Vascular Ca overload produced by vitamin D3 plus nicotine diminishes arterial distensibility in rats

1994 ◽  
Vol 266 (2) ◽  
pp. H540-H547 ◽  
Author(s):  
J. Atkinson ◽  
P. Poitevin ◽  
J. M. Chillon ◽  
I. Lartaud ◽  
B. Levy
Keyword(s):  
Vitamin D3 ◽  
Structural Changes ◽  
Arterial Compliance ◽  
Linear Regression Analysis ◽  
Characteristic Impedance ◽  
Calcium Overload ◽  
Suitable Model ◽  
Plasma Parameters ◽  
Arterial Distensibility ◽  
Young Rats

In humans, aging produces many structural changes in blood vessels, one of the most pronounced being arterial calcium overload. Simultaneously arteries become increasingly rigid. The slow evolution of the two processes renders it difficult to evaluate the importance of vascular calcium overload in the development of decreased compliance. To gain insight into this relationship, rapid vascular calcium overload was produced by treating young rats with vitamin D3 and nicotine. When rats were allowed 16 days or longer to recover from such treatment, analysis of plasma parameters revealed no overt toxicity, and growth rate was similar to that of controls. Pronounced calcium overload was seen primarily in compliance arteries. Changes in systemic arterial compliance, characteristic impedance, pulse-wave velocity, and carotid compliance all reflected a substantial increase in arterial rigidity. Linear regression analysis revealed significant correlations between the various indicators of arterial distensibility and arterial calcium content. In conclusion, treatment of young rats with vitamin D3 and nicotine may provide a suitable model with which to investigate how calcium overload is involved in the induration of compliance arteries.

The consequences of aortic calcium overload following vitamin D3 plus nicotine treatment in young rats

1991 ◽  
Vol 9 (10) ◽  
pp. 919???926 ◽  
Author(s):  
Daniel Henrion ◽  
Jean M. Chillon ◽  
Gaston Godeau ◽  
Fran??oise Muller ◽  
Christine Capdeville-Atkinson ◽  
...  
Keyword(s):  
Vitamin D3 ◽  
Calcium Overload ◽  
Nicotine Treatment ◽  
Young Rats

Abstract 17788: Repaired Coarctation is Associated With Central Hypertension, Increased Vessel Stiffness and Abnormal Wave Reflections - A Novel CMR Hemodynamics Study

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Michael A Quail ◽  
Rebekah Short ◽  
Bejal Pandya ◽  
Jennifer A Steeden ◽  
Abbas Khushnood ◽  
...  
Keyword(s):  
Arterial Compliance ◽  
Linear Regression Analysis ◽  
Characteristic Impedance ◽  
Systolic Pressure ◽  
High Temporal Resolution ◽  
Wave Reflections ◽  
Compression Waves ◽  
Arterial Hemodynamics ◽  
Coarctation Repair ◽  
Multivariable Linear Regression Analysis

Introduction: The basis of late cardiovascular mortality following coarctation repair is poorly understood. Although hypertension has been implicated, peripheral systolic pressure (pSBP) has not been shown to be definitively higher in this group. This may be because mortality is more related to central systolic pressure (cSBP) than pSBP. We have developed a novel cardiovascular magnetic resonance (CMR) protocol that allows assessment of cSBP and it components: resistance, compliance and wave reflections. The main aims of this study were i) characterize hemodynamic differences between patients and controls ii) define hemodynamic determinants of cSBP in patients and iii) Identify possible biomarkers amongst covariates associated with LV mass (LVM). Methods: 75 subjects, 50 patients with repaired coarctation, median age 23.5yrs (74% male) and 25 matched controls; 21.0yrs (72% male) were recruited. Ascending aorta area and flow waveforms were obtained using a high temporal resolution (10ms) spiral phase-contrast MR flow sequence. This data was used to derive cSBP and perform wave intensity analysis (WIA) non-invasively using previously validated techniques. The determinants of cSBP and LVM were assessed using multivariable linear regression analysis. Results: Central SBP was significantly higher in patients compared to controls (115±13 vs 107±9mmHg [mean±sd], p=0.002). However, there was only a trend towards higher pSBP (123±15 vs 117±11mmHg, p=0.052). Patients had reduced arterial compliance, increased characteristic impedance and larger backward compression waves (BCW) than controls; and these parameters were independently associated with cSBP. LVM index was significantly higher in patients than controls (73.1±14.6 vs 58.9±9.7g/m 2 , p=0.0001). Independent predictors of LVM included cSBP (p=0.001) and BCW (p=0.002), but importantly not pSBP or coarctation index. Conclusions: Non-invasive assessment of fundamental arterial hemodynamics by CMR is feasible. Using these techniques we have shown elevated cSBP in patients after coarctation repair. Elevated cSBP and BCW are important determinants of increased LVM following coarctation repair. These metrics represent superior biomarkers of afterload than coarctation index and pSBP.

scholarly journals Regional analysis using the Geomorphologic Instantaneous Unit Hydrograph (GIUH) method

2014 ◽  
Vol 9 (No. 1) ◽  
pp. 25-30 ◽  
Author(s):  
M.R. Khaleghi ◽  
J. Ghodusi ◽  
H. Ahmadi
Keyword(s):  
High Efficiency ◽  
Linear Regression Analysis ◽  
Regional Analysis ◽  
Suitable Model ◽  
Rainfall Runoff ◽  
Unit Hydrograph ◽  
Design Flood ◽  
Ungauged Catchments ◽  
Northern Iran ◽  
Simulation Accuracy

The construction of design flood hydrographs for ungauged drainage areas has traditionally been approached by regionalization, i.e. the transfer of information from the gauged to the ungauged catchments in a region. Such approaches invariably depend upon the use of multiple linear regression analysis to relate unit hydrograph parameters to catchment characteristics and generalized rainfall statistics. In the present study, Geomorphologic Instaneous Unit Hydrograph (GIUH) was applied to simulate the rainfall-runoff process and also to determine the shape and dimensions of outlet runoff hydrographs in a 37.1 km<sup>2</sup> area in the Ammameh catchment, located at northern Iran. The first twenty-one equivalent rainfall-runoff events were selected, and a hydrograph of outlet runoff was calculated for each event. An intercomparison was made for the three applied approaches in order to propose a suitable model approach that is the overall objective of this study. Hence, the time to peak and peak flow of outlet runoff in the models were then compared, and the model that most efficiently estimated hydrograph of outlet flow for similar regions was determined. Statistical analyses of the models demonstrated that the GIUH model had the smallest main relative and square error. The results obtained from the study confirmed the high efficiency of the GIUH and its ability to increase simulation accuracy for runoff and hydrographs. The modified GIUH approach as described is therefore recommended for further investigation and intercomparison with regression-based regionalization methods.

Role of adrenergic tone in mechanical and functional properties of carotid artery during aging

1993 ◽  
Vol 265 (4) ◽  
pp. H1132-H1138 ◽  
Author(s):  
A. Benetos ◽  
F. Huguet ◽  
P. Albaladejo ◽  
A. M. Brisac ◽  
M. Pappo ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Arterial Compliance ◽  
Structural Parameter ◽  
Cross Sectional ◽  
Arterial Distensibility ◽  
Beta Adrenoceptor ◽  
Alpha Blockade ◽  
The Media ◽  
Carotid Arterial

The present study was designed to assess the role of the adrenergic tone in the regulation of carotid arterial compliance during aging. An experimental model of in situ isolated carotid arteries has been used to evaluate the elastic properties of the arterial wall in young (3-mo-old) and older (18-mo-old) Wistar rats. Binding experiments were performed in the same strain of rats to evaluate alpha 1- and beta-adrenoceptor affinity and density. In a third set of experiments, structural parameter of the carotid artery in younger and older rats was evaluated. Arterial distensibility (compliance per unit of volume) was significantly lower in older rats. This was associated with a significant thickness of the media (45.6 +/- 2.8 vs. 57.5 +/- 5.7 microns, P < 0.01) and increased collagen content in older rats (4,420 +/- 310 vs. 7,320 +/- 850 microns 2/mm, P < 0.001). However, carotid arterial compliance was not altered in older rats because of the significant increase in cross-sectional area with aging. Aging did not affect alpha 1-adrenoceptor affinity and density, whereas it decreased beta-density without changing their affinity. Pharmacological stimulation of alpha 1-adrenoceptor with phenylephrine (10(-5) M) decreased compliance in older but not in younger animals. Blockade of these receptors with prazosin or labetalol increased compliance in younger and had no effect on older rats. beta-receptor stimulation with isoproterenol or blockade with propranolol had no effect in any of the studied groups. We suggest that with aging there is an increased vasoconstricting effect of alpha-agonists and a decreased vasodilatative action of alpha-blockade.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of Erosions in Sacroiliac Joints of Patients with Axial Spondyloarthritis Using the Magnetic Resonance Imaging Volumetric Interpolated Breath-hold Examination

2019 ◽  
Vol 46 (11) ◽  
pp. 1445-1449 ◽  
Author(s):  
Xenofon Baraliakos ◽  
Florian Hoffmann ◽  
Xiaohu Deng ◽  
Yan-Yan Wang ◽  
Feng Huang ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Structural Changes ◽  
Axial Spondyloarthritis ◽  
Linear Regression Analysis ◽  
Cartilage Defects ◽  
Breath Hold ◽  
Resonance Imaging ◽  
Sacroiliac Joints ◽  
Magnetic Resonance Imaging Mri

Objective.The volumetric interpolated breath-hold examination (VIBE) magnetic resonance imaging (MRI) technique can visualize erosive cartilage defects in peripheral joints. We evaluated the ability of VIBE to detect erosions in sacroiliac joints (SIJ) of patients with axial spondyloarthritis (axSpA) compared to the established T1-weighted MRI sequence and computed tomography (CT).Methods.MRI (T1-weighted and VIBE) and CT scans of SIJ of 109 patients with axSpA were evaluated by 2 blinded readers based on SIJ quadrants (SQ). Erosions were defined according to Assessment of Spondyloarthritis international Society (ASAS) definitions. Scores were recorded if readers were in agreement.Results.Erosions were less frequently detected by CT (153 SQ) than by T1-weighted MRI (182 SQ; p = 0.008) and VIBE-MRI (199 SQ; p < 0.001 vs CT and p = 0.031 vs T1-weighted MRI). Taking CT as the gold standard, the sensitivity of VIBE-MRI (71.2%) was higher than that for T1-weighted MRI (63.4%), with similar specificity (87.3% vs 88%, respectively). In linear regression analysis, younger age was significantly associated with occurrence of erosions independently in VIBE-MRI (β = 0.384, p < 0.001) and T1-weighted MRI (β = 0.369, p < 0.001) compared to CT.Conclusion.The VIBE-MRI sequence was more sensitive than T1-weighted MRI in identifying erosive damage in the SIJ, especially in younger patients. This might be due to the ability of VIBE-MRI to identify structural changes in the cartilage that have not yet extended to the underlying bone, where CT seems to be superior.

Intestinal absorption of triglyceride and vitamin D3 in aged and young rats

1981 ◽  
Vol 26 (12) ◽  
pp. 1109-1115 ◽  
Author(s):  
Peter R. Holt ◽  
Amelia A. Dominguez
Keyword(s):  
Intestinal Absorption ◽  
Vitamin D3 ◽  
Young Rats

A Virtual Instrument for Automated Measurement of Arterial Compliance

2010 ◽  
Vol 4 (4) ◽  
Author(s):  
Jayaraj Joseph ◽  
V. Jayashankar
Keyword(s):  
Virtual Instrument ◽  
Arterial Compliance ◽  
Single Element ◽  
Prototype System ◽  
Automated Measurement ◽  
General Medical Practitioner ◽  
Arterial Distensibility ◽  
Minimal Operator ◽  
Vascular Ultrasonography ◽  
Better Than

Measurement of arterial distensibility is very important in cardiovascular diagnosis for early detection of coronary heart disease and possible prediction of future cardiac events. Conventionally, B-mode ultrasound imaging systems have been used along with expensive vessel wall tracking systems for estimation of arterial distension and calculation of various estimates of compliance. We present a simple instrument for noninvasive in vivo evaluation of arterial compliance using a single element ultrasound transducer. The measurement methodology is initially validated using a proof of concept pilot experiment using a commercial ultrasound pulser-receiver. A prototype system is then developed around a PXI chassis using LABVIEW software. The virtual instrument employs a dynamic threshold algorithm to identify the artery walls and then utilizes a correlation based tracking technique to estimate arterial distension. The end-diastolic echo signals are averaged to reduce error in the automated diameter measurement process. The instrument allows automated measurement of the various measures of arterial compliance with minimal operator intervention. The performance of the virtual instrument was first analyzed using simulated data sets to establish the maximum measurement accuracy achievable under different input signal to noise ratio (SNR) levels. The system could measure distension with accuracy better than 10 μm for positive SNR. The measurement error in diameter was less than 1%. The system was then thoroughly evaluated by the experiments conducted on phantom models of the carotid artery and the accuracy and resolution were found to meet the requirements of the application. Measurements performed on human volunteers indicate that the instrument can measure arterial distension with a precision better than 5%. The end-diastolic arterial diameter can be measured with a precision better than 2% and an accuracy of 1%. The measurement system could lead to the development of small, portable, and inexpensive equipment for estimation of arterial compliance suitable in mass screening of “at risk” patients. The automated compliance measurement algorithm implemented in the instrument requires minimal operator input. The instrument could pave the way for dedicated systems for arterial compliance evaluation targeted at the general medical practitioner who has little or no expertise in vascular ultrasonography.

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