying; Xie, Zhiyong

    2003-01-01

    A sensitive liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed to determine carbocysteine in human plasma using 2-pyridylacetic acid as the internal standard (IS). The method employed derivatization with 10 M hydrochloric acid/methanol, which significantly improved the ionization efficiency of carbocysteine. After methanol-induced protein precipitation of plasma samples, carbocysteine and the IS were derivatized and subjected to LC/MS/MS analysis using atmospheric pressure chemical ionization. The method has a lower limit of quantitation of 20 ng/mL for a 0.2-mL plasma aliquot. The intra- and inter-day precision (RSD), calculated from quality control (QC) samples, was less than 7%. The accuracy, determined using QC samples, was within +/- 1%. The method offered increased sensitivity, selectivity and speed of analysis over existing methods. The method was utilized to support clinical pharmacokinetic studies of carbocysteine in volunteers following oral administration. Copyright 2002 John Wiley & Sons, Ltd.

  20. Simultaneous determination of niacin, niacinamide and nicotinuric acid in human plasma.

    Science.gov (United States)

    Pfuhl, P; Kärcher, U; Häring, N; Baumeister, A; Tawab, Mona Abdel; Schubert-Zsilavecz, M

    2005-01-04

    A sensitive, specific, accurate, and reproducible HPLC/MS-method for the simultaneous quantitative determination of niacin (NA) and its main metabolites niacinamide (NAM) and nicotinuric acid (NUR) in human plasma using chinolin-3-carboxylic acid as an internal standard was developed and validated according to international guidelines for method validation. All analytes and the internal standard were separated from acidified plasma by solid phase extraction. Afterwards the extracted samples were analyzed by HPLC/MS in the positive electrospray ionization mode (ESI) and selected ion monitoring (SIM). The total run time was 7 min between injections. The assay had a lower limit of quantification of 50.0 ng/mL for each analyte using 1 mL of plasma. The calibration curves were linear in the measured range between 50.0 and 750 ng/mL plasma. The overall precision and accuracy for all concentrations of quality controls and standards was better than 15%. No indications were found for possible instabilities of niacin, niacinamide and nicotinuric acid in plasma at -20 degrees C, in the extraction solvent or after repeated thawing/freezing cycles. In stabilities were observed in whole blood and in plasma at room temperature. The recovery of the extraction method ranged from 86 to 89% for the three analytes.

  1. Bone marrow stromal cells with a combined expression of BMP-2 and VEGF-165 enhanced bone regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Xiao Caiwen; Zhou Huifang; Fu Yao; Gu Ping; Fan Xianqun [Department of Ophthalmology, Shanghai Ninth People' s Hospital, Shanghai JiaoTong University School of Medicine, Shanghai 200011 (China); Liu Guangpeng [Key Laboratory of Tissue Engineering, Shanghai Ninth People' s Hospital, Shanghai JiaoTong University School of Medicine, Shanghai 200011 (China); Zhang Peng [Center for Translational Medicine Research and Development, Shenzhen Institute of Advanced Technology, Chinese Academy of Science (China); Hou Hongliang; Tang Tingting, E-mail: drfanxianqun@126.com [Department of Orthopedics, Shanghai Ninth People' s Hospital, Shanghai JiaoTong University School of Medicine, Shanghai 200011 (China)

    2011-02-15

    Bone graft substitutes with osteogenic factors alone often exhibit poor bone regeneration due to inadequate vascularization. Combined delivery of osteogenic and angiogenic factors from biodegradable scaffolds may enhance bone regeneration. We evaluated the effects of bone morphogenetic protein 2 (BMP2) and vascular endothelial growth factor (VEGF), combined with natural coral scaffolds, on the repair of critical-sized bone defects in rabbit orbits. In vitro expanded rabbit bone marrow stromal cells (BMSCs) were transfected with human BMP2 and VEGF165 genes. Target protein expression and osteogenic differentiation were confirmed after gene transduction. Rabbit orbital defects were treated with a coral scaffold loaded with BMP2-transduced and VEGF-transduced BMSCs, BMP2-expressing BMSCs, VEGF-expressing BMSCs, or BMSCs without gene transduction. Volume and density of regenerated bone were determined by micro-computed tomography at 4, 8, and 16 weeks after implantation. Neovascularity, new bone deposition rate, and new bone formation were measured by immunostaining, tetracycline and calcein labelling, and histomorphometric analysis at different time points. The results showed that VEGF increased blood vessel formation relative to groups without VEGF. Combined delivery of BMP2 and VEGF increased new bone deposition and formation, compared with any single factor. These findings indicate that mimicking the natural bone development process by combined BMP2 and VEGF delivery improves healing of critical-sized orbital defects in rabbits.

  2. Determination of chlordiazepoxide, diazepam, and their major metabolites in blood or plasma by spectrophotodensitometry.

    Science.gov (United States)

    Stronjny, N; Bratin, K; Brooks, M A; de Silva, J A

    1977-07-01

    An analytical procedure was developed for the determination of chlordiazepoxide, diazepam and their major metabolites in blood or plasma. Demoxepam, a metabolite of chlordiazepoxide, is determined by spectrofluorometry after extraction. The remaining compounds are determined by spectrophotodensitometry after thin-layer chromatographic separation. The sensitivity limit of the spectrofluorometric determination of demoxepam is 0.1 to 0.2 microgram while that of the spectrophotodensitometric determination of chlordiazepoxide, diazepam and their N-desmethyl metabolites is 0.05 to 0.2 microgram. The sensitivity and specificity of the assay renders it suitable for monitoring plasma levels of chlordiazepoxide and its major metabolites following single or chronic oral administration of chlordiazepoxide hydrochloride. The sensitivity limit for diazepam and nordiazepam, its major metabolite, renders the assay useful only for the determination of plasma concentrations resulting from high dosage of diazepam. The assay was used to determine chlordiazepoxide and its metabolites following oral administration of Librium. The data showed a significant correlation to those obtained on the same specimens by differential pulse polarography and by radioimmunoassay.

  3. Quantitative Determination of Levonorgestrel in Fish Plasma using UPLC-MS/MS

    Science.gov (United States)

    In this study, a sensitive high-performance liquid chromatography electrospray tandem mass spectrometric method was developed for the determination of levonorgestrel in fish plasma using levonorgestrel-d6 as an internal standard (IS). In the laboratory, the fish cunner, (Tautogol...

  4. Betaine and folate status as cooperative determinants of plasma homocysteine in humans.

    NARCIS (Netherlands)

    Holm, P.I.; Ueland, P.M.; Vollset, S.E.; Midttun, O.; Blom, H.J.; Keijzer, M.B.; Heijer, M. den

    2005-01-01

    OBJECTIVE: Two published studies have demonstrated that betaine in the circulation is a determinant of plasma total homocysteine, but none had sufficient power to investigate the possible effect modification by folate status. METHODS AND RESULTS: We measured homocysteine, betaine, folate, vitamin B(

  5. Spectroscopic Methods for Determination of Excitation Temperatures of High-Pressure Plasma

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yu; WEN Xiaohui; ZHAN Rujuan; YANG Weihong

    2007-01-01

    A method to determine excitation temperatures based on the optical emission spectroscopy(OES)and Fermi-Dirac distribution was set up,and the temperatures of pure-argon and mixed-gases at different pressures were investigated.In this way we set up a standard process to get the excitation temperatures of plasmas operated at atmospheric and sub-atmospheric pressures.

  6. Determination of platinum in human subcellular microsamples by inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Björn, Erik; Nygren, Yvonne; Nguyen, Tam T. T. N.

    2007-01-01

    A fast and robust method for the determination of platinum in human subcellular microsamples by inductively coupled plasma mass spectrometry was developed, characterized, and validated. Samples of isolated DNA and exosome fractions from human ovarian (2008) and melanoma (T289) cancer cell lines...

  7. Determination of telmisartan in human blood plasma: Part I: Immunoassay development

    NARCIS (Netherlands)

    Hempen, C.M.; Gläsle-Schwarz, Liane; Kunz, Ulrich; Karst, U.

    2006-01-01

    Telmisartan is an angiotensin II receptor antagonist and a known drug against high blood pressure. In this report, the development of a new and rapid analytical technique, an enzyme-linked immunosorbent assay (ELISA) for the determination of telmisartan in human blood plasma is described. The

  8. Temperature dependence of the cosphi conductance in Josephson tunnel junctions determined from plasma resonance experiments

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig; Sørensen, O. H.; Mygind, Jesper

    1978-01-01

    The microwave response at 9 GHz of Sn-O-Sn tunnel-junction current biased at zero dc voltage has been measured just below the critical temperature Tc of the Sn films. The temperature dependence of the cosφ conductance is determined from the resonant response at the junction plasma frequency fp...... of the experiment....

  9. Quantitative Determination of Levonorgestrel in Fish Plasma using UPLC-MS/MS

    Science.gov (United States)

    In this study, a sensitive high-performance liquid chromatography electrospray tandem mass spectrometric method was developed for the determination of levonorgestrel in fish plasma using levonorgestrel-d6 as an internal standard (IS). In the laboratory, the fish cunner, (Tautogol...

  10. 妊高征肾病患者血清TGF-β1、IL-8和VEGF检测的临床意义%Clinical Significance of Determination of Changes of Serum TGF-β1, IL-8 and VEGF Levels in Patients with Pregnancy Induced Hypertension Complicated with Nephropathy

    Institute of Scientific and Technical Information of China (English)

    李明; 吴玲; 陈海霞

    2011-01-01

    Objective To explore the significance of changes of serum TGF-β1, IL-8 and VEGF levels in patients with hyper tensive disorder complicating pregnancy. Methods Serum IL-8 ( with RiA ), serum TGF-β1, VEGF ( with ELISA ) levels were measured in 33 patients with pregnancy induced hypertension complicated with nephropathy, as well as in 35 healthy controls. Results The serum TGF-β1, IL-8 and VEGF levels in patients were significantly higher than those in controls ( P <0.01 ). Serum TGF-β1 levels were positively correlated to IL-8 ( r = 0. 6132, 0. 5834, P < 0.01 ). Conclusion VEGF levels were closely related with the diseases process of PIH. Determination of their changes might be useful for clinical diagnosis and predicting therapeutic effects in patients with PIH.%目的:探讨了妊高征肾病患者血清TGF-β1、IL-8和VEGF水平的变化及临床意义.方法:应用放射免疫分析和酶联法对33例妊高征肾病患者进行了血清TGF-β1、IL-8和VEGF测定,并与35名正常健康人作比较.结果:妊高征肾病患者血清TGF-β1、IL-8和VEGF水平均非常显著地高于正常人组(P<0.01),且血清TGF-β1水平与IL-8和VEGF水平呈正相关(r=0.6132、0.5834,P<0.01).结论:检测妊高征患者血清TGF-β1、IL-8和VEGF水平的变化对患者的病情的判断、临床治疗效果均有重要的临床价值.

  11. Enantioselective high-performance liquid chromatographic determination of nicardipine in human plasma.

    Science.gov (United States)

    Uno, T; Ohkubo, T; Sugawara, K

    1997-09-26

    A sensitive method for the enantioselective high-performance liquid chromatography (HPLC) determination of nicardipine in human plasma is described. (+)-Nicardipine, (-)-nicardipine and (+)-barnidipine as an internal standard are detected by an ultraviolet detector at 254 nm. Racemic nicardipine in human plasma was extracted by a rapid and simple procedure based on C18 bonded-phase extraction. The extraction samples were purified and concentrated on a pre-column using a C1 stationary phase and the enantiomers of nicardipine are quantitatively separated by HPLC on a Sumichiral OA-4500 column, containing a chemically modified Pirkle-type stationary phase. Determination of (+)- and (-)-nicardipine was possible in a concentration range of 5-100 ng ml(-1) and the limit of detection in plasma was 2.5 ng ml(-1). The recoveries of (+)- and (-)-nicardipine added to plasma were 91.4-98.4% and 93.3-96.7%, respectively, with coefficients of variation of less than 9.0 and 9.4% respectively. The method was applied to low level monitoring of (+)- and (-)-nicardipine in plasma from healthy volunteers.

  12. Vascular endothelial growth factor C (VEGF-C in esophageal cancer correlates with lymph node metastasis and poor patient prognosis

    Directory of Open Access Journals (Sweden)

    Naganawa Yasuhiro

    2010-06-01

    Full Text Available Abstract Background The diagnosis of lymph node metastasis in esophageal cancer by the presence and number of metastatic lymph nodes is an extremely important prognostic factor. In addition, the indication of non-surgical therapy is gaining more attention. Vascular endothelial growth factor C (VEGF-C is potentially lymphangiogenic and selectively induces hyperplasia of the lymphatic vasculature. In this study, we investigated the expression of VEGF-C and whether it correlated with various clinico-pathologic findings. Methods KYSE series of esophageal cancer cell lines and 106 patients with primary esophageal squamous cell carcinomas who had undergone radical esophagectomy were analyzed. VEGF-C mRNA expression was determined by quantitative RT-PCR. Results High expression of VEGF-C was detected in most of the KYSE cell lines, especially KYSE410, yet, in an esophageal normal epithelium cell line, Het-1A, VEGF-C was not detected. In the clinical specimen, the expression of VEGF-C in the cancerous tissue was higher than in the corresponding noncancerous esophageal mucosa (p = 0.026. The expression of VEGF-C was found to be higher in Stage2B-4A tumors than in Stage0-2A tumors (p = 0.049. When the patients were divided into two groups according to their expression levels of VEGF-C (a group of 53 cases with high expression and a group of 53 cases with low expression, the patients with high VEGF-C expression had significantly shorter survival after surgery than the patients with low expression (p = 0.0065. Although univariate analysis showed that high expression of VEGF-C was a statistically significant prognostic factor, this was not shown in multivariate analysis. In the subgroup of patients with Tis and T1 tumors, the expression of VEGF-C was higher in N1 tumors than in N0 tumors (p = 0.029. The survival rate of patients from the high expression group (n = 10 was lower than that in the low expression group (n = 11, and all the patients in the low

  13. Association of mast cell-derived VEGF and proteases in Dengue shock syndrome.

    Directory of Open Access Journals (Sweden)

    Takahisa Furuta

    Full Text Available BACKGROUND: Recent in-vitro studies have suggested that mast cells are involved in Dengue virus infection. To clarify the role of mast cells in the development of clinical Dengue fever, we compared the plasma levels of several mast cell-derived mediators (vascular endothelial cell growth factor [VEGF], soluble VEGF receptors [sVEGFRs], tryptase, and chymase and -related cytokines (IL-4, -9, and -17 between patients with differing severity of Dengue fever and healthy controls. METHODOLOGY/PRINCIPAL FINDINGS: The study was performed at Children's Hospital No. 2, Ho Chi Minh City, and Vinh Long Province Hospital, Vietnam from 2002 to 2005. Study patients included 103 with Dengue fever (DF, Dengue hemorrhagic fever (DHF, and Dengue shock syndrome (DSS, as diagnosed by the World Health Organization criteria. There were 189 healthy subjects, and 19 febrile illness patients of the same Kinh ethnicity. The levels of mast cell-derived mediators and -related cytokines in plasma were measured by ELISA. VEGF and sVEGFR-1 levels were significantly increased in DHF and DSS compared with those of DF and controls, whereas sVEGFR-2 levels were significantly decreased in DHF and DSS. Significant increases in tryptase and chymase levels, which were accompanied by high IL-9 and -17 concentrations, were detected in DHF and DSS patients. By day 4 of admission, VEGF, sVEGFRs, and proteases levels had returned to similar levels as DF and controls. In-vitro VEGF production by mast cells was examined in KU812 and HMC-1 cells, and was found to be highest when the cells were inoculated with Dengue virus and human Dengue virus-immune serum in the presence of IL-9. CONCLUSIONS: As mast cells are an important source of VEGF, tryptase, and chymase, our findings suggest that mast cell activation and mast cell-derived mediators participate in the development of DHF. The two proteases, particularly chymase, might serve as good predictive markers of Dengue disease severity.

  14. VEGF-A and VEGFR1 SNPs associate with preeclampsia in a Philippine population.

    Science.gov (United States)

    Amosco, Melissa D; Villar, Van Anthony M; Naniong, Justin Michael A; David-Bustamante, Lara Marie G; Jose, Pedro A; Palmes-Saloma, Cynthia P

    The vascular endothelial growth factor (VEGF) family is important for establishing normal pregnancy, and related single nucleotide polymorphisms (SNPs) are implicated in abnormal placentation and preeclampsia. We evaluated the association between preeclampsia and several VEGF SNPs among Filipinos, an ethnically distinct group with high prevalence of preeclampsia. The genotypes and allelic variants were determined in a case-control study (191 controls and 165 preeclampsia patients) through SNP analysis of VEGF-A (rs2010963, rs3025039) and VEGF-C (rs7664413) and their corresponding receptors VEGFR1 (rs722503, rs12584067, rs7335588) and VEGFR3 (rs307826) from venous blood DNA. VEGF-A rs3025039 C allele has been shown to associate with preeclampsia (odds ratio of 1.648 (1.03-2.62)), while the T allele bestowed an additive effect for the maintenance of normal, uncomplicated pregnancy and against the development of preeclampsia (odds ratio of 0.62 (0.39-0.98)). VEGFR1 rs722503 is associated with preeclampsia occurring at or after the age of 40 years. The results showed that genetic variability of VEGF-A and VEGFR1 are important in the etiology of preeclampsia among Filipinos.

  15. The Schlemm's canal is a VEGF-C/VEGFR-3-responsive lymphatic-like vessel.

    Science.gov (United States)

    Aspelund, Aleksanteri; Tammela, Tuomas; Antila, Salli; Nurmi, Harri; Leppänen, Veli-Matti; Zarkada, Georgia; Stanczuk, Lukas; Francois, Mathias; Mäkinen, Taija; Saharinen, Pipsa; Immonen, Ilkka; Alitalo, Kari

    2014-09-01

    In glaucoma, aqueous outflow into the Schlemm's canal (SC) is obstructed. Despite striking structural and functional similarities with the lymphatic vascular system, it is unknown whether the SC is a blood or lymphatic vessel. Here, we demonstrated the expression of lymphatic endothelial cell markers by the SC in murine and zebrafish models as well as in human eye tissue. The initial stages of SC development involved induction of the transcription factor PROX1 and the lymphangiogenic receptor tyrosine kinase VEGFR-3 in venous endothelial cells in postnatal mice. Using gene deletion and function-blocking antibodies in mice, we determined that the lymphangiogenic growth factor VEGF-C and its receptor, VEGFR-3, are essential for SC development. Delivery of VEGF-C into the adult eye resulted in sprouting, proliferation, and growth of SC endothelial cells, whereas VEGF-A obliterated the aqueous outflow system. Furthermore, a single injection of recombinant VEGF-C induced SC growth and was associated with trend toward a sustained decrease in intraocular pressure in adult mice. These results reveal the evolutionary conservation of the lymphatic-like phenotype of the SC, implicate VEGF-C and VEGFR-3 as critical regulators of SC lymphangiogenesis, and provide a basis for further studies on therapeutic manipulation of the SC with VEGF-C in glaucoma treatment.

  16. Thymosin beta 10 Prompted the VEGF-C Expression in Lung Cancer Cell

    Directory of Open Access Journals (Sweden)

    Zixuan LI

    2014-05-01

    Full Text Available Background and objective Our previous study found that thymosin β10 overexpressed in lung cancer and positively correlated with differentiation, lymph node metastasis and stage of lung cancer. In this reasearch we aim to study the effects and mechanism of exogenous human recombinant Tβ10 on the expression of VEGF-C on non-small cell lung cancer. Methods After SPC, A549 and LK2 cells were treated with 100 ng/mL recombinant human Tβ10, the mRNA level of VEGF-C were detected by RT-PCR. The mean while the protein expression of VEGF-C, P-AKT and AKT were determined by Western blot assay. Results Exogenous recombinant human Tβ10 were significantly promote the expression levels of VEGF-C mRNA and protein while promoting the phosphorylation of AKT. Exogenous Tβ10 can promote the expression of VEGF-C mRNA and protein in lung cancer cell lines A549 and LK2 (P<0.05, and this effect can be inhibited by use AKT inhibitor LY294002 (P<0.05. Conclusion Tβ10 human recombinant proteins can promote the expression of VEGF-C by activating AKT phosphorylation in lung cancer cell lines.

  17. VEGF-A Regulates Cellular Localization of SR-BI as Well as Transendothelial Transport of HDL but Not LDL.

    Science.gov (United States)

    Velagapudi, Srividya; Yalcinkaya, Mustafa; Piemontese, Antonio; Meier, Roger; Nørrelykke, Simon Flyvbjerg; Perisa, Damir; Rzepiela, Andrzej; Stebler, Michael; Stoma, Szymon; Zanoni, Paolo; Rohrer, Lucia; von Eckardstein, Arnold

    2017-05-01

    Low- and high-density lipoproteins (LDL and HDL) must pass the endothelial layer to exert pro- and antiatherogenic activities, respectively, within the vascular wall. However, the rate-limiting factors that mediate transendothelial transport of lipoproteins are yet little known. Therefore, we performed a high-throughput screen with kinase drug inhibitors to identify modulators of transendothelial LDL and HDL transport. Microscopy-based high-content screening was performed by incubating human aortic endothelial cells with 141 kinase-inhibiting drugs and fluorescent-labeled LDL or HDL. Inhibitors of vascular endothelial growth factor (VEGF) receptors (VEGFR) significantly decreased the uptake of HDL but not LDL. Silencing of VEGF receptor 2 significantly decreased cellular binding, association, and transendothelial transport of (125)I-HDL but not (125)I-LDL. RNA interference with VEGF receptor 1 or VEGF receptor 3 had no effect. Binding, uptake, and transport of HDL but not LDL were strongly reduced in the absence of VEGF-A from the cell culture medium and were restored by the addition of VEGF-A. The restoring effect of VEGF-A on endothelial binding, uptake, and transport of HDL was abrogated by pharmacological inhibition of phosphatidyl-inositol 3 kinase/protein kinase B or p38 mitogen-activated protein kinase, as well as silencing of scavenger receptor BI. Moreover, the presence of VEGF-A was found to be a prerequisite for the localization of scavenger receptor BI in the plasma membrane of endothelial cells. The identification of VEGF as a regulatory factor of transendothelial transport of HDL but not LDL supports the concept that the endothelium is a specific and, hence, druggable barrier for the entry of lipoproteins into the vascular wall. © 2017 American Heart Association, Inc.

  18. "Determination of mycophenolic acid in human plasma by high-performance liquid chromatography"

    OpenAIRE

    "Mehdi Ahadi Barzoki; Mohammadreza Rouini; Kheirolla Gholami; Mahboob Lessan-Pezeshki; Saeed Rezaee

    2005-01-01

    A simple, sensitive and reproducible HPLC method is presented for determination of mycophenolic acid(MPA) in human plasma. Samples were prepared after precipitation of the plasma protein by addition of acetonitrile and naproxen was used as internal standard (I.S.). Separation was performed by reversedphase HPLC, using a Hamilton PRP-C18 Column, 51% acetonitrile and 49% potassium phosphate buffer (20 mM) at pH 3.0 as mobile phase, flow rate of 1.0 ml/min, and UV detection at 215 nm. MPA and I....

  19. Native and Reconstituted Plasma Lipoproteins in Nanomedicine: Physicochemical Determinants of Nanoparticle Structure, Stability, and Metabolism.

    Science.gov (United States)

    Pownall, Henry J; Rosales, Corina; Gillard, Baiba K; Ferrari, Mauro

    2016-09-01

    Although many acute and chronic diseases are managed via pharmacological means, challenges remain regarding appropriate drug targeting and maintenance of therapeutic levels within target tissues. Advances in nanotechnology will overcome these challenges through the development of lipidic particles, including liposomes, lipoproteins, and reconstituted high-density lipoproteins (rHDL) that are potential carriers of water-soluble, hydrophobic, and amphiphilic molecules. Herein we summarize the properties of human plasma lipoproteins and rHDL, identify the physicochemical determinants of lipid transfer between phospholipid surfaces, and discuss strategies for increasing the plasma half-life of lipoprotein- and liposome-associated molecules.

  20. Rapid determination of succinylcholine in human plasma by high-performance liquid chromatography with fluorescence detection.

    Science.gov (United States)

    Lagerwerf, A J; Vanlinthout, L E; Vree, T B

    1991-10-04

    A high-performance liquid chromatographic method with fluorometric detection has been developed for the determination of succinylcholine in human plasma. Succinylcholine shows fluorescence at 282 nm with an excitation at 257 nm. The assay is sensitive, reproducible and linear for concentrations ranging from 100 ng/ml to 100 micrograms/ml of succinylcholine. In a pilot study the plasma concentration-time curve showed a triphasic elimination, with half-lives of 0.4, 1.2 and 8 min, respectively. In a clinical setting, drugs commonly administered during anaesthesia did not interfere with the assay. This method provides a simple and time-saving alternative to existing methods.

  1. Determination of talniflumate and niflumic acid in human plasma by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Kang, Wonku; Kim, Kibum

    2009-04-01

    A simple and rapid quantification method was developed for determining both talniflumate and niflumic acid in human plasma. After simple protein precipitation with acetonitrile, the analytes were chromatographed on a reversed-phase C(18) column and detected by LC/MS/MS with electrospray ionization. The assay accuracy and precision were within the FDA guidance for the analytical method validation. This method was used to measure the plasma concentrations of both compounds from healthy subjects after a single oral dose of talniflumate, 740 mg.

  2. High Performance Liquid Chromatographic Method for Determination of Dipyridamole in Human Plasma

    Directory of Open Access Journals (Sweden)

    DAVOOD BEIGI BAND ARAB ADI

    1999-08-01

    Full Text Available A simple, rapid and specific high-performance liquid chromatographic procedure is reported for"nquantitative determination of dipyridamole in human -plasma. The assay uses a reversed-phase"nhigh-performance liquid chromatographic (HPLC and UV detection at 280nm and has a limit"nof detection of approximately 5ng/mL. The mobile phase consists of MeOH-H20 (60:40"nadjusted to pH 3.3. Dipyridamole was extracted from plasma by back-extraction procedure, with"npropranolol as the internal standard. The reproducibility of the method is satisfactory

  3. Determination of fenbendazole, praziquantel and pyrantel pamoate in dog plasma by high-performance liquid chromatography.

    Science.gov (United States)

    Morovján, G; Csokán, P; Makranszki, L; Abdellah-Nagy, E A; Tóth, K

    1998-02-27

    Simple and rapid high-performance liquid chromatographic methods were developed for the determination of fenbendazole, praziquantel and pyrantel pamoate in dog plasma. The combination of these drugs is the most powerful treatment against most types of worms. Blood plasma samples obtained in a pharmacokinetic trial were prepared using solid-phase extraction. Fenbendazole and praziquantel were analyzed simultaneously by reversed-phase high-performance liquid chromatography on an octadecyl-modified silica stationary phase employing acetonitrile-phosphate buffer (pH 3.0) eluent and ultraviolet detection at 220 nm. Pyrantel was analyzed separately on a base-deactivated reversed-phase column using methanol-tetrahydrofuran-ammonium acetate buffer (pH 4.6) eluent and ultraviolet detection at 317 nm. Average recoveries for fenbendazole, praziquantel and pyrantel pamoate were 76.8, 93.4 and 90.5%, respectively. Limits of quantitation were in the range of 15-25 ng/ml plasma.

  4. A cell-free assay to determine the stoichiometry of plasma membrane proteins.

    Science.gov (United States)

    Trigo, Cesar; Vivar, Juan P; Gonzalez, Carlos B; Brauchi, Sebastian

    2013-04-01

    Plasma membrane receptors, transporters, and ion channel molecules are often found as oligomeric structures that participate in signaling cascades essential for cell survival. Different states of protein oligomerization may play a role in functional control and allosteric regulation. Stochastic GFP-photobleaching (SGP) has emerged as an affordable and simple method to determine the stoichiometry of proteins at the plasma membrane. This non-invasive optical approach can be useful for total internal reflection of fluorescence microscopy (TIRFM), where signal-to-noise ratio is very high at the plasma membrane. Here, we report an alternative methodology implemented on a standard laser scanning confocal microscope (LSCM). The simplicity of our method will allow for its implementation in any epifluorescence microscope of choice.

  5. Determination of albendazole sulfoxide in human plasma by using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Saraner, Nihal; Özkan, Güler Yağmur; Güney, Berrak; Alkan, Erkin; Burul-Bozkurt, Nihan; Sağlam, Onursal; Fikirdeşici, Ezgi; Yıldırım, Mevlüt

    2016-06-01

    A rapid, simple and sensitive method was developed and validated using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for determination of albendazole sulfoxide (ABZOX) in human plasma. The plasma samples were extracted by protein precipitation using albendazole sulfoxide-d3 as internal standard (IS). The chromatographic separation was performed on Waters Xbridge C18Column (100×4.6mm, 3.5μm) with a mobile phase consisting of ammonia solution, water and methanol at a flow rate of 0.70mL/min. ABZOX was detected and identified by mass spectrometry with electrospray ionization (ESI) in positive ion and multiple-reaction monitoring (MRM) mode. The method was linear in the range of 3-1500ng/mL for ABZOX. This method was successfully applied to the bioequivalence study in human plasma samples.

  6. Magnetoresistive polyaniline-silicon carbide metacomposites: plasma frequency determination and high magnetic field sensitivity.

    Science.gov (United States)

    Gu, Hongbo; Guo, Jiang; Khan, Mojammel Alam; Young, David P; Shen, T D; Wei, Suying; Guo, Zhanhu

    2016-07-20

    The Drude model modified by Debye relaxation time was introduced to determine the plasma frequency (ωp) in the surface initiated polymerization (SIP) synthesized β-silicon carbide (β-SiC)/polyaniline (PANI) metacomposites. The calculated plasma frequency for these metacomposites with different loadings of β-SiC nanoparticles was ranging from 6.11 × 10(4) to 1.53 × 10(5) rad s(-1). The relationship between the negative permittivity and plasma frequency indicates the existence of switching frequency, at which the permittivity was changed from negative to positive. More interestingly, the synthesized non-magnetic metacomposites, observed to follow the 3-dimensional (3-D) Mott variable range hopping (VRH) electrical conduction mechanism, demonstrated high positive magnetoresistance (MR) values of up to 57.48% and high MR sensitivity at low magnetic field regimes.

  7. Physical mechanism determining the radial electric field and its radial structure in a toroidal plasma

    Energy Technology Data Exchange (ETDEWEB)

    Ida, Katsumi; Miura, Yukitoshi; Itoh, Sanae [and others

    1994-10-01

    Radial structures of plasma rotation and radial electric field are experimentally studied in tokamak, heliotron/torsatron and stellarator devices. The perpendicular and parallel viscosities are measured. The parallel viscosity, which is dominant in determining the toroidal velocity in heliotron/torsatron and stellarator devices, is found to be neoclassical. On the other hand, the perpendicular viscosity, which is dominant in dictating the toroidal rotation in tokamaks, is anomalous. Even without external momentum input, both a plasma rotation and a radial electric field exist in tokamaks and heliotrons/torsatrons. The observed profiles of the radial electric field do not agree with the theoretical prediction based on neoclassical transport. This is mainly due to the existence of anomalous perpendicular viscosity. The shear of the radial electric field improves particle and heat transport both in bulk and edge plasma regimes of tokamaks. (author) 95 refs.

  8. Determination of salicylic acid by HPLC in plasma and saliva from children with juvenile chronic arthritis.

    Science.gov (United States)

    Legaz, M E; Acitores, E; Valverde, F

    1992-12-01

    A high performance liquid chromatography (HPLC) method has been developed for measuring salicylic acid in the plasma and saliva of children with juvenile chronic arthritis (JCA). Samples were extracted with diethyl ether and, after drying, redissolved in methanol to be chromatographed. Quantitation of salicylic acid was performed by reverse phase HPLC on a spherisorb ODS-2 column, using methanol: water: acetic acid as mobile phase. Phenolic was monitored by absorbance at 237 nm. Linearity between the amount of mass injected and the response in the detector was determined. This method was applied to compare concentrations of salivary and plasma salicylic acid. The method also permitted the quantitation of salivary salicylate as a non-invasive, indirect method for monitoring the concentration of plasma salicylate in patients with JCA.

  9. Validated HPLC-MS-MS method for determination of azithromycin in human plasma.

    Science.gov (United States)

    Barrett, B; Borek-Dohalský, V; Fejt, P; Vaingátová, S; Huclová, J; Nemec, B; Jelínek, I

    2005-09-01

    A validated, highly sensitive, and selective HPLC method with MS-MS detection has been developed for quantitative determination of azithromycin (AZI) in human Na2EDTA plasma. Roxithromycin (ROX) was used as internal standard. Human plasma containing AZI and internal standard was ultrafiltered through Centrifree Micropartition devices and the concentration of AZI was determined by isocratic HPLC-MS-MS. Multiple reaction monitoring mode (MRM) was used for MS-MS detection. The calibration plot was linear in the concentration range 2.55-551.43 ng mL(-1). Inter-day and Intra-day precision and accuracy of the proposed method were characterized by R.S.D and percentage deviation, respectively; both were less than 8%. Limit of quantification was 2.55 ng mL(-1). The proposed method was used to determine the pharmacokinetic profile of AZI (250-mg tablets).

  10. High-performance liquid chromatographic determination of memantine hydrochloride in rat plasma using sensitive fluorometric derivatization.

    Science.gov (United States)

    Xie, Mei-Fen; Zhou, Wei; Tong, Xin-Yi; Chen, Yi-Le; Cai, Yi; Li, Yan; Duan, Geng-Li

    2011-02-01

    In this study, we investigated a simple, sensitive and reliable liquid chromatography-fluorescence detection method for the determination of memantine hydrochloride in rat plasma which was based on derivatization with 9-fluorenylmethyl chloroformate (FMOC-Cl). For the first time, FMOC-Cl was introduced into derivatization of memantine hydrochloride in rat plasma. The amino groups of memantine hydrochloride and amantadine hydrochloride (internal standard) were trapped with FMOC-Cl to form memantine hydrochloride-FMOC-Cl and amantadine hydrochloride-FMOC-Cl compositions, which can be very compatible for LC-FLD. Precipitation of plasma proteins by acetonitrile was followed by vortex mixing and centrifugation. Chromatographic separation was performed on a C(18) column (DIAMONSIL 150 × 4.6 mm, id 5 μm) with a mobile phase consisting of acetonitrile and water at a flow rate of 1.0 mL/min. The retention times of memantine hydrochloride-FMOC-Cl and amantadine hydrochloride-FMOC-Cl compositions were 23.69 and 40.27 min, respectively. Optimal conditions for the derivatization of memantine hydrochloride were also described. The limit of quantification (LOQ) was 25 ng/mL for memantine hydrochloride in plasma, the linear range was 0.025-5.0 μg/mL in plasma with a correlation coefficient (r) of 0.9999. The relative standard deviations (RSDs) of intra-day and inter-day assays were 4.46-12.19 and 5.23-11.50%, respectively. The validated method was successfully applied to the determination of memantine hydrochloride in rat plasma samples.

  11. Effect of combined VEGF165/ SDF-1 gene therapy on vascular remodeling and blood perfusion in cerebral ischemia.

    Science.gov (United States)

    Hu, Guo-Jie; Feng, Yu-Gong; Lu, Wen-Peng; Li, Huan-Ting; Xie, Hong-Wei; Li, Shi-Fang

    2016-12-16

    OBJECTIVE Therapeutic neovascularization is a promising strategy for treating patients after an ischemic stroke; however, single-factor therapy has limitations. Stromal cell-derived factor 1 (SDF-1) and vascular endothelial growth factor (VEGF) proteins synergistically promote angiogenesis. In this study, the authors assessed the effect of combined gene therapy with VEGF165 and SDF-1 in a rat model of cerebral infarction. METHODS An adenoviral vector expressing VEGF165 and SDF-1 connected via an internal ribosome entry site was constructed (Ad- VEGF165-SDF-1). A rat model of middle cerebral artery occlusion (MCAO) was established; either Ad- VEGF165-SDF-1 or control adenovirus Ad- LacZ was stereotactically microinjected into the lateral ventricle of 80 rats 24 hours after MCAO. Coexpression and distribution of VEGF165 and SDF-1 were examined by reverse-transcription polymerase chain reaction, Western blotting, and immunofluorescence. The neurological severity score of each rat was measured on Days 3, 7, 14, 21, and 28 after MCAO. Angiogenesis and vascular remodeling were evaluated via bromodeoxyuridine and CD34 immunofluorescence labeling. Relative cerebral infarction volumes were determined by T2-weighted MRI and triphenyltetrazolium chloride staining. Cerebral blood flow, relative cerebral blood volume, and relative mean transmit time were assessed using perfusion-weighted MRI. RESULTS The Ad- VEGF165-SDF-1 vector mediated coexpression of VEGF165 and SDF-1 in multiple sites around the ischemic core, including the cortex, corpus striatum, and hippocampal granular layer. Coexpression of VEGF165 and SDF-1 improved neural function, reduced cerebral infarction volume, increased microvascular density and promoted angiogenesis in the ischemic penumbra, and improved cerebral blood flow and perfusion. CONCLUSIONS Combined VEGF165 and SDF-1 gene therapy represents a potential strategy for improving vascular remodeling and recovery of neural function after cerebral

  12. Decreased TGF-β1 and VEGF Release in Cystic Fibrosis Platelets: Further Evidence for Platelet Defects in Cystic Fibrosis

    Science.gov (United States)

    Maloney, James P.; Narasimhan, Jayashree; Biller, Julie

    2016-01-01

    Purpose Cystic fibrosis (CF) patients suffer from chronic lung inflammation. This inflammation may activate platelets. There are limited data on the role of platelet-secreted cytokines in CF. Platelet cytokines with inflammatory effects include vascular endothelial growth factor (VEGF) and transforming growth factor-β1 (TGF-β1). As levels of these cytokines are tenfold greater in serum than plasma due to platelet release, serum levels may be one index of platelet content; but a more specific index is release during the aggregation of isolated platelets. We postulated that altered release of these platelet cytokines occurs in CF. Methods We obtained sera and plasma from CF outpatients (n=21) and from healthy controls (n=20), measured VEGF and TGF-β1, assessed for correlations with platelet number, analyzed cytokine release during platelet aggregation to collagen, and analyzed differences in maximal platelet aggregation. Results Platelet number and maximal aggregation levels were higher in CF. Plasma and serum levels of TGF-β1 and VEGF were higher in CF, but these levels were similar after adjusting for platelet number (serum cytokines correlated with platelet count). The release of VEGF and TGF-β1 during aggregation was decreased in CF platelets (by 52% and 29%, respectively). Conclusion Platelet release is not a source of the elevated blood proinflammatory cytokines TGF-β1 and VEGF in CF, as platelets from CF patients actually release less of these cytokines. These data provide further evidence for platelet defects in CF. PMID:27423781

  13. VEGF-A levels in bevacizumab-treated breast cancer patients: a systematic review and meta-analysis.

    Science.gov (United States)

    Santos, Lucas Vieira dos; Cruz, Marcelo Rocha; Lopes, Gilberto de Lima; Lima, Joao Paulo da Silveira Nogueira

    2015-06-01

    Bevacizumab may improve outcomes of patients with breast cancer, but the absence of an established biomarker hampers patient selection and researchers´ ability to demonstrate a clear survival benefit. Its putative target, circulating VEGF-A, emerged as the main candidate and we sought to identify the relationship between VEGF-A levels and outcomes through systematic review. We searched electronic databases and meeting proceedings for randomized controlled trials (RCTs) comparing the addition of bevacizumab to standard chemotherapy for breast cancer. RCTs were included if outcomes were presented separately according to VEGF-A plasma levels. Random-effects model were applied to calculate the pooled hazard ratios for progression-free survival, event-free survival (EFS), comprising disease recurrence, progression or any-cause death, and overall survival (OS), with respective confidence intervals (95 % CI). High and low VEGF-A levels subgroups followed each trial definition, and results were compared using the interaction test. Heterogeneity was calculated using χ (2) test (I (2)). Three trials enrolled a total of 3748 patients. 1713 patients had baseline VEGF-A levels in plasma available for assessment and were included. One trial added bevacizumab in the adjuvant setting (N = 2591) and two on first-line metastatic disease with taxane-based therapy (N = 1160) There was no interaction between VEGF-A levels and study setting (adjuvant vs. first line therapy). Bevacizumab improved PFS of patients with above median VEGF-A plasma levels (HR 0.56; 95 % CI 0.43-0.73; P cancer. Further studies have to confirm its surrogacy in overall survival and in other scenarios including other anti-angiogenic therapies.

  14. Effect of the platelet-rich plasma on the proliferation and the expression of PDGF, TGF-β and VEGF of human dermal fibroblasts in vitro%富血小板血浆对人真皮细胞增殖及PDGF、TGF-β和VEGF表达的影响

    Institute of Scientific and Technical Information of China (English)

    王悦; 朱喆; 成荣杰; 张丽红; 马英智; 周延民

    2012-01-01

    Objective:To study the effects of platelet-rich plasma (PRP) on the proliferation and differentiation of human dermal fi-broblasts (hFbs) and on the expression of platelet-derived growth factor (PDGF) , transforming growth factor (TGF-p) and vascular endothelial growth factor ( VEGF) in hFbs. Methods; PRP was prepared by twice centrifugation method. hFbs were treated by different concentrations of PRP and cultured under osteogenesis induction medium. The mineralization of the hFbs was examined by calcium- cobalt staining and the alizarin red staining at 12 d and 21 d. The expression of PDGF, TGF-p and VEGF was evaluated by immunocyto-chemistry, alkaline phosphatase (ALP) expression was tested by ALP staining, cell proliferation was detected by CCK-8 assay. Results : The formation of calcium node in 2. 8% PRP group in mineralization induction culture was significant. The expression of PDGF was PRP dose-dependence, but TGF-p and VEGF expression needed an appropriate PRP concentration. ALP expression increased in 3% PRP group significantly. Proliferation of hFbs in mineralization induction culture was increased more. Conclusion; PRP may promote the proliferation, differentiation and relative growth factor expression of hFbs.%目的:研究富血小板血浆(PRP)对人真皮成纤维细胞(hFbs)增殖、分化及胞质中PDGF、TGF-β和VEGF表达量的影响.方法:2次离心法制备PRP,成骨诱导条件下hFbs培养液中加入不同浓度PRP于第12天、21天钙-钴法染色,第21天茜素红染色;免疫细胞化学法检测加不同浓度PRP后第4天细胞PDGF、TGF-β和VEGF的表达;碱性磷酸酶染色(ALP)检测细胞活性;CCK-8法检测有和无成骨诱导条件下不同浓度PRP对细胞增殖的影响.结果:茜素红染色显示,2.8% PRP组钙结节形成最明显;钙-钴法染色显示,2.8% PRP组矿化作用最强;免疫细胞化学结果表明PDGF表达存在剂量依赖性,TGF-β和VEGF表达虽无剂量依赖性,但有适宜

  15. Determination of total plasma hydroperoxides using a diphenyl-1-pyrenylphosphine fluorescent probe.

    Science.gov (United States)

    Santas, Jonathan; Guardiola, Francesc; Rafecas, Magda; Bou, Ricard

    2013-03-01

    Plasma hydroperoxides (HPs) are widely accepted to be good indicators of oxidative stress. By means of the method proposed here, which uses diphenyl-1-pyrenylphosphine (DPPP) as a fluorescent probe, all types of plasma HP were determined. The limits of detection and quantification of the method were 0.08 and 0.25 nmol of cumene hydroperoxide (CHP) equivalents in 40 μl of plasma, respectively. The method is satisfactory in terms of precision (5.3% for 14.5 μM CHP eq., n=8), and the recoveries were 91% and 92% after standard additions of 26 and 52 μM CHP, respectively. The selectivity of the proposed method is higher than 96%. Moreover, optimization of the reaction conditions and the addition of ethylenediaminetetraacetic acid (EDTA) disodium salt and 2,6-di-tert-butyl-4-methylphenol (BHT) prevented the formation of HP artifacts during the analysis. Therefore, the proposed method is useful for simple and quantitative determination of total plasma HPs.

  16. Indirect determination of the electric field in plasma discharges using laser-induced fluorescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Vaudolon, J., E-mail: julien.vaudolon@cnrs-orleans.fr; Mazouffre, S., E-mail: stephane.mazouffre@cnrs-orleans.fr [CNRS - ICARE (Institut de Combustion Aérothermique Réactivité et Environnement), 1 C Av. de la Recherche Scientifique, 45071 Orléans Cedex 2 (France)

    2014-09-15

    The evaluation of electric fields is of prime interest for the description of plasma characteristics. In this work, different methods for determining the electric field profile in low-pressure discharges using one- and two-dimensional Laser-Induced Fluorescence (LIF) measurements are presented and discussed. The energy conservation, fluid, and kinetic approaches appear to be well-suited for the electric field evaluation in this region of the plasma flow. However, the numerical complexity of a two-dimensional kinetic model is penalizing due to the limited signal-to-noise ratio that can be achieved, making the computation of the electric field subject to large error bars. The ionization contribution which appears in the fluid model makes it unattractive on an experimental viewpoint. The energy conservation and 1D1V kinetic approaches should therefore be preferred for the determination of the electric field when LIF data are used.

  17. Determination of catecholamines in plasma by HPLC and amperometric detection. Comparison with a radioenzymatic method.

    Science.gov (United States)

    Bauersfeld, W; Ratge, D; Knoll, E; Wisser, H

    1986-03-01

    The determination of norepinephrine and epinephrine in plasma by HPLC with amperometric detection was modified, giving detection limits of 25 ng/l for norepinephrine and epinephrine, respectively, using 1 ml plasma. In order to achieve this sensitivity, it was necessary to minimize the background noise by modification of instrumentation and specimen handling. Particularly important was the extra purification of the reagents, the application of micro-bore HPLC, the enzymatic cleavage of uric acid and temperature control of the amperometric cell and the amplifier. Comparison of the present method with the radioenzymatic determination of catecholamines resulted in coefficients of correlation of r = 0.924 and 0.919 for norepinephrine and epinephrine, resp. (n = 38). The concentrations of the 38 different samples used for the comparison were in the physiological range.

  18. Fetal sex determination of macaque monkeys by a nested PCR using maternal plasma.

    Science.gov (United States)

    Mitsunaga, Fusako; Ueiwa, Miyuki; Kamanaka, Yoshirou; Morimoto, Mayumi; Nakamura, Shin

    2010-01-01

    Non-invasive fetal sex determination is required for biomedical studies, in which some sexual difference would be expected in fetal events, in order to make a choice of male or female fetus. To detect male fetal DNA of the sex-determining region Y gene (SRY) in maternal macaque plasma, nested real-time PCR using the SYBR Green system was developed. In all cases of pregnant macaques with male fetuses, a nested PCR product of SRY was amplified from the mother's plasma, while no amplicon was detected in any case of pregnancy with a female fetus. Interestingly, fetal SRY DNA appeared to be cleared rapidly from the maternal blood after parturition. The current method is sensitive and can be performed with a regular PCR machine.

  19. Liquid chromatography-mass spectrometric determination of rufinamide in low volume plasma samples.

    Science.gov (United States)

    Gáll, Zsolt; Vancea, Szende; Dogaru, Maria T; Szilágyi, Tibor

    2013-12-01

    Quantification of rufinamide in plasma was achieved using a selective and sensitive liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method. The chromatographic separation was achieved on a reversed phase column (Zorbax SB-C18 100mm×3mm, 3.5μm) under isocratic conditions. The mobile phase consisted of a mixture of water containing 0.1% formic acid and methanol (50:50, v/v). The mass spectrometric detection of the analyte was in multiple reaction monitoring mode (MRM) using an electrospray positive ionization (ESI positive). The monitored ions were 127m/z derived from 239m/z rufinamide and 108m/z derived from 251m/z the internal standard (lacosamide). Protein precipitation with methanol was applied for sample preparation using only 50μl aliquots. The concentration range was 40-2000ng/ml for rufinamide in plasma. The limit of detection was 1.25ng/ml and the lower limit of quantification was established at 5ng/ml rufinamide concentration. Selectivity and matrix effect was verified using individual human, rat and rabbit plasma samples. Short-term, post-preparative and freeze-thaw stability was also investigated. The proposed method provides accuracy, precision and high-throughput (short runtime 4.5min) for quantitative determination of rufinamide in plasma. This is the first reported liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for analysis of rufinamide from low volume plasma samples. The LC-MS/MS method was validated according to the current official guidelines and can be applied to accurately measure rufinamide level of large number of plasma samples from clinical studies or therapeutic drug monitoring.

  20. Spectrophotometric determination of total proteins in blood plasma: a comparative study among dye-binding methods

    OpenAIRE

    Dimas Augusto Morozin Zaia; Fábio Rangel Marques; Cássia Thaïs Bussamra Vieira Zaia

    2005-01-01

    A comparative study between the biuret method (standard method for total proteins) and spectrophotometric methods using dyes (Bradford, 3',3",5',5"-tetrabromophenolphthalein ethyl ester-TBPEE, and erythrosin-B) was carried out for the determination of total proteins in blood plasma from rats. Bradford method showed the highest sensitivity for proteins and biuret method showed the lowest. For all the methods, the absorbance for different proteins (BSA, casein, and egg albumin) was measured and...

  1. Determination of diclofenac concentrations in human plasma using a sensitive gas chromatography mass spectrometry method

    OpenAIRE

    2016-01-01

    Background A gas chromatography mass spectrometry (GCMS) method for the determination of diclofenac in human plasma has been developed and validated. Results This method utilizes hexane which is a relatively less toxic extraction solvent compared to heptane and benzene. In addition, phosphoric acid and acetone were added to the samples as deproteination agents, which increased the recovery of diclofenac. These revised processes allow clean extraction and near-quantitative recovery of analyte ...

  2. Determination of diclofenac concentrations in human plasma using a sensitive gas chromatography mass spectrometry method

    OpenAIRE

    Shah, Iltaf; Barker, James; Naughton, Declan P; Barton, Stephen J.; Ashraf, Syed Salman

    2016-01-01

    Background\\ud A gas chromatography mass spectrometry (GCMS) method for the determination of diclofenac in human plasma has been developed and validated.\\ud \\ud Results\\ud This method utilizes hexane which is a relatively less toxic extraction solvent compared to heptane and benzene. In addition, phosphoric acid and acetone were added to the samples as deproteination agents, which increased the recovery of diclofenac. These revised processes allow clean extraction and near-quantitative recover...

  3. High Performance Liquid Chromatography Tandem Mass Spectrometry Assay for the Determination of Cobinamide in Pig Plasma

    Science.gov (United States)

    McCracken, Brent A.; Brittain, Matthew K.

    2015-01-01

    Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been widely utilized for the analysis of compounds in biological matrices due to its selectivity and sensitivity. This study describes the application of an LC-MS/MS-based approach toward the analysis of cobinamide in Yorkshire pig plasma. The selectivity, accuracy, precision, recovery, linearity, range, carryover, sensitivity, matrix effect, interference, stability, reproducibility, and ruggedness of the method were investigated in pig plasma. The accuracy and precision of the method was determined to be within 10% over three different days over a range of concentrations (25–10,000 ng/mL) that spanned more than two orders of magnitude. The lower limit of quantitation (LLOQ) for dicyanocobinamide was determined to be 25 ng/mL in pig plasma. Carryover was acceptable, as the area response of the carryover blanks were ≤15% of the area response of the nearest LLOQ standard for the analyte, while it was nonexistent for the internal standard. Specificity was ensured using six different lots of pig plasma. While the matrix effects of dicyanocobinamide in plasma were enhanced, ginsenoside Rb1 experienced signal suppression under the described conditions. The absolute recovery results for both compounds were consistent, precise, and reproducibly lower than expected at ~60% for dicyanocobinamide and ~22% for ginsenoside Rb1, confirming that a matrix standard curve was required for accurate quantitation. Cobinamide was shown to be very stable in matrix at various storage conditions including room temperature, refrigerated, and frozen at time intervals of 20 hours, 4 days, and 60 days respectively. This method was demonstrated to be sensitive, reproducible, stable, and rugged, and it should be applicable to the analysis of cobinamide in other biological matrices and species. PMID:26540437

  4. PH metric method for the determination of nicotinic acid in plasma.

    Science.gov (United States)

    Gravesen, J

    1977-04-01

    The acidimetric method for the determination of nicotinic acid (NA) using Lactobacillus plantarum ATCC 8014 (Lactobacillus arabinosus 17-5) has been simplified and thus made less time consuming, and the sensitivity has been increased fivefold by replacement of the titration by a pH determination. As the regression of the decrease in pH on the amount of NA was found linear within a range of 1 to 4 ng of NA per ml, the calculations were performed according to the slope-ratio principle. The NA concentration of plasma was determined with a coefficient of variation of 5 to 7%, which rose to about 10% at low NA concentrations. Assays of fasting plasma samples from 13 hyperlipidemic male patients showed a group mean NA concentration of 80 +/- 55 ng/ml (mean +/- 2 standard deviation), before treatment, and 705 +/- 544 ng/ml (mean +/- 2 standard deviation) during therapy with sustained release NA preparations, of which a single dose, ingested during steady-state conditions, doubled or tripled the plasma concentration within 1 to 3 h.

  5. Activator of G-protein signaling 8 is involved in VEGF-mediated signal processing during angiogenesis.

    Science.gov (United States)

    Hayashi, Hisaki; Al Mamun, Abdullah; Sakima, Miho; Sato, Motohiko

    2016-03-15

    Activator of G-protein signaling 8 (AGS8, also known as FNDC1) is a receptor-independent accessory protein for the Gβγ subunit, which was isolated from rat heart subjected to repetitive transient ischemia with the substantial development of collaterals. Here, we report the role of AGS8 in vessel formation by endothelial cells. Knockdown of AGS8 by small interfering RNA (siRNA) inhibited vascular endothelial growth factor (VEGF)-induced tube formation, as well as VEGF-stimulated cell growth and migration. VEGF stimulated the phosphorylation of the VEGF receptor-2 (VEGFR-2, also known as KDR), ERK1/2 and p38 MAPK; however, knockdown of AGS8 inhibited these signaling events. Signal alterations by AGS8 siRNA were associated with a decrease of cell surface VEGFR-2 and an increase of VEGFR-2 in the cytosol. Endocytosis blockers did not influence the decrease of VEGFR-2 by AGS8 siRNA, suggesting the involvement of AGS8 in VEGFR-2 trafficking to the plasma membrane. VEGFR-2 formed a complex with AGS8 in cells, and a peptide designed to disrupt AGS8-Gβγ interaction inhibited VEGF-induced tube formation. These data suggest a potential role for AGS8-Gβγ in VEGF signal processing. AGS8 might play a key role in tissue adaptation by regulating angiogenic events.

  6. Structural basis for the selective vascular endothelial growth factor-A (VEGF-A) binding to neuropilin-1

    Energy Technology Data Exchange (ETDEWEB)

    Parker, Matthew W.; Xu, Ping; Li, Xiaobo; Vander Kooi, Craig W. (Kentucky)

    2012-07-25

    Neuropilin-1 (Nrp1) is an essential receptor for angiogenesis that binds to VEGF-A. Nrp1 binds directly to VEGF-A with high affinity, but the nature of their selective binding has remained unclear. Nrp1 was initially reported to bind to the exon 7-encoded region of VEGF-A and function as an isoform-specific receptor for VEGF-A164/165. Recent data have implicated exon 8-encoded residues, which are found in all proangiogenic VEGF-A isoforms, in Nrp binding. We have determined the crystal structure of the exon 7/8-encoded VEGF-A heparin binding domain in complex with the Nrp1-b1 domain. This structure clearly demonstrates that residues from both exons 7 and 8 physically contribute to Nrp1 binding. Using an in vitro binding assay, we have determined the relative contributions of exon 7- and 8-encoded residues. We demonstrate that the exon 8-encoded C-terminal arginine is essential for the interaction of VEGF-A with Nrp1 and mediates high affinity Nrp binding. Exon 7-encoded electronegative residues make additional interactions with the L1 loop of Nrp1. Although otherwise conserved, the primary sequences of Nrp1 and Nrp2 differ significantly in this region. We further show that VEGF-A{sub 164} binds 50-fold more strongly to Nrp1 than Nrp2. Direct repulsion between the electronegative exon 7-encoded residues of the heparin binding domain and the electronegative L1 loop found only in Nrp2 is found to significantly contribute to the observed selectivity. The results reveal the basis for the potent and selective binding of VEGF-A{sub 164} to Nrp1.

  7. Determination and pharmacokinetic study of pirfenidone in rat plasma by UPLC-MS/MS.

    Science.gov (United States)

    Sun, Wei; Jiang, Zhe-li; Zhou, Lei; Chen, Rui-min; Wang, Zhe; Li, Wan-shu; Jiang, Shuo-min; Hu, Guo-xin; Chen, Rui-jie

    2015-02-15

    A rapid, sensitive and selective ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was developed and validated for the determination and pharmacokinetic investigation of pirfenidone in rat plasma. Sample preparation was accomplished through a simple one-step deproteinization procedure with 0.2 mL of acetonitrile to a 0.1 mL plasma sample. Plasma samples were separated by UPLC on an Acquity UPLC BEH C18 column using a mobile phase consisting of acetonitrile-0.1% formic acid in water with gradient elution. The total run time was 3.0 min and the elution of pirfenidone was at 1.39 min. The detection was performed on a triple quadrupole tandem mass spectrometer in the multiple reaction-monitoring (MRM) mode using the respective transitions m/z 186.2→92.1 for pirfenidone and m/z 237.1→194.2 for carbamazepine (IS), respectively. The calibration curve was linear over the range of 5-2000 ng/mL with a lower limit of quantitation (LLOQ) of 5 ng/mL. Mean recovery of pirfenidone in plasma was in the range of 80.4-84.3%. Intra-day and inter-day precision were both pirfenidone in rats.

  8. [Simultaneous determination of glucocorticoids in bovine plasma by high-pressure liquid chromatography].

    Science.gov (United States)

    Sasaki, Y; Tsuiki, M; Higashimaki, T

    1982-09-20

    A method is described for the simultaneous determination of major glucocorticoids in bovine plasma, that is, Cortisol, Corticosterone and Cortisone, which includes separation by high-pressure liquid chromatography and measurement using a UV detector (254 nm). Chromatography on the Zorbax CN column is carried out with the eluent system, that is, n-hexane/ethanol (=87/13 v/v). First, Dexamethasone was selected as the best internal standard under the previously mentioned conditions. The calibration curves for the glucocorticoids were all clearly linear. The recoveries for each 5 ng of added Cortisol, Corticosterone and Cortisone were 96.7 +/- 3.2%, 100.4 +/- 2.3% and 96.1 +/- 2.2%, respectively. The reproducibility of Cortisol was good and its coefficient of variation of intraassay was small (2.7%), whereas such coefficient was not so in Corticosterone (7.7%) and Cortisone (7.3%). This appears to be due to low concentrations of Corticosterone and Cortisone in the plasma. Specificity of this method to each glucocorticoid was ascertained using plasma from adrenalectomized wethers. In addition, the correlation coefficient between measurements of Cortisol by radioimmunoassay and those by this method was 0.978. In conclusion, the method described in this paper appears to be satisfactory for the simultaneous quantification of plasma glucocorticoids.

  9. Determination of fatty acid profile in ram spermatozoa and seminal plasma.

    Science.gov (United States)

    Díaz, R; Torres, M A; Bravo, S; Sanchez, R; Sepúlveda, N

    2016-08-01

    Fatty acids are important in male reproductive function because they are associated with membrane fluidity, acrosome reaction, sperm motility and viability, but limited information exists about the fatty acid profile of ram semen. Our aim was to determine the fatty acid composition in ram spermatozoa and seminal plasma. Sixty ejaculates were obtained from three ram (20 ejaculates/ram) using artificial vagina. Ram spermatozoa (RS) and seminal plasma (SP) were separated using centrifugation, and the fatty acids were analysed by gas chromatography. Total lipids obtained in ram spermatozoa were 1.8% and 1.6% in seminal plasma. Saturated fatty acid (SFA) was proportionally major in SP (66.6%) that RS (49.9%). The highest proportions of SFA corresponded to C4:0 (RS = 16.3% and SP = 28.8%) and C16:0 (RS = 16.3% and PS = 20%). The most important unsaturated fatty acid (UFA) was docosahexaenoic acid (DHA), 44.9% in RS and 31.5% in SP. The profile of fatty acid and their proportions showed differences between spermatozoa and seminal plasma.

  10. Determination of Febuxostat in Human Plasma Using RP-LC-UV Method.

    Science.gov (United States)

    Younes, Kareem M; El-Kady, Ehab F; Elzanfaly, Eman S

    2016-07-01

    A simple and sensitive bioanalytical high-performance liquid chromatographic method with ultraviolet detection was developed and validated for the quantification of febuxostat (FEB) in human plasma. Ketoprofen was used as an internal standard. The analytes were extracted from human plasma samples by precipitation with acetonitrile. The reconstituted samples were chromatographed on C18 Bondapack 10 µm, 250 × 4.6 mm, Waters Column (Ireland) by using a mixture of acetonitrile and 0.5% aqueous phosphoric acid (pH 3) (52 : 48, v/v) as the mobile phase. The chromatographic separation was isocratically performed at room temperature at a flow rate of 1.0 mL/min with UV detection at 315 nm. The method exhibited a linear dynamic range over 0.05-5.00 µg/mL FEB in human plasma. The lower limit of quantification was 0.05 µg/mL. The results of the intra- and interday precision and accuracy studies were within the acceptable limits. The validated method was successfully applied for the determination of FEB in human plasma samples for application in bioequivalence studies.

  11. Treadmill Exercise Promotes Neurogenesis in Ischemic Rat Brains via Caveolin-1/VEGF Signaling Pathways.

    Science.gov (United States)

    Zhao, Yun; Pang, Qiongyi; Liu, Meixia; Pan, Jingzi; Xiang, Bingwu; Huang, Tingting; Tu, Fengxia; Liu, Chan; Chen, Xiang

    2017-02-01

    Using a model of middle cerebral artery occlusion (MCAO), we have previously demonstrated that treadmill exercise promotes angiogenesis in the ischemic penumbra through caveolin-1/VEGF signaling pathways. However, the function of caveolin-1/VEGF signaling in neurogenesis after MCAO has not been determined. In this study, we aimed to investigate the potential of treadmill exercise to promote neurogenesis after MCAO and whether caveolin-1/VEGF signaling pathways are involved. After MCAO, rats were subjected to a program of treadmill exercise. Daidzein (a specific inhibitor of caveolin-1 protein expression, 0.4 mg/kg) was used to confirm the effect of caveolin-1/VEGF signaling on exercise-mediated neurogenesis. We found that the total protein expression of both caveolin-1 and VEGF was increased by exercise and consistent with the improved neurological recovery, decreased infarct volumes and increased 5-bromo-2'-deoxyuridine (BrdU) in the ipsilateral Subventricular zone (SVZ), as well as increased numbers of BrdU/DCX and BrdU/Neun-positive cells in the peri-infarct region. Furthermore, we observed that the treadmill exercise-induced increased VEGF expression, improved neurological recovery, decreased infarct volumes, increased BrdU/DCX and BrdU/Neun-positive cells were significantly inhibited by the caveolin-1 inhibitor. Our results indicate that treadmill exercise improves neurological recovery in ischemic rats, possibly by enhancement of SVZ-derived neural stem cell (NSC) proliferation, migration and differentiation in the penumbra. Moreover, caveolin-1/VEGF signaling is involved in exercise-mediated NSC migration and neuronal differentiation.

  12. Comparing protein VEGF inhibitors: In vitro biological studies

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Lanlan; Liang, Xiao Huan [Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080 (United States); Ferrara, Napoleone, E-mail: nf@gene.com [Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080 (United States)

    2011-05-06

    Highlights: {yields} VEGF is a mediator of angiogenesis. {yields} VEGF inhibitors have clinical applications in cancer and eye disorders. {yields} Five protein VEGF inhibitors were compared for their ability to inhibit. {yields} VEGF-induced activities in cultured endothelial cells. -- Abstract: VEGF inhibitors are widely used as a therapy for tumors and intravascular neovascular disorders, but limited and conflicting data regarding their relative biological potencies are available. The purpose of the study is to compare different protein VEGF inhibitors for their ability to inhibit VEGF-stimulated activities. We tested ranibizumab, the full-length variant of ranibizumab (Mab Y0317), bevacizumab, the VEGF-TrapR1R2 and Flt(1-3)-IgG in bioassays measuring VEGF-stimulated proliferation of bovine retinal microvascular endothelial cells or chemotaxis of human umbilical vein endothelial cells (HUVEC). The inhibitors were also compared for their ability to inhibit MAP kinase activation in HUVECs following VEGF addition. Ranibizumab, VEGF-TrapR1R2 and Flt(1-3)-IgG had very similar potencies in the bioassays tested. Bevacizumab was over 10-fold less potent than these molecules. Mab Y0317 was over 30-fold more potent than bevacizumab. The findings reported in this manuscript describe important intrinsic characteristics of several VEGF inhibitors that may be useful to design and interpret preclinical or clinical studies.

  13. HPLC-UV determination of metformin in human plasma for application in pharmacokinetics and bioequivalence studies.

    Science.gov (United States)

    Porta, Valentina; Schramm, Simone Grigoleto; Kano, Eunice Kazue; Koono, Eunice Emiko; Armando, Yara Popst; Fukuda, Kazuo; Serra, Cristina Helena Dos Reis

    2008-01-07

    In this study, a simple, rapid and sensitive HPLC method with UV detection is described for determination of metformin in plasma samples from bioequivalence assays. Sample preparation was accomplished through protein precipitation with acetonitrile and chromatographic separation was performed on a reversed-phase phenyl column at 40 degrees C. Mobile phase consisted of a mixture of phosphate buffer and acetonitrile at flow rate of 1.0 ml/min. Wavelength was set at 236 nm. The method was applied to a bioequivalence study of two drug products containing metformin, and allowed determination of metformin at low concentrations with a higher throughput than previously described methods.

  14. Fetal male lineage determination by analysis of Y-chromosome STR haplotype in maternal plasma.

    Science.gov (United States)

    Barra, Gustavo Barcelos; Santa Rita, Ticiane Henriques; Chianca, Camilla Figueiredo; Velasco, Lara Francielle Ribeiro; de Sousa, Claudia Ferreira; Nery, Lídia Freire Abdalla; Costa, Sandra Santana Soares

    2015-03-01

    The aim of this study is to determine the fetus Y-STR haplotype in maternal plasma during pregnancy and estimate, non-invasively, if the alleged father and fetus belong to the same male lineage. The study enrolled couples with singleton pregnancies and known paternity. All participants signed informed consent and the local ethics committee approved the study. Peripheral blood was collected in EDTA tubes (mother) and in FTA paper (father). Maternal plasma DNA was extracted by using NucliSens EasyMAG. Fetal gender was determined by qPCR targeting DYS-14 in maternal plasma and it was also confirmed after the delivery. From all included volunteers, the first consecutive 20 mothers bearing male fetuses and 10 mothers bearing female fetuses were selected for the Y-STR analysis. The median gestational age was 12 weeks (range 12-36). All DNA samples were subjected to PCR amplification by PowerPlex Y23, ampFLSTR Yfiler, and two in-house multiplexes, which together accounts for 27 different Y-STR. The PCR products were detected with 3500 Genetic Analyzer and they were analyzed using GeneMapper-IDX. Fetuses' haplotypes (Yfiler format) were compared to other 5328 Brazilian haplotypes available on Y-chromosome haplotypes reference database (YHRD). As a result, between 22 and 27 loci were successfully amplified from maternal plasma in all 20 cases of male fetuses. None of the women bearing female fetuses had a falsely amplified Y-STR haplotype. The haplotype detected in maternal plasma completely matched the alleged father haplotype in 16 out of the 20 cases. Four cases showed single mismatches and they did not configure exclusions; 1 case showed a mutation in the DYS 458 locus due to the loss of one repeat unit and 3 cases showed one DYS 385I/II locus dropout. All mismatches were confirmed after the delivery. Seventeen fetuses' haplotypes were not found in YHRD and one of them had a mutation, which corresponded to the paternity probability of 99.9812% and 95.7028%, respectively

  15. Glucose and TGF β2 Modulate the Viability of Cultured Human Retinal Pericytes and Their VEGF Release

    Science.gov (United States)

    Vidro, Eileen K.; Gee, Stephen; Unda, Richard; Ma, Jian-xing; Tsin, Andrew

    2015-01-01

    Purpose Determine the effects of glucose and exogenous TGFβ2 on viability and VEGF release by human retinal pericytes (HRP). Methods Human retinal pericytes (HRP) were cultured in 5 mM (physiologic) or high (18 mM) glucose with or without added TGFβ2. Viable cells were counted; TGFβ2 and VEGF in the conditioned media (CM) were measured by ELISA. Results High glucose significantly reduced viable cell number and increased the levels of TGFβ2 and VEGF. TGFβ2 caused a significant dose-dependent effect on viable cell number and on the level of VEGF secreted into the CM by HRP in physiologic glucose, decreasing viable cell number, and increasing VEGF release per 1000 cells at a low concentration (0.1 ng/ml) and increasing viable cell number and decreasing VEGF release per 1000 cells at higher concentrations (1.0 and 10 ng/ml). TGFβ2 affected neither parameter in high glucose. Conclusions Elevated glucose decreased HRP viability and modulated changes in TGFβ2 and VEGF release. This suggests a novel mechanism for HRP dropout in diabetic retinopathy. PMID:19085381

  16. Effect of HIF-1α on VEGF-C Induced Lymphangiogenesis and Lymph Nodes Metastases of Pancreatic Cancer

    Institute of Scientific and Technical Information of China (English)

    TAO Jing; LI Tao; LI Kai; XIONG Jiongxin; YANG Zhiyong; WU Heshui; WANG Chunyou

    2006-01-01

    The effect of hypoxia inducible factor-1 α (HIF-1α) on vascular endothelial growth factor C (VEGF-C) and the correlation between HIF-1α and lymphangiogenesis and lymph nodes metastases (LNM) in pancreatic cancer were investigated. Immunohistochemical SP method was used to detect the protein expression of HIF-1α and VEGF-C, and Lymphatic vessel density (LVD) was determined by stain of VEGFR-3, collagen type Ⅳ in 75 pancreatic head cancers from regional pancreatectomy (RP) during Dec. 2001 to Dec. 2003. The relationship between HIF-1α and VEGF-C, lymphangiogenesis, LNM was analyzed statistically. The results showed that the positive expression rate of HIF-1α and VEGF-C in pancreatic cancer tissues was 48.00 % (36/75) and 65.33 % (49/75) respectively. In positive group of HIF-1α, the positive rate of VEGF-C and LVD, and LVD rate was 80.56 % (29/36), 13.22±3.76 and 88.89 % (32/36) respectively, and in negative group of HIF-1α,positive rate of VEGF-C and LVD was 51.28 % (20/39), 5.98±2.17 and 66.67 % (26/39) respectively (P<0.01 or P<0.05). It was suggested that HIF-1α could promote the expression of VEGF-C, lymphangiogenesis and LNM in pancreatic cancer.

  17. Radiation-induced VEGF-C expression and endothelial cell proliferation in lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yu-Hsuan [National Taiwan University Hospital, Department of Oncology, Taipei (China); National Taiwan University, Pharmacological Institute, College of Medicine, Taipei (China); Pan, Shiow-Lin; Wang, Jing-Chi; Teng, Che-Ming [National Taiwan University, Pharmacological Institute, College of Medicine, Taipei (China); Kuo, Sung-Hsin [National Taiwan University Hospital, Department of Oncology, Taipei (China); National Taiwan University College of Medicine, Department of Internal Medicine, Taipei (China); Cheng, Jason Chia-Hsien [National Taiwan University Hospital, Department of Oncology, Taipei (China); National Taiwan University College of Medicine, Graduate Institute of Clinical Medicine, Taipei (China)

    2014-12-15

    The present study was undertaken to investigate whether radiation induces the expression of vascular endothelial growth factor C (VEGF-C) through activation of the PI3K/Akt/mTOR pathway,subsequently affecting endothelial cells. Radiotherapy-induced tumor micro-lymphatic vessel density (MLVD) was determined in a lung cancer xenograft model established in SCID mice. The protein expression and phosphorylation of members of the PI3K/Akt/mTOR pathway and VEGF-C secretion and mRNA expression in irradiated lung cancer cells were assessed by Western blot analysis, enzyme-linked immunosorbent assays (ELISAs), and reverse transcriptase-polymerase chain reaction (RT-PCR). Moreover, specific chemical inhibitors were used to evaluate the role of the PI3K/Akt/mTOR signaling pathway. Conditioned medium (CM) from irradiated control-siRNA or VEGF-C-siRNA-expressing A549 cells was used to evaluate the proliferation of endothelial cells by the MTT assay. Radiation increased VEGF-C expression in a dose-dependent manner over time at the protein but not at the mRNA level. Radiation also up-regulated the phosphorylation of Akt, mTOR, 4EBP, and eIF4E, but not of p70S6K. Radiation-induced VEGF-C expression was down-regulated by LY294002 and rapamycin (both p < 0.05). Furthermore, CM from irradiated A549 cells enhanced human umbilical vein endothelial cell (HUVEC) and lymphatic endothelial cell (LEC) proliferation, which was not observed with CM from irradiated VEGF-C-siRNA-expressing A549 cells. Radiation-induced activation of the PI3K/Akt/mTOR signaling pathway increases VEGF-C expression in lung cancer cells, thereby promoting endothelial cell proliferation. (orig.) [German] Die vorliegende Studie untersucht, ob die Strahlung die Expression von VEGF-C (vascular endothelial growth factor C) mittels Aktivierung des PI3K/Akt/mTOR-Signalwegs induziert und anschliessend die endothelialen Zellen beeinflusst. Die durch Strahlentherapie induzierte Mikrolymphgefaessdichte (MLVD) im Tumor wurde in

  18. Determination of nimodipine in plasma by HPLC-MS/MS and pharmacokinetic application

    Directory of Open Access Journals (Sweden)

    Demétrius Fernandes do Nascimento

    2010-12-01

    Full Text Available To develop and validate a rapid, specific and highly sensitive method to quantify nimodipine in human plasma using dibucaine as the internal standard (IS. The analyte and IS were extracted from plasma samples by liquid-liquid extraction using hexane-ethyl acetate (1:1 v/v. The chromatographic separation was performed on a Varian® Polaris C18 analytical column (3 μm, 50 x 2.0 mm and pre-column SecurityguardTM C18 (4.0 x 3.0 mm with a mobile phase of Acetonitrile-Ammonium acetate 0.02 ml/L (80:20v/v. The method had a chromatographic run time of 4.5 min and linear calibration curve over the range of 0.1- 40 ng/mL (r > 0.9938. The limit of quantification was 100 pg/mL. Acceptable precision and accuracy were obtained for concentrations over the standard curve ranges. This validated method was successfully applied in determining the pharmacokinetic profile of nimodipine tablets of 30 mg administered to 24 healthy volunteers. The proposed method of analysis provided a sensitive and specific assay for nimodipine determination in human plasma. The time for the determination of one plasma sample was 4.5 min. This method is suitable for the analysis of nimodipine in human plasma samples collected for pharmacokinetic, bioavailability or bioequivalence studies in humans.Um método rápido, específico e sensível para quantificar nimodipino em plasma humano usando dibucaína como padrão interno (IS é descrito. O analito e o IS foram extraídos das amostras de plasma por extração líquido-líquido usando hexano-acetato de etila (1:1 v/v. A separação cromatográfica foi realizada utilizando-se uma coluna analítica C18 Varian® Polaris (3 μm, 50 x 2,0 mm e uma pré-coluna SecurityguardTM C18 (4,0 x 3,0 mm e acetonitrila-acetato de amônia 0,02 mol/L (80:20 v/v como fase móvel. O método apresentou tempo total de corrida de 4,5 min e curva de calibração linear com concentrações entre 0,1-40 ng/mL (r > 0,9938. O limite de quantificação foi de 100

  19. Determination of linsidomine in human plasma by tandem LC-MS with ESI.

    Science.gov (United States)

    Sutherland, F C; de Jager, A D; Swart, K J; Hundt, H K; Scanes, T; Hundt, A F

    2000-04-01

    A sensitive method for the determination of linsidomine in plasma was developed, using high-performance liquid chromatographic (HPLC) separation with tandem mass spectrometric detection. Linsidomine was derivatised with propyl chloroformate and extracted with tert-butyl methyl ether/1,2-dichloroethane (55:45, v/v), back-extracted into HCl (0.01 M) followed by alkalinisation and back-extraction into ether; the final ether extract evaporated, reconstituted in mobile phase and then separated on a Phenomenex Luna C18 (2) 5 micron 2.1 x 150 mm column with a mobile phase consisting of methanol water formic acid (98/100%) (400:600:0.05, v/v/v) at a flow-rate of 0.4 ml min(-1). Detection was achieved by a Finnigan MAT mass spectrometer (LCQ) at unit resolution in the selected reaction monitoring (SRM) mode monitoring the transition of the protonated molecular ion m/z 257.0 to the product ion m/z 86.0. The mean recovery for linsidomine was 51% with a lower limit of quantification of 0.70 ng/ml using 1 ml plasma for extraction. This LC-MS/MS method for the determination of linsidomine in human plasma allows for better specificity and a higher sample throughput than the traditional LC-UV methods. It also demonstrates the profound effect that the composition of acidic modifiers and matrix constituents can have on the electrospray ionisation (ESI) of the analyte.

  20. The determination of phenazone in blood plasma for obtained sistem suitable test of monitoring drug level

    Directory of Open Access Journals (Sweden)

    Mochamad Lazuardi

    2007-09-01

    Full Text Available The determining of Phenazone to human blood plasma from healthy man after separated by solid phase extraction (SPE and spectroscopic measurements has been investigated. The objective of that research was to obtain system suitable test for determine the Phenazone level in biological fluids (human blood plasma, for new performed dosage regimented in clinical dentistry. The method can be divided into the following four steps. 1. Centrifugation the blood sample, 2. Extraction from blood plasma and, 3. Separation by SPE with manual pressured, 4. Elution to SPE followed by the measurement on a spectrophotometer in the ultra violet region. The critical value of  │t │at the 5% confidence level indicates that there is no systematic error in the linearity proposed method. Recoveries for this research were obtained at ranging 93.460 to 95.598%. The coefficient variation precision of this procedure was clearly good at smallest than 2%. The analytical procedure can be carried out in one working operation as a monitored therapeutic activity.

  1. Determination of doxepin and desmethyldoxepin in human plasma using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Badenhorst, D; Sutherland, F C; de Jager, A D; Scanes, T; Hundt, H K; Swart, K J; Hundt, A F

    2000-05-26

    A sensitive method for the simultaneous determination of doxepin and its active metabolite desmethyldoxepin in plasma was established, using high-performance liquid chromatographic separation with tandem mass spectrometric detection. The samples were extracted with hexane-isoamyl alcohol, separated on a Phenomenex Luna C18 5 microm, 150x2.1 mm column with a mobile phase consisting of methanol-water-formic acid (600:400:0.5, v/v) at a flow-rate of 0.25 ml/min. Detection was achieved by a Perkin-Elmer API 2000 mass spectrometer at unit resolution in multiple reaction monitoring mode monitoring the transition of the protonated molecular ions m/z 280.2, 266.2 and 250.1 to the product ions m/z 107.1, 107.1 and 191.0 for analyte, metabolite and internal standard (benzoctamine-HCl), respectively. TurbolonSpray ionisation was used for ion production. The mean recovery for doxepin and desmethyldoxepin was 90% and 75%, respectively, with a lower limit of quantification at 0.320 ng/ml and 0.178 ng/ml for the analyte and its metabolite, respectively, using 0.5 ml plasma for extraction. This is the first assay method described for the simultaneous determination of doxepin and desmethyldoxepin in plasma using LC-MS-MS. The method is sensitive enough to be used in drug bioavailability studies with doxepin.

  2. The determination of bromazepam in plasma by reversed-phase high-performance liquid chromatography.

    Science.gov (United States)

    Le Solleu, H; Demotes-Mainard, F; Vinçon, G; Bannwarth, B

    1993-08-01

    A reversed-phase high-performance liquid chromatographic method has been developed for the determination of bromazepam, an anxiolytic benzodiazepine, in plasma. After a single-step extraction from alkalinized plasma with diethyl-ether in the presence of an internal standard (alpha-hydroxy-triazolam), the residues were chromatographed on a reversed-phase Nova Pak 5 microns C18 column, with a mobile phase of acetonitrile-water-triethylamine (700:300:4, v/v/v) adjusted to pH 7.4 with orthophosphoric acid. The limit of detection was 50 ng ml-1, using a 20 microliters injection with UV detection at 240 nm. Between-day and within-day relative standard deviations were lower than 6%. Studies of drug stability during sample storage at -20 degrees C and at +4 degrees C showed no degradation of bromazepam. However, bromazepam seemed to be degraded at ambient temperature, without any influence of light. This method is applied to the determination of bromazepam plasma levels in analytical toxicology.

  3. Cattle fetal sex determination by polymerase chain reaction using DNA isolated from maternal plasma.

    Science.gov (United States)

    da Cruz, A S; Silva, D C; Costa, E O A; De M-Jr, P; da Silva, C C; Silva, D M; da Cruz, A D

    2012-03-01

    The objective of this study was to evaluate the use of polymerase chain reaction analysis (PCR) of fetal cells/DNA in the maternal plasma of pregnant cows to determine the sex of the fetus. Plasma was harvested from 35 cows of mixed genotype at different stages of pregnancy ranging from 5 to 35 weeks. A male calf and a heifer calf provided the control samples. Fetal sex was determined by amplification of Y-specific sequences. For the 35 cows, the fetal sex predicted by this technique was in accordance with the sex of the calf at birth in 88.6% of cases. The agreement between predicted and observed fetal sex was less for cows with a gestational length of 35-48 days (63.6%). Regression analysis showed that there was a strong relationship between the probability of correctly predicting fetal sex and the stage of gestation. It was estimated that the test performed at 43.8 days post fertilization would have 95% accuracy, increasing to 99% accuracy for testing at 48.4 days and 99.9% accuracy for tests at 55.0 days or later. It was concluded that PCR analysis of fetal cells in maternal plasma can be used to predict successfully the sex of the fetus in cattle.

  4. Determination of Candesartan in Human Plasma with Liquid Chromatography - Tandem Mass Spectrometry.

    Science.gov (United States)

    Forjan, Vanja; Cvitkovič Maričič, Lea; Prosen, Helena; Brodnjak Vončina, Darinka

    2016-01-01

    A sensitive, specific and rapid liquid chromatography - tandem mass spectrometry method was developed and validated for the determination of candesartan in human plasma. Analyte was separated from endogenous components present in plasma by solid phase extraction. Chromatographic separation was performed on Gemini C18 analytical column using mobile phase acetonitrile - 5 mM ammonium formate pH 2 (90:10, v/v) at flow rate of 0.3 mL/min. For detection, tandem mass spectrometry in SRM mode with positive electrospray ionization was used. The mass transitions m/z 441.1 > 263.1 and 445.1 > 267.1 were used to determine candesartan by using candesartan-d4 as an internal standard. After development, the method was validated according to the requirements of EMA regulatory guidelines in the concentration range 1 - 400 ng/ml in human plasma. Limit of quantification (LLOQ) was 1 ng/ml. The developed and validated method proved to be very fast and reproducible and was therefore successfully implemented in pharmacokinetic and bioequivalence studies with large number of study samples.

  5. Determination of Alprazolam in Rabbit Plasma by GC-MS Method

    Directory of Open Access Journals (Sweden)

    Bilal Yilmaz

    2010-02-01

    Full Text Available This paper describes a gas chromatography-mass spectrometry (GC-MS method for determination of alprazolam in rabbit plasma. Alprazolam and internal standard (IS medazepam were extracted from plasma by using liquid-liquid extraction method. The samples were separated by GC on a DB-5MS analytical column and determined by a quadrupole mass spectrometer detector operated under selected ion monitoring mode (SIM. Excellent linearity was found between 50 and 1000 ng/mL r=0.998 for plasma samples. Intra-day and inter-day precisions expressed as the relative standard deviation (RSD for the method were 1.07-2.69% and 2.42-3.98%, respectively. The mean recovery of alprazolam samples was 98.82%. The limits of detection and uantification of alprazolam were 15 and 50 ng/mL, respectively. Also, the method was successfully applied to three New Zealand white abbits which had been given an oral tablet of 1.0 mg alprazolam.

  6. Kinetic and Related Determinants of Plasma Triglyceride Concentration in Abdominal Obesity: Multicenter Tracer Kinetic Study.

    Science.gov (United States)

    Borén, Jan; Watts, Gerald F; Adiels, Martin; Söderlund, Sanni; Chan, Dick C; Hakkarainen, Antti; Lundbom, Nina; Matikainen, Niina; Kahri, Juhani; Vergès, Bruno; Barrett, P Hugh R; Taskinen, Marja-Riitta

    2015-10-01

    Patients with obesity and diabetes mellitus have increased risk of cardiovascular disease. A major cause is an atherogenic dyslipidemia related primarily to elevated plasma concentrations of triglyceride-rich lipoproteins. The aim of this study was to clarify determinants of plasma triglyceride concentration. We focused on factors that predict the kinetics of very-low density lipoprotein 1 (VLDL1) triglycerides. A multicenter study using dual stable isotopes (deuterated leucine and glycerol) and multicompartmental modeling was performed to elucidate the kinetics of triglycerides and apoB in VLDL1 in 46 subjects with abdominal obesity and additional cardiometabolic risk factors. Results showed that plasma triglyceride concentrations were dependent on both the secretion rate (r=0.44, Ptriglycerides and VLDL1-apoB. Liver fat mass was independently and directly associated with secretion rates of VLDL1-triglycerides (r=0.56, Ptriglycerides (r=0.48, Ptriglyceride concentrations in abdominal obesity are determined by the kinetics of VLDL1 subspecies, catabolism being mainly dependent on apoC-III concentration and secretion on liver fat content. Reduction in liver fat and targeting apoC-III may be an effective approach for correcting triglyceride metabolism atherogenic dyslipidemia in obesity. © 2015 American Heart Association, Inc.

  7. Determination of trace amounts of morphine in human plasma by anodic adsorptive stripping differential pulse voltammetry

    Institute of Scientific and Technical Information of China (English)

    Ali Niazi; Ateesa Yazdanipour

    2008-01-01

    New adsorptive anodic differential pulse stripping voltammetry method for the direct determination of morphine at trace levels in human plasma of addicts is proposed.The procedure involves an adsorptive accumulation of morphine on a HMDE,followed by oxidation of adsorbed morphine by voltammetry scan using differential pulse modulation.The optimum conditions for the analysis of morphine are pH 10.5,Eacc of - 100 mV (vs.Ag/AgCl),and tacc of 120 s.The peak current is proportional to the concentration of morphine,and a linear calibration graph is obtained at 0.01-3.10 μg mL-1.A relative standard deviation of 1.06% (n=5) was obtained,and the limit of detection was 3 ng mL- 1.The capability of the method for the analysis of real samples was evaluated by the determination of morphine in spiked human plasma and addicts human plasma with satisfactory results.

  8. High-performance liquid chromatography determination of dipotassium clorazepate and its major metabolite nordiazepam in plasma.

    Science.gov (United States)

    Colin, P; Sirois, G; Lelorier, J

    1983-04-08

    A rapid and sensitive high-performance liquid chromatographic method is described for the quantitative analysis of dipotassium clorazepate (CZP) and its major metabolite nordiazepam (ND) in fresh human and dog plasma. The method consists of two separate selective ND extractions from a plasma sample without and with conversion of all the CZP to ND. For quantitation, diazepam (DZP) is used as the internal standard. The chromatographic phase utilized in a reversed-phase Hibar EC-RT analytical column prepacked with LiChrosolv RP-18 with a solvent system consisting of acetonitrile-0.05 M sodium acetate buffer, pH 5.0 (45:55). The UV absorbance is monitored at 225 nm using a variable-wavelength detector. The mean assay coefficient of variation over a concentration range of 20-400 ng per ml of plasma is less than 3% for the within-day precision. Recoveries of ND, DZP and CZP (as ND) are essentially quantitative at all levels investigated. The calibration curves of ND are rectilinear (r2 = 0.99) from the lower limit of sensitivity (2 ng/ml) to at least 2000 ng/ml in plasma. Applicability of the method to CZP and ND disposition studies in the anaesthetized mongrel dog is illustrated. When the two separate selective nordiazepam extractions from plasma cannot be performed immediately after blood sampling, an extrapolation kinetic method is suggested for the estimation of CZP concentration. In all previous in vivo studies, CZP has been determined only with gas-liquid chromatographic methods.

  9. Derivation and Testing of Computer Algorithms for Automatic Real-Time Determination of Space Vehicle Potentials in Various Plasma Environments

    Science.gov (United States)

    1988-05-31

    COMPUTER ALGORITHMS FOR AUTOMATIC REAL-TIME DETERMINATION OF SPACE VEHICLE POTENTIALS IN VARIOUS PLASMA ENVIRONMENTS May 31, 1988 Stanley L. Spiegel...crrnaion DiviSiofl 838 12 2 DERIVATION AND TESTING OF COMPUTER ALGORITHMS FOR AUTOMATIC REAL-TIME DETERMINATION OF SPACE VEHICLE POTENTIALS IN VARIOUS...S.L., "Derivation and testing of computer algorithms for automatic real time determination of space vehicle poteuatials in various plasma

  10. Determinants of plasma pepsinogen levels in a population at high risk for stomach cancer in Venezuela.

    Science.gov (United States)

    Kato, I; Miki, K; Muñoz, N; Vivas, J H; Lopez, G; Peraza, S; Carillo, E; Castro, D; Andrade, O; Sanchez, V

    1995-09-04

    Determinants of plasma pepsinogens (PG) levels were studied in 1365 participants in a chemoprevention trial for gastric pre-cancerous lesions being conducted in Venezuela. Gastric biopsies, plasma samples and information on smoking and dietary habits were obtained at baseline examination. Both PG-I and PG-II levels increased progressively with the level of Helicobacter pylori infection in gastric biopsies, resulting in no clear trend in the I/II ratio. Instead, there was a progressive decrease in the I/II ratio with increasing degrees of infiltration of polynuclear cells and monocytes, atrophy, intestinal metaplasia and the stage of pre-cancerous lesions. The mean I/II ratios for atrophic gastritis or more advanced lesions were less than 4.0. When subjects with the I/II ratio 4 or higher were used as controls, severe reduction in the I/II ratio (food on the development of atrophic gastritis need to be studied further.

  11. High performance liquid chromatography method for rapid and accurate determination of homocysteine in plasma and serum

    DEFF Research Database (Denmark)

    Vester, Birte; Rasmussen, K

    1991-01-01

    Determination of homocysteine in plasma or serum for evaluation of cobalamin and folate deficiency is becoming an important diagnostic procedure. Accurate, rapid and low cost methods for measuring homocysteine are therefore required. We have improved an HPLC method and made it suitable for clinical...... application. The more important changes are the addition of an internal standard, mercaptopropionylglycine, and the use of a plasma/serum based calibration material. The method consists of the following steps: reduction of the sample with tri-n-butylphosphine, precipitation of proteins, derivatisation...... with ammonium 7-fluorobenzo-2-oxa-1,3-diazole-4-sulphonate, and HPLC separation followed by fluorescence detection. The linearity of the assays is established and the coefficient of variation is 3.0%. Stability studies show that blood samples must be cooled or centrifuged immediately after venipuncture...

  12. Single-dose subcutaneous iodine-131-iodohippurate for determination of renal plasma flow

    Energy Technology Data Exchange (ETDEWEB)

    Grant, M.E.; Herron, K.G.; MacDougall, M.L.; Preston, D.F.; Moore, W.V.; Wiegmann, T.B. (Department of Medicine, University of Kansas Medical Center, Kansas City (USA))

    1991-07-01

    Subcutaneous administration of a single dose of 131I-iodohippurate was used for determination of renal plasma flow (RPF) in 20 subjects during water diuresis. Slow release of tracer (200 microCi) permitted serial clearance measurements over 5 hr that were compared to standard, constant infusion, PAH clearance (mean 379.5 {plus minus} 34.9 ml/min/1.73 m2, range 50.9 to 696.3 ml/min/1.73 m2). RPF(Isotope) was 424.9 {plus minus} 30.3 ml/min/1.73 m2 (range 144.4 to 746.5 ml/min/1.73 m2) and highly correlated with RPFPAH (r = 0.883, p less than 0.0001). This technique permits prolonged studies of renal plasma flow under steady-state conditions without constant infusion.

  13. A comparison among optical emission spectroscopic methods of determining electron temperature in low pressure argon plasmas

    Institute of Scientific and Technical Information of China (English)

    Niu Tian-Ye; Cao Jin-Xiang; Liu Lei; Liu Jin-Ying; Wang Yan; Wang Liang

    2007-01-01

    In this article, four kinds of optical emission spectroscopic methods of determining electron temperature are used to investigate the relationship between electron temperature and pressure in the cylindrical plasmas of dc glow discharges at low pressures in laboratory by measuring the relative intensities of ArI lines at various pressures. These methods are developed respectively on the basis of the Fermi-Dirac model, corona model, and two kinds of electron collision cross section models according to the kinetic analysis. Their theoretical bases and the conditions to which they are applicable are reviewed, and their calculation results and fitting errors are compared with each other. The investigation has indicated that the electron temperatures obtained by the four methods become consistent with each other when the pressure increases in the low pressure argon plasmas.

  14. Determination of barnidipine in human serum and dog plasma by HPLC with electrochemical detection.

    Science.gov (United States)

    Takamura, K; Abdel-Wadood, H M; Kusu, F; Rafaat, I H; Saleh, G A; el-Rabbat, N A; Otagiri, M

    1995-10-01

    Barnidipine is a 1,4-dihydropyridine calcium antagonist. HPLC was conducted on a polybutadiene coated alumina column using an alkaline mobile phase and an electrochemical detector to determine the content of this drug in serum and plasma. A good linear relationship between barnidipine concentration and peak height was found in 5-500 ng/ml with a correlation coefficient of 0.998. The detection limit was 1 ng/ml. The within-day and day-to-day variations were examined for control human serum. Relative standard deviation of within-day assay for serum spiked with 10 ng/ml barnidipine.HCl was 6.9% and the recovery was 104%. A pharmacokinetic study was made in which the time course of barnidipine in dog plasma was followed.

  15. Development of a chromatographic method for the determination of saquinavir in plasma samples of HIV patients.

    Science.gov (United States)

    Campanero, M A; Escolar, M; Arangoa, M A; Sádaba, B; Azanza, J R

    2002-02-01

    A simple, sensitive and reproducible high-performance liquid chromatographic method for detecting and quantifying saquinavir in human plasma is described. Verapamil was used as internal standard. The method employes a single liquid-liquid extraction step with tert-butil methyl ether followed by chromatography on a Lichrospher 60 Select B C8 reversed-phase column. Ultraviolet detection was used to identify the compounds of interest. The quantitation limit of saquinavir was 1 ng/mL and only 0.5 mL of plasma sample was required for the determination. The average saquinavir recoveries over a concentration range of 2.5-500 ng/mL ranged from 86 to 95%. Precision and accuracy did not exceed 5%.

  16. GLC determination of plasma drug levels after oral administration of clorazepate potassium salts.

    Science.gov (United States)

    Hoffman, D J; Chun, A H

    1975-10-01

    Plasma nordiazepam levels resulting from the oral administration of clorazepate potassium salts were determined by a sensitive GLC assay. Nordiazepam and the internal standard (diazepam) were selectively extracted into ether at pH 9.2, hydrolyzed to their respective benzophenones, and quantified by electron-capture detection. The assay was used in a comparative bioavailability study of single equimolar oral doses of monopotassium and dipotassium salts of clorazepate in dogs. Both clorazepate salts were rapidly absorbed and exhibited mean peak total drug levels after 1 hr. Clorazepate levels accounted for about 50% of the total drug levels present. No statistical difference in the plasma drug levels of clorazepate mono- and dipotassium salts and the metabolite was found in dogs.

  17. Clinical significance of plasma level of AT-Ⅲ determination in sepsis patients

    Institute of Scientific and Technical Information of China (English)

    Wei Chen; Zhi-Hua Hu; Chen-Mian

    2015-01-01

    Objective:Through measure changes of anticoagulant enzyme (AT-Ⅲ) activity in plasma in sepsis patients, this paper discusses the clinical significance of AT-Ⅲ activity changes in predicting sepsis occurrence and prognosis.Methods: The non-sepsis 30 cases, with sepsis 76 cases, including 25 cases of severe sepsis, use method of thrombin gelatum lacuna for determining activity of AT-Ⅲ in plasma, platelet count and APACHEⅢ score simultaneously. Results:Sepsis group, severe sepsis groups contrast with the non-sepsis group respectively, activity of AT-Ⅲ reduced significantly (P<0.01), severe sepsis group lower than sepsis group (P=0.055).Conclusion:AT-Ⅲ activity reduced early in sepsis patients, with patient's condition aggravat, its value further reduced, hints measurement of AT-Ⅲ activity has certainly clinical significance in predicting sepsis occurrence and prognosis.

  18. Quantitative determination of amisulpride in rat plasma by HPLC-MS/MS.

    Science.gov (United States)

    Noh, Keumhan; Jang, Yoo-Jeong; Kwon, Kwang-il; Kim, Eunyoung; Jeong, Tae Cheon; Yun, Hwi-yeol; Kang, Wonku

    2015-01-01

    Amisulpride, a selective antagonist of D2 and D3 dopamine receptors, is used as an antipsychotic drug. In this study, we reported a sensitive LC-MS/MS method for determining amisulpride concentrations in rat plasma, and a preclinical pharmacokinetic study in the rat. After a simple protein precipitation with acetonitrile containing methaqualone as an internal standard, the analytes were separated on a reversed-phase column with a mobile phase of 0.2 % aqueous formic acid and acetonitrile (3:7, v/v). The accuracy and precision of the assay were in accordance with FDA guidance for the validation of bioanalytical methods. This analytical method was used successfully to characterize the time course of the plasma concentration of amisulpride following oral administration of a single 10 mg/kg dose in rats.

  19. RP-HPLC Method Development and Its Validation for Quantitative Determination of Rimonabant in Human Plasma

    Directory of Open Access Journals (Sweden)

    Shravan Bankey

    2012-01-01

    Full Text Available A simple, accurate, and precise HPLC method was developed and validated for determination of rimonabant in human plasma. Following liquid-liquid extraction, chromatographic separation was accomplished using C18 column with mobile phase consisting of acetonitrile : water (90 : 10, v/v, drug was detected at 260 nm using UVdetector. The LOD and LOQ were 3.0 and 10.0 μg/L, respectively. The method is linear in the interval 50.0–1000.0 μg/L. The average extraction recovery of drug from plasma was found to be 92.2%. The percent CV of the method was found to be less than 10.8%, and accuracy was found between 94.5 and 106.7%. The assay may be applied to a pharmacokinetic and bioequivalence study of rimonabant.

  20. Quantitative determination of citric acid in seminal plasma by using Raman spectroscopy.

    Science.gov (United States)

    Huang, Zufang; Chen, Xiwen; Li, Yongzeng; Chen, Jinhua; Lin, Juqiang; Wang, Jing; Lei, Jinping; Chen, Rong

    2013-07-01

    In this study, Raman spectroscopy was first used to study the linear relationship between Raman spectral intensities and citric acid concentrations in aqueous solution. By using the specific Raman band of 942 cm(-1), concentrations of citric acid ranging from 2 to 20 mg/mL were observed linearly (R(2) = 0.993), and the limit of detection was 1.0 mg/mL. Then, citric acid detection in clinical seminal plasma ultrafiltrate samples was performed, and the intensity of the Raman-specific peak demonstrates a good linear correlation (R(2) = 0.946) with citric acid concentrations determined by the enzymatic method. Our results showed that Raman spectroscopy has the potential of being applied to detect concentrations of citric acid in seminal plasma in clinic.

  1. Determination of structure tilting in magnetized plasmas - Time delay estimation in two dimensions

    CERN Document Server

    Guszejnov, Dávid; Zoletnik, Sándor; Andreas-Krämer-Flecken,

    2013-01-01

    Time delay estimation (TDE) is a well-known technique to investigate poloidal flows in fusion plasmas. The present work is an extension of the earlier works of A. Bencze and S. Zoletnik 2005 and B. T\\'al et al. 2011. From the prospective of the comparison of theory and experiment it seem to be important to estimate the statistical properties of the TDE based on solid mathematical groundings. This paper provides analytic derivation of the variance of the TDE using a two-dimensional model for coherent turbulent structures in the plasma edge and also gives an explicit method for determination of the tilt angle of structures. As a demonstration this method is then applied to the results of a quasi-2D Beam Emission Spectroscopy (BES) measurement performed at the TEXTOR tokamak.

  2. Regional differences in expression of VEGF mRNA in rat gastrocnemius following 1 hr exercise or electrical stimulation

    Directory of Open Access Journals (Sweden)

    Tang Kechun

    2002-06-01

    Full Text Available Abstract Background Vascular endothelial growth factor (VEGF mRNA levels increase in rat skeletal muscle after a single bout of acute exercise. We assessed regional differences in VEGF165 mRNA levels in rat gastrocnemius muscle using in situ hybridization after inducing upregulation of VEGF by treadmill running (1 hr or electrical stimulation (1 hr. Muscle functional regions were defined as oxidative (primarily oxidative fibers, I and IIa, or glycolytic (entirely IIb or IId/x fibers. Functional regions were visualized on muscle cross sections that were matched in series to slides processed through in situ hybridization with a VEGF165 probe. A greater upregulation in oxidative regions was hypothesized. Results Total muscle VEGF mRNA (via Northern blot was upregulated 3.5-fold with both exercise and with electrical stimulation (P = 0.015. Quantitative densitometry of the VEGF mRNA signal via in situ hybridization reveals significant regional differences (P ≤ 0.01 and protocol differences (treadmill, electrical stimulation, and control, P ≤ 0.05. Mean VEGF mRNA signal was higher in the oxidative region in both treadmill run (~7%, N = 4 muscles, P ≤ 0.05 and electrically stimulated muscles (~60%, N = 4, P ≤ 0.05. These regional differences were not significantly different from control muscle (non-exercised, non-stimulated, N = 2 muscles, although nearly so for electrically stimulated muscle (P = 0.056. Conclusions Moderately higher VEGF mRNA signal in oxidative muscle regions is consistent with regional differences in capillary density. However, it is not possible to determine if the VEGF mRNA signal difference is important in either the maintenance of regional capillarity differences or exercise induced angiogenesis.

  3. [Rapid determination of propranolol enantiomers in rat plasma by column-switching-high performance liquid chromatography].

    Science.gov (United States)

    Wu, Xiaoyu; Wang, Rong; Xie, Hua; Wang, Jianfeng; Jia, Zhengping; Zhang, Qiang; Wang, Xianhua

    2011-12-01

    A high performance liquid chromatographic (HPLC) method with column-switching was developed and validated for rapid determination of two propranolol enantiomers in rat plasma. The column of restricted-access media was used as a pre-treatment column and a Chiralcel OD-RH was used as analytical column. The plasma samples were injected directly into the pretreatment column to remove plasma protein and endogenous constituents as well as to retent the propranolol enantiomers in the column using the mobile phase of borate buffer (pH 8.5)-methanol (95:5, v/v) at the flow rate of 1.0 mL/min. Then the propranolol enantiomers were transferred to the Chiralcel OD-RH column using the mobile phase of isopropanol-ethanol-0.2 mmol/L borate buffer (pH 8.5) (30: 30: 40, v/v/v) at a flow rate of 0.8 mL/min by column-switching technology. The column-switching time was 3.0 min, the used wavelength was 293 nm and the column temperature was set at 25 degrees C. The calibration curve showed excellent linear relationship (r = 0.999 5) in the concentration range from 25 mg/L to 500 mg/L for propranolol enantiomers in plasma. The intra-day and inter-day assay precisions and accuracies were well and the relative standard deviations (RSDs) were less than 5%. The average recoveries (n = 6) of the two enantiomers at 3 spiked levels were from 97.89% to 101.56%. All the values of the method validation were within the generally accepted criteria for biological sample analysis. The results show that the method is convenient, quick, sensitive and accurate. The method was successfully applied in the determination of propranolol enantiomers in rat blood pharmacokinetics study.

  4. Control plasma renin activity and changes in sympathetic tone as determinants of minoxidil-induced increase in plasma renin activity.

    Science.gov (United States)

    O'Malley, K; Velasco, M; Wells, J; McNay, J L

    1975-01-01

    A study was made of the possible mechanism(s) underlying minoxidil-induced increase in plasma renin activity (PRA). 10 patients with essential hypertension were treated with minoxidil and subsequently with a combination of minoxidil plus propranolol. Minoxidil lowered mean arterial pressure 31.6 plus or minus 3.3 mm Hg, mean plus or minus SEM. There was an associated increase in both PRA, 6.26 plus or minus 2.43 NG/ML/H, and heart rate, 21.4 plus or minus 2.7 beats/min. The changes in PRA and heart rate were positively correlated, r, 0.79. Addition of propranolol reduced mean arterial pressure by a further 10.1 plus or minus 1.5 mm Hg and returned heart rate to control levels. Propranolol reduced PRA significantly but not to control levels. Control PRA positively correlated with PRA on minoxidil, r, 0.97, and with PRA on minoxidil plus propranolol, r, 0.98. We conclude that control PRA is a major determinant of change in PRA with minoxidil. Minoxidil increased PRA by at least two mechanisms: (a) an adrenergic mechanism closely related to change in heart rate and blocked by propranolol, and (b) a mechanism(s) not sensitive to propranolol and possibly related to decrease in renal perfusion pressure. PMID:1127099

  5. Application of poloidal beta and plasma internal inductance in determination of input power time of Damavand tokamak

    Science.gov (United States)

    Noori, Ehsanallah; Sadeghi, Yahya; Ghoranneviss, Mahmood

    2016-10-01

    In this study, magnetic measurement of poloidal fields were used to determine poloidal beta and plasma internal inductance of Damavand tokamak combination of poloidal beta and plasma internal inductance (β _p+{l_i}/{2} ), known as Shafranov parameter, was obtained experimentally in terms of normal and tangential components of the magnetic field. Plasma internal inductance and poloidal beta were obtained using parametrization method based on analytical solution of Grad-Shafranov equation (GSE) and compared with parabolic-like profile of toroidal current density approach for determination of the plasma internal inductance. Finding evolution of β _p+{l_i}/{2} and plasma internal inductance. Finding poloidal beta (Shafranov parameter and internal inductance) and using energy balance equation, thermal energy and energy confinement were determined qualitatively in terms of poloidal beta during a regular discharge of Damavand tokamak.

  6. Expression of VEGF and semaphorin genes define subgroups of triple negative breast cancer.

    Directory of Open Access Journals (Sweden)

    R Joseph Bender

    Full Text Available Triple negative breast cancers (TNBC are difficult to treat due to a lack of targets and heterogeneity. Inhibition of angiogenesis is a promising therapeutic strategy, but has had limited effectiveness so far in breast cancer. To quantify heterogeneity in angiogenesis-related gene expression in breast cancer, we focused on two families--VEGFs and semaphorins--that compete for neuropilin co-receptors on endothelial cells. We compiled microarray data for over 2,600 patient tumor samples and analyzed the expression of VEGF- and semaphorin-related ligands and receptors. We used principal component analysis to identify patterns of gene expression, and clustering to group samples according to these patterns. We used available survival data to determine whether these clusters had prognostic as well as therapeutic relevance. TNBC was highly associated with dysregulation of VEGF- and semaphorin-related genes; in particular, it appeared that expression of both VEGF and semaphorin genes were altered in a pro-angiogenesis direction. A pattern of high VEGFA expression with low expression of secreted semaphorins was associated with 60% of triple-negative breast tumors. While all TNBC groups demonstrated poor prognosis, this signature also correlated with lower 5-year survival rates in non-TNBC samples. A second TNBC pattern, including high VEGFC expression, was also identified. These pro-angiogenesis signatures may identify cancers that are more susceptible to VEGF inhibition.

  7. VEGF EXPRESSION IS INHIBITED BY APIGENIN IN HUMAN BREAST CANCER CELLS

    Institute of Scientific and Technical Information of China (English)

    JIN Xue-ying; REN Chang-shan

    2006-01-01

    Objective: To study the effects of apigenin on vascular endothelial growth factor (VEGF) in human breast cancer cells(MDA-MB-231. Methods: MTT assay was used to detect the cell proliferation inhibitory effect of apigenin on MDA-MB-231 cell. ELISA was used to determine the protein level of VEGF secreted by MDA-MB-231 cells. RT-PCR was used to detect mRNA levels of VEGF in MDA-MB-231 cells. The protein levels of HIF-1α,p-AKT,p-ERK1/2,and p53 were detected by Western Blotting. Results: Apigenin did not inhibit the cell viability of MDA-MB-231 cell. Apigenin reduced the secretion and mRNA levels of VEGF in MDA-MB-231 cells. Additionally, apigenin decreased the expressions of HIF-1α,p-AKT and p-ERK1/2, but induced the expression of p53. Conclusion: Apigenin can inhibit VEGF expression in human breast cancer cells, and this may be achieved through decreasing HIF-1α.

  8. DC electric stimulation upregulates angiogenic factors in endothelial cells through activation of VEGF receptors.

    Science.gov (United States)

    Bai, Huai; Forrester, John V; Zhao, Min

    2011-07-01

    Small direct current (DC) electric fields direct some important angiogenic responses of vascular endothelial cells. Those responses indicate promising use of electric fields to modulate angiogenesis. We sought to determine the regulation of electric fields on transcription and expression of a serial of import angiogenic factors by endothelial cells themselves. Using semi-quantitative PCR and ELISA we found that electric stimulation upregulates the levels of mRNAs and proteins of a number of angiogenic proteins, most importantly VEGF165, VEGF121 and IL-8 in human endothelial cells. The up-regulation of mRNA levels might be specific, as the mRNA encoding bFGF, TGF-beta and eNOS are not affected by DC electric stimulation at 24h time-point. Inhibition of VEGF receptor (VEGFR1 or VEGFR2) signaling significantly decreased VEGF production and completely abolished IL-8 production. DC electric stimulation selectively regulates production of some growth factors and cytokines important for angiogenesis through a feed-back loop mediated by VEGF receptors. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Homoharringtonine induces apoptosis of endothelium and down-regulates VEGF expression of K562 cells

    Institute of Scientific and Technical Information of China (English)

    叶琇锦; 林茂芳

    2004-01-01

    Homoharringtonine (HHT) has currently been used successfully in the treatment of acute and chronic myeloid leukemias and has been shown to induce apoptosis of different types of leukemic cells in vitro. Emerging evidence suggests that angiogenesis may play an important role in hematological malignancies, such as leukemia. However, whether HHT can relieve leukemia by anti-angiogenesis is still unknown. We investigated the anti-angiogenesis potential of HHT with the human umbilical vein endothelial cell line (ECV304) and leukemic cell line (K562) in vitro. Cellular proliferation was determined by MTT assay and apoptosis was analyzed by flow cytometry, The mRNA expression of vascular endothelial growth factor (VEGF) was assessed by RT-PCR and VEGF protein production was detected by Western blot. Inhibition of cell proliferation and induction of apoptosis by HHT were discovered in ECV304 cells, and appeared in a dose- and time-dependent manner, Also, treatment with HHT caused down-regulation of VEGF mRNA expression in K562 cells in similar dose- and time-dependent manner and inhibition of VEGF protein production in K562 cells in response to the enhancing concentration of HHT. The results demonstrated that HHT could also induce apoptosis in endothelium and down-regulate VEGF expression in K562 cells. In conclusion, we believe HHT has anti-angiogenesis potential and speculate that HHT might exert its anti-leukemia effects via reduction of angiogenesis.

  10. Dependence of LTX plasma performance on surface conditions as determined by in situ analysis of plasma facing components

    Energy Technology Data Exchange (ETDEWEB)

    Lucia, M., E-mail: mlucia@pppl.gov [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ 08543 (United States); Kaita, R.; Majeski, R. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ 08543 (United States); Bedoya, F.; Allain, J.P. [University of Illinois at Urbana-Champaign (UIUC), Urbana, IL 61801 (United States); Abrams, T.; Bell, R.E.; Boyle, D.P.; Jaworski, M.A.; Schmitt, J.C. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ 08543 (United States)

    2015-08-15

    The Materials Analysis and Particle Probe (MAPP) diagnostic has been implemented on the Lithium Tokamak Experiment (LTX) at PPPL, providing the first in situ X-ray photoelectron spectroscopy (XPS) surface characterization of tokamak plasma facing components (PFCs). MAPP samples were exposed to argon glow discharge conditioning (GDC), lithium evaporations, and hydrogen tokamak discharges inside LTX. Samples were analyzed with XPS, and alterations to surface conditions were correlated against observed LTX plasma performance changes. Argon GDC caused the accumulation of nm-scale metal oxide layers on the PFC surface, which appeared to bury surface carbon and oxygen contamination and thus improve plasma performance. Lithium evaporation led to the rapid formation of a lithium oxide (Li{sub 2}O) surface; plasma performance was strongly improved for sufficiently thick evaporative coatings. Results indicate that a 5 h argon GDC or a 50 nm evaporative lithium coating will both significantly improve LTX plasma performance.

  11. Betaine as a determinant of postmethionine load total plasma homocysteine before and after B-vitamin supplementation.

    NARCIS (Netherlands)

    Holm, P.I.; Bleie, O.; Ueland, P.M.; Lien, E.A.; Refsum, H.; Nordrehaug, J.E.; Nygard, O.

    2004-01-01

    OBJECTIVE: Betaine is a substrate in the betaine-homocysteine methyltransferase reaction, converting homocysteine to methionine. There are only sparse data on plasma betaine as a determinant of the plasma total homocysteine (tHcy) concentration. METHODS AND RESULTS: Ninety patients undergoing corona

  12. QUANTITATIVE-DETERMINATION OF THE DOPAMINE AGONIST LISURIDE IN PLASMA USING HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH FLUORESCENCE DETECTION

    NARCIS (Netherlands)

    WOLTHERS, BG; KAMERBEEK, WDJV; VANBEUSEKOM, CM; ELSHOF, F; BUITENHUIS, AWD; BRUNT, EPR; LAKKE, JPWF

    1993-01-01

    An HPLC method for the determination of lisuride hydrogen maleate in plasma is described. After addition of ergotamine tartrate as internal standard, plasma is extracted with diethyl ether. Following evaporation of the solvent and redissolving in methanol the extract is injected on a silica HPLC col

  13. The VEGF signaling pathway in cancer: the road ahead

    Institute of Scientific and Technical Information of China (English)

    Steven A.Stacker; Marc G.Achen

    2013-01-01

    The vascular endothelial growth factor (VEGF) family of soluble protein growth factors consists of key mediators of angiogenesis and lymphangiogenesis in the context of tumor biology.The members of the family,VEGF-A (also known as VEGF),VEGF-B,VEGF-C,VEGF-D,and placenta growth factor (PIGF),play important roles in vascular biology in both normal physiology and pathology.The generation of a humanized neutralizing antibody to VEGF-A (bevacizumab,also known as Avastin) and the demonstration of its benefit in numerous human cancers have confirmed the merit of an anti-angiogenesis approach to cancer treatment and have validated the VEGF-A signaling pathway as a therapeutic target.Other members of the VEGF family are now being targeted,and their relevance to human cancer and the development of resistance to anti-VEGF-A treatment are being evaluated in the clinic.Here,we discuss the potential of targeting VEGF family members in the diagnosis and treatment of cancer.

  14. Determination of plasma protein synthesis index in liver diseases by means of /sup 75/Se-selenomethionine

    Energy Technology Data Exchange (ETDEWEB)

    Pirwitz, B. (Centrum Medyczne Ksztalcenia Podyplomowego, Warsaw (Poland))

    1979-01-01

    The investigations were carried out in 96 patients with chronic liver diseases and 44 controls. After intravenous administration of /sup 75/Se-selenomethionine plasma and plasma-protein radioactivity was measured at intervals of 2 hours. On the basis of these measurements the index of plasma protein synthesis rate was determined. It was found that the index of plasma protein synthesis in liver cirrhosis was significantly decreased in an overwhelming number of cases in relation to controls. On the other hand, in liver neoplasms this index was statistically significantly increased. It is possible that this fact will be used in future for differential diagnosis.

  15. Significance of VEGF and NF-κB Expression in Thyroid Carcinoma

    Institute of Scientific and Technical Information of China (English)

    Zhenxian Du; Haiyan Zhang; Daxin Gao; Huaqin Wang; Yongjun Li; Guoliang Liu

    2006-01-01

    OBJECTIVE To investigate the significance of vascular endothelial growth factor (VEGF) and nuclear factor-kappaB (NF-κB) expression in thyroid carcinoma.METHODS The expression of NF-κB and VEGF was determined by immunohistochemistry in formalin-fixed and paraffin-embedded specimens obtained from 10 normal thyroid tissues (NT), 12 cases of thyroid adenoma (TA) and 68 cases of thyroid carcinoma (TC).Differences in expression between NT, TA and TC were statistically analyzed. In addition, in cases of TC, the relationship of NF-κB and VEGF expression with various clinicopathological factors, including histological typing, clinical staging and lymph node metastasis, as well as the correlation between NF-κB and VEGF expression was examined.RESULTS In contrast to the negative immunoreactivity for VEGF in NT,there was a significantly higher positive incidence (PI) in TA (41.7%, P=0.040) and TC (75.0%, P<0.001), and a significant difference between TA and TC (P=0.036). Immunoreactivity for NF-κB in NT was negative and significantly higher in TC (63.2%, P<0.001),but not in TA (16.7%, P=0.481). However the PI difference between TA and TC (P=0.003) was significant. Between the histological types of TC, a significantly higher PI was found in undifferentiated thyroid carcinoma (UTC),namely, 100% for VEGF and 90.0% for NF-κB. We also found significant positive relationships of VEGF and NF-κB expression with the clinical stage and lymph node metastasis. Furthermore, a significant positive correlation between VEGF and NF-κB expression in TC was observed.CONCLUSION Our data showed that the expression of VEGF and NFκB/P65 was greater in TC and UTC, and documented their significant positive correlations with the clinical stage and lymph node metastasis in TC. In addition there was a significant positive relationship between their expression, suggesting that they have important roles in TC and that they may be potential targets for gene therapy in TC patients.

  16. Increased serum levels of sortilin are associated with depression and correlated with BDNF and VEGF

    DEFF Research Database (Denmark)

    Buttenschøn, Henriette Nørmølle; Demontis, Ditte; Ollendorff, Mathias Kaas;

    2015-01-01

    measured by immunoassay, and potential determinants of the serum sortilin level were assessed by generalized linear models. Serum levels of brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) were measured in previous studies. We identified a significant increase of serum...... sortilin levels in depressed individuals compared with controls (P = 0.0002) and significant positive correlation between serum sortilin levels and the corresponding levels of BDNF and VEGF. None of the genotyped SNPs were associated with depression. Additional analyses showed that the serum sortilin level...... was influenced by several other factors. Alcohol intake and body mass index, as well as depression, serum BDNF and serum VEGF were identified as predictors of serum sortilin levels in our final multivariate model. In conclusion, the results suggest a role of circulating sortilin in depression which may relate...

  17. The Structural Basis for the Function of Two Anti-VEGF Receptor 2 Antibodies

    Energy Technology Data Exchange (ETDEWEB)

    M Franklin; E Navarro; Y Wang; S Patel; P Singh; Y Zhang; K Persaud; A Bari; H Griffith; et al.

    2011-12-31

    The anti-VEGF receptor 2 antibody IMC-1121B is a promising antiangiogenic drug being tested for treatment of breast and gastric cancer. We have determined the structure of the 1121B Fab fragment in complex with domain 3 of VEGFR2, as well as the structure of a different neutralizing anti-VEGFR2 antibody, 6.64, also in complex with VEGFR2 domain 3. The two Fab fragments bind at opposite ends of VEGFR2 domain 3; 1121B directly blocks VEGF binding, whereas 6.64 may prevent receptor dimerization by perturbing the domain 3:domain 4 interface. Mutagenesis reveals that residues essential for VEGF, 1121B, and 6.64 binding are nonoverlapping among the three contact patches.

  18. The Structural Basis for the Function of Two Anti-VEGF Receptor 2 Antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Franklin, Matthew C.; Navarro, Elizabeth C.; Wang, Yujie; Patel, Sheetal; Singh, Pinki; Zhang, Yi; Persaud, Kris; Bari, Amtul; Griffith, Heather; Shen, Leyi; Balderes, Paul; Kussie, Paul (ImClone)

    2011-10-28

    The anti-VEGF receptor 2 antibody IMC-1121B is a promising antiangiogenic drug being tested for treatment of breast and gastric cancer. We have determined the structure of the 1121B Fab fragment in complex with domain 3 of VEGFR2, as well as the structure of a different neutralizing anti-VEGFR2 antibody, 6.64, also in complex with VEGFR2 domain 3. The two Fab fragments bind at opposite ends of VEGFR2 domain 3; 1121B directly blocks VEGF binding, whereas 6.64 may prevent receptor dimerization by perturbing the domain 3:domain 4 interface. Mutagenesis reveals that residues essential for VEGF, 1121B, and 6.64 binding are nonoverlapping among the three contact patches.

  19. Determination of Trace Elements in High Purity Gold by High Resolution Inductively Coupled Plasma Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    XIE Hualin; HUANG Kelong; NIE Xidu; FU Liang

    2009-01-01

    Trace elements were determined in high purity gold by high resolution inductively coupled plasma mass spectrometry(HR-ICP-MS).Sample were decomposed by aqua regia.To overcome some potentially problematic spectral interference,measurements were acquired in both medium and high resolution modes.The matrix effects due to the presence of excessive HCl and Au were evaluated.The optimum conditions for the determination was tested and discussed.The standard addition method was employed for quantitative analysis.The detection limits range from 0.01 μg/g to 0.28 μg/g depending on the elements.The method is accurate,quick and convenient.It has been applied to the determination of trace elements in high purity gold with satisfactory results.

  20. Inductively coupled plasma optical emission spectroscopy determination of trace element composition of argan oil.

    Science.gov (United States)

    Gonzálvez, A; Ghanjaoui, M E; El Rhazi, M; de la Guardia, M

    2010-02-01

    A methodology based on inductively coupled plasma optical emission spectroscopy (ICP-OES) after microwave assisted acid digestion has been developed to determine the trace element content of Moroccan argan oil. Limit of detection values equal or lower than few mg/kg were obtained for all elements under study. To assure the accuracy of the whole procedure, recovery studies were carried out on argan oil samples spiked at different concentration levels from 10 to 200 µg/L. Quantitative average recovery values were obtained for all elements evaluated, demonstrating the suitability of this methodology for the determination of trace elements in argan oil samples. Aluminum, calcium, chromium, iron, potassium, lithium, magnesium, sodium, vanadium and zinc were quantitatively determined in Moroccan argan oils being found that their concentration is different of that found in other edible oils thus offering a way for authentication and for the evaluation of possible adulterations.

  1. Comparison of risk of tumor invasion and metastasis under paravertebral block combined with general anesthesia versus general anesthesia in the patients undergoing radical lung cancer resection performed via video-assisted thoracoscope:plasma VEGF and M%椎旁神经阻滞联合全麻与全麻下胸腔镜肺癌根治术病人肿瘤侵袭和转移风险的比较:VEGF和MMP-9血浓度

    Institute of Scientific and Technical Information of China (English)

    陈冀衡; 范志毅; 张云霄; 金云玉; 李萍

    2015-01-01

    Objective To compare the risk of tumor invasion and metastasis under paravertebral block (PVB) combined with general anesthesia versus general anesthesia in the patients undergoing radical resection for lung cancer performed via video-assisted thoracoscope in terms of plasma concentrations of vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9).Methods Forty ASA physical status Ⅰ or Ⅱ patients of both sexes,aged 30-64 yr,with body mass index of 18-25 kg/m2,scheduled for elective radical resection for lung cancer performed via video-assisted thoracoscope,were randomly divided into 2 groups (n =20 each) using a random number table:general anesthesia group (group G) and PVB combined with general anesthesia (group PG).PVB of T4-7 was performed successfully with local injection of 0.375% ropivacaine 5 ml before induction of anesthesia.Double-lumen endotracheal tube was placed after induction of anesthesia,and the patients were mechanically ventilated.Anesthesia was maintained with inhalation of sevoflurane (end-tidal concentration 1%-2%),and intravenous infusion of remifentanil 0.2-0.3 μg · kg-1 · min-1,and intermittent intravenous boluses of atracurium.Before anesthesia and at 24 h after surgery,the venous blood samples were collected for measurement of plasma concentrations of VEGF and MMP-9.Results The plasma VEGF and MMP-9 concentrations were significantly lower after surgery in group PG than in group G.Conclusion PVB combined with general anesthesia significantly decreases the risk of tumor invasion and metastasis in the patients undergoing radical lung cancer resection performed via video-assisted thoracoscope in comparison to general anesthesia.%目的 采用血管内皮生长因子(VEGF)和基质金属蛋白酶-9(MMP-9)血浓度,比较椎旁神经阻滞联合全麻与全麻下胸腔镜肺癌根治术病人肿瘤侵袭和转移风险.方法 择期行胸腔镜肺癌根治术病人40例,年龄30 ~ 64岁,性别不限,BMI 18

  2. [Simultaneous determination of adrenaline, noradrenaline, cortisone and cortisol in plasma with HPLC/MS/MS].

    Science.gov (United States)

    Yong, Li; Wang, Yu; Zou, Xiao-Li; Zhu, Lan; Xie, Hui-Ru; Li, Long-Jiang

    2014-01-01

    To develop a method for simultaneous determination of adrenaline, noradrenaline, cortisone and cortisol in plasma using HPLC/MS/MS. Sample proteins were precipitated with acetonitrile and the sample solution was injected into HPLC/MS/MS after centrifugation at 15,000 r/min for 5 min. Electrospray ionization (ESI) and the positive ion detection were applied with a multiple reaction monitoring (MRM) mode for quantitative analyses. Under the optimal conditions, good linearity (r > 0.999) was observed in the range of 0.02-200.00 ng/mL of target compounds. The detection limit reached 4.13 pg/mL, 4.64 pg/mL, 4.29 pg/mL and 4.52 pg/mL for adrenaline, noradrenaline, cortisone and cortisol respectively. The inter-day and intra-day precisions ranged from 1.19%-5.42% and 2.16%-6.04% respectively. Satisfied results were achieved using human plasma samples, with a spiked recovery in the range of 80.0%-109.0% and a relative standard deviation of 3.93%-7.57%. The proposed method is quick, sensitive and suitable for batch analyses of plasma samples.

  3. Liquid Chromatography-Electrospray Ionization Mass Spectrometry Method for Determination of Protopanaxadiol in Rat Plasma

    Institute of Scientific and Technical Information of China (English)

    WU Yi; TENG Guo-sheng; LIANG Yong-tao; ZHONG Da-fang; LIU Bing

    2009-01-01

    A simple, rapid and sensitive method for the determination of protopanaxadiol in rat plasma with ginse-noside Rh2 as internal standard was developed and validated. The analyte and internal standard were extracted from plasma with ether-dichloromethane(3:2, volume ratio) and then were analyzed by reversed-phase HPLC on a short Zorbax Extend C_(18) column(50 mm×2.1 mm, 3.5 μm i.d.) eluted with a mobile phase consisting of acetoni-trile/methanol 0.10 mmol/L ammonium acetate(45:45:10, volume ratio) at 0.4 mL/min. Detection was performed on an Applied Biosystems Sciex API 4000 mass spectrometer set at unit resolution in the multiple reaction monitoring mode. Electrospray ionization was used for ion production. The assay method shows linear over a range of 5-2000 ng/mL and intra- and inter-day precisions over this range were <10.0% with accuracy ranged from 86.3% to 114.1%. The limit of detection was 500 pg/mL in the plasma. The method was successfully applied to a preclinical pharmaco-kinetic study of protopanaxadiol(17.5 mg/kg) administered as a single oral dose.

  4. Determination of moxonidine in human plasma by liquid chromatography-electrospray ionisation-mass spectrometry.

    Science.gov (United States)

    Zhao, Luhua; Ding, Li; Wei, Xin

    2006-01-23

    A sensitive and specific liquid chromatography-electrospray ionisation-mass spectrometry (LC-ESI-MS) method has been developed and validated for the identification and quantification of moxonidine in human plasma. After the addition of clonidine-HCl, the internal standard (IS) and sodium hydrogen carbonate, plasma samples were extracted using 5 mL ethyl acetate. The compounds were separated on a Lichrospher ODS (5 microm, 250 mm x 4.6 mm) column using an elution system of 10 mmol/L ammonium acetate buffer-methanol (20:80 v/v) as the mobile phase. Analytes were determined using electrospary ionization in a single quadrupole mass spectrometer. LC-ESI-MS was performed in the selected-ion monitoring (SIM) mode using target ions at m/z: 242.2 for moxonidine and m/z: 230.1 for the IS. The method has shown to be sensitive and specific by testing six different blank plasma batches. Linearity was established for the range of concentrations 0.01976-9.88 ng/mL with a coefficient of correlation (r) of 0.9999. The lower limit of quantification (LOQ) was identifiable and reproducible at 0.01976 ng/mL. The method has been successfully applied to study the pharmacokinetics of moxonidine in healthy male Chinese volunteers.

  5. Determination of Duloxetine and Its Major Metabolites in Rabbit Plasma by High-Performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    T. K. Laha

    2015-03-01

    Full Text Available A rapid and sensitive high performance liquid chromatographic method is described for simultaneous determination of duloxetine and its major metabolites, such as 4- hydroxy duloxetine (M7, Glucuronide conjugate of 5-hydroxy-6-methoxy duloxetine (M6 and Glucuronide conjugate of dihydrodiol duloxetine (M12 in rabbit plasma. HPLC analysis was carried out on a µ-Bondapak C18 column (250 mm × 4.6 mm, 5µm particle size using methanol: phosphate buffer (pH 7.9, 50 mM (7:3 v/v as the mobile phase at a flow rate of 1.5 ml/min. Detection was carried out at 224 nm with an UV detector. The above metabolites present in the rabbit plasma were characterized by retro-synthesis followed by NMR and MS study for structure confirmation and finally injected separately into the HPLC system. All the three retention time matches with the metabolites present in the plasma sample.

  6. Sensitive determination of ranitidine in rabbit plasma by HPLC with fluorescence detection.

    Science.gov (United States)

    Khedr, Alaa

    2008-02-01

    A sensitive high-performance liquid chromatographic method for determination of ranitidine (RAN) in rabbit plasma is described. The method is based on liquid-liquid extraction, labeling with dansyl chloride and monitoring with fluorescence detector at 338nm (ex)/523nm (em). Plasma samples were extracted with diethyl ether alkalinized with 1M sodium hydroxide. Ephedrine HCl (EPH-HCl) was used as internal standard. Both, RAN and EPH were completely derivatized after heating at 60 degrees C for 10min in sodium bicarbonate solution (pH 9.5). The derivatized samples were analyzed by HPLC using Agilent Zorbax Extended C18 column (150mmx4.6mm i.d.) and mobile phase consists of 48% acetonitrile and 52% sodium acetate solution (0.02M, pH 4.6). The linearity of the method was in the range of 0.025-10microg/ml. The limits of detection (LOD) and quantification (LOQ) were 7.5+/-0.18 and 22.5+/-0.12ng/ml, respectively. Ranitidine recovery was 97.5+/-1.1% (n=6; R.S.D.=1.8%). The method was applied on plasma collected from rabbits at different time intervals after oral administration of 5mg/kg ranitidine HCl.

  7. Determination and pharmacokinetic study of catechin in rat plasma by HPLC

    Institute of Scientific and Technical Information of China (English)

    Li Xie; Xin-Nan Li; De-Xi Jiang; Dan Zhang

    2011-01-01

    A high performance liquid chromatographic method was developed and validated for the quantitative determination of catechin in rat plasma and its pharmacokinetic study after intragastric administration of Catechu and Xiongdanjiangre Wan into SD rats. Plasma samples were prepared by protein precipitation using methanol-5% aqueous zinc sulfate (70:30, v/v) as precipitant. Chromatographic separation was achieved on Hypersil Cl8 column (250 mm~ 4.6 mm, 10 pm) with acetonitrile-water-triethylamine (6:94:0.3, v/v/v, pH 4.0+0.1, adjusted with phos- phoric acid) as mobile phase, followed by a UV detection at 207 nm. Good linearity was obtained over the range of 0.143-7.15 mg/L of catechin, with correlation coefficient of 0.9992. The method was simple, sensitive, accurate and reproducible and' has been successfully applied to the pharmacokinetic study of catechin in rat plasma.

  8. Determination of quinolones in plasma samples by capillary electrophoresis using solid-phase extraction.

    Science.gov (United States)

    Hernández, M; Borrull, F; Calull, M

    2000-06-09

    The potential of capillary zone electrophoresis (CZE) and micellar electrokinetic capillary chromatography (MEKC) have been investigated for the separation and quantitative determination of 10 quinolone antibiotics. The influence of different conditions, such as the buffer and pH of the electrolyte, the surfactant and the ion-pairing agents added to the electrolyte and the organic modifier were studied. A buffer consisting of 40 mM sodium tetraborate at pH 8.1 containing 10% (v/v) methanol was found to be a highly efficient electrophoretic system for separating lomefloxacin, enoxacin, norfloxacin, pipemidic acid, ofloxacin, piromidic acid, flumequine, oxolinic acid, cinoxacin and nalidixic acid. A solid-phase extraction method to remove the sample matrix (pig plasma samples) was developed on a C(18) cartridge using a mixture of methanol-water (70:30, v/v). The method is specific and reproducible and mean recoveries were in the range 94.0+/-4.2% and 123.3+/-4.1% for pig plasma samples over the range used. A linear relationship between concentration and peak area for each compound in pig plasma samples was obtained in the concentration range 5-20 mg l(-1) and detection limits were between 1.1 and 2.4 mg l(-1).

  9. Determination of tolperisone in human plasma by liquid chromatography/tandem mass spectrometry for clinical application.

    Science.gov (United States)

    Choi, Chang-Ik; Park, Jung-In; Lee, Hye-In; Lee, Yun-Jeong; Jang, Choon-Gon; Bae, Jung-Woo; Lee, Seok-Yong

    2012-12-12

    We have developed and validated a simple, rapid, and sensitive liquid chromatography analytical method employing tandem mass spectrometry (LC-MS/MS) for the determination of tolperisone, a centrally acting muscle relaxant, in human plasma. After liquid-liquid extraction with methyl t-butyl ether, chromatographic separation of tolperisone was performed using a reversed-phase Luna C(18) column (2.0mm×50mm, 5μm particles) with a mobile phase of 10mM ammonium formate buffer (pH 3.5) - methanol (12:88, v/v) and quantified by tandem mass detection in ESI positive ion mode. The flow rate of the mobile phase was 250μL/min and the retention times of tolperisone and the internal standard (IS, dibucaine) were both 0.6min. The calibration curves were linear over a range of 0.5-300ng/mL (r>0.999). The lower limit of quantification, using 200μL human plasma, was 0.5ng/mL. The mean accuracy and precision for intra- and inter-day validation of tolperisone were within acceptable limits. The LC-MS/MS method reported here showed improved sensitivity for quantification of tolperisone in human plasma compared with previously described analytical methods. Lastly, the validated method was successfully applied to a pharmacokinetic study in humans.

  10. Determination of trovafloxacin and marbofloxacin in sheep plasma samples by HPLC using UV detection.

    Science.gov (United States)

    Mahmood, Adnan H; Medley, Gregory A; Grice, Jeffrey E; Liu, Xin; Roberts, Michael S

    2012-03-25

    A simple and rapid high performance liquid chromatographic method was developed, validated and applied for the simultaneous determination of marbofloxacin (MBX) and trovafloxacin (TVX) in sheep plasma. Samples were extracted with 20% perchloric acid and MBX and TVX were separated on a C(18) column using a gradient mobile phase system consisting of 17.5mM of NaH(2)PO(4) and 1.5mM of tetrabutylammonium hydroxide aqueous solution, pH 3 (A) and 50% acetonitrile and 50% methanol (B), with UV detection at 293 and 270 nm. The retention times of MBX and TVX were 4.9 and 6.6 min respectively. The detection and quantification limits for MBX and TVX were 2 ng/mL and 10 ng/mL respectively for both compounds. The calibration curves were linear over a concentration range of 10-50,000 ng/mL for both antibiotics. The linearity, precision, accuracy, recovery and stability of the assay were evaluated from spiked sheep plasma. The method was successfully applied to sheep plasma samples obtained from MBX and TVX pharmacokinetic studies.

  11. DETERMINATION OF PROMINENCE PLASMA {beta} FROM THE DYNAMICS OF RISING PLUMES

    Energy Technology Data Exchange (ETDEWEB)

    Hillier, Andrew [Kwasan and Hida Observatories, Kyoto University, Kyoto (Japan); Hillier, Richard [Department of Aeronautics, Imperial College, London (United Kingdom); Tripathi, Durgesh, E-mail: andrew@kwasan.kyoto-u.ac.jp [Inter-University Centre for Astronomy and Astrophysics, Post Bag 4, Ganeshkhind, Pune 411 007 (India)

    2012-12-20

    Observations by the Hinode satellite show in great detail the dynamics of rising plumes, dark in chromospheric lines, in quiescent prominences that propagate from large ({approx}10 Mm) bubbles that form at the base of the prominences. These plumes present a very interesting opportunity to study magnetohydrodynamic (MHD) phenomena in quiescent prominences, but obstacles still remain. One of the biggest issues is that of the magnetic field strength, which is not easily measurable in prominences. In this paper we present a method that may be used to determine a prominence's plasma {beta} when rising plumes are observed. Using the classic fluid dynamic solution for flow around a circular cylinder with an MHD correction, the compression of the prominence material can be estimated. This has been successfully confirmed through simulations; application to a prominence gave an estimate of the plasma {beta} as {beta} = 0.47 {+-} 0.079 to 1.13 {+-} 0.080 for the range {gamma} = 1.4-1.7. Using this method it may be possible to estimate the plasma {beta} of observed prominences, therefore helping our understanding of a prominence's dynamics in terms of MHD phenomena.

  12. [Isolation, extractive concentration, and determination of caffeine in the studies of blood plasma].

    Science.gov (United States)

    Korenman, Ia I; Shormanov, V K; Mokshina, N Ia; Krivosheeva, O A; Golubitskiĭ, G B

    2012-01-01

    The optimal conditions for the isolation of caffeine from human blood by means of acetone extraction are described with special reference to the peculiarities of extraction from aqueous solutions. The possibility of concentration and purification of caffeine from blood plasma using acetone and aceton-chlorophorm mixture (2:8) as the solvents is illustrated. In addition, purification by silica-gel thin layer chromatography is discussed. Thin layer chromatography, UV-spectrophotometry, and high performance liquid chromatography are considered as potential methods for the identification and quantitative determination of caffeine.

  13. Determination of rhoifolin and daidzin in human plasma by high-performance liquid chromatography.

    Science.gov (United States)

    Ishii, K; Urano, S; Furuta, T; Kasuya, Y

    1994-05-13

    A method for determining flavonoids in human plasma is presented for application to pharmacokinetic studies of two flavonoids, rhoifolin and daidzin. Isocratic reversed-phase high-performance liquid chromatography (HPLC) was used with genistin as an internal standard and solid-phase extraction using a Sep-Pak C18 cartridge. The mobile phases were acetonitrile-0.1 M ammonium acetate solution (20:80, v/v) for rhoifolin and methanol-0.1 M ammonium acetate solution (33:67, v/v) for daidzin. The detection limits on-column were 2 ng for rhoifolin and 0.5 ng for daidzin.

  14. Inductively Coupled Plasma Optical-Emission Spectroscopy Determination of Major and Minor Elements in Vinegar

    Directory of Open Access Journals (Sweden)

    Arzu AKPINAR-BAYIZIT

    2010-12-01

    Full Text Available This study characterizes the mineral content of vinegar samples. The concentrations of Na, K, Ca, Mg and P (major elements as well as Fe, Mn, Sn, Cu, Ni, Zn, Pb and Cd (minor elements were determined in 35 commercial vinegar samples using inductively coupled plasma optical-emission spectrometry (ICP-OES. The elements with the highest concentrations were K, Na, Ca, Mg and P. The concentrations of heavy metals in the vinegar samples, including Cd, Ni, Sn and Pb, were not considered a health risk.

  15. [Determination of total sulfur in coal by inductively coupled plasma atomic emission spectrometry].

    Science.gov (United States)

    Liu, Dong-yan; Zhang, Yuan-li

    2002-02-01

    A direct method was reported for the determination of total sulfur in coal by inductively coupled plasma atomic emission spectrometry (ICP-AES). The dissolution conditions of coal samples as well as interference conditions of hydrochloric acid and matrix were studied. The recommended method not only proved to be simple and rapid than traditional gravimetric method but show satisfying precision and accuracy as well. The results of samples are as same as gravimetry. The recoveries are more than 96%, and the relative standard deviation of six samples are less than 3%.

  16. Iodine Determination by Microwave Plasma Torch Atomic Emission Spectrometer Coupled with Online Preconcentration Vapor Generation Technique

    Institute of Scientific and Technical Information of China (English)

    FEI Yan-qun; LUO Gui-min; FENG Guo-dong; CHEN Huan-wen; FEI Qiang; HUAN Yan-fu; JIN Qin-han

    2008-01-01

    This article focuses on iodine determination by microwave plasma torch atomic emission spectrometry (MPT-AES) coupled with online preconcentration vapor generation method.A new desolvation device,multistrand Nation dryer,was used as the substitute for condenser desolvation system.Some experimental conditions,such as preconcentration time,acidity of sample solution,rinsing solution acidity and dynamic linear range were investigated and optimized.The new desolvation system eliminates the problem of decreasing emission intensity of I(I) 206.238 nm line with the increase of working time on a conventional condenser desolvation system,thus greatly improving the reproducibility.

  17. Determination of Free Levels of Cinitipride in Human Plasma by Liquid Chromatography-Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Shikha M. N. Roy

    2008-01-01

    4.6 mm, 5 µm i.d.. The assay of cinitapride was linear calibration curve over the range 20.118 pg mL−1 to 2011.797 pg mL−1. Plasma concentrations of cinitapride were determined by LC-MS/MS with a limit of quantification of 20.118 pg mL−1 that allowed an appropriate characterization of the pharmacokinetic profile of cinitapride at the therapeutic dose. The method was successfully applied to the bioequivalence study of cinitapride tablet (1.0 mg administered as a single oral dose.

  18. Analyses of the plasma generated by laser irradiation on sputtered target for determination of the thickness used for plasma generation

    Energy Technology Data Exchange (ETDEWEB)

    Kumaki, Masafumi, E-mail: masafumi.kumaki@riken.jp [Cooperative Major in Nuclear Energy, Waseda University, Shinjuku, Tokyo (Japan); RIKEN, Wako, Saitama (Japan); Ikeda, Shunsuke; Sekine, Megumi; Munemoto, Naoya [RIKEN, Wako, Saitama (Japan); Department of Energy Sciences, Tokyo Institute of Technology, Meguro, Tokyo (Japan); Fuwa, Yasuhiro [RIKEN, Wako, Saitama (Japan); Department of Physics and Astronomy, Kyoto University, Uji, Kyoto (Japan); Cinquegrani, David [American Nuclear Society, University of Michigan, Ann Arbor, Michigan 48109 (United States); Kanesue, Takeshi; Okamura, Masahiro [Collider-Accelerator Department, Brookhaven National Laboratory, Upton, New York 11973 (United States); Washio, Masakazu [Cooperative Major in Nuclear Energy, Waseda University, Shinjuku, Tokyo (Japan)

    2014-02-15

    In Brookhaven National Laboratory, laser ion source has been developed to provide heavy ion beams by using plasma generation with 1064 nm Nd:YAG laser irradiation onto solid targets. The laser energy is transferred to the target material and creates a crater on the surface. However, only the partial material can be turned into plasma state and the other portion is considered to be just vaporized. Since heat propagation in the target material requires more than typical laser irradiation period, which is typically several ns, only the certain depth of the layers may contribute to form the plasma. As a result, the depth is more than 500 nm because the base material Al ions were detected. On the other hand, the result of comparing each carbon thickness case suggests that the surface carbon layer is not contributed to generate plasma.

  19. COX-2, VEGF and tumour angiogenesis.

    LENUS (Irish Health Repository)

    Toomey, D P

    2009-06-01

    Epidemiological evidence suggests a protective effective of regular NSAID use against developing cancer. Cyclooxygenase-2, a target of NSAIDs, is upregulated in many cancers and has been associated with increased VEGF production and angiogenesis. Angiogenesis is the formation of new vessels from existing vasculature and as an essential process for tumour development represents an important therapeutic target. Following an extensive review of the literature this article details the current knowledge on the role of COX-2 in tumorigenesis focusing on its relationship to angiogenesis and VEGF production by tumour cells. While COX-2 is clearly detrimental to prognosis and NSAIDs have a beneficial effect, the possibility of COX-2 independent effects being partly or wholly responsible for this benefit cannot be excluded.

  20. Expression of CXCR4 and VEGF-C is correlated with lymph node metastasis in non-small cell lung cancer.

    Science.gov (United States)

    Bi, Ming Ming; Shang, Bin; Wang, Zhou; Chen, Gang

    2017-09-19

    This study investigated the correlations between CXCR4 and VEGF-C expression and lymph node metastasis in non-small cell lung cancer (NSCLC). Tumor specimens, lymph nodes, and normal lung tissues were obtained from 110 NSCLC patients who underwent complete resection. Quantitative reverse transcription-PCR and immunohistochemistry assays were conducted to evaluate messenger RNA (mRNA) and protein expression of CXCR4 and VEGF-C. Logistic regression analysis was performed to determine the independent risk factors for lymph node metastasis in NSCLC. CXCR4 and VEGF-C mRNA expression were observed in 78 (70.9%) and 64 (58.2%) lung cancer tissues, while CXCR4 and VEGF-C protein expression were observed in 76 (69.9%) and 58 (52.7%) lung cancer tissues, respectively. The expression rates of CXCR4 and VEGF-C mRNA in metastatic lymph nodes were 84.8% and 66.7%, which were higher than that in non-metastatic lymph nodes (27.3% and 18.2%), respectively. Logistic regression analysis revealed that positive expressions of CXCR4 and VEGF-C mRNA were independent risk factors for lymph node metastasis in NSCLC. Furthermore, combined expression of CXCR4 and VEGF-C showed a much higher odds ratio than CXCR4 or VEGF-C expression alone. CXCR4 and VEGF-C were highly expressed in lung cancer tissues and metastatic lymph nodes. CXCR4 and VEGF-C expression levels were significantly correlated with lymph node metastasis in NSCLC. CXCR4 and VEGF-C might synergically promote lymphatic metastasis in lung cancer and might be a clinical predictor of lymph node metastasis in NSCLC patients. © 2017 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.

  1. [Plasma ibuprofen enantiomers and their pharmacokinetics in Beagle dogs determined by HPLC].

    Science.gov (United States)

    Wang, Hong-yan; Kong, Ai-ying; Yang, Bo; Yan, Liang-ping; Di, Xin

    2015-12-01

    A chiral high-performance liquid chromatography method was developed for the simultaneous determination of ibuprofen enantiomers in dog plasma. It was used to study the pharmacokinetics in the Beagle dog after intravenous administration of racemic-ibuprofen, S-ibuprofen and R-ibuprofen. Ketoprofen was chosen as the internal standard. After a simple precipitation using methanol as the precipitating solvent, both analytes and IS were separated on a Kromasil 100-5CHI-TBB chiral column (250 mm x4.6 mm, 5 μm) with isocratic elution using acetonitrile - 20 mmol x L(-1) phosphate buffer (pH 3.0, containing 5% methanol) (6 : 4) as the mobile phase. The detection wavelength was 220 nm. Liner calibration curves for both of the ibuprofen enantiomers were over the concentration range from 0.5 to 50 μg x mL(-1) with a lower limit of quantification of 0.5 μg x mL(-1), the accuracies were all in standard ranges. The intra- and inter- assay precisions were all below 7%. The recovery rate was 93.1% to 100.4%. The experiments proved that the method was simple, rapid and sensitive. It can be used in the quantitative determination of ibuprofen enantiomers in dog plasma. The method was used to determine the concentration of ibuprofen enantiomers in Beagle dog plasma after a single intravenous administration of racemic-ibuprofen, S-ibuprofen and R-ibuprofen (9 mg x kg(-1)) and the pharmacokinetics parameters were calculated based on the concentration-time curves. The C(max) of S-ibuprofen in Beagle dog plasma after a single intravenous administration of racemic-ibuprofen, S-ibuprofen and R-ibuprofen were 30.8 ± 4.7, 46.1 ± 5.9 and 20.0 ± 2.6 μg x mL(-1), respectively. In terms of the exposure of active ingredient, it revealed a significant difference between the administration of S-ibuprofen and the other two groups. The systematical R- to S- chiral inversion was discussed. Comparing the pharmacokinetic parameters at different doses, chiral inversion were 70.1% ± 36.6% and 76

  2. Src Kinase becomes preferentially associated with the VEGFR, KDR/Flk-1, following VEGF stimulation of vascular endothelial cells

    Directory of Open Access Journals (Sweden)

    Wang Jing

    2002-12-01

    Full Text Available Abstract Background The cytoplasmic tyrosine kinase, Src, has been found to play a crucial role in VEGF (vascular endothelial growth factor – dependent vascular permeability involved in angiogenesis. The two main VEGFRs present on vascular endothelial cells are KDR/Flk-1 (kinase insert domain-containing receptor/fetal liver kinase-1 and Flt-1 (Fms-like tyrosine kinase-1. However, to date, it has not been determined which VEGF receptor (VEGFR is involved in binding to and activating Src kinase following VEGF stimulation of the receptors. Results In this report, we demonstrate that Src preferentially associates with KDR/Flk-1 rather than Flt-1 in human umbilical vein endothelial cells (HUVECs, and that VEGF stimulation resulted in an increase of Src activity associated with activated KDR/Flk-1. These findings were determined through immunoprecipitation-kinase experiments and coimmunoprecipitation studies, and were further confirmed by GST-pull-down assays and Far Western studies. However, Fyn and Yes, unlike Src, were found to associate preferentially with Flt-1. Conclusions Thus, Src preferentially associates with KDR/Flk-1, rather than with Flt-1, upon VEGF stimulation in endothelial cells. Our findings further highlight the potential significance of upregulated KDR/Flk-1-associated Src activity in the process of angiogenesis, and help to elucidate more clearly the specific roles and mechanisms involving Src family tyrosine kinase in VEGF-stimulated signal transduction events.

  3. Determination of plasma lactic acid concentration and specific activity using high-performance liquid chromatography.

    Science.gov (United States)

    Bleiberg, B; Steinberg, J J; Katz, S D; Wexler, J; LeJemtel, T

    1991-08-23

    Assessment of lactate metabolism is of particular interest during exercise and in disease states such as diabetes, shock, and absorptive abnormalities of short-chain fatty acids by the colon. We describe an analytical method that introduces radio-active tracers and high-performance liquid chromatography (HPLC) to simultaneously analyze concentrations and specific activities (SAs) of plasma lactate. The HPLC conditions included separation on a reversed-phase column (octadecylsilane) and an isocratic buffer (30% acetonitrile in water). [3H]Acetate served as an internal standard. Lactate and acetate were extracted from plasma samples with diethyl ether following a pH adjustment to less than 1.0 and back-extracted into a hydrophilic phase with sodium carbonate (2 mM, pH greater than 10.0). Lactate is detected in the ultraviolet range (242 and 320 nm) by derivatization with alpha-bromoacetophenone. Control plasma samples were studied after an overnight fast for precision and analytical recovery. Calibration curves were linear in the range 0.18-6.0 mM (r = 0.92). The precision was 3% and the analytical recovery was 87%. The detection limit of the method was 36 pmol. Determination of lactate metabolism was performed in a patient with chronic congestive heart failure who was administered primed-continuous L-[U-14C]lactate (10 microCi bolus and 0.3 microCi/min continuously) during a 60-min rest period. Mean arterial lactate concentration and SA were 1.69 +/- 0.2 mM and 253.8 +/- 22 dpm/mumol, respectively. Systemic lactate turnover was 25.65 mumol/kg per min. Lactic acid systemic turnover, organ uptake and release rates can be accurately determined by isocratic HPLC.

  4. [Determination of minor elements in stainless steel by laser-induced plasma spectroscopy (LIPS)].

    Science.gov (United States)

    Li, Jing; Zhai, Chao; Zhang, Shi-Ding; Zhang, Jian-Qiu; Meng, Xiang-Ru

    2008-04-01

    Laser-induced plasma spectroscopy (LIPS) is characterized by its non-contact and real-time analysis. Its application to the determination of steel composition can meet the need of high-speed, continuous and automatic production in large steel companies. In the present article the minor elements concentrations of aluminum, manganese, cobalt, molybdenum, and titanium in a series of stainless steel 1Cr18Ni9Ti samples were determinate by laser-induced plasma spectroscopy, based on a Nd : YAG Q-switched solid laser with wavelength 1 064 nm as an exciting source and ICCD as detector. In the experiment the working delay time and gate time of ICCD were set suitably to get high signal-to-noise ratio emission spectral lines, and the internal standardization method related to matrix effect was used to deal with spectral data. Experiment results show that the concentration ratios of all the measured elements versus the reference element ferrum have a good linear relationship with the intensity ratios of them, the detection limits of the five tested elements are within 150 microg x g(-1).

  5. "Determination of mycophenolic acid in human plasma by high-performance liquid chromatography"

    Directory of Open Access Journals (Sweden)

    "Mehdi Ahadi Barzoki

    2005-05-01

    Full Text Available A simple, sensitive and reproducible HPLC method is presented for determination of mycophenolic acid(MPA in human plasma. Samples were prepared after precipitation of the plasma protein by addition of acetonitrile and naproxen was used as internal standard (I.S.. Separation was performed by reversedphase HPLC, using a Hamilton PRP-C18 Column, 51% acetonitrile and 49% potassium phosphate buffer (20 mM at pH 3.0 as mobile phase, flow rate of 1.0 ml/min, and UV detection at 215 nm. MPA and I.S. had retention times of 7.5 and 11.35 min, respectively. The method showed an acceptable linearity in the range of 0.1µg/ml-40µg/ml with r2 of .9992. The concentration of 0.1µg/ml was determined as quantification limit. Mean absolute recovery was 94.8%. The mean intra- and inter-day reproducibility of method was 4.6 and 11.4% respectively.

  6. Is a deuterated internal standard appropriate for the reliable determination of olmesartan in human plasma?

    Science.gov (United States)

    Piórkowska, Edyta; Musijowski, Jacek; Buś-Kwaśnik, Katarzyna; Rudzki, Piotr J

    2017-01-01

    A right choice of the internal standard is one of the most challenging tasks during bioanalytical method development. Surprisingly, among the HPLC-MS methods for the determination of a cardiovascular drug olmesartan in plasma only structural analogues or similar compounds were used as internal standards. We have tried to answer the question whether the stable isotope labelled (deuterated) internal standard, as recommended by regulatory agencies, can be used for the reliable determination of olmesartan in human plasma. An HPLC-MS method using this standard in a simplified liquid-liquid extraction procedure led to accurate and precise results in the linearity range of 5-2500ng/mL. The method is well suited for pharmacokinetic studies following a single 40mg oral dose of olmesartan medoxomil in humans. The method was fully validated according to international guidelines and successfully applied in a bioequivalence study in humans. The use of deuterated olmesartan as the internal standard afforded a reliable tool for regulatory bioanalysis that can indirectly contribute to therapy efficacy and improve the safety of patients treated with generic medicines. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Determination of triamterene in human plasma and urine after its cloud point extraction

    Directory of Open Access Journals (Sweden)

    Ahad Bavili Tabrizi

    2014-01-01

    Full Text Available A new analytical approach was developed involving cloud point extraction (CPE and spectrofluorimetric determination of triamterene (TM in biological fluids. A urine or plasma sample was prepared and adjusted to pH 7, then TM was quickly extracted using CPE, using 0.05% (w/v of Triton X-114 as the extractant. The main factors that affected the extraction efficiency (the pH of the sample, the Triton X-114 concentration, the addition of salt, the extraction time and temperature, and the centrifugation time and speed were studied and optimized. The method gave calibration curves for TM with good linearities and correlation coefficients (r higher than 0.99. The method showed good precision and accuracy, with intra- and inter-assay precisions of less than 8.50% at all concentrations. Standard addition recovery tests were carried out, and the recoveries ranged from 94.7% to 114%. The limits of detection and quantification were 3.90 and 11.7 µg L-1, respectively, for urine and 5.80 and 18.0 µg L-1, respectively, for plasma. The newly developed, environmentally friendly method was successfully used to extract and determine TM in human urine samples.

  8. Instability-Enhanced Collisional Friction Determines the Bohm Criterion in Multiple-Ion-Species Plasmas

    Science.gov (United States)

    Baalrud, S. D.; Hegna, C. C.; Callen, J. D.

    2009-11-01

    Ion-ion streaming instabilities are excited in the presheath region of plasmas with multiple ion species if the ions are much colder than the electrons. Streaming instabilities onset when the relative fluid flow between ion species exceeds a critical speed, δVc, of order the ion thermal speeds. Using a generalized Lenard-Balescu theory that accounts for instability-enhanced collective responses [1], one is able to show the instabilities rapidly enhance the collisional friction between ion species far beyond the contribution from Coulomb collisions alone. This strong frictional force determines the relative fluid speed between species. When this condition is combined with the Bohm criterion generalized for multiple ion species, the fluid speed of each ion species is determined at the sheath edge. For each species, this speed differs from the common ``system'' sound speed by a factor that depends on the species concentrations, masses and δVc.[4pt] [1] S.D. Baalrud, J.D. Callen, and C.C. Hegna, Phys. Plasmas 15, 092111 (2008).

  9. Determinants of folate and vitamin B12 plasma levels in the French E3N-EPIC cohort.

    Science.gov (United States)

    de Batlle, Jordi; Matejcic, Marco; Chajes, Veronique; Moreno-Macias, Hortensia; Amadou, Amina; Slimani, Nadia; Cox, David G; Clavel-Chapelon, Françoise; Fagherazzi, Guy; Romieu, Isabelle

    2016-12-21

    Impaired B vitamin status has been identified as a risk factor for major chronic diseases. This study aims at examining the determinants of plasma folate and vitamin B12 concentrations, considering lifestyle factors and MTHFR polymorphisms. A total of 988 women aged 40-65 years from the French E3N cohort were investigated. Intakes of folate and vitamin B12 were assessed using food frequency questionnaires, and plasma concentrations were measured by microbiological assay. Dietary scores were computed to summarize folate and vitamin B12 dietary sources. MTHFR-C677T and MTHFR-A1298C were determined by Kaspar assay. Pearson's partial correlation coefficients and multivariable linear regression models were used to assess correlations between main determinants and plasma folate and vitamin B12 levels. The partial correlation coefficient between dietary intakes and plasma folate was 0.19 (p value vitamin B12. Dietary scores were the main determinant of B vitamin plasma concentrations with a percent change per unit increase of 12.64% (p value vitamin B12. Homozygous (T/T) or heterozygous (C/T) women for MTHFR-C677T had lower plasma folate concentrations [C/T: -6.48% (p value = 0.038) and T/T: -15.89% (p value vitamin plasma concentration include: smoking status for folate, and age and hormone replacement therapy for vitamin B12. We confirmed previous findings on the role of diet as main determinant of folate and vitamin B12 plasma concentrations. However, the impact of genetic polymorphisms and lifestyle factors on plasma B vitamin concentrations should not be neglected.

  10. VEGF Expression in Patellar Tendinopathy: A Preliminary Study

    Science.gov (United States)

    Lian, Øystein; Bahr, Roald; Hart, David A.; Duronio, Vincent

    2008-01-01

    Vascular function and angiogenesis are regulated by vascular endothelial growth factor-A (VEGF). The purpose of this preliminary study was to address the following questions: Is VEGF expression in the patellar tendon more prevalent in patients with patellar tendinopathy than in individuals with normal, pain-free patellar tendons? Which cell populations express VEGF in normal and tendinopathic tendon? Is there a difference in symptom duration between VEGF+ and VEGF− tendons? We collected patellar tendon tissue from 22 patients undergoing open débridement of the patellar tendon and from 10 patients undergoing intramedullary nailing of the tibia. VEGF expression was assessed immunohistochemically. Relevant inflammatory and repair cell types were immunolabeled. VEGF expression was absent from control tendons, but was present in a subset of patients with histopathological evidence of angiofibroblastic tendinosis. VEGF was expressed in the intimal layer of tendon vessels, but was absent in other cell types. Patients demonstrating VEGF expression in the patellar tendon had a shorter symptom duration (12 ± 7.8 months) than patients with no detectable VEGF (32.8 ± 23.5 months). VEGF may contribute to the vascular hyperplasia that is a cardinal feature of symptomatic tendinosis, particularly in cases with more recent onset. PMID:18459027

  11. Increased plasma levels of soluble vascular endothelial growth factor receptor 1 (sFlt-1) in women by moderate exercise and increased plasma levels of vascular endothelial growth factor in overweight/obese women.

    Science.gov (United States)

    Makey, Kristina L; Patterson, Sharla G; Robinson, James; Loftin, Mark; Waddell, Dwight E; Miele, Lucio; Chinchar, Edmund; Huang, Min; Smith, Andrew D; Weber, Mark; Gu, Jian-Wei

    2013-01-01

    The incidence of breast cancer is increasing worldwide, and this seems to be related to an increase in lifestyle risk factors, including physical inactivity and overweight/obesity. We have reported previously that exercise induced a circulating angiostatic phenotype characterized by increased soluble fms-like tyrosine kinase-1 (sFlt-1) and endostatin and decreased unbound vascular endothelial growth factor (VEGF) in men. However, there are no data on women. The present study determines the following: (a) whether moderate exercise increased sFlt-1 and endostatin and decreased unbound VEGF in the circulation of adult female volunteers and (b) whether overweight/obese women have a higher plasma level of unbound VEGF than lean women. A total of 72 African American and White adult women volunteers ranging in age from 18 to 44 years were enrolled in the exercise study. All the participants walked on a treadmill for 30 min at a moderate intensity (55-59% heart rate reserve), and oxygen consumption (VO(2)) was quantified utilizing a metabolic cart. We obtained blood samples before and immediately after exercise from 63 participants. ELISA assays showed that the plasma levels of sFlt-1 were 67.8±3.7 pg/ml immediately after exercise (30 min), significantly higher than the basal levels, 54.5±3.3 pg/ml, before exercise (P<0.01; n=63). There was no significant difference in the % increase in the sFlt-1 levels after exercise between African American and White (P=0.533) women or between lean and overweight/obese women (P=0.892). There was no significant difference in the plasma levels of unbound VEGF (35.28±5.47 vs. 35.23±4.96 pg/ml; P=0.99) or endostatin (111.12±5.48 vs. 115.45±7.15 ng/ml; P=0.63) before and after exercise. The basal plasma levels of unbound VEGF in overweight/obese women were 52.26±9.6 pg/ml, significantly higher than the basal levels of unbound VEGF in lean women, 27.34±4.99 pg/ml (P<0.05). The results support our hypothesis that exercise

  12. Determination of {sup 233}U by inductively coupled argon plasma - atomic emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Patwardhan, A.B.; Kulkarni, V.T.; Radhakrishnan, K.; Ramanujam, A.; Page, A.G. [Bhabha Atomic Research Centre, Bombay (India)

    1994-09-01

    The paper describes studies carried out for the determination of {sup 233}U at various stages during the recovery and purification of {sup 233}U from {sup 233}U-Al alloy scraps generated during the fabrication of {sup 233}U-Al alloy fuel. Employing a high resolution sequential spectrometer and Inductively Coupled argon Plasma (ICP) as the spectral excitation source, isotope shift for {sup 233}U with respect to {sup 238}U has been resolved and recorded. The shift for the 424.437 nm emission line of {sup 238}U is found to be of the order of 0.040 nm on the lower wavelength side for {sup 233}U and this isotopic effect has been utilised for the quantitative determination of {sup 233}U. The overall precision of the method is 5% RSD with the detection limit of 0.01 {mu}g/ml.

  13. Determination of metals in composite diet samples by inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Melnyk, Lisa Jo; Morgan, Jeffrey N; Fernando, Reshan; Pellizzari, Edo D; Akinbo, Olujide

    2003-01-01

    A study was conducted to evaluate the applicability of inductively coupled plasma-mass spectrometry (ICP-MS) techniques for determination of metals in composite diets. Aluminum, cadmium, chromium, copper, lead, manganese, nickel, vanadium, and zinc were determined by this method. Atmospheric pressure microwave digestion was used to solubilize analytes in homogenized composite diet samples, and this procedure was followed by ICP-MS analysis. Recovery of certified elements from standard reference materials ranged from 92 to 119% with relative standard deviations (RSDs) of 0.4-1.9%. Recovery of elements from fortified composite diet samples ranged from 75 to 129% with RSDs of 0-11.3%. Limits of detection ranged from 1 to 1700 ng/g; high values were due to significant amounts of certain elements naturally present in composite diets. Results of this study demonstrate that low-resolution quadrupole-based ICP-MS provides precise and accurate measurements of the elements tested in composite diet samples.

  14. Determination of trace multi-elements in coal fly ash by inductively coupled plasma mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    XIE Hua-lin; TANG You-gen; LI Yu-jie; LI Li-bo

    2007-01-01

    The contents of Cr,Cu, Ni, As, Cd and Pb in coal fly ash were determined by a high resolution inductively coupled plasma mass spectrometry method.The sample digestions were performed in closed microwave vessels with HN03, HClO4 and HF.The optimum conditions for the determination were obtained.The applicability of the proposed method was validated by the analysis of coal fly ash reference material (NIST SRM 1633a). The results show that most of the spectral interferences can be avoided by measuring in the high resolution mode(maximum mass resolution R=9 000).The detection limit is from 0.05 to 0.21μg/g,and the precision is fine with relative standard deviation less than 4.3%.

  15. Determining the Concentrations and Temperatures of Products in a CF_4/CHF_3/N_2 Plasma via Submillimeter Absorption Spectroscopy

    Science.gov (United States)

    Helal, Yaser H.; Neese, Christopher F.; De Lucia, Frank C.; Ewing, Paul R.; Agarwal, Ankur; Craver, Barry; Stout, Phillip J.; Armacost, Michael D.

    2017-06-01

    Plasmas used for the manufacturing of semiconductor devices are similar in pressure and temperature to those used in the laboratory for the study of astrophysical species in the submillimeter (SMM) spectral region. The methods and technology developed in the SMM for these laboratory studies are directly applicable for diagnostic measurements in the semiconductor manufacturing industry. Many of the molecular neutrals, radicals, and ions present in processing plasmas have been studied and their spectra have been cataloged or are in the literature. In this work, a continuous wave, intensity calibrated SMM absorption spectrometer was developed as a remote sensor of gas and plasma species. A major advantage of intensity calibrated rotational absorption spectroscopy is its ability to determine absolute concentrations and temperatures of plasma species from first principles without altering the plasma environment. An important part of this work was the design of the optical components which couple 500-750 GHz radiation through a commercial inductively coupled plasma chamber. The measurement of transmission spectra was simultaneously fit for background and absorption signal. The measured absorption was used to calculate absolute densities and temperatures of polar species. Measurements for CHF_3, CF_2, FCN, HCN, and CN made in a CF_4/CHF_3/N_2 plasma will be presented. Temperature equilibrium among species will be shown and the common temperature is leveraged to obtain accurate density measurements for simultaneously observed species. The densities and temperatures of plasma species are studied as a function of plasma parameters, including flow rate, pressure, and discharge power.

  16. Predictors of anti-VEGF treatment response in neovascular age-related macular degeneration.

    Science.gov (United States)

    Finger, Robert P; Wickremasinghe, Sanjeewa S; Baird, Paul N; Guymer, Robyn H

    2014-01-01

    Currently available evidence on predictors of anti-vascular endothelial growth factor (VEGF) treatment response in neovascular age-related macular degeneration was reviewed. No meta-analysis of results is possible because of a lack of controlled and randomized trials, varying treatment regimes and outcome measures used, as well as suboptimal reporting. For genetic factors, most evidence to date has been generated for single nucleotide polymorphisms (SNPs) in the complement factor H (CFH), and VEGF-A genes. Just under half of the SNPs assessed in the CFH gene and 15% of the SNPs assessed in the VEGF gene were found to be associated with visual outcomes or the number of injections required during follow-up. Some evidence suggests association of worse treatment outcomes as well as a younger age at treatment onset with an increasing number of risk alleles in known risk genes (CFH and ARMS2/HTRA1) and polymorphisms in the VEGF-A gene. Clinical factors such as higher age, a better visual acuity (VA), a larger choroidal neovascularization (CNV) lesion at baseline, and a delay between symptom onset and initiation of treatment of more than 3 weeks also impact outcomes. Conversely, a worse acuity at baseline predicted more gain in vision. Overall, patients presenting with good acuity at baseline were more likely to have good VA at follow up, but the gain afforded by treatment was impacted by a ceiling effect. Most available evidence suggests a strong association of clinical factors such as age, baseline VA, and CNV lesion size with anti-VEGF treatment outcomes. No behavioral factors such as smoking influence treatment outcomes. Based on the studies conducted so far, the evidence suggests that underlying genotype of known AMD risk associated genes or of the VEGF-A gene have a limited effect, whereas presenting clinical factors appear to be more important in determining treatment outcomes.

  17. Spectrofluorimetric determination of certain biologically active phenothiazines in commercial dosage forms and human plasma.

    Science.gov (United States)

    Mohamed, Abdel-Maaboud I; Abdelmageed, Osama H; Salem, Hesham; Nagy, Dalia M; Omar, Mahmoud A

    2013-01-01

    A validated simple and sensitive spectrofluorimetric method was developed for the determination of chlorpromazine hydrochloride, promethazine hydrochloride, trifluperazine hydrochloride, thioridazine hydrochloride, perazine maleate and oxomemazine. The method was based on condensation of malonic acid/acetic anhydride (MAA) under the catalytic effect of the tertiary amine moiety of the studied phenothiazines to provide a deep yellow to brown colour with green fluorescence. Relative fluorescence intensity of the products was measured at λ exc 398 nm and λ em 432 nm. Different variables affecting the reaction were studied and optimized. The method was successfully applied for the determination of the studied drugs in commercial dosage forms. The lower detection limits allowed the application of this method for the determination of the compounds in plasma as an example of a biological fluid. In addition, the method was considered specific for the determination of tertiary amines in the presence of primary and secondary amines; as a result, it was deemed suitable for the determination of the cited drugs in the presence of their degradation products resulting from N-dealkylation or oxidation of the corresponding sulphoxides or sulphones.

  18. A Switch in the Dynamics of Intra-Platelet VEGF-A from Cancer to the Later Phase of Liver Regeneration after Partial Hepatectomy in Humans.

    Directory of Open Access Journals (Sweden)

    Bibek Aryal

    Full Text Available Liver regeneration (LR involves an early inductive phase characterized by the proliferation of hepatocytes, and a delayed angiogenic phase distinguished by the expansion of non-parenchymal compartment. The interest in understanding the mechanism of LR has lately shifted from the proliferation and growth of parenchymal cells to vascular remodeling during LR. Angiogenesis accompanied by LR exerts a pivotal role to accomplish the process. Vascular endothelial growth factor (VEGF has been elucidated as the most dynamic regulator of angiogenesis. From this perspective, platelet derived/Intra-platelet (IP VEGF-A should be associated with LR.Thirty-seven patients diagnosed with hepatocellular carcinoma and undergoing partial hepatectomy (PH were enrolled in the study. Serum and IP VEGF-A was monitored preoperatively and at four weeks of PH. Liver volumetry was determined on computer models derived from computed tomography (CT scan.Serum and IP VEGF-A was significantly elevated at four weeks of PH. Preoperative IP VEGF-A was higher in patients with advanced cancer and vascular invasion. Postoperative IP VEGF-A was higher after major liver resection. There was a statistically significant correlation between postoperative IP VEGF-A and the future remnant liver volume. Moreover, the soluble vascular endothelial growth factor receptor-1 (sVEGFR1 was distinctly down-regulated suggesting a fine-tuned angiogenesis at the later phase of LR.IP VEGF-A is overexpressed during later phase of LR suggesting its implications in inducing angiogenesis during LR.

  19. Differential stimulation of VEGF-C production by adhesion/growth-regulatory galectins and plant lectins in human breast cancer cells.

    Science.gov (United States)

    Timoshenko, Alexander V; Kaltner, Herbert; André, Sabine; Gabius, Hans-Joachim; Lala, Peeyush K

    2010-12-01

    The present study tested the hypothesis that the production of vascular endothelial growth factor C (VEGF-C), a key lymphangiogenic factor, by human breast cancer cells can be stimulated by human lectins, using plant lectins as controls. The effects of human galectins and five plant lectins reacting with distinct determinants of N- and O-glycans on the accumulation of VEGF-C in serum-free cell culture media of human breast cancer cells endowed with high (MDA-MB-231) and low (MCF7, T-47D, and SK-BR-3) VEGF-C-producing abilities were examined. All tested lectins stimulated VEGF-C production by MDA-MB-231 cells, albeit with different potency. Concanavalin A, but not galectins, was also able to stimulate VEGF-C production by low VEGF-C-producing cell lines MCF7 and T-47D. Both VEGF-C mRNA and protein were strongly up-regulated in SK-BR-3 cells by concanavalin A and wheat germ agglutinin, but not jacalin. The differential response of breast cancer cell lines separated by the endogenous level of VEGF-C production suggests that galectins may contribute to tumor-associated lymphangiogenesis in a cell-specific manner.

  20. Expression of VEGF, b-FGF, and their receptors after injection of VEGF on ischemic heart muscle

    Institute of Scientific and Technical Information of China (English)

    XU Xun-yu; SUN Lin; HAN Tao; CHEN Wen-hong; CUI Yong; LI Yan

    2004-01-01

    Objective: To study the expression of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (b-FGF) and their receptors after injection of external VEGF on ischemic heart muscle and to investigate the mechanism of therapeutic myocardial angiogenesis of VEGF. Methods: Standard experimental pigs underwent placement of a left circumflex artery ameroid occluder. Six weeks later, the animals in the experimental group were treated with VEGF (20μg) by direct epicardial injection ( n = 8) and other animals in the control group did not receive any treatment ( n = 8).Four weeks after therapy, the animals were evaluated with regard to mRNA and protein expression of VEGF and b-FGF and their receptors by RT-PCR and Western blotting. Results: The mRNA expression of VEGF and b-FGF and their receptors by RT-PCR expressing as percentage of density ratio to the GAPDH control was increased in experimental group versus control group. The protein expression of VEGF and b-FGF and their receptors by Western blot expressing as percentage of density ratio to the Commassie Blue control was increased in experimental group versus control Group. Conclusion: Exogenous VEGF can induce the expression of endogenous VEGF, b-FGF, and their receptors; b-FGF may play a role in the angiogenesis of VEGF.

  1. Determination of sodium cromoglycate in human plasma by liquid chromatography with tandem mass.

    Science.gov (United States)

    Liu, Xiao-yan; Qu, Ting-ting; Wang, Ben-jie; Wei, Chun-min; Yuan, Gui-yan; Zhang, Rui; Guo, Rui-chen

    2008-09-01

    A sensitive and selective liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed and validated for the determination of sodium cromoglycate (SCG) in human plasma after a nasal dose of 10.4 mg sodium cromoglycate nasal spray, using pravastatin sodium as the internal standard. The method was validated over a linear range of 0.300-20.0 ng/mL. SCG and I.S. were extracted from 1.0 mL of heparinized plasma by C(18) solid-phase extraction cartridges using methanol as eluting solvent. The dried residue was reconstituted with 100 microL of mobile phase, and 10 microL was injected onto the LC-MS/MS system. Chromatographic separation was achieved on a C(18) column (250 x 4.6 mm i.d., 5 microm particle size) with a mobile phase of methanol-acetonitrile-water (containing 2 mmol/L ammonium acetate; 42.5:42.5:15, v/v/v) at a flow rate of 0.4 mL/min. The analytes were detected with a triple quad LC-MS/MS using ESI with positive ionization. Ions monitored in the multiple reaction monitoring mode were m/z 469.0 (precursor ion) to m/z 245.0 (product ion) for SCG and m/z 447.2 (precursor ion) to m/z327.1 (product ion) for pravastatin sodium (internal standard) The average recovery of SCG from human plasma was 94.88% and the lower limit of quantitation was 0.3 ng/mL. Results from a 3-day validation study demonstrated excellent precision and accuracy across the calibration range of 0.3-20 ng/mL. The method was successfully applied to the pharmacokinetic study of SCG in healthy Chinese volunteers.

  2. High Performance Liquid Chromatographic Assay for the Simultaneous Determination of Posaconazole and Vincristine in Rat Plasma

    Directory of Open Access Journals (Sweden)

    Hadeel A. Khalil

    2015-01-01

    Full Text Available Purpose. Developing a validated HPLC-DAD method for simultaneous determination of posaconazole (PSZ and vincristine (VCR in rat plasma. Methods. PSZ, VCR, and itraconazole (ITZ were extracted from 200 μL plasma using diethyl ether in the presence of 0.1 M sodium hydroxide solution. The organic layer was evaporated in vacuo and dried residue was reconstituted and injected through HC-C18 (4.6 × 250 mm, 5 μm column. In the mobile phase, acetonitrile and 0.015 M potassium dihydrogen orthophosphate (30 : 70 to 80 : 20, linear gradient over 7 minutes pumped at 1.5 mL/min. VCR and PSZ were measured at 220 and 262 nm, respectively. Two Sprague Dawley rats were orally dosed PSZ followed by iv dosing of VCR and serial blood sampling was performed. Results. VCR, PSZ, and ITZ were successfully separated within 11 min. Calibration curves were linear over the range of 50–5000 ng/mL for both drugs. The CV% and % error of the mean were ≤18% and limit of quantitation was 50 ng/mL for both drugs. Rat plasma concentrations of PSZ and VCR were simultaneously measured up to 72 h and their calculated pharmacokinetics parameters were comparable to the literature. Conclusion. The assay was validated as per ICH guidelines and is appropriate for pharmacokinetics drug-drug interaction studies.

  3. Validated enzyme-linked immunosorbent assay for determination of rosuvastatin in plasma at picogram level.

    Science.gov (United States)

    Darwish, Ibrahim A; Al-Obaid, Abdul-Rahman M; Al-Malaq, Hamoud A

    2013-05-01

    In this study, a highly sensitive enzyme-linked immunosorbent assay (ELISA) has been developed and validated for the determination of rosuvastatin (ROS) in plasma samples at picogram level. The assay employed a polyclonal antibody that specifically recognizes ROS with high affinity, and ROS conjugate of bovine serum albumin (ROS-BSA) immobilized onto microplate wells as a solid phase. The assay involved a competitive binding reaction between ROS, in plasma sample, and the immobilized ROS-BSA for the binding sites on a limited amount of the anti-ROS antibody. The bound anti-ROS antibody was quantified with horseradish peroxidase-labelled second anti-rabbit IgG antibody (HRP-IgG) and 3,3`,5,5`-tetramethylbenzidine (TMB) as a substrate for the peroxidase enzyme. The concentration of ROS in the sample was quantified by its ability to inhibit the binding of the anti-ROS antibody to the immobilized ROS-BSA and subsequently the colour intensity in the assay wells. The assay limit of detection was 25 pg ml(-1) and the effective working range at relative standard deviations (RSD) of ≤ 5% was 40-2000 pg ml(-1). Analytical recovery of ROS from spiked plasma was 96.2 - 104.8 ± 2.12 - 5.42%. The precision of the assay was satisfactory; RSD was 2.47 - 4.46 and 3.24 - 5.27% for the intra- and inter-assay precision, respectively. The analytical procedure is convenient, and one can analyze ~ 200 samples per working day, facilitating the processing of large-number batch of samples. The proposed ELISA has a great value in routine analysis of ROS for its pharmacokinetic studies.

  4. Determination of ammonium and organic bound nitrogen by inductively coupled plasma emission spectroscopy.

    Science.gov (United States)

    Jaber, A M Y; Mehanna, N A; Sultan, S M

    2009-06-15

    The continuous flow sample introduction technique with a hydride generator system in conjunction with an inductively coupled plasma emission spectrometer (ICP-AES-HG), is used in this study for quantitative determination of ammonium and organic bound nitrogen in aqueous and solid samples. Ammonia vapor released from ammonium salt after treatment with concentrated NaOH is transferred by argon to plasma for detection at 174.273 nm using axial argon plasma mode. The calibration curves were linear within a range of 25-1000 mg L(-1)N as ammonium molybdate with correlation coefficients of better than 0.99 and limits of detection of about 10-25mg L(-1)N. The percent recovery of N (25-500 mg L(-1)N) in soft (distilled) water and high salt content (1.7 mol L(-1) NaCl) matrices was found to be in the range of about 97-102% with %RSD in the range of 4.6-0.62. The sensitivity, limit of detection, and blank contribution from the atmospheric nitrogen, were tremendously improved in this method compared with the available ICP-AES spray chamber counterpart. Furthermore, the ICP-AES-HG method gave results for real samples (soil, fertilizer, waste water) containing about 50-1800 mg L(-1)N in good agreement with those obtained by the standard Kjeldahl method. No statistical differences at the 95% confidence level on applying the t-test were observed between the values obtained by the two methods. Thus, the ICP-AES-HG method is reliable and faster than the conventional tedious Kjeldahl method, superior to the ICP-AES spray chamber method, and almost free from matrix interference which is usually a critical factor in atomic emission spectroscopic techniques.

  5. Evaluation of an immunoassay for determination of plasma efavirenz concentrations in resource-limited settings

    Directory of Open Access Journals (Sweden)

    Alemseged Abdissa

    2014-06-01

    Full Text Available Introduction: Therapeutic drug monitoring (TDM may improve antiretroviral efficacy through adjustment of individual drug administration. This could result in reduced toxicity, prevent drug resistance, and aid management of drug–drug interactions. However, most measurement methods are too costly to be implemented in resource-limited settings. This study evaluated a commercially available immunoassay for measurement of plasma efavirenz. Methods: The immunoassay-based method was applied to measure efavirenz using a readily available Humastar 80 chemistry analyzer. We compared plasma efavirenz concentrations measured by the immunoassay with liquid chromatography tandem mass spectrometry (LC-MS/MS (reference method in 315 plasma samples collected from HIV patients on treatment. Concentrations were categorized as suboptimal4 µg/ml. Agreement between results of the methods was assessed via Bland-Altman plot and κ statistic values. Results: The median Interquartile range (IQR efavirenz concentration was 2.8 (1.9; 4.5 µg/ml measured by the LC–MS/MS method and 2.5 (1.8; 3.9 µg/ml by the immunoassay and the results were well correlated (ρ=0.94. The limits of agreement assessed by Bland–Altman plots were −2.54; 1.70 µg/ml. Although immunoassay underestimated high concentrations, it had good agreement for classification into low, normal or high concentrations (K=0.74. Conclusions: The immunoassay is a feasible alternative to determine efavirenz in areas with limited resources. The assay provides a reasonable approximation of efavirenz concentration in the majority of samples with a tendency to underestimate high concentrations. Agreement between tests evaluated in this study was clinically satisfactory for identification of low, normal and high efavirenz concentrations.

  6. Determination of triapine, a ribonucleotide reductase inhibitor, in human plasma by liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Feng, Ye; Kunos, Charles A; Xu, Yan

    2015-09-01

    Triapine is an inhibitor of ribonucleotide reductase (RNR). Studies have shown that triapine significantly decreases the activity of RNR and enhanced the radiation-mediated cytotoxicity in cervical and colon cancer. In this work, we have developed and validated a selective and sensitive LC-MS/MS method for the determination of triapine in human plasma. In this method, 2-[(3-fluoro-2-pyridinyl)methylene] hydrazinecarbothioamide (NSC 266749) was used as the internal standard (IS); plasma samples were prepared by deproteinization with acetonitrile; tripaine and the IS were separated on a Waters Xbridge Shield RP18 column (3.5 µm; 2.1 × 50 mm) using a mobile phase containing 25.0% methanol and 75.0% ammonium bicarbonate buffer (10.0 mM, pH 8.50; v/v); column eluate was monitored by positive turbo-ionspray tandem mass spectrometry; and quantitation of triapine was carried out in multiple-reaction-monitoring mode. The method developed had a linear calibration range of 0.250-50.0 ng/mL with correlation coefficient of 0.999 for triapine in human plasma. The IS-normalized recovery and the IS-normalized matrix factor of triapine were 101-104% and 0.89-1.05, respectively. The accuracy expressed as percentage error and precision expressed as coefficient of variation were ≤±6 and ≤8%, respectively. The validated LC-MS/MS method was applied to the measurement of triapine in patient samples from a phase I clinical trial.

  7. Liquid Chromatography-Tandem Mass Spectrometric Assay for Determination of Stavudine in Human Plasma

    Directory of Open Access Journals (Sweden)

    Fengdan Jin

    2014-01-01

    Full Text Available A LC-MS/MS method for determination of stavudine in human plasma was established and validated, and it was applied to the pharmaceutical formulations bioequivalence study. 0.5 mL plasma sample was extracted by liquid-liquid extraction. Stavudine was detected by a LC-MS/MS system. The pharmacokinetic parameters of stavudine in different formulations were calculated by noncompartment model statistics. The method was linear over the concentration ranges 5.00–1000 ng/mL in plasma. The intra- and interassay relative standard deviation (RSD was <10%. The average accuracies for the assay at three concentrations (5.00, 80.0, and 900 ng/mL were from 100.2% to 102.5%. Pharmacokinetic parameters of stavudine reference formulation were obtained as follows: Tmax was 0.6±0.2 h, Cmax was 480.7±150.9 g/L, t1/2 was 1.7±0.4 h, and AUC0-t was 872.8±227.8 g·h/L, and pharmacokinetic parameters of stavudine test formulation were obtained as follows: Tmax was 0.5±0.2 h, Cmax was 537.5±178.5 g/L, t1/2 was 1.7±0.3 h, and AUC0-t was (914.1±284.5 g·h/L. Calculated with AUC0-t, the bioavailability of two formulations was 105.0%.

  8. Local controlled release of VEGF and PDGF from a combined brushite-chitosan system enhances bone regeneration.

    Science.gov (United States)

    De la Riva, Beatriz; Sánchez, Esther; Hernández, Antonio; Reyes, Ricardo; Tamimi, Faleh; López-Cabarcos, Enrique; Delgado, Araceli; Evora, Carmen

    2010-04-02

    The two growth factors VEGF and PDGF are involved in the process of bone regeneration. For this reason, we developed a brushite-chitosan system which controls the release kinetics of incorporated VEGF and PDGF to enhance bone healing. PDGF (250 ng) was incorporated in the liquid phase. Alginate microsphere-encapsulated VEGF (350 ng) was pre-included in small cylindrical chitosan sponges. VEGF and PDGF release kinetics and tissue distribution were determined using iodinated ((125)I) growth factor. In vivo, PDGF was more rapidly delivered from these systems implanted in rabbit femurs than VEGF. 80% of PDGF was released by the end of two weeks while only 70% of VEGF was delivered after a period of three weeks. Both GFs released from the brushite-chitosan constructs remained located around the implantation site (5 cm) with negligible systemic exposure. A PDGF bone peak concentration of approximately 5 ng/g was achieved on the 4th day. Thereafter, PDGF concentrations stayed higher than 2 ng/g during the first week. These scaffolds also provided a local VEGF bone concentration above 3 ng/g during a total of 4weeks, with a peak concentration of 5.5 ng/g on the 7th day. The present work demonstrates that our brushite-chitosan system is capable of controlling the release rate and localization of both GFs within a bone defect. The effect on bone formation was considerably enhanced with PDGF loaded brushite-chitosan scaffolds as well as with the PDGF/VEGF combination.

  9. Functional relevance of the switch of VEGF receptors/co-receptors during peritoneal dialysis-induced mesothelial to mesenchymal transition.

    Directory of Open Access Journals (Sweden)

    María Luisa Pérez-Lozano

    Full Text Available Vascular endothelial growth factor (VEGF is up-regulated during mesothelial to mesenchymal transition (MMT and has been associated with peritoneal membrane dysfunction in peritoneal dialysis (PD patients. It has been shown that normal and malignant mesothelial cells (MCs express VEGF receptors (VEGFRs and co-receptors and that VEGF is an autocrine growth factor for mesothelioma. Hence, we evaluated the expression patterns and the functional relevance of the VEGF/VEGFRs/co-receptors axis during the mesenchymal conversion of MCs induced by peritoneal dialysis. Omentum-derived MCs treated with TGF-β1 plus IL-1β (in vitro MMT and PD effluent-derived MCs with non-epithelioid phenotype (ex vivo MMT showed down-regulated expression of the two main receptors Flt-1/VEGFR-1 and KDR/VEGFR-2, whereas the co-receptor neuropilin-1 (Nrp-1 was up-regulated. The expression of the Nrp-1 ligand semaphorin-3A (Sema-3A, a functional VEGF competitor, was repressed throughout the MMT process. These expression pattern changes were accompanied by a reduction of the proliferation capacity and by a parallel induction of the invasive capacity of MCs that had undergone an in vitro or ex vivo MMT. Treatment with neutralizing anti-VEGF or anti-Nrp-1 antibodies showed that these molecules played a relevant role in cellular proliferation only in naïve omentum-derived MCs. Conversely, treatment with these blocking antibodies, as well as with recombinant Sema-3A, indicated that the switched VEGF/VEGFRs/co-receptors axis drove the enhanced invasion capacity of MCs undergoing MMT. In conclusion, the expression patterns of VEGFRs and co-receptors change in MCs during MMT, which in turn would determine their behaviour in terms of proliferation and invasion in response to VEGF.

  10. New Spectrofluorimetric Method with Enhanced Sensitivity for Determination of Paroxetine in Dosage Forms and Plasma

    Directory of Open Access Journals (Sweden)

    Ibrahim A. Darwish

    2008-01-01

    Full Text Available New simple spectrofluorimetric method with enhanced sensitivity has been developed and validated for the determination of the antidepressant paroxetine (PXT in its dosage forms and plasma. The method was based on nucleophilic substitution reaction of PXT with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole in an alkaline medium (pH 8 to form a highly fluorescent derivative that was measured at 545 nm after excitation at 490 nm. The factors affecting the reaction was carefully studied and optimized. The kinetics of the reaction was investigated, and the reaction mechanism was presented. Under the optimized conditions, linear relationship with good correlation coefficient (0.9993 was found between the fluorescence intensity and PXT concentration in the range of 80–800 ng ml−1. The limits of detection and quantitation for the method were 25 and 77 ng ml−1, respectively. The precision of the method was satisfactory; the values of relative standard deviations did not exceed 3%. The proposed method was successfully applied to the determination of PXT in its pharmaceutical tablets with good accuracy; the recovery values were 100.2 ± 1.61%. The results obtained by the proposed method were comparable with those obtained by the official method. The proposed method is superior to the previously reported spectrofluorimetric method for determination of PXT in terms of its higher sensitivity and wider linear range. The high sensitivity of the method allowed its successful application to the analysis of PXT in spiked human plasma. The proposed method is practical and valuable for its routine application in quality control and clinical laboratories for analysis of PXT.

  11. The Schlemm’s canal is a VEGF-C/VEGFR-3–responsive lymphatic-like vessel

    Science.gov (United States)

    Aspelund, Aleksanteri; Tammela, Tuomas; Antila, Salli; Nurmi, Harri; Leppänen, Veli-Matti; Zarkada, Georgia; Stanczuk, Lukas; Francois, Mathias; Mäkinen, Taija; Saharinen, Pipsa; Immonen, Ilkka; Alitalo, Kari

    2014-01-01

    In glaucoma, aqueous outflow into the Schlemm’s canal (SC) is obstructed. Despite striking structural and functional similarities with the lymphatic vascular system, it is unknown whether the SC is a blood or lymphatic vessel. Here, we demonstrated the expression of lymphatic endothelial cell markers by the SC in murine and zebrafish models as well as in human eye tissue. The initial stages of SC development involved induction of the transcription factor PROX1 and the lymphangiogenic receptor tyrosine kinase VEGFR-3 in venous endothelial cells in postnatal mice. Using gene deletion and function-blocking antibodies in mice, we determined that the lymphangiogenic growth factor VEGF-C and its receptor, VEGFR-3, are essential for SC development. Delivery of VEGF-C into the adult eye resulted in sprouting, proliferation, and growth of SC endothelial cells, whereas VEGF-A obliterated the aqueous outflow system. Furthermore, a single injection of recombinant VEGF-C induced SC growth and was associated with trend toward a sustained decrease in intraocular pressure in adult mice. These results reveal the evolutionary conservation of the lymphatic-like phenotype of the SC, implicate VEGF-C and VEGFR-3 as critical regulators of SC lymphangiogenesis, and provide a basis for further studies on therapeutic manipulation of the SC with VEGF-C in glaucoma treatment. PMID:25061878

  12. Lithium decreases VEGF mRNA expression in leukocytes of healthy subjects and patients with bipolar disorder.

    Science.gov (United States)

    Kikuchi, Kumiko; Iga, Jun-ichi; Tayoshi, Sumiko; Nakataki, Masahito; Watanabe, Shinya; Numata, Shusuke; Ohmori, Tetsuro

    2011-01-01

    Vascular endothelial growth factor (VEGF) is thought to be involved in the pathophysiology of mood disorders and the target of antidepressants. The aim of this study was to elucidate molecular effects of lithium on VEGF expression by using leukocytes of healthy subjects and patients with bipolar disorder. Eight healthy male subjects participated in the first study. Lithium was prescribed for 2 weeks, enough to reach therapeutic serum concentration. Leukocyte counts and serum lithium concentrations were determined at baseline, at 1- and 2-week medication, and at 2 weeks after stopping medication. VEGF mRNA levels were also examined in nine lithium-treated bipolar patients and healthy controls in the second study. In the first study, leukocyte counts were significantly increased at 2 weeks compared with those at baseline and were normalized after 2 weeks. VEGF mRNA levels were significantly decreased at 2 weeks and after 2 weeks compared with those at baseline. Consistent with the first study, VEGF mRNA levels were significantly decreased in the lithium-treated bipolar patients compared with healthy controls. Our investigation suggests that VEGF mRNA expression may be useful as a peripheral marker of the effects of lithium. Copyright © 2011 John Wiley & Sons, Ltd.

  13. Determination of selenoprotein P in human plasma by solid phase extraction and inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Bendahl, L.; Sidenius, U.; Gammelgaard, Bente

    2000-01-01

    measured by inductively coupled plasma mass spectrometry (ICP-MS) monitoring the Se-82 isotope. Linear response was observed in the concentration range 0.3-70.8 mu g/l selenium as selenoprotein P with a correlation coefficient of 0.9994. The precision expressed as relative standard deviation was better...

  14. [Determination of chlorine in gasoline by inductively coupled plasma atomic emission spectrometry].

    Science.gov (United States)

    Zhao, Yan; Chen, Xiao-yan; Xu, Dong-yu; Zhang, Shi-yuan; Chen, Ze-yong

    2014-12-01

    A new method was studied for the analysis of chlorine in gasoline by inductively coupled plasma atomic emission spectrometry (ICP-AES). Samples werediluted 1+4(φ) with kerosene. The intense spectral line for chlorine (134.724 nm) was used. In order to eliminate carbon and maintain stable plasma, small amounts of oxygen (0.050 L · min(-1)) were added to the auxiliary gas. The instrumental main condition was optimized in terms of effects of generator power, nebulizer gas flow, auxiliary gas flow, and oxygen flow on SBR for chlorine. Standard addition method was used to compensate matrix effect and signal drift. The recovery for spiking gasoline samples and the limit of detection were in the range of 96.6%~103.9% and 0.27 mg · L(-1) respectively. The relative standard deviation (RSD) was between 1.57% and 4.49%. Compared with microcoulometry, the analysis results of organic chlorine were basically the same. Moreover, chlorine content, including organic chlorine and inorganic chloride was determined by ICP-AES. The proposed method had the advantages of simplicity, speediness and sensitivity, and expanded the ICP-AES application in non-metals especially halogen elements. It can be used for the analysis of chlorine in gasoline and provides technical support for quality evaluation.

  15. Monitoring trace metals in urban aerosols from Buenos Aires city. Determination by plasma-based techniques.

    Science.gov (United States)

    Smichowski, Patricia; Gómez, Dario R; Dawidowski, Laura E; Giné, María Fernanda; Bellato, Ana Claudia Sánchez; Reich, Silvia L

    2004-04-01

    A study was undertaken, within the framework of a 3 years national project, to assess the content of 13 elements in airborne particulate matter collected in representative zones of the metropolitan area of Buenos Aires. The sampling strategy followed consisted in collecting simultaneously 67 samples of PM10 particulate matter in 9 sampling sites covering an area of about 30 km2 during one week. The collection was performed on ash-free fibre-glass filters using high volume samplers. A combination of aqua regia and perchloric acid was used for leaching metals from filters. Key elements, namely Al, Ca, Cu, Fe, Mn, Mo, Ni, Pb, S, Sb, Sn, Zn and Zr, were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES) and inductively coupled plasma-mass spectrometry (ICP-MS) at micro g g(-1) and ng g(-1) levels. Analyte concentration varied from 130 ng g(-1)(Mo) to over 30%(Ca). Multivariate statistical analysis was performed on the data set including the measured elemental compositions for the monitored period. The atmospheric concentration found for Pb confirms the decreasing levels of this element since the introduction of unleaded gasoline in 1995: 88 ng m(-3)(2001) gas imply low emissions of this element from combustion activities. To the best of our knowledge, S concentrations are reported for the first time for this city.

  16. Determination of strychnine and brucine in rat plasma using liquid chromatography electrospray ionization mass spectrometry.

    Science.gov (United States)

    Xu, Yanyan; Si, Duanyun; Liu, Changxiao

    2009-02-20

    A simple, sensitive and selective liquid chromatography-electrospray mass spectrometric (LC-ESI-MS) method was developed and validated for simultaneous determination of strychnine and brucine in rat plasma, using tacrine as the internal standard (IS). Sample preparation involved a liquid-liquid extraction of the analytes with n-hexane, dichloromethane and isopropanol (65:30:5, v/v/v) from 0.1mL of plasma. Chromatographic separation was carried out on a Waters C(18) column using a mobile phase of methanol-20mM ammonium formate-formic acid (32:68:0.68, v/v/v). Positive selected ion monitoring mode was used for detection of strychnine, brucine and the IS at m/z 335.2, m/z 395.2 and m/z 199.2, respectively. Linearity was obtained over the concentration range of 0.5-500ng/mL for strychnine and 0.1-100ng/mL for brucine. The lower limit of quantification was 0.5ng/mL and 0.1ng/mL for strychnine and brucine, respectively. The intra- and inter-day precision for both strychnine and brucine was less than 7.74%, and accuracy ranged from -4.38% to 2.21% at all QC levels. The method has been successfully applied to a pharmacokinetic study of processed Semen Strychni after oral administration to rats.

  17. Determination of piroxicam from rat articular tissue and plasma based on LC-MS/MS.

    Science.gov (United States)

    Kim, Han Sol; Cho, Ha Ra; Ho, Myoung Jin; Kang, Myung Joo; Choi, Yong Seok

    2016-12-01

    Osteoarthritis (OA) is the most common type of arthritis. To manage OA, in general, oral administration of non-steroidal anti-inflammatory drugs (NSAIDs) is used. Recently, the analgesic and anti-inflammatory efficacy of piroxicam (PX), a long-acting NSAID, by intra-articular (IA) administration in OA was reported, and the possibility that PX is distributed in articular tissues at a certain concentration was raised. Thus, herein, novel LC-MS/MS methods to detect PX in rat articular tissue and plasma are presented. For articular tissue, solvent extraction with acetonitrile for 12 h was employed and a protein precipitation method was used for the preparation of a plasma sample. The developed methods were validated by following the FDA guidelines, and the validated methods were successfully applied to a PK study of IA PX. The present study presents, to our knowledge, the first method of determining a drug in articular tissue. Additionally, the level of PX in articular tissue after IA PX administration was experimentally confirmed for the first time using the present methods. Therefore, the present methods provide a new direction for in vivo evaluation for IA PX formulations and contribute to the development of alternative IA PX formulations with better effects for the treatment of OA.

  18. Determination of additives in PVC material by UV laser ablation inductively coupled plasma atomic emission spectrometry

    Science.gov (United States)

    Hemmerlin, M.; Mermet, J. M.; Bertucci, M.; Zydowicz, P.

    1997-04-01

    UV laser ablation inductively coupled plasma atomic emission spectrometry (LA-ICP-AES) has been applied to the direct determination of additives in solid poly(vinyl chloride) materials. A Nd:YAG laser, operating at its fourth harmonic (266 nm), was used with a beam masking device, in the most reproducible conditions, to introduce solid particles into the plasma torch of a simultaneous ICP-AES system. Emphasis was placed on both precision and accuracy in the analysis of PVC materials by LA-ICP-AES. A series of six in-house PVC reference materials was prepared by incorporating several additives in increasing concentrations. Three alternative methods were evaluated to certify the amount of incorporated elements: ICP-AES with sample dissolution, NAA and XRF. Satisfactory results and good agreement were obtained for seven elements (Al, Ca, Cd, Mg, Sb, Sn and Ti) among the ten incorporated. Sample homogeneity appeared to be satisfactory, and calibration graphs obtained by LA-ICP-AES for several elements are presented. Finally, the performance of the technique in terms of repeatability (1.6-5%), reproducibility (2-5%), and limits of detection was investigated.

  19. DETERMINATION OF PLASMA LEVELS OF UREA AND CREATININE IN PANTANAL HORSES POCONÉ REGION - MT

    Directory of Open Access Journals (Sweden)

    M. R. Guazina

    2016-09-01

    Full Text Available This study aimed to determine the plasma levels of urea and creatinine, besides evaluating the influence of sex and age factors on these substances in Pantaneiros horses, animals of high economic and social importance in the Pantanal. In Poconé-MT region, 80 animals were used, which were divided into four groups: Group 1: male foals (n= 20, aged 8 months and 2 years, Group 2: female foals (n= 20, aged 8 months and 2 years, Group 3: adult males (n= 20, aged from 3 years, Group 4: adult females (n= 20, aged from 3 years. All animals were classified as healthy after clinical examinations, as well as serum negativity for Equine Infectious Anemia (EIA. Blood samples for subsequent laboratory analysis were taken from the jugular vein. The mean values of urea and creatinine found for Pantaneiros horses were similar to other breeds of horses and did not vary influenced by the sexual factor, however plasma levels of creatinine increased with the age

  20. [Simultaneous determination of gestodene, etonogestrel and ethinylestradiol in plasma by LC-MS/MS following derivatization].

    Science.gov (United States)

    Liu, Xiao-Fen; Ding, Cun-Gang; Ge, Qing-Hua; Zhou, Zhen; Zhi, Xiao-Jin

    2010-01-01

    To establish a sensitive and specific method for simultaneous determination of gestodene, etonogestrel and ethinylestradiol in plasma by LC-MS/MS, plasma samples were extracted and derivatized before injection. An ESI ion source was used and operated in the positive ion mode with multiple reaction monitoring (MRM). Norgestrel was chosen as internal standard and performed on a C18 (100 mm x 2.1 mm, 5 microm) column. The concentrations of gestodene, etonogestrel and ethinylestradiol were measured, using step-gradient mobile phase and step-gradient flow rate. The method was validated over the concentration range of 0.1-20 ng x mL(-1) for gestodene and etonogestrel and 0.01-2 ng x mL(-1) for ethinylestradiol, and showed excellent linearity. The intra- and inter-assay accuracy and precision were below 10.0% and recovery was 93.6%-110.9% over the three concentration levels evaluated. The method was applied in pharmacokinetic study of the compound gestodene patch and the compound etonogestrel patch in rabbits. The LC-MS/MS method was selective, accurate and sensitive, especially the LOQ were 100 pg x mL(-1) for gestodene and etonogestrel and 10 pg x mL(-1) for ethinylestradiol. The method was successfully applied in pharmacokinetic study for contraceptives.

  1. Determination of mycophenolic acid in human plasma by ultra performance liquid chromatography tandem mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    Vivek Upadhyay; Vikas Trivedi; Gaurang Shah; Manish Yadav; Pranav S. Shrivastav

    2014-01-01

    A simple, sensitive and high throughput ultra performance liquid chromatography tandem mass spectrometry method has been developed for the determination of mycophenolic acid in human plasma. The method involved simple protein precipitation of MPA along with its deuterated analog as an internal standard (IS) from 50 mL of human plasma. The chromatographic analysis was done on Acquity UPLC C18 (100mm*2.1mm,1.7mm) column under isocratic conditions using acetonitrile and 10 mM ammonium formate, pH 3.00 (75:25, v/v) as the mobile phase. A triple quadrupole mass spectrometer operating in the positive ionization mode was used for quantitation. In-source conversion of mycophenolic glucuronide metabolite to the parent drug was selectively controlled by suitable optimization of cone voltage, cone gas flow and desolvation temperature. The method was validated over a wide concentration range of 15–15000 ng/mL. The mean extraction recovery for the analyte and IS was 495%. Matrix effect expressed as matrix factors ranged from 0.97 to 1.02. The method was successfully applied to support a bioequivalence study of 500 mg mycophenolate mofetil tablet in 72 healthy subjects.

  2. The self-consistent determination of HF electroconductivity of strongly coupled plasmas

    CERN Document Server

    Sreckovic, V A; Ignjatovic, Lj M; Mihajlov, A A; 10.1016/j.physleta.2009.11.073

    2012-01-01

    Here is presented the calculation of the dynamic electrical conductivity of fully ionized, strongly coupled plasmas as a function of the external electric field frequency $\\omega$. The calculations are based on the the formula for the energy-dependent collision frequency which is determined by means of the Green function theory methods, as a sum over the Matsubara frequencies. The domain of extremely high electron density: $10^{21}\\leq n_{e}\\leq 10^{24} \\textrm{cm}^{-3}$, and for the temperature varying from $10 \\textrm{kK}$ to $1.000 \\textrm{kK}$ was examined. The real and imaginary parts of the conductivity for every electron density are presented in the generalized Drude-like form as a two-parameter function of the frequency $\\omega$ in the region $0 < \\omega < 0.5\\omega_{p}$, where $\\omega_{p}$ is the plasma frequency. A good agreement between the obtained results and the existing theoretical and computing simulation data is shown.

  3. Coronal magnetic field and the plasma beta determined from radio and multiple satellite observations

    CERN Document Server

    Iwai, Kazumasa; Nozawa, Satoshi; Takahashi, Takuya; Sawada, Shinpei; Kitagawa, Jun; Miyawaki, Shun; Kashiwagi, Hirotaka

    2014-01-01

    We derived the coronal magnetic field, plasma density, and temperature from the observation of polarization and intensity of radio thermal free-free emission using the Nobeyama Radioheliograph (NoRH) and extreme ultraviolet (EUV) observations. We observed a post-flare loop on the west limb 11 April 2013. The line-of-sight magnetic field was derived from the circularly polarized free-free emission observed by NoRH. The emission measure and temperature were derived from the Atmospheric Imaging Assembly (AIA) onboard Solar Dynamics Observatory (SDO). The derived temperature was used to estimate the emission measure from the NoRH radio free-free emission observations. The derived density from NoRH was larger than that determined using AIA, which can be explained by the fact that the low temperature plasma is not within the temperature coverage of the AIA filters used in this study. We also discuss the other observation of the post-flare loops by the EUV Imager onboard the Solar Terrestrial Relations Observatory (...

  4. Plasma Membrane Protein Ubiquitylation and Degradation as Determinants of Positional Growth in Plants

    Institute of Scientific and Technical Information of China (English)

    Barbara Korbei; Christian Luschnig

    2013-01-01

    Being sessile organisms, plants evolved an unparalleled plasticity in their post-embryonic development, allowing them to adapt and fine-tune their vital parameters to an ever-changing environment. Cross-talk between plants and their environment requires tight regulation of information exchange at the plasma membrane (PM). Plasma membrane proteins mediate such communication, by sensing variations in nutrient availability, external cues as well as by controlled solute transport across the membrane border. Localiza-tion and steady-state levels are essential for PM protein function and ongoing research identified cis- and trans-acting determinants, involved in control of plant PM protein localization and turnover. In this overview, we summarize recent progress in our understanding of plant PM protein sorting and degradation via ubiquitylation, a post-translational and reversible modification of proteins. We highlight characterized components of the machinery involved in sorting of ubiquitylated PM proteins and discuss consequences of protein ubiquitylation on fate of selected PM proteins. Specifically, we focus on the role of ubiquitylation and PM protein degradation in the regulation of polar auxin transport (PAT). We combine this regulatory circuit with further aspects of PM protein sorting control, to address the interplay of events that might control PAT and polarized growth in higher plants.

  5. Determination and pharmacokinetic studies of arecoline in dog plasma by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Li, Bing; Zhou, Xu-Zheng; Li, Jian-Yong; Yang, Ya-Jun; Niu, Jian-Rong; Wei, Xiao-Juan; Liu, Xi-Wang; Li, Jin-Shan; Zhang, Ji-Yu

    2014-10-15

    A rapid and sensitive high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the determination of arecoline concentration in dog plasma. Plasma sample was prepared by protein precipitation using n-hexane (containing 1% isoamyl alcohol) with β-pinene as an internal standard. Chromatographic separation was achieved on an Agilent C18 column (4.6×75mm, 3.5μm) using methanol: 5mM ammonium acetate as the mobile phase with isocratic elution. Mass detection was carried out using positive electrospray ionization in multiple reaction monitoring mode. The calibration curve for arecoline was linear over a concentration range of 2-500ng/mL. The intra-day and inter-day accuracy and precision were within the acceptable limits of ±10% at all concentrations. In summary, the LC-MS/MS method described herein was fully validated and successfully applied to the pharmacokinetic study of arecoline hydrobromide tablets in dogs after oral administration. Copyright © 2014. Published by Elsevier B.V.

  6. Determination of the neutral oxygen atom density in a plasma reactor loaded with metal samples

    Energy Technology Data Exchange (ETDEWEB)

    Mozetic, Miran; Cvelbar, Uros [Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia)], E-mail: miran.mozetic@ijs.si

    2009-08-15

    The density of neutral oxygen atoms was determined during processing of metal samples in a plasma reactor. The reactor was a Pyrex tube with an inner diameter of 11 cm and a length of 30 cm. Plasma was created by an inductively coupled radiofrequency generator operating at a frequency of 27.12 MHz and output power up to 500 W. The O density was measured at the edge of the glass tube with a copper fiber optics catalytic probe. The O atom density in the empty tube depended on pressure and was between 4 and 7 x 10{sup 21} m{sup -3}. The maximum O density was at a pressure of about 150 Pa, while the dissociation fraction of O{sub 2} molecules was maximal at the lowest pressure and decreased with increasing pressure. At about 300 Pa it dropped below 10%. The measurements were repeated in the chamber loaded with different metallic samples. In these cases, the density of oxygen atoms was lower than that in the empty chamber. The results were explained by a drain of O atoms caused by heterogeneous recombination on the samples.

  7. Determination of mycophenolic acid in human plasma by ultra performance liquid chromatography tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Vivek Upadhyay

    2014-06-01

    Full Text Available A simple, sensitive and high throughput ultra performance liquid chromatography tandem mass spectrometry method has been developed for the determination of mycophenolic acid in human plasma. The method involved simple protein precipitation of MPA along with its deuterated analog as an internal standard (IS from 50 µL of human plasma. The chromatographic analysis was done on Acquity UPLC C18 (100 mm×2.1 mm, 1.7 µm column under isocratic conditions using acetonitrile and 10 mM ammonium formate, pH 3.00 (75:25, v/v as the mobile phase. A triple quadrupole mass spectrometer operating in the positive ionization mode was used for quantitation. In-source conversion of mycophenolic glucuronide metabolite to the parent drug was selectively controlled by suitable optimization of cone voltage, cone gas flow and desolvation temperature. The method was validated over a wide concentration range of 15–15000 ng/mL. The mean extraction recovery for the analyte and IS was >95%. Matrix effect expressed as matrix factors ranged from 0.97 to 1.02. The method was successfully applied to support a bioequivalence study of 500 mg mycophenolate mofetil tablet in 72 healthy subjects.

  8. Determination by high-performance liquid chromatography of phenylbutazone in samples of plasma from fighting bulls.

    Science.gov (United States)

    Marti, M I González; Sánchez, González C I; Jiménez, Hernández; Cachán, García; Castro, de Cabo M J; Cuadrado, A L Garzón

    2002-03-25

    The purpose of this study was to investigate the possible presence of phenylbutazone in plasma samples from fighting bulls killed in 2nd and 3rd category bullrings in the province of Salamanca (Spain) in 1998, 1999 and 2000. For quantitative and qualitative determination, a high-performance liquid chromatograph was used, equipped with a photodiode-array detector and setting wavelengths at 240, 254 and 284 nm. The mobile phase optimized for the simultaneous detection of dexamethasone, betamethasone, flunixin and phenylbutazone, was 0.01 M acetic acid pH 3 in methanol (35:65 v/v) at a flow rate of 1 ml/min. Plasma samples were deproteinized with 400 microl of acetonitrile and 20 microl of the supernatant were injected directly into the chromatographic system equipped with a Lichrospher 60 RP select B column and guard column. For the quantitative analysis, standard calibration curves were made in a concentration range between 0.25 and 30 microg/ml, using betamethasone as internal standard. The retention time of phenylbutazone was 8.7 +/- 0.2 min and recovery was 83%. The detection and quantification limits were 0.016 and 0.029, respectively for A=240 nm. The study results show that 17 of the 74 samples analyzed in 1998, 18 of those from 1999 and 10 of those from 2000 were positive for phenylbutazone.

  9. Direct injection HPLC method for the determination of selected benzodiazepines in plasma using a Hisep column.

    Science.gov (United States)

    Pistos, C; Stewart, James T

    2003-12-04

    A direct plasma injection HPLC method has been developed for the determination of selected benzodiazepines (nitrazepam, clobazam, oxazepam, lorazepam). The method uses an analytical hydrophobic shielded phase (Hisep) column equipped with a Hisep guard column, are easy to perform and requires 20 ul of a filtered plasma sample. The chromatographic run time is less than 15 min using a mobile phase of 15:85 v/v acetonitrile-0.18 M ammonium acetate pH 2.5. The method is good for 175 injections before replacement of the guard column. The method was linear in the range 0.5-18 ug ml(-1) (r>0.99, n=6) for the analytes with R.S.D. less than 10.82%. Interday and intraday variability were found to be less than 14%. The limits of detection and quantitation were 0.16 (s/n>3) and 0.5 ug ml(-1) (s/n>10), respectively, for each of the four benzodiazepines.

  10. VEGF Deficit is Involved in Endothelium Dysfunction in Preeclampsia

    Institute of Scientific and Technical Information of China (English)

    周琼; 刘海意; 乔福元; 吴媛媛; 徐京晶

    2010-01-01

    This study examined the association of expression of vascular endothelial growth factor(VEGF),a promoter of angiogenesis,with endothelium dysfunction in preeclampsia.The level of VEGF protein and mRNA in the placenta and peripheral blood samples of 30 preeclampsia patients and 30 normotensive pregnant women was measured by immunohistochemistry,real-time reverse transcriptase-polymerase chain reaction(RT-PCR) and enzyme-linked immunosorbent assay(ELISA),respectively.VEGF expression in the human umbilical vei...

  11. Anti-VEGF Cancer Therapy in Nephrology Practice

    Directory of Open Access Journals (Sweden)

    Hassan Izzedine

    2014-01-01

    Full Text Available Expanded clinical experience with the antivascular endothelial growth factor (VEGF agents has come with increasing recognition of their renal adverse effects. Although renal histology is rarely sought in antiangiogenic-treated cancer patients, kidney damage related to anti-VEGF is now established. Its manifestations include hypertension, proteinuria, and mainly glomerular thrombotic microangiopathy. Then, in nephrology practice, should we continue to perform kidney biopsy, and what should be done with the anti-VEGF agents in case of renal toxicity?

  12. Spectrophotometric determination of total proteins in blood plasma: a comparative study among dye-binding methods

    Directory of Open Access Journals (Sweden)

    Dimas Augusto Morozin Zaia

    2005-05-01

    Full Text Available A comparative study between the biuret method (standard method for total proteins and spectrophotometric methods using dyes (Bradford, 3',3",5',5"-tetrabromophenolphthalein ethyl ester-TBPEE, and erythrosin-B was carried out for the determination of total proteins in blood plasma from rats. Bradford method showed the highest sensitivity for proteins and biuret method showed the lowest. For all the methods, the absorbance for different proteins (BSA, casein, and egg albumin was measured and Bradford method showed the lowest variation of absorbance. The concentration of total protein obtained by using Bradford method was not statistically different (p>0.05 from concentration of total protein obtained by the biuret method. But in regard to erythrosin-B and TBPEE methods the concentrations of total protein were statistically different (pA determinação de proteínas totais em plasma sangüíneo é importante em diversas áreas de pesquisa. Um estudo comparativo entre o método de biureto (método padrão para proteínas totais e diversos métodos que utilizam corantes (Bradford, tetrabromofenolftaleína etil éster-TBPEE, e eritrosina-B foi realizado para a determinação de proteínas totais em plasma sangüíneo de ratos. O método de Bradford mostrou a maior sensibilidade para proteínas e o de biureto a menor. Para todos os métodos, as absorbâncias para diferentes proteínas (BSA, caseína, e ovoalbumina foram medidas e o método de Bradford mostrou a menor variação da absorbância. Utilizando o método de Bradford a concentração de proteínas totais obtida não foi estatisticamente diferente (p>0.05 daquela obtida pelo método do biureto. Porém, para os métodos da eritrosina-B e TBPEE as concentrações de proteínas totais foram estatisticamente diferentes (p<0.05 da obtida pelo método de biureto. Portanto o método de Bradford pode ser utilizado no lugar do método de biureto para a determinação de proteínas totais em plasma sangüíneo.

  13. Mapping of Fab-1:VEGF Interface Using Carboxyl Group Footprinting Mass Spectrometry

    Science.gov (United States)

    Wecksler, Aaron T.; Kalo, Matt S.; Deperalta, Galahad

    2015-12-01

    A proof-of-concept study was performed to demonstrate that carboxyl group footprinting, a relatively simple, bench-top method, has utility for first-pass analysis to determine epitope regions of therapeutic mAb:antigen complexes. The binding interface of vascular endothelial growth factor (VEGF) and the Fab portion of a neutralizing antibody (Fab-1) was analyzed using carboxyl group footprinting with glycine ethyl ester (GEE) labeling. Tryptic peptides involved in the binding interface between VEGF and Fab-1 were identified by determining the specific GEE-labeled residues that exhibited a reduction in the rate of labeling after complex formation. A significant reduction in the rate of GEE labeling was observed for E93 in the VEGF tryptic peptide V5, and D28 and E57 in the Fab-1 tryptic peptides HC2 and HC4, respectively. Results from the carboxyl group footprinting were compared with the binding interface identified from a previously characterized crystal structure (PDB: 1BJ1). All of these residues are located at the Fab-1:VEGF interface according to the crystal structure, demonstrating the potential utility of carboxyl group footprinting with GEE labeling for mapping epitopes.

  14. [VEGF gene expression in transfected human multipotent stromal cells].

    Science.gov (United States)

    Smirnikhina, S A; Lavrov, A V; Bochkov, N P

    2011-01-01

    Dynamics of VEGF gene expression in transfected multipotent stromal cells from adipose tissue was examined using electroporation and lipofection. Differences in the potency and dynamics of plasmid elimination (up to day 9) between cell cultures were observed. All cultures were divided into fast and slow plasmid-eliminating ones. Interculture differences in VEGF expression were detected. The possibility of a 5-6-fold increase of VEGF expression was shown. There were no differences in transfection potency, plasmid elimination dynamics, and VEGF expression after transfection by both nonviral methods.

  15. Genetic variations in VEGF and VEGFR2 and glioblastoma outcome

    DEFF Research Database (Denmark)

    Sjöström, S; Wibom, C; Andersson, U

    2010-01-01

    Vascular endothelial growth factor (VEGF) and its receptors (VEGFR) are central components in the development and progression of glioblastoma. To investigate if genetic variation in VEGF and VEGFR2 is associated with glioblastoma prognosis, we examined blood samples from 154 glioblastoma cases...... collected in Sweden and Denmark between 2000 and 2004. Seventeen tagging single nucleotide polymorphisms (SNPs) in VEGF and 27 in VEGFR2 were genotyped and analysed, covering 90% of the genetic variability within the genes. In VEGF, we found no SNPs associated with survival. In VEGFR2, we found two SNPs...

  16. Genetic variations in VEGF and VEGFR2 and glioblastoma outcome

    DEFF Research Database (Denmark)

    Sjöström, S; Wibom, C; Andersson, U

    2011-01-01

    Vascular endothelial growth factor (VEGF) and its receptors (VEGFR) are central components in the development and progression of glioblastoma. To investigate if genetic variation in VEGF and VEGFR2 is associated with glioblastoma prognosis, we examined blood samples from 154 glioblastoma cases...... collected in Sweden and Denmark between 2000 and 2004. Seventeen tagging single nucleotide polymorphisms (SNPs) in VEGF and 27 in VEGFR2 were genotyped and analysed, covering 90% of the genetic variability within the genes. In VEGF, we found no SNPs associated with survival. In VEGFR2, we found two SNPs...

  17. Rapid Determination of Isomeric Benzoylpaeoniflorin and Benzoylalbiflorin in Rat Plasma by LC-MS/MS Method

    Directory of Open Access Journals (Sweden)

    Chuanqi Zhou

    2017-01-01

    Full Text Available Benzoylpaeoniflorin (BP is a potential therapeutic agent against oxidative stress related Alzheimer’s disease. In this study, a more rapid, selective, and sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS method was developed to determine BP in rat plasma distinguishing with a monoterpene isomer, benzoylalbiflorin (BA. The method showed a linear response from 1 to 1000 ng/mL (r>0.9950. The precision of the interday and intraday ranged from 2.03 to 12.48% and the accuracy values ranged from −8.00 to 10.33%. Each running of the method could be finished in 4 minutes. The LC-MS/MS method was validated for specificity, linearity, precision, accuracy, recovery, and stability and was found to be acceptable for bioanalytical application. Finally, this fully validated method was successfully applied to a pharmacokinetic study in rats following oral administration.

  18. High-performance liquid chromatographic determination of vertilmicin in rat plasma using sensitive fluorometric derivatization.

    Science.gov (United States)

    Liu, Zhen; Sha, Yunfei; Huang, Taomin; Yang, Bei; Duan, Geng-Li

    2005-12-15

    A sensitive and reliable high-performance liquid chromatographic method was developed for the determination of vertilmicin in rat plasma. Derivatization with 9-fluorenylmethyl chloroformate (FMOC-Cl) followed by C(18) reversed-phase chromatography allowed the fluorimetric detection of vertilmicin. Optimal conditions for the derivatization of vertilmicin are described. The limit of quantification was 0.02 mg/L. The pharmacokinetics of vertilmicin was studied in 24 rats following intramuscular injection (i.m.) of different doses (4, 8, 16, 32 mg/kg of body weight). The pharmacokinetic parameter values were estimated by use of 3P97 program. In this study, we assessed the dose proportionality of vertilmicin after single intramuscular injection doses and obtained new information on the pharmacokinetics of the compound.

  19. DETERMINATION OF FLUCONAZOLE IN HUMAN PLASMA BY REVERSE PHASE HIGH PERFORMANCE LIQUID CHROMATOGRAPHY.

    Science.gov (United States)

    Safaei, Zahra; Alipour, Eskandar; Shafaati, Alireza; Zarghp, Afshin

    2015-01-01

    A rapid, simple and reproducible high performance liquid chromatographic method was developed and validated for determination of fluconazole in human plasma. The separation was performed on MZ C8 column (125 x 4 mm, 5 µm) using acetonitrile - potassium dihydrogen phosphate buffer (15 : 85, v/v), pH 3.0, as the mobile phase at a flow rate of 1.5 mL/min. The wavelength was set at 261 nm. The assay enables the measurement of fluconazole for therapeutic drug monitoring with a minimum quantification limit of 20 ng/mL. The method involves simple, protein precipitation procedure and analytical recovery was complete. The calibration curve was linear over the concentration range 0.1-4 µg/mL. The coefficients of variation for inter-day and intra-day assay were found to be less than 10%.

  20. Improved Cd determination in glasses by laser ablation inductively coupled plasma mass spectrometry using nitrogen as a matrix modifier

    Institute of Scientific and Technical Information of China (English)

    Qian Ni; Zhao Chu Hu; Zheng Yu Bao; Ya Feng Zhang

    2009-01-01

    The addition of 5-10 mL min-1 nitrogen to the central channel of plasma in Laser ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) increases the sensitivities of Cd by a factor of 3 and decreases oxide interferences by one order of magnitude, which allows the direct analysis of trace levels of Cd in glass samples. This simple method shows a great potential for the direct determination of Cd in various kinds of samples.

  1. Electron density in amplitude modulated microwave atmospheric plasma jet as determined from microwave interferometry and emission spectroscopy

    Science.gov (United States)

    Faltýnek, J.; Hnilica, J.; Kudrle, V.

    2017-01-01

    Time resolved electron density in an atmospheric pressure amplitude modulated microwave plasma jet is determined using the microwave interferometry method, refined by numerical modelling of the propagation of non-planar electromagnetic waves in the vicinity of a small diameter, dense collisional plasma filament. The results are compared to those from the Stark broadening of the {{\\text{H}}β} emission line. Both techniques show, both qualitatively and quantitatively, a similar temporal evolution of electron density during one modulation period.

  2. Intramyocardial VEGF-B167 gene delivery delays the progression towards congestive failure in dogs with pacing-induced dilated cardiomyopathy.

    Science.gov (United States)

    Pepe, Martino; Mamdani, Mohammed; Zentilin, Lorena; Csiszar, Anna; Qanud, Khaled; Zacchigna, Serena; Ungvari, Zoltan; Puligadda, Uday; Moimas, Silvia; Xu, Xiaobin; Edwards, John G; Hintze, Thomas H; Giacca, Mauro; Recchia, Fabio A

    2010-06-25

    Vascular endothelial growth factor (VEGF)-B selectively binds VEGF receptor (VEGFR)-1, a receptor that does not mediate angiogenesis, and is emerging as a major cytoprotective factor. To test the hypothesis that VEGF-B exerts non-angiogenesis-related cardioprotective effects in nonischemic dilated cardiomyopathy. AAV-9-carried VEGF-B(167) cDNA (10(12) genome copies) was injected into the myocardium of chronically instrumented dogs developing tachypacing-induced dilated cardiomyopathy. After 4 weeks of pacing, green fluorescent protein-transduced dogs (AAV-control, n=8) were in overt congestive heart failure, whereas the VEGF-B-transduced (AAV-VEGF-B, n=8) were still in a well-compensated state, with physiological arterial Po(2). Left ventricular (LV) end-diastolic pressure in AAV-VEGF-B and AAV-control was, respectively, 15.0+/-1.5 versus 26.7+/-1.8 mm Hg and LV regional fractional shortening was 9.4+/-1.6% versus 3.0+/-0.6% (all P<0.05). VEGF-B prevented LV wall thinning but did not induce cardiac hypertrophy and did not affect the density of alpha-smooth muscle actin-positive microvessels, whereas it normalized TUNEL-positive cardiomyocytes and caspase-9 and -3 activation. Consistently, activated Akt, a major negative regulator of apoptosis, was superphysiological in AAV-VEGF-B, whereas the proapoptotic intracellular mediators glycogen synthase kinase (GSK)-3beta and FoxO3a (Akt targets) were activated in AAV-control, but not in AAV-VEGF-B. Cardiac VEGFR-1 expression was reduced 4-fold in all paced dogs, suggesting that exogenous VEGF-B(167) exerted a compensatory receptor stimulation. The cytoprotective effects of VEGF-B(167) were further elucidated in cultured rat neonatal cardiomyocytes exposed to 10(-8) mol/L angiotensin II: VEGF-B(167) prevented oxidative stress, loss of mitochondrial membrane potential, and, consequently, apoptosis. We determined a novel, angiogenesis-unrelated cardioprotective effect of VEGF-B(167) in nonischemic dilated cardiomyopathy

  3. Structural and dynamical aspects of the distant magnetotail determined from ISEE-3 plasma measurements

    Energy Technology Data Exchange (ETDEWEB)

    Hones, E.W.; Zwicki, R.D.; Fritz, T.A.; Bame, S.J.

    1986-10-01

    Large lateral displacements of the magnetotail at ISEE-3 orbital distances can result from the angular variations of solar wind flow that occur frequently. To determine the tail's shape and structure from the ISEE-3 measurements it is desirable to determine quantitatively the tail's displacement during such measurements. Three-dimensional solar wind measurements by IMP-8 have been used together with a new coordinate system, the Geocentric Solar Wind (GSW) system, which reflects solar wind direction changes (as well as earth dipole motion), to estimate the location of ISEE-3 within the tail cross-section. Preliminary tests suggest that at least those changes of satellite location within the tail resulting from long term (few hour) solar wind changes can be determined by the method. Energetic ion spectra, measured in plasmoids by ISEE-3 in the distant tail and by ISEE-2 at the time of the plasmoid's departure from the near tail, have the same exponential form, distinctly different from the power law form that has earlier been ascribed to plasma sheet ion spectra. The ions are trapped in the closed loops of the plasmoid and the major anisotropy that they show is due to their convective motion with the moving plasmoid, not to field-aligned streaming.

  4. The validation of the Z-Scan technique for the determination of plasma glucose

    Science.gov (United States)

    Alves, Sarah I.; Silva, Elaine A. O.; Costa, Simone S.; Sonego, Denise R. N.; Hallack, Maira L.; Coppini, Ornela L.; Rowies, Fernanda; Azzalis, Ligia A.; Junqueira, Virginia B. C.; Pereira, Edimar C.; Rocha, Katya C.; Fonseca, Fernando L. A.

    2013-11-01

    Glucose is the main energy source for the human body. The concentration of blood glucose is regulated by several hormones including both antagonists: insulin and glucagon. The quantification of glucose in the blood is used for diagnosing metabolic disorders of carbohydrates, such as diabetes, idiopathic hypoglycemia and pancreatic diseases. Currently, the methodology used for this determination is the enzymatic colorimetric with spectrophotometric. This study aimed to validate the use of measurements of nonlinear optical properties of plasma glucose via the Z-Scan technique. For this we used samples of calibrator patterns that simulate commercial samples of patients (ELITech ©). Besides calibrators, serum glucose levels within acceptable reference values (normal control serum - Brazilian Society of Clinical Pathology and Laboratory Medicine) and also overestimated (pathological control serum - Brazilian Society of Clinical Pathology and Laboratory Medicine) were used in the methodology proposal. Calibrator dilutions were performed and determined by the Z-Scan technique for the preparation of calibration curve. In conclusion, Z-Scan method can be used to determinate glucose levels in biological samples with enzymatic colorimetric reaction and also to apply the same quality control parameters used in biochemistry clinical.

  5. Determination of myo-inositol hexakisphosphate (phytate) in urine by inductively coupled plasma atomic emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Grases, F.; Perello, J.; Isern, B.; Prieto, R.M

    2004-05-10

    Myo-inositol hexakisphosphate (phytate) is a substance present in urine with an important role in preventing calcium renal calculi development. In spite of this, the use of urinary phytate levels on stone-formers' evaluation and treatment is still notably restricted as a consequence of the enormous difficulty to analyze this substance in urine. In this paper, a simple procedure for routinary urinary phytate determination based on phosphorus determination through inductively coupled plasma atomic emission spectrometry is described. The method only requires a previous separation of phytate from other components by column anion exchange chromatography. The working linear range used was 0-2 mg l{sup -1} phosphorus (0-7 mg l{sup -1} phytate). The limit of detection was 64 {mu}g l{sup -1} of phytate and the limit of quantification was 213 {mu}g l{sup -1}. The relative standard deviation (R.S.D.) for 1.35 mg l{sup -1} phytate was 2.4%. Different urine samples were analyzed using an alternative analytical methodology based on gas chromatography (GC)/mass detection used for inositol determination (phytate was previously hydrolyzed), resulting both methods comparable using as criterion to assess statistical significance P<0.05.

  6. HPTLC Method for the Determination of Paracetamol, Pseudoephedrine and Loratidine in Tablets and Human Plasma.

    Science.gov (United States)

    Farid, Nehal Fayek; Abdelaleem, Eglal A

    2016-04-01

    A sensitive, accurate and selective high performance thin layer chromatography (HPTLC) method was developed and validated for the simultaneous determination of paracetamol (PAR), its toxic impurity 4-aminophenol (4-AP), pseudoephedrine HCl (PSH) and loratidine (LOR). The proposed chromatographic method has been developed using HPTLC aluminum plates precoated with silica gel 60 F254 using acetone-hexane-ammonia (4:5:0.1, by volume) as a developing system followed by densitometric measurement at 254 nm for PAR, 4-AP and LOR, while PSH was scanned at 208 nm. System suitability testing parameters were calculated to ascertain the quality performance of the developed chromatographic method. The method was validated with respect to USP guidelines regarding accuracy, precision and specificity. The method was successfully applied for the determination of PAR, PSH and LOR in ATSHI(®) tablets. The three drugs were also determined in plasma by applying the proposed method in the ranges of 0.5-6 µg/band, 1.6-12 µg/band and 0.4-2 µg/band for PAR, PSH and LOR, respectively. The results obtained by the proposed method were compared with those obtained by a reported HPLC method, and there was no significance difference between both methods regarding accuracy and precision.

  7. Application of new membrane selective electrodes for the determination of drotaverine hydrochloride in tablets and plasma.

    Science.gov (United States)

    El-Saharty, Y S; Metwaly, F H; Refaat, M; El-Khateeb, S Z

    2006-06-07

    The construction and electrochemical response characteristics of poly vinyl chloride (PVC) membrane sensors for the determination of drotaverine hydrochloride were described. The sensors are based on the use of the ion association complexes of drotaverine cation with sodium phosphotungestate (Dro-PTA) or ammonium reineckate (Dro-R) counter anions as ion exchange sites in the PVC matrix. The performance characteristics of these sensors, which were evaluated according to IUPAC recommendations, reveal a fast, stable and linear response for drotaverine over the concentration range 10(-5) to 10(-2) M with cationic slopes of 49.55 and 51.36 mV per concentration decade. The direct potentiometric determination of drotaverine hydrochloride using the proposed sensors gave average recoveries of 99.95+/-0.71 and 100.04+/-0.60 for Dro-PTA and Dro-R, respectively. The sensors are used for determination of drotaverine hydrochloride in tablets, in its mixture with caffeine and paracetamol and in plasma. Validation of the method shows suitability of the proposed sensors for use in the quality control assessment of drotaverine hydrochloride. The developed method was found to be simple, accurate and precise when compared with a reported HPLC method.

  8. Chemiluminescence Determination of Local Anaesthetic Mepivacaine in Human Plasma and Pharmaceuticals.

    Science.gov (United States)

    Mokhtari, Ali

    2016-12-01

    In this study, a new method has been developed for the simple determination of mepivacaine (carbocaine). The method is based on the enhancement effect of mepivacaine in the chemiluminescence (CL) reaction of tris(1,10 phenanthroline) ruthenium(II) with cerium(IV). A mechanism for the CL reaction has been proposed on the basis of UV-Vis, fluorescent and CL spectra. Under optimum conditions, the CL intensity was proportional to the concentration of the drug in solution over the range 0.45-226.25 μg mL-1 (R2 = 0.9996). The LOD was 0.34 μg mL-1 (S/N = 3). LOD was about 10 times lower than the therapeutic concentration of mepivacaine. The percent of relative standard deviation for determination of 11 replicates at level of 9.05 μg mL-1 and 90.50 μg mL-1 of mepivacaine were 1.8 and 3.7%, respectively. The proposed method was applied successfully for the determination of mepivacaine in human plasma and injectable solutions.

  9. The endogenous anti-angiogenic VEGF isoform, VEGF165b inhibits human tumour growth in mice.

    NARCIS (Netherlands)

    Rennel, E.; Waine, E.; Guan, H.; Schuler, Y.; Leenders, W.P.J.; Woolard, J.; Sugiono, M.; Gillatt, D.; Kleinerman, E.; Bates, D.; Harper, S.

    2008-01-01

    Vascular endothelial growth factor-A is widely regarded as the principal stimulator of angiogenesis required for tumour growth. VEGF is generated as multiple isoforms of two families, the pro-angiogenic family generated by proximal splice site selection in the terminal exon, termed VEGFxxx, and the

  10. Novel VEGF decoy receptor fusion protein conbercept targeting multiple VEGF isoforms provide remarkable anti-angiogenesis effect in vivo.

    Directory of Open Access Journals (Sweden)

    Qin Wang

    Full Text Available VEGF family factors are known to be the principal stimulators of abnormal angiogenesis, which play a fundamental role in tumor and various ocular diseases. Inhibition of VEGF is widely applied in antiangiogenic therapy. Conbercept is a novel decoy receptor protein constructed by fusing VEGF receptor 1 and VEGF receptor 2 extracellular domains with the Fc region of human immunoglobulin. In this study, we systematically evaluated the binding affinity of conbercept with VEGF isoforms and PlGF by using anti-VEGF antibody (Avastin as reference. BIACORE and ELISA assay results indicated that conbercept could bind different VEGF-A isoforms with higher affinity than reference. Furthermore, conbercept could also bind VEGF-B and PlGF, whereas Avastin showed no binding. Oxygen-induced retinopathy model showed that conbercept could inhibit the formation of neovasularizations. In tumor-bearing nude mice, conbercept could also suppress tumor growth very effectively in vivo. Overall, our study have demonstrated that conbercept could bind with high affinity to multiple VEGF isoforms and consequently provide remarkable anti-angiogenic effect, suggesting the possibility to treat angiogenesis-related diseases such as cancer and wet AMD etc.

  11. VEGF and colon cancer growth beyond angiogenesis: does VEGF directly mediate colon cancer growth via a non-angiogenic mechanism?

    Science.gov (United States)

    Ahluwalia, Amrita; Jones, Michael K; Matysiak-Budnik, Tamara; Tarnawski, Andrzej S

    2014-01-01

    In this article we review the role of vascular endothelial growth factor (VEGF) in colon cancer growth and the underlying mechanisms. Angiogenesis, the growth of new capillary blood vessels in the body, is critical for tissue injury healing and cancer growth. In 1971, Judah Folkman proposed the concept that tumor growth beyond 2 mm is critically dependent on angiogenesis. Tumors including colon cancers release angiogenic growth factors that stimulate blood vessels to grow into the tumors thus providing oxygen and nutrients that enable exponential growth. VEGF is the most potent angiogenic growth factor. Several studies have highlighted the role of VEGF in colon cancer, specifically in the stimulation of angiogenesis. This role of VEGF is strongly supported by studies showing that inhibition of VEGF using the blocking antibody, bevacizumab, results in decreased angiogenesis and abrogation of cancer growth. In the United States, bevacizumab in combination with chemotherapy is FDA approved for the treatment of metastatic colon cancer. However, the source of VEGF in colon cancer tissue, the mechanisms of VEGF generation in colon cancer cells and the molecular pathways involved in VEGF mediated angiogenesis in colon cancer are not fully known. The possibility that VEGF directly stimulates cancer cell growth in an autocrine manner has not been explored in depth.

  12. Expression of Vascular Endothelial Growth Factor (VEGF) in Human Osteosarcoma Cells Transfected with Adeno-associated Virus-antisense VEGF

    Institute of Scientific and Technical Information of China (English)

    徐卫国; 陈安民; 张衣北; 易成腊

    2004-01-01

    Summary: The expression of protein vascular endothelial growth factor (VEGF) in osteosarcoma cells transfected with adeno-associated virus (rAAV)-antisense VEGF was studied to provide the foundation of osteosarcoma treatment through antivascularization. The rAAV-antisense VEGF at different doses (0, 20, 50, 100, 200, 240 μl) was transfected into osteosarcoma MG-63 cell. The cells and culture supernatants were collected before and after tansfection. The expression of VEGF protein was detected by using immunohistochemical staining (SP) and Western blot. SP and Western-blot tests revealed that the MG-63 Cells transfected with rAAV-antisense VEGF had less staining than those without transfection with rAAV-antisense VEGF, and the staining intensity was negatively correlated with the doses of genes. The corresponding A values of transfected genes with different doses of rAAV-antisense VEGF (0, 20, 50, 100, 200, 240 μA) were 86 614±13 776, 73 245±15 414, 61 078±12 124, 54 657±10 953, 39 802±11 308, 32 014±15 057 respectively,w ith the difference being significant (P<0.05). It was concluded that the expression of VEGF protein in MG-63 cells could be inhibited by rAAV-antisense VEGF.

  13. Relationship between the Changes of VEGF Level and Dendritic Cells in Peripheral Blood of Patients with Hepatocellular Carcinoma after Transcatheter Arterial Chemoembolization

    Institute of Scientific and Technical Information of China (English)

    LIU jinwen; YI Jilin

    2007-01-01

    In order to investigate the relationship between the VEGF level and the counts of dendritic cells (DCs) in peripheral blood of patients with hepatocellular carcinoma (HCC) before and after transcatheter arterial chemoembolization (TACE), the peripheral blood was obtained from 37 patients with HCC who treated by TACE. The blood was obtained on the day before TACE, the first day, the 7th day and the 15th day after TACE respectively. The counts of DCs were quantified by flow cytometry. The plasma VEGF level was measured by ELESA kit. It was shown after TACE, the counts of DCs in peripheral blood were decreased significantly (P<0.05), and the VEGF level in peripheral blood was increased significantly (P<0.05). The counts of DCs in peripheral blood had an inverse correlation with the plasma VEGF level (r=-0.57, P<0.05) after TACE. It was concluded that in patients with HCC after TACE, the increased plasma VEGF level appeared to have the effect to suppress the maturation of DCs, which may contribute to reduction of the body's anti-tumor immunity effect, with a consequence of recur and metastasis of tumor.

  14. Clinical significance of the VEGF level in urinary bladder carcinoma.

    Science.gov (United States)

    Sankhwar, Monica; Sankhwar, Satya Narayan; Abhishek, Amar; Rajender, Singh

    2015-01-01

    To investigate the correlation of Vascular Endothelial Growth Factor (VEGF) and micro-vessel density (MVD) with urinary bladder tumor and its stage. The study was conducted between January 2010 and December 2012. The study included screening of 122 patients at elevated risk for bladder cancer, of which 35 patients were finally enrolled in the study. Diagnosis was made on the basis of urine cytology, radiological investigation (ultrasound KUB, and CT-scan) and histopathology. Thirty-five normal cancer-free individuals were enrolled as controls. Human VEGF levels were measured using an enzyme linked immunoassay and protein content (pg/mg protein) by Lowry method. SPSS for Windows version 10.0.7 (SPSS, Chicago, IL, USA) was used for statistical analysis of the data. Mean urine VEGF level in the cases was significantly higher in comparison to the control group. There was a direct correlation between VEGF level and tumor stage. Mean urine VEGF values were minimum in the control group (22.75 ± 15.41 pg/mg creatinine) and maximum in stage IV patients (180.15 ± 75.93 pg/mg creatinine). Tissue VEGF levels also showed a similar trend of increase with increase in stage. Urine VEGF level also showed a correlation with tissue VEGF level. Similarly, MVD showed a significant increase with increase in tumor stage. A correlation between bladder cancer and MVD and VEGF suggest that the latter can serve as markers for therapeutic guidance. This is the first study from India on clinical and pathological correlation among urine VEGF, tumor tissue VEGF levels, and Micro Vessel Density (MVD) in urinary bladder cancer patients.

  15. Novel transcriptional regulation of VEGF in inflammatory processes.

    Science.gov (United States)

    Tang, Xiaoren; Yang, Yu; Yuan, Huaiping; You, Jian; Burkatovskaya, Marina; Amar, Salomon

    2013-03-01

    Vascular endothelial growth factor (VEGF) is a critical angiogenic factor affecting endothelial cells, inflammatory cells and neuronal cells. In addition to its well-defined positive role in wound healing, pathological roles for VEGF have been described in cancer and inflammatory diseases (i.e. atherosclerosis, rheumatoid arthritis, inflammatory bowel disease and osteoarthritis). Recently, we showed that transcription factors LITAF and STAT6B affected the inflammatory response. This study builds upon our previous results in testing the role of mouse LITAF and STAT6B in the regulation of VEGF-mediated processes. Cells cotransfected with a series of VEGF promoter deletions along with truncated forms of mLITAF and/or mSTAT6B identified a DNA binding site (between -338 and -305 upstream of the transcription site) important in LITAF and/or STAT6B-mediated transcriptional regulation of VEGF. LITAF and STAT6B corresponding protein sites were identified. In addition, siRNA-mediated knockdown of mLITAF and/or mSTAT6B leads to significant reduction in VEGF mRNA levels and inhibits LPS-induced VEGF secretion in mouse RAW 264.7 cells. Furthermore, VEGF treatment of mouse macrophage or endothelial cells induces LITAF/STAT6B nuclear translocation and cell migration. To translate these observations in vivo, VEGF164-soaked matrigel were implanted in whole-body LITAF-deficient animals (TamLITAF(-/-) ), wild-type mice silenced for STAT6B, and in respective control animals. Vessel formation was found significantly reduced in TamLITAF(-/-) as well as in STAT6B-silenced wild-type animals compared with control animals. The present data demonstrate that VEGF regulation by LITAF and/or STAT6B is important in angiogenesis signalling pathways and may be a useful target in the treatment of VEGF diseases. © 2013 The Authors. Published by Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.

  16. Targeting VEGF in canine oxygen-induced retinopathy - a model for human retinopathy of prematurity

    Directory of Open Access Journals (Sweden)

    McLeod DS

    2016-05-01

    Full Text Available D Scott McLeod, Gerard A Lutty Department of Ophthalmology, Wilmer Ophthalmological Institute, Johns Hopkins Hospital, Baltimore, MD, USA Abstract: Development of the dog superficial retinal vasculature is similar to the mechanism of human retinal vasculature development; they both develop by vasculogenesis, differentiation, and assembly of vascular precursors called angioblasts. Canine oxygen-induced retinopathy (OIR was first developed by Arnall Patz in an effort to experimentally determine the effects of hyperoxia on the development of the retinal vasculature. The canine OIR model has many characteristics in common with human retinopathy of prematurity. Exposure of 1-day-old dogs to hyperoxia for 4 days causes a vaso-obliteration throughout the retina. Vasoproliferation, after the animals have returned to room air, is robust. The initial small preretinal neovascular formations anastomose to form large preretinal membranes that eventually cause tractional retinal folds. The end-stage pathology of the canine model is similar to stage IV human retinopathy of prematurity. Therefore, canine OIR is an excellent forum to evaluate the response to drugs targeting VEGF and its receptors. Evaluation of an antibody to VEGF-R2 and the VEGF-Trap demonstrated that doses should be titered down so that preretinal neovascularization is inhibited but retinal revascularization is able to proceed, vascularizing peripheral retina and preventing it from being a source of VEGF. Keywords: angioblasts, blood vessels, endothelial cells, oxygen, retinopathy, retina, vascular endothelial cell growth factor

  17. The Application of OCTA in Assessment of Anti-VEGF Therapy for Idiopathic Choroidal Neovascularization

    Directory of Open Access Journals (Sweden)

    Qin Chen

    2016-01-01

    Full Text Available Purpose. To assess the morphology of idiopathic choroidal neovascularization (ICNV by optical coherence tomography angiography (OCTA and determine the therapeutic effects of intravitreal antivascular endothelial growth factor (anti-VEGF. Method. Patients with naive ICNV were assessed by spectral domain optical coherence tomography (SD-OCT and OCTA in this observational study. The timing of observation was before treatment, 1 day after treatment with intravitreal anti-VEGF injection, and 1 month after the treatment. The central retina thickness (CRT on SD-OCT, selected CNV area, and flow area on OCTA were measured. Results. A total of 17 eyes from 17 patients with ICNV were included in this study. OCTA showed visible irregular choroidal neovascularization with “tree-in-bud” form on outer retinal layer. After treatment, as well as in the 1-day follow-up, CNV decreased in size from the periphery, and the vessel density was reduced. As shown on OCTA, the selected CNV area and flow area were significantly reduced compared to pretreatment. The rate of CNV vessel area changes was higher on OCTA than the changes in CRT on SD-OCT at 1-day and 1-month follow-up. Conclusion. Intravitreal injection of anti-VEGF is effective for idiopathic choroidal neovascularization, and the treatment outcomes are observable after 1 day. OCTA provides a useful approach for monitoring and evaluating the treatment of intravitreal anti-VEGF for CNV.

  18. Impact of VEGF gene polymorphisms and haplotypes on radiation-induced late toxicity in prostate cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Langsenlehner, Tanja; Thurner, Eva-Maria; Kapp, Karin S. [Medical Univ. of Graz (Austria). Dept. of Therapeutic Radiology and Oncology; Renner, Wilfried [Medical Univ. of Graz (Austria). Clinical Inst. of Medical and Chemical Lab. Diagnostics; Gerger, Armin; Hofmann, Guenter [Medical Univ. of Graz (Austria). Division of Oncology; Langsenlehner, Uwe [GKK Outpatient Dept. Graz (Austria). Division of Internal Medicine

    2011-12-15

    Vascular endothelial growth factor (VEGF) is an important determinant of microvascular permeability and angiogenesis and has been shown to be up-regulated during the late phase of radiation injury. The present prospective study was performed to evaluate the role of VEGF gene polymorphisms and haplotypes in the development of radiation-induced late side effects in prostate cancer patients. The association of VEGF gene polymorphisms and haplotypes with high-grade late rectal or urinary toxicity (defined as late toxicity EORTC/RTOG {>=}2) was analyzed using 493 prostate cancer patients from the Austrian PROCAGENE study treated with definitive radiotherapy. Seven candidate polymorphisms in the VEGF gene were selected and determined by 5'-nuclease (TaqMan) assays. Within a median follow-up time of 48 months, 42 patients (8.6%) developed high-grade late rectal and 47 patients (9.6%) urinary toxicity, respectively. In a Kaplan-Meier analysis, carriers of the VEGF -7C > T polymorphism were at increased risk of high-grade late rectal toxicity (p = 0.003) and in a multivariate analysis including clinical and dosimetric parameters as potential confounders the VEGF -7C > T polymorphism remained a significant predictor (HR = 2.8, 95% CI 1.349-5.813; p = 0.006). Furthermore, the ATTGT haplotype formed by five polymorphisms upstream of the coding sequence demonstrated a significant association with late rectal toxicity grade {>=}2 (p = 0.001). No significant associations were found for the remaining polymorphisms and haplotypes. We conclude that genetic variants in the VEGF gene may influence the risk of high-grade late rectal toxicity after definitive radiotherapy for prostate cancer.

  19. Determination of lamivudine in human plasma by HPLC and its use in bioequivalence studies.

    Science.gov (United States)

    Kano, Eunice Kazue; dos Reis Serra, Cristina Helena; Koono, Eunice Emiko Mori; Andrade, Simone Schramm; Porta, Valentina

    2005-06-13

    A simple, accurate, precise and sensitive high-performance liquid chromatographic (HPLC) method with ultraviolet detection was developed to quantificate lamivudine (3-TC) in human plasma samples from bioequivalence studies. 3-TC and stavudine (internal standard, I.S.) were extracted from 0.5 ml of human plasma by acetonitrile protein precipitation. The method was validated over a concentration range of 0.05-3.00 microg/ml and used in a bioequivalence trial between two lamivudine formulations, to assess its usefulness in this kind of study. FURP-lamivudine (Fundação para o Remédio Popular, Brazil, as test formulation) and Epivir (GlaxoSmithKline, Brazil, as reference formulation) were evaluated following a single 150 mg oral dose to 24 healthy volunteers of both genders. The dose was administered after an overnight fast according to a two-way crossover design. Bioequivalence between the products was determined by calculating 90% confidence intervals (90% CI) for the ratio of Cmax, AUC0-t and AUC0-inf values for the test and reference products, using logarithmic transformed data. The 90% confidence intervals for the ratio of Cmax (0.86-1.06), AUC0-t (0.96-1.04) and AUC0-inf (0.97-1.05) values for the test and reference products are within the 0.80-1.25 interval proposed by FDA and EMEA. It was concluded that the two 3-TC formulations are bioequivalent in their rate and extent of absorption, and thus, may be used interchangeably.

  20. Development and Validation of a HPLC Method for Determination of Pefloxacin in Tablet and Human Plasma

    Directory of Open Access Journals (Sweden)

    Shahnaz Gauhar

    2009-03-01

    Full Text Available Objective(sDeveloping and validating a simple, efficient, reproducible and economic reversed phase high performance liquid chromatographic (RP-HPLC method for the quantitative determination of pefloxacin in bulk material, tablets and in human plasma. Materials and MethodsA shim-pack CLC-ODS column and a mobile phase constituting acetonitrile: 0.025 M phosphoric acid solution (13:87 v/v, pH 2.9 adjusted with KOH were used. The flow rate was 1 ml/min and the analyses performed using ultraviolet (UV detector at a wavelength of 275 nm using acetaminophen as an internal standard.ResultsThe developed method showed good resolution between pefloxacin and acetaminophen. It was selective to pefloxacin and able to resolve the drug peak from internal standard and from formulation excipients. The percentage of coefficient variation (CV of the retention times and peak areas of pefloxacin from the six consecutive injections were 0.566% and 0.989%, respectively. The results showed that the peak area responses are linear within the concentration range of 0.125 µg/ml-12 µg/ml (R2= 0.9987. The limits of detection (LOD and limits of quantitation (LOQ for pefloxacin were 0.03125 µg/ml and 0.125 µg/ml. The intra-day and inter-day variation, RSD were 0.376-0.9056 and 0.739-0.853 respectively; also, inter-day variation with relative standard deviation (RSD were 0.1465-0.821 in plasma. The accuracy results of 70%, 100%, and 130% drugs were 100.72%, 100.34%, and 100.09%, respectively.ConclusionThe method is linear, quantitative, reproducible and could be used as a more convenient, efficient and economical method for the trace analysis of drug in biological fluids, in raw material and tablets.

  1. Separation and Determination of Methylnaltrexone in Human Plasma Samples After Oral Administration by HPLC Coupled with Electrochemical Detection

    Institute of Scientific and Technical Information of China (English)

    WANG An-bao; Joseph F. Foss; YUAN Chun-su; Joachim Osinski

    2005-01-01

    A high performance liquid chromatography(HPLC) method coupled with electrochemical detection and solid phase extraction is described for the separation and determination of methylnaltrexone(MNTX), a quaternary opioid antagonist, in human clinical plasma samples after oral administration. Linearity of the standard curve for MNTX was found in the range of 4.0_150 ng/mL and was statistically conformed. The correlation coefficient(r2) and calibration equation obtained from linear regression analysis are 0.9999 and Y=54.27X-0.22, where Y and X represent the peak area and concentration of MNTX, respectively. The detection limit of MNTX under the present experimental conditions is 2.0 ng/mL by estimating at a ratio of 3 of signal to noise. The mean recovery of MNTX in human plasma is higher than 97%. The analytical method was applied to the pharmacokinetic determination of MNTX after single dose oral administration. These data demonstrate that the change of MNTX plasma concentration versus time is obvious. MNTX level of plasma reaches to a plateau between 45 to 120 minutes and then falls slowly. The content of MNTX in plasma sample maintains at an obviously detectable level after twelve hours of oral administration. The pharmacokinetic parameters for a single dose of 19.2 mg/kg in plasma are cmax=206.42(±16.53) ng/mL and tmax=60 min.

  2. Highly sensitive spectrofluorimetric method for determination of certain aminoglycosides in pharmaceutical formulations and human plasma.

    Science.gov (United States)

    Omar, Mahmoud A; Nagy, Dalia M; Hammad, Mohamed A; Aly, Alshymaa A

    2013-06-01

    A simple, reliable, highly sensitive and selective spectrofluorimetric method has been developed for determination of certain aminoglycosides namely amikacin sulfate, tobramycin, neomycin sulfate, gentamicin sulfate, kanamycin sulfate and streptomycin sulfate. The method is based on the formation of a charge transfer complexes between these drugs and safranin in buffer solution of pH 8. The formed complexes were quantitatively extracted with chloroform under the optimized experimental conditions. These complexes showed an excitation maxima at 519-524 nm and emission maxima at 545-570 nm. The calibration plots were constructed over the range of 4-60 pg mL(-1) for amikacin, 4-50 pg mL(-1) for gentamicin, neomycin and kanamycin, 4-40 pg mL(-1) for streptomycin and 5-50 pg mL(-1) for tobramycin. The proposed method was successfully applied to the analysis of the cited drugs in dosage forms. The proposed method was validated according to ICH and USP guidelines with respect to specificity, linearity, accuracy, precision and robustness. The high sensitivity of the proposed method allowed determination of amikacin and gentamicin in spiked and real human plasma.

  3. Accurate determination of silver nanoparticles in animal tissues by inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Veverková, Lenka [Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacky University, 17.listopadu 12, CZ 771 46 Olomouc (Czech Republic); Hradilová, Šárka [Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University, 17.listopadu 12, CZ 771 46 Olomouc (Czech Republic); Milde, David, E-mail: david.mlde@upol.cz [Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacky University, 17.listopadu 12, CZ 771 46 Olomouc (Czech Republic); Panáček, Aleš [Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University, 17.listopadu 12, CZ 771 46 Olomouc (Czech Republic); Skopalová, Jana [Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacky University, 17.listopadu 12, CZ 771 46 Olomouc (Czech Republic); Kvítek, Libor [Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University, 17.listopadu 12, CZ 771 46 Olomouc (Czech Republic); Petrželová, Kamila [Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacky University, 17.listopadu 12, CZ 771 46 Olomouc (Czech Republic); National Reference Laboratory for Chemical Elements, Department of Residues in Kroměříž, State Veterinary Institute Olomouc, Hulínská 2286, CZ 767 60 Kroměříž (Czech Republic); and others

    2014-12-01

    This study examined recoveries of silver determination in animal tissues after wet digestion by inductively coupled plasma mass spectrometry. The composition of the mineralization mixture for microwave assisted digestion was optimized and the best recoveries were obtained for mineralization with HNO{sub 3} and addition of HCl promptly after digestion. The optimization was performed on model samples of chicken meat spiked with silver nanoparticles and a solution of ionic silver. Basic calculations of theoretical distribution of Ag among various silver-containing species were implemented and the results showed that most of the silver is in the form of soluble complexes AgCl{sub 2}{sup −} and AgCl{sub 3}{sup 2−} for the optimized composition of the mineralization mixture. Three animal tissue certified reference materials were then analyzed to verify the trueness and precision of the results. - Highlights: • We performed detailed optimization of microwave assisted digestion procedure of animal tissue used prior to Ag determination by ICP-MS. • We provide basic equilibrium calculations to give theoretical explanation of results from optimization of tested mineralization mixtures. • Results from method validation that was done by analysis of several matrix CRMs are presented.

  4. Determination of fetal rhesus d status by maternal plasma DNA analysis.

    Science.gov (United States)

    Aykut, A; Onay, H; Sagol, S; Gunduz, C; Ozkinay, F; Cogulu, O

    2013-12-01

    In this study, we assessed the feasibility of fetal RhD genotyping by analysis of cell-free fetal DNA(cffDNA) extracted from plasma samples of Rhesus (Rh) D-negative pregnant women by using real-time polymerase chain reaction (PCR). Fetal genotyping was performed on 30 RhD-negative women between 9 and 39 weeks of gestation who were referred to us for invasive testing [amniocentesis/chorionic villi sampling (CVS)]. The fetal RHD genotype was determined based on real-time PCR method. Exons 7 and 10 of the RHD and SRY genes were targeted. Among the pregnant women, 12 were carrying male and 17 were carrying female fetuses. Out of 29 pregnant women, 21 had RhD-positive and nine had RhD-negative fetuses. One sample (case 12, whose blood group was found to be AB Rh [+]) was excluded due to controversial results from repeated serological analyses. All prenatal results were in concordance with postnatal RhD status and fetal sex without false- positive or -negative results. Performing real-time PCR on cffDNA showed accurate, efficient and reliable results, allowing rapid and high throughput non invasive determination of fetal sex and RhD status in clinical samples.

  5. Electrochemistry of raloxifene on glassy carbon electrode and its determination in pharmaceutical formulations and human plasma.

    Science.gov (United States)

    Bagheri, Akbar; Hosseini, Hadi

    2012-12-01

    The electrochemical behavior of raloxifene (RLX) on the surface of a glassy carbon electrode (GCE) has been studied by cyclic voltammetry (CV). The CV studies were performed in various supporting electrolytes, wide range of potential scan rates, and pHs. The results showed an adsorption-controlled and quasi-reversible process for the electrochemical reaction of RLX, and a probable redox mechanism was suggested. Under the optimum conditions, differential pulse voltammetry (DPV) was applied for quantitative determination of the RLX in pharmaceutical formulations. The DPV measurements showed that the anodic peak current of the RLX was linear to its concentration in the range of 0.2-50.0μM with a detection limit of 0.0750μM, relative standard deviation (RSD %) below 3.0%, and a good sensitivity. The proposed method was successfully applied for determination of the RLX in pharmaceutical and human plasma samples with a good selectivity and suitable recovery. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. [Determination of Heavy Metal Elements in Diatomite Filter Aid by Inductively Coupled Plasma Mass Spectrometry].

    Science.gov (United States)

    Nie, Xi-du; Fu, Liang

    2015-11-01

    This study established a method for determining Be, Cr, Ni, As, Cd, Sb, Sn, Tl, Hg and Pb, total 10 heavy metals in diatomite filter aid. The diatomite filter aid was digested by using the mixture acid of HNO₃ + HF+ H₃PO₄ in microwave system, 10 heavy metals elements were determined by inductively coupled plasma mass spectrometry (ICP-MS). The interferences of mass spectrometry caused by the high silicon substrate were optimized, first the equipment parameters and isotopes of test metals were selected to eliminate these interferences, the methane was selected as reactant gas, and the mass spectral interferences were eliminated by dynamic reaction cell (DRC). Li, Sc, Y, In and Bi were selected as the internal standard elements to correct the interferences caused by matrix and the drift of sensitivity. The results show that the detection limits for analyte is in the range of 3.29-15.68 ng · L⁻¹, relative standard deviations (RSD) is less than 4.62%, and the recovery is in the range of 90.71%-107.22%. The current method has some advantages such as, high sensitivity, accurate, and precision, which can be used in diatomite filter aid quality control and safety estimations.

  7. Diffusion effects on the determination of surface catalysis in Inductively Coupled Plasma facility

    Science.gov (United States)

    Viladegut, Alan; Düzel, Ümran; Chazot, Olivier

    2017-03-01

    Atomic recombination is an important process to consider when computing the heat flux transferred to the wall of a re-entry vehicle. Two chemical processes are influencing the species diffusion in the boundary layer surrounding a re-usable Thermal Protection System: gas phase reactions and catalytic recombination at the surface. The coupling between them is not normally taken into account when determining the catalytic recombination coefficient (γ) in plasma facilities. This work aims to provide evidence of such coupling based on both a theoretical analysis and an experimental campaign in the VKI-Plasmatron facility. Recombination coefficient measurements at off-stagnation point configuration on a linear copper calorimeter are provided. An evolution from a high-catalytic to a low-catalytic condition due to the boundary layer growth along the probe is observed. This result is consistent with a parametric analysis carried out using the in-house non-equilibrium boundary layer solver, which shows how the experimentally determined catalysis could be influenced by the amount of gas-phase recombination inside the boundary layer.

  8. Determination of Nickel, Vanadium and Iron in Crude Oil by Three-Phase Plasma Arc Spectrometry

    Science.gov (United States)

    Ghatass, Zekry F.

    2002-12-01

    Three-phase plasma arc (TPPA) with ultrasonic nebulizer is developed for simultaneous determination of trace elements in crude oil samples. Ultrasonic nebulizer is used instead of pneumatic nebulizer in order to minimize the problems caused by the oil viscosity during the operation. This system was used for determination of some trace elements (V, Ni, and Fe) in a crude oil samples. Methyl isobutyl ketone (MIBK) was used to dilute the oil samples. The TPPA instrument offers several advantages including a low cost power supply with no radio frequency, linear dynamic ranges from 4 to 5 of orders of magnitude, and detection limits (0.121, 0.313 and 0.242 (μg/ml) for Ni, V and Fe respectively. The average concentrations were 31 ± 0.45 (μg/ml) for Ni, 40 ± 0.88 (μg/ml) for V and 8 ± 0.74 (μg/ml) for Fe at Balaaiem fields and 2 ± 0.05 (μg/ml) for Ni, 4.8 ± 0.25 (μg/ml) for V and 2 ± 0.10 (μg/ml) for Fe at Wastern Desert fields.

  9. Determination of trace elements in refined gold samples by inductively coupled plasma atomic emission spectrometry

    Directory of Open Access Journals (Sweden)

    Steharnik Mirjana

    2013-01-01

    Full Text Available This paper presents a method for determination the trace contents of silver, copper, iron, palladium, zinc and platinum in refined gold samples. Simultaneous inductively coupled plasma atomic emission spectrometer with radial torch position and cross flow nebulizer was used for determination. In order to compare the different calibration strategies, two sets of calibration standards were prepared. The first set was based on matrix matched calibration standards and the second was prepared without the addition of matrix material. Detection limits for matrix matching calibrations were higher for some elements than those without matrix matching. In addition, the internal standardization method was applied and experiments indicated that indium was the best option as internal standard. The obtained results for gold sample by matrix matching and matrix free calibrations were compared with the obtained results by standard addition method. The accuracy of the methods was tested performing recovery test. Recoveries for spiked sample were in the range of 90-115 %. The accuracy of the methods was also tested by analysis of certified reference material of high pure goldAuGHP1. The best results were achieved by matrix free calibration and standard addition method using indium as internal standard at wavelength of 230 nm. [Projekat Ministarstva nauke Republike Srbije, br. 34024: Development of Technologies for Recycling of Precious, Rare and Associated Metals from Solid Waste in Serbia to High Purity Products

  10. Rapid and Sensitive Method for Quantitative Determination of Lopinavir and Ritonavir in Human Plasma by Liquid Chromatography- Tandem Mass Specrtometry

    Directory of Open Access Journals (Sweden)

    G. A. Temghare

    2009-01-01

    Full Text Available A rapid and sensitive liquid chromatography-mass spectrometric (LC-MS-MS method for the simultaneous determination of lopinavir and ritonavir in human plasma using abacavir as internal standard has been developed and validated. Sample preparation of plasma involved solid phase extraction. Detection was performed using an Applied Biosystems Sciex API 2000 Mass spectrometer. The assay of lopinavir and ritonavir was linear over the range of 50 ng mL-1 to 20000 ng mL -1 and 20 ng mL -1 to 3000 ng mL-1 respectively with a precision of <15% and accuracy in the range of 85-115%. The limit of quantification in plasma for lopinavir and ritonavir was 50 ng mL -1 and 20 ng mL -1 respectively. The described method has the advantage of being rapid and easy and it could be applied in therapeutic monitoring of these drugs in human plasma

  11. Anti-VEGF Treatment Strategies for Wet AMD

    Directory of Open Access Journals (Sweden)

    Jaclyn L. Kovach

    2012-01-01

    Full Text Available Over the past few years, antivascular endothelial growth factor (VEGF therapy has become a standard treatment for neovascular age-related macular degeneration (AMD. During this time, treatment strategies have evolved from a monthly dosing schedule to individualized regimens. This paper will review the currently available anti-VEGF agents and evidence-based treatment strategies.

  12. Anti-VEGF Treatment Strategies for Wet AMD.

    Science.gov (United States)

    Kovach, Jaclyn L; Schwartz, Stephen G; Flynn, Harry W; Scott, Ingrid U

    2012-01-01

    Over the past few years, antivascular endothelial growth factor (VEGF) therapy has become a standard treatment for neovascular age-related macular degeneration (AMD). During this time, treatment strategies have evolved from a monthly dosing schedule to individualized regimens. This paper will review the currently available anti-VEGF agents and evidence-based treatment strategies.

  13. Anti-VEGF Treatment Strategies for Wet AMD

    Science.gov (United States)

    Kovach, Jaclyn L.; Schwartz, Stephen G.; Flynn, Harry W.; Scott, Ingrid U.

    2012-01-01

    Over the past few years, antivascular endothelial growth factor (VEGF) therapy has become a standard treatment for neovascular age-related macular degeneration (AMD). During this time, treatment strategies have evolved from a monthly dosing schedule to individualized regimens. This paper will review the currently available anti-VEGF agents and evidence-based treatment strategies. PMID:22523653

  14. Regulation of the hyperosmotic induction of aquaporin 5 and VEGF in retinal pigment epithelial cells: Involvement of NFAT5

    Science.gov (United States)

    Vogler, Stefanie; Reichenbach, Andreas; Wiedemann, Peter; Bringmann, Andreas; Kohen, Leon

    2015-01-01

    Purpose High intake of dietary salt increases extracellular osmolarity, which results in hypertension, a risk factor of neovascular age-related macular degeneration. Neovascular retinal diseases are associated with edema. Various factors and channels, including vascular endothelial growth factor (VEGF) and aquaporins (AQPs), influence neovascularization and the development of edema. Therefore, we determined whether extracellular hyperosmolarity alters the expression of VEGF and AQPs in cultured human retinal pigment epithelial (RPE) cells. Methods Human RPE cells obtained within 48 h of donor death were prepared and cultured. Hyperosmolarity was induced by the addition of 100 mM NaCl or sucrose to the culture medium. Alterations in gene expression and protein secretion were determined with real-time RT–PCR and ELISA, respectively. The levels of signaling proteins and nuclear factor of activated T cell 5 (NFAT5) were determined by western blotting. DNA binding of NFAT5 was determined with EMSA. NFAT5 was knocked down with siRNA. Results Extracellular hyperosmolarity stimulated VEGF gene transcription and the secretion of VEGF protein. Hyperosmolarity also increased the gene expression of AQP5 and AQP8, induced the phosphorylation of p38 MAPK and ERK1/2, increased the expression of HIF-1α and NFAT5, and induced the DNA binding of NFAT5. The hyperosmotic expression of VEGF was dependent on the activation of p38 MAPK, ERK1/2, JNK, PI3K, HIF-1, and NFAT5. The hyperosmotic induction of AQP5 was in part dependent on the activation of p38 MAPK, ERK1/2, NF-κB, and NFAT5. Triamcinolone acetonide inhibited the hyperosmotic expression of VEGF but not AQP5. The expression of AQP5 was decreased by hypoosmolarity, serum, and hypoxia. Conclusions Hyperosmolarity induces the gene transcription of AQP5, AQP8, and VEGF, as well as the secretion of VEGF from RPE cells. The data suggest that high salt intake resulting in osmotic stress may aggravate neovascular retinal diseases and

  15. Changing paradigms of anti-VEGF in the Indian scenario

    Directory of Open Access Journals (Sweden)

    P Mahesh Shanmugam

    2014-01-01

    Full Text Available Anti-vascular endothelial growth factors (VEGF agents have revolutionized the treatment of retinal diseases. Use of anti-VEGF agents in the Indian Scenario present some unique challenges considering the absence of compounding pharmacies, poor penetrance of health insurance and limited affordability of the citizens of a developing economy. To study the changing paradigms of anti-VEGF use in the Indian scenario, all articles published by Indian authors, data from web-based surveys amongst Indian vitreo-retinal specialists were reviewed. In the paucity of compounding pharmacies in India, fractionation and injection techniques differ from those of developed countries. Frequent anti-VEGF monotherapy offers the best anatomical and visual results, but economics of scale do not allow the same in the Indian scenario, resulting in PRN dosing and combination of anti-VEGF with laser photocoagulation, being the commonly employed treatment protocols.

  16. Reduction of acid effects on trace element determination in food samples by CH4 mixed plasma-DRC-MS.

    Science.gov (United States)

    Guo, Wei; Hu, Shenghong; Zhang, Jiangyi; Hu, Zhaochu; Zhang, Hongfei; Wang, Yanxin

    2012-03-15

    A robust method for trace element determination in food samples by addition of methane to the plasma of a dynamic reaction cell mass spectrometer (CH(4) mixed plasma-DRC-MS) was developed. Addition of 3 mL min(-1) methane to Ar-plasma eliminates the signal suppressions of various elements (As, Se, Hg, etc.) due to the high concentration of nitric acid (10%, v/v). The CH(4)-Ar mixed plasma may compensate for the plasma cooling effects due to the highly concentrated nitric acid. The interfering polyatomic ions (40)Ar(12)C(+), (40)Ar(35)Cl(+) and (40)Ar(40)Ar(+) on (52)Cr(+), (75)As(+) and (80)Se(+) determination were removed effectively using the DRC with CH(4) as the reaction gas. The limits of quantification (LOQ, 10σ) were 0.35 ng g(-1), 0.07 ng g(-1), 0.35 ng g(-1), 0.07 ng g(-1), 0.15 ng g(-1), and 0.07 ng g(-1) for As, Cd, Cr, Hg, Pb and Se, respectively. The proposed method was applied to the determination of these trace elements in four food standard reference materials (NIST1577b, GBW10018, NIST1570a and GBW10016), and the results were in good agreement with the certified values.

  17. Spectrofluorimetric determination of sertraline in dosage forms and human plasma through derivatization with 9-fluorenylmethyl chloroformate

    Directory of Open Access Journals (Sweden)

    Belal Fathalla

    2011-10-01

    Full Text Available Abstract Background Sertraline is primarily used to treat major depression in adult outpatients as well as obsessive-compulsive, panic and social anxiety disorders in both adults and children. A survey of the literature reveals that most of the reported methods are either insufficiently sensitive or tedious and require highly sophisticated and dedicated instrumentation. The proposed method is considered to be specific for determination of SER in presence of its metabolite (deaminated form. Results A sensitive, simple and specific spectrofluorimetric method was developed for the determination of sertraline (SER in pharmaceutical formulations and biological fluids. The method is based on its reaction with 9-fluorenylmethyl chloroformate (FMOC-Cl in borate buffer of pH 8.0 to yield a highly fluorescent derivative peaking at 315 nm after excitation at 265 nm. The different experimental parameters affecting the development and stability of the reaction product were carefully studied and optimized. The fluorescence concentration plot was rectilinear over the range of 0.05-1.0 μg mL-1 with a lower detection limit of 5.34 × 10-3 μg mL-1 and limit of quantitation of 0.016 μg mL-1. Conclusions The proposed method was successfully applied to the analysis of commercial tablets and the results obtained were in good agreement with those obtained using the reference method. Furthermore, the method was applied for the determination of SER in spiked and real human plasma. The mean % recovery (n = 3 was 94.33 ± 1.53 and 92.00 ± 2.65, respectively. A proposal of the reaction pathway was postulated.

  18. Experimental determination of the weld penetration evolution in keyhole plasma arc welding

    Institute of Scientific and Technical Information of China (English)

    Hu Qingxian; Wu Chuansong; Zhang Yuming

    2007-01-01

    Keyhole plasma arc welding experiments are conducted to measure the weld geometry and penetration at different moments during the initial phase from igniting arc to quasi-steady state. Indirect information on keyhole formation and evolution in plasma arc welding can be extracted based on the weld macrophotograph at cross section. It has laid foundation to verify the mathematical models of keyhole plasma arc welding.

  19. Improved endothelialization of NiTi alloy by VEGF functionalized nanocoating.

    Science.gov (United States)

    Shen, Weixing; Cai, Kaiyong; Yang, Zaixiang; Yan, Ying; Yang, Weihu; Liu, Peng

    2012-06-01

    To improve surface endothelialization of NiTi alloy substrate, a nano-structured coating functionalized with vascular endothelial growth factor (VEGF) was fabricated via polydopamine (PDOP) as intermediate layer. The successful preparation of VEGF conjugated nanocoating was demonstrated by X-ray diffraction (XRD), atomic force microscope (AFM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS), respectively. Inductively coupled plasma mass spectrometry (ICP-MS) test showed that the formed nanocoating significantly reduced the release of Ni ion from NiTi alloy in simulated body fluid. The biological behaviors of endothelial cells adhered to modified NiTi alloy substrates, including cell proliferation, cell spreading and production of nitric oxide and prostacyclin were investigated in vitro. The results suggest that surface functionalization of NiTi alloy substrate with VEGF is beneficial for cell growth. The approach presented here affords an alternative for surface modification of NiTi implants applied as heart and vascular implant devices. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Vascular endothelial growth factor (VEGF), produced by feline infectious peritonitis (FIP) virus-infected monocytes and macrophages, induces vascular permeability and effusion in cats with FIP.

    Science.gov (United States)

    Takano, Tomomi; Ohyama, Taku; Kokumoto, Aiko; Satoh, Ryoichi; Hohdatsu, Tsutomu

    2011-06-01

    Feline infectious peritonitis virus (FIPV) causes a fatal disease called FIP in Felidae. The effusion in body cavity is commonly associated with FIP. However, the exact mechanism of accumulation of effusion remains unclear. We investigated vascular endothelial growth factor (VEGF) to examine the relationship between VEGF levels and the amounts of effusion in cats with FIP. Furthermore, we examined VEGF production in FIPV-infected monocytes/macrophages, and we used feline vascular endothelial cells to examine vascular permeability induced by the culture supernatant of FIPV-infected macrophages. In cats with FIP, the production of effusion was related with increasing plasma VEGF levels. In FIPV-infected monocytes/macrophages, the production of VEGF was associated with proliferation of virus. Furthermore, the culture supernatant of FIPV-infected macrophages induced hyperpermeability of feline vascular endothelial cells. It was suggested that vascular permeability factors, including VEGF, produced by FIPV-infected monocytes/macrophages might increase the vascular permeability and the amounts of effusion in cats with FIP.

  1. Minimally invasive colon resection is associated with a persistent increase in plasma PlGF levels following cancer resection.

    Science.gov (United States)

    Shantha Kumara, H M C; Cabot, Jenny C; Yan, Xiaohong; Herath, Sonali A C; Luchtefeld, Martin; Kalady, Matthew F; Feingold, Daniel L; Baxter, Raymond; Whelan, Richard L

    2011-07-01

    Minimally invasive colorectal resection (MICR) is associated with persistently elevated plasma VEGF levels that may stimulate angiogenesis in residual tumor foci. Placenta growth factor (PlGF) stimulates neovascularization in tumors by modulating VEGF's effects. This study's purpose was to determine the impact of MICR on blood PlGF levels in cancer patients (Study A) and to compare PreOp levels in patients with cancer and benign (BEN) disease (Study B). Blood samples were collected preoperatively, on postoperative day (POD) 1, POD 3, and at various time points 2-4 weeks after surgery. Samples from 7-day periods after POD 6 were bundled to allow analysis. Plasma PlGF levels were determined via ELISA, results reported as mean±SD, and data analyzed via t test. Significance was set at pMICR (laparoscopic, 59%; hand-assisted, 41%). The mean length of stay was 5.8±2.1 days. The mean PreOp PlGF level was 15.4±4.3 pg/ml. Significantly increased levels were noted on POD 1 (25.8±7.7 pg/ml, pMICR and PreOp plasma levels are higher in CRC patients than in BEN disease patients. The cause of the postoperative increase is unclear. The persistently higher blood levels of PlGF and VEGF after MICR may stimulate angiogenesis in residual tumor foci. Further studies regarding late blood protein alterations after surgery appear to be indicated.

  2. VEGF and Pleiotrophin Modulate the Immune Profile of Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lynn, Kristi D.; Roland, Christina L. [Division of Surgical Oncology, Department of Surgery, Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, TX, 75390-8593 (United States); Brekken, Rolf A., E-mail: rolf.brekken@utsouthwestern.edu [Division of Surgical Oncology, Department of Surgery, Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, TX, 75390-8593 (United States); Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, 75390-8593 (United States)

    2010-05-26

    Angiogenesis, the sprouting of the existing vascular network to form new vessels, is required for the growth of solid tumors. For this reason, the primary stimulant of angiogenesis, vascular endothelial growth factor-A (VEGF), is an attractive target for tumor therapy. In fact, there are currently numerous anti-VEGF therapies in clinical development for the treatment of various cancers, including breast cancer. VEGF signals through two primary VEGF receptors, VEGFR1 and VEGFR2. VEGFR2 is the primary angiogenic receptor, and VEGFR1 has been implicated in macrophage chemotaxis and tumor cell survival and invasion. It has only been appreciated recently that the VEGFRs are expressed not only on endothelial cells and tumor cells but also on many host immune cells. Therefore, to better understand the effects of anti-VEGF therapy it is important to consider the effects of VEGF on all cells in the tumor microenvironment, including immune cells. Bevacizumab (Avastin{sup ®}, Genetech), which binds VEGF and inhibits interaction with VEGFR1 and VEGFR2, was approved for the treatment of metastatic HER2/NEU-negative breast cancer in 2008, however, the majority of human mammary tumors are either innately resistant or will acquire resistance to anti-VEGF therapy. This suggests that these tumors activate alternate angiogenesis pathways. Pleiotrophin (PTN) is an important angiogenic cytokine in breast cancer and is expressed at high levels in approximately 60% of human breast tumors. PTN functions as an angiogenic factor and promotes remodeling of the tumor microenvironment as well as epithelial-mesenchymal transition (EMT). In addition, PTN can have profound effects on macrophage phenotype. The present review focuses on the functions of VEGF and PTN on immune cell infiltration and function in breast cancer. Furthermore, we will discuss how anti-VEGF therapy modulates the immune cell profile.

  3. Single-Chain VEGF/Cy5.5 Targeting VEGF Receptors to Indicate Atherosclerotic Plaque Instability

    NARCIS (Netherlands)

    Lam, Ming Kai; Al-Ansari, Sali; van Dam, Gooitzen M.; Tio, Rene A.; Breek, Jan-Cees; Slart, Riemer H. J. A.; Hillebrands, Jan-Luuk; Zeebregts, Clark J.

    2013-01-01

    Unstable plaques may cause clinical events. Plaque destabilization results from the synergy between intraplaque angiogenesis and inflammation. Vascular endothelial growth factor (VEGF) and VEGF receptors (VEGFRs) are considered to be involved in these processes. We investigated the efficacy of the a

  4. Hypothermia reduces VEGF-165 expression, but not osteogenic differentiation of human adipose stem cells under hypoxia

    Science.gov (United States)

    Bakker, Astrid D.; Hogervorst, Jolanda M. A.; Nolte, Peter A.; Klein-Nulend, Jenneke

    2017-01-01

    Cryotherapy is successfully used in the clinic to reduce pain and inflammation after musculoskeletal damage, and might prevent secondary tissue damage under the prevalent hypoxic conditions. Whether cryotherapy reduces mesenchymal stem cell (MSC) number and differentiation under hypoxic conditions, causing impaired callus formation is unknown. We aimed to determine whether hypothermia modulates proliferation, apoptosis, nitric oxide production, VEGF gene and protein expression, and osteogenic/chondrogenic differentiation of human MSCs under hypoxia. Human adipose MSCs were cultured under hypoxia (37°C, 1% O2), hypothermia and hypoxia (30°C, 1% O2), or control conditions (37°C, 20% O2). Total DNA, protein, nitric oxide production, alkaline phosphatase activity, gene expression, and VEGF protein concentration were measured up to day 8. Hypoxia enhanced KI67 expression at day 4. The combination of hypothermia and hypoxia further enhanced KI67 gene expression compared to hypoxia alone, but was unable to prevent the 1.2-fold reduction in DNA amount caused by hypoxia at day 4. Addition of hypothermia to hypoxic cells did not alter the effect of hypoxia alone on BAX-to-BCL-2 ratio, alkaline phosphatase activity, gene expression of SOX9, COL1, or osteocalcin, or nitric oxide production. Hypothermia decreased the stimulating effect of hypoxia on VEGF-165 gene expression by 6-fold at day 4 and by 2-fold at day 8. Hypothermia also decreased VEGF protein expression under hypoxia by 2.9-fold at day 8. In conclusion, hypothermia decreased VEGF-165 gene and protein expression, but did not affect differentiation, or apoptosis of MSCs cultured under hypoxia. These in vitro results implicate that hypothermia treatment in vivo, applied to alleviate pain and inflammation, is not likely to harm early stages of callus formation. PMID:28166273

  5. Effect of saffron extract on VEGF-A expression in MCF7 cell line

    Directory of Open Access Journals (Sweden)

    Marzieh Mousavi

    2014-03-01

    Full Text Available Background: Various studies have focused on the anticancer effects of saffron. Angiogenesis or new blood vessel formation, which is required for embryonic development and many physiological events, plays a crucial role in many pathological conditions such as tumor growth. One of the main genes which is involved in the process of angiogenesis is VEGF-A. In this in vitro study, the effects of saffron extract on VEGF-A expression were examined. Methods: In this experimental study, the saffron extract was obtained by Soxhlet extractor and then the powder was frozen and dried in vacuum (lyophilisation using a freeze dryer. MCF7 cells were grown in RPMI 1640 medium supplemented with 10% Fetal Bovine Serum (FBS and incubated at 37˚C with 5% CO2. After 24 h of cell culture, their adhesion to the bottom flasks was investigated, then, they were treated by the aqueous extract of saffron at concentrations of 100, 200, 400 and 800 µg/ml. 48 hours after treatment, total RNA was extracted and cDNA was synthesized using the sequence of target gene. Finally, the synthesized products were analysed by Real Time PCR to determine the expression level of VEGF-A. Results: The results of data analysis showed the inhibitory effect of saffron extract in concentrations of 100, 200, 400 and 800 µg/ml on VEGF-A expression in MCF7 cells in comparison with control group, indicating the highest reduction of gen expression for the highest concentration of saffron extract (800 µg/ml. Conclusion: Results indicated a decrease in the expression of VEGF-A, specific biomarker of angiogenesis, in the treated samples compared to the control group.

  6. CXCR4-mediated osteosarcoma growth and pulmonary metastasis is promoted by mesenchymal stem cells through VEGF.

    Science.gov (United States)

    Zhang, Peng; Dong, Ling; Yan, Kang; Long, Hua; Yang, Tong-Tao; Dong, Ming-Qing; Zhou, Yong; Fan, Qing-Yu; Ma, Bao-An

    2013-10-01

    Chemokines and chemokine receptor 4 (CXCR4) play an important role in metastasis. CXCR4 is also expressed in the human osteosarcoma cell line 9607-F5M2 (F5M2), which has a high tumorigenic ability and potential for spontaneous pulmonary metastasis. Mesenchymal stem cells (MSCs) contribute to the formation of the tumor stroma and promote metastasis. However, mechanisms underlying the promotion of osteosarcoma growth and pulmonary metastasis by MSCs are still elusive. Our study co-injected the human MSCs and F5M2 cells into the caudal vein of nude mice. The total number of tumor nodules per lung was significantly increased in the F5M2+MSC group compared to the other groups (control, F5M2 cells alone and MSCs alone) at week six. Moreover, a high number of Dil-labeled MSCs was present also at the osteosarcoma metastasis sites in the lung. Using Transwell assays, we found that F5M2 cells migrate towards MSCs, while the CXCR4 inhibitor AMD3100 decreased the migration potential of F5M2 cells towards MSCs. Furthermore, upon treatment with F5M2-conditioned medium, MSCs expressed and secreted higher levels of VEGF as determined by immunohistochemistry, western blotting and ELISA, respectively. Importantly, co-cultured with F5M2 cells, MSCs expressed and secreted higher VEGF levels, while AMD3100 dramatically decreased the VEGF secretion by MSCs. However, CXCR4 expression on F5M2 cells was not significantly increased in the co-culture system. Additionally, VEGF increased the proliferation of both MSCs and F5M2 cells. These findings suggest that CXCR4-mediated osteosarcoma growth and pulmonary metastasis are promoted by MSCs through VEGF.

  7. Editing VEGFR2 Blocks VEGF-Induced Activation of Akt and Tube Formation

    Science.gov (United States)

    Huang, Xionggao; Zhou, Guohong; Wu, Wenyi; Ma, Gaoen; D'Amore, Patricia A.; Mukai, Shizuo; Lei, Hetian

    2017-01-01

    Purpose Vascular endothelial growth factor receptor 2 (VEGFR2) plays a key role in VEGF-induced angiogenesis. The goal of this project was to test the hypothesis that editing genomic VEGFR2 loci using the technology of clustered regularly interspaced palindromic repeats (CRISPR)-associated DNA endonuclease (Cas)9 in Streptococcus pyogenes (SpCas9) was able to block VEGF-induced activation of Akt and tube formation. Methods Four 20 nucleotides for synthesizing single-guide RNAs based on human genomic VEGFR2 exon 3 loci were selected and cloned into a lentiCRISPR v2 vector, respectively. The DNA fragments from the genomic VEGFR2 exon 3 of transduced primary human retinal microvascular endothelial cells (HRECs) were analyzed by Sanger DNA sequencing, surveyor nuclease assay, and next-generation sequencing (NGS). In the transduced cells, expression of VEGFR2 and VEGF-stimulated signaling events (e.g., Akt phosphorylation) were determined by Western blot analyses; VEGF-induced cellular responses (proliferation, migration, and tube formation) were examined. Results In the VEGFR2-sgRNA/SpCas9–transduced HRECs, Sanger DNA sequencing indicated that there were mutations, and NGS demonstrated that there were 83.57% insertion and deletions in the genomic VEGFR2 locus; expression of VEGFR2 was depleted in the VEGFR2-sgRNA/SpCas9–transduced HRECs. In addition, there were lower levels of Akt phosphorylation in HRECs with VEGFR2-sgRNA/SpCas9 than those with LacZ-sgRNA/SpCas9, and there was less VEGF-stimulated Akt activation, proliferation, migration, or tube formation in the VEGFR2-depleted HRECs than those treated with aflibercept or ranibizumab. Conclusions The CRISPR-SpCas9 technology is a potential novel approach to prevention of pathologic angiogenesis. PMID:28241310

  8. Low-power Helium-Neon laser irradiation enhances the expression of VEGF in murine myocardium

    Institute of Scientific and Technical Information of China (English)

    张卫光; 吴长燕; 潘文潇; 田珑; 夏家骝

    2004-01-01

    Background Low-power helium-neon (He-Ne) lasers have been increasingly widely applied in the treatment of cardiovascular diseases, and its vasodilation effect has been proven. The aim of this study was to determine the effects of low-power He-Ne laser irradiation directed at the precardial region of Wistar rats on capillary permeability in the myocardium and the expression of myocardial vascular endothelial growth factor (VEGF). Methods Sixteen rats were divided randomly into control and irradiated groups (n=8, each). A He-Ne laser (632.8 nm) was applied to the irradiated group with a dose of 60.5 J/cm2. Ferritin was perfused into the left femoral vein and capillary permeability was examined under an electron microscope. VEGF expression in the myocardium was investigated by immunohistochemical methods, RT-PCR, and image analysis. Results The ultrastructures of the myocardial capillaries were examined. Compared to the control group, more high-density granules (ferritin), which were present within the capillary endothelium and the mitochondrions of myocardial cells in the internal layer of the myocardium, were observed in the irradiated group. VEGF staining of the myocardium was stronger in the irradiated group than that in the control group. The optic density of the irradiated group (0.246±0.015) was significantly higher than that of the control group (0.218±0.012, P<0.05). Finally, the levels of RT-PCR products of VEGF165 mRNA were 2.79 times higher in irradiated rats than in the control rats.Conclusions Our study demonstrates that He-Ne laser irradiation (in doses of 60.5 J/cm2) increases myocardial capillary permeability and the production of VEGF in myocardial microvessels and in myocardium. Our study provides experimental morphological evidence that myocardial microcirculation can be improved using He-Ne laser irradiation.

  9. Serum 25(OHD and VEGF in diabetes mellitus type 2: gender-specific associations '

    Directory of Open Access Journals (Sweden)

    Nikolaos Tentolouris

    2011-10-01

    Full Text Available Background: Vitamin D insufficiency has been defined as serum 25-hydroxyvitamin D (25(OHD levels below 30 ng/mL and is common among patients with diabetes mellitus (DM type 2 and the elderly.Aim & Objectives: Our aim was to investigate clinically meaningful associations implicating low serum levels of 25(OHD and vascular endothelial growth factor (VEGF levels in DM type 2.Methods: Serum 25(OHD and VEGF levels were determined in 40 patients with DM type 2 and vitamin D insufficiency. Their correlation with markers of advanced diabetic disease (amputation, diabetic foot, proliferative diabetic retinopathy, insulin dependence as well as with serum biochemical parameters was examined. Subanalyses were performed on men and women.Results: Compared with males, female patients exhibited lower 25(OHD levels (p<0.0001 but higher serum VEGF (p=0.018. There was a trend towards an inverse vitamin D - VEGF association. Subanalysis on women showed low serum 25(OHD levels strongly associated with amputation (p=0.003. High serum VEGF levels were associated with amputation (p=0.038, and marginally with diabetic foot (p=0.058, insulin dependence (p=0.084 and proliferative diabetic retinopathy (p=0.086. Higher serum 25(OHD levels were associated with serum uric acid (p=0.007, calcium (p=0.042 and albumin levels (p=0.033. Subanalysis on men demonstrated positive correlation between 25(OHD levels, albumin (p=0.004 and calcium levels (p=0.060, borderline association.Conclusion: The association between low serum 25(OHD levels and amputation in women may be inscribed into the wider context portraying vitamin D insufficiency as a poor prognostic factor. Vitamin D insufficiency may exert gender-specific effects in the context of DM type 2.

  10. Immune modulation associated with vascular endothelial growth factor (VEGF) blockade in patients with glioblastoma.

    Science.gov (United States)

    Thomas, Alissa A; Fisher, Jan L; Hampton, Thomas H; Christensen, Brock C; Tsongalis, Gregory J; Rahme, Gilbert J; Whipple, Chery A; Steel, Sandra E; Davis, Melissa C; Gaur, Arti B; Lewis, Lionel D; Ernstoff, Marc S; Fadul, Camilo E

    2017-03-01

    Vascular endothelial growth factor (VEGF), in addition to being pro-angiogenic, is an immunomodulatory cytokine systemically and in the tumor microenvironment. We previously reported the immunomodulatory effects of radiation and temozolomide (TMZ) in newly diagnosed glioblastoma. This study aimed to assess changes in peripheral blood mononuclear cell (PBMC) populations, plasma cytokines, and growth factor concentrations following treatment with radiation, TMZ, and bevacizumab (BEV). Eleven patients with newly diagnosed glioblastoma were treated with radiation, TMZ, and BEV, following surgery. We measured immune-related PBMC subsets using multi-parameter flow cytometry and plasma cytokine and growth factor concentrations using electrochemiluminescence-based multiplex analysis at baseline and after 6 weeks of treatment. The absolute number of peripheral blood regulatory T cells (Tregs) decreased significantly following treatment. The lower number of peripheral Tregs was associated with a CD4+ lymphopenia, and thus, the ratio of Tregs to PBMCs was unchanged. The addition of bevacizumab to standard radiation and temozolomide led to the decrease in the number of circulating Tregs when compared with our prior study. There was a significant decrease in CD8+ cytotoxic and CD4+ recent thymic emigrant T cells, but no change in the number of myeloid-derived suppressor cells. Significant increases in plasma VEGF and placental growth factor (PlGF) concentrations were observed. Treatment with radiation, TMZ, and BEV decreased the number but not the proportion of peripheral Tregs and increased the concentration of circulating VEGF. This shift in the peripheral immune cell profile may modulate the tumor environment and have implications for combining immunotherapy with anti-angiogenic therapy.

  11. A transgenic model for conditional induction and rescue of portal hypertension reveals a role of VEGF-mediated regulation of sinusoidal fenestrations.

    Directory of Open Access Journals (Sweden)

    Dalit May

    Full Text Available Portal hypertension (PH is a common complication and a leading cause of death in patients with chronic liver diseases. PH is underlined by structural and functional derangement of liver sinusoid vessels and its fenestrated endothelium. Because in most clinical settings PH is accompanied by parenchymal injury, it has been difficult to determine the precise role of microvascular perturbations in causing PH. Reasoning that Vascular Endothelial Growth Factor (VEGF is required to maintain functional integrity of the hepatic microcirculation, we developed a transgenic mouse system for a liver-specific-, reversible VEGF inhibition. The system is based on conditional induction and de-induction of a VEGF decoy receptor that sequesters VEGF and preclude signaling. VEGF blockade results in sinusoidal endothelial cells (SECs fenestrations closure and in accumulation and transformation of the normally quiescent hepatic stellate cells, i.e. provoking the two processes underlying sinusoidal capillarization. Importantly, sinusoidal capillarization was sufficient to cause PH and its typical sequela, ascites, splenomegaly and venous collateralization without inflicting parenchymal damage or fibrosis. Remarkably, these dramatic phenotypes were fully reversed within few days from lifting-off VEGF blockade and resultant re-opening of SECs' fenestrations. This study not only uncovered an indispensible role for VEGF in maintaining structure and function of mature SECs, but also highlights the vasculo-centric nature of PH pathogenesis. Unprecedented ability to rescue PH and its secondary manifestations via manipulating a single vascular factor may also be harnessed for examining the potential utility of de-capillarization treatment modalities.

  12. Validation of a simple gas chromatographic-mass spectrometric method for the determination of gamma-butyrolactone in human plasma.

    Science.gov (United States)

    Fukui, Yousuke; Matsusima, Eiji; Muramoto, Kouichi; Nagai, Nobutaka; Ohama, Koso; Yamashita, Kazumasa

    2003-02-25

    A gas chromatographic-mass spectrometric (GC-MS) method is described for the determination of human plasma levels of gamma-butyrolactone (GBL) is described. The method is sensitive and simple. The plasma sample spiked with the internal standard was extracted by dichloromethane (CH(2)Cl(2)) in acidic conditions, and the concentrated organic layer was injected into GC-MS. Because of endogenous GBL in human plasma, the method used a standard calibration curve. The calibration curve was linear from 10 to 1000 ng/ml. The method has been validated for accuracy and precision with the relative error and C.V. for intra- and inter-day within 10%. GBL-spiked plasma samples stored at -80 degrees C were stable for a 3-month period. The stability of plasma samples after three cycles of freezing and thawing and of prepared samples on an autosampler for 48 h were demonstrated. Plasma concentrations of GBL before and after administration of UFT were 24.3+/-14.2 and 84.9+/-22.4 ng/ml, respectively.

  13. A Validated HPLC-DAD Method for Simultaneous Determination of Etodolac and Pantoprazole in Rat Plasma

    Directory of Open Access Journals (Sweden)

    Ali S. Abdelhameed

    2014-01-01

    Full Text Available A simple, sensitive, and accurate HPLC-DAD method has been developed and validated for the simultaneous determination of pantoprazole and etodolac in rat plasma as a tool for therapeutic drug monitoring. Optimal chromatographic separation of the analytes was achieved on a Waters Symmetry C18 column using a mobile phase that consisted of phosphate buffer pH~4.0 as eluent A and acetonitrile as eluent B in a ratio of A : B, 55 : 45 v/v for 6 min, pumped isocratically at a flow rate of 0.8 mL min−1. The eluted analytes were monitored using photodiode array detector set to quantify samples at 254 nm. The method was linear with r2=0.9999 for PTZ and r2=0.9995 for ETD at a concentration range of 0.1–15 and 5–50 μgmL−1 for PTZ and ETD, respectively. The limits of detection were found to be 0.033 and 0.918 μgmL−1 for PTZ and ETD, respectively. The method was statistically validated for linearity, accuracy, precision, and selectivity following the International Conference for Harmonization (ICH guidelines. The reproducibility of the method was reliable with the intra- and interday precision (% RSD <7.76% for PTZ and <7.58 % for ETD.

  14. Metal and metalloid determination in bioethanol through inductively coupled plasma-optical emission spectroscopy

    Science.gov (United States)

    Sánchez, Carlos; Lienemann, Charles-Philippe; Todolí, José-Luis

    2016-01-01

    A new method to carry out the elemental determination of metals in bioethanol through ICP-OES has been developed. The procedure is based on the use of a heated torch integrated sample introduction system (hTISIS) to directly introduce the vaporized sample into the plasma. Two injection modes (continuous liquid aspiration and air-segmented flow injection analysis) have been evaluated. In a first step, the matrix effects caused by several ethanol-water mixtures were removed by operating the hTISIS at 400 °C in segmented injection. Meanwhile, the results also proved that the system could be operated in continuous mode at 200 °C with the complete interference removal. Finally, twenty-eight real samples with bioethanol contents between 55% and 100% were analyzed with the methods previously developed. Regarding validation, recoveries from 80% to 120% were obtained for 18 analytes and the concentrations found with the proposed method were in agreement with those encountered with a preconcentration method, taken as a reference procedure. Limits of detection went from 3 ng mL- 1 for manganese to about 500 ng mL- 1 for calcium. This allowed to quantify Cr, Fe, Mg, Mn and Zn in segmented flow injection and Al, Cd, Cr, Cu, K, Mg, Mn, Na and Zn in continuous sample aspiration mode in bioethanol samples.

  15. Determination of Menthol in Plasma and Urine by Gas Chromatography/Mass Spectrometry (GC/MS).

    Science.gov (United States)

    Peat, Judy; Frazee, Clint; Kearns, Gregory; Garg, Uttam

    2016-01-01

    Menthol, a monoterpene, is a principal component of peppermint oil and is used extensively in consumer products as a flavoring aid. It is also commonly used medicinally as a topical skin coolant; to treat inflammation of the mucous membranes, digestive problems, and irritable bowel syndrome (IBS); and in preventing spasms during endoscopy and for its spasmolytic effect on the smooth muscle of the gastrointestinal tract. Menthol has a half life of 3-6 h and is rapidly metabolized to menthol glucuronide which is detectable in urine and serum following menthol use. We describe a method for the determination of total menthol in human plasma and urine using liquid/liquid extraction, gas chromatography/mass spectrometry (GC/MS) in selected ion monitoring mode and menthol-d4 as the internal standard. Controls are prepared with menthol glucuronide and all samples undergo enzymatic hydrolysis for the quantification of total menthol. The method has a linear range of 5-1000 ng/mL, and coefficient of variation <10%.

  16. Determination of impurity elements in MnZn ferrites by inductively coupled plasma mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    张萍; 符靓; 马俊才; 唐有根

    2015-01-01

    An inductively coupled plasma mass spectrometry (ICP-MS) method was developed for the determination of Na, Mg, Al, K, Ca, Ti, Cr, Co, Ni, Cu, Ga, As, Mo, Ag, Cd and Pb in MnZn ferrites. The sample was digested by HNO3+HCl with microwave digestion followed by dilution with ultrapure water, then the above 16 impurity elements in the solution were analyzed directly by ICP-MS. The impurity elements were introduced by the helium gas or hydrogen gas into the octopole reaction system (ORS) to eliminate the polyatomic interferences caused by the high salty matrixes. The matrix effect was minimized through matrix matching, and Be, Y and Rh were used as internal standard elements. The working parameters of the instrument were optimized. The results show that the method has good precision and high accuracy. The detection limits for the investigated elements are in the range of 0.9−37.5 ng/L, the relative standard deviation of each element is within 1.1%−4.8%, and the recovery of each element is 90%−108%.

  17. Experimental Determination of DT Yield in High Current DD Dense Plasma Focii

    Energy Technology Data Exchange (ETDEWEB)

    Lowe, D. R. [National Security Technologies, LLC; Hagen, E. C. [National Security Technologies, LLC; Meehan, B. T. [National Security Technologies, LLC; Springs, R. K. [University of Nevada, Las Vegas; O' Brien, R. J. [University of Nevada, Las Vegas

    2013-06-18

    Dense Plasma Focii (DPF), which utilize deuterium gas to produce 2.45 MeV neutrons, may in fact also produce DT fusion neutrons at 14.1 MeV due to the triton production in the DD reaction. If beam-target fusion is the primary producer of fusion neutrons in DPFs, it is possible that ejected tritons from the first pinch will interact with the second pinch, and so forth. The 2 MJ DPF at National Security Technologies’ Losee Road Facility is able to, and has produced, over 1E12 DD neutrons per pulse, allowing an accurate measurement of the DT/DD ratio. The DT/DD ratio was experimentally verified by using the (n,2n) reaction in a large piece of praseodymium metal, which has a threshold reaction of 8 MeV, and is widely used as a DT yield measurement system1. The DT/DD ratio was experimentally determined for over 100 shots, and then compared to independent variables such as tube pressure, number of pinches per shot, total current, pinch current and charge voltage.

  18. Determination of stable cesium and strontium in rice samples by inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Srinuttrakul, W.; Yoshida, S.

    2017-06-01

    For long-term radiation dose assessment models, food ingestion is one of the major exposure pathways to human. In general, the stable isotopes can serve as analogues of radioisotopes. In this study, rice samples were collected from 30 paddy fields in Si Sa Ket, Yasothon and Roi Et in the northeast of Thailand in November 2014. The concentrations of stable cesium (Cs-133) and strontium (Sr-88) in polished rice were determined by inductively coupled plasma mass spectrometry (ICP-MS). The standard reference material of rice flour (NIST 1568a) with spiked Cs and Sr was used to validate the analytical method. The concentration of Cs in polished rice from Si Sa Ket, Yasothon and Roi Et was 0.158 ± 0.167 mg kg-1, 0.090 ± 0.117 mg kg-1 and 0.054 ± 0.031 mg kg-1, respectively. The concentration of Sr in polished rice from Si Sa Ket, Yasothon and Roi Et was 0.351 ± 0.108 mg kg-1, 0.364 ± 0.215 mg kg-1 and 0.287 ± 0.102 mg kg-1, respectively. Comparison of the results with Japanese data before the Fukushima Di-ichi nuclear power plant accident showed that the concentrations of both Cs and Sr for Thai rice were higher than those for Japanese rice.

  19. Determination of cobalamins using capillary electrophoresis inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Baker, S. A.; Miller-Ihli, N. J.

    2000-12-01

    The determination of cobalamins using capillary electrophoresis inductively coupled plasma mass spectrometry (CE-ICP-MS) was investigated. Both capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography (MEKC) modes of operation were studied. The optimal separation of four cobalamin species (cyanocobalamin, hydroxocobalamin, methylcobalamin, and 5'-deoxyadenosylcobalamin) and a potentially harmful corrinoid analogue (cobinamide dicyanide) was obtained using CZE at a pH of 2.5. Both 20 mM phosphate and 20 mM formate buffers were used with success, although the formate buffer provided improved resolution. The CZE-ICP-MS method was used to quantify cyanocobalamin in a vitamin supplement and the analytical results were in good agreement (±5%) with values obtained by ICP-MS for total Co levels. The solution detection limits for cobalamins using CZE-ICP-MS were approximately 50 ng/ml. MEKC was found to be useful for the screening of vitamin preparations because it provided a rapid means of distinguishing cyanocobalamin (the form most commonly used in vitamin preparations) from free cobalt. The separation of free cobalt and cyanocobalamin using MEKC was achieved in less than 10 min.

  20. Determination of omeprazole and its metabolites in human plasma by liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Kanazawa, Hideko; Okada, Akiko; Matsushima, Yoshikazu; Yokota, Hiromitsu; Okubo, Shigeo; Mashige, Fumiko; Nakahara, Kazuhiko

    2002-03-08

    Omeprazole is a benzimidazole compound that acts as a proton-pump inhibitor. Because the metabolism of omeprazole is mainly catalyzed by cytochrome P-450 (CYP) 3A4 and CYP2C19. the genetic polymorphism of CYP2C19 could be of clinical concern in the treatment of acid-related diseases with omeprazole. Therefore, a reliable method for omeprazole phenotyping is desirable in clinical situations. This study has demonstrated the determination of omeprazole and its metabolites in human plasma by liquid chromatography-three-dimensional quadrupole mass spectrometry with a sonic spray ionization interface. The analytical column was YMC-Pack Pro C18(50x2.0 mm I.D.) using acetonitrile-50 mM ammonium acetate (pH 7.25) (1:4) at a flow-rate of 0.2 ml/min. The drift voltage was 30 V. The sampling aperture was heated at 110 degrees C and Shield temperature was 230 degrees C. In the mass spectrum, the molecular ions of omeprazole, hydroxyomeprazole and omeprazole sulfone were clearly observed as base peaks. This method is sufficiently sensitive and accurate for pharmacokinetic studies of omeprazol.

  1. In situ determination of the static inductance and resistance of a plasma focus capacitor bank.

    Science.gov (United States)

    Saw, S H; Lee, S; Roy, F; Chong, P L; Vengadeswaran, V; Sidik, A S M; Leong, Y W; Singh, A

    2010-05-01

    The static (unloaded) electrical parameters of a capacitor bank are of utmost importance for the purpose of modeling the system as a whole when the capacitor bank is discharged into its dynamic electromagnetic load. Using a physical short circuit across the electromagnetic load is usually technically difficult and is unnecessary. The discharge can be operated at the highest pressure permissible in order to minimize current sheet motion, thus simulating zero dynamic load, to enable bank parameters, static inductance L(0), and resistance r(0) to be obtained using lightly damped sinusoid equations given the bank capacitance C(0). However, for a plasma focus, even at the highest permissible pressure it is found that there is significant residual motion, so that the assumption of a zero dynamic load introduces unacceptable errors into the determination of the circuit parameters. To overcome this problem, the Lee model code is used to fit the computed current trace to the measured current waveform. Hence the dynamics is incorporated into the solution and the capacitor bank parameters are computed using the Lee model code, and more accurate static bank parameters are obtained.

  2. Determination of marbofloxacin in plasma and synovial fluid by ultrafiltration followed by HPLC-MS/MS.

    Science.gov (United States)

    Montesano, Camilla; Curini, Roberta; Sergi, Manuel; Compagnone, Dario; Celani, Gianluca; Varasano, Vincenzo; Petrizzi, Lucio; Amorena, Michele

    2016-05-10

    A rapid LC-MS/MS method for the determination of marbofloxacin in plasma and synovial fluid is presented in this study. The method uses a rapid sample preparation which only requires an ultrafiltration step with centrifugal filter devices. The optimized procedure allows a minimal need of sample (175 μL), particularly useful for synovial fluid samples which amount is rather limited; it is simple, rapid and easily applicable providing anyhow a satisfactory clean up, demonstrated by post-infusion experiments. On the other hand to maximize the speed of the analysis an ultrafast chromatographic separation has been obtained by selecting a column of 20 mm; the reduced run-time is suitable for processing numerous samples on a daily basis. Linearity was assessed in the range 5-2500 ng mL(-1); ofloxacin was used as internal standard. LOD and LOQ were respectively 1 and 5 ng/mL. The method was successfully applied to a set of samples generated during an experimental veterinary study.

  3. Simultaneous determination of clobazam and its major metabolite in human plasma by a rapid HPLC method.

    Science.gov (United States)

    Rouini, Mohammadreza; Ardakani, Yalda H; Hakemi, Lida; Mokhberi, Maryam; Badri, Gheise

    2005-09-05

    A rapid and specific HPLC method has been developed and validated for simultaneous determination of clobazam, the anticonvulsant agent, and its major metabolite in human plasma. The sample preparation was a liquid-liquid extraction with tuloene yielding almost near 100% recoveries of two compounds. Chromatographic separation was achieved with a Chromolith Performance RP-18e 100 mm x 4.6mm column, using a mixture of a phosphate buffer (pH 3.5; 10mM)-acetonitrile (70:30, v/v), in isocratic mode at 2 ml/min at a detection wave-length of 228 nm. The calibration curves were linear (r(2)>0.998) in the concentration range of 5-450 ng ml(-1). The lower limit of quantification was 5 ng ml(-1) for two compounds studied. The within- and between-day precisions in the measurement of QC samples at four tested concentrations were in the range of 0.89-9.1% and 2.1-10.1% R.S.D., respectively. The developed procedure was applied to assess the pharmacokinetics of clobazam and its major metabolite following administration of a single 10mg oral dose of clobazam to healthy volunteers.

  4. Determination of piracetam in rat plasma by LC-MS/MS and its application to pharmacokinetics.

    Science.gov (United States)

    Wang, Xianqin; Zhu, Jiayin; Xu, Renai; Yang, Xuezhi; Wu, Haiya; Lin, Dan; Ye, Faqing; Hu, Lufeng

    2010-10-01

    A sensitive and selective liquid chromatography-tandem mass spectrometry method for the determination of piracetam in rat plasma was developed and validated over the concentration range of 0.1-20 µg/mL. After addition of oxiracetam as internal standard, a simplified protein precipitation with trichloroacetic acid (5%) was employed for the sample preparation. Chromatographic separation was performed by a Zorbax SB-Aq column (150 × 2.1 mm, 3.5 µm). The mobile phase was acetonitrile-1% formic acid in water (10:90 v/v) delivered at a flow rate of 0.3 mL/min. The MS data acquisition was accomplished in multiple reaction monitoring mode with a positive electrospray ionization interface. The lower limit of quantification was 0.1 µg/mL. For inter-day and intra-day tests, the precision (RSD) for the entire validation was less than 9%, and the accuracy was within the 94.6-103.2% range. The developed method was successfully applied to pharmacokinetic studies of piracetam in rats following single oral administration dose of 50 mg/kg. Copyright © 2010 John Wiley & Sons, Ltd.

  5. Determination of memantine in plasma and vitreous humour by HPLC with precolumn derivatization and fluorescence detection.

    Science.gov (United States)

    Puente, Belen; Hernandez, Esther; Perez, Susana; Pablo, Luis; Prieto, Esther; Garcia, Maria Angeles; Bregante, Miguel Angel

    2011-01-01

    A new HPLC procedure with precolumn derivatization and rimantadine as the internal standard for determining memantine, a candidate agent for the treatment of glaucoma in plasma and vitreous humour, has been developed and validated. Precolumn derivatization was performed with 9-fluorenylmethyl-chloroformate-chloride (FMOC-Cl) as the derivatization reagent and followed by a liquid-liquid extraction with n-hexane. Optimal conditions for derivatization were an FMOC-Cl concentration of 1.5 mM, a reaction time of 20 min, the temperature at 30°C, the borate buffer pH 8.5, and a borate buffer-acetonitrile ratio of 1:1. The derivatives were analyzed by isocratic HPLC with the fluorescence detector λex 260 nm λem 315 nm on a Novapack C(18) reversed-phase column with a mobile phase of acetonitrile-water (73:27, v/v), 40°C, and a flow rate of 1.2 mL/min. The linear range was 10-1000 ng/mL with a quantification limit of ∼ 10 ng/mL for both types of samples. This analytical method may be suitable for using in ocular availability studies.

  6. Determination of Dynamics of Plant Plasma Membrane Proteins with Fluorescence Recovery and Raster Image Correlation Spectroscopy.

    Science.gov (United States)

    Laňková, Martina; Humpolíčková, Jana; Vosolsobě, Stanislav; Cit, Zdeněk; Lacek, Jozef; Čovan, Martin; Čovanová, Milada; Hof, Martin; Petrášek, Jan

    2016-04-01

    A number of fluorescence microscopy techniques are described to study dynamics of fluorescently labeled proteins, lipids, nucleic acids, and whole organelles. However, for studies of plant plasma membrane (PM) proteins, the number of these techniques is still limited because of the high complexity of processes that determine the dynamics of PM proteins and the existence of cell wall. Here, we report on the usage of raster image correlation spectroscopy (RICS) for studies of integral PM proteins in suspension-cultured tobacco cells and show its potential in comparison with the more widely used fluorescence recovery after photobleaching method. For RICS, a set of microscopy images is obtained by single-photon confocal laser scanning microscopy (CLSM). Fluorescence fluctuations are subsequently correlated between individual pixels and the information on protein mobility are extracted using a model that considers processes generating the fluctuations such as diffusion and chemical binding reactions. As we show here using an example of two integral PM transporters of the plant hormone auxin, RICS uncovered their distinct short-distance lateral mobility within the PM that is dependent on cytoskeleton and sterol composition of the PM. RICS, which is routinely accessible on modern CLSM instruments, thus represents a valuable approach for studies of dynamics of PM proteins in plants.

  7. Evaluation of an immunoassay for determination of plasma efavirenz concentrations in resource-limited settings

    DEFF Research Database (Denmark)

    Abdissa, Alemseged; Wiesner, Lubbe; McIlleron, Helen

    2014-01-01

    to be implemented in resource-limited settings. This study evaluated a commercially available immunoassay for measurement of plasma efavirenz. Methods: The immunoassay-based method was applied to measure efavirenz using a readily available Humastar 80 chemistry analyzer. We compared plasma efavirenz concentrations...

  8. Determination of lidocaine in plasma by direct solid-phase microextraction combined with gas chromatography

    NARCIS (Netherlands)

    Koster, EHM; Wemes, C; Morsink, JB; de Jong, GJ

    2000-01-01

    Direct-immersion solid-phase microextraction (SPME) has been used to extract the local anesthetic lidocaine from human plasma. A simplified model shows the relationship between the total amount of drug in plasma and the amount of drug extracted. The model takes into account that the drug participate

  9. Collective Thomson scattering system for determination of ion properties in a high flux plasma beam

    NARCIS (Netherlands)

    van der Meiden, H. J.; Vernimmen, J. W. M.; Bystrov, K.; Jesko, K.; Kantor, M. Y.; De Temmerman, G.; Morgan, T. W.

    2016-01-01

    A collective Thomson scattering system has been developed for measuring ion temperature, plasma velocity and impurity concentration in the high density magnetized Magnum-PSI plasma beam, allowing for measurements at low temperature (<5 eV) and high electron density >4 × 1020 m−3, while

  10. Determination of platinum surface contamination in veterinary and human oncology centres using inductively coupled plasma mass spectrometry

    NARCIS (Netherlands)

    Janssens, T.; Brouwers, E. E M; de Vos, J. P.; de Vries, N.; Schellens, J. H M; Beijnen, J. H.

    2015-01-01

    The objective of this study was to determine the surface contamination with platinum-containing antineoplastic drugs in veterinary and human oncology centres. Inductively coupled plasma mass spectrometry was used to measure platinum levels in surface samples. In veterinary and human oncology

  11. IFCC reference measurement procedure for substance concentration determination of total carbon dioxide in blood, plasma or serum

    NARCIS (Netherlands)

    Burnett, RW; Covington, AK; Fogh-Andersen, N; Kulpmann, WR; Lewenstam, A; Mas, AHJ; VanKessel, AL; Zijlstra, WG

    2001-01-01

    A reference measurement procedure for substance concentration determination of total CO, in blood, plasma (the anticoagulant is usually heparin) or serum is described. The document covers the principle of the method, the materials and equipment needed and essential aspects of the procedure. The subs

  12. Rapid and simple clean-up and derivatizaton procedure for the gas chromatographic determination of acidic drugs in plasma

    NARCIS (Netherlands)

    Roseboom, H.; Hulshoff, A.

    1979-01-01

    A rapid and simple clean-up and derivatization procedure that can be generally applied to the gas chromatographie (GC) determination of acidic drugs of various chemical and therapeutic classes is described. The drugs are extracted from acidified plasma with chloroform containing 5% of isopropanol, w

  13. Copper Determination in Gunshot Residue by Cyclic Voltammetric and Inductive Coupled Plasma-Optical Emission Spectroscopy

    Directory of Open Access Journals (Sweden)

    Mohd Hashim Nurul’Afiqah Hashimah

    2016-01-01

    Full Text Available Analysis of gunshot residue (GSR is a crucial evidences for a forensic analyst in the fastest way. GSR analysis insists a suitable method provides a relatively simple, rapid and precise information on the spot at the crime scene. Therefore, the analysis of Cu(II in GSR using cyclic voltammetry (CV on screen printed carbon electrode (SPCE is a better choice compared to previous alternative methods such as Inductive Coupled Plasma-Optical Emission Spectroscopy (ICP-OES those required a long time for analysis. SPCE is specially designed to handle with microvolumes of sample such as GSR sample. It gives advantages for identification of copper in GSR on-site preliminary test to prevent the sample loss on the process to be analyzed in the laboratory. SPCE was swabbed directly on the shooter’s arm immediately after firing and acetate buffer was dropped on SPCE before CV analysis. For ICP-OES analysis, cotton that had been soaked in 0.5 M nitric acid was swabbed on the shooter’s arm immediately after firing and kept in a tightly closed sampling tube. Gold coated SPCE that had been through nanoparticles modification exhibits excellent performance on voltammograms. The calibration was linear from 1 to 50 ppm of copper, the limit of detection for copper was 0.3 ppm and a relative standard deviation was 6.1 %. The method was successfully applied to the determination of copper in GSR. The Cu determination on SPCE was compared and validated by ICP-OES method with 94 % accuracy.

  14. Determination of iodine and bromine compounds in foodstuffs by CE-inductively coupled plasma MS.

    Science.gov (United States)

    Chen, Jing-Huan; Wang, Kai-en; Jiang, Shiuh-Jen

    2007-11-01

    A CE-inductively coupled plasma mass spectrometric (CE-ICP-MS) method for iodine and bromine speciation analysis is described. Samples containing ionic iodine (I(-) and IO(3)(-)) and bromine (Br(-) and BrO(3)(-)) species are subjected to electrophoretic separation before injection into the microconcentric nebulizer (CEI-100). The separation has been achieved in a 50 cm length x 75 microm id fused-silica capillary. The electrophoretic buffer used is 10 mmol/L Tris (pH 8.0), while the applied voltage is set at -8 kV. Detection limits are 1 and 20-50 ng/mL for various I and Br compounds, respectively, based on peak height. The RSD of the peak areas for seven injections of 0.1 microg/mL I(-), IO(3)(-) and 1 microg/mL Br(-), BrO(3)(-) mixture is in the range of 3-5%. This method has been applied to determine various iodine and bromine species in NIST SRM 1573a Tomato Leaves reference material and a salt and seaweed samples obtained locally. A microwave-assisted extraction method is used for the extraction of these compounds. Over 87% of the total iodine and 83% of the total bromine are extracted using a 10% m/v tetramethylammonium hydroxide (TMAH) solution in a focused microwave field within a period of 10 min. The spike recoveries are in the range of 94-105% for all the determinations. The major species of iodine and bromine in tomato leaves, salt, and seaweed are Br(-), IO(3)(-), I(-), and Br(-), respectively.

  15. The effect of sample size on fresh plasma thromboplastin ISI determination

    DEFF Research Database (Denmark)

    Poller, L; Van Den Besselaar, A M; Jespersen, J;

    1999-01-01

    The possibility of reduction of numbers of fresh coumarin and normal plasmas has been studied in a multicentre manual prothrombin (PT) calibration of high international sensitivity index (ISI) rabbit and low ISI human reference thromboplastins at 14 laboratories. The number of calibrant plasmas...... was reduced progressively by a computer program which generated random numbers to provide 1000 different selections for each reduced sample at each participant laboratory. Results were compared with those of the full set of 20 normal and 60 coumarin plasma calibrations. With the human reagent, 20 coumarins...... and seven normals still achieved the W.H.O. precision limit (3% CV of the slope), but with the rabbit reagent reduction coumarins with 17 normal plasmas led to unacceptable CV. Little reduction of numbers from the full set of 80 fresh plasmas appears advisable. For maximum confidence, when calibrating...

  16. Unbound fraction of fluconazole and linezolid in human plasma as determined by ultrafiltration: Impact of membrane type.

    Science.gov (United States)

    Kratzer, Alexander; Kees, Frieder; Dorn, Christoph

    2016-12-15

    Ultrafiltration is a rapid and convenient method to determine the free concentrations of drugs in plasma. Several ultrafiltration devices based on Eppendorf cups are commercially available, but are not validated for such use by the manufacturer. Plasma pH, temperature and relative centrifugal force as well as membrane type can influence the results. In the present work, we developed an ultrafiltration method in order to determine the free concentrations of linezolid or fluconazole, both neutral and moderately lipophilic antiinfective drugs for parenteral as well as oral administration, in plasma of patients. Whereas both substances behaved relatively insensitive in human plasma regarding variations in pH (7.0-8.5), temperature (5-37°C) or relative centrifugal force (1000-10.000xg), losses of linezolid were observed with the Nanosep Omega device due to adsorption onto the polyethersulfone membrane (unbound fraction 75% at 100mg/L and 45% at 0.1mg/L, respectively). No losses were observed with Vivacon which is equipped with a membrane of regenerated cellulose. With fluconazole no differences between Nanosep and Vivacon were observed. Applying standard conditions (pH 7.4/37°C/1000xg/20min), the mean unbound fraction of linezolid in pooled plasma from healthy volunteers was 81.5±2.8% using Vivacon, that of fluconazole was 87.9±3.5% using Nanosep or 89.4±3.3% using Vivacon. The unbound fraction of linezolid was 85.4±3.7% in plasma samples from surgical patients and 92.1±6.2% in ICU patients, respectively. The unbound fraction of fluconazole was 93.9±3.3% in plasma samples from ICU patients.

  17. Concentrations of haptoglobin in bovine plasma determined by ELISA or a colorimetric method based on peroxidase activity.

    Science.gov (United States)

    Cooke, R F; Arthington, J D

    2013-06-01

    The objective was to compare different procedures for determination of haptoglobin in bovine plasma. Nine Angus steers were vaccinated against Mannheimia haemolytica to stimulate an acute-phase response. Blood samples were collected immediately prior to vaccination (day 0), and on days 1, 3, 5, 7 and 10. Plasma samples were frozen in duplicates at -80 °C. One set of the duplicates was analysed for haptoglobin concentrations using a commercial ELISA kit. A day effect was detected (p peroxidase activity (CPPA) with results expressed as optical density. Further, based on the ELISA results, the plasma sample with the greatest haptoglobin concentration was also serially diluted into a plasma sample with negligible haptoglobin concentration from the same steer (1:1 through 1:1024 dilution). These dilutions were used within the CPPA method to generate a standard curve and estimate plasma haptoglobin concentrations (CPPA + STD). A linear standard curve was generated (r(2)  = 0.99). A day effect similar to the ELISA method was detected for the CPPA and CPPA + STD methods (p ELISA methods were positively correlated (r = 0.97; p ELISA method. In conclusion, assessing concentrations of haptoglobin in bovine plasma using the CPPA and CPPA + STD methods generate highly correlated or similar results, respectively, compared to ELISA. Therefore, the CPPA + STD and CPPA methods can be used as a less expensive alternative to ELISA to determine concentrations or monitor changes in plasma haptoglobin in bovine samples.

  18. Determining plasma morphine levels using GC-MS after solid phase extraction to monitor drug levels in the postoperative period

    Directory of Open Access Journals (Sweden)

    Veronica Santos

    2008-01-01

    Full Text Available OBJECTIVE: To implement a selective and sensitive analytical method to quantify morphine in small volumes of plasma by gas-liquid chromatography-mass spectrometry (GC-MS, aimed at post-operatively monitoring the drug. METHOD: A gas-liquid chromatographic method with mass detection has been developed to determine morphine concentration in plasma after solid phase extraction. Morphine-d3 was used as an internal standard. Only 0.5 mL of plasma is required for the drug solid-phase extraction in the Bond Elut-Certify®, followed by the quantification of morphine derivative by GC-MS using a linear temperature program, a capillary fused silica column, and helium as the carrier and make-up gas. The method was applied to determine morphine content in plasma samples of four patients during the postoperative period of cardiac surgery. Patient-controlled analgesia with morphine was performed by a venous catheter, and a series of venous blood samples were collected. After the oro-After the orotracheal extubation, morphine plasma levels were monitored for up to 36 hours. RESULTS: The run time was 16 minutes because morphine and the internal standard were eluted after 8.8 minutes. The GC-MS method had 0.5 -1000 ng/mL linearity range (r²=0.9995, 0.1 ng/mL limit of detection, intraday and interday precision equivalent to 1.9% and 6.8%, and 0.1% and 0.8% systematic error (intraday and interday, respectively. The analytical method showed optimal absolute (98% and relative (100.7% recoveries. Morphine dose requirements and plasma levels are discussed. CONCLUSION: The analytical gas-liquid chromatography-mass spectrometry method is selective and adequate for morphine measurements in plasma for applications in clinical studies.

  19. Determining plasma morphine levels using GC-MS after solid phase extraction to monitor drug levels in the postoperative period.

    Science.gov (United States)

    Santos, Veronica; López, Karin Jannet Vera; Santos, Luciana Moraes; Yonamine, Mauricio; Carmona, Maria José Carvalho; Santos, Silvia Regina Cavani Jorge

    2008-06-01

    To implement a selective and sensitive analytical method to quantify morphine in small volumes of plasma by gas-liquid chromatography-mass spectrometry (GC-MS), aimed at post-operatively monitoring the drug. A gas-liquid chromatographic method with mass detection has been developed to determine morphine concentration in plasma after solid phase extraction. Morphine-d3 was used as an internal standard. Only 0.5 mL of plasma is required for the drug solid-phase extraction in the Bond Elut-Certify, followed by the quantification of morphine derivative by GC-MS using a linear temperature program, a capillary fused silica column, and helium as the carrier and make-up gas. The method was applied to determine morphine content in plasma samples of four patients during the postoperative period of cardiac surgery. Patient-controlled analgesia with morphine was performed by a venous catheter, and a series of venous blood samples were collected. After the oro-After the orotracheal extubation, morphine plasma levels were monitored for up to 36 hours. The run time was 16 minutes because morphine and the internal standard were eluted after 8.8 minutes. The GC-MS method had 0.5 -1000 ng/mL linearity range (r(2)=0.9995), 0.1 ng/mL limit of detection, intraday and interday precision equivalent to 1.9% and 6.8%, and 0.1% and 0.8% systematic error (intraday and interday, respectively). The analytical method showed optimal absolute (98%) and relative (100.7%) recoveries. Morphine dose requirements and plasma levels are discussed. The analytical gas-liquid chromatography-mass spectrometry method is selective and adequate for morphine measurements in plasma for applications in clinical studies.

  20. High performance liquid chromatography for the determination of glucosamine sulfate in human plasma after derivatization with 9-fluorenylmethyl chloroformate.

    Science.gov (United States)

    Huang, Tao-min; Deng, Chun-Hui; Chen, Nian-zhu; Liu, Zhen; Duan, Geng-Li

    2006-10-01

    In this study, we developed a simple, rapid, sensitive, and reliable method for the determination of glucosamine sulfate in human plasma, which was based on derivatization with 9-fluorenylmethyl chloroformate (FMOC-Cl) followed by reverse-phase HPLC-FLD. For the first time, FMOC-Cl was introduced into derivatization of glucosamine sulfate in human plasma. The amino groups of glucosamine sulfate and vertilmicin sulfate (the internal standard) were trapped with FMOC-Cl to form glucosamine-FMOC-Cl and vertilmicin-FMOC-Cl adducts, which can be very suitable for HPLC-FLD. Precipitation of plasma proteins by acetonitrile was followed by vortex mixing and centrifugation. Chromatographic separation was performed on a C18 column (DIAMONSIL 150 x 4 mm id, 5 microm) with a mobile phase gradient consisting of acetonitrile and water at a flow-rate of 1 mL/min. The retention times of glucosamine-FMOC-Cl and vertilmicin-FMOC-Cl adducts were 8.9 and 21.2 min, respectively. This method was shown to be selective and sensitive for glucosamine sulfate. The limit of detection was 15 ng/mL for glucosamine sulfate in plasma and the linear range was 0.1-10 mg/mL in plasma with a correlation coefficient (r) of 0.9999. The relative standard deviations (RSDs) of intra-day and inter-day assays were 5.2-8.1% and 6.1- 8.5%, respectively. Extraction recoveries of glucosamine sulfate in plasma were greater than 90%. The validated method was successfully applied to the determination of glucosamine sulfate in human plasma samples.

  1. Bioanalytical method development and validation for determination of metoprolol tartarate and hydrochlorothiazide using HPTLC in human plasma

    Directory of Open Access Journals (Sweden)

    Ambadas Ranganath Rote

    2013-12-01

    Full Text Available A simple, sensitive, rapid and economic chromatographic method has been developed for determination of metoprolol tartarate and hydrochlorothiazide in human plasma using paracetamol as an internal standard. The analytical technique used for method development was high-performance thin-layer chromatography. HPTLC Camag with precoated silica gel Plate 60F254 (20 cm×10 cm at 250 µm thicknesses (E. Merck, Darmstadt, Germany was used as the stationary phase. The mobile phase used consisted of chloroform: methanol: ammonia (9:1:0.5v/v/v. Densitometric analysis was carried out at a wavelength of 239 nm. The rf values for hydrochlorothiazide, paracetamol and metoprolol tartarate were 0.13±0.04, 0.28±0.05, 0.48±0.04, respectively. Plasma samples were extracted by protein precipitation with methanol. Concentration ranges of 200, 400, 600, 800, 1000, 1200 ng/mL and 2000, 4000, 6000, 8000, 10000, 12000 ng/mL of hydrochlorothiazide and metoprolol tartarate, respectively, were used with plasma for the calibration curves. The percent recovery of metoprolol tartarate and hydrochlorothiazide was found to be 77.30 and 77.02 %, respectively. The stability of metoprolol tartarate and hydrochlorothiazide in plasma were confirmed during three freeze-thaw cycles (-20 ºC on a bench for 24 hours and post-preparatively for 48 hours. The proposed method was validated statistically and proved suitable for determination of metoprolol tartarate and hydrochlorothiazide in human plasma.

  2. A simple high-performance liquid chromatography for the determination of linezolid in human plasma and saliva.

    Science.gov (United States)

    Hara, Shuuji; Uchiyama, Masanobu; Yoshinari, Masami; Matsumoto, Taichi; Jimi, Shiro; Togawa, Atsushi; Takata, Tohru; Takamatsu, Yasushi

    2015-09-01

    Linezolid is an antimicrobial agent for the treatment of multiresistant Gram-positive infections. A practical high-performance liquid chromatography method was developed for the determination of linezolid in human plasma and saliva. Linezolid and an internal standard (o-ethoxybenzamide) were extracted from plasma and saliva with ethyl acetate and analyzed on a Capcell Pak C18 MG column with UV detection at 254 nm. The calibration curve was linear through the range 0.5-50 µg/mL using a 200 μL sample volume. The intra- and interday precisions were all saliva. The accuracies ranged from 98.8 to 110% for both matrices. The mean recoveries of linezolid were 80.8% for plasma and 79.0% for saliva. This method was used to determine the plasma and saliva concentrations of linezolid in healthy volunteers who were orally administered a 600 mg dose of linezolid. Our liquid-liquid extraction procedure is easy and requires a small volume of plasma or saliva (200 μL). This small volume can be advantageous in clinical pharmacokinetic studies, especially if children participate.

  3. Determination of Ephedrine Alkaloids in Human Urine and Plasma by Liquid Chromatography/Tandem Mass Spectrometry: Collaborative Study

    Science.gov (United States)

    Trujillo, William A.; Sorenson, Wendy R.

    2008-01-01

    A collaborative study was conducted to evaluate the accuracy and precision of a method for ephedrine-type alkaloids (i.e., norephedrine, norpseudoephedrine, ephedrine, pseudoephedrine, methylephedrine, and methylpseudoephedrine) in human urine and plasma. The amount of ephedrine-type alkaloids present was determined using liquid chromatography (LC) with tandem mass selective detection. The test samples were diluted to reflect a concentration of 5.00–100 ng/mL for each alkaloid. An internal standard was added and the alkaloids were separated using a 5 μm phenyl LC column with an ammonium acetate, glacial acetic acid, acetonitrile, and water mobile phase. Eight blind duplicates of human urine and eight blind duplicates of human plasma were analyzed by 10 collaborators. In addition to negative controls, test portions of urine and plasma were fortified at 3 different levels with each of the 6 ephedrine-type alkaloids at approximately 1, 2, and 5 μg/mL for urine and 100, 200, and 500 ng/mL for plasma. On the basis of the accuracy and precision results for this collaborative study, it is recommended that this method be adopted Official First Action for the determination of 6 different ephedrine-type alkaloids in human urine and plasma. PMID:14509420

  4. Determination of uranium from nuclear fuel in environmental samples using inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Boulyga, S.F. [Forschungszentrum Juelich GmbH (Germany). Zentralabteilung fuer Chemische Analysen]|[Radiation Physics and Chemistry Problems Inst., Minsk (Belarus); Becker, J.S. [Forschungszentrum Juelich GmbH (Germany). Zentralabteilung fuer Chemische Analysen

    2000-11-01

    As a result of the accident at the Chernobyl nuclear power plant (NPP) the environment was contaminated with spent nuclear fuel. The {sup 236}U isotope was used in this study to monitor the spent uranium from nuclear fallout in soil samples collected in the vicinity of the Chernobyl NPP. A rapid and sensitive analytical procedure was developed for uranium isotopic ratio measurement in environmental samples based on inductively coupled plasma quadrupole mass spectrometry with a hexapole collision cell (HEX-ICP-QMS). The figures of merit of the HEX-ICP-QMS were studied with a plasma-shielded torch using different nebulizers (such as an ultrasonic nebulizer (USN) and Meinhard nebulizer) for solution introduction. A {sup 238}U{sup +} ion intensity of up to 27000 MHz/ppm in HEX-ICP-QMS with USN was observed by introducing helium into the hexapole collision cell as the collision gas at a flow rate of 10 ml min{sup -1}. The formation rate of uranium hydride ions UH{sup +}/U{sup +} of 2 x 10{sup -6} was obtained by using USN with a membrane desolvator. The limit of {sup 236}U/{sup 238}U ratio determination in 10 {mu}g 1{sup -1} uranium solution was 3 x 10{sup -7} corresponding to the detection limit for {sup 236}U of 3 pg 1{sup -1}. The precision of uranium isotopic ratio measurements in 10 {mu}g 1{sup -1} laboratory uranium isotopic standard solution was 0.13% ({sup 235}U/{sup 238}U) and 0.33% ({sup 236}U/{sup 238}U) using a Meinhard nebulizer and 0.45% ({sup 235}U/{sup 238}U) and 0.88% ({sup 236}U/{sup 238}U) using a USN. The isotopic composition of all investigated Chernobyl soil samples differed from those of natural uranium; i.e. in these samples the {sup 236}U/{sup 238}U ratio ranged from 10{sup -5} to 10{sup -3}. (orig.)

  5. Application of laser-produced-plasmas to determination of carbon content in steel; Aplicacion de los plasmas generados por laser a la determinacion de carbono en aceros

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, M.; Aragon, C.; Aguilera, J. A.; Campos, J.

    1994-07-01

    This paper describes an analytical method to determine carbon content in solid and molten steel. It is based on the study of the emission spectrum from a Nd-YAG laser produced plasma. The light emitted from the plasma is focused to the entrance slit of a spectrometer and detected by an OMA III system. For every laser pulse an spectral range of 100 A are recorded. With the use of time-resolved spectroscopy a precision of 1.6 % and a detection limit of 65 ppm of carbon content in steel have been obtained. These values are similar to those of other accurate conventional techniques but using optics fiber and laser excitation it is possible to made sample calibrations in hostile environments. Also, as the analysis are made in real time changes in sample composition can be measured without stopping production processes. (Author) 26 refs.

  6. Assessment of 7.5% NaCl /6% Dextran-70 (HSD) Effects on Serum or Plasma Protein Determinations

    Science.gov (United States)

    1990-12-26

    determined by modified Lowry, dye-binding, and an automated biuret method, as well as by refractometry , before, and at various times following HSD...protein concentrations determined by the biuret assay or refractometry when dextran serum concentrations exceeded 1.2 g/dl. The in vivo studies... refractometry , before, and at various times following HSD infusion in both euvolemic and hemorrhaged animals. Other studies analyzed plasma protein

  7. Continuous Emission Spectrum Measurement for Electron Temperature Determination in Low-Temperature Collisional Plasmas%Continuous Emission Spectrum Measurement for Electron Temperature Determination in Low-Temperature Collisional Plasmas

    Institute of Scientific and Technical Information of China (English)

    刘秋艳; 李弘; 陈志鹏; 谢锦林; 刘万东

    2011-01-01

    Continuous emission spectrum measurement is applied for the inconvenient diagnos- tics of low-temperature collisional plasmas. According to the physical mechanism of continuous emission, a simplified model is presented to analyze the spectrum in low temperature plasma. The validity of this model is discussed in a wide range of discharge parameters, including electron tem- perature and ionization degree. Through the simplified model, the continuous emission spectrum in a collisional argon internal inductively coupled plasma is experimentally measured to determine the electron temperature distribution for different gas pressures and radio-frequency powers. The inverse Abel transform is also applied for a better spatially resoluted results. Meanwhile, the result of the continuous emission spectrum measurement is compared to that of the electrostatic double probes, which indicates the effectiveness of this method.

  8. [Determination of 10 sedative-hypnotics in human plasma using pulse splitless injection technique and gas chromatography-mass spectrometry].

    Science.gov (United States)

    Chang, Qing; Ma, Hongying; Wang, Fangjie; Ou, Honglian; Zou, Ming

    2011-11-01

    A simple, precise and sensitive gas chromatography-mass spectrometry (GC-MS) method coupled with pulse splitless injection technique was developed for the determination of 10 sedative-hypnotics (barbital, amobarbital, phenobarbital, oxazepam, diazepam, nitrazepam, clonazepam, estazolam, alprazolam, triazolam) in human plasma. The drugs spiked in plasma were extracted with ethyl acetate after alkalization with 0.1 mol/L NaOH solution. The organic solvent was evaporated under nitrogen stream, and the residues were redissolved by ethyl acetate. The separation was performed on an HP-5MS column (30 m x 250 microm x 0.25 microm). The analytes were determined and identified using selected ion monitoring (SIM) mode and scan mode, respectively. The internal standard method was used for the determination. The target analytes were well separated from each other on their SIM chromatograms and also on the total ion current (TIC) chromatograms. The blank extract from human plasma gave no peaks that interfered with all the analytes on the chromatogram. The calibration curves for 10 sedative-hypnotics showed excellent linearity. The correlation coefficients of all the drugs were higher than 0.9954. The recoveries of the drugs spiked in human plasma ranged from 92.28% to 111.7%, and the relative standard deviations (RSDs) of intra-day and inter-day determinations were from 4.09% to 14.26%. The detection limits ranged from 2 to 20 microg/L. The method is simple, reliable, rapid and sensitive for the determination and the quantification of 10 sedative-hypnotics in human plasma and seems to be useful in the practice of clinical toxicological cases.

  9. VEGF Correlates with Inflammation and Fibrosis in Tuberculous Pleural Effusion

    Directory of Open Access Journals (Sweden)

    Mauo-Ying Bien

    2015-01-01

    Full Text Available Objective. To investigate the relationship among angiogenic cytokines, inflammatory markers, and fibrinolytic activity in tuberculous pleural effusion (TBPE and their clinical importance. Methods. Forty-two patients diagnosed with TBPE were studied. Based on chest ultrasonography, there were 26 loculated and 16 nonloculated TBPE patients. The effusion size radiological scores and effusion vascular endothelial growth factor (VEGF, interleukin- (IL- 8, plasminogen activator inhibitor type-1 (PAI-1, and tissue type plasminogen activator (tPA were measured. Treatment outcome and pleural fibrosis, defined as radiological residual pleural thickening (RPT, were assessed at 6-month follow-up. Results. The effusion size and effusion lactate dehydrogenase (LDH, VEGF, IL-8, PAI-1, and PAI-1/tPA ratio were significantly higher, while effusion glucose, pH value, and tPA were significantly lower, in loculated than in nonloculated TBPE. VEGF and IL-8 correlated positively with LDH and PAI-1/tPA ratio and negatively with tPA in both loculated and nonloculated TBPE. Patients with higher VEGF or greater effusion size were prone to develop RPT (n=14; VEGF, odds ratio 1.28, P=0.01; effusion size, odds ratio 1.01, P=0.02, and VEGF was an independent predictor of RPT in TBPE (receiver operating characteristic curve AUC=0.985, P<0.001. Conclusions. Effusion VEGF correlates with pleural inflammation and fibrosis and may be targeted for adjunct therapy for TBPE.

  10. Correlation between the expression of vegf and survival in osteosarcoma.

    Science.gov (United States)

    Baptista, André Mathias; Camargo, André Ferrari De França; Filippi, Renée Zon; Oliveira, Cláudia Regina Gomes Cardim Mendes De; Azevedo Neto, Raymundo Soares De; Camargo, Olavo Pires De

    2014-01-01

    To present a series of 50 consecutive patients with non-metastatic extremity osteosarcoma, and attempt to correlate expression of the vascular endothelial growth factor (VEGF) protein in biopsy tissue to their prognosis regarding overall survival, disease-free survival and local recurrence. Fifty cases of non-metastatic osteosarcoma of the extremities treated between 1986 and 2006 at Instituto de Ortopedia e Traumatologia da Universidade de São Paulo, São Paulo, Brasil, were evaluated regarding expression of the VEGF protein. There were 19 females and 31 males. The mean age was 16 years old (range 5-28 years old) and the mean follow-up was 60.6 months (range 25-167 months). The variables studied were age, gender, anatomic location, type of surgery, surgical margins, tumor size, post chemotherapy necrosis, local recurrence, pulmonary metastasis and death. Thirty-six patients showed VEGF expression on 30% or less cells (low), and the remaining 14 cases had VEGF expression above 30% (high). Among the 36 patients with low VEGF expression, nine developed pulmonary metastasis and four died (11.1%). Among the 14 patients with high VEGF expression, six developed pulmonary metastasis and three died (21.4%). There was no statistically significant correlation between the expression of VEGF and any of the variables studied. Level of Evidence IV, Therapeutic Study.

  11. Circulating VEGF as a biological marker in patients with rheumatoid arthritis? Preanalytical and biological variability in healthy persons and in patients

    DEFF Research Database (Denmark)

    Hetland, Merete Lund; Christensen, Ib Jarle; Lottenburger, Tine

    2008-01-01

    -analytical factors were investigated. A reference interval for VEGF was established in serum and plasma from 306 healthy persons. Diurnal, day-to-day, week-to-week, long-term variability, and impact of exercise were evaluated. RESULTS: Delayed processing time, room temperature, low centrifugal force...

  12. Kaempferol inhibited VEGF and PGF expression and in vitro angiogenesis of HRECs under diabetic-like environment.

    Science.gov (United States)

    Xu, X H; Zhao, C; Peng, Q; Xie, P; Liu, Q H

    2017-03-02

    Diabetic retinopathy (DR) is one of the common and specific microvascular complications of diabetes. This study aimed to investigate the anti-angiogenic effect of kaempferol and explore its underlying molecular mechanisms. The mRNA expression level of vascular endothelial growth factor (VEGF) and placenta growth factor (PGF) and the concentrations of secreted VEGF and PGF were measured by qTR-PCR and ELISA assay, respectively. Human retinal endothelial cells (HRECs) proliferation, migration, and sprouting were measured by CCK-8 and transwell, scratching wound, and tube formation assays, respectively. Protein levels were determined by western blot. High glucose (25 mM) increased the mRNA expression levels of VEGF and PGF as well as the concentrations of secreted VEGF and PGF in HRECs, which can be antagonized by kaempferol (25 µM). Kaempferol (5-25 µM) significantly suppressed cell proliferation, migration, migration distance and sprouting of HRECs under high glucose condition. The anti-angiogenic effect of kaempferol was mediated via downregulating the expression of PI3K and inhibiting the activation of Erk1/2, Src, and Akt1. This study indicates that kaempferol suppressed angiogenesis of HRECs via targeting VEGF and PGF to inhibit the activation of Src-Akt1-Erk1/2 signaling pathway. The results suggest that kaempferol may be a potential drug for better management of DR.

  13. Androgen receptor YAC transgenic mice recapitulate SBMA motor neuronopathy and implicate VEGF164 in the motor neuron degeneration.

    Science.gov (United States)

    Sopher, Bryce L; Thomas, Patrick S; LaFevre-Bernt, Michelle A; Holm, Ida E; Wilke, Scott A; Ware, Carol B; Jin, Lee-Way; Libby, Randell T; Ellerby, Lisa M; La Spada, Albert R

    2004-03-04

    X-linked spinal and bulbar muscular atrophy (SBMA) is an inherited neuromuscular disorder characterized by lower motor neuron degeneration. SBMA is caused by polyglutamine repeat expansions in the androgen receptor (AR). To determine the basis of AR polyglutamine neurotoxicity, we introduced human AR yeast artificial chromosomes carrying either 20 or 100 CAGs into mouse embryonic stem cells. The AR100 transgenic mice developed a late-onset, gradually progressive neuromuscular phenotype accompanied by motor neuron degeneration, indicating striking recapitulation of the human disease. We then tested the hypothesis that polyglutamine-expanded AR interferes with CREB binding protein (CBP)-mediated transcription of vascular endothelial growth factor (VEGF) and observed altered CBP-AR binding and VEGF reduction in AR100 mice. We found that mutant AR-induced death of motor neuron-like cells could be rescued by VEGF. Our results suggest that SBMA motor neuronopathy involves altered expression of VEGF, consistent with a role for VEGF as a neurotrophic/survival factor in motor neuron disease.

  14. A new mouse model resembling human diabetic nephropathy: uncoupling of VEGF with eNOS as a novel pathogenic mechanism.

    Science.gov (United States)

    Nakagawa, T

    2009-02-01

    Diabetics develop a variety of histological abnormalities in the kidney. Early features include glomerular hypertrophy, glomerular basement membrane thickening, and mesangial expansion, whereas mesangiolysis, glomerular capillary aneurysm and nodular lesions develop in late phase. The goal of preventing diabetic nephropathy is important, but its achievement has been difficult due in part to a lack of an animal model for human diabetic nephropathy. Most animal models develop mild lesions in early phase diabetes, but not advanced lesions in late phase. Vascular endothelial growth factor (VEGF) mediates diabetic nephropathy, but its precise role remains to be determined. A complexity of VEGF function is that it is protective in nondiabetic renal diseases but is deleterious in diabetic nephropathy. Because diabetes is associated with endothelial dysfunction, we hypothesized that VEGF is deleterious in the setting of endothelial dysfunction. To test this hypothesis, we recently developed a new model of diabetic nephropathy in mice deficient in endothelial nitric oxide synthase (eNOS). Importantly, these mice developed the advanced lesions of diabetic nephropathy resembling to those in human diabetic nephropathy. In addition, these models also exhibit an uncoupling condition of VEGF with NO. In this review, we discuss our hypothesis which is that uncoupling of VEGF with NO causes advanced diabetic nephropathy.

  15. Microwave diagnostic for the determination of the electron temperature of a low density shock-heated argon plasma

    Science.gov (United States)

    Schneider, C. P.; Exberger, R. J.

    1978-01-01

    The diffraction, defocusing and beam bending effects of microwaves transmitted through a bounded shock-heated argon plasma with low electron density are investigated with the purpose of developing an accurate method for electron temperature (Te) determination. This report describes the evaluation technique and presents results for an argon plasma with pressure between 3 and 10 torr, and T2 between 5500 and 9500 K. The electron temperature values obtained have a range of uncertainty between -20% and +10% only. The electron temperature is equal or lower by approximately 1000 K in comparison to the heavy particle temperature (T2).

  16. The pathophysiologic role of VEGF in hematologic malignancies: therapeutic implications.

    Science.gov (United States)

    Podar, Klaus; Anderson, Kenneth C

    2005-02-15

    Besides its role as an essential regulator of physiologic and pathologic angiogenesis, vascular endothelial growth factor (VEGF) triggers growth, survival, and migration of leukemia and multiple myeloma cells; plays a pivotal role in hematopoiesis; inhibits maturation of dendritic cells; and increases osteoclastic bone-resorbing activity as well as osteoclast chemotaxis. Dysregulation of VEGF expression and signaling pathways therefore plays an important role in the pathogenesis and clinical features of hematologic malignancies, in particular multiple myeloma. Direct and indirect targeting of VEGF and its receptors therefore may provide a potent novel therapeutic approach to overcome resistance to therapies and thereby improve patient outcome.

  17. Determination of roxithromycin in human plasma by HPLC with fluorescence and UV absorbance detection: application to a pharmacokinetic study.

    Science.gov (United States)

    Główka, Franciszek K; Karaźniewicz-Łada, Marta

    2007-06-01

    A selective HPLC method with fluorescence detection for the determination of roxithromycin (ROX) in human plasma was described. After solid-phase extraction (SPE), ROX and erythromycin (internal standard, I.S.) were derivatized by treatment with 9-fluorenylmethyl chloroformate (FMOC-Cl). Optimal resolution of fluorescence derivatives of ROX and I.S. was obtained during one analytical run using reversed phase, C(18) column. The mobile phase was composed of potassium dihydrogenphosphate solution, pH 7.5 and acetonitrile. Fluorescence of the compounds was measured at the maximum excitation, 255 nm and emission, 313 nm, of ROX derivatives. Validation parameters of the method were also established. After SPE, differences in recoveries of ROX and erythromycin from human plasma were observed. The linear range of the standard curve of ROX in plasma was 0.5-10.0 mg/l. The validated method was successfully applied for pharmacokinetic studies of ROX after administration of a single tablet of ROX.

  18. Real-time DSP-based shape determination and plasma position control in the ISTTOK tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, B. E-mail: bernardo@cfn.ist.utl.pt; Fernandes, H.; Silva, C.; Borba, D.; Varandas, C.A.F

    2004-06-01

    We have developed a digital signal processor-based system for real-time control of the ISTTOK plasma position based on a low-cost digital signal processor (DSP) board. A novel plasma shape reproduction method was developed using a Cauchy-condition expansion applied to the vacuum region around the plasma. This method showed to be best suited than classic methods such as Legendre-Fourier expansion (LFE) or current filaments (CF), particularly in small tokamaks with passive stabilizer conductors where the presence of strong eddy currents can cause significant errors in magnetic field sensors. We compare the results of the boundary reconstruction method with the measurements from a microwave interferometer diagnostic. We present an implementation in the DSP system that allows the real time control of the plasma position with a required 1 ms period.

  19. Simultaneous Determination of Silybin A and Silybin B in Rat Plasma and Pharmacokinetic Study

    Institute of Scientific and Technical Information of China (English)

    CHU Yang; LI Wei; LI Zhi-wen; LI Xin-xin; MA Xiao-hui; ZHOU Shui-ping; ZHU Yong-hong

    2011-01-01

    Objective To investigate the bioavailability and pharmacokinetics of silybin A and silybin B in rats,respectively.Methods Following iv and ig administration of silybin to 20 Wistar rats,the plasma samples were collected at different time points up to 12 h.Sample pretreatment was involved in one-step protein precipitation with acetonitrile.Silybin A and silybin B were simultaneously determined by LC-MS/MS.Results After ig dosing silybin 28,56,and 112 mg/kg to rats,the t1/2β values were 5.48,5.08,and 5.73 h for silybin A,and 4.56,4.12,and 5.53 h for silybin B; The Cmax were 674.3,1349.4,and 2042.5 ng/mL for silybin A,and 671.0,1365.4,and 2066.2 ng/mL for silybin B; The Tmax were 0.20,0.23,and 0.20 h for silybin A,and 0.20,0.23,and 0.20 h for silybin B; The AUC were 454.4,845.9,and 1219.5 h·ng/mL for silybin A,and 432.0,817.1,and 1153.6 h·ng/mL for silybin B.The absolute bioavailabilities of silybin A and silybin B were 2.86% and 1.93%,respectively.Conclusion Silybin A and silybin B have very low bioavailability after ig administration,and there is no significant difference in the pharmacokinetic parameters between silybin A and silybin B,which indicates that the two diastereoisomers have similar pharmacokinetic behavior in rats.

  20. Determination of minor elements in steelmaking flue dusts using laser ablation inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Coedo, A G; Padilla, I; Dorado, M T

    2005-07-15

    Element determination in solid waste products from the steel industry usually involves the time-consuming step of preparing a solution of the solid. Laser ablation (LA) inductively coupled plasma mass spectrometry (ICP-MS) has been applied to the analysis of Cr, Ni, Cu, As, Cd and Sn, elements of importance from the point of view of their impact on the environment, in electric arc furnace flue dust (EAFD). A simple method of sample preparation as pressed pellets using a mixture of cellulose and paraffin as binder material was applied. Calibration standards were prepared spiking multielement solution standards to a 1:1 ZnO+Fe(2)O(3) synthetic matrix. The wet powder was dried and mechanically homogenised. Quantitative analysis were based on external calibration using a set of matrix matched calibration standards with Rh as a internal standard. Results obtained using only one-point for calibration without matrix matched, needing less time for standardization and data processing, are also presented. Data are calculated for flue dust reference materials: CRM 876-1 (EAFD), AG-6203 (EAFD), AG-6201 (cupola dust) and AG-SX3705 (coke ashes), and for two representative electrical arc furnace flue dusts samples from Spanish steelmaking companies: MS-1 and MS-2. For the reference materials, an acceptable agreement with certificate values was achieved, and the results for the MS samples matched with those obtained from conventional nebulization solutions (CN). The analytical precision was found to be better than 7% R.S.D. both within a single pellet and between several pellets of the same sample for all the elements.

  1. Determination of plasma cholesterol sulfate by LC-APCI-MS/MS in the context of pediatric autism.

    Science.gov (United States)

    Fong, Bonnie Mei-Wah; Tam, Sidney; Leung, Kelvin Sze-Yin

    2013-11-15

    Cholesterol sulfate (CS) has various biological functions. Previously, plasma CS was measured primarily as a means to diagnose X-linked ichthyosis; however, a recent hypothesis suggests that CS deficiency might be related to autism. As such, an assay capable of measuring both very high (in the case of X-linked ichthyosis) and very low (in the case of autism) plasma CS levels is required. Here we describe a novel LC-APCI-MS/MS method for the determination of CS in human plasma, and we propose normal CS ranges for children, based on studies of a local population of normal Chinese children between the ages of 2 and 10. In addition, we have used this method to measure plasma CS in autistic children. CS was isolated by solid-phase extraction, and quantified by isotope-dilution LC-APCI-MS/MS in negative ion mode monitoring 465.3>97.1 m/z (CS) and 472.3>97.1 m/z (CS-d7). Mean recovery of the assay ranged from 88.1 to 112.7%; within- and between-run imprecisions have CVs less than 7.2 and 8.1%, respectively. The assay was linear up to at least 100 µmol L(-1). The reference interval of plasma CS in males (range: 1.16-4.23 µmol L(-1)) was found to be higher than in females (range: 0.86-3.20 µmol L(-1)). Comparison of normal and autistic children showed no statistically significant difference in the plasma CS level. In conclusion, a robust LC-APCI-MS/MS method for plasma CS was developed, and a pediatric reference interval was derived from applying the method to normal and autistic children.

  2. High Performace Liquid Chromtographic Determination of Nicardipine Hydrochloride in Human Plasma

    Directory of Open Access Journals (Sweden)

    Y. S. R. Krishnaiah

    2004-01-01

    Full Text Available A sensitive high-performance liquid chromatographic method was developed for the estimation of nicardipine hydrochloride in human plasma. Varying amount of nicardipine hydrochloride (2.5 to 150 ng/0.5 mL and fixed quantity (100 ng/0.5 mL of nifedipine (internal standard was added to blank human plasma, and a single step extraction was carried out with ethyl acetate. The mixture was centrifuged, ethyl acetate layer separated, dried and reconstituted with 100 μL of acetonitrile. Twenty microliters of this solution was injected into a reverse phase C-18 column using a mobile phase consisting of acetonitrile: 0.02 M potassium dihydrogen phosphate (pH 4.0 in the ratio of 60:40 v/v and the eluents were monitored at 239 nm. The method was validated for its linearity, precision and accuracy. The calibration curve was linear in the range of 5-150 ng/0.5 mL of plasma and the lower detection limit was 2.5 ng/0.5 mL of plasma. The intra- and inter-day variation was found to be less than 2.5% indicating that the method is highly precise. The mean recovery of nicardipine hydrochloride from plasma samples was 89.6±2.60%. The proposed HPLC method was applied for the estimation of nicardipine hydrochloride in human plasma after oral administration of an immediate release nicardipine hydrochloride capsule (dose 30 mg to 6 adult male volunteers. There was no interference of either the drug metabolites or other plasma components with the proposed HPLC method for the estimation of nicardipine hydrochloride in human plasma. Due to its simplicity, sensitivity, high precision and accuracy, the proposed HPLC method may be used for biopharmaceutical and pharmacokinetic evaluation of nicardipine hydrochloride and its formulations in humans

  3. Determination of loperamide in human plasma and saliva by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Arafat, Tawfiq; Arafat, Basil; awad, Riad; awwad, Ahmad Abu

    2014-12-01

    A simple and sensitive liquid chromatography-tandem mass spectrometric method for quantification of loperamide in human plasma and saliva was developed and validated, and then successfully applied in pharmacokinetic clinical study to investigate and correlate bioavailability of Imodium(®) 2mg quartet tablet dose in both human plasma and saliva. Loperamide with labeled internal standard was extracted from its biological matrix by methanol as protein direct precipitant in single extraction step. Adequate chromatographic separation for analytes from plasma and saliva matrices was achieved using ACE C18 (50mm×2.1mm, 5μm) column, eluted by water/methanol/formic acid (30:70:0.1%, v/v), delivered isocratically at constant flow rate of 0.75ml/min. The method validation intends to investigate specificity, sensitivity, linearity, precision, accuracy, recovery, matrix effect and stability according to European guideline, and partial validation was applied on saliva, specificity, matrix effect, recovery, sensitivity, within and between day precision and accuracy. The calibration curve was linear through the range of 20-3000pg/ml in both plasma and saliva using a 50μl sample volume. The partial validation sections outcome in saliva was so close to those in plasma. The within- and between-day precisions were all below 8.7% for plasma and below 11.4% for saliva. Accuracies ranged from 94 to 105% for both matrices. In this study, 26 healthy volunteers participated in the clinical study, and 6 of gave their saliva samples in addition to plasma at the same time schedule. The pharmacokinetic parameters of Cmax, AUC0-t and AUC0-∞, Tmax and T1/2 in both plasma and saliva were calculated and correlated.

  4. Plasma-based determination of inorganic contaminants in waste of electric and electronic equipment after microwave-induced combustion

    Science.gov (United States)

    Mello, Paola A.; Diehl, Lisarb O.; Oliveira, Jussiane S. S.; Muller, Edson I.; Mesko, Marcia F.; Flores, Erico M. M.

    2015-03-01

    A systematic study was performed for the determination of inorganic contaminants in polymeric waste from electrical and electronic equipment (EEE) for achieving an efficient digestion to minimize interferences in determination using plasma-based techniques. The determination of As, Br, Cd, Co, Cr, Cu, Ni, Pb, Sb, and Zn by inductively coupled plasma mass spectrometry (ICP-MS) and also by inductively coupled plasma optical emission spectrometry (ICP OES) was carried out after digestion using microwave-induced combustion (MIC). Arsenic and Hg were determined by flow-injection chemical vapor generation inductively coupled plasma mass spectrometry (FI-CVG-ICP-MS). Dynamic reaction cell inductively coupled plasma mass spectrometry (DRC-ICP-MS) with ammonia was also used for Cr determination. The suitability of MIC for digestion of sample masses up to 400 mg was demonstrated using microcrystalline cellulose as aid for combustion of polymers from waste of EEEs that usually contain flame retardants that impair the combustion. The composition and concentration of acid solutions (HNO3 or HNO3 plus HCl) were evaluated for metals and metalloids and NH4OH solutions were investigated for Br absorption. Accuracy was evaluated by comparison of results with those obtained using high pressure microwave-assisted wet digestion (HP-MAWD) and also by the analysis of certified reference material (CRM) of polymer (EC680k-low-density polyethylene). Bromine determination was only feasible using digestion by MIC once losses were observed when HP-MAWD was used. Lower limits of detection were obtained for all analytes using MIC (from 0.005 μg g- 1 for Co by ICP-MS up to 3.120 μg g-1 for Sb by ICP OES) in comparison to HP-MAWD due to the higher sample mass that can be digested (400 mg) and the use of diluted absorbing solutions. The combination of HNO3 and HCl for digestion showed to be crucial for quantitative recovery of some elements, as Cr and Sb. In addition, suitable agreement of Cr to

  5. Determination of plasma trace elements in tumor-bearing animals by proton-induced X-ray emission spectroscopy.

    Science.gov (United States)

    Fogle, M; Daly, B; Evans, M; Justiniano, E L; Kovacs, C J; Shinpaugh, J L; Toburen, L H

    2001-11-01

    Although altered levels of circulating essential trace elements are known to accompany malignant disease, the lack of sensitivity of conventional detection methods has generally limited their study to clinical conditions involving extensive disease (i.e., significant tumor burden). As such, the application of altered trace element levels as potential prognostic guides or as response indicators subsequent to treatment has been of limited use. During this study, proton-induced X-ray emission spectroscopy was evaluated as a tool to determine trace element imbalances in a murine tumor model. Using plasma from C57B1/6 mice bearing the syngeneic Lewis lung carcinoma (LLCa), levels of Fe, Cu, and Zn, as well as changes in the Cu /Zn ratio, were measured in animals carrying an increasing primary tumor burden. The plasma levels of Fe, Cu, and Zn were found to decrease significantly 7 d following implants of LLCa cells with no significant change observed in the Cu/Zn ratio. By d 21, however, an increase in the Cu/Zn ratio was found to accompany increased growth of the LLCa tumor; the plasma levels of Cu had returned to normal levels, whereas both the Fe and Zn plasma levels remained lowered. Collectively, the results suggest that although a net change in individual plasma trace element concentrations might not be accurately associated with tumor growth, a clear relationship was established between the Cu/Zn ratio and tumor size.

  6. A hepatitis C avidity test for determining recent and past infections in both plasma and dried blood spots.

    Science.gov (United States)

    Shepherd, Samantha J; Kean, Joy; Hutchinson, Sharon J; Cameron, Sheila O; Goldberg, David J; Carman, William F; Gunson, Rory N; Aitken, Celia

    2013-05-01

    DBS testing has been used successfully to detect HCV antibody positive individuals. Determining how long someone has been infected is important for surveillance initiatives. Antibody avidity is a method that can be used to calculate recency of infection. A HCV avidity assay was evaluated for both plasma and DBS. To measure antibody avidity a commercial HCV ELISA was modified using 7 M urea. The plasma samples were split into: group 1 (recently infected N = 19), group 2 (chronic carrier N = 300) and group 3 (resolved infection N = 82). Mock DBS made from group 1 (N = 12), group 2 (N = 50), group 3 (N = 25) and two seroconverter panels were evaluated. 133 DBS taken from patients known to have a resolved infection or be a chronic carrier were also tested. The avidity assay cut-off was set at AI≤30 for a recent infection. Using sequential samples the assay could detect a recent infection in the first 4-5 months from the point of infection. Most of the false positive results (AI plasma and DBS; as a result, a testing algorithm has been designed incorporating both PCR and two dilution factors. The sensitivity and specificity of the assay on plasma was 100% and 99.3%, respectively, while DBS had 100% sensitivity and 98.3% specificity. The HCV avidity assay can be used to distinguish between chronic and recent infection using either plasma or DBS as the sample type. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Use of Dried Plasma Spots for HIV-1 Viral Load Determination and Drug Resistance Genotyping in Mexican Patients

    Science.gov (United States)

    Rodriguez-Auad, Juan Pablo; Rojas-Montes, Othon; Maldonado-Rodriguez, Angelica; Alvarez-Muñoz, Ma. Teresa; Muñoz, Onofre; Torres-Ibarra, Rocio; Vazquez-Rosales, Guillermo

    2015-01-01

    Monitoring antiretroviral therapy using measurements of viral load (VL) and the genotyping of resistance mutations is not routinely performed in low- to middle-income countries because of the high costs of the commercial assays that are used. The analysis of dried plasma spot (DPS) samples on filter paper may represent an alternative for resource-limited settings. Therefore, we evaluated the usefulness of analyzing DPS samples to determine VL and identify drug resistance mutations (DRM) in a group of HIV-1 patients. The VL was measured from 22 paired plasma and DPS samples. In these samples, the average VL was 4.7 log10 copies/mL in liquid plasma and 4.1 log10 copies/mL in DPS, with a correlation coefficient of R = 0.83. A 1.1 kb fragment of HIV pol could be amplified in 14/22 (63.6%) of the DPS samples and the same value was amplified in plasma samples. A collection of ten paired DPS and liquid plasma samples was evaluated for the presence of DRM; an excellent correlation was found in the identification of DRM between the paired samples. All HIV-1 pol sequences that were obtained corresponded to HIV subtype B. The analysis of DPS samples offers an attractive alternative for monitoring ARV therapy in resource-limited settings. PMID:26779533

  8. Use of Dried Plasma Spots for HIV-1 Viral Load Determination and Drug Resistance Genotyping in Mexican Patients

    Directory of Open Access Journals (Sweden)

    Juan Pablo Rodriguez-Auad

    2015-01-01

    Full Text Available Monitoring antiretroviral therapy using measurements of viral load (VL and the genotyping of resistance mutations is not routinely performed in low- to middle-income countries because of the high costs of the commercial assays that are used. The analysis of dried plasma spot (DPS samples on filter paper may represent an alternative for resource-limited settings. Therefore, we evaluated the usefulness of analyzing DPS samples to determine VL and identify drug resistance mutations (DRM in a group of HIV-1 patients. The VL was measured from 22 paired plasma and DPS samples. In these samples, the average VL was 4.7 log10 copies/mL in liquid plasma and 4.1 log10 copies/mL in DPS, with a correlation coefficient of R = 0.83. A 1.1 kb fragment of HIV pol could be amplified in 14/22 (63.6% of the DPS samples and the same value was amplified in plasma samples. A collection of ten paired DPS and liquid plasma samples was evaluated for the presence of DRM; an excellent correlation was found in the identification of DRM between the paired samples. All HIV-1 pol sequences that were obtained corresponded to HIV subtype B. The analysis of DPS samples offers an attractive alternative for monitoring ARV therapy in resource-limited settings.

  9. Determination of AJ-3941, a possible agent for the treatment of cerebrovascular disorders, in plasma and brain by means of high-performance liquid chromatography with fluorescence detection.

    Science.gov (United States)

    Kurono, M; Yoshida, K; Naruto, S

    1992-07-01

    A sensitive and selective high-performance liquid chromatographic method with fluorescence detection is described for the determination of AJ-3941 (I), a possible agent for the treatment of cerebrovascular disorders, in plasma and brain tissue. A simple hexane extraction was used for plasma, and for brain homogenate the hexane extract was further purified by solid-phase extraction. The determination limit was ca. 3 ng/ml for both plasma (0.5 ml) and 10% (w/v) brain homogenate (1 ml). The method was applied to the determination of I in plasma and brain samples of experimental animals.

  10. Silver nanoparticles inhibit VEGF-and IL-1β-induced vascular permeability via Src dependent pathway in porcine retinal endothelial cells

    Directory of Open Access Journals (Sweden)

    Park Jongsun

    2009-10-01

    Full Text Available Abstract The aim of this study is to determine the effects of silver nanoparticles (Ag-NP on vascular endothelial growth factor (VEGF-and interleukin-1 beta (IL-1β-induced vascular permeability, and to detect the underlying signaling mechanisms involved in endothelial cells. Porcine retinal endothelial cells (PRECs were exposed to VEGF, IL-1β and Ag-NP at different combinations and endothelial cell permeability was analyzed by measuring the flux of RITC-dextran across the PRECs monolayer. We found that VEGF and IL-1β increase flux of dextran across a PRECs monolayer, and Ag-NP block solute flux induced by both VEGF and IL-1β. To explore the signalling pathway involved VEGF- and IL-1β-induced endothelial alteration, PRECs were treated with Src inhibitor PP2 prior to VEGF and IL-1β treatment, and the effects were recorded. Further, to clarify the possible involvement of the Src pathways in endothelial cell permeability, plasmid encoding dominant negative(DN and constitutively active(CA form of Src kinases were transfected into PRECs, 24 h prior to VEGF and IL-1β exposure and the effects were recorded. Overexpression of DN Src blocked both VEGF-and IL-1β-induced permeability, while overexpression of CA Src rescues the inhibitory action of Ag-NP in the presence or absence of VEGF and IL-1β. Further, an in vitro kinase assay was performed to identify the presence of the Src phosphorylation at Y419. We report that VEGF and IL-1β-stimulate endothelial permeability via Src dependent pathway by increasing the Src phosphorylation and Ag-NP block the VEGF-and IL-1β-induced Src phosphorylation at Y419. These results demonstrate that Ag-NP may inhibit the VEGF-and IL-1β-induced permeability through inactivation of Src kinase pathway and this pathway may represent a potential therapeutic target to inhibit the ocular diseases such as diabetic retinopathy.

  11. Relationship between breast cancer-related lymphoedema and VEGF-C and VEGFR-3%乳腺癌相关淋巴水肿与VEGF-C及VEGFR-3的关系

    Institute of Scientific and Technical Information of China (English)

    贺建业; 吴庆华; 伍冀湘; 钟晨熙; 陈东; 王伟

    2009-01-01

    目的 研究探讨乳腺癌组织中VEGF-C及癌周淋巴管密度(poritumoral lymph vesselsdensity,PLVD)的表达和分布情况及其临床病理学特征,初步探讨其与乳腺癌相关淋巴水肿(breastcancer-related lymphoedema,BCRL)发生间的关系. 方法应用免疫组化技术检测47例乳腺癌组织中VEGF-C及VEGFR-3,观察乳腺癌组织中VEGF-C的表达情况并计数,检测患者双侧上肢周径,判断有无水肿并分级.结果 47例乳腺癌组织中VEGF-C阳性表达者33例,VEGF-C阳性组的PLVD(30.39±10.46)较阴性组(23.16±11.67)明显增高(P<0.05).癌组织内VEGF-C半定量评分与PLVD呈正相关(r=0.334).淋巴结转移组VEGF-C的阳性表达率(42.55%)及半定量评分(3.68±1.59)均高于未转移组(27.66%,2.48±2.31)(P<0.05);淋巴结转移组PLVD高于未转移组(32.12±10.29 vs.24.82±11.06),P<0.05.47例患者中一年内发生BCRL者17例,一年后仍有BCRL的8例.VEGF-C阴性组发生水肿者(5/14)较阳性组(3/33)增加(P<0.05).结论 VEGF-C在乳腺癌组织中有较高的阳性表达率,并且与PLVD呈正相关.乳腺癌组织中VEGF-C高表达可减少BCRL发生的机会.%Objective To study the distribution and clinicopathological characteristics between VEGF-C and pefitumoral lymph vessels density(PLVD) in breast cancer tissue, and to investigate the development and the mechanism of breast cancer-related lymphoedema (BCRL). Methods VEGF-C and VEGFR-3 were detected by using immunohistochemical technique for the detection of VEGF-C and its receptor VEGFR-3 in forty-seven breast cancer specimens. We measured the patients' circumferences of bilateral upper limbs to determine whether there was lymphoedema and made classification in the follow-ups. Results VEGF-C was positive in 33 out of 47 cases. PLVD significantly increased in VEGF-C positive groups (30.39±10. 46) than in negative groups (23.16±11.67) (P<0.05). VEGF-C semi-quantitative score was in a positive correlation with PLVD (r=0.334). The positive

  12. Gene Expression of VEGF-A and VEGF-C in Peripheral Blood Mononuclear Cells of Iranian Patients with Acute Myeloid Leukemia

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Aliparasti

    2013-06-01

    Full Text Available OBJECTIVE: The crucial role of angiogenesis in the pathophysiology of acute myeloid leukemia (AML has been proposed. One of the key regulators of angiogenesis is the vascular endothelial growth factor (VEGF. Among the VEGF family, it has been observed that VEGF-A and VEGF-C are expressed by AML cells and mediate leukemic cell proliferation, survival, and resistance to chemotherapy. Emerging evidence, however, suggests that elevated levels of VEGF or a proangiogenic phenotype may impede, rather than promote, early tumor development and progression. As the significance of VEGF-A and VEGF-C levels in the pathogenesis of AML has not been clarified well, the aim of this study is to evaluate gene expression of these angiogenesis promoters and its possible prognostic value in peripheral blood mononuclear cells of Iranian patients with AML. METHODS: We investigated the mRNA expression of VEGF-A and VEGF-C in peripheral blood mononuclear cells of 27 patients with newly diagnosed AML and 28 healthy controls by quantitative real-time PCR. RESULTS: Expression of VEGF-C mRNA was significantly lower in AML patients than in healthy controls (p<0.001. However, there was no significant decrement in expression of VEGF-A mRNA of AML patients compared to the control group (p=0.861. VEGF-A and VEGF-C expression were not able to predict clinical outcome. CONCLUSION: Our data showed that AML is associated with a decreased expression of VEGF-C mRNA. However, expression levels did not influence the clinical outcome in our study. It seems that angiogenesis is affected by different cytokines other than VEGF-C or VEGF-A, and VEGF is also affected by different cytokines. Taken together, these findings help to provide new insights into the investigation of other angiogenic factors and cytokines that may play roles in the pathogenesis of AML.

  13. A Comparison between Ion chromatography and Inductively Coupled Plasma for the Determination of Bromate in Certain Samples of Foodstuffs

    Directory of Open Access Journals (Sweden)

    Alanowd O. Mehder

    2015-06-01

    Full Text Available Ion chromatography (IC and inductively coupled plasma (ICP-MS both were applied for the determination of bromate in some food samples. Attempts were made to establish calibration curves, however in case of IC, an additional abnormal peak was found to overlap with the bromate peak. This renders IC to be unsuccessful in the determination of bromate compared to ICP-MS technique. ICP-MS was found to give accurate results; therefore, it was applied for the determination of bromate in different samples of food stuffs.

  14. Simultaneous determination of triple therapy for Helicobacter pylori in human plasma by reversed phase chromatography with online wavelength switching

    Science.gov (United States)

    Ahmed, Sameh; Atia, Noha N.

    2015-02-01

    The infection of gastric mucosa by Helicobacter pylori (HP) is an essential cofactor in the aetiology of gastroduodenal ulcer and gastric carcinoma. Because of the bacterial resistance, combination therapy containing omeprazole (OME), tinidazole (TNZ) and clarithromycin (CLA) is commonly used for eradication of HP. However, the simultaneous determination of the triple therapy in human plasma was not reported. A simple, reproducible, and selective HPLC method was developed for the simultaneous determination of the triple therapy mixture used for management of HP infections in human plasma. An HPLC procedure based on a liquid-liquid extraction, enrichment of the analytes and subsequent reversed-phase chromatography with UV detection was used. To enable sensitive and selective detection, the method involved the use of online wavelength switching detection, with two different detection wavelengths; 280 nm for detection of OME and TNZ and 210 nm for detection of CLA. Separations were performed on C18 analytical column with acetonitrile-10 mM phosphate buffer of pH = 3.0 at flow rate of 1.0 mL min-1. The linear ranges in human plasma were 0.05-10 μg mL-1 with correlation coefficients >0.9990. The detection limits in human plasma were 0.02-0.07 μg mL-1. Validation parameters were assessed in compliance with US-FDA guidelines. The method proved to be valuable for the therapeutic drug monitoring after oral administration of triple therapy tablets.

  15. Quantitative determination of fentanyl in newborn pig plasma and cerebrospinal fluid samples by HPLC-MS/MS.

    Science.gov (United States)

    Blanco, M E; Encinas, E; González, O; Rico, E; Vozmediano, V; Suárez, E; Alonso, R M

    2015-09-01

    In this study, a selective and sensitive high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method requiring low sample volume (≤100 μL) was developed and validated for the quantitative determination of the opioid drug fentanyl in plasma and cerebrospinal fluid (CSF). A protein precipitation extraction with acetonitrile was used for plasma samples whereas CSF samples were injected directly on the HPLC column. Fentanyl and (13) C6 -fentanyl (Internal Standard) were analyzed in an electrospray ionization source in positive mode, with multiple reaction monitoring (MRM) of the transitions m/z 337.0/188.0 and m/z 337.0/105.0 for quantification and confirmation of fentanyl, and m/z 343.0/188.0 for (13) C6 -fentanyl. The respective lowest limits of quantification for plasma and CSF were 0.2 and 0.25 ng/mL. Intra- and inter-assay precision and accuracy did not exceed 15%, in accordance with bioanalytical validation guidelines. The described analytical method was proven to be robust and was successfully applied to the determination of fentanyl in plasma and CSF samples from a pharmacokinetic and pharmacodynamic study in newborn piglets receiving intravenous fentanyl (5 µg/kg bolus immediately followed by a 90-min infusion of 3 µg/kg/h).

  16. Rapid determination of piracetam in human plasma and cerebrospinal fluid by micellar electrokinetic chromatography with sample direct injection.

    Science.gov (United States)

    Yeh, Hsin-Hua; Yang, Yuan-Han; Ko, Ju-Yun; Chen, Su-Hwei

    2006-07-07

    A simple micellar electrokinetic chromatography (MEKC) method with UV detection at 200 nm for analysis of piracetam in plasma and in cerebrospinal fluid (CSF) by direct injection without any sample pretreatment is described. The separation of piracetam from biological matrix was performed at 25 degrees C using a background electrolyte consisting of Tris buffer with sodium dodecyl sulfate (SDS) as the electrolyte solution. Several parameters affecting the separation of the drug from biological matrix were studied, including the pH and concentrations of the Tris buffer and SDS. Under optimal MEKC condition, good separation with high efficiency and short analyses time is achieved. Using imidazole as an internal standard (IS), the linear ranges of the method for the determination of piracetam in plasma and in CSF were all between 5 and 500 microg/mL; the detection limit of the drug in plasma and in CSF (signal-to-noise ratio=3; injection 0.5 psi, 5s) was 1.0 microg/mL. The applicability of the proposed method for determination of piracetam in plasma and CSF collected after intravenous administration of 3g piracetam every 6h and oral administration 1.2g every 6h in encephalopathy patients with aphasia was demonstrated.

  17. VEGF in hepatocellular carcinoma and surrounding cirrhotic liver tissues

    Institute of Scientific and Technical Information of China (English)

    Muriel Mathonnet; Bernard Descottes; Denis Valleix; Francois Labrousse; Yves Denizot

    2006-01-01

    @@ TO THE EDITOR We read with a great interest the recent work of Deli and colleagues.[1] in the World Journal of Gastroenterology reporting vascular endothelial growth factor (VEGF) expression in hepatocellular carcinoma (HCC) and cirrhotic liver tissues.

  18. Determination of snake-necked turtle Hydromedusa tectifera (Cope, 1870) (Testudines: Chelidae) plasma protein concentrations by refractometry and the biuret method.

    OpenAIRE

    2011-01-01

    The purpose of this study was to evaluate the accuracy of hand-held refractometer in determining plasma protein concentrations in South American snake-necked turtle (Hydromedusa tectifera) as compared with the standard biuret method. The results indicated that plasma protein values may be accurately determined in snake- necked turtle with a hand-held refractometer.

  19. Analysis of diabetic retinopathy biomarker VEGF gene by computational approaches

    OpenAIRE

    Jayashree Sadasivam; Ramesh, N.; K. Vijayalakshmi; Vinni Viridi; Shiva prasad

    2012-01-01

    Diabetic retinopathy, the most common diabetic eye disease, is caused by changes in the blood vessels of the retina which remains the major cause. It is characterized by vascular permeability and increased tissue ischemia and angiogenesis. One of the biomarker for Diabetic retinopathy has been identified as Vascular Endothelial Growth Factor ( VEGF )gene by computational analysis. VEGF is a sub-family of growth factors, the platelet-derived growth factor family of cystine-knot growth factors...

  20. Vascular endothelial growth factor (VEGF and prostate pathology

    Directory of Open Access Journals (Sweden)

    Francisco Botelho

    2010-08-01

    Full Text Available PURPOSE: Previous studies suggest that vascular endothelial growth factor (VEGF circulating levels might improve identification of patients with prostate cancer but results are conflicting. Our aim was to compare serum VEGF levels across different prostate pathologies (including benign prostatic hyperplasia, prostatitis, high grade prostate intraepithelial neoplasia and prostate cancer in patients at high risk of prostate cancer. MATERIALS AND METHODS: We consecutively enrolled 186 subjects with abnormal digital rectal examination and/or total PSA (tPSA = 2.5 ng/mL. Blood was collected before diagnostic ultrasound guided trans-rectal prostate biopsy, or any prostate oncology treatment, to measure PSA isoforms and VEGF. Unconditional logistic regression was used to compute age-, tPSA- and free/total PSA-adjusted odds ratios (OR and respective 95% confidence intervals (95% CI for the association between serum VEGF and different prostatic pathologies. RESULTS: Prostate biopsy main diagnoses were normal or benign prostatic hyperplasia (27.3%, prostatitis (16.6%, and prostatic cancer (55.0%. The median VEGF levels (ng/mL in these groups were 178.2, 261.3 and 266.4 (p = 0.029, respectively, but no significant differences were observed for benign vs. malignant pathologies (215.2 vs. 266.4, p = 0.551. No independent association was observed between VEGF (3rd vs. 1st third and prostate cancer, when compared to benign conditions (adjusted OR = 1.44; CI 95%: 0.64-3.26. CONCLUSIONS: In patients at high risk of prostate cancer, circulating VEGF levels have no clinical role in deciding which patients should be submitted to prostate biopsy. Prostatitis patients, often with higher PSA levels, also present high serum levels of VEGF, and their inclusion in control groups might explain the heterogeneous results in previous studies.

  1. [Selenium determination in plasma/serum by inductively coupled plasma mass spectrometry (ICP-MS): comparison with graphite furnace atomic absorption spectrometry (GF-AAS)].

    Science.gov (United States)

    Janasik, Beata; Trzcinka-Ochocka, Małgorzata; Brodzka, Renata

    2011-01-01

    The present study was aimed at comparing two techniques of selenium (Se) determination in serum/plasma samples: inductively coupled plasma mass spectrometry (ICP-MS) and graphite furnace atomic absorption (GF-AAS). Blood samples were collected by venipuncture, using Venosafe closed blood sampling system. The samples were centrifuged. The measurements were performed by Elan DRC-e mass spectrometry, Perkin Elmer, SCIEX, USA and Unicam Solar 989 QZ atomic absorption spectrometry. Reference material, Clincheck Serum Control Level 1 (Recipe, Germany), was used to verify the determinations. The Laboratory participates in external quality control (G-EQUAS). Analytical parameters for both techniques are respectively: ICP-MS--precision 5.9%, limit of detection 0.19 microg/l, repeatability 5.5%, trueness 2.4%, bias 97.6%, GF-AAS--precision 8%, limit of detection 3.4 microg/l, repeatability 7.2%, trueness 6.8%, bias 93.2%. The benefits of the ICP-MS technique are high accuracy, low detection limits and the possibility of multi-element analysis.

  2. Novel determinants of H-Ras plasma membrane localization and transformation

    DEFF Research Database (Denmark)

    Willumsen, B M; Cox, A D; Solski, P A;

    1996-01-01

    cysteine did not abolish palmitoylation. However, despite continued lipid modification the mutant proteins failed to bind to plasma membranes and instead accumulated on internal membranes and, importantly, were not transforming. Addition of an N-terminal myristoylation signal to these defective mutants......, or to proteins entirely lacking the C-terminal 25 residues restored both plasma membrane association and transforming activity. Thus, H-Ras does not absolutely require prenylation or palmitoylation nor indeed its hypervariable domain in order to interact with effectors that ultimately cause transformation....... However, in this native state, the C-terminus appears to provide a combination of lipids and a previously unrecognized signal for specific plasma membrane targeting that are essential for the correct localization and biological function of H-Ras....

  3. Liquid chromatography determination of clobazam and its major metabolite N-desmethylclobazam in human plasma.

    Science.gov (United States)

    Brachet-Liermain, A; Jarry, C; Faure, O; Guyot, M; Loiseau, P

    1982-01-01

    A specific procedure for the analysis of clobazam and N-desmethylclobazam in plasma is described. Reversed-phase liquid chromatography was performed on a Radial-pak cartridge using a mixture of 45% acetonitrile and 55% buffer solution (pH 7); the ultraviolet detector was set at 254 nm. The method used diazepam as internal standard and diethylether as extraction solvent. The calibration curves are linear between 50 and 500 ng/ml for clobazam and between 100 and 1000 ng/ml for N-desmethylclobazam. The day-to-day precision of the procedure at clobazam plasma concentrations of 50, 250, and 500 ng/ml generated coefficients of variation of 2.2, 6.6, and 11.3%, respectively. No interference occurred in plasma from patients treated with various drugs. The method has been used to study the pharmacokinetics of clobazam and N-desmethylclobazam in patients receiving oral clobazam.

  4. Determination of the Ion Velocity Distribution in a Rotating Plasma from Measurements of Doppler Broadening

    DEFF Research Database (Denmark)

    Jørgensen, L. W.; Sillesen, Alfred Hegaard

    1979-01-01

    The Doppler-broadened profile of the He II 4685.75 AA line was measured along a chord in a rotating plasma, transverse to the magnetic field. Using a single-particle orbit picture, the corresponding velocity spectrum of ions confirm the measurements, so it can be concluded that the single......-particle orbit picture is valid for the discharge period under investigation, except for the first few microseconds during breakdown when a strong interaction between plasma and remaining neutral gas takes place by Alfvens critical velocity mechanism. A simple relation is given between the measured half......-width and shift of the Doppler profile and the macroscopic quantities of ion velocity and energy. Several Doppler-broadened profiles are shown for different plasma parameters....

  5. Determination of elastic modulus and residual stress of plasma-sprayed tungsten coating on steel substrate

    Energy Technology Data Exchange (ETDEWEB)

    You, J.H. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmann Street 2, 85748 Garching (Germany)]. E-mail: jeong-ha.you@ipp.mpg.de; Hoeschen, T. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmann Street 2, 85748 Garching (Germany); Lindig, S. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmann Street 2, 85748 Garching (Germany)

    2006-01-01

    Plasma-sprayed tungsten, which is a candidate material for the first wall armour, shows a porous, heterogeneous microstructure. Due to its characteristic morphology, the properties are significantly different from those of its dense bulk material. Measurements of the elastic modulus of this coating have not been reported in the literature. In this work Young's modulus of highly porous plasma-sprayed tungsten coatings deposited on steel (F82H) substrates was measured. For the fabrication of the coating system the vacuum plasma-spray process was applied. Measurements were performed by means of three-point and four-point bending tests. The obtained modulus values ranged from 53 to 57 GPa. These values could be confirmed by the test result of a detached coating strip, which was 54 GPa. The applied methods produced consistent results regardless of testing configurations and specimen sizes. The errors were less than 1%. Residual stress of the coating was also estimated.

  6. Determination of elastic modulus and residual stress of plasma-sprayed tungsten coating on steel substrate

    Science.gov (United States)

    You, J. H.; Höschen, T.; Lindig, S.

    2006-01-01

    Plasma-sprayed tungsten, which is a candidate material for the first wall armour, shows a porous, heterogeneous microstructure. Due to its characteristic morphology, the properties are significantly different from those of its dense bulk material. Measurements of the elastic modulus of this coating have not been reported in the literature. In this work Young's modulus of highly porous plasma-sprayed tungsten coatings deposited on steel (F82H) substrates was measured. For the fabrication of the coating system the vacuum plasma-spray process was applied. Measurements were performed by means of three-point and four-point bending tests. The obtained modulus values ranged from 53 to 57 GPa. These values could be confirmed by the test result of a detached coating strip, which was 54 GPa. The applied methods produced consistent results regardless of testing configurations and specimen sizes. The errors were less than 1%. Residual stress of the coating was also estimated.

  7. Thrombospondin-1 and VEGF in inflammatory bowel disease

    Directory of Open Access Journals (Sweden)

    Canan Alkim

    2012-01-01

    Full Text Available Angiogenesis is an important process in the pathogenesis of chronic inflammation. We aimed to study the angiogeneic balance in inflammatory bowel disease (IBD by evaluating the expression of vascular endothelial growth factor (VEGF and thrombospondin-1 (TSP-1 on colonic epithelial cells, together with the expression of inducible nitric oxide synthase (iNOS.Twenty-one ulcerative colitis (UC, 14 Crohn's disease (CD, 11 colorectal cancer patients, and 11 healthy controls colonic biopsy samples were evaluated immunohistochemically.The expressions of TSP-1, VEGF, and iNOS in UC and CD groups were higher than expression in healthy control group, all with statistical significance. However, in colorectal cancer group, VEGF and iNOS expressions were increased importantly, but TSP-1 expression was not statistically different from healthy control group's expression. Both TSP-1 and VEGF expressions were correlated with iNOS expression distinctly but did not correlate with each other.Both pro-angiogeneic VEGF and antiangiogeneic TSP-1 expressions were found increased in our IBD groups, but in colorectal cancer group, only VEGF expression was increased. TSP-1 increases in IBD patients as a response to inflammatory condition, but this increase was not enough to suppress pathologic angiogenesis and inflammation in IBD.

  8. Gas temperature determination in an argon non-thermal plasma at atmospheric pressure from broadenings of atomic emission lines

    Science.gov (United States)

    Yubero, C.; Rodero, A.; Dimitrijevic, M. S.; Gamero, A.; García, M. C.

    2017-03-01

    In this work a new spectroscopic method, allowing gas temperature determination in argon non-thermal plasmas sustained at atmospheric pressure, is presented. The method is based on the measurements of selected pairs of argon atomic lines (Ar I 603.2 nm/Ar I 549.6 nm, Ar I 603.2 nm/Ar I 522.1 nm, Ar I 549.6 nm/Ar I 522.1 nm). For gas temperature determination using the proposed method, there is no need of knowing the electron density, neither making assumptions on the degree of thermodynamic equilibrium existing in the plasma. The values of the temperatures obtained using this method, have been compared with the rotational temperatures derived from the OH ro-vibrational bands, using both, the well-known Boltzmann-plot technique and the best fitting to simulated ro-vibrational bands. A very good agreement has been found.

  9. A fast and sensitive method for the determination of nitrite in human plasma by capillary electrophoresis with fluorescence detection.

    Science.gov (United States)

    Wang, Xu; Adams, Erwin; Van Schepdael, Ann

    2012-08-15

    Analysis of nitrite, the indicator of nitric oxide (NO) generation in vivo, provides a useful tool to study NO synthesis in vivo. A fast and sensitive fluorometric CE method was developed for determination of nitrite in human plasma through its derivatization with 2,3-diaminonaphthalene (DAN). Nitrite in human plasma was easily reacted with DAN under acid conditions to yield the highly fluorescent 2,3-naphthotriazole (NAT). Fluorescence detection was optimized to achieve subnanomolar detection which allows a direct analysis of plasma samples unlike most CE-UV methods using sample stacking. Acetonitrile was used to remove the protein. Short-end injection and a high voltage (-30 kV) were used to shorten the analysis time. The good separation was achieved with 20 mM borate buffer at pH 9.23. The separation of NAT was obtained within 1.4 min. The deproteinized plasma sample was injected hydrodynamically for 5s at -50 mbar into a 60 cm × 75 μm internal diameter uncoated fused-silica capillary. Excitation wavelength was selected with a broad-band filter (240-400 nm), and the emitted light was measured at 418 nm by the use of a cutoff filter. A good linearity (R(2)=0.9975) was obtained in the range from 2 to 500 nM. The detection limit of nitrite was 0.6 nM in original plasma samples, which is 750 times lower than our previous CE-UV method. The developed fluorometric CE method offers the advantages of more simple system and lower cost compared with the current fluorometric HPLC methods without losing sensitivity. The detected mean nitrite concentration in human plasma by this method was consistent with the most frequently reported values.

  10. Simultaneous determination of oxysterols, cholesterol and 25-hydroxy-vitamin D3 in human plasma by LC-UV-MS.

    Directory of Open Access Journals (Sweden)

    Rohini Narayanaswamy

    Full Text Available Oxysterols are promising biomarkers of neurodegenerative diseases that are linked with cholesterol and vitamin D metabolism. There is an unmet need for methods capable of sensitive, and simultaneous quantitation of multiple oxysterols, vitamin D and cholesterol pathway biomarkers.A method for simultaneous determination of 5 major oxysterols, 25-hydroxy vitamin D3 and cholesterol in human plasma was developed. Total oxysterols were prepared by room temperature saponification followed by solid phase extraction from plasma spiked with deuterated internal standards. Oxysterols were resolved by reverse phase HPLC using a methanol/water/0.1% formic acid gradient. Oxysterols and 25-hydroxy vitamin D3 were detected with atmospheric pressure chemical ionization mass spectrometry in positive ion mode; in-series photodiode array detection at 204nm was used for cholesterol. Method validation studies were performed. Oxysterol levels in 220 plasma samples from healthy control subjects, multiple sclerosis and other neurological disorders patients were quantitated.Our method quantitated 5 oxysterols, cholesterol and 25-hydroxy vitamin D3 from 200 μL plasma in 35 minutes. Recoveries were >85% for all analytes and internal standards. The limits of detection were 3-10 ng/mL for oxysterols and 25-hydroxy vitamin D3 and 1 μg/mL for simultaneous detection of cholesterol. Analytical imprecision was <10 %CV for 24(S-, 25-, 27-, 7α-hydroxycholesterol (HC and cholesterol and ≤15 % for 7-keto-cholesterol. Multiple Sclerosis and other neurological disorder patients had lower 27-hydroxycholesterol levels compared to controls whereas 7α-hydroxycholesterol was lower specifically in Multiple Sclerosis.The method is suitable for measuring plasma oxysterols levels in human health and disease. Analysis of human plasma indicates that the oxysterol, bile acid precursors 7α-hydroxycholesterol and 27-hydroxycholesterol are lower in Multiple Sclerosis and may serve as potential

  11. A Re-Evaluation of Trapped Plasma in the Microhematocrit Determination.

    Science.gov (United States)

    1986-01-01

    reported that trapped plasma values were increased in samples of healthy subjects with hereditary spherocytosis . Economou-Marvou and Tsenghi in 1965 (9...TARGETS LF 2.50 31.9 83.8 28.1 33.5 13.8 *MOD ELLIPTOCYTOSIS SP 2.85 30.3 83.6 32.5 38.9 27.8 *MOD SPHEROCYTOSIS AN 2.09 35.2 82.7 26.5 32.1 15.6...lower red cell size. They stated that anisocytosis and spherocytosis by themselves do not alter the amount of trapped plasma, and that microcytic cells

  12. Synthesis of silicon carbide in a nitrogen plasma torch: rotational temperature determination and material analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Camacho, J; Castell, R [Universidad Simon BolIvar, Departamento de Fisica, Caracas (Venezuela, Bolivarian Republic of); Castro, A; Manrique, M [Universidad Simon BolIvar, Departamento de Ciencias de los Materiales, Caracas (Venezuela, Bolivarian Republic of)], E-mail: jgruiz@usb.ve

    2008-09-07

    Experiments on silicon carbide synthesis were performed using a dc nitrogen plasma torch. Measurements of rotational temperature of nitrogen molecules by emission spectroscopy were performed, based on the band (0, 1) of the first negative system of nitrogen N{sub 2}{sup +}(B{sup 2}{sigma}{sub u}{sup +}{yields}X{sup 2}{sigma}{sub g}{sup +}) for the R branch. Three different plasma torch powers were studied in order to optimize the production of silicon carbide with our experimental set-up. The synthesized products were characterized by x-ray diffraction, scanning electron microscopy and energy dispersive x-ray spectroscopy.

  13. Synthesis of silicon carbide in a nitrogen plasma torch: rotational temperature determination and material analysis

    Science.gov (United States)

    Ruiz-Camacho, J.; Castell, R.; Castro, A.; Manrique, M.

    2008-09-01

    Experiments on silicon carbide synthesis were performed using a dc nitrogen plasma torch. Measurements of rotational temperature of nitrogen molecules by emission spectroscopy were performed, based on the band (0, 1) of the first negative system of nitrogen N_2^+ (B\\,{}^2\\Sigma_u^+ \\to X\\,{}^2\\Sigma _g^+) for the R branch. Three different plasma torch powers were studied in order to optimize the production of silicon carbide with our experimental set-up. The synthesized products were characterized by x-ray diffraction, scanning electron microscopy and energy dispersive x-ray spectroscopy.

  14. Determination of albumin transport rate between plasma and peritoneal space in decompensated cirrhosis

    DEFF Research Database (Denmark)

    Ring-Larsen, H; Henriksen, Jens Henrik Sahl

    1984-01-01

    the abdominal puncture may lead to overestimation of TERperit.space, whereas systematic understimation seems less likely. This may besides differences in patient selection and unsteady state, account for the discrepancy between the present relatively low value and earlier reports on much higher values.......10-0.59). The transport rate of albumin from ascitic fluid back to plasma was measured in eight patients by plasma sampling after intraperitoneal injection of 131I-labelled serum albumin. After correction for tracer re-extravasation this back transport (median 0.31, range 0.07-0.44% IVM/h-1) was not significantly...

  15. Determination of desmethyldiazepam in plasma by electron-capture GLC: application to pharmacokinetic studies of clorazepate.

    Science.gov (United States)

    Greenblatt, D J

    1978-03-01

    Plasma desmethyldiazepam concentrations were quantitated by a rapid and sensitive technique using electron-capture GLC. Following addition of diazepam as the internal standard, plasma is extracted at physiological pH into benzene-isoamyl alcohol. The extract is evaporated to dryness and reconstituted with toluene-isoamyl alcohol prior to chromatography. Both diazepam and desmethyldiazepam are quantitatively extracted. The variation of identical samples is 5%, and the sensitivity is 5 ng of desmethyldiazepam/ml of original sample. The method is applicable to pharmacokinetic studies of clorazepate, a benzodiazepine derivative transformed to desmethyldiazepam prior to absorption.

  16. Polylysine-modified polyethylenimine (PEI-PLL) mediated VEGF gene delivery protects dopaminergic neurons in cell culture and in rat models of Parkinson's Disease (PD).

    Science.gov (United States)

    Sheikh, Muhammad Abid; Malik, Yousra Saeed; Xing, Zhenkai; Guo, Zhaopei; Tian, Huayu; Zhu, Xiaojuan; Chen, Xuesi

    2017-05-01

    Parkinson's Disease (PD) is a chronic neurodegenerative disorder characterized by motor deficits which result from the progressive loss of dopaminergic neurons. Gene therapy using growth factors such as VEGF seems to be a viable approach for potential therapeutic treatment of PD. In this study, we utilized a novel non-viral gene carrier designated as PEI-PLL synthesized by our laboratory to deliver VEGF gene to study its effect by using both cell culture as well as animal models of PD. For cell culture experiments, we utilized 6-hydroxydopamine (6-OHDA) mediated cell death model of MN9D cells following transfection with either a control plasmid or VEGF expressing plasmid. As compared to control transfected cells, PEI-PLL mediated VEGF gene delivery to MN9D cells resulted in increased cell viability, increase in the number of Tyrosine hydroxylase (TH) positive cells and decreased apoptosis following 6-OHDA insult. Next, we studied the therapeutic potential of PEI-PLL mediated VEGF gene delivery in SNPc by using unilateral 6-OHDA Medial forebrain bundle (MFB) lesion model of PD in rats. VEGF administration prevented the loss of motor functions induced by 6-OHDA as determined by behavior analysis. Similarly, VEGF inhibited the 6-OHDA mediated loss of DA neurons in Substantia Nigra Pars Compacta (SNPc) as well as DA nerve fibers in striatum as determined by TH immunostaining. In addition, PEI-PLL mediated VEGF gene delivery also prevented apoptosis and microglial activation in PD rat models. Together, these results clearly demonstrated the beneficial effects of PEI-PLL mediated VEGF gene delivery on dopaminergic system in both cell culture and animal models of PD. In this report, we exploited the potential of PEI-PLL to deliver VEGF gene for the potential therapeutic treatment of PD by using both cell culture and animal models of PD. To the best of our knowledge, this is the first report describing the use of novel polymeric gene carriers for the delivery of VEGF gene

  17. A New Liquid Chromatography-Tandem Mass Spectrometry Method for Determination of Bisoprolol in Human Plasma Samples

    OpenAIRE

    Gabriela Peste; Nela Bibire; Mihai Apostu; Aurel Vlase; Corneliu Oniscu

    2009-01-01

    Liquid chromatography (LC) coupled with mass spectrometry (MS) detection is one of the most powerful analytical tools for organic compound analysis. The advantages of using LC/MS methods over HPLC methods include: selectivity, chromatographic integrity, peak assignment, structural information, and rapid method development. In this paper, a new liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the determination of bisoprolol in human plasma s...

  18. Application of inductively coupled plasma quadrupole mass spectrometry for the determination of monazite ages by lead isotope ratios

    OpenAIRE

    Godoy,José Marcus; Godoy,Maria Luiza D. P; Aronne,Cláudia C.

    2007-01-01

    In order to evaluate the applicability of inductively coupled plasma quadrupole mass spectrometry to the determination of Pb/Pb, U/Pb and Th/Pb ages of monazite, studies were carried out initially applying lead atom ratio reference standards (NIST SRM 981 and 982). Further, the optimized methodology was applied to monazite sands from three different sites, Sugar Loaf Hill (Rio de Janeiro city), Buena (Rio de Janeiro state) and Black Sands Beach (Guarapari, Espirito Santo state); the obtained ...

  19. Isolation of Francisella tularensis and Yersinia pestis from Blood Cultures by Plasma Purification and Immunomagnetic Separation Accelerates Antibiotic Susceptibility Determination

    Science.gov (United States)

    Aloni-Grinstein, Ronit; Schuster, Ofir; Yitzhaki, Shmuel; Aftalion, Moshe; Maoz, Sharon; Steinberger-Levy, Ida; Ber, Raphael

    2017-01-01

    The early symptoms of tularemia and plague, which are caused by Francisella tularensis and Yersinia pestis infection, respectively, are common to other illnesses, resulting in a low index of suspicion among clinicians. Moreover, because these diseases can be treated only with antibiotics, rapid isolation of the bacteria and antibiotic susceptibility testing (AST) are preferable. Blood cultures of patients may serve as a source for bacteria isolation. However, due to the slow growth rates of F. tularensis and Y. pestis on solid media, isolation by plating blood culture samples on proper agar plates may require several days. Thus, improving the isolation procedure prior to antibiotic susceptibility determination is a major clinically relevant need. In this study, we developed a rapid, selective procedure for the isolation of F. tularensis and Y. pestis from blood cultures. We examined drop-plating and plasma purification followed by immunomagnetic separation (IMS) as alternative isolation methods. We determined that replacing the classical isolation method with drop-plating is advantageous with respect to time at the expense of specificity. Hence, we also examined isolation by IMS. Sub-localization of F. tularensis within blood cultures of infected mice has revealed that the majority of the bacteria are located within the extracellular fraction, in the plasma. Y. pestis also resides within the plasma. Therefore, the plasma fraction was isolated from blood cultures and subjected to an IMS procedure using polyclonal anti-F. tularensis live vaccine strain (LVS) or anti-Y. pestis antibodies conjugated to 50-nm nano-beads. The time required to reach an inoculum of sufficient bacteria for AST was shortest when using the plasma and IMSs for both bacteria, saving up to 2 days of incubation for F. tularensis and 1 day for Y. pestis. Our isolation procedure provides a proof of concept for the clinical relevance of rapid isolation for AST from F. tularensis- and Y. pestis

  20. A pilot study on potential plasma hypoxia markers in the radiotherapy of non-small cell lung cancer. Osteopontin, carbonic anhydrase IX and vascular endothelial growth factor

    Energy Technology Data Exchange (ETDEWEB)

    Ostheimer, C.; Bache, M.; Guettler, A.; Vordermark, D. [Martin-Luther-University Halle-Wittenberg, Department of Radiation Oncology, Halle (Saale) (Germany); Kotzsch, M. [Technical University Dresden, Department of Pathology, Dresden (Germany)

    2014-03-15

    Hypoxic radioresistance plays a critical role in the radiotherapy of cancer and adversely impacts prognosis and treatment response. This prospective study investigated the interrelationship and the prognostic significance of several hypoxia-related proteins in non-small cell lung cancer (NSCLC) patients treated by radiotherapy ± chemotherapy. Pretreatment osteopontin (OPN), vascular endothelial growth factor (VEGF) and carbonic anhydrase IX (CA IX) plasma levels were determined by ELISA in 55 NSCLC (M0) patients receiving 66 Gy curative-intent radiotherapy or chemoradiation. Marker correlation, association with clinicopathological parameters and the prognostic value of a biomarker combination was evaluated. All biomarkers were linearly correlated and linked to different clinical parameters including lung function, weight loss (OPN), gross tumor volume (VEGF) and T stage (CA IX). High OPN (p = 0.03), VEGF (p = 0.02) and CA IX (p = 0.04) values were significantly associated with poor survival. Double marker combination additively increased the risk of death by a factor of 2 and high plasma levels of the triple combination OPN/VEGF/CA IX yielded a 5.9-fold risk of death (p = 0.009). The combined assessment of OPN/VEGF/CA IX correlated independently with prognosis (p = 0.03) in a multivariate Cox regression model including N stage, T stage and GTV. This pilot study suggests that a co-detection augments the prognostic value of single markers and that the integration of OPN, VEGF and CA IX into a hypoxic biomarker profile for the identification of patients with largely hypoxic and radioresistant tumors should be further evaluated. (orig.) [German] Hypoxische Radioresistenz spielt eine kritische Rolle in der Radiotherapie maligner Tumoren und beeinflusst Prognose und Therapieansprechen negativ. Diese prospektive Studie untersuchte den Zusammenhang und die prognostische Bedeutung einiger hypoxieassoziierter Proteine bei Patienten mit nicht-kleinzelligem Bronchialkarzinom

  1. Serum TNF-α, IL-8, VEGF Levels in Helicobacter pylori Infection and Their Association with Degree of Gastritis

    Directory of Open Access Journals (Sweden)

    Gontar A Siregar

    2015-04-01

    Full Text Available Aim: to investigate the serum levels of TNF-α, IL-8, VEGF in Helicobacter pylori infection, and their association with the degrees of gastritis histopathology. Methods: a cross-sectional study was done on 80 consecutive gastritis patients admitted to endoscopy units at Adam Malik General Hospital and Permata Bunda Hospital, Medan, Indonesia from July-December 2014. The Rapid Urease test was used for the diagnosis of H. pylori infection. The severity of chronic inflammation, neutrophil infiltration, atrophy, and intestinal metaplasia were assessed. Serum samples were obtained to determine circulating TNF-α, IL-8, and VEGF. Univariate and bivariate analysis (chi square, fisher’s exact, and mann-whitney test were done using SPSS version-22. Results: there were 41.25% of 80 patients infected with Helicobacter pylori. Serum TNF-α and VEGF levels in the infected group were significantly higher compared to H. pylori negative, but there were no significant differences between serum levels of IL-8 in H. pylori positive and negative. There were significant associations between serum level of TNF-α and IL-8 with degree of chronic inflammation, and also between serum level of IL-8 and degree of neutrophil infiltration. There were significant associations between serum level of VEGF and degree of atrophy, and also between serum level of VEGF and degree of intestinal metaplasia. Conclusion: High levels of TNF-α were associated with severe degree of chronic inflammation, high levels of IL-8 associated with severe degree of chronic inflammation and neutrophil infiltration, and high levels of VEGF associated with severe degree of premalignant gastric lesion. Key words: cytokine, neoangiogenesis, Helicobacter pylori, atrophic gastritis, intestinal metaplasia.

  2. Electrochemical detection of vascular endothelial growth factors (VEGFs) using VEGF antibody fragments modified Au NPs/ITO electrode.

    Science.gov (United States)

    Kim, Gang-Il; Kim, Kyung-Woo; Oh, Min-Kyu; Sung, Yun-Mo

    2010-03-15

    A new electrochemical technique for the detection of vascular endothelial growth factors (VEGFs) as a cancer-related biomarker is presented in this paper. Gold nanoparticles (Au NPs) were self-assembled onto an indium tin oxide (ITO) electrode to prepare a modified sandwich type electrochemical immunoassay platform. VEGF antibodies were cleaved into two half-fragments by 2-mercaptoethylamine-HCl (2-MEA) and the fragments were immobilized onto the Au NP substrates by their thiol groups. Through this strategy, randomly oriented attachment of antibodies was prevented which frequently occurs in a general use of whole antibody and reduces the number of available sites for the attachment of target molecules. VEGF target molecules were applied to the immunoelectrodes and they combined with the antibody fragments covering the Au NP electrode, forming antigen-antibody complexes. Then, ferrocene-tagged antibodies, which release electrons under a proper applied potential, were added to the system and they combined with the VEGF molecules pre-attached to the antibody fragments. The redox current of ferrocene measured by the differential pulse voltammetry (DPV) increased almost linearly from 1.27 x 10(-4) to 4.17 x 10(-4)A according to the increase in the concentration of the VEGF target molecules from 100 to 600 pg/ml. The measured current values represent the concentration of the VEGF since they are proportional to the number of ferrocene molecules which is in turn proportional to the concentration of VEGF target molecules. Using this modified sandwich immunoassay with the Au NP/ITO electrode, VEGFs as low as 100 pg/ml were detected with high specificity.

  3. Plasma interactions determine the composition in pulsed laser deposited thin films

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jikun; Stender, Dieter; Conder, Kazimierz; Wokaun, Alexander; Schneider, Christof W.; Lippert, Thomas, E-mail: thomas.lippert@psi.ch [Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland); Döbeli, Max [Laboratory of Ion Beam Physics, ETH Zurich, CH-8093 Zurich (Switzerland)

    2014-09-15

    Plasma chemistry and scattering strongly affect the congruent, elemental transfer during pulsed laser deposition of target metal species in an oxygen atmosphere. Studying the plasma properties of La{sub 0.6}Sr{sub 0.4}MnO{sub 3}, we demonstrate for as grown La{sub 0.6}Sr{sub 0.4}MnO{sub 3-δ} films that a congruent transfer of metallic species is achieved in two pressure windows: ∼10{sup −3} mbar and ∼2 × 10{sup −1} mbar. In the intermediate pressure range, La{sub 0.6}Sr{sub 0.4}MnO{sub 3-δ} becomes cation deficient and simultaneously almost fully stoichiometric in oxygen. Important for thin film growth is the presence of negative atomic oxygen and under which conditions positive metal-oxygen ions are created in the plasma. This insight into the plasma chemistry shows why the pressure window to obtain films with a desired composition and crystalline structure is narrow and requires a careful adjustment of the process parameters.

  4. Determination of Arsenic in Sinus Wash and Tap Water by Inductively Coupled Plasma-Mass Spectrometry

    Science.gov (United States)

    Donnell, Anna M.; Nahan, Keaton; Holloway, Dawone; Vonderheide, Anne P.

    2016-01-01

    Arsenic is a toxic element to which humans are primarily exposed through food and water; it occurs as a result of human activities and naturally from the earth's crust. An experiment was developed for a senior level analytical laboratory utilizing an Inductively Coupled Plasma-Mass Spectrometer (ICP-MS) for the analysis of arsenic in household…

  5. Determination of trace elements in petroleum products by inductively coupled plasma techniques: A critical review

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez, Raquel [Department of Analytical Chemistry, Nutrition and Food Sciences, P.O. Box 99, 03080, Alicante (Spain); Todolí, José Luis, E-mail: jose.todoli@ua.es [Department of Analytical Chemistry, Nutrition and Food Sciences, P.O. Box 99, 03080, Alicante (Spain); Lienemann, Charles-Philippe [IFP Energies Nouvelles, Rond-point de l' échangeur de Solaize, BP 3, F-69360 Solaize (France); Mermet, Jean-Michel [Spectroscopy Forever, 01390 Tramoyes (France)

    2013-10-01

    The fundamentals, applications and latter developments of petroleum products analysis through inductively coupled plasma optical emission spectrometry (ICP-OES) and mass spectrometry (ICP-MS) are revisited in the present bibliographic survey. Sample preparation procedures for the direct analysis of fuels by using liquid sample introduction systems are critically reviewed and compared. The most employed methods are sample dilution, emulsion or micro-emulsion preparation and sample decomposition. The first one is the most widely employed due to its simplicity. Once the sample has been prepared, an organic matrix is usually present. The performance of the sample introduction system (i.e., nebulizer and spray chamber) depends strongly upon the nature and properties of the solution finally obtained. Many different devices have been assayed and the obtained results are shown. Additionally, samples can be introduced into the plasma by using an electrothermal vaporization (ETV) device or a laser ablation system (LA). The recent results published in the literature showing the feasibility, advantages and drawbacks of latter alternatives are also described. Therefore, the main goal of the review is the discussion of the different approaches developed for the analysis of crude oil and its derivates by inductively coupled plasma (ICP) techniques. - Highlights: • Analysis of petroleum products by inductively coupled plasma techniques is revisited. • Fundamental studies are included together with reports dealing with applications. • Conventional and non-conventional sample introduction methods are considered. • Sample preparation methods are critically compared and described.

  6. Plasminogen activator inhibitor-type I: its plasma determinants and relation with cardiovascular risk

    NARCIS (Netherlands)

    Hoekstra, T.; Geleijnse, J.M.; Schouten, E.G.; Kluft, C.

    2004-01-01

    The habitual level of PAI-1 is influenced by many factors, of which obesity and insulin resistance are the most important. It is possible to reduce plasma PAI-1 by changes in life style, e.g. weight reduction and physical activity. Data on potential interactions between environmental and metabolic v

  7. Smad4 Inhibits VEGF-A and VEGF-C Expressions via Enhancing Smad3 Phosphorylation in Colon Cancer.

    Science.gov (United States)

    Li, Xuemei; Li, Xinlei; Lv, Xiaohong; Xiao, Jianbing; Liu, Baoquan; Zhang, Yafang

    2017-09-01

    Smad4 is a critical factor in the TGF-β pathway and is involved in tumor progression and metastasis, but the role of Smad4 in colon cancer cells is unclear. The aim of this study is to explore the effect and the underlying mechanism of Smad4 on the growth, migration and apoptosis of colon cancer cells as well as vascular endothelial growth factor (VEGF)-A and VEGF-C secreted by these cells. In this study, we showed that Smad4, VEGF-A, and VEGF-C are independent prognostic factors of colon cancer, and Smad4 expression was negatively correlated with VEGF-A and -C in samples. We found that Smad4 mRNA and protein levels in colon cancer cells, particularly in HCT-116 cells, were significantly lower than those in the human intestinal epithelial cell line (HIEC). Smad4 overexpression promoted tumor cell apoptosis, inhibited VEGF-A and -C expression in vitro and in vivo, but had no effect on cell proliferation and migration. Tail vein injection of the virus inhibited xenograft growth in nude mice. Importantly, we also demonstrated that Smad4 could increase the phosphorylation level of Smad3, but not Smad2, which may be one of the mechanisms underlying these effects of Smad4 in colon cancer. Therefore, Smad4 may be a new target for the treatment of colon cancer. Anat Rec, 300:1560-1569, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  8. A method for determination of dimethyl benzoylphenyl urea (BPU) in human plasma by using LC/UV.

    Science.gov (United States)

    Rudek, Michelle A; Zabelina, Yelena; Zhao, Ming; Wolff, Antonio C; Baker, Sharyn D

    2004-06-01

    Dimethyl benzoylphenyl urea (BPU) inhibited tubulin polymerization, caused microtubule depolymerization in vitro and demonstrated activity against solid tumors. BPU is being tested in phase I clinical trials. A rapid and specific method using LC/UV has been developed for quantitation of BPU in human heparin-containing plasma to perform pharmacokinetic and pharmacodynamic studies. BPU is extracted from plasma into acetonitrile:n-butyl-chloride using paclitaxel as the internal standard and separated on a Waters Symmetry C18 (3.9 x 150 mm, 5 microm) column with acetonitrile-water mobile phase (70:30, v/v) using isocratic flow at 1 mL/min for a run time of 5 min. Ultraviolet detection was utilized and performed at 225 nm for BPU and paclitaxel. The retention times were 1.9 min for paclitaxel and 4.1 min for BPU. Calibration curves were generated over the range of 0.01-10 microg/mL with coefficient of determination of > 0.99. The values for within-day and between-day precision were BPU 320 mg as a weekly oral dose to a patient with advanced solid tumor malignancies, the maximum plasma concentration was 2 micro g/mL and concentrations were quantifiable up to 168 h after administration. The lower limit of quantitation of 0.01 microg/mL allows for successful measurement of plasma concentrations in patients.

  9. [Deuterated surrogate and UPLC-MS/MS method for simultaneous determination of 22 endocannabinoids in ovariectomized rat plasma].

    Science.gov (United States)

    Xiang, Shi-Xie; Xu, Ying; Zhu, Jing-Jing; Wang, Zhi-Min; Zhang, Dong; Chen, Liang-Mian; Feng, Wei-Hong

    2016-11-01

    A new method based on ultraperformance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) was developed for the simultaneous determination of 22 endocannabinoids(eCBs) and relevant compounds in ovariectomized rat plasma. After being extracted by solid-phase column(SPE), the plasma samples were detected by using UPLC-MS/MS. Analysis was carried out with ACQUITY UPLC BEH C₁₈ column. The mobile phase was 0.1% acetic acid solution(A)-acetonitrile and isopropanol(9∶1, B) for the gradient elution. In the positive ion multiple reaction monitoring(MRM) mode, deuterated reagents were taken as standard alternatives to calculate recoveries and simultaneously quantify 22 endocannabinoids. The established method provided a good linearity for the 22 eCBs, and their linearly dependent coefficients were all higher than 0.99. The limits of quantitation(LOQs) ranged from 0.089 6 to 1.965 2 nmol•L-1. Relative recoveries of 5 deuterated surrogates ranged between 11.40% and 129.9%. The repeatability study results showed that RSD was all less than 8.0%. The established method could be used to analyze PGF2a EA, AEA and other endogenous cannabinoids in plasma samples of ovariectomized rats. In summary, this method was proved to boast a high sensitivity, repeatability and practicability, and thus could be used in rat plasma lipid metabolomics study. Copyright© by the Chinese Pharmaceutical Association.

  10. Anisotropic Mechanical Properties of Plasma-Sprayed Thermal Barrier Coatings at High Temperature Determined by Ultrasonic Method

    Science.gov (United States)

    Wei, Qin; Zhu, Jianguo; Chen, Wei

    2016-02-01

    The mechanical properties of plasma-sprayed thermal barrier coatings (TBC) are of great scientific and technological significance for the design and fabrication of TBC systems. The ultrasonic method combined with a sing-around method for mechanical properties measurement of TBC is deduced and the elastic modulus can be determined in the spray, or longitudinal, direction, and the transverse direction. Tested specimens of plasma-sprayed TBC are detached from the substrate and treated with thermal exposure at 1400 °C. The elastic moduli along the longitudinal and transverse directions of the TBCs are measured by different types of ultrasonic waves combined with a sing-around method, while the Poisson's ratio is also obtained simultaneously. The experimental results indicate that the magnitude of longitudinal elastic modulus is larger than that of the transverse one, and thus the plasma-sprayed TBC has an anisotropic mechanical property. Moreover, the elastic moduli along both longitudinal and transverse directions change with high-temperature exposure time, which consists of a rapid increasing stage followed by a slow decreasing stage. In addition, the magnitude of Poisson's ratio increases slightly from 0.05 to 0.2 with the high-temperature exposure time. Generally, the microstructures in the plasma-sprayed coatings and their evolution in a high-temperature environment are the main causes of the varying anisotropic mechanical properties.

  11. Determination of salbutamol in human plasma and urine using liquid chromatography coupled to tandem mass spectrometry and its pharmacokinetic study.

    Science.gov (United States)

    Zhang, Dujuan; Teng, Yanni; Chen, Keguang; Liu, Sha; Wei, Chunmin; Wang, Benjie; Yuan, Guiyan; Zhang, Rui; Liu, Xiaoyan; Guo, Ruichen

    2012-10-01

    A sensitive and selective liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) was developed and validated for the determination of salbutamol in human plasma and urine, and successfully applied to the pharmacokinetic study of salbutamol in Chinese healthy volunteers after inhalation of salbutamol sulfate aerosol. Salbutamol and the internal standard (IS) acetaminophen in plasma and urine were extracted with ethyl acetate, separated on a C(18) reversed-phase column, eluted with mobile phase of acetonitrile-ammonium acetate (5 m m; 30:70, v/v), ionized by positive ion pneumatically assisted electrospray and detected in the multi-reaction monitoring mode using precursor → product ions of m/z 240.2 → 148.1 for salbutamol and 152 → 110 for the IS. The lower limits of quantitation of salbutamol in human plasma and urine by this method were 0.02 and 1 ng/mL, respectively. The specificity, matrix effect, recovery, sensitivity, linearity, accuracy, precision and several stabilities were validated for salbutamol in human plasma and urine. In conclusion, the validation results showed that this method is robust, specific and sensitive, and can successfully fulfill the requirement of clinical pharmacokinetic study of salbutamol in healthy Chinese volunteers.

  12. Detection of aqueous VEGF concentrations before and after intravitreal injection of anti-VEGF antibody using low-volume sampling paper-based ELISA.

    Science.gov (United States)

    Hsu, Min-Yen; Hung, Yu-Chien; Hwang, De-Kuang; Lin, Shang-Chi; Lin, Keng-Hung; Wang, Chun-Yuan; Choi, Hin-Yeung; Wang, Yu-Ping; Cheng, Chao-Min

    2016-10-11

    Intraocular vascular endothelial growth factor (VEGF) levels play an important role in the pathogenesis of blindness-related diseases, such as age-related macular degeneration (AMD). Here, we aimed to develop a paper-based enzyme-linked immunosorbent assay (P-ELISA) to analyze the suppression of aqueous VEGF concentrations following intravitreal injection (IVI) of anti-VEGF antibody (bevacizumab or ranibizumab). A total of 25 eyes with wet AMD, one with myopic neovascularization, and one with polypoidal choroidal vasculopathy were enrolled in this study. The limit of detection using P-ELISA was 0.03 pg/mL. Forty-six consecutive samples of aqueous humor were acquired. From all samples, 66.67% (10/15) achieved complete VEGF suppression (below the detection limit) within 5 weeks of receiving IVI of anti-VEGF antibody. Only 13.33% of samples (2/15) achieved complete VEGF suppression 5 weeks after receiving treatment. In some patients, elevated VEGF was still detected 5 weeks after receipt of anti-VEGF antibody, and all samples (10/10) were found to have elevated VEGF levels 49 days after treatment. Thus, we suggest that monthly IVI of anti-VEGF antibody may be required to ensure durable VEGF inhibition. Ultrasensitive P-ELISA can detect elevated VEGF at an earlier time point and may facilitate decision-making regarding appropriate treatment strategies.

  13. VEGF111b, a new member of VEGFxxxb isoforms and induced by mitomycin C, inhibits angiogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Fang; Li, Xiuli [Department of Obstetrics and Gynecology, Chinese PLA General Hospital, Beijing (China); Kong, Jian [Department of Hepatobiliary Surgery, Beijing Chaoyang Hospital, Capital Medical University, Beijing (China); Pan, Bing [The Institute of Cardiovascular Sciences, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Sciences of Education Ministry, Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides of Health Ministry, Beijing (China); Institute of Systems Biomedicine, School of Basic Medical Sciences, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Sciences of Education Ministry, Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides of Health Ministry, Beijing (China); Sun, Min [Department of Obstetrics and Gynecology, Tangdu Hospital, Fourth Military Medical University, Xian (China); Zheng, Lemin, E-mail: zhengl@bjmu.edu.cn [The Institute of Cardiovascular Sciences, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Sciences of Education Ministry, Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides of Health Ministry, Beijing (China); Institute of Systems Biomedicine, School of Basic Medical Sciences, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Sciences of Education Ministry, Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides of Health Ministry, Beijing (China); Yao, Yuanqing, E-mail: yqyao@126.com [Department of Obstetrics and Gynecology, Chinese PLA General Hospital, Beijing (China)

    2013-11-08

    Highlights: •We discovered a new member of VEGFxxxb family-VEGF111b. •We found VEGF111b mRNA and protein can be induced by mitomycin C. •We confirmed VEGF111b over-expression inhibits angiogenesis. •VEGF111b inhibits angiogenesis through inhibiting VEGF-R2/PI3K/Akt and VEGF-R2/ERK1/2 phosphorylation. -- Abstract: Vascular endothelial growth factor (VEGF-A) stimulating angiogenesis is required for tumor growth and progression. The conventional VEGF-A isoforms have been considered as pro-angiogenic factors. Another family of VEGF-A isoforms generated by alternative splicing, termed VEGFxxxb isoforms, has anti-angiogenic property, exemplified by VEGF165b. Here, we identify a new number of VEGFxxx family-VEGF111b induced by mitomycin C, although not detected in mitomycin C-unexposed ovarian cancer cells. SKOV3 cells were transfected with pcDNA{sub 3.1} empty vector, pcDNA{sub 3.1}-VEGF111b or pcDNA{sub 3.1}-VEGF165b to collect conditioned mediums respectively. VEGF111b overexpression inhibits proliferation, migration and tube formation of endothelial cell by inhibiting VEGF-R2 phosphorylation and its downstream signaling, similar to VEGF165b but slightly lower than VEGF165b. The anti-angiogenic property depends on the six amino acids of exon 8b of the VEGFxxxb isoforms. Our results show that VEGF111b is a novel potent anti-angiogenic agent that can target the VEGF-R2 and its signaling pathway to inhibit ovarian tumor growth.

  14. Formation of VEGF isoform-specific spatial distributions governing angiogenesis: computational analysis

    Directory of Open Access Journals (Sweden)

    Mac Gabhann Feilim

    2011-05-01

    Full Text Available Abstract Background The spatial distribution of vascular endothelial growth factor A (VEGF is an important mediator of vascular patterning. Previous experimental studies in the mouse hindbrain and retina have suggested that VEGF alternative splicing, which controls the ability of VEGF to bind to heparan sulfate proteoglycans (HSPGs in the extracellular matrix (ECM, plays a key role in controlling VEGF diffusion and gradients in tissues. Conversely, proteolysis notably by matrix metalloproteinases (MMPs, plays a critical role in pathological situations by releasing matrix-sequestered VEGF and modulating angiogenesis. However, computational models have predicted that HSPG binding alone does not affect VEGF localization or gradients at steady state. Results Using a 3D molecular-detailed reaction-diffusion model of VEGF ligand-receptor kinetics and transport, we test alternate models of VEGF transport in the extracellular environment surrounding an endothelial sprout. We show that differences in localization between VEGF isoforms, as observed experimentally in the mouse hindbrain, as well as the ability of proteases to redistribute VEGF in pathological situations, are consistent with a model where VEGF is endogenously cleared or degraded in an isoform-specific manner. We use our predictions of the VEGF distribution to quantify a tip cell's receptor binding and gradient sensing capacity. A novel prediction is that neuropilin-1, despite functioning as a coreceptor to VEGF165-VEGFR2 binding, reduces the ability of a cell to gauge the relative steepness of the VEGF distribution. Comparing our model to available in vivo vascular patterning data suggests that vascular phenotypes are most consistently predicted at short range by the soluble fraction of the VEGF distributions, or at longer range by matrix-bound VEGF detected in a filopodia-dependent manner. Conclusions Isoform-specific VEGF degradation provides a possible explanation for numerous examples

  15. Inductively coupled plasma-atomic emission spectroscopy: a computer controlled, scanning monochromator system for the rapid determination of the elements

    Energy Technology Data Exchange (ETDEWEB)

    Floyd, M.A.

    1980-03-01

    A computer controlled, scanning monochromator system specifically designed for the rapid, sequential determination of the elements is described. The monochromator is combined with an inductively coupled plasma excitation source so that elements at major, minor, trace, and ultratrace levels may be determined, in sequence, without changing experimental parameters other than the spectral line observed. A number of distinctive features not found in previously described versions are incorporated into the system here described. Performance characteristics of the entire system and several analytical applications are discussed.

  16. Uncertainty Estimation of Metals and Semimetals Determination in Wastewater by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES)

    Science.gov (United States)

    Marques, J. R.; Villa-Soares, S. M.; Stellato, T. B.; Silva, T. B. S. C.; Faustino, M. G.; Monteiro, L. R.; Pires, M. A. F.; Cotrim, M. E. B.

    2016-07-01

    The measurement uncertainty is a parameter that represents the dispersion of the results obtained by a method of analysis. The estimation of measurement uncertainty in the determination of metals and semimetals is important to compare the results with limits defined by environmental legislation and conclude if the analytes are meeting the requirements. Therefore, the aim of this paper is present all the steps followed to estimate the uncertainty of the determination of amount of metals and semimetals in wastewater by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Measurement uncertainty obtained was between 4.6 and 12.2% in the concentration range of mg.L-1.

  17. RP-HPLC Determination of Three Anti-Hyperlipidemic Drugs in Spiked Human Plasma and in Dosage Forms

    Directory of Open Access Journals (Sweden)

    Ola. M. Abdallah

    2011-01-01

    Full Text Available Sensitive, simple and accurate high performance liquid chromatographic (HPLC methods for the determination of atorvastatin (AT, fluvastatin (FL and pravastatin (PV have been developed. The proposed methods involve the use of a 150 mmx4.6 mm Zorbax Extend-C18 column (5 μm particle size and different chromatographic conditions for the separation of the three statins. Linearity range was 5-40, 5-30 and 10-60 μg mL-1 for AT, FL and PV respectively. The developed methods proved to be successful in the determination of all studied drugs in spiked human plasma samples.

  18. Renin-angiotensin system transgenic mouse model recapitulates pathophysiology similar to human preeclampsia with renal injury that may be mediated through VEGF.

    Science.gov (United States)

    Denney, J Morgan; Bird, Cynthia; Gendron-Fitzpatrick, Annette; Sampene, Emmanuel; Bird, Ian M; Shah, Dinesh M

    2017-03-01

    Using a transgenic cross, we evaluated features of preeclampsia, renal injury and the sFlt1/VEGF changes. Transgenic hAGT and hREN, or wild-type (WT) C57Bl/6 mice were cross-bred: female hAGT × male hREN for preeclampsia (PRE) model and female WT × male WT for pregnant controls (WTP). Samples were collected for plasma VEGF, sFlt1, and urine albumin. Blood pressures (BP) were monitored by telemetry. Vascular reactivity was investigated by wire myography. Kidneys and placenta were immunostained for sFlt1 and VEGF. Eleven PRE and 9 WTP mice were compared. PRE more frequently demonstrated albuminuria, glomerular endotheliosis (80% vs. 11%; P = 0.02), and placental necrosis (60% vs. 0%; P preeclampsia recapitulates human preeclamptic state with high fidelity, and that, vascular adaptation to pregnancy is suggested by declining BPs and reduced vascular response to PE and increased response to acetylcholine. Placental damage with resultant increased release of sFlt1, proteinuria, deficient spiral artery remodeling, and glomerular endotheliosis were observed in this model of PRE. Increased VEGF binding to glomerular endothelial cells in this model of PRE is similar to human PRE and leads us to hypothesize that renal injury in preeclampsia may be mediated through local VEGF. Copyright © 2017 the American Physiological Society.

  19. Expression of VEGF and collagen using a latex biomembrane as bladder replacement in rabbits

    Directory of Open Access Journals (Sweden)

    André Luís Alonso Domingos

    2012-08-01

    Full Text Available OBJECTIVE: To investigate the VEGF expression and collagen deposition using a latex biomembrane as bladder replacement in rabbits. MATERIALS AND METHODS: After partial cystectomy, a patch of a non-vulcanized latex biomembrane (2 x 2 cm was sewn to the bladder of rabbits with 5/0 monofilament polydioxanone sulfate sutures in a watertight manner. Groups of 5 animals were killed at 15, 45 and 90 days after surgery and the bladder was removed. Sections of 5µm were cut and stained with picrosirius-red in order to estimate the amount of extracellular matrix in the graft. To confirm the presence of VEGF in tissues, protein expression was determined by immunohistochemistry. RESULTS: No death, urinary leakage or graft extrusion occurred in any group. All bladders showed a spherical shape. A progressive reduction in the amount of collagen occurred in the graft area and was negatively and linearly correlated with time (p < 0.001. VEGF expression was higher in grafted areas when compared to controls at 15 and 45 days after surgery and decreased with time (p < 0.001. CONCLUSION: The latex biomembrane as a matrix for partial bladder replacement in rabbits promotes temporary collagen deposition and stimulates the angiogenic process.

  20. Predictive value of CA125, VEGF,β-HCG in the early diagnosis of ectopic gestation and drug conservative treatment prognosis

    Institute of Scientific and Technical Information of China (English)

    Hua Shi; Shao-Hua Pei

    2016-01-01

    Objective:To investigate the predictive value of carbohydrate antigen 125 (CA125), vascular endothelial growth factor (VEGF),β-human chorionic gonadotropin (β-HCG) in the early diagnosis of ectopic gestation and its prognosis of the patients.Method:A total of 125 patients with ectopic gestation treated in our hospital from January 2015 to October 2015 were selected as the research object, and 120 patients with normal intrauterine pregnancy after routine physical examination were selected as the control group. The serum levels of CA125, VEGF,β-HCG in two groups were determined with ELISA.Results:The serum levels of CA125, VEGF in ectopic gestation group were significantly higher than control groups, while the level ofβ-HCG was lower than the normal control group. The levels of CA125, VEGF of effective group in patients with ectopic gestation were lower than ineffective group, while the level ofβ-HCG was higher than ineffective group. The detection area, sensitivity, specificity, positive predictive value, negative predictive value under the ROC curve were greater than single index detection when combined the detection of serum CA125, VEGF,β-HCG.Conclusion:the detection of serum CA125, VEGF,β-HCG can be used as the evaluation index in the early diagnosis and prognosis of ectopic gestation, by combing various indexes detection to improve the clinical diagnosis accuracy for ectopic gestation, and the detection method is simple and fast that worth clinical promotion.

  1. Mercury determination in non- and biodegradable materials by cold vapor capacitively coupled plasma microtorch atomic emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Frentiu, Tiberiu, E-mail: ftibi@chem.ubbcluj.ro [Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos 11, 400028 Cluj-Napoca (Romania); Mihaltan, Alin I., E-mail: alinblaj2005@yahoo.com [National Institute for Research and Development of Optoelectronics Bucharest - Research Institute for Analytical Instrumentation, Donath 67, 400293 Cluj-Napoca (Romania); Ponta, Michaela, E-mail: mponta@chem.ubbcluj.ro [Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos 11, 400028 Cluj-Napoca (Romania); Darvasi, Eugen, E-mail: edarvasi@chem.ubbcluj.ro [Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos 11, 400028 Cluj-Napoca (Romania); Frentiu, Maria, E-mail: frentiu.maria@yahoo.com [National Institute for Research and Development of Optoelectronics Bucharest - Research Institute for Analytical Instrumentation, Donath 67, 400293 Cluj-Napoca (Romania); Cordos, Emil, E-mail: emilcordos@gmail.com [National Institute for Research and Development of Optoelectronics Bucharest - Research Institute for Analytical Instrumentation, Donath 67, 400293 Cluj-Napoca (Romania)

    2011-10-15

    Highlights: {yields} Use of a miniaturized analytical system with microtorch plasma for Hg determination. {yields} Determination of Hg in non- and biodegradable materials using cold vapor generation. {yields} Figures of merit and advantages of the miniaturized system for Hg determination. - Abstract: A new analytical system consisting of a low power capacitively coupled plasma microtorch (20 W, 13.56 MHz, 150 ml min{sup -1} Ar) and a microspectrometer was investigated for the Hg determination in non- and biodegradable materials by cold-vapor generation, using SnCl{sub 2} reductant, and atomic emission spectrometry. The investigated miniaturized system was used for Hg determination in recyclable plastics from electronic equipments and biodegradable materials (shopping bags of 98% biodegradable polyethylene and corn starch) with the advantages of easy operation and low analysis costs. Samples were mineralized in HNO{sub 3}-H{sub 2}SO{sub 4} mixture in a high-pressure microwave system. The detection limits of 0.05 ng ml{sup -1} or 0.08 {mu}g g{sup -1} in solid sample were compared with those reported for other analytical systems. The method precision was 1.5-9.4% for Hg levels of 1.37-13.9 mg kg{sup -1}, while recovery in two polyethylene certified reference materials in the range 98.7 {+-} 4.5% (95% confidence level).

  2. Pretreatment of plasma samples by a novel hollow fiber centrifugal ultrafiltrate device for the determination of cefaclor concentrations in human plasma.

    Science.gov (United States)

    Li, Jun-Mei; Li, Cen; Jiang, Ye; Ren, Shu-Meng

    2010-10-29

    A simple sample preparation method was developed by using a centrifugal ultrafiltration (CF-UF) device with hollow fiber (HF) for the determination of cefaclor in plasma by HPLC. Samples were placed into a homemade device, which was consisted of a glass tube and a U-shaped hollow fiber. The filtrate was withdrawn from the hollow fiber into a syringe after centrifugation and 20 μL was directly injected into the HPLC for analysis. The HPLC method had a linear calibration curve in the concentration range of 6.00×10(-2)-30.7 μg mL(-1)(r=0.9996). The limit of detection (LOD) and limit of quantitation (LOQ) were 0.02 and 0.06 μg mL(-1), respectively. The intra and inter-day precisions (RSD) were 1.7%, 1.2%, 1.0% and 3.6%, 2.5%, 1.9%, respectively, for three concentrations. Assay accuracy was higher than 99.2% and the absolute recovery was 86.8-92.5%. It is feasible to use this novel and low cost device for sample pretreatment for the analysis of cefaclor in plasma.

  3. Pharmacokinetics of Anti-VEGF Agent Aflibercept in Cancer Predicted by Data-Driven, Molecular-Detailed Model.

    Science.gov (United States)

    Finley, S D; Angelikopoulos, P; Koumoutsakos, P; Popel, A S

    2015-11-01

    Mathematical models can support the drug development process by predicting the pharmacokinetic (PK) properties of the drug and optimal dosing regimens. We have developed a pharmacokinetic model that includes a biochemical molecular interaction network linked to a whole-body compartment model. We applied the model to study the PK of the anti-vascular endothelial growth factor (VEGF) cancer therapeutic agent, aflibercept. Clinical data is used to infer model parameters using a Bayesian approach, enabling a quantitative estimation of the contributions of specific transport processes and molecular interactions of the drug that cannot be examined in other PK modeling, and insight into the mechanisms of aflibercept's antiangiogenic action. Additionally, we predict the plasma and tissue concentrations of unbound and VEGF-bound aflibercept. Thus, we present a computational framework that can serve as a valuable tool for drug development efforts.

  4. PET imaging of tumor angiogenesis in mice with VEGF-A-targeted (86)Y-CHX-A″-DTPA-bevacizumab.

    Science.gov (United States)

    Nayak, Tapan K; Garmestani, Kayhan; Baidoo, Kwamena E; Milenic, Diane E; Brechbiel, Martin W

    2011-02-15

    Bevacizumab is a humanized monoclonal antibody that binds to tumor-secreted vascular endothelial growth factor (VEGF)-A and inhibits tumor angiogenesis. In 2004, the antibody was approved by the US Food and Drug Administration (FDA) for the treatment of metastatic colorectal carcinoma in combination with chemotherapy. This report describes the preclinical evaluation of a radioimmunoconjugate, (86)Y-CHX-A″-DTPA-bevacizumab, for potential use in Positron Emission Tomography (PET) imaging of VEGF-A tumor angiogenesis and as a surrogate marker for (90)Y-based radioimmunotherapy. Bevacizumab was conjugated to CHX-A″-DTPA and radiolabeled with (86)Y. In vivo biodistribution and PET imaging studies were performed on mice bearing VEGF-A-secreting human colorectal (LS-174T), human ovarian (SKOV-3) and VEGF-A-negative human mesothelioma (MSTO-211H) xenografts. Biodistribution and PET imaging studies demonstrated highly specific tumor uptake of the radioimmunoconjugate. In mice bearing VEGF-A-secreting LS-174T, SKOV-3 and VEGF-A-negative MSTO-211H tumors, the tumor uptake at 3 days postinjection was 13.6 ± 1.5, 17.4 ± 1.7 and 6.8 ± 0.7 % ID/g, respectively. The corresponding tumor uptake in mice coinjected with 0.05 mg cold bevacizumab were 5.8 ± 1.3, 8.9 ± 1.9 and 7.4 ± 1.0 % ID/g, respectively at the same time point, demonstrating specific blockage of the target in VEGF-A-secreting tumors. The LS-174T and SKOV3 tumors were clearly visualized by PET imaging after injecting 1.8-2.0 MBq (86)Y-CHX-A″-DTPA-bevacizumab. Organ uptake quantified by PET closely correlated (r(2) = 0.87, p = 0.64, n = 18) to values determined by biodistribution studies. This preclinical study demonstrates the potential of the radioimmunoconjugate, (86)Y-CHX-A″-DTPA-be