The aim of this paper was to demonstrate the usefulness of magnetic resonance imaging (MRI) for detecting the ability of compression material in narrowing superficial and deep veins in the lower ...extremity.
MRI of the legs was performed in one healthy volunteer and in 11 patients with CEAP C2-C4 without and with different kinds of compression devices. The cross section area of superficial and deep veins was measured by planimetry in mid-calf and mid-thigh slices. The interface pressure of compression was measured at the same level.
Examples are presented showing that the narrowing of veins does not only depend on the exerted pressure but also on the body position and the resulting distortion of the tissue. In the prone and the standing position deep veins may show a greater reduction of the cross section area than in superficial veins.
MRI is a powerful method to assess venous narrowing by external compression. Especially in the standing position new insights regarding the effects of different compression devices may be expected.
Due to be launched in late 2021, the Imaging X-ray Polarimetry Explorer (IXPE) is a NASA Small Explorer mission designed to perform polarization measurements in the 2–8 keV band, complemented with ...imaging, spectroscopy and timing capabilities. At the heart of the focal plane is a set of three polarization-sensitive Gas Pixel Detectors (GPD), each based on a custom ASIC acting as a charge-collecting anode.
In this paper we shall review the design, manufacturing, and test of the IXPE focal-plane detectors, with particular emphasis on the connection between the science drivers, the performance metrics and the operational aspects. We shall present a thorough characterization of the GPDs in terms of effective noise, trigger efficiency, dead time, uniformity of response, and spectral and polarimetric performance. In addition, we shall discuss in detail a number of instrumental effects that are relevant for high-level science analysis—particularly as far as the response to unpolarized radiation and the stability in time are concerned.
Due to be launched in late 2021, the Imaging X-Ray Polarimetry Explorer (IXPE) is a NASA Small Explorer mission designed to perform polarization measurements in the 2-8 keV band, complemented with ...imaging, spectroscopy and timing capabilities. At the heart of the focal plane is a set of three polarization-sensitive Gas Pixel Detectors (GPD), each based on a custom ASIC acting as a charge-collecting anode. In this paper we shall review the design, manufacturing, and test of the IXPE focal-plane detectors, with particular emphasis on the connection between the science drivers, the performance metrics and the operational aspects. We shall present a thorough characterization of the GPDs in terms of effective noise, trigger efficiency, dead time, uniformity of response, and spectral and polarimetric performance. In addition, we shall discuss in detail a number of instrumental effects that are relevant for high-level science analysis -- particularly as far as the response to unpolarized radiation and the stability in time are concerned.
Objective/Background The objective of this study was to compare the efficacy and comfort of inelastic bandages (IBs) and adjustable Velcro® compression devices (AVCDs) in reducing venous leg edema in ...the initial treatment phase. Methods Forty legs from 36 patients with untreated venous edema (C3EpsAsdPr) were randomized to two groups. Patients in the first group received IBs ( n = 20) and those in the second AVCDs ( n = 20). Both compression devices were left on the leg day and night, and were renewed after 1 day. Patients in the AVCD group were asked to re-adjust the device as needed when it felt loose. Leg volume was calculated using the truncated cone formula at baseline (T0), after 1 day (T1) and after 7 days (T7). The interface pressure of the two compression devices was measured by an air filled probe, and the static stiffness index calculated after applying compression at T0 and T1, and just before removal of compression on T1 and T7. Patient comfort with regard to the two compression systems was assessed by grading signs and symptoms using a visual analog scale. Results At T1, the median percent volume reduction was 13% for the IB group versus 19% for the AVCD group; at T7 it was 19% versus 26%, respectively ( p < .001). The pressure of the IBs was significantly higher compared with the AVCDs at T0 (63 vs. 43 mmHg) but dropped by > 50% over time, while it remained unchanged with AVCDs owing to the periodic readjustment by the patient. Comfort was reported to be similar with the two compression devices. Conclusion Re-adjustable AVCDs with a resting pressure of around 40 mmHg are more effective in reducing chronic venous edema than IBs with a resting pressure of around 60 mmHg. AVCDs are effective and well tolerated, not only during maintenance therapy, but also in the initial decongestive treatment phase of patients with venous leg edema.
Estrogen deficiency causes bone loss and skeletal muscle dysfunction, and attenuates the musculoskeletal effects of exercise. The anti-diabetic drug metformin has been suggested to promote beneficial ...skeletal effects. To explore whether metformin can improve musculoskeletal training response during estrogen deficiency, we investigated the skeletal effects of plyometric exercise and metformin, in an ovarectomized (OVX) rat model of osteoporosis. Female Sprague Dawley rats, 12 weeks of age, rats were allocated to a sham-operated group (Sham), and four OVX groups; metformin (OVX-Met), exercise (OVX-Ex), combined metformin and exercise (OVX-MetEx) and a control group (OVX-Ctr), n = 12/group. Dual X-ray absorptiometry, micro computed tomography, fracture toughness testing, histomorphometry and plasma analyses were performed to explore skeletal effects. All intervention groups exhibited a higher gain in femoral bone mineral density (BMD) than OVX-Ctr (p < .01). The combined intervention also resulted in a higher gain in femoral and spine BMD compared to OVX-Met (p < .01). Both exercise groups displayed improved microarchitecture, including both cortical and trabecular parameters (p < .05). This was most evident in the OVX-MetEx group where several indices were at sham level or superior to OVX-Ctr (p < .05). The OVX-MetEx group also exhibited an enhanced toughening effect compared to the other OVX groups (p < .05). The beneficial skeletal effects seemed to be mediated by inhibition of bone resorption and stimulation of bone formation. The training response (i.e. jumping height) was also greater in the metformin treated rats compared to OVX-Ex (p < .01), indicating a performance-enhancing effect of metformin. Both exercise groups displayed higher lean mass than OVX-Ctr (p < .05). In conclusion, the combination of plyometric exercise and metformin improved trabecular microarchitecture and bone material properties relative to OVX controls. However, no additive effect of the combined intervention was observed compared to exercise alone.
•Plyometric exercise and metformin, alone or in combination enhanced femoral BMD in ovariectomized rats•The combined intervention improved trabecular microarchitecture and bone material properties relative to controls•No additive effect of the combined intervention was observed compared to exercise alone
Mild traumatic brain injury (mTBI) is highly prevalent, with an estimated occurrence in the United States of more than 1.3 million per year. While one consequence of mTBI is impulsive aggressive ...behavior, very few studies have examined the relationship between history of mTBI and aggressive behavior in impulsively aggressive individuals. The authors examined the relationship between history of mTBI in a healthy control group (HC; N=453), a control group with psychiatric disorders (PC; N=486), and individuals with intermittent explosive disorder (IED; N=695), a disorder of primary impulsive aggression. Results demonstrated that IED study participants were significantly more likely to have a history of mTBI (with or without history of a brief loss of consciousness LOC) compared with both HC and PC participants. A similar observation was made with regard to self-directed aggression (i.e., suicidal or self-injurious behavior), although group differences were only among those with mTBI with LOC. For both other- and self-directed aggression variables, the authors observed a stepwise increase in dimensional aggression and impulsivity scores across participants as a function of mTBI history. Given that impulsive aggressive behavior begins very early in life, these data are consistent with the hypothesis that lifelong presence of an impulsive aggressive temperament places impulsive aggressive individuals in circumstances that put them at greater risk for mTBI compared with other individuals with and without nonimpulsive aggressive psychopathology.
Background
The prevalence of super obesity has increased considerably in recent years, representing up to the 0.5% of the population. Even though bariatric surgery induces significant weight loss in ...these patients, it has been reported that up to 50% of the patients with super obesity will fail according to the current primary response criteria.
Objective
To evaluate and compare different primary response criteria and their impact regarding comorbidities remission.
Patients and Methods
A total of 104 patients with super obesity who underwent Roux-en-Y gastric bypass (RYGB) were identified in our institution from March 2004 to February 2019. An evaluation of the primary response at a 2-year follow-up was made using different criteria. A multivariate analysis was made to evaluate related variables to comorbidities remission.
Results
Two years later, the rate of patients who achieved an EWL > 50%, %EWL > 70%, and BMI < 35 kg/m
2
were 84.5%, 52.1%, and 62%, respectively. Regarding the comorbidities, 85%, 84.8%, and 81.1% of the patients improved or remitted T2D, HBP, and hyperlipidemia, respectively. An EWL > 50% 2 years later was related to complete remission of hyperlipidemia (
p
= 0.047), whereas weight regain above 10% is a risk factor for failure of complete remission of HBP in 3 years.
Conclusions
More than 75% of patients with super obesity yield an EWL > 50% 2 years later. In terms of hyperlipidemia, it is desirable to achieve an EWL of at least 50%. Whereas for T2D and HBP, a minimum of 25% TWL yields 72% and 60.5% of complete remission.
Graphical abstract
Estrogen deficiency promotes bone loss and skeletal muscle dysfunction. Peroxisome proliferator-activated receptors (PPARs) have 3 subtypes (α, δ, and γ). PPARγ agonists induce bone loss, whereas ...PPARα agonists increase bone mass. Although PPARδ agonists are known to influence skeletal muscle metabolism, the skeletal effects are unsettled. This study investigated the musculoskeletal effects of the PPARδ agonist GW501516 in ovariectomized (OVX) rats. Female Sprague Dawley rats, 12 weeks of age, were allocated to a sham-operated group and 3 OVX groups; high-dose GW501516 (OVX-GW5), low-dose GW501516 (OVX-GW1), and a control group (OVX-CTR), respectively (n = 12 per group). Animals received GW501516 or vehicle (methylcellulose) daily for 4 months by gavage. Bone mineral density (BMD) was assessed by dual x-ray absorptiometry at the femur, spine, and whole body. Bone microarchitecture at the proximal tibia was assessed by microcomputed tomography, and dynamic histomorphometry was performed. Quadriceps muscle morphology and the relative expression of mitochondrial proteins were analyzed. Bone metabolism markers and metabolic markers were measured in plasma. After 4 months, the OVX-GW5 group displayed lower femoral BMD than OVX-CTR. Trabecular separation was higher in the GW-treated groups, compared with OVX-CTR. The OVX-GW5 group also exhibited lower cortical area fraction and a higher structure model index than OVX-CTR. These effects coincided with impaired bone formation in both GW groups. The OVX-GW5 group displayed elevated triglyceride levels and reduced adiponectin levels, whereas no effects on muscle morphology or mitochondrial gene expression appeared. In summary, the PPARδ agonist GW501516 negatively affected bone properties in OVX rats, whereas no effects were detected in skeletal muscle.
Background
The body mass index (BMI) is the most commonly used anthropometric indicator. However, it does not discern among the different body components. The body fat content, expressed as fat mass ...index (FMI), is an accurate way to estimate adiposity. Since most metabolic diseases are associated with excess fat tissue, our aims were to comparatively analyze the frequency of associated metabolic abnormalities in patients with different obesity degrees based on BMI and FMI and to determine the best cut-off value of both indicators to predict metabolic abnormalities.
Methods
From a cohort of 2007 patients, BMI and FMI were calculated using DXA. Individuals were classified into the different obesity degrees according to the reference ranges from the World Health Organization (WHO) and the National Health and Nutrition Examination Survey (NHANES). A comparative analysis between BMI, FMI, and their correlation to the presence of metabolic alterations was performed.
Results
BMI underestimated the degree of obesity when compared with FMI. Spearman’s rank-order correlation for both indexes resulted in very high coefficients (rho Spearman’s = 0.857;
p
= 0.0001). The prevalence of metabolic alterations increased as BMI and FMI also increased. Despite the high positive statistical correlation between BMI and FMI, it was seen that some comorbidities were more specifically related to one particular index.
Conclusions
There were no significant differences between the BMI and the FMI for predicting the degree of obesity. Likewise, there were no significant differences between them for the prediction of metabolic alterations.
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