Vessel Lumen Area Research Articles

Drought-induced oak decline in the western Mediterranean region: an overview on current evidences, mechanisms and management options to improve forest resilience

Abstract: Increased forest vulnerability is being reflected as more widespread and severe drought-induced decline episodes. In particular, the Mediterranean area is revealing a high susceptibility to phenomena of loss in tree vitality across species. Within tree species, oaks (Quercus spp.) are experiencing extensive decline in many countries. However, in the wake of the so-called “oak decline phenomenon”, the attention on these species has generally been limited. In this paper, we review the current available literature on oak-decline cases reported within the Mediterranean Basin, with particular remark for those occurred in Italy and Spain. More specifically our main aims were to: (i) provide an update on the patterns and mechanisms of decline by focusing on tree-ring and wood-anatomical variables; (ii) provide some hints for improving the resistance and resilience of oak stands experiencing decline. Our review reveals that drought is reported as the main driver triggering oak decline within the Mediterranean Basin, although other causes (i.e., increasing temperature, pathogens attack or excessive stand density) could exacerbate decline. In most reported cases, drought induced a substantial reduction of growth and changes in some wood anatomical properties. Indeed, growth decline prior death is also indicated as an early-warning signal of impending death. In ring-porous oak species, declining trees were often characterized by a very low production of latewood and a decrease in lumen area of the widest earlywood vessels, suggesting a potential reduction of hydraulic conductivity. Moreover, hydraulic dysfunction is reported as the main cause of decline. Finally, regarding management actions that should be considered for improving the resilience of declining stands and preserve the species-specific stand composition, it could be useful to shorten the rotation period of coppice stands or promoting their gradual conversion towards high forests, and favoring more drought-resistant species should also be considered. In addition, regeneration prior to regeneration cuts should be improved by anticipating seed dispersal or by planting oak seedlings obtained from local germoplasm.

CorMatrix Wrapped Around the Adventitia of the Arteriovenous Fistula Outflow Vein Attenuates Venous Neointimal Hyperplasia

Venous neointimal hyperplasia (VNH) at the outflow vein of hemodialysis AVF is a major factor contributing to failure. CorMatrix is an extracellular matrix that has been used in cardiovascular procedures primarily as scaffolding during surgery. In the present study, we sought to determine whether CorMatrix wrapped around the outflow vein of arteriovenous fistula (AVF) at the time of creation could reduce VNH. In mice, the carotid artery to the ipsilateral jugular vein was connected to create an AVF, and CorMatrix scaffold was wrapped around the outflow vein compared to control mice that received no scaffolding. Immunohistochemistry, Western blot, and qRT-PCR were performed on the outflow vein at 7 and 21 days after AVF creation. In outflow veins treated with CorMatrix, there was an increase in the mean lumen vessel area with a decrease in the ratio of neointima area/media + adventitia area (P < 0.05). Furthermore, there was a significant increase in apoptosis, with a reduction in cell density and proliferation in the outflow veins treated with CorMatrix compared to controls (P < 0.05). Immunohistochemical analysis revealed a significant reduction in fibroblasts, myofibroblasts, macrophages, and leukocytes with a reduction in Tnf-α gene expression (P < 0.05). In conclusion, outflow veins treated with CorMatrix have reduced VNH.

Further insights into the components of resistance to Ophiostoma novo-ulmi in Ulmus minor: hydraulic conductance, stomatal sensitivity and bark dehydration

Dutch elm disease (DED) is a vascular disease that has killed over 1 billion elm trees. The pathogen spreads throughout the xylem network triggering vessel blockage, which results in water stress, tissue dehydration and extensive leaf wilting in susceptible genotypes. We investigated the differences between four Ulmus minor Mill. clones of contrasting susceptibility to Ophiostoma novo-ulmi Brasier regarding morphological, anatomical and physiological traits affecting water transport, in order to gain a better understanding of the mechanisms underlying DED susceptibility. We analyzed the differential response to water shortage and increased air vapor pressure deficit (VPD) to investigate whether resistance to water stress might be related to DED tolerance. Sixteen plants per clone, aged 2 years, were grown inside a greenhouse under differential watering. Stomatal conductance was measured under ambient and increased VPD. Growth, bark water content and stem hydraulic and anatomical parameters were measured 22 days after starting differential watering. Vessel lumen area, lumen fraction and hydraulic conductance were highest in susceptible clones. Stomatal conductance was lowest under low VPD and decreased faster under increased VPD in resistant clones. We found a negative relationship between the decrease in stomatal conductance at increased VPD and specific hydraulic conductance, revealing a narrower hydraulic margin for sustaining transpiration in resistant clones. The effect of water shortage was greater on radial stem growth than on leaf area, which could be explained through an extensive use of capacitance water to buffer xylem water potential. Water shortage reduced stomatal conductance and vessel lumen area. Bark water content under conditions of water shortage only decreased in susceptible clones. Higher hydraulic constraints to sap flow in resistant clones may determine higher stomatal sensitivity to VPD and so contribute to DED resistance by limiting pathogen expansion and reducing water loss and metabolic impairment in cells involved in fighting against infection.

Anatomical and morphological changes in scion of some olive grafting combinations under water deficit

Effects of water stress deficit were studied on xylem anatomical fea- tures and some growth parameters among six olive grafting combinations; Amygdalifolia/Arbequina (Am/Ar), Amygdalifolia/Koroneiki (Am/Ko), Amygdalifolia/Zard (Am/Z), Conservallia/Koroneiki (Co/Ko), Conservallia/Zard (Co/Z) and Conservallia/Arbequina (Co/Ar) of about three-year-old olive trees ( Olea europaea L.) under greenhouse conditions. To realize this, a factorial experiment was conducted in a completely randomized design (CRD). The results showed that rootstocks exhibited significant effects on scions xylem anatomical physiognomies, such as vessel lumen area (VLA) and vessel diame- ter (VD) and additionally on some growth indices including main stem length (SL), lateral shoot number (LSN) and graft union-cross sectional area (GU-CSA). Xylem anatomical characteristics including VLA, porosity, vessel frequency (VF) and VD of scions decreased when they were grafted onto Arbequina and Koroneiki rootstocks, but increased onto Zard rootstock. All growth parameters showed a decrease under drought stress, while this reduction was more pro- nounced for Zard rootstock than the other rootstocks. However, Co/Z showed the highest VF and the lowest vulnerability index (VI) and exhibited a better performance at the end of recovery.

Amygdalin ameliorates the progression of atherosclerosis in LDL receptor‑deficient mice.

Previous studies have demonstrated that regulatory T cells (Tregs) are pivotal in the regulation of T cell-mediated immune responses in atherosclerosis, a chronic autoimmune-like disease. In the authors' previous studies, it was demonstrated that amygdalin ameliorated atherosclerosis by the regulation of Tregs in apolipoprotein E-deficient (ApoE−/−) mice. Therefore, the aim of the present study was to investigate the therapeutic effect of amygdalin on low-density lipoprotein (LDL) receptor deficient (LDLR−/−) mice, and to examine its immune regulatory function by the stimulation of Tregs. To establish an atherosclerosis mouse model, the LDLR−/− mice were fed a high fat and high cholesterol diet then the total plasma cholesterol, triglyceride, LDL and chemokines levels were measured by an ELISA. Following sacrificing the mice, the upper sections of the aorta were stained by hematoxylin and eosin, and Oil red O to assess the plaque area. Then western blotting and reverse transcription polymerase chain reactions were performed to analysis the expression levels of cluster of differentiation 68, monocyte chemoattractant protein-1, matrix metalloproteinase (MMP)-2, MMP-9 and forkhead box P3 (Foxp3). To further confirm the activation of FOXP3 by amygdalin, lentiviruses carrying Foxp3 shRNA were injected into the mice, and the serum cytokines levels were measured by ELISA. Following feeding of the mice with a high-fat/high-cholesterol diet, the LDLR−/− mice demonstrated comparatively higher levels of triglyceride, total cholesterol and LDL, compared with levels in the amygdalin-treated mice. By comparing the vessel area, lumen area, plaque area, and percentage aortic plaque coverage, the effects of amygdalin on pre-existing lesions were assessed. In addition, the levels of CD68, monocyte chemoattractant protein-1, MMP-2 and MMP-9 were analyzed, and analysis of the expression of interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α indicated that the mice treated with amygdalin had decreased expression of pro-inflammatory cytokines. The mRNA and protein levels of Foxp3 were also quantified, and the mice treated with amygdalin demonstrated an increased number of Tregs. The knockdown of Foxp3mRNA resulted in the increased secretion of IL-1β, IL-6 and TNF-α. Therefore, the data indicated that amygdalin regulated the formation of atherosclerosis and stabilized the plaque by suppressing inflammatory responses and promoting the immune-modulation function of Tregs. Taken together, the results demonstrated the therapeutic effect of amygdalin on atherosclerosis.

Influence of artificial alteration of groundwater level on vessel lumen area and tree-ring width of Quercus robur

The response of tree-ring widths to groundwater-level decline varies among individual trees in forest stands. By contrast, vessel lumen area series contain common climatic signal of previous summer temperature. Drought events and the overuse of groundwater for water supply can cause significant declines of groundwater levels in naturally poorly drained forest stands. However, the documented growth reactions of trees to declines in groundwater level vary a lot and range from positive because of increased soil aeration to strongly negative because of drought stress. We analysed changes in tree-ring width and earlywood average vessel lumen area of Quercus robur from sites above an artesian aquifer, whose groundwater level declined in the late 1980s by about 5 m due to water pumping. Because we expected different responses of individual trees due to local microtopography and fine root distribution, we performed both site-level and tree-level analyses. Our results show that the site-level response of tree growth to groundwater-level pumping was not uniform. Individual trees were clustered into groups of drought-limited and water abundance-limited individuals. The response of trees to groundwater pumping differed between clusters—drought-sensitive trees responded negatively, whereas the growth of trees limited by water abundance remained stable or slightly increased. Inter-series correlation of drought-limited trees significantly increased in the period with the lowest groundwater level. In contrast to tree-ring widths, earlywood vessel lumen area series contained common temperature signal, with no imprint of groundwater-level alteration. Our results indicate that poorly drained forest ecosystems are characterized by a significantly individualistic response of radial growth to groundwater-level alteration. These individualistic responses could be, however, overshadowed in stand-level average tree-ring width chronologies.

Xylem Anatomical Trait Variability Provides Insight on the Climate-Growth Relationship of Betula nana in Western Greenland

ABSTRACTClimate change has been reported to affect shrub growth positively at several sites at high northern latitudes, including several arctic environments. The observed growth rates are, however, not uniform in space and time, and the mechanistic drivers of these patterns remain poorly understood. Here we investigated spatio-temporal interactions between climatic conditions, xylem anatomical traits, and annual growth of 21 Betula nana L. individuals from western Greenland for the period 2001–2011. Structural equation modeling showed that summer precipitation and winter temperature are affecting annual growth positively. Furthermore, vessel lumen area and vessel grouping, which are related to water conductivity and hydraulic connectivity of the xylem, respectively, positively influenced annual growth. To optimize growth B. nana was thus able to adjust its water transporting system. Annual variation in vessel lumen area seemed to be driven mostly by spring and summer temperatures, whereas annual variation in vessel grouping was driven by winter temperature. Linear models did not reveal a pattern in the spatial variation of xylem anatomical traits across the sampled climatic gradient. However, growth was positively correlated with local variation in insolation. Our results suggest that B. nana can adjust its hydraulic capacity to annual fluctuations in climatic conditions in order to optimize its total radial stem growth rate.

Influence of Root Diameter and Soil Depth on the Xylem Anatomy of Fine- to Medium-Sized Roots of Mature Beech Trees in the Top- and Subsoil.

Despite their importance for water uptake and transport, the xylem anatomical and hydraulic properties of tree roots have only rarely been studied in the field. We measured mean vessel diameter (D), vessel density (VD), relative vessel lumen area (lumen area per xylem area) and derived potential hydraulic conductivity (Kp) in the xylem of 197 fine- to medium-diameter roots (1–10 mm) in the topsoil and subsoil (0–200 cm) of a mature European beech forest on sandy soil for examining the influence of root diameter and soil depth on xylem anatomical and derived hydraulic traits. All anatomical and functional traits showed strong dependence on root diameter and thus root age but no significant relation to soil depth. Averaged over topsoil and deep soil and variable flow path lengths in the roots, D increased linearly with root diameter from ∼50 μm in the smallest diameter class (1–2 mm) to ∼70 μm in 6–7 mm roots (corresponding to a mean root age of ∼12 years), but remained invariant in roots >7 mm. D never exceeded ∼82 μm in the 1–10 mm roots, probably in order to control the risk of frost- or drought-induced cavitation. This pattern was overlain by a high variability in xylem anatomy among similar-sized roots with Kp showing a higher variance component within than between root diameter classes. With 8% of the roots exceeding average Kp in their diameter class by 50–700%, we obtained evidence of the existence of ‘high-conductivity roots’ indicating functional differentiation among similar-sized roots. We conclude that the hydraulic properties of small to medium diameter roots of beech are mainly determined by root age, rendering root diameter a suitable predictor of hydraulic functioning, while soil depth – without referring to path length – had a negligible effect.

Abstract 4044: LY3039579, a novel Notch inhibit, potentiates the anti-tumoral effects of sorafenib in hepatocellular carcinoma (HCC)

Abstract Introduction: Notch pathway has been involved in cell fate determination, cell differentiation, proliferation and death. Notch promotes cell survival, angiogenesis and treatment resistance in numerous cancers, making it a promising target for cancer therapy. The role of the Notch pathways in HCC tumorigenesis has shown some controversies over time and across studies, being endowed with both oncogenic and tumor suppressive properties. Our study aimed at investigating the anti-tumoral effects of combining LY3039478, a novel Notch inhibitor, to sorafenib in an in vivo transgenic model of HCC. Methods: Transgenic mice developing stage-defined HCC were treated for 8 weeks (W) from W8 to W16 with either vehicle, LY3039478 (8mg/kg, thrice weekly, oral gavage), sorafenib (30mg/kg, daily, oral gavage) or LY3039478 plus sorafenib. Tumor growth was evaluated by ultrasound (liver size), by the number of macronodules, and the number of micronodules on HPS sections at sacrifice. Angiogenesis was evaluated by doppler (blood flow in the coeliac trunk) and by CD31 staining. Results: Liver size and the number of liver tumor macronodules were significantly lower in all treatment arms compared to control placebo at both the W12 intermediary sacrifice and W16 final sacrifice; the combination of LY3039478 and sorafenib showing increased tumor control at W16 (4,39±0,82 in mean liver volumes (in mm3) in the combination arm vs 5,41±1,0, 5,84±0,47, 7,09±1,5 in the sorafenib, LY3039478 and placebo arms respectively). Angiogenesis assessed by measuring the mean blood flow in the coeliac trunk (TCm), decreased in all treatment arms, compared to placebo. At W16, LY3039478 potentiated the effect of sorafenib, with a TCm decrease of 36% compared to 23% and18% the sorafenib and LY3039478 arms, respectively. These results will be confirmed by the assessment of micronodules number on HPS section for tumor growth and CD31 staining for angiogenesis analysis (number of vessels and the vessel lumen area). The effects of the combination versus monotherapies will be evaluated on the immune landscape. Conclusion: The combination of LY3039478 and sorafenib showed promising anti-tumor activities that were associated with decreased angiogenesis. Citation Format: Annemilai Tijeras-Raballand, Christian Hobeika, Elise Payen, Matthieu Martinet, Philippe Bonnin, Karim A. Benhadji, Bharvin R. Patel, Clarisse Eveno, Marc Pocard, Sandrine Faivre, Eric Raymond, Armand de Gramont. LY3039579, a novel Notch inhibit, potentiates the anti-tumoral effects of sorafenib in hepatocellular carcinoma (HCC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4044. doi:10.1158/1538-7445.AM2017-4044

Abstract 29: Addition of Galunisertib to DC101 increased angiogenesis inhibition and tumor growth control in hepatocellular carcinoma (HCC)

Abstract Introduction: Galunisertib is a selective ATP-mimetic TGF-β receptor (TGFβR)-I inhibitor and DC101 is a rat antagonist antibody to mouse VEGFR-2 and is used to model VEGFR-2 blockade in murine tumor models. Ramucirumab and galunisertib being independently under clinical investigation in HCC patients, our study aimed at exploring the anti-tumoral potency of a combination of galunisertib and DC101 in an in vivo transgenic model of HCC. Methods: Transgenic mice developing stage-defined HCC were treated for 8 weeks (W) from W8 to W16 with either vehicle, DC101 (40mg/kg, twice weekly, IP), galunisertib (100mg/kg, daily, oral gavage) or DC101 plus galunisertib. Tumor growth was evaluated by ultrasound (liver size) and by the number of macronodules at sacrifice. Angiogenesis was evaluated by doppler (blood flow in the coeliac trunk) and by CD31 staining. Results: Liver size and the number of liver tumor macronodules were significantly lower in all treatment arms compared to placebo control at both the W12 intermediary sacrifice and W16 final sacrifice; the combination of galunisertib and DC101 showing increased tumor control at W16 (4,43±0,55 mean liver volume (in mm3) in the combination arm vs 5,22±0,86, 5,68±0,78, 7,09±1,54 in the DC101, galunisertib and placebo arms respectively). Angiogenesis assessed by measuring the mean blood flow in the coeliac trunk (TCm), decreased in all treatment arms compared to placebo. At W16, galunisetib potentiated the effect of DC101 with a TCm decrease of 66% compared to 59% and 10% in the DC101 and galunisertib, respectively. These results will be confirmed by the assessment of micronodules number on HPS section for tumor growth and CD31 staining for angiogenesis analysis (number of vessels and the vessel lumen area). The effects of the combination versus monotherapies will be evaluated on the immune landscape. Conclusion: The combination of galunisertib and DC101 showed promising anti-tumor activities that were associated with decreased angiogenesis. Citation Format: Annemilai Tijeras-Raballand, Christian Hobeika, Elise Payen, Matthieu Martinet, Philippe Bonnin, Karim A. Benhadji, Clarisse Eveno, Marc Pocard, Sandrine Faivre, Eric Raymond, Armand de Gramont. Addition of Galunisertib to DC101 increased angiogenesis inhibition and tumor growth control in hepatocellular carcinoma (HCC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 29. doi:10.1158/1538-7445.AM2017-29

The correlation of hyperopia and choroidal thickness, vessel diameter and area.

This study evaluates the effect of axial length and hyperopia error on macular choroidal thickness as well as choroidal vessel lumen diameter and area with EDI-OCT in short eyes. The study includes 64 volunteers who are over 18years of ages and applied to Eye Clinic of Ankara Training and Research Hospital. Choroidal thickness, choroidal vessel lumen diameter and areas were measured with Spectralis® OCT device using EDI technique. The study group included 44 volunteers with hyperopic refractive error, and control group included 20 emmetropic volunteers. Macular choroid was statistically significantly thicker in all quadrants as the hyperopia error increased (p<0.001). There was a statistically significant negative correlation between axial lengths and macular choroidal thicknesses in all quadrants (p<0.001). There was a statistically significant difference in choroidal vessel lumen diameter and area between hyperopia groups for both large and small vessels (p<0.01). The relationships between mean axial length and mean large choroidal vessel diameter and mean area measurements were negatively correlated and they were statistically significant. On the other hand, there was no such negative correlation with small choroidal vessels that have small diameter and area. Macular choroid thickens as the hyperopic error increases as well as axial length decreases in short eyes. The diameters and areas of noticeable large choroidal vessels in EDI-OCT also increase. These findings in EDI-OCT measurements may play a role in developing population nomograms, as a correcting parameter and in understanding the pathophysiology of certain diseases in short eyes.

Compressed sensing based simultaneous black- and gray-blood carotid vessel wall MR imaging

ObjectiveIn this study, we sought to demonstrate the blood suppression performance, image quality and morphological measurements for compressed sensing (CS) based simultaneous 3D black- and gray-blood imaging sequence (CS-siBLAG) in carotid vessel wall MR imaging. Materials and methodsSeven healthy volunteers and five patients were recruited. Healthy subjects underwent five CS-siBLAG scans with 1, 2, 3, 4 and 5-fold accelerations. Signal-to-tissue ratio (STR) and contrast-to-tissue ratio (CTR) were computed as the measures of flowing signal suppression performance and the image quality for black-blood imaging of the technique. Vessel lumen area (LA) and wall area (WA) were compared between fully sampled acquisition and each accelerated acquisition. Patients underwent three CS-siBLAG scans with 1, 3 and 5-fold accelerations as well as a 3D time of flight (3D TOF) scan. Two radiologists reviewed the under-sampled black- and gray-blood image quality. ResultsSTR and CTR values obtained with 2 to 5-fold accelerations were not significantly different from those with full acquisition. LA and WA measured at 2×, 3×, 4× and 5× were all highly correlated to the corresponding values at 1×. For patients imaging, two radiologists both found that the dual-contrast images at 3× acceleration exhibited comparable image quality to that of the fully sampled acquisition, and that the images at 5× exhibited slightly blurred vessel wall and outer vessel wall boundaries. ConclusionBy combining the CS under-sampling pattern and reconstruction, pseudo-centric phase encoding order and dual blood contrast sequences, this technique provides spatially registered black- and gray-blood images and excellent visualization for vessel wall imaging and gray-blood imaging in a short scan time.

Magnesium alloy covered stent for treatment of a lateral aneurysm model in rabbit common carotid artery: An in vivo study.

Magnesium alloy covered stents have rarely been used in the common carotid artery (CCA). We evaluated the long-term efficacy of magnesium alloy covered stents in a lateral aneurysm model in rabbit CCA. Magnesium alloy covered stents (group A, n = 7) or Willis covered stents (group B, n = 5) were inserted in 12 New Zealand White rabbits and they were followed up for 12 months. The long-term feasibility for aneurysm occlusion was studied through angiograms; the changes in vessel area and lumen area were assessed with IVUS. Complete aneurysmal occlusion was achieved in all aneurysms. Angiography showed that the diameter of the stented CCA in group A at 6 and 12 months was significantly greater than the diameter immediately after stent placement. On intravascular ultrasound (IVUS) examination, the mean lumen area of the stented CCA in group A was significantly greater at 6 and 12 months than that immediately after stent placement; the mean lumen area was also significantly greater in group A than in group B at the same time points. The magnesium alloy covered stents proved to be an effective approach for occlusion of lateral aneurysm in the rabbit CCA; it provides distinct advantages that are comparable to that obtained with the Willis covered stent.

Fluid permeability in poplar tension and normal wood in relation to ray and vessel properties

The impact of ray and vessel features on the radial air permeability and liquid penetration was compared between poplar (Populus nigra) tension and normal wood. Air permeability was measured by the falling-water volume-displacement method. To measure liquid penetration, specimens were saturated with safranin solution by the full-cell process at low pressure, and the pattern of red color penetration was then examined. Results revealed no significant difference in vessel frequency, intervessel and vessel-ray pit diameter between tension and normal wood, whereas porosity and average vessel lumen area in normal wood were significantly greater than those in tension wood. Regarding rays, their length was not different between normal and tension wood, but the latter had more frequent rays per millimeter. Since xylem rays are important flow conduits in lateral movement of fluids, it could be hypothesized that a larger number of rays in tension wood would lead to improved radial permeability. However, neither air permeability nor liquid penetration varied significantly in the studied specimens. Consequently, the results proved that ray frequency has no determining role in radial fluid flow in poplar tension and normal wood and that the share of intervessel and vessel-ray pits in radial permeability is more important.

Abstract P221: Vascular Smooth Muscle-Specific Overexpression of Cyp4a12-20-HETE Synthase Causes Hypertension and Vascular Remodeling

20-Hydroxyeicosatetraenoic acid (20-HETE) is a potent vasoactive eicosanoid of the microcirculation exhibiting effects on vascular smooth muscle (VSM) function that include stimulation of contractility, migration and growth. We have previously demonstrated in mice which globally overexpress 20-HETE that hypertension as well as vascular remodeling is not fully prevented by pharmacological normalization of blood pressure. However, both hypertension and vascular remodeling are prevented by antagonism of 20-HETE, suggesting that 20-HETE exerts vascular effects independent of hypertension. To examine the contribution of VSM-derived 20-HETE to hypertension and vascular remodeling, we have developed a transgenic mouse model that overexpresses the primary mouse 20-HETE synthase, Cyp4a12, specifically in VSM by crossbreeding floxed Cyp4a12 with Myh11-Cre mice. All mice carry the floxed Cyp4a12 gene and express a GFP protein under control of a modified CMV promoter. Cre-recombination excises the GFP cDNA and inserts the Cyp4a12 cDNA. Three to four month old male Cyp4a12-floxed mice carrying the Myh11-Cre gene (Cyp4a12 fl/fl Myh11 Cre+/- ) exhibited higher systolic blood pressure than control mice Cyp4a12 fl/fl Myh11 Cr-/- (WT) mice (135 vs. 115 mmHg, n=4, *p&lt;0.05). 20-HETE production in Cyp4a12 fl/fl Myh11 Cre+/- mice were higher than in WT in mesenteric (3333±891 vs. 545± 196 ng/mg/h) and renal interlobar arteries (RIA; 1859±376 vs. 242±62 ng/mg/h). Plasma levels of 20-HETE were also elevated (324±61 vs. 185±34 pg/mL) while urinary levels were not significantly different (146±26 vs. 117±29 pg/mL). We also observed increased medial thickness and decreased lumen area of blood vessels by Myh11 immunofluorescence in heart and kidney sections. RIA from male Myh11-Cyp4a12 mice displayed higher constrictor sensitivity to phenylephrine and impaired relaxation to acetylcholine compared to WT. Taken together, these data suggest that this model displays hypertension and pathological hypertrophic vascular remodeling. We therefore conclude that the Cyp4a12 fl/fl Myh11 Cre/- is a promising and unique transgenic mouse model to examine the contribution of smooth muscle-derived 20-HETE to hypertension and hypertrophic vascular remodeling.

Response of floodplain pedunculate oak (Quercus robur L.) tree-ring width and vessel anatomy to climatic trends and extreme hydroclimatic events

Increasing temperatures and recent changes in runoff regimes observed in Central Europe might alter the growth and relative water uptake of floodplain trees. To predict responses of floodplain forests to climate change, it is necessary to determine the climatic controls over tree growth and vessel anatomy. We analysed the responses of tree-ring width and earlywood vessel anatomical parameters (average vessel lumen area, vessel density and total vessel lumen area) of pedunculate oak (Quercus robur L.) growing in a floodplain to hydroclimatic conditions represented by temperature, the drought index (scPDSI), river discharge, groundwater level, and occurrence of floods and drought events. Site chronologies were assembled for floodplain and reference sites and, subsequently, correlated with time series of hydroclimatic conditions. Our results show that radial growth of floodplain trees is particularly positively influenced by temperature during the growing season and during previous year’s summer. By contrast, the growth of reference trees is highly drought-limited. Earlywood average vessel lumen area chronologies from both floodplain and reference sites share a positive temperature signal from January to April. However, the effect of water availability (indicated by the drought index) on vessel size is mostly negative for floodplain trees (with a maximum response to the autumn of the year preceding tree-ring formation) and positive or non-significant for reference trees. Vessel density chronologies contain the inverse environmental information as tree-ring width, however, with amplified negative correlations with current year temperatures at floodplain sites. Total vessel area is associated mostly with temperature in previous May and June. The drought index recorded exactly the same information in tree-rings as did river discharges and groundwater levels. The results of both correlation and trend analysis evidence that tree-ring width of floodplain Q. robur unambiguously increases with increasing temperature; on the other hand, droughts can become a serious problem affecting the productivity of reference trees growing in more distal parts of the lowland. Vessel size of Q. robur growing outside the floodplain recently tends to increase with increasing temperatures, making xylem more effective at water transport but also more vulnerable to cavitation.

Vascular morphology differentiates prostate cancer mortality risk among men with higher Gleason grade.

Higher Gleason grade is associated with prostate cancer mortality; however, there is significant heterogeneity in this association. We evaluated whether vessel morphology, a biomarker of angiogenesis, aided in distinguishing mortality risks among men with high Gleason grading. We characterized vessel morphology (area and irregularity) among 511 patients diagnosed with prostate cancer during 1986 to 2000, re-reviewed Gleason grade, and followed men through 2012. Men were grouped according to integrated vessel lumen irregularity and vessel area across Gleason grade. The more angiogenic group was identified as those with more irregular vessel lumen and smaller vessel area. Crude rates (95% confidence intervals) and survival probability were estimated across Gleason grade and vessel morphology. During a median 14-year follow-up, 62 men developed bone metastases or died of prostate cancer. Lethality rates were uniformly low within Gleason grade categories 6 and 7(3+4), regardless of vessel morphology. However, among men with Gleason grades of 7(4+3) or 8-10, the more angiogenic group was associated with fourfold higher risk of lethal outcomes compared to those with less angiogenic potential. Ten-year survival probability ranged from 95 to 74% according to the extent of vessel morphology (p<0.0001, log-rank test). Vessel morphology may aid Gleason grading in predicting prostate cancer mortality risks among men diagnosed with high-grade Gleason cancers.

Response of tree growth and wood structure of Larix kaempferi, Kalopanax septemlobus and Betula platyphylla saplings to elevated CO2 concentration for 5 years exposure in a FACE system

Elevated CO 2 concentration affected biomass partitioning in above-ground biomass, but size and number of water-conducting cells were unchanged in Larix kaempferi, Kalopanax septemlobus and Betula platyphylla. Using a Free-Air CO2 Enrichment (FACE) system, we studied the effect of elevated CO2 on the growth, leaf gas exchange and xylem anatomy of a conifer, Larix kaempferi, and two angiospermous tree species, Kalopanax septemlobus and Betula platyphylla. Two-year-old seedlings were grown at control sites (ambient; 370 ppm) and FACE sites (elevated; 500 ppm) for 5 years. We measured the lumen area and number of water-conducting cells, as well as biomass and leaf gas exchange, and visualized the functional region of water transport using a dye injection experiment. Elevated CO2 did not induce any significant changes in growth or in leaf gas exchange or lumen area of earlywood tracheids in L. kaempferi relative to ambient CO2. In two other tree species, elevated CO2 was found to enhance tree height and total leaf area (LA), with no change in stomatal conductance. In K. septemlobus, there were no changes in lumen area or number of earlywood vessels, or in the functional region of water transport. B. platyphylla also underwent no changes in lumen area or number of vessels, although there was a yearly variation in the size of the vessels. Our results show that 5 years of CO2 exposure did not notably affect the anatomical features of water-conducting cells. This finding suggests that, under elevated CO2, trees respond to changes in water balance due to changes in LA by extending the hydraulically active area of xylem.

The Role of Repeat Administration of Adventitial Delivery of Lentivirus-shRNA-Vegf-A in Arteriovenous Fistula to Prevent Venous Stenosis Formation

PurposeTo determine if a second dose of a lentivirus mediated small hairpin RNA that inhibits Vegf-A gene expression (LV-shRNA-Vegf-A) can improve lumen vessel area (LVA) of the outflow vein of an arteriovenous fistula (AVF) and decrease venous neointimal hyperplasia. Materials and MethodsChronic kidney disease was created in C57BL/6 mice; 28 days later, an AVF was created by connecting the right carotid artery to the ipsilateral jugular vein. Immediately after AVF creation, 5 × 106 plaque-forming units of LV-shRNA-Vegf-A or control shRNA was administered to the adventitia of the outflow vein, and a second dose of the same treatment was administered 14 days later. Animals were sacrificed at 21 days, 28 days, and 42 days after AVF creation for reverse transcription polymerase chain reaction and histomorphometric analyses. ResultsBy day 21, there was a 125% increase in the average LVA (day 21, P = .11), with a decrease in cell proliferation (day 21, P = .0079; day 28, P = .28; day 42, P = .5), decrease in α-smooth muscle cell actin staining (day 21, P < .0001; day 28, P < .05; day 42, P = .59), and decrease in hypoxic stress (day 21, P < .001; day 28, P = .28; day 42, P = .46) in LV versus control shRNA vessels. ConclusionsA second dose of LV-shRNA-Vegf-A administration results in a moderate improvement in LVA at day 21.

Analysis of Plaque Composition in Coronary Chronic Total Occlusion Lesion Using Virtual Histology-Intravascular Ultrasound.

Background and ObjectivesSuccess rates of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) have recently been reported to range from 80% to 90%. A better understanding of the pathologic characteristics of the CTO lesion may helpful to improving CTO PCI success rates. We evaluated the CTO lesion in patients with stable angina (SA) by virtual histology-intravascular ultrasound (VH-IVUS).Subjects and MethodsThe study population consisted of 149 consecutive patients with SA underwent VH-IVUS examination. We analyzed demographic and VH-IVUS findings in 22 CTO patients (17 males; mean, 62.3 years old) compared with 127 non-CTO patients (82 males; mean, 61.3 years old).ResultsA significantly lower ejection fraction (57.6±13.0% vs. 65.4±8.8%, p=0.007) was detected in the CTO group compared with the non-CTO group. Reference vessel lumen area of the proximal and distal segment was significantly less in CTO group than in non-CTO group. The lesion length of the CTO group was significantly longer than those of the non-CTO group (24.4±9.6 mm vs. 17.2±7.4 mm, p<0.001). Total atheroma volume (224±159 mm3 vs. 143±86 mm3, p=0.006) and percent atheroma volume (63.2±9.6% vs. 55.8±8.5%, p=0.011) of the CTO group were also significantly greater than those of non-CTO group. However, the lesion length adjusted plaque composition of the CTO group was not significantly different compared with that of the non-CTO group.ConclusionCTO lesions had a longer lesion length and greater plaque burden than the non-CTO lesion in patients with SA. However, lesion length adjusted plaque composition showed similar between the two groups. These results support that plaque characteristics of CTO lesions are similar to non-CTO lesions in patients with SA.