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VEGF Concentration (vegf + concentration)

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Medical Sciences	93%

Selected Abstracts

Serum vascular endothelial growth factor in adult haematological patients with neutropenic fever: a comparison with C-reactive protein

EUROPEAN JOURNAL OF HAEMATOLOGY, Issue 3 2009
Sari Hämäläinen
Abstract Objectives:, Vascular endothelial growth factor (VEGF) is considered to be of importance in patients with sepsis. No data are available on VEGF kinetics in haematological patients with neutropenic fever. Methods:, Forty-two haematological patients were included into this prospective study. Median age was 57 yr (range 18,70). Fifteen patients received therapy for acute myeloid leukaemia and 27 patients received autologous stem cell transplantation for haematological malignancy. Laboratory samples for the determination of C-reactive protein (CRP) and VEGF were collected at the start of fever (d0) and then daily. Results:, The median serum VEGF concentrations were low in all study patients. In patients with severe sepsis (n = 5) the median VEGF on d0 was higher than in septic patients without signs of hypoperfusion or hypotension (n = 37) (77 pg/mL vs. 52 pg/mL, P = 0.061). Also on d1 the median VEGF concentration was higher in patients with severe sepsis (82 pg/mL vs. 56 pg/mL, P = 0.048). There were no statistically significant differences in CRP values on any day during the study period between patients with severe sepsis and those without. Time from d0 to the peak VEGF concentration (mean 1.02, SE 0.18 d) was shorter than that to the peak CRP concentration (mean 1.93, SE 0.15 d) (P = 0.002). Conclusion:, Compared to CRP, serum VEGF was a more rapid indicator for sepsis in our haematological patients with neutropenic fever. Those with severe sepsis had higher VEGF concentrations than those without on d0 and d1 after the onset of fever. Further studies on VEGF are warranted in haematological patients. [source]

Non-viral VEGF165 gene therapy , magnetofection of acoustically active magnetic lipospheres (,magnetobubbles') increases tissue survival in an oversized skin flap model

JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 3 2010
Thomas Holzbach
Abstract Adenoviral transduction of the VEGF gene in an oversized skin flap increases flap survival and perfusion. In this study, we investigated the potential of magnetofection of magnetic lipospheres containing VEGF165 -cDNA on survival and perfusion of ischemic skin flaps and evaluated the method with respect to the significance of applied magnetic field and ultrasound. We prepared perfluoropropane-filled magnetic lipospheres (,magnetobubbles') from Tween60-coated magnetic nanoparticles, Metafectene, soybean-oil and cDNA and studied the effect in an oversized random-pattern-flap model in the rats (n= 46). VEGF-cDNA-magnetobubbles were administered under a magnetic field with simultaneously applied ultrasound, under magnetic field alone and with applied ultrasound alone. Therapy was conducted 7 days pre-operative. Flap survival and necrosis were measured 7 days post-operatively. Flap perfusion, VEGF-protein concentration in target and surrounding tissue, formation and appearance of new vessels were analysed additionally. Magnetofection with VEGF-cDNA-magnetobubbles presented an increased flap survival of 50% and increased flap perfusion (P < 0.05). Without ultrasound and without magnetic field, the effect is weakened. VEGF concentration in target tissue was elevated (P < 0.05), while underlying muscle was not affected. Our results demonstrate the successful VEGF gene therapy by means of magnetobubble magnetofection. Here, the method of magnetofection of magnetic lipospheres is equally efficient as adenoviral transduction, but has a presumable superior safety profile. [source]

VEGF concentration from plasma-activated platelets rich correlates with microvascular density and grading in canine mast cell tumour spontaneous model

JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 3 2009
R. Patruno
Abstract Canine cutaneous mast cell tumour (CMCT) is a common cutaneous tumour in dog, with a higher incidence than in human. CMCT is classified in three subgroups, well and intermediately differentiated (G1 and G2), corresponding to a benign disease, and poorly differentiated (G3), corresponding to a malignant disease, which metastasize to lymph nodes, liver, spleen and bone marrow. In this study, we have evaluated serum (S), platelet-poor plasma (P-PP), plasma-activated platelet rich (P-APR) and cytosol vascular endothelial growth factor (VEGF) concentrations, microvascular density (MVD) and mast cell density (MCD) in a series of 86 CMCTs and we have correlated these parameters with each other, by means of ELISA detection of VEGF and immunohistochemistry. Results show that VEGF level from cytosol P-APR and MVD were significantly higher in G3 CMCTs as compared to G1 or G2 subgroups. Moreover, a significantly strong correlation among VEGF levels from P-PAR and cytosol, MVD and MCD was found in G3 subgroup. Because VEGF levels from P-APR well correlated with MVD and malignancy grade in CMCT, we suggest that VEGF might be secreted from MCs and it may be a suitable surrogate inter-species angiogenetic markers of tumour progression in CMCT. Finally, CMCT seems to be a useful model to study the role of MCs in tumour angiogenesis and inhibition of MCs degranulation or activation might be a new anti-angiogenic strategy worthy to further investigations. [source]

Non-patient related variables affecting levels of vascular endothelial growth factor in urine biospecimens

JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 4 2008
M. J. Kirk
Abstract Vascular endothelial growth factor (VEGF) is an angiogenic protein proposed to be an important biomarker for the prediction of tumour growth and disease progression. Recent studies suggest that VEGF measurements in biospecimens, including urine, may have predictive value across a range of cancers. However, the reproducibility and reliability of urinary VEGF measurements have not been determined. We collected urine samples from patients receiving radiation treatment for glioblastoma multiforme (GBM) and examined the effects of five variables on measured VEGF levels using an ELISA assay. To quantify the factors affecting the precision of the assay, two variables were examined: the variation between ELISA kits with different lot numbers and the variation between different technicians. Three variables were tested for their effects on measured VEGF concentration: the time the specimen spent at room temperature prior to assay, the addition of protease inhibitors prior to specimen storage and the alteration of urinary pH. This study found that VEGF levels were consistent across three different ELISA kit lot numbers. However, significant variation was observed between results obtained by different technicians. VEGF concentrations were dependent on time at room temperature before measurement, with higher values observed 3,7 hrs after removal from the freezer. No significant difference was observed in VEGF levels with the addition of protease inhibitors, and alteration of urinary pH did not significantly affect VEGF measurements. In conclusion, this determination of the conditions necessary to reliably measure urinary VEGF levels will be useful for future studies related to protein biomarkers and disease progression. [source]

Hypoxic damage to the periventricular white matter in neonatal brain: role of vascular endothelial growth factor, nitric oxide and excitotoxicity

JOURNAL OF NEUROCHEMISTRY, Issue 4 2006
Charanjit Kaur
Abstract The present study examined factors that may be involved in the development of hypoxic periventricular white matter damage in the neonatal brain. Wistar rats (1-day old) were subjected to hypoxia and the periventricular white matter (corpus callosum) was examined for the mRNA and protein expression of hypoxia-inducible factor-1, (HIF-1,), endothelial, neuronal and inducible nitric oxide synthase (eNOS, nNOS and iNOS), vascular endothelial growth factor (VEGF) and N-methyl-D-aspartate receptor subunit 1 (NMDAR1) between 3 h and 14 days after hypoxic exposure by real-time RT-PCR, western blotting and immunohistochemistry. Up-regulated mRNA and protein expression of HIF-1,, VEGF, NMDAR1, eNOS, nNOS and iNOS in corpus callosum was observed in response to hypoxia. NMDAR1 and iNOS expression was found in the activated microglial cells, whereas VEGF was localized to astrocytes. An enzyme immunoassay showed that the VEGF concentration in corpus callosum was significantly higher up to 7 days after hypoxic exposure. NO levels, measured by colorimetric assay, were also significantly higher in hypoxic rats up to 14 days after hypoxic exposure as compared with the controls. A large number of axons undergoing degeneration were observed between 3 h and 7 days after the hypoxic exposure at electron-microscopic level. Our findings point towards the involvement of excitotoxicity, VEGF and NO in periventricular white matter damage in response to hypoxia. [source]

Phosphatidylethanol Mediates its Effects on the Vascular Endothelial Growth Factor via HDL Receptor in Endothelial Cells

ALCOHOLISM, Issue 2 2009
Marja Katriina Liisanantti
Background:, Previous epidemiological studies have shown that light to moderate alcohol consumption has protective effects against coronary heart disease but the mechanisms of the beneficial effect of alcohol are not known. Ethanol may increase high density lipoprotein (HDL) cholesterol concentration, augment the reverse cholesterol transport, or regulate growth factors or adhesion molecules. To study whether qualitative changes in HDL phospholipids mediate part of the beneficial effects of alcohol on atherosclerosis by HDL receptor, we investigated whether phosphatidylethanol (PEth) in HDL particles affects the secretion of vascular endothelial growth factor (VEGF) by a human scavenger receptor CD36 and LIMPII analog-I (CLA-1)-mediated pathway. Methods:, Human EA.hy 926 endothelial cells were incubated in the presence of native HDL or PEth-HDL. VEGF concentration and CLA-1 protein expression were measured. Human CLA-1 receptor-mediated mechanisms in endothelial cells were studied using CLA-1 blocking antibody and protein kinase inhibitors. Results:, Phosphatidylethanol-containing HDL particles caused a 6-fold increase in the expression of CLA-1 in endothelial cells compared with the effect of native HDL. That emergent effect was mediated mainly through protein kinase C and p44/42 mitogen-activated protein kinase pathways. PEth increased the secretion of VEGF and that increase could be abolished by a CLA-1 blocking antibody. Conclusions:, High density lipoprotein particles containing PEth bind to CLA-1 receptor and thereby increase the secretion of VEGF from endothelial cells. Ethanol-induced protective effects against coronary heart disease may be explained, at least partly, by the effects of PEth-modified HDL particles on VEGF via CLA-1-mediated mechanisms in endothelial cells. [source]

Plasma levels and skin-eosinophil-expression of vascular endothelial growth factor in patients with chronic urticaria

ALLERGY, Issue 11 2009
A. Tedeschi
Background:, Although chronic urticaria (CU) is often regarded as autoimmune in nature, only less than 50% of sera from CU patients contain histamine-releasing autoantibodies. This suggests that other factors may contribute to its pathogenesis. We evaluated the possible involvement of vascular endothelial growth factor (VEGF), one of the major mediators of vascular permeability, in CU. Methods:, Eighty consecutive adult patients with CU and 53 healthy subjects were studied. VEGF and prothrombin fragment F1+2 were measured by enzyme immunoassays. Autologous plasma skin test (APST) was performed in CU patients and, in six of them, skin biopsy specimens were taken from wheals to evaluate the immunohistochemical expression of VEGF and eosinophil cationic protein (ECP). Results:, Plasma VEGF concentrations were higher in CU patients (8.00 ± 0.90 pmol/l) than in controls (0.54 ± 0.08 pmol/l) (P = 0.0001) and tended to parallel both the severity of CU and to correlate with F1+2 levels. APST was positive in 85.1% of patients. VEGF concentration was significantly higher in APST-positive than in APST-negative patients (P = 0.0003). Immunohistochemically, all specimens from patients with CU showed a strong expression of VEGF (P = 0.002) that colocalized with ECP, a classic eosinophil marker. Conclusions:, VEGF plasma levels are elevated in CU and parallel the disease severity. This supports a possible role of this molecule in CU pathophysiology. Eosinophils are the main cellular source of VEGF in CU lesional skin. [source]

Microvessels Promote Motor Nerve Survival and Regeneration Through Local VEGF Release Following Ectopic Reattachment

MICROCIRCULATION, Issue 8 2004
SHAWN E. BEARDEN
ABSTRACT Objectives: Nerves and blood vessels form a close association during embryogenesis. Growth and guidance factors initially attributed to either nerves or vessels are now known to affect both tissues; prominent among these is vascular endothelial growth factor (VEGF). The authors investigated whether axons would associate with blood vessels in a regenerating system and questioned whether VEGF is integral to neurotization following axotomy. Methods: In hamsters 8,12 weeks of age, the accessory nerve (CN XI) to the retractor muscle of the cheek pouch was cut and the proximal stump was reattached ectopically onto the muscle. Vascular casting and immunolabeling were used to quantify the extent of neurovascular association during regeneration. A role for VEGF was investigated using immunolocalization of VEGF and its receptor (sVEGFR2) as well as local sequestration of VEGF with soluble receptor (sVEGFR1). Results: Regenerating axons aligned with microvessels of the vasa nervorum along a "chaperone" region during outgrowth from the reattachment site and while entering the muscle. In this ,1-mm region, VEGF protein was expressed by growing microvessels despite a ,50% reduction (p < .05) in total muscle VEGF concentration. VEGFR2 was expressed by regenerating axons and growth cones. Sequestration of VEGF by sVEGFR1 impaired neurotization by ,40% (p < .05). The chaperone region ended where regenerating microvessels anastomosed with the native microcirculation and their expression of VEGF protein diminished. Conclusions: Regenerating axons and blood vessels align during outgrowth from ectopic reattachment. This interaction dissipates as vascular anastomoses form with established microvessels and axons target muscle fibers. Local production of VEGF by growing microvessels supports motor nerve survival and regeneration. [source]

Intravitreal anti-vascular endothelial growth factor therapy with bevacizumab for tuberous sclerosis with macular oedema

ACTA OPHTHALMOLOGICA, Issue 3 2010
Wataru Saito
Abstract. Purpose:, To describe two patients with macular oedema secondary to tuberous sclerosis complex (TSC) who were treated with intravitreal bevacizumab injection. Methods:, Interventional case reports. Bevacizumab 1.25 mg was injected into the vitreous of two patients with TSC-associated macular oedema / exudative retinal detachment. Vascular endothelial growth factor (VEGF) concentration in the vitreous fluid was measured by enzyme-linked immunosorbent assay (ELISA) in one of these patients. Results:, Patient 1: a 22-year-old woman with TSC was diagnosed as having multiple retinal hamartomas in both eyes. Eleven years later, the patient developed macular oedema with epiretinal membrane formation in the right eye. The patient underwent pars-plana vitrectomy with retinal photocoagulation for retinal tumours. VEGF concentration in the vitreous fluid was high compared to that in patients without retinal vascular diseases. Recurrent macular oedema disappeared by intravitreal injection of bevacizumab. Patient 2: a 32-year-old woman with TSC-associated retinal hamartoma, temporally showing macular exudative retinal detachment, developed neovascularization originated from the tumour. By intravitreal bevacizumab injection, the tumour size reduced markedly with regression of neovascularization. Conclusion:, These results suggest that VEGF derived from retinal hamartomas causes macular oedema associated with TSC. Intravitreal injections of bevacizumab may be a useful therapeutic option for macular oedema secondary to TSC. [source]

Serum vascular endothelial growth factor in adult haematological patients with neutropenic fever: a comparison with C-reactive protein

Non-patient related variables affecting levels of vascular endothelial growth factor in urine biospecimens

Prognostic value of serum angiogenic activity in colorectal cancer patients

JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 1 2007
Francisco-Jesus Gonzalez
Abstract Angiogenesis, resulting from an imbalance between angiogenic activator factors and inhibitors, is required for tumour growth and metastasis. The determination of the circulating concentration of all angiogenic factors (activators and inhibitors) is not feasible at present. We have evaluated diagnostic and prognostic values of the measurement of serum angiogenic activity in colorectal carcinoma (CRC) patients. Serum proliferative activity (PA) on human umbilical vein endothelial cells (HUVEC) in vitro, and serum vascular endothelial growth factor (VEGF) levels were determined by ELISA in 53 patients with primary CRC, 16 subjects with non-neoplastic gastrointestinal disease (SC) and 34 healthy individuals. Data were compared with clinical outcome of the patients. Although serum from CRC patients significantly increased the PA of HUVEC, compared to culture control (HUVEC in medium + 10% foetal bovine serum (FBS); P < 0.001); our results indicate that serum PA in CRC patients was similar to that of SC or healthy individuals. There was no correlation between serum PA and circulating VEGF concentrations. Surgery produced a decrease of PA at 8 hrs after tumour resection in CRC patients compared to pre-surgery values (186 ± 47 versus 213 ± 41, P < 0.001). However, an increase in serum VEGF values was observed after surgery (280 [176,450] versus 251 [160,357] pg/ml, P = 0.004). Patients with lower PA values after surgery showed a worse outcome that those with higher PA values. Therefore, this study does not support a diagnostic value for serum angiogenic activity measured by proliferative activity on HUVEC but suggests it could have a prognostic value in CRC patients. [source]

Plasma levels and skin-eosinophil-expression of vascular endothelial growth factor in patients with chronic urticaria

Vascular endothelial growth factor in preterm infants with respiratory distress syndrome

PEDIATRIC PULMONOLOGY, Issue 5 2005
Po-Nien Tsao MD
Abstract Respiratory distress syndrome (RDS) secondary to surfactant deficiency is a common cause of morbidity and mortality in premature infants. Increasing evidence suggests that vascular endothelial growth factor (VEGF) may contribute to surfactant secretion and pulmonary maturation. However, differences in cord blood VEGF concentrations in infants with and without respiratory distress syndrome have not been reported. We hypothesized that premature infants with higher VEGF levels in cord blood had a lower risk of developing RDS. Cord blood samples were obtained from preterm infants born at 32 weeks of gestation or earlier. Infants were excluded if there was evidence of prenatal maternal infection or any infection within the first 3 days of life. Cord blood VEGF levels were measured using an enzyme-linked immunosorbent assay (ELISA). We found that neonates with clinically diagnosed RDS had a lower gestational age (GA), lower birth weight (BW), higher incidence of mechanical ventilation requirements, longer duration of mechanical ventilation, and lower Apgar scores at 1 and 5 min. Infants with RDS had significantly lower cord blood VEGF levels. GA, BW, premature rupture of membranes (PROM), and antenatal steroid treatment were not associated with changes in cord blood VEGF levels. The specificity of cord blood VEGF above 34 pg/ml for predicting the absence of RDS was 86%, the sensitivity was 53%, the positive predictive value was 84%, and the negative predictive value was 56%. Our data demonstrated that cord blood VEGF elevation was significantly correlated with an absence of RDS. © 2005 Wiley-Liss, Inc. [source]

Serum vascular endothelial growth factor as a tumour marker in soft tissue sarcoma,

BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 2 2004
A. J. Hayes
Background: Vascular endothelial growth factor (VEGF) is a potent tumour-produced angiogenic factor. In this study serum levels of VEGF were measured before treatment and during follow-up in patients undergoing primary treatment for suspected soft tissue sarcoma (STS) to assess the value of serum VEGF as a tumour marker. Methods: Between April 2001 and September 2002, serum VEGF levels were analysed prospectively in 144 patients undergoing primary treatment (surgery, 123; cytotoxic chemotherapy, ten; oral imatinib, eight; radiotherapy, three) for suspected soft tissue sarcoma. Serum VEGF was measured by immunoassay before treatment, in the immediate postoperative interval in patients undergoing surgery, and during follow-up. Serum VEGF concentrations were also measured in 15 healthy volunteers. Results: Median pretreatment serum VEGF levels were significantly raised in patients with grade 2 and grade 3 sarcomas compared with concentrations in patients with benign lesions (413 and 467 versus 233 pg/ml respectively; P = 0·007 and P = 0·003 respectively). In patients with tumours that had a high level of VEGF expression before treatment, follow-up measurements reflected disease status after treatment. Conclusion: Serum VEGF expression correlated with grade in soft tissue sarcoma and reflected response to treatment. Copyright © 2003 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source]