Peptide growth factors and their receptors in the vein wall.

The varicose vein wall remodeling is a very complex process, which is controlled by numerous factors, including peptide growth factors. The aim of the study was to assess a/b FGF, IGF-1, TGF-ß1, VEGF-A and their receptors in the vein wall. Varicose vein samples were taken from 24 patients undergoing varicose vein surgery. The control material consisted of vein specimens collected from 12 patients with chronic limb ischemia. Contents of aFGF, bFGF, IGF-I, TGF-ß1, VEGF, IGF-1R, VEGF R1 and VEGF R2 were assessed with ELISA method. Protein expression of FGF R1 and TGF-ß RII were evaluated with western blot. Increased contents of aFGF, IGF-1 and VEGF-A were found in varicose veins in comparison with normal ones (p<0.05). In contrast, a significant decrease in TGF-ß content was demonstrated in varicose veins (p<0.05). Furthermore, there was no difference in bFGF content in both groups (p>0.05). IGF-1 R content was significantly increased in varicose veins (p<0.05). There was no difference in VEGF R1 content between varicose and normal veins (p>0.05), whereas VEGF R2 content was significantly increased in varicose veins (p<0.05). Western blot demonstrated increased expression of TGF-ß RII in varicose veins (p<0.05) and similar expression of FGF R1 in both groups (p>0.05). Demonstrated changes in peptide growth factors and their receptors may disturb metabolism of extracellular matrix in the varicose vein wall and contribute to the development of the disease to its more advanced stages.

MT1-MMP evaluation in neointimal hyperplasia in the late follow-up after prosthesis implantation.

Vascular surgical interventions are often burdened with late complications, including thrombosis or restenosis. The latter is generally caused by neointimal hyperplasia. Although extracellular matrix (ECM) remodelling is an important part of neointima formation, this process is not clearly understood. The aim of the study was to assess the content and activity of membrane-type 1 matrix metalloproteinase in human neointima in the late stages of its development. Matrix metalloproteinase-2 and tissue inhibitor of matrix metalloproteinase-2 were also evaluated. The research was performed on neointima samples collected during secondary vascular interventions from patients with chronic limb ischaemia who developed vascular occlusion at 6-18 months after aorto/ilio-femoral bypass grafting. The control material consisted of segments of femoral arteries collected from organ donors. Western blot and/or ELISA were used for the determination of MT1-MMP and TIMP-2 expression. The activity of MT1-MMP was measured by fluorometric assay and that of MMP-2 by zymography. We demonstrated significantly increased MT1-MMP protein content in neointima when compared to normal arteries. However, the activity of MT1-MMP was significantly lower in neointima than in control samples. The decreased MT1-MMP activity was concomitant with reduced activity of MMP-2. The TIMP-2 protein levels in neointima and normal arteries were not significantly different. The results of our study suggest that the reduced activity of MT1-MMP and consequently MMP-2 in human neointima may play a role in decreased degradation of ECM components and thus promote neointimal overgrowth.

Cross-sectional area of the femoral vein varies with leg position and distance from the inguinal ligament.

PURPOSE: The risk of complications associated with femoral venous catheterization could be potentially reduced if the procedure was performed at the location where the cross-sectional area (CSA) of the vessel is the largest. The diameter of the femoral vein depends on leg position as well as the distance from the inguinal ligament. We determined the CSA of the right femoral vein in three different leg positions at two distances from the inguinal ligament. SUBJECTS AND METHODS: Informed consent was given by 205 healthy volunteers aged 19-39 years, mean: 23±3 years (108 women, 97 men). Ultrasonographic examinations were performed using a linear 14-MHz transducer with CSA measurements in three leg positions: abduction, abduction+external rotation, abduction+external rotation+90° knee flexion/frog-leg position; at levels 20 mm caudally to the inguinal ligament, and 20 mm caudally to the inguinal crease. RESULTS: We found significant differences in mean values of CSA in three leg positions regardless of the measurement level. The largest mean CSA (114 mm2±35 mm2) was found at the proximal level in the frog-leg position. There was a significant association of the CSA with sex and height. The CSA in males was greater than in females in all leg positions at the level of 20 mm caudally to the inguinal crease, while 20 mm caudally to the inguinal ligament the CSA was larger in females. The CSA of 25% of the femoral vein was smaller than 45.0 mm2 at the proximal level, and 31.5 mm2 at the distal level, which refers to diameters of 5.3 mm, and 4.5 mm, respectively. CONCLUSIONS: The cross-sectional area of the femoral vein is the largest in the frog-leg position, and depends on gender.

Evaluation of Vascular Endothelial Growth Factor and Its Receptors in Human Neointima.

OBJECTIVE: The potential contribution of vascular endothelial growth factor (VEGF) in neointima development has been evaluated in numerous animal studies. However, its role remains controversial. Moreover, little is known about neointima formation in humans. In this study we assessed the expression of VEGF-A and its receptors in the human neointima formed within vascular anastomosis. METHODS: The studied material comprised neointima samples harvested during secondary vascular operations from patients with chronic limb ischemia after aorto-/iliofemoral bypass grafting who developed vascular graft occlusion at 6-18 months after the initial surgical treatment. The control material consisted of segments of femoral arteries without visible macroscopic lesions collected from organ donors. The expression and content of VEGF-A, VEGFR-1 and VEGFR-2 were analyzed with PCR and ELISA methods, respectively. RESULTS: We observed a significantly increased expression of VEGF-A and VEGFR-2 mRNA in neointima compared to the normal aorta. A significantly higher protein content of VEGF-A and VEGFR-2 in neointima samples compared to the controls was also observed. No significant difference of VEGFR-1 content and VEGFR-1 mRNA expression was found in the studied material. CONCLUSION: These results indicate a possible involvement of the VEGF-A and VEGFR-2 system in the pathologic process of human neointima formation after vascular interventions.

Assessment of inflammatory infiltration and angiogenesis in the thrombus and the wall of abdominal aortic aneurysms on the basis of histological parameters and computed tomography angiography study.

The proliferation of vessels within the aneurysm's wall and the intraluminal thrombus of abdominal aortic aneurysm (AAA) may be the main factor responsible for progression and rupture of AAA. The aim of this study was to compare the parameters of the thrombus (size, density, contrast enhancement) measured by computed tomography (CT) with histological assessment of thrombi removed during surgery. 29 patients with AAA were examined with angio-CT. Post-surgery histopathological evaluation of AAA was performed. Slides were stained with markers of B- (CD20) and T-lymphocytes (CD3), and markers of endothelial cells (CD34). Thrombi were enhanced after contrast media administration in angio-CT (p = 0.002). There was a statistically significant correlation between contrast enhancement and the presence of B lymphocytes. Intensity of endothelial cell marker expression significantly correlated with the presence of inflammatory T- and B-cells. No statistical significant correlation was found between contrast enhancement of the thrombus and markers of endothelial cells. The accumulation of inflammatory cells in the wall of AAA thrombus results in the formation of new vessels which participates to the instability of the thrombus and AAA wall. Assessment of the inflammation and neovascularization in the wall and thrombus of the AAA might be an important factor in monitoring the progression and the risk of aneurysm's rupture.

Assessment of effectiveness of endovascular treatment of common and external iliac artery stenosis/occlusion using self-expanding Jaguar SM stents.

The goal of this work was to assess the effectiveness of endovascular treatment of common and external iliac artery stenosis/occlusion classified according to TASC using a self-expanding stent Jaguar SM. The study group included 95 patients (61 men and 34 women) who underwent treatment for stenosis or occlusion of lower limb arteries at the Department of Radiology of the University Hospital in Bialystok and the Diagnostic Radiology Department of the Central Clinical Hospital of the Ministry of Interior (MSWiA) in Warsaw between 2005 and 2007. All arterial lesions were of atherosclerotic etiology. The shortest stenotic fragment was 10 mm long and the longest occluded arterial fragment did not exceed 90 mm. Morphological classification of iliac artery lesions in treated patients was performed according to TASC II classification and included 10 patients with type A, 39 cases of type B, 36 with type C and 10 patients with type D lesions. Endovascular procedure failed to restore flow in five patients with TASC type D lesions, who were later referred for surgery. One patient suffered a complication - vessel perforation during predilatation, and had a stentgraft implanted. In 95% of patients stents were expanded using a balloon after implantation. Good results were achieved in practically all patients who underwent stent implantation. Patients were subjected to follow-up clinical and imaging evaluation during next 1-24 months. Success rate of the performed procedures as well as in a 30-day observation period was 100% in case of stenosis and 80% in case of vessel occlusion. A follow-up after 12 and 24 months showed patency of treated vessels in 84% and 76% of patients, respectively.

Evaluation of transforming growth factor-beta signaling pathway in the wall of normal and varicose veins.

OBJECTIVE(S): Extracellular matrix remodeling in the vein wall is involved in varicose vein pathogenesis, with transforming growth factor beta(1) (TGF-beta(1)) playing a potential role. The aim of the study was to assess the TGF-beta signaling pathway including its receptor (TGF-beta RII) and phosphorylated receptor-regulated Smads (p-Smad2/3) in varicose veins. METHODS: Varicose veins from patients undergoing varicose vein surgery were the studied material, whereas normal greater saphenous veins from patients undergoing infrainguinal arterial bypass surgery were the control material. Expression of TGF-beta RII mRNA was assessed with RT-PCR, whereas expression of TGF-beta RII and p-Smad2/3 proteins was assessed with Western blot. RESULTS: A significantly increased TGF-beta RII mRNA level was found in varicose veins (287 +/- 24%), when compared with normal veins (100 +/- 26%). The receptor protein expression reflected a changed mRNA level with significantly increased TGF-beta RII protein in varicose veins (290 +/- 21%), when compared with controls (100 +/- 16%). Enhanced TGF-beta RII expression was accompanied by increased p-Smad2/3 protein expression in varicose veins (257 +/- 19%) in comparison with normal veins (100 +/- 9%). CONCLUSION(S): Increased TGF-beta RII expression and activation in the wall of varicose veins may be involved in extracellular matrix remodeling related to TGF-beta(1) and supports its role in the disease pathogenesis.

Influence of thrombophlebitis on TGF-ß1 and its signaling pathway in the vein wall.

Extensive extracellular matrix remodeling of the vein wall is involved in varicose veins pathogenesis. This process is controlled by numerous factors, including peptide growth factors. The aim of the study was to evaluate influence of thrombophlebitis on TGF-ß1 and its signaling pathway in the vein wall. TGF-ß1 mRNAlevels, growth factor content and its expression were evaluated by RT-PCR, ELISA, and western blot methods, respectively, in the walls of normal veins, varicose veins and varicose veins complicated by thrombophlebitis. Western blot analysis was used to assess TGF-ß receptor type II (TGF-ß RII) and p-Smad2/3 protein expression in the investigated material. Unchanged mRNA levels of TGF-ß1, decreased TGF-ß1 content, as well as decreased expression of latent and active forms of TGF-ß1 were found in varicose veins. Increased expression of TGF-ß RII and p-Smad2/3 were found in varicose veins. Thrombophlebitis led to increased protein expression of the TGF-ß1 active form and p-Smad2/3 in the vein wall compared to varicose veins. TGF-ß1 may play a role in the disease pathogenesis because of increased expression and activation of its receptor in the wall of varicose veins. Thrombophlebitis accelerates activation of TGF-ß1 and activity of its receptor in the varicose vein wall.

Evaluation of aFGF/bFGF and FGF signaling pathway in the wall of varicose veins.

BACKGROUND: Extensive extracellular matrix remodeling of the vein wall is involved in varicose veins pathogenesis. The process is controlled by numerous factors, including peptide growth factors. The aim of the study was to evaluate acidic (aFGF) and basic (bFGF) fibroblast growth factors, their receptor (FGFR) and the MAP kinase pathway (ERK 1/2) in the wall of varicose and varicose veins complicated by thrombophlebitis, when compared to normal ones. METHODS: Segments of normal, varicose, and varicose veins complicated by thrombophlebitis were collected during varicose veins surgery in 17 patients. Expression and content of aFGF and bFGF were evaluated with Western blot and enzyme-linked immunosorbent assay (ELISA) methods, respectively, whereas RT-PCR was employed to assess mRNA level of growth factors. Expression of FGFR and ERK 1/2 was examined with Western blot method. RESULTS: Increased aFGF expression and content were accompanied by increased aFGF mRNA level in the wall of varicose veins. Furthermore, alternatively spliced aFGF mRNA was shown in varicose veins complicated by thrombophlebitis. Expression, content, and mRNA level of bFGF were comparable in the investigated material. FGFR and ERK 1/2 expression was demonstrated in the wall of diseased veins, however, without any significant differences in comparison with the wall of normal veins. CONCLUSIONS: Overexpressed aFGF in the wall of varicose veins via FGFR and the MAP kinase pathway may influence expression of enzymes involved in extracellular matrix metabolism and play a role in vein wall remodeling, as well as in the disease pathogenesis.

Contrast-enhanced ultrasonography versus computed tomographic angiography in the monitoring of patients after endovascular repair of abdominal aortic aneurysm -- preliminary experience.

BACKGROUND: Computed tomographic angiography (CTA) is routinely used in the monitoring of patients after endovascular repair of abdominal aortic aneurysm. The aim of the study was to determine if contrast-enhanced ultrasonography (CEUS) provides equivalent results to CTA in detection of endo-leaks in patients after abdominal aortic stentgraft placement. MATERIAL AND METHODS: In a group of 7 patients (6 men and 1 woman; aged 71+/-7 years) after repair procedure, 16 CTA and 16 CEUS follow-up examinations were performed. Second-generation contrast agent (Sonovue) and low-mechanical index technique were used for ultrasonography imaging. RESULTS: Computed tomographic angiography showed seven cases of type I, five cases of type II, and no endo-leaks in four examinations. In 15 out of 16 studies, the results of CEUS were consistent with the results of CTA. In one discrepant study, type II endo-leak was detected with CEUS while CTA was negative. CONCLUSIONS: Contrast-enhanced ultrasonography and CTA examinations in patients after endovascular repair of abdominal aortic aneurysm provide comparable results. CEUS may be considered an alternative technique to CTA.

[Antiheparin activity of the aneurysm wall and parietal thrombus and blood plasma of patients with aortic aneurysm]. / Aktywnosc antyheparynowa sciany i skrzepliny przysciennej tetniaka oraz osocza krwi chorych z tetniakiem aorty.

Aneurysm dilatation is filled by parietal thrombus. Its magnitude is determined by the ratio of coagulative to anticoagulative activities above all. The aim of the study was to assess antiheparin activity, contents of heparin neutralizing chemical compounds and glycosaminoglycans with anticoagulative activity as well in the aneurysm wall, parietal thrombus filling the aneurysm dilatation and blood plasma/blood serum of patients with aortic aneurysm. The studied material consisted of aneurysm walls and parietal thrombi extracts, as well as of blood plasma/serum of patients with aortic aneurysm. Extracts of normal aorta from organ donors and blood plasma/serum of healthy subjects were the control material. Antiheparin and antithrombin III activities, as well as contents of heparin neutralizing compounds and heparin-like acting glycosaminoglycans were evaluated in the investigated material with chemical methods. The aneurysm wall, parietal thrombus filling the aneurysm dilatation and blood plasma of patients with aortic aneurysm show high antiheparin activity and increased content of heparin neutralizing compounds. However differences in glycosaminoglycans content were not demonstrated. That can predispose to formation and enlargement of parietal thrombus in aneurysm dilatation.

Evaluation of enzymes involved in proteoglycan degradation in the wall of abdominal aortic aneurysms.

The abdominal aortic aneurysm (AAA) wall represents an extreme example of arterial remodeling with disturbed elastin, collagen and proteoglycan metabolism. The aim of this study was to evaluate enzymes involved in the degradation of glycosaminoglycan chains and core proteins of proteoglycans in the AAA wall. The study material consisted of wall samples from 10 AAA. Fragments of 5 normal abdominal aortas from organ donors were used as a control. The activity of endoglycosidases, exoglycosidases and sulfatases was measured using colorimetric methods. To assess matrix metalloproteinases (MMPs), Western blot and zymography were performed. The activity of endoglycosidase degrading chondroitin-4-sulfate was lower in the AAA wall. Endoglycosidase degrading heparan sulfate and dermatan sulfate, arylosulfatase B, as well as all the exoglycosidases assessed demonstrated higher activities in the AAA wall. Furthermore, increased expression of MMP1, MMP2 and MMP9 was also shown in the AAA wall. Zymography revealed decreased activity of pro-MMP2 and presence of pro-MMP9 in the AAA wall compared to the wall of normal aorta. Extensive changes in the activity of glycosaminoglycan-degrading enzymes and MMPs may influence the organization of the extracellular matrix network and lead to previously demonstrated changes in the proteoglycan and glycosaminoglycan content in the AAA wall.

Evaluation of urokinase-type plasminogen activator and its receptor in neointima of polyester vascular grafts.

The aim of the study was to assess the expression of urokinase-type plasminogen activator (uPA) and its receptor (uPAR) in neointima of polyester vascular grafts. Anastomotic areas were examined at 1, 4 and 12 months after prosthesis implantation in dogs, as well as in human vascular grafts. Immunohistochemistry was performed for uPA and uPAR. Graft neointima in dogs was positively stained for uPA with increased intensity at 4 and 12 months, whereas uPAR expression appeared at 4 and its intensity was increased at 12 months. Intensive uPA and positive uPAR labeling was shown in human grafts. The results demonstrated that in the early period of the healing process of polyester vascular grafts only uPA is present in the neointima in the region of the graft to adjacent artery anastomosis, whereas in healed grafts in dogs and humans uPAR is found as well.

Decrease of force capabilities as an index of upper limb fatigue.

The aim of the study was to assess upper limb fatigue on the basis of the force change index (FCI), which expresses changes in developed force, and to demonstrate that this index differentiates muscle fatigue of the upper limb depending on external load. The study was performed on ten young men in 12 conditions of external load. Ten conditions characterized repetitive work in a two-period cycle, in which both or one of the periods were loaded, and two conditions characterized continuous work with constant load. The participants tried to maintain hand-grip force at an imposed level during a determined time in the standard upper limb posture. Changes in values of recorded force exerted during successive cycles were approximated by a regression function. In most cases there was a strong correlation between the measurement data and the logarithmic regression curve. However, several cases of lower external load showed absence of such correlation. In 75% of the cases, there were statistically significant differences between the values of FCI calculated for individual conditions of external load. That means that FCI not only expresses muscle fatigue quantitatively but also points to the differences in upper limb fatigue resulting from differences in the external load. The study results have shown that the developed index (FCI) can be applied for fatigue assessment and discrimination with a more sophisticated model of a repetitive task than just a simple two-period work and rest model.

Expression of fibrinolysis activators and their inhibitor in neointima of polyester vascular grafts.

The aim of the study was to evaluate dynamic changes in the expression of fibrinolytic system components in neointima forming in polyester vascular grafts. The study was carried out on 18 mongrel dogs divided into three groups, that underwent replacement of abdominal aorta with a polyester double velour prosthesis. Grafts were removed at 1, 4 and 12 months. The specimens were fixed according to AMeX method. Immunohistochemical labeling for von Willebrand factor (vWf), tissue plasminogen activator (t-PA), urokinase (u-PA), its receptor (u-PAR), plasminogen activator inhibitor type 1 (PAI-1) and D-dimer (DD) was performed. Increasing intensity of vWf expression on the graft luminal surface was found in successive periods of the study. A light positive t-PA and u-PA staining was shown in neointima at 1 month and its intensity was significantly increased at 4 and 12 months. Expression of u-PAR appeared at 4 months. A light positive PAI-1 and DD staining was demonstrated in neointima in all periods of the study. The results demonstrated increasing expression of fibrinolysis activators in neointima of polyester vascular grafts. Intensive expression of plasminogen activators, when compared to their inhibitor may reduce thrombotic properties of graft neointima particularly in the late period after prosthesis implantation.

Coagulation activators and inhibitors in the neointima of polyester vascular grafts.

The surface of synthetic vascular grafts is thrombogenic, which implies a risk for their occlusion. The aim of the study was to evaluate expression of coagulation components in the polyester vascular grafts neointima. The study was carried out on 18 dogs, which underwent replacement of the abdominal aorta with a polyester prosthesis. Grafts were removed after 1, 4 and 12 months. Immunohistochemical labeling for von Willebrand factor, tissue factor, factor XII, tissue factor pathway inhibitor, thrombomodulin, protein C, protein S and prothrombin activation fragment F1 + 2 was performed. Increasing intensity of von Willebrand factor expression was found in successive periods of the study. Factor XII was shown in the whole neointima after 1 month, whereas in the following periods its presence was limited to the luminal surface. Tissue factor expression was demonstrated after 1 month and its intensity increased in later periods. Tissue factor pathway inhibitor and thrombomodulin expression was demonstrated after 4 and 12 months. Protein C and protein S were present in all observation periods, as well as prothrombin activation fragment F1 + 2. Results indicate a high thrombotic potential of the graft neointima early after prosthesis implantation, whereas in the late postoperative follow-up increasing expression of coagulation inhibitors reduces thrombotic properties of the graft neointima.