Peripheral Vascular Resistance Impairment during Isometric Physical Exercise in Normotensive Offspring of Hypertensive Parents

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Natália Portela

Full Text Available Abstract Background: A family history of hypertension is associated with vascular and autonomic abnormalities, as well as an impaired neurohemodynamic response to exercise. Objective: To test the hypothesis that normotensive individuals with a family history of hypertension present an impaired peripheral vascular resistance response to exercise. Methods: The study included 37 normotensive volunteers of both sexes who were sedentary, eutrophic, and nonsmokers, comprising 23 with (FH+; 24 ± 3 years and 14 without (FH-; 27 ± 5 years a family history of hypertension. Blood pressure, heart rate (DIXTAL®, forearm blood flow (Hokanson®, and peripheral vascular resistance were simultaneously measured for 3 minutes during rest and, subsequently, for 3 minutes during an isometric exercise at 30% of maximal voluntary contraction (Jamar®. Results: At rest, the FH+ and FH- groups present similar mean blood pressure (83 ± 7 versus 83 ± 5 mmHg, p = 0.96, heart rate (69 ± 8 bpm versus 66 ± 7 bpm, p = 0.18, forearm blood flow (3 ± 1 mL/min/100 mL versus 2.7 ± 1 mL/min/100 mL, p = 0.16, and peripheral vascular resistance (30 ± 9 units versus 34±9 units, p = 0.21, respectively. Both groups showed a significant and similar increase in mean blood pressure (∆ = 15 ± 7 mmHg versus 14 ± 7 mmHg, p = 0.86, heart rate (∆ = 12 ± 8 bpm versus 13 ± 7 bpm, p = 0.86, and forearm blood flow (∆ = 0.8 ± 1.2 mL/min/100 mL versus 1.4 ± 1.1 mL/min/100 mL, p = 0.25, respectively, during exercise. However, individuals in the FH+ group showed no reduction in peripheral vascular resistance during exercise, which was observed in the FH- group (∆ = -0.4 ± 8.6 units versus -7.2 ± 6.3 units, p = 0.03. Conclusion: Normotensive individuals with a family history of hypertension present an impaired peripheral vascular resistance response to exercise.

Pendulating—A grounded theory explaining patients’ behavior shortly after having a leg amputated due to vascular disease

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Madsen, Ulla Riis; Hommel, Ami; Bååth, Carina; Berthelsen, Connie Bøttcher

2016-01-01

Introduction Although the group of vascular leg amputated patients constitutes some of the most vulnerable and frail on the orthopedic wards, previous research of amputated patients has focused on patients attending gait training in rehabilitation facilities leaving the patient experience shortly after surgery unexplored. Understanding patients’ behavior shortly after amputation could inform health professionals in regard to how these vulnerable patients’ needs at hospital can be met as well as how to plan for care post-discharge. Aim To construct a grounded theory (GT) explaining patients’ behavior shortly after having a leg amputated as a result of vascular disease. Method In line with constructivist GT methodology, data from ethnographic observations and interviews were simultaneously collected and analyzed using the constant comparative method covering the patients’ experiences during the first 4 weeks post-surgery. Data collection was guided by theoretical sampling and comprised 11 patients. A GT was constructed. Results Patients went through a three-phased process as they realized they were experiencing a life-changing event. The first phase was “Losing control” and comprised the sub-categories “Being overwhelmed” and “Facing dependency.” The second phase was “Digesting the shock” and comprised the sub-categories “Swallowing the life-changing decision,” “Detecting the amputated body” and “Struggling dualism.” The third phase was “Regaining control” and comprised the sub-categories “Managing consequences” and “Building-up hope and self-motivation.” “Pendulating” was identified as the core category describing the general pattern of behavior and illustrated how patients were swinging both cognitively and emotionally throughout the process. Conclusion The theory of “Pendulating” offers a tool to understand the amputated patients’ behavior and underlying concerns and to recognize where they are in the

The effects of angiotensin II receptor antagonist (candesartan on rat renal vascular resistance

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Supatraviwat, J

2004-05-01

Full Text Available The present study aimed to investigate the action of angiotensin II (AII on renal perfusion pressure and renal vascular resistance using noncompetitive AT1-receptor antagonist (candesartan or CV 11974. Experiments were performed in isolated kidney of adult male Wistar rats. Kreb's Henseleit solution was perfused into the renal artery at the rate of 3.5 ml/min. This flow rate was designed in order to maintain renal perfusion pressure between 80-120 mm Hg. Dose-response relationship between perfusion flow rate and AII concentration were studied. Renal perfusion pressure in response to 1, 10 and 100 nM AII were increased from basal perfusion pressure of 94±8 mm Hg to 127±6, 157±12 and 190±16 mm Hg, respectively. Administration of perfusate containing 11.4 μM candesartan for 30 min had no effect on the basal perfusion pressure. However, this significantly reduced renal perfusion pressure in the presence of AII (1, 10 and 100 nM by 39%, 47% and 61%, (n=7, P<0.05 respectively. At the basal perfusion pressure, calculated renal vascular resistance was 27±2 mm Hg · min · ml-1. However, the vascular resistance were found to be 41±1, 45±2 and 47±2 mm Hg · min · ml-1 when 1, 10 and 100 nM AII were added. Moreover, this dose of candesartan also showed a significant decrease in renal vascular resistance at the corresponding doses of AII by 38%, 48% and 43%, (n=7, P<0.05 respectively. The higher dose of candesartan (22.7 μM completely inhibited the action of 1, 10 and 100 nM AII on renal vasoconstriction. These results may indicate that the action of AII on renal vascular resistance is via AT1-receptor, at least in rat isolated perfusion kidney.

Insulin sensitizers prevent fine particulate matter-induced vascular insulin resistance and changes in endothelial progenitor cell homeostasis.

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Haberzettl, Petra; McCracken, James P; Bhatnagar, Aruni; Conklin, Daniel J

2016-06-01

Exposure to fine particular matter (PM2.5) increases the risk of developing cardiovascular disease and Type 2 diabetes. Because blood vessels are sensitive targets of air pollutant exposure, we examined the effects of concentrated ambient PM2.5 (CAP) on vascular insulin sensitivity and circulating levels of endothelial progenitor cells (EPCs), which reflect cardiovascular health. We found that CAP exposure for 9 days decreased insulin-stimulated Akt phosphorylation in the aorta of mice maintained on control diet. This change was accompanied by the induction of IL-1β and increases in the abundance of cleaved IL-18 and p10 subunit of Casp-1, consistent with the activation of the inflammasome pathway. CAP exposure also suppressed circulating levels of EPCs (Flk-1(+)/Sca-1(+) cells), while enhancing the bone marrow abundance of these cells. Although similar changes in vascular insulin signaling and EPC levels were observed in mice fed high-fat diet, CAP exposure did not exacerbate diet-induced changes in vascular insulin resistance or EPC homeostasis. Treatment with an insulin sensitizer, metformin or rosiglitazone, prevented CAP-induced vascular insulin resistance and NF-κB and inflammasome activation and restored peripheral blood and bone marrow EPC levels. These findings suggest that PM2.5 exposure induces diet-independent vascular insulin resistance and inflammation and prevents EPC mobilization, and that this EPC mobilization defect could be mediated by vascular insulin resistance. Impaired vascular insulin sensitivity may be an important mechanism underlying PM2.5-induced vascular injury, and pharmacological sensitization to insulin action could potentially prevent deficits in vascular repair and mitigate vascular inflammation due to exposure to elevated levels of ambient air pollution. Copyright © 2016 the American Physiological Society.

ANATOMIC AND PHYSIOLOGICAL FEATURES OF DISTAL LOWER LEG AND THEIR INFLUENCE ON THE PROCESS OF OSTEOGENESIS

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Desimir Mladenović

2010-06-01

Full Text Available Osteogenesis is the process of bone tissue forming, i.e. bone or callus regeneration. This process is influenced by many factors, and the degree of bone fragments’ stability and vascularization in the fracture area are the basic local factors which determine the nature of reparative process. Regenerative process of all bone structures increases with increasing of blood supply.The distal lower leg has its specific biomechanical features, and plays an important role in the transfer of body weight to foot. The distal part of tibia has a small diameter, which as a consequence has reduced diameter in medullar cave. Through this anatomic feature, the medullar network in the lower tibia part is also reduced.As for anatomic aspect, vascularization in the lower end of tibia is poor. It primarily depends on periosteal vascularization, because medullar vascularization is reduced. Fasciae, tendons and skin cover the lower part of the leg, and there is no muscle mass. These tissues have poor vascular network and that is why the extraosseous blood circulation in tibia is poor, and does not participate in the osteogenesis process. For these reasons, distal lower leg represents a predelection site for delayed osteogenesis and pseudoarthrosys development.Osteosynthesis causes secondary damage to bone and soft tissue circulation. The screw plate damages the periosteal circulation – in the lower part of tibia it is the main source of vascularization, and for this reason, this method of osteosynthesis should not be applied. The external fixator has a sparing role regarding vascularization, and that is the reason why this method is recommended for fracture stabilization at the level of distal lower leg.

Frozen White-Leg Shrimp (Litopenaeus vannamei) in Korean Markets as a Source of Aeromonas spp. Harboring Antibiotic and Heavy Metal Resistance Genes.

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De Silva, Benthotage C J; Hossain, Sabrina; Dahanayake, Pasan S; Heo, Gang-Joon

2018-05-24

As the most consumed shrimp variety, white-leg shrimp (Litopenaeus vannamei) owns a high market demand in Korea. This study sought to screen the frozen white-leg shrimp for Aeromonas spp. harboring antimicrobial and heavy metal resistance characteristics. A total of 44 Aeromonas spp. strains were isolated and tested for antibiotic susceptibility and heavy metal tolerance followed by PCR-based detection of resistance genes and integrons. It was observed that resistance to ampicillin and oxacillin was 100% among isolates. Besides, 95%, 89%, 86%, 80%, 66%, and 43% of the isolates were resistant to nalidixic acid, tetracycline, cephalothin, streptomycin, trimethoprim-sulfamethoxazole, and imipenem, respectively, and less resistance to other antibiotics was also observed. Cr resistance was the highest (91%) among five heavy metals tested, whereas 57%, 32%, 20%, and 9% of the isolates were tolerant to Cu, Pb, Cd, and Hg, respectively. The PCR assays implied the presence of qnrB, qnrS, tetA, tetE, aac(6')-Ib, and aphAI-IAB, and intI1 genes among 80%, 77%, 18%, 30%, 9%, 0.25%, and 82% of the isolates, respectively. There were 35 (80%) integron 1-positive isolates harboring qacE2, dfrA1, orfC, orfD, aadB, catB3, oxa-10, and aadA1 genes in varying combinations. In addition, heavy metal resistance genes, CopA, merA, and CzcA were positive in 9%, 7%, and 27% of the isolates, respectively. According to these outcomes, the frozen white-leg shrimp in Korean markets can be suggested as a source of multidrug and heavy metal-resistant Aeromonas spp. that carries genetic determinants.

WNT5A-JNK regulation of vascular insulin resistance in human obesity.

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Farb, Melissa G; Karki, Shakun; Park, Song-Young; Saggese, Samantha M; Carmine, Brian; Hess, Donald T; Apovian, Caroline; Fetterman, Jessica L; Bretón-Romero, Rosa; Hamburg, Naomi M; Fuster, José J; Zuriaga, María A; Walsh, Kenneth; Gokce, Noyan

2016-12-01

Obesity is associated with the development of vascular insulin resistance; however, pathophysiological mechanisms are poorly understood. We sought to investigate the role of WNT5A-JNK in the regulation of insulin-mediated vasodilator responses in human adipose tissue arterioles prone to endothelial dysfunction. In 43 severely obese (BMI 44±11 kg/m 2 ) and five metabolically normal non-obese (BMI 26±2 kg/m 2 ) subjects, we isolated arterioles from subcutaneous and visceral fat during planned surgeries. Using videomicroscopy, we examined insulin-mediated, endothelium-dependent vasodilator responses and characterized adipose tissue gene and protein expression using real-time polymerase chain reaction and Western blot analyses. Immunofluorescence was used to quantify endothelial nitric oxide synthase (eNOS) phosphorylation. Insulin-mediated vasodilation was markedly impaired in visceral compared to subcutaneous vessels from obese subjects (p<0.001), but preserved in non-obese individuals. Visceral adiposity was associated with increased JNK activation and elevated expression of WNT5A and its non-canonical receptors, which correlated negatively with insulin signaling. Pharmacological JNK antagonism with SP600125 markedly improved insulin-mediated vasodilation by sixfold (p<0.001), while endothelial cells exposed to recombinant WNT5A developed insulin resistance and impaired eNOS phosphorylation (p<0.05). We observed profound vascular insulin resistance in the visceral adipose tissue arterioles of obese subjects that was associated with up-regulated WNT5A-JNK signaling and impaired endothelial eNOS activation. Pharmacological JNK antagonism markedly improved vascular endothelial function, and may represent a potential therapeutic target in obesity-related vascular disease. © The Author(s) 2016.

Independent associations of insulin resistance with high whole-body intermuscular and low leg subcutaneous adipose tissue distribution in obese HIV-infected women123

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Albu, Jeanine B; Kenya, Sonjia; He, Qing; Wainwright, Marsha; Berk, Evan S; Heshka, Stanley; Kotler, Donald P; Engelson, Ellen S

2009-01-01

Background Obesity and insulin resistance are growing problems in HIV-positive (HIV+) women receiving highly active antiretroviral therapy (HAART). Objective The objective was to determine the contribution of adipose tissue (AT) enlargement and distribution to the presence of insulin resistance in obese HIV+ women. Design Whole-body intermuscular AT (IMAT), visceral AT (VAT), subcutaneous AT (SAT), and SAT distribution (leg versus upper body) were measured by whole-body magnetic resonance imaging. Insulin sensitivity (SI) was measured with an intravenous glucose tolerance test in obese HIV+ women recruited because of their desire to lose weight (n = 17) and in obese healthy controls (n = 32). Results The HIV+ women had relatively less whole-body SAT and more VAT and IMAT than did the controls (P < 0.05 for all). A significant interaction by HIV status was observed for the relation of total SAT with SI (P < 0.001 for the regression’s slope interactions after adjustment for age, height, and weight). However, relations of IMAT, VAT, and SAT distribution (leg SAT as a percentage of total SAT; leg SAT%) with SI did not differ significantly between groups. For both groups combined, the best model predicting a low SI included significant contributions by both high IMAT and low leg SAT%, independent of age, height, and weight, and no interaction between groups was observed (overall r2 = 0.44, P = 0.0003). Conclusion In obese HIV+ women, high whole-body IMAT and low leg SAT% distribution are independently associated with insulin resistance. PMID:17616768

Peripheral Vascular Resistance Impairment during Isometric Physical Exercise in Normotensive Offspring of Hypertensive Parents.

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Portela, Natália; Amaral, Josária Ferraz; Mira, Pedro Augusto de Carvalho; Souza, Livia Victorino de; Martinez, Daniel Godoy; Laterza, Mateus Camaroti

2017-07-10

A family history of hypertension is associated with vascular and autonomic abnormalities, as well as an impaired neurohemodynamic response to exercise. To test the hypothesis that normotensive individuals with a family history of hypertension present an impaired peripheral vascular resistance response to exercise. The study included 37 normotensive volunteers of both sexes who were sedentary, eutrophic, and nonsmokers, comprising 23 with (FH+; 24 ± 3 years) and 14 without (FH-; 27 ± 5 years) a family history of hypertension. Blood pressure, heart rate (DIXTAL®), forearm blood flow (Hokanson®), and peripheral vascular resistance were simultaneously measured for 3 minutes during rest and, subsequently, for 3 minutes during an isometric exercise at 30% of maximal voluntary contraction (Jamar®). At rest, the FH+ and FH- groups present similar mean blood pressure (83 ± 7 versus 83 ± 5 mmHg, p = 0.96), heart rate (69 ± 8 bpm versus 66 ± 7 bpm, p = 0.18), forearm blood flow (3 ± 1 mL/min/100 mL versus 2.7 ± 1 mL/min/100 mL, p = 0.16), and peripheral vascular resistance (30 ± 9 units versus 34±9 units, p = 0.21), respectively. Both groups showed a significant and similar increase in mean blood pressure (∆ = 15 ± 7 mmHg versus 14 ± 7 mmHg, p = 0.86), heart rate (∆ = 12 ± 8 bpm versus 13 ± 7 bpm, p = 0.86), and forearm blood flow (∆ = 0.8 ± 1.2 mL/min/100 mL versus 1.4 ± 1.1 mL/min/100 mL, p = 0.25), respectively, during exercise. However, individuals in the FH+ group showed no reduction in peripheral vascular resistance during exercise, which was observed in the FH- group (∆ = -0.4 ± 8.6 units versus -7.2 ± 6.3 units, p = 0.03). Normotensive individuals with a family history of hypertension present an impaired peripheral vascular resistance response to exercise. O histórico familiar para hipertensão arterial está relacionado a anormalidades vasculares e autonômicas, bem como disfunções no comportamento neuro-hemodinâmico durante o exerc

Arterial stiffness and peripheral vascular resistance in offspring of hypertensive parents

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Buus, Niels Henrik; Carlsen, Rasmus K; Khatir, Dinah S

2018-01-01

AIM: Established essential hypertension is associated with increased arterial stiffness and peripheral resistance, but the extent of vascular changes in persons genetically predisposed for essential hypertension is uncertain. METHODS: Participants from the Danish Hypertension Prevention Project...... (DHyPP) (both parents hypertensive) (n = 95, 41 ± 1 years, 53% men) were compared with available spouses (n = 45, 41 ± 1 years) using measurements of ambulatory blood pressure (BP), left ventricular mass index (LVMI), pulse wave velocity, central BP and augmentation index (AIx) in addition to forearm...... than men (P hypertension display increased AIx and LVMI, although vascular stiffness...

Maximal muscular vascular conductances during whole body upright exercise in humans

DEFF Research Database (Denmark)

Calbet, J A L; Jensen-Urstad, M; Van Hall, Gerrit

2004-01-01

76% of VO(2,max) and at VO(2,max) with different techniques: diagonal stride (combined arm and leg exercise), double poling (predominantly arm exercise) and leg skiing (predominantly leg exercise). During submaximal exercise cardiac output (26-27 l min(-1)), mean blood pressure (MAP) (approximately......That muscular blood flow may reach 2.5 l kg(-1) min(-1) in the quadriceps muscle has led to the suggestion that muscular vascular conductance must be restrained during whole body exercise to avoid hypotension. The main aim of this study was to determine the maximal arm and leg muscle vascular...... (VO(2,max)) 5.1 +/- 0.1 l min(-1) participated in the study. Femoral and subclavian vein blood flows, intra-arterial blood pressure, cardiac output, as well as blood gases in the femoral and subclavian vein, right atrium and femoral artery were determined during skiing (roller skis) at approximately...

Multidrug-Resistant Candida haemulonii and C. auris, Tel Aviv, Israel

OpenAIRE

Ben-Ami, Ronen; Berman, Judith; Novikov, Ana; Bash, Edna; Shachor-Meyouhas, Yael; Zakin, Shiri; Maor, Yasmin; Tarabia, Jalal; Schechner, Vered; Adler, Amos; Finn, Talya

2017-01-01

Candida auris and C. haemulonii are closely related, multidrug-resistant emerging fungal pathogens that are not readily distinguishable with phenotypic assays. We studied C. auris and C. haemulonii clinical isolates from 2 hospitals in central Israel. C. auris was isolated in 5 patients with nosocomial bloodstream infection, and C. haemulonii was found as a colonizer of leg wounds at a peripheral vascular disease clinic. Liberal use of topical miconazole and close contact among patients were ...

Erythropoietin resistance in end-stage renal disease patient with gastric antral vascular ectasia

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Desiree Ji Re Lee

2015-09-01

Full Text Available AbstractWe observed a case of recombinant human erythropoietin resistance caused by Gastric Antral Vascular Ectasia in a 40-year-old female with ESRD on hemodialysis. Some associated factors such as autoimmune disease, hemolysis, heart and liver disease were discarded on physical examination and complementary tests. The diagnosis is based on the clinical history and endoscopic appearance of watermelon stomach. The histologic findings are fibromuscular proliferation and capillary ectasia with microvascular thrombosis of the lamina propria. However, these histologic findings are not necessary to confirm the diagnosis. Gastric Antral Vascular Ectasia is a serious condition and should be considered in ESRD patients on hemodialysis with anemia and resistance to recombinant human erythropoietin because GAVE is potentially curable with specific endoscopic treatment method or through surgical procedure.

Successful Use of Vacuum-Assisted Closure Therapy for Leg Ulcers Caused by Occluding Vasculopathy and Inflammatory Vascular Diseases - A Case Series

OpenAIRE

Zutt, Markus; Haas, Ellen; Krüger, Ullrich; Distler, Meike; Neumann, Christine

2007-01-01

Background: Leg ulcers caused by vasculitis, small vessel occlusion or other rare conditions often prove to be very difficult to treat. Despite polypragmatic, systemic and localized therapy, many of these wounds are progressive and characterized by severe pain. Methods and Results: We here portray the cases of 5 patients with ulcers resistant to systemic therapy for the underlying disease, who were treated successfully using vacuum-assisted closure (VAC) for wound mana...

Hemodynamic effect and safety of intermittent sequential pneumatic compression leg sleeves in patients with congestive heart failure.

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Bickel, Amitai; Shturman, Alexander; Sergeiev, Michael; Ivry, Shimon; Eitan, Arieh; Atar, Shaul

2014-10-01

Pneumatic leg sleeves are widely used after prolonged operations for prevention of venous stasis. In healthy volunteers they increase cardiac function. We evaluated the hemodynamic effects and safety of intermittent sequential pneumatic compression (ISPC) leg sleeves in patients with chronic congestive heart failure (CHF). We studied 19 patients with systolic left ventricular dysfunction and CHF. ISPC leg sleeves, each with 10 air cells, were operated by a computerized compressor, exerting 2 cycles/min. Hemodynamic and echocardiographic parameters were measured before, during, and after ISPC activation. The baseline mean left ventricular ejection fraction was 29 ± 9.2%, median 32%, range 10%-40%. Cardiac output (from 4.26 to 4.83 L/min; P = .008) and stroke volume (from 56.1 to 63.5 mL; P = .029) increased significantly after ISPC activation, without a reciprocal increase in heart rate, and declined after sleeve deactivation. Systemic vascular resistance (SVR) decreased significantly (from 1,520 to 1,216 dyne-s/cm5; P = .0005), and remained lower than the baseline level throughout the study. There was no detrimental effect on diastolic function and no adverse clinical events, despite increased pulmonary venous return. ISPC leg sleeves in patients with chronic CHF do not exacerbate symptoms and transiently improve cardiac output through an increase in stroke volume and a reduction in SVR. Copyright © 2014 Elsevier Inc. All rights reserved.

Diffusion tensor imaging, intracranial vascular resistance and cognition in middle-aged asymptomatic subjects.

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López-Olóriz, Jorge; López-Cancio, Elena; Arenillas, Juan F; Hernández, María; Dorado, Laura; Dacosta-Aguayo, Rosalía; Barrios, Maite; Soriano-Raya, Juan José; Miralbell, Júlia; Bargalló, Núria; Cáceres, Cynthia; Torán, Pere; Alzamora, Maite; Dávalos, Antonio; Mataró, Maria

2014-01-01

The contribution of traditional vascular risk factors to cognitive impairment and dementia is well known. However, in order to obtain possible targets for prevention of vascular cognitive impairment (VCI), it may be important to identify other early and noninvasive markers in asymptomatic middle-aged adults. The calculation of middle cerebral artery-pulsatility index (MCA-PI) is an ultrasonologic, noninvasive, validated and easily reproducible technique to assess increased distal resistance to blood flow. This study aims to assess the relationship between MCA-PI, microstructural white matter (WM) integrity and cognition in a middle-aged asymptomatic population. Ninety-five participants from the Barcelona-Asymptomatic Intracranial Atherosclerosis (AsIA) neuropsychology study were included. Subjects were 50-65 years old, free from dementia and without history of vascular disease. Transcranial color-coded duplex ultrasound examination was performed to assess MCA-PI as a measure of vascular resistance. WM integrity was evaluated by fractional anisotropy (FA) measurements of diffusion tensor images (DTI) acquired on a 3T-MRI. The neuropsychological battery was specifically selected to be sensitive to VCI, and included tests that were grouped into six cognitive domains: executive functioning, attention, verbal fluency, memory, visuospatial skills and psychomotor speed. A multivariate linear regression model adjusted for age, gender, years of education, diabetes and hypertension was performed. MCA-PI was significantly associated with WM disintegration in different tracts (fornix, corticospinal and anterior thalamic), all p gender, years of education, and vascular risk factors (all p cognitive domains, except for visuospatial skills. Our data suggest that MCA-PI may be related to WM disintegration and early vascular cognitive impairment in middle-aged subjects. Although further prospective studies are needed to provide evidence for its validity in longitudinal studies, our

Probenecid inhibits α-adrenergic receptor-mediated vasoconstriction in the human leg vasculature

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Nyberg, Michael Permin; Piil, Peter Bergmann; Kiehn, Oliver Thistrup

2018-01-01

to α1- and α2-adrenergic receptor stimulation in the human forearm and leg vasculature of young healthy male subjects (23±3 years). By use of immunolabeling and confocal microscopy, Panx1 channels were found to be expressed in vascular smooth muscle cells of arterioles in human leg skeletal muscle....... Probenecid treatment increased (Padrenergic receptor stimulation) by ≈15%, whereas the response to the α1-agonist phenylephrine was unchanged. Inhibition...

Endocrine factors related to changes in total peripheral vascular resistance after treatment of thyrotoxic and hypothyroid patients

NARCIS (Netherlands)

Diekman, M. J.; Harms, M. P.; Endert, E.; Wieling, W.; Wiersinga, W. M.

2001-01-01

Total peripheral vascular resistance (TPR) decreases in thyrotoxicosis and increases in hypothyroidism. Several mechanisms may be involved, including adaptation to changes in heat production and direct non-genomic effects of tri-iodothyronine (T3) on vascular smooth muscle cells. The aim of this

The role of inflammation in vascular insulin resistance with focus on IL-6

DEFF Research Database (Denmark)

Andersen, Kirsten; Pedersen, B.K.

2008-01-01

The present review focuses on the possible role of interleukin-(IL)-6 in vascular insulin resistance. The endothelium plays an important role in regulating the tone of the vasculature by releasing nitric oxide (NO) to the smooth muscles of the vessels, thereby regulating the distribution of blood....... It is likely that chronic low-level inflammation plays an important role in developing endothelial dysfunction mainly through proinflammatory actions of tumor necrosis factor alpha (TNF-alpha). TNF-alpha induces production of IL-6 and it has been suggested that a causal relationship exists between endothelial...... dysfunction and these cytokines. With regard to vascular insulin resistance, the available data point to a direct pathogenic role of TNF-alpha in mediating endothelial dysfunction, whereas with regard to IL-6 evidence is sparse and does not allow any firm conclusions Udgivelsesdato: 2008/9...

Hemodynamic comparison of mild and severe preeclampsia: concept of stroke systemic vascular resistance index.

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Scardo, J; Kiser, R; Dillon, A; Brost, B; Newman, R

1996-01-01

Our purpose was to compare baseline hemodynamic parameters of mild and severe preeclampsia. Patients admitted to the Medical University Labor and Delivery Unit with the diagnosis of preeclampsia who had not received prior antihypertensive or magnesium sulfate therapy were recruited for noninvasive hemodynamic monitoring with thoracic electrical bioimpedance. After stabilization in the lateral recumbent position, hemodynamic monitoring was begun. Baseline hemodynamic parameters, mean arterial pressure (MAP), heart rate (HR), systemic vascular resistance index (SVRI), cardiac index (CI), and stroke index (SI) were recorded. Stroke systemic vascular resistance index (SSVRI), the resistance imposed by vasculature on each beat of the heart, was calculated for each patient by multiplying SVRI by HR. For statistical analysis, unpaired Student's t-tests (two-tailed) were utilized (P preclampsia appears to be a more intensely vasoconstricted state than mild preeclampsia. Although CI is inversely proportional to SVRI, increased HR in severe preeclampsia prevents this expected decrease in cardiac output.

Combined whole-body vibration, resistance exercise, and sustained vascular occlusion increases PGC-1α and VEGF mRNA abundances.

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Item, Flurin; Nocito, Antonio; Thöny, Sandra; Bächler, Thomas; Boutellier, Urs; Wenger, Roland H; Toigo, Marco

2013-04-01

We previously reported that high load resistance exercise with superimposed whole-body vibration and sustained vascular occlusion (vibroX) markedly improves cycling endurance capacity, increases capillary-to-fibre ratio and skeletal muscle oxidative enzyme activity in untrained young women. These findings are intriguing, since increases in oxidative muscle phenotype and endurance capacity are typically induced by endurance but not heavy resistance exercise. Here, we tested the hypothesis that vibroX activates genes associated with mitochondrial biogenesis and angiogenesis. Eight healthy, recreationally resistance-trained young men performed either vibroX or resistance exercise (RES) in a randomised, cross-over design. Needle biopsies (M. vastus lateralis) were obtained at rest and 3 h post-exercise. Changes in relative gene expression levels were assessed by real-time quantitative PCR. After vibroX, vascular endothelial growth factor and peroxisome proliferator-activated receptor-γ coactivator 1α mRNA abundances increased to 2- and 4.4-fold, respectively, but did not significantly change above resting values after RES. Other genes involved in mitochondrial biogenesis were not affected by either exercise modality. While vibroX increased the expression of hexokinase II, xanthine dehydrogenase, and manganese superoxide dismutase mRNA, there were no changes in these transcripts after RES. This study demonstrates that high load resistance exercise with superimposed whole-body vibration and sustained vascular occlusion activates metabolic and angiogenic gene programs, which are usually activated after endurance but not resistance exercise. Thus, targeted modification of high load resistance exercise by vibration and vascular occlusion might represent a novel strategy to induce endurance-type muscle adaptations.

a-Adrenergic vasoconstrictor responsiveness is preserved in the heated human leg

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Keller, David M; Sander, Mikael; Stallknecht, Bente Merete

2010-01-01

This study tested the hypothesis that passive leg heating attenuates a-adrenergic vasoconstriction within that limb. Femoral blood flow (FBF, femoral artery ultrasound Doppler) and femoral vascular conductance (FVC, FBF/mean arterial blood pressure), as well as calf muscle blood flow (Calf...

The Effects of High-Intensity versus Low-Intensity Resistance Training on Leg Extensor Power and Recovery of Knee Function after ACL-Reconstruction

DEFF Research Database (Denmark)

Bieler, Theresa; Sobol, Nanna Aue; Andersen, Lars L

2014-01-01

OBJECTIVE: Persistent weakness is a common problem after anterior cruciate ligament- (ACL-) reconstruction. This study investigated the effects of high-intensity (HRT) versus low-intensity (LRT) resistance training on leg extensor power and recovery of knee function after ACL-reconstruction. METH...

Leptin receptor blockade reduces intrahepatic vascular resistance and portal pressure in an experimental model of rat liver cirrhosis.

Science.gov (United States)

Delgado, María Gabriela; Gracia-Sancho, Jordi; Marrone, Giusi; Rodríguez-Vilarrupla, Aina; Deulofeu, Ramon; Abraldes, Juan G; Bosch, Jaume; García-Pagán, Juan Carlos

2013-10-01

Increased hepatic vascular resistance mainly due to elevated vascular tone and to fibrosis is the primary factor in the development of portal hypertension in cirrhosis. Leptin, a hormone associated with reduction in nitric oxide bioavailability, vascular dysfunction, and liver fibrosis, is increased in patients with cirrhosis. We aimed at evaluating whether leptin influences the increased hepatic resistance in portal hypertension. CCl4-cirrhotic rats received the leptin receptor-blocker ObR antibody, or its vehicle, every other day for 1 wk. Hepatic and systemic hemodynamics were measured in both groups. Hepatic nitric oxide production and bioavailability, together with oxidative stress, nitrotyrosinated proteins, and liver fibrosis, were evaluated. In cirrhotic rats, leptin-receptor blockade significantly reduced portal pressure without modifying portal blood flow, suggesting a reduction in the intrahepatic resistance. Portal pressure reduction was associated with increased nitric oxide bioavailability and with decreased O2(-) levels and nitrotyrosinated proteins. No changes in systemic hemodynamics and liver fibrosis were observed. In conclusion, the present study shows that blockade of the leptin signaling pathway in cirrhosis significantly reduces portal pressure. This effect is probably due to a nitric oxide-mediated reduction in the hepatic vascular tone.

Impaired autonomic regulation of resistance arteries in mice with low vascular endothelial growth factor or upon vascular endothelial growth factor trap delivery

DEFF Research Database (Denmark)

Storkebaum, Erik; Ruiz de Almodovar, Carmen; Meens, Merlijn

2010-01-01

BACKGROUND: Control of peripheral resistance arteries by autonomic nerves is essential for the regulation of blood flow. The signals responsible for the maintenance of vascular neuroeffector mechanisms in the adult, however, remain largely unknown. METHODS AND RESULTS: Here, we report that VEGF( ...

Acute impact of intermittent pneumatic leg compression frequency on limb hemodynamics, vascular function, and skeletal muscle gene expression in humans.

Science.gov (United States)

Sheldon, Ryan D; Roseguini, Bruno T; Thyfault, John P; Crist, Brett D; Laughlin, M H; Newcomer, Sean C

2012-06-01

The mechanisms by which intermittent pneumatic leg compression (IPC) treatment effectively treats symptoms associated with peripheral artery disease remain speculative. With the aim of gaining mechanistic insight into IPC treatment, the purpose of this study was to investigate the effect of IPC frequency on limb hemodynamics, vascular function, and skeletal muscle gene expression. In this two study investigation, healthy male subjects underwent an hour of either high-frequency (HF; 2-s inflation/3-s deflation) or low-frequency (LF; 4-s inflation/16-s deflation) IPC treatment of the foot and calf. In study 1 (n = 11; 23.5 ± 4.7 yr), subjects underwent both HF and LF treatment on separate days. Doppler/ultrasonography was used to measure popliteal artery diameter and blood velocity at baseline and during IPC treatment. Flow-mediated dilation (FMD) and peak reactive hyperemia blood flow (RHBF) were determined before and after IPC treatment. In study 2 (n = 19; 22.0 ± 4.6 yr), skeletal muscle biopsies were taken from the lateral gastrocnemius of the treated and control limb at baseline and at 30- and 150-min posttreatment. Quantitative PCR was used to assess mRNA concentrations of genes associated with inflammation and vascular remodeling. No treatment effect on vascular function was observed. Cuff deflation resulted in increased blood flow (BF) and shear rate (SR) in both treatments at the onset of treatment compared with baseline (P < 0.01). BF and SR significantly diminished by 45 min of HF treatment only (P < 0.01). Both treatments reduced BF and SR and elevated oscillatory shear index compared with baseline (P < 0.01) during cuff inflation. IPC decreased the mRNA expression of cysteine-rich protein 61 from baseline and controls (P <0 .01) and connective tissue growth factor from baseline (P < 0.05) in a frequency-dependent manner. In conclusion, a single session of IPC acutely impacts limb hemodynamics and skeletal muscle gene expression in a frequency

Tributyltin chloride increases phenylephrine-induced contraction and vascular stiffness in mesenteric resistance arteries from female rats

International Nuclear Information System (INIS)

Ribeiro Júnior, Rogério Faustino; Marques, Vinicius Bermond; Nunes, Dieli Oliveira; Ronconi, Karoline de Sousa; Araújo, Julia F.P. de; Rodrigues, Paula Lopes; Padilha, Alessandra Simão; Vassallo, Dalton Valentim; Graceli, Jones B.; Stefanon, Ivanita

2016-01-01

Tributyltin chloride (TBT) is an organotin compound that reduces estrogen levels in female rats. We aimed to investigate the effects of TBT exposure on vascular tonus and vascular remodelling in the resistance arteries of female rats. Rats were treated daily with TBT (500 ng/kg) for 15 days. TBT did not change arterial blood pressure but did modify some morpho-physiological parameters of third-order mesenteric resistance arteries in the following ways: (1) decreased lumen and external diameters; (2) increased wall/lm ratio and wall thickness; (3) decreased distensibility and increased stiffness; (4) increased collagen deposition; and (5) increased pulse wave velocity. TBT exposure increased the phenylephrine-induced contractile response in mesenteric resistance arteries. However, vasodilatation responses induced by acetylcholine and sodium nitroprusside were not modified by TBT. It is suggested that TBT exposure reduces vascular nitric oxide (NO) production, because:(1) L-NAME incubation did not cause a leftward shift in the concentration–response curve for phenylephrine; (2) both eNOS protein expression; (3) in situ NO production were reduced. Incubation with L-NAME; and (4) SOD shifted the phenylephrine response curve to the left in TBT rats. Tiron, catalase, ML-171 and VAS2870 decreased vascular reactivity to phenylephrine only in TBT rats. Moreover, increased superoxide anion production was observed in the mesenteric resistance arteries of TBT rats accompanied by an increase in gp91phox, catalase, AT 1 receptor and total ERK1/2 protein expression. In conclusion, these findings show that TBT induced alterations are most likely due to a reduction of NO production combined with increased O 2 − production derived from NADPH oxidase and ERK1/2 activation. These findings offer further evidence that TBT is an environmental risk factor for cardiovascular disease. - Highlights: • Tributyltin chloride reduces estrogen levels in female rats. • Treatment with TBT

Tributyltin chloride increases phenylephrine-induced contraction and vascular stiffness in mesenteric resistance arteries from female rats

Energy Technology Data Exchange (ETDEWEB)

Ribeiro Júnior, Rogério Faustino, E-mail: rogeriofaustinoribeiro@hotmail.com [Department of Physiological Sciences, Federal University of Espirito Santo, Vitoria, ES (Brazil); Marques, Vinicius Bermond; Nunes, Dieli Oliveira; Ronconi, Karoline de Sousa [Department of Physiological Sciences, Federal University of Espirito Santo, Vitoria, ES (Brazil); Araújo, Julia F.P. de [Department of Morphology, Federal University of Espírito Santo (Brazil); Rodrigues, Paula Lopes; Padilha, Alessandra Simão; Vassallo, Dalton Valentim [Department of Physiological Sciences, Federal University of Espirito Santo, Vitoria, ES (Brazil); Graceli, Jones B. [Department of Morphology, Federal University of Espírito Santo (Brazil); Stefanon, Ivanita [Department of Physiological Sciences, Federal University of Espirito Santo, Vitoria, ES (Brazil)

2016-03-15

Tributyltin chloride (TBT) is an organotin compound that reduces estrogen levels in female rats. We aimed to investigate the effects of TBT exposure on vascular tonus and vascular remodelling in the resistance arteries of female rats. Rats were treated daily with TBT (500 ng/kg) for 15 days. TBT did not change arterial blood pressure but did modify some morpho-physiological parameters of third-order mesenteric resistance arteries in the following ways: (1) decreased lumen and external diameters; (2) increased wall/lm ratio and wall thickness; (3) decreased distensibility and increased stiffness; (4) increased collagen deposition; and (5) increased pulse wave velocity. TBT exposure increased the phenylephrine-induced contractile response in mesenteric resistance arteries. However, vasodilatation responses induced by acetylcholine and sodium nitroprusside were not modified by TBT. It is suggested that TBT exposure reduces vascular nitric oxide (NO) production, because:(1) L-NAME incubation did not cause a leftward shift in the concentration–response curve for phenylephrine; (2) both eNOS protein expression; (3) in situ NO production were reduced. Incubation with L-NAME; and (4) SOD shifted the phenylephrine response curve to the left in TBT rats. Tiron, catalase, ML-171 and VAS2870 decreased vascular reactivity to phenylephrine only in TBT rats. Moreover, increased superoxide anion production was observed in the mesenteric resistance arteries of TBT rats accompanied by an increase in gp91phox, catalase, AT{sub 1} receptor and total ERK1/2 protein expression. In conclusion, these findings show that TBT induced alterations are most likely due to a reduction of NO production combined with increased O{sub 2}{sup −} production derived from NADPH oxidase and ERK1/2 activation. These findings offer further evidence that TBT is an environmental risk factor for cardiovascular disease. - Highlights: • Tributyltin chloride reduces estrogen levels in female rats. �

Relationship between the shoot characteristics and plant resistance to vascular-streak dieback on cocoa

Directory of Open Access Journals (Sweden)

Agung Wahyu Soesilo

2014-12-01

Full Text Available Vascular-streak dieback (Oncobasidium theobromae is a serious disease on cocoa damaging the vegetative tissue especially on the branches and leaves. This research was aimed to identify the relationship between characteristics of sprouting ability and VSD resistance to confirm the response of cocoa to pruning treatment on VSD control and developing criteria for selection. Trial was carried out at Kaliwining Experimental Station of ICCRI, a VSD-endemic area by using 668 plants of hybrid populayion which were derivated from intercrossing among seven clones performing different response to VSD. The resistance was evaluated by scoring the plant damage with the scale of 0-6 on drought season in the year of 2009 and 2011. The characteristics of sprouting ability was assessed by recording the pruned trees for the variables of the number of re-growth shoot, shoot height, number of new shoot per pruned branches, shoot diameter and number of leaves per shoot. It was analyzed that the variables of the number of shoot per pruned branches, shoot diameter, shoot height and number of leaves per shoot were not significantly correlated to the score of VSD damage. Grouping of the resistance also performed similar results whereas mean of the sprouting variables were not different among group but the percentage of sprouted branches tend to be higher with the higher of the resistance (lower score. This result confirmed any mechanism of tolerance on VSD resistance by accelerating shoot rejuvenation on resistant plant. Key words : vascular-streak diaback, cocoa, resistance, characteristics of sprouting

Are left ventricular mass, geometry and function related to vascular changes and/or insulin resistance in long-standing hypertension? ICARUS: a LIFE substudy

DEFF Research Database (Denmark)

Olsen, M H; Hjerkinn, E; Wachtell, K

2003-01-01

Vascular hypertrophy and insulin resistance have been associated with abnormal left ventricular (LV) geometry in population studies. We wanted to investigate the influence of vascular hypertrophy and insulin resistance on LV hypertrophy and its function in patients with hypertension. In 89 patients...

Tributyltin chloride increases phenylephrine-induced contraction and vascular stiffness in mesenteric resistance arteries from female rats.

Science.gov (United States)

Ribeiro Júnior, Rogério Faustino; Marques, Vinicius Bermond; Nunes, Dieli Oliveira; Ronconi, Karoline de Sousa; de Araújo, Julia F P; Rodrigues, Paula Lopes; Padilha, Alessandra Simão; Vassallo, Dalton Valentim; Graceli, Jones B; Stefanon, Ivanita

2016-03-15

Tributyltin chloride (TBT) is an organotin compound that reduces estrogen levels in female rats. We aimed to investigate the effects of TBT exposure on vascular tonus and vascular remodelling in the resistance arteries of female rats. Rats were treated daily with TBT (500 ng/kg) for 15 days. TBT did not change arterial blood pressure but did modify some morpho-physiological parameters of third-order mesenteric resistance arteries in the following ways: (1) decreased lumen and external diameters; (2) increased wall/lm ratio and wall thickness; (3) decreased distensibility and increased stiffness; (4) increased collagen deposition; and (5) increased pulse wave velocity. TBT exposure increased the phenylephrine-induced contractile response in mesenteric resistance arteries. However, vasodilatation responses induced by acetylcholine and sodium nitroprusside were not modified by TBT. It is suggested that TBT exposure reduces vascular nitric oxide (NO) production, because:(1) L-NAME incubation did not cause a leftward shift in the concentration-response curve for phenylephrine; (2) both eNOS protein expression; (3) in situ NO production were reduced. Incubation with L-NAME; and (4) SOD shifted the phenylephrine response curve to the left in TBT rats. Tiron, catalase, ML-171 and VAS2870 decreased vascular reactivity to phenylephrine only in TBT rats. Moreover, increased superoxide anion production was observed in the mesenteric resistance arteries of TBT rats accompanied by an increase in gp91phox, catalase, AT1 receptor and total ERK1/2 protein expression. In conclusion, these findings show that TBT induced alterations are most likely due to a reduction of NO production combined with increased O2(-) production derived from NADPH oxidase and ERK1/2 activation. These findings offer further evidence that TBT is an environmental risk factor for cardiovascular disease. Copyright © 2016 Elsevier Inc. All rights reserved.

Pulmonary vascular input impedance is a combined measure of pulmonary vascular resistance and stiffness and predicts clinical outcomes better than pulmonary vascular resistance alone in pediatric patients with pulmonary hypertension.

Science.gov (United States)

Hunter, Kendall S; Lee, Po-Feng; Lanning, Craig J; Ivy, D Dunbar; Kirby, K Scott; Claussen, Lori R; Chan, K Chen; Shandas, Robin

2008-01-01

Pulmonary vascular resistance (PVR) is the current standard for evaluating reactivity in children with pulmonary arterial hypertension (PAH). However, PVR measures only the mean component of right ventricular afterload and neglects pulsatile effects. We recently developed and validated a method to measure pulmonary vascular input impedance, which revealed excellent correlation between the zero harmonic impedance value and PVR and suggested a correlation between higher-harmonic impedance values and pulmonary vascular stiffness. Here we show that input impedance can be measured routinely and easily in the catheterization laboratory, that impedance provides PVR and pulmonary vascular stiffness from a single measurement, and that impedance is a better predictor of disease outcomes compared with PVR. Pressure and velocity waveforms within the main pulmonary artery were measured during right heart catheterization of patients with normal pulmonary artery hemodynamics (n = 14) and those with PAH undergoing reactivity evaluation (49 subjects, 95 conditions). A correction factor needed to transform velocity into flow was obtained by calibrating against cardiac output. Input impedance was obtained off-line by dividing Fourier-transformed pressure and flow waveforms. Exceptional correlation was found between the indexed zero harmonic of impedance and indexed PVR (y = 1.095x + 1.381, R2 = 0.9620). In addition, the modulus sum of the first 2 harmonics of impedance was found to best correlate with indexed pulse pressure over stroke volume (y = 13.39x - 0.8058, R2 = 0.7962). Among a subset of patients with PAH (n = 25), cumulative logistic regression between outcomes to total indexed impedance was better (R(L)2 = 0.4012) than between outcomes and indexed PVR (R(L)2 = 0.3131). Input impedance can be consistently and easily obtained from pulse-wave Doppler and a single catheter pressure measurement, provides comprehensive characterization of the main components of RV afterload, and

Successful use of vacuum-assisted closure therapy for leg ulcers caused by occluding vasculopathy and inflammatory vascular diseases--a case series.

Science.gov (United States)

Zutt, Markus; Haas, Ellen; Kruger, Ullrich; Distler, Meike; Neumann, Christine

2007-01-01

Leg ulcers caused by vasculitis, small vessel occlusion or other rare conditions often prove to be very difficult to treat. Despite polypragmatic, systemic and localized therapy, many of these wounds are progressive and characterized by severe pain. We here portray the cases of 5 patients with ulcers resistant to systemic therapy for the underlying disease, who were treated successfully using vacuum-assisted closure (VAC) for wound management. We present the advantages and disadvantages of this method, as well as illustrating the essential and known therapeutic principles. Our experience shows VAC to be an excellent and effective alternative in the treatment of therapy-resistant chronic wounds caused by vasculopathy (small vessel occlusion or vasculitis). We did not observe any pathergy or proinflammatory effects caused by VAC. 2007 S. Karger AG, Basel

The Role of Complex Treatment in Mixed Leg Ulcers - A Case Report of Vascular, Surgical and Physical Therapy.

Science.gov (United States)

Wollina, Uwe; Heinig, Birgit; Stelzner, Christian; Hansel, Gesina; Schönlebe, Jacqueline; Tchernev, Georgi; Lotti, Torello

2018-01-25

Leg ulcers are a burden to patients, their families and society. The second most common cause of chronic leg ulcers is the mixed arterio-venous type. An 80-year-old female patient presented to our department due to painful enlarging chronic leg ulcer of mixed arteriovenous origin on her left lower leg. She suffered from peripheral arterial occlusive disease stage I and chronic venous insufficiency Widmer grade IIIa, and a number of comorbidities. The aim of our ulcer treatment was a complete and stable wound closure that was hampered by arterial occlusion, exposed tendon, and renal insiffuciency. To improve the prognosis for ulcer surgery, we performed percutaneous transluminal angioplasty, transcutaneous CO 2 and deep ulcer shaving. The wound was closed by sandwich transplantation using elastin-collagen dermal template and meshed split skin graft. She had a 100% graft take with rapid reduction of severe wound pain. Complex approaches are necessary, to gain optimum results in leg ulcer therapy in mixed leg ulcers. Therapeutic nihilism should be abandonend.

Effects of One Resistance Exercise Session on Vascular Smooth Muscle of Hypertensive Rats

International Nuclear Information System (INIS)

Silva, Tharciano Luiz Teixeira Braga da; Mota, Marcelo Mendonça; Fontes, Milene Tavares; Araújo, João Eliakim dos Santos; Carvalho, Vitor Oliveira; Bonjardim, Leonardo Rigoldi; Santos, Márcio Roberto Viana

2015-01-01

Hypertension is a public health problem and increases the incidence of cardiovascular diseases. To evaluate the effects of a resistance exercise session on the contractile and relaxing mechanisms of vascular smooth muscle in mesenteric arteries of N G -nitro L-arginine methyl ester (L-NAME)-induced hypertensive rats. Wistar rats were divided into three groups: control (C), hypertensive (H), and exercised hypertensive (EH). Hypertension was induced by administration of 20 mg/kg of L-NAME for 7 days prior to experimental protocols. The resistance exercise protocol consisted of 10 sets of 10 repetitions and intensity of 40% of one repetition maximum. The reactivity of vascular smooth muscle was evaluated by concentration‑response curves to phenylephrine (PHEN), potassium chloride (KCl) and sodium nitroprusside (SNP). Rats treated with L-NAME showed an increase (p < 0.001) in systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) compared to the initial period of induction. No difference in PHEN sensitivity was observed between groups H and EH. Acute resistance exercise reduced (p < 0.001) the contractile response induced by KCl at concentrations of 40 and 60 mM in group EH. Greater (p < 0.01) smooth muscle sensitivity to NPS was observed in group EH as compared to group H. One resistance exercise session reduces the contractile response induced by KCl in addition to increasing the sensitivity of smooth muscle to NO in mesenteric arteries of hypertensive rats

Effects of One Resistance Exercise Session on Vascular Smooth Muscle of Hypertensive Rats

Energy Technology Data Exchange (ETDEWEB)

Silva, Tharciano Luiz Teixeira Braga da; Mota, Marcelo Mendonça; Fontes, Milene Tavares; Araújo, João Eliakim dos Santos; Carvalho, Vitor Oliveira; Bonjardim, Leonardo Rigoldi; Santos, Márcio Roberto Viana, E-mail: marciorvsantos@bol.com.br [Universidade Federal de Sergipe, Universidade de São Paulo (Brazil)

2015-08-15

Hypertension is a public health problem and increases the incidence of cardiovascular diseases. To evaluate the effects of a resistance exercise session on the contractile and relaxing mechanisms of vascular smooth muscle in mesenteric arteries of N{sup G}-nitro L-arginine methyl ester (L-NAME)-induced hypertensive rats. Wistar rats were divided into three groups: control (C), hypertensive (H), and exercised hypertensive (EH). Hypertension was induced by administration of 20 mg/kg of L-NAME for 7 days prior to experimental protocols. The resistance exercise protocol consisted of 10 sets of 10 repetitions and intensity of 40% of one repetition maximum. The reactivity of vascular smooth muscle was evaluated by concentration‑response curves to phenylephrine (PHEN), potassium chloride (KCl) and sodium nitroprusside (SNP). Rats treated with L-NAME showed an increase (p < 0.001) in systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) compared to the initial period of induction. No difference in PHEN sensitivity was observed between groups H and EH. Acute resistance exercise reduced (p < 0.001) the contractile response induced by KCl at concentrations of 40 and 60 mM in group EH. Greater (p < 0.01) smooth muscle sensitivity to NPS was observed in group EH as compared to group H. One resistance exercise session reduces the contractile response induced by KCl in addition to increasing the sensitivity of smooth muscle to NO in mesenteric arteries of hypertensive rats.

Effects of One Resistance Exercise Session on Vascular Smooth Muscle of Hypertensive Rats

Directory of Open Access Journals (Sweden)

Tharciano Luiz Teixeira Braga da Silva

2015-01-01

Full Text Available Abstract Background: Hypertension is a public health problem and increases the incidence of cardiovascular diseases. Objective: To evaluate the effects of a resistance exercise session on the contractile and relaxing mechanisms of vascular smooth muscle in mesenteric arteries of NG-nitro L-arginine methyl ester (L-NAME-induced hypertensive rats. Methods: Wistar rats were divided into three groups: control (C, hypertensive (H, and exercised hypertensive (EH. Hypertension was induced by administration of 20 mg/kg of L-NAME for 7 days prior to experimental protocols. The resistance exercise protocol consisted of 10 sets of 10 repetitions and intensity of 40% of one repetition maximum. The reactivity of vascular smooth muscle was evaluated by concentration‑response curves to phenylephrine (PHEN, potassium chloride (KCl and sodium nitroprusside (SNP. Results: Rats treated with L-NAME showed an increase (p < 0.001 in systolic blood pressure (SBP, diastolic blood pressure (DBP and mean arterial pressure (MAP compared to the initial period of induction. No difference in PHEN sensitivity was observed between groups H and EH. Acute resistance exercise reduced (p < 0.001 the contractile response induced by KCl at concentrations of 40 and 60 mM in group EH. Greater (p < 0.01 smooth muscle sensitivity to NPS was observed in group EH as compared to group H. Conclusion: One resistance exercise session reduces the contractile response induced by KCl in addition to increasing the sensitivity of smooth muscle to NO in mesenteric arteries of hypertensive rats.

The α and Δ isoforms of CREB1 are required to maintain normal pulmonary vascular resistance.

Directory of Open Access Journals (Sweden)

Lili Li

Full Text Available Chronic hypoxia causes pulmonary hypertension associated with structural alterations in pulmonary vessels and sustained vasoconstriction. The transcriptional mechanisms responsible for these distinctive changes are unclear. We have previously reported that CREB1 is activated in the lung in response to alveolar hypoxia but not in other organs. To directly investigate the role of α and Δ isoforms of CREB1 in the regulation of pulmonary vascular resistance we examined the responses of mice in which these isoforms of CREB1 had been inactivated by gene mutation, leaving only the β isoform intact (CREB(αΔ mice. Here we report that expression of CREB regulated genes was altered in the lungs of CREB(αΔ mice. CREB(αΔ mice had greater pulmonary vascular resistance than wild types, both basally in normoxia and following exposure to hypoxic conditions for three weeks. There was no difference in rho kinase mediated vasoconstriction between CREB(αΔ and wild type mice. Stereological analysis of pulmonary vascular structure showed characteristic wall thickening and lumen reduction in hypoxic wild-type mice, with similar changes observed in CREB(αΔ. CREB(αΔ mice had larger lungs with reduced epithelial surface density suggesting increased pulmonary compliance. These findings show that α and Δ isoforms of CREB1 regulate homeostatic gene expression in the lung and that normal activity of these isoforms is essential to maintain low pulmonary vascular resistance in both normoxic and hypoxic conditions and to maintain the normal alveolar structure. Interventions that enhance the actions of α and Δ isoforms of CREB1 warrant further investigation in hypoxic lung diseases.

Body Size Predicts Cardiac and Vascular Resistance Effects on Men's and Women's Blood Pressure

Directory of Open Access Journals (Sweden)

Joyce M. Evans

2017-08-01

Full Text Available Key Points SummaryWe report how blood pressure, cardiac output and vascular resistance are related to height, weight, body surface area (BSA, and body mass index (BMI in healthy young adults at supine rest and standing.Much inter-subject variability in young adult's blood pressure, currently attributed to health status, may actually result from inter-individual body size differences.Each cardiovascular variable is linearly related to height, weight and/or BSA (more than to BMI.When supine, cardiac output is positively related, while vascular resistance is negatively related, to body size. Upon standing, the change in vascular resistance is positively related to size.The height/weight relationships of cardiac output and vascular resistance to body size are responsible for blood pressure relationships to body size.These basic components of blood pressure could help distinguish normal from abnormal blood pressures in young adults by providing a more effective scaling mechanism.Introduction: Effects of body size on inter-subject blood pressure (BP variability are not well established in adults. We hypothesized that relationships linking stroke volume (SV, cardiac output (CO, and total peripheral resistance (TPR with body size would account for a significant fraction of inter-subject BP variability.Methods: Thirty-four young, healthy adults (19 men, 15 women participated in 38 stand tests during which brachial artery BP, heart rate, SV, CO, TPR, and indexes of body size were measured/calculated.Results: Steady state diastolic arterial BP was not significantly correlated with any index of body size when subjects were supine. However, upon standing, the more the subject weighed, or the taller s/he was, the greater the increase in diastolic pressure. Systolic pressure strongly correlated with body weight and height both supine and standing. Diastolic and systolic BP were more strongly related to height, weight and body surface area than to body mass

[Localized purpura revealing vascular prosthetic graft infection].

Science.gov (United States)

Boureau, A S; Lescalie, F; Cassagnau, E; Clairand, R; Connault, J

2013-07-01

Prosthetic graft infection after vascular reconstruction is a rare but serious complication. We report a case of infection occurring late after implantation of an iliofemoral prosthetic vascular graft. The Staphylococcus aureus infection was revealed by vascular purpura localized on the right leg 7 years after implantation of a vascular prosthesis. This case illustrates an uncommonly late clinical manifestation presenting as an acute infection 7 years after the primary operation. In this situation, the presentation differs from early infection, which generally occurs within the first four postoperative months. Diagnosis and treatment remain a difficult challenge because prosthetic graft infection is a potentially life-threatening complication. Morbidity and mortality rates are high. Here we detail specific aspects of the clinical and radiological presentation. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Ultrasonography of Skin Changes in Legs with Chronic Venous Disease.

Science.gov (United States)

Caggiati, A

2016-10-01

In daily practice, ultrasonography (US) is used only to designate the location and pattern of venous lesions. Skin US is not performed between routine venous investigations. Skin morphology is evaluated by the same probes used for routine Duplex evaluation of superficial veins. US findings from evident skin lesions are comparatively evaluated with those from the surrounding apparently normal skin and from the contralateral leg. Inflammation and dermal edema can be found in the apparently normal skin of C2 legs. Swollen legs show thickening of the subcutaneous layer as a result of diffuse soaking or anechoic cavities, with or without dermal edema. Chronic hypodermitis is characterized by inflammatory edema in initial phases, and by liposclerosis in advanced cases. Recrudescence of inflammation provokes focal rarefactions of the subcutaneous layer, possibly related to ulcer opening. In legs with venous disorders, sonography refines clinical evaluation of the skin and may reveal changes not highlighted by inspection. Some of these changes could require further investigation because they have not yet been explained or described. Skin sonography should improve knowledge of the natural history of skin changes, as well as contribute to a better grading of venous diseases severity In particular, US evidence of cutaneous and subcutaneous changes in C2 legs should be considered to stratify the treatment in C2 legs, by identifying those in which varicose veins are not simply a cosmetic problem. Copyright © 2016 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Hypertrophic osteoarthropathy of one leg - a sign of aortic graft infection

Energy Technology Data Exchange (ETDEWEB)

Spruijt, S.; Krijgsman, A.A. [Department of Orthopaedic and Trauma Surgery, Elkerliek Hospital, Helmond (Netherlands); Broek, J.A.C. van den [Department of Radiology, Elkerliek Hospital, Helmond (Netherlands); Tutein Nolthenius-Puylaert, M.C.B.J.E. [Department of Pathology, Elkerliek Hospital, Helmond (Netherlands)

1999-04-01

We report a rare case of hypertrophic osteoarthropathy (HOA) confined to the right leg secondary to aortic graft infection. The development of HOA exclusively localized to areas distal to a vascular prosthesis may be the presenting manifestation of graft infection and a crucial diagnostic clue in the early detection of vascular graft infection. HOA is diagnosed by its characteristic radiographic and scintigraphic pattern. Most prosthetic, especially aortic, graft infections are uniformly fatal if not treated by aggressive surgical and antibiotic therapy. Recognition of this uncommon association may facilitate an early diagnosis, which usually requires immediate surgical therapy. (orig.) With 6 figs., 28 refs.

Hypertrophic osteoarthropathy of one leg - a sign of aortic graft infection

International Nuclear Information System (INIS)

Spruijt, S.; Krijgsman, A.A.; Broek, J.A.C. van den; Tutein Nolthenius-Puylaert, M.C.B.J.E.

1999-01-01

We report a rare case of hypertrophic osteoarthropathy (HOA) confined to the right leg secondary to aortic graft infection. The development of HOA exclusively localized to areas distal to a vascular prosthesis may be the presenting manifestation of graft infection and a crucial diagnostic clue in the early detection of vascular graft infection. HOA is diagnosed by its characteristic radiographic and scintigraphic pattern. Most prosthetic, especially aortic, graft infections are uniformly fatal if not treated by aggressive surgical and antibiotic therapy. Recognition of this uncommon association may facilitate an early diagnosis, which usually requires immediate surgical therapy. (orig.)

Maximal muscular vascular conductances during whole body upright exercise in humans

Science.gov (United States)

Calbet, J A L; Jensen-Urstad, M; van Hall, G; Holmberg, H -C; Rosdahl, H; Saltin, B

2004-01-01

That muscular blood flow may reach 2.5 l kg−1 min−1 in the quadriceps muscle has led to the suggestion that muscular vascular conductance must be restrained during whole body exercise to avoid hypotension. The main aim of this study was to determine the maximal arm and leg muscle vascular conductances (VC) during leg and arm exercise, to find out if the maximal muscular vasodilatory response is restrained during maximal combined arm and leg exercise. Six Swedish elite cross-country skiers, age (mean ± s.e.m.) 24 ± 2 years, height 180 ± 2 cm, weight 74 ± 2 kg, and maximal oxygen uptake (V̇O2,max) 5.1 ± 0.1 l min−1 participated in the study. Femoral and subclavian vein blood flows, intra-arterial blood pressure, cardiac output, as well as blood gases in the femoral and subclavian vein, right atrium and femoral artery were determined during skiing (roller skis) at ∼76% of V̇O2,max and at V̇O2,max with different techniques: diagonal stride (combined arm and leg exercise), double poling (predominantly arm exercise) and leg skiing (predominantly leg exercise). During submaximal exercise cardiac output (26–27 l min−1), mean blood pressure (MAP) (∼87 mmHg), systemic VC, systemic oxygen delivery and pulmonary V̇O2 (∼4 l min−1) attained similar values regardless of exercise mode. The distribution of cardiac output was modified depending on the musculature engaged in the exercise. There was a close relationship between VC and V̇O2 in arms (r = 0.99, P arm VC (63.7 ± 5.6 ml min−1 mmHg−1) was attained during double poling, while peak leg VC was reached at maximal exercise with the diagonal technique (109.8 ± 11.5 ml min−1 mmHg−1) when arm VC was 38.8 ± 5.7 ml min−1 mmHg−1. If during maximal exercise arms and legs had been vasodilated to the observed maximal levels then mean arterial pressure would have dropped at least to 75–77 mmHg in our experimental conditions. It is concluded that skeletal muscle vascular conductance is

Prognostic Value of Pulmonary Vascular Resistance by Magnetic Resonance in Systolic Heart Failure

OpenAIRE

Fabregat-Andrés, Óscar; Estornell-Erill, Jordi; Ridocci-Soriano, Francisco; Pérez-Boscá, José Leandro; García-González, Pilar; Payá-Serrano, Rafael; Morell, Salvador; Cortijo, Julio

2016-01-01

Abstract Background: Pulmonary hypertension is associated with poor prognosis in heart failure. However, non-invasive diagnosis is still challenging in clinical practice. Objective: We sought to assess the prognostic utility of non-invasive estimation of pulmonary vascular resistances (PVR) by cardiovascular magnetic resonance to predict adverse cardiovascular outcomes in heart failure with reduced ejection fraction (HFrEF). Methods: Prospective registry of patients with left ventricular e...

[When to ask for a skin biopsy in a patient with leg ulcer? Retrospective study of 143 consecutive biopsies].

Science.gov (United States)

Stansal, A; Khayat, K; Duchatelle, V; Tella, E; Gautier, V; Sfeir, D; Attal, R; Lazareth, I; Priollet, P

2018-02-01

A vascular cause is found in around 85% of leg ulcer patients, but non-vascular causes are also observed. Their diagnosis is based on a set of clinical arguments and skin biopsy with histological analysis. The aim of this study was to analyze the results of these biopsies and to find common criteria for ulcers whose skin biopsies had led to the diagnosis of a non-vascular ulcer. A retrospective study was carried out on the analysis of 143 skin biopsies of leg ulcers. The reasons for the biopsy were mainly atypical clinical signs and/or the lack of improvement in care after 6 months, as advocated by the French health authorities. The skin biopsies led to a diagnosis of non-vascular ulcer in 4.9% of cases (7/143), including skin cancer (n=5, 3.5%), cutaneous leishmaniasis (n=1, 0.7%) and Pyoderma gangrenosum (n=1, 0.7%). The univariate statistical analysis revealed that an elevated rim and abnormal excessive granulation tissue were significantly more frequently found in these ulcers. All patients with a positive skin biopsy had associated vascular involvement. This study found a 5% rate of non-vascular causes of ulcers, mainly skin cancer. Elevated rims and abnormal excessive granulation tissue were the unusual features most commonly found in these ulcers. All patients whose skin biopsy revealed a non-vascular cause had associated vascular involvement. This information confirms the need to perform a skin biopsy, even in the presence of a vascular disease. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Evaluation of Thermoelectric Performance and Durability of Functionalized Skutterudite Legs

Science.gov (United States)

Skomedal, Gunstein; Kristiansen, Nils R.; Sottong, Reinhard; Middleton, Hugh

2017-04-01

Thermoelectric generators are a promising technology for waste heat recovery. As new materials and devices enter a market penetration stage, it is of interest to employ fast and efficient measurement methods to evaluate the long-term stability of thermoelectric materials in combination with metallization and coating (functionalized thermoelectric legs). We have investigated a method for measuring several thermoelectric legs simultaneously. The legs are put under a common temperature gradient, and the electrical characteristics of each leg are measured individually during thermal cycling. Using this method, one can test different types of metallization and coating applied to skutterudite thermoelectric legs and look at the relative changes over time. Postcharacterization of these initial tests with skutterudite legs using a potential Seebeck microprobe and an electron microscope showed that oxidation and interlayer diffusion are the main reasons for the gradual increase in internal resistance and the decrease in open-circuit voltage. Although we only tested skutterudite material in this work, the method is fully capable of testing all kinds of material, metallization, and coating. It is thus a promising method for studying the relationship between failure modes and mechanisms of functionalized thermoelectric legs.

Age related changes in tumor vascularity

International Nuclear Information System (INIS)

Loerelius, L.E.; Stridbeck, H.

1984-01-01

VX 2 tumors in the rabbit hind leg were investigated at one, two and three weeks of age. Angiograms were compared with vascular casts. The tumors grew rapidly the first two weeks of age. Large variations in vascularity were noted between tumors of different ages. With increasing age arteriovenous shunts at the tumor periphery and areas of avascularity of necrosis in the tumor center increased in size. Possible reasons for tumor necrosis are increased tissue pressure, anoxia caused by arteriovenous shunts and elevation in venous pressure. The natural history of the VX 2 tumor must be considered in every experimental study of the effect of any treatment. (orig.)

[Applied anatomy study and clinical application of great saphenous veno-saphenous neurocutaneous vascular flap].

Science.gov (United States)

Li, Zelong; Ding, Zihai; Wang, Peixin; Xie, Yibo; Zeng, Bo

2006-03-01

To provide the anatomic basis for defect repair of the knee, leg, foot and ankle with great saphenous veno-saphenous neurocutaneous vascular island flaps. The origin, diameter, branches, distribution and anastomoses of the saphenous artery and saphenous neurocutaneous vascular were observed on 20 sides of adult leg specimens and 4 fresh cadaver voluntary legs. Another 4 fresh cadaver voluntary legs were radiographed with a soft X-ray system after the intravenous injection of Vermilion and cross-sections under profound fascial, other hand, micro-anatomic examination was also performed in these 4 fresh cadaver legs. The soft tissue defects in lower extremity, upper extremity, heel or Hucou in hand were repaired with the proximal or distal pedicle flaps or free flaps in 18 patients (12 males and 6 females,aging from 7 to 53 years). The defect was caused by trauma, tumour, ulcer and scar. The locations were Hucou (1 case), upper leg (3 cases), lower extremity and heal (14 cases). Of then, 7 cases were complicated by bone exposure, 3 cases by tendon exposure and 1 case by steel espouse, the defect size were 4 cm x 4 cm to 7 cm x 13 cm. The flap sizes were 4 cm x 6 cm to 8 cm x 15 cm, which pedicle length was 8-11 cm with 2.5-4.0 cm fascia and 1-2 cm skin at width. Genus descending genicular artery began from 9.33 +/- 0.81 cm away from upper the condyles medialis, it branched saphenous artery accompanying saphenous nerve descendent. And saphenous artery reached the surface of the skin 7.21 +/- 0.82 cm away from lower the condyles medialis, and anastomosed with the branches of tibialis posterior artery, like "Y" or "T" pattern. The chain linking system of arteries were found accompanying along the great saphenous vein as saphenous nerve, and then a axis blood vessel was formed. The small artery of only 0.05-0.10 mm in diameter, distributed around the great saphenous vein within 5-8 mm and arranged parallelly along the vein like water wave in soft X-ray film. All proximal

Evidence for a local sympathetic venoarteriolar "reflex" in the dog hindleg

DEFF Research Database (Denmark)

Henriksen, O; Amtorp, O; Faris, I

1983-01-01

24%. In subcutaneous tissue, vascular resistance decreased by 12%. The effect of acute lumbar sympathectomy was studied in another group of seven dogs. Operation caused an immediate decrease in vascular resistance of 40%. The increase in vascular resistance during venous stasis in the total leg......, as well as in muscle and subcutaneous tissue, was not affected. However, acute lumbar sympathectomy combined with injection of phenoxybenzamine into the femoral artery almost abolished the vasoconstriction induced by venous stasis. In muscle, the increase in vascular resistance was still present...

Compartment syndrome and popliteal vascular injury complicating unicompartmental knee arthroplasty

NARCIS (Netherlands)

Kort, Nanne Pieter; Van Raay, Jos J. J. A. M.; van Horn, Jim R.

Popliteal vascular injury and the compartment syndrome of the leg are rare but important complications of knee arthroplasties. Early diagnosis and treatment are of paramount importance in preventing the devastating complications of these conditions. To our knowledge, these complications have not

Men exhibit greater fatigue resistance than women in alternated bench press and leg press exercises.

Science.gov (United States)

Monteiro, Estêvão R; Steele, James; Novaes, Jefferson S; Brown, Amanda F; Cavanaugh, Mark T; Vingren, Jakob L; Behm, David G

2017-11-17

The purpose of this study was to evaluate the influence of sex, exercise order, and rest interval on neuromuscular fatigue resistance for an alternated strength training sequence of bench press (BP) and leg press (LP) exercises. Twelve women and 16 men, both recreationally trained, performed four sessions in a random order: 1) BP followed by LP with three-minutes rest (BP+LP with rest), 2) LP followed by BP with three-minutes rest (LP+BP with rest), 3) BP followed by LP without rest interval (BP+LP no rest), and 4) LP followed by BP without rest interval (LP+BP no rest). Participants performed four sets with 100% of 10RM load to concentric failure with the goal of completing the maximum number of repetitions in both exercises. The fatigue index was analyzed from the first and last sets of each exercise bout. A main effect for sex showed that women exhibited 25.5% (p=0.001) and 24.5% (p=0.001) greater BP and LP fatigue than men respectively when performing 10RM. Men exhibited greater BP (p<0.0001; 34.1%) and LP (p<0.0001; 30.5%) fatigue resistance when a rest period was provided. Men did not show an exercise order effect for BP fatigue and exhibited greater (p=0.0003; 14.5%) LP fatigue resistance when BP was performed first. The present study demonstrated the greater fatigue resistance of men when performing 10RM BP and LP exercises. Since men tend to experience less fatigue with the second exercise in the exercise pairing, women's training programs should be adjusted to ensure they do not parallel men's resistance training programs.

High performance p-type segmented leg of misfit-layered cobaltite and half-Heusler alloy

International Nuclear Information System (INIS)

Hung, Le Thanh; Van Nong, Ngo; Snyder, G. Jeffrey; Viet, Man Hoang; Balke, Benjamin; Han, Li; Stamate, Eugen; Linderoth, Søren; Pryds, Nini

2015-01-01

Highlights: • p-type segmented leg of oxide and half-Heusler was for the first time demonstrated. • The maximum conversion efficiency reached a value of about 5%. • The results are among the highest reported values so far for oxide-based legs. • Oxide-based segmented leg is very promising for generating electricity. - Abstract: In this study, a segmented p-type leg of doped misfit-layered cobaltite Ca 2.8 Lu 0.15 Ag 0.05 Co 4 O 9+δ and half-Heusler Ti 0.3 Zr 0.35 Hf 0.35 CoSb 0.8 Sn 0.2 alloy was fabricated and characterized. The thermoelectric properties of single components, segmented leg, and the electrical contact resistance of the joint part were measured as a function of temperature. The output power generation characteristics of segmented legs were characterized in air under various temperature gradients, ΔT, with the hot side temperature up to 1153 K. At ΔT ≈ 756 K, the maximum conversion efficiency reached a value of ∼5%, which is about 65% of that expected from the materials without parasitic losses. The long-term stability investigation for two weeks at the hot and cold side temperatures of 1153/397 K shows that the segmented leg has good durability as a result of stable and low electrical resistance contacts

Relationship between Leg Mass, Leg Composition and Foot Velocity on Kicking Accuracy in Australian Football.

Science.gov (United States)

Hart, Nicolas H; Nimphius, Sophia; Spiteri, Tania; Cochrane, Jodie L; Newton, Robert U

2016-06-01

Kicking a ball accurately over a desired distance to an intended target is arguably the most important skill to acquire in Australian Football. Therefore, understanding the potential mechanisms which underpin kicking accuracy is warranted. The aim of this study was to examine the relationship between leg mass, leg composition and foot velocity on kicking accuracy in Australian Football. Thirty-one Australian Footballers (n = 31; age: 22.1 ± 2.8 years; height: 1.81 ± 0.07 m; weight: 85.1 ± 13.0 kg; BMI: 25.9 ± 3.2) each performed ten drop punt kicks over twenty metres to a player target. Athletes were separated into accurate (n = 15) and inaccurate (n = 16) kicking groups. Leg mass characteristics were assessed using whole body DXA scans. Foot velocity was determined using a ten-camera optoelectronic, three-dimensional motion capture system. Interactions between leg mass and foot velocity evident within accurate kickers only (r = -0.670 to -0.701). Relative lean mass was positively correlated with kicking accuracy (r = 0.631), while no relationship between foot velocity and kicking accuracy was evident in isolation (r = -0.047 to -0.083). Given the evident importance of lean mass, and its interaction with foot velocity for accurate kickers; future research should explore speed-accuracy, impulse-variability, limb co-ordination and foot-ball interaction constructs in kicking using controlled with-in subject studies to examine the effects of resistance training and skill acquisition programs on the development of kicking accuracy. Key pointsAccurate kickers expressed a very strong inverse relationship between leg mass and foot velocity. Inaccurate kickers were unable to replicate this, with greater volatility in their performance, indicating an ability of accurate kickers to mediate foot velocity to compensate for leg mass in order to deliver the ball over the required distance.Accurate kickers exhibited larger quantities of relative lean mass and lower quantities

Endothelial mechanotransduction proteins and vascular function are altered by dietary sucrose supplementation in healthy young male subjects.

Science.gov (United States)

Gliemann, Lasse; Rytter, Nicolai; Lindskrog, Mads; Slingsby, Martina H Lundberg; Åkerström, Thorbjörn; Sylow, Lykke; Richter, Erik A; Hellsten, Ylva

2017-08-15

Mechanotransduction in endothelial cells is a central mechanism in the regulation of vascular tone and vascular remodelling Mechanotransduction and vascular function may be affected by high sugar levels in plasma because of a resulting increase in oxidative stress and increased levels of advanced glycation end-products (AGE). In healthy young subjects, 2 weeks of daily supplementation with 3 × 75 g of sucrose was found to reduce blood flow in response to passive lower leg movement and in response to 12 W of knee extensor exercise. This vascular impairment was paralleled by up-regulation of platelet endothelial cell adhesion molecule (PECAM)-1, endothelial nitric oxide synthase, NADPH oxidase and Rho family GTPase Rac1 protein expression, an increased basal phosphorylation status of vascular endothelial growth factor receptor 2 and a reduced phosphorylation status of PECAM-1. There were no measurable changes in AGE levels. The findings of the present study demonstrate that daily high sucrose intake markedly affects mechanotransduction proteins and has a detrimental effect on vascular function. Endothelial mechanotransduction is important for vascular function but alterations and activation of vascular mechanosensory proteins have not been investigated in humans. In endothelial cell culture, simple sugars effectively impair mechanosensor proteins. To study mechanosensor- and vascular function in humans, 12 young healthy male subjects supplemented their diet with 3 × 75 g sucrose day -1 for 14 days in a randomized cross-over design. Before and after the intervention period, the hyperaemic response to passive lower leg movement and active knee extensor exercise was determined by ultrasound doppler. A muscle biopsy was obtained from the thigh muscle before and after acute passive leg movement to allow assessment of protein amounts and the phosphorylation status of mechanosensory proteins and NADPH oxidase. The sucrose intervention led to a reduced flow

Evaluation and percutaneous management of atherosclerotic peripheral vascular disease

International Nuclear Information System (INIS)

Widlus, D.M.; Osterman, F.A. Jr.

1989-01-01

Atherosclerotic peripheral vascular disease (PVD) of the lower extremities deprives a person of the ability to exercise to their satisfaction, later of the ability to perform the activities of their daily life, and finally of their legs themselves. Peripheral vascular disease has long been managed by the vascular surgeon utilizing endarterectomy and peripheral arterial bypass. Patient acceptance of nonsurgical, percutaneous procedures such as percutaneous transluminal balloon angioplasty (PTA) is high. Increased utilization of these procedures has led to improved techniques and adjuncts to therapy, as well as more critical review of long-term results. This article will review the evaluation and nonoperative management of PVD, with an emphasis on the newer modalities of management presently being investigated

Terpene Profile, Leaf Anatomy, and Enzyme Activity of Resistant and Susceptible Cocoa Clonesto Vascular Streak Dieback Disease

Directory of Open Access Journals (Sweden)

Adi Prawoto

2014-10-01

Full Text Available Vascular-streak dieback (VSD, Oncobasidium theobromae is the most prevalent disease of Theobroma cacao L. in Indonesia. This study aims to analyze resistance mechanism to VSD based on terpene profile, leaf anatomy, chitinase, and peroxidase study. Resistant clones of Sulawesi 1 and Sca 6 and susceptible clones of ICS 60 and TSH 858 were used for terpene profile, leaf anatomy analysis, chitinase, peroxides, polyphenol, lignin, and cellulose analysis. Those clones and KEE 2, KKM 22 and ICS 13 were used for peroxides analysis. For trichome study, the resistant clones of Sulawesi 1, Sca 6, KEE 2, and KKM 22, and susceptible clones of ICS 60 and TSH 858 were used. GCMS analysis showed that chromatogram pattern of resistant and susceptible groups were quite similar, but resistant clones contained 22% more components than the susceptible ones. Resistant clones contained groups of pinene, decane, myrcene, and octadecanoic acid, while those substances on usceptible clones were absent. Trichome was thicker on younger leaf, and its density on the basal was higher than that on the middle and tip leaf parts. Trichome density of resistant clone was not always thicker than that of susceptible ones. On resistant clones, stomatal density was lower and width of stomate pits was narrower, while thickness of epidermis layer and pallisade parenchym were higher. Polyphenol content of resistant clones were higher but lignin and cellulose of both groups were similar. Chitinase activity which has a role in hydrolysis of mycelia cell wall was higher on the resistant clones, but peroxides which has a role in polymeration of lignin biosynthesis was similar between both groups. It is concluded that groups of terpene pinene, decane, myrcene, and octadecanoic acid, thickness of leaf epidermis, density and width of stomata pit, and chitinase activity plays important role in cocoa resistance to VSD. Key words: Theobroma cacaoL., clone, vascular-streak dieback, resistance, leaf

Muscle Activity in Single- vs. Double-Leg Squats.

Science.gov (United States)

DeFOREST, Bradley A; Cantrell, Gregory S; Schilling, Brian K

Muscular activity, vertical displacement and ground reaction forces of back squats (BS), rear-leg elevated split squats (RLESS) and split squats (SS) were examined. Nine resistance-trained men reported for two sessions. The first session consisted of the consent process, practice, and BS 1-repetition maximum testing. In the second session, participants performed the three exercises while EMG, displacment and ground reaction force data (one leg on plate) were collected. EMG data were collected from the gluteus maximus (GMX), biceps femoris (BF), semitendinosus (ST), rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM), tibialis anterior (TA), and medial gastrocnemius (MGas) of the left leg (non-dominant, front leg for unilateral squats). Load for BS was 85% one repetition maximum, and RLESS and SS were performed at 50% of BS load. Repeated measures ANOVA was used to compare all variables for the three exercises, with Bonferroni adjustments for post hoc multiple comparisons, in addition to calculation of standardized mean differences (ES). Muscle activity was similar between exercises except for biceps femoris, which was significantly higher during RLESS than SS during both concentric and eccentric phases (ES = 2.11; p=0.012 and ES= 2.19; p=0.008), and significantly higher during BS than the SS during the concentric phase (ES = 1.78; p=0.029). Vertical displacement was similar between all exercises. Peak vertical force was similar between BS and RLESS and significantly greater during RLESS than SS (ES = 3.03; p=0.001). These findings may be helpful in designing resistance training programs by using RLESS if greater biceps femoris activity is desired.

Relationship between Leg Mass, Leg Composition and Foot Velocity on Kicking Accuracy in Australian Football

Directory of Open Access Journals (Sweden)

Nicolas H. Hart, Jodie L. Cochrane, Tania Spiteri, Sophia Nimphius, Robert U. Newton

2016-06-01

Full Text Available Kicking a ball accurately over a desired distance to an intended target is arguably the most important skill to acquire in Australian Football. Therefore, understanding the potential mechanisms which underpin kicking accuracy is warranted. The aim of this study was to examine the relationship between leg mass, leg composition and foot velocity on kicking accuracy in Australian Football. Thirty-one Australian Footballers (n = 31; age: 22.1 ± 2.8 years; height: 1.81 ± 0.07 m; weight: 85.1 ± 13.0 kg; BMI: 25.9 ± 3.2 each performed ten drop punt kicks over twenty metres to a player target. Athletes were separated into accurate (n = 15 and inaccurate (n = 16 kicking groups. Leg mass characteristics were assessed using whole body DXA scans. Foot velocity was determined using a ten-camera optoelectronic, three-dimensional motion capture system. Interactions between leg mass and foot velocity evident within accurate kickers only (r = -0.670 to -0.701. Relative lean mass was positively correlated with kicking accuracy (r = 0.631, while no relationship between foot velocity and kicking accuracy was evident in isolation (r = -0.047 to -0.083. Given the evident importance of lean mass, and its interaction with foot velocity for accurate kickers; future research should explore speed-accuracy, impulse-variability, limb co-ordination and foot-ball interaction constructs in kicking using controlled with-in subject studies to examine the effects of resistance training and skill acquisition programs on the development of kicking accuracy.

Vascular resistance of central retinal artery is reduced in postmenopausal women after use of estrogen.

Science.gov (United States)

Faria, Alice Fátima Melgaço; de Souza, Marco Aurélio Martins; Geber, Selmo

2011-08-01

The aim of this study was to evaluate the effect of estrogen on the vascular resistance of the central retinal artery in postmenopausal women, compared with placebo, using transorbital ultrasound with Doppler velocimetry. We performed a prospective, randomized, triple-blinded placebo-controlled study. A total of 51 healthy postmenopausal women (follicle-stimulating hormone, >40 IU/L) with a mean (SD) age of 53.6 (4.8) years were studied. Participants were randomly allocated into two groups: placebo (n = 23) and estrogen (0.625 mg conjugated estrogens; n = 28). Transorbital Doppler velocimetric ultrasound was performed before and after treatment in sitting and supine positions. The mean age was similar in both groups. The pulsatility index of the central retinal arteries had a significant decrease after the use of estrogen, when women were evaluated in the sitting position. Women who received placebo did not show any difference in pulsatility index of the central retinal arteries after treatment. When the same comparison was done with participants in the supine position, no difference was observed in either group. Our study demonstrates that estrogen reduces the vascular resistance of the central retinal artery in postmenopausal women because of a vasodilatory effect.

Vascular thermal adaptation in tumors and normal tissue in rats

International Nuclear Information System (INIS)

Nah, Byung Sik; Choi, Ihl-Bohng; Oh, Won Young; Osborn, James L.; Song, Chang W.

1996-01-01

Purpose: The vascular thermal adaptation in the R3230 adenocarcinoma, skin and muscle in the legs of Fischer rats was studied. Methods and Materials: The legs of Fischer rats bearing the R3230 AC adenocarcinoma (subcutaneously) were heated once or twice with a water bath, and the blood flow in the tumor, skin and muscle of the legs was measured with the radioactive microsphere method. Results: The blood flow in control R3230 AC tumors was 23.9 ml/100 g/min. The tumor blood flow increased about 1.5 times in 30 min and then markedly decreased upon heating at 44.5 deg. C for 90 min. In the tumors preheated 16 h earlier at 42.5 deg. C for 60 min, reheating at 44.5 deg. C increased the tumor blood flow by 2.5-fold in 30 min. Contrary to the decline in blood flow following an initial increase during the 44.5 deg. C heating without preheating, the tumor blood flow remained elevated throughout the 90 min reheating at 44.5 deg. C. These results indicated that thermal adaptation or thermotolerance developed in the tumor vasculatures after the preheating at 42.5 deg. C for 60 min. The magnitude of vascular thermal adaptation in the tumors 24 h and 48 h after the preheating, as judged from the changes in blood flow, were smaller than that 16 h after the preheating. Heating at 42.5 deg. C for 60 min induced vascular thermal adaptation also in the skin and muscle, which peaked in 48 h and 24 h, respectively, after the heating. Conclusion: Heating at 42.5 deg. C for 1 h induced vascular thermal adaptation in the R3230 AC tumor, skin, and muscle of rats that peaked 16-48 h after the heating. When the tumor blood vessels were thermally adapted, the tumor blood flow increased upon heating at temperatures that would otherwise reduce the tumor blood flow. Such an increase in tumor blood flow may hinder raising the tumor temperature while it may increase tumor oxygenation.

The effect of starting or stopping skin cooling on the thermoregulatory responses during leg exercise in humans.

Science.gov (United States)

Demachi, K; Yoshida, T; Kume, M; Tsuneoka, H

2012-07-01

To assess the effects of starting or stopping leg cooling on the thermoregulatory responses during exercise, 60 min of cycling exercise at 30% of maximal oxygen uptake was performed under 4 conditions using tube trouser perfused with water at 10 °C; no leg cooling (NC), starting of leg cooling after 30 min of exercise (delayed cooling, DC), continuous leg cooling (CC), and stopping of continuous leg cooling after 30 min of exercise (SC) at an environmental temperature of 28.5 °C. During exercise under the DC conditions, an instantaneous increase in the esophageal temperature (Tes), a suppression of the cutaneous vascular conductance at the forearm (%CVC), and a decrease in the mean skin temperature (Tsk) were observed after leg cooling. The total sweat loss (Δm sw,tot) was lower under the DC than the NC condition. In the SC study, however, the Tes remained constant, while the %CVC increased gradually after leg cooling was stopped, and the Δm sw,tot was greater than that under the CC condition. These results suggest that during exercise, rapid skin cooling of the leg may cause an increase in core temperature, while also enhancing thermal stress. However, stopping skin cooling did not significantly affect the core temperature long-term, because the skin blood flow and sweat rate subsequently increased. © Georg Thieme Verlag KG Stuttgart · New York.

The incidence and characterization of deep vein thrombosis following ultrasound-guided foam sclerotherapy in 1000 legs with superficial venous reflux.

Science.gov (United States)

Kulkarni, Sachin R; Messenger, David E; Slim, Fiona J A; Emerson, Lorraine G; Bulbulia, Richard A; Whyman, Mark R; Poskitt, Keith R

2013-07-01

The incidence of deep vein thrombosis (DVT) following ultrasound-guided foam sclerotherapy (UGFS) ranges from 0% to 5.7%. The aim of this study was to assess the incidence of DVT following UGFS in a single vascular center. Patients undergoing UGFS between December 2005 and September 2011 underwent quality control duplex imaging within 2 weeks of treatment. This was performed by an independent senior vascular technologist, and data were entered on a prospectively maintained database. Deep venous segments assessed included common femoral vein, femoral vein, above- and below-knee popliteal veins, gastrocnemius, and tibial veins. DVT when present was labeled as endovenous foam-induced thrombosis (EFIT) type 1 when thrombus was lining <25% of the lumen of the deep vein; type 2 when thrombus extension was 25% to 50%; type 3 when thrombus extension was 50% to 99%; and type 4 when the deep vein was occluded. A total of 1166 UGFS treatments were performed in 1000 legs (776 patients). Complete occlusion of the treated veins was seen in 84.5% of the legs after one session of treatment. Overall, 17 DVTs were detected (1.5%) with no DVTs detected in legs undergoing multiple treatments. Of the 17 episodes of DVT, 16 legs had DVT following treatment for truncal reflux (658 legs; 2.43%). Seven DVTs were EFIT type 1, two were type 2, two were type 3, and five were type 4. One DVT was seen in the gastrocnemius vein alone. Two of 1166 treatments (0.2%) resulted in a symptomatic DVT, both of which were EFIT type 4. On regression analysis, there was an increase in the risk of DVT when ≥10 mL of foam was injected (odds ratio, 4.63; 95% confidence interval, 1.44-14.9; P = .01). The incidence of duplex-detected DVT following foam sclerotherapy is low and may be associated with the injection of ≥10 mL of foam. Copyright © 2013 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Endothelial dysfunction in metabolic and vascular disorders.

Science.gov (United States)

Polovina, Marija M; Potpara, Tatjana S

2014-03-01

Vascular endothelium has important regulatory functions in the cardiovascular system and a pivotal role in the maintenance of vascular health and metabolic homeostasis. It has long been recognized that endothelial dysfunction participates in the pathogenesis of atherosclerosis from early, preclinical lesions to advanced, thrombotic complications. In addition, endothelial dysfunction has been recently implicated in the development of insulin resistance and type 2 diabetes mellitus (T2DM). Considering that states of insulin resistance (eg, metabolic syndrome, impaired fasting glucose, impaired glucose tolerance, and T2DM) represent the most prevalent metabolic disorders and risk factors for atherosclerosis, it is of considerable scientific and clinical interest that both metabolic and vascular disorders have endothelial dysfunction as a common background. Importantly, endothelial dysfunction has been associated with adverse outcomes in patients with established cardiovascular disease, and a growing body of evidence indicates that endothelial dysfunction also imparts adverse prognosis in states of insulin resistance. In this review, we discuss the association of insulin resistance and T2DM with endothelial dysfunction and vascular disease, with a focus on the underlying mechanisms and prognostic implications of the endothelial dysfunction in metabolic and vascular disorders. We also address current therapeutic strategies for the improvement of endothelial dysfunction.

[Pulse wave velocity of the leg minus that of the arm measured with a custom device correlates to the coronary calcium quantification].

Science.gov (United States)

Rico Martín, S; de Nicolás Jiménez, J M; Moyano Calvente, S L; Mogollón Jiménez, M V; Vega Fernández, J; Calderón García, J F; Bacaicoa Lopez de Sabando, M A; Tardio, M; Sánchez Muñoz-Torrero, J F

2016-05-01

The pulse wave velocity (PWV) in the great arteries is an indicator of vascular risk. Our objective was to identify the PWV index between the arms and legs that best correlates with the coronary calcium quantification (CCQ) and to compare it with other methods. Eight-one patients without vascular disease underwent the following measurements: CCQ; carotid intima-media thickness (IMT); carotid-femoral PWV (cfPWV), using COMPLIOR; and PWV in the arms and legs, with our own device (abiPWV, ankle brachial index PWV). The difference in PWVs between the leg and arm (l-a PWV) measured with abiPWV was the index that best correlated with CCQ (r=0.401, P<.001). The correlation between IMT and CCQ and between CF-PWV and CCQ were r=0.366, P=.001; and r=0.385, P=.001, respectively. For a CCQ score higher than 100 as a marker of significant coronary arteriosclerosis, the areas under the curve for l-a PWV, IMT and cfPWV were 0.721 (P=.002), 0.758 (P<.001) and 0.636 (P=.058), respectively. For patients without vascular disease, the l-a PWV measured with abiPWV appears to be the index that best correlates with the CCQ. This association is comparable to that between IMT and CCQ and between cfPWV and CCQ. The abiPWV is an easy-to-use device that can help improve vascular risk stratification. Copyright © 2016 Elsevier España, S.L.U. y Sociedad Española de Medicina Interna (SEMI). All rights reserved.

Task driven optimal leg trajectories in insect-scale legged microrobots

Science.gov (United States)

Doshi, Neel; Goldberg, Benjamin; Jayaram, Kaushik; Wood, Robert

Origami inspired layered manufacturing techniques and 3D-printing have enabled the development of highly articulated legged robots at the insect-scale, including the 1.43g Harvard Ambulatory MicroRobot (HAMR). Research on these platforms has expanded its focus from manufacturing aspects to include design optimization and control for application-driven tasks. Consequently, the choice of gait selection, body morphology, leg trajectory, foot design, etc. have become areas of active research. HAMR has two controlled degrees-of-freedom per leg, making it an ideal candidate for exploring leg trajectory. We will discuss our work towards optimizing HAMR's leg trajectories for two different tasks: climbing using electroadhesives and level ground running (5-10 BL/s). These tasks demonstrate the ability of single platform to adapt to vastly different locomotive scenarios: quasi-static climbing with controlled ground contact, and dynamic running with un-controlled ground contact. We will utilize trajectory optimization methods informed by existing models and experimental studies to determine leg trajectories for each task. We also plan to discuss how task specifications and choice of objective function have contributed to the shape of these optimal leg trajectories.

Measurement of pulmonary vascular resistance of Fontan candidates with pulmonary arterial distortion by means of pulmonary perfusion imaging

International Nuclear Information System (INIS)

Park, In-Sam; Mizukami, Ayumi; Tomimatsu, Hirofumi; Kondou, Chisato; Nakanishi, Toshio; Nakazawa, Makoto; Momma, Kazuo

1998-01-01

We measured the distribution of blood flow to the right (R) and left lung (L) by means of pulmonary perfusion imaging and calculated pulmonary vascular resistance (Rp) in 13 patients, whose right and left pulmonary artery pressures were different by 2 to 9 mmHg due to pulmonary arterial distortion (5 interruption, 8 stenosis). The right lung/left lung blood flow ratio was determined and from the ratio and the total pulmonary blood flow, which was determined using the Fick's principle, the absolute values of right and left pulmonary blood flow were calculated. Using the right and left pulmonary blood flow and the right and left pulmonary arterial pressures, right and left pulmonary vascular resistance were calculated, separately. Vascular resistance of the whole lung (Rp) was then calculated using the following equation. 1/(Rp of total lung)=1/(Rp of right lung)+1/(Rp of left lung). Rp calculated from this equation was 1.8+/-0.8 U·m 2 and all values were less than 3 U·m 2 (range 0.3-2.8). Rp estimated from the conventional method using the total pulmonary blood flow and pulmonary arterial pressures, without using the right/left blood flow ratio, ranging from 0.4 to 3.8 U·m 2 and 5 of 13 patients showed Rp>3 U·m 2 . All patients underwent Fontan operation successfully. These data indicated that this method is useful to estimate Rp and to determine the indication of Fontan operation in patients with pulmonary arterial distortions. (author)

Temperature and blood flow distribution in the human leg during passive heat stress.

Science.gov (United States)

Chiesa, Scott T; Trangmar, Steven J; González-Alonso, José

2016-05-01

The influence of temperature on the hemodynamic adjustments to direct passive heat stress within the leg's major arterial and venous vessels and compartments remains unclear. Fifteen healthy young males were tested during exposure to either passive whole body heat stress to levels approaching thermal tolerance [core temperature (Tc) + 2°C; study 1; n = 8] or single leg heat stress (Tc + 0°C; study 2; n = 7). Whole body heat stress increased perfusion and decreased oscillatory shear index in relation to the rise in leg temperature (Tleg) in all three major arteries supplying the leg, plateauing in the common and superficial femoral arteries before reaching severe heat stress levels. Isolated leg heat stress increased arterial blood flows and shear patterns to a level similar to that obtained during moderate core hyperthermia (Tc + 1°C). Despite modest increases in great saphenous venous (GSV) blood flow (0.2 l/min), the deep venous system accounted for the majority of returning flow (common femoral vein 0.7 l/min) during intense to severe levels of heat stress. Rapid cooling of a single leg during severe whole body heat stress resulted in an equivalent blood flow reduction in the major artery supplying the thigh deep tissues only, suggesting central temperature-sensitive mechanisms contribute to skin blood flow alone. These findings further our knowledge of leg hemodynamic responses during direct heat stress and provide evidence of potentially beneficial vascular alterations during isolated limb heat stress that are equivalent to those experienced during exposure to moderate levels of whole body hyperthermia. Copyright © 2016 the American Physiological Society.

Compromised Agency: The Case of BabyLegs

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Max Liboiron

2017-09-01

Full Text Available The concept of agency is ubiquitous in STS, particularly regarding cases of alternative ways of knowing and doing science such as civic, citizen, and feminist sciences, among others. Yet the focus on agency often glosses over the constraints placed on agents, particularly within asymmetrical power relations. This article follows the case of BabyLegs, a do-it-yourself monitoring tool for marine microplastic pollution, and the attempt to keep the technology open source within an intellectual property (IP system set up to privatize it. The tactics used to design BabyLegs as a feminine, silly, doll-tool to discredit the device in the eyes of an IP system that valued traditional gender roles lead to the eventual success of keeping the device open source. Yet, those same tactics also reinforced and reproduced the structures of power and essentialism they were designed to resist. I characterize this technological ambivalence as compromise, and argue that all agency exercised within asymmetrical power relations is compromised. This is not to say resistance is futile, but that agency is never pure, and this recognition lets us be more intentional in how we might compromise as practitioners of diverse scientific knowledges.

THE EFFECTS OF SINGLE LEG HOP PROGRESSION AND DOUBLE LEGS HOP PROGRESSION EXERCISE TO INCREASE SPEED AND EXPLOSIVE POWER OF LEG MUSCLE

Directory of Open Access Journals (Sweden)

Nining W. Kusnanik

2015-05-01

Full Text Available The main purpose of this study was to determine the effect of single leg hop progression and double legs hop progression exercise to increase speed and explosive power of leg muscles. Plyometric is one of the training methods that can increase explosive power. There are many models of plyometric training including single leg hop progression and double leg hop progression. This research was experimental using match subject design techniques. The subjects of this study were 39 students who joined basketball school club. There were 3 groups in this study: Group 1 were 13 students who given sin¬gle leg hop progression exercise, Group 2 were 13 students who given double legs hop progression exercise, Group 3 were 13 students who given conventional exercise. The data was collected during pre test and post test by testing 30m speed running and vertical jump. The data was analyzed using Analysis of Varians (Anova. It was found that there were significantly increased on speed and explosive power of leg muscles of Group 1 and Group 2. It can be stated that single leg hop progression exercise was more effective than double leg hop progression exercise. The recent findings supported the hypothesis that single leg hop progression and double legs hop progression exercise can increase speed and explosive power of leg muscles. These finding were supported by some previous studies (Singh, et al, 2011; Shallaby, H.K., 2010. The single leg hop progression is more effective than double legs hop progression. This finding was consistent with some previous evidences (McCurdy, et al, 2005; Makaruk et al, 2011.

Systolic and Diastolic Left Ventricular Mechanics during and after Resistance Exercise.

Science.gov (United States)

Stöhr, Eric J; Stembridge, Mike; Shave, Rob; Samuel, T Jake; Stone, Keeron; Esformes, Joseph I

2017-10-01

To improve the current understanding of the impact of resistance exercise on the heart, by examining the acute responses of left ventricular (LV) strain, twist, and untwisting rate ("LV mechanics"). LV echocardiographic images were recorded in systole and diastole before, during and immediately after (7-12 s) double-leg press exercise at two intensities (30% and 60% of maximum strength, one-repetition maximum). Speckle tracking analysis generated LV strain, twist, and untwisting rate data. Additionally, beat-by-beat blood pressure was recorded and systemic vascular resistance (SVR) and LV wall stress were calculated. Responses in both exercise trials were statistically similar (P > 0.05). During effort, stroke volume decreased, whereas SVR and LV wall stress increased (P mechanics (P 0.05). Immediately after exercise, systolic LV mechanics returned to baseline levels (P mechanics, but increases diastolic mechanics after exercise, suggesting that resistance exercise has a differential impact on systolic and diastolic heart muscle function. The findings may explain why acute resistance exercise has been associated with reduced stroke volume but chronic exercise training may result in increased LV volumes.

The effects of stair climbing on arterial stiffness, blood pressure, and leg strength in postmenopausal women with stage 2 hypertension.

Science.gov (United States)

Wong, Alexei; Figueroa, Arturo; Son, Won-Mok; Chernykh, Oksana; Park, Song-Young

2018-02-12

Menopause is accompanied by a progressive arterial stiffening associated with increases in blood pressure (BP) and decline in muscular function. It is crucial to prevent or reduce the negative effects of menopause on vascular and muscular function by implementing appropriate lifestyle interventions, such as exercise training. We examined the effects of a stair climbing (SC) regimen on arterial stiffness (pulse wave velocity [PWV]), BP, and leg strength in postmenopausal women with stage 2 hypertension. Using a parallel experimental design, participants were randomly assigned to either SC (n = 21) or nonexercising control group (n = 20) for 12 weeks. Participants in the SC group trained 4 d/wk, climbing 192 steps 2 to 5 times/d. Participants' brachial-to-ankle PWV (baPWV), BP, and leg strength were measured at baseline and after 12 weeks of their assigned intervention. There was a significant group by time interaction (P hypertensive postmenopausal women. The decrease in arterial stiffness partially explained the improvements in SBP and leg strength. SC may be an effective intervention in the prevention and treatment of menopause/aging-related vascular complications and muscle weakness.

Aluminum exposure for one hour decreases vascular reactivity in conductance and resistance arteries in rats

International Nuclear Information System (INIS)

Schmidt, Patrícia Medeiros; Escobar, Alyne Goulart; Torres, João Guilherme Dini; Martinez, Caroline Silveira; Rizzetti, Danize Aparecida; Kunz, Simone Noremberg; Vassallo, Dalton Valentim; Alonso, María Jesús; Peçanha, Franck Maciel; Wiggers, Giulia Alessandra

2016-01-01

Aims: Aluminum (Al) is an important environmental contaminant; however, there are not enough evidences of Al-induced cardiovascular dysfunction. We investigated the effects of acute exposure to aluminum chloride (AlCl 3 ) on blood pressure, vascular reactivity and oxidative stress. Methods and results: Male Wistar rats were divided into two groups: Untreated: vehicle (ultrapure water, ip) and AlCl 3 : single dose of AlCl 3 (100 mg/kg,ip). Concentration-response curves to phenylephrine in the absence and presence of endothelium, the nitric oxide synthase inhibitor L-NAME, the potassium channel blocker tetraethylammonium, and the NADPH oxidase inhibitor apocynin were performed in segments from aortic and mesenteric resistance arteries. NO released was assessed in aorta and reactive oxygen species (ROS), malondialdehyde, non-protein thiol levels, antioxidant capacity and enzymatic antioxidant activities were investigated in plasma, aorta and/or mesenteric arteries. After one hour of AlCl 3 exposure serum Al levels attained 147.7 ± 25.0 μg/L. Al treatment: 1) did not affect blood pressure, heart rate and vasodilator responses induced by acetylcholine or sodium nitroprusside; 2) decreased phenylephrine-induced vasoconstrictor responses; 3) increased endothelial modulation of contractile responses, NO release and vascular ROS production from NADPH oxidase; 4) increased plasmatic, aortic and mesenteric malondialdehyde and ROS production, and 5) decreased antioxidant capacity and affected the antioxidant biomarkers non-protein thiol levels, glutathione peroxidase, glutathione-S-transferase, superoxide dismutase and catalase enzymatic activities. Conclusion: AlCl 3 -acute exposure reduces vascular reactivity. This effect is associated with increased NO production, probably acting on K + channels, which seems to occur as a compensatory mechanism against Al-induced oxidative stress. Our results suggest that Al exerts toxic effects to the vascular system. - Highlights: �

Aluminum exposure for one hour decreases vascular reactivity in conductance and resistance arteries in rats

Energy Technology Data Exchange (ETDEWEB)

Schmidt, Patrícia Medeiros; Escobar, Alyne Goulart; Torres, João Guilherme Dini; Martinez, Caroline Silveira; Rizzetti, Danize Aparecida; Kunz, Simone Noremberg [Postgraduate Program in Biochemistry, Universidade Federal do Pampa, Uruguaiana, Rio Grande do Sul (Brazil); Vassallo, Dalton Valentim [Department of Physiological Sciences, Universidade Federal do Espírito Santo, Espirito Santo (Brazil); Alonso, María Jesús [Department of Basic Health Sciences, Universidad Rey Juan Carlos, Alcorcón (Spain); Peçanha, Franck Maciel [Postgraduate Program in Biochemistry, Universidade Federal do Pampa, Uruguaiana, Rio Grande do Sul (Brazil); Wiggers, Giulia Alessandra, E-mail: giuliawp@gmail.com [Postgraduate Program in Biochemistry, Universidade Federal do Pampa, Uruguaiana, Rio Grande do Sul (Brazil)

2016-12-15

Aims: Aluminum (Al) is an important environmental contaminant; however, there are not enough evidences of Al-induced cardiovascular dysfunction. We investigated the effects of acute exposure to aluminum chloride (AlCl{sub 3}) on blood pressure, vascular reactivity and oxidative stress. Methods and results: Male Wistar rats were divided into two groups: Untreated: vehicle (ultrapure water, ip) and AlCl{sub 3}: single dose of AlCl{sub 3} (100 mg/kg,ip). Concentration-response curves to phenylephrine in the absence and presence of endothelium, the nitric oxide synthase inhibitor L-NAME, the potassium channel blocker tetraethylammonium, and the NADPH oxidase inhibitor apocynin were performed in segments from aortic and mesenteric resistance arteries. NO released was assessed in aorta and reactive oxygen species (ROS), malondialdehyde, non-protein thiol levels, antioxidant capacity and enzymatic antioxidant activities were investigated in plasma, aorta and/or mesenteric arteries. After one hour of AlCl{sub 3} exposure serum Al levels attained 147.7 ± 25.0 μg/L. Al treatment: 1) did not affect blood pressure, heart rate and vasodilator responses induced by acetylcholine or sodium nitroprusside; 2) decreased phenylephrine-induced vasoconstrictor responses; 3) increased endothelial modulation of contractile responses, NO release and vascular ROS production from NADPH oxidase; 4) increased plasmatic, aortic and mesenteric malondialdehyde and ROS production, and 5) decreased antioxidant capacity and affected the antioxidant biomarkers non-protein thiol levels, glutathione peroxidase, glutathione-S-transferase, superoxide dismutase and catalase enzymatic activities. Conclusion: AlCl{sub 3}-acute exposure reduces vascular reactivity. This effect is associated with increased NO production, probably acting on K{sup +} channels, which seems to occur as a compensatory mechanism against Al-induced oxidative stress. Our results suggest that Al exerts toxic effects to the vascular

Impact of UK NICE clinical guidelines 168 on referrals to a specialist academic leg ulcer service.

Science.gov (United States)

Davies, Huw Ob; Popplewell, Matthew; Bate, Gareth; Kelly, Lisa; Darvall, Katy; Bradbury, Andrew W

2018-03-01

Background Leg ulcers are a common cause of morbidity and disability and result in significant health and social care expenditure. The UK National Institute for Health and Care Excellence (NICE) Clinical Guideline (CG)168, published in July 2013, sought to improve care of patients with leg ulcers, recommending that patients with a break in the skin below the knee that had not healed within two weeks be referred to a specialist vascular service for diagnosis and management. Aim Determine the impact of CG168 on referrals to a leg ulcer service. Methods Patients referred with leg ulceration during an 18-month period prior to CG168 (January 2012-June 2013) and an 18-month period commencing six months after (January 2014-June 2015) publication of CG168 were compared. Results There was a two-fold increase in referrals (181 patients, 220 legs vs. 385 patients, 453 legs) but no change in mean age, gender or median-duration of ulcer at referral (16.6 vs. 16.2 weeks). Mean-time from referral to specialist appointment increased (4.8 vs. 6 weeks, p = 0.0001), as did legs with superficial venous insufficiency (SVI) (36% vs. 44%, p = 0.05). There was a trend towards more SVI endovenous interventions (32% vs. 39%, p = 0.271) with an increase in endothermal (2 vs. 32 legs, p = 0.001) but no change in sclerotherapy (24 vs. 51 legs) treatments. In both groups, 62% legs had compression. There was a reduction in legs treated conservatively with simple dressings (26% vs. 15%, p = 0.0006). Conclusions Since CG168, there has been a considerable increase in leg ulcer referrals. However, patients are still not referred until ulceration has been present for many months. Although many ulcers are multi-factorial and the mainstay of treatment remains compression, there has been an increase in SVI endovenous intervention. Further efforts are required to persuade community practitioners to refer patients earlier, to educate patients and encourage further investment in

Clinical and angiographic evaluation of the topic application of nitrate compounds in obstructive distal arteriopathies of the legs

International Nuclear Information System (INIS)

Perini, L.; Cavallo, A.; Perin, B.; Natale, F.; Borelli, G.; Bisiato, R.

1988-01-01

The vasodilatator effect obtained by the topic use of a nytroglycerin compound (TNG) has been angiographically tested on 11 patients affected by distal arteriopathy of the legs. All patients presented arteriosclerotic vascular lesions; two of them also suffered from diabetic angiopathy. Arteriography of the legs has proved to be a very important tool in the evaluation of the patients'response to the administration of the drug. An hour after 80 mg of TNG had been applied to the skin of the examined leg, arteriography showed a marked dilatation, especially of the muscular arteries and the undamaged tracts of the arteries of the legs. Angiographic evaluation of the functional blood supply thus obtained provides prognostic information and helps in the choice of the subsequent therapy. Furthermore, the clinical efficacy of prolonged treatment with this drug has been tested in 10 out of the 11 patients. They all responded with an immediate and persistent hemodynamic improvement, evaluated according to Fontaine's classification

Insulin Sensitivity Determines Effects of Insulin and Meal Ingestion on Systemic Vascular Resistance in Healthy Subjects.

Science.gov (United States)

Woerdeman, Jorn; Meijer, Rick I; Eringa, Etto C; Hoekstra, Trynke; Smulders, Yvo M; Serné, Erik H

2016-01-01

In addition to insulin's metabolic actions, insulin can dilate arterioles which increase blood flow to metabolically active tissues. This effect is blunted in insulin-resistant subjects. Insulin's effect on SVR, determined by resistance arterioles, has, however, rarely been examined directly. We determined the effects of both hyperinsulinemia and a mixed meal on SVR and its relationship with insulin sensitivity. Thirty-seven lean and obese women underwent a hyperinsulinemic-euglycemic clamp, and 24 obese volunteers underwent a mixed-meal test. SVR was assessed using CPP before and during hyperinsulinemia as well as before and 60 and 120 minutes after a meal. SVR decreased significantly during hyperinsulinemia (-13%; p Insulin decreased SVR more strongly in insulin-sensitive individuals (standardized β: -0.44; p = 0.01). In addition, SVR at 60 minutes after meal ingestion was inversely related to the Matsuda index (β: -0.39; p = 0.04) and the change in postprandial SVR was directly related to postprandial glycemia (β: 0.53; p insulin resistance. This suggests that resistance to insulin-induced vasodilatation contributes to regulation of vascular resistance. © 2015 John Wiley & Sons Ltd.

A new approach to the evaluation of peripheral vascular disease using the gamma camera

International Nuclear Information System (INIS)

Gerritsen, H.A.M.

1976-01-01

To estimate the degree of impaired perfusion in legs, and the extent of improvement after treatment, a functional test was developed using a gamma camera to follow the perfusion of intravenously injected sup(99m)Tc-pertechnetate. An analysis is given of normal and pathologic curve patterns. The influence of the severity of occlusive arterial disease on the arrival and distribution of radioactivity in the leg is demonstrated. After vascular surgery, changes in the curve pattern and the imaging of activity distribution reflected the function of the inserted bypass grafts. The test proved to be useful in the differentiation between patients with false claudication complaints due to non-arterial disease and patients with true claudication. It is concluded that the technique presented in this thesis can serve as a useful, non-invasive, screening test prior to arteriography and as a functional assessment of vascular reconstruction

A study on the strength of leg extention and leg curl exercise measured with the "Tremax System" and the "ADR" (Aero Dynamic Resistance System)

OpenAIRE

安藤, 勝英

1995-01-01

This is a study on the nature of the extensor and flexor muscles by the leg extention and leg curl exercise. The strength of the static muscles were measured with the "Tremax system" and for the strength of the dynamic muscles the "ADR" was used. Measuring the strength of the extensor muscles at bar no.1 to 4 of the Tremax System，it comes to a maximum at bar no.2 (extention 60°) but it declines radically when approaching extention 0°. Compared to the extensor muscles, the flexor muscules show...

Lung irradiation induces pulmonary vascular remodelling resembling pulmonary arterial hypertension

NARCIS (Netherlands)

Ghobadi, G.; Bartelds, B.; van der Veen, S. J.; Dickinson, M. G.; Brandenburg, S.; Berger, R. M. F.; Langendijk, J. A.; Coppes, R. P.; van Luijk, P.

Background Pulmonary arterial hypertension (PAH) is a commonly fatal pulmonary vascular disease that is often diagnosed late and is characterised by a progressive rise in pulmonary vascular resistance resulting from typical vascular remodelling. Recent data suggest that vascular damage plays an

VASCULAR INJURIES IN TEHRAN: A REVIEW OF 123 CASES

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M. Karbakhsh M. R. Zarei

2006-09-01

Full Text Available Abstract- Studies of the epidemiology of civilian vascular trauma in developing countries are rather few. This is a prospective study of our experience with vascular trauma in a referral university hospital in Tehran, Iran. The aim was to study the etiology, pattern of injuries and the mortality and morbidity rates due to vascular trauma in our population. In this cross-sectional study, all trauma patients suspicious of having vascular injuries who were admitted to Sina Hospital between March 2002 and May 2003 were included. Among 123 studied cases, there were 109 males and 14 females.Blunt injuries were more common than penetrating ones (56.1% vs. 43.9%. The most common anatomical site of vascular injuries had been knee and lower leg. In fact, cases with lower extremities vascular trauma were twice as common as those with vascular trauma in upper limbs (59.1% vs. 27.3%. The commonest injured vessels were popliteal artery followed by femoral artery. Arterial repair with graft interposition was done in 23 cases and bypass graft in 13 cases. Procedures on veins were performed in 24 cases. Five patients (4.06% died and in 3 cases the patients died because of non-vascular reasons. The present study allows an understanding of the epidemiology of vascular trauma in the one of the major trauma centers in the metropolitan city of Tehran. The majority of our cases were young males sustaining vascular injuries due to road traffic accidents or being stabbed with knives. It also has important implications for vascular injury prevention in our community.

Vascular resistance of central retinal and ophthalmic arteries in postmenopausal women after use of tibolone.

Science.gov (United States)

de Souza, Marco Aurélio Martins; de Souza, Bruno Martins; Geber, Selmo

2012-03-01

The aim of this study was to evaluate the effect of tibolone on vascular resistance of the central retinal and ophthalmic artery in postmenopausal women and to compare this effect with that of placebo using transorbital ultrasound with Doppler velocimetry. We performed a prospective randomized, double-blinded, placebo-controlled study. A total of 100 healthy postmenopausal women (follicle-stimulating hormone, >40 IU/L) younger than 65 years were studied. The participants were randomly allocated to two groups: placebo (n = 50) and tibolone (2.5 mg; n = 50). Transorbital Doppler velocimetric ultrasound was performed before treatment and 80 days after. The mean age was similar in both groups. Participants who received tibolone did not show any difference in pulsatility index, resistance index, and systole/diastole ratio of the central retinal and ophthalmic arteries after treatment. The same was observed in participants who received placebo. Our study demonstrates that tibolone administration to healthy postmenopausal women does not affect the resistance of small-caliber cerebral arteries.

The Relationship among Leg Strength, Leg Power and Alpine Skiing Success.

Science.gov (United States)

Gettman, Larry R.; Huckel, Jack R.

The purpose of this study was to relate leg strength and power to alpine skiing success as measured by FIS points. Isometric leg strength was represented by the knee extension test described by Clarke. Leg power was measured by the vertical jump test and the Margaria-Kalamen stair run. Results in the strength and power tests were correlated with…

Increased systemic vascular resistance in neonates with pulmonary hypertension.

Science.gov (United States)

Milstein, J M; Goetzman, B W; Riemenschneider, T A; Wennberg, R P

1979-11-01

The time necessary for aortic diastolic pressure to decrease to 50 percent of an initially selected value after dissipation of the dicrotic notch (T 1/2) was determined in newborn infants with and without pulmonary hypertension. The mean T 1/2 was 671 +/- 167 msec in seven infants with clinical evidence of pulmonary hypertension and documented right to left ductus arteriosus shunting; 849 +/- 243 msec in nine infants with clinical evidence of pulmonary hypertension but no documented right to left ductus arteriosus shunting; and 457 +/- 66 msec in eight infants with hyaline membrane disease and no clinical evidence of pulmonary hypertension or a patent ductus arteriosus. The mean T 1/2 values in the former two groups were significantly different from that in the group with no pulmonary hypertension (P less than 0.01). An evaluation of factors affecting T 1/2 leads to the conclusion that the patients with pulmonary hypertension had increased systemic vascular resistance as well. This finding has important diagnostic, etiologic and therapeutic implications.

Simvastatin-induced nocturnal leg pain disappears with pravastatin substitution

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Stojaković Nataša

2013-01-01

Full Text Available Introduction. Statins have similar side effects that do not always occur at the same rate among the various statins. We present a case of simvastatin-induced muscle toxicity that disappeared when pravastatin was substituted for the original drug. Case Outline. A 74-year-old male, a nonsmoker, complained of severe nocturnal leg cramps. The patient also complained that similar painful cramping occurred when he walked rapidly or jogged. Because some components of his lipid panel exceeded the ‘desirable’ range, and as he had a history of myocardial infarction, his family physician prescribed simvastatin (40 mg/day. The patient had taken this medication for the past eight years. The painful nocturnal episodes started two years ago and affected either one or the other leg. Four months ago we discontinued his simvastatin and prescribed pravastatin (80 mg/day. At a follow-up visit six weeks later, the patient reported that his leg pains at night and the pain experienced after brisk walking had disappeared. Four months after the substitution of pravastatin for simvastatin, the patient reported that his complete lack of symptoms had continued. Conclusion. These painful muscle cramps were probably caused by an inadequate vascular supply to the calf and foot muscles. Perhaps a combination of advanced age and atherosclerotic changes created a predisposition for the simvastatin-induced leg cramps. Pravastatin differs from simvastatin in several ways. It is not metabolized by cytochrome P450 (CYP 3A4 oxidases, and thus is not influenced by CYP 3A4 inhibitors like simvastatin. Also, simvastatin is associated with single-nucleotide polymorphisms located within the SLCO1B1 gene on the chromosome 12 and established myopathy, while pravastatin lacks this association. These differences may contribute to increased tolerance to pravastatin in this particular case.

Simvastatin-lnduced nocturnal leg pain disappears with pravastatin substitution.

Science.gov (United States)

Stojaković, Natasa; Igić, Rajko

2013-01-01

Statins have similar side effects that do not always occur at the same rate among the various statins. We present a case of simvastatin-induced muscle toxicity that disappeared when pravastatin was substituted for the original drug. A 74-year-old male, a nonsmoker, complained of severe nocturnal leg cramps. The patient also complained that similar painful cramping occurred when he walked rapidly or jogged. Because some components of his lipid panel exceeded the'desirable' range, and as he had a history of myocardial infarction, his family physician prescribed simvastatin (40 mg/day). The patient had taken this medication for the past eight years. The painful nocturnal episodes started two years ago and affected either one or the other leg. Four months ago we discontinued his simvastatin and prescribed pravastatin (80 mg/day). At a follow-up visit six weeks later, the patient reported that his leg pains at night and the pain experienced after brisk walking had disappeared. Four months after the substitution of pravastatin for simvastatin, the patient reported that his complete lack of symptoms had continued. These painful muscle cramps were probably caused by an inadequate vascular supply to the calf and foot muscles. Perhaps a combination of advanced age and atherosclerotic changes created a predisposition for the simvastatin-induced leg cramps. Pravastatin differs from simvastatin in several ways.l It is not metabolized by cytochrome P450 (CYP) 3A4 oxidases, and thus is not influenced by CYP 3A4 inhibitors like simvastatin. Also, simvastatin is associated with single-nucleotide polymorphisms located within the SLCO1B1 gene on the chromosome 12 and established myopathy, while pravastatin lacks this association. These differences may contribute to increased tolerance to pravastatin in this particular case.

The one-leg standing radiograph

OpenAIRE

Pinsornsak, P.; Naratrikun, K.; Kanitnate, S.; Sangkomkamhang, T.

2016-01-01

Objectives The purpose of this study was to compare the joint space width between one-leg and both-legs standing radiographs in order to diagnose a primary osteoarthritis of the knee. Methods Digital radiographs of 100 medial osteoarthritic knees in 50 patients were performed. The patients had undergone one-leg standing anteroposterior (AP) views by standing on the affected leg while a both-legs standing AP view was undertaken while standing on both legs. The severity of the osteoarthritis wa...

Single-leg squats can predict leg alignment in dancers performing ballet movements in "turnout".

Science.gov (United States)

Hopper, Luke S; Sato, Nahoko; Weidemann, Andries L

2016-01-01

The physical assessments used in dance injury surveillance programs are often adapted from the sports and exercise domain. Bespoke physical assessments may be required for dance, particularly when ballet movements involve "turning out" or external rotation of the legs beyond that typically used in sports. This study evaluated the ability of the traditional single-leg squat to predict the leg alignment of dancers performing ballet movements with turnout. Three-dimensional kinematic data of dancers performing the single-leg squat and five ballet movements were recorded and analyzed. Reduction of the three-dimensional data into a one-dimensional variable incorporating the ankle, knee, and hip joint center positions provided the strongest predictive model between the single-leg squat and the ballet movements. The single-leg squat can predict leg alignment in dancers performing ballet movements, even in "turned out" postures. Clinicians should pay careful attention to observational positioning and rating criteria when assessing dancers performing the single-leg squat.

Inflammation relates to resistance training-induced hypertrophy in elderly patients

DEFF Research Database (Denmark)

Norheim, Kristoffer L.; Cullum, Christopher K.; Andersen, Jesper L.

2017-01-01

on the relationship between systemic inflammatory marker C-reactive protein (CRP) and changes in muscle mass, as well as the influence of resistance training upon muscle mass. Method: Unilateral leg press resistance exercise was conducted daily during the hospital period. Outcomes included changes in whole body...... although our findings are potentially affected by changes in hydration status. Resistance training during hospitalization increases skeletal muscle mass, and patients with high levels of systemic inflammation demonstrate less ability to increase or preserve muscle mass in response to resistance training...... = 84.8 T 1.9 yr, mean T SE). Lean mass at the midthigh region of the trained leg increased by 2.4% T 1.1% (P G 0.05) after the intervention period. There was a negative association between changes in midthigh lean mass of the trained leg and CRP (rs = j0.53, P G 0.05). Leg extension power increased...

Insulin-resistance HCV infection-related affects vascular stiffness in normotensives.

Science.gov (United States)

Perticone, Maria; Maio, Raffaele; Tassone, Eliezer Joseph; Tripepi, Giovanni; Di Cello, Serena; Miceli, Sofia; Caroleo, Benedetto; Sciacqua, Angela; Licata, Anna; Sesti, Giorgio; Perticone, Francesco

2015-01-01

BACKGROUND AND AIMS. Arterial stiffness evaluated as pulse wave velocity, is an early marker of vascular damage and an independent predictor for cardiovascular events. We investigated if the insulin resistance/hyperinsulinemia chronic hepatitis C virus infection-related could influence arterial stiffness. METHODS. We enrolled 260 outpatients matched for age, body mass index, gender, ethnicity: 52 with never-treated uncomplicated chronic hepatitis C virus infection (HCV(+)), 104 never-treated hypertensives (HT) and 104 healthy subjects (NT). Pulse wave velocity was evaluated by a validated system employing high-fidelity applanation tonometry. We also measured: fasting plasma glucose and insulin, total, LDL- and HDL-cholesterol, triglyceride, creatinine, e-GFR-EPI, HOMA, quantitative HCV-RNA. RESULTS. HCV(+) patients with respect to NT had an increased pulse wave velocity (7.9 ± 2.1 vs 6.4 ± 2.1 m/s; P direct correlation between HOMA and pulse wave velocity in HCV(+) patients, similar to that observed in hypertensives. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Foot, leg, and ankle swelling

Science.gov (United States)

Swelling of the ankles - feet - legs; Ankle swelling; Foot swelling; Leg swelling; Edema - peripheral; Peripheral edema ... Foot, leg, and ankle swelling is common when the person also: Is overweight Has a blood clot in the leg Is older Has ...

Management of vascular lesions using advanced laser technology

Directory of Open Access Journals (Sweden)

Christofer Tzermias

2017-04-01

Full Text Available One of the most widely used cutaneous applications of Light Amplification by Stimulated Emission of Radiation (laser concerns the treatment of vascular lesions. During the past two decades, very significant advances in the application of laser technology in dermatology have occurred, with selective photothermolysis being the most important. This review focuses on the application of modern laser devices (Pulsed Dye Laser, or PDL; potassium titanyl phosphate laser, or KTP; diode laser; and neodymium-doped yttrium-aluminium-garnet laser, or Nd:YAG, as well as the combination of laser and photodynamic therapy (PDT for the treatment of vascular lesions. In particular, both congenital (haemangiomas and port-wine stains and acquired vascular lesions (facial and leg telangiectasias, rosacea, Poikiloderma of Civatte, spider angioma, pyogenic granuloma, and venous lakes are discussed. The review of many recent research studies demonstrates that modern applications of lasers in dermatology constitute the finest method for the treatment of vascular lesions, combining the advantages of invasive therapy with the security offered by non-invasive therapy, while in certain cases they are the single and only choice for the treatment of these lesions.

Efeitos hemodinâmicos e vasculares do treinamento resistido: implicações na doença cardiovascular Hemodynamic and vascular effects of resistance training: implications for cardiovascular disease

Directory of Open Access Journals (Sweden)

Daniel Umpierre

2007-10-01

ções vasculares.Resistance training has been proposed as a possible strategy for cardiovascular prevention and rehabilitation, and in this context, this review describes the cardiovascular effects mediated by this type of intervention. Increments in both muscular strength and capacity to perform daily tasks are well-characterized benefits of this type of training. More recently, studies using hemodynamic evaluation have shown cardiovascular stability in patients with coronary disease or heart failure during the performance of resistance exercise, with no apparent detriment to ventricular function or exacerbated increase in exercise blood pressure. Additionally, resting blood pressure also seems to be influenced by chronic resistance training, with a slight reduction in both systolic blood pressure (SBP and diastolic blood pressure (DBP. The measurement of pressure levels after a single resistance exercise session shows the occurrence of post-exercise hypotension in normal and hypertensive individuals; however, there is controversy as to the intensity of the effort necessary to induce this effect. Recently, intervention studies have investigated resistance exercise effects on vascular variables as arterial compliance and endothelial function. Despite the small number of experiments available, evidence has shown a potential influence of resistance training on the reduction of arterial compliance. On the other hand, peripheral blood flow is increased after resistance training, whereas the endothelial function seems to be improved especially after combined aerobic and resistance training. Additional research is necessary for an analysis of the efficacy of this intervention on validated outcomes, and for a greater understanding of the physiological mechanisms responsible for vascular adaptations.

GABAergic inhibition of leg motoneurons is required for normal walking behavior in freely moving Drosophila.

Science.gov (United States)

Gowda, Swetha B M; Paranjpe, Pushkar D; Reddy, O Venkateswara; Thiagarajan, Devasena; Palliyil, Sudhir; Reichert, Heinrich; VijayRaghavan, K

2018-02-27

Walking is a complex rhythmic locomotor behavior generated by sequential and periodical contraction of muscles essential for coordinated control of movements of legs and leg joints. Studies of walking in vertebrates and invertebrates have revealed that premotor neural circuitry generates a basic rhythmic pattern that is sculpted by sensory feedback and ultimately controls the amplitude and phase of the motor output to leg muscles. However, the identity and functional roles of the premotor interneurons that directly control leg motoneuron activity are poorly understood. Here we take advantage of the powerful genetic methodology available in Drosophila to investigate the role of premotor inhibition in walking by genetically suppressing inhibitory input to leg motoneurons. For this, we have developed an algorithm for automated analysis of leg motion to characterize the walking parameters of wild-type flies from high-speed video recordings. Further, we use genetic reagents for targeted RNAi knockdown of inhibitory neurotransmitter receptors in leg motoneurons together with quantitative analysis of resulting changes in leg movement parameters in freely walking Drosophila Our findings indicate that targeted down-regulation of the GABA A receptor Rdl (Resistance to Dieldrin) in leg motoneurons results in a dramatic reduction of walking speed and step length without the loss of general leg coordination during locomotion. Genetically restricting the knockdown to the adult stage and subsets of motoneurons yields qualitatively identical results. Taken together, these findings identify GABAergic premotor inhibition of motoneurons as an important determinant of correctly coordinated leg movements and speed of walking in freely behaving Drosophila . Copyright © 2018 the Author(s). Published by PNAS.

Control of nasal vasculature and airflow resistance in the dog.

Science.gov (United States)

Lung, M A; Phipps, R J; Wang, J C; Widdicombe, J G

1984-01-01

Nasal vascular and airflow resistances have been measured in dogs, simultaneously on both sides separately. Vascular resistance was measured either by constant flow perfusion of the terminal branch of the maxillary artery (which supplies, via the sphenopalatine artery, the nasal septum, most of the turbinates and the nasal sinuses) or by measuring blood flow through this artery, maintained by the dog's own blood pressure. Airflow resistance was assessed by inserting balloon-tipped endotracheal catheters into the back of each nasal cavity via the nasopharynx, and measuring transnasal pressure at constant airflow through each side of the nose simultaneously. Preliminary experiments indicated that there was 5-10% collateral anastomosis between the two sides. Close-arterial injection of drugs showed different patterns of response. Adrenaline, phenylephrine, chlorpheniramine and low doses of prostaglandin F2 alpha increased vascular resistance and lowered airway resistance. Salbutamol, methacholine and histamine lowered vascular resistance and increased airway resistance. Dobutamine decreased airway resistance with a small increase in vascular resistance. Prostaglandins E1, E2 and F2 alpha (high dose) decreased both vascular and airway resistances. Substance P, eledoisin-related peptide and vasoactive intestinal polypeptide lowered vascular resistance with little change in airway resistance. The results are interpreted in terms of possible drug actions on precapillary resistance vessels, sinusoids and venules, and arteriovenous anastomoses. It is concluded that nasal airway resistance cannot be correlated with vascular resistance or blood flow, since the latter has a complex and ill-defined relationship with nasal vascular blood volume. PMID:6204040

ATP induced vasodilatation and purinergic receptors in the human leg: roles of nitric oxide, prostaglandins and adenosine

DEFF Research Database (Denmark)

Mortensen, Stefan P; Gonzalez-Alonso, Jose; Bune, Laurids

2009-01-01

.05) and was associated with a parallel lowering in leg vascular conductance and cardiac output and a compensatory increase in leg O2 extraction. Infusion of theophylline did not alter the ATP induced leg hyperemia or systemic variables. Real time PCR analysis of the mRNA content from the vastus lateralus muscle of 8...... subjects showed the highest expression of P2Y2 receptors of the 10 investigated P2 receptor subtypes. Immunohistochemistry showed that P2Y2 receptors were located in the endothelium of microvessels and smooth muscle cells, whereas P2X1 receptors were located in the endothelium and the sacrolemma....... Collectively, these results indicate that NO and prostaglandins, but not adenosine, play a role in ATP induced vasodilation in human skeletal muscle. The localization of the P2Y2 and P2X1 receptors suggest that these receptors may mediate ATP induced vasodilation in skeletal muscle. Key words: Skeletal Muscle...

Phenotypic evaluation of the resistance in F1 carnation populations to vascular wilt caused by Fusarium oxysporum f.sp. dianthi

Directory of Open Access Journals (Sweden)

Johana Carolina Soto-Sedano

2012-08-01

Full Text Available One of the most important phytosanitary problems of the carnation crops in Colombia and in the entire world is vascular wilting produced by Fusarium oxysporum f.sp. dianthi. Currently, an effective treatment against the pathogen does not exist; the search for resistant varieties has been the most successful method for control of this disease. Breeding programs are vital to solving the problem of the carnation fusariosis. The objective of this research was the phenotypic evaluation of carnation F1 populations, products of contrasting crossing, resistant per susceptible to F. oxysporum f.sp. dianthi, in order to determine if the resistance is inherited in the lines. This information will contribute to the selection of material and to the successful introduction of the resistant characteristic, whose expression is commercially acceptable, to the gene pool. The methodology adopted was a phenotypic evaluation of the response to the parasite in the population (450 individuals and in the parental. This evaluation estimated the area under the curve (AU DPC, using a scale of symptoms reported for carnation vascular wilt. Three different phenotypes were established with this evaluation. The moderately susceptible one is the predominant phenotype and an analysis of phenotypic frequencies was carried out on it. The results show that the individuals of the evaluated F1 population were distributed between two extreme ranges, resistant and susceptible; this shows that there is segregation for the trait resistant to F. oxysporum f.sp dianthi. We did not observe clearly differentiated classes, i.e. with complete absence or presence of the disease, indicating a possible control of the resistance in the evaluated carnation material, governed by more than one gene and with a possible additive genetic action

Circulating Angiogenic Growth Factors in Diabetes Patients with Peripheral Arterial Disease and Exertional Leg Pain in Ghana

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Kwame Yeboah

2017-01-01

Full Text Available Objective. Peripheral arterial disease (PAD is a common complication of diabetes, associated with impairment in angiogenesis. Angiogenesis is regulated by angiogenic growth factors such as angiopoietin 1 (Ang-1, Ang-2, and vascular endothelial growth factor (VEGF. We studied the association between angiogenic growth factors versus PAD and exertional leg symptoms in diabetes patients in Ghana. Method. In this cross-sectional study, ankle-brachial index was measured with oscillometrically and exertional leg symptoms were screened with Edinburgh claudication questionnaire in 140 diabetes patients and 110 nondiabetes individuals. Circulating levels of Ang-1, Ang-2, and VEGF were measured with immunosorbent assay. Results. The prevalence of PAD and exertional leg pain was 16.8% and 24.8%, respectively. Compared to non-PAD participants, PAD patients had higher VEGF levels [85.8 (37.5–154.5 versus 57.7 (16.6–161.1 p=0.032] and lower Ang-1 levels [31.3 (24.8–42.6 versus 40.9 (28.2–62.1, p=0.017]. In multivariable logistic regression, patients with exertional leg pain had increased the odds of plasma Ang-2 levels [OR (95% CI: 2.08 (1.08–6.41, p=0.036]. Conclusion. Diabetes patients with PAD and exertional leg pain have imbalance in angiogenic growth factors, indicating impaired angiogenesis. In patients with exertional leg pains, Ang-2 may be an important biomarker.

Single-leg squats can predict leg alignment in dancers performing ballet movements in “turnout”

Science.gov (United States)

Hopper, Luke S; Sato, Nahoko; Weidemann, Andries L

2016-01-01

The physical assessments used in dance injury surveillance programs are often adapted from the sports and exercise domain. Bespoke physical assessments may be required for dance, particularly when ballet movements involve “turning out” or external rotation of the legs beyond that typically used in sports. This study evaluated the ability of the traditional single-leg squat to predict the leg alignment of dancers performing ballet movements with turnout. Three-dimensional kinematic data of dancers performing the single-leg squat and five ballet movements were recorded and analyzed. Reduction of the three-dimensional data into a one-dimensional variable incorporating the ankle, knee, and hip joint center positions provided the strongest predictive model between the single-leg squat and the ballet movements. The single-leg squat can predict leg alignment in dancers performing ballet movements, even in “turned out” postures. Clinicians should pay careful attention to observational positioning and rating criteria when assessing dancers performing the single-leg squat. PMID:27895518

Cavitation Resistance in Seedless Vascular Plants: The Structure and Function of Interconduit Pit Membranes1[W][OPEN

Science.gov (United States)

Brodersen, Craig; Jansen, Steven; Choat, Brendan; Rico, Christopher; Pittermann, Jarmila

2014-01-01

Plant water transport occurs through interconnected xylem conduits that are separated by partially digested regions in the cell wall known as pit membranes. These structures have a dual function. Their porous construction facilitates water movement between conduits while limiting the spread of air that may enter the conduits and render them dysfunctional during a drought. Pit membranes have been well studied in woody plants, but very little is known about their function in more ancient lineages such as seedless vascular plants. Here, we examine the relationships between conduit air seeding, pit hydraulic resistance, and pit anatomy in 10 species of ferns (pteridophytes) and two lycophytes. Air seeding pressures ranged from 0.8 ± 0.15 MPa (mean ± sd) in the hydric fern Athyrium filix-femina to 4.9 ± 0.94 MPa in Psilotum nudum, an epiphytic species. Notably, a positive correlation was found between conduit pit area and vulnerability to air seeding, suggesting that the rare-pit hypothesis explains air seeding in early-diverging lineages much as it does in many angiosperms. Pit area resistance was variable but averaged 54.6 MPa s m−1 across all surveyed pteridophytes. End walls contributed 52% to the overall transport resistance, similar to the 56% in angiosperm vessels and 64% in conifer tracheids. Taken together, our data imply that, irrespective of phylogenetic placement, selection acted on transport efficiency in seedless vascular plants and woody plants in equal measure by compensating for shorter conduits in tracheid-bearing plants with more permeable pit membranes. PMID:24777347

Genetic parameters for claw and leg health, foot and leg conformation, and locomotion in Danish Holsteins

DEFF Research Database (Denmark)

Laursen, M. V.; Boelling, D.; Mark, Thomas

2009-01-01

was defined as absence of hock infection, swollen hock, and bruising. The potential indicators were locomotion and foot and leg conformation, represented by rear leg side view, rear leg rear view, foot angle, and apparent hock quality and bone structure. The study was conducted using records from 429......,877 Danish Holstein cows in first lactation. Binary health traits were divided into 3 subcategories: claw health, leg health, and absence of all claw and leg disorders. Genetic (r(g)) and phenotypic correlations were estimated using a bivariate linear sire model and REML. Estimated heritabilities were 0.......01 for all 3 combined claw and leg health traits (on the observed binary scale), 0.09 for locomotion, 0.14 for rear leg rear view, 0.19 for rear leg side view, 0.13 for foot angle, 0.22 for apparent hock quality, and 0.27 for apparent bone structure. Heritabilities were 0.06 and 0.01 for claw health and leg...

Intermittent pneumatic leg compressions acutely upregulate VEGF and MCP-1 expression in skeletal muscle.

Science.gov (United States)

Roseguini, Bruno T; Mehmet Soylu, S; Whyte, Jeffrey J; Yang, H T; Newcomer, Sean; Laughlin, M Harold

2010-06-01

Application of intermittent pneumatic compressions (IPC) is an extensively used therapeutic strategy in vascular medicine, but the mechanisms by which this method works are unclear. We tested the hypothesis that acute application (150 min) of cyclic leg compressions in a rat model signals upregulation of angiogenic factors in skeletal muscle. To explore the impact of different pressures and frequency of compressions, we divided rats into four groups as follows: 120 mmHg (2 s inflation/2 s deflation), 200 mmHg (2 s/2 s), 120 mmHg (4 s/16 s), and control (no intervention). Blood flow and leg oxygenation (study 1) and the mRNA expression of angiogenic mediators in the rat tibialis anterior muscle (study 2) were assessed after a single session of IPC. In all three groups exposed to the intervention, a modest hyperemia (approximately 37% above baseline) between compressions and a slight, nonsignificant increase in leg oxygen consumption (approximately 30%) were observed during IPC. Compared with values in the control group, vascular endothelial growth factor (VEGF) and monocyte chemotactic protein-1 (MCP-1) mRNA increased significantly (P < 0.05) only in rats exposed to the higher frequency of compressions (2 s on/2 s off). Endothelial nitric oxide synthase, matrix metalloproteinase-2, and hypoxia-inducible factor-1alpha mRNA did not change significantly following the intervention. These findings show that IPC application augments the mRNA content of key angiogenic factors in skeletal muscle. Importantly, the magnitude of changes in mRNA expression appeared to be modulated by the frequency of compressions such that a higher frequency (15 cycles/min) evoked more robust changes in VEGF and MCP-1 compared with a lower frequency (3 cycles/min).

3D mathematical modeling of glioblastoma suggests that transdifferentiated vascular endothelial cells mediate resistance to current standard-of-care therapy

Science.gov (United States)

Yan, Huaming; Romero-López, Mónica; Benitez, Lesly I.; Di, Kaijun; Frieboes, Hermann B.; Hughes, Christopher C. W.; Bota, Daniela A.; Lowengrub, John S.

2017-01-01

Glioblastoma (GBM), the most aggressive brain tumor in human patients, is decidedly heterogeneous and highly vascularized. Glioma stem/initiating cells (GSC) are found to play a crucial role by increasing cancer aggressiveness and promoting resistance to therapy. Recently, crosstalk between GSC and vascular endothelial cells has been shown to significantly promote GSC self-renewal and tumor progression. Further, GSC also transdifferentiate into bona-fide vascular endothelial cells (GEC), which inherit mutations present in GSC and are resistant to traditional anti-angiogenic therapies. Here we use 3D mathematical modeling to investigate GBM progression and response to therapy. The model predicted that GSC drive invasive fingering and that GEC spontaneously form a network within the hypoxic core, consistent with published experimental findings. Standard-of-care treatments using DNA-targeted therapy (radiation/chemo) together with anti-angiogenic therapies, reduced GBM tumor size but increased invasiveness. Anti-GEC treatments blocked the GEC support of GSC and reduced tumor size but led to increased invasiveness. Anti-GSC therapies that promote differentiation or disturb the stem cell niche effectively reduced tumor invasiveness and size, but were ultimately limited in reducing tumor size because GEC maintain GSC. Our study suggests that a combinatorial regimen targeting the vasculature, GSC, and GEC, using drugs already approved by the FDA, can reduce both tumor size and invasiveness and could lead to tumor eradication. PMID:28536277

Stable walking with asymmetric legs

International Nuclear Information System (INIS)

Merker, Andreas; Rummel, Juergen; Seyfarth, Andre

2011-01-01

Asymmetric leg function is often an undesired side-effect in artificial legged systems and may reflect functional deficits or variations in the mechanical construction. It can also be found in legged locomotion in humans and animals such as after an accident or in specific gait patterns. So far, it is not clear to what extent differences in the leg function of contralateral limbs can be tolerated during walking or running. Here, we address this issue using a bipedal spring-mass model for simulating walking with compliant legs. With the help of the model, we show that considerable differences between contralateral legs can be tolerated and may even provide advantages to the robustness of the system dynamics. A better understanding of the mechanisms and potential benefits of asymmetric leg operation may help to guide the development of artificial limbs or the design novel therapeutic concepts and rehabilitation strategies.

Venous leg ulcers

Science.gov (United States)

2008-01-01

Introduction Leg ulcers usually occur secondary to venous reflux or obstruction, but 20% of people with leg ulcers have arterial disease, with or without venous disorders. Between 1.5 and 3.0/1000 people have active leg ulcers. Prevalence increases with age to about 20/1000 in people aged over 80 years. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of standard treatments, adjuvant treatments, and organisational interventions for venous leg ulcers? What are the effects of interventions to prevent recurrence of venous leg ulcers? We searched: Medline, Embase, The Cochrane Library, and other important databases up to September 2007 (BMJ Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 80 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: compression bandages and stockings, cultured allogenic (single or bilayer) skin replacement, debriding agents, dressings (cellulose, collagen, film, foam, hyaluronic acid-derived, semi-occlusive alginate), hydrocolloid (occlusive) dressings in the presence of compression, intermittent pneumatic compression, intravenous prostaglandin E1, larval therapy, laser treatment (low-level), leg ulcer clinics, multilayer elastic system, multilayer elastomeric (or non-elastomeric) high-compression regimens or bandages, oral treatments (aspirin, flavonoids, pentoxifylline, rutosides, stanozolol, sulodexide, thromboxane alpha2 antagonists, zinc), peri

A study on the temperature distribution in the hot leg pipe

International Nuclear Information System (INIS)

Choe, Yoon-Jae; Baik, Se-Jin; Jang, Ho-Cheol; Lee, Byung-Jin; Im, In-Young; Ro, Tae-Sun

2003-01-01

In the hot leg pipes of reactor coolant system of the Korean Standard Nuclear Power Plant (KSNP), a non-uniform distribution in temperature has been observed across the cross-section, which is attributed to the non-uniformity of power distribution in the reactor core usually having a peak in the center region, and to the colder coolant bypass flow through the reactor vessel outlet nozzle clearances. As a result, the arithmetic mean temperature of four Resistance Temperature Detectors (RTDs) installed in each hot leg - two in the upper region and two in the lower region around the pipe wall may not correctly represent the actual coolant bulk temperature. It is also believed that there is a skewness in the velocity profile in the hot leg pipe due to the sudden changes in the flow direction and area from the core to the hot leg pipe, through the reactor vessel outlet plenum. These temperature non-uniformity and velocity skewness affect the measurement of the plant parameter such as the reactor coolant flow rate which is calculated by using the bulk temperature of hot leg pipes. A computational analysis has been performed to simulate the temperature and velocity distributions and to evaluate the uncertainty of temperature correction offset in the hot leg pipe. A commercial CFD code, FLUENT, is used for this analysis. The analysis results are compared with the operational data of KSNP and the scaled-down model test data for System 80. From the comparisons, an uncertainty of correction offset is obtained to measure the bulk temperature of hot leg more accurately, which can be also applied to the operating plants, leading to the reduction of temperature measurement uncertainty. Since the uncertainty of temperature in the hot leg pipe is one of major parameters to calculate the uncertainty of the reactor coolant flow rate, the analysis results can contribute to the improvement of the plant performance and safety by reducing the uncertainty of temperature measurement

Straight configuration saphenous vein transposition to popliteal artery for vascular access.

Science.gov (United States)

Caco, Gentian; Golemi, Dhurata; Likaj, Eriola

2017-03-21

The saphenous vein is commonly used as a vascular graft in peripheral artery surgery but rarely used for vascular access. The literature on straight configuration saphenous vein transposition to the popliteal artery is scarce. Here we present two cases of straight configuration saphenous vein transposition to the popliteal artery for vascular access, the surgical technique and respective follow-up. Two young men, aged 29 and 36 years, were chosen for lower-limb vascular access for hemodialysis. The first patient was paraplegic since birth. He used his arms to move so upper extremity vascular access was avoided. The second patient presented with an infected upper extremity arteriovenous graft (AVG) and after multiple closed AVFs he had no more available arm veins. Both patients received autologous lower extremity straight configuration saphenous vein transpositions to the popliteal artery under spinal anesthesia in May and October 2012, respectively. Cannulation of the fistula was allowed after one month. There were no early complications. Slight swelling on the leg appeared in one of the patients. Both fistulas were still functional after 36 and 32 months, respectively. The straight configuration saphenous vein transposition to popliteal artery is simple to perform, offers a long and straight segment for cannulation and may be a suitable autologous vascular access in selected patients.

Lyden-af-Leg

DEFF Research Database (Denmark)

Toft, Herdis

Præsentation af seniorforsker-projekt Lyden-af-Leg i et traderingsperspektiv og med indledende fokus på YouTube som traderings-platform.......Præsentation af seniorforsker-projekt Lyden-af-Leg i et traderingsperspektiv og med indledende fokus på YouTube som traderings-platform....

Chronic hindlimb ischemia impairs functional vasodilation and vascular reactivity in mouse feed arteries

Directory of Open Access Journals (Sweden)

Trevor R Cardinal

2011-12-01

Full Text Available Vasodilation of lower leg arterioles is impaired in animal models of chronic peripheral ischemia. In addition to arterioles, feed arteries are a critical component of the vascular resistance network, accounting for as much as 50% of the pressure drop across the arterial circulation. Despite the critical importance of feed arteries in blood flow control, the impact of ischemia on feed artery vascular reactivity is unknown. At 14 days following unilateral resection of the femoral-saphenous artery-vein pair, functional vasodilation of the profunda femoris artery was severely impaired, 11 ± 9% versus 152 ± 22%. Although endothelial and smooth muscle-dependent vasodilation were both impaired in ischemic arteries compared to control arteries (Ach: 40 ± 14% vs 81 ± 11%, SNP: 43 ± 12% vs and 85 ± 11%, the responses to acetylcholine and sodium nitroprusside were similar, implicating impaired smooth muscle-dependent vasodilation. Conversely, vasoconstriction responses to norepinephrine were not different between ischemic and control arteries, -68 ± 3% versus -66 ± 3%, indicating that smooth muscle cells were functional following the ischemic insult. Finally, maximal dilation responses to acetylcholine, in vitro, were significantly impaired in the ischemic artery compared to control, 71 ± 9% versus 97 ± 2%, despite a similar generation of myogenic tone to the same intravascular pressure (80 mmHg. These data indicate that ischemia impairs feed artery vasodilation by impairing the vascular wall’s responsiveness to vasodilating stimuli. Future studies to examine the mechanistic basis for these observations or treatment strategies to improve feed artery vasodilation following ischemia could provide the foundation for an alternative therapeutic paradigm for peripheral arterial occlusive disease.

Increasing trunk flexion transforms human leg function into that of birds despite different leg morphology.

Science.gov (United States)

Aminiaghdam, Soran; Rode, Christian; Müller, Roy; Blickhan, Reinhard

2017-02-01

Pronograde trunk orientation in small birds causes prominent intra-limb asymmetries in the leg function. As yet, it is not clear whether these asymmetries induced by the trunk reflect general constraints on the leg function regardless of the specific leg architecture or size of the species. To address this, we instructed 12 human volunteers to walk at a self-selected velocity with four postures: regular erect, or with 30 deg, 50 deg and maximal trunk flexion. In addition, we simulated the axial leg force (along the line connecting hip and centre of pressure) using two simple models: spring and damper in series, and parallel spring and damper. As trunk flexion increases, lower limb joints become more flexed during stance. Similar to birds, the associated posterior shift of the hip relative to the centre of mass leads to a shorter leg at toe-off than at touchdown, and to a flatter angle of attack and a steeper leg angle at toe-off. Furthermore, walking with maximal trunk flexion induces right-skewed vertical and horizontal ground reaction force profiles comparable to those in birds. Interestingly, the spring and damper in series model provides a superior prediction of the axial leg force across trunk-flexed gaits compared with the parallel spring and damper model; in regular erect gait, the damper does not substantially improve the reproduction of the human axial leg force. In conclusion, mimicking the pronograde locomotion of birds by bending the trunk forward in humans causes a leg function similar to that of birds despite the different morphology of the segmented legs. © 2017. Published by The Company of Biologists Ltd.

Single-leg squats can predict leg alignment in dancers performing ballet movements in “turnout”

Directory of Open Access Journals (Sweden)

Hopper LS

2016-11-01

Full Text Available Luke S Hopper,1 Nahoko Sato,2 Andries L Weidemann1 1Western Australian Academy of Performing Arts, Edith Cowan University, Mt Lawley, WA, Australia; 2Department of Physical Therapy, Nagoya Gakuin University, Seto, Japan Abstract: The physical assessments used in dance injury surveillance programs are often adapted from the sports and exercise domain. Bespoke physical assessments may be required for dance, particularly when ballet movements involve “turning out” or external rotation of the legs beyond that typically used in sports. This study evaluated the ability of the traditional single-leg squat to predict the leg alignment of dancers performing ballet movements with turnout. Three-dimensional kinematic data of dancers performing the single-leg squat and five ballet movements were recorded and analyzed. Reduction of the three-dimensional data into a one-dimensional variable incorporating the ankle, knee, and hip joint center positions provided the strongest predictive model between the single-leg squat and the ballet movements. The single-leg squat can predict leg alignment in dancers performing ballet movements, even in “turned out” postures. Clinicians should pay careful attention to observational positioning and rating criteria when assessing dancers performing the single-leg squat. Keywords: injury, motion capture, clinical assessment

Immediate changes in estimated cardiac output and vascular resistance after 60Co exposure in monkeys: implication for performance decrement

International Nuclear Information System (INIS)

Bruner, A.

1977-01-01

Aortic blood flow velocity, blood pressure, and heart rate were recorded in 12 unanesthetized, nonperforming monkeys during exposure to 1000 rad 60 Co at 129--164 rad/min. The first postradiation changes were seen within 3--4 min of the exposure's start and included tachycardia, a transient hypotension secondary to a loss in peripheral resistance, and a brief increase followed by a decrease to subnormal levels in cardiac output. The lowest cardiac output occurred between 10 and 20 min postexposure while blood pressure and peripheral resistance were recovering. It was proposed that the concurrent combination of low cardiac output, low blood pressure, and supranormal peripheral resistance might sufficiently attenuate cerebral perfusion temporarily to account for the transient behavioral decrements often seen during this time. Histamine release was postulated as responsible for this vascular shock syndrome

Similar acute physiological responses from effort and duration matched leg press and recumbent cycling tasks

Directory of Open Access Journals (Sweden)

James Steele

2018-02-01

Full Text Available The present study examined the effects of exercise utilising traditional resistance training (leg press or ‘cardio’ exercise (recumbent cycle ergometry modalities upon acute physiological responses. Nine healthy males underwent a within session randomised crossover design where they completed both the leg press and recumbent cycle ergometer conditions. Conditions were approximately matched for effort and duration (leg press: 4 × 12RM using a 2 s concentric and 3 s eccentric repetition duration controlled with a metronome, thus each set lasted  60 s; recumbent cycle ergometer: 4 × 60 s bouts using a resistance level permitting 80–100 rpm but culminating with being unable to sustain the minimum cadence for the final 5–10 s. Measurements included VO2, respiratory exchange ratio (RER, blood lactate, energy expenditure, muscle swelling, and electromyography. Perceived effort was similar between conditions and thus both were well matched with respect to effort. There were no significant effects by ‘condition’ in any of the physiological responses examined (all p > 0.05. The present study shows that, when both effort and duration are matched, resistance training (leg press and ‘cardio’ exercise (recumbent cycle ergometry may produce largely similar responses in VO2, RER, blood lactate, energy expenditure, muscle swelling, and electromyography. It therefore seems reasonable to suggest that both may offer a similar stimulus to produce chronic physiological adaptations in outcomes such as cardiorespiratory fitness, strength, and hypertrophy. Future work should look to both replicate the study conducted here with respect to the same, and additional physiological measures, and rigorously test the comparative efficacy of effort and duration matched exercise of differing modalities with respect to chronic improvements in physiological fitness.

Leg Injuries and Disorders

Science.gov (United States)

... are important for motion and standing. Playing sports, running, falling, or having an accident can damage your legs. Common leg injuries include sprains and strains, joint dislocations, and fractures. ...

Quality assurance of lower limb venous duplex scans performed by vascular surgeons.

Science.gov (United States)

Kordowicz, A; Ferguson, G; Salaman, R; Onwudike, M

2015-02-01

Duplex scanning is the gold standard for investigating venous reflux; increasingly surgeons perform these scans themselves. There has been no data published analysing the accuracy of Duplex scans performed by vascular surgeons. We aimed to evaluate an objective method of comparing the results of lower limb Duplex scans performed by one consultant vascular surgeon with those performed by a vascular technologist. We assessed 100 legs with symptomatic varicose veins. Each patient underwent two lower limb venous Duplex scans; one performed by a consultant vascular surgeon and one by a vascular technologist. Scan results were randomised and sent to two consultant vascular surgeons blinded to the identity and experience of the sonographer. They were asked to recommend treatment. A k score was calculated in each case to assess the level of agreement between the scans performed by the consultant and the technologist. Eighty-one patients were studied (53 females). The kappa score for assessor 1 was 0.60 (95%CI:0.44-0.75) and for assessor 2 was 0.62 (95%CI:0.48-0.75). k scores >0.60 represent a substantial strength of agreement. Duplex scans performed by this surgeon were comparable to those performed by a vascular technologist. It is possible to quality-assure duplex performed by vascular surgeons without directly observing the scanning process or reviewing digitally recorded images. We propose standardisation of training, assessment and quality assurance for vascular surgeons wishing to perform ultrasound scans.

Endothelial mechanotransduction proteins and vascular function are altered by dietary sucrose supplementation in healthy young male subjects

DEFF Research Database (Denmark)

Gliemann, Lasse; Rytter, Nicolai; Lindskrog, Mads

2017-01-01

Endothelial mechanotransduction is important for vascular function but alterations and activation of vascular mechanosensory proteins have not been investigated in humans. In endothelial cell culture, simple sugars effectively impair mechanosensor proteins. To study mechanosensor- and vascular...... by ultrasound doppler. A muscle biopsy was obtained from the thigh muscle before and after acute passive leg movement, to asses the protein amount and phosphorylation status of mechanosensory proteins and NADPH oxidase. The sucrose intervention led to a reduced flow response to passive movement (by 17 ± 2...... %) and to 12 watts of active exercise (by 9 ± 1 %), indicating impaired vascular function. Reduced flow response to passive and active exercise was paralleled by a significant upregulation of Platelet endothelial cell adhesion molecule (PECAM-1), endothelial nitric oxide synthase, NADPH oxidase and the Rho...

EFFECT OF MODERATE ALTITUDE ON PERIPHERAL MUSCLE OXYGENATION DURING LEG RESISTANCE EXERCISE IN YOUNG MALES

Directory of Open Access Journals (Sweden)

Toshio Matsuoka

2004-09-01

Full Text Available Training at moderate altitude (~1800m is often used by athletes to stimulate muscle hypoxia. However, limited date is available on peripheral muscle oxidative metabolism at this altitude (1800AL. The purpose of this study was to determine whether acute exposure to 1800AL alters muscle oxygenation in the vastus lateralis muscle during resistance exercise. Twenty young active male subjects (aged 16 - 21 yr performed up to 50 repetitions of the parallel squat at 1800AL and near sea level (SL. They performed the exercise protocol within 3 h after arrival at 1800 AL. During the exercise, the changes in oxygenated hemoglobin (OxyHb in the vastus lateralis muscle, arterial oxygen saturation (SpO2, and heart rate were measured using near infrared continuous wave spectroscopy (NIRcws and pulse oximetry, respectively. Changes in OxyHb were expressed by Deff defined as the relative index of the maximum change ratio (% from the resting level. OxyHb in the vastus lateralis muscle decreased dramatically from the resting level immediately after the start of exercise at both altitudes. The Deff during exercise was significantly (p < 0.001 lower at 1800AL (60.4 ± 6.2 % than at near SL (74.4 ± 7.6 %. SpO2 during exercise was significantly (p < 0.001 lower at 1800AL (92.0 ± 1.7 % than at near SL (96.7 ± 1.2 %. Differences (SL - 1800AL in Deff during exercise correlated fairly strongly with differences in SpO2 during exercise (r = 0.660. These results suggested that acute exposure to moderate altitude caused a more dramatical decrease in peripheral muscle oxygenation during leg resistance exercise. It is salient to note, therefore , that peripheral muscle oxygenation status at moderate altitude could be evaluated using NIRcws and that moderate altitudes might be effectively used to apply hypoxic stress on peripheral muscles.

Microbiologic evaluation of skin wounds: alarming trend toward antibiotic resistance in an inpatient dermatology service during a 10-year period.

Science.gov (United States)

Valencia, Isabel C; Kirsner, Robert S; Kerdel, Francisco A

2004-06-01

Increasing resistance to commonly used antibiotics has been seen for patients with superficial skin wounds and leg ulcers. We sought to evaluate bacterial isolates from leg ulcers and superficial wounds for resistance to commonly used antibiotics and to compare current data with previous data. We performed a chart review for patients admitted to a tertiary care dermatology inpatient unit from January to December 2001. Comparison was made with 2 previous surveys of the same inpatient service from 1992 and 1996. Bacterial isolates were cultured from 148 patients, 84% (72 of 86) with leg ulcers and 38% (76 of 202) with superficial wounds. Staphylococcus aureus and Pseudomonas aeruginosa were the most common bacterial isolates in both groups. For patients with leg ulcers, S aureus grew in 67% of isolates (48/72) of which 75% (36/48) were methicillin-resistant (MRSA). Of leg ulcers, 35% (25/72) grew P aeruginosa, which was resistant to quinolones in 56% of cultures (14/25). For patients with superficial wounds, S aureus was isolated in 75% (57/76) and 44% were MRSA (25/57). P aeruginosa grew in 17% of isolates (13/76) and was resistant to quinolones in 18%. We found a marked increase in antibiotic resistance for both leg ulcers and superficial wounds. Over time, MRSA increased in leg ulcers from 26% in 1992 to 75% in 2001. For superficial wounds, MRSA increased from 7% in 1992 to 44% in 2001. P aeruginosa resistance to quinolones in leg ulcers increased from 19% in 1992 to 56% in 2001, whereas for superficial wounds there was no resistance in 1992 and 18% resistance in 2001. Rapid emergence of antibiotic-resistant bacteria continues and is a problem of increasing significance in dermatology. Common pathogenic bacteria, S aureus and P aeruginosa, showed increased resistance to commonly used antibiotics. Selection of antibiotics should be on the basis of local surveillance programs.

Are the hamstrings from the drive leg or landing leg more active in baseball pitchers? An electromyographic study.

Science.gov (United States)

Erickson, Brandon J; Zaferiou, Antonia; Chalmers, Peter N; Ruby, Deana; Malloy, Phillip; Luchetti, Timothy J; Verma, Nikhil N; Romeo, Anthony A

2017-11-01

Ulnar collateral ligament reconstruction (UCLR) has become a common procedure among baseball players of all levels. There are several graft choices in performing UCLR, one of which is a hamstring (gracilis or semitendinosus) autograft. It is unclear whether the hamstring muscle from a pitcher's drive leg (ipsilateral side of the UCLR) or landing leg (contralateral side of the UCLR) is more active during the pitching motion. We hypothesized that the landing leg semitendinosus will be more electromyographically active than the drive leg. Healthy, elite male pitchers aged 16-21 years were recruited. Sixteen pitchers (average age, 17.6 ± 1.6 years; 67% threw right handed) underwent electromyographic analysis. Pitchers threw 5 fastballs at 100% effort from the wind-up with electromyographic analysis of every pitch. Activation of the semitendinosus and biceps femoris in both legs was compared within pitchers and between pitchers. Hamstring activity was higher in the drive leg than in the landing leg during each phase and in sum, although the difference was significant only during the double support phase (P = .021). On within-pitcher analysis, 10 of 16 pitchers had significantly more sum hamstring activity in the drive leg than in the landing leg, while only 4 of 16 had more activity in the landing leg (P = .043). During the baseball pitch, muscle activity of the semitendinosus was higher in the drive leg than in the landing leg in most pitchers. Surgeons performing UCLR using hamstring autograft should consider harvesting the graft from the pitcher's landing leg to minimize disruption to the athlete's pitching motion. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Effect of alternating and direct currents on Pseudomonas ...

African Journals Online (AJOL)

ONOS

2010-09-20

Sep 20, 2010 ... Based on the effect of natural selection, these bacteria become resistant to ..... Effect of electrical stimulation on chronic leg ulcer size and appearance. Phys. ... stimulation directly induces pre-angiogenic responses in vascular.

Vascular Remodeling in Experimental Hypertension

Directory of Open Access Journals (Sweden)

Norma R. Risler

2005-01-01

Full Text Available The basic hemodynamic abnormality in hypertension is an increased peripheral resistance that is due mainly to a decreased vascular lumen derived from structural changes in the small arteries wall, named (as a whole vascular remodeling. The vascular wall is an active, flexible, and integrated organ made up of cellular (endothelial cells, smooth muscle cells, adventitia cells, and fibroblasts and noncellular (extracellular matrix components, which in a dynamic way change shape or number, or reorganize in response to physiological and pathological stimuli, maintaining the integrity of the vessel wall in physiological conditions or participating in the vascular changes in cardiovascular diseases such as hypertension. Research focused on new signaling pathways and molecules that can participate in the mechanisms of vascular remodeling has provided evidence showing that vascular structure is not only affected by blood pressure, but also by mechanisms that are independent of the increased pressure. This review will provide an overview of the evidence, explaining some of the pathophysiologic mechanisms participating in the development of the vascular remodeling, in experimental models of hypertension, with special reference to the findings in spontaneously hypertensive rats as a model of essential hypertension, and in fructose-fed rats as a model of secondary hypertension, in the context of the metabolic syndrome. The understanding of the mechanisms producing the vascular alterations will allow the development of novel pharmacological tools for vascular protection in hypertensive disease.

Central and peripheral fat and subclinical vascular damage in older women.

Science.gov (United States)

Fantin, Francesco; Rossi, Andrea P; Cazzadori, Marco; Comellato, Gabriele; Mazzali, Gloria; Gozzoli, Maria Paola; Grison, Elisa; Zamboni, Mauro

2013-05-01

the aim of this study was to evaluate the relationship between fat distribution and arterial compliance in a group of elderly women, in particular to test a possible independent role of abdominal fat mass and peripheral fat mass on subclinical vascular damage, defined by a pulse wave velocity (PWV) >12 m/s. in 96 women with age range 60-80 years (68.65 ± 4.98 years) and BMI range from 18.8 to 41.2 kg/m(2) (27.07 ± 4.61 kg/m(2)), we evaluated the body mass index, waist circumference, systolic and diastolic blood pressure, fasting glucose, cholesterol, LDL and HDL cholesterol, triglycerides and body composition by dual energy X-ray absorptiometry (DXA). Arterial stiffness was assessed by carotid-femoral (PWVcf) and carotid-radial pulse wave velocity (PWVcr). significant associations were found between PWVcf, age, waist circumference, BMI and trunk fat assessed by DXA, as well as TG and HDL cholesterol. After adjustment for the total fat mass a negative statistically significant association between PWVcf and leg fat mass was shown. In multiple regression analyses the mean arterial pressure, trunk fat mass and leg fat mass were significant predictors of vascular damage with OR, respectively, of 1.06 (CI: 1.01-1.11), 1.25 (CI: 1.06-1.48) and 0.73 (CI: 0.53-0.99). the results of this study show, in a sample of apparently healthy elderly women, that central and peripheral adiposity are independent predictors, with an opposite effect on subclinical vascular damage, confirming and strengthening the protective role of the gluteal-femoral fat on cardiovascular risk even in elderly.

Effect of Roux-en-Y Bariatric Surgery on Lipoproteins, Insulin Resistance, and Systemic and Vascular Inflammation in Obesity and Diabetes

Directory of Open Access Journals (Sweden)

Rahul Yadav

2017-11-01

Full Text Available PurposeObesity is a major modifiable risk factor for cardiovascular disease. Bariatric surgery is considered to be the most effective treatment option for weight reduction in obese patients with and without type 2 diabetes (T2DM.ObjectiveTo evaluate changes in lipoproteins, insulin resistance, mediators of systemic and vascular inflammation, and endothelial dysfunction following Roux-en-Y bariatric surgery in obese patients with and without diabetes.Materials and methodsLipoproteins, insulin resistance, mediators of systemic and vascular inflammation, and endothelial dysfunction were measured in 37 obese patients with (n = 17 and without (n = 20 T2DM, before and 6 and 12 months after Roux-en-Y bariatric surgery. Two way between subject ANOVA was carried out to study the interaction between independent variables (time since surgery and presence of diabetes and all dependent variables.ResultsThere was a significant effect of time since surgery on (large effect size weight, body mass index (BMI, waist circumference, triglycerides (TG, small-dense LDL apolipoprotein B (sdLDL ApoB, HOMA-IR, CRP, MCP-1, ICAM-1, E-selectin, P-selectin, leptin, and adiponectin. BMI and waist circumference had the largest impact of time since surgery. The effect of time since surgery was noticed mostly in the first 6 months. Absence of diabetes led to a significantly greater reduction in total cholesterol, low-density lipoprotein cholesterol, and non-high-density lipoprotein cholesterol although the effect size was small to medium. There was a greater reduction in TG and HOMA-IR in patients with diabetes with a small effect size. No patients were lost to follow up.ConclusionLipoproteins, insulin resistance, mediators of systemic and vascular inflammation, and endothelial dysfunction improve mostly 6 months after bariatric surgery in obese patients with and without diabetes.Clinical Trial Registrationwww.ClinicalTrials.gov, identifier: NCT02169518. https

In Vivo Imaging Reveals Significant Tumor Vascular Dysfunction and Increased Tumor Hypoxia-Inducible Factor-1α Expression Induced by High Single-Dose Irradiation in a Pancreatic Tumor Model

Energy Technology Data Exchange (ETDEWEB)

Maeda, Azusa [Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario (Canada); Chen, Yonghong; Bu, Jiachuan; Mujcic, Hilda [Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario (Canada); Wouters, Bradly G. [Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); DaCosta, Ralph S., E-mail: rdacosta@uhnres.utoronto.ca [Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario (Canada); Techna Institute, University Health Network, Toronto, Ontario (Canada)

2017-01-01

Purpose: To investigate the effect of high-dose irradiation on pancreatic tumor vasculature and microenvironment using in vivo imaging techniques. Methods and Materials: A BxPC3 pancreatic tumor xenograft was established in a dorsal skinfold window chamber model and a subcutaneous hind leg model. Tumors were irradiated with a single dose of 4, 12, or 24 Gy. The dorsal skinfold window chamber model was used to assess tumor response, vascular function and permeability, platelet and leukocyte adhesion to the vascular endothelium, and tumor hypoxia for up to 14 days after 24-Gy irradiation. The hind leg model was used to monitor tumor size, hypoxia, and vascularity for up to 65 days after 24-Gy irradiation. Tumors were assessed histologically to validate in vivo observations. Results: In vivo fluorescence imaging revealed temporary vascular dysfunction in tumors irradiated with a single dose of 4 to 24 Gy, but most significantly with a single dose of 24 Gy. Vascular functional recovery was observed by 14 days after irradiation in a dose-dependent manner. Furthermore, irradiation with 24 Gy caused platelet and leukocyte adhesion to the vascular endothelium within hours to days after irradiation. Vascular permeability was significantly higher in irradiated tumors compared with nonirradiated controls 14 days after irradiation. This observation corresponded with increased expression of hypoxia-inducible factor-1α in irradiated tumors. In the hind leg model, irradiation with a single dose of 24 Gy led to tumor growth delay, followed by tumor regrowth. Conclusions: Irradiation of the BxPC3 tumors with a single dose of 24 Gy caused transient vascular dysfunction and increased expression of hypoxia-inducible factor-1α. Such biological changes may impact tumor response to high single-dose and hypofractionated irradiation, and further investigations are needed to better understand the clinical outcomes of stereotactic body radiation therapy.

Effects of tham, isoprenaline and propranolol on blood flow and vascular resistances of the liver after in- and outflow occlusion. Relation with the splanchnic shock.

Science.gov (United States)

Stoitchcov, E; Kawai, T; Bleser, F; Benichoux, R

1976-01-01

The responsibility of the portal and the hepatic artery circulations during shock states has been established by studying the effects of a 15-min occlusion of two of the following blood vessels on 23 dogs: inferior vena cava below the diaphragm, portal vein and hepatic artery. Intrahepatic vascular resistances were computed from blood pressure records in these vessels and transhepatic blood flow studies using the 133Xe clearance method. The animals were treated with THAM, plasmagel, isoprenaline, and propranolol. The tolerance of the occlusion is significantly improved when the animals are treated with the association of the four drugs. The portal and the systemic arterial blood pressures return to normal more promptly. Sinusoid and peribiliary resistances are remarkably stable if compared to the changes occurring in the control animals. The well-known benefit of THAM is improved by the apparently paradoxical association of isoprenaline and propranolol. In fact, at the doses which have been used, they counterbalance their mutual disadvantages. Finally, the analysis of the hepatic blood flow rates and vascular resistances suggests that the splanchnic shock has two components: hepatic and visceral.

Compatibility between Co-Metallized PbTe Thermoelectric Legs and an Ag-Cu-In Brazing Alloy.

Science.gov (United States)

Ben-Ayoun, Dana; Sadia, Yatir; Gelbstein, Yaniv

2018-01-10

In thermoelectric (TE) generators, maximizing the efficiency of conversion of direct heat to electricity requires the reduction of any thermal and electrical contact resistances between the TE legs and the metallic contacts. This requirement is especially challenging in the development of intermediate to high-temperature TE generators. PbTe-based TE materials are known to be highly efficient up to temperatures of around 500 °C; however, only a few practical TE generators based on these materials are currently commercially available. One reason for that is the insufficient bonding techniques between the TE legs and the hot-side metallic contacts. The current research is focused on the interaction between cobalt-metallized n -type 9.104 × 10 -3 mol % PbI₂-doped PbTe TE legs and the Ag 0.32 Cu 0.43 In 0.25 brazing alloy, which is free of volatile species. Clear and fine interfaces without any noticeable formation of adverse brittle intermetallic compounds were observed following prolonged thermal treatment testing. Moreover, a reasonable electrical contact resistance of ~2.25 mΩmm² was observed upon brazing at 600 °C, highlighting the potential of such contacts while developing practical PbTe-based TE generators.

Compatibility between Co-Metallized PbTe Thermoelectric Legs and an Ag–Cu–In Brazing Alloy

Science.gov (United States)

Ben-Ayoun, Dana; Sadia, Yatir; Gelbstein, Yaniv

2018-01-01

In thermoelectric (TE) generators, maximizing the efficiency of conversion of direct heat to electricity requires the reduction of any thermal and electrical contact resistances between the TE legs and the metallic contacts. This requirement is especially challenging in the development of intermediate to high-temperature TE generators. PbTe-based TE materials are known to be highly efficient up to temperatures of around 500 °C; however, only a few practical TE generators based on these materials are currently commercially available. One reason for that is the insufficient bonding techniques between the TE legs and the hot-side metallic contacts. The current research is focused on the interaction between cobalt-metallized n-type 9.104 × 10−3 mol % PbI2-doped PbTe TE legs and the Ag0.32Cu0.43In0.25 brazing alloy, which is free of volatile species. Clear and fine interfaces without any noticeable formation of adverse brittle intermetallic compounds were observed following prolonged thermal treatment testing. Moreover, a reasonable electrical contact resistance of ~2.25 mΩmm2 was observed upon brazing at 600 °C, highlighting the potential of such contacts while developing practical PbTe-based TE generators. PMID:29320430

IR imaging of blood circulation of patients with vascular disease

Science.gov (United States)

Wang, Hsin; Wade, Dwight R., Jr.; Kam, Jack

2004-04-01

We conducted a preliminary IR imaging study of blood circulation in patients with peripheral vascular diseases. Abnormal blood flow is common in older adults, especially those with elevated blood lipids, diabetes, hypertension, and a history of smoking. All of these conditions have a high prevalence in our population, often with more than one condition in the same individual. The differences in blood flow is revealed by temperature differences in areas of the extremities as well as other regions of the body. However, what is needed is an imaging technique that is relatively inexpensive and can reveal the blood flow in real time. The IR imaging can show detailed venous system and small tempearture changes associated with blood flow. Six patients with vascular diseases were tested in a clinic set up. Their legs and feet were imaged. We observed large temperature differences (cooling of more than 10° C) at the foot, especially toes. More valuable information were obtained from the temperature distribution maps. IR thermography is potentially a very valuable tool for medical application, especially for vascular diseases.

A Study on Temperature Distribution in the Hot Leg Pipes considering the Variation of Flow Rate in RCS

Energy Technology Data Exchange (ETDEWEB)

Cho, Hyuksu; Yi, Kunwoo; Choe, Yoonjae; Jang, Hocheol; Yune, Seokjeong; Park, Seongchan [KEPCO Engineering and Construction, Daejeon (Korea, Republic of)

2016-10-15

In this study, a computational analysis is performed to predict the deviation in the temperature distribution in the hot leg pipe according to the flow rate variation in RCS. In the hot leg pipes of Reactor Coolant System (RCS) of APR1400, four Resistance Temperature Detectors (RTDs), to obtain the average hot leg temperature, are installed at each hot leg pipe (two in the upper region and the other two in the lower region around the wall of the hot leg pipe). There is a deviation in temperature distribution in the hot leg pipe due to the sudden changes in the flow direction and area from the reactor core exit to the hot leg pipe. The non-uniform temperature distribution in the hot leg pipe can affect the measurement of the plant parameters such as the reactor power and the reactor coolant flow rate. The following conclusions are reached 1) The non-uniform temperature distribution in the core exit is sustained to some extent through the entire region of hot leg pipe. 2) The temperature ranges having a uniform pattern are 45 - 120° and 240 - 315°. The sensor positions of RTDs are located in this interval (45 - 120° and 240 - 315°) and this sensor positions of RTDs show the appropriate temperature measurement. Also, the temperature distribution shows the similar pattern without reference to the flow rate variation in RCS.

Analysis of large break loss of coolant accident with simultaneous injection into cold leg and hot leg

International Nuclear Information System (INIS)

Luo Bangqi

1997-01-01

When a large break loss of coolant accident occurs, the most part of the safety injection water injected into the cold leg by the safety injection system will flow through the channel between the pressure vessel and the barrel out of the break into the containment, only a little part of the safety injection water can flow into the reactor core. If the safety injection can inject into both the cold leg and the hot leg simultaneously, the safety injection water injected from the cold leg will flow into the core more easily, because the safety injection water injected from the hot leg will carry out more heat from the upper plenum and the core, so the upper plenum and the core is depressed. In addition, a small part of the safety injection water injected from the hot leg will flow down in the core after impinging the guide tubes in the upper plenum, so the core will get more safety injection water than only cold leg injection, and the core will be much safer

Vascular endothelial dysfunction in β-thalassemia occurs despite increased eNOS expression and preserved vascular smooth muscle cell reactivity to NO.

Directory of Open Access Journals (Sweden)

Ekatherina Stoyanova

Full Text Available The hereditary β-thalassemia major condition requires regular lifelong blood transfusions. Transfusion-related iron overloading has been associated with the onset of cardiovascular complications, including cardiac dysfunction and vascular anomalies. By using an untransfused murine model of β-thalassemia major, we tested the hypothesis that vascular endothelial dysfunction, alterations of arterial structure and of its mechanical properties would occur despite the absence of treatments.Vascular function and structure were evaluated ex vivo. Compared to the controls, endothelium-dependent vasodilation with acetylcholine was blunted in mesenteric resistance arteries of β-thalassemic mice while the endothelium-independent vasodilator (sodium nitroprusside produced comparable vessel dilation, indicating endothelial cell impairment with preserved smooth muscle cell reactivity to nitric oxide (NO. While these findings suggest a decrease in NO bioavailability, Western blotting showed heightened expression of aortic endothelial NO synthase (eNOS in β-thalassemia. Vascular remodeling of the common carotid arteries revealed increased medial elastin content. Under isobaric conditions, the carotid arteries of β-thalassemic mice exhibited decreased wall stress and softening due to structural changes of the vessel wall.A complex vasculopathy was identified in untransfused β-thalassemic mice characterized by altered carotid artery structure and endothelial dysfunction of resistance arterioles, likely attributable to reduced NO bioavailability despite enhanced vascular eNOS expression.

Decreased distensibility of a passive vascular bed in diabetes mellitus

DEFF Research Database (Denmark)

Faris, I; Agerskov, K; Henrikson, O

1982-01-01

exercise and (b) in a vascular bed locally paralysed by the injection of papaverine. Five normal subjects, six patients with long-standing Type 1 diabetes and six non-diabetic patients with severe atherosclerosis affecting the legs were studied. Blood flow was measured in the anterior tibial muscle......This study was undertaken to determine whether the distensibility of a passive vascular bed is reduced in Type 1 (insulin-dependent) diabetic patients with microangiopathy. The change in blood flow induced by 45 degrees head-up tilting was studied in two systems: (a) following maximal ischaemic...... by the isotope washout technique. The median increase in blood flow produced by tilting was greater in normal subjects than in diabetic subjects in both the locally-relaxed bed (58% and 14% respectively) and after maximal ischaemic exercise (45% and 4% respectively). In the atherosclerotic subjects, the increase...

Leg og dannelse

DEFF Research Database (Denmark)

Skovbjerg, Helle Marie

2017-01-01

lederen i det pædagogiske tidskrift Asterisk: ”Leg i skolen, leg i klasserummet, ja legende læring i skolen udgør derimod en enorm, seriøs og ubrugt læringsressource – ikke alene med effekter på kreativiteten, men også på den faglige læring” (Holm, 2015, p. 2). Legens værdi gøres altså først og fremmest...

The Motor and the Brake of the Trailing Leg in Human Walking: Leg Force Control Through Ankle Modulation and Knee Covariance

Science.gov (United States)

Toney, Megan E.; Chang, Young-Hui

2016-01-01

Human walking is a complex task, and we lack a complete understanding of how the neuromuscular system organizes its numerous muscles and joints to achieve consistent and efficient walking mechanics. Focused control of select influential task-level variables may simplify the higher-level control of steady state walking and reduce demand on the neuromuscular system. As trailing leg power generation and force application can affect the mechanical efficiency of step-to-step transitions, we investigated how joint torques are organized to control leg force and leg power during human walking. We tested whether timing of trailing leg force control corresponded with timing of peak leg power generation. We also applied a modified uncontrolled manifold analysis to test whether individual or coordinated joint torque strategies most contributed to leg force control. We found that leg force magnitude was adjusted from step-to-step to maintain consistent leg power generation. Leg force modulation was primarily determined by adjustments in the timing of peak ankle plantar-flexion torque, while knee torque was simultaneously covaried to dampen the effect of ankle torque on leg force. We propose a coordinated joint torque control strategy in which the trailing leg ankle acts as a motor to drive leg power production while trailing leg knee torque acts as a brake to refine leg power production. PMID:27334888

A Hydroxyurea-induced Leg Ulcer

OpenAIRE

Hwang, Seon-Wook; Hong, Soon-Kwon; Kim, Sang-Hyun; Seo, Jong-Keun; Lee, Deborah; Sung, Ho-Suk

2009-01-01

Hydroxyurea is a cytostatic agent that has recently become the drug of choice in the treatment of various myeloproliferative diseases. The cutaneous side effects of hydroxyurea include xerosis, hyperpigmentation, nail discoloration, and scaling. Leg ulcers have only rarely been reported in association with hydroxyurea treatment. A 75-year-old woman presented with leg ulcers, nail discoloration, and xerosis. The leg ulcers were refractory to conventional treatment. She had been taking oral hyd...

Pipe crawler with extendable legs

International Nuclear Information System (INIS)

Zollinger, W.T.

1992-01-01

A pipe crawler for moving through a pipe in inchworm fashion having front and rear leg assemblies separated by air cylinders to increase and decrease the spacing between assemblies. Each leg of the four legs of an assembly is moved between a wall-engaging, extended position and a retracted position by a separate air cylinder. The air cylinders of the leg assemblies are preferably arranged in pairs of oppositely directed cylinders with no pair lying in the same axial plane as another pair. Therefore, the cylinders can be as long as a leg assembly is wide and the crawler can crawl through sections of pipes where the diameter is twice that of other sections. The crawler carries a valving system, a manifold to distribute air supplied by a single umbilical air hose to the various air cylinders in a sequence controlled electrically by a controller. The crawler also utilizes a rolling mechanism, casters in this case, to reduce friction between the crawler and pipe wall thereby further extending the range of the pipe crawler. 8 figs

Pipe crawler with extendable legs

Science.gov (United States)

Zollinger, W.T.

1992-06-16

A pipe crawler for moving through a pipe in inchworm fashion having front and rear leg assemblies separated by air cylinders to increase and decrease the spacing between assemblies. Each leg of the four legs of an assembly is moved between a wall-engaging, extended position and a retracted position by a separate air cylinder. The air cylinders of the leg assemblies are preferably arranged in pairs of oppositely directed cylinders with no pair lying in the same axial plane as another pair. Therefore, the cylinders can be as long as a leg assembly is wide and the crawler can crawl through sections of pipes where the diameter is twice that of other sections. The crawler carries a valving system, a manifold to distribute air supplied by a single umbilical air hose to the various air cylinders in a sequence controlled electrically by a controller. The crawler also utilizes a rolling mechanism, casters in this case, to reduce friction between the crawler and pipe wall thereby further extending the range of the pipe crawler. 8 figs.

Insulin resistance in vascular endothelial cells promotes intestinal tumour formation

DEFF Research Database (Denmark)

Wang, X; Häring, M-F; Rathjen, Thomas

2017-01-01

in vascular endothelial cells. Strikingly, these mice had 42% more intestinal tumours than controls, no change in tumour angiogenesis, but increased expression of vascular cell adhesion molecule-1 (VCAM-1) in primary culture of tumour endothelial cells. Insulin decreased VCAM-1 expression and leukocyte...... adhesion in quiescent tumour endothelial cells with intact insulin receptors and partly prevented increases in VCAM-1 and leukocyte adhesion after treatment with tumour necrosis factor-α. Knockout of insulin receptors in endothelial cells also increased leukocyte adhesion in mesenteric venules...

Effects of ouabain on vascular reactivity

Directory of Open Access Journals (Sweden)

Vassallo D.V.

1997-04-01

Full Text Available Ouabain is an endogenous substance occurring in the plasma in the nanomolar range, that has been proposed to increase vascular resistance and induce hypertension. This substance acts on the a-subunit of Na+,K+-ATPase inhibiting the Na+-pump activity. In the vascular smooth muscle this effect leads to intracellular Na+ accumulation that reduces the activity of the Na+/Ca2+ exchanger and to an increased vascular tone. It was also suggested that circulating ouabain, even in the nanomolar range, sensitizes the vascular smooth muscle to vasopressor substances. We tested the latter hypothesis by studying the effects of ouabain in the micromolar and nanomolar range on phenylephrine (PE-evoked pressor responses. The experiments were performed in normotensive and hypertensive rats in vivo, under anesthesia, and in perfused rat tail vascular beds. The results showed that ouabain pretreatment increased the vasopressor responses to PE in vitro and in vivo. This sensitization after ouabain treatment was also observed in hypertensive animals which presented an enhanced vasopressor response to PE in comparison to normotensive animals. It is suggested that ouabain at nanomolar concentrations can sensitize vascular smooth muscle to vasopressor stimuli possibly contributing to increased tone in hypertension

Leg som ustyrlig deltagelseskultur

DEFF Research Database (Denmark)

Toft, Herdis

2017-01-01

- og spilteoretikere Johan Huizinga og Roger Caillois. Deres teorier og begrebsdannelser har været brugt til at påpege leg dels som et æstetisk baseret betydningssystem, dels som et affektivt og stemningsbaseret oplevelsessystem samt endelig som et socialt baseret relationssystem. I artiklen vælger vi...... at fokusere på leg som et socialt baseret relationssystem og yderligere zoome ind på et af legens systemiske væsenstræk, nemlig brugen af regulerbare regelsæt, som legerne uden ’politi’ forhandler sig frem til før, under og efter legen. Fælles for Huizinga og Caillois er, at de knytter leg uløseligt sammen...

Complications impaired endothelial progenitor cell function in Type 2 diabetic patients with or without critical leg ischaemia: implication for impaired neovascularization in diabetes.

Science.gov (United States)

Chen, M-C; Sheu, J-J; Wang, P-W; Chen, C-Y; Kuo, M-C; Hsieh, C-J; Chen, J-F; Chang, H-W

2009-02-01

This study tested the hypothesis that migratory function of endothelial progenitor cells (EPCs) is impaired in Type 2 diabetic patients with or without critical leg ischaemia. Seventy-four patients were classified into four groups: Type 2 diabetic (n = 21) and non-diabetic patients (n = 10) with critical leg ischaemia and Type 2 diabetic patients without lower extremity vascular disease (n = 30) and healthy subjects (n = 13). The number and functional activity of circulating and cultured EPCs were determined. The migratory function of cultured EPCs was significantly impaired in diabetic patients without (median, 48, interquartile range, 46, 49 count/view/well) and with (median, 51, interquartile range, 46, 60 count/view/well) critical leg ischaemia and non-diabetic patients with critical leg ischaemia (median, 49, interquartile range, 47, 55 count/view/well) compared with healthy subjects (median, 63, interquartile range, 57, 65 count/view/well) (P interquartile range, 1600, 6600/10(6) cytometric events) than Type 2 diabetic patients with critical leg ischaemia (median, 5300, interquartile range, 2400, 11,100/10(6) cytometric events), non-diabetic patients with critical leg ischaemia (median, 5550, interquartile range, 2000, 32,100/10(6) cytometric events) and healthy subjects (median, 5400, interquartile range, 2700, 8700/10(6) cytometric events) (P = 0.413). The migratory function of EPCs is impaired in patients with Type 2 diabetes, even in those without critical leg ischaemia. These findings present an important new insight into the pathogenesis of impaired neovascularization and critical limb ischaemia in diabetic patients and provide avenues of future clinical study.

Potential benefits of exercise on blood pressure and vascular function.

Science.gov (United States)

Pal, Sebely; Radavelli-Bagatini, Simone; Ho, Suleen

2013-01-01

Physical activity seems to enhance cardiovascular fitness during the course of the lifecycle, improve blood pressure, and is associated with decreased prevalence of hypertension and coronary heart disease. It may also delay or prevent age-related increases in arterial stiffness. It is unclear if specific exercise types (aerobic, resistance, or combination) have a better effect on blood pressure and vascular function. This review was written based on previous original articles, systematic reviews, and meta-analyses indexed on PubMed from years 1975 to 2012 to identify studies on different types of exercise and the associations or effects on blood pressure and vascular function. In summary, aerobic exercise (30 to 40 minutes of training at 60% to 85% of predicted maximal heart rate, most days of the week) appears to significantly improve blood pressure and reduce augmentation index. Resistance training (three to four sets of eight to 12 repetitions at 10 repetition maximum, 3 days a week) appears to significantly improve blood pressure, whereas combination exercise training (15 minutes of aerobic and 15 minutes of resistance, 5 days a week) is beneficial to vascular function, but at a lower scale. Aerobic exercise seems to better benefit blood pressure and vascular function. Copyright © 2013 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

Vascular function in health, hypertension, and diabetes

DEFF Research Database (Denmark)

Nyberg, Michael Permin; Gliemann, Lasse; Hellsten, Ylva

2015-01-01

muscle, which can affect muscle function. Central aspects in the vascular impairments are alterations in the formation of prostacyclin, the bioavailability of NO and an increased formation of vasoconstrictors and reactive oxygen species (ROS). Regular physical activity effectively improves vascular......, the increase in muscle blood flow required for oxygen supply during exercise is achieved through a substantial increase in vasodilators locally formed in the active muscle tissue that overcome the vasoconstrictor signals. Most of the vasodilator signals are mediated via endothelial cells, which lead...... to the formation of vasodilators such as nitric oxide (NO) and prostacyclin. In essential hypertension and type II diabetes, the endothelial function and regulation of vascular tone is impaired with consequent increases in peripheral vascular resistance and inadequate regulation of oxygen supply to the skeletal...

Legāti

OpenAIRE

Segliņa, Aiga

2010-01-01

Autore teorētiski analizē legāta jēdzienu testamentārās mantošanas ietvaros un atspoguļo praktiska pētījuma rezultātus. Teorētiskā daļa apskata legāta nodibināšanas formu un spēkā esamību, tā iegūšanu un atraidīšanu, izpildi un zaudēšanu, novēlējuma robežas un aprobežojumus. Pētījums veikts aptaujas veidā ar mērķi noskaidrot, cik liela Latvijas iedzīvotāju daļa apzinās legāta nodrošinātās priekšrocības testamentārajā mantošanā. Apskatīts notāra neitralitātes jautājums attiecībā pret mantošana...

Immediate effects of the trunk stabilizing exercise on static balance parameters in double-leg and one-leg stances

OpenAIRE

Kim, Jwa-jun; Park, Se-yeon

2016-01-01

[Purpose] The purpose of this study was to evaluate the immediate effect of stabilizing exercise using the PNF technique on standing balance in one-leg and double-leg stances. [Subjects and Methods] The present study recruited 34 healthy participants from a local university. The Participants performed four balance tests (double-leg stance with and without vision, one-leg stance with and without vision), before and after exercise. The exercise consisted of exercises performed using PNF techniq...

Artificial Leg Design and Control Research of a Biped Robot with Heterogeneous Legs Based on PID Control Algorithm

Directory of Open Access Journals (Sweden)

Hualong Xie

2015-04-01

Full Text Available A biped robot with heterogeneous legs (BRHL is proposed to provide an ideal test-bed for intelligent bionic legs (IBL. To make artificial leg gait better suited to a human, a four-bar mechanism is used as its knee joint, and a pneumatic artificial muscle (PAM is used as its driving source. The static mathematical model of PAM is established and the mechanical model of a single degree of freedom of a knee joint driven by PAM is analyzed. A control simulation of an artificial leg based on PID control algorithm is carried out and the simulation results indicate that the artificial leg can simulate precisely a normal human walking gait.

An interesting case of peripheral vascular disease, vascular reperfusion, and subsequent development of pain due to Paget's disease of bone.

Science.gov (United States)

Kwun, Sunna; Tucci, Joseph R

2013-01-01

To present a case of Paget's disease of bone that was unmasked after vascular reperfusion. In this case study, we review the presentation, evaluation, diagnosis, and management of a patient with Paget's disease and peripheral vascular disease. A 79-year-old-woman with a history of coronary artery heart disease and recent finding of a T5 compression fracture was hospitalized for evaluation of right lower extremity claudication. Angiography demonstrated a focal complete occlusion of the distal right femoral and popliteal arteries. A self-expanding stent was placed in the distal femoral and popliteal arteries. Approximately 48 hours after the procedure, the patient developed severe, right lower leg pain. On endocrine evaluation, the patient was found to have clinical signs suggesting Paget's disease of bone, which was subsequently confirmed by imaging. This patient's development of severe pain following reperfusion of distal femoral and popliteal arteries is in keeping with the known and aforementioned hypervascularity of pagetic bone. The finding of increased warmth over an area of skeletal deformation should always raise the possibility of Paget's disease of bone.

Creatine Loading Does Not Preserve Muscle Mass or Strength During Leg Immobilization in Healthy, Young Males

NARCIS (Netherlands)

Backx, Evelien M.P.; Hangelbroek, Roland; Snijders, Tim; Verscheijden, Marie Louise; Verdijk, Lex B.; Groot, de Lisette C.P.G.M.; Loon, van Luc J.C.

2017-01-01

Background: A short period of leg immobilization leads to rapid loss of muscle mass and strength. Creatine supplementation has been shown to increase lean body mass in active individuals and can be used to augment gains in muscle mass and strength during prolonged resistance-type exercise

Robust and efficient walking with spring-like legs

Energy Technology Data Exchange (ETDEWEB)

Rummel, J; Blum, Y; Seyfarth, A, E-mail: juergen.rummel@uni-jena.d, E-mail: andre.seyfarth@uni-jena.d [Lauflabor Locomotion Laboratory, University of Jena, Dornburger Strasse 23, 07743 Jena (Germany)

2010-12-15

The development of bipedal walking robots is inspired by human walking. A way of implementing walking could be performed by mimicking human leg dynamics. A fundamental model, representing human leg dynamics during walking and running, is the bipedal spring-mass model which is the basis for this paper. The aim of this study is the identification of leg parameters leading to a compromise between robustness and energy efficiency in walking. It is found that, compared to asymmetric walking, symmetric walking with flatter angles of attack reveals such a compromise. With increasing leg stiffness, energy efficiency increases continuously. However, robustness is the maximum at moderate leg stiffness and decreases slightly with increasing stiffness. Hence, an adjustable leg compliance would be preferred, which is adaptable to the environment. If the ground is even, a high leg stiffness leads to energy efficient walking. However, if external perturbations are expected, e.g. when the robot walks on uneven terrain, the leg should be softer and the angle of attack flatter. In the case of underactuated robots with constant physical springs, the leg stiffness should be larger than k-tilde = 14 in order to use the most robust gait. Soft legs, however, lack in both robustness and efficiency.

Robust and efficient walking with spring-like legs

International Nuclear Information System (INIS)

Rummel, J; Blum, Y; Seyfarth, A

2010-01-01

The development of bipedal walking robots is inspired by human walking. A way of implementing walking could be performed by mimicking human leg dynamics. A fundamental model, representing human leg dynamics during walking and running, is the bipedal spring-mass model which is the basis for this paper. The aim of this study is the identification of leg parameters leading to a compromise between robustness and energy efficiency in walking. It is found that, compared to asymmetric walking, symmetric walking with flatter angles of attack reveals such a compromise. With increasing leg stiffness, energy efficiency increases continuously. However, robustness is the maximum at moderate leg stiffness and decreases slightly with increasing stiffness. Hence, an adjustable leg compliance would be preferred, which is adaptable to the environment. If the ground is even, a high leg stiffness leads to energy efficient walking. However, if external perturbations are expected, e.g. when the robot walks on uneven terrain, the leg should be softer and the angle of attack flatter. In the case of underactuated robots with constant physical springs, the leg stiffness should be larger than k-tilde = 14 in order to use the most robust gait. Soft legs, however, lack in both robustness and efficiency.

Does a crouched leg posture enhance running stability and robustness?

Science.gov (United States)

Blum, Yvonne; Birn-Jeffery, Aleksandra; Daley, Monica A; Seyfarth, Andre

2011-07-21

Humans and birds both walk and run bipedally on compliant legs. However, differences in leg architecture may result in species-specific leg control strategies as indicated by the observed gait patterns. In this work, control strategies for stable running are derived based on a conceptual model and compared with experimental data on running humans and pheasants (Phasianus colchicus). From a model perspective, running with compliant legs can be represented by the planar spring mass model and stabilized by applying swing leg control. Here, linear adaptations of the three leg parameters, leg angle, leg length and leg stiffness during late swing phase are assumed. Experimentally observed kinematic control parameters (leg rotation and leg length change) of human and avian running are compared, and interpreted within the context of this model, with specific focus on stability and robustness characteristics. The results suggest differences in stability characteristics and applied control strategies of human and avian running, which may relate to differences in leg posture (straight leg posture in humans, and crouched leg posture in birds). It has been suggested that crouched leg postures may improve stability. However, as the system of control strategies is overdetermined, our model findings suggest that a crouched leg posture does not necessarily enhance running stability. The model also predicts different leg stiffness adaptation rates for human and avian running, and suggests that a crouched avian leg posture, which is capable of both leg shortening and lengthening, allows for stable running without adjusting leg stiffness. In contrast, in straight-legged human running, the preparation of the ground contact seems to be more critical, requiring leg stiffness adjustment to remain stable. Finally, analysis of a simple robustness measure, the normalized maximum drop, suggests that the crouched leg posture may provide greater robustness to changes in terrain height

Don't break a leg: running birds from quail to ostrich prioritise leg safety and economy on uneven terrain.

Science.gov (United States)

Birn-Jeffery, Aleksandra V; Hubicki, Christian M; Blum, Yvonne; Renjewski, Daniel; Hurst, Jonathan W; Daley, Monica A

2014-11-01

Cursorial ground birds are paragons of bipedal running that span a 500-fold mass range from quail to ostrich. Here we investigate the task-level control priorities of cursorial birds by analysing how they negotiate single-step obstacles that create a conflict between body stability (attenuating deviations in body motion) and consistent leg force-length dynamics (for economy and leg safety). We also test the hypothesis that control priorities shift between body stability and leg safety with increasing body size, reflecting use of active control to overcome size-related challenges. Weight-support demands lead to a shift towards straighter legs and stiffer steady gait with increasing body size, but it remains unknown whether non-steady locomotor priorities diverge with size. We found that all measured species used a consistent obstacle negotiation strategy, involving unsteady body dynamics to minimise fluctuations in leg posture and loading across multiple steps, not directly prioritising body stability. Peak leg forces remained remarkably consistent across obstacle terrain, within 0.35 body weights of level running for obstacle heights from 0.1 to 0.5 times leg length. All species used similar stance leg actuation patterns, involving asymmetric force-length trajectories and posture-dependent actuation to add or remove energy depending on landing conditions. We present a simple stance leg model that explains key features of avian bipedal locomotion, and suggests economy as a key priority on both level and uneven terrain. We suggest that running ground birds target the closely coupled priorities of economy and leg safety as the direct imperatives of control, with adequate stability achieved through appropriately tuned intrinsic dynamics. © 2014. Published by The Company of Biologists Ltd.

Acute vascular effects of waterpipe smoking: Importance of physical activity and fitness status.

Science.gov (United States)

Alomari, Mahmoud A; Khabour, Omar F; Alzoubi, Karem H; Shqair, Dana M; Stoner, Lee

2015-06-01

While new forms of tobacco, including waterpipe (WP) smoking, continue to gain popularity, limited literature has examined the vascular health consequences. The purpose of the current study was to examine: (i) the acute WP-induced changes in vascular function; (ii) whether acute changes in vascular function are modified by lifestyle behaviors (habitual physical activity, physical fitness). Fifty three (22.7 y, 36% F, 23.4 kg/m(2)) otherwise healthy WP smokers were recruited. Strain-gauge plethysmography was used to measure forearm blood flow, vascular resistance, venous capacitance, and venous outflow at rest and following occlusion. Habitual physical activity was determined using the Arabic version of short-form international physical activity questionnaire, while physical fitness was assessed using the 6 min walk test and handgrip strength. Partial correlations were used to examine the relationships between post-smoking vascular function and lifestyle behaviors, controlling for pre-smoking vascular measures. (i) WP had a small effect on forearm post-occlusion blood flow (d = -0.19), a moderate effect on venous outflow (d = 0.30), and a moderate effect on post-occlusion vascular resistance (d = 0.32). (ii) Total habitual physical activity strongly correlated with resting blood flow (r = 0.50) and moderately with vascular resistance (r = -0.40). Handgrip strength moderately correlated with venous capacitance (r = 0.30) and post-occlusion blood flow (r = 0.30), while 6 min walked distance moderately correlated with resting venous capacitance (r = 0.30). Waterpipe smoking is associated with immediate changes in vascular function, which are exacerbated in individuals with low habitual physical activity and physical fitness levels in young otherwise healthy individuals. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Arabidopsis wat1 (walls are thin1)-mediated resistance to the bacterial vascular pathogen, Ralstonia solanacearum, is accompanied by cross-regulation of salicylic acid and tryptophan metabolism

NARCIS (Netherlands)

Denancé, N.; Ranocha, P.; Oria, N.; Barlet, X.; Rivière, M.P.; Yadeta, K.A.; Hoffmann, L.; Perreau, F.; Clément, G.; Maia-Grondard, A.; Berg, van den G.C.M.; Savelli, B.; Fournier, S.; Aubert, Y.; Pelletier, S.; Thomma, B.P.H.J.; Molina, A.; Jouanin, L.; Marco, Y.; Goffner, D.

2013-01-01

Inactivation of Arabidopsis WAT1 (Walls Are Thin1), a gene required for secondary cell-wall deposition, conferred broad-spectrum resistance to vascular pathogens, including the bacteria Ralstonia solanacearum and Xanthomonas campestris pv. campestris, and the fungi Verticillium dahliae and

Low molecular weight heparin for prevention of venous thromboembolism in patients with lower-leg immobilization.

Science.gov (United States)

Testroote, Mark; Stigter, Willem A H; Janssen, Loes; Janzing, Heinrich M J

2014-04-25

Immobilization of the lower leg is associated with venous thromboembolism (VTE). Low molecular weight heparin (LMWH) is an anticoagulant treatment which might be used in adult patients with lower-leg immobilization to prevent deep venous thrombosis (DVT) and its complications. This is an update of the review first published in 2008. To assess the effectiveness of low molecular weight heparin for the prevention of venous thromboembolism in patients with lower-leg immobilization in an ambulant setting. For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched June 2013) and CENTRAL (2013, Issue 5). Randomized controlled trials (RCTs) and controlled clinical trials (CCTs) that described thromboprophylaxis by means of LMWH compared with no prophylaxis or placebo in adult patients with lower-leg immobilization. Immobilization was by means of a plaster cast or brace. Two authors independently assessed trial quality and extracted data. The review authors contacted the trial authors for additional information if required. Statistical analysis was carried out using Review Manager (RevMan 5). We included six RCTs fulfilling the above criteria with a total of 1490 patients. We found an incidence of VTE ranging from 4.3% to 40% in patients who had a leg injury that had been immobilized in a plaster cast or a brace for at least one week and who received no prophylaxis, or placebo. This number was significantly lower in patients who received daily subcutaneous injections of LMWH during immobilization (event rates ranging from 0% to 37%; odds ratio (OR) 0.49; fixed 95% confidence interval (CI) 0.34 to 0.72; with minimal evidence of heterogeneity with an I(2) of 20%, P = 0. 29). Comparable results were seen in the following subcategories: operated patients, conservatively treated patients, patients with fractures, patients with soft-tissue injuries, patients with proximal thrombosis, patients with

Passive leg movement enhances interstitial VEGF protein, endothelial cell proliferation, and eNOS mRNA content in human skeletal muscle

DEFF Research Database (Denmark)

Hellsten, Ylva; Rufener, Nora; Nielsen, Jens J

2008-01-01

.05) in blood flow without a significant enhancement in oxygen uptake. Muscle interstitial fluid was sampled with microdialysis technique and analyzed for vascular endothelial growth factor (VEGF) protein and for the effect on endothelial cell proliferation. Biopsies obtained from the musculus vastus lateralis...... to cultured endothelial cells revealed that dialysate obtained during leg movement induced a 3.2-fold higher proliferation rate (P level fourfold above resting levels. VEGF mRNA and MMP-2 mRNA levels were...

Assessment of the vibration on the foam legged and sheet metal-legged passenger seat

Directory of Open Access Journals (Sweden)

L. Dahil

2015-10-01

Full Text Available In this study, it was aim ed to decrease the vibration reaching to passenger from the legs of vehicle seats. In order to determine the levels of vibrations reaching at passengers, a test pad placed under the passenger seat was used, and HVM100 device was used for digitizing the information obtained. By transferring the vibration data to system by using HVM100 device, the acceleration graphics were prepared with Blaze software. As a result, it was determined that the acceleration values of seat legs made of foam material were lower than that of seat legs made of 2 mm thick sheet metal, so they damped the vibration better.

Frustrated S = 1/2 Two-Leg Ladder with Different Leg Interactions

Science.gov (United States)

Tonegawa, Takashi; Okamoto, Kiyomi; Hikihara, Toshiya; Sakai, Tôru

2017-04-01

We explore the ground-state phase diagram of the S = 1/2 two-leg ladder. The isotropic leg interactions J1,a and J1,b between nearest neighbor spins in the legs a and b, respectively, are different from each other. The xy and z components of the uniform rung interactions are denoted by Jr and ΔJr, respectively, where Δ is the XXZ anisotropy parameter. This system has a frustration when J1,aJ1,b employ the physical consideration, the level spectroscopy analysis of the results obtained by the exact diagonalization method and also the density-matrix renormalization-group method. It is found that the non-collinear ferrimagnetic (NCFR) state appears as the ground state in the frustrated region of the parameters. Furthermore, the direct-product triplet-dimer (TD) state in which all rungs form the TD pair is the exact ground state, when J1,a + J1,b = 0 and 0≤ Δ ≲ 0.83. The obtained phase diagrams consist of the TD, XY and Haldane phases as well as the NCFR phase.

Approach to leg edema

Directory of Open Access Journals (Sweden)

Fulvio Pomero

2017-09-01

Full Text Available Edema is defined as a palpable swelling caused by an increase in interstitial fluid volume. Leg edema is a common problem with a wide range of possible causes and is the result of an imbalance in the filtration system between the capillary and interstitial spaces. Major causes of edema include venous obstruction, increased capillary permeability and increased plasma volume secondary to sodium and water retention. In both hospital and general practice, the patient with a swollen leg presents a common dilemma in diagnosis and treatment. The cause may be trivial or life-threatening and it is often difficult to determine the clinical pathway. The diagnosis can be narrowed by categorizing the edema according to its duration, distribution (unilateral or bilateral and accompanying symptoms. This work provides clinically oriented recommendations for the management of leg edema in adults.

Resveratrol prevents high-fructose corn syrup-induced vascular insulin resistance and dysfunction in rats.

Science.gov (United States)

Babacanoglu, C; Yildirim, N; Sadi, G; Pektas, M B; Akar, F

2013-10-01

Dietary intake of fructose and sucrose can cause development of metabolic and cardiovascular disorders. The consequences of high-fructose corn syrup (HFCS), a commonly consumed form of fructose and glucose, have poorly been examined. Therefore, in this study, we investigated whether HFCS intake (10% and 20% beverages for 12 weeks) impacts vascular reactivity to insulin and endothelin-1 in conjunction with insulin receptor substrate-1(IRS-1), endothelial nitric oxide synthase (eNOS) and inducible NOS (iNOS) mRNA/proteins levels in aorta of rats. At challenge, we tested the effectiveness of resveratrol (28-30 mg/kg body weight/day) on outcomes of HFCS feeding. HFCS (20%) diet feeding increased plasma triglyceride, VLDL, cholesterol, insulin and glucose levels, but not body weights of rats. Impaired nitric oxide-mediated relaxation to insulin (10⁻⁹ to 3×10⁻⁶ M), and enhanced contraction to endothelin-1 (10⁻¹¹ to 10⁻⁸ M) were associated with decreased expression of IRS-1 and eNOS mRNA and protein, but increased expression of iNOS, in aortas of rats fed with HFCS. Resveratrol supplementation restored many features of HFCS-induced disturbances, probably by regulating eNOS and iNOS production. In conclusion, dietary HFCS causes vascular insulin resistance and endothelial dysfunction through attenuating IRS-1 and eNOS expressions as well as increasing iNOS in rats. Resveratrol has capability to recover HFCS-induced disturbances. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Enhanced Vascular Endothelial Growth Factor Gene Expression in Ischaemic Skin of Critical Limb Ischaemia Patients

Directory of Open Access Journals (Sweden)

Silvia Bleda

2012-01-01

Full Text Available Objectives. To perform a quantitative analysis of the vascular endothelial growth factor (VEGF gene transcription in the skin of ischemic legs and provide information for VEGF in the pathogenesis in critical limb ischemia (CLI. Methods. Skin biopsies were obtained from 40 patients with CLI. Control samples came from 44 patients with chronic venous disease. VEGF gene expression was analysed using quantitative polymerase chain reaction. Results. Patients with CLI had higher skin VEGF expression than control group (RQ: 1.3 ± 0.1 versus 1, P=0.04. Conclusions. We found an association between ischemic skin and an elevated VEGF expression in legs from patients with CLI. These data support that the mechanism for VEGF upregulation in hypoxia conditions is intact and acts appropriately in the ischaemic limbs from patients with CLI.

Evaluation of arm-leg coordination in flat breaststroke.

Science.gov (United States)

Chollet, D; Seifert, L; Leblanc, H; Boulesteix, L; Carter, M

2004-10-01

This study proposes a new method to evaluate arm-leg coordination in flat breaststroke. Five arm and leg stroke phases were defined with a velocity-video system. Five time gaps quantified the time between arm and leg actions during three paces of a race (200 m, 100 m and 50 m) in 16 top level swimmers. Based on these time gaps, effective glide, effective propulsion, effective leg insweep and effective recovery were used to identify the different stroke phases of the body. A faster pace corresponded to increased stroke rate, decreased stroke length, increased propulsive phases, shorter glide phases, and a shorter T1 time gap, which measured the effective body glide. The top level swimmers showed short time gaps (T2, T3, T4, measuring the timing of arm-leg recoveries), which reflected the continuity in arm and leg actions. The measurement of these time gaps thus provides a pertinent evaluation of swimmers' skill in adapting their arm-leg coordination to biomechanical constraints.

Proliferation and mitogenic response to PDGF-BB of fibroblasts isolated from chronic venous leg ulcers is ulcer-age dependent

DEFF Research Database (Denmark)

Agren, M S; Steenfos, H H; Dabelsteen, S

1999-01-01

Several pathophysiologic mechanisms have been proposed to explain slow-healing leg ulcers, but little is known about the growth behavior of cells in these wounds. Platelet-derived growth factor-BB applied topically to chronic wounds has shown beneficial effects, although the effects have been less...... pronounced than would have been expected based on studies on acute wounds. The objective of this study was to compare fibroblasts in culture obtained from chronic wounds (non-healing chronic venous leg ulcers), acute wounds and normal dermis regarding growth, mitogenic response to platelet-derived growth...... chronic wounds have approached or even reached the end of their lifespan (phase III). This might provide one explanation for the non-healing state and therapy resistance to topical platelet-derived growth factor-BB of some venous leg ulcers....

Reversing resistance to vascular-disrupting agents by blocking late mobilization of circulating endothelial progenitor cells.

Science.gov (United States)

Taylor, Melissa; Billiot, Fanny; Marty, Virginie; Rouffiac, Valérie; Cohen, Patrick; Tournay, Elodie; Opolon, Paule; Louache, Fawzia; Vassal, Gilles; Laplace-Builhé, Corinne; Vielh, Philippe; Soria, Jean-Charles; Farace, Françoise

2012-05-01

The prevailing concept is that immediate mobilization of bone marrow-derived circulating endothelial progenitor cells (CEP) is a key mechanism mediating tumor resistance to vascular-disrupting agents (VDA). Here, we show that administration of VDA to tumor-bearing mice induces 2 distinct peaks in CEPs: an early, unspecific CEP efflux followed by a late yet more dramatic tumor-specific CEP burst that infiltrates tumors and is recruited to vessels. Combination with antiangiogenic drugs could not disrupt the early peak but completely abrogated the late VDA-induced CEP burst, blunted bone marrow-derived cell recruitment to tumors, and resulted in striking antitumor efficacy, indicating that the late CEP burst might be crucial to tumor recovery after VDA therapy. CEP and circulating endothelial cell kinetics in VDA-treated patients with cancer were remarkably consistent with our preclinical data. These findings expand the current understanding of vasculogenic "rebounds" that may be targeted to improve VDA-based strategies. Our findings suggest that resistance to VDA therapy may be strongly mediated by late, rather than early, tumor-specific recruitment of CEPs, the suppression of which resulted in increased VDA-mediated antitumor efficacy. VDA-based therapy might thus be significantly enhanced by combination strategies targeting late CEP mobilization. © 2012 AACR

Duplex sonography of the near-surface leg veins

International Nuclear Information System (INIS)

Mendoza, E.

2007-01-01

The book contains the following contributions: The ultrasonograph, selection of the ultrasonic transducer, anatomy of the near-surface vein system, physiology of the near-surface vein system, varicose status classification, systematics of the duplex sonography of near-surface leg veins, provocational maneuver for the duplex sonographic varicose diagnostics, exploration of vena saphena parva, perforans veins, side branches, phlebitis, sonography for varicose therapy, postsurgical sonography, deep leg veins, examination of near-surface leg veins for the pathology of the deep vein system, differential diagnostic clarification of leg oedema from the phlebologic-lymphological view, diagnostic side features along the near-surface leg veins

Vascular and renal function in experimental thyroid disorders.

Science.gov (United States)

Vargas, Félix; Moreno, Juan Manuel; Rodríguez-Gómez, Isabel; Wangensteen, Rosemary; Osuna, Antonio; Alvarez-Guerra, Miriam; García-Estañ, Joaquín

2006-02-01

This review focuses on the effects of thyroid hormones in vascular and renal systems. Special emphasis is given to the mechanisms by which thyroid hormones affect the regulation of body fluids, vascular resistance and, ultimately, blood pressure. Vascular function is markedly affected by thyroid hormones that produce changes in vascular reactivity and endothelial function in hyper- and hypothyroidism. The hypothyroid state is accompanied by a marked decrease in sensitivity to vasoconstrictors, especially to sympathetic agonists, alteration that may play a role in the reduced blood pressure of hypothyroid rats, as well as in the preventive effects of hypothyroidism on experimental hypertension. Moreover, in hypothyroid rats, the endothelium-dependent and nitric oxide donors vasodilation is reduced. Conversely, the vessels from hyperthyroid rats showed an increased endothelium-dependent responsiveness that may be secondary to the shear-stress induced by the hyperdynamic circulation, and that may contribute to the reduced vascular resistance characteristic of this disease. Thyroid hormones also have important effects in the kidney, affecting renal growth, renal haemodynamics, and salt and water metabolism. In hyperthyroidism, there is a resetting of the pressure-natriuresis relationship related to hyperactivity of the renin-angiotensin system, which contributes to the arterial hypertension associated with this endocrine disease. Moreover, thyroid hormones affect the development and/or maintenance of various forms of arterial hypertension. This review also describes recent advances in our understanding of thyroid hormone action on nitric oxide and oxidative stress in the regulation of cardiovascular and renal function and in the long-term control of blood pressure.

Measures of total stress-induced blood pressure responses are associated with vascular damage.

Science.gov (United States)

Nazzaro, Pietro; Seccia, Teresa; Vulpis, Vito; Schirosi, Gabriella; Serio, Gabriella; Battista, Loredana; Pirrelli, Anna

2005-09-01

The role of cardiovascular reactivity to study hypertension, and the assessment methods, are still controversial. We aimed to verify the association of hypertension and vascular damage with several measures of cardiovascular response. We studied 40 patients with normal-high (132 +/- 1/87 +/- 1 mm Hg) blood pressure (Group 1) and 80 untreated hypertensive subjects. Postischemic forearm vascular resistance (mFVR) served to differentiate hypertensive subjects (142 +/- 2/92 +/- 1 mm Hg v 143 +/- 2/94 +/- 2 mm Hg, P = NS) with a lower (Group 2) and higher (Group 3) hemodynamic index of vascular damage (4.8 +/- .05 v 6.3 +/- .09, P blood pressure, heart rate, forearm blood flow, and vascular resistance. Reactivity measures included: a) change from baseline, b) residualized score, c) cumulative change from baseline and residualized score, and d) total reactivity as area-under-the-curve (AUC), including changes occurring during baseline and recovery phases. The AUC of systolic blood pressure, diastolic blood pressure, and mFVR progressively increased in the groups (P AUC of SBP, DBP, and forearm blood flow and resistance demonstrated the highest (P AUC of SBP (beta = 0.634) and forearm blood flow (beta = -0.337) were predictive (P blood pressure stress response, as AUC, including baseline and recovery phases, was significantly better associated with hypertension and vascular damage than the other reactivity measures studied.

Acute L-arginine alpha ketoglutarate supplementation fails to improve muscular performance in resistance trained and untrained men.

Science.gov (United States)

Wax, Benjamin; Kavazis, Andreas N; Webb, Heather E; Brown, Stanley P

2012-04-17

Dietary supplements containing L-arginine are marketed to improve exercise performance, but the efficacy of such supplements is not clear. Therefore, this study examined the efficacy of acute ingestion of L-arginine alpha-ketoglutarate (AAKG) muscular strength and endurance in resistance trained and untrained men. Eight resistance trained and eight untrained healthy males ingested either 3000mg of AAKG or a placebo 45 minutes prior to a resistance exercise protocol in a randomized, double-blind crossover design. One-repetition maximum (1RM) on the standard barbell bench press and leg press were obtained. Upon determination of 1RM, subjects completed repetitions to failure at 60% 1RM on both the standard barbell bench press and leg press. Heart rate was measured pre and post exercise. One week later, subjects ingested the other supplement and performed the identical resistance exercise protocol. Our data showed statistical significant differences (p0.05) between supplementation conditions for either resistance trained or untrained men in the bench press or leg press exercises. Heart rate was similar at the end of the upper and lower body bouts of resistance exercise with AAKG vs. placebo. The results from our study indicate that acute AAKG supplementation provides no ergogenic benefit on 1RM or TLV as measured by the standard barbell bench press and leg press, regardless of the subjects training status.

Determinants of Intravascular Resistance in Indian Diabetic Nephropathy Patients: A Hospital-Based Study

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Anubhav Thukral

2011-01-01

Full Text Available Aims and Objectives. Metabolic dysregulation has failed to explain clinical variability of patients with diabetic nephropathy and hence a renewed interest emerged in haemodynamic factors as determinant of progression and development of diabetic nephropathy. We therefore studied for various factors which can correlate with raised renal vascular resistance in diabetic nephropathy. Material and Methods. Renal vascular resistance was measured in patients with established and incipient diabetic nephropathy and compared with controls using noninvasive color Doppler examinations of intrarenal vasculature. Results. Renal vascular resistance correlated with age, duration of disease, GFR, serum creatinine, and stage of retinopathy. Renal vascular resistance was significantly reduced in patients on treatment with RAAS inhibitors and insulin, than those on OHA and antihypertensives other than RAAS inhibitors. Conclusion. The study implies that renal vascular resistance may help identify diabetics at high risk of developing nephropathy, and these set of patients could be candidates for RAAS inhibition and early insulin therapy even in patients without albuminuria.

Review of gestational diabetes mellitus effects on vascular structure and function.

Science.gov (United States)

Jensen, Louise A; Chik, Constance L; Ryan, Edmond A

2016-05-01

Vascular dysfunction has been described in women with a history of gestational diabetes mellitus. Furthermore, previous gestational diabetes mellitus increases the risk of developing Type 2 diabetes mellitus, a risk factor for cardiovascular disease. Factors contributing to vascular changes remain uncertain. The aim of this review was to summarize vascular structure and function changes found to occur in women with previous gestational diabetes mellitus and to identify factors that contribute to vascular dysfunction. A systematic search of electronic databases yielded 15 publications from 1998 to March 2014 that met the inclusion criteria. Our review confirmed that previous gestational diabetes mellitus contributes to vascular dysfunction, and the most consistent risk factor associated with previous gestational diabetes mellitus and vascular dysfunction was elevated body mass index. Heterogeneity existed across studies in determining the relationship of glycaemic levels and insulin resistance to vascular dysfunction. © The Author(s) 2016.

Leg pain

Science.gov (United States)

... in the blood Medicines (such as diuretics and statins) Muscle fatigue or strain from overuse, too much exercise, or holding a muscle in the same position for a long time An injury can also cause leg pain from: A torn or overstretched muscle ( strain ) Hairline ...

Broken Leg

Science.gov (United States)

... the leg, which can result in a fracture. Stress fractures outside of sport situations are more common in people who have: ... shoes. Choose the appropriate shoe for your favorite sports or activities. And ... can prevent stress fractures. Rotate running with swimming or biking. If ...

Red cell 2, 3-diphosphoglycerate levels among diabetic patents with and without vascular complications.

Science.gov (United States)

Kanter, Y; Bessman, S P; Bessman, A

1975-08-01

There have been differences of opinion among authors concening in the levels of red cell 2,3-diphosphoglycerate (2,3-DPG) and nucleotides in nonacidotic diabetic patients. Our data suggest that abnormal levels of 2, 3-DPG in diabetic patients are related to the presence of vascular complications and not to the duration of the disease per sec. 2,3-DPG levels are normal in diabetic patients with no evidence of vascular complications (group A). In ambulatory patients with vascular complications (group B), significantly higher levels of 2,3-DPG are found than in normal subjects and patients in group A. In hospitalized diabetic patients with active peripheral vascular complications (group C), levels of 2,3-DPG are likewise significantly increased over those of normal subjects and patients of group A. 2,3-DPG was found to be significantly elevated in patients of group C as compared with group B. 2,3-DPG levels in venous blood from infected legs as compared with those of the peripheral venous blood were not significantly different, thereby ruling out local factors. There were no differences in the blood lactate levels in any of the group studied. The elevation of the 2,3-DPG levels may be a reflection of attempted red blood cell compensation for tissue hypoxia in the diabetic with vascular disease.

Not letting the left leg know what the right leg is doing: limb-specific locomotor adaptation to sensory-cue conflict.

Science.gov (United States)

Durgin, Frank H; Fox, Laura F; Hoon Kim, Dong

2003-11-01

We investigated the phenomenon of limb-specific locomotor adaptation in order to adjudicate between sensory-cue-conflict theory and motor-adaptation theory. The results were consistent with cue-conflict theory in demonstrating that two different leg-specific hopping aftereffects are modulated by the presence of conflicting estimates of self-motion from visual and nonvisual sources. Experiment 1 shows that leg-specific increases in forward drift during attempts to hop in place on one leg while blindfolded vary according to the relationship between visual information and motor activity during an adaptation to outdoor forward hopping. Experiment 2 shows that leg-specific changes in performance on a blindfolded hopping-to-target task are similarly modulated by the presence of cue conflict during adaptation to hopping on a treadmill. Experiment 3 shows that leg-specific aftereffects from hopping additionally produce inadvertent turning during running in place while blindfolded. The results of these experiments suggest that these leg-specific locomotor aftereffects are produced by sensory-cue conflict rather than simple motor adaptation.

Utilizing CMP-Sialic Acid Analogs to Unravel Neisseria gonorrhoeae Lipooligosaccharide-Mediated Complement Resistance and Design Novel Therapeutics.

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Sunita Gulati

2015-12-01

Full Text Available Neisseria gonorrhoeae deploys a novel immune evasion strategy wherein the lacto-N-neotetraose (LNnT structure of lipooligosaccharide (LOS is capped by the bacterial sialyltransferase, using host cytidine-5'-monophosphate (CMP-activated forms of the nine-carbon nonulosonate (NulO sugar N-acetyl-neuraminic acid (Neu5Ac, a sialic acid (Sia abundant in humans. This allows evasion of complement-mediated killing by recruiting factor H (FH, an inhibitor of the alternative complement pathway, and by limiting classical pathway activation ("serum-resistance". We utilized CMP salts of six additional natural or synthetic NulOs, Neu5Gc, Neu5Gc8Me, Neu5Ac9Ac, Neu5Ac9Az, legionaminic acid (Leg5Ac7Ac and pseudaminic acid (Pse5Ac7Ac, to define structural requirements of Sia-mediated serum-resistance. While all NulOs except Pse5Ac7Ac were incorporated into the LNnT-LOS, only Neu5Gc incorporation yielded high-level serum-resistance and FH binding that was comparable to Neu5Ac, whereas Neu5Ac9Az and Leg5Ac7Ac incorporation left bacteria fully serum-sensitive and did not enhance FH binding. Neu5Ac9Ac and Neu5Gc8Me rendered bacteria resistant only to low serum concentrations. While serum-resistance mediated by Neu5Ac was associated with classical pathway inhibition (decreased IgG binding and C4 deposition, Leg5Ac7Ac and Neu5Ac9Az incorporation did not inhibit the classical pathway. Remarkably, CMP-Neu5Ac9Az and CMP-Leg5Ac7Ac each prevented serum-resistance despite a 100-fold molar excess of CMP-Neu5Ac in growth media. The concomitant presence of Leg5Ac7Ac and Neu5Ac on LOS resulted in uninhibited classical pathway activation. Surprisingly, despite near-maximal FH binding in this instance, the alternative pathway was not regulated and factor Bb remained associated with bacteria. Intravaginal administration of CMP-Leg5Ac7Ac to BALB/c mice infected with gonorrhea (including a multidrug-resistant isolate reduced clearance times and infection burden. Bacteria recovered

Quantifying Leg Movement Activity During Sleep.

Science.gov (United States)

Ferri, Raffaele; Fulda, Stephany

2016-12-01

Currently, 2 sets of similar rules for recording and scoring leg movement (LM) exist, including periodic LM during sleep (PLMS) and periodic LM during wakefulness. The former were published in 2006 by a task force of the International Restless Legs Syndrome Study Group, and the second in 2007 by the American Academy of Sleep Medicine. This article reviews the basic recording methods, scoring rules, and computer-based programs for PLMS. Less frequent LM activities, such as alternating leg muscle activation, hypnagogic foot tremor, high-frequency LMs, and excessive fragmentary myoclonus are briefly described. Copyright © 2016 Elsevier Inc. All rights reserved.

Bioinspired template-based control of legged locomotion

OpenAIRE

Ahmad Sharbafi, Maziar

2018-01-01

cient and robust locomotion is a crucial condition for the more extensive use of legged robots in real world applications. In that respect, robots can learn from animals, if the principles underlying locomotion in biological legged systems can be transferred to their artificial counterparts. However, legged locomotion in biological systems is a complex and not fully understood problem. A great progress to simplify understanding locomotion dynamics and control was made by introducing simple mo...

Acute limb heating improves macro- and microvascular dilator function in the leg of aged humans.

Science.gov (United States)

Romero, Steven A; Gagnon, Daniel; Adams, Amy N; Cramer, Matthew N; Kouda, Ken; Crandall, Craig G

2017-01-01

Local heating of an extremity increases blood flow and vascular shear stress throughout the arterial tree. Local heating acutely improves macrovascular dilator function in the upper limbs of young healthy adults through a shear stress-dependent mechanism but has no such effect in the lower limbs of this age group. The effect of acute limb heating on dilator function within the atherosclerotic prone vasculature of the lower limbs of aged adults is unknown. Therefore, the purpose of this study was to test the hypothesis that acute lower limb heating improves macro- and microvascular dilator function within the leg vasculature of aged adults. Nine young and nine aged adults immersed their lower limbs at a depth of ~33 cm into a heated (~42°C) circulated water bath for 45 min. Before and 30 min after heating, macro (flow-mediated dilation)- and microvascular (reactive hyperemia) dilator functions were assessed in the lower limb, following 5 min of arterial occlusion, via Doppler ultrasound. Compared with preheat, macrovascular dilator function was unchanged following heating in young adults (P = 0.6) but was improved in aged adults (P = 0.04). Similarly, microvascular dilator function, as assessed by peak reactive hyperemia, was unchanged following heating in young adults (P = 0.1) but was improved in aged adults (P lower limb heating improves both macro- and microvascular dilator function in an age dependent manner. We demonstrate that lower limb heating acutely improves macro- and microvascular dilator function within the atherosclerotic prone vasculature of the leg in aged adults. These findings provide evidence for a potential therapeutic use of chronic lower limb heating to improve vascular health in primary aging and various disease conditions. Copyright © 2017 the American Physiological Society.

Pulmonary Vascular Input Impedance is a Combined Measure of Pulmonary Vascular Resistance and Stiffness and Predicts Clinical Outcomes Better than PVR Alone in Pediatric Patients with Pulmonary Hypertension

Science.gov (United States)

Hunter, Kendall S.; Lee, Po-Feng; Lanning, Craig J.; Ivy, D. Dunbar; Kirby, K. Scott; Claussen, Lori R.; Chan, K. Chen; Shandas, Robin

2011-01-01

Background Pulmonary vascular resistance (PVR) is the current standard for evaluating reactivity in children with pulmonary arterial hypertension (PAH). However, PVR measures only the mean component of right ventricular afterload and neglects pulsatile effects. We recently developed and validated an method to measure pulmonary vascular input impedance, which revealed excellent correlation between the zero-harmonic impedance value and PVR, and suggested a correlation between higher harmonic impedance values and pulmonary vascular stiffness (PVS). Here we show that input impedance can be measured routinely and easily in the catheterization laboratory, that impedance provides PVR and PVS from a single measurement, and that impedance is a better predictor of disease outcomes compared to PVR. Methods Pressure and velocity waveforms within the main PA were measured during right-heart catheterization of patients with normal PA hemodynamics (n=14) and those with PAH undergoing reactivity evaluation (49 subjects; 95 conditions). A correction factor needed to transform velocity into flow was obtained by calibrating against cardiac output. Input impedance was obtained off-line by dividing Fourier-transformed pressure and flow waveforms. Results Exceptional correlation was found between the indexed zero harmonic of impedance and indexed PVR (y=1.095·x+1.381, R2=0.9620). Additionally, the modulus sum of the first two harmonics of impedance was found to best correlate with indexed pulse pressure over stroke volume (PP/SV) (y=13.39·x-0.8058, R2=0.7962). Amongst a subset of PAH patients (n=25), cumulative logistic regression between outcomes to total indexed impedance was better (RL2=0.4012) than between outcomes and indexed PVR (RL2=0.3131). Conclusions Input impedance can be consistently and easily obtained from PW Doppler and a single catheter pressure measurement, provides comprehensive characterization of the main components of RV afterload, and better predicts patient

Six weeks' aerobic retraining after two weeks' immobilization restores leg lean mass and aerobic capacity but does not fully rehabilitate leg strenght in young and older men

DEFF Research Database (Denmark)

Vigelsø Hansen, Andreas; Gram, Martin; Wiuff, Caroline

2015-01-01

OBJECTIVE: To determine the effect of aerobic retraining as rehabilitation after short-term leg immobilization on leg strength, leg work capacity, leg lean mass, leg muscle fibre type composition and leg capillary supply, in young and older men. SUBJECTS AND DESIGN: Seventeen young (23 ± 1 years...... immobilization had marked effects on leg strength, and work capacity and 6 weeks' retraining was sufficient to increase, but not completely rehabilitate, muscle strength, and to rehabilitate aerobic work capacity and leg lean mass (in the young men)....

Experience with peroneus brevis muscle flaps for reconstruction of distal leg and ankle defects

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Babu Bajantri

2013-01-01

Full Text Available Objective: Peroneus brevis is a muscle in the leg which is expendable without much functional deficit. The objective of this study was to find out its usefulness in coverage of the defects of the lower leg and ankle. Patients and Methods: A retrospective analysis of the use of 39 pedicled peroneus brevis muscle flaps used for coverage of defects of the lower leg and ankle between November 2010 and December 2012 was carried out. The flaps were proximally based for defects of the lower third of the leg in 12 patients and distally based for reconstruction of defects of the ankle in 26 patients, with one patient having flaps on both ankles. Results: Partial flap loss in critical areas was found in four patients requiring further flap cover and in non-critical areas in two patients, which were managed with a skin graft. Three of the four critical losses occurred when we used it for covering defects over the medial malleolus. There was no complete flap loss in any of the patients. Conclusion: This flap has a unique vascular pattern and fails to fit into the classification of the vasculature of muscles by Mathes and Nahai. The unusual feature is an axial vessel system running down the deep aspect of the muscle and linking the perforators from the peroneal artery and anterior tibial artery, which allows it to be raised proximally or distally on a single perforator. The flap is simple to raise and safe for the reconstruction of small-to moderate-sized skin defects of the distal third of the tibia and all parts of the ankle except the medial malleolus, which is too far from the pedicle of the distally based flap. The donor site can be closed primarily to provide a linear scar. The muscle flap thins with time to provide a good result aesthetically at the primary defect.

INTRA-RATER RELIABILITY OF THE MULTIPLE SINGLE-LEG HOP-STABILIZATION TEST AND RELATIONSHIPS WITH AGE, LEG DOMINANCE AND TRAINING.

Science.gov (United States)

Sawle, Leanne; Freeman, Jennifer; Marsden, Jonathan

2017-04-01

Balance is a complex construct, affected by multiple components such as strength and co-ordination. However, whilst assessing an athlete's dynamic balance is an important part of clinical examination, there is no gold standard measure. The multiple single-leg hop-stabilization test is a functional test which may offer a method of evaluating the dynamic attributes of balance, but it needs to show adequate intra-tester reliability. The purpose of this study was to assess the intra-rater reliability of a dynamic balance test, the multiple single-leg hop-stabilization test on the dominant and non-dominant legs. Intra-rater reliability study. Fifteen active participants were tested twice with a 10-minute break between tests. The outcome measure was the multiple single-leg hop-stabilization test score, based on a clinically assessed numerical scoring system. Results were analysed using an Intraclass Correlations Coefficient (ICC 2,1 ) and Bland-Altman plots. Regression analyses explored relationships between test scores, leg dominance, age and training (an alpha level of p = 0.05 was selected). ICCs for intra-rater reliability were 0.85 for the dominant and non-dominant legs (confidence intervals = 0.62-0.95 and 0.61-0.95 respectively). Bland-Altman plots showed scores within two standard deviations. A significant correlation was observed between the dominant and non-dominant leg on balance scores (R 2 =0.49, ptest demonstrated strong intra-tester reliability with active participants. Younger participants who trained more, have better balance scores. This test may be a useful measure for evaluating the dynamic attributes of balance. 3.

Adaptive leg coordination with a biologically inspired neurocontroller

Science.gov (United States)

Braught, Grant; Thomopoulos, Stelios C.

1996-10-01

Natural selection is responsible for the creation of robust and adaptive control systems. Nature's control systems are created only from primitive building blocks. Using insect neurophysiology as a guide, a neural architecture for leg coordination in a hexapod robot has been developed. Reflex chains and sensory feedback mechanisms from various insects and crustacea form the basis of a pattern generator for intra-leg coordination. The pattern generator contains neural oscillators which learn from sensory feedback to produce stepping patterns. Using sensory feedback as the source of learning information allows the pattern generator to adapt to changes in the leg dynamics due to internal or external causes. A coupling between six of the single leg pattern generators is used to produce the inter-leg coordination necessary to establish stable gaits.

Peripheral and central vascular conductance influence on post-exercise hypotension

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Endo Masako Y

2012-12-01

Full Text Available Abstract Background Post-exercise hypotension (PEH following prolonged dynamic exercise arises from increased total vascular conductance (TVC via skeletal muscle vasodilation. However, arterial vasodilation of skeletal musculatures does not entirely account for the rise in TVC. The aim of the present study was to determine the contribution of vascular conductance (VC of the legs, arms, kidneys and viscera to TVC during PEH. Methods Eight subjects performed a single period of cycling at 60% of heart rate (HR reserve for 60 minutes. Blood flow in the right renal, superior mesenteric, right brachial and right femoral arteries was measured by Doppler ultrasonography in a supine position before exercise and during recovery. HR and mean arterial pressure (MAP were measured continuously. MAP decreased significantly from approximately 25 minutes after exercise cessation compared with pre-exercise baseline. TVC significantly increased (approximately 23%; P Conclusion PEH was not induced by decreased cardiac output, but by increased TVC, two-thirds of the rise in which can be attributed to increased VC in active and inactive limbs.

Excellent outcome of immunomodulation or Bruton’s tyrosine kinase inhibition in highly refractory primary cutaneous diffuse large B-cell lymphoma, leg type

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Eva Gupta

2015-12-01

Full Text Available Primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL-LT is a rare diffuse large B-cell lymphoma confined to the skin of the legs. The typical presentation is characterized by solitary or multiple growing plaques, usually confined to one leg. We report a case of PCDLBCL-LT of activated B-cell subtype characterized by multiple local relapses in the legs, initially, and systemic relapses about seven years after the diagnosis. Local relapses were sensitive to radiation therapy. Cutaneous and systemic relapses responded well to immunomodulatory therapy with lenalidomide followed by Bruton’s tyrosine kinase inhibition with ibrutinib. Ibrutinib is the only treatment that resulted in long-lasting complete remission. Lenalidomide and especially ibrutinib appear to have a significant activity against this lymphoma and should be incorporated in the treatment of this resistant and aggressive lymphoma. To our knowledge, this is the first case of PCDLBCL-LT reported in the literature exhibiting a complete response to ibrutinib.

Acute L-arginine alpha ketoglutarate supplementation fails to improve muscular performance in resistance trained and untrained men

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Wax Benjamin

2012-04-01

Full Text Available Abstract Background Dietary supplements containing L-arginine are marketed to improve exercise performance, but the efficacy of such supplements is not clear. Therefore, this study examined the efficacy of acute ingestion of L-arginine alpha-ketoglutarate (AAKG muscular strength and endurance in resistance trained and untrained men. Methods Eight resistance trained and eight untrained healthy males ingested either 3000mg of AAKG or a placebo 45 minutes prior to a resistance exercise protocol in a randomized, double-blind crossover design. One-repetition maximum (1RM on the standard barbell bench press and leg press were obtained. Upon determination of 1RM, subjects completed repetitions to failure at 60% 1RM on both the standard barbell bench press and leg press. Heart rate was measured pre and post exercise. One week later, subjects ingested the other supplement and performed the identical resistance exercise protocol. Results Our data showed statistical significant differences (p0.05 between supplementation conditions for either resistance trained or untrained men in the bench press or leg press exercises. Heart rate was similar at the end of the upper and lower body bouts of resistance exercise with AAKG vs. placebo. Conclusion The results from our study indicate that acute AAKG supplementation provides no ergogenic benefit on 1RM or TLV as measured by the standard barbell bench press and leg press, regardless of the subjects training status.

Analytic study of transverse shunt resistance and even-odd mode coupling of a rod type RFQ

International Nuclear Information System (INIS)

Koscielniak, S.

1994-06-01

To minimize the ohmic power losses, it is necessary to maximize the transverse shunt resistance, R shunt . The cell of a rod-type RFQ is modelled by a parallel two-rod transmission line supported above a parallel ground conductor by two legs. Due to coupling between neighboring supports, the loading impedance is modified depending on the leg spacing. The shunt resistance is improved by reducing the cell length and increasing the leg spacing, and maximized when the legs are equally spaced. However, this is also the condition for strong excitation of the unwanted 'even-mode' in which a potential difference exists between the ends of the rods mid-plane and the grounding conductor or tank, Once the legs of the support are longitudinally separated, some even-mode excitation of the structure is inevitable because some current must be injected into the ground conductor; the even-mode excitation rises as leg separation increases. Further, when the desired odd-mode voltage is symmetric about the cell centre, the even-mode voltage is anti-symmetric This paper is a very much abridged version of two internal design notes[3], [4]. (author). 4 refs.,1 fig

Børns leg og eksperimenterende virksomhed

DEFF Research Database (Denmark)

Damgaard Warrer, Sarah; Broström, Stig

Børns leg og eksperimenterende virksomhed er et rigt felt med mange perspektiver, indgangsvinkler og nuancer. I denne bog kædes leg og det eksperimenterende og skabende sammen som to gensidigt forbundne fænomener og belyses i pædagogisk og didaktisk perspektiv. Desuden beskrives potentialet i båd...

Lower limb progressive resistance training improves leg strength but not gait speed or balance in Parkinson's disease: a systematic review and meta-analysis.

Science.gov (United States)

Tillman, Alex; Muthalib, Makii; Hendy, Ashlee M; Johnson, Liam G; Rantalainen, Timo; Kidgell, Dawson J; Enticott, Peter G; Teo, Wei-Peng

2015-01-01

The use of progressive resistance training (PRT) to improve gait and balance in people with Parkinson's disease (PD) is an emerging area of interest. However, the main effects of PRT on lower limb functions such as gait, balance, and leg strength in people with PD remain unclear. Therefore, the aim of the meta-analysis is to evaluate the evidence surrounding the use of PRT to improve gait and balance in people with PD. Five electronic databases, from inception to December 2014, were searched to identify the relevant studies. Data extraction was performed by two independent reviewers and methodological quality was assessed using the PEDro scale. Standardized mean differences (SMD) and 95% confidence intervals (CIs) of fixed and random effects models were used to calculate the effect sizes between experimental and control groups and I (2) statistics were used to determine levels of heterogeneity. In total, seven studies were identified consisting of 172 participants (experimental n = 84; control n = 88). The pooled results showed a moderate but significant effect of PRT on leg strength (SMD 1.42, 95% CI 0.464-2.376); however, no significant effects were observed for gait speed (SMD 0.418, 95% CI -0.219 to 1.055). No significant effects were observed for balance measures included in this review. In conclusion, our results showed no discernable effect of PRT on gait and balance measures, although this is likely due to the lack of studies available. It may be suggested that PRT be performed in conjunction with balance or task-specific functional training to elicit greater lower limb functional benefits in people with PD.

Evaluation of an isotope washout technique to measure skin vascular resistance and skin perfusion pressure: influence of age, site and arterial surgery

International Nuclear Information System (INIS)

Duncan, H.J.; Faris, I.B.

1986-01-01

1. A simplified isotope (sup(99m)Tc) washout technique has been devised to calculate the skin perfusion pressure (SPP) and skin vascular resistance (SVR). This test is simple, requires inexpensive equipment and is well tolerated by patients. 2. SPP and SVR were calculated in 20 patients 30 years of age and in 15 patients with peripheral vascular disease (PVD). With increasing age the SPP and SVP were increased. The SPP was similar to the mean arterial pressure in normal individuals but was decreased in patients with PVD. The SPP is a useful indicator of the severity of the PVD. 3. The SPP and SVR were higher in the calf than in the foot. This is probably related to the decrease in pressure in the distal arterial tree. 4. SPP was increased by 110% and skin blood flow by 190% by arterial reconstructive surgery. This test may be of use in assessing the effectiveness of arterial surgery. (author)

Comparison Between the Acute Pulmonary Vascular Effects of Oxygen with Nitric Oxide and Sildenafil

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Ronald W. Day

2015-03-01

Full Text Available Objective. Right heart catheterization is performed in patients with pulmonary arterial hypertension to determine the severity of disease and their pulmonary vascular reactivity. The acute pulmonary vascular effect of inhaled nitric oxide is frequently used to identify patients who will respond favorably to vasodilator therapy. This study sought to determine whether the acute pulmonary vascular effects of oxygen with nitric oxide and intravenous sildenafil are similar. Methods. A retrospective, descriptive study of 13 individuals with pulmonary hypertension who underwent heart catheterization and acute vasodilator testing was performed. The hemodynamic measurements during five phases (21% to 53% oxygen, 100% oxygen, 100% oxygen with 20 ppm nitric oxide, 21% to 51% oxygen, and 21% to 51% oxygen with 0.05 mg/kg to 0.29 mg/kg intravenous sildenafil of the procedures were compared.Results. Mean pulmonary arterial pressure and pulmonary vascular resistance acutely decreased with 100% oxygen with nitric oxide, and 21% to 51% oxygen with sildenafil. Mean pulmonary arterial pressure (mm Hg, mean ± standard error of the mean was 38 ± 4 during 21% to 53% oxygen, 32 ± 3 during 100% oxygen, 29 ± 2 during 100% oxygen with nitric oxide, 37 ± 3 during 21% to 51% oxygen, and 32 ± 2 during 21% to 51% oxygen with sildenafil. There was not a significant correlation between the percent change in pulmonary vascular resistance from baseline with oxygen and nitric oxide, and from baseline with sildenafil (r2 = 0.011, p = 0.738. Conclusions. Oxygen with nitric oxide and sildenafil decreased pulmonary vascular resistance. However, the pulmonary vascular effects of oxygen and nitric oxide cannot be used to predict the acute response to sildenafil. Additional studies are needed to determine whether the acute response to sildenafil can be used to predict the long-term response to treatment with an oral phosphodiesterase V inhibitor.

The effects of passive leg press training on jumping performance, speed, and muscle power.

Science.gov (United States)

Liu, Chiang; Chen, Chuan-Shou; Ho, Wei-Hua; Füle, Róbert János; Chung, Pao-Hung; Shiang, Tzyy-Yuang

2013-06-01

Passive leg press (PLP) training was developed based on the concepts of the stretch-shortening cycle (SSC) and the benefits of high muscle contraction velocity. Passive leg press training enables lower limb muscle groups to apply a maximum downward force against a platform moved up and down at high frequency by an electric motor. Thus, these muscle groups accomplished both concentric and eccentric isokinetic contractions in a passive, rapid, and repetitive manner. This study investigates the effects of 10 weeks of PLP training at high and low movement frequencies have on jumping performance, speed, and muscle power. The authors selected 30 college students who had not performed systematic resistance training in the previous 6 months, including traditional resistance training at a squat frequency of 0.5 Hz, PLP training at a low frequency of 0.5 Hz, and PLP training at a high frequency of 2.5 Hz, and randomly divided them into 3 groups (n = 10). The participants' vertical jump, drop jump, 30-m sprint performance, explosive force, and SSC efficiency were tested under the same experimental procedures at pre- and post-training. Results reveal that high-frequency PLP training significantly increased participants' vertical jump, drop jump, 30-m sprint performance, instantaneous force, peak power, and SSC efficiency (p training (p training significantly increased participants' vertical jump, 30-m sprint performance, instantaneous force, and peak power (p training only increased participants' 30-m sprint performance and peak power (p training at high movement frequency. A PLP training machine powered by an electrical motor enables muscles of the lower extremities to contract faster compared with voluntary contraction. Therefore, muscle training with high contraction velocity is one of the main methods of increasing muscle power. Passive leg press training is a unique method for enhancing jump performance, speed, and muscle power.

Restless Legs Syndrome -- Self-Tests and Diagnosis

Science.gov (United States)

... legs syndrome Diagnosis Talk to a board certified sleep medicine physician if you think you have restless legs ... He or she can refer you to a sleep medicine physician if necessary. The sleep physician may ask ...

Six-legged walking robot for service operations

OpenAIRE

Ihme, T.; Schneider, A.; Schmucker, U.

1998-01-01

This paper presents the control system of a six-legged vehicle including force control. Considered control schemes are control of forces and control of body motion. The experimental result with a six-legged robot is presented.

GPR68 Senses Flow and Is Essential for Vascular Physiology.

Science.gov (United States)

Xu, Jie; Mathur, Jayanti; Vessières, Emilie; Hammack, Scott; Nonomura, Keiko; Favre, Julie; Grimaud, Linda; Petrus, Matt; Francisco, Allain; Li, Jingyuan; Lee, Van; Xiang, Fu-Li; Mainquist, James K; Cahalan, Stuart M; Orth, Anthony P; Walker, John R; Ma, Shang; Lukacs, Viktor; Bordone, Laura; Bandell, Michael; Laffitte, Bryan; Xu, Yan; Chien, Shu; Henrion, Daniel; Patapoutian, Ardem

2018-04-19

Mechanotransduction plays a crucial role in vascular biology. One example of this is the local regulation of vascular resistance via flow-mediated dilation (FMD). Impairment of this process is a hallmark of endothelial dysfunction and a precursor to a wide array of vascular diseases, such as hypertension and atherosclerosis. Yet the molecules responsible for sensing flow (shear stress) within endothelial cells remain largely unknown. We designed a 384-well screening system that applies shear stress on cultured cells. We identified a mechanosensitive cell line that exhibits shear stress-activated calcium transients, screened a focused RNAi library, and identified GPR68 as necessary and sufficient for shear stress responses. GPR68 is expressed in endothelial cells of small-diameter (resistance) arteries. Importantly, Gpr68-deficient mice display markedly impaired acute FMD and chronic flow-mediated outward remodeling in mesenteric arterioles. Therefore, GPR68 is an essential flow sensor in arteriolar endothelium and is a critical signaling component in cardiovascular pathophysiology. Copyright © 2018 Elsevier Inc. All rights reserved.

Sensitivity of sensor-based sit-to-stand peak power to the effects of training leg strength, leg power and balance in older adults.

Science.gov (United States)

Regterschot, G Ruben H; Folkersma, Marjanne; Zhang, Wei; Baldus, Heribert; Stevens, Martin; Zijlstra, Wiebren

2014-01-01

Increasing leg strength, leg power and overall balance can improve mobility and reduce fall risk. Sensor-based assessment of peak power during the sit-to-stand (STS) transfer may be useful for detecting changes in mobility and fall risk. Therefore, this study investigated whether sensor-based STS peak power and related measures are sensitive to the effects of increasing leg strength, leg power and overall balance in older adults. A further aim was to compare sensitivity between sensor-based STS measures and standard clinical measures of leg strength, leg power, balance, mobility and fall risk, following an exercise-based intervention. To achieve these aims, 26 older adults (age: 70-84 years) participated in an eight-week exercise program aimed at improving leg strength, leg power and balance. Before and after the intervention, performance on normal and fast STS transfers was evaluated with a hybrid motion sensor worn on the hip. In addition, standard clinical tests (isometric quadriceps strength, Timed Up and Go test, Berg Balance Scale) were performed. Standard clinical tests as well as sensor-based measures of peak power, maximal velocity and duration of normal and fast STS showed significant improvements. Sensor-based measurement of peak power, maximal velocity and duration of normal STS demonstrated a higher sensitivity (absolute standardized response mean (SRM): ≥ 0.69) to the effects of training leg strength, leg power and balance than standard clinical measures (absolute SRM: ≤ 0.61). Therefore, the presented sensor-based method appears to be useful for detecting changes in mobility and fall risk. Copyright © 2013 Elsevier B.V. All rights reserved.

Improving venous leg ulcer management

OpenAIRE

Weller, Carolina Dragica

2017-01-01

This thesis reports several different methods to develop and evaluate complex interventions designed to improve venous leg ulcer management. Chronic venous leg ulcers (VLU) are the most common chronic wound problem in the community. Its health and economic burden is predicted to increase due to ageing of the community and increase in prevalence of diabetes and obesity. Although many patients seek health care for VLU, most do not receive the most effective management. Patients with this condi...

Assessing Children's Legs and Feet

OpenAIRE

Wedge, John H.

1985-01-01

Shoes are necessary for protection and warmth. Normal children do not require shoes for support. There is no scientific evidence that shoes—‘orthopedic’ or otherwise—influence or alter the growth or shape of the normal child's foot except, perhaps, adversely if they fit poorly. Family physicians must understand common variations of normal foot and leg development if they are to effectively advise and reassure parents about appropriate footwear. Flat feet, knock knees, bow legs, in-toeing, and...

On the regulatory functions of neuropeptide Y (NPY) with respect to vascular resistance and exocrine and endocrine secretion in the pig pancreas

DEFF Research Database (Denmark)

Holst, J J; Orskov, C; Knuhtsen, S

1989-01-01

We compared the effects of electrical stimulation of the splanchnic nerves and infusions of neuropeptide Y, noradrenaline or a combination of the two on pancreatic vascular resistance and exocrine and endocrine secretion. For these studies we used isolated perfused pig pancreas with preserved...... splanchnic nerve supply. The exocrine secretion was stimulated with physiological concentrations of secretin and cholecystokinin octapeptide. Noradrenaline and NPY at 10(-8) M both increased pancreatic perfusion pressure. Their effects were additive and similar in magnitude to that of electrical stimulation...

Promethus Hot Leg Piping Concept

International Nuclear Information System (INIS)

AM Girbik; PA Dilorenzo

2006-01-01

The Naval Reactors Prime Contractor Team (NRPCT) recommended the development of a gas cooled reactor directly coupled to a Brayton energy conversion system as the Space Nuclear Power Plant (SNPP) for NASA's Project Prometheus. The section of piping between the reactor outlet and turbine inlet, designated as the hot leg piping, required unique design features to allow the use of a nickel superalloy rather than a refractory metal as the pressure boundary. The NRPCT evaluated a variety of hot leg piping concepts for performance relative to SNPP system parameters, manufacturability, material considerations, and comparison to past high temperature gas reactor (HTGR) practice. Manufacturability challenges and the impact of pressure drop and turbine entrance temperature reduction on cycle efficiency were discriminators between the piping concepts. This paper summarizes the NRPCT hot leg piping evaluation, presents the concept recommended, and summarizes developmental issues for the recommended concept

RESTLESS LEGS SYNDROME

Directory of Open Access Journals (Sweden)

Dmitriy Valer'evich Artem'ev

2009-01-01

Full Text Available The paper describes the epidemiology, etiology, pathogenesis, clinical picture, diagnosis, differential diagnosis, and treatment of restless legs syndrome. Recommendations are given how to choose therapeutic modalities and drugs in relation to different factors.

Exploring the Association Between the Doppler Findings of Endometriomal Wall Vascularization and Volume of the Endometrioma

Directory of Open Access Journals (Sweden)

Berna Seçkin

2016-05-01

CONCLUSION: We could not demonstrate a significant association between endometriomal volume and amount of blood flow along the endometrioma wall. However, the increased volume of endometrioma is found to be correlated with high vascular resistance, thus decreased vascularization compared to smaller endometriomas assessed by pulsed Doppler indices. This finding may aid in the development of adjuvant treatments for patients with smaller endometriomas and lower resistance to blood flow.

Role of endogenous nitric oxide on PAF-induced vascular and respiratory effects

Directory of Open Access Journals (Sweden)

M. Clement

1995-01-01

Full Text Available The role of endogenous nitric oxide (NO on vascular and respiratory smooth muscle basal tone was evaluated in six anaesthetized, paralysed, mechanically ventilated pigs. The involvement of endogenous NO in PAF-induced shock and airway hyperresponsiveness was also studied. PAF (50 ng/kg, i.v. was administered before and after pretreatment with NG-nitro-L-arginine methyl ester (L-NAME, 10 mg/kg, i.v., an NO synthesis inhibitor. PAF was also administered to three of these pigs after indomethacin infusion (3 mg/kg, i.v.. In normal pigs, L-NAME increased systemic and pulmonary vascular resistances, caused pulmonary hypertension and reduced cardiac output and stroke volume. The pulmonary vascular responses were correlated with the increase in static and dynamic lung elastances, without changing lung resistance. Inhibition of NO synthesis enhanced the PAF-dependent increase in total, intrinsic and viscoelastic lung resistances, without affecting lung elastances or cardiac activity. The systemic hypotensive effect of PAF was not abolished by pretreatment with L-NAME or indomethacin. This indicates that systemic hypotension is not correlated with the release of endogenous NO or prostacyclines. Indomethacin completely abolished the PAF-dependent respiratory effects.

The examination assessment of technical competence in vascular surgery.

Science.gov (United States)

Pandey, V A; Wolfe, J H N; Liapis, C D; Bergqvist, D

2006-09-01

The European Board of Surgery Qualification in Vascular Surgery is a pan-European examination for vascular surgeons who have attained a national certificate of completion of specialist training. A 2-year study was conducted before the introduction of a technical skills assessment in the examination. The study included 30 surgeons: 22 candidates and eight examiners. They were tested on dissection (on a synthetic saphenofemoral junction model), anastomosis (on to anterior tibial artery of a synthetic leg model) and dexterity (a knot-tying simulator with electromagnetic motion analysis). Validated rating scales were used by two independent examiners. Composite knot-tying scores were calculated for the computerized station. The stations were weighted 35, 45 and 20 percent, respectively. Examiners performed better than candidates in the dissection (P<0.001), anastomosis (P=0.002) and dexterity (P=0.005) stations. Participants performed consistently in the examination (dissection versus anastomosis: r=0.79, P<0.001; dexterity versus total operative score: r=-0.73, P<0.001). Interobserver reliability was high (alpha=0.91). No correlation was seen between a candidate's technical skill and oral examination performance or logbook-accredited scores. Current surgical examinations do not address technical competence. This model appears to be a valid assessment of technical skills in an examination setting. The standards are set at a level appropriate for a specialist vascular surgeon. Copyright (c) 2006 British Journal of Surgery Society Ltd.

Protection against high intravascular pressure in giraffe legs

DEFF Research Database (Denmark)

Petersen, Karin K; Hørlyck, Arne; Østergaard, Kristine Hovkjær

2013-01-01

The high blood pressure in giraffe leg arteries renders giraffes vulnerable to edema. We investigated in 11 giraffes whether large and small arteries in the legs and the tight fascia protect leg capillaries. Ultrasound imaging of foreleg arteries in anesthetized giraffes and ex vivo examination....... All three findings can contribute to protection of the capillaries in giraffe legs from a high arterial pressure....... revealed abrupt thickening of the arterial wall and a reduction of its internal diameter just below the elbow. At and distal to this narrowing, the artery constricted spontaneously and in response to norepinephrine and intravascular pressure recordings revealed a dynamic, viscous pressure drop along...

Skipping on uneven ground: trailing leg adjustments simplify control and enhance robustness.

Science.gov (United States)

Müller, Roy; Andrada, Emanuel

2018-01-01

It is known that humans intentionally choose skipping in special situations, e.g. when descending stairs or when moving in environments with lower gravity than on Earth. Although those situations involve uneven locomotion, the dynamics of human skipping on uneven ground have not yet been addressed. To find the reasons that may motivate this gait, we combined experimental data on humans with numerical simulations on a bipedal spring-loaded inverted pendulum model (BSLIP). To drive the model, the following parameters were estimated from nine subjects skipping across a single drop in ground level: leg lengths at touchdown, leg stiffness of both legs, aperture angle between legs, trailing leg angle at touchdown (leg landing first after flight phase), and trailing leg retraction speed. We found that leg adjustments in humans occur mostly in the trailing leg (low to moderate leg retraction during swing phase, reduced trailing leg stiffness, and flatter trailing leg angle at lowered touchdown). When transferring these leg adjustments to the BSLIP model, the capacity of the model to cope with sudden-drop perturbations increased.

Matrix Metalloproteinase-2 Activity is Associated with Divergent Regulation of Calponin-1 in Conductance and Resistance Arteries in Hypertension-induced Early Vascular Dysfunction and Remodelling.

Science.gov (United States)

Parente, Juliana M; Pereira, Camila A; Oliveira-Paula, Gustavo H; Tanus-Santos, José E; Tostes, Rita C; Castro, Michele M

2017-10-01

Matrix metalloproteinase (MMP)-2 participates in hypertension-induced maladaptive vascular remodelling by degrading extra- and intracellular proteins. The consequent extracellular matrix rearrangement and phenotype switch of vascular smooth muscle cells (VSMCs) lead to increased cellular migration and proliferation. As calponin-1 degradation by MMP-2 may lead to VSMC proliferation during hypertension, the hypothesis of this study is that increased MMP-2 activity contributes to early hypertension-induced maladaptive remodelling in conductance and resistance arteries via regulation of calponin-1. The main objective was to analyse whether MMP-2 exerts similar effects on the structure and function of the resistance and conductance arteries during early hypertension. Two-kidney, one-clip (2K-1C) hypertensive male rats and corresponding controls were treated with doxycycline (30 mg/kg/day) or water until reaching one week of hypertension. Systolic blood pressure was increased in 2K-1C rats, and doxycycline did not reduce it. Aortas and mesenteric arteries were analysed. MMP-2 activity and expression were increased in both arteries, and doxycycline reduced it. Significant hypertrophic remodelling and VSMC proliferation were observed in aortas but not in mesenteric arteries of 2K-1C rats. The contractility of mesenteric arteries to phenylephrine was increased in 2K-1C rats, and doxycycline prevented this alteration. The potency of phenylephrine to contract aortas of 2K-1C rats was increased, and doxycycline decreased it. Whereas calponin-1 expression was increased in 2K-1C mesenteric arteries, calponin-1 was reduced in aortas. Doxycycline treatment reverted changes in calponin-1 expression. MMP-2 contributes to hypertrophic remodelling in aortas by decreasing calponin-1 levels, which may result in VSMC proliferation. On the other hand, MMP-2-dependent increased calponin-1 in mesenteric arteries may contribute to vascular hypercontractility in 2K-1C rats. Divergent

Flexible thermoelectric generator using bulk legs and liquid metal interconnects for wearable electronics

International Nuclear Information System (INIS)

Suarez, Francisco; Parekh, Dishit P.; Ladd, Collin; Vashaee, Daryoosh; Dickey, Michael D.; Öztürk, Mehmet C.

2017-01-01

Highlights: •Flexible thermoelectric generator (TEG) with bulk legs. •Flexible thermoelectric generator with liquid metal interconnects. •Flexible TEG with potential to match the performance of rigid TEGs. •Flexible TEG for wearable electronics. -- Abstract: Interest in wearable electronics for continuous, long-term health and performance monitoring is rapidly increasing. The reduction in power levels consumed by sensors and electronic circuits accompanied by the advances in energy harvesting methods allows for the realization of self-powered monitoring systems that do not have to rely on batteries. For wearable electronics, thermoelectric generators (TEGs) offer the unique ability to continuously convert body heat into usable energy. For body harvesting, it is preferable to have TEGs that are thin, soft and flexible. Unfortunately, the performances of flexible modules reported to date have been far behind those of their rigid counterparts. This is largely due to lower efficiencies of the thermoelectric materials, electrical or thermal parasitic losses and limitations on leg dimensions posed by the synthesis techniques. In this work, we present an entirely new approach and explore the possibility of using standard bulk legs in a flexible package. Bulk thermoelectric legs cut from solid ingots are far superior to thermoelectric materials synthesized using other techniques. A key enabler of the proposed technology is the use of EGaIn liquid metal interconnects, which not only provide extremely low interconnect resistance but also stretchability with self-healing, both of which are essential for flexible TE modules. The results suggest that this novel approach can finally produce flexible TEGs that have the potential to challenge the rigid TEGs and provide a pathway for the realization of self-powered wearable electronics.

Cold leg condensation tests. Task C. Steam--water interaction tests

International Nuclear Information System (INIS)

Brodrick, J.R.; Loiselle, V.

1974-03-01

A report is presented of tests to determine the condensation efficiency of ECC water injected into a quality fluid mixture flowing through the cold leg. In particular, a specific objective was to determine if the mixture of ECC water and quality fluid reached thermodynamic equilibrium before exiting the cold leg. Further, the stability of the ECC water/quality fluid interaction would be assessed by interpretation of thermocouple records and utilization of a section of cold leg piping with view ports to film the interaction whenever possible. The cold leg condensation tests showed complete condensation of the 5 lbm/sec steam quality mixtures in the cold leg by the ECC water flows of the test matrix. The cold leg exit fluid temperature remained below the saturation temperature and had good agreement with the predicted cold leg outlet temperature, calculated assuming total condensation. (U.S.)

Near-Infrared Spectroscopic Measurement of the Effect of Leg Dominance on Muscle Oxygen Saturation During Cycling

Science.gov (United States)

Ellerby, Gwenn E. C.; Lee, Stuart M. C.; Paunescu, Lelia Adelina; Pereira, Chelsea; Smith, Charles P.; Soller, Babs R.

2011-01-01

The effect of leg dominance on the symmetry of the biomechanics during cycling remains uncertain -- asymmetries have been observed in kinematics and kinetics, while symmetries were found in muscle activation. No studies have yet investigated the symmetry of muscle metabolism during cycling. Near-infrared spectroscopy (NIRS) provides a non-invasive method to investigate the metabolic responses of specific muscles during cycling. PURPOSE: To determine whether there was an effect of leg dominance on thigh muscle oxygen saturation (SmO2) during incrementally loaded submaximal cycling using NIRS. METHODS: Eight right leg dominant, untrained subjects (5 men, 3 women; 31+/-2 yrs; 168.6+/-1.0 cm; 67.2+/-1.8 kg, mean +/- SE) volunteered to participate. Spectra were collected bilaterally from the vastus lateralis (VL) during supine rest and cycling. SmO2 was calculated using previously published methods. Subjects pedaled at 65 rpm while resistance to pedaling was increased in 0.5 kp increments from 0.5 kp every 3 min until the subject reached 80% of age-predicted maximal heart rate. SmO2 was averaged over 3 min for each completed stage. A two-way ANOVA was performed to test for leg differences. A priori contrasts were used to compare work levels to rest. RESULTS: VL SmO2 was not different between the dominant and non-dominant legs at rest and during exercise (p=0.57). How SmO2 changed with workload was also not different between legs (p=0.32). SmO2 at 0.5 kp (60.3+/-4.0, p=0.12) and 1.0 kp (59.5+/-4.0, p=0.10) was not different from rest (69.1+/-4.0). SmO2 at 1.5 kp (55.4 4.0, p=0.02), 2.0 kp (55.7+/-5.0, p=0.04), and 2.5 kp (43.4+/-7.9, p=0.01) was significantly lower than rest. CONCLUSION: VL SmO2 during cycling is not different between dominant and non-dominant legs and decreases with moderate workload in untrained cyclists. Assuming blood flow is directed equally to both legs, similar levels of oxygen extraction (as indicated by SmO2) suggests the metabolic load of

Protein Kinase C Inhibitors as Modulators of Vascular Function and Their Application in Vascular Disease

Directory of Open Access Journals (Sweden)

Raouf A. Khalil

2013-03-01

Full Text Available Blood pressure (BP is regulated by multiple neuronal, hormonal, renal and vascular control mechanisms. Changes in signaling mechanisms in the endothelium, vascular smooth muscle (VSM and extracellular matrix cause alterations in vascular tone and blood vessel remodeling and may lead to persistent increases in vascular resistance and hypertension (HTN. In VSM, activation of surface receptors by vasoconstrictor stimuli causes an increase in intracellular free Ca2+ concentration ([Ca2+]i, which forms a complex with calmodulin, activates myosin light chain (MLC kinase and leads to MLC phosphorylation, actin-myosin interaction and VSM contraction. Vasoconstrictor agonists could also increase the production of diacylglycerol which activates protein kinase C (PKC. PKC is a family of Ca2+-dependent and Ca2+-independent isozymes that have different distributions in various blood vessels, and undergo translocation from the cytosol to the plasma membrane, cytoskeleton or the nucleus during cell activation. In VSM, PKC translocation to the cell surface may trigger a cascade of biochemical events leading to activation of mitogen-activated protein kinase (MAPK and MAPK kinase (MEK, a pathway that ultimately increases the myofilament force sensitivity to [Ca2+]i, and enhances actin-myosin interaction and VSM contraction. PKC translocation to the nucleus may induce transactivation of various genes and promote VSM growth and proliferation. PKC could also affect endothelium-derived relaxing and contracting factors as well as matrix metalloproteinases (MMPs in the extracellular matrix further affecting vascular reactivity and remodeling. In addition to vasoactive factors, reactive oxygen species, inflammatory cytokines and other metabolic factors could affect PKC activity. Increased PKC expression and activity have been observed in vascular disease and in certain forms of experimental and human HTN. Targeting of vascular PKC using PKC inhibitors may function in

Effects of Mild Blast Traumatic Brain Injury on Cerebral Vascular, Histopathological, and Behavioral Outcomes in Rats

Science.gov (United States)

Zeng, Yaping; Deyo, Donald; Parsley, Margaret A.; Hawkins, Bridget E.; Prough, Donald S.; DeWitt, Douglas S.

2018-01-01

Abstract To determine the effects of mild blast-induced traumatic brain injury (bTBI), several groups of rats were subjected to blast injury or sham injury in a compressed air-driven shock tube. The effects of bTBI on relative cerebral perfusion (laser Doppler flowmetry [LDF]), and mean arterial blood pressure (MAP) cerebral vascular resistance were measured for 2 h post-bTBI. Dilator responses to reduced intravascular pressure were measured in isolated middle cerebral arterial (MCA) segments, ex vivo, 30 and 60 min post-bTBI. Neuronal injury was assessed (Fluoro-Jade C [FJC]) 24 and 48 h post-bTBI. Neurological outcomes (beam balance and walking tests) and working memory (Morris water maze [MWM]) were assessed 2 weeks post-bTBI. Because impact TBI (i.e., non-blast TBI) is often associated with reduced cerebral perfusion and impaired cerebrovascular function in part because of the generation of reactive oxygen and nitrogen species such as peroxynitrite (ONOO−), the effects of the administration of the ONOO− scavenger, penicillamine methyl ester (PenME), on cerebral perfusion and cerebral vascular resistance were measured for 2 h post-bTBI. Mild bTBI resulted in reduced relative cerebral perfusion and MCA dilator responses to reduced intravascular pressure, increases in cerebral vascular resistance and in the numbers of FJC-positive cells in the brain, and significantly impaired working memory. PenME administration resulted in significant reductions in cerebral vascular resistance and a trend toward increased cerebral perfusion, suggesting that ONOO− may contribute to blast-induced cerebral vascular dysfunction. PMID:29160141

Bio-Inspired Design and Kinematic Analysis of Dung Beetle-Like Legs

DEFF Research Database (Denmark)

Aditya, Sai Krishna Venkata; Ignasov, Jevgeni; Filonenko, Konstantin

2017-01-01

The African dung beetle Scarabaeus galenus can use its front legs to walk and manipulate or form a dung ball. The interesting multifunctional legs have not been fully investigated or even used as inspiration for robot leg design. Thus, in this paper, we present the development of real dung beetle......-like front legs based on biological investigation. As a result, each leg consists of three main segments which were built using 3D printing. The segments were combined with in total four active DOFs in order to mimic locomotion and object manipulation of the beetle. Kinematics analysis of the leg was also...... performed to identify its workspace as well as to design its trajectory. To this end, the study contributes not only novel multifunctional robotic legs but also the methodology of the bio-inspired leg design....

Clinical quality indicators of venous leg ulcers

DEFF Research Database (Denmark)

Kjaer, Monica L; Mainz, Jan; Soernsen, Lars T

2005-01-01

In the clinical setting, diagnosis and treatment of venous leg ulcers can vary considerably from patient to patient. The first step to reducing this variation is to document venous leg ulcer care through use of quantitative scientific documentation principles. This requires the development of val...

Ubx regulates differential enlargement and diversification of insect hind legs.

Directory of Open Access Journals (Sweden)

Najmus Mahfooz

2007-09-01

Full Text Available Differential enlargement of hind (T3 legs represents one of the hallmarks of insect evolution. However, the actual mechanism(s responsible are yet to be determined. To address this issue, we have now studied the molecular basis of T3 leg enlargement in Oncopeltus fasciatus (milkweed bug and Acheta domesticus (house cricket. In Oncopeltus, the T3 tibia displays a moderate increase in size, whereas in Acheta, the T3 femur, tibia, and tarsus are all greatly enlarged. Here, we show that the hox gene Ultrabithorax (Ubx is expressed in the enlarged segments of hind legs. Furthermore, we demonstrate that depletion of Ubx during embryogenesis has a primary effect in T3 legs and causes shortening of leg segments that are enlarged in a wild type. This result shows that Ubx is regulating the differential growth and enlargement of T3 legs in both Oncopeltus and Acheta. The emerging view suggests that Ubx was co-opted for a novel role in regulating leg growth and that the transcriptional modification of its expression may be a universal mechanism for the evolutionary diversification of insect hind legs.

Laterality of the legs in young female soccer players

Directory of Open Access Journals (Sweden)

Antosiak-Cyrak Katarzyna Z.

2015-12-01

Full Text Available Purpose. The aim of the present study was assessment of laterality of the legs of young female soccer players and their non-training counterparts. Methods. The study sample comprised 9 female soccer players and 19 non-training girls. They underwent three measurement sessions, one every six months. The applied tests included kinesthetic differentiation, rate of local movements, static balance, single-leg hop, rate of global movements, strength and speed, and functional asymmetry of the legs tests. Results. The soccer players were better than the controls in their performance of the rate of local movements, rate of global movements, kinesthetic differentiation, single-leg 15m timed hop and static balance tests. Smaller differences between the results of the left and the right legs in soccer players, than in non-training girls, were noted in the rate of local movements, rate of global movements and kinesthetic differentiation tests. In the static balance test, the differences were greater in the group of soccer players. Conclusions. Lateralization of the lower limbs is a highly complex characteristic with a different variability in athletes than in nontraining individuals. The results of the present study also point to the specialization of soccer players’ left legs in body balance and single-leg hop tests.

Vascular risk factors, cognitve decline, and dementia

Directory of Open Access Journals (Sweden)

E Duron

2008-04-01

Full Text Available E Duron, Olivier HanonBroca Hospital, Paris, FranceAbstract: Dementia is one of the most important neurological disorders in the elderly. Aging is associated with a large increase in the prevalence and incidence of degenerative (Alzheimer’s disease and vascular dementia, leading to a devastating loss of autonomy. In view of the increasing longevity of populations worldwide, prevention of dementia has turned into a major public health challenge. In the past decade, several vascular risk factors have been found to be associated with vascular dementia but also Alzheimer’s disease. Some longitudinal studies, have found significant associations between hypertension, diabetus mellitus, and metabolic syndrome, assessed at middle age, and dementia. Studies assessing the link between hypercholesterolemia, atrial fibrillation, smoking, and dementia have given more conflicting results. Furthermore, some studies have highlighted the possible protective effect of antihypertensive therapy on cognition and some trials are evaluating the effects of statins and treatments for insulin resistance. Vascular risk factors and their treatments are a promising avenue of research for prevention of dementia, and further long-term, placebo-controlled, randomized studies, need to be performed.Keywords: dementia, hypertension, diabetus mellitus, hypercholesterolemia, metabolic syndrome

Restless Legs Syndrome

Science.gov (United States)

... disorder, particularly if they experience onset at an early age; many years may pass before symptoms occur regularly. top What causes restless legs syndrome? In most cases, the cause of RLS is unknown (called primary RLS). However, RLS has a genetic component and ...

Bioprinting for vascular and vascularized tissue biofabrication.

Science.gov (United States)

Datta, Pallab; Ayan, Bugra; Ozbolat, Ibrahim T

2017-03-15

Bioprinting is a promising technology to fabricate design-specific tissue constructs due to its ability to create complex, heterocellular structures with anatomical precision. Bioprinting enables the deposition of various biologics including growth factors, cells, genes, neo-tissues and extra-cellular matrix-like hydrogels. Benefits of bioprinting have started to make a mark in the fields of tissue engineering, regenerative medicine and pharmaceutics. Specifically, in the field of tissue engineering, the creation of vascularized tissue constructs has remained a principal challenge till date. However, given the myriad advantages over other biofabrication methods, it becomes organic to expect that bioprinting can provide a viable solution for the vascularization problem, and facilitate the clinical translation of tissue engineered constructs. This article provides a comprehensive account of bioprinting of vascular and vascularized tissue constructs. The review is structured as introducing the scope of bioprinting in tissue engineering applications, key vascular anatomical features and then a thorough coverage of 3D bioprinting using extrusion-, droplet- and laser-based bioprinting for fabrication of vascular tissue constructs. The review then provides the reader with the use of bioprinting for obtaining thick vascularized tissues using sacrificial bioink materials. Current challenges are discussed, a comparative evaluation of different bioprinting modalities is presented and future prospects are provided to the reader. Biofabrication of living tissues and organs at the clinically-relevant volumes vitally depends on the integration of vascular network. Despite the great progress in traditional biofabrication approaches, building perfusable hierarchical vascular network is a major challenge. Bioprinting is an emerging technology to fabricate design-specific tissue constructs due to its ability to create complex, heterocellular structures with anatomical precision

Lower Limb Progressive Resistance Training Improves Leg Strength but Not Gait Speed or Balance in Parkinson’s Disease: A Systematic Review and Meta-Analysis

Science.gov (United States)

Tillman, Alex; Muthalib, Makii; Hendy, Ashlee M.; Johnson, Liam G.; Rantalainen, Timo; Kidgell, Dawson J.; Enticott, Peter G.; Teo, Wei-Peng

2015-01-01

The use of progressive resistance training (PRT) to improve gait and balance in people with Parkinson’s disease (PD) is an emerging area of interest. However, the main effects of PRT on lower limb functions such as gait, balance, and leg strength in people with PD remain unclear. Therefore, the aim of the meta-analysis is to evaluate the evidence surrounding the use of PRT to improve gait and balance in people with PD. Five electronic databases, from inception to December 2014, were searched to identify the relevant studies. Data extraction was performed by two independent reviewers and methodological quality was assessed using the PEDro scale. Standardized mean differences (SMD) and 95% confidence intervals (CIs) of fixed and random effects models were used to calculate the effect sizes between experimental and control groups and I2 statistics were used to determine levels of heterogeneity. In total, seven studies were identified consisting of 172 participants (experimental n = 84; control n = 88). The pooled results showed a moderate but significant effect of PRT on leg strength (SMD 1.42, 95% CI 0.464–2.376); however, no significant effects were observed for gait speed (SMD 0.418, 95% CI −0.219 to 1.055). No significant effects were observed for balance measures included in this review. In conclusion, our results showed no discernable effect of PRT on gait and balance measures, although this is likely due to the lack of studies available. It may be suggested that PRT be performed in conjunction with balance or task-specific functional training to elicit greater lower limb functional benefits in people with PD. PMID:25852550

Epidemiology of leg amputation

DEFF Research Database (Denmark)

Ebskov, L B; Schroeder, T V; Holstein, P E

1994-01-01

The number of amputations performed for vascular disease in Denmark has decreased from 1777 (34.5 per 100,000 population) in 1983 to 1288 (25.0 per 100,000) in 1990, a reduction of 28 per cent. This decline coincided with an increase in vascular surgical activity of up to 100 per cent, including...... a marked rise in the rate of femorodistal reconstruction. Moreover, regional variation in vascular surgical activity correlated with percentage reduction in amputation rate (rS = 0.65, P amputations also decreased in favour of more distal levels during the period...... studied. These findings suggest that vascular surgery may be responsible for the lower amputation rate....

The acute hormonal response to free weight and machine weight resistance exercise.

Science.gov (United States)

Shaner, Aaron A; Vingren, Jakob L; Hatfield, Disa L; Budnar, Ronald G; Duplanty, Anthony A; Hill, David W

2014-04-01

Resistance exercise can acutely increase the concentrations of circulating neuroendocrine factors, but the effect of mode on this response is not established. The purpose of this study was to examine the effect of resistance exercise selection on the acute hormonal response using similar lower-body multijoint movement free weight and machine weight exercises. Ten resistance trained men (25 ± 3 years, 179 ± 7 cm, 84.2 ± 10.5 kg) completed 6 sets of 10 repetitions of squat or leg press at the same relative intensity separated by 1 week. Blood samples were collected before (PRE), immediately after (IP), and 15 (P15) and 30 minutes (P30) after exercise, and analyzed for testosterone (T), growth hormone (GH), and cortisol (C) concentrations. Exercise increased (p ≤ 0.05) T and GH at IP, but the concentrations at IP were greater for the squat (T: 31.4 ± 10.3 nmol·L(-1); GH: 9.5 ± 7.3 μg·L(-1)) than for the leg press (T: 26.9 ± 7.8 nmol·L(-1); GH: 2.8 ± 3.2 μg·L(-1)). At P15 and P30, GH was greater for the squat (P15: 12.3 ± 8.9 μg·L(-1); P30: 12.0 ± 8.9 μg·L(-1)) than for the leg press (P15: 4.8 ± 3.4 μg·L(-1); P30: 5.4 ± 4.1 μg·L(-1)). C was increased after exercise and was greater for the squat than for the leg press. Although total work (external load and body mass moved) was greater for the squat than for the leg press, rating of perceived exertion did not differ between the modes. Free weight exercises seem to induce greater hormonal responses to resistance exercise than machine weight exercises using similar lower-body multijoint movements and primary movers.

Extension and customization of self-stability control in compliant legged systems

International Nuclear Information System (INIS)

Ernst, M; Blickhan, R; Geyer, H

2012-01-01

Several recent studies on the control of legged locomotion in animal and robot running focus on the influence of different leg parameters on gait stability. In a preceding investigation self-stability controls showing deadbeat behavior could be obtained by studying the dynamics of the system in dependence of the leg orientation carefully adjusted during the flight phase. Such controls allow to accommodate disturbances of the ground level without having to detect them. Here we further this method in two ways. Besides the leg orientation, we allow changes in leg stiffness during flight and show that this extension substantially improves the rejection of ground disturbances. In a human like example the tolerance of random variation in ground level over many steps increased from 3.5% to 35% of leg length. In single steps changes of about 70% leg length (either up or down) could be negotiated. The variable leg stiffness not only allows to start with flat leg orientations maximizing step tolerances but also increase the control subspace. This allows to customize self-stability controls and to consider physical and technical limitations found in animals and robots. (paper)

[Design and application of medical electric leg-raising machine].

Science.gov (United States)

Liang, Jintang; Chen, Jinyuan; Zhao, Zixian; Lin, Jinfeng; Li, Juanhong; Zhong, Jingliang

2017-08-01

Passive leg raising is widely used in clinic, but it lacks of specialized mechanical raise equipment. It requires medical staff to raise leg by hand or requires a multi-functional bed to raise leg, which takes time and effort. Therefore we have developed a new medical electric leg-raising machine. The equipment has the following characteristics: simple structure, stable performance, easy operation, fast and effective, safe and comfortable. The height range of the lifter is 50-120 cm, the range of the angle of raising leg is 10degree angle-80degree angle, the maximum supporting weight is 40 kg. Because of raising the height of the lower limbs and making precise angle, this equipment can completely replace the traditional manner of lifting leg by hand with multi-functional bed to lift patients' leg and can reduce the physical exhaustion and time consumption of medical staff. It can change the settings at any time to meet the needs of the patient; can be applied to the testing of PLR and dynamically assessing the hemodynamics; can prevent deep vein thrombosis and some related complications of staying in bed; and the machine is easy to be cleaned and disinfected, which can effectively avoid hospital acquired infection and cross infection; and can also be applied to emergency rescue of various disasters and emergencies.

Leg-adjustment strategies for stable running in three dimensions

International Nuclear Information System (INIS)

Peuker, Frank; Maufroy, Christophe; Seyfarth, André

2012-01-01

The dynamics of the center of mass (CoM) in the sagittal plane in humans and animals during running is well described by the spring-loaded inverted pendulum (SLIP). With appropriate parameters, SLIP running patterns are stable, and these models can recover from perturbations without the need for corrective strategies, such as the application of additional forces. Rather, it is sufficient to adjust the leg to a fixed angle relative to the ground. In this work, we consider the extension of the SLIP to three dimensions (3D SLIP) and investigate feed-forward strategies for leg adjustment during the flight phase. As in the SLIP model, the leg is placed at a fixed angle. We extend the scope of possible reference axes from only fixed horizontal and vertical axes to include the CoM velocity vector as a movement-related reference, resulting in six leg-adjustment strategies. Only leg-adjustment strategies that include the CoM velocity vector produced stable running and large parameter domains of stability. The ability of the model to recover from perturbations along the direction of motion (directional stability) depended on the strategy for lateral leg adjustment. Specifically, asymptotic and neutral directional stability was observed for strategies based on the global reference axis and the velocity vector, respectively. Additional features of velocity-based leg adjustment are running at arbitrary low speed (kinetic energy) and the emergence of large domains of stable 3D running that are smoothly transferred to 2D SLIP stability and even to 1D SLIP hopping. One of the additional leg-adjustment strategies represented a large convex region of parameters where stable and robust hopping and running patterns exist. Therefore, this strategy is a promising candidate for implementation into engineering applications, such as robots, for instance. In a preliminary comparison, the model predictions were in good agreement with the experimental data, suggesting that the 3D SLIP is an

Lower Limb Symmetry: Comparison of Muscular Power Between Dominant and Nondominant Legs in Healthy Young Adults Associated With Single-Leg-Dominant Sports.

Science.gov (United States)

Vaisman, Alex; Guiloff, Rodrigo; Rojas, Juan; Delgado, Iris; Figueroa, David; Calvo, Rafael

2017-12-01

Achieving a symmetrical power performance (difference power between the dominant and nondominant legs in healthy young adults, (2) evaluate the effect of a single-leg-dominant sport activity performed at the professional level, and (3) propose a parameter of normality for maximal power difference in the lower limbs of this young adult population. Controlled laboratory study. A total of 78 healthy, male, young adults were divided into 2 groups according to sport activity level. Group 1 consisted of 51 nonathletes (mean ± SD age, 20.8 ± 1.5 years; weight, 71.9 ± 10.5 kg) who participated in less than 8 hours a week of recreational physical activity with nonspecific training; group 2 consisted of 27 single-leg-dominant professional soccer players (age, 18.4 ± 0.6 years; weight, 70.1 ± 7.5 kg) who specifically trained and competed at their particular activity 8 hours or more a week. For assessment of maximal leg power, both groups completed the single-leg squat jump test. Dominance was determined when participants completed 2 of 3 specific tests with the same extremity. Statistical analysis included the Student t test. No statistical difference was found for maximal power between dominant and nondominant legs for nonathletes ( t = -1.01, P = .316) or single-leg-dominant professional soccer players ( t = -1.10, P = .281). A majority (95%) of participants studied showed a power difference of less than 15% between their lower extremities. Among young healthy adults, symmetrical power performance is expected between lower extremities independent of the existence of dominance and difference in sport activity level. A less than 15% difference in power seems to be a proper parameter to define symmetrical power performance assessed by vertical single-leg jump tests.

Dopaminergic treatment of restless legs syndrome in spinal cord injury patients with neuropathic pain.

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Kumru, Hatice; Albu, Sergiu; Vidal, Joan; Barrio, Manuela; Santamaria, Joan

2016-01-01

Recent studies report high incidence of restless legs syndrome (RLS) in patients with spinal cord injury (SCI), who may also present pain and sensory disturbances. In the present manuscript, we examine and discuss diagnostic and treatment challenges of comorbid RLS and neuropathic pain (NP) in SCI. We evaluated seven men with a mean age of 55.6 (s.d.=14.0) years, with chronic complete or incomplete SCI at the thoracic or lumbar level, for complaints of sensory disturbances in the legs, which initially were attributed to drug-resistant NP. Because overlapped RLS was suspected, clinical evaluation of NP and RLS, serum ferritin and iron level assessment, and video polysomnographic (VPSG) studies were conducted. Pramipexole (0.18 mg q.d. -1 ) was added to treat RLS, and a follow-up was performed at 2 months. We found that in six subjects the RLS was comorbid with NP and in one subject the symptoms of RLS were misdiagnosed as NP. VPSG revealed periodic limb movements (PLMs) in all patients, including PLMs of the legs, arms or both. Serum ferritin was patients. RLS improved significantly after 2 months with pramipexole. On the basis of current findings, we recommend physicians to be aware of the comorbidity between RLS and NP secondary to SCI to include suitable diagnostic procedures and effective treatments.

Aerobic exercise and other healthy lifestyle factors that influence vascular aging.

Science.gov (United States)

Santos-Parker, Jessica R; LaRocca, Thomas J; Seals, Douglas R

2014-12-01

Cardiovascular diseases (CVDs) remain the leading cause of death in the United States and other modern societies. Advancing age is the major risk factor for CVD, primarily due to stiffening of the large elastic arteries and the development of vascular endothelial dysfunction. In contrast, regular aerobic exercise protects against the development of large elastic artery stiffness and vascular endothelial dysfunction with advancing age. Moreover, aerobic exercise interventions reduce arterial stiffness and restore vascular endothelial function in previously sedentary middle-aged/older adults. Aerobic exercise exerts its beneficial effects on arterial function by modulating structural proteins, reducing oxidative stress and inflammation, and restoring nitric oxide bioavailability. Aerobic exercise may also promote "resistance" against factors that reduce vascular function and increase CVD risk with age. Preventing excessive increases in abdominal adiposity, following healthy dietary practices, maintaining a low CVD risk factor profile, and, possibly, selective use of pharmaceuticals and nutraceuticals also play a major role in preserving vascular function with aging. Copyright © 2014 The American Physiological Society.

Peripheral occlusive vascular disease: Diagnostic performance of MRA and DSA

International Nuclear Information System (INIS)

Krug, B.; Kugel, H.; Harnischmacher, U.; Heindel, W.; Altenburg, A.; Fischbach, R.; Schmidt, R.

1995-01-01

In 59 patients with arterial flow disturbances 2-D inflow sequence of the abdominal and lower leg arteries were prospectively obtained on a 1.5 T MR-imager and were compared with additional DSA examinations. Supplementary Phase Contraste RSE ('Rapid Sequential Excitation') sequences were carried out in 29 patients. MRA and DSA angiograms were evaluated in random order by 4 readers using a questionnaire. The assessment of image quality were evaluated by variance analysis. Diagnostic performance of MRA and DSA was assessed by comparison of the readers' diagnostic assessments with reference diagnoses established by a radiologist and a vascular surgeon with full knowledge of all data concerning a patient. Image quality of inflow MRA was considered inferior to i.a. DSA (p [de

[Electromyographic determination of the fatigability of respiratory and leg muscles before and after aortocoronary bypass operation].

Science.gov (United States)

Worth, H; Grundmann, C; Goeckenjan, G; Smidt, U; Irlich, G; Loogen, F

1984-01-01

To study the effect of postoperative confinement to bed on respiratory muscle fatigue, 31 male subjects (age, 34-66 years) undergoing coronary artery revascularization were examined. Fatigue of both respiratory muscles (musculi intercostales externi) and leg muscles (musculus gastrocnemius) was determined by electromyography prior to and 7 and 12 days after operation. Additionally, oscillatory resistance to breathing and phase angle were measured. Pre- and postoperative routine lung function tests were performed. A comparison between preoperative and postoperative measurements reveals that respiratory as well as leg muscle fatigue occurred at higher loads during the preoperative and the second postoperative than during the first postoperative determination. After surgery vital capacity, total lung capacity, 1-second capacity, and, to a lower extent, thoracic gas volume were diminished, while specific airway conductance, oscillatory resistance to breathing, phase angle, residual volume, and relative 1-second capacity remained unchanged. The constancy of the latter parameters indicates that neither airway obstruction nor a significant restriction of the lung and/or thorax occurred due to surgery. Therefore, the increase of respiratory muscle fatigue after surgery may more probably be attributed to a lack of training of respiratory muscles which may contribute to limitation of ventilation in bedridden patients.

Flexural characteristics of a stack leg

International Nuclear Information System (INIS)

Cook, J.

1979-06-01

A 30 MV tandem Van de Graaff accelerator is at present under construction at Daresbury Laboratory. The insulating stack of the machine is of modular construction, each module being 860 mm in length. Each live section stack module contains 8 insulating legs mounted between bulkhead rings. The design, fabrication (from glass discs bonded to stainless steel discs using an epoxy film adhesive) and testing of the stack legs is described. (U.K.)

Resistance of essential fatty acid-deficient rats to endotoxin-induced increases in vascular permeability

International Nuclear Information System (INIS)

Li, E.J.; Cook, J.A.; Spicer, K.M.; Wise, W.C.; Rokach, J.; Halushka, P.V.

1990-01-01

Resistance to endotoxin in essential fatty acid-deficient (EFAD) rats is associated with reduced synthesis of certain arachidonic acid metabolites. It was hypothesized that EFAD rats would manifest decreased vascular permeability changes during endotoxemia as a consequence of reduced arachidonic acid metabolism. To test this hypothesis, changes in hematocrit (HCT) and mesenteric localization rate of technetium-labeled human serum albumin (99mTc-HSA) and red blood cells (99mTc-RBC) were assessed in EFAD and normal rats using gamma-camera imaging. Thirty minutes after Salmonella enteritidis endotoxin, EFAD rats exhibited less hemoconcentration as determined by % HCT than normal rats. Endotoxin caused a less severe change in permeability index in the splanchnic region in EFAD rats than in normal rats (1.2 +/- 0.6 x 10(-3)min-1 vs. 4.9 +/- 1.7 x 10(-3)min-1 respectively, P less than 0.05). In contrast to 99mTc-HSA, mesenteric localization of 99mTc-RBC was not changed by endotoxin in control or EFAD rats. Supplementation with ethyl-arachidonic acid did not enhance susceptibility of EFAD rats to endotoxin-induced splanchnic permeability to 99mTc-HSA. Leukotrienes have been implicated as mediators of increased vascular permeability in endotoxin shock. Since LTC3 formation has been reported to be increased in EFA deficiency, we hypothesized that LTC3 may be less potent than LTC4. Thus the effect of LTC3 on mean arterial pressure and permeability was compared to LTC4 in normal rats. LTC3-induced increases in peak mean arterial pressure were less than LTC4 at 10 micrograms/kg (39 +/- 5 mm Hg vs. 58 +/- 4 mm Hg respectively, P less than 0.05) and at 20 micrograms/kg (56 +/- 4 mm Hg vs. 75 +/- 2 mm Hg respectively, P less than 0.05). LY171883 (30 mg/kg), an LTD4/E4 receptor antagonist, attenuated the pressor effect of LTC4, LTD4, and LTC3

Leg deformation during imaginal ecdysis in the downy emerald, Cordulia aenea (Odonata, Corduliidae).

Science.gov (United States)

Frantsevich, Leonid; Frantsevich, Ludmilla

2018-04-01

A dragonfly larva migrates from the water to the shore, perches on a plant stem and grasps it with strongly flexed legs. Adult legs inside the larval exoskeleton fit to the larval legs joint-to-joint. The adult emerges with stretched legs. During the molt, an imaginal leg must follow all the angles in exuvial joints. In turn, larval apodemes are withdrawn from imaginal legs. We visualized transient shapes of the imaginal legs by the instant fixation of insects at different moments of the molt, photographed isolated exuvial legs with the imaginal legs inside and then removed the exuvial sheath. Instant shapes of the imaginal tibia show sharp intrapodomere bends copying the angle in the larval femoro-tibial joint. The site of bending shifts distad during the molt. This is possible if the imaginal leg is pliable. The same problem of leg squeezing is also common in hemimetabolous insects as well as in other arthropods, whereas holometabolous insects overcome problems of a tight confinement either by using leg pliability in other ways but not squeezing (cyclorrhaphan flies, mosquitoes) or by pulling hardened legs out without change of their pupal zigzag configuration (moths, ants, honey bees). The pupal legs are not intended to grasp any external substrate. Copyright © 2018 Elsevier GmbH. All rights reserved.

Running over unknown rough terrain with a one-legged planar robot

International Nuclear Information System (INIS)

Andrews, Ben; Miller, Bruce; Clark, Jonathan E; Schmitt, John

2011-01-01

The ability to traverse unknown, rough terrain is an advantage that legged locomoters have over their wheeled counterparts. However, due to the complexity of multi-legged systems, research in legged robotics has not yet been able to reproduce the agility found in the animal kingdom. In an effort to reduce the complexity of the problem, researchers have developed single-legged models to gain insight into the fundamental dynamics of legged running. Inspired by studies of animal locomotion, researchers have proposed numerous control strategies to achieve stable, one-legged running over unknown, rough terrain. One such control strategy incorporates energy variations into the system during the stance phase by changing the force-free leg length as a sinusoidal function of time. In this research, a one-legged planar robot capable of implementing this and other state-of-the-art control strategies was designed and built. Both simulated and experimental results were used to determine and compare the stability of the proposed controllers as the robot was subjected to unknown drop and raised step perturbations equal to 25% of the nominal leg length. This study illustrates the relative advantages of utilizing a minimal-sensing, active energy removal control scheme to stabilize running over rough terrain.

Spider diffraction: a comparison of curved and straight legs

International Nuclear Information System (INIS)

Richter, J.L.

1984-01-01

It has been known for some time that, if curved legs rather than the usual straight ones are used in the spider that supports the secondary optics in certain telescopes, the visible diffraction effect is reduced. Fraunhofer theory is used to calculate the diffraction effects due to the curved leg spider. Calculated and photographic diffraction patterns are compared for straight and curved leg spiders

Straight leg elevation to rule out pelvic injury.

Science.gov (United States)

Bolt, Caroline; O'Keeffe, Francis; Finnegan, Pete; Dickson, Kristofer; Smit, De Villiers; Fitzgerald, Mark C; Mitra, Biswadev

2018-02-01

Pelvic x-ray is frequently used as a screening tool during initial assessment of injured patients. However routine use in the awake and alert blunt trauma patient may be questioned due to low yield. We propose a clinical tool that may avoid unnecessary imaging by examining whether the ability to straight leg raise, without pain, can rule out pelvic injury. We conducted a prospective cohort study with the exposure variables of ability to straight leg raise and presence of pain on doing so, and presence of pelvic fracture on x-ray as the primary outcome variable. Of the 328 participants, 35 had pelvic fractures, and of these 32 were either unable to straight leg raise, or had pain on doing so, with a sensitivity of 91.43% (95% CI: 76.94-98.2%) and a negative predictive value of 98.57% (95% CI: 95.88-99.70%). The 3 participants with a pelvic fracture who could straight leg raise with no pain, all had a GCS of less than 15, and therefore, among the sub-group of patients with GCS15, a 100% sensitivity and 100% negative predictive value for straight leg raise with no pain to rule out pelvic fracture was demonstrated. Among awake, alert patients, painless straight leg raise can exclude pelvic fractures and be incorporated into initial examination during reception and resuscitation of injured patients. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Whole-body heat stress and exercise stimulate the appearance of platelet microvesicles in plasma with limited influence of vascular shear stress.

Science.gov (United States)

Wilhelm, Eurico N; González-Alonso, José; Chiesa, Scott T; Trangmar, Steven J; Kalsi, Kameljit K; Rakobowchuk, Mark

2017-11-01

Intense, large muscle mass exercise increases circulating microvesicles, but our understanding of microvesicle dynamics and mechanisms inducing their release remains limited. However, increased vascular shear stress is generally thought to be involved. Here, we manipulated exercise-independent and exercise-dependent shear stress using systemic heat stress with localized single-leg cooling (low shear) followed by single-leg knee extensor exercise with the cooled or heated leg (Study 1, n  = 8) and whole-body passive heat stress followed by cycling (Study 2, n  = 8). We quantified femoral artery shear rates (SRs) and arterial and venous platelet microvesicles (PMV-CD41 + ) and endothelial microvesicles (EMV-CD62E + ). In Study 1, mild passive heat stress while one leg remained cooled did not affect [microvesicle] ( P  ≥ 0.05). Single-leg knee extensor exercise increased active leg SRs by ~12-fold and increased arterial and venous [PMVs] by two- to threefold, even in the nonexercising contralateral leg ( P  body passive heat stress increased arterial [PMV] compared with baseline (mean±SE, from 19.9 ± 1.5 to 35.5 ± 5.4 PMV . μ L -1. 10 3 , P  stress increased [PMV] further in the venous circulation (from 27.5 ± 2.2 at baseline to 57.5 ± 7.2 PMV . μ L -1. 10 3 during cycling with heat stress, P  body heat stress may increase arterial [PMV], and intense exercise engaging either large or small muscle mass promote PMV formation locally and systemically, with no influence upon [EMV]. Local shear stress, however, does not appear to be the major stimulus modulating PMV formation in healthy humans. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

A survey of bio-inspired compliant legged robot designs

International Nuclear Information System (INIS)

Zhou Xiaodong; Bi Shusheng

2012-01-01

The roles of biological springs in vertebrate animals and their implementations in compliant legged robots offer significant advantages over the rigid legged ones in certain types of scenarios. A large number of robotics institutes have been attempting to work in conjunction with biologists and incorporated these principles into the design of biologically inspired robots. The motivation of this review is to investigate the most published compliant legged robots and categorize them according to the types of compliant elements adopted in their mechanical structures. Based on the typical robots investigated, the trade-off between each category is summarized. In addition, the most significant performances of these robots are compared quantitatively, and multiple available solutions for the future compliant legged robot design are suggested. Finally, the design challenges for compliant legged robots are analysed. This review will provide useful guidance for robotic designers in creating new designs by inheriting the virtues of those successful robots according to the specific tasks. (topical review)

Necrotizing cellulitis with multiple abscesses on the leg caused by Serratia marcescens.

Science.gov (United States)

Hau, Estelle; Bouaziz, Jean-David; Lafaurie, Matthieu; Saussine, Anne; Masson, Vincent; Rausky, Jonathan; Bagot, Martine; Guibal, Fabien

2016-03-01

Serratia marcescens is an unusual cause of severe skin infection initially described in immunocompromised patients. We report a case of necrotizing cellulitis of the leg caused by S marcescens in a 68-year-old woman with diabetes mellitus and a history of chronic lymphoedema of the leg. We reviewed the literature and found 49 cases of severe skin infections from S marcescens that included 20 cases of necrotizing fasciitis (NF) as well as 29 cases of severe skin infections without NF (non-NF cases). Patients were immunocompromised in 59% to 70% of cases. The mortality rate was high in NF cases (60%) versus non-NF cases (3%). Surgery was required in 95% of NF cases and in 24% of non-NF cases. The other clinical manifestations of S marcescens skin infection reported in the literature included disseminated papular eruptions in patients infected with human immunodeficiency virus with folliculitis on the trunk. Serratia marcescens is naturally resistant to amoxicillin alone and amoxicillin associated with clavulanic acid. Broad-spectrum antibiotics are indicated to treat S marcescens skin infections, and surgery should be promptly considered in cases of severe skin infections if appropriate antibiotic therapy does not lead to rapid improvement.

Intermittent pneumatic compression of legs increases microcirculation in distant skeletal muscle.

Science.gov (United States)

Liu, K; Chen, L E; Seaber, A V; Johnson, G W; Urbaniak, J R

1999-01-01

Intermittent pneumatic compression has been established as a method of clinically preventing deep vein thrombosis, but the mechanism has not been documented. This study observed the effects of intermittent pneumatic compression of legs on the microcirculation of distant skeletal muscle. The cremaster muscles of 80 male rats were exposed, a specially designed intermittent pneumatic-compression device was applied to both legs for 60 minutes, and the microcirculation of the muscles was assessed by measurement of the vessel diameter in three categories (10-20, 21-40, and 41-70 microm) for 120 minutes. The results showed significant vasodilation in arterial and venous vessels during the application of intermittent pneumatic compression, which disappeared after termination of the compression. The vasodilation reached a maximum 30 minutes after initiation of the compression and could be completely blocked by an inhibitor of nitric oxide synthase, NG-monomethyl-L-arginine (10 micromol/min). A 120-minute infusion of NG-monomethyl-L-arginine, beginning coincident with 60 minutes of intermittent pneumatic compression, resulted in a significant decrease in arterial diameter that remained at almost the same level after termination of the compression. The magnitude of the decrease in diameter in the group treated with intermittent pneumatic compression and NG-monomethyl-L-arginine was comparable with that in the group treated with NG-monomethyl-L-arginine alone. The results imply that the production of nitric oxide is involved in the positive influence of intermittent pneumatic compression on circulation. It is postulated that the rapid increase in venous velocity induced by intermittent pneumatic compression produces strong shear stress on the vascular endothelium, which stimulates an increased release of nitric oxide and thereby causes systemic vasodilation.

Exocrine glands in the legs of the social wasp Vespula vulgaris.

Science.gov (United States)

Nijs, Catherine; Billen, Johan

2015-09-01

This study brings a survey of the exocrine glands in the legs of Vespula vulgaris wasps. We studied workers, males, virgin queens as well as mated queens. A variety of 17 glands is found in the different leg segments. Among these, five glands are novel exocrine structures for social insects (trochanter-femur gland, ventrodistal tibial gland, distal tibial sac gland, ventral tibial gland, and ventral tarsomere gland). Most leg glands are present in the three leg pairs of all castes. This may indicate a mechanical function. This is likely for the numerous glands that occur near the articulation between the various leg segments, where lubricant production may be expected. Other possible functions include antenna cleaning, acting as a hydraulic system, or pheromonal. Further research including leg-related behavioural observations and chemical analyses may help to clarify the functions of these glandular structures in the legs. Copyright © 2015 Elsevier Ltd. All rights reserved.

Antibiotic-resistant Escherichia coli in migratory birds inhabiting remote Alaska

Science.gov (United States)

Ramey, Andy M.; Hernandez, Jorge; Tyrlöv, Veronica; Uher-Koch, Brian D.; Schmutz, Joel A.; Atterby, Clara; Järhult, Josef D.; Bonnedahl, Jonas

2018-01-01

We explored the abundance of antibiotic-resistant Escherichia coli among migratory birds at remote sites in Alaska and used a comparative approach to speculate on plausible explanations for differences in detection among species. At a remote island site, we detected antibiotic-resistant E. coli phenotypes in samples collected from glaucous-winged gulls (Larus glaucescens), a species often associated with foraging at landfills, but not in samples collected from black-legged kittiwakes (Rissa tridactyla), a more pelagic gull that typically inhabits remote areas year-round. We did not find evidence for antibiotic-resistant E. coli among 347 samples collected primarily from waterfowl at a second remote site in western Alaska. Our results provide evidence that glaucous-winged gulls may be more likely to be infected with antibiotic-resistant E. coli at remote breeding sites as compared to sympatric black-legged kittiwakes. This could be a function of the tendency of glaucous-winged gulls to forage at landfills where antibiotic-resistant bacterial infections may be acquired and subsequently dispersed. The low overall detection of antibiotic-resistant E. coli in migratory birds sampled at remote sites in Alaska is consistent with the premise that anthropogenic inputs into the local environment or the relative lack thereof influences the prevalence of antibiotic-resistant bacteria among birds inhabiting the area.

Development and Physical Control Research on Prototype Artificial Leg

Directory of Open Access Journals (Sweden)

Fei Li

2016-03-01

Full Text Available To provide an ideal platform for research on intelligent bionic leg (IBL, this paper proposes a model of a biped robot with heterogeneous legs (BRHL. A prototype of an artificial leg is developed based on biological structure and motion principle analysis of human lower extremities. With regard to the driving sources, servomotors are chosen for the hip joint and ankle joint, while pneumatic muscle actuators (PMAs are chosen for the knee joint. The control system of the bionic artificial leg is designed and a physical experimental platform is established. The physical control experiments are done based on proportional-integral-derivative (PID control strategy. The experimental results show that such a system can realize the expected goals.

Seismic response analysis for hinged-leg type port crane

Energy Technology Data Exchange (ETDEWEB)

Kashiwazaki, A.; Kanayama, T.; Arai, K. [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

2000-04-01

Container cranes and unloaders in Kobe Pont were severely damaged during the Southern Hyogo Prefecture Earthquake in 1995. Notably, some of the hinged-leg type of cranes with hinges at the end of sea-or land-side of legs were overturned. These damages were derived from the uplifting of their legs. To explain the uplifting and overturning behavior, we carried out nonlinear analyses and shaking table tests using a 1/8-scale model of the container crane. The results of nonlinear response analyses of hinged-leg type of crane, which are in an agreement with the state of damages in the Southern Hyogo Prefecture Earthquake and the result of shaking table tests, are described. (author)

Anatomic and functional leg-length inequality: A review and recommendation for clinical decision-making. Part I, anatomic leg-length inequality: prevalence, magnitude, effects and clinical significance

Directory of Open Access Journals (Sweden)

Knutson Gary A

2005-07-01

Full Text Available Abstract Background Leg-length inequality is most often divided into two groups: anatomic and functional. Part I of this review analyses data collected on anatomic leg-length inequality relative to prevalence, magnitude, effects and clinical significance. Part II examines the functional "short leg" including anatomic-functional relationships, and provides an outline for clinical decision-making. Methods Online database – Medline, CINAHL and MANTIS – and library searches for the time frame of 1970–2005 were done using the term "leg-length inequality". Results and Discussion Using data on leg-length inequality obtained by accurate and reliable x-ray methods, the prevalence of anatomic inequality was found to be 90%, the mean magnitude of anatomic inequality was 5.2 mm (SD 4.1. The evidence suggests that, for most people, anatomic leg-length inequality does not appear to be clinically significant until the magnitude reaches ~ 20 mm (~3/4". Conclusion Anatomic leg-length inequality is near universal, but the average magnitude is small and not likely to be clinically significant.

Vascular dysfunction in preeclampsia.

Science.gov (United States)

Brennan, Lesley J; Morton, Jude S; Davidge, Sandra T

2014-01-01

Preeclampsia is a complex disorder which affects an estimated 5% of all pregnancies worldwide. It is diagnosed by hypertension in the presence of proteinuria after the 20th week of pregnancy and is a prominent cause of maternal morbidity and mortality. As delivery is currently the only known treatment, preeclampsia is also a leading cause of preterm delivery. Preeclampsia is associated with maternal vascular dysfunction, leading to serious cardiovascular risk both during and following pregnancy. Endothelial dysfunction, resulting in increased peripheral resistance, is an integral part of the maternal syndrome. While the cause of preeclampsia remains unknown, placental ischemia resulting from aberrant placentation is a fundamental characteristic of the disorder. Poor placentation is believed to stimulate the release of a number of factors including pro- and antiangiogenic factors and inflammatory activators into the maternal systemic circulation. These factors are critical mediators of vascular function and impact the endothelium in distinctive ways, including enhanced endothelial oxidative stress. The mechanisms of action and the consequences on the maternal vasculature will be discussed in this review. © 2013 John Wiley & Sons Ltd.

Modeling posture-dependent leg actuation in sagittal plane locomotion

International Nuclear Information System (INIS)

Schmitt, J; Clark, J

2009-01-01

The spring loaded inverted pendulum template has been shown to accurately model the steady locomotion dynamics of a variety of running animals, and has served as the inspiration for an entire class of dynamic running robots. While the template models the leg dynamics by an energy-conserving spring, insects and animals have structures that dissipate, store and produce energy during a stance phase. Recent investigations into the spring-like properties of limbs, as well as animal response to drop-step perturbations, suggest that animals use their legs to manage energy storage and dissipation, and that this management is important for gait stability. In this paper, we extend our previous analysis of control of the spring loaded inverted pendulum template via changes in the leg touch-down angle to include energy variations during the stance phase. Energy variations are incorporated through leg actuation that varies the force-free leg length during the stance phase, yet maintains qualitatively correct force and velocity profiles. In contrast to the partially asymptotically stable gaits identified in previous analyses, incorporating energy and leg angle variations in this manner produces complete asymptotic stability. Drop-step perturbation simulations reveal that the control strategy is rather robust, with gaits recovering from drops of up to 30% of the nominal hip height.

Constructal vascularized structures

Science.gov (United States)

Cetkin, Erdal

2015-06-01

Smart features such as self-healing and selfcooling require bathing the entire volume with a coolant or/and healing agent. Bathing the entire volume is an example of point to area (or volume) flows. Point to area flows cover all the distributing and collecting kinds of flows, i.e. inhaling and exhaling, mining, river deltas, energy distribution, distribution of products on the landscape and so on. The flow resistances of a point to area flow can be decreased by changing the design with the guidance of the constructal law, which is the law of the design evolution in time. In this paper, how the flow resistances (heat, fluid and stress) can be decreased by using the constructal law is shown with examples. First, the validity of two assumptions is surveyed: using temperature independent Hess-Murray rule and using constant diameter ducts where the duct discharges fluid along its edge. Then, point to area types of flows are explained by illustrating the results of two examples: fluid networks and heating an area. Last, how the structures should be vascularized for cooling and mechanical strength is documented. This paper shows that flow resistances can be decreased by morphing the shape freely without any restrictions or generic algorithms.

Successful treatment of a child with vascular pythiosis

Directory of Open Access Journals (Sweden)

Sirisanthana Virat

2011-01-01

Full Text Available Abstract Background Human pythiosis is an emerging and life-threatening infectious disease caused by Pythium insidiosum. It occurs primarily in tropical, subtropical and temperate areas of the world, including Thailand. The aim of this report is to present the first pediatric case of typical vascular pythiosis. Case Presentation A 10-year-old boy with underlying β-thalassemia presented with gangrenous ulcers and claudication of the right leg which were unresponsive to antibiotic therapy for 6 weeks. Computerized tomography angiography indicated chronic arterial occlusion involving the right distal external iliac artery and its branches. High-above-knee amputation was urgently done to remove infected arteries and tissues, and to stop disease progression. Antibody to P. insidiosum was detected in a serum sample by the immunoblot and the immunochromatography tests. Fungal culture followed by nucleic sequence analysis was positive for P. insidiosum in the resected iliac arterial tissue. Immunotherapeutic vaccine and antifungal agents were administered. The patient remained well and was discharged after 2 months hospitalization without recurrence of the disease. At the time of this communication he has been symptom-free for 2 years. Conclusions The child presented with the classical manifestations of vascular pythiosis as seen in adult cases. However, because pediatricians were unfamiliar with the disease, diagnosis and surgical treatment were delayed. Both early diagnosis and appropriate surgical and medical treatments are crucial for good prognosis.

Numerical study of hot-leg ECC injection into the upper plenum of a pressurized water reactor

International Nuclear Information System (INIS)

Daly, B.J.; Torrey, M.D.; Rivard, W.C.

1981-01-01

In certain pressurized water reactor (PWR) designs, emergency core coolant (ECC) is injected through the hot legs into the upper plenum. The condensation of steam on this subcooled liquid stream reduces the pressure in the hot legs and upper plenum and thereby affects flow conditions throughout the reactor. In the present study, we examine countercurrent steam-water flow in the hot leg to determine the deceleration of the ECC flow that results from an adverse pressure gradient and from momentum exchange from the steam by interfacial drag and condensation. For the parameters examined in the study, water flow reversal is observed for a pressure drop of 22 to 32 mBar over the 1.5 m hot leg. We have also performed a three-dimensional study of subcooled water injection into air and steam environments of the upper plenum. The ECC water is deflected by an array of cylindrical guide tubes in its passage through the upper plenum. Comparisons of the air-water results with data obtained in a full scale experiment shows reasonable agreement, but indicates that there may be too much resistance to horizontal flow about the columns because of the use of a stair-step representation of the cylindrical guide tube cross section. Calculations of flow past single columns of stair-step, square and circular cross section do indicate excessive water deeentrainment by the noncircular column. This has prompted the use of an arbitrary mesh computational procedure to more accuratey represent the circular cross-section guide tubes. 15 figures

A Dung Beetle-like Leg and its Adaptive Neural Control

DEFF Research Database (Denmark)

Di Canio, Giuliano; Stoyanov, Stoyan; Larsen, Jørgen Christian

2016-01-01

Dung beetles show fascinating locomotion abilities. They can use their legs to not only walk but also manipulate objects. Furthermore, they can perform their leg movements at a proper frequency with respect to their biomechanical properties and quickly adapt the movements to deal with external pe...... also apply adaptive neural control, based on a central pattern generator (CPG) circuit with synaptic plasticity, to autonomously generate a proper stepping frequency of the leg. The controller can also adapt the leg movement to deal with external perturbations within a few steps....

The efficacy of early initiated, supervised, progressive resistance training compared to unsupervised, home-based exercise after unicompartmental knee arthroplasty: a single-blinded randomized controlled trial.

Science.gov (United States)

Jørgensen, Peter B; Bogh, Søren B; Kierkegaard, Signe; Sørensen, Henrik; Odgaard, Anders; Søballe, Kjeld; Mechlenburg, Inger

2017-01-01

To examine if supervised progressive resistance training was superior to home-based exercise in rehabilitation after unicompartmental knee arthroplasty. Single blinded, randomized clinical trial. Surgery, progressive resistance training and testing was carried out at Aarhus University Hospital and home-based exercise was carried out in the home of the patient. Fifty five patients were randomized to either progressive resistance training or home-based exercise. Patients were randomized to either progressive resistance training (home based exercise five days/week and progressive resistance training two days/week) or control group (home based exercise seven days/week). Preoperative assessment, 10-week (primary endpoint) and one-year follow-up were performed for leg extension power, spatiotemporal gait parameters and knee injury and osteoarthritis outcome score (KOOS). Forty patients (73%) completed 1-year follow-up. Patients in the progressive resistance training group participated in average 11 of 16 training sessions. Leg extension power increased from baseline to 10-week follow-up in progressive resistance training group (progressive resistance training: 0.28 W/kg, P= 0.01, control group: 0.01 W/kg, P=0.93) with no between-group difference. Walking speed and KOOS scores increased from baseline to 10-week follow-up in both groups with no between-group difference (six minutes walk test P=0.63, KOOS P>0.29). Progressive resistance training two days/week combined with home based exercise five days/week was not superior to home based exercise seven days/week in improving leg extension power of the operated leg.

Conjoined legs: Sirenomelia or caudal regression syndrome?

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Sakti Prasad Das

2013-01-01

Full Text Available Presence of single umbilical persistent vitelline artery distinguishes sirenomelia from caudal regression syndrome. We report a case of a12-year-old boy who had bilateral umbilical arteries presented with fusion of both legs in the lower one third of leg. Both feet were rudimentary. The right foot had a valgus rocker-bottom deformity. All toes were present but rudimentary. The left foot showed absence of all toes. Physical examination showed left tibia vara. The chest evaluation in sitting revealed pigeon chest and elevated right shoulder. Posterior examination of the trunk showed thoracic scoliosis with convexity to right. The patient was operated and at 1 year followup the boy had two separate legs with a good aesthetic and functional results.

Conjoined legs: Sirenomelia or caudal regression syndrome?

Science.gov (United States)

Das, Sakti Prasad; Ojha, Niranjan; Ganesh, G Shankar; Mohanty, Ram Narayan

2013-07-01

Presence of single umbilical persistent vitelline artery distinguishes sirenomelia from caudal regression syndrome. We report a case of a12-year-old boy who had bilateral umbilical arteries presented with fusion of both legs in the lower one third of leg. Both feet were rudimentary. The right foot had a valgus rocker-bottom deformity. All toes were present but rudimentary. The left foot showed absence of all toes. Physical examination showed left tibia vara. The chest evaluation in sitting revealed pigeon chest and elevated right shoulder. Posterior examination of the trunk showed thoracic scoliosis with convexity to right. The patient was operated and at 1 year followup the boy had two separate legs with a good aesthetic and functional results.

Effects of Moderate-Volume, High-Load Lower-Body Resistance Training on Strength and Function in Persons with Parkinson's Disease: A Pilot Study

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Brian K. Schilling

2010-01-01

Full Text Available Background. Resistance training research has demonstrated positive effects for persons with Parkinson's disease (PD, but the number of acute training variables that can be manipulated makes it difficult to determine the optimal resistance training program. Objective. The purpose of this investigation was to examine the effects of an 8-week resistance training intervention on strength and function in persons with PD. Methods. Eighteen men and women were randomized to training or standard care for the 8-week intervention. The training group performed 3 sets of 5–8 repetitions of the leg press, leg curl, and calf press twice weekly. Tests included leg press strength relative to body mass, timed up-and-go, six-minute walk, and Activities-specific Balance Confidence questionnaire. Results. There was a significant group-by-time effect for maximum leg press strength relative to body mass, with the training group significantly increasing their maximum relative strength (P.05. Conclusions. Moderate volume, high-load weight training is effective for increasing lower-body strength in persons with PD.

Treatment of vasovagal syncope: pacemaker or crossing legs?

NARCIS (Netherlands)

van Dijk, N.; Harms, M. P.; Linzer, M.; Wieling, W.

2000-01-01

A 50-year-old male patient continued to experience syncope after implantation of a pacemaker. During cardiovascular examination, the patient showed a typical vasovagal response, with normal pacemaker function. Leg crossing, which prohibits the pooling of blood in the legs and abdomen, at the onset

Leg for life? The use of sartorius muscle flap for the treatment of an infected vascular reconstructions after VA-ECMO use. A case report

Directory of Open Access Journals (Sweden)

George V. Patrut

2015-01-01

Conclusion: Although ischemic complications associated with VA-ECMO are accepted by intensivists under the slogan “leg for life”, for the repair of the femoral artery in the presence of groin infection the sartorius muscle remains an efficient solution for limb salvage.

Prosthetic fitting in a patient with a transtibial amputation due to a congenital vascular malformation of the right leg

NARCIS (Netherlands)

Simmelink, Elisabeth K.; Rommers, Gerardus M.; Gardeniers, Jean W. M.; Zijlstra, Henk

Background: The problems of prescribing a prosthesis for a young girl with severe congenital vascular malformation deformity leading to a transtibial amputation. Case description and methods: Due to the high risk of recurrent bleeding and limitations regarding full weight bearing of the stump, a

33 CFR 147.809 - Mars Tension Leg Platform safety zone.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Mars Tension Leg Platform safety... SECURITY (CONTINUED) OUTER CONTINENTAL SHELF ACTIVITIES SAFETY ZONES § 147.809 Mars Tension Leg Platform safety zone. (a) Description. The Mars Tension Leg Platform (Mars TLP) is located at position 28°10′10.29...

The effect of spinal manipulation on imbalances in leg strength.

Science.gov (United States)

Chilibeck, Philip D; Cornish, Stephen M; Schulte, Al; Jantz, Nathan; Magnus, Charlene R A; Schwanbeck, Shane; Juurlink, Bernhard H J

2011-09-01

We hypothesized that spinal manipulation (SM) would reduce strength imbalances between legs. Using an un-blinded randomized design, 28 males and 21 females (54 ± 19y) with at least a 15% difference in isometric strength between legs for hip flexion, extension, abduction, or knee flexion were randomized to treatment or placebo (mock spinal manipulation). Strength of the stronger and weaker legs for hip flexion, extension, abduction, and/or knee flexion was assessed before and after the intervention. SM reduced the relative strength difference between legs for knee flexion (mean ± SD 57 ± 53 to 5 ± 14%) and hip flexion (24 ± 12 to 11 ± 15%) compared to placebo (34 ± 29 to 24 ± 36%, and 20 ± 18 to 22 ± 26%, respectively) (p = 0.05). SM also improved strength in the weak leg for hip abduction (104 ± 43 to 116 ± 43 Nm) compared to placebo (84 ± 24 to 85 ± 31 Nm) (p = 0.03). This study suggests that spinal manipulation may reduce imbalances in strength between legs for knee and hip flexion.

Emphysematous Pyelonephritis Presenting as Necrotizing Fasciitis of the Leg

Directory of Open Access Journals (Sweden)

Yu-Xiong Ye

2009-03-01

Full Text Available We report a 50-year-old man with poorly controlled diabetes mellitus who presented with a painful, swollen right leg. He had also experienced right flank pain for 1 week prior to admission. Physical examination was notable for tenderness over the right flank. The right leg was diffusely swollen and exquisitely tender to touch, with palpable crepitance. Laboratory tests revealed leukocytosis and pyuria. Computed tomography showed a right ureteral stone with hydronephrosis and characteristic findings of emphysematous pyelonephritis. Furthermore, a right perirenal gas-forming abscess with extension to the right leg was noted. The patient was successfully treated with antibiotic therapy, aggressive control of blood sugar, percutaneous drainage of the hydronephrosis and perirenal abscess, and aggressive debridement of the leg.

Dipoles on a Two-leg Ladder

DEFF Research Database (Denmark)

Gammelmark, Søren; Zinner, Nikolaj Thomas

2013-01-01

We study polar molecules with long-range dipole-dipole interactions confined to move on a two-leg ladder for different orientations of the molecular dipole moments with respect to the ladder. Matrix product states are employed to calculate the many-body ground state of the system as function...... that there is a critical angle at which ordering disappears. This angle is slightly larger than the angle at which the dipoles are non-interacting along a single leg. This behavior should be observable using current experimental techniques....

Reasonable designing method for fillet welding leg length

Energy Technology Data Exchange (ETDEWEB)

Kiso, T; Michiyuki, T; Nagao, S; Yoshikawa, M; Miyazaki, S

1976-12-01

In VLCC and ULCC vessels, the scantling of structural members, especially the thickness of web plate, increases naturally. The present rule of each classification society generally prescribes that welding leg length should be based on the thickness of the web plate. Welding leg length between this web plate and skin plate such as shell plate, deck plate, etc., or face plate, increases according to increase of the thickness of the web plate. We investigated the method to decide reasonable welding leg length and its programming by using the results of finite element method structural analysis, without adhering to the above rule about welding leg length. As a result of applying this method to actual ships under classification societies' approval, the amount of welding decreased by from about 10 percent to 15 percent compared with that required by the above rule. The rationality of the method has been already confirmed by successful results of the application to several vessels in service.

UPTF/TEST10B/RUN081, Steam/Water Flow Phenomena Reflood PWR Cold Leg Break LOCA

International Nuclear Information System (INIS)

1998-01-01

hot leg region of a PWR which may occur in the reflood phase during a large cold leg break LOCA with cold leg ECC injection. Boundary Conditions: There was no ECC injection. Steam and saturated water were injected into the core simulator. The cold leg break valve was open. The hot leg break valve and all pump simulators were partially open to establish the desired loop flow resistances. Significant Findings: During an initial time period - about 40 s - the water that was injected into the core simulator was distributed within the upper plenum and the adjacent loops. After these regions were 'saturated' with water, the water was carried by the steam into the steam generator simulator inlet plenum and into the cyclones of these simulators where it was separated. The amount of water separated by the cyclones in the steam generator simulators was in good agreement with the amount of water injected into the core simulator after the initial time period of about 40 s. After termination of the steam injection into the core simulator, the water flow back into the core region was in quantitative agreement with the amount of water that was distributed during the initial time periods. During the entire test phase there was no significant pool formation above the tie plate. 3 - Experimental limitations or shortcomings: The system operating pressure was limited to 20 bar. So for some experiments pressure scaling was necessary

Effects of immobility on sensory and motor symptoms of restless legs syndrome.

Science.gov (United States)

Michaud, Martin; Lavigne, Gilles; Desautels, Alex; Poirier, Gaétan; Montplaisir, Jacques

2002-01-01

Restless legs syndrome (RLS) is defined by an irresistible need to move associated with leg paresthesia. Two additional features are essential for diagnosis: (1) worsening of symptoms at rest with temporary relief by activity, and (2) worsening of symptoms during the evening and/or during the night. The suggested immobilization test (SIT) has been developed to evaluate the presence of these criteria. This test quantifies leg movements and leg discomfort during a 1-hour period of immobility prior to bedtime. We used the SIT to evaluate the effects of immobility on leg discomfort and leg movements experienced by 19 patients with RLS and 19 control subjects. Results show that immobility significantly worsens both leg discomfort and periodic leg movements (PLM) in patients with RLS but not in controls. Patients with RLS showed a higher leg discomfort score (32.6 +/- 15.1 mm vs. 5.7 +/- 7.9 mm; P < 0.00001), a greater maximum leg discomfort value (63.4 +/- 27.4 mm vs. 13.7 +/- 23.0 mm; P < 0.00001) and a greater PLM index (88.4 +/- 62.6 vs. 10.4 +/- 20.6; P < 0.00004) than control subjects. These results further validate the use of the SIT as a diagnostic and research tool for RLS and confirm the contention of the International RLS study group that RLS symptoms worsen at rest. Copyright 2001 Movement Disorder Society.

Congenital vascular malformations: the persistence of marginal and embryonal veins.

Science.gov (United States)

Weber, J; Daffinger, N

2006-05-01

In about 18% of cases with conginental vascular malformations we find a perspective of an atypical truncular vein, located along the outside of the leg, frequently extended from the dorsal foot up to the bottom. In presence of a normally developed system of the deep collecting veins of the lower limb and within the pelvic outflow we are talking about a persisting marginal vein (MV). Hypoplasia or even aplasia of the main deep veins in contrary defines the persisting embryonal vein (EV). Already in childhood these truncular dysplastic veins tend to develop varicose enlargement, causing severe reflux of a huge volume of blood--even more when being associated with av-fistulas (46%). In consequence a rapidly growing chronic venous insufficiency will guide to additional injuries. We have analysed 97 patients showing a persisting MV (n: 92 ) within a total of 102 legs. A persistent embryonal vein (EV) was seen 10 times within this clientel. The persisting truncular veins, associated with phlebectasias and typical clinical symptoms have been examined in a diagnostic "step-by-step" procedure, mainly phlebographically (ascending leg phlebography and varicography), including direct venous blood pressure measurements (phlebodynamometry) and--if needed--by arteriography, showing av-shunting fistulae in 46% of cases. CT and MRI were consulted for the exact therapy planing (frequently initially offered as a non-invasive, however, inadequate key of diagnostic). Actually now these techniques cannot replace pre-operatively the angiographic imaging techniques. The analysis of clinical, morphologic and functional signs, guiding to a specific therapy-relevant classification of MV's and EV's will be presented. And a specific strategy of surgical repair, interventional treatment of av-fistulas and conservative compressive follow-up treatment attempting palliative recompensation of the diseased venous outflow will be discussed also.

Aerobic interval training reduces vascular resistances during submaximal exercise in obese metabolic syndrome individuals.

Science.gov (United States)

Mora-Rodriguez, Ricardo; Fernandez-Elias, V E; Morales-Palomo, F; Pallares, J G; Ramirez-Jimenez, M; Ortega, J F

2017-10-01

The aim of this study was to determine the effects of high-intensity aerobic interval training (AIT) on exercise hemodynamics in metabolic syndrome (MetS) volunteers. Thirty-eight, MetS participants were randomly assigned to a training (TRAIN) or to a non-training control (CONT) group. TRAIN consisted of stationary interval cycling alternating bouts at 70-90% of maximal heart rate during 45 min day -1 for 6 months. CONT maintained baseline physical activity and no changes in cardiovascular function or MetS factors were detected. In contrast, TRAIN increased cardiorespiratory fitness (14% in VO 2PEAK ; 95% CI 9-18%) and improved metabolic syndrome (-42% in Z score; 95% CI 83-1%). After TRAIN, the workload that elicited a VO 2 of 1500 ml min -1 increased 15% (95% CI 5-25%; P exercise heart rate (109 ± 15-106 ± 13 beats min -1 ; P exercise in MetS patients. Specifically, it reduces diastolic blood pressure, systemic vascular resistances, and the double product. The reduction in double product, suggests decreased myocardial oxygen demands which could prevent the occurrence of adverse cardiovascular events during exercise in this population. CLINICALTRIALS. NCT03019796.

The effect of interstitial pressure on therapeutic agent transport: coupling with the tumor blood and lymphatic vascular systems.

Science.gov (United States)

Wu, Min; Frieboes, Hermann B; Chaplain, Mark A J; McDougall, Steven R; Cristini, Vittorio; Lowengrub, John S

2014-08-21

Vascularized tumor growth is characterized by both abnormal interstitial fluid flow and the associated interstitial fluid pressure (IFP). Here, we study the effect that these conditions have on the transport of therapeutic agents during chemotherapy. We apply our recently developed vascular tumor growth model which couples a continuous growth component with a discrete angiogenesis model to show that hypertensive IFP is a physical barrier that may hinder vascular extravasation of agents through transvascular fluid flux convection, which drives the agents away from the tumor. This result is consistent with previous work using simpler models without blood flow or lymphatic drainage. We consider the vascular/interstitial/lymphatic fluid dynamics to show that tumors with larger lymphatic resistance increase the agent concentration more rapidly while also experiencing faster washout. In contrast, tumors with smaller lymphatic resistance accumulate less agents but are able to retain them for a longer time. The agent availability (area-under-the curve, or AUC) increases for less permeable agents as lymphatic resistance increases, and correspondingly decreases for more permeable agents. We also investigate the effect of vascular pathologies on agent transport. We show that elevated vascular hydraulic conductivity contributes to the highest AUC when the agent is less permeable, but to lower AUC when the agent is more permeable. We find that elevated interstitial hydraulic conductivity contributes to low AUC in general regardless of the transvascular agent transport capability. We also couple the agent transport with the tumor dynamics to simulate chemotherapy with the same vascularized tumor under different vascular pathologies. We show that tumors with an elevated interstitial hydraulic conductivity alone require the strongest dosage to shrink. We further show that tumors with elevated vascular hydraulic conductivity are more hypoxic during therapy and that the response

Gulf of Mexico Gas Hydrate Joint Industry Project Leg II logging-while-drilling data acquisition and analysis

Science.gov (United States)

Collett, Timothy S.; Lee, Wyung W.; Zyrianova, Margarita V.; Mrozewski, Stefan A.; Guerin, Gilles; Cook, Ann E.; Goldberg, Dave S.

2012-01-01

One of the objectives of the Gulf of Mexico Gas Hydrate Joint Industry Project Leg II (GOM JIP Leg II) was the collection of a comprehensive suite of logging-while-drilling (LWD) data within gas-hydrate-bearing sand reservoirs in order to make accurate estimates of the concentration of gas hydrates under various geologic conditions and to understand the geologic controls on the occurrence of gas hydrate at each of the sites drilled during this expedition. The LWD sensors just above the drill bit provided important information on the nature of the sediments and the occurrence of gas hydrate. There has been significant advancements in the use of downhole well-logging tools to acquire detailed information on the occurrence of gas hydrate in nature: From using electrical resistivity and acoustic logs to identify gas hydrate occurrences in wells to where wireline and advanced logging-while-drilling tools are routinely used to examine the petrophysical nature of gas hydrate reservoirs and the distribution and concentration of gas hydrates within various complex reservoir systems. Recent integrated sediment coring and well-log studies have confirmed that electrical resistivity and acoustic velocity data can yield accurate gas hydrate saturations in sediment grain supported (isotropic) systems such as sand reservoirs, but more advanced log analysis models are required to characterize gas hydrate in fractured (anisotropic) reservoir systems. In support of the GOM JIP Leg II effort, well-log data montages have been compiled and presented in this report which includes downhole logs obtained from all seven wells drilled during this expedition with a focus on identifying and characterizing the potential gas-hydrate-bearing sedimentary section in each of the wells. Also presented and reviewed in this report are the gas-hydrate saturation and sediment porosity logs for each of the wells as calculated from available downhole well logs.

Gulf of Mexico Gas Hydrate Joint Industry Project Leg II logging-while-drilling data acquisition and anaylsis

Science.gov (United States)

Collett, Timothy S.; Lee, Myung W.; Zyrianova, Margarita V.; Mrozewski, Stefan A.; Guerin, Gilles; Cook, Ann E.; Goldberg, Dave S.

2012-01-01

One of the objectives of the Gulf of MexicoGasHydrateJointIndustryProjectLegII (GOM JIP LegII) was the collection of a comprehensive suite of logging-while-drilling (LWD) data within gas-hydrate-bearing sand reservoirs in order to make accurate estimates of the concentration of gashydrates under various geologic conditions and to understand the geologic controls on the occurrence of gashydrate at each of the sites drilled during this expedition. The LWD sensors just above the drill bit provided important information on the nature of the sediments and the occurrence of gashydrate. There has been significant advancements in the use of downhole well-logging tools to acquire detailed information on the occurrence of gashydrate in nature: From using electrical resistivity and acoustic logs to identify gashydrate occurrences in wells to where wireline and advanced logging-while-drilling tools are routinely used to examine the petrophysical nature of gashydrate reservoirs and the distribution and concentration of gashydrates within various complex reservoir systems. Recent integrated sediment coring and well-log studies have confirmed that electrical resistivity and acoustic velocity data can yield accurate gashydrate saturations in sediment grain supported (isotropic) systems such as sand reservoirs, but more advanced log analysis models are required to characterize gashydrate in fractured (anisotropic) reservoir systems. In support of the GOM JIP LegII effort, well-log data montages have been compiled and presented in this report which includes downhole logs obtained from all seven wells drilled during this expedition with a focus on identifying and characterizing the potential gas-hydrate-bearing sedimentary section in each of the wells. Also presented and reviewed in this report are the gas-hydrate saturation and sediment porosity logs for each of the wells as calculated from available downhole well logs.

Eplerenone prevents salt-induced vascular stiffness in Zucker diabetic fatty rats: a preliminary report

Directory of Open Access Journals (Sweden)

Brunner Sabine

2011-10-01

Full Text Available Abstract Background Aldosterone levels are elevated in a rat model of type 2 diabetes mellitus, the Zucker Diabetic fatty rat (ZDF. Moreover blood pressure in ZDF rats is salt-sensitive. The aim of this study was to examine the effect of the aldosterone antagonist eplerenone on structural and mechanical properties of resistance arteries of ZDF-rats on normal and high-salt diet. Methods After the development of diabetes, ZDF animals were fed either a normal salt diet (0.28% or a high-salt diet (5.5% starting at an age of 15 weeks. ZDF rats on high-salt diet were randomly assigned to eplerenone (100 mg/kg per day, in food (ZDF+S+E, hydralazine (25 mg/kg per day (ZDF+S+H, or no treatment (ZDF+S. Rats on normal salt-diet were assigned to eplerenone (ZDF+E or no treatment (ZDF. Normoglycemic Zucker lean rats were also divided into two groups receiving normal (ZL or high-salt diet (ZL+S serving as controls. Systolic blood pressure was measured by tail cuff method. The experiment was terminated at an age of 25 weeks. Mesenteric resistance arteries were studied on a pressurized myograph. Specifically, vascular hypertrophy (media-to-lumen ratio and vascular stiffness (strain and stress were analyzed. After pressurized fixation histological analysis of collagen and elastin content was performed. Results Blood pressure was significantly higher in salt-loaded ZDF compared to ZDF. Eplerenone and hydralazine prevented this rise similarily, however, significance niveau was missed. Media-to-lumen ratio of mesenteric resistance arteries was significantly increased in ZDF+S when compared to ZDF and ZL. Both, eplerenone and hydralazine prevented salt-induced vascular hypertrophy. The strain curve of arteries of salt-loaded ZDF rats was significantly lower when compared to ZL and when compared to ZDF+S+E, but was not different compared to ZDF+S+H. Eplerenone, but not hydralazine shifted the strain-stress curve to the right indicating a vascular wall composition

Outcomes of Soft Tissue Reconstruction for Traumatic Lower Extremity Fractures with Compromised Vascularity.

Science.gov (United States)

Badash, Ido; Burtt, Karen E; Leland, Hyuma A; Gould, Daniel J; Rounds, Alexis D; Azadgoli, Beina; Patel, Ketan M; Carey, Joseph N

2017-10-01

Traumatic lower extremity fractures with compromised arterial flow are limb-threatening injuries. A retrospective review of 158 lower extremities with traumatic fractures, including 26 extremities with arterial injuries, was performed to determine the effects of vascular compromise on flap survival, successful limb salvage and complication rates. Patients with arterial injuries had a larger average flap surface area (255.1 vs 144.6 cm2, P = 0.02) and a greater number of operations (4.7 vs 3.8, P = 0.01) than patients without vascular compromise. Patients presenting with vascular injury were also more likely to require fasciotomy [odds ratio (OR): 6.5, confidence interval (CI): 2.3-18.2] and to have a nerve deficit (OR: 16.6, CI: 3.9-70.0), fracture of the distal third of the leg (OR: 2.9, CI: 1.15-7.1) and intracranial hemorrhage (OR: 3.84, CI: 1.1-12.9). After soft tissue reconstruction, patients with arterial injuries had a higher rate of amputation (OR: 8.5, CI: 1.3-53.6) and flap failure requiring a return to the operating room (OR: 4.5, CI: 1.5-13.2). Arterial injury did not correlate with infection or overall complication rate. In conclusion, arterial injuries resulted in significant complications for patients with lower extremity fractures requiring flap coverage, although limb salvage was still effective in most cases.

Major Vascular Neurocognitive Disorder: A Reappraisal to Vascular Dementia

Directory of Open Access Journals (Sweden)

Emre Kumral

2017-03-01

Full Text Available Major vascular neurocognitive disorder (NCD is the second leading form of dementia after Alzheimer’s disease, accounting for 17-20% of all dementias. Vascular NCD is a progressive disease caused by reduced cerebral blood flow related to multiple large volume or lacunar infarcts that induce a sudden onset and stepwise decline in cognitive abilities. Despite its prevalence and clinical importance, there is still controversy in the terminology of vascular NCD. Only after the release of Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5 (2013 did the American Psychiatric Association define vascular dementia as “major vascular NCD”. This review includes an overview of risk factors, pathophysiology, types, diagnostic and clinical features of major vascular NCD, and current treatment options of vascular NCD regarding to DSM-5 criteria

Terminology: resistance or stiffness for medical compression stockings?

Directory of Open Access Journals (Sweden)

André Cornu-Thenard

2013-04-01

Full Text Available Based on previous experimental work with medical compression stockings it is proposed to restrict the term stiffness to measurements on the human leg and rather to speak about resistance when it comes to characterize the elastic property of compression hosiery in the textile laboratory.

Effect of high altitude exposure on the hemodynamics of the bidirectional Glenn physiology: modeling incremented pulmonary vascular resistance and heart rate.

Science.gov (United States)

Vallecilla, Carolina; Khiabani, Reza H; Sandoval, Néstor; Fogel, Mark; Briceño, Juan Carlos; Yoganathan, Ajit P

2014-06-03

The considerable blood mixing in the bidirectional Glenn (BDG) physiology further limits the capacity of the single working ventricle to pump enough oxygenated blood to the circulatory system. This condition is exacerbated under severe conditions such as physical activity or high altitude. In this study, the effect of high altitude exposure on hemodynamics and ventricular function of the BDG physiology is investigated. For this purpose, a mathematical approach based on a lumped parameter model was developed to model the BDG circulation. Catheterization data from 39 BDG patients at stabilized oxygen conditions was used to determine baseline flows and pressures for the model. The effect of high altitude exposure was modeled by increasing the pulmonary vascular resistance (PVR) and heart rate (HR) in increments up to 80% and 40%, respectively. The resulting differences in vascular flows, pressures and ventricular function parameters were analyzed. By simultaneously increasing PVR and HR, significant changes (p fails to overcome the increased preload and implied low oxygenation in BDG patients at higher altitudes, especially for those with high baseline PVRs. The presented mathematical model provides a framework to estimate the hemodynamic performance of BDG patients at different PVR increments. Copyright © 2014 Elsevier Ltd. All rights reserved.

The influence of perivascular adipose tissue on vascular homeostasis.

Science.gov (United States)

Szasz, Theodora; Bomfim, Gisele Facholi; Webb, R Clinton

2013-01-01

The perivascular adipose tissue (PVAT) is now recognized as an active contributor to vascular function. Adipocytes and stromal cells contained within PVAT are a source of an ever-growing list of molecules with varied paracrine effects on the underlying smooth muscle and endothelial cells, including adipokines, cytokines, reactive oxygen species, and gaseous compounds. Their secretion is regulated by systemic or local cues and modulates complex processes, including vascular contraction and relaxation, smooth muscle cell proliferation and migration, and vascular inflammation. Recent evidence demonstrates that metabolic and cardiovascular diseases alter the morphological and secretory characteristics of PVAT, with notable consequences. In obesity and diabetes, the expanded PVAT contributes to vascular insulin resistance. PVAT-derived cytokines may influence key steps of atherogenesis. The physiological anticontractile effect of PVAT is severely diminished in hypertension. Above all, a common denominator of the PVAT dysfunction in all these conditions is the immune cell infiltration, which triggers the subsequent inflammation, oxidative stress, and hypoxic processes to promote vascular dysfunction. In this review, we discuss the currently known mechanisms by which the PVAT influences blood vessel function. The important discoveries in the study of PVAT that have been made in recent years need to be further advanced, to identify the mechanisms of the anticontractile effects of PVAT, to explore the vascular-bed and species differences in PVAT function, to understand the regulation of PVAT secretion of mediators, and finally, to uncover ways to ameliorate cardiovascular disease by targeting therapeutic approaches to PVAT.

[Physical treatment modalities for chronic leg ulcers].

Science.gov (United States)

Dissemond, J

2010-05-01

An increasing numbers of physical treatment options are available for chronic leg ulcer. In this review article, compression therapy, therapeutic ultrasound, negative pressure therapy, extracorporeal shock wave therapy, electrostimulation therapy, electromagnetic therapy, photodynamic therapy, water-filtered infrared-A-radiation and hydrotherapy are discussed in terms of their practical applications and the underlying evidence. With the exception of compression therapy for most of these treatments, good scientific data are not available. However this is a widespread problem in the treatment of chronic wounds. Nevertheless, several of the described methods such as negative pressure therapy represent one of the gold standards in practical treatment of patients with chronic leg ulcers. Although the use of physical treatment modalities may improve healing in patients with chronic leg ulcers, the diagnosis and treatment of the underlying causes are essential for long-lasting success.

The role of vegetative and vascular disturbances in development of sexual dysfunctions. Chapter 11

International Nuclear Information System (INIS)

2000-01-01

It is well known that in clinics of late consequences of low radiation doses action the principle place takes vegetative and vascular dysfunctions. For estimation of vegetative-vascular system tone the Danini-Ashner of eye-heard reflex is studied. Status of the reflex for 120 examined patients was studied. Results of investigation of Danini-Ashner reflex in relation of received dose of radiation, as well as results of skin temperature of sicks with different levels of low radiation doses late consequences are presented. For study of vegetative-vascular system the electro-skin resistance method was used as well

Sleep board review question: restless legs

Directory of Open Access Journals (Sweden)

Omobomi O

2018-02-01

Full Text Available No abstract available. Article truncated after 150 words. Ms. Jones (not her real name is a 63-year-old woman who states that she gets very fidgety when sitting in a theater, watching a movie or when flying long distances on a plane. She is unable to find words to describe the sensation but she states that moving her legs make them feel better. Lately, she has been getting this feeling almost every night. She reports no leg discomfort in the daytime. She denies muscle cramps her legs. She had some recent investigations done by her primary care physician because of complaints of fatigue. Which of the following will be helpful in the diagnosis and management in this patient? 1. An overnight polysomnogram showing apnea hypopnea index of 1.6 events per hour and no periodic limb movements (PLMs 2. Ferritin level of 18 ng/ml (normal range 20-200 ng/ml 3. Serum Bicarbonate of 29 mEq/L (normal range 23-29 mEq/L 4. Thyroid …

Arm to leg coordination in elite butterfly swimmers.

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Chollet, D; Seifert, L; Boulesteix, L; Carter, M

2006-04-01

This study proposed the use of four time gaps to assess arm-to-leg coordination in the butterfly stroke at increasing race paces. Fourteen elite male swimmers swam at four velocities corresponding to the appropriate paces for, respectively, the 400-m, 200-m, 100-m, and 50-m events. The different stroke phases of the arm and leg were identified by video analysis and then used to calculate four time gaps (T1: time gap between entry of the hands in the water and the high break-even point of the first undulation; T2: time gap between the beginning of the hands' backward movement and the low break-even point of the first undulation; T3: time gap between the hands' arrival in a vertical plane to the shoulders and the high break-even point of the second undulation; T4: time gap between the hands' release from the water and the low break-even point of the second undulation), the values of which described the changing relationship of arm to leg movements over an entire stroke cycle. With increases in pace, elite swimmers increased the stroke rate, the relative duration of the arm pull, the recovery and the first downward movement of the legs, and decreased the stroke length, the relative duration of the arm catch phase and the body glide with arms forward (measured by T2), until continuity in the propulsive actions was achieved. Whatever the paces, the T1, T3, and T4 values were close to zero and revealed a high degree of synchronisation at key motor points of the arm and leg actions. This new method to assess butterfly coordination could facilitate learning and coaching by situating the place of the leg undulation in relation with the arm stroke.

PP064. Total vascular resistances in early pregnancy: A key to understand abnormal cardiovascular adaptation associated with spontaneous abortion.

Science.gov (United States)

Lo Presti, Damiano; Scala, Roberta Licia; Tiralongo, Grazia Maria; Pisani, Ilaria; Gagliardi, Giulia; Novelli, Gian Paolo; Vasapollo, Barbara; Valensise, Herbert

2013-04-01

From early pregnancy, maternal hemodynamic profile begins to change. The absence of these changes leads to increased risk of complication during the gestation. Aim of this study is to understand in early pregnancy the behaviour of total vascular resistances (TVR) as a sign of maternal cardiovascular adaptation to pregnancy. A cross section study was conducted. We followed 160 healthy women with singleton pregnancy during the first trimester of gestation. We evaluated cardiac output (CO) and TVR at 7, 9 and 11 weeks of gestation. We obtained the following haemodynamic measurements with the USCOM system, a non invasive method: heart rate (HR), systolic and diastolic blood pressure (SBP, DBP), CO and TVR. 160 healthy pregnant women were selected, 8 patients, were excluded for a bad signal. Absolute values of the haemodynamic measures are shown in Fig. 1. 41 patients underwent spontaneous embryonic demise. This last group of patients showed in 54% (group A) TVR values within the normal limits (TVR1200) and CO values below the normal adaptation to pregnancy. Table 1 shows hemodynamic measures for the group A and group B; we found differences in term of CO, TVR and PAS between the two groups. Elevated TVR might indicate an abnormal vascular adaptation already in first weeks of pregnancy. Moreover, in women who undergo to abortion, elevated TVR could be use to distinguish genetic or environmental causes of miscarriage. Copyright © 2013. Published by Elsevier B.V.

Additive Manufacturing of Vascular Grafts and Vascularized Tissue Constructs.

Science.gov (United States)

Elomaa, Laura; Yang, Yunzhi Peter

2017-10-01

There is a great need for engineered vascular grafts among patients with cardiovascular diseases who are in need of bypass therapy and lack autologous healthy blood vessels. In addition, because of the severe worldwide shortage of organ donors, there is an increasing need for engineered vascularized tissue constructs as an alternative to organ transplants. Additive manufacturing (AM) offers great advantages and flexibility of fabrication of cell-laden, multimaterial, and anatomically shaped vascular grafts and vascularized tissue constructs. Various inkjet-, extrusion-, and photocrosslinking-based AM techniques have been applied to the fabrication of both self-standing vascular grafts and porous, vascularized tissue constructs. This review discusses the state-of-the-art research on the use of AM for vascular applications and the key criteria for biomaterials in the AM of both acellular and cellular constructs. We envision that new smart printing materials that can adapt to their environment and encourage rapid endothelialization and remodeling will be the key factor in the future for the successful AM of personalized and dynamic vascular tissue applications.

Duplex sonography of the near-surface leg veins; Duplexsonographie der oberflaechlichen Beinvenen

Energy Technology Data Exchange (ETDEWEB)

Mendoza, E.

2007-07-01

The book contains the following contributions: The ultrasonograph, selection of the ultrasonic transducer, anatomy of the near-surface vein system, physiology of the near-surface vein system, varicose status classification, systematics of the duplex sonography of near-surface leg veins, provocational maneuver for the duplex sonographic varicose diagnostics, exploration of vena saphena parva, perforans veins, side branches, phlebitis, sonography for varicose therapy, postsurgical sonography, deep leg veins, examination of near-surface leg veins for the pathology of the deep vein system, differential diagnostic clarification of leg oedema from the phlebologic-lymphological view, diagnostic side features along the near-surface leg veins.

PELATIHAN PLIOMETRIK ALTERNATE LEG BOUND DAN DOUBLE LEG BOUND MENINGKATKAN DAYA LEDAK OTOT TUNGKAI PADA SISWA PUTRA KELAS VII SMP NEGERI 3 SUKAWATI TAHUN PELAJARAN 2012/2013

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Komang Ayu Tri Widhiyanti

2013-11-01

Full Text Available This study was conducted to know the improvement the explosive power of leg muscle. It was done through 5 set 12 repetitions during 6 weeks in the field of SMP Negeri 3 Sukawati started from 4 p.m. until 6 p.m. There were 3 groups applied in this study such as group 1 (control group that was instructed to kick a ball, group 2 (plyometric training of alternate leg bound, and group 3 (plyometric training of double leg bound. The sample was 14 male students who were in the seventh grade class of SMP Negeri 3 Sukawati in the academic year 2012/2013. The data was gained by doing the movement of alternate leg bound and double leg bound that each movement was done three times before and after the training. The hypothesis was examined by using independent t-test with the result 0.05 (p<0.05. Based on the different result of analysis test in each group, the gain score of the group 2 with the group 1 about 0,51 that shows the significant differences p = 0,00, the gain score of the group 2 with the group 3 about 0,31 that shows the significant differences p = 0,00, the gain score of the group 3 with the group 1 about 0,20 that shows the significant differences p = 0,00. Thus, alternate leg bound plyometric training is more effective than double leg bound. It is expected that the coach and the gym teacher to apply alternate leg bound plyometric training as an alternative to improve the explosive power of leg muscle.

Prosthetic fitting in a patient with a transtibial amputation due to a congenital vascular malformation of the right leg.

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Simmelink, Elisabeth K; Rommers, Gerardus M; Gardeniers, Jean W M; Zijlstra, Henk

2014-04-01

The problems of prescribing a prosthesis for a young girl with severe congenital vascular malformation deformity leading to a transtibial amputation. Due to the high risk of recurrent bleeding and limitations regarding full weight bearing of the stump, a normal socket fitting process was not possible. Using a multidisciplinary approach, a prosthesis was designed to enable full weight bearing in a flexed knee position with ischial tuberosity support to prevent full weight bearing on the tibial part of the stump. After training and adjustments to the design, a definitive prosthesis with a free motion mechanical knee joint could be used. During the training with this prosthesis, no skin problems were observed, and at the end of the rehabilitation, the patient had a high level of activities of daily living and sports. The above prosthetic solution with an adjusted socket design proved to be successful in this case. Clinical relevance In a patient with severe congenital vascular malformation deformity leading to a transtibial amputation, fitting of a good prosthesis without full weight bearing of the stump proved to be successful.

Leg kinematics and kinetics in landing from a single-leg hop for distance. A comparison between dominant and non-dominant leg

NARCIS (Netherlands)

van der Harst, J. J.; Gokeler, A.; Hof, A. L.

Background. Anterior cruciate ligament (ACL) deficiency can be a major problem for athletes and subsequent reconstruction of the ACL may be indicated if a conservative regimen has failed. After ACL reconstruction signs of abnormality in the use of the leg remain for a long time. It is expected that

Roll type conducting polymer legs for rigid-flexible thermoelectric generator

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Teahoon Park

2017-07-01

Full Text Available A roll-type conducting polymer film was explored as a flexible organic p-type thermoelectric leg using poly(3,4-ethylenedioxythiophene (PEDOT doped with tosylate. The PEDOT films were prepared through solution casting polymerization and rolled up for a roll-type leg. Due to the high flexibility, the roll-type PEDOT leg enabled easy contact to both top and bottom electrodes. Simulation on the dynamic heat transfer and convective cooling for a vertically roosted rod- and roll-type PEDOT leg showed that the temperature difference (ΔT between the hot and cold sides of the leg was much higher in the roll than that of the rod. The PEDOT legs were integrated with n-type Bi2Te3 blocks, to give a 36-couple rigid-flexible thermoelectric generator (RF-TEG. The maximum output voltage from the 36-couple RF-TEG under a ΔT of 7.9 K was determined as 36.7 mV along with a high output power of 115 nW. A wearable RF-TEG was prepared upon the combination of the 36-couple RF-TEG with an arm warmer, to afford an output voltage of 10.6 mV, which was generated constantly and steadily from human wrist heat.

Metabolic Vascular Syndrome: New Insights into a Multidimensional Network of Risk Factors and Diseases.

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Scholz, Gerhard H; Hanefeld, Markolf

2016-10-01

Since 1981, we have used the term metabolic syndrome to describe an association of a dysregulation in lipid metabolism (high triglycerides, low high-density lipoprotein cholesterol, disturbed glucose homeostasis (enhanced fasting and/or prandial glucose), gout, and hypertension), with android obesity being based on a common soil (overnutrition, reduced physical activity, sociocultural factors, and genetic predisposition). We hypothesized that main traits of the syndrome occur early and are tightly connected with hyperinsulinemia/insulin resistance, procoagulation, and cardiovascular diseases. To establish a close link between the traits of the metabolic vascular syndrome, we focused our literature search on recent original work and comprehensive reviews dealing with the topics metabolic syndrome, visceral obesity, fatty liver, fat tissue inflammation, insulin resistance, atherogenic dyslipidemia, arterial hypertension, and type 2 diabetes mellitus. Recent research supports the concept that the metabolic vascular syndrome is a multidimensional and interactive network of risk factors and diseases based on individual genetic susceptibility and epigenetic changes where metabolic dysregulation/metabolic inflexibility in different organs and vascular dysfunction are early interconnected. The metabolic vascular syndrome is not only a risk factor constellation but rather a life-long abnormality of a closely connected interactive cluster of developing diseases which escalate each other and should continuously attract the attention of every clinician.

Role of Renin-Angiotensin system and oxidative stress on vascular inflammation in insulin resistence model.

Science.gov (United States)

Renna, N F; Lembo, C; Diez, E; Miatello, R M

2013-01-01

(1) This study aims to demonstrate the causal involvement of renin angiotensin system (RAS) and oxidative stress (OS) on vascular inflammation in an experimental model of metabolic syndrome (MS) achieved by fructose administration to spontaneously hypertensive rats (FFHR) during 12 weeks. (2) Chronic treatment with candesartan (C) (10 mg/kg per day for the last 6 weeks) or 4OH-Tempol (T) (10(-3) mmol/L in drinking water for the last 6 weeks) reversed the increment in metabolic variables and systolic blood pressure. In addition, chronic C treatment reverted cardiovascular remodeling but not T. (3) Furthermore, chronic treatment with C was able to completely reverse the expression of NF-κB and VCAM-1, but T only reduced the expression. C reduced the expression of proatherogenic cytokines as CINC2, CINC3, VEGF, Leptin, TNF-alpha, and MCP-1 and also significantly reduced MIP-3, beta-NGF, and INF-gamma in vascular tissue in this experimental model. T was not able to substantially modify the expression of these cytokines. (4) The data suggest the involvement of RAS in the expression of inflammatory proteins at different vascular levels, allowing the creation of a microenvironment suitable for the creation, perpetuation, growth, and destabilization of vascular injury.

Role of Renin-Angiotensin System and Oxidative Stress on Vascular Inflammation in Insulin Resistence Model

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N. F. Renna

2013-01-01

Full Text Available (1 This study aims to demonstrate the causal involvement of renin angiotensin system (RAS and oxidative stress (OS on vascular inflammation in an experimental model of metabolic syndrome (MS achieved by fructose administration to spontaneously hypertensive rats (FFHR during 12 weeks. (2 Chronic treatment with candesartan (C (10 mg/kg per day for the last 6 weeks or 4OH-Tempol (T (10−3 mmol/L in drinking water for the last 6 weeks reversed the increment in metabolic variables and systolic blood pressure. In addition, chronic C treatment reverted cardiovascular remodeling but not T. (3 Furthermore, chronic treatment with C was able to completely reverse the expression of NF-κB and VCAM-1, but T only reduced the expression. C reduced the expression of proatherogenic cytokines as CINC2, CINC3, VEGF, Leptin, TNF-alpha, and MCP-1 and also significantly reduced MIP-3, beta-NGF, and INF-gamma in vascular tissue in this experimental model. T was not able to substantially modify the expression of these cytokines. (4 The data suggest the involvement of RAS in the expression of inflammatory proteins at different vascular levels, allowing the creation of a microenvironment suitable for the creation, perpetuation, growth, and destabilization of vascular injury.

Hereditary Lymphedema of the Leg – A Case Report

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Birgit Heinig

2017-07-01

Full Text Available Primary of hereditary lymphedema is a rare but progressive disease. It is yet not curable. We present a 48-year-old male patient with hereditary lymphedema of his left leg, that was realised by minor trauma (able twist when he was seven years old. He had never been treated for lymphedema but experienced multiple erysipelas during his life. After diagnostic procedures to exclude other causes of leg swelling, the diagnosis of hereditary lymphedema of the leg, stage III was confirmed. We initialized complex decongestive therapy. During two weeks of intensive treatment, the circumference of the left leg could be reduced by 10 cm. This case illustrates the "natural course" hereditary lymphedema. But it raises the hope that even after decades of ignorance, the patients benefits from complex decongestive treatment. Therapeutic nihilism is unnecessary and poses lymphedema patients to risks of infection and secondary malignancies like Stewart-Trewes syndrome.

A SHORT-TERM CIRCUIT RESISTANCE PROGRAMME REDUCED EPICARDIAL FAT IN OBESE AGED WOMEN.

Science.gov (United States)

Rosety, Miguel Angel; Pery, Maria Teresa; Rodriguez-Pareja, Maria Antonia; Diaz, Antonio; Rosety, Jesus; Garcia, Natalia; Brenes-Martin, Francisco; Rosety-Rodríguez, Manuel; Toro, Rocío; Ordoñez, Francisco Javier; Rosety, Ignacio

2015-11-01

this study was conducted to ascertain the effects of resistance circuit training on epicardial adipose tissue (EAT) in obese aged women. A secondary objective was to assess muscle damage induced by supervised resistance training to confirm the intervention program was effective and safe. in the present interventional study, a total of 48 obese aged women were recruited from the community. Twenty-four of them were randomly assigned to perform a 12-week resistance circuit training programme, 3-days per week. This training was circularly performed in 6 stations: arm curl, leg extension, seated row, leg curl, triceps extension and leg press. The Jamar handgrip electronic dynamometer was used to assess maximal handgrip strength of the dominant hand. Two experienced observers assessed EAT by transthoracic two-dimensional echocardiography. Lastly, serum samples were analysed using one-step sandwich assays for creatine kinase activity (CK) and myoglobin (MB) concentration. as was hypothesized, resistance training significantly reduced EAT thickness (8.4 ± 1.0 vs. 7.3 ± 1.3 mm; p = 0.014; d = 0.76) in the experimental group. Resistance training induced no significant changes in markers of muscle damage such as CK (181.6 ± 36.9 vs. 194.2 ± 37.8 U/l; p = 0.31) and MB (62.4 ± 7.1 vs. 67.3 ± 7.7 ng/ml; p = 0.26). No significant changes in any of the tested outcomes were found in the control group. resistance training reduced EAT in aged obese women. A secondary finding was that the training program was effective and safe. While current results are promising, future studies are still required to consolidate this approach in clinical application. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Leg symptoms associated with sacroiliac joint disorder and related pain.

Science.gov (United States)

Murakami, Eiichi; Aizawa, Toshimi; Kurosawa, Daisuke; Noguchi, Kyoko

2017-06-01

The symptoms of sacroiliac joint (SIJ) disorders are usually detected in the buttock and groin, and occasionally referred to the thigh and leg. However, lumbar disorders also cause symptoms in these same body regions. The presence of a characteristic, symptomatic pattern in the legs would be useful for diagnosing SIJ disorders. This study aimed to identify specific leg symptoms in patients with SIJ pain originating from the posterior sacroiliac ligament and determine the rate of occurrence of these symptoms. The source population consisted of 365 consecutive patients from February 2005 to December 2007. One hundred patients were diagnosed with SIJ pain by a periarticular SIJ injection (42 males and 58 females, average age 46 years, age range, 18-75 years). A leg symptom map was made by subtracting the symptoms after a periarticular SIJ injection from the initial symptoms, and evaluating the rate of each individual symptom by area. Ninety-four patients reported pain at or around the posterior-superior iliac spine (PSIS). Leg symptoms comprised pain and a numbness/tingling sensation; ≥60% of the patients had these symptoms. Pain was mainly detected in the back, buttock, groin, and thigh areas, while numbness/tingling was mainly detected in the lateral to posterior thigh and back of the calf. Leg symptoms associated with SIJ pain originating from the posterior sacroiliac ligament include both pain and numbness, which do not usually correspond to the dermatome. These leg symptoms in addition to pain around the PSIS may indicate SIJ disorders. Copyright © 2017 Elsevier B.V. All rights reserved.

CALCANEAL MINERAL DENSITY IN CHILDREN ATHLETES AND TAKE-OFF LEG

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Borislav Obradović

2010-06-01

Full Text Available It is well-known that physical activity has an anabolic effect on the bone tissue. To examine the influence of the take-off lower limb to the bone density we studied a group of prepubertal boys and girls at the initial phase of their peak bone mass acquisition. A sample consisted of 60 subjects ie., 32 soccer players (boys, 10.7±0.5 years old and 28 swimmers (15 girls and 13 boys, 10.8±0.8 years old, who had performed at least one year of high-level sport training (10-15 hours per week for soccer players, 8-12 hours per week for swimmers. The sample was divided into two groups: the first consisted of 40 subjects, with the left take-off leg, while the second consisted of 20 subjects, with the right take-off leg. The bone mineral density (BMD measurements of the left and the right calcaneus were performed using ultrasound densitometer “Sahara” (Hologic, Inc., MA, USA. There were no significant differences between the groups in regard to BUA and SOS of both the left and the right take-off lower legs. Mean BUA of the take-off left leg and the take-off right leg were different, but not significantly (p>0.05. Likewise, mean SOS of the take-off left leg and the take-off right leg were different, but it was not significant (p>0.05. The results do not indicate that the take-off lower limb has an influence on calcaneal bone mineral density.

The second leg home advantage: evidence from European football cup competitions.

Science.gov (United States)

Page, Lionel; Page, Katie

2007-12-01

The home advantage is a widely acknowledged sporting phenomenon, especially in association football. Here, we examine the second leg home advantage, an effect that is discussed in the public domain but which has received very little scientific attention. The second leg home advantage effect occurs when on average teams are more likely to win a two-stage knock-out competition when they play at home in the second leg. That is, both teams have a home advantage but this advantage is significantly greater for the team that plays at home second. Examining data from three different European Cup football competitions spanning 51 years, we show that the second leg home advantage is a real phenomenon. The second leg home team has more than a 50% probability to qualify for the next round in the competition even after controlling for extra time and team ability as possible alternative explanations. The second leg home advantage appears, however, to have decreased significantly over the past decade. Possible reasons for its existence and subsequent decline are presented.

Differential glucose uptake in quadriceps and other leg muscles during one-legged dynamic submaximal knee-extension exercise

DEFF Research Database (Denmark)

Kalliokoski, Kari K; Boushel, Robert; Langberg, Henning

2011-01-01

One-legged dynamic knee-extension exercise (DKE) is a widely used model to study the local cardiovascular and metabolic responses to exercise of the quadriceps muscles. In this study, we explored the extent to which different muscles of the quadriceps are activated during exercise using positron...... emission tomography (PET) determined uptake of [18F]-fluoro-deoxy-glucose (GU) during DKE. Five healthy male subjects performed DKE at 25 W for 35 min and both the contracting and contralateral resting leg were scanned with PET from mid-thigh and distally. On average, exercise GU was the highest...

The mangled lower leg

NARCIS (Netherlands)

Hoogendoorn, Jochem Maarten

2002-01-01

A surgeon faced with a patient presenting with an open tibial/fibular fracture in combination with severe damage of the surrounding soft tissues, has to make the difficult decision whether to attempt salvage or to perform an immediate amputation of the leg. Until late in the nineteenth century the

Locomotor-like leg movements evoked by rhythmic arm movements in humans.

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Francesca Sylos-Labini

Full Text Available Motion of the upper limbs is often coupled to that of the lower limbs in human bipedal locomotion. It is unclear, however, whether the functional coupling between upper and lower limbs is bi-directional, i.e. whether arm movements can affect the lumbosacral locomotor circuitry. Here we tested the effects of voluntary rhythmic arm movements on the lower limbs. Participants lay horizontally on their side with each leg suspended in an unloading exoskeleton. They moved their arms on an overhead treadmill as if they walked on their hands. Hand-walking in the antero-posterior direction resulted in significant locomotor-like movements of the legs in 58% of the participants. We further investigated quantitatively the responses in a subset of the responsive subjects. We found that the electromyographic (EMG activity of proximal leg muscles was modulated over each cycle with a timing similar to that of normal locomotion. The frequency of kinematic and EMG oscillations in the legs typically differed from that of arm oscillations. The effect of hand-walking was direction specific since medio-lateral arm movements did not evoke appreciably leg air-stepping. Using externally imposed trunk movements and biomechanical modelling, we ruled out that the leg movements associated with hand-walking were mainly due to the mechanical transmission of trunk oscillations. EMG activity in hamstring muscles associated with hand-walking often continued when the leg movements were transiently blocked by the experimenter or following the termination of arm movements. The present results reinforce the idea that there exists a functional neural coupling between arm and legs.

Effects of hypothyroidism on vascular 125I-albumin permeation and blood flow in rats

International Nuclear Information System (INIS)

Tilton, R.G.; Pugliese, G.; Chang, K.; Speedy, A.; Province, M.A.; Kilo, C.; Williamson, J.R.

1989-01-01

Effects of hypothyroidism on vascular 125I-albumin permeation and on blood flow were assessed in multiple tissues of male Sprague-Dawley rats rendered hypothyroid by dietary supplementation with 0.5% (wt/wt) 2-thiouracil or by thyroidectomy. In both thiouracil-treated and thyroidectomized rats, body weights, kidney weight, arterial blood pressure, and pulse rate were decreased significantly v age-matched controls. After 10 to 12 weeks of thiouracil treatment, 125I-albumin permeation was increased significantly in the kidney, aorta, eye (anterior uvea, choroid, retina), skin, and new granulation tissue, remained unchanged in brain, sciatic nerve, and heart, and was decreased in forelimb skeletal muscle. A similar pattern was observed in thyroidectomized rats, except that increases in 125I-albumin permeation for all tissues were smaller than those observed in thiouracil-treated rats, and 125I-albumin permeation in retina did not differ from controls. In both thiouracil-treated and thyroidectomized rats, changes in blood flow (assessed with 15-microns, 85Sr-labeled microspheres) relative to the decrease in arterial blood pressure were indicative of a decrease in regional vascular resistance except in the choroid and in the kidney, in which vascular resistance was increased significantly. Glomerular filtration rate was decreased, but filtration fraction and urinary excretion of albumin remained unchanged by thiouracil treatment and thyroidectomy. These results indicate that vascular hemodynamics and endothelial cell barrier functional integrity are modulated in many different tissues by the thyroid. In view of the correspondence of hypothyroid- and diabetes-induced vascular permeability changes, these results raise the possibility that altered thyroid function in diabetes may play a role in the pathogenesis of diabetic vascular disease

Orthostatic leg blood volume changes assessed by near-infrared spectroscopy

DEFF Research Database (Denmark)

Truijen, J; Kim, Y S; Krediet, C T P

2012-01-01

posture, volume accumulation in small blood vessels contributes significantly to the total fluid volume accumulated in the legs. Considering that near-infrared spectroscopy (NIRS) tracks postural blood volume changes within the small blood vessels of the lower leg, we evaluated the NIRS-determined changes......-linear accumulation of blood volume in the small vessels of the leg, with an initial fast phase followed by a more gradual increase at least partly contributing to the relocation of fluid during orthostatic stress....

Deconstructing the power resistance relationship for squats: A joint-level analysis.

Science.gov (United States)

Farris, D J; Lichtwark, G A; Brown, N A T; Cresswell, A G

2016-07-01

Generating high leg power outputs is important for executing rapid movements. Squats are commonly used to increase leg strength and power. Therefore, it is useful to understand factors affecting power output in squatting. We aimed to deconstruct the mechanisms behind why power is maximized at certain resistances in squatting. Ten male rowers (age = 20 ± 2.2 years; height = 1.82 ± 0.03 m; mass = 86 ± 11 kg) performed maximal power squats with resistances ranging from body weight to 80% of their one repetition maximum (1RM). Three-dimensional kinematics was combined with ground reaction force (GRF) data in an inverse dynamics analysis to calculate leg joint moments and powers. System center of mass (COM) velocity and power were computed from GRF data. COM power was maximized across a range of resistances from 40% to 60% 1RM. This range was identified because a trade-off in hip and knee joint powers existed across this range, with maximal knee joint power occurring at 40% 1RM and maximal hip joint power at 60% 1RM. A non-linear system force-velocity relationship was observed that dictated large reductions in COM power below 20% 1RM and above 60% 1RM. These reductions were due to constraints on the control of the movement. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effects of Ibuprofen and Resistance Training on Bone and Muscle: A Randomized Controlled Trial in Older Women.

Science.gov (United States)

Duff, Whitney R D; Chilibeck, Philip D; Candow, Darren G; Gordon, Julianne J; Mason, Riley S; Taylor-Gjevre, Regina; Nair, Bindu; Szafron, Michael; Baxter-Jones, Adam; Zello, Gordon A; Kontulainen, Saija A

2017-04-01

Resistance training with ibuprofen supplementation may improve musculoskeletal health in postmenopausal women. The study purpose was to determine the efficacy of resistance training and ibuprofen supplementation on bone and muscle properties in postmenopausal women. Participants (n = 90, 65.3 ± 4.9 yr) were randomly assigned to: supervised resistance training or stretching (placebo-exercise) with postexercise ibuprofen (400 mg) or placebo supplementation for 3 d·wk (9 months). Baseline and postintervention measurements included distal and shaft scans of the forearm and lower leg using peripheral quantitative computed tomography. Distal site outcomes included cross-sectional area, content, and density for total and trabecular bone, as well as estimated bone strength in compression. Shaft site outcomes included total bone area; cortical bone area, content, and density; estimated bone strength in torsion; and muscle area and density. Exercise-supplement-time interactions for total bone content at the distal radius (P = 0.009) and cortical density at the radius shaft (P = 0.038) were significant. Resistance training with ibuprofen decreased total bone content (-1.5%) at the distal radius in comparison to the resistance training (0.6%; P = 0.032) and ibuprofen alone (0.5%; P = 0.050). Change in cortical density at the radius shaft differed between the stretching with placebo and ibuprofen supplementation groups (-1.8% vs 1.1%; P = 0.050). Resistance training preserved muscle density in the lower leg more so than stretching (-3.1% vs -5.4%; P = 0.015). Ibuprofen consumed immediately after resistance training had a deleterious effect on bone mineral content at the distal radius, whereas resistance training or ibuprofen supplementation individually prevented bone loss. Resistance training prevented muscle density decline in the lower leg.

Eyelash Transplantation Using Leg Hair by Follicular Unit Extraction

Directory of Open Access Journals (Sweden)

Sanusi Umar, MD

2015-03-01

Full Text Available Summary: Fine hairs of the head and nape areas have been used as donor sources in eyelash transplantation but are straight, coarse, and grow rapidly, requiring frequent eyelash maintenance. This is the first reported case of eyelash transplantation by follicular unit extraction using leg hair as a donor source; findings were compared with that of another patient who underwent a similar procedure with donor hairs from the nape area. Although both patients reported marked improvement in fullness of eyelashes within 3 months postsurgery, the transplanted leg hair eyelashes required less frequent trimming (every 5–6 weeks compared with nape hair eyelashes (every 2–3 weeks. Additionally, in leg hair eyelashes, the need for perming to sustain a natural looking eyelash curl was eliminated. Eyelash transplantation using leg donor hair in hirsute women may result in good cosmetic outcomes and require less maintenance compared with nape donor hair.

Sleep apnea in patients reporting insomnia or restless legs symptoms.

Science.gov (United States)

Bianchi, M T; Goparaju, B; Moro, M

2016-01-01

Insomnia and restless legs syndrome (RLS) are defined by self-reported symptoms, and polysomnography (PSG) is not routinely indicated. Occult obstructive sleep apnea (OSA), common even in asymptomatic adults, may complicate management of patients presenting with insomnia or restless legs. To this end, we investigated objective sleep apnea metrics in a large retrospective cohort according to self-reported symptom profiles. We compared sleep apnea findings in patients referred to our center according to self-reported symptoms associated with insomnia, sleep apnea, and restless legs. The cohort included over 1900 adults who underwent diagnostic (n = 1418) or split-night (n = 504) PSGs and completed a symptom and medical history questionnaire. More than 30% of patients who did not endorse any OSA symptoms, but did endorse insomnia or restless legs symptoms, were found to have OSA based on apnea-hypopnea index (AHI) >5 during overnight laboratory testing. Regression models of the full cohort showed that the risk of OSA was related, as expected, to older age, male sex, elevated body mass index, and presence of OSA symptoms. The presence of insomnia symptoms did not alter the risk of OSA. The presence of restless legs symptoms showed a small odds ratio for lowered OSA risk. Objective evidence of OSA occurs similarly in those with insomnia or restless legs symptoms, even among those without self-reported OSA symptoms. Providers should be aware of the potential for occult OSA in populations with insomnia and restless legs, which may complicate their management in addition to presenting an independent medical risk itself. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Assessment of nutritional status in adult patients with cystic fibrosis: whole-body bioimpedance vs body mass index, skinfolds, and leg-to-leg bioimpedance

NARCIS (Netherlands)

Hollander, F.M.; Roos, de N.M.; Vries, de J.H.M.; Berkhout, van F.T.

2005-01-01

Objective: To investigate whether body mass index (BMI) or body fat percentage estimated from BMI, skinfolds, or leg-to-leg bioimpedance are good indicators of nutritional status in adult patients with cystic fibrosis. Body fat percentage measured by whole-body bioimpedance was used as the reference

Sensitivity of sensor-based sit-to-stand peak power to the effects of training leg strength, leg power and balance in older adults

NARCIS (Netherlands)

Regterschot, G Ruben H; Folkersma, Marjanne; Zhang, Wei; Baldus, Heribert; Stevens, Martin; Zijlstra, Wiebren

Increasing leg strength, leg power and overall balance can improve mobility and reduce fall risk. Sensor-based assessment of peak power during the sit-to-stand (STS) transfer may be useful for detecting changes in mobility and fall risk. Therefore, this study investigated whether sensor-based STS

Inflammation-induced microvascular insulin resistance is an early event in diet-induced obesity

Science.gov (United States)

Zhao, Lina; Fu, Zhuo; Wu, Jing; Aylor, Kevin W.; Barrett, Eugene J.; Cao, Wenhong

2015-01-01

Endothelial dysfunction and vascular insulin resistance usually coexist and chronic inflammation engenders both. In the present study, we investigate the temporal relationship between vascular insulin resistance and metabolic insulin resistance. We assessed insulin responses in all arterial segments, including aorta, distal saphenous artery and the microvasculature, as well as the metabolic insulin responses in muscle in rats fed on a high-fat diet (HFD) for various durations ranging from 3 days to 4 weeks with or without sodium salicylate treatment. Compared with controls, HFD feeding significantly blunted insulin-mediated Akt (protein kinase B) and eNOS [endothelial nitric oxide (NO) synthase] phosphorylation in aorta in 1 week, blunted vasodilatory response in small resistance vessel in 4 weeks and microvascular recruitment in as early as 3 days. Insulin-stimulated whole body glucose disposal did not begin to progressively decrease until after 1 week. Salicylate treatment fully inhibited vascular inflammation, prevented microvascular insulin resistance and significantly improved muscle metabolic responses to insulin. We conclude that microvascular insulin resistance is an early event in diet-induced obesity and insulin resistance and inflammation plays an essential role in this process. Our data suggest microvascular insulin resistance contributes to the development of metabolic insulin resistance in muscle and muscle microvasculature is a potential therapeutic target in the prevention and treatment of diabetes and its related complications. PMID:26265791

Endothelial Estrogen Receptor-α Does Not Protect Against Vascular Stiffness Induced by Western Diet in Female Mice.

Science.gov (United States)

Manrique, Camila; Lastra, Guido; Ramirez-Perez, Francisco I; Haertling, Dominic; DeMarco, Vincent G; Aroor, Annayya R; Jia, Guanghong; Chen, Dongqing; Barron, Brady J; Garro, Mona; Padilla, Jaume; Martinez-Lemus, Luis A; Sowers, James R

2016-04-01

Consumption of a diet high in fat and refined carbohydrates (Western diet [WD]) is associated with obesity and insulin resistance, both major risk factors for cardiovascular disease (CVD). In women, obesity and insulin resistance abrogate the protection against CVD likely afforded by estrogen signaling through estrogen receptor (ER)α. Indeed, WD in females results in increased vascular stiffness, which is independently associated with CVD. We tested the hypothesis that loss of ERα signaling in the endothelium exacerbates WD-induced vascular stiffening in female mice. We used a novel model of endothelial cell (EC)-specific ERα knockout (EC-ERαKO), obtained after sequential crossing of the ERα double floxed mice and VE-Cadherin Cre-recombinase mice. Ten-week-old females, EC-ERαKO and aged-matched genopairs were fed either a regular chow diet (control diet) or WD for 8 weeks. Vascular stiffness was measured in vivo by pulse wave velocity and ex vivo in aortic explants by atomic force microscopy. In addition, vascular reactivity was assessed in isolated aortic rings. Initial characterization of the model fed a control diet did not reveal changes in whole-body insulin sensitivity, aortic vasoreactivity, or vascular stiffness in the EC-ERαKO mice. Interestingly, ablation of ERα in ECs reduced WD-induced vascular stiffness and improved endothelial-dependent dilation. In the setting of a WD, endothelial ERα signaling contributes to vascular stiffening in females. The precise mechanisms underlying the detrimental effects of endothelial ERα in the setting of a WD remain to be elucidated.

Non-invasive vascular imaging: assessing tumour vascularity

International Nuclear Information System (INIS)

Delorme, S.; Knopp, M.V.

1998-01-01

Non-invasive assessment of vascularity is a new diagnostic approach to characterise tumours. Vascular assessment is based on the pathophysiology of tumour angiogenesis and its diagnostic implications for tumour biology, prognosis and therapy response. Two current techniques investigating vascular features in addition to morphology are Doppler ultrasonography and contrast-enhanced MRI. Diagnostic differentiation has been shown to be possible with Doppler, and a high degree of observed vascularity could be linked to an aggressive course of the disease. Dynamic MRI using gadolinium chelates is already used clinically to detect and differentiate tumours. The histological correlation shows that capillary permeability is increased in malignant tumours and is the best criterion for differentiation from benign processes. Permeability and perfusion factors seem to be more diagnostic than overall vessel density. New clinical applications are currently being established for therapy monitoring. Further instrumental developments will bring harmonic imaging in Doppler, and faster imaging techniques, higher spatial resolution and novel pharmacokinetic concepts in MRI. Upcoming contrast agents for both Doppler and MRI will further improve estimation of intratumoural blood volume and vascular permeability. (orig.)

Estimation of pulmonary vascular resistance in patients with pulmonary fibrosis by phase-contrast magnetic resonance imaging

International Nuclear Information System (INIS)

Ayukawa, Yuichiro; Murayama, Sadayuki; Tsuchiya, Nanae; Yara, Satomi; Fujita, Jiro

2011-01-01

The aim of this study was to assess pulmonary vascular resistance (PVR) in patients with pulmonary fibrosis (PF) by phase-contrast magnetic resonance imaging (MRI). Subjects were 11 healthy volunteers and 11 patients with PF. Using phase-contrast MRI, we measured pulmonary arterial blood flow and calculated the parameters of PVR. Parameters were compared between volunteers and patients using unpaired t-tests. The diagnostic capability of the parameters was evaluated by receiver operating characteristic (ROC) curve analysis. Patients underwent respiratory function tests (RFTs) and chest computed tomography (CT), and they were correlated with MRI parameters. Most MRI parameters were significantly different between volunteers and patients (t-test P values were <0.05 in 9 of 10 parameters). Regarding the RFT and CT visual score, only the %DLco/VA and acceleration time and the CT visual score and average flow volume had significant correlation [r=-0.667 (P=0.024) and r=-0.6 (P=0.031)], respectively. Our findings suggest that PVR derived from phase-contrast MRI is significantly higher in patients with PF than in volunteers. However, all but two of these parameters may not correlate with the severity of PF. (author)

BETHSY ISP-38 flow behaviour in hot leg

International Nuclear Information System (INIS)

Petelin, S.; Jurkovic, M.

1998-01-01

Betsy Test 6.9c OECD ISP-38 RELAP5/MOD3.2 input model was developed and simulation performed for loss of RHR system during mid-loop operation. Initial liquid level in RCS was at horizontal axis of the hot legs. Pressurizer and steam generator manways were opened 1 s after the transient was initiated. Secondary side is full of air and isolated. Results of calculations were satisfied except in surge line and in pressurizer where larger amount of water is presented. Liquid was entrained in that part of the system during bubbly or varies stratified flow in the hot leg. Due to non-physical results in hot leg pipe with connected surge line and pressurizer, RELAP5 horizontal stratification model deficiencies was studied and possible improvements investigated.(author)

[Fractures of the lower leg in professional skiers].

Science.gov (United States)

Mückley, T; Kruis, C; Schütz, T; Brucker, P; Bühren, V

2004-03-01

Fractures of the lower leg due to skiing accidents remain an important concern. Few studies have focussed on the special demands of professional athletes who sustain these injuries. We present our experience with three cases of lower leg fractures in competitive professional downhill skiers and discuss management and treatment concepts. We performed limited reamed compression nailing in all the patients presented because it offers the advantages of high mechanical stability and optimized fragment apposition. Plate osteosynthesis of the fibula is not required in most typical fractures. All patients resumed ski training. Two of them returned to World Cup. Only one achieved her pre-injury World Cup level of performance and success. In conclusion, a successful return for professional skiers with lower leg fractures is feasible using an optimized treatment strategy.

Evaluation of elastic bands for lower extremity resistance training in adults with and without musculo-skeletal pain

DEFF Research Database (Denmark)

Sundstrup, E; Jakobsen, M D; Andersen, C H

2014-01-01

these findings. However, pain in the lower back decreased muscular activity of the gluteus maximus and vastus medialis (P resistance induce high levels of muscle activity in all the large muscle groups at the hip, knee, and back. Importantly, the efficiency of these exercises......Therapists commonly use elastic bands in resistance exercises during rehabilitation of smaller muscles, such as in the shoulder. However, the effectiveness has not yet been investigated for larger muscle groups. This study investigates muscle activity during lower extremity exercises....... Electromyographic (EMG) activity of 10 muscles was measured in 24 women and 18 men during lunges with elastic resistance, lunges with dumbbells, and unilateral leg press in machine using 10 repetition maximum loadings, and normalized to maximal voluntary isometric contraction EMG. Lunges with dumbbells and leg...

Laboratory on Legs: An Architecture for Adjustable Morphology with Legged Robots

Science.gov (United States)

2012-04-01

including walking, running,7 pronking,8,9 leaping and flipping,10 climbing stairs ,11,12 recovering from failures,13 and even running upright on (modified...speed activities requiring large leg torques, such as clambering over rocks and climbing stairs , as well as high speed activities with moderate torques...8] McMordie, D. and Buehler, M., “Towards pronking with a hexapod robot ,” in [International Conference on Climbing and Walking Robots

Role of vascular potassium channels in the regulation of renal hemodynamics

DEFF Research Database (Denmark)

Sørensen, Charlotte Mehlin; Braunstein, Thomas Hartig; von Holstein-Rathlou, Niels-Henrik

2012-01-01

of one or more classes of K+ channels will lead to a change in hemodynamic resistance and therefore of renal blood flow and glomerular filtration pressure. Through these effects, the activity of renal vascular K+ channels influences renal salt and water excretion, fluid homeostasis, and ultimately blood...... pressure. Four main classes of K+ channels [calcium activated (KCa), inward rectifier (Kir), voltage activated (KV), and ATP sensitive (KATP)] are found in the renal vasculature. Several in vitro experiments have suggested a role for individual classes of K+ channels in the regulation of renal vascular...... function. Results from in vivo experiments are sparse. We discuss the role of the different classes of renal vascular K+ channels and their possible role in the integrated function of the renal microvasculature. Since several pathological conditions, among them hypertension, are associated with alterations...

Arm and leg substrate utilization and muscle adaptation after prolonged low-intensity training

DEFF Research Database (Denmark)

Helge, Jørn Wulff

2010-01-01

This review will focus on current data where substrate metabolism in arm and leg muscle is investigated and discuss the presence of higher carbohydrate oxidation and lactate release observed during arm compared with leg exercise. Furthermore, a basis for a possible difference in substrate partiti...... at comparable workloads. Finally, the influence and capacity of low-intensity training to influence metabolic fitness in the face of a limited effect on aerobic fitness will be challenged....... partitioning between endogenous and exogenous substrate during arm and leg exercise will be debated. Moreover the review will probe if differences between arm and leg muscle are merely a result of different training status rather than a qualitative difference in limb substrate regulation. Along this line...... the review will address the available studies on low-intensity training performed separately with arm or legs or as whole-body training to evaluate if this leads to different adaptations in arm and leg muscle resulting in different substrate utilization patterns during separate arm or leg exercise...

Multi-Axis Prosthetic Knee Resembles Alpine Skiing Movements of an Intact Leg

Science.gov (United States)

Demšar, Ivan; Duhovnik, Jože; Lešnik, Blaž; Supej, Matej

2015-01-01

The purpose of the study was to analyse the flexion angles of the ski boot, ankle and knee joints of an above-knee prosthesis and to compare them with an intact leg and a control group of skiers. One subject with an above-knee amputation of the right leg and eight healthy subjects simulated the movement of a skiing turn by performing two-leg squats in laboratory conditions. By adding additional loads in proportion to body weight (BW; +1/3 BW, +2/3 BW, +3/3 BW), various skiing regimes were simulated. Change of Flexion Angle (CoFA) and Range of Motion (RoM) in the ski boot, ankle and knee joints were calculated and compared. An average RoM in the skiing boot on the side of prosthesis (4.4 ± 1.1°) was significantly lower compared to an intact leg (5.9 ± 1.8°) and the control group (6.5 ± 2.3°). In the ankle joint, the average RoM was determined to be 13.2±2.9° in the prosthesis, 12.7 ± 2.8° in an intact leg and 14.8±3.6 in the control group. However, the RoM of the knee joint in the prosthesis (42.2 ± 4.2°) was significantly larger than that of the intact leg (34.7 ± 4.4°). The average RoM of the knee joint in the control group was 47.8 ± 5.4°. The influences of additional loads on the kinematics of the lower extremities were different on the side of the prosthesis and on the intact leg. In contrast, additional loads did not produce any significant differences in the control group. Although different CoFAs in the ski boot, ankle and knee joints were used, an above-knee prosthesis with a built-in multi-axis prosthetic knee enables comparable leg kinematics in simulated alpine skiing. Key points The RoM in the ski boot on the side of the prosthetic leg was smaller than the RoM of the intact leg and the control group of healthy subjects. The RoM in the ankle joint of prosthetic leg was comparable to that of the intact leg and the control group of healthy subjects. The RoM in the prosthetic knee joint was greater than the RoM in the knee joint of the

The influence of perivascular adipose tissue on vascular homeostasis

Directory of Open Access Journals (Sweden)

Szasz T

2013-03-01

Full Text Available Theodora Szasz,1 Gisele Facholi Bomfim,2 R Clinton Webb1 1Department of Physiology, Georgia Regents University, Augusta, USA; 2Department of Pharmacology, University of São Paulo, São Paulo, Brazil Abstract: The perivascular adipose tissue (PVAT is now recognized as an active contributor to vascular function. Adipocytes and stromal cells contained within PVAT are a source of an ever-growing list of molecules with varied paracrine effects on the underlying smooth muscle and endothelial cells, including adipokines, cytokines, reactive oxygen species, and gaseous compounds. Their secretion is regulated by systemic or local cues and modulates complex processes, including vascular contraction and relaxation, smooth muscle cell proliferation and migration, and vascular inflammation. Recent evidence demonstrates that metabolic and cardiovascular diseases alter the morphological and secretory characteristics of PVAT, with notable consequences. In obesity and diabetes, the expanded PVAT contributes to vascular insulin resistance. PVAT-derived cytokines may influence key steps of atherogenesis. The physiological anticontractile effect of PVAT is severely diminished in hypertension. Above all, a common denominator of the PVAT dysfunction in all these conditions is the immune cell infiltration, which triggers the subsequent inflammation, oxidative stress, and hypoxic processes to promote vascular dysfunction. In this review, we discuss the currently known mechanisms by which the PVAT influences blood vessel function. The important discoveries in the study of PVAT that have been made in recent years need to be further advanced, to identify the mechanisms of the anticontractile effects of PVAT, to explore the vascular-bed and species differences in PVAT function, to understand the regulation of PVAT secretion of mediators, and finally, to uncover ways to ameliorate cardiovascular disease by targeting therapeutic approaches to PVAT. Keywords: adipokines

Parental smoking during pregnancy shortens offspring's legs.

Science.gov (United States)

Żądzińska, E; Kozieł, S; Borowska-Strugińska, B; Rosset, I; Sitek, A; Lorkiewicz, W

2016-12-01

One of the most severe detrimental environmental factors acting during pregnancy is foetal smoke exposure. The aim of this study was to assess the effect of maternal, paternal and parental smoking during pregnancy on relative leg length in 7- to 10-year-old children. The research conducted in the years 2001-2002 included 978 term-born children, 348 boys and 630 girls, at the age of 7-10 years. Information concerning the birth weight of a child was obtained from the health records of the women. Information about the mother's and the father's smoking habits during pregnancy and about the mothers' education level was obtained from a questionnaire. The influence of parental smoking on relative leg length, controlled for age, sex, birth weight and the mother's education, as a proxy measure of socioeconomic status, and controlled for an interaction between sex and birth weight, was assessed by an analysis of covariance, where relative leg length was the dependent variable, smoking and sex were the independent variables, and birth weight as well as the mother's education were the covariates. Three separate analyses were run for the three models of smoking habits during pregnancy: the mother's smoking, the father's smoking and both parents' smoking. Only both parents' smoking showed a significant effect on relative leg length of offspring. It is probable that foetal hypoxia caused by carbon monoxide contained in smoke decelerated the growth of the long bones of foetuses. Copyright © 2016 Elsevier GmbH. All rights reserved.

Design of a Single Motor Based Leg Structure with the Consideration of Inherent Mechanical Stability

Science.gov (United States)

Taha Manzoor, Muhammad; Sohail, Umer; Noor-e-Mustafa; Nizami, Muhammad Hamza Asif; Ayaz, Yasar

2017-07-01

The fundamental aspect of designing a legged robot is constructing a leg design that is robust and presents a simple control problem. In this paper, we have successfully designed a robotic leg based on a unique four bar mechanism with only one motor per leg. The leg design parameters used in our platform are extracted from design principles used in biological systems, multiple iterations and previous research findings. These principles guide a robotic leg to have minimal mechanical passive impedance, low leg mass and inertia, a suitable foot trajectory utilizing a practical balance between leg kinematics and robot usage, and the resultant inherent mechanical stability. The designed platform also exhibits the key feature of self-locking. Theoretical tools and software iterations were used to derive these practical features and yield an intuitive sense of the required leg design parameters.

Increase in Leg Stiffness Reduces Joint Work During Backpack Carriage Running at Slow Velocities.

Science.gov (United States)

Liew, Bernard; Netto, Kevin; Morris, Susan

2017-10-01

Optimal tuning of leg stiffness has been associated with better running economy. Running with a load is energetically expensive, which could have a significant impact on athletic performance where backpack carriage is involved. The purpose of this study was to investigate the impact of load magnitude and velocity on leg stiffness. We also explored the relationship between leg stiffness and running joint work. Thirty-one healthy participants ran overground at 3 velocities (3.0, 4.0, 5.0 m·s -1 ), whilst carrying 3 load magnitudes (0%, 10%, 20% weight). Leg stiffness was derived using the direct kinetic-kinematic method. Joint work data was previously reported in a separate study. Linear models were used to establish relationships between leg stiffness and load magnitude, velocity, and joint work. Our results found that leg stiffness did not increase with load magnitude. Increased leg stiffness was associated with reduced total joint work at 3.0 m·s -1 , but not at faster velocities. The association between leg stiffness and joint work at slower velocities could be due to an optimal covariation between skeletal and muscular components of leg stiffness, and limb attack angle. When running at a relatively comfortable velocity, greater leg stiffness may reflect a more energy efficient running pattern.

33 CFR 147.817 - Sir Douglas Morpeth Tension Leg Platform safety zone.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Sir Douglas Morpeth Tension Leg... HOMELAND SECURITY (CONTINUED) OUTER CONTINENTAL SHELF ACTIVITIES SAFETY ZONES § 147.817 Sir Douglas Morpeth Tension Leg Platform safety zone. (a) Description. The Sir Douglas Morpeth Tension Leg Platform (Morpeth...

In pursuit of vehicle landmine occupant protection: Evaluating the dynamic response characteristic of the military lower extremity leg (MiL-Lx) compared to the Hybrid III (HIII) lower leg

CSIR Research Space (South Africa)

Pandelani, T

2010-09-01

Full Text Available typical mine-protected vehicle landmine blast load conditions. Tests were performed using the Lower Limb Impactor (LLI) on both the MiL-Lx leg and the Hybrid III leg, and the relative responses compared. The results show that the MiL-Lx leg appears...

The causes of skin damage and leg ulceration in chronic venous disease.

Science.gov (United States)

Smith, Philip Coleridge

2006-09-01

Chronic venous disease with skin changes of the leg is a common condition affecting up to 1 in 20 people in westernized countries. The causes of this problem are not fully understood, although research in recent years has revealed a number of important mechanisms that contribute to the disease process. Patients with chronic venous disease suffer persistently raised pressures in their deep and superficial veins in the lower limb. Leucocytes become "trapped" in the circulation of the leg during periods of venous hyper-tension produced by sitting or standing. Studies of the plasma levels of neutrophil granule enzymes shows that these are increased during periods of venous hypertension, suggesting that this causes activation of the neutrophils. Investigation of the leucocyte surface ligands CD11b and CD62L shows that the more activated neutrophils and monocytes are sequestered during venous hypertension. Measurement of plasma levels of the soluble parts of the endothelial adhesion molecules VCAM, ICAM, and ELAM show that these are all elevated in patients with chronic venous disease compared to controls. Following 30 minutes of venous hypertension produced by standing, these levels are further increased. These data suggest that venous hypertension causes neutrophil and monocyte activation, which in turn causes injury to the endothelium. Chronic injury to the endothelium leads to a chronic inflammatory condition of the skin that we know clinically as lipodermatosclerosis. This is mediated by perivascular inflammatory cells, principally macrophages, in the skin microcirculation. These stimulate fibroblasts in the skin leading to tissue remodeling and laying down of fibrous tissue. Vascular endothelial growth factor stimulates proliferation of capillaries within the skin. Skin in this state has the potential to ulcerate in response to minor injury.

Reproducibility and day time bias correction of optoelectronic leg volumetry: a prospective cohort study.

Science.gov (United States)

Engelberger, Rolf P; Blazek, Claudia; Amsler, Felix; Keo, Hong H; Baumann, Frédéric; Blättler, Werner; Baumgartner, Iris; Willenberg, Torsten

2011-10-05

Leg edema is a common manifestation of various underlying pathologies. Reliable measurement tools are required to quantify edema and monitor therapeutic interventions. Aim of the present work was to investigate the reproducibility of optoelectronic leg volumetry over 3 weeks' time period and to eliminate daytime related within-individual variability. Optoelectronic leg volumetry was performed in 63 hairdressers (mean age 45 ± 16 years, 85.7% female) in standing position twice within a minute for each leg and repeated after 3 weeks. Both lower leg (legBD) and whole limb (limbBF) volumetry were analysed. Reproducibility was expressed as analytical and within-individual coefficients of variance (CVA, CVW), and as intra-class correlation coefficients (ICC). A total of 492 leg volume measurements were analysed. Both legBD and limbBF volumetry were highly reproducible with CVA of 0.5% and 0.7%, respectively. Within-individual reproducibility of legBD and limbBF volumetry over a three weeks' period was high (CVW 1.3% for both; ICC 0.99 for both). At both visits, the second measurement revealed a significantly higher volume compared to the first measurement with a mean increase of 7.3 ml ± 14.1 (0.33% ± 0.58%) for legBD and 30.1 ml ± 48.5 ml (0.52% ± 0.79%) for limbBF volume. A significant linear correlation between absolute and relative leg volume differences and the difference of exact day time of measurement between the two study visits was found (P correction formula permitted further improvement of CVW. Leg volume changes can be reliably assessed by optoelectronic leg volumetry at a single time point and over a 3 weeks' time period. However, volumetry results are biased by orthostatic and daytime-related volume changes. The bias for day-time related volume changes can be minimized by a time-correction formula.

Reproducibility and day time bias correction of optoelectronic leg volumetry: a prospective cohort study

Directory of Open Access Journals (Sweden)

Baumgartner Iris

2011-10-01

Full Text Available Abstract Background Leg edema is a common manifestation of various underlying pathologies. Reliable measurement tools are required to quantify edema and monitor therapeutic interventions. Aim of the present work was to investigate the reproducibility of optoelectronic leg volumetry over 3 weeks' time period and to eliminate daytime related within-individual variability. Methods Optoelectronic leg volumetry was performed in 63 hairdressers (mean age 45 ± 16 years, 85.7% female in standing position twice within a minute for each leg and repeated after 3 weeks. Both lower leg (legBD and whole limb (limbBF volumetry were analysed. Reproducibility was expressed as analytical and within-individual coefficients of variance (CVA, CVW, and as intra-class correlation coefficients (ICC. Results A total of 492 leg volume measurements were analysed. Both legBD and limbBF volumetry were highly reproducible with CVA of 0.5% and 0.7%, respectively. Within-individual reproducibility of legBD and limbBF volumetry over a three weeks' period was high (CVW 1.3% for both; ICC 0.99 for both. At both visits, the second measurement revealed a significantly higher volume compared to the first measurement with a mean increase of 7.3 ml ± 14.1 (0.33% ± 0.58% for legBD and 30.1 ml ± 48.5 ml (0.52% ± 0.79% for limbBF volume. A significant linear correlation between absolute and relative leg volume differences and the difference of exact day time of measurement between the two study visits was found (P W. Conclusions Leg volume changes can be reliably assessed by optoelectronic leg volumetry at a single time point and over a 3 weeks' time period. However, volumetry results are biased by orthostatic and daytime-related volume changes. The bias for day-time related volume changes can be minimized by a time-correction formula.

Lifestyle and metabolic approaches to maximizing erectile and vascular health.

Science.gov (United States)

Meldrum, D R; Gambone, J C; Morris, M A; Esposito, K; Giugliano, D; Ignarro, L J

2012-01-01

Oxidative stress and inflammation, which disrupt nitric oxide (NO) production directly or by causing resistance to insulin, are central determinants of vascular diseases including ED. Decreased vascular NO has been linked to abdominal obesity, smoking and high intakes of fat and sugar, which all cause oxidative stress. Men with ED have decreased vascular NO and circulating and cellular antioxidants. Oxidative stress and inflammatory markers are increased in men with ED, and all increase with age. Exercise increases vascular NO, and more frequent erections are correlated with decreased ED, both in part due to stimulation of endothelial NO production by shear stress. Exercise and weight loss increase insulin sensitivity and endothelial NO production. Potent antioxidants or high doses of weaker antioxidants increase vascular NO and improve vascular and erectile function. Antioxidants may be particularly important in men with ED who smoke, are obese or have diabetes. Omega-3 fatty acids reduce inflammatory markers, decrease cardiac death and increase endothelial NO production, and are therefore critical for men with ED who are under age 60 years, and/or have diabetes, hypertension or coronary artery disease, who are at increased risk of serious or even fatal cardiac events. Phosphodiesterase inhibitors have recently been shown to improve antioxidant status and NO production and allow more frequent and sustained penile exercise. Some angiotensin II receptor blockers decrease oxidative stress and improve vascular and erectile function and are therefore preferred choices for lowering blood pressure in men with ED. Lifestyle modifications, including physical and penile-specific exercise, weight loss, omega-3 and folic acid supplements, reduced intakes of fat and sugar, and improved antioxidant status through diet and/or supplements should be integrated into any comprehensive approach to maximizing erectile function, resulting in greater overall success and patient

Prognostic Value of Pulmonary Vascular Resistance by Magnetic Resonance in Systolic Heart Failure

Energy Technology Data Exchange (ETDEWEB)

Fabregat-Andrés, Óscar, E-mail: osfabregat@gmail.com [Departamento de Cardiologia - Hospital General Universitario de Valencia, Valencia (Spain); Fundación para la Investigación - Hospital General Universitario de Valencia, Valencia (Spain); Estornell-Erill, Jordi [Unidad de Imagen Cardiaca - ERESA - Hospital General Universitario de Valencia, Valencia (Spain); Ridocci-Soriano, Francisco [Departamento de Cardiologia - Hospital General Universitario de Valencia, Valencia (Spain); Departamento de Medicina. Universitat de Valencia, Valencia (Spain); Pérez-Boscá, José Leandro [Departamento de Cardiologia - Hospital General Universitario de Valencia, Valencia (Spain); García-González, Pilar [Unidad de Imagen Cardiaca - ERESA - Hospital General Universitario de Valencia, Valencia (Spain); Payá-Serrano, Rafael [Departamento de Cardiologia - Hospital General Universitario de Valencia, Valencia (Spain); Departamento de Medicina. Universitat de Valencia, Valencia (Spain); Morell, Salvador [Departamento de Cardiologia - Hospital General Universitario de Valencia, Valencia (Spain); Cortijo, Julio [Fundación para la Investigación - Hospital General Universitario de Valencia, Valencia (Spain); Departamento de Farmacologia. Universitat de Valencia, Valencia (Spain)

2016-03-15

Pulmonary hypertension is associated with poor prognosis in heart failure. However, non-invasive diagnosis is still challenging in clinical practice. We sought to assess the prognostic utility of non-invasive estimation of pulmonary vascular resistances (PVR) by cardiovascular magnetic resonance to predict adverse cardiovascular outcomes in heart failure with reduced ejection fraction (HFrEF). Prospective registry of patients with left ventricular ejection fraction (LVEF) < 40% and recently admitted for decompensated heart failure during three years. PVRwere calculated based on right ventricular ejection fraction and average velocity of the pulmonary artery estimated during cardiac magnetic resonance. Readmission for heart failure and all-cause mortality were considered as adverse events at follow-up. 105 patients (average LVEF 26.0 ±7.7%, ischemic etiology 43%) were included. Patients with adverse events at long-term follow-up had higher values of PVR (6.93 ± 1.9 vs. 4.6 ± 1.7estimated Wood Units (eWu), p < 0.001). In multivariate Cox regression analysis, PVR ≥ 5 eWu(cutoff value according to ROC curve) was independently associated with increased risk of adverse events at 9 months follow-up (HR2.98; 95% CI 1.12-7.88; p < 0.03). In patients with HFrEF, the presence of PVR ≥ 5.0 Wu is associated with significantly worse clinical outcome at follow-up. Non-invasive estimation of PVR by cardiac magnetic resonance might be useful for risk stratification in HFrEF, irrespective of etiology, presence of late gadolinium enhancement or LVEF.

Prognostic Value of Pulmonary Vascular Resistance by Magnetic Resonance in Systolic Heart Failure

International Nuclear Information System (INIS)

Fabregat-Andrés, Óscar; Estornell-Erill, Jordi; Ridocci-Soriano, Francisco; Pérez-Boscá, José Leandro; García-González, Pilar; Payá-Serrano, Rafael; Morell, Salvador; Cortijo, Julio

2016-01-01

Pulmonary hypertension is associated with poor prognosis in heart failure. However, non-invasive diagnosis is still challenging in clinical practice. We sought to assess the prognostic utility of non-invasive estimation of pulmonary vascular resistances (PVR) by cardiovascular magnetic resonance to predict adverse cardiovascular outcomes in heart failure with reduced ejection fraction (HFrEF). Prospective registry of patients with left ventricular ejection fraction (LVEF) < 40% and recently admitted for decompensated heart failure during three years. PVRwere calculated based on right ventricular ejection fraction and average velocity of the pulmonary artery estimated during cardiac magnetic resonance. Readmission for heart failure and all-cause mortality were considered as adverse events at follow-up. 105 patients (average LVEF 26.0 ±7.7%, ischemic etiology 43%) were included. Patients with adverse events at long-term follow-up had higher values of PVR (6.93 ± 1.9 vs. 4.6 ± 1.7estimated Wood Units (eWu), p < 0.001). In multivariate Cox regression analysis, PVR ≥ 5 eWu(cutoff value according to ROC curve) was independently associated with increased risk of adverse events at 9 months follow-up (HR2.98; 95% CI 1.12-7.88; p < 0.03). In patients with HFrEF, the presence of PVR ≥ 5.0 Wu is associated with significantly worse clinical outcome at follow-up. Non-invasive estimation of PVR by cardiac magnetic resonance might be useful for risk stratification in HFrEF, irrespective of etiology, presence of late gadolinium enhancement or LVEF

An analysis methodology for hot leg break mass and energy release

International Nuclear Information System (INIS)

Song, Jin Ho; Kwon, Young Min; Kim, Taek Mo; Chung, Hae Yong; Lee, Sang Jong

1996-07-01

An analysis methodology for the hot leg break mass and energy release is developed. For the blowdown period a modified CEFLASH-4A analysis is suggested. For the post-blowdown period a new computer model named COMET is developed. Differently from previous post-blowdown analysis model FLOOD3, COMET is capable of analyzing both cold leg and hot leg break cases. The cold leg break model is essentially same as that of FLOOD3 with some improvements. The analysis results by the newly proposed hot leg break model in the COMET is in the same trend as those observed in scaled-down integral experiment. And the analyses results for the UCN 3 and 4 by COMET are qualitatively and quantitatively in good agreement with those predicted by best-estimate analysis by using RELAP5/MOD3. Therefore, the COMET code is validated and can be used for the licensing analysis. 6 tabs., 82 figs., 9 refs. (Author)

Monocoque structure for the SKITTER three-legged walker

Science.gov (United States)

Bansek, Robert N.; Booth, Andrew J.; Daneman, Steven A.; Dresser, James A.; Haney, Todd G.; Johnson, Gregory R.; Lindzen, Eric C.; Montgomery, Robert C.; Warren, Andrew L.

1988-01-01

The SKITTER 2 design is a monocoque version of the proposed lunar three-legged walker. By the definition of monocoque, the body and legs are a shell with no internal ribbing or supports added for absorbing stresses. The purpose of the monocoque is to encase the elements used for power transmission, power supply, and control of the motion. The material for the structure is a vinyl ester resin, Derakane 8084. This material is easily formable and locally obtainable. The body consists of a hexagonally shaped cylinder with truncated hexagonal pyramids on the top and botton. The legs are eight inch diameter cylinders. The legs are comprised of a tibia section and a femur section. The SKITTER 2 is powered by six actuators which provide linear forces that are transformed into rotary torques by a series of chains and sprockets. The joints connect the femur to the body and the tibia to the femur. Surrounding the joints are flexible rubber hoses that fully encase the chains and sprockets. The SKITTER 2 is capable of walking upside down, righting itself after being overturned, and has the ability to perform in many environments. Applications for this walker include lunar transport or drilling, undersea exploration, and operation in severe surroundings such as arctic temperatures or high radiation.

The role of microRNAs on angiogenesis and vascular pressure in ...

African Journals Online (AJOL)

Harapan Harapan

2015-04-28

Apr 28, 2015 ... parts as miRNAs have diverse effects on preeclampsia patho- ..... sFlt-1: soluble Fms-like tyrosine kinase-1, TGF-b: transforming growth factor beta, VEGF: vascular endothelial growth .... lower VEGF level, and greater insulin resistance than ... expression of IL-6 and indoleamine 2,3-dioxygenase (IDO).

Effects of hypothyroidism on vascular /sup 125/I-albumin permeation and blood flow in rats

Energy Technology Data Exchange (ETDEWEB)

Tilton, R.G.; Pugliese, G.; Chang, K.; Speedy, A.; Province, M.A.; Kilo, C.; Williamson, J.R.

1989-05-01

Effects of hypothyroidism on vascular 125I-albumin permeation and on blood flow were assessed in multiple tissues of male Sprague-Dawley rats rendered hypothyroid by dietary supplementation with 0.5% (wt/wt) 2-thiouracil or by thyroidectomy. In both thiouracil-treated and thyroidectomized rats, body weights, kidney weight, arterial blood pressure, and pulse rate were decreased significantly v age-matched controls. After 10 to 12 weeks of thiouracil treatment, 125I-albumin permeation was increased significantly in the kidney, aorta, eye (anterior uvea, choroid, retina), skin, and new granulation tissue, remained unchanged in brain, sciatic nerve, and heart, and was decreased in forelimb skeletal muscle. A similar pattern was observed in thyroidectomized rats, except that increases in 125I-albumin permeation for all tissues were smaller than those observed in thiouracil-treated rats, and 125I-albumin permeation in retina did not differ from controls. In both thiouracil-treated and thyroidectomized rats, changes in blood flow (assessed with 15-microns, 85Sr-labeled microspheres) relative to the decrease in arterial blood pressure were indicative of a decrease in regional vascular resistance except in the choroid and in the kidney, in which vascular resistance was increased significantly. Glomerular filtration rate was decreased, but filtration fraction and urinary excretion of albumin remained unchanged by thiouracil treatment and thyroidectomy. These results indicate that vascular hemodynamics and endothelial cell barrier functional integrity are modulated in many different tissues by the thyroid. In view of the correspondence of hypothyroid- and diabetes-induced vascular permeability changes, these results raise the possibility that altered thyroid function in diabetes may play a role in the pathogenesis of diabetic vascular disease.

PWR hot leg natural circulation modeling with MELCOR code

Energy Technology Data Exchange (ETDEWEB)

Park, Jae Hong; Lee, Jong In [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of)

1998-12-31

Previous MELCOR and SCDAP/RELAP5 nodalizations for simulating the counter-current, natural circulation behavior of vapor flow within the RCS hot legs and SG U-tubes when core damage progress can not be applied to the steady state and water-filled conditions during the initial period of accident progression because of the artificially high loss coefficients in the hot legs and SG U-tubes which were chosen from results of COMMIX calculation and the Westinghouse natural circulation experiments in a 1/7-scale facility for simulating steam natural circulation behavior in the vessel and circulation modeling which can be used both for the liquid flow condition at steady state and for the vapor flow condition at the later period of in-vessel core damage. For this, the drag forces resulting from the momentum exchange effects between the two vapor streams in the hot leg was modeled as a pressure drop by pump model. This hot leg natural circulation modeling of MELCOR was able to reproduce similar mass flow rates with those predicted by previous models. 6 refs., 2 figs. (Author)

PWR hot leg natural circulation modeling with MELCOR code

Energy Technology Data Exchange (ETDEWEB)

Park, Jae Hong; Lee, Jong In [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of)

1997-12-31

Previous MELCOR and SCDAP/RELAP5 nodalizations for simulating the counter-current, natural circulation behavior of vapor flow within the RCS hot legs and SG U-tubes when core damage progress can not be applied to the steady state and water-filled conditions during the initial period of accident progression because of the artificially high loss coefficients in the hot legs and SG U-tubes which were chosen from results of COMMIX calculation and the Westinghouse natural circulation experiments in a 1/7-scale facility for simulating steam natural circulation behavior in the vessel and circulation modeling which can be used both for the liquid flow condition at steady state and for the vapor flow condition at the later period of in-vessel core damage. For this, the drag forces resulting from the momentum exchange effects between the two vapor streams in the hot leg was modeled as a pressure drop by pump model. This hot leg natural circulation modeling of MELCOR was able to reproduce similar mass flow rates with those predicted by previous models. 6 refs., 2 figs. (Author)

Dynamically Stable Legged Locomotion.

Science.gov (United States)

1983-01-27

digitai~y thro)ugh a ribbon cable. lhe dcsign effort required to mount power sources and computing u(m board would hive distracted us fiorn our main...angular momentum. "The model used in this paper, shown in Fig. 6-1, has 3 single springy leg that articular •s ,ith respect to a body about a simple hince

Postural control of typical developing boys during the transition from double-leg stance to single-leg stance.

Science.gov (United States)

Deschamps, Kevin; Staes, Filip; Peerlinck, Kathelijne; Van Geet, Kristel; Hermans, Cedric; Lobet, Sebastien

2017-02-01

Literature is lacking information about postural control performance of typically developing children during a transition task from double-leg stance to single-leg stance. The purpose of the present study was therefore to evaluate the clinical feasibility of a transition task in typical developing age groups as well as to study the correlation between associated balance measures and age.Thirty-three typically developing boys aged 6-20 years performed a standard transition task from DLS to SLS with eyes open (EO) and eyes closed (EC). Balance features derived from the center of pressure displacement captured by a single force platform were correlated with age on the one hand and considered for differences in the perspective of limb dominance on the other hand.All TDB (typically developing boys) were able to perform the transition task with EO. With respect to EC condition, all TDB from the age group 6-7 years and the youngest of the age group 8-12 years (N = 4) were unable to perform the task. No significant differences were observed between the balance measures of the dominant and non-dominant limbs.With respect to EO condition, correlation analyses indicated that time to new stability point (TNSP) as well as the sway measure after this TNSP were correlated with age (p postural balance of typically developing children during walking, running, sit-to-stand, and bipodal and unipodal stance has been well documented in the literature. • These reference data provided not only insight into the maturation process of the postural control system, but also served in diagnosing and managing functional repercussions of neurological and orthopedic pathologies. What is New: • Objective data regarding postural balance of typical developing children during a transition task from double-leg stance to single-leg stance. • Insight into the role of maturation on the postural control system.

Fatal pox infection in a rough-legged hawk

Science.gov (United States)

Pearson, G.L.; Pass, D.A.; Beggs, E.C.

1975-01-01

Natural pox infection occurred in a free-living rough-legged hawk (Buteo lagopus) in northeastern North Dakota. Gross, histological and electron microscopic findings were typical of pox infection, and characteristic lesions developed in red-tailed hawks (Buteo jamaicensis) but not in great horned owls (Bubo virginianus) following inoculation with case material. Death of the rough-legged hawk was attributed to starvation resulting from inability to capture prey and to blood loss from foot lesions.

In vitro and ex vivo hemocompatibility of off-the-shelf modified poly(vinyl alcohol) vascular grafts

OpenAIRE

Cutiongco, Marie Francene A.; Anderson, Deirdre E. J.; Hinds, Monica T.; Yim, Evelyn K. F.

2015-01-01

Synthetic small diameter vascular grafts with mechanical properties of native arteries, resistance to thrombosis and capacity to stimulate in situ endothelialization are an unmet clinical need. Poly(vinyl alcohol) hydrogel (PVA) is an excellent candidate as a vascular graft due to its tunable mechanical properties. However, the hydrophilicity and bio-inertness of PVA prevents endothelialization in vivo. We hypothesize that the modification of PVA with biomolecules and topographies creates a h...

The Interday Measurement Consistency of and Relationships Between Hamstring and Leg Musculo-articular Stiffness.

Science.gov (United States)

Waxman, Justin P; Schmitz, Randy J; Shultz, Sandra J

2015-10-01

Hamstring stiffness (K(HAM)) and leg stiffness (K(LEG)) are commonly examined relative to athletic performance and injury risk. Given these may be modifiable, it is important to understand day-to-day variations inherent in these measures before use in training studies. In addition, the extent to which K(HAM) and K(LEG) measure similar active stiffness characteristics has not been established. We investigated the interday measurement consistency of K(HAM) and K(LEG), and examined the extent to which K(LEG) predicted K(HAM) in 6 males and 9 females. K(HAM) was moderately consistent day-to-day (ICC(2,5) = .71; SEM = 76.3 N·m(-1)), and 95% limits of agreement (95% LOA) revealed a systematic bias with considerable absolute measurement error (95% LOA = 89.6 ± 224.8 N·m(-1)). Day-to-day differences in procedural factors explained 59.4% of the variance in day-to-day differences in K(HAM). Bilateral and unilateral K(LEG) was more consistent (ICC(2,3) range = .87-.94; SEM range = 1.0-2.91 kN·m(-1)) with lower absolute error (95% LOA bilateral= -2.0 ± 10.3; left leg = -0.36 ± 3.82; right leg = -1.05 ± 3.61 kN·m(-1)). K(LEG) explained 44% of the variance in K(HAM) (P consistent and precise K(HAM) measures. The ease and consistency of K(LEG), and moderate correlation with K(HAM), may steer clinicians toward K(LEG) when measuring lower-extremity stiffness for screening studies and monitoring the effectiveness of training interventions over time.

Military boot attenuates axial loading to the lower leg.

Science.gov (United States)

Yoganandan, Narayan; Schlick, Michael; Arun, Mike W J; Pintar, Frank A

2014-01-01

Biomechanical tests to understand injury mechanisms and derive injury tolerance information using Post-Mortem Human Subjects (PMHS) have not used foot protection and they have primarily focused on civilian environments such as automotive and athletic- and sports-related events. As military personnel use boots, tests with the boot are required to understand their effect on attenuating lower leg loads. The purpose of this study was therefore, to determine the modulation of human lower leg kinematics with boot compressions and share of the force absorbed by the boot from underbody blast loading. Axial impacts were delivered to the Hybrid III dummy lower leg in the neutral position. The dummy leg was instrumented with its internal upper and lower tibia load cells, and in addition, a knee load cell was attached to the proximal end. Tests were conducted at 4.4 to 8.9 m/s, with and without boots, and repeat tests were done. Morphologies of the force-time responses were similar at the three load cell locations and for all input combinations and booted and unbooted conditions. However, booted tests resulted in considerably lower maximum forces (approximately two-third reduction) than unbooted tests. These results clearly show that boots can absorb a considerable share of the impact energy and decrease impact loads transmitted to the lower leg under vertical loading, thus necessitating the generation of tolerance data using PMHS for this environment.

Dynamic Leg Exercise Improves Tolerance to Lower Body Negative Pressure

Science.gov (United States)

Watenpaugh, D. E.; Ballard, R. E.; Stout, M. S.; Murthy, G.; Whalen, R. T.; Hargens, A. R.

1994-01-01

These results clearly demonstrate that dynamic leg exercise against the footward force produced by LBNP substantially improves tolerance to LBNP, and that even cyclic ankle flexion without load bearing also increases tolerance. This exercise-induced increase of tolerance was actually an underestimate, because subjects who completed the tolerance test while exercising could have continued for longer periods. Exercise probably increases LBNP tolerance by multiple mechanisms. Tolerance was increased in part by skeletal muscle pumping venous blood from the legs. Rosenhamer and Linnarsson and Rosenhamer also deduced this for subjects cycling during centrifugation, although no measurements of leg volume were made in those studies: they found that male subjects cycling at 98 W could endure 3 Gz centrifugation longer than when they remained relaxed during centrifugation. Skeletal muscle pumping helps maintain cardiac filling pressure by opposing gravity-, centrifugation-, or LBNP-induced accumulation of blood and extravascular fluid in the legs.

Resistance Training in Type 2 Diabetic Patients Improves Uric Acid Levels

Directory of Open Access Journals (Sweden)

R. Sousa Moisés S.S.

2014-12-01

Full Text Available Resistance training (RT can provide several benefits for individuals with Type 2 diabetes. The aim of this study was to investigate the effects of resistance training on the strength levels and uric acid (UA concentration in individuals with Type 2 diabetes. The study included 68 patients (57.7±9.0 years that participated in an organized program of RT for 12 weeks. The volunteers were divided into two groups: an experimental group (EG; n=34 that performed the resistance training program consisting of seven exercises executed in an alternating order based on segments; and a control group (CG; n=34 that maintained their normal daily life activities. Muscle strength and uric acid were measured both pre- and post-experiment. The results showed a significant increase in strength of the subjects in the EG for all exercises included in the study (p<0.001. Comparing the strength levels of the post-test, intergroup differences were found in supine sitting (p<0.001, leg extension (p<0.001, shoulder press (p<0.001, leg curl (p=0.001, seated row (p<0.001, leg press (p=0.001 and high pulley (p<0.001. The measured uric acid was significantly increased in both experimental and control groups (p<0.001 and p=0.001, respectively. The intergroup comparison showed a significant increase for the EG (p=0.024. We conclude that the training program was effective for strength gains despite an increase in uric acid in Type 2 diabetics.

Experimental research on pedestrian lower leg impact

Science.gov (United States)

Constantin, B. A.; Iozsa, D. M.; Stan, C.

2017-10-01

The present paper is centred on the research of deceleration measured at the level of the lower leg during a pedestrian impact in multiple load cases. Basically, the used methodology for physical test setup is similar to EuroNCAP and European Union regulatory requirements. Due cost reduction reasons, it was not used a pneumatic system in order to launch the lower leg impactor in the direction of the vehicle front-end. During the test it was used an opposite solution, namely the vehicle being in motion, aiming the standstill lower leg impactor. The impactor has similar specifications to those at EU level, i.e. dimensions, materials, and principle of measurement of the deceleration magnitude. Therefore, all the results obtained during the study comply with the requirements of both EU regulation and EuroNCAP. As a limitation, due to unavailability of proper sensors in the equipment of the lower leg impactor, that could provide precise results, the bending angle, the shearing and the detailed data at the level of knee ligaments were not evaluated. The knee joint should be improved for future studies as some bending angles observed during the post processing of several impact video files were too high comparing to other studies. The paper highlights the first pedestrian impact physical test conducted by the author, following an extensive research in the field. Deceleration at the level of pedestrian knee can be substantially improved by providing enough volume between the bumper fascia and the front-end structure and by using pedestrian friendly materials for shock absorbers, such as foams.

Toward Balance Recovery With Leg Prostheses Using Neuromuscular Model Control

Science.gov (United States)

Geyer, Hartmut

2016-01-01

Objective Lower limb amputees are at high risk of falling as current prosthetic legs provide only limited functionality for recovering balance after unexpected disturbances. For instance, the most established control method used on powered leg prostheses tracks local joint impedance functions without taking the global function of the leg in balance recovery into account. Here we explore an alternative control policy for powered transfemoral prostheses that considers the global leg function and is based on a neuromuscular model of human locomotion. Methods We adapt this model to describe and simulate an amputee walking with a powered prosthesis using the proposed control, and evaluate the gait robustness when confronted with rough ground and swing leg disturbances. We then implement and partially evaluate the resulting controller on a leg prosthesis prototype worn by a non-amputee user. Results In simulation, the proposed prosthesis control leads to gaits that are more robust than those obtained by the impedance control method. The initial hardware experiments with the prosthesis prototype show that the proposed control reproduces normal walking patterns qualitatively and effectively responds to disturbances in early and late swing. However, the response to mid-swing disturbances neither replicates human responses nor averts falls. Conclusions The neuromuscular model control is a promising alternative to existing prosthesis controls, although further research will need to improve on the initial implementation and determine how well these results transfer to amputee gait. Significance This work provides a potential avenue for future development of control policies that help improve amputee balance recovery. PMID:26315935

Differences in kinematics of single leg squatting between anterior cruciate ligament-injured patients and healthy controls.

Science.gov (United States)

Yamazaki, J; Muneta, T; Ju, Y J; Sekiya, I

2010-01-01

Seventy to eighty percent of all anterior cruciate ligament (ACL) injuries are due to non-contact injury mechanisms. It has been reported that the majority of injuries due to single leg landing come from valgus positioning of the lower leg. Preventing valgus positioning during single leg landing is expected to help reduce the number of ACL injuries. We found that many ACL-deficient patients cannot perform stable single leg squatting. Therefore, we performed 3D motion analysis of the single-legged half squat for ACL-injured patients to evaluate its significance as a risk factor for ACL injuries. We evaluated the relative angles between the body, thigh, and lower leg using an electromagnetic device during single leg half squatting performed by 63 ACL-injured patients (32 males, 31 females) the day before ACL reconstruction and by 26 healthy control subjects with no knee problems. The uninjured leg of ACL-injured male subjects demonstrated significantly less external knee rotation than that of the dominant leg of the male control. The uninjured leg of ACL-injured female subjects demonstrated significantly more external hip rotation and knee flexion and less hip flexion than that of the dominant leg of the female control. Comparing injured and uninjured legs, the injured leg of male subjects demonstrated significantly less external knee and hip rotation, less knee flexion, and more knee varus than that of the uninjured leg of male subjects. The injured leg of female subjects demonstrated more knee varus than that of the uninjured leg of female subjects. Regarding gender differences, female subjects demonstrated significantly more external hip rotation and knee valgus than male subjects did in both the injured and uninjured legs (P < 0.05). The current kinematic study exhibited biomechanical characteristics of female ACL-injured subjects compared with that of control groups. Kinematic correction during single leg half squat would reduce ACL reinjury in female ACL

Operation analysis of a Chebyshev-Pantograph leg mechanism for a single DOF biped robot

Science.gov (United States)

Liang, Conghui; Ceccarelli, Marco; Takeda, Yukio

2012-12-01

In this paper, operation analysis of a Chebyshev-Pantograph leg mechanism is presented for a single degree of freedom (DOF) biped robot. The proposed leg mechanism is composed of a Chebyshev four-bar linkage and a pantograph mechanism. In contrast to general fully actuated anthropomorphic leg mechanisms, the proposed leg mechanism has peculiar features like compactness, low-cost, and easy-operation. Kinematic equations of the proposed leg mechanism are formulated for a computer oriented simulation. Simulation results show the operation performance of the proposed leg mechanism with suitable characteristics. A parametric study has been carried out to evaluate the operation performance as function of design parameters. A prototype of a single DOF biped robot equipped with two proposed leg mechanisms has been built at LARM (Laboratory of Robotics and Mechatronics). Experimental test shows practical feasible walking ability of the prototype, as well as drawbacks are discussed for the mechanical design.

Superconductivity in doped two-leg ladder cuprates

International Nuclear Information System (INIS)

Qin Jihong; Yuan Feng; Feng Shiping

2006-01-01

Within the t-J ladder model, superconductivity with a modified d-wave symmetry in doped two-leg ladder cuprates is investigated based on the kinetic energy driven superconducting mechanism. It is shown that the spin-liquid ground-state at the half-filling evolves into the superconducting ground-state upon doping. In analogy to the doping dependence of the superconducting transition temperature in the planar cuprate superconductors, the superconducting transition temperature in doped two-leg ladder cuprates increases with increasing doping in the underdoped regime, and reaches a maximum in the optimal doping, then decreases in the overdoped regime

Two-legged walking robot prescribed motion on a rough cylinder

Science.gov (United States)

Golubev, Yury; Melkumova, Elena

2018-05-01

The motion of a walking robot with n legs, that ensure the desired motion of the robot body, is described using general dynamics theoretical framework. When each of the robot legs contacts the surface in a single foothold, the momentum and angular momentum theorems yield a system of six differential equations that form a complete description of the robot motion. In the case of two-leg robot (n = 2) the problem of the existence of the solution can be reduced to a system of algebraic inequalities. Using numerical analysis, the classification of footholds positions for different values of the friction coefficient is obtained.

STRUCTURE OF PROMINENCE LEGS: PLASMA AND MAGNETIC FIELD

Energy Technology Data Exchange (ETDEWEB)

Levens, P. J.; Labrosse, N. [SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ (United Kingdom); Schmieder, B. [Observatoire de Paris, Meudon, F-92195 (France); Ariste, A. López, E-mail: p.levens.1@research.gla.ac.uk [Institut de Recherche en Astrophysique et Planétologie, Toulouse (France)

2016-02-10

We investigate the properties of a “solar tornado” observed on 2014 July 15, and aim to link the behavior of the plasma to the internal magnetic field structure of the associated prominence. We made multi-wavelength observations with high spatial resolution and high cadence using SDO/AIA, the Interface Region Imaging Spectrograph (IRIS) spectrograph, and the Hinode/Solar Optical Telescope (SOT) instrument. Along with spectropolarimetry provided by the Télescope Héliographique pour l’Etude du Magnétisme et des Instabilités Solaires telescope we have coverage of both optically thick emission lines and magnetic field information. AIA reveals that the two legs of the prominence are strongly absorbing structures which look like they are rotating, or oscillating in the plane of the sky. The two prominence legs, which are both very bright in Ca ii (SOT), are not visible in the IRIS Mg ii slit-jaw images. This is explained by the large optical thickness of the structures in Mg ii, which leads to reversed profiles, and hence to lower integrated intensities at these locations than in the surroundings. Using lines formed at temperatures lower than 1 MK, we measure relatively low Doppler shifts on the order of ±10 km s{sup −1} in the tornado-like structure. Between the two legs we see loops in Mg ii, with material flowing from one leg to the other, as well as counterstreaming. It is difficult to interpret our data as showing two rotating, vertical structures that are unrelated to the loops. This kind of “tornado” scenario does not fit with our observations. The magnetic field in the two legs of the prominence is found to be preferentially horizontal.

RSRM Nozzle-to-Case Joint J-leg Development

Science.gov (United States)

Albrechtsen, Kevin U.; Eddy, Norman F.; Ewing, Mark E.; McGuire, John R.

2003-01-01

Since the beginning of the Space Shuttle Reusable Solid Rocket Motor (RSRM) program, nozzle-to-case joint polysulfide adhesive gas paths have occurred on several flight motors. These gas paths have allowed hot motor gases to reach the wiper O-ring. Even though these motors continue to fly safely with this condition, a desire was to reduce such occurrences. The RSRM currently uses a J-leg joint configuration on case field joints and igniter inner and outer joints. The J-leg joint configuration has been successfully demonstrated on numerous RSRM flight and static test motors, eliminating hot gas intrusion to the critical O-ring seals on these joints. Using the proven technology demonstrated on the case field joints and igniter joints, a nozzle-to-case joint J-leg design was developed for implementation on RSRM flight motors. This configuration provides an interference fit with nozzle fixed housing phenolics at assembly, with a series of pressurization gaps incorporated outboard of the joint mating surface to aid in joint pressurization and to eliminate any circumferential flow in this region. The joint insulation is bonded to the nozzle phenolics using the same pressure sensitive adhesive used in the case field joints and igniter joints. An enhancement to the nozzle-to-case joint J-leg configuration is the implementation of a carbon rope thermal barrier. The thermal barrier is located downstream of the joint bondline and is positioned within the joint in a manner where any hot gas intrusion into the joint passes through the thermal barrier, reducing gas temperatures to a level that would not affect O-rings downstream of the thermal barrier. This paper discusses the processes used in reaching a final nozzle-to-case joint J-leg design, provides structural and thermal results in support of the design, and identifies fabrication techniques and demonstrations used in arriving at the final configuration.

Restless Legs Syndrome in a Nigerian Elderly Population

Science.gov (United States)

Fawale, Michael B.; Ismaila, Isiaka Alani; Mustapha, Adekunle F.; Komolafe, Morenikeji A.; Adedeji, Tewogbade A.

2016-01-01

Study Objectives: The prevalence of restless legs syndrome (RLS) is highest in the elderly in Caucasian populations; the prevalence of RLS in elderly Africans is not known. This study aimed at determining the frequency and associations of RLS in a Nigerian elderly population. Methods: The study population comprised of 633 consecutive elderly individuals aged 65–105 years attending the general outpatient clinic of the State Hospital, Ilesa, for minor complaints and routine check-up. The diagnosis of RLS was made using the 2003 minimal criteria of the International Restless Legs Syndrome Study Group. Relevant sociodemographic and clinical data, including sleep duration, were also obtained. Results: Restless legs syndrome was found in 3.5% of the study population with a male-female ratio of 2:1. There was no significant age (p = 0.427) or gender (p = 0.178) influence on the prevalence of RLS except in the 75- to 84-year age group where there was significant male preponderance (p = 0.044). A strong independent association between RLS and sleep duration (OR, 3.229; 95% CI, 1.283–8.486; p = 0.013) and past history of head injury (OR, 4.691; 95% CI, 1.750–12.577; p = 0.002) was found. Conclusions: Our finding support previous reports of a possible lower prevalence of RLS in Africans. Restless legs syndrome independently increases the odds of habitual sleep curtailment in elderly individuals. Head injury may be a risk factor for future RLS; this requires further investigation as indirect evidence for a possible link between RLS and traumatic brain injury exists. Citation: Fawale MB, Ismaila IA, Mustapha AF, Komolafe MA, Adedeji TA. Restless legs syndrome in a Nigerian elderly population. J Clin Sleep Med 2016;12(7):965–972. PMID:27070251

Bioinspired legged-robot based on large deformation of flexible skeleton

International Nuclear Information System (INIS)

Mayyas, Mohammad

2014-01-01

In this article we present STARbot, a bioinspired legged robot capable of multiple locomotion modalities by using large deformation of its skeleton. We construct STARbot by using origami-style folding of flexible laminates. The long-term goal is to provide a robotic platform with maximum mobility on multiple surfaces. This paper particularly studies the quasistatic model of STARbot’s leg under different conditions. We describe the large elastic deformation of a leg under external force, payload, and friction by using a set of non-dimensional, nonlinear approximate equations. We developed a test mechanism that models the motion of a leg in STARbot. We augmented several foot shapes and then tested them on soft to rough grounds. Both simulation and experimental findings were in good agreement. We utilized the model to develop several scales of tri and quad STARbot. We demonstrated the capability of these robots to locomote by combining their leg deformations with their foot motions. The combination provided a design platform for an active suspension STARbot with controlled foot locomotion. This included the ability of STARbot to change size, run over obstacles, walk and slide. Furthermore, in this paper we discuss a cost effective manufacturing and production method for manufacturing STARbot. (paper)

Bioinspired legged-robot based on large deformation of flexible skeleton.

Science.gov (United States)

Mayyas, Mohammad

2014-11-11

In this article we present STARbot, a bioinspired legged robot capable of multiple locomotion modalities by using large deformation of its skeleton. We construct STARbot by using origami-style folding of flexible laminates. The long-term goal is to provide a robotic platform with maximum mobility on multiple surfaces. This paper particularly studies the quasistatic model of STARbot's leg under different conditions. We describe the large elastic deformation of a leg under external force, payload, and friction by using a set of non-dimensional, nonlinear approximate equations. We developed a test mechanism that models the motion of a leg in STARbot. We augmented several foot shapes and then tested them on soft to rough grounds. Both simulation and experimental findings were in good agreement. We utilized the model to develop several scales of tri and quad STARbot. We demonstrated the capability of these robots to locomote by combining their leg deformations with their foot motions. The combination provided a design platform for an active suspension STARbot with controlled foot locomotion. This included the ability of STARbot to change size, run over obstacles, walk and slide. Furthermore, in this paper we discuss a cost effective manufacturing and production method for manufacturing STARbot.

Impaired vascular function in physically active premenopausal women with functional hypothalamic amenorrhea is associated with low shear stress and increased vascular tone.

Science.gov (United States)

O'Donnell, Emma; Goodman, Jack M; Mak, Susanna; Harvey, Paula J

2014-05-01

Exercise-trained hypoestrogenic premenopausal women with functional hypothalamic amenorrhea (ExFHA) exhibit impaired endothelial function. The vascular effects of an acute bout of exercise, a potent nitric oxide stimulus, in these women are unknown. Three groups were studied: recreationally active ExFHA women (n = 12; 24.2 ± 1.2 years of age; mean ± SEM), and recreationally active (ExOv; n = 14; 23.5 ± 1.2 years of age) and sedentary (SedOv; n = 15; 23.1 ± 0.5 years of age) ovulatory eumenorrheic women. Calf blood flow (CBF) and brachial artery flow-mediated dilation (FMD) were evaluated using plethysmographic and ultrasound techniques, respectively, both before and 1 hour after 45 minutes of moderate-intensity exercise. Endothelium-independent dilation was assessed at baseline using glyceryl trinitrate. Calf vascular resistance (CVR) and brachial peak shear rate, as determined by the area under the curve (SRAUCpk), were also calculated. FMD and glyceryl trinitrate responses were lower (P .05) the findings. CBF was lower (P .05) between the groups. CBF in ExFHA was increased (P < .05) and CVR decreased (P < .05) to levels observed in ovulatory women. Acute dynamic exercise improves vascular function in ExFHA women. Although the role of estrogen deficiency per se is unclear, our findings suggest that low shear rate and increased vasoconstrictor tone may play a role in impaired basal vascular function in these women.

Surface modification and endothelialization of biomaterials as potential scaffolds for vascular tissue engineering applications.

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Ren, Xiangkui; Feng, Yakai; Guo, Jintang; Wang, Haixia; Li, Qian; Yang, Jing; Hao, Xuefang; Lv, Juan; Ma, Nan; Li, Wenzhong

2015-08-07

Surface modification and endothelialization of vascular biomaterials are common approaches that are used to both resist the nonspecific adhesion of proteins and improve the hemocompatibility and long-term patency of artificial vascular grafts. Surface modification of vascular grafts using hydrophilic poly(ethylene glycol), zwitterionic polymers, heparin or other bioactive molecules can efficiently enhance hemocompatibility, and consequently prevent thrombosis on artificial vascular grafts. However, these modified surfaces may be excessively hydrophilic, which limits initial vascular endothelial cell adhesion and formation of a confluent endothelial lining. Therefore, the improvement of endothelialization on these grafts by chemical modification with specific peptides and genes is now arousing more and more interest. Several active peptides, such as RGD, CAG, REDV and YIGSR, can be specifically recognized by endothelial cells. Consequently, graft surfaces that are modified by these peptides can exhibit targeting selectivity for the adhesion of endothelial cells, and genes can be delivered by targeting carriers to specific tissues to enhance the promotion and regeneration of blood vessels. These methods could effectively accelerate selective endothelial cell recruitment and functional endothelialization. In this review, recent developments in the surface modification and endothelialization of biomaterials in vascular tissue engineering are summarized. Both gene engineering and targeting ligand immobilization are promising methods to improve the clinical outcome of artificial vascular grafts.

[Experimental study of angiography using vascular interventional robot-2(VIR-2)].

Science.gov (United States)

Tian, Zeng-min; Lu, Wang-sheng; Liu, Da; Wang, Da-ming; Guo, Shu-xiang; Xu, Wu-yi; Jia, Bo; Zhao, De-peng; Liu, Bo; Gao, Bao-feng

2012-06-01

To verify the feasibility and safety of new vascular interventional robot system used in vascular interventional procedures. Vascular interventional robot type-2 (VIR-2) included master-slave parts of body propulsion system, image navigation systems and force feedback system, the catheter movement could achieve under automatic control and navigation, force feedback was integrated real-time, followed by in vitro pre-test in vascular model and cerebral angiography in dog. Surgeon controlled vascular interventional robot remotely, the catheter was inserted into the intended target, the catheter positioning error and the operation time would be evaluated. In vitro pre-test and animal experiment went well; the catheter can enter any branch of vascular. Catheter positioning error was less than 1 mm. The angiography operation in animal was carried out smoothly without complication; the success rate of the operation was 100% and the entire experiment took 26 and 30 minutes, efficiency was slightly improved compared with the VIR-1, and the time what staff exposed to the DSA machine was 0 minute. The resistance of force sensor can be displayed to the operator to provide a security guarantee for the operation. No surgical complications. VIR-2 is safe and feasible, and can achieve the catheter remote operation and angiography; the master-slave system meets the characteristics of traditional procedure. The three-dimensional image can guide the operation more smoothly; force feedback device provides remote real-time haptic information to provide security for the operation.

Quality of Life in People with Leg Ulcer, Integrative Review

Directory of Open Access Journals (Sweden)

Daniela Alves

2016-04-01

Full Text Available Objective: To identify the main changes in the daily life of people with leg ulcer and how that affects the person’s quality of life. Methodology: We used the methodology PI [C] OD and selected four research articles, taken from EBSCO, PubMed, and EWMA. Results: The main changes identified in the people’s daily live with leg ulcers are physical (pain, decreased mobility, presence of exudate, bad smell from the wound and change in the style of clothing, psychological (sleep disorders, depression, anxiety, feelings of rejection and low self-steem, social (isolation, restriction in leisure activities, inability to perform household chores. Conclusions: The literature about the person’s quality of life with leg ulcer reported a significant impact in the daily life. The care provided by nurses should be centered on the person, integrating all the kind of needs and the leg ulcer must not be the sole focus of care

Intrauterine nutrition: long-term consequences for vascular health

Directory of Open Access Journals (Sweden)

Szostak-Wegierek D

2014-07-01

Full Text Available Dorota Szostak-WegierekDepartment of Human Nutrition, Medical University of Warsaw, Warsaw, Poland Abstract: There is a growing body of evidence that improper intrauterine nutrition may negatively influence vascular health in later life. Maternal malnutrition may result in intrauterine growth retardation and, in turn, metabolic disorders such as insulin resistance, diabetes, hypertension, and dyslipidemia, and also enhanced risk of atherosclerosis and cardiovascular death in the offspring. Energy and/or protein restriction is the most critical determinant for fetal programming. However, it has also been proposed that intrauterine n-3 fatty acid deficiency may be linked to later higher blood pressure levels and reduced insulin sensitivity. Moreover, it has been shown that inadequate supply of micronutrients such as folate, vitamin B12, vitamin A, iron, magnesium, zinc, and calcium may contribute to impaired vascular health in the progeny. In addition, hypertensive disorders of pregnancy that are linked to impaired placental blood flow and suboptimal fetal nutrition may also contribute to intrauterine growth retardation and aggravated cardiovascular risk in the offspring. On the other hand, maternal overnutrition, which often contributes to obesity and/or diabetes, may result in macrosomia and enhanced cardiometabolic risk in the offspring. Progeny of obese and/or diabetic mothers are relatively more prone to develop obesity, insulin resistance, diabetes, and hypertension. It was demonstrated that they may have permanently enhanced appetites. Their atheromatous lesions are usually more pronounced. It seems that, particularly, a maternal high-fat/junk food diet may be detrimental for vascular health in the offspring. Fetal exposure to excessive levels of saturated fatty and/or n-6 fatty acids, sucrose, fructose and salt, as well as a maternal high glycemic index diet, may also contribute to later enhanced cardiometabolic risk. Keywords: maternal

Leg stiffness during phases of countermovement and take-off in vertical jump.

Science.gov (United States)

Struzik, Artur; Zawadzki, Jerzy

2013-01-01

With respect to cyclic movements such as human gait, running or hopping, leg stiffness is a little variable parameter. The aim of this study was to investigate changes in leg stiffness during the phase of countermovement and take-off when performing a single maximum counter-movement jump. Kistler force plates and a BTS SMART system for comprehensive motion analysis were employed in the study. The study covered a group of 12 athletes from university basketball teams. Leg stiffness was calculated in those parts of countermovement and take-off phases where its level is relatively constant and the relationship F(Δl) is similar to linear one. Mean total stiffness (±SD) in both legs in the countermovement phase amounted to 6.5 ± 1.5 kN/m, whereas during the take-off phase this value was 6.9 ± 1 kN/m. No statistically significant differences were found between leg stiffness during the countermovement phase and takeoff phase in the study group at the level of significance set at α = 0.05. This suggests that the leg stiffness in phase of countermovement and phase of take-off are much similar to each other, despite different function of both phases. Similar to cyclic movements, leg stiffness turned out relatively constant when performing a single vertical jump. There are also reported statistically significant correlations between body mass, body height, length of lower limbs and leg stiffness. The stiffness analysed by the authors should be understood as quasi-stiffness because the measurements of ΔF(Δl) were made during transient states where inertia and dumping forces are likely to affect the final result.

Diffuse vascular damage in a transplanted kidney: an indication for nuclear magnetic resonance?

Science.gov (United States)

Burdese, M; Consiglio, V; Mezza, E; Savio, D; Guarena, C; Rossetti, M; Messina, M; Soragna, G; Suriani, C; Rabbia, C; Segoloni, G P; Piccoli, G B

2005-06-01

Vascular lesions are an increasing challenge after renal transplantation due to the wider indications for recipients and acceptance criteria for donors. Diagnostic approach and prognostic interpretation are still matter of controversy. The case reported herein may summarize some of the issues in this regard. A 54-year-old woman, on renal replacement therapy since 1974, and a kidney graft recipient from 1975 to 1999, received a second graft in 2001. The donor age was 65 years (cold ischemia 22 hours; two mismatches). The early posttransplant follow-up was characterized by delayed graft function, hypertension, and diabetes. During the initial hypertension workup, renal graft ultrasound (US) Doppler demonstrated increased vascular resistances, stable over time (resistance index 0.74 to 0.77); renal scintiscan displayed homogeneously parenchymoa and angio-magnetic resonance imaging (MRI), an homogeneous parenchymal vascularization. Initial immunosuppression with tacrolimus and steroids was modulated by adding mycophenolate mofetil to taper tacrolimus (to reduce nephrotoxicity and hypertension). Despite this, kidney function slowly deteriorated; serum creatinine reached 3 to 3.5 mg/dL by the second year. After a severe hypertensive crisis with unchanged scintiscan and US doppler examinations, angio-MRI revealed the almost complete disappearance of parenchymal enhancement beyond the lobar arteries. A renal biopsy confirmed the severe vascular damage. The patient was switched to rapamycine and a low-dose of an angiotension converting enzyme (ACE) inhibitor. She did relatively well (serum creatinine 2.2 to 3 mg/dL) for 6 months, when rapid functional impairment forced her to restart hemodialysis. This case, almost paradigmatic of the problems occurring when the rigid vasculature of long-term dialysis patients is matched with "marginal kidneys," suggests that MRI may be a sensible good to define vascular damage in the grafted kidney.

A tracked robot with novel bio-inspired passive "legs".

Science.gov (United States)

Sun, Bo; Jing, Xingjian

2017-01-01

For track-based robots, an important aspect is the suppression design, which determines the trafficability and comfort of the whole system. The trafficability limits the robot's working capability, and the riding comfort limits the robot's working effectiveness, especially with some sensitive instruments mounted on or operated. To these aims, a track-based robot equipped with a novel passive bio-inspired suspension is designed and studied systematically in this paper. Animal or insects have very special leg or limb structures which are good for motion control and adaptable to different environments. Inspired by this, a new track-based robot is designed with novel "legs" for connecting the loading wheels to the robot body. Each leg is designed with passive structures and can achieve very high loading capacity but low dynamic stiffness such that the robot can move on rough ground similar to a multi-leg animal or insect. Therefore, the trafficability and riding comfort can be significantly improved without losing loading capacity. The new track-based robot can be well applied to various engineering tasks for providing a stable moving platform of high mobility, better trafficability and excellent loading capacity.

Effects of leg dominance on performance of ballet turns (pirouettes) by experienced and novice dancers.

Science.gov (United States)

Lin, Chia-Wei; Su, Fong-Chin; Wu, Hong-Wen; Lin, Cheng-Feng

2013-01-01

Turns (pirouettes) are an important movement in ballet and may be affected by "lateral bias". This study investigated physiological differences exhibited by experienced and novice dancers, respectively, when performing pirouette with dominant and non-dominant leg supports, respectively. Thirteen novice and 13 experienced dancers performed turns on dominant or non-dominant legs. The maximum ankle plantarflexion, knee extension and hip extension were measured during the single-leg support phase. The inclination angle of rotation axis is the angle between instantaneous rotation axis and global vertical axis in the early single-leg support phase. Both groups exhibited a greater hip extension, knee extension, and ankle plantarflexion when performing a turn on the non-dominant leg. For experienced dancers, the inclination angle of rotation axis during the pre-swing phase was generally smaller for dominant leg support than non-dominant leg. However, no significant difference was found in inclination angle of rotation axis of novice dancers. For experienced dancers, an improved performance is obtained when using the dominant leg for support. By contrast, for novice dancers, the performance is independent of choice of support leg. The significant lateral bias in experienced dancers indicates the possible influence of training. That is, repetitive rehearsal on the preferred leg strengthens the impact of side dominance in experienced dancers.

How to determine leg dominance: The agreement between self-reported and observed performance in healthy adults.

Directory of Open Access Journals (Sweden)

Nicky van Melick

Full Text Available Since decades leg dominance is suggested to be important in rehabilitation and return to play in athletes with anterior cruciate ligament injuries. However, an ideal method to determine leg dominance in relation to task performance is still lacking.To test the agreement between self-reported and observed leg dominance in bilateral mobilizing and unilateral stabilizing tasks, and to assess whether the dominant leg switches between bilateral mobilizing tasks and unilateral stabilizing tasks.Cross-sectional study.Forty-one healthy adults: 21 men aged 36 ± 17 years old and 20 women aged 36 ±15 years old.Participants self-reported leg dominance in the Waterloo Footedness Questionnaire-Revised (WFQ-R, and leg dominance was observed during performance of four bilateral mobilizing tasks and two unilateral stabilizing tasks. Descriptive statistics and crosstabs were used to report the percentages of agreement.The leg used to kick a ball had 100% agreement between the self-reported and observed dominant leg for both men and women. The dominant leg in kicking a ball and standing on one leg was the same in 66.7% of the men and 85.0% of the women. The agreement with jumping with one leg was lower: 47.6% for men and 70.0% for women.It is appropriate to ask healthy adults: "If you would shoot a ball on a target, which leg would you use to shoot the ball?" to determine leg dominance in bilateral mobilizing tasks. However, a considerable number of the participants switched the dominant leg in a unilateral stabilizing task.

Voluntary enhanced cocontraction of hamstring muscles during open kinetic chain leg extension exercise: its potential unloading effect on the anterior cruciate ligament.

Science.gov (United States)

Biscarini, Andrea; Benvenuti, Paolo; Botti, Fabio M; Brunetti, Antonella; Brunetti, Orazio; Pettorossi, Vito E

2014-09-01

A number of research studies provide evidence that hamstring cocontraction during open kinetic chain knee extension exercises enhances tibiofemoral (TF) stability and reduces the strain on the anterior cruciate ligament. To determine the possible increase in hamstring muscle coactivation caused by a voluntary cocontraction effort during open kinetic chain leg-extension exercises, and to assess whether an intentional hamstring cocontraction can completely suppress the anterior TF shear force during these exercises. Descriptive laboratory study. Knee kinematics as well as electromyographic activity in the semitendinosus (ST), semimembranosus (SM), biceps femoris (BF), and quadriceps femoris muscles were measured in 20 healthy men during isotonic leg extension exercises with resistance (R) ranging from 10% to 80% of the 1-repetition maximum (1RM). The same exercises were also performed while the participants attempted to enhance hamstring coactivation through a voluntary cocontraction effort. The data served as input parameters for a model to calculate the shear and compressive TF forces in leg extension exercises for any set of coactivation patterns of the different hamstring muscles. For R≤ 40% 1RM, the peak coactivation levels obtained with intentional cocontraction (l) were significantly higher (P hamstring muscle, maximum level l was reached at R = 30% 1RM, corresponding to 9.2%, 10.5%, and 24.5% maximum voluntary isometric contraction (MVIC) for the BF, ST, and SM, respectively, whereas the ratio l/l 0 reached its maximum at R = 20% 1RM and was approximately 2, 3, and 4 for the BF, SM, and ST, respectively. The voluntary enhanced coactivation level l obtained for R≤ 30% 1RM completely suppressed the anterior TF shear force developed by the quadriceps during the exercise. In leg extension exercises with resistance R≤ 40% 1RM, coactivation of the BF, SM, and ST can be significantly enhanced (up to 2, 3, and 4 times, respectively) by a voluntary hamstring

Comparison between Unilateral and Bilateral Plyometric Training on Single and Double Leg Jumping Performance and Strength.

Science.gov (United States)

Bogdanis, Gregory C; Tsoukos, Athanasios; Kaloheri, Olga; Terzis, Gerasimos; Veligekas, Panagiotis; Brown, Lee E

2017-04-18

This study compared the effects of unilateral and bilateral plyometric training on single and double-leg jumping performance, maximal strength and rate of force development (RFD). Fifteen moderately trained subjects were randomly assigned to either a unilateral (U, n=7) or bilateral group (B, n=8). Both groups performed maximal effort plyometric leg exercises two times per week for 6 weeks. The B group performed all exercises with both legs, while the U group performed half the repetitions with each leg, so that total exercise volume was the same. Jumping performance was assessed by countermovement jumps (CMJ) and drop jumps (DJ), while maximal isometric leg press strength and RFD were measured before and after training for each leg separately and both legs together. CMJ improvement with both legs was not significantly different between U (12.1±7.2%) and B (11.0±5.5%) groups. However, the sum of right and left leg CMJ only improved in the U group (19.0±7.1%, pplyometric training was more effective at increasing both single and double-leg jumping performance, isometric leg press maximal force and RFD when compared to bilateral training.

H:q ratios and bilateral leg strength in college field and court sports players.

Science.gov (United States)

Cheung, Roy T H; Smith, Andrew W; Wong, Del P

2012-06-01

One of the key components in sports injury prevention is the identification of imbalances in leg muscle strength. However, different leg muscle characteristics may occur in large playing area (field) sports and small playing area (court) sports, which should be considered in regular injury prevention assessment. This study examined the isokinetic hamstrings-to-quadriceps (H:Q) ratio and bilateral leg strength balance in 40 male college (age: 23.4 ± 2.5 yrs) team sport players (field sport = 23, soccer players; court sport = 17, volleyball and basketball players). Five repetitions of maximal knee concentric flexion and concentric extension were performed on an isokinetic dynamometer at two speeds (slow: 60°·s(-1) and fast: 300°·s(-1)) with 3 minutes rest between tests. Both legs were measured in counterbalanced order with the dominant leg being determined as the leg used to kick a ball. The highest concentric peak torque values (Nm) of the hamstrings and quadriceps of each leg were analyzed after body mass normalization (Nm·kg(-1)). Court sport players showed significantly weaker dominant leg hamstrings muscles at both contraction speeds (P Sport-specific leg muscle strength was evident in college players from field and court sports. These results suggest the need for different muscle strength training and rehabilitation protocols for college players according to the musculature requirements in their respective sports.

Remodeling the Vascular Microenvironment of Glioblastoma with α-Particles.

Science.gov (United States)

Behling, Katja; Maguire, William F; Di Gialleonardo, Valentina; Heeb, Lukas E M; Hassan, Iman F; Veach, Darren R; Keshari, Kayvan R; Gutin, Philip H; Scheinberg, David A; McDevitt, Michael R

2016-11-01

Tumors escape antiangiogenic therapy by activation of proangiogenic signaling pathways. Bevacizumab is approved for the treatment of recurrent glioblastoma, but patients inevitably develop resistance to this angiogenic inhibitor. We previously investigated targeted α-particle therapy with 225 Ac-E4G10 as an antivascular approach and showed increased survival and tumor control in a high-grade transgenic orthotopic glioblastoma model. Here, we investigated changes in tumor vascular morphology and functionality caused by 225 Ac-E4G10. We investigated remodeling of the tumor microenvironment in transgenic Ntva glioblastoma mice using a therapeutic 7.4-kBq dose of 225 Ac-E4G10. Immunofluorescence and immunohistochemical analyses imaged morphologic changes in the tumor blood-brain barrier microenvironment. Multicolor flow cytometry quantified the endothelial progenitor cell population in the bone marrow. Diffusion-weighted MR imaged functional changes in the tumor vascular network. The mechanism of drug action is a combination of remodeling of the glioblastoma vascular microenvironment, relief of edema, and depletion of regulatory T and endothelial progenitor cells. The primary remodeling event is the reduction of both endothelial and perivascular cell populations. Tumor-associated edema and necrosis were lessened, resulting in increased perfusion and reduced diffusion. Pharmacologic uptake of dasatinib into tumor was enhanced after α-particle therapy. Targeted antivascular α-particle radiation remodels the glioblastoma vascular microenvironment via a multimodal mechanism of action and provides insight into the vascular architecture of platelet-derived growth factor-driven glioblastoma. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Asymmetry between the Dominant and Non-Dominant Legs in the Kinematics of the Lower Extremities during a Running Single Leg Jump in Collegiate Basketball Players.

Science.gov (United States)

Sugiyama, Takashi; Kameda, Mai; Kageyama, Masahiro; Kiba, Kazufusa; Kanehisa, Hiroaki; Maeda, Akira

2014-12-01

The present study aimed to clarify the asymmetry between the dominant (DL) and non-dominant takeoff legs (NDL) in terms of lower limb behavior during running single leg jumps (RSJ) in collegiate male basketball players in relation to that of the jump height. Twenty-seven players performed maximal RSJ with a 6 m approach. Three-dimensional kinematics data during RSJ was collected using a 12 Raptor camera infrared motion analysis system (MAC 3D system) at a sampling frequency of 500 Hz. The symmetry index in the jump heights and the kinematics variables were calculated as {2 × (DL - NDL) / (DL + NDL)} × 100. The run-up velocity was similar between the two legs, but the jump height was significantly higher in the DL than in the NDL. During the takeoff phase, the joint angles of the ankle and knee were significantly larger in the DL than the NDL. In addition, the contact time for the DL was significantly shorter than that for the NDL. The symmetry index of the kinematics for the ankle joint was positively correlated with that of jump height, but that for the knee joint was not. The current results indicate that, for collegiate basketball players, the asymmetry in the height of a RSJ can be attributed to that in the joint kinematics of the ankle during the takeoff phase, which may be associated with the ability to effectively transmit run-up velocity to jump height. Key pointsAsymmetry of height during running single leg jump between two legs is due to the behavior of the ankle joint (i.e. stiffer the ankle joint and explosive bounding).The dominant leg can transmit run-up velocity into the vertical velocity at takeoff phase to jump high compared with the non-dominant leg.Basketball players who have a greater asymmetry of the RSJ at the collegiate level could be assessed as non-regulars judging by the magnitude of asymmetry.

[Can the vascular specialist improve patient awareness about advanced directives?].

Science.gov (United States)

Sanson, H; Priollet, P

2016-05-01

In France, the Leonetti law, adopted on April 22, 2005, stipulates the regulations concerning advanced directives. This is a patient's right that is not well known and rarely applied. In 2015, a new law project was thus presented in which the French National Authority for Health recommended that doctors, including all specialists, bring up the subject, especially during consultation. To evaluate the vascular specialist's possibility to mention the topic of advanced directives during consultations. A single and non-interventional prospective study conducted with the help of patients who consulted a private practitioner vascular specialist: recurrent patients regularly consulting a private practitioner vascular specialist were included. First-time consultants, minors and patients to whom it was not adapted to speak about the subject were not included. Between July 27 and September 23, 2015, 159 consecutive patients were examined. Fifty-five first-time consultants and four patients for whom the interview was unsuitable were excluded. In all, 100 patients were questioned. None of them refused to talk about the subject. Women made up a majority of the population (63 %) with an average age of 67 years (23-97). The principal diagnostics were common to vascular medicine consultations: deep vein thrombosis (20 %), peripheral arterial disease (15 %), varicose veins (11 %), lymphedema (11 %) and leg ulcers (9 %). Thirteen percent of the people had a history of cancer. Half of the patients had had follow-ups for over 10 years. The average time devoted to discussing the topic was 12minutes (5-40). Only 22 % of the patients declared having been familiar with advance directives. Once informed however, 78 % chose to write up an adapted form: 36 % with the help of their doctor and 42 % with a doctor and a relative. Seventy-three percent of the consultants thought that talking about the advance directives would reinforce the confidence link between the doctor and the

Genetic correlations between claw health and feet and leg conformation in Norwegian Red cows.

Science.gov (United States)

Ødegård, C; Svendsen, M; Heringstad, B

2014-07-01

The aim of this study was to estimate genetic correlations between claw disorders and feet and leg conformation traits in Norwegian Red cows. A total of 188,928 cows with claw health status recorded at claw trimming from 2004 to September 2013 and 210,789 first-lactation cows with feet and leg conformation scores from 2001 to September 2013 were included in the analyses. Traits describing claw health were corkscrew claw, infectious claw disorders (dermatitis, heel horn erosion, and interdigital phlegmon), and laminitis-related claw disorders (sole ulcer, white line disorder, and hemorrhage of sole and white line). The feet and leg conformation traits were rear leg rear view (new and old definition), rear leg side view, foot angle, and hoof quality. Feet and leg conformation traits were scored linearly from 1 to 9, with optimum scores depending on the trait. Claw disorders were defined as binary (0/1) traits for each lactation. Threshold sire models were used to model claw disorders, whereas the feet and leg conformation traits were described by linear sire models. Three multivariate analyses were performed, each including the 5 feet and leg conformation traits and 1 of the 3 claw disorders at a time. Posterior means of heritability of liability of claw disorders ranged from 0.10 to 0.20 and heritabilities of feet and leg conformation traits ranged from 0.04 to 0.11. Posterior standard deviation of heritability was ≤0.01 for all traits. Genetic correlations between claw disorders and feet and leg conformation traits were all low or moderate, except between corkscrew claw and hoof quality (-0.86), which are supposed to measure the same trait. The genetic correlations between rear leg rear view (new) and infectious claw disorders (-0.20) and laminitis-related claw disorders (0.26), and between hoof quality and laminitis-related claw disorders (-0.33) were moderate. Eight of the 15 genetic correlations between claw disorders and feet and leg conformation traits had 0

Volume measurement of the leg with the depth camera for quantitative evaluation of edema

Science.gov (United States)

Kiyomitsu, Kaoru; Kakinuma, Akihiro; Takahashi, Hiroshi; Kamijo, Naohiro; Ogawa, Keiko; Tsumura, Norimichi

2017-02-01

Volume measurement of the leg is important in the evaluation of leg edema. Recently, method for measurement by using a depth camera is proposed. However, many depth cameras are expensive. Therefore, we propose a method using Microsoft Kinect. We obtain a point cloud of the leg by Kinect Fusion technique and calculate the volume. We measured the volume of leg for three healthy students during three days. In each measurement, the increase of volume was confirmed from morning to evening. It is known that the volume of leg is increased in doing office work. Our experimental results meet this expectation.

Changes in muscle size and MHC composition in response to resistance exercise with heavy and light loading intensity

DEFF Research Database (Denmark)

Holm, L.; Reitelseder, S.; Pedersen, T.G.

2008-01-01

resonance imaging, muscle biopsies were obtained bilaterally from vastus lateralis for determination of myosin heavy chain (MHC) composition, and maximal muscle strength was assessed by 1RM testing and in an isokinetic dynamometer at 60 degrees /s. Quadriceps muscle cross-sectional area increased (P ...Muscle mass accretion is accomplished by heavy-load resistance training. The effect of light-load resistance exercise has been far more sparsely investigated with regard to potential effect on muscle size and contractile strength. We applied a resistance exercise protocol in which the same...... individual trained one leg at 70% of one-repetition maximum (1RM) (heavy load, HL) while training the other leg at 15.5% 1RM (light load, LL). Eleven sedentary men (age 25 +/- 1 yr) trained for 12 wk at three times/week. Before and after the intervention muscle hypertrophy was determined by magnetic...

Effects of resistance-guided high intensity interval functional electrical stimulation cycling on an individual with paraplegia: A case report.

Science.gov (United States)

Dolbow, David R; Credeur, Daniel P

2018-03-01

Individuals with spinal cord injury (SCI) are more than twice as likely to develop and die from cardio-metabolic diseases as compared to able-bodied. This increased risk is thought to be in part due to accelerated muscle atrophy and reduced blood flow through sublesional arteries. Thus, strategies to recondition paralyzed skeletal muscles may help reduce cardio-metabolic disease risk. The purpose of this case report was to examine the impact of a novel, resistance-guided, high intensity interval training functional electrical stimulation (RG-HIIT-FES) cycling program on cardio-metabolic health in people with chronic SCI. One adult female with chronic T10 SCI. A novel RG-HIIT-FES cycling program three times per week for 10 weeks. Measures of body composition and cardio-metabolic health (vascular endothelial function of the brachial artery via flow-mediated dilation) and HbA1c blood values were performed at baseline and following completion of the RG-HIIT-FES program. Total body lean mass and legs lean mass increased 2.8% and 5.3% respectively while vastus lateralis thickness increased by 59.5%. Reactive hyperemia and flow mediated dilation change in brachial artery diameter increased by 11.1% and 147.7% following the program, respectively. HbA1c level changed minimally (5 to 4.9%). This case report suggests that RG-HIIT-FES cycling was an effective strategy to improve lean mass, and systemic vascular endothelial health in an individual with chronic SCI.

Effects of combined high intensity arm and leg training on performance and cardio-respiratory measures.

Science.gov (United States)

Zinner, Christoph; Sperlich, Billy; Born, Dennis-Peter; Michels, Guido

2017-01-01

The purpose of this study was to investigate the effects of combined arm and leg high-intensity low-volume interval training (HIITarm+leg) on maximal oxygen uptake, myocardial measures (i.e. stroke volume, cardiac output, ejection fraction), Tissue Oxygenation Index (TOI) of the vastus lateralis and triceps brachii, as well as power output in comparison to leg HIIT (HIITleg) only. The 20 healthy, male and female volunteers completed six sessions of either HIITleg on a cycle ergometer or HIITarm+leg on an arm and leg cycle ergometer. During pre- and post-testing, the volunteers completed a submaximal and incremental test to exhaustion on a cycle ergometer. Magnitude based interference revealed likely to very likely beneficial effects for HIITarm+leg compared to HIITleg in maximal oxygen uptake, cardiac measures as well peak power output. The TOI following HIITarm+leg demonstrated likely to very likely increased oxygenation in the triceps brachii or the vastus lateralis when compared to HIITleg. The results suggest that six sessions of HIITarm+leg may likely to very likely improve maximal oxygen uptake, some inotropy-related cardiac measures with improved tissue oxygenation of the triceps brachii and vastus lateralis muscles resulting in greater leg peak power output.

Vascular Function and Regulation of Blood Flow in Resting and Contracting Skeletal Muscle

DEFF Research Database (Denmark)

Nyberg, Michael Permin

importance. The present work provides new insight in to vasodilator interactions important for exercise hyperemia and sheds light on mechanisms important for vascular function and regulation of skeletal muscle blood flow in essential hypertension (high blood pressure) and aging and identifies mechanisms......The precise matching of blood flow, oxygen delivery and metabolism is essential as it ensures that any increase in muscle work is precisely matched by increases in oxygen delivery. Therefore, understanding the control mechanisms of skeletal muscle blood flow regulation is of great biological...... in the regulation of exercise hyperemia. Furthermore, blood flow to contracting leg skeletal muscles is reduced both in essential hypertension and with aging. The potential difference in vasoactive system(s) responsible for the reduction in blood flow in the two conditions is in agreement with the suggestion...

Gait Planning Research for an Electrically Driven Large-Load-Ratio Six-Legged Robot

Directory of Open Access Journals (Sweden)

Hong-Chao Zhuang

2017-03-01

Full Text Available Gait planning is an important basis for the walking of a legged robot. To improve the walking stability of multi-legged robots and to reduce the impact force between the foot and the ground, gait planning strategies are presented for an electrically driven large-load-ratio six-legged robot. First, the configuration and walking gait of the electrically driven large-load-ratio six-legged robot are designed. The higher-stable swing sequences of legs and typical walking modes are respectively obtained. Based on the Denavit–Hartenberg (D–H method, the analyses of the forward and inverse kinematics are implemented. The mathematical models of the articulated rotation angles are respectively established. In view of the buffer device installed at the end of shin to decrease the impact force between the foot and the ground, an initial lift height of the leg is brought into gait planning when the support phase changes into the transfer phase. The mathematical models of foot trajectories are established. Finally, a prototype of the electrically driven large-load-ratio six-legged robot is developed. The experiments of the prototype are carried out regarding the aspects of the walking speed and surmounting obstacle. Then, the reasonableness of gait planning is verified based on the experimental results. The proposed strategies of gait planning lay the foundation for effectively reducing the foot–ground impact force and can provide a reference for other large-load-ratio multi-legged robots.

Influences of maternal nutritional status on vascular function in the offspring.

Science.gov (United States)

Poston, Lucilla

2007-08-01

Fetal growth restriction leading to low birthweight is associated with increased risk of ischaemic heart disease and hypertension in later life. Increasingly, it is recognised that cardiovascular risk may also be initiated in early life when the fetus and neonate are exposed to maternal nutritional excess. This review summarises the studies in man and animals that have investigated the potential role of vascular disorders in the aetiology of atherosclerosis and hypertension arising from early life nutritional deprivation or excess. Malfunction of the arterial endothelial cell layer in the offspring has been frequently described in association with both maternal under and overnutritional states and may play a permissive role in the origin of these disorders. Also prevalent is evidence for increased stiffness of the large arteries which may contribute to systolic hypertension. Further investigation is required into the intriguing suggestion that early life nutritional imbalance may adversely influence vascular angiogenesis leading to rarefaction and increased peripheral vascular resistance.

Leg og læring

DEFF Research Database (Denmark)

Pedersen, Annette

2008-01-01

Leg synes at have et potentiale som metode til at fremme læring. Men hvordan? Legen har en vis grad af parallelitet med den virkelige verden i dens interaktive og relationelle strukturer. Det bliver muligt at finde nye meninger i interaktioner, som refererer til vante interaktionsformer, men...

[AA amyloidosis: a little-known complication of chronic leg ulcer].

Science.gov (United States)

Waton, J; Fays-Michel, S; Chandeclerc, M L; Corby, S; Cuny, J F; Barbaud, A; Schmutz, J-L

2008-02-01

AA amyloidosis, secondary to inflammatory chronic diseases like rheumatoid arthritis, is often complicated by renal failure. Chronic inflammatory dermatoses constitute rare causes of AA amyloidosis. We describe two cases of AA amyloidosis discovered after renal failure in patients presenting leg ulcers for several years. AL amyloidosis was suspected in both cases because of a history of monoclonal gammopathy in one patient and of plasmocytoma in the other. The diagnosis of AA amyloidosis was confirmed on renal histology through the detection of AA antibodies in amyloid deposits. No extrarenal amyloidosis was seen in either patient and there were no inflammatory diseases other than chronic leg ulcers. AA amyloidosis is caused by serum amyloid protein A (SAA), a reactive inflammatory protein. AA amyloidosis is thus caused by chronic inflammatory diseases, but only rarely by cutaneous inflammatory diseases. To our knowledge, the literature contains only seven other published cases of AA amyloidosis secondary to chronic leg ulcers. A review of the literature does not indicate whether cure of ulcers has any effect on the accompanying renal failure. We imagine that AA amyloidosis secondary to leg ulcer is in fact under-diagnosed. However, since the first specific treatment for AA amyloidosis is currently being evaluated by the Food and Drug Administration, it is essential that this serious complication of chronic leg ulcers be widely recognised.

Pictorial essay: Ultrasonography in 'tennis leg'.

Science.gov (United States)

Shah, Jeshil R; Shah, Bipin R; Shah, Ankit B

2010-11-01

Tennis leg is caused by a rupture of the medial head of the gastrocnemius muscle, usually at its distal musculotendinous junction region. However, tears in this muscle and its tendon are also included under the term 'tennis leg'. It is seen regularly in practice and is an important cause of a painful calf. The common USG findings include: disruption of the pinnate pattern of the distal medial gastrocnemius, usually near the junction of the triceps surae (which is the echogenic line between the gastrocnemius, the soleus, and the plantaris muscles), fluid tracking along the fascia, adjacent hematoma, and intramuscular tears as well as hematomas. USG is useful for confirming the diagnosis, excluding other causes of a painful calf, for assessing the severity of the disease, and in follow-up.

Lipid induced insulin resistance affects women less than men and is not accompanied by inflammation or impaired proximal insulin signaling

DEFF Research Database (Denmark)

Høeg, Louise D; Sjøberg, Kim Anker; Jeppesen, Jacob

2011-01-01

than men. We therefore hypothesized that women would be less prone to lipid induced insulin resistance. Research and design methods: Insulin sensitivity of whole body and leg glucose disposal was studied in 16 young well matched healthy men and women infused with intralipid or saline for 7h. Muscle...... ratio was decreased by intralipid. Conclusion: Intralipid infusion causes less insulin resistance of muscle glucose uptake in women than in men. This insulin resistance is not due to decreased canonical insulin signaling, accumulation of lipid intermediates, inflammation or direct inhibition of glucose......AbstractObjective: We have previously shown that overnight fasted women have higher insulin stimulated whole body and leg glucose uptake despite a higher intramyocellular triacylglycerol concentration than men. Women also express higher muscle mRNA levels of proteins related to lipid metabolism...

Catecholamine-resistant hypotension and myocardial performance following patent ductus arteriosus ligation.

LENUS (Irish Health Repository)

Noori, S

2014-08-14

Objective:We performed a multicenter study of preterm infants, who were about to undergo patent ductus arteriosus ligation, to determine whether echocardiographic indices of impaired myocardial performance were associated with subsequent development of catecholamine-resistant hypotension following ligation.Study Design:A standardized treatment approach for hypotension was followed at each center. Infants were considered to have catecholamine-resistant hypotension if their dopamine infusion was >15 μg kg(-1)min(-1). Echocardiograms and cortisol measurements were obtained between 6 and 14 h after the ligation (prior to the presence of catecholamine-resistant hypotension).Result:Forty-five infants were enrolled, 10 received catecholamines (6 were catecholamine-responsive and 4 developed catecholamine-resistant hypotension). Catecholamine-resistant hypotension was not associated with decreased preload, shortening fraction or ventricular output. Infants with catecholamine-resistant hypotension had significantly lower levels of systemic vascular resistance and postoperative cortisol concentration.Conclusion:We speculate that low cortisol levels and impaired vascular tone may have a more important role than impaired cardiac performance in post-ligation catecholamine-resistant hypotension.Journal of Perinatology advance online publication, 14 August 2014; doi:10.1038\\/jp.2014.151.

Hox gene expression leads to differential hind leg development between honeybee castes.

Science.gov (United States)

Bomtorin, Ana Durvalina; Barchuk, Angel Roberto; Moda, Livia Maria; Simoes, Zila Luz Paulino

2012-01-01

Beyond the physiological and behavioural, differences in appendage morphology between the workers and queens of Apis mellifera are pre-eminent. The hind legs of workers, which are highly specialized pollinators, deserve special attention. The hind tibia of worker has an expanded bristle-free region used for carrying pollen and propolis, the corbicula. In queens this structure is absent. Although the morphological differences are well characterized, the genetic inputs driving the development of this alternative morphology remain unknown. Leg phenotype determination takes place between the fourth and fifth larval instar and herein we show that the morphogenesis is completed at brown-eyed pupa. Using results from the hybridization of whole genome-based oligonucleotide arrays with RNA samples from hind leg imaginal discs of pre-pupal honeybees of both castes we present a list of 200 differentially expressed genes. Notably, there are castes preferentially expressed cuticular protein genes and members of the P450 family. We also provide results of qPCR analyses determining the developmental transcription profiles of eight selected genes, including abdominal-A, distal-less and ultrabithorax (Ubx), whose roles in leg development have been previously demonstrated in other insect models. Ubx expression in workers hind leg is approximately 25 times higher than in queens. Finally, immunohistochemistry assays show that Ubx localization during hind leg development resembles the bristles localization in the tibia/basitarsus of the adult legs in both castes. Our data strongly indicate that the development of the hind legs diphenism characteristic of this corbiculate species is driven by a set of caste-preferentially expressed genes, such as those encoding cuticular protein genes, P450 and Hox proteins, in response to the naturally different diets offered to honeybees during the larval period.

Biomechanical Modeling of Split-leg Squat and Heel Raise on the Hybrid Ultimate Lifting Kit (HULK)

Science.gov (United States)

Thompson, William K.; Gallo, Christopher A.; Lewandowski, Beth E.; Jagodnik, Kathleen M.; Humphreys, Brad; Funk, Justin; Funk, Nathan; Dewitt, John K.

2016-01-01

Long duration space travel will expose astronauts to extended periods of reduced gravity. Since gravity is not present to aid loading, astronauts will use resistive and aerobic exercise regimes for the duration of the space flight to minimize the loss of bone density, muscle mass and aerobic capacity that occurs during exposure to a reduced gravity environment. Unlike the International Space Station (ISS), the area available for an exercise device in the next generation of spacecraft is limited and therefore compact resistance exercise device prototypes are being developed. The Advanced Resistive Exercise Device (ARED) currently on the ISS is being used as a benchmark for the functional performance of these new devices. Biomechanical data collection and computational modeling aid the device design process by quantifying the joint torques and musculoskeletal forces that occur during exercises performed on the prototype devices. Computational models currently use OpenSim software, an open source code for musculoskeletal modeling, with biomechanical input data from subjects for estimation of muscle and joint loads. Subjects are instrumented with reflective markers for motion capture data collection while exercising on the Hybrid Ultimate Lifting Kit (HULK) prototype device. Ground reaction force data is collected with force plates under the feet and device loading is recorded through load cells internal to the HULK. This data is input into the OpenSim biomechanical model, which has been scaled to match the anthropometrics of the test subject, to calculate the loads on the body. Multiple exercises are performed and evaluated during a test session such as a full squat, single leg squat, heel raise and dead lift. Variables for these exercises include applied device load, narrow or wide foot stance, slow or fast cadence and the harness or long bar interface between the test subject and the device. Data from free weights are compared to the resistively loaded exercise

Activation of vascular cholinergic and adrenergic receptors induced by gamma rays

International Nuclear Information System (INIS)

Alya, G.

1999-10-01

Activation of vascular cholinergic receptors and adrenoceptors plays an important role in vasomotoricity and peripheric vascular resistance. These factors are essential in maintaining a stable blood pressure. The aim of this study is to investigate the radiosensitivity differences between vascular cholinergic receptors and adrenoceptors, and consequently to determinate the effects of ionizing radiation (whole body irradiation) on contractile response regulation of vascular smooth muscle fibers VSMF isolated from rat portal vein. Our results show that Clonidine, (non-specific adrenergic agonist), and phenylephrine which is more specific α1-adrenoceptor agonist, increase the VSMF contractions. The maximum effect is obtained at 10 -5 - 3.10 -5 M. On irradiated rats (1-3-5 Gy), there is an important shift thus, the maximal response (E m ax) can be obtained in lower concentrations of clonidine and phenylephrine. Irradiation deceases the contractile responses of VSMF mediated by cholinergic stimulation, in a dose dependant manner. With E m ax 1 Gy>E m ax 3 Gy>E m ax 5 Gy. Irradiated muscular fibers became less sensitive to acetylcholine, thus 3.10 -8 M. A. ch induced more than 50% of contraction force increase in normal conditions. This concentration induce generally a negligible effect after irradiation. The results reveal the existence of radiosensitivity differences between vascular cholinergic and adrenergic receptors. (author)

Survival of Salmonella typhimurium ATCC 14028 on the surface of chicken legs or in mechanically deboned chicken meat gamma irradiated in air or vacuum at temperatures of -20 to +20 C

International Nuclear Information System (INIS)

Thayer, D.W.; Boyd, G.

1991-01-01

Response-surface methodology was used to develop predictive equations for the response of Salmonella typhimurium ATCC 14028 on the surface of chicken legs or within mechanically deboned chicken meat (MDCM) to the effects of γ radiation doses of 0 to 3.60 kGy (100 krad = 1 kGy) at temperatures of -20 to +20 C in air or vacuum. A streptomycin-resistant mutant was used in these studies to allow accurate estimations of the surviving salmonellae in the presence of residual normal flora. This strain has been demonstrated to have no significant shift in its biological properties nor in its resistance to ionizing radiation. The response of S. typhimurium to gamma radiation was similar on both chicken legs and MDCM. The radiation was significantly more lethal to the bacterial cells at temperatures above freezing. The response-surface equations developed from the studies predict that the number of viable cells per gram of MDCM or per square centimeter of the surface of chicken legs would be reduced approximately 2.8 to 5.1 log units at 0 C by radiation doses within the range of 1.5 to 3.0 kGy. The results of the present studies are similar to those obtained previously with sterile mechanically deboned chicken meat

Pseudotumor from Metal-on-Metal Total Hip Arthroplasty Causing Unilateral Leg Edema: Case Presentation and Literature Review

Directory of Open Access Journals (Sweden)

Caleb W. Grote

2018-03-01

Full Text Available Metal-on-metal (MoM total hip arthroplasty (THA can be associated with adverse metal reactions, including pseudotumors. This case report describes a 58-year-old female with an MoM THA-related pseudotumor that caused unilateral leg edema from compression of her external iliac vein. After thorough preoperative workup to rule out infection and deep vein thrombosis and consultation with a vascular surgeon, the patient underwent revision THA and excision of her pseudotumor. She had complete resolution of her swelling at 4 years after surgery. Review of all available case reports for this rare complication revealed that almost all patients were female. All patients underwent revision THA, with resolution of their symptoms. Literature review demonstrates that women are disproportionally affected by complications associated with MoM THA. We recommend close monitoring of patients with MoM THA, particularly women, for development of adverse metal reactions.

Compression therapy in patients with venous leg ulcers.

Science.gov (United States)

Dissemond, Joachim; Assenheimer, Bernd; Bültemann, Anke; Gerber, Veronika; Gretener, Silvia; Kohler-von Siebenthal, Elisabeth; Koller, Sonja; Kröger, Knut; Kurz, Peter; Läuchli, Severin; Münter, Christian; Panfil, Eva-Maria; Probst, Sebastian; Protz, Kerstin; Riepe, Gunnar; Strohal, Robert; Traber, Jürg; Partsch, Hugo

2016-11-01

Wund-D.A.CH. is the umbrella organization of the various wound care societies in German-speaking countries. The present consensus paper on practical aspects pertinent to compression therapy in patients with venous leg ulcers was developed by experts from Germany, Austria, and Switzerland. In Europe, venous leg ulcers rank among the most common causes of chronic wounds. Apart from conservative and interventional wound and vein treatment, compression therapy represents the basis of all other therapeutic strategies. To that end, there are currently a wide variety of materials and systems available. While especially short-stretch bandages or multicomponent systems should be used in the initial decongestion phase, ulcer stocking systems are recommended for the subsequent maintenance phase. Another - to date, far less common - alternative are adaptive Velcro bandage systems. Medical compression stockings have proven particularly beneficial in the prevention of ulcer recurrence. The large number of treatment options currently available enables therapists to develop therapeutic concepts geared towards their patients' individual needs and abilities, thus resulting in good acceptance and adherence. Compression therapy plays a crucial role in the treatment of patients with venous leg ulcers. In recent years, a number of different treatment options have become available, their use and application differing among German-speaking countries. The present expert consensus is therefore meant to outline concrete recommendations for routine implementation of compression therapy in patients with venous leg ulcers. © 2016 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

Association of restless legs syndrome, pain, and mood disorders in Parkinson's disease.

Science.gov (United States)

Rana, Abdul Qayyum; Qureshi, Abdul Rehman M; Rahman, Labiba; Jesudasan, Ajantha; Hafez, Kevin K; Rana, Mohammad A

2016-01-01

The objectives of the study were to analyze the association between Parkinson's disease and restless legs syndrome, and to explore the relationship between mood disorder comorbidity (anxiety and depression), pain, and restless legs syndrome. This study included 123 Parkinson's disease patients and 123 non-Parkinson's disease patients matched for age and gender, and evaluated for anxiety severity, depression severity, pain severity, pain interference, pain disability, and restless legs syndrome prevalence. This was performed using semi-structured interviews and a neurological examination through the restless legs syndrome diagnostic criteria and the following inventories; Hospital Anxiety and Depression Scale, Brief Pain Inventory, and Pain Disability Index. Parkinson's disease patients had significantly greater anxiety severity, depression severity, pain severity, pain interference, pain disability, and restless legs syndrome prevalence in comparison to controls. In addition, Parkinson's disease patients' comorbid for anxiety and depression had significantly greater pain severity, pain interference, and pain disability, but not RLS prevalence, in comparison to Parkinson's disease only, Parkinson's disease anxiety, and Parkinson's disease depression patients. Pain interference, pain severity, and pain disability is greater among Parkinson's disease patients with anxiety and depression, in comparison to Parkinson's disease patients without anxiety and depression. On the contrary, the prevalence of restless legs syndrome was not found to be relevant.

Numerical simulation of thermal stratification in cold legs by using openFOAM

International Nuclear Information System (INIS)

Cai, Jiejin; Watanabe, Tadashi

2010-01-01

During a small-break loss-of-coolant accident in pressurized water reactors (PWRs), emergency core cooling system (ECCS) is actuated and cold water is injected into cold legs. Insufficient mixing of injected cold water and hot primary coolant results in thermal stratification, which is a matter of concern for evaluation of pressurized thermal shock (PTS) in view of aging and life extension of nuclear power plants. In this study, an open source CFD software, OpenFOAM, is used to simulate mixing and thermal stratification in the cold leg of ROSA/LSTF, which is the largest thermal-hydraulic integral test facility simulating PWR. One of the cold-leg is numerically simulated from the outlet of primary coolant pump to the inlet of downcomer. ECCS water is injected from injection nozzle connected at the top of the cold leg into the steady-state natural circulation flow under high-pressure and high-temperature conditions. The temperature distribution in the cold leg is compared with experimental and FLUENT's results. Effects of turbulent flow models and secondary flow due to the elbow section of the cold leg are discussed for the case with the single-phase natural circulation. Injection into a two-phase stratified flow is also simulated and predictive and numerical capabilities of OpenFOAM are discussed. (author)

Side-to-side sutureless vascular anastomosis with magnets.

Science.gov (United States)

Erdmann, Detlev; Sweis, Ranya; Heitmann, Christoph; Yasui, Koji; Olbrich, Kevin C; Levin, L Scott; Sharkawy, A Adam; Klitzman, Bruce

2004-09-01

Abbe and Payr introduced vascular techniques and devices to facilitate vessel anastomosis over a century ago. Obora published the idea of a sutureless vascular anastomosis with use of magnetic rings in 1978. The purpose of this study was to assess the performance of a new magnetic device to perform a side-to-side arteriovenous anastomosis in a dog model. Male fox hounds (25 kg) were treated preoperatively and daily postoperatively with clopidogrel bisulfate (Plavix) and aspirin. The femoral artery and vein were exposed unilaterally in 3 dogs and bilaterally in 4 dogs (n = 11 anastomoses). A 4-mm arteriotomy was performed, and 1 oval magnet 0.5 mm thick was inserted into the lumen of the artery and a second magnet was applied external to the artery, compressing and stabilizing the arterial wall to create a magnetic port. An identical venous magnetic port was created with another pair of oval magnets. When the 2 ports were allowed to approach each other, they self-aligned and magnetically coupled to complete the arteriovenous anastomosis. Patency was assessed for the first hour with direct observation, again after 9 weeks with duplex ultrasound scanning, and at 10 weeks under direct open observation. The anastomoses were explanted after 10 weeks. Hydrodynamic resistance was measured ex vivo on the final 8 anastomoses by measuring the pressure drop across an anastomosis with a known flow rate. After implantation, very high flow created visible turbulence and palpable vibration. All 11 anastomoses were patent under direct observation and palpation. Ten of 11 anastomoses were clearly patent on duplex scans, and patency of 1 anastomosis was questionable. Hydrodynamic resistance averaged 0.73 +/- 0.33 mm Hg min/mL (mean +/- SEM). Vascular anastomoses performed with magnets demonstrated feasibility; exhibited 100% patency after 10 weeks in a dog arteriovenous shunt model; lacked apparent aneurysm or other potentially catastrophic failure; demonstrated remodeling of the

Myonecrosis in the leg caused by Salmonella enteritidis

DEFF Research Database (Denmark)

Jørring, S; Kolmos, H J; Klareskov, B

1994-01-01

Five weeks after an episode of gastroenteritis, a 65-year-old diabetic male developed an extensive myonecrosis, with gas production in the left leg caused by Salmonella enteritidis. The patient was treated with surgical revision and antibiotics. To our knowledge, this is the first case of myonecr......Five weeks after an episode of gastroenteritis, a 65-year-old diabetic male developed an extensive myonecrosis, with gas production in the left leg caused by Salmonella enteritidis. The patient was treated with surgical revision and antibiotics. To our knowledge, this is the first case...

Dynamically Stable Legged Locomotion

Science.gov (United States)

1981-11-30

the laboratory. Harry Asada, Wayne Book, Nancy Cornelius, Sesh Murthy and Ivan Sutherland read various drafts of this report, for which we are...particularly helpful in providing an atmosphere where things could get started. Craig Fields and Clint Kelly deserve special credit for letting the idea of...legged technology capture their imaginations, even before we could show them tangible results. We are especially indebted to Ivan Sutherland for his

Exercise order affects the total training volume and the ratings of perceived exertion in response to a super-set resistance training session

Directory of Open Access Journals (Sweden)

Balsamo S

2012-02-01

Full Text Available Sandor Balsamo1–3, Ramires Alsamir Tibana1,2,4, Dahan da Cunha Nascimento1,2, Gleyverton Landim de Farias1,2, Zeno Petruccelli1,2, Frederico dos Santos de Santana1,2, Otávio Vanni Martins1,2, Fernando de Aguiar1,2, Guilherme Borges Pereira4, Jéssica Cardoso de Souza4, Jonato Prestes41Department of Physical Education, Centro Universitário UNIEURO, Brasília, 2GEPEEFS (Resistance training and Health Research Group, Brasília/DF, 3Graduate Program in Medical Sciences, School of Medicine, Universidade de Brasília (UnB, Brasília, 4Graduation Program in Physical Education, Catholic University of Brasilia (UCB, Brasília/DF, BrazilAbstract: The super-set is a widely used resistance training method consisting of exercises for agonist and antagonist muscles with limited or no rest interval between them – for example, bench press followed by bent-over rows. In this sense, the aim of the present study was to compare the effects of different super-set exercise sequences on the total training volume. A secondary aim was to evaluate the ratings of perceived exertion and fatigue index in response to different exercise order. On separate testing days, twelve resistance-trained men, aged 23.0 ± 4.3 years, height 174.8 ± 6.75 cm, body mass 77.8 ± 13.27 kg, body fat 12.0% ± 4.7%, were submitted to a super-set method by using two different exercise orders: quadriceps (leg extension + hamstrings (leg curl (QH or hamstrings (leg curl + quadriceps (leg extension (HQ. Sessions consisted of three sets with a ten-repetition maximum load with 90 seconds rest between sets. Results revealed that the total training volume was higher for the HQ exercise order (P = 0.02 with lower perceived exertion than the inverse order (P = 0.04. These results suggest that HQ exercise order involving lower limbs may benefit practitioners interested in reaching a higher total training volume with lower ratings of perceived exertion compared with the leg extension plus leg curl

A randomised clinical trial of the efficacy of drop squats or leg extension/leg curl exercises to treat clinically diagnosed jumper's knee in athletes: pilot study

Science.gov (United States)

Cannell, L; Taunton, J; Clement, D; Smith, C; Khan, K

2001-01-01

Objectives—To compare the therapeutic effect of two different exercise protocols in athletes with jumper's knee. Methods—Randomised clinical trial comparing a 12 week programme of either drop squat exercises or leg extension/leg curl exercises. Measurement was performed at baseline and after six and 12 weeks. Primary outcome measures were pain (visual analogue scale 1–10) and return to sport. Secondary outcome measures included quadriceps and hamstring moment of force using a Cybex II isokinetic dynamometer at 30°/second. Differences in pain response between the drop squat and leg extension/curl treatment groups were assessed by 2 (group) x 3 (time) analysis of variance. Two by two contingency tables were used to test differences in rates of return to sport. Analysis of variance (2 (injured versus non-injured leg) x 2 (group) x 3 (time)) was also used to determine differences for secondary outcome measures. Results—Over the 12 week intervention, pain diminished by 2.3 points (36%) in the leg extension/curl group and 3.2 points (57%) in the squat group. There was a significant main effect of both exercise protocols on pain (psquat group returned to sporting activity by 12 weeks, but five of those subjects still had low level pain. Six of nine of the leg extension/curl group returned to sporting activity by 12 weeks and four patients had low level pain. There was no significant difference between groups in numbers returning to sporting activity. There were no differences in the change in quadriceps or hamstring muscle moment of force between groups. Conclusions—Progressive drop squats and leg extension/curl exercises can reduce the pain of jumper's knee in a 12 week period and permit a high proportion of patients to return to sport. Not all patients, however, return to sport by that time. Key Words: knee; patellar tendon; tendinopathy; tendinosis; eccentric strengthening; strength training PMID:11157465

Balanced gait generations of a two-legged robot on sloping surface

Indian Academy of Sciences (India)

legged robot moving up and down through the sloping surface is presented. The gait of the lower links during locomotion is obtained after assuming suitable trajectories for the swing leg and hip joint. The trunk motion is initially generated based on ...

Near infrared spectroscopy for controlling the quality of distal leg perfusion in remote access cardiopulmonary bypass.

Science.gov (United States)

Schachner, Thomas; Bonaros, Nikolaos; Bonatti, Johannes; Kolbitsch, Christian

2008-12-01

The prevention of leg ischemia is necessary in all patients undergoing femoral artery cannulation for extracorporeal circulation. Near infrared spectroscopy (NIRS) is an established non-invasive method for measuring tissue oxygen saturation. Ten patients underwent robotically assisted endoscopic coronary surgery or ASD repair on the arrested heart using aortic endo-occlusion catheters. They were monitored by transcutaneous NIRS (placed on both lower legs) for quality control of distal leg perfusion during femoral access cardiopulmonary bypass. The baseline NIRS values were 61 (52-80) on the cannulated side versus 70 (53-80) on the contralateral leg (p=n.s.). During clamping of the femoral artery for installation of the remote access perfusion system the tissue oxygen saturation dropped to 38 (18-58) (p=0.001 vs baseline) while it remained stable on the contralateral leg. After successful implantation of the distal leg perfusion the NIRS values normalized to similar amounts on both legs. We conclude that transcutaneous NIRS of the lower legs might be a useful non-invasive tool for monitoring leg perfusion in patients undergoing extracorporeal circulation via the femoral vessels.

Dynamic legged locomotion in robots and animals

Science.gov (United States)

Raibert, Marc; Playter, Robert; Ringrose, Robert; Bailey, Dave; Leeser, Karl

1995-01-01

This report documents our study of active legged systems that balance actively and move dynamically. The purpose of this research is to build a foundation of knowledge that can lead both to the construction of useful legged vehicles and to a better understanding of how animal locomotion works. In this report we provide an update on progress during the past year. Here are the topics covered in this report: (1) Is cockroach locomotion dynamic? To address this question we created three models of cockroaches, each abstracted at a different level. We provided each model with a control system and computer simulation. One set of results suggests that 'Groucho Running,' a type of dynamic walking, seems feasible at cockroach scale. (2) How do bipeds shift weight between the legs? We built a simple planar biped robot specifically to explore this question. It shifts its weight from one curved foot to the other, using a toe-off and toe-on strategy, in conjunction with dynamic tipping. (3) 3D biped gymnastics: The 3D biped robot has done front somersaults in the laboratory. The robot changes its leg length in flight to control rotation rate. This in turn provides a mechanism for controlling the landing attitude of the robot once airborne. (4) Passively stabilized layout somersault: We have found that the passive structure of a gymnast, the configuration of masses and compliances, can stabilize inherently unstable maneuvers. This means that body biomechanics could play a larger role in controlling behavior than is generally thought. We used a physical 'doll' model and computer simulation to illustrate the point. (5) Twisting: Some gymnastic maneuvers require twisting. We are studying how to couple the biomechanics of the system to its control to produce efficient, stable twisting maneuvers.

Genetic association between leg conformation in young pigs and sow reproduction

DEFF Research Database (Denmark)

Le, Thu Hong; Nilsson, Katja; Norberg, Elise

2015-01-01

Lameness is an issue of concern in pig production due both to animal welfare and to economical aspects. Lame sows are believed to suffer from pain and stress which is reported to have a negative influence on reproduction. Leg conformation and locomotion traits in young animals are associated...... with the risk of lameness at higher age. The purpose of this study was to estimate the genetic parameters of leg conformation traits recorded at performance testing (around 5 months of age) and their genetic correlations with reproduction traits. Information on leg conformation traits from 123,307 pigs scored...... and on reproduction traits from 22,204 litters in the first and second parity from Swedish Yorkshire nucleus herds were available for genetic analysis. Eight conformation and locomotion traits, coming from the old or the new scoring system in Sweden, included old movement, old overall leg score, new movement, new...

Normalized knee-extension strength or leg-press power after fast-track total knee arthroplasty

DEFF Research Database (Denmark)

Aalund, Peter K; Larsen, Kristian; Hansen, Torben Bæk

2013-01-01

OBJECTIVE: (s): To investigate which of the two muscle-impairment measures for the operated leg, normalized knee extension strength or leg press power, is more closely associated to performance-based and self-reported measures of function shortly following total knee arthroplasty (TKA). DESIGN...... and dynamic leg presses to determine their body-mass normalized knee extension strength and leg press power, respectively. The 10-m fast speed walking and 30-s chair stand tests were used to determine performance-based function, while the Western Ontario McMaster University Osteoarthritis Index (WOMAC......) and Oxford Knee scores were used to determine self-reported function. RESULTS: Normalized leg press power was more closely associated to both performance-based (r=.82, P...

Leg loss in Lutzomyia longipalpis (Diptera: Psychodidae) due to pyrethroid exposure: Toxic effect or defense by autotomy?

Science.gov (United States)

Santamaría, E; Cabrera, O L; Avendaño, J; Pardo, R H

2016-01-01

Phlebotomine sandflies lose their legs after exposure to pyrethroids. In some insects leg loss helps to defend them from intoxication and predation, a phenomenon known as autotomy. A field observation has shown that sandflies that have lost some legs are still able to blood-feed. The aims of the study were to determine whether leg loss in sandflies, after exposure to deltamethrin, is due to autotomy and to establish the effect of the leg loss on blood-feeding. Two experiments were carried out with Lutzomyia longipalpis: (i) Females were individually exposed to a sublethal time of deltamethrin and mortality and the number of leg loss were recorded; and (ii) Groups of females with complete legs or with 1-3 legs lost due to pyrethroid exposure were offered a blood meal and percentages of blood-fed and fully-fed females were recorded. Most females lost a median of 1 leg within 1-48 h post-exposure to deltamethrin. Mortality (after 24 h) was significantly higher for exposed females with lost legs (31.1%), compared to exposed females with complete legs (7.3%), and there were no differences in mortality between females with complete legs and the control (unexposed females). There were no differences between the three treatments in the percentages of blood-fed and fully-fed females. Leg loss in sandflies is a toxic effect of pyrethroids and there was no evidence of autotomy. The loss of up to three legs after exposure to pyrethroids does not affect blood-feeding behaviour in laboratory and probably also in wild conditions.

Living with clipped wings—Patients’ experience of losing a leg

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Annelise Norlyk

2013-10-01

Full Text Available This study explores the lived experience of losing a leg as described by the patients themselves post-discharge. Studies have documented that regardless of aetiology patients are faced with severe physical as well as psychosocial challenges post-amputation. However, only few studies explore in-depth the patients’ perspective on the various challenges following the loss of a leg. The study uses the phenomenological approach of Reflective Lifeworld Research (RLR. Data were collected from 24 in-depth interviews with 12 Danish patients. Data analysis was performed according to the guidelines given in RLR. The essential meaning of losing a leg is a radical and existential upheaval, which restricts patients’ lifestyle and irretrievably alters their lifeworld. Life after the operation is associated with despair, and a painful sense of loss, but also with the hope of regaining personal independence. The consequences of losing a leg gradually materialize as the patients realize how the loss of mobility limits their freedom. Patients experience the professional help as primarily directed towards physical care and rehabilitation. The findings show that the loss of a leg and, subsequently, the restricted mobility carry with them an existential dimension which refers to limitation of action space and loss of freedom experienced as an exclusion from life. Our findings demonstrate a need for complementary care and stress the importance of an increased awareness of the psychosocial and existential consequences of losing a limb.

Second-leg home advantage in the Copa Libertadores da América (2005-2015

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Cesar Cavinato Cal Abad

2017-11-01

Full Text Available ABSTRACT 24. Aims To investigate the home advantage (HA in the Copa Libertadores da América (CLA from 2005 to 2015. Methods A naive analysis was applied considering how many times a team that played the second leg at home qualified for the next round. To verify differences between home, away and draw results, the Chi-square ( χ2 and the Full Bayesian Significance Test were applied. For the binomial variables ("Home" or "Away", the probability of second-leg knockout occurrence was calculated. Results The probability of second-leg HA varied from 27.27% to 63.64% suggesting fluctuations of second-leg HA during competitive phases (round of 16, quarterfinals, semi-finals and final matches and decision forms (full time, goals away rule or penalty-shoots. Conclusion The results counteract the common belief that there is a large advantage to playing the second match of a two-leg tie at home during all competition phases. Penalty-shots seemed to affect positively the second-leg HA. Despite the causes of second leg HA in CLA need to be better investigated, soccer coaches could to use these results to think better strategies to win your knockout matches.

Effects of acute caffeine ingestion on resistance training performance and perceptual responses during repeated sets to failure.

Science.gov (United States)

Da Silva, V L; Messias, F R; Zanchi, N E; Gerlinger-Romero, F; Duncan, M J; Guimarães-Ferreira, L

2015-05-01

The aim of the present study was to evaluate the effect of oral caffeine ingestion during repeated sets of resistance. Fourteen moderately resistance-trained men (20.9 ± 0.36 years and 77.62 ± 2.07 kg of body weight) ingested a dose of caffeine (5 mg.kg-1) or placebo prior to 3 sets of bench press and 3 sets of leg press exercises, respectively. The study used a double-blind, counterbalanced, crossover design. Repetitions completed and total weight lifted were recorded in each set. Readiness to invest in both physical (RTIPE) and mental (RTIME) effort were assessed prior each set, and rating of perceived exertion (RPE) was recorded after each set. Rest and peak heart rates were determined via telemetry. Caffeine ingestion result in increased number of repetitions to failure in bench press (F[1,13]=6.16, P=0.027) and leg press (F[1,13]=9.33, P=0.009) compared to placebo. The sum of repetitions performed in the 3 sets was 11.60% higher in bench press (26.86 ± 1.74; caffeine: 30.00 ± 1.87; P=0.027) and 19.10% in leg press (placebo: 40.0 ± 4.22; caffeine: 47.64 ± 4.69; P=0.009). Also, RTIME was increased in the caffeine condition both in bench press (F[1,13]=7.02, P=0.02) and in leg press (F[1,13]=5.41, P=0.03). There were no differences in RPE, RTIPE and HR (P>0.05) across conditions. Acute caffeine ingestion can improve performance in repeated sets to failure and increase RTIME in resistance-trained men.

Numerical simulation of thermal stratification in cold legs by using OpenFOAM

International Nuclear Information System (INIS)

Cai, Jiejin; Watanabe, Tadashi

2011-01-01

During a small-break loss-of-coolant accident in pressurized water reactors (PWRs), emergency core cooling system (ECCS) is actuated and cold water is injected into cold legs. Insufficient mixing of injected cold water and hot primary coolant results in thermal stratification, which is a matter of concern for evaluation of pressurized thermal shock (PTS) in view of aging and life extension of nuclear power plants. In this study, an open source CFD software, OpenFOAM, is used to simulate mixing and thermal stratification in the cold leg of ROSA/LSTF, which is the largest thermal-hydraulic integral test facility simulating PWR. One of the cold-leg is numerically simulated from the outlet of primary coolant pump to the inlet of downcomer. ECCS water is injected from injection nozzle connected at the top of the cold leg into the steady-state natural circulation flow under high-pressure and high-temperature conditions. The temperature distribution in the cold leg is compared with experimental and FLUENT's results. Effects of turbulent flow models and secondary flow due to the elbow section of the cold leg are discussed for the case with the single-phase natural circulation. Injection into a two-phase stratified flow is also simulated and predictive and numerical capabilities of OpenFOAM are discussed. (author)

Vascular regulation of glioma stem-like cells: a balancing act.

Science.gov (United States)

Brooks, Lucy J; Parrinello, Simona

2017-12-01

Glioblastoma (GBM) are aggressive and therapy-resistant brain tumours driven by glioma stem-like cells (GSCs). GSC behaviour is controlled by the microenvironment, or niche, in which the cells reside. It is well-established that the vasculature is a key component of the GSC niche, which drives maintenance in the tumour bulk and invasion at the margin. Emerging evidence now indicates that the specific properties of the vasculature within these two regions impose different functional states on resident GSCs, generating distinct subpopulations. Here, we review these recent findings, focusing on the mechanisms that underlie GSC/vascular communication. We further discuss how plasticity enables GSCs to respond to vascular changes by interconverting bidirectionally between states, and address the therapeutic implications of this dynamic response. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

A comparison and update of direct kinematic-kinetic models of leg stiffness in human running.

Science.gov (United States)

Liew, Bernard X W; Morris, Susan; Masters, Ashleigh; Netto, Kevin

2017-11-07

Direct kinematic-kinetic modelling currently represents the "Gold-standard" in leg stiffness quantification during three-dimensional (3D) motion capture experiments. However, the medial-lateral components of ground reaction force and leg length have been neglected in current leg stiffness formulations. It is unknown if accounting for all 3D would alter healthy biologic estimates of leg stiffness, compared to present direct modelling methods. This study compared running leg stiffness derived from a new method (multiplanar method) which includes all three Cartesian axes, against current methods which either only include the vertical axis (line method) or only the plane of progression (uniplanar method). Twenty healthy female runners performed shod overground running at 5.0 m/s. Three-dimensional motion capture and synchronised in-ground force plates were used to track the change in length of the leg vector (hip joint centre to centre of pressure) and resultant projected ground reaction force. Leg stiffness was expressed as dimensionless units, as a percentage of an individual's bodyweight divided by standing leg length (BW/LL). Leg stiffness using the line method was larger than the uniplanar method by 15.6%BW/LL (P method by 24.2%BW/LL (P stiffness from the uniplanar method was larger than the multiplanar method by 8.5%BW/LL (6.5 kN/m) (P stiffness estimate with the multiplanar method. Given that limb movements typically occur in 3D, the new multiplanar method provides the most complete accounting of all force and length components in leg stiffness calculation. Copyright © 2017 Elsevier Ltd. All rights reserved.

X-Ray Exam: Femur (Upper Leg)

Science.gov (United States)

... Staying Safe Videos for Educators Search English Español X-Ray Exam: Femur (Upper Leg) KidsHealth / For Parents / X- ... Muscles, and Joints Broken Bones Getting an X-ray (Video) X-Ray (Video) View more Partner Message About Us ...

Pediatric vascular access

International Nuclear Information System (INIS)

Donaldson, James S.

2006-01-01

Pediatric interventional radiologists are ideally suited to provide vascular access services to children because of inherent safety advantages and higher success from using image-guided techniques. The performance of vascular access procedures has become routine at many adult interventional radiology practices, but this service is not as widely developed at pediatric institutions. Although interventional radiologists at some children's hospitals offer full-service vascular access, there is little or none at others. Developing and maintaining a pediatric vascular access service is a challenge. Interventionalists skilled in performing such procedures are limited at pediatric institutions, and institutional support from clerical staff, nursing staff, and technologists might not be sufficiently available to fulfill the needs of such a service. There must also be a strong commitment by all members of the team to support such a demanding service. There is a slippery slope of expected services that becomes steeper and steeper as the vascular access service grows. This review is intended primarily as general education for pediatric radiologists learning vascular access techniques. Additionally, the pediatric or adult interventional radiologist seeking to expand services might find helpful tips. The article also provides education for the diagnostic radiologist who routinely interprets radiographs containing vascular access devices. (orig.)

High pulmonary vascular resistance in addition to low right ventricular stroke work index effectively predicts biventricular assist device requirement.

Science.gov (United States)

Imamura, Teruhiko; Kinugawa, Koichiro; Kinoshita, Osamu; Nawata, Kan; Ono, Minoru

2016-03-01

Although the right ventricular stroke work index (RVSWI) is a good index for RV function, a low RVSWI is not necessarily an indicator for the need for a right ventricular assist device at the time of left VAD implantation. We here aimed to determine a more precise indicator for the need for a biventricular assist device (BiVAD). In total, 116 patients (mean age, 38 ± 14 years), who underwent hemodynamic assessments preoperatively including 12 BiVAD patients, and had been followed at our institute from 2003 to 2015, were included. Multivariate logistic regression analysis indicated that RVSWI and pulmonary vascular resistance (PVR) were independent predictors of BiVAD requirement (P 5 g/m, PVR 5, PVR > 3.7), (3) RV failure (RVSWI 3.7), and examined. Most of the patients in Group 4 (75 %), with acutely depressed hemodynamics and inflammatory responses in the myocardium, required BiVAD. Overall, patients with BiVAD had a worse survival rate as compared with those with LVAD alone. In conclusion, high PVR in addition to low RVSWI effectively predicts BiVAD requirement.

The bothersomeness of sciatica: patients' self-report of paresthesia, weakness and leg pain.

Science.gov (United States)

Grøvle, Lars; Haugen, Anne Julsrud; Keller, Anne; Natvig, Bård; Brox, Jens Ivar; Grotle, Margreth

2010-02-01

The objective of the study was to investigate how patients with sciatica due to disc herniation rate the bothersomeness of paresthesia and weakness as compared to leg pain, and how these symptoms are associated with socio-demographic and clinical characteristics. A cross-sectional study was conducted on 411 patients with clinical signs of radiculopathy. Items from the Sciatica Bothersomeness Index (0 = none to 6 = extremely) were used to establish values for paresthesia, weakness and leg pain. Associations with socio-demographic and clinical variables were analyzed by multiple linear regression. Mean scores (SD) were 4.5 (1.5) for leg pain, 3.4 (1.8) for paresthesia and 2.6 (2.0) for weakness. Women reported higher levels of bothersomeness for all three symptoms with mean scores approximately 10% higher than men. In the multivariate models, more severe symptoms were associated with lower physical function and higher emotional distress. Muscular paresis explained 19% of the variability in self-reported weakness, sensory findings explained 10% of the variability in paresthesia, and straight leg raising test explained 9% of the variability in leg pain. In addition to leg pain, paresthesia and weakness should be assessed when measuring symptom severity in sciatica.

Elastin and Mechanics of Pig Pericardial Resistance Arteries (pPRA)

DEFF Research Database (Denmark)

Bloksgaard, Maria; Leurgans, Thomas; Rosenstand, Kristoffer

Resistance arteries are remodeled in hypertension and diabetes. Elastin was reported to play a role herein. The parietal pericardium is opened during cardio-thoracic surgeries and might be a valuable biopsy for research in cardio-vascular diseases. We tested the hypothesis that resistance arteries...... can be isolated from the pericardium to study the micro-architecture of elastin and vascular wall mechanics. The pericardium of pigs served to test the hypothesis. pPRAs were microdissected. Their structure was examined using multiphoton excitation fluorescence microscopy. Diameter......-tension and pressure-diameter-length relationships were recorded in myographs. Findings are compared to rodent mesenteric resistance arteries and –basilar arteries (rMRA, rBA) with comparable lumen diameter (±300µm at 100mmHg). pPRA have no clear external elastic lamina (present in rMRA, but not rBA), scant elastin...

Influence of “J”-Curve Spring Stiffness on Running Speeds of Segmented Legs during High-Speed Locomotion

Directory of Open Access Journals (Sweden)

Runxiao Wang

2016-01-01

Full Text Available Both the linear leg spring model and the two-segment leg model with constant spring stiffness have been broadly used as template models to investigate bouncing gaits for legged robots with compliant legs. In addition to these two models, the other stiffness leg spring models developed using inspiration from biological characteristic have the potential to improve high-speed running capacity of spring-legged robots. In this paper, we investigate the effects of “J”-curve spring stiffness inspired by biological materials on running speeds of segmented legs during high-speed locomotion. Mathematical formulation of the relationship between the virtual leg force and the virtual leg compression is established. When the SLIP model and the two-segment leg model with constant spring stiffness and with “J”-curve spring stiffness have the same dimensionless reference stiffness, the two-segment leg model with “J”-curve spring stiffness reveals that (1 both the largest tolerated range of running speeds and the tolerated maximum running speed are found and (2 at fast running speed from 25 to 40/92 m s−1 both the tolerated range of landing angle and the stability region are the largest. It is suggested that the two-segment leg model with “J”-curve spring stiffness is more advantageous for high-speed running compared with the SLIP model and with constant spring stiffness.

Cervical cord compression presenting with sciatica-like leg pain

OpenAIRE

Chan, Chee Keong; Lee, Ho-Yeon; Choi, Won-Chul; Cho, Ji Young; Lee, Sang-Ho

2010-01-01

Sciatica-like leg pain can be the main presenting symptom in patients with cervical cord compression. It is a false localizing presentation, which may lead to missed or delayed diagnosis, resulting in the wrong plan of management, especially in the presence of concurrent lumbar lesions. Medical history, physical findings and the results of imaging studies were reviewed in two cases of cervical cord compressions, which presented with sciatica-like leg pain. There was multi-level cervical spond...

Why do arms extract less oxygen than legs during exercise?

DEFF Research Database (Denmark)

Calbet, J A L; Holmberg, H-C; Rosdahl, H

2005-01-01

To determine whether conditions for O2 utilization and O2 off-loading from the hemoglobin are different in exercising arms and legs, six cross-country skiers participated in this study. Femoral and subclavian vein blood flow and gases were determined during skiing on a treadmill at approximately 76...... exercise (diagonal stride), the corresponding mean values were 93 and 85% (n = 3; P hemoglobin to be 50% saturated (P50: r = 0.93, P ...Hg, respectively. Because conditions for O2 off-loading from the hemoglobin are similar in leg and arm muscles, the observed differences in maximal arm and leg O2 extraction should be attributed to other factors, such as a higher heterogeneity in blood flow distribution, shorter mean transit time, smaller...

Multi-Axis Prosthetic Knee Resembles Alpine Skiing Movements of an Intact Leg

Directory of Open Access Journals (Sweden)

Ivan Demšar, Jože Duhovnik, Blaž Lešnik, Matej Supej

2015-12-01

Full Text Available The purpose of the study was to analyse the flexion angles of the ski boot, ankle and knee joints of an above-knee prosthesis and to compare them with an intact leg and a control group of skiers. One subject with an above-knee amputation of the right leg and eight healthy subjects simulated the movement of a skiing turn by performing two-leg squats in laboratory conditions. By adding additional loads in proportion to body weight (BW; +1/3 BW, +2/3 BW, +3/3 BW, various skiing regimes were simulated. Change of Flexion Angle (CoFA and Range of Motion (RoM in the ski boot, ankle and knee joints were calculated and compared. An average RoM in the skiing boot on the side of prosthesis (4.4 ± 1.1° was significantly lower compared to an intact leg (5.9 ± 1.8° and the control group (6.5 ± 2.3°. In the ankle joint, the average RoM was determined to be 13.2±2.9° in the prosthesis, 12.7 ± 2.8° in an intact leg and 14.8±3.6 in the control group. However, the RoM of the knee joint in the prosthesis (42.2 ± 4.2° was significantly larger than that of the intact leg (34.7 ± 4.4°. The average RoM of the knee joint in the control group was 47.8 ± 5.4°. The influences of additional loads on the kinematics of the lower extremities were different on the side of the prosthesis and on the intact leg. In contrast, additional loads did not produce any significant differences in the control group. Although different CoFAs in the ski boot, ankle and knee joints were used, an above-knee prosthesis with a built-in multi-axis prosthetic knee enables comparable leg kinematics in simulated alpine skiing.

Effect of oxidative stress on racial differences in vascular function at rest and during hand grip exercise.

Science.gov (United States)

Kappus, Rebecca M; Bunsawat, Kanokwan; Brown, Michael D; Phillips, Shane A; Haus, Jacob M; Baynard, Tracy; Fernhall, Bo

2017-10-01

African-Americans have a higher prevalence of hypertension compared with whites, possibly due to elevated oxidative stress and subsequent vascular dysfunction. It is unclear the contribution of aging on oxidative stress and vascular function in a racially diverse cohort. Ninety-three young and older African-American and white participants received antioxidant (AOX) or placebo supplementation in a double-blind, randomized, cross-over design. Measures of endothelial function (reactive hyperemia, flow-mediated dilation), exercise blood flow, and biomarkers of oxidative stress and AOX activity were measured following supplementation. In young adults, there were racial differences in resistance vessel response to reactive hyperemia and no effects of race on macrovascular function following AOX supplementation. Following AOX supplementation, older white adults improved while African-Americans reduced resistance vessel function responses to reactive hyperemia, whereas macrovascular function improved in both races, with a greater increase in African-Americans. There were racial differences in blood flow normalized to lean mass during handgrip exercise at 20% maximal voluntary contraction in the young group and AOX supplementation led to increased forearm vascular conductance in older whites with a decrease in older African-Americans. There was a supplement effect in superoxide dismutase activity in younger adults only. The results of the current study show that there are differential effects of AOX supplementation on macrovascular and resistance vessel function, and this is impacted by both age and race.

Vascular responses to radiotherapy and androgendeprivation therapy in experimental prostate cancer

LENUS (Irish Health Repository)

2012-05-23

AbstractBackgroundRadiotherapy (RT) and androgen-deprivation therapy (ADT) are standard treatments for advanced prostate cancer (PC). Tumor vascularization is recognized as an important physiological feature likely to impact on both RT and ADT response, and this study therefore aimed to characterize the vascular responses to RT and ADT in experimental PC.MethodsUsing mice implanted with CWR22 PC xenografts, vascular responses to RT and ADT by castration were visualized in vivo by DCE MRI, before contrast-enhancement curves were analyzed both semi-quantitatively and by pharmacokinetic modeling. Extracted image parameters were correlated to the results from ex vivo quantitative fluorescent immunohistochemical analysis (qIHC) of tumor vascularization (9 F1), perfusion (Hoechst 33342), and hypoxia (pimonidazole), performed on tissue sections made from tumors excised directly after DCE MRI.ResultsCompared to untreated (Ctrl) tumors, an improved and highly functional vascularization was detected in androgen-deprived (AD) tumors, reflected by increases in DCE MRI parameters and by increased number of vessels (VN), vessel density ( VD), and vessel area fraction ( VF) from qIHC. Although total hypoxic fractions ( HF) did not change, estimated acute hypoxia scores ( AHS) – the proportion of hypoxia staining within 50 μm from perfusion staining – were increased in AD tumors compared to in Ctrl tumors. Five to six months after ADT renewed castration-resistant (CR) tumor growth appeared with an even further enhanced tumor vascularization. Compared to the large vascular changes induced by ADT, RT induced minor vascular changes. Correlating DCE MRI and qIHC parameters unveiled the semi-quantitative parameters area under curve ( AUC) from initial time-points to strongly correlate with VD and VF, whereas estimation of vessel size ( VS) by DCE MRI required pharmacokinetic modeling. HF was not correlated to any DCE MRI parameter, however, AHS may be estimated after

Nocturnal variations in lower-leg subcutaneous blood flow in paraplegic men

DEFF Research Database (Denmark)

Sindrup, J H; Wroblewski, H; Kastrup, J

1992-01-01

1. Lower-leg subcutaneous adipose tissue blood flow rates were measured over 12-20 h under ambulatory conditions by means of the 133Xe-washout technique in nine paraplegic men, all with complete spinal cord lesions at or below the Th 6 level, and in nine age-matched healthy men. Portable Cd......Te(Cl) detectors and data-storage units were used. 2. The central and local sympathetic vasoconstrictive activity at the lower leg was measured under laboratory conditions by means of the 133Xe-washout technique and a stationary NaI(Tl) detector system. 3. The paraplegic men were found to have intact central...... the paraplegic men suffered from complete lower-leg somaesthetic denervation. 5. A significant correlation was found between the time of going to bed and the nightly hyperaemic response in the right and left lower legs (P less than 0.01). 6. It is concluded that the present data are in accordance...