Vessel Perimeter Research Articles

Immunohistochemical study of CD34 and podoplanin in periodontal disease.

The aim of this study was to evaluate the angiogenesis and lymphangiogenesis in gingival tissue biopsy specimens of individuals with clinically healthy gingiva, chronic gingivitis, and chronic periodontitis (n=30 per clinical condition). Histological sections were stained using hematoxylin and eosin as well as immunohistochemically with hematopoietic progenitor cell antigen CD34 and podoplanin (PDPN) antibodies to evaluate the microvascular count, area, and perimeter of blood and lymphatic vessels, respectively. The results revealed a correlation between the microvascular count of blood and lymphatic vessels (P=0.03; however, in individuals with chronic periodontitis, fewer lymphatic vessels were present than in the clinically healthy gingival tissue (P=0.01), which was not observed in the case of microvascular area and perimeter. Podoplanin labeling was present in the epithelium, and the intensity of labeling was positively correlated to the intensity of the inflammatory infiltrate (P=0.03). In this study, we concluded that an increase in the number of blood and lymphatic vessels was not observed in bouth gingivitis and periodontitis samples. Podoplanin expression is highly associated with an increased inflammatory infiltration suggesting that PDPN might play an additional role in periodontal disease, other than solely as a lymphangiogenesis marker.

Evaluation of retinal vasculature before and after treatment of children with obstructive sleep apnea-hypopnea syndrome by optical coherence tomography angiography.

To evaluate the effect of adenoidectomy on the brains of children with obstructive sleep apnea-hypopnea syndrome (OSAS) through observation of the alteration of retinal perfusion by optical coherence tomography angiography (OCTA). Sixty-two children with OSAS (124 eyes; 5.94 ± 1.64years old; 53.2% boys) were enrolled in this study. Their retinal vascular network density indices, including vascular diameter (VD), vascular area density (VAD), vessel skeleton density (VSD), vessel perimeter index (VPI) on the macular superficial/deep capillary plexus (SCP/DCP), and the size of the foveal avascular zone (FAZ) were analyzed by OCTA before treatment and at 1month after the adenoidectomy. After the adenoidectomy, the values of VD, VAD, VSD, and VPI in the SCP/DCP of the parafovea were significantly increased (p < 0.01). The FAZ was significantly diminished in the SCP (t = 4.50, p < 0.05) and increased in the DCP (t = - 4.43, p < 0.05). The peripapillary indices in the SCP/DCP were not significantly changed (p > 0.05). By improvement of hypoxia, the response of the parafoveal vessels was more sensitive than that of the peripapillary region in children with OSAS. Therefore, OCTA may be an ideal method to evaluate the changes of the retinal vascular system, which could be an effective parameter for the early evaluation of adenoidectomy on cases of pediatric OSAS.

The irradiated human mandible: A quantitative study on bone vascularity

ObjectivesHypovascularisation is thought to play an important role in the pathogenesis of osteoradionecrosis. The objective of this study was to assess the microvascular system in the irradiated mandibular bone marrow. Materials and methodsMandibular bone biopsies were taken from 20 irradiated patients and 24 controls. Blood vessels were visualized using CD34 antibody stain to detect endothelial cells. The vascular density (VD) and vascular area fraction (VAF) were measured. Mean vessel lumen area, perimeter and diameter of the vessels were calculated for each vessel. A distinction was made between large and small vessels (cut-off point <400 µm2). ResultsVascular density and vascular area fraction were lower in the irradiated group. The mean vascular perimeter and mean vascular diameter were higher in samples with a local radiation dose of ≥50 Gy, whereas the percentage of small vessels was lower. Larger vessel perimeter is associated with higher radiation dose. A longer interval between biopsy and radiotherapy is associated with a larger mean vessel perimeter and a lower percentage of small vessels. ConclusionsRadiation dosages higher than 50 Gy mainly affect the smaller vessels. With increased time after irradiation, the share of smaller vessels in the mandibular bone marrow seems to decrease. In search of the exact mechanisms of irradiation damage and osteoradionecrosis of the mandible, the role of the microvascular system in the mandibular bone marrow should be further explored.

Tongue development in stillborns autopsied at different gestational ages

ObjectivesThis study aimed to analyze, through the morphometric method, the perimeter and length of the tongue, the collagen fibers, and the perimeter of blood vessels at different gestational ages and fetal weights. Material and methodsTongues (n=55) of stillborns autopsied at 23–40 weeks of gestational age were macroscopically analyzed, and their length and perimeter were measured. Fifty‐five tongue fragments were collected through a longitudinal section in the region that accompanies the median lingual sulcus and histologically processed. Slides were stained with picrosirius and immunolabeled with CD31 antibody. Quantification was performed on collagen fibers under polarized light, and on the perimeter of vessels with the CD31. ResultsA positive and significant correlation of gestational age with tongue perimeter and length was found. There was a positive and significant correlation between collagen fibers and gestational age, as well as between gestational age and the perimeter of blood vessels. Between collagen fibers and fetal weight, a positive and significant increase was observed. Regarding the correlation between the perimeter of blood vessels and the fetal weight, an increase was observed. ConclusionAs gestational age advances, there is an increase in tongue perimeter and length, in the percentage of collagen fibers, and in vascular perimeter, demonstrating that tongue formation is directly related to tongue growth and development.

Segmentation of the lumen and media‐adventitial borders in intravascular ultrasound images using a geometric deformable model

This study presents a geometric deformable model-based segmentation approach to segmentation of the intima and media-adventitial (MA) borders in sequential intravascular ultrasound (IVUS) images. The initial estimation of the vessel borders was done manually only for the first frame of each sequence. After the border initialisation, pre-processing including edge preservation, noise reduction, and dead zone preservation was successively performed on each IVUS frame. To improve segmentation performance, the image masks were determined preliminarily by local binary pattern-based mask initialisation. Then, the inner and outer borders were approximated using a modified distance regularised level set evolution model. The results showed superior performance of the suggested approach for estimating intima and MA layers from the IVUS images. The corresponding correlation coefficients of area, vessel perimeter, maximum vessel diameter, and maximum lumen diameter were r = 0.782, r = 0.716, r = 0.956, and r = 0.874 for the 20 MHz images, respectively, and r = 0.990, r = 0.995, r = 0.989, and r = 0.996 for the 45 MHz images, respectively. In addition, linear regression analysis indicated that the manual segmentation had significantly high similarity at r > 0.967 and r > 0.993 for 20 and 45 MHz images, respectively.

Repeatability and Reproducibility of Quantitative Assessment of the Retinal Microvasculature Using Optical Coherence Tomography Angiography Based on Optical Microangiography

ObjectiveThe aim of this study was to determine the repeatability and reproducibility of optical coherence tomography angiography (OCTA) based on optical microangiography (OMAG) measurements of macular vessels in normal eyes. MethodsIn this prospective cohort study, 40 eyes of 40 healthy volunteers underwent repeated OCTA (Cirrus HD-OCT 5000 angiography system, Carl Zeiss Meditec, Inc.) scans on two separate visit days. On each visit day, the eyes were scanned three times. The following parameters were used to quantitatively describe the OCTA images of the superficial vascular network: vessel area density (VAD), vessel skeleton density (VSD), vessel diameter index (VDI), vessel perimeter index (VPI), vessel complexity index (VCI), flux, and foveal avascular zone (FAZ). Coefficient of variation (CV) and intraclass correlation coefficient (ICC) were calculated for evaluating intravisit and intervisit repeatability, as well as interobserver reproducibility. ResultsThe measurements showed high repeatability [CVs ≤ 4.2% (intravisit) and ≤ 4.6% (intervisit)] and interobserver reproducibility (ICCs ≥ 0.923) for all parameters. ConclusionThis study demonstrated good repeatability and reproducibility of OCTA based on OMAG for the measurement of superficial vessel parameters in normal eyes.

Tongue development in stillborns autopsied at different gestational ages

ObjectivesThis study aimed to analyze, through the morphometric method, the perimeter and length of the tongue, the collagen fibers, and the perimeter of blood vessels at different gestational ages and fetal weights. Material and methodsTongues (n=55) of stillborns autopsied at 23–40 weeks of gestational age were macroscopically analyzed, and their length and perimeter were measured. Fifty-five tongue fragments were collected through a longitudinal section in the region that accompanies the median lingual sulcus and histologically processed. Slides were stained with picrosirius and immunolabeled with CD31 antibody. Quantification was performed on collagen fibers under polarized light, and on the perimeter of vessels with the CD31. ResultsA positive and significant correlation of gestational age with tongue perimeter and length was found. There was a positive and significant correlation between collagen fibers and gestational age, as well as between gestational age and the perimeter of blood vessels. Between collagen fibers and fetal weight, a positive and significant increase was observed. Regarding the correlation between the perimeter of blood vessels and the fetal weight, an increase was observed. ConclusionAs gestational age advances, there is an increase in tongue perimeter and length, in the percentage of collagen fibers, and in vascular perimeter, demonstrating that tongue formation is directly related to tongue growth and development.

The Functional Angiosome: Clinical Implications of the Anatomical Concept.

The angiosome is a three-dimensional block of tissue supplied by a source vessel with its boundary outlined either by an anastomotic perimeter of reduced-caliber choke vessels or by true anastomoses with no reduction of vessel caliber. This article focuses on the role of these anastomotic vessels in defining flap survival or the necrotic pattern seen in fulminating meningococcal septicemia. Experiments in pigs, dogs, guinea pigs, and rabbits over the past 46 years were reviewed, focusing on the necrosis line of flaps, the effects of various toxins in vivo, and correlating these results in the clinical setting. Experimentally, choke anastomoses are functional and control flow between perforator angiosomes. They (1) permit capture of an adjacent angiosome when the flap is raised on a cutaneous perforator in 100 percent of cases, with the necrosis line occurring usually in the next interperforator connection; (2) confine flow to the territory of the involved artery when a toxin is introduced by spasm around its perimeter; and (3) lose this property of spasm when choke vessels are converted to true anastomoses following surgical delay, or where true anastomoses occur naturally, thereby allowing unimpeded blood flow and capture of additional angiosome territories. Clinical experience supports these observations. The functional angiosome is the volume of tissue that clinically can be isolated on a source vessel. The area extends beyond its anatomical territory to capture an adjacent territory if connections are by choke anastomoses, or more if they are by true anastomoses.

Transfer of Learning from Practicing Microvascular Anastomosis on Silastic Tubes to Rat Abdominal Aorta.

Learning to perform microvascular anastomosis is difficult. Laboratory practice models using artificial vessels are frequently used for this purpose. However, the efficacy of such practice models has not been objectively assessed for the performance of microvascular anastomosis during live surgical settings. This study was conducted to assess the transfer of learning from practicing microvascular anastomosis on tubes to anastomosing rat abdominal aorta. Ten surgeons without any experience in microvascular anastomosis were randomly assigned to an experimental or a control group. Both groups received didactic and visual training on end-to-end microvascular anastomosis. The experimental group received 24 sessions of hands-on training on microanastomosis using Silastic tubes. Next, both groups underwent recall tests on weeks 1, 2, and 8 after training. The recall test consisted of completing an end-to-end anastomosis on the rat's abdominal aorta. Anastomosis score, the time to complete the anastomosis, and the average time to place 1 stitch on the vessel perimeter were compared between the 2 groups. Compared with the control group, the experimental group did significantly better in terms of anastomosis score, total time, and per-stitch time. The measured variables showed stability and did not change significantly between the 3 recall tests. The skill of microvascular anastomosis is transferred from practicing on Silastic tubes to rat's abdominal aorta. Considering the relative advantages of Silastic tubes to live rodent surgeries, such as lower cost and absence of ethical issues, our results support the widespread use of Silastic tubes in training programs for microvascular anastomosis.

Computer-aided classification of sickle cell retinopathy using quantitative features in optical coherence tomography angiography.

As a new optical coherence tomography (OCT) imaging modality, there is no standardized quantitative interpretation of OCT angiography (OCTA) characteristics of sickle cell retinopathy (SCR). This study is to demonstrate computer-aided SCR classification using quantitative OCTA features, i.e., blood vessel tortuosity (BVT), blood vessel diameter (BVD), vessel perimeter index (VPI), foveal avascular zone (FAZ) area, FAZ contour irregularity, parafoveal avascular density (PAD). It was observed that combined features show improved classification performance, compared to single feature. Three classifiers, including support vector machine (SVM), k-nearest neighbor (KNN) algorithm, and discriminant analysis, were evaluated. Sensitivity, specificity, and accuracy were quantified to assess the performance of each classifier. For SCR vs. control classification, all three classifiers performed well with an average accuracy of 95% using the six quantitative OCTA features. For mild vs. severe stage retinopathy classification, SVM shows better (97% accuracy) performance, compared to KNN algorithm (95% accuracy) and discriminant analysis (88% accuracy).

Effect of prenatal exposure to alcohol on the development of brain vessels in human embryos and fetuses

IntroductionHuman embryos are most susceptible to exogenous effects during the first weeks of development.AimStudy the effects of prenatal alcohol intoxication on morphometric measures of developing vessels in the human embryonic and fetal cerebrum.MethodsEmbryos and fetuses (7–12 weeks): 23 obtained from alcoholic women with stage II alcoholism (the experimental group) and 30 from healthy women (the control group). The research involved electron microscopy, computer morphometry, parametric method of variational statistics and Scion software to determine mean vascular cross-sectional area, the relative cross-sectional area of vessels, the number of vessels per unit area, and the perimeter of vessels.ResultsFrom 10 weeks, vessels in the human brain start to differentiate into arteries and veins. At 12 weeks, capillary basal membranes were already clearly visible. We established a series of characteristics distinguishing brain tissues in the experimental group vs. that in controls: mean vessel cross-sectional areas and vessel perimeters were significantly reduced by 11 weeks vs. controls. The tendency persisted at 12 weeks. Relative vessel cross-sectional area in the experimental group was greater than in controls.ConclusionsMaternal alcoholization during pregnancy significantly influences the development of the cerebral circulatory system, manifesting mainly in changes in the vascularization of the growing brain.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Quantitative characteristics of sickle cell retinopathy in optical coherence tomography angiography

Early detection is an essential step for effective intervention of sickle cell retinopathy (SCR). Emerging optical coherence tomography angiography (OCTA) provides excellent three-dimensional (3D) resolution to enable label-free, noninvasive visualization of retinal vascular structures, promising improved sensitivity in detecting SCR. However, quantitative analysis of SCR characteristics in OCTA images is yet to be established. In this study, we conducted comprehensive analysis of six OCTA parameters, including blood vessel tortuosity, vessel diameter, vessel perimeter index (VPI), area of foveal avascular zone (FAZ), contour irregularity of FAZ and parafoveal avascular density. Compared to traditional retinal thickness analysis, five of these six OCTA parameters show improved sensitivity for SCR detection than retinal thickness. It is observed that the most sensitive parameters were the contour irregularity of FAZ in the superficial layer and avascular density in temporal regions, while the area of FAZ, tortuosity and mean diameter of the vessel were moderately sensitive.

Quantitative assessment of the retinal microvasculature using optical coherence tomography angiography

Optical coherence tomography angiography (OCTA) is clinically useful for the qualitative assessment of the macular microvasculature. However, there is a need for comprehensive quantitative tools to help objectively analyze the OCT angiograms. Few studies have reported the use of a single quantitative index to describe vessel density in OCT angiograms. In this study, we introduce a five-index quantitative analysis of OCT angiograms in an attempt to detect and assess vascular abnormalities from multiple perspectives. The indices include vessel area density, vessel skeleton density, vessel diameter index, vessel perimeter index, and vessel complexity index. We show the usefulness of the proposed indices with five illustrative cases. Repeatability is tested on both a healthy case and a stable diseased case, giving interclass coefficients smaller than 0.031. The results demonstrate that our proposed quantitative analysis may be useful as a complement to conventional OCTA for the diagnosis of disease and monitoring of treatment.

Quantification and Correlation of Angiogenesis with Macrophages by Histomorphometric Method in Central and Peripheral Giant Cell Granuloma: An Immunohistochemical Analysis.

Angiogenesis is a fundamental process that affects physiologic reactions and pathological processes such as tumour development and metastasis. It is the process of formation of new microvessel from the preexisting vessels. The purpose of this study was to evaluate angiogenesis, macrophage index and correlate the impact of macrophages on angiogenesis in the central and peripheral giant cell granulomas by evaluating immunohistochemically microvessel density, microvessel perimeter and macrophage index. Immunohistochemical analysis was carried on 20 cases of central and peripheral giant cell granulomas each for CD34 and CD68 proteins expression. Inferential statistical analysis was performed using Independent student t-test to assess the microvessel density, microvessel perimeter and macrophage index on continuous scale between Group I and Group II. Level of significance was determined at 5%. Further bivariate analysis using Pearson correlation test was carried out to see the relationship between microvessel density and macrophage index in each group. Microvessel density, micro vessel perimeter and macrophage index was higher in central giant cell granuloma compared to that of peripheral giant cell granuloma. Correlation between microvessel density and macrophage index among these two lesions was statistically insignificant. Angiogenesis as well as the number of macrophages appeared to increase in Central Giant Cell Granuloma in present study. These findings suggest that macrophages may up regulate the angiogenesis in these giant cell granulomas and angiogenesis do have a role in clinical behaviour. However, we could not establish a positive correlation between microvessel density and macrophage index as the values were statistically insignificant. This insignificance may be presumed due to fewer samples taken for study.

Perturbed mechanotransduction by endothelial surface glycocalyx modification greatly impairs the arteriogenic process.

The mechanisms that trigger initiation of arteriogenesis in response to pathogenic obstruction of arterial flow are not fully understood. Our objective is to determine whether glycocalyx mediated mechanotransduction of fluid shear stress to the endothelial layer is an essential first step in inducing arteriogenesis. Mice were implanted with an osmotic minipump containing saline or hyaluronan synthase inhibitor 4-methylesculetin (4ME) 2 wk before femoral artery ligation. 4ME was effective in modifying the endothelial glycocalyx as measured by dextran exclusion and perfused boundary region changes. Glycocalyx modification resulted in a 52% (P = 0.002) reduction in perfusion restoration through the 21-day follow-up [area under the curve, 4.9 ± 1.1 (n = 11) vs. 10.2 ± 3.2 (n = 10), 4ME vs. control (Ctrl)]. Upon femoral artery ligation, no change in collateral vessel diameter in 4ME treated mice (49.8 ± 26.3 vs. 47.1 ± 14.0 μm, ligated vs unligated) was observed (Ctrl, 88.5 ± 18.8 vs. 35.1 ± 3.0 μm, ligated vs unligated, P < 0.05). This impaired arteriogenic process was accompanied by lack of local induction of both endothelial and smooth muscle cell activation (Ki67, endothelial nitric oxide synthase, and ICAM-1), as well as a failure to recruit CD11b-positive cells in 4ME-treated collateral vessels (0.012 ± 0.003 vs. 0.010 ± 0.003 cells/μm vessel perimeter, ligated vs. unligated), whereas in Ctrls, the number of CD11b cells was increased (0.024 ± 0.002 vs. 0.010 ± 0.004 cells/μm vessel perimeter, P < 0.05). Modification of the glycocalyx by inhibition of hyaluronan synthesis renders the endothelium unresponsive to altered hemodynamic conditions resulting from femoral artery ligation, which results in a hampered restoration of distal perfusion.

Does the use of compression garments increase venous stasis in the common femoral vein?

Abdominoplasty is one of the most frequently performed procedures in plastic surgery. The impact of deep venous thrombosis and pulmonary embolism after this operation is well described and is a feared complication. Most plastic surgeons recommend the use of compression garment after this procedure. The purpose of this study was to evaluate the venous changes at the common femoral vein induced by the use compression garments. Fifteen female volunteers with no history of abdominal surgery were selected. Doppler examination was used to evaluate maximum and average flow speed and the vessel perimeter, area, and diameter of the common femoral vein of the patients using no garments and using a compressive garment and a Velcro binder in the supine position. Also patients were evaluated in the Fowler position. The t test was used to compare the parameters among all situations. The level of significance was stated as 0.05 (5 percent). The use of both garments increased venous flow stasis, and there were no significant differences between them. Also, it has been demonstrated that the Fowler position can worsen venous stasis. Therefore, the use of compressive garments can increase femoral vein stasis. The use of compressive garments promotes venous stasis. There was no difference in stasis reduction when using the two different types of garments. The Fowler position increases venous stasis compared with the supine position.

Radiation-induced impairment in lung lymphatic vasculature.

The lymphatic vasculature has been shown to play important roles in lung injury and repair, particularly in lung fibrosis. The effects of ionizing radiation on lung lymphatic vasculature have not been previously reported. C57Bl/6 mice were immobilized in a lead shield exposing only the thoracic cavity, and were irradiated with a single dose of 14 Gy. Animals were sacrificed and lungs collected at different time points (1, 4, 8, and 16 weeks) following radiation. To identify lymphatic vessels in lung tissue sections, we used antibodies that are specific for lymphatic vessel endothelial receptor 1 (LYVE-1), a marker of lymphatic endothelial cells (LEC). To evaluate LEC cell death and oxidative damage, lung tissue sections were stained for LYVE-1 and with TUNEL staining, or 8-oxo-dG respectively. Images were imported into ImageJ v1.36b and analyzed. Compared to a non-irradiated control group, we observed a durable and progressive decrease in the density, perimeter, and area of lymphatic vessels over the study period. The decline in the density of lymphatic vessels was observed in both subpleural and interstitial lymphatics. Histopathologically discernible pulmonary fibrosis was not apparent until 16 weeks after irradiation. Furthermore, there was significantly increased LEC apoptosis and oxidative damage at one week post-irradiation that persisted at 16 weeks. There is impairment of lymphatic vasculature after a single dose of ionizing radiation that precedes architectural distortion and fibrosis, suggesting important roles for the lymphatic circulation in the pathogenesis of the radiation-induced lung injury.

Correlation between dynamic contrast-enhanced MRI and quantitative histopathologic microvascular parameters in organ-confined prostate cancer.

To correlate pharmacokinetic parameters of 3-T dynamic contrast-enhanced (DCE-)MRI with histopathologic microvascular and lymphatic parameters in organ-confined prostate cancer. In 18 patients with unilateral peripheral zone (pT2a) tumours who underwent DCE-MRI prior to radical prostatectomy (RP), the following pharmacokinetic parameters were assessed: permeability surface area volume transfer constant (K (trans)), extravascular extracellular volume (Ve) and rate constant (K ep). In the RP sections blood and lymph vessels were visualised immunohistochemically and automatically examined and analysed. Parameters assessed included microvessel density (MVD), area (MVA) and perimeter (MVP) as well as lymph vessel density (LVD), area (LVA) and perimeter (LVP). A negative correlation was found between age and K (trans) and K ep for tumour (r = -0.60, p = 0.009; r = -0.67, p = 0.002) and normal (r = -0.54, p = 0.021; r = -0.46, p = 0.055) tissue. No correlation existed between absolute values of microvascular parameters from histopathology and DCE-MRI. In contrast, the ratio between tumour and normal tissue (correcting for individual microvascularity variations) significantly correlated between K ep and MVD (r = 0.61, p = 0.007) and MVP (r = 0.54, p = 0.022). The lymphovascular parameters showed only a correlation between LVA and K ep (r = -0.66, p = 0.003). Significant correlations between DCE-MRI and histopathologic parameters were found when correcting for interpatient variations in microvascularity. • Normal prostate tissue shows strong heterogeneity in microvascularity. • Peripheral zone prostate cancer shows increased and less heterogeneous microvascularity. • Normal and tumour tissue shows considerable variation in microvascularity between patients. • DCE-MRI should take into account the interprostatic heterogeneity of microvasculature between patients.

Correlation between in vivo 18F-FDG PET and immunohistochemical markers of glucose uptake and metabolism in pheochromocytoma and paraganglioma.

Pheochromocytomas and paragangliomas (PPGLs) can be localized by (18)F-FDG PET. The uptake is particularly high in tumors with an underlying succinate dehydrogenase (SDH) mutation. SDHx-related PPGLs are characterized by compromised oxidative phosphorylation and a pseudohypoxic response, which mediates an increase in aerobic glycolysis, also known as the Warburg effect. The aim of this study was to explore the hypothesis that increased uptake of (18)F-FDG in SDHx-related PPGLs is reflective of increased glycolytic activity and is correlated with expression of different proteins involved in glucose uptake and metabolism through the glycolytic pathway. Twenty-seven PPGLs collected from patients with hereditary mutations in SDHB (n = 2), SDHD (n = 3), RET (n = 5), neurofibromatosis 1 (n = 1), and myc-associated factor X (n = 1) and sporadic patients (n = 15) were investigated. Preoperative (18)F-FDG PET/CT studies were analyzed; mean and maximum standardized uptake values (SUVs) in manually drawn regions of interest were calculated. The expression of proteins involved in glucose uptake (glucose transporters types 1 and 3 [GLUT-1 and -3, respectively]), phosphorylation (hexokinases 1, 2, and 3 [HK-1, -2, and -3, respectively]), glycolysis (monocarboxylate transporter type 4 [MCT-4]), and angiogenesis (vascular endothelial growth factor [VEGF], CD34) were examined in paraffin-embedded tumor tissues using immunohistochemical staining with peroxidase-catalyzed polymerization of diaminobenzidine as a read-out. The expression was correlated with corresponding SUVs. Both maximum and mean SUVs for SDHx-related tumors were significantly higher than those for sporadic and other hereditary tumors (P < 0.01). The expression of HK-2 and HK-3 was significantly higher in SDHx-related PPGLs than in sporadic PPGLs (P = 0.022 and 0.025, respectively). The expression of HK-2 and VEGF was significantly higher in SDHx-related PPGLs than in other hereditary PPGLs (P = 0.039 and 0.008, respectively). No statistical differences in the expression were observed for GLUT-1, GLUT-3, and MCT-4. The percentage anti-CD 34 staining and mean vessel perimeter were significantly higher in SDHx-related PPGLs than in sporadic tumors (P = 0.050 and 0.010, respectively). Mean SUVs significantly correlated with the expression of HK-2 (P = 0.027), HK-3 (P = 0.013), VEGF (P = 0.049), and MCT-4 (P = 0.020). The activation of aerobic glycolysis in SDHx-related PPGLs is associated with increased (18)F-FDG accumulation due to accelerated glucose phosphorylation by hexokinases rather than increased expression of glucose transporters.

Abstract 343: Endothelial Regulator of G-Protein Signaling-5 Maintains Endothelial Permeability and Controls Vascular Smooth Muscle Cell Migration in vitro

GAP-inhibitor, RGS5 has been described as a VSMC marker and is associated with plaque stability. Its role in endothelial cells (EC) is unclear. We examined RGS5 expression patterns in human vasculature and hypothesized that loss of RGS5 alters EC biology and crosstalk with VSMC such, that it could promote atherogenesis. Methods: Human internal mammary artery (IMA), saphenous vein (SV) and failing myocardium (MYO) samples were stained for RGS5, αSMA and vWF. RGS5 or scrambled siRNA knocked down (RGS5-KD) HUVECs were used. oxLDL or TNFα induced THP1-adhesion to HUVECs was assessed. The 2h diffusion rate of Evans-blue bound to 0.1%-BSA/DPBS through a HUVEC monolayer was spectrophotometrically measured in the presence of PTX. HUVECs were also subjected to spheroid sprouting in collagen/methylcellulose. qRT-PCR using the Δ(ΔCT) method with HPRT as house-keeper was used to assess MMP-9, VEGF-A and caveolin-1 expression in transfected cells. To test RGS5-dependent paracrine effects of EC-secreted factors on VSMC, isotonic buffer was conditioned for 2h by transfected HUVECs (CB). CB was added to VSMC during a scratch assay. Results: RGS5 signal was enhanced in the endothelium of SV compared to IMA (63±9 vs 22±4 %vessel perimeter, p&lt;0.05, n=4). Similar patterns were observed in myocardium. In IMA plaques RGS5 was prominently reduced in medial VSMC underlying and in the endothelium covering the plaque compared to non-diseased vessels. No effect on TNFα- or oxLDL-induced adhesion was observed in RGS5-KD HUVECs. HUVEC permeability increased in RGS5-KD cells (1 vs 2.5± 0.2 normalized OD, n=4, p&lt;0.05), which was reduced by PTX (1.4±0.25). MMP-9 (1.0±0.03 vs 2.5±0.54, p&lt;0.05, n=5), VEGF-A (1.0±0.02 vs 2.8±0.76, p&lt;0.05, n=5) and Caveolin-1 (1.0±0.01 vs 1.6±0.17, n=3) expression (2-Δ (ΔCT)) were increased in RGS5-KD HUVECs. RGS5-KD increased the number of spheroid sprouts (2.1± 0.5 vs 3.5± 0.3,n=4, p&lt;0.05). CB of RGS5-KD HUVECs increased VSMC migration (49±2.2 vs 67±2.6 %coverage, p&lt;0.05, n=7). Conclusion: In conclusion, RGS5 levels could be involved in vascular differentiation. Its effects on permeability and VSMC migration point towards a prominent role in angiogenesis and atherogenesis. Atherosclerosis studies in RGS5-deficient animals are warranted.