Larger Vessel Area Research Articles

Species with larger vessel area have higher bias for the original Granier equation in calculating sap flux density

Accurate estimate of transpiration is crucial to understanding global water and carbon cycles. The thermal dissipation (TD) method with Granier’s equation, which is the most popular approach to measure whole-tree water use, requires species-specific calibration parameters to calculate transpiration. Calibrations require direct measurement of water uptake, often through gravimetric or potometric methods; therefore, it is often disregarded because of limited time and resources. It remains unclear which factor influences the variation of calibration parameters. In this study, we compiled published calibration experiments to elucidate the factors that could influence the variation in coefficients and attempted to predict the correction parameter. The results showed that: (1) only 14 % of the experiments provided accurate sap flux density estimates using the default parameter values in the Granier’s equation, and sap flux was underestimated to varying degrees in 72% of the experiments; (2) the regression slope of TD-measured and the actual sap flow with the y-axis intercept set to zero (hereinafter referred to as “Slope”) was significantly correlated to the mean vessel area (VA), i.e., species with larger VA consistently had higher Slope and greater bias. Stem diameter also had a positive influence on the Slope after accounting for covariation with the VA. Finally, a multiple linear regression model based on these two characteristics (VA and stem diameter) explained 89% of the variation of Slope. This study provides a simple calibration procedure for the users of TD-sensors with a linear correction model based on easily measurable vessel area and stem diameter. It may also provide a new development avenue for sensor manufacturers or others to improve the TD method to reduce its sensitivity to wood characteristics – or provide some “out-of-the-box” correction factors across a range of wood characteristics.

Establishing clinical remission criteria forgiant cell arteritis: Results ofa Delphi exercise carried out by an expert panel ofthe Japan Research Committee ofthe Ministry ofHealth, Labour, andWelfare forIntractableVasculitis.

To develop a proposal for giant cell arteritis remission criteria in order to implement a treat-to-targetalgorithm. A task force consisting of 10 rheumatologists, 3 cardiologists, 1 nephrologist, and 1 cardiac surgeon was established in the Large-vessel Vasculitis Group of the Japanese Research Committee of the Ministry of Health, Labour and Welfare for IntractableVasculitis to conduct a Delphi survey of remission criteria for giant cell arteritis. The survey was circulated among the members over four reiterations with four face-to-face meetings. Items with a mean score of ≥4 were extracted as items for defining remission criteria. An initial literature review yielded a total of 117 candidate items for disease activity domains and treatment/comorbidity domains of remission criteria, of which 35 were extracted as disease activity domains (systematic symptoms, signs and symptoms of cranial and large-vessel area, inflammatory markers, and imaging findings). For the treatment/comorbidity domain, ≤5 mg/day of prednisolone 1 year after starting glucocorticoids was extracted. The definition of achievement of remission was the disappearance of active disease in the disease activity domain, normalization of inflammatory markers, and ≤5 mg/day of prednisolone. We developed proposals for remission criteria to guide the implementation of a treat-to-targetalgorithm for giant cell arteritis.

Whole-brain perfusion mapping in mice by dynamic BOLD MRI with transient hypoxia

Non-invasive mapping of cerebral perfusion is critical for understanding neurovascular and neurodegenerative diseases. However, perfusion MRI methods cannot be easily implemented for whole-brain studies in mice because of their small size. To overcome this issue, a transient hypoxia stimulus was applied to induce a bolus of deoxyhemoglobins as an endogenous paramagnetic contrast in blood oxygenation level-dependent (BOLD) MRI. Based on stimulus-duration-dependent studies, 5 s anoxic stimulus was chosen, which induced a decrease in arterial oxygenation to 59%. Dynamic susceptibility changes were acquired with whole-brain BOLD MRI using both all-vessel-sensitive gradient-echo and microvascular-sensitive spin-echo readouts. Cerebral blood flow (CBF) and cerebral blood volume (CBV) were quantified by modeling BOLD dynamics using a partial-volume-corrected arterial input function. In the mouse under ketamine/xylazine anesthesia, total CBF and CBV were 112.0 ± 15.0 ml/100 g/min and 3.39 ± 0.59 ml/100 g (n = 15 mice), respectively, whereas microvascular CBF and CBV were 85.8 ± 6.9 ml/100 g/min and 2.23 ± 0.27 ml/100 g (n = 7 mice), respectively. Regional total vs. microvascular perfusion metrics were highly correlated but a slight mismatch was observed in the large-vessel areas and cortical depth profiles. Overall, this non-invasive, repeatable, simple hypoxia BOLD-MRI approach is viable for perfusion mapping of rodents.

Vasculogenic Potency of Bone Marrow- and Adipose Tissue-Derived Mesenchymal Stem/Stromal Cells Results in Differing Vascular Network Phenotypes in a Microfluidic Chip.

The vasculature is an essential, physiological element in virtually all human tissues. Formation of perfusable vasculature is therefore crucial for reliable tissue modeling. Three-dimensional vascular networks can be formed through the co-culture of endothelial cells (ECs) with stromal cells embedded in hydrogel. Mesenchymal stem/stromal cells (MSCs) derived from bone marrow (BMSCs) and adipose tissue (ASCs) are an attractive choice as stromal cells due to their natural perivascular localization and ability to support formation of mature and stable microvessels in vitro. So far, BMSCs and ASCs have been compared as vasculature-supporting cells in static cultures. In this study, BMSCs and ASCs were co-cultured with endothelial cells in a fibrin hydrogel in a perfusable microfluidic chip. We demonstrated that using MSCs of different origin resulted in vascular networks with distinct phenotypes. Both types of MSCs supported formation of mature and interconnected microvascular networks-on-a-chip. However, BMSCs induced formation of fully perfusable microvasculature with larger vessel area and length whereas ASCs resulted in partially perfusable microvascular networks. Immunostainings revealed that BMSCs outperformed ASCs in pericytic characteristics. Moreover, co-culture with BMSCs resulted in significantly higher expression levels of endothelial and pericyte-specific genes, as well as genes involved in vasculature maturation. Overall, our study provides valuable knowledge on the properties of MSCs as vasculature-supporting cells and highlights the importance of choosing the application-specific stromal cell source for vascularized organotypic models.

Morphologic and Microvascular Differences Between Macular Neovascularization With and Without Subretinal Fibrosis.

PurposeTo evaluate morphologic and microvascular differences between eyes with and without subretinal fibrosis (SF) caused by neovascular age-related macular degeneration (nAMD).MethodsPatients with nAMD with a minimum history of 12 months of anti-VEGF treatment were prospectively included in this cross-sectional study. Patients were imaged using standard imaging, swept-source optical coherence tomography angiography for quantitative microvascular analysis and polarization-sensitive OCT as an ancillary method for automated SF segmentation. The presence of reticular pseudodrusen, hyperreflective foci (HRF), and outer retinal tubulation (ORT) were also evaluated.ResultsSixty eyes of 60 participants (37 female) with nAMD and a mean 3.1 (±2.7)-year history of anti-VEGF treatment were included, 20 (33%) of which were diagnosed with SF. Eyes with SF had a higher prevalence of ORT (P < 0.001) and a lower prevalence of HRF (P = 0.004) than eyes without SF. Fifty eyes were analyzed quantitatively for microvascular biomarkers. Eyes with SF had a larger greatest vascular caliber (P = 0.001) and greatest linear diameter (P = 0.042), a larger microvascular neovascularization (MNV) area (P = 0.026), larger vessel area (P = 0.037), higher number of vessel junctions (P = 0.025), longer total vessel length (P = 0.027), higher number of vessel endpoints (P = 0.007), and higher endpoint density (P = 0.047).ConclusionsThis multimodal imaging approach demonstrated in vivo microvascular and morphological differences in eyes with and without SF. Eyes with SF tend to have larger MNV lesions with thicker vessels and are often associated with the presence of ORT.Translational RelevanceThis study points out imaging biomarkers in patients with SF, which may help identifying high-risk patients.

Aspirin use and prostate tumor angiogenesis.

Aspirin use has been shown to be associated with reduced risk of aggressive prostate cancer, although the mechanisms are not fully understood. We examined associations between regular aspirin use and prostate tumor angiogenesis among 572 men from the Health Professionals Follow-up Study. Participants reported aspirin use on biennial questionnaires. Prostatectomy tumor blocks were immunostained for CD34 to assess microvessel size and irregularity. Multivariable linear regression was used to calculate percent differences in biomarker measures comparing use vs nonuse, and by duration and tablets per day. Current aspirin users had larger vessel area (14.5%) and diameter (6.5%), and lower vessel irregularity (- 8.1%) compared to non-users, indicating a less angiogenic profile. Duration of use and current tablets per day were also associated with larger vessel diameter. Similar patterns were seen for low- and high-grade prostate cancers. Our findings suggest that aspirin use, particularly current use, can lower prostate cancer carcinogenesis through angiogenic mechanisms.

Different response of earlywood vessel features of Fraxinus mandshurica to rapid warming in warm-dry and cold-wet areas

Xylem anatomical features are constantly adapting to changing environmental conditions, and are directly related to the key functions and physiological processes of trees. However, little is known about the responses of xylem to recent rapid warming in many areas. Based on the anatomical features of the xylem of Fraxinus mandshurica Rupr. from 14 sites in two contrasting areas (warm-dry and cold-wet) of northeast China, the plasticity response and adaptation strategies of radial growth, earlywood vessels (EWV), and hydraulic features of F. mandshurica to climate change were studied. Results showed that, compared with the cold-wet area, F. mandshurica in warm-dry area had wider rings, larger vessel area, higher number of vessels (VN), larger hydraulic diameters (Dh) and higher theoretical tree-ring hydraulic conductivity (Kh). On the contrary, the vessel density (VD), percentage of EWV (PC) and xylem-specific theoretical hydraulic conductivity (Ks) in warm-dry area was lower than those in cold-wet area. In these two areas, the RW, mean vessel area (MVA), total vessel area (TVA), VN, Dh, and Kh were significantly positively correlated with temperature, and negatively correlated with winter moisture. However, the PC, VD, and Ks were inversely related to climate factors in the two areas. F. mandshurica can adjust the density and proportion of EWV by changing the configuration of earlywood and latewood to cope with the interannual climate change and balance the hydraulic efficiency and safety. Rapid warming significantly increased the growing season length and hydraulic efficiency of F. mandshurica in warm-dry and cold-wet areas, thus maximizing carbon fixation. This provides a potential physiological explanation for the growth increase and range expansion of the main broadleaf tree species in temperate zone of northeast China in recent years. F. mandshurica in warm-dry areas benefits greatly from continuous climate warming, but the risk of hydraulic failure may increase.

Detectability on Plain CT is an Effective Discriminator between Carcinoma and Benign Disorder for a Polyp >10 mm in the Gallbladder.

An appropriate diagnosis is required to avoid unnecessary surgery for gallbladder cholesterol polyps (GChPs) and to appropriately treat pedunculated gallbladder carcinomas (GCs). Generally, polyps >10 mm are regarded as surgical candidates. We retrospectively evaluated plain and contrast-enhanced (CE) computed tomography (CT) findings and histopathological features of 11 early GCs and 10 GChPs sized 10–30 mm to differentiate between GC and GChP >10 mm and determine their histopathological background. Patient characteristics, including polyp size, did not significantly differ between groups. All GCs and GChPs were detected on CE-CT; GCs were detected more often than GChPs on plain CT (73% vs. 9%; p < 0.01). Sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy for GCs were 73%, 90%, 89%, 75%, and 81%, respectively. On multivariate analysis, lesion detectability on plain CT was independently associated with GCs (odds ratio, 27.1; p = 0.044). Histopathologically, GChPs consisted of adipose tissue. Although larger vessel areas in GCs than in GChPs was not significant (52,737 μm2 vs. 31,906 μm2; p = 0.51), cell densities were significantly greater in GCs (0.015/μm2 vs. 0.0080/μm2; p < 0.01). Among GPs larger than 10 mm, plain CT could contribute to differentiating GCs from GChPs.

Responses of leaf photosynthetic traits, water use efficiency, and water relations in five urban shrub tree species under drought stress and recovery

In urban shrub trees, the species-specific photosynthetic response and water-use properties are related to the xylem anatomy of the petiole. It is becoming essential to select urban tree species based on drought response in warm temperate regions, because water limitation is prone to occur in an urban environment, and furthermore, urban warming along with global warming intensifies drought stress even in relatively humid regions. We focused on leaf photosynthesis, water use efficiency, and leaf water relations as key factors for the evaluation of drought response in urban trees, and compared their responses to drought stress and re-watering (recovery) in five major urban shrub tree species planted in Japan. In addition, species-specific xylem anatomical traits in the leaf petiole were evaluated. The five species showed diverse responses to drought and recovery. Rhaphiolepis umbellata possessed both the highest photosynthesis (A) and highest intrinsic water use efficiency (A/gs) under drought, as well as full recovery in the midday leaf water potential (Ψmid). These results suggest that R. umbellata is the most favorable species as an urban tree among the five species. In contrast, A and A/gs in Rhododendron obtusum were only 19% and 55%, respectively, of those in R. umbellata under drought, along with incomplete recovery in Ψmid. The responses of A, A/gs, and Ψmid for the other three species were intermediate between R. umbellata and R. obtusum. We found that during recovery, the species-specific coordination between photosynthesis and leaf hydraulic traits was mediated by stomatal regulation. The species with large stomatal conductance had both high photosynthesis and high leaf hydraulic conductance, along with a large vessel area in the leaf petiole. The selection of trees with consideration of the drought response, along with appropriate watering management, will improve the photosynthetic ability, and thus, will enhance CO2 absorption by urban trees.

Alterations in mechanical properties of carotid artery in overweight and obese children

Abstract Background Atherosclerosis begins at a young age in a process that is clinically silent before events occur. Obesity in childhood has been associated with the alterations of vascular properties. Purpose The aim of this study was to investigate the subtle changes of mechanical properties of carotid artery (CA) in overweight and obese children. Methods We prospectively recruited a cohort of overweight (n=25) and obese (n=176) children aged 7–17 years and non-obese children with same age and gender (controls, n=31). Overweight is defined as a body mass index (BMI) at or above the 85th percentile and below the 95th percentile and obesity as a BMI at or above the 95th percentile for children of the same age and gender. The mechanical properties of carotid artery were directly measured in a cross-sectional image of common carotid artery using a velocity-vector imaging (VVI) analysis including instantaneous vessel area and deformation parameters as fractional area change (FAC), circumferential strain, and strain rate (SR). Results Compared to controls, obese children had higher blood pressures and serum glucose and worse lipid profiles than controls, whereas overweight children showed no any difference in blood pressure and laboratory findings. Among vascular properties, there were no differences in carotid intima-media thickness (cIMT) between the three groups. However, obese children showed larger vessel area and higher arterial stiffness presented as lower FAC, circumferential strain and SR than controls, whereas overweight children showed no difference in vascular properties with obese children and with controls except for circumferential SR. Circumferential SR in overweight children was significantly reduced than controls (0.47±0.19 cm/s, 0.75±0.22 cm/s, respectively, p&amp;lt;0.001) and was the only vascular parameter distinguishing overweight children from controls. In multiple linear regression analysis, independent determining factors of the circumferential SR of carotid artery were age (β=−0.13, p=0.03), serum triglycerides (β=−0.14, p=0.01) and BMI (β=−0.37, p&amp;lt;0.001) in this population. Conclusions In overweight and obese children, a decrease in circumferential SR of carotid artery precedes the changes of vessel wall thickness and vessel area. We demonstrated the subtle changes of mechanical properties of carotid artery precede the changes of structural properties in overweight and obese children. Funding Acknowledgement Type of funding source: None

Sensitivity of stomatal conductance to vapor pressure deficit and its dependence on leaf water relations and wood anatomy in nine canopy tree species in a Malaysian wet tropical rainforest

Canopy tree species with a large mean xylem vessel diameter has a high sensitivity of stomatal conductance to vapor pressure deficit in a wet tropical rainforest in Malaysia. We investigated the diurnal variation of stomatal conductance to water vapor (gs) and leaf water relations in nine tropical rainforest canopy tree species in Malaysia to investigate the sensitivity of stomatal conductance to VPD and its dependence on leaf water relations. We focused on the effect of wood anatomical properties on the stomatal sensitivity to VPD. Negative correlations were obtained between leaf-to-air VPD (VPDleaf) and gs for all species, in which interspecific variation was obtained for the sensitivity of gs to VPDleaf with the range of VPDleaf being 1.2–5.9 kPa. The species with large mean xylem vessel diameter had high sensitivity of gs to VPDleaf. Although significant variations were obtained among the species for leaf water relations, such as relative water content at the turgor loss point (RWCtlp) and water potential at the turgor loss point (Ψtlp), these water relations were not related to the stomatal sensitivity to VPDleaf. In the wet tropical forest in the present study, VPDleaf was the main regulator of gs in the nine tree species. The high sensitivity of gs to VPDleaf in the trees with a large vessel area may contribute to the maintenance of an adequate leaf water status, e.g., high levels of Ψleaf, throughout the day, across a period of varying air temperature.

Associated factors of poor treatment outcomes in patients with giant cell arteritis: clinical implication of large vessel lesions

BackgroundRelapses frequently occur in giant cell arteritis (GCA), and long-term glucocorticoid therapy is required. The identification of associated factors with poor treatment outcomes is important to decide the treatment algorithm of GCA.MethodsWe enrolled 139 newly diagnosed GCA patients treated with glucocorticoids between 2007 and 2014 in a retrospective, multi-center registry. Patients were diagnosed with temporal artery biopsy, 1990 American College of Rheumatology classification criteria, or large vessel lesions (LVLs) detected by imaging based on the modified classification criteria. Poor treatment outcomes (non-achievement of clinical remission by week 24 or relapse during 52 weeks) were evaluated. Clinical remission was defined as the absence of clinical signs and symptoms in cranial and large vessel areas, polymyalgia rheumatica (PMR), and elevation of C-reactive protein (CRP) levels. A patient was determined to have a relapse if he/she had either one of the signs and symptoms that newly appeared or worsened after achieving clinical remission. Re-elevation of CRP without clinical manifestations was considered as a relapse if other causes such as infection were excluded and the treatment was intensified. Associated factors with poor treatment outcomes were analyzed by using the Cox proportional hazard model.ResultsCranial lesions, PMR, and LVLs were detected in 77.7%, 41.7%, and 52.5% of the enrolled patients, respectively. Treatment outcomes were evaluated in 119 newly diagnosed patients who were observed for 24 weeks or longer. The mean initial dose of prednisolone was 0.76 mg/kg/day, and 29.4% received any concomitant immunosuppressive drugs at baseline. Overall, 41 (34.5%) of the 119 patients had poor treatment outcomes; 13 did not achieve clinical remission by week 24, and 28 had a relapse after achieving clinical remission. Cumulative rates of the events of poor treatment outcomes in patients with and without LVLs were 47.5% and 17.7%, respectively. A multivariable model showed the presence of LVLs at baseline was significantly associated with poor treatment outcomes (adjusted hazard ratio [HR] 3.54, 95% CI 1.52–8.24, p = 0.003). Cranial lesions and PMR did not increase the risk of poor treatment outcomes.ConclusionThe initial treatment intensity in the treatment algorithm of GCA could be determined based upon the presence or absence of LVLs detected by imaging at baseline.

Personalising cardiovascular network models in pregnancy: A two-tiered parameter estimation approach.

Uterine artery Doppler waveforms are often studied to determine whether a patient is at risk of developing pathologies such as pre‐eclampsia. Many uterine waveform indices have been developed, which attempt to relate characteristics of the waveform with the physiological adaptation of the maternal cardiovascular system, and are often suggested to be an indicator of increased placenta resistance and arterial stiffness.Doppler waveforms of four patients, two of whom developed pre‐eclampsia, are compared with a comprehensive closed‐loop model of pregnancy. The closed‐loop model has been previously validated but has been extended to include an improved parameter estimation technique that utilises systolic and diastolic blood pressure, cardiac output, heart rate, and pulse wave velocity measurements to adapt model resistances, compliances, blood volume, and the mean vessel areas in the main systemic arteries. The shape of the model‐predicted uterine artery velocity waveforms showed good agreement with the characteristics observed in the patient Doppler waveforms. The personalised models obtained now allow a prediction of the uterine pressure waveforms in addition to the uterine velocity. This allows for a more detailed mechanistic analysis of the waveforms, eg, wave intensity analysis, to study existing clinical indices. The findings indicate that to accurately estimate arterial stiffness, both pulse pressure and pulse wave velocities are required. In addition, the results predict that patients who developed pre‐eclampsia later in pregnancy have larger vessel areas in the main systemic arteries compared with the two patients who had normal pregnancy outcomes.

Increased pulmonary blood volume variation in patients with heart failure compared to healthy controls: a noninvasive, quantitative measure of heart failure.

Variation of the blood content of the pulmonary vascular bed during a heartbeat can be quantified by pulmonary blood volume variation (PBVV) using magnetic resonance imaging (MRI). The aim was to evaluate whether PBVV differs in patients with heart failure compared with healthy controls and investigate the mechanisms behind the PBVV. Forty-six patients and 10 controls underwent MRI. PBVV was calculated from blood flow measurements in the main pulmonary artery and a pulmonary vein, defined as the maximum difference in cumulative PBV over one heartbeat. PBVV was indexed to stroke volume (SV) in the main pulmonary artery (PBVVSV). Patients displayed higher PBVVSV than controls (58 ± 14 vs. 43 ± 7%, P < 0.001). The change in PBVVSV could be explained by left ventricular (LV) longitudinal contribution to SV (R2 = 0.15, P = 0.02) and the phase shift between in- and outflow (R2 = 0.31, P < 0.001) in patients. Both variables contributed to the multiple regression analysis model and predicted PBVVSV (R2 = 0.38); however, the phase shift alone explained ~30% of the variation in PBVVSV. No correlation was found between PBVVSV and large vessel area. In conclusion, PBVVSV was higher in patients compared with controls. Approximately 40% of the variation of PBVVSV in patients can be explained by the LV longitudinal contribution to SV and the phase shift between pulmonary in- and outflow, where the phase shift alone accounts for ~30%. The remaining variation (60-70%) most likely occurs on a small vessel level. Future studies are needed to show the clinical added value of PBVVSV compared with right-heart catheterization.NEW & NOTEWORTHY This study shows that the pulmonary blood volume variation indexed to the stroke volume is higher in patients with heart failure compared with controls. The mechanisms behind this are lack of systolic suction from the left ventricular atrioventricular plane descent and increased phase shift between the in- and outflow to the pulmonary circulation (~40%), where the phase shift alone accounts for ~30%. The remaining variation (60-70%) is suggested to occur on a small vessel level.

Influence of Axial Length on Parafoveal and Peripapillary Metrics from Swept Source Optical Coherence Tomography Angiography

ABSTRACT Purpose To assess the effect of axial length (AL) on the quantification of superficial vessel density of both macular and disc region using swept source optical coherence tomography angiography (SSOCTA). Methods This is a cross-sectional clinical study. Seventy-five eyes from 75 Chinese healthy participants (56 females) with a mean age of 26.6 ± 6.8 (range 19–50) years were included in this study. All eyes were imaged with SSOCTA, using a 3 × 3mm scan pattern centered on the macular and optic disc, respectively, and the superficial layer was used for evaluation. The image size was corrected with AL using Bennett formula. Outcome measurements included perfusion density (PD), vessel length density (VLD) in parafoveal and disc regions, averaged peripapillary large vessel diameter and area of foveal avascular zone (FAZ). Image processing and measurements was performed using Image J software. Multivariate regression analysis adjusting for age and signal strength was used to assess the influence of AL on the metrics. Results AL was the only predictive factor for parafoveal PD (β = −0.273, P = .047) and VLD (β = −0.396, P = .003). There was no correlation between AL and area of FAZ, large vessel diameter, or the vessel density on any location in disc region. Age was the only predictor for PD (β = −0.287, P = .024) and VLD (β = −0.289, P = .023) on optic nerve head. Conclusions AL was negatively correlated with superficial parafoveal microvasculature, but not correlated with peripapillary capillaries, suggesting that the inner retina stretches more in the distal end of the disc with increased AL.

The effect of polyploidization on tree hydraulic functioning

Recent research has highlighted the importance of living tissue in wood. Polyploidization can impact amounts and arrangements of living cells in wood, potentially leading to increased drought tolerance. Tetraploid variants were created from the apple cultivar Malus ×domestica 'Gala' (Gala-4x), and their vulnerability to drought-induced cavitation and their hydraulic capacitance were compared to those of their diploid predecessors (Gala-2x). Assuming a positive correlation between polyploidy and drought tolerance, we hypothesized lower vulnerability and higher capacitance for the tetraploid. Vulnerability to drought-induced cavitation and the hydraulic capacitance were quantified through acoustic emission and continuous weighing of shoots during a bench-top dehydration experiment. To underpin the hydraulic trait results, anatomical variables such as vessel area, conduit diameter, cell wall reinforcement, and ray and vessel-associated parenchyma were measured. Vulnerability to drought-induced cavitation was intrinsically equal for both ploidy variants, but Gala-4x proved to be more vulnerable than Gala-2x during the early phase of desiccation as was indicated by its significantly lower air entry value. Higher change in water content of the leafy shoot, higher amount of parenchyma, and larger vessel area and size resulted in a significantly higher hydraulic capacitance and efficiency for Gala-4x compared to Gala-2x. Both ploidy variants were typified as highly sensitive to drought-induced cavitation, with no significant difference in their overall drought vulnerability. But, when water deficit is short and moderate, Gala-4x may delay a drought-induced decrease in performance by trading hydraulic safety for increased release of capacitively stored water from living tissue.

Abstract 123: Subtle Changes in Mechanical Properties of Carotid Artery in Overweight and Obese Children

Objective: Obesity in childhood has also been associated with the development of cardiovascular abnormalities. The aim of this study was to investigate the subtle changes of mechanical properties of carotid artery in overweight and obese children. Methods: We prospectively recruited a cohort of overweight (n=25) and obese (n=176) children aged 7 - 17 years and non-obese children with same age and gender (controls, n=31). Overweight is defined as a body mass index (BMI) at or above the 85th percentile and below the 95th percentile and obesity as a BMI at or above the 95th percentile for children of the same age and gender. The mechanical properties of carotid artery were directly measured in a cross-sectional image of common carotid artery using a velocity-vector imaging (VVI) analysis including instantaneous vessel area and deformation parameters as fractional area change (FAC), circumferential strain, and strain rate (SR). Results: Compared to controls, obese children had higher blood pressures and serum glucose and worse lipid profiles than controls, whereas overweight children showed no any difference in blood pressure and laboratory findings. Among vascular properties, there were no differences in carotid intima-media thickness between the three groups. However, obese children showed larger vessel area and higher arterial stiffness as lower FAC, circumferential strain and SR than controls, whereas overweight children showed no difference in vascular properties with obese children and with controls except for circumferential SR. Circumferential SR in overweight children was significantly reduced than controls (0.47±0.19 cm/s, 0.75±0.22 cm/s, respectively, p&lt;0.001) and was the only vascular parameter distinguishing overweight children from controls. In linear regression analysis, age (β=-0.13, p=0.03), BMI (β=- 0.37, p&lt;0.001), and serum triglycerides (β=-0.14, p=0.01) were independent determinants predicting the circumferential SR of carotid artery in this population. Conclusion: A decrease in circumferential SR of carotid artery precedes the changes of other vascular properties as well as blood pressure and laboratory findings in overweight and obese children.

Univariate and multivariate models for the prediction of life-threatening complications in 586 cases of deep neck space infections: retrospective multi-institutional study.

To identify deep neck infection factors related to life-threatening complications. This retrospective multi-institutional study comprised 586 patients treated for deep neck infections between 2002 and 2012. The statistical significance of variables associated with life-threatening complications of deep neck infections was assessed. During treatment, life-threatening complications occurred in 60 out of 586 cases. On univariate analysis, life-threatening complications were linked to: dyspnoea, neck movement disturbance and dysphonia (all p < 0.001); and parapharyngeal, anterior visceral or pretracheal deep neck involvement (all p < 0.002). Aetiology was significantly linked to tonsils (p < 0.001). Regarding infection type, fasciitis was a significant factor (p < 0.001). Candida albicans was a significant bacterial culture (p < 0.001). A multivariate step-wise model disclosed fewer significant variables: retropharyngeal space (p = 0.005) and major blood vessels area (p = 0.006) involvement, and bacterial culture C albicans (p < 0.001). It can be predicted that patients with deep neck infections, with neck movement disturbances, dysphonia, dyspnoea and swelling of the external neck, accompanied by severe pain, and inflammatory changes in the retropharyngeal space and large vessel areas, with culture-confirmed infection of C albicans, are likely to develop life-threatening complications.

The anti-angiogenic role of soluble-form VEGF receptor in malignant gliomas.

Anti-angiogenic therapy represents a promising, new therapeutic modality for malignant gliomas. The present study was designed to define the malignant glioma cases most suitable for anti-angiogenic therapy and to demonstrate the efficacy of anti-angiogenic therapy using soluble-form Flt1 (sFlt1) gene delivery in mice. In human malignant glioma samples (39 glioblastomas, 21 anaplastic astrocytomas and 4 anaplastic oligoastrocytomas), protein expression of VEGF, and its specific natural inhibitor, sFlt1, as well as vessel architecture were assessed. Among these variables, VEGF >1000ng/ml, VEGF/sFlt1 ratio >1, vessel density >30, and vessel area >7% were prognostic factors for malignant gliomas. VEGF/sFlt1 ratio >1 was the most powerful prognostic marker for survival in multivariate analysis. The sFlt1 gene was also successfully introduced into U87 glioma cells invitro, resulting in 31% tumor growth inhibition invivo. sFlt1-transfected tumor demonstrated high sFlt-1 expression along with diminished vessel density and area compared with the control tumor. In transfected tumor, VEGF expression was decreased in the viable area, but still high in the hypoxic area. sFlt1 and VEGF expression was re-evaluated invitro using glioma cells under normoxic and hypoxic conditions. For sFlt1-transfected cells, VEGF expression was upregulated, but sFlt1 expression was downregulated, resulting in an increase of VEGF/sFlt1 ratio in hypoxic conditions. We conclude that malignant gliomas with a high VEGF/sFlt1 ratio and large vessel area are good candidates for anti-angiogenic therapy. Soluble Flt1 gene delivery was demonstrated to inhibit glioma growth, but this was limited in hypoxic areas.

Age- and Sex-Dependency of Laser Speckle Flowgraphy Measurements of Optic Nerve Vessel Microcirculation.

PurposeTo investigate the relationship between various characteristics of a normal population and laser speckle flowgraphy (LSFG) measurements of mean blur rate (MBR) in the optic nerve head (ONH).MethodsA total of 189 eyes of 189 normal subjects (93 male, 96 female, mean age 45 ± 14 years old, age range: 20–72) without any history of hypertension, hyperlipidemia or diabetes were enrolled. ONH microcirculation was measured with LSFG and overall MBR (MA), vessel-area MBR (MV), and tissue-area MBR (MT) were derived from these measurements. The statistical association of these measurements with characteristics such as sex, age, intraocular pressure (IOP) and systolic blood pressure (SBP) was then determined.ResultsThere was a trend towards decreased IOP and MV and increased SBP with age (P = 0.002, P = 0.035, and P = 0.006, respectively). Furthermore, IOP, MV and SBP were correlated with age (r = -0.23, P = 0.011; r = -0.24, P < 0.001; and r = 0.30, P < 0.001, respectively). Separate multiple regression analyses of independent contributing factors revealed that sex and IOP contributed to MA (P < 0.001 and P = 0.002, respectively), sex, IOP, and age contributed to MV (P < 0.001, P = 0.003, and P = 0.024, respectively), while only IOP contributed to MT (P = 0.003).ConclusionIn a normal population, MBR was affected by IOP in both the large vessel and capillary areas of the ONH, but not by SBP. MV was also affected by age and sex, while MT was stable independent of age or sex.