Diameter Wall Research Articles

Exercise Training Induces Left- but not Right-sided Cardiac Remodelling in Olympic Rowers.

Whilst the athlete's heart has been extensively described, less work has focused on the potential for elite athletes to demonstrate further cardiac remodelling upon an increase in training volume. Moreover, little work explored potential side-specific cardiac remodelling. Therefore, we examined the impact of an increase in training volume across 9-months in elite rowers on left- and right-sided cardiac structure, function and mechanics (i. e. longitudinal, radial and circumferential strain, twist and strain-volume loops). As part of the preparations to the 2012 Olympic Games, twenty-seven elite rowers (26.4±3.7years, 19 male) underwent echocardiography prior to and post (9 months) an increase in training volume (24 to 30-35 h weekly). Training increased left ventricular structure, including wall thickness, diameter, volume, mass and LV twist (all p<0.05). Female rowers demonstrated larger adaptation in left ventricular diameter and mass compared to male rowers (both p<0.05). No changes were observed in other measures of left ventricular function in both sexes (all p>0.05). The 9-month intervention showed no change in right ventricular/atrial structure, function or mechanics (all p>0.05). In conclusion, our data revealed that 9-month increased training volume in elite rowers induced left-sided (but not right-sided) structural remodelling, concomitant with an increase in left ventricular twist, with some changes larger in women.

Implantation of Bone Marrow Mesenchymal Stem Cells into Small Intestinal Submucosa Improves Bile Duct Injury in Rabbits.

Bile duct injury (BDI), which may occur during cholecystectomy procedures and living-donor liver transplantation, leads to life-altering complications and significantly increased mortality and morbidity. Tissue engineering, as an emerging method, has shown great potential to treat BDI. Here, we aimed to explore the application of small intestinal submucosa (SIS) matrix composites with bone marrow mesenchymal stem cells (BMSCs) to treat BDI in a rabbit model. Rabbit-derived BMSCs were used as seed cells. Porcine SIS was used as the support material. Five centimetres of the common bile duct was dissected, and 1/3-1/2 of the anterior wall diameter was transversely incised to construct the rabbit BDI model. Then, SIS materials without/with BMSCs were inserted into the common bile duct of the BDI rabbits. After 1, 2, 4, and 8weeks of implantation, the common bile duct was removed. Haematoxylin and eosin (HE) staining was used to assess pathological alterations in the common bile duct, while immunohistochemical staining and western blotting were used to detect expression of the epithelial cell markers CK19 and E-cadherin. Scanning electron microscopy was used to evaluate BMSC growth. Compared with BMSCs alone, SIS-attached BMSCs had increased growth. HE staining showed that the injured bile duct healed well and that the complex gradually degraded as the time from implantation increased. Immunohistochemical staining and western blotting showed that compared with the control group, the in vivo complex group had significantly elevated expression levels of CK19 and E-cadherin. BMSC implantation into SIS could improve BDI in rabbits, which might have clinical value for BDI treatment.

Changes of Stem Characteristics, Senescence Indexes and Yield and Quality of Wintering Rye under Different Populations

In response to the production crisis caused by a winter feed shortage due to the rapid development of the animal husbandry industry, winter rye 001 was selected to study differences in stalk and senescence characteristics in yield formation in cold regions. Five density treatments were established in a randomized design as 225 × 104 plant·hm−2 (D1), 275 × 104 plant·hm−2 (D2), 325 × 104 plant·hm−2 (D3), 375 × 104 plant·hm−2 (D4), and 425 × 104 plant·hm−2 (D5). Stem characteristics, SOD activity, POD activity, MDA content, and differences in yield and feeding quality under different population densities were analyzed. The plant height, center of gravity, and stem basal internode length showed an increasing trend with an increase in planting density. The stem wall thickness, diameter, strength, and lodging resistance indices decreased. At 275 × 104 plants·hm−2, the rye crude protein content was the highest while neutral washing fiber and acid washing fiber were the lowest, and feed quality was the best. With an increase in density, spike number, grain number per spike, and thousand-grain weight first increased and then decreased. We concluded that the yield and feeding quality were best when the basic seedling was at 275 × 104 plants hm−2.

Influence of ring type flow turbulators on the local heat transfer coefficients in an annular passage – An experimental and numerical investigation

In this experimental and numerical investigation, the use of circular cross sectioned ring-type flow turbulators was considered as a method to increase local heat transfer coefficients in annular heat transfer passages. Experimental data was obtained for cases with and without ring turbulators within a horizontal annular test section using water for average Reynolds numbers ranging from 2000 to 7500, and average Prandtl numbers ranging from 6.73 to 6.79. The test section was heated uniformly on the inner annular wall and had a hydraulic diameter of 14.8 mm, a diameter ratio (inner wall diameter to outer wall diameter) of 0.648, and a length to hydraulic diameter ratio of approximately 71. A set of turbulators were inserted which had a thickness of 1 mm, a ring diameter of 15.1 mm and a pitch of 50 mm. Local heat transfer coefficients were obtained using liquid crystal thermography to map the effects of adding the set of ring turbulators. This method provided results which could be used to compare the turbulator effects between turbulators. It was found that the presence of the flow turbulators increased the average Nusselt number by between 34% and 54%. The experimental tests were followed by numerical simulations to identify the response in the heat transfer coefficient by changing the geometry of the turbulators. For this, the turbulator diameters were ranged from 0.5 mm to 2 mm, and the gap size (between the inner wall and a turbulator ring) ranged from 0.125 mm to 4 mm at a pitch of 50 mm. The results showed that the use of turbulators can significantly increase the Nusselt number. Heat transfer was optimised in terms of the turbulator diameter and the wall gap size. From the numeric determined pressure drop values it was found that the smaller gap size had the lowest pressure drop and the smallest turbulators also produced the lowest pressure drop.

Atherosclerotic Burden and Remodeling Patterns of the Popliteal Artery as Detected in the Magnetic Resonance Imaging Osteoarthritis Initiative Data Set.

BackgroundAn artificial intelligence vessel segmentation tool, Fully Automated and Robust Analysis Technique for Popliteal Artery Evaluation (FRAPPE), was used to analyze a large databank of popliteal arteries imaged through the OAI (Osteoarthritis Initiative) to study the impact of atherosclerosis risk factors on vessel dimensions and characterize remodeling patterns.Methods and ResultsMagnetic resonance images from 4668 subjects contributing 9189 popliteal arteries were analyzed using FRAPPE. Age ranged from 45 to 79 years (median, 61), and 58% were women. Mean lumen diameter, mean outer wall diameter, and mean wall thickness (MWT) were measured per artery. Their median values were 5.8 mm (interquartile range, 5.2–6.5 mm), 7.3 mm (interquartile range, 6.7–8.1 mm), and 0.78 mm (interquartile range, 0.73–0.84 mm) respectively. MWT was associated with multiple cardiovascular risk factors, with age (4.2% increase in MWT per 10‐year increase in age; 95% CI, 3.9%–4.5%) and sex (8.6% higher MWT in men than women; 95% CI, 7.7%–9.3%) being predominant. On average, lumen and outer wall diameters increased with increasing MWT until the thickness was 0.92 mm for men and 0.84 mm for women. After this point, lumen diameter decreased steadily, more rapidly in men than women (−7.9% versus −6.1% per 25% increase in MWT; P<0.001), with little change in outer wall diameter.ConclusionsFRAPPE has enabled the analysis of the large OAI knee magnetic resonance imaging data set, successfully showing that popliteal atherosclerosis is predominantly associated with age and sex. The average vessel remodeling pattern consisted of an early phase of compensatory enlargement, followed by a negative remodeling, which is more pronounced in men.

Role of AMPK in Determining the Mediator of Flow Induced Dilation in the Human Microvasculature

An important measure of microvascular endothelial function is flow-induced dilation (FID), the ability of an arteriole to dilate in response to increased flow. In healthy adults, FID is predominantly mediated by endothelial-derived nitric oxide (NO), a vasoactive compound with anti-inflammatory properties. In microvessels from patients with coronary artery disease (CAD), FID occurs via formation and release of hydrogen peroxide (H2O2), a pro-inflammatory vasoactive mediator. We have previously shown that exogenous adiponectin restores NO-mediated FID in CAD arterioles, however the mechanism remains unknown. Because AMP kinase (AMPK), a downstream target of adiponectin receptors, increases cellular NO, we hypothesized that inhibition of AMPK would promote H2O2 as the mediator of FID in arterioles from healthy, nonCAD subjects. Human microvessels (80-200µm) were dissected from discarded surgical adipose specimens, cannulated onto micropipettes and pressurized. Arterioles were pre-constricted with endothelin-1 and changes in vessel wall diameter were measured during graded increases in flow using videomicroscopy. FID was observed in healthy arterioles treated with the AMPK inhibitor, Compound C (1µM, 16hrs) in the presence of the NO scavenger c-PTIO (100µM) (77.9 % max dilation ± 6, n=3), as well as with the H2O2 degradation enzyme PEG-Catalase (500U), (62.4% max dilation ±15, n=3). Interestingly, FID was suppressed only in the presence of both c-PTIO and PEG-Catalase (42.1% max dilation ±16, n=3) compared to controls (69.4% max dilation ±6, n=3). Together, these data may suggest that NO and H2O2 compensate for loss of one another during inhibition of AMPK. Future studies will investigate whether adiponectin-induced restoration of NO requires activation of AMPK as thorough understanding of this pathway during FID is critical for understanding the mechanism by which adiponectin improves microvascular endothelial function during disease.

To the forecast of martensitic transformation development during sink drawing of austenitic steel pipes

The work aim is the mathematical modeling of the austenitic steel pipes sink drawing process to establish the effect of the pipe wall thickness on the material stress-strain state and to predict the martensitic transformation development. The drawing process was simulated for thin-walled and thick-walled pipes by the finite element method using the DEFORM-2D software package. There are determined the shape change and deformations distribution, the deformations intensity and the average normal stress for seven variants of pipes with different wall thickness ratios and diameter are determined. Distribution patterns for two extreme variants are shown. The difference is shown in the stress state at the drawing process of thin-walled and thick-walled pipes. The change in the average normal stress in time t of a particle passage through the deformation zone for the outer and the inner surfaces for a thin-walled and extra thick-walled pipe is given. In either case, the compression stresses up to &ndash;400 MPa for the inner surface and tensile stresses for the outer surface up to +200 MPa are prevail at the entrance to the deformation zone. Inside the deformation zone, a thin-walled pipe is characterized by the presence of approximately equal compressive stresses both on the outer surface and on the inner one. However, the stresses are close to zero outside and reach &ndash;600 MPa inside for a thick-walled pipe. The deformation zone numerical simulation in the sink drawing made of austenitic steel showed that there are differences in the stress-strain state in the case of processing thin-walled and thick-walled pipes. The performed calculations and comparison with the literature data on the stress state influence on the cold martensitic transformation process made it possible to predict the development of this transformation in the drawing process. It was revealed that during thin-walled pipes drawing process are created more favorable conditions for the phase transition development.This work was performed with partial financial support of Resolution No. 211 of the Government of the Russian Federation, contract No. 02.A03.21.

Study of deformation-force parameters of rolling-off process and plugless screw rolling of pipes on three-roll mills

The possibility of using continuously cast billets and expanding the range of seamless pipes on pipe rolling units with a screw rolling-off mill is an urgent task today. In this regard, it is necessary to resolve issues related to the study of deformation-force parameters of the process of rolling-off and plugless screw rolling, which is especially important when developing new modes of rolling pipes. In order to expand the technological capabilities of units, which use rolling and calibration three-roll mills, such as TPA-160, the method of rolling, allowing the deformation of the shell on the wall thickness and diameter (more than 5 %). Application of this method to obtain a wide range of pipes sizes and grades requires the development of rational modes of deformation, which would increase the total reduction in diameter, while maintaining a sufficient level of force parameters, to avoid the appearance of end defects, the formation of which is characteristic for screw rolling on a three-roll mill. The results of the theoretical study of deformation parameters of the reduction site of the working zone, the influence of which is enhanced by rolling with increasing reduction in diameter, are presented. The results of experimental rolling of pipes made of 09G2S steel on the TPA-160 rolling mill with a total reduction in diameter of 24 % are presented. According to the results, the behavior of the oval coefficient responsible for expansion of the reduction zone and contact surface of metal with the roll was studied. The results of experimental and industrial rolling of a wide size and grade range of pipes from continuously cast billets with a diameter of 156 and 220 mm in conditions of TPA-160 using rolling of pipes in a rolling-off mill with additional reduction in diameter up to 37 % are described. Based on the results of experimental-industrial rolling, statistical analysis and verification of the adequacy of the results of theoretical studies of deformation-force parameters of the rolling-off and plugless pipes rolling were carried out.

A Transgenic Mouse Model of Eccentric Left Ventricular Hypertrophy With Preserved Ejection Fraction Exhibits Alterations in the Autophagy-Lysosomal Pathway.

The ubiquitin-proteasome system (UPS) and the autophagy-lysosomal pathway (ALP) are the main proteolytic systems involved in cellular homeostasis. Since cardiomyocytes, as terminally differentiated cells, lack the ability to share damaged proteins with their daughter cells, they are especially reliant on these protein degradation systems for their proper function. Alterations of the UPS and ALP have been reported in a wide range of cardiac diseases, including cardiomyopathies. In this study, we determined whether the UPS and ALP are altered in a mouse model of eccentric left ventricular (LV) hypertrophy expressing both cyclin T1 and Gαq under the control of the cardiac-specific α-myosin heavy chain promoter (double transgenic; DTG). Compared to wild-type (WT) littermates, DTG mice showed higher end-diastolic (ED) LV wall thicknesses and diameter with preserved ejection fraction (EF). The cardiomyopathic phenotype was further confirmed by an upregulation of the fetal gene program and genes associated with fibrosis as well as a downregulation of genes involved in Ca2+ handling. Likewise, higher NT-proBNP levels were detected in DTG mice. Investigation of the UPS showed elevated steady-state levels of (poly)ubiquitinated proteins without alterations of all proteasomal activities in DTG mice. Evaluation of ALP key marker revealed a mixed pattern with higher protein levels of microtubule-associated protein 1 light chain 3 beta (LC3)-I and lysosomal-associated membrane protein-2, lower protein levels of beclin-1 and FYVE and coiled-coil domain-containing protein 1 (FYCO1) and unchanged protein levels of p62/SQSTM1 in DTG mice when compared to WT. At transcriptional level, a > 1.2-fold expression was observed for Erbb2, Hdac6, Lamp2, Nrg1, and Sqstm1, while a < 0.8-fold expression was revealed for Fyco1 in DTG mice. The results related to the ALP suggested overall a repression of the ALP during the initiation process, but an induction of the ALP at the level of autophagosome-lysosome fusion and the delivery of ubiquitinated cargo to the ALP for degradation.

Galectin-3 and neutrophil-to-lymphocyte ratio are indicative of heart remodelling and disease severity in patients with obstructive sleep apnoea

BackgroundGalectin-3, considered as a new inflammatory marker; it is increased in cardiovascular disease. We investigated Galectin-3 in relation to heart damage in patients with OSA and its role in inflammation, based on the Neutrophil-to-Lymphocyte Ratio (NLR). MethodsSixty-three consecutive patients (45 males, 18 females, 58.60 ± 12.28 years old) were studied. According to the Apnoea–Hypopnoea Index (AHI) patients were divided into Group 1 – non-severe (AHI <30) (17 males and 10 females, 59.89 ± 10.62 years old) and Group 2 – severe (AHI ≥30) (29 males and 6 females, aged 57.53 ± 13.30 years old) OSA. All patients underwent morning blood gas analysis, laboratory tests, nocturnal polygraphy, and echocardiography. ResultsGalectin-3 was significantly increased in Group 2 (p = 0.027) patients. Moreover, it was directly related to left ventricle (LV) mass, left ventricle hypertrophy and LV posterior wall diameter. Tissue Doppler septal velocity (e′), that measures wall motion, was inversely correlated to Galectin-3. Furthermore, a direct association to diastolic dysfunction, evaluated as E/e′ ratio, was observed. In line with these data, a direct correlation between Galectin-3 and left atrium volume was also found. Galectin-3 and percentage of total registration time with nocturnal oxygen saturation <90% (TST90) were directly correlated (p = 0.0003), while Galectin-3 and mean nocturnal SpO2 were negatively correlated (p = 0.0045). We found a direct correlation between Galectin-3 and NLR (p = 0.011). Finally, Galectin-3 was able to predict 3-yr mortality with a specificity of 83.33% and a sensitivity of 91.84%. ConclusionGalectin-3 showed a direct association to nocturnal respiratory indices and to cardiac remodelling in patients with OSA. OSA-induced inflammation may play an important role in the pathogenesis of heart damage.

Does Iron Deficiency Affect the Heart in Children?

It is well known that serum iron parameters are closely related to cardiovascular health. Iron deficiency may lead to significant cardiac problems, such as atrioventricular conduction abnormalities, and systolic and/or diastolic dysfunction. Studies related to the effect of iron deficiency on cardiac functions are limited in children. Therefore, the aim of this study was to evaluate the effect of low iron stores on cardiac repolarization parameters which are used to predict arrhythmia and cardiac functions. Onehundred thirty-five children 2 to 18 years of age without structural heart disease who were referred to the Pediatric Cardiology Department for various reasons such as chest pain, heart murmur, or evaluation before sports participation were evaluated prospectively. The cases were separated into 3 groups according to ferritin levels (group 1: ferritin <15 ng/mL [n=48], group 2: ferritin 15 to 25 ng/mL [n=51], and group 3: ferritin >25 ng/mL [n=36]). Evaluations were made with detailed 12-lead surface electrocardiography (ECG) and transthoracic echocardiogram. Cardiac repolarization parameters were measured from surface ECG and systolic functions, left ventricular wall diameters were evaluated from transthoracic echocardiogram. Eighty-four (62.2%) girls and 51 (37.8%) boys are included in the study. The average age of the groups was similar. In children with low ferritin levels (group 1); Pw, Pw max, and Pw dis; QT, QTc, and QTc dis; Tp-Te, Tp-Te dis, Tp-Te/QT, and Tp-Te/QTc were significantly longer compared with the group 3 (P<0.05). There was a negative correlation between ferritin level and Pw, P max, and Pw dis; QT, QT dis, QTc, and QTc dis; Tp-Te, Tp-Te dis, Tp-Te/QT, and Tp-Te/QTc (P<0.05). No correlation was found between ferritin level and Pw min. There was no difference between the groups in respect of ejection phase indices, heart wall measurements, and end-diastolic diameter measurements. Iron deficiency may be related to the tendency of arrhythmias in children without structural heart disease. Therefore, careful evaluation of ECG parameters of healthy children with low iron stores, and follow up with intermittent monitoring is highly important.

Effects of rosin treatment on hygroscopicity, dimensional stability, and pore structure of round bamboo culm

Round bamboo culm maintains the natural texture, shape, and mechanical structure of raw bamboo materials compared with modern bamboo engineering materials, which break down bamboo culms into small elements. Promoting the use of round bamboo is an efficient and sophisticated way to utilize bamboo resources. However, the high hygroscopicity and poor dimensional stability are disadvantages that obstruct the utilization of round bamboo culm in construction and building applications. To solve these problem, rosin was used to modify the bamboo culm material in this work. The results show that the weight percentage gain of rosin was 9.98% after 8 h of impregnation. Part of the rosin formed transparent hydrophobic films on the surface of the bamboo culm, and decreased its surface wettability. Moreover, rosin was introduced into internal pores of bamboo where it decreased the porosity and total pore volume of bamboo by 14.42% and 23.81%, respectively. Additionally, the moisture absorption for 144 h at 65% relative humidity decreased by 39.27%, while rosin treatment decreased the swellings of wall thickness and diameter of bamboo culm from oven-dry to water saturation by 42.20% and 25.40%, respectively.

Seismic response analysis of buried pipelines with the high drop

To study the seismic response of buried pipelines with the high drop, a small-size test based on shaking table was conducted to analyze the effects of pipeline wall thickness, pipeline diameter and inclination angle on the seismic response of buried pipelines with high drop. Meanwhile, a finite element model was proposed for numerical simulation. The research results show that the peak axial strain of the pipeline increases with the decrease of the thickness and the diameter of the pipeline in the action of seismic waves and the increase of the inclination of the pipeline. Based on the results of experiments and finite element simulations, a regression equation of the peak axial strain of buried pipelines with the high drop was developed with the consideration of the effects of the ratio of wall diameter to wall thickness and height. Meanwhile, some valuable conclusions were obtained for the instruction of the seismic design of pipelines in engineering.

Generation-based study of airway remodeling in smokers with normal-looking CT with normalization to control inter-subject variability

PurposeWith the help of quantitative computed tomography (QCT), it is possible to identify smoking-associated airway remodeling. However, there is currently little information on whether QCT-based airway metrics are sensitive to early airway wall remodeling in subclinical phases of smoking-associated airway disease. This study aimed to evaluate a predictive model that normalized airway parameters and investigate structural airway alterations in smokers with normal-looking CT using the normalization scheme. MethodsIn this retrospective analysis, 222 non-smokers (male 97, female 125) and 69 smokers (male 66, female 3) from January 2014 to December 2016 were included, and airway parameters were quantitatively analyzed. To control inter-subject variability, multiple linear regressions of tracheal wall thickness (WT), diameter (D), and luminal area (LA) were performed, adjusted for age, sex, and height. Using this normalization scheme, airway parameters with matched generation were compared between smokers and non-smokers. ResultsUsing the normalization scheme, it was possible to assess generation-based structural alterations of the airways in subclinical smokers. Smokers showed diffuse luminal narrowing of airways for most generations (P < 0.05, except 3rd generation), no change in wall thickness of the proximal bronchi (1st-3rd generation), and a thinning of distal airways (P <0.05, ≥4th generation). ConclusionQCT assessment for subclinical smokers can help identify minimal structural changes in airways induced by smoking.

Synthesis and formation mechanism of novel double-thick-walled silicon carbide nanotubes from multiwalled carbon nanotubes

In this study, double-thick-walled (DTW) silicon carbide (SiC) nanotubes, the walls of which comprise connected disordered polycrystalline nanograins, were successfully synthesized for the first time via the reaction of multiwalled carbon nanotubes (MWCNTs) with Si powder. DTW SiC nanotubes are expected to exhibit novel properties unlike other SiC nanomaterials, owing to their intriguing geometries. The DTW SiC nanotubes had a wall thickness exceeding 20 nm, regardless of the external diameter, as indicated by transmission electron microscopy results. The DTW SiC nanotubes with a spacing of above 30 nm between the outer and inner nanotubes exhibited perfect double-walled structures. The inner and outer nanotubes were not connected in any region. When all the carbon was transformed into SiC, the volume of carbon increased to 2.2 times the initial value. These results reveal that DTW SiC nanotubes with perfect structures cannot be synthesized without an MWCNT wall thickness of at least 50 nm. Several types of DTW SiC nanotubes with different morphologies, such as diameter, end structure, and distance between the inner and outer nanotubes, were synthesized. The morphology of DTW SiC nanotubes can be controlled by changing the wall thickness and/or diameter of the original MWCNTs and the reaction conditions.

Natural progression of cardiac features and long-term effects of enzyme replacement therapy in Taiwanese patients with mucopolysaccharidosis II

BackgroundCardiac abnormalities have been observed in patients with mucopolysaccharidosis type II (MPS II). The aim of this study was to investigate the cardiac features and natural progression of Taiwanese patients with MPS II, and evaluate the impact of enzyme replacement therapy (ERT) on cardiac structure and function.MethodsThe medical records and echocardiograms of 48 Taiwanese patients with MPS II (median age, 6.9 years; age range, 0.1–27.9 years) were reviewed. The relationships between age and each echocardiographic parameter were analyzed.ResultsThe mean z-scores of left ventricular mass index (LVMI), interventricular septum diameter in diastole (IVSd), left ventricular posterior wall diameter in diastole (LVPWd), and aortic diameter were 1.10, 2.70, 0.95 and 1.91, respectively. Z scores > 2 were identified in 33%, 54%, 13%, and 46% for LVMI, IVSd, LVPWd, and aortic diameter, respectively. The most prevalent cardiac valve abnormality was mitral regurgitation (MR) (56%), followed by aortic regurgitation (AR) (33%). The severity of mitral stenosis (MS), MR, aortic stenosis (AS), AR, and the existence of valvular heart disease were all positively correlated with increasing age (p < 0.01). We also compared the echocardiographic parameters between two groups: (1) 12 patients who had up to 17 years of follow-up echocardiographic data without ERT, and (2) nine patients who had up to 12 years of follow-up data with ERT. The results showed that z-score changes of LVMI significantly improved in the patients who received ERT compared to those who did not receive ERT (0.05 versus 1.52, p < 0.05). However, the severity score changes of MS, MR, AS, and AR all showed gradual progression in both groups (p > 0.05).ConclusionsHigh prevalence rates of valvular heart disease and cardiac hypertrophy were observed in the MPS II patients in this study. The existence and severity of cardiac hypertrophy and valvular heart disease in these patients worsened with increasing age, reinforcing the concept of the progressive nature of this disease. ERT for MPS II appeared to be effective in stabilizing or reducing the progression of cardiac hypertrophy, but it only had a limited effect on valvulopathy.

Ultrasound imaging for assessing functions of the GI tract

Objective. In the following review we outline how ultrasound can be used to measure physiological processes in the gastrointestinal tract. Approach. We have investigated the potential of ultrasound in assessing gastrointestinal physiology including original research regarding both basic methodology and clinical applications. Main results. Our main findings show the use of ultrasound to study esophageal motility, measure volume and contractility of the stomach, assess motility, wall thickness, and perfusion of the small bowel, and evaluate wall vascularization and diameters of the large bowel. Significance. Ultrasound is a widely accessible technology that can be used for both scientific and clinical purposes. Being radiation-free and user friendly, the examination can be frequently repeated enabling longitudinal studies. Furthermore, it does not influence normal GI physiology, thus being useful to estimate motility and subtle changes in physiology. Accordingly, ultrasound scanning and physiological measurements may make a big difference for the scientist and the doctor; and for the patients who receive an efficient work-up.

Radiation dosimetry of a clinical prototype dedicated cone-beam breast CT system with offset detector.

A clinical-prototype, dedicated, cone-beam breast computed tomography (CBBCT) system with offset detector is undergoing clinical evaluation at our institution. This study is to estimate the normalized glandular dose coefficients ( ) that provide air kerma-to-mean glandular dose conversion factors using Monte Carlo simulations. The clinical prototype CBBCT system uses 49kV x-ray spectrum with 1.39mm 1st half-value layer thickness. Monte Carlo simulations (GATE, version 8) were performed with semi-ellipsoidal, homogeneous breasts of various fibroglandular weight fractions ( , chest wall diameters ( cm), and chest wall to nipple length ( ), aligned with the axis of rotation (AOR) located at 65cm from the focal spot to determine the . Three geometries were considered - -cm detector with no offset that served as reference and corresponds to a clinical CBBCT system, -cm detector with 5cm offset, and a -cm detector with 10cm offset. For 5cm lateral offset, the ranged mGy/mGy and reduction in with respect to reference geometry was observed only for 18cm ( ) and 20cm ( ) diameter breasts. For the 10cm lateral offset, the ranged mGy/mGy and reduction in was observed for all breast diameters. The reduction in was , , , , and for 8, 10, 14, 18, and 20cm diameter breasts, respectively. For a given breast diameter, the reduction in with offset-detector geometries was not dependent on . Numerical fits of were generated for each geometry. The and the numerical fit, would be of benefit for current CBBCT systems using the reference geometry and for future generations using offset-detector geometry. There exists a potential for radiation dose reduction with offset-detector geometry, provided the same technique factors as the reference geometry are used, and the image quality is clinically acceptable.

Age- and Sex-Differences in Cardiac Characteristics Determined by Echocardiography in Masters Athletes.

BackgroundCardiac function and morphology are known to differ between men and women. Sex differences seen with echocardiography have not been studied systematically in masters athletes.PurposeTo evaluate sex differences in cardiac structure, function and left ventricular (LV) systolic global longitudinal strain among masters athletes.MethodsThis cross-sectional study comprises of 163 masters athletes (M = 109, 60 ± 12 years; F = 55, 57 ± 12 years, range 36–91 years) who participated at the 23rd World Masters Athletics Championship held in Málaga, Spain. All athletes underwent state-of-the-art echocardiography including cardiac function, morphology, strain and hemodynamic assessment.ResultsLeft ventricular mass was higher in male than in female athletes (174 ± 44 vs. 141 ± 36 g, p < 0.01) due to greater end-diastolic intraventricular septal, LV posterior wall and LV basal diameter. However, LV mass index did not differ between the groups. End-diastolic LV volume and right ventricular area, both indexed to body-surface-area, were greater in men than in women (52.8 ± 11.0 vs. 46.1 ± 8.5 ml/m2, p < 0.01, 9.5 ± 2.4 vs. 8.1 ± 1.7 cm2/m2, p < 0.01). In contrast, women had higher LV systolic global longitudinal strain (-20.2 ± 2.6 vs. -18.8 ± 2.6%, p < 0.01) and LV outflow tract flow velocity (75.1 ± 11.1 vs. 71.2 ± 11.1 cm/s, p = 0.04). Systolic and diastolic blood pressure, LV ejection fraction, and stroke volume index were not different between sexes.ConclusionCardiac sex differences are present even among masters athletes. Lifelong exercise training does not appear to exasperate morphological difference to a point of cardiac risk or dysfunction in both male and female athletes.

Carotid Occlusion Accentuates Aortic Stenosis and Cardiac Remodeling With Preserved Systolic Function in LDL Receptor-Deficient Mice.

Background: Carotid atherosclerotic disease is associated with aortic stenosis and reduced cardiac function. The causality between carotid and cardiac pathologies is unknown. We aim to explore the effects of carotid stenosis or occlusion on cardiac pathology and function.Methods and Results: We produced carotid obstruction or stenosis in 36 atherogenic mice with 150- or 300-μm tandem surgery or sham surgery. The structure and function of the heart were assessed by histology and animal ultrasound. The 150-μm group had larger plaque burden and thicker valve leaflets in the aortic root than did the control group. Also, the two surgery groups had a thicker left ventricular posterior wall and smaller internal diameter compared with controls. Increased myocardial fibrosis was also found in the 150-μm group compared with controls, although the surgery groups had preserved systolic function compared with that of controls.Conclusions: In a mouse model, carotid occlusion accentuated the formation of aortic stenosis and promoted ventricular remodeling without impairing systolic function. Carotid atherosclerotic plaque may be a pathogenic factor for aortic stenosis and ventricular remodeling.