Subanalysis of the CONFIRM Registries: Acute Procedural Outcomes in Claudicant and Critical Limb Ischemia Patients With Varying Levels of Calcification Treated for Peripheral Arterial Disease With Orbital Atherectomy.

PubMed

Adams, George L; Das, Tony; Lee, Michael S; Beasley, Robert; Mustapha, Jihad

2015-11-01

Patients with peripheral arterial disease (PAD) can be classified into groups based upon the severity of the disease using the Rutherford classification system. This analysis compares the procedural outcomes of PAD patients treated with orbital atherectomy stratified by Rutherford class (1-3 = intermittent claudication; 4-6 = critical limb ischemia [CLI]), and acute angiographic outcomes of these patients stratified by degree of lesion calcification. The CONFIRM registry series was analyzed and included 1697 patients with intermittent claudication (Rutherford class 1-3) and 1320 patients with CLI (Rutherford class 4-6) treated with orbital atherectomy. The composite rate of dissection, perforation, slow-flow, vessel closure, spasm, embolism, and thrombus formation was compared between claudicants and CLI patients with varying degrees of lesion calcification. Patients with CLI were older and had a higher prevalence of diabetes, coronary artery disease, and renal disease (P<.001). Claudicants with moderately/severely calcified lesions had a lower rate of dissection (both non-flow limiting and flow-limiting) than claudicants with mildly/minimally calcified lesions. CLI patients with mildly/minimally calcified lesions had higher rates of embolism and thrombus than CLI patients with moderately/severely calcified lesions. Plaque modification with orbital atherectomy resulted in similar low procedural complication rates in the CLI group compared with the claudicant group. These results suggest that orbital atherectomy is safe and effective for treating calcified lesions in high-risk patients with varying severity of PAD symptoms.

Abdominal Aortic Hemodynamics in Intermittent Claudication Patients at Rest and During Dynamic Pedaling Exercise

PubMed Central

Cheng, Christopher P.; Taylor, Charles A.; Dalman, Ronald L.

2015-01-01

Introduction Lower extremity exercise has been shown to eliminate adverse hemodynamics conditions, such as low and oscillating blood flow and wall shear stress, in the abdominal aortas of healthy young and older adults. Methods We use cine phase-contrast magnetic resonance imaging and a custom MRI-compatible exercise cycle to quantify hemodynamic changes due to pedaling exercise in patients diagnosed with intermittent claudication. Results and Conclusions With only an average heart increase of 35±18% and exercise workload of 36±16 Watts, the patients experienced approximately 3- and 6-fold increases in blood flow, and 4- and 16-fold increases in wall shear stress at the supraceliac and infrarenal aortic locations, respectively. Also, all oscillations in flow and shear stress at rest were eliminated with exercise. Claudication patients experience 3 to 4-fold lower oscillations in flow and shear stress at rest as compared to healthy age-matched controls, likely due to reduced distal arterial compliance as a result of distal atherosclerosis. The magnitude of flow and shear oscillatory indices may be good indicators of distal arterial compliance and health, and may provide predictive power for the efficacy of focal interventions. PMID:26315797

The severity of muscle ischemia during intermittent claudication.

PubMed

Egun, Anselm; Farooq, Vasim; Torella, Francesco; Cowley, Richard; Thorniley, Maureen S; McCollum, Charles N

2002-07-01

The degree of ischemia during intermittent claudication is difficult to quantify. We evaluated calf muscle ischemia during exercise in patients with claudication with near infrared spectroscopy. A Critikon Cerebral Redox Model 2001 (Johnson & Johnson Medical, Newport, Gwent, United Kingdom) was used to measure calf muscle deoxygenated hemoglobin (HHb), oxygenated hemoglobin (O(2)Hb), and total hemoglobin levels and oxygenation index (HbD; HbD = O(2)Hb - HHb) in 16 patients with claudication and in 14 control subjects before, during, and after walking on a treadmill for 1 minute (submaximal exercise). These measures were repeated after a second maximal exercise in patients with claudication and after 7 minutes walking in control subjects. Near-infrared spectroscopy readings during maximal exercise were then compared with a model of total ischemia induced with tourniquet in 16 young control subjects. Total hemoglobin level changed little during exercise in both patients with claudication and control subjects. HHb levels rose, and O(2)Hb level and HbD falls were more pronounced in patients with claudication than in control subjects after submaximal and maximal exercise. During maximal exercise, HbD fell markedly by a median (interquartile range) of 210.5 micromol/cm (108.2 to 337.0 micromol/cm) in patients with claudication compared with 66.0 micromol/cm (44.0 to 101.0 micromol/cm) in elderly control subjects and 41.0 micromol/cm (36.0 to 65.0 micromol/cm) in young control subjects (P <.001). This fall also was greater than the HbD fall induced with tourniquet ischemia at 90.8 micromol/cm (57.6 to 126.2 micromol/cm; P =.006). Hemoglobin desaturation in exercising calf muscle is profound in patients with claudication, considerably greater even than that induced with three minutes of tourniquet occlusion. Further studies are necessary to investigate the relationship between the inflammatory response and near-infrared spectroscopy during exercise in patients with claudication.

Patient Characteristics and Comorbidities Influence Walking Distances in Symptomatic Peripheral Arterial Disease: A Large One-Year Physiotherapy Cohort Study.

PubMed

Dörenkamp, Sarah; Mesters, Ilse; de Bie, Rob; Teijink, Joep; van Breukelen, Gerard

2016-01-01

The aim of this study is to investigate the association between age, gender, body-mass index, smoking behavior, orthopedic comorbidity, neurologic comorbidity, cardiac comorbidity, vascular comorbidity, pulmonic comorbidity, internal comorbidity and Initial Claudication Distance during and after Supervised Exercise Therapy at 1, 3, 6 and 12 months in a large sample of patients with Intermittent Claudication. Data was prospectively collected in standard physiotherapy care. Patients received Supervised Exercise Therapy according to the guideline Intermittent Claudication of the Royal Dutch Society for Physiotherapy. Three-level mixed linear regression analysis was carried out to analyze the association between patient characteristics, comorbidities and Initial Claudication Distance at 1, 3, 6 and 12 months. Data from 2995 patients was analyzed. Results showed that being female, advanced age and a high body-mass index were associated with lower Initial Claudication Distance at all-time points (p = 0.000). Besides, a negative association between cardiac comorbidity and Initial Claudication Distance was revealed (p = 0.011). The interaction time by age, time by body-mass index and time by vascular comorbidity were significantly associated with Initial Claudication Distance (p≤ 0.05). Per year increase in age (range: 33-93 years), the reduction in Initial Claudication Distance was 8m after 12 months of Supervised Exercise Therapy. One unit increase in body-mass index (range: 16-44 kg/m2) led to 10 m less improvement in Initial Claudication Distance after 12 months and for vascular comorbidity the reduction in improvement was 85 m after 12 months. This study reveals that females, patients at advanced age, patients with a high body-mass index and cardiac comorbidity are more likely to show less improvement in Initial Claudication Distances (ICD) after 1, 3, 6 and 12 months of Supervised Exercise Therapy. Further research should elucidate treatment adaptations that optimize treatment outcomes for these subgroups.

Sagittal plane joint kinetics during stair ascent in patients with peripheral arterial disease and intermittent claudication.

PubMed

King, Stephanie L; Vanicek, Natalie; O'Brien, Thomas D

2017-06-01

Stair negotiation poses a substantial physical demand on the musculoskeletal system and this challenging task can place individuals at risk of falls. Peripheral arterial disease (PAD) can cause intermittent claudication (IC) pain in the calf and results in altered gait mechanics during level walking. However, whether those with PAD-IC adopt alternate strategies to climb stairs is unknown. Twelve participants with PAD-IC (six bilateral and six unilateral) and 10 healthy controls were recruited and instructed to ascend a five-step staircase whilst 3D kinematic data of the lower-limbs were recorded synchronously with kinetic data from force plates embedded into the staircase on steps two and three. Limbs from the unilateral group and both limbs from the bilateral claudicants were categorised as claudicating (N=18), asymptomatic (N=6) and control (N=10). Claudicants walked more slowly than healthy controls (trend; P=<0.066). Both claudicating- and asymptomatic-limb groups had reduced propulsive GRF (P=0.025 and P=0.002, respectively) and vertical GRF (P=0.005 and P=0.001, respectively) compared to controls. The claudicating-limb group had a reduced knee extensor moment during forward continuance (P=0.060), ankle angular velocity at peak moment (P=0.039) and ankle power generation (P=0.055) compared to the controls. The slower gait speed, irrespective of laterality of symptoms, indicates functional capacity was determined by the limitations of the claudicating limb. Reduced ankle power generation and angular velocity (despite adequate plantarflexor moment) implies velocity-dependent limitations existed in the calf. The lack of notable compensatory strategies indicates reliance on an impaired muscle group to accomplish this potentially hazardous task, highlighting the importance of maintaining plantarflexor strength and power in those with PAD-IC. Copyright © 2017 Elsevier B.V. All rights reserved.

Validation of the Walking Impairment Questionnaire for Spanish patients.

PubMed

Lozano, Francisco S; March, José R; González-Porras, José R; Carrasco, Eduardo; Lobos, José M; Areitio-Aurtena, Alix

2013-09-01

The Walking Impairment Questionnaire (WIQ) is a short, easy to complete, disease-specific questionnaire to assess intermittent claudication. A Spanish version of the WIQ for Hispanic Americans has recently been validated in Texas, but it needs to be validated for European Spanish people. After translation and cultural adaptation of the WIQ, 920 patients with intermittent claudication (ankle brachial index < 0.9) completed two questionnaires (Spanish version of the WIQ and European Quality of Life 5 Dimension [EQ-5D]). The validity of the WIQ was determined by correlating WIQ and EQ-5D. Test-retest reliability and internal consistency were determined using the intra-class correlation coefficient (ICC) and Cronbach's alpha, respectively. The three domains of the WIQ were moderately correlated with the EQ-5D health outcome (r = 0.54 to 0.60; p < 0.001). Test-retest reliabilities ranged from ICC = 0.89 to 0.91 and internal consistency (Cronbach's alpha = 0.92) was high. The Spanish version of the WIQ for European Spanish patients was valid and reproducible, suggesting that it could be used in Spanish patients with intermittent claudication.

Gender and ethnic differences in arterial compliance in patients with intermittent claudication.

PubMed

Gardner, Andrew W; Montgomery, Polly S; Blevins, Steve M; Parker, Donald E

2010-03-01

To assess the gender and ethnic differences in arterial compliance in patients with intermittent claudication. A total of 114 patients participated, including 38 Caucasian men, 32 Caucasian women, 16 African American men, and 28 African American women. Patients were assessed on large artery elasticity index (LAEI), small artery elasticity index (SAEI), age, weight, body mass index, ankle-brachial index (ABI), smoking status, and metabolic syndrome components. Group differences were found for LAEI (P = .042), SAEI (P = .019), body mass index (P = .020), prevalence of elevated fasting glucose (P = .001), and prevalence of abdominal obesity (P = .025). Significant covariates for LAEI included age (P = .0002) and elevated triglycerides (P = .0719). LAEI (units = 10 mL x mm Hg) adjusted for age and triglycerides was 39% lower (P = .0005) in African Americans (11.4 +/- .90; mean +/- SE) than in Caucasians (15.8 +/- 0.72), whereas no significant difference (P = .7904) existed between men (13.8 +/- 0.81) and women (13.5 +/- 0.79). Significant covariates for SAEI included age (P = .0001), abdominal obesity (P = .0030), and elevated blood pressure (P = .0067). SAEI (units = 100 mL x mm Hg) adjusted for age, abdominal obesity, and elevated blood pressure was 32% lower (P = .0007) in African-Americans (2.8 +/- 0.3) than in Caucasians 4.1 +/- 0.2), and was 18% lower (P = .0442) in women (3.1 +/- 0.2) than in men (3.8 +/- 0.2). African American patients with intermittent claudication have more impaired macrovascular and microvascular function than Caucasian patients, and women have more impaired microvascular function than men. These ethnic and gender differences in arterial compliance are evident even though ABI was similar among groups, suggesting that arterial compliance provides unique information to quantify vascular impairment in patients with intermittent claudication.

Imaging popliteal artery disease in young adults with claudication: self-assessment module.

PubMed

Chew, Felix S; Bui-Mansfield, Liem T

2007-09-01

The educational objectives of this self-assessment module on imaging popliteal artery disease in young adults with intermittent claudication are for the participant to exercise, self-assess, and improve his or her knowledge of the imaging and clinical features of popliteal artery entrapment syndrome, cystic adventitial disease,and masses associated with popliteal artery obstruction.

[Objective evaluation of arterial intermittent claudication by the walking tolerance test. Comparative study of physiological walking and walking on a conveyor belt (author's transl)].

PubMed

Bouchet, J Y; Franco, A; Morzol, B; Beani, J C

1980-01-01

Two methods are used to evaluate the walking distance: physiological walking along a standard path (0% - 6 mk/h) and walking on a tread mill (10% - 3 km/h). In both tests, four data are checked: -- initial trouble distance, -- cramp or walking-distance, -- localisation of pain, -- recovery time. These tests are dependable for the diagnosis of arterial claudication, reproducible and well tolerated. Their results have been compared: there is no correlation between the initial trouble distance and the cramp distance. However there is a correlation between the cramp distance by physiological walking and on treadmill. Recovery time, if long, is a criteria of gravity. Interests of both methods are discussed.

[Lumbar spondylosis].

PubMed

Seichi, Atsushi

2014-10-01

Lumbar spondylosis is a chronic, noninflammatory disease caused by degeneration of lumbar disc and/or facet joints. The etiology of lumbar spondylosis is multifactorial. Patients with lumbar spondylosis complain of a broad variety of symptoms including discomfort in the low back lesion, whereas some of them have radiating leg pain or neurologenic intermittent claudication (lumbar spinal stenosis). The majority of patients with spondylosis and stenosis of the lumbosacral spine can be treated nonsurgically. Nonsteroidal anti-inflammatory drugs and COX-2 inhibitors are helpful in controlling symptoms. Prostaglandin, epidural injection, and transforaminal injection are also helpful for leg pain and intermittent claudication. Operative therapy for spinal stenosis or spondylolisthesis is reserved for patients who are totally incapacitated by their condition.

A systematic review to evaluate the effectiveness of carnitine supplementation in improving walking performance among individuals with intermittent claudication.

PubMed

Delaney, Christopher L; Spark, J Ian; Thomas, Jolene; Wong, Yew Toh; Chan, Lok Tsung; Miller, Michelle D

2013-07-01

To evaluate the evidence for the use of carnitine supplementation in improving walking performance among individuals with intermittent claudication. Systematic review. An electronic search of the literature was performed using MEDLINE (PubMed), Scopus, Cochrane Central Register of Controlled Trials and The Cochrane Library from inception through to November 2012. Search terms included peripheral arterial disease, intermittent claudication and carnitine. Reference lists of review articles and primary studies were also examined. Full reports of published experimental studies including randomized controlled trials and pre-test/post-test trials were selected for inclusion. A quality assessment was undertaken according to the Jadad scale. A total of 40 articles were retrieved, of which 23 did not meet the inclusion criteria. The 17 included articles reported on a total of 18 experimental studies of carnitine supplementation (5 pre-test/post-test; 8 parallel RCT; 5 cross-over RCT) for improving walking performance in adults with intermittent claudication. For pre-test/post-test studies, 300-2000 mg propionyl-L-carnitine (PLC) was administered orally or intravenously for a maximum of 90 days (7-42 participants) with statistically significant improvements of between 74 m and 157 m in pain free walking distance and between 71 m and 135 m in maximal walking distance across 3 out of 5 studies. Similarly, PLC (600 mg-3000 mg) was administered orally in 7 out of 8 parallel RCTs (22-485 participants), the longest duration being 12 months. All but one of the smallest trials demonstrated statistically significant improvements in walking performance between 31 and 54 m greater than placebo for pain free walking distance and between 9 and 86 m greater than placebo for maximal walking distance. A double-blind parallel RCT of cilostazol plus 2000 mg oral L-carnitine or placebo for 180 days (145 participants) did not demonstrate any significant improvement in walking performance. Of 5 cross-over RCTs (8-20 participants), 4 demonstrated significant improvements in walking performance following administration of 300-6000 mg L-carnitine or PLC. Compared to placebo, pain free walking distance and maximal walking distance improved by 23-132 m and 104 m respectively following carnitine intervention. Most trials demonstrated a small or modest improvement in walking performance with administration of PLC or L-carnitine. These findings were largely independent of level or quality of evidence, while there was some evidence that intravenous administration was more effective than oral administration and those with severe claudication may achieve greater benefits than those with moderate claudication. Routine carnitine supplementation in the form of PLC may therefore be a useful adjunct therapy for management of intermittent claudication. Further research is warranted to determine the optimal form, duration, dose and safety of carnitine supplementation across the spectrum of peripheral arterial disease severity and its effect with concurrent supervised exercise programs and best medical therapy. These studies should be supplemented with cost effectiveness studies to ensure that the return on the investment is acceptable. Crown Copyright © 2013. Published by Elsevier Ireland Ltd. All rights reserved.

Transcutaneous Electrical Nerve Stimulation Improves Walking Performance in Patients With Intermittent Claudication.

PubMed

Seenan, Chris; McSwiggan, Steve; Roche, Patricia A; Tan, Chee-Wee; Mercer, Tom; Belch, Jill J F

2016-01-01

The purpose of this study was to investigate the effects of 2 types of transcutaneous electrical nerve stimulation (TENS) on walking distance and measures of pain in patients with peripheral arterial disease (PAD) and intermittent claudication (IC). In a phase 2a study, 40 participants with PAD and IC completed a graded treadmill test on 2 separate testing occasions. Active TENS was applied to the lower limb on the first occasion; and placebo TENS, on the second. The participants were divided into 2 experimental groups. One group received high-frequency TENS; and the other, low-frequency TENS. Measures taken were initial claudication distance, functional claudication distance, and absolute claudication distance. The McGill Pain Questionnaire (MPQ) vocabulary was completed at the end of the intervention, and the MPQ-Pain Rating Index score was calculated. Four participants were excluded from the final analysis because of noncompletion of the experimental procedure. Median walking distance increased with high-frequency TENS for all measures (P < .05, Wilcoxon signed rank test, all measures). Only absolute claudication distance increased significantly with low-frequency TENS compared with placebo (median, 179-228; Ws = 39; z = 2.025; P = .043; r = 0.48). No difference was observed between reported median MPQ-Pain Rating Index scores: 21.5 with placebo TENS and 21.5 with active TENS (P = .41). Transcutaneous electrical nerve stimulation applied to the lower limb of the patients with PAD and IC was associated with increased walking distance on a treadmill but not with any reduction in pain. Transcutaneous electrical nerve stimulation may be a useful adjunctive intervention to help increase walking performance in patients with IC.

The reliability of differentiating neurogenic claudication from vascular claudication based on symptomatic presentation.

PubMed

Nadeau, Mélissa; Rosas-Arellano, M Patricia; Gurr, Kevin R; Bailey, Stewart I; Taylor, David C; Grewal, Ruby; Lawlor, D Kirk; Bailey, Chris S

2013-12-01

Intermittent claudication can be neurogenic or vascular. Physicians use a profile based on symptom attributes to differentiate the 2 types of claudication, and this guides their investigations for diagnosis of the underlying pathology. We evaluated the validity of these symptom attributes in differentiating neurogenic from vascular claudication. Patients with a diagnosis of lumbar spinal stenosis (LSS) or peripheral vascular disease (PVD) who reported claudication answered 14 questions characterizing their symptoms. We determined the sensitivity, specificity and positive and negative likelihood ratios (PLR and NLR) for neurogenic and vascular claudication for each symptom attribute. We studied 53 patients. The most sensitive symptom attribute to rule out LSS was the absence of "triggering of pain with standing alone" (sensitivity 0.97, NLR 0.050). Pain alleviators and symptom location data showed a weak clinical significance for LSS and PVD. Constellation of symptoms yielded the strongest associations: patients with a positive shopping cart sign whose symptoms were located above the knees, triggered with standing alone and relieved with sitting had a strong likelihood of neurogenic claudication (PLR 13). Patients with symptoms in the calf that were relieved with standing alone had a strong likelihood of vascular claudication (PLR 20.0). The classic symptom attributes used to differentiate neurogenic from vascular claudication are at best weakly valid independently. However, certain constellation of symptoms are much more indicative of etiology. These results can guide general practitioners in their evaluation of and investigation for claudication.

Development of quality indicators for physiotherapy for patients with PAOD in the Netherlands: a Delphi study.

PubMed

Gijsbers, H J H; Lauret, G J; van Hofwegen, A; van Dockum, T A; Teijink, J A W; Hendriks, H J M

2016-06-01

The aim of the study was to develop quality indicators (QIs) for physiotherapy management of patients with intermittent claudication (IC) in the Netherlands. As part of an international six-step method to develop QIs, an online survey Delphi-procedure was completed. After two Delphi-rounds a validation round was performed. Twenty-six experts were recruited to participate in this study. Twenty-four experts completed two Delphi-rounds. A third round was conducted inviting 1200 qualified and registered physiotherapists of the Dutch integrated care network 'Claudicationet' to validate a draft set of quality indicators. Out of 83 potential QIs in the Dutch physiotherapy guideline on 'Intermittent claudication', consensus among the experts selected nine indicators. All nine quality indicators were validated by 300 physiotherapists. A final set of nine indicators was derived from (1) a Dutch evidence-based physiotherapy guideline, (2) an expert Delphi procedure and (3) a validation by 300 physiotherapists. This set of indicators should be validated in clinical practice. Copyright © 2015 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

Ginkgo biloba for intermittent claudication.

PubMed

Nicolaï, Saskia P A; Kruidenier, Lotte M; Bendermacher, Bianca L W; Prins, Martin H; Stokmans, Rutger A; Broos, Pieter P H L; Teijink, Joep A W

2013-06-06

People with intermittent claudication (IC) suffer from pain in the muscles of the leg occurring during exercise which is relieved by a short period of rest. Symptomatic relief can be achieved by (supervised) exercise therapy and pharmacological treatments. Ginkgo biloba is a vasoactive agent and is used to treat IC. To assess the effect of Ginkgo biloba on walking distance in people with intermittent claudication. For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (March 2013) and CENTRAL (2013, Issue 2). Randomised controlled trials of Ginkgo biloba extract, irrespective of dosage, versus placebo in people with IC. Two authors independently assessed trials for selection, assessed study quality and extracted data. We extracted number of patients, mean walking distances or times and standard deviations. To standardise walking distance or time, caloric expenditures were used to express the difference between the different treadmill protocols, which were calculated from the speed and incline of the treadmill. Fourteen trials with a total of 739 participants were included. Eleven trials involving 477 participants compared Ginkgo biloba with placebo and assessed the absolute claudication distance (ACD). Following treatment with Ginkgo biloba at the end of the study the ACD increased with an overall effect size of 3.57 kilocalories (confidence interval (CI) -0.10 to 7.23, P = 0.06), compared with placebo. This translates to an increase of just 64.5 ( CI -1.8 to 130.7) metres on a flat treadmill with an average speed of 3.2 km/h. Publication bias leading to missing data or "negative" trials is likely to have inflated the effect size. Overall, there is no evidence that Ginkgo biloba has a clinically significant benefit for patients with peripheral arterial disease.

The Claudication: Exercise Vs. Endoluminal Revascularization (CLEVER) study: rationale and methods.

PubMed

Murphy, Timothy P; Hirsch, Alan T; Ricotta, John J; Cutlip, Donald E; Mohler, Emile; Regensteiner, Judith G; Comerota, Anthony J; Cohen, David J

2008-06-01

Intermittent claudication is the primary symptom of peripheral arterial disease, affecting between 1 and 3 million Americans. Symptomatic improvement can be achieved by endovascular revascularization, but such procedures are invasive, expensive, and may be associated with procedural adverse events. Medical treatment options, including claudication medications and supervised exercise training, are also known to be effective, albeit also with associated limitations. The CLEVER (Claudication: Exercise Vs. Endoluminal Revascularization) study, funded by the Heart, Lung, and Blood Institute of the National Institutes of Health, is a prospective, multicenter, randomized, controlled clinical trial evaluating the relative efficacy, safety, and health economic impact of four treatment strategies for people with aortoiliac peripheral arterial disease and claudication. The treatment arms are: (1) optimal medical care (claudication pharmacotherapy); (2) primary stent placement; (3) supervised exercise rehabilitation; and (4) combined stenting with supervised exercise rehabilitation. The CLEVER study is a 5-year randomized, controlled clinical trial to be conducted at approximately 25 centers in the United States that will monitor 252 patients and their responses to treatment during an 18-month follow-up period. The primary end point is change in maximum walking duration on a graded treadmill test. Secondary end points include the change at 18 months in maximum walking duration from baseline, comparisons of free-living daily activity levels assessed by pedometer, health-related quality of life, and cost-effectiveness. Other analyses include the effect of these treatment strategies on anthropomorphic and physiologic variables, including body mass index, waist circumference, blood pressure, pulse pressure, and resting pulse as well as biochemical markers of cardiovascular health, including fasting lipids, fibrinogen, C-reactive protein, and hemoglobin A 1c values.

Intermittent claudication-like syndrome secondary to atherosclerosis in a yellow-naped Amazon parrot (Amazona ochrocephala auropalliata).

PubMed

Beaufrère, Hugues; Holder, Kali A; Bauer, Rudy; Schnellbacher, Rodney; Pariaut, Romain; Tully, Thomas N; Wakamatsu, Nobuko

2011-12-01

A 25-year-old yellow-naped Amazon parrot (Amazona ochrocephala auropalliata) was presented for nasal discharge and sneezing. Physical examination revealed poor feather quality, a mild serous nasal discharge, and a mass on the dorsal surface of the oral cavity. Cytologic examination of a mass aspirate as well as results of a choanal culture revealed squamous metaplasia of the salivary glands and bacterial rhinitis, respectively. Following resolution of the presenting conditions, the patient was presented for hind limb weakness and ataxia. The clinical signs were transient and generally resolved with rest but could be reproduced after stressful episodes, such as restraint for procedures or treatment. Test results from a complete blood count, biochemistry profile, whole-body radiographs, needle electromyography of the leg muscles, and an edrophonium challenge test were within reference limits. Based on the clinical signs and results of the diagnostic workup, the presumptive diagnosis was intermittent claudication, a condition caused by peripheral vascular disease and defined as intermittent weakness and pain in the legs induced by exercise and relieved by rest. Shortly after initiation of treatment with isoxsuprine, the bird died. Postmortem examination and histopathology revealed severe atherosclerotic lesions throughout the vascular system with stenotic lesions present in the abdominal aorta and femoral arteries. Electron microscopic examination of the great arteries was also performed and helped to further characterize the nature of the lesions. This case is the first report, to our knowledge, of an intermittent claudication-like syndrome associated with peripheral atherosclerosis in a psittacine bird. In addition, the distribution and some of the macroscopic and histopathologic features of the lesions differ from previous descriptions of atherosclerosis in psittacine birds.

[The modern principles of management of intermittent claudication].

PubMed

Gamzatov, T H; Svetlikov, A V

2016-01-01

Number of patients with peripheral arterial disease, despite various national public health programs, remains high and has no steady downward trend over the past few decades. Despite recent advances in drug therapy, сonservative approach in the management of peripheral arterial disease is often neglected by vascular surgeons. However, vast majority of patients with intermittent claudication, who receive comprehensive conservative treatment, including risk factor modification, exercise and drug therapy, may get significant improvement in quality of life by partial or complete relief of symptoms related to the disease. Patients strictly adhering to medical recommendations has favorable prognosis and progression of disease to the stage of critical limb ischemia is very unlikely. Noncompliant patients and those who continue smoking in particular, often experience progression of symptoms related to the disease. That may result in the need for surgical intervention aiming to prevent or delay the onset of critical limb ischemia.

Effect of reconstructive vascular surgery on red cell deformability--preliminary results.

PubMed Central

Irwin, S T; Rocks, M J; McGuigan, J A; Patterson, C C; Morris, T C; O'Reilly, M J

1983-01-01

Using a simple filtration method, red cell deformability was measured in healthy control subjects and in patients with peripheral vascular disease. Impaired red cell deformability was demonstrated in patients with rest pain or gangrene and in patients with intermittent claudication. An improvement in red cell deformability was demonstrated after successful reconstructive vascular surgery in both patient groups. An improvement in red cell deformability was demonstrated in patients undergoing major limb amputation. PMID:6619311

Skeletal muscle adaptation in response to supervised exercise training for intermittent claudication.

PubMed

Beckitt, T A; Day, J; Morgan, M; Lamont, P M

2012-09-01

There is evidence that the improvement following supervised exercise for claudication results from skeletal muscle adaptation. The myosin heavy chain (MHC) determines muscle fibre type and therefore efficiency. Immunohistochemical analysis has failed to take account of hybrid MHC expression within myofibres. This study sought evidence of differential MHC protein expression following supervised exercise for claudication. 38 claudicants were recruited. Subjects undertook a three-month supervised exercise programme. Controls were patients awaiting angioplasty for claudication. Subjects underwent paired gastrocnemius biopsy. Relative expression of MHC proteins was determined by SDS-PAGE electrophoresis. Non-parametric data is presented as median with the inter-quartile range and parametric as the mean ± standard deviation. Upon completion of the exercise programme there was a 94% increase (124 (106-145) to 241 (193-265) metres, p = 0.002) in maximum walking distance, which was not evident in the control group. An 11.1% (p = 0.02) increase in MHC I expression was observed in the exercise but not the control group (34.3% ± 6.8 to 45.4% ± 4.4). There was a positive correlation between the change in MHC I expression and the improvement in claudication distance (r = 0.69, p < 0.05). Supervised exercise training for claudication results in an increase in the proportion of MHC type I expression within the symptomatic gastrocnemius muscle. Copyright © 2012 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Complementary therapies for peripheral arterial disease: systematic review.

PubMed

Pittler, Max H; Ernst, Edzard

2005-07-01

While peripheral arterial disease (PAD) affects a considerable proportion of patients in the primary care setting, there is a high level of use of complementary treatment options. The aim was to assess the effectiveness of any type of complementary therapy for peripheral arterial disease. A systematic review was performed. Literature searches were conducted on Medline, Embase, Amed, and the Cochrane Library until December 2004. Hand-searches of medical journals and bibliographies were conducted. There were no restrictions regarding the language of publication. The screening of studies, selection, data extraction, the assessment of methodologic quality and validation were performed independently by the two reviewers. Data from randomized controlled trials, and systematic reviews and meta-analyses, which based their findings on the results of randomized controlled trials were included. Seven systematic reviews and meta-analyses and three additional randomized controlled trials met the inclusion criteria and were reviewed. The evidence relates to acupuncture, biofeedback, chelation therapy, CO(2)-applications and the dietary supplements Allium sativum (garlic), Ginkgo biloba (ginkgo), omega-3 fatty acids, padma 28 and Vitamin E. Most studies included only patients with peripheral arterial disease in Fontaine stage II (intermittent claudication). The reviewed RCTs, systematic reviews and meta-analyses which based their findings on the results of RCTs suggest that G. biloba is effective compared with placebo for patients with intermittent claudication. Evidence also suggests that padma 28 is effective for intermittent claudication, although more data are required to confirm these findings. For all other complementary treatment options there is no evidence beyond reasonable doubt to suggest effectiveness for patients with peripheral arterial disease.

Mild peripheral neuropathy prevents both leg muscular ischaemia and activation of exercise-induced coagulation in Type 2 diabetic patients with peripheral artery disease.

PubMed

Piarulli, F; Sambataro, M; Minicuci, N; Scarano, L; Laverda, B; Baiocchi, M R; Baldo-Enzi, G; Galasso, S; Bax, G; Fedele, D

2007-10-01

To study the influence of peripheral neuropathy on intermittent claudication in patients with Type 2 diabetes (T2DM). Twenty-five patients with T2DM were grouped according to the ankle/brachial index (ABI): 10 with ABI > 0.9 without peripheral artery disease (PAD; group T2DM) and 15 with ABI < 0.9 with PAD (group T2DM + PAD). Twelve individuals without T2DM with PAD (group PAD without T2DM) were also enrolled. Tests for peripheral neuropathy were performed in all patients. ABI, rate pressure product, prothrombin fragments 1 + 2 (F1+2), thrombin-anti-thrombin complex (TAT), and d-dimer were measured before and after a treadmill test. During exercise both initial and absolute claudication distance and electrocardiogram readings were recorded. We found mild peripheral neuropathy in 20% of group T2DM and 46.7% of group T2DM + PAD (P < 0.01). After exercise, the rate pressure product increased in each group; ABI fell in T2DM + PAD (P < 0.0001) and in PAD without T2DM (P = 0.0005); the fall was greater in the latter group. Initial and absolute claudication distances were similar in PAD patients. In group T2DM + PAD, absolute claudication distance was longer in the subgroup without peripheral neuropathy (P < 0.05), whereas ABI and rate pressure products were similar. F1+2 values at rest were higher in group T2DM + PAD. After exercise, F1+2 values and TAT increased only in group PAD without T2DM. Only group PAD without T2DM experienced muscular ischaemia, whereas group T2DM + PAD did not. Mild peripheral neuropathy may have prevented them from reaching the point of muscular ischaemia during the treadmill test, because they stopped exercising with the early onset of pain. Reaching a false absolute claudication distance may induce ischaemic preconditioning. These findings suggest a possible protective role of mild peripheral neuropathy in T2DM patients with intermittent claudication, by preventing further activation of coagulation during treadmill testing.

[Double-blind randomized comparative study of nicergoline naftidrofuryl on the quality of life in chronic obliterative arteriopathy of lower limbs with intermittent claudication].

PubMed

Meilhac, B; Montestruc, F; Aubin, F; Djian, F; Rouffy, J

1997-01-01

The functional limitation of patients with obliterative arterial disease, and with intermittent claudication, damages their quality of life. The purpose of this trial was to compare the effects of nicergoline and naftidrofuryl on the quality of life and the functional discomfort of the 131 patients with claudication. It was a multicentre, randomised, double-blind trial with parallel groups. The patients were asked to complete a quality of life questionnaire and a Visual Analogue Scale, and to evaluate the number of steps on flat ground before the pain began. After 6 months of treatment, we observed, for all treatments combined, a significant improvement (p = 0.0001) in the quality of life and in the functional discomfort. Three variables favoured nicergoline: the estimated time before the onset of the pain (p = 0.003), the functional discomfort quantified by the Visual Analogue Scale (p < 0.05), the distance covered on flat ground (p = 0.013). The other variables, and especially the total score on the self-questionnaire, confirmed this impression, without reaching significance (p = 0.136). The data suggest that in terms of quality of life nicergoline is superior. The clinical tolerance is good and comparable between the two treatments.

Self-administered versus interview-based questionnaires among patients with intermittent claudication: Do they give different results? A cross-sectional study.

PubMed

Lozano, Francisco; Lobos, José María; March, José Ramón; Carrasco, Eduardo; Barros, Marcello Barbosa; González-Porras, José Ramón

2016-01-01

Many clinical investigations use generic and/or specific questionnaires to obtain information about participants and patients. There is disagreement about whether the administration method can affect the results. The aim here was to determine whether, among patients with intermittent claudication (IC), there are differences in the Walking Impairment Questionnaire (WIQ) and European Quality of Life-5 Dimension (EQ-5D) scores with regard to: 1) the questionnaire administration method (self-administration versus face-to-face interview); and 2) the type of interviewer (vascular surgeon, VS, versus general practitioner, GP). Cross-sectional observational multicenter epidemiological study carried out within the Spanish National Health Service. 1,641 evaluable patients with IC firstly completed the WIQ and EQ-5D questionnaires and then were interviewed by their doctor on the same day. Pearson correlations and Chi-square tests were used. There was a strong correlation (r > 0.800; P < 0.001) between the two methods of administering the WIQ and EQ-5D questionnaires, and between the VS and GP groups. Likewise, there was a high level of concordance (P > 0.05) between the different dimensions of the WIQ-distance and EQ-5D (self-administration versus face-to-face) in the VS and GP groups. There was no difference between the different methods of administering the WIQ and EQ-5D questionnaires, among the patients with IC. Similarly, the two types of interviewers (VS or GP) were equally valid. Therefore, it seems unnecessary to expend effort to administer these questionnaires by interview, in studies on IC.

Effect of diabetes on the cutaneous microcirculation of the feet in patients with intermittent claudication.

PubMed

Klonizakis, M; Manning, G; Lingam, K; Donnelly, R; Yeung, J M C

2015-01-01

To evaluate endothelial-dependent and - independent cutaneous vasodilator responses in the feet of patients with peripheral arterial disease (PAD) with or without Type 2 diabetes. Cutaneous microvascular responses in the dorsum of both lower limbs were measured in the supine position using Laser Doppler Fluximetry combined with iontophoretic administration of endothelial-dependent (acetylcholine, Ach) and -independent (sodium nitroprusside, SNP) vasodilators in diabetic (n = 19) and non diabetic (n = 17) patients with PAD (presenting as unilateral calf intermittent claudication (IC). In patients with diabetes and IC, endothelial-dependent vasodilation was significantly impaired in the symptomatic limb [74 (57,105) vs 68 (24,81) PU, Z =-2.79, p = 0.005] compared to the asymptomatic limb. Patients without diabetes showed no impairment of vasodilation. Resting ankle-brachial pressure index did not identify the presence of abnormalities in microvascular function. The combination of diabetes and PAD is associated with a reduction in endothelial-dependent cutaneous vasodilation in the feet without an associated reduction in endothelial independent vasodilation.

[Medial longitudinal fasciculus (MLF) syndrome in a patient with giant cell arteritis].

PubMed

Uenaka, Takeshi; Hamaguchi, Hirotoshi; Sekiguchi, Kenji; Kowa, Hisatomo; Kanda, Fumio; Toda, Tatsushi

2015-01-01

A 76-year-old female was referred to our department because of diplopia for two months and intermittent claudication for five months. She showed medial longitudinal fasciculus (MLF) syndrome. Brain MRI (T2WI) showed multiple infarctions in the right pontine tegmentum and left paramedian midbrain. A biopsy of superficial temporal artery showed the characteristic findings of glanulomatous inflammation indicative of giant cell arteritis. We thought the mechanism of this cerebral infarction as artery to artery embolization or intracranial arteritis. Treatment with oral prednisolone (1 mg/kg/day) improved her limb claudication and normalized serum C-reactive protein level.

Cilostazol prevents foot ulcers in diabetic patients with peripheral vascular disease.

PubMed

de Franciscis, Stefano; Gallelli, Luca; Battaglia, Luigi; Molinari, Vincenzo; Montemurro, Rossella; Stillitano, Domenico M; Buffone, Gianluca; Serra, Raffaele

2015-06-01

Diabetic patients are at high risk of foot ulcerations that may lead to limb amputations with important socio-economic impact. Peripheral vascular disease may be frequently associated in diabetes mellitus type II with its main symptom, intermittent claudication. Many studies reported the known efficacy of cilostazol in treating vascular claudication. Metalloproteinase-9 (MMP-9) seems to be a biochemical marker implicated in chronic wounds and in particular in diabetic foot ulcers. Cilostazol appears to have a lowering effect on MMP-9 levels and this may suggest a beneficial effect in order to prevent or retard the onset of foot ulcer in diabetic patients. In our study, two groups of diabetic patients with peripheral vascular disease were divided into two groups according to the presence of claudication in order to receive cilostazol. Group A (31 patients without claudication) were not eligible to receive cilostazol whereas Group B (47 patients with claudication) received cilostazol administration for 24 weeks (100 mg orally twice daily). Median follow up was of 16 months. During the follow up, 4·25% of patients of Group B and 35·48% of patients of Group A (P < 0·01) showed onset of foot ulceration. Although further randomised and controlled studies are required cilostazol seems to show beneficial effects for primary prevention of diabetic foot ulcers. © 2013 The Authors. International Wound Journal © 2013 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

One-Year Outcomes Following Directional Atherectomy of Infrapopliteal Artery Lesions: Subgroup Results of the Prospective, Multicenter DEFINITIVE LE Trial.

PubMed

Rastan, Aljoscha; McKinsey, James F; Garcia, Lawrence A; Rocha-Singh, Krishna J; Jaff, Michael R; Noory, Elias; Zeller, Thomas

2015-12-01

To report a subgroup analysis of the prospective, multicenter, single-arm DEFINITIVE LE trial to assess the effectiveness of directional atherectomy for the treatment of infrapopliteal artery lesions at 1 year. In the DEFINITIVE LE trial, follow-up assessments occurred up to 1 year postprocedure. Of the 800 patients enrolled, 145 subjects with 189 infrapopliteal lesions met the criteria for this analysis. Seventy (48.3%) and 75 (51.7%) patients were suffering critical limb ischemia (CLI) and intermittent claudication, respectively; 68.3% (99/145) had diabetes. The mean lesion length was 58±44 mm (all lesions); 20.2% were occluded. The primary endpoint for patients with claudication was duplex ultrasound-derived primary patency, while for subjects with CLI it was freedom from major amputation of the target limb at 1 year. Endpoints and adverse events were independently assessed. Procedure success (≤30% residual stenosis) was achieved in 84% of treated lesions. The 1-year primary patency rate was 84% (claudicants 89.6% and CLI patients 78%, p=0.11), and the freedom from major amputation rate was 97.1% (claudicants 100% and CLI 93.8%, p=0.03). In both claudication and CLI patients, significant improvements in Rutherford category and objective measures of walking distance and quality of life were seen at 1 year in comparison to baseline. This study demonstrates that directional atherectomy in infrapopliteal arteries results in promising technical and clinical results at 1 year for claudicant as well as CLI patients. © The Author(s) 2015.

Association Between Albuminuria and Duration of Diabetes and Myocardial Dysfunction and Peripheral Arterial Disease Among Patients With Stable Coronary Artery Disease in the BARI 2D Study

PubMed Central

Escobedo, Jorge; Rana, Jamal S.; Lombardero, Manuel S.; Albert, Stewart G.; Davis, Andrew M.; Kennedy, Frank P.; Mooradian, Arshag D.; Robertson, David G.; Srinivas, V. S.; Gebhart, Suzanne S. P.

2010-01-01

OBJECTIVE: To evaluate the effect of prior duration of diabetes, glycated hemoglobin level at study entry, and microalbuminuria or macroalbuminuria on the extent and severity of coronary artery disease (CAD) and peripheral arterial disease. PATIENTS AND METHODS: We studied baseline characteristics of the 2368 participants of the BARI 2D (Bypass Angioplasty Revascularization Investigation 2 Diabetes) study, a randomized clinical trial that evaluates treatment efficacy for patients with type 2 diabetes and angiographically documented stable CAD. Patients were enrolled from January 1, 2001, through March 31, 2005. Peripheral arterial disease was ascertained by an ankle-brachial index (ABI) of 0.9 or less, and extent of CAD was measured by presence of multivessel disease, a left ventricular ejection fraction (LVEF) of less than 50%, and myocardial jeopardy index. RESULTS: Duration of diabetes of 20 or more years was associated with increased risk of ABI of 0.9 or less (odds ratio [OR], 1.54; 95% confidence interval [CI], 1.04-2.26), intermittent claudication (OR, 1.61; 95% CI, 1.10-2.35), and LVEF of less than 50% (OR, 2.03; 95% CI, 1.37-3.02). Microalbuminuria was associated with intermittent claudication (OR, 1.53; 95% CI, 1.16-2.02) and ABI of 0.9 or less (OR, 1.31; 95% CI, 0.98-1.75), whereas macroalbuminuria was associated with abnormal ABI, claudication, and LVEF of less than 50%. There was a significant association between diabetes duration and extent of CAD as manifested by number of coronary lesions, but no other significant associations were observed between duration of disease, glycated hemoglobin levels, or albumin-to-creatinine ratio and other manifestations of CAD. CONCLUSION: Duration of diabetes and microalbuminuria or macroalbuminuria are important predictors of severity of peripheral arterial disease and left ventricular dysfunction in a cohort of patients selected for the presence of CAD. PMID:20042560

Application of adaptive design and decision making to a phase II trial of a phosphodiesterase inhibitor for the treatment of intermittent claudication.

PubMed

Lewis, Roger J; Connor, Jason T; Teerlink, John R; Murphy, James R; Cooper, Leslie T; Hiatt, William R; Brass, Eric P

2011-05-25

Claudication secondary to peripheral artery disease (PAD) is associated with substantial functional impairment. Phosphodiesterase (PDE) inhibitors have been shown to increase walking performance in these patients. K-134 is a selective PDE 3 inhibitor being developed as a potential treatment for claudication. The use of K-134, as with other PDE 3 inhibitors, in patients with PAD raises important safety and tolerability concerns, including the induction of cardiac ischemia, tachycardia, and hypotension. We describe the design, oversight, and implementation of an adaptive, phase II, dose-finding trial evaluating K-134 for the treatment of stable, intermittent claudication. The study design was a double-blind, multi-dose (25 mg, 50 mg, and 100 mg of K-134), randomized trial with both placebo and active comparator arms conducted in the United States and Russia. The primary objective of the study was to compare the highest tolerable dose of K-134 versus placebo using peak walking time after 26 weeks of therapy as the primary outcome. Study visits with intensive safety assessments were included early in the study period to provide data for adaptive decision making. The trial used an adaptive, dose-finding strategy to efficiently identify the highest dose(s) most likely to be safe and well tolerated, based on the side effect profiles observed within the trial, so that less promising doses could be abandoned. Protocol specified criteria for safety and tolerability endpoints were used and modeled prior to the adaptive decision making. The maximum target sample size was 85 subjects in each of the retained treatment arms. When 199 subjects had been randomized and 28-day data were available from 143, the Data Monitoring Committee (DMC) recommended termination of the lowest dose (25 mg) treatment arm. Safety evaluations performed during 14- and 28-day visits which included in-clinic dosing and assessments at peak drug concentrations provided core data for the DMC review. At the time of review, no subject in any of the five treatment arms (placebo, three K-134-containing arms, and cilostazol) had met pre-specified definitions for resting tachycardia or ischemic changes on exercise ECG. If, instead of dropping the 25-mg K-134 treatment arm, all arms had been continued to full enrollment, then approximately 43 additional research subjects would have been required to complete the trial. In this phase II, dose-finding trial of K-134 in the treatment of stable intermittent claudication, no concerning safety signals were seen at interim analysis, allowing the discontinuation of the lowest-dose-containing arm and the retention of the two highest-dose-containing arms. The adaptive design facilitated safe and efficient evaluation of K-134 in this high-risk cardiovascular population. ClinicalTrials.gov: NCT00783081.

Exploring physical activity behaviour - needs for and interest in a technology-delivered, home-based exercise programme among patients with intermittent claudication.

PubMed

Cornelis, Nils; Buys, Roselien; Fourneau, Inge; Dewit, Tijl; Cornelissen, Véronique

2018-02-01

Supervised walking is a first line therapy in peripheral arterial disease (PAD) with complaints of intermittent claudication. However, uptake of supervised programmes is low. Home-based exercise seems an appealing alternative; especially since technological advances, such as tele-coaching and tele-monitoring, may facilitate the process and support patients when adopting a physically active lifestyle. To guide the development of such an intervention, it is important to identify barriers of physical activity and the needs and interests for technology-enabled exercise in this patient group. PAD patients were recruited at the vascular centre of UZ Leuven (Belgium). A questionnaire assessing PA (SF-International Physical Activity Questionnaire), barriers to PA, and interest in technology-supported exercise (Technology Usage Questionnaire) was completed. Descriptive and correlation analyses were performed. Ninety-nine patients (76 men; mean age 69 years) completed the survey. Physical activity levels were low in 48 %, moderate in 29 %, and high in 23 %. Intermittent claudication itself is the most important barrier for enhanced PA, with most patients reporting pain (93 %), need for rest (92 %), and obstacles worsening their pain (74 %) as barriers. A total of 93 % participants owned a mobile phone; 76 % had Internet access. Eighty-seven reported the need for an exercise programme, with 67 % showing interest in tele-coaching to support exercise. If technology was available, three-quarter stated they would be interested in home-based tele-coaching using the Internet (preferably e-mails, 86 %); 50 % via mobile phone, 87 % preferred text messages. Both were inversely related to age (rpb = 0.363 and rpb = 0.255, p < 0.05). Acquaintance with elastic bands or gaming platforms was moderate (55 and 49 %, respectively), but patients were interested in using them as alternatives (84 and 42 %). Interest in platforms was age-dependent (rs = -0.508, p < 0.01). PAD patients show significant interest in technology-delivered exercise, offering opportunities to develop a guided home-based exercise programme.

Bilateral paracoccidioidomycotic iliopsoas abscess associated with ileo-colonic lesion.

PubMed

Duani, Helena; Nunes, Vinícius Rodrigues Taranto; Assumpção, Anísio Borges; Saraiva, Isadora Sofia Borges; Rosa, Rodrigo Macedo; Neiva, Augusto Motta; Pedroso, Enio Roberto Pietra

2012-10-01

This case report shows the clinical development of a patient with systemic paracoccidioidomycosis presenting with lymphatic-intestinalmanifestation. The patient initially had a substantial clinical improvement but had a recrudescence after six months of sulfamethoxazoletrimethoprim oral treatment, with the emergence of feverish syndrome, lumbar pain, and intermittent claudication, characterizing a bilateral iliopsoas muscle abscess, necessitating clinicosurgical therapeutics.

Are the barriers for physical activity practice equal for all peripheral artery disease patients?

PubMed

Cavalcante, Bruno R; Farah, Breno Q; dos A Barbosa, João Paulo; Cucato, Gabriel Grizzo; da Rocha Chehuen, Marcel; da Silva Santana, Fábio; Wolosker, Nelson; de Moraes Forjaz, Cláudia Lúcia; Ritti-Dias, Raphael M

2015-02-01

To investigate barriers to physical activity related to the sociodemographic comorbidities and clinical variables of patients with intermittent claudication. Cross-sectional study. Ambulatory care. The medical histories of patients (N=145) aged ≥50 years with intermittent claudication were examined. Not applicable. Sociodemographic data (sex, race, level of education, socioeconomic status, marital status), comorbidities (overweight, hypertension, dyslipidemia, diabetes, currently smoking, heart disease), and clinical variables (initial claudication distance, total walking distance, ankle-brachial index). Information on personal and environmental barriers was obtained by questionnaire. Low economic status was most associated with "being afraid of falling" (odd ratios [OR]=2.22; 95% confidence interval [CI], 1.08-4.54). Low education level was most associated with "lack of street pedestrian crossing" (OR=3.34; 95% CI, 1.48-7.52). Diabetes was associated with lack of energy (OR=3.38; 95% CI, 1.68-6.79) and other medical conditions (eg, arthritis, angina) (OR=3.44; 95% CI, 1.65-7.16). Ankle brachial index was associated with "some difficulty in getting to a place where physical activity can be performed" (OR=2.75; 95% CI, 1.22-6.21). Walking capacity was strongly associated with barriers relating to leg pain (OR=7.39; 95% CI, 1.66-32.88). Older patients, those with a low education level, patients with diabetes, low ankle brachial index, and those with a lower walking capacity are more likely to experience barriers to physical activity. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Effectiveness of interspinous implant surgery in patients with intermittent neurogenic claudication: a systematic review and meta-analysis.

PubMed

Moojen, Wouter A; Arts, Mark P; Bartels, Ronald H M A; Jacobs, Wilco C H; Peul, Wilco C

2011-10-01

Despite an increasing implantation rate of interspinous process distraction (IPD) devices in the treatment of intermittent neurogenic claudication (INC), definitive evidence on the clinical effectiveness of implants is lacking. The main objective of this review was to perform a meta-analysis of all systematic reviews, randomized clinical trials and prospective cohort series to quantify the effectiveness of IPDs and to evaluate the potential side-effects. Data from all studies prospectively describing clinical results based on validated outcome scales and reporting complications of treatment of patients with INC with IPD placement. We searched MEDLINE, EMBASE, Web of Science, Cochrane (CENTRAL), CINAHL, Academic Search Premier, Science Direct up to July 2010. Studies describing patients with INC caused by lumbar stenosis, reporting complication rate and reporting based on validated outcome scores, were eligible. Studies with only instrumented IPD results were excluded. Eleven studies eligible studies were identified. Two independently RCTs and eight prospective cohorts were available. In total 563 patients were treated with IPDs. All studies showed improvement in validated outcome scores after 6 weeks and 1 year. Pooled data based on the Zurich Claudication Questionnaire of the RCTs were more in favor of IPD treatment compared with conservative treatment (pooled estimate 23.2, SD 18.5-27.8). Statistical heterogeneity after pooled data was low (I-squared 0.0, p = 0.930). Overall complication rate was 7%. As the evidence is relatively low and the costs are high, more thorough (cost-) effectiveness studies should be performed before worldwide implementation is introduced.

Changes in Function After a 6-Month Walking Intervention in Patients With Intermittent Claudication Who Are Obese or Nonobese.

PubMed

Addison, Odessa; Ryan, Alice S; Prior, Steven J; Katzel, Leslie I; Kundi, Rishi; Lal, Brajesh K; Gardner, Andrew W

Both obesity and peripheral artery disease (PAD) limit function and may work additively to reduce mobility. The purpose of this study was to compare the effects of a 6-month, center-based walking program on mobility function between adults who are weight-stable obese and nonobese with PAD. This is a secondary data analysis of 2 combined studies taken from previous work. Fifty-three adults with PAD and intermittent claudication participated in 6 months of treadmill training or standard of care. Patients were divided into 4 groups for analyses: exercise nonobese (Ex), exercise obese (ExO), standard-of-care nonobese (SC), and standard-of-care obese (SCO). Mobility was assessed by a standardized treadmill test to measure claudication onset time (COT) and peak walking time (PWT) as well as the distance walked during a 6-minute walk distance (6MWD) test. There was a significant (P < .001) interaction (intervention × obesity) effect on 6MWD, wherein both exercise groups improved (Ex = 7%, ExO = 16%; P < .02), the SC group did not change (0.9%; P > .05), and the SCO group tended to decline (-18%; P = .06). Both exercise intervention groups significantly improved COT (Ex = 92%, ExO = 102%; P < .01) and PWT (Ex = 54%, ExO = 103%; P < .001). There was no change (P > .05) in either standard-of-care group. Individuals who are obese and nonobese with PAD made similar improvements after a 6-month, center-based walking program. However, patients who are obese with PAD and do not exercise may be susceptible to greater declines in mobility. Exercise may be particularly important in patients who are obese with PAD to avoid declines in mobility.

Evaluation of patient compliance, quality of life impact and cost-effectiveness of a "test in-train out" exercise-based rehabilitation program for patients with intermittent claudication.

PubMed

Malagoni, Anna Maria; Vagnoni, Emidia; Felisatti, Michele; Mandini, Simona; Heidari, Mahdi; Mascoli, Francesco; Basaglia, Nino; Manfredini, Roberto; Zamboni, Paolo; Manfredini, Fabio

2011-01-01

Patients with intermittent claudication (IC) could benefit from low-cost, effective rehabilitative programs. This retrospective study evaluates compliance, impact on Quality of Life (QoL) and cost-effectiveness of a hospital prescribed, at-home performed (Test-in/Train-out) rehabilitative program for patients with IC. Two-hundred and eighty-nine patients with IC (71 ± 10.1 years, M = 210) were enrolled for a 2-year period. Two daily 10-min home walking sessions at maximal asymptomatic speed were prescribed, with serial check-ups at the hospital. Compliance with the program was assessed by assigning a score of 1 (lowest compliance) to 4 (highest compliance). The SF-36 questionnaire and a constant-load treadmill test were used to evaluate QoL and Initial/Absolute Claudication Distance, respectively. Both direct and indirect costs of the program were considered for cost-effectiveness analysis. Two-hundred and fifty patients (70.5 ± 9.2 years, M = 191), at Fontaine's II-B stage (86%), were included in the study. No adverse events were reported. The average compliance score was 3.1. At discharge, both SF-36 domains and walking performance significantly increased (P < 0.0001). A total of 1,839 in-hospital check-ups (7.36 /patient) were performed. Direct and indirect costs represented 93% and 7% of the total costs, respectively. The average costs of a visit and of a therapy cycle were C68.93 and C507.20, respectively. The cost to walk an additional meter before stopping was C9.22. A Test-in/Train-out program provided favourable patient compliance, QoL impact and cost-effectiveness in patients with IC.

Superion Interspinous Spacer Treatment of Moderate Spinal Stenosis: 4-Year Results.

PubMed

Nunley, Pierce D; Patel, Vikas V; Orndorff, Douglas G; Lavelle, William F; Block, Jon E; Geisler, Fred H

2017-08-01

To determine 4-year clinical outcomes in patients with moderate lumbar spinal stenosis treated with minimally invasive stand-alone interspinous process decompression using the Superion device. The 4-year Superion data were extracted from a randomized, controlled Food and Drug Administration investigational device exemption trial. Patients with intermittent neurogenic claudication relieved with back flexion who failed at least 6 months of nonsurgical management were enrolled. Outcomes included Zurich Claudication Questionnaire (ZCQ) symptom severity (ss), physical function (pf) and patient satisfaction (ps) subdomains, leg and back pain visual analog scale (VAS), and Oswestry Disability Index (ODI). At 4-year follow-up, 89 of the 122 patients (73%) provided complete clinical outcome evaluations. At 4 years after index procedure, 75 of 89 patients with Superion (84.3%) demonstrated clinical success on at least 2 of 3 ZCQ domains. Individual component responder rates were 83% (74/89), 79% (70/89), and 87% (77/89) for ZCQss, ZCQpf, and ZCQps; 78% (67/86) and 66% (57/86) for leg and back pain VAS; and 62% (55/89) for ODI. Patients with Superion also demonstrated percentage improvements over baseline of 41%, 40%, 73%, 69%, and 61% for ZCQss, ZCQpf, leg pain VAS, back pain VAS, and ODI. Within-group effect sizes all were classified as very large (>1.0): 1.49, 1.65, 1.42, 1.12, and 1.46 for ZCQss, ZCQpf, leg pain VAS, back pain VAS, and ODI. Minimally invasive implantation of the Superion device provides long-term, durable relief of symptoms of intermittent neurogenic claudication for patients with moderate lumbar spinal stenosis. Copyright © 2017 Elsevier Inc. All rights reserved.

Introducing the Concept of the Minimally Important Difference to Determine a Clinically Relevant Change on Patient-Reported Outcome Measures in Patients with Intermittent Claudication

DOE Office of Scientific and Technical Information (OSTI.GOV)

Conijn, Anne P., E-mail: a.p.conijn@amc.nl; Jonkers, Wilma, E-mail: wilma.jonkers@achmea.nl; Rouwet, Ellen V., E-mail: e.rouwet@erasmusmc.nl

PurposeThe minimally important difference (MID) represents the smallest change in score on patient-reported outcome measures that is relevant to patients. The aim of this study was to introduce the MID for the Vascular Quality of Life Questionnaire (VascuQol) and the walking impairment questionnaire (WIQ) for patients with intermittent claudication (IC).MethodsIn this multicenter study, we recruited 294 patients with IC between July and October 2012. Patients completed the VascuQol, with scores ranging from 1 to 7 (worst to best), and the WIQ, with scores ranging from 0 to 1 (worst to best) at first visit and after 4 months follow-up. Inmore » addition, patients answered an anchor-question rating their health status compared to baseline, as being improved, unchanged, or deteriorated. The MID for improvement and deterioration was calculated by an anchor-based approach, and determined with the upper and lower limits of the 95 % confidence interval of the mean change of the group who had not changed according to the anchor-question.ResultsFor the MID analyses of the VascuQol and WIQ, 163 and 134 patients were included, respectively. The MID values for the VascuQol (mean baseline score 4.25) were 0.87 for improvement and 0.23 for deterioration. For the WIQ (mean baseline score 0.39), we found MID values of 0.11 and −0.03 for improvement and deterioration, respectively.ConclusionIn this study, we calculated the MID for the VascuQol and the WIQ. Applying these MID facilitates better interpretation of treatment outcomes and can help to set treatment goals for individual care.« less

Long-term results with percutaneous interspinous process devices in the treatment of neurogenic intermittent claudication.

PubMed

Fransen, Patrick

2017-12-01

Neurogenic intermittent claudication (NIC) is the main symptom of degenerative lumbar spinal stenosis. Percutaneous interspinous process decompression devices (IPDs) have been designed as an alternative therapy to conservative treatment and to open decompressive surgery for patients suffering from NIC. Initial short-term results were encouraging. We present the long-term results of a group of patients that we followed to provide insight on long-term outcomes and effectiveness of this technique compared to other decompression methods. Fifteen patients operated for NIC by implantation of percutaneous IPDs have been prospectively monitored for reoperations or complications. Follow-up (FU) was interrupted if the patient was reoperated. Results were considered poor if the patient had to be reoperated at any stage of the FU or if the treatment failed to alleviate the pain after 6 months. Results were considered average if the patient still suffered some pain but did not require reoperation. The patients were followed up to 7 years after the initial surgery. The mean length of the FU was 3.53 years and all patients could be followed. At the end of the FU, the results were good in only 20.0% (3/15), average in 13.3% (2/15) and poor in 66.7% (10/15). Despite initial satisfactory results, long-term FU is disappointing, with 80% poor or average results. The long-term reoperation rate is high (66.6%), increases over time and is higher than after implantation of IPDs for decompression augmentation. Although this technique is simple and safe, its effectiveness seems short-lived. We recommend cautious use and informing patients about the risk of relatively early failure and recurrence.

Pain threshold is achieved at intensity above anaerobic threshold in patients with intermittent claudication.

PubMed

Ritti-Dias, Raphael Mendes; de Moraes Forjaz, Cláudia Lúcia; Cucato, Gabriel Grizzo; Costa, Luis Augusto Riani; Wolosker, Nelson; de Fátima Nunes Marucci, Maria

2009-01-01

Walking training is considered as the first treatment option for patients with peripheral arterial disease and intermittent claudication (IC). Walking exercise has been prescribed for these patients by relative intensity of peak oxygen uptake (VO2peak), ranging from 40% to 70% VO2peak, or pain threshold (PT). However, the relationship between these methods and anaerobic threshold (AT), which is considered one of the best metabolic markers for establishing training intensity, has not been analyzed. Thus, the aim of this study was to compare, in IC patients, the physiological responses at exercise intensities usually prescribed for training (% VO2peak or % PT) with the ones observed at AT. Thirty-three IC patients performed maximal graded cardiopulmonary treadmill test to assess exercise tolerance. During the test, heart rate (HR), VO2, and systolic blood pressure were measured and responses were analyzed at the following: 40% of VO2peak; 70% of VO2peak; AT; and PT. Heart rate and VO2 at 40% and 70% of VO2peak were lower than those at AT (HR: -13 +/- 9% and -3 +/- 8%, P < .01, respectively; VO2: -52 +/- 12% and -13 +/- 15%, P < .01, respectively). Conversely, HR and VO2 at PT were slightly higher than those at AT (HR: +3 +/- 8%, P < .01; VO2: +6 +/- 15%, P = .04). None of the patients achieved the respiratory compensation point. Prescribing exercise for IC patients between 40% and 70% of VO2peak will induce a lower stimulus than that at AT, whereas prescribing exercise at PT will result in a stimulus above AT. Thus, prescribing exercise training for IC patients on the basis of PT will probably produce a greater metabolic stimulus, promoting better cardiovascular benefits.

Endofibrosis of Iliac Arteries in High-Performance Athletes: Diagnostic Approach and Minimally Invasive Endovascular Treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giannoukas, Athanasios D., E-mail: agiannoukas@hotmail.com; Berczi, Viktor; Anoop, Unnikrishnan

The aim of this article is to report our experience in the diagnosis of two cases of iliac artery endofibrosis or arteriopathy, a rare entity occurring in high-performance athletes, presenting with intermittent claudication (right-sided in both) after maximal exercise. External iliac artery endofibrosis or arteriopathy is a likely diagnosis in competitive athletes free of cardiovascular risk factors who present with leg claudication. Arteriography and a papaverine-assisted mean pressure gradient across the iliac arteries of more than 10 mmHg is a useful diagnostic approach. Moreover, balloon angioplasty of the iliac artery in that patient, in whom a pressure gradient was detected,more » resulted in symptomatic relief for 2 months followed by mild symptom recurrence. Thus, although balloon angioplasty is feasible and safe, it might not be adequate to treat this entity and, thus, its value remains undefined.« less

Evaluation of Cell Therapy on Exercise Performance and Limb Perfusion in Peripheral Artery Disease: The CCTRN PACE Trial (Patients With Intermittent Claudication Injected With ALDH Bright Cells).

PubMed

Perin, Emerson C; Murphy, Michael P; March, Keith L; Bolli, Roberto; Loughran, John; Yang, Phillip C; Leeper, Nicholas J; Dalman, Ronald L; Alexander, Jason; Henry, Timothy D; Traverse, Jay H; Pepine, Carl J; Anderson, R David; Berceli, Scott; Willerson, James T; Muthupillai, Raja; Gahremanpour, Amir; Raveendran, Ganesh; Velasquez, Omaida; Hare, Joshua M; Hernandez Schulman, Ivonne; Kasi, Vijaykumar S; Hiatt, William R; Ambale-Venkatesh, Bharath; Lima, João A; Taylor, Doris A; Resende, Micheline; Gee, Adrian P; Durett, April G; Bloom, Jeanette; Richman, Sara; G'Sell, Patricia; Williams, Shari; Khan, Fouzia; Gyang Ross, Elsie; Santoso, Michelle R; Goldman, JoAnne; Leach, Dana; Handberg, Eileen; Cheong, Benjamin; Piece, Nichole; DiFede, Darcy; Bruhn-Ding, Barb; Caldwell, Emily; Bettencourt, Judy; Lai, Dejian; Piller, Linda; Simpson, Lara; Cohen, Michelle; Sayre, Shelly L; Vojvodic, Rachel W; Moyé, Lem; Ebert, Ray F; Simari, Robert D; Hirsch, Alan T

2017-04-11

Atherosclerotic peripheral artery disease affects 8% to 12% of Americans >65 years of age and is associated with a major decline in functional status, increased myocardial infarction and stroke rates, and increased risk of ischemic amputation. Current treatment strategies for claudication have limitations. PACE (Patients With Intermittent Claudication Injected With ALDH Bright Cells) is a National Heart, Lung, and Blood Institute-sponsored, randomized, double-blind, placebo-controlled, phase 2 exploratory clinical trial designed to assess the safety and efficacy of autologous bone marrow-derived aldehyde dehydrogenase bright (ALDHbr) cells in patients with peripheral artery disease and to explore associated claudication physiological mechanisms. All participants, randomized 1:1 to receive ALDHbr cells or placebo, underwent bone marrow aspiration and isolation of ALDHbr cells, followed by 10 injections into the thigh and calf of the index leg. The coprimary end points were change from baseline to 6 months in peak walking time (PWT), collateral count, peak hyperemic popliteal flow, and capillary perfusion measured by magnetic resonance imaging, as well as safety. A total of 82 patients with claudication and infrainguinal peripheral artery disease were randomized at 9 sites, of whom 78 had analyzable data (57 male, 21 female patients; mean age, 66±9 years). The mean±SEM differences in the change over 6 months between study groups for PWT (0.9±0.8 minutes; 95% confidence interval [CI] -0.6 to 2.5; P =0.238), collateral count (0.9±0.6 arteries; 95% CI, -0.2 to 2.1; P=0.116), peak hyperemic popliteal flow (0.0±0.4 mL/s; 95% CI, -0.8 to 0.8; P =0.978), and capillary perfusion (-0.2±0.6%; 95% CI, -1.3 to 0.9; P=0.752) were not significant. In addition, there were no significant differences for the secondary end points, including quality-of-life measures. There were no adverse safety outcomes. Correlative relationships between magnetic resonance imaging measures and PWT were not significant. A post hoc exploratory analysis suggested that ALDHbr cell administration might be associated with an increase in the number of collateral arteries (1.5±0.7; 95% CI, 0.1-2.9; P =0.047) in participants with completely occluded femoral arteries. ALDHbr cell administration did not improve PWT or magnetic resonance outcomes, and the changes in PWT were not associated with the anatomic or physiological magnetic resonance imaging end points. Future peripheral artery disease cell therapy investigational trial design may be informed by new anatomic and perfusion insights. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01774097. © 2017 American Heart Association, Inc.

Parental intermittent claudication as risk factor for claudication in adults.

PubMed

Prushik, Scott G; Farber, Alik; Gona, Philimon; Shrader, Peter; Pencina, Michael J; D'Agostino, Ralph B; Murabito, Joanne M

2012-03-01

Little is known about the familial aggregation of intermittent claudication (IC). Our objective was to examine whether parental IC increased the risk of IC in adult offspring, independent of the established cardiovascular risk factors. We evaluated the Offspring Cohort Participants of the Framingham Heart Study who were ≥30 years old, cardiovascular disease free, and had both parents enrolled in the Framingham Heart Study (n = 2,970 unique participants, 53% women). Pooled proportional hazards regression analysis was used to examine whether the 12-year risk of incident IC in offspring participants was associated with parental IC, adjusting for age, gender, diabetes, smoking, systolic blood pressure, total cholesterol, high-density lipoprotein cholesterol, and antihypertensive and lipid treatment. Of the 909 person-examinations in the parental IC history group and 5,397 person-examinations in the no-parental IC history group, there were 101 incident IC events (29 with parental IC history and 72 without a parental IC history) during follow-up. The age- and gender-adjusted 12-year cumulative incidence rate per 1,000 person-years was 5.08 (95% confidence interval [CI] 2.74 to 7.33) and 2.34 (95% CI 1.46 to 3.19) in participants with and without a parental IC history. A parental history of IC significantly increased the risk of incident IC in the offspring (multivariable adjusted hazard ratio 1.81, 95% CI 1.14 to 2.88). The hazard ratio was unchanged, with an adjustment for the occurrence of cardiovascular disease (hazard ratio 1.83, 95% CI 1.15 to 2.91). In conclusion, IC in parents increases the risk of IC in adult offspring, independent of the established risk factors. These data suggest a genetic component of peripheral artery disease and support future research into genetic causes. Copyright © 2012 Elsevier Inc. All rights reserved.

Influence of regular exercise on body fat and eating patterns of patients with intermittent claudication.

PubMed

Leicht, Anthony; Crowther, Robert; Golledge, Jonathan

2015-05-18

This study examined the impact of regular supervised exercise on body fat, assessed via anthropometry, and eating patterns of peripheral arterial disease patients with intermittent claudication (IC). Body fat, eating patterns and walking ability were assessed in 11 healthy adults (Control) and age- and mass-matched IC patients undertaking usual care (n = 10; IC-Con) or supervised exercise (12-months; n = 10; IC-Ex). At entry, all groups exhibited similar body fat and eating patterns. Maximal walking ability was greatest for Control participants and similar for IC-Ex and IC-Con patients. Supervised exercise resulted in significantly greater improvements in maximal walking ability (IC-Ex 148%-170% vs. IC-Con 29%-52%) and smaller increases in body fat (IC-Ex -2.1%-1.4% vs. IC-Con 8.4%-10%). IC-Con patients exhibited significantly greater increases in body fat compared with Control at follow-up (8.4%-10% vs. -0.6%-1.4%). Eating patterns were similar for all groups at follow-up. The current study demonstrated that regular, supervised exercise significantly improved maximal walking ability and minimised increase in body fat amongst IC patients without changes in eating patterns. The study supports the use of supervised exercise to minimize cardiovascular risk amongst IC patients. Further studies are needed to examine the additional value of other lifestyle interventions such as diet modification.

Nonsurgically managed patients with degenerative spondylolisthesis: a 10- to 18-year follow-up study.

PubMed

Matsunaga, S; Ijiri, K; Hayashi, K

2000-10-01

Controversy exists concerning the indications for surgery and choice of surgical procedure for patients with degenerative spondylolisthesis. The goals of this study were to determine the clinical course of nonsurgically managed patients with degenerative spondylolisthesis as well as the indications for surgery. A total of 145 nonsurgically managed patients with degenerative spondylolisthesis were examined annually for a minimum of 10 years follow-up evaluation. Radiographic changes, changes in clinical symptoms, and functional prognosis were surveyed. Progressive spondylolisthesis was observed in 49 patients (34%). There was no correlation between changes in clinical symptoms and progression of spondylolisthesis. The intervertebral spaces of the slipped segments were decreased significantly in size during follow-up examination in patients in whom no progression was found. Low-back pain improved following a decrease in the total intervertebral space size. A total of 84 (76%) of 110 patients who had no neurological deficits at initial examination remained without neurological deficit after 10 years of follow up. Twenty-nine (83%) of the 35 patients who had neurological symptoms, such as intermittent claudication or vesicorectal disorder, at initial examination and refused surgery experienced neurological deterioration. The final prognosis for these patients was very poor. Low-back pain was improved by restabilization. Conservative treatment is useful for patients who have low-back pain with or without pain in the lower extremities. Surgical intervention is indicated for patients with neurological symptoms including intermittent claudication or vesicorectal disorder, provided that a good functional outcome can be achieved.

Effect of diabetes mellitus on walking distance parameters after supervised exercise therapy for intermittent claudication: A systematic review.

PubMed

Hageman, David; Gommans, Lindy Nm; Scheltinga, Marc Rm; Teijink, Joep Aw

2017-02-01

Some believe that certain patients with intermittent claudication may be unsuitable for supervised exercise therapy (SET), based on the presence of comorbidities and the possibly increased risks. We conducted a systematic review (MEDLINE, EMBASE and CENTRAL) to summarize evidence on the potential influence of diabetes mellitus (DM) on the response to SET. Randomized and nonrandomized studies that investigated the effect of DM on walking distance after SET in patients with IC were included. Considered outcome measures were maximal, pain-free and functional walking distance (MWD, PFWD and FWD). Three articles met the inclusion criteria ( n = 845). In one study, MWD was 111 meters (128%) longer in the non-DM group compared to the DM group after 3 months of follow-up ( p = 0.056). In a second study, the non-DM group demonstrated a significant increase in PFWD (114 meters, p ⩽ 0.05) after 3 months of follow-up, whereas there was no statistically significant increase for the DM group (54 meters). On the contrary, the largest study of this review did not demonstrate any adverse effect of DM on MWD and FWD after SET. In conclusion, the data evaluating the effects of DM on SET were inadequate to determine if DM impairs the exercise response. While trends in the data do not suggest an impairment, they are not conclusive. Practitioners should consider this limitation when making clinical decisions.

The ClaudicatioNet concept: design of a national integrated care network providing active and healthy aging for patients with intermittent claudication.

PubMed

Lauret, Gert-Jan; Gijsbers, Harm J H; Hendriks, Erik J M; Bartelink, Marie-Louise; de Bie, Rob A; Teijink, Joep A W

2012-01-01

Intermittent claudication (IC) is a manifestation of peripheral arterial occlusive disease (PAOD). Besides cardiovascular risk management, supervised exercise therapy (SET) should be offered to all patients with IC. Outdated guidelines, an insufficient number of specialized physiotherapists (PTs), lack of awareness of the importance of SET by referring physicians, and misguided financial incentives all seriously impede the availability of a structured SET program in The Netherlands. By initiating regional care networks, ClaudicatioNet aims to improve the quality of care for patients with IC. Based on the chronic care model as a conceptual framework, these networks should enhance the access, continuity, and (cost) efficiency of the health care system. With the aid of a national database, health care professionals will be able to benchmark patient results while ClaudicatioNet will be able to monitor quality of care by way of functional and patient reported outcome measures. The success of ClaudicatioNet is dependent on several factors. Vascular surgeons, general practitioners and coordinating central caregivers will need to team up and work in close collaboration with specialized PTs. A substantial task in the upcoming years will be to monitor the quality, volume, and distribution of ClaudicatioNet PTs. Finally, misguided financial incentives within the Dutch health care system need to be tackled. With ClaudicatioNet, integrated care pathways are likely to improve in the upcoming years. This should result in the achievement of optimal quality of care for all patients with IC.

Naftidrofuryl for intermittent claudication.

PubMed

De Backer, T L M; Vander Stichele, R; Lehert, P; Van Bortel, L

2008-04-16

Lifestyle changes and cardiovascular prevention measures are a primary treatment for intermittent claudication (IC). Symptomatic treatment with vasoactive agents (Anatomic Therapeutic Chemical Classification (ATC) for medicines from the World Health Organisation class CO4A) is controversial. To evaluate evidence on the efficacy and safety of oral naftidrofuryl (ATC CO4 21) versus placebo on the pain-free walking distance (PFWD) of people with IC by using a meta-analysis based on individual patient data (IPD). The Cochrane Peripheral Vascular Diseases Group searched their Trials Register (last searched December 2007) and CENTRAL (last searched 2007, Issue 4). We searched MEDLINE, EMBASE, International Pharmaceutical Abstracts, the Science Citation Index and contacted the authors and checked the reference lists of retrieved articles. We asked the manufacturing company for IPD. We included only randomized controlled trials (RCTs) with low or moderate risk of bias for which the IPD were available. We collected data from the electronic data file or from the case report form and checked the data by a statistical quality control procedure. All randomized patients were analyzed following the intention-to-treat (ITT) principle. The geometric mean of the relative improvement in PFWD was calculated for both treatment groups in all identified studies. The effect of the drug was assessed compared with placebo on final walking distance (WDf) using multilevel and random-effect models and adjusting for baseline walking distance (WD0). For the responder analysis, therapeutic success was defined as an improvement of walking distance of at least 50%. We included seven studies in the IPD (n = 1266 patients). One of these studies (n = 183) was only used in the sensitivity analysis so that the main analysis included 1083 patients. The ratio of the relative improvement in PFWD (naftidrofuryl compared with placebo) was 1.37 (95% confidence interval (CI) 1.32 to 1.51, P < 0.001). The absolute difference in responder rate, or proportion successfully treated, was 22.3% (95% CI 17.1% to 27.6%). The calculated number needed to treat was 4.5 (95% CI 3.6 to 5.8). Naftidrofuryl has a statistically significant and clinically meaningful effect of improving walking distance in the six months after initiation of therapy for people with intermittent claudication. Access by researchers to data from RCTs that is suitable for IPD analysis should be possible through repositories of data from pharmacological trials. Regular formal appraisal of the balance of risk and benefit is needed for older pharmaceutical products.

Lumbar vertebral hemangioma causing cauda equina syndrome: a case report.

PubMed

Ahn, Henry; Jhaveri, Subir; Yee, Albert; Finkelstein, Joel

2005-11-01

Case report. To report a case of lumbar hemangioma causing neurogenic claudication and early cauda equina, managed with hemostatic vertebroplasty and posterior decompression. This is the first report to our knowledge of a lumbar hemangioma causing neurogenic claudication and early cauda equina syndrome. Most hemangiomas causing neurologic symptoms occur in thoracic spine and cause spinal cord compression. Vertebroplasty as a method of hemostasis and for providing mechanical stability in this situation has not been discussed previously in the literature. L4 hemangioma was diagnosed in a 64-year-old woman with severe neurogenic claudication and early cauda equina syndrome. Preoperative angiograms showed no embolizable vessels. Posterior decompression was performed followed by bilateral transpedicular vertebroplasty. The patient received postoperative radiation to prevent recurrence. Complete relief of neurogenic claudication and cauda equina with less than 100 mL of blood loss. A lumbar hemangioma of the vertebral body, although rare, can cause neurogenic claudication and cauda equina syndrome. Intraoperative vertebroplasty can be an effective method of hemostasis and provide stability of the vertebra following posterior decompression.

The effect of pharmacological treatment on gait biomechanics in peripheral arterial disease patients

PubMed Central

2010-01-01

Background Pharmacological treatment has been advocated as a first line therapy for Peripheral Arterial Disease (PAD) patients suffering from intermittent claudication. Previous studies document the ability of pharmacological treatment to increase walking distances. However, the effect of pharmacological treatment on gait biomechanics in PAD patients has not been objectively evaluated as is common with other gait abnormalities. Methods Sixteen patients were prescribed an FDA approved drug (Pentoxifylline or Cilostazol) for the treatment of symptomatic PAD. Patients underwent baseline gait testing prior to medication use which consisted of acquisition of ground reaction forces and kinematics while walking in a pain free state. After three months of treatment, patients underwent repeat gait testing. Results Patients with symptomatic PAD had significant gait abnormalities at baseline during pain free walking as compared to healthy controls. However, pharmacological treatment did not produce any identifiable alterations on the biomechanics of gait of the PAD patients as revealed by the statistical comparisons performed between pre and post-treatment and between post-treatment and the healthy controls. Conclusions Pharmacological treatment did not result in statistically significant improvements in the gait biomechanics of patients with symptomatic PAD. Future studies will need to further explore different cohorts of patients that have shown to improve significantly their claudication distances and/or their muscle fiber morphology with the use of pharmacological treatment and determine if this is associated with an improvement in gait biomechanics. Using these methods we may distinguish the patients who benefit from pharmacotherapy and those who do not. PMID:20529284

Primary Self-EXPANDing Nitinol Stenting vs Balloon Angioplasty With Optional Bailout Stenting for the Treatment of Infrapopliteal Artery Disease in Patients With Severe Intermittent Claudication or Critical Limb Ischemia (EXPAND Study).

PubMed

Schulte, Karl-Ludwig; Pilger, Ernst; Schellong, Sebastian; Tan, Kong Ten; Baumann, Frederic; Langhoff, Ralf; Torsello, Giovanni; Zeller, Thomas; Amendt, Klaus; Brodmann, Marianne

2015-10-01

To compare primary placement of a self-expanding nitinol stent to percutaneous transluminal angioplasty (PTA) with bailout stenting in infrapopliteal arteries of patients with severe intermittent claudication or critical limb ischemia (CLI). In the EXPAND trial (ClinicalTrials.gov; identifier NCT00906022), 92 patients (mean age 72.9±9.5 years; 62 men) undergoing treatment for infrapopliteal stenosis in 11 European centers were randomized 1:1 to either self-expanding nitinol stenting with the Astron Pulsar/Pulsar-18 nitinol stent or PTA with bailout stenting. The primary endpoint was sustainable clinical improvement after 12 months, defined as a ≥1-category increase for Rutherford category 3 patients or a ≥2-category increase for CLI patients (Rutherford categories 4/5) compared with baseline. Furthermore, target lesion revascularization (TLR), mortality, and amputation were assessed after 12 months. Sustained clinical improvement at 1 year was observed in 74.3% of the patients treated with primary stenting and in 68.6% of the patients treated with PTA and bailout stenting (p>0.05). Kaplan-Meier estimates of freedom from TLR (76.6% and 77.6%), mortality (7.4% vs 2.1%), and amputation [8.9% (major 6.7%) vs 13.2% (major 8.7%)] at 1 year were not significantly different. Primary self-expanding nitinol stenting did not show statistically different clinical outcomes compared to angioplasty with bailout stenting for infrapopliteal lesions. © The Author(s) 2015.

Exercise performance and peripheral vascular insufficiency improve with AMPK activation in high-fat diet-fed mice.

PubMed

Baltgalvis, Kristen A; White, Kathy; Li, Wei; Claypool, Mark D; Lang, Wayne; Alcantara, Raniel; Singh, Baljit K; Friera, Annabelle M; McLaughlin, John; Hansen, Derek; McCaughey, Kelly; Nguyen, Henry; Smith, Ira J; Godinez, Guillermo; Shaw, Simon J; Goff, Dane; Singh, Rajinder; Markovtsov, Vadim; Sun, Tian-Qiang; Jenkins, Yonchu; Uy, Gerald; Li, Yingwu; Pan, Alison; Gururaja, Tarikere; Lau, David; Park, Gary; Hitoshi, Yasumichi; Payan, Donald G; Kinsella, Todd M

2014-04-15

Intermittent claudication is a form of exercise intolerance characterized by muscle pain during walking in patients with peripheral artery disease (PAD). Endothelial cell and muscle dysfunction are thought to be important contributors to the etiology of this disease, but a lack of preclinical models that incorporate these elements and measure exercise performance as a primary end point has slowed progress in finding new treatment options for these patients. We sought to develop an animal model of peripheral vascular insufficiency in which microvascular dysfunction and exercise intolerance were defining features. We further set out to determine if pharmacological activation of 5'-AMP-activated protein kinase (AMPK) might counteract any of these functional deficits. Mice aged on a high-fat diet demonstrate many functional and molecular characteristics of PAD, including the sequential development of peripheral vascular insufficiency, increased muscle fatigability, and progressive exercise intolerance. These changes occur gradually and are associated with alterations in nitric oxide bioavailability. Treatment of animals with an AMPK activator, R118, increased voluntary wheel running activity, decreased muscle fatigability, and prevented the progressive decrease in treadmill exercise capacity. These functional performance benefits were accompanied by improved mitochondrial function, the normalization of perfusion in exercising muscle, increased nitric oxide bioavailability, and decreased circulating levels of the endogenous endothelial nitric oxide synthase inhibitor asymmetric dimethylarginine. These data suggest that aged, obese mice represent a novel model for studying exercise intolerance associated with peripheral vascular insufficiency, and pharmacological activation of AMPK may be a suitable treatment for intermittent claudication associated with PAD.

Hemorrhagic lumbar facet cysts accompanying a spinal subdural hematoma at the same level

PubMed Central

Ikeda, Osamu; Minami, Norihiko; Yamazaki, Masashi; Koda, Masao; Morinaga, Tatsuo

2015-01-01

Context We present a rare and interesting case of hemorrhagic lumbar facet cysts accompanying a spinal subdural hematoma at the same level suggesting a possible mechanism by which spinal subdural hematomas can arise. Findings A 71-year-old man presented with persistent sciatic pain and intermittent claudication. Magnetic resonance imaging demonstrated a multilocular mass lesion that showed high signal intensity in both T1- and T2-weighted images, and was located both inside and outside of the spinal canal. Computed tomographic myelography showed a cap-shaped block of the dural tube at L5 and computed tomography with L5–S facet arthrography demonstrated cystic masses. The patient was diagnosed with lumbar radiculopathy caused by hemorrhagic facet cysts, and then progressed to surgical treatment. Surgery revealed that the cysts contained blood clots, and intraoperative findings that the inside of the dural tube appeared blackish and that the dural tube was tensely ballooned after removal of the cysts led us to explorative durotomy. The durotomy demonstrated concentrated old blood pooling both in the dorsal and ventral subdural space, and these spaces were subsequently drained. After surgery, his sciatic pain and intermittent claudication resolved. There was no evidence of cyst mass recurrence at 2 years of follow-up. Conclusion We propose a newly described mechanism for the formation of spinal subdural hematomas. We recommend surgeons be alert to epidural lesions causing repeated acute compression of the dural tube, which can cause spinal subdural hematoma, and consider the possible coexistence of these lesions in diagnosis and strategic surgical decisions. PMID:24976137

Hemorrhagic lumbar facet cysts accompanying a spinal subdural hematoma at the same level.

PubMed

Ikeda, Osamu; Minami, Norihiko; Yamazaki, Masashi; Koda, Masao; Morinaga, Tatsuo

2015-03-01

We present a rare and interesting case of hemorrhagic lumbar facet cysts accompanying a spinal subdural hematoma at the same level suggesting a possible mechanism by which spinal subdural hematomas can arise. A 71-year-old man presented with persistent sciatic pain and intermittent claudication. Magnetic resonance imaging demonstrated a multilocular mass lesion that showed high signal intensity in both T1- and T2-weighted images, and was located both inside and outside of the spinal canal. Computed tomographic myelography showed a cap-shaped block of the dural tube at L5 and computed tomography with L5-S facet arthrography demonstrated cystic masses. The patient was diagnosed with lumbar radiculopathy caused by hemorrhagic facet cysts, and then progressed to surgical treatment. Surgery revealed that the cysts contained blood clots, and intraoperative findings that the inside of the dural tube appeared blackish and that the dural tube was tensely ballooned after removal of the cysts led us to explorative durotomy. The durotomy demonstrated concentrated old blood pooling both in the dorsal and ventral subdural space, and these spaces were subsequently drained. After surgery, his sciatic pain and intermittent claudication resolved. There was no evidence of cyst mass recurrence at 2 years of follow-up. We propose a newly described mechanism for the formation of spinal subdural hematomas. We recommend surgeons be alert to epidural lesions causing repeated acute compression of the dural tube, which can cause spinal subdural hematoma, and consider the possible coexistence of these lesions in diagnosis and strategic surgical decisions.

The ClaudicatioNet concept: design of a national integrated care network providing active and healthy aging for patients with intermittent claudication

PubMed Central

Lauret, Gert-Jan; Gijsbers, Harm JH; Hendriks, Erik JM; Bartelink, Marie-Louise; de Bie, Rob A; Teijink, Joep AW

2012-01-01

Introduction: Intermittent claudication (IC) is a manifestation of peripheral arterial occlusive disease (PAOD). Besides cardiovascular risk management, supervised exercise therapy (SET) should be offered to all patients with IC. Outdated guidelines, an insufficient number of specialized physiotherapists (PTs), lack of awareness of the importance of SET by referring physicians, and misguided financial incentives all seriously impede the availability of a structured SET program in The Netherlands. Description of care practice: By initiating regional care networks, ClaudicatioNet aims to improve the quality of care for patients with IC. Based on the chronic care model as a conceptual framework, these networks should enhance the access, continuity, and (cost) efficiency of the health care system. With the aid of a national database, health care professionals will be able to benchmark patient results while ClaudicatioNet will be able to monitor quality of care by way of functional and patient reported outcome measures. Discussion: The success of ClaudicatioNet is dependent on several factors. Vascular surgeons, general practitioners and coordinating central caregivers will need to team up and work in close collaboration with specialized PTs. A substantial task in the upcoming years will be to monitor the quality, volume, and distribution of ClaudicatioNet PTs. Finally, misguided financial incentives within the Dutch health care system need to be tackled. Conclusion: With ClaudicatioNet, integrated care pathways are likely to improve in the upcoming years. This should result in the achievement of optimal quality of care for all patients with IC. PMID:22942648

Modified fenestration with restorative spinoplasty for lumbar spinal stenosis.

PubMed

Matsudaira, Ko; Yamazaki, Takashi; Seichi, Atsushi; Hoshi, Kazuto; Hara, Nobuhiro; Ogiwara, Satoshi; Terayama, Sei; Chikuda, Hirotaka; Takeshita, Katsushi; Nakamura, Kozo

2009-06-01

The authors developed an original procedure, modified fenestration with restorative spinoplasty (MFRS) for the treatment of lumbar spinal stenosis. The first step is to cut the spinous process in an L-shape, which is caudally reflected. This procedure allows easy access to the spinal canal, including lateral recesses, and makes it easy to perform a trumpet-style decompression of the nerve roots without violating the facet joints. After the decompression of neural tissues, the spinous process is anatomically restored (spinoplasty). The clinical outcomes at 2 years were evaluated using the Japanese Orthopaedic Association (JOA) scale and patients' satisfaction. Radiological follow-up included radiographs and CT. Between January 2000 and December 2002, 109 patients with neurogenic intermittent claudication with or without mild spondylolisthesis underwent MFRS. Of these, 101 were followed up for at least 2 years (follow-up rate 93%). The average score on the self-administered JOA scale in 89 patients without comorbidity causing gait disturbance improved from 13.3 preoperatively to 22.9 at 2 years' follow-up. Neurogenic intermittent claudication disappeared in all cases. The patients' assessment of treatment satisfaction was "satisfied" in 74 cases, "slightly satisfied" in 12, "slightly dissatisfied" in 2, and "dissatisfied" in 1 case. In 16 cases (18%), a minimum progression of slippage occurred, but no symptomatic instability or recurrent stenosis was observed. Computed tomography showed that the lateral part of the facet joints was well preserved, and the mean residual ratio was 80%. The MFRS technique produces an adequate and safe decompression of the spinal canal, even in patients with narrow and steep facet joints in whom conventional fenestration is technically demanding.

One-Year Outcomes Following Directional Atherectomy of Popliteal Artery Lesions: Subgroup Analysis of the Prospective, Multicenter DEFINITIVE LE Trial

PubMed Central

Rastan, Aljoscha; McKinsey, James F.; Garcia, Lawrence A.; Rocha-Singh, Krishna J.; Jaff, Michael R.; Harlin, Stuart; Kamat, Suraj; Janzer, Sean; Zeller, Thomas

2017-01-01

Purpose: To report the effectiveness of directional atherectomy for the treatment of popliteal artery occlusive disease. Methods: This subset of the prospective, multicenter, single-arm DEFINITIVE LE trial included 158 patients (mean age 72.0±10.9 years; 82 men) who underwent directional atherectomy in 162 popliteal artery lesions between 2009 and 2011. Forty-eight (30.4%) patients were suffering from critical limb ischemia (CLI). The mean lesion length was 5.8±3.9 cm; 38 (23.5%) arteries were occluded. The primary outcome measure for patients with intermittent claudication (IC) was duplex ultrasound–defined primary patency at 1 year; the outcome for subjects with CLI was freedom from major amputation of the target limb at 1 year. Outcomes and adverse events were independently assessed. Results: Procedure success (≤30% residual stenosis) was achieved in 84.4% of treated lesions; adjunctive stenting was required in 6 (3.7%) of the 162 lesions. The 1-year primary patency rate was 75.0% (IC patients 78.2% and CLI patients 67.5%, p=0.118). The freedom from major amputation in both cohorts was 100%. In both IC and CLI patients, significant improvements were demonstrated at 1 year in the Rutherford category, walking distance, and quality of life in comparison to baseline. Conclusion: This study indicates that directional atherectomy in popliteal arteries leads to favorable technical and clinical results at 1 year for claudicant as well as CLI patients. PMID:29117818

Design of the multicenter standardized supervised exercise training intervention for the claudication: exercise vs endoluminal revascularization (CLEVER) study.

PubMed

Bronas, Ulf G; Hirsch, Alan T; Murphy, Timothy; Badenhop, Dalynn; Collins, Tracie C; Ehrman, Jonathan K; Ershow, Abby G; Lewis, Beth; Treat-Jacobson, Diane J; Walsh, M Eileen; Oldenburg, Niki; Regensteiner, Judith G

2009-11-01

The CLaudication: Exercise Vs Endoluminal Revascularization (CLEVER) study is the first randomized, controlled, clinical, multicenter trial that is evaluating a supervised exercise program compared with revascularization procedures to treat claudication. In this report, the methods and dissemination techniques of the supervised exercise training intervention are described. A total of 217 participants are being recruited and randomized to one of three arms: (1) optimal medical care; (2) aortoiliac revascularization with stent; or (3) supervised exercise training. Of the enrolled patients, 84 will receive supervised exercise therapy. Supervised exercise will be administered according to a protocol designed by a central CLEVER exercise training committee based on validated methods previously used in single center randomized control trials. The protocol will be implemented at each site by an exercise committee member using training methods developed and standardized by the exercise training committee. The exercise training committee reviews progress and compliance with the protocol of each participant weekly. In conclusion, a multicenter approach to disseminate the supervised exercise training technique and to evaluate its efficacy, safety and cost-effectiveness for patients with claudication due to peripheral arterial disease (PAD) is being evaluated for the first time in CLEVER. The CLEVER study will further establish the role of supervised exercise training in the treatment of claudication resulting from PAD and provide standardized methods for use of supervised exercise training in future PAD clinical trials as well as in clinical practice.

Korean Guidelines for Interventional Recanalization of Lower Extremity Arteries

PubMed Central

Bae, Jae Ik; Jeon, Yong Sun; Kim, Chang Won; Jae, Hwan Jun; Park, Kwang Bo; Cho, Young Kwon; Kim, Man Deuk

2015-01-01

Peripheral arterial occlusive disease caused by atherosclerosis can present with intermittent claudication or critical limb ischemia. Proper diagnosis and management is warranted to improve symptoms and salvage limbs. With the introduction of new techniques and dedicated materials, endovascular recanalization is widely performed for the treatment of peripheral arterial occlusive disease because it is less invasive than surgery. However, there are various opinions regarding the appropriate indications and procedure methods for interventional recanalization according to operator and institution in Korea. Therefore, we intend to provide evidence based guidelines for interventional recanalization by multidisciplinary consensus. These guidelines are the result of a close collaboration between physicians from many different areas of expertise including interventional radiology, interventional cardiology, and vascular surgery. The goal of these guidelines is to ensure better treatment, to serve as a guide to the clinician, and consequently, to contribute to public health care. PMID:26175569

Bias in benefit-risk appraisal in older products: the case of buflomedil for intermittent claudication.

PubMed

De Backer, Tine L M; Vander Stichele, Robert H; Van Bortel, Luc M

2009-01-01

Benefit-risk assessment should be ongoing during the life cycle of a pharmaceutical agent. New products are subjected to rigorous registration laws and rules, which attempt to assure the availability and validity of evidence. For older products, bias in benefit-risk assessment is more likely, as a number of safeguards were not in place at the time these products were registered. This issue of bias in benefit-risk assessment of older products is illustrated here with an example: buflomedil in intermittent claudication. Data on efficacy were retrieved from a Cochrane systematic review. Data on safety were obtained by comparing the number of reports of serious adverse events and fatalities published in the literature with those reported in postmarketing surveillance databases. In the case of efficacy, the slim basis of evidence for the benefit of buflomedil is undermined by documented publication bias. In the case of safety, bias in reporting to international safety databases is illustrated by the discrepancy between the number of drug-related deaths published in the literature (20), the potentially drug-related deaths in the WHO database (20) and deaths attributed to buflomedil in the database of the international marketing authorization holder (11). In older products, efficacy cannot be evaluated without a thorough search for publication bias. For safety, case reporting of drug-related serious events and deaths in the literature remains a necessary instrument for risk appraisal of older medicines, despite the existence of postmarketing safety databases. The enforcement of efficient communication between healthcare workers, drug companies, national centres of pharmacovigilance, national poison centers and the WHO is necessary to ensure the validity of postmarketing surveillance reporting systems. Drugs considered obsolete because of unfavourable benefit-risk assessment should not be allowed to stay on the market.

Lower functional capacity is associated with higher cardiovascular risk in Brazilian patients with intermittent claudication.

PubMed

Gengo e Silva, Rita de Cassia; de Melo, Vanessa Ferreira Amorim; Wolosker, Nelson; Consolim-Colombo, Fernanda Marciano

2015-03-01

The purpose of this study was to examine the association between cardiovascular risk estimated by the Framingham Risk Score and functional capacity in patients with peripheral artery disease using a 6-minute walk test. Fifty-six participants with intermittent claudication were recruited. The Framingham Risk Score was calculated and used to split the participants into two groups: Group A (mild and moderate risk) and group B (severe risk). The ankle-brachial index (ABI) was calculated for each leg using a handheld Doppler probe. Walking ability was verified by a 6-minute walk test. Descriptive statistics were used to describe the sample's demographic and clinical characteristics. To compare clinical data between the two groups, a t test or Mann-Whitney test was used as appropriate according to the type of variable being analyzed. The Pearson coefficient was used to verify the association between cardiovascular risk and functional capacity. Group A had 19 participants (60.5 ± 6.3 years; 36.8% male) and group B had 37 participants (63.4 ± 8.7 years; 73% male). No differences were observed when comparing the ABI between both groups. The total distances covered by the men in group A were shorter compared with those of group B (331.4 + 51.5 vs 257.9 + 84.0; P = .02). The cardiovascular risk score was negative and was significantly correlated with total distances for men (r = -0.53; P = .001) and with pain-free distances for women (r = -0.46; P = .03). Functional capacity, evaluated through a 6-minute walk test, seems to be associated with 10-year total mortality risk. Copyright © 2015 Society for Vascular Nursing, Inc. Published by Elsevier Inc. All rights reserved.

Exercise training for intermittent claudication.

PubMed

McDermott, Mary M

2017-11-01

The objective of this study was to provide an overview of evidence regarding exercise therapies for patients with lower extremity peripheral artery disease (PAD). This manuscript summarizes the content of a lecture delivered as part of the 2016 Crawford Critical Issues Symposium. Multiple randomized clinical trials demonstrate that supervised treadmill exercise significantly improves treadmill walking performance in people with PAD and intermittent claudication symptoms. A meta-analysis of 25 randomized trials demonstrated a 180-meter increase in treadmill walking distance in response to supervised exercise interventions compared with a nonexercising control group. Supervised treadmill exercise has been inaccessible to many patients with PAD because of lack of medical insurance coverage. However, in 2017, the Centers for Medicare and Medicaid Services issued a decision memorandum to support health insurance coverage of 12 weeks of supervised treadmill exercise for patients with walking impairment due to PAD. Recent evidence also supports home-based walking exercise to improve walking performance in people with PAD. Effective home-exercise programs incorporate behavioral change interventions such as a remote coach, goal setting, and self-monitoring. Supervised treadmill exercise programs preferentially improve treadmill walking performance, whereas home-based walking exercise programs preferentially improve corridor walking, such as the 6-minute walk test. Clinical trial evidence also supports arm or leg ergometry exercise to improve walking endurance in people with PAD. Treadmill walking exercise appears superior to resistance training alone for improving walking endurance. Supervised treadmill exercise significantly improves treadmill walking performance in people with PAD by approximately 180 meters compared with no exercise. Recent evidence suggests that home-based exercise is also effective and preferentially improves over-ground walking performance, such as the 6-minute walk test. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Patterns and determinants of use of pharmacological therapies for intermittent claudication in PAD outpatients: results of the IDOMENEO study.

PubMed

Cimminiello, Claudio; Polo Friz, Hernan; Marano, Giuseppe; Arpaia, Guido; Boracchi, Patrizia; Spezzigu, Gabriella; Visonà, Adriana

2017-06-01

Peripheral arterial disease (PAD) usually presents with intermittent claudication (IC). The aim of the present study was to assess, in clinical practice, the pattern of use of pharmacological therapies for IC in stable PAD outpatients. A propensity analysis was performed using data from the IDOMENEO study, an observational prospective multicenter cohort study. The association between any pharmacological symptomatic IC therapy with different variables was investigated using generalized linear mixed models with pharmacological therapy as response variable and binomial error. Study population: 213 patients, male sex 147 (69.0%), mean age 70.0±8.6 years. Only 36.6% was under pharmacological treatment for IC, being cilostazol the most used medication (21.6%). Univariate analysis showed a probability of a patient of being assigned to any pharmacological symptomatic IC therapy of 67.0% when Ankle-Brachial Index (ABI) <0.6 and 29.8% when ABI>0.6 (P=0.0048), and a propensity to avoid pharmacological treatment for patients with a high number of drugs to treat cardiovascular risk factors (probability of 55.2% for <4 drugs and 19.6% for >4 drugs, P=0.0317). Multivariate analysis confirmed a higher probability of assigning treatment for ABI<0.6 (P=0.0274), and a trend to a lower probability in patients under polypharmacy (>4 drugs: OR=0.13, P=0.0546). In clinical practice, only one third of stable outpatients with IC used symptomatic pharmacological therapy for IC. We found a propensity of clinicians to assign any symptomatic pharmacological IC therapy to patients with lower values of ABI and a propensity to avoid this kind of treatment in patients under polypharmacy.

Peripheral arterial disease decreases muscle torque and functional walking capacity in elderly.

PubMed

Dziubek, Wioletta; Bulińska, Katarzyna; Stefańska, Małgorzata; Woźniewski, Marek; Kropielnicka, Katarzyna; Jasiński, Tomasz; Jasiński, Ryszard; Pilch, Urszula; Dąbrowska, Grażyna; Skórkowska-Telichowska, Katarzyna; Wojcieszczyk-Latos, Joanna; Kałka, Dariusz; Janus, Agnieszka; Zywar, Katarzyna; Paszkowski, Rafał; Szuba, Andrzej

2015-08-01

The aim of this study is to compare values of force-velocity and functional walking capacity in elderly patients with intermittent claudication with respect to the control group. The study involved 135 individuals: 85-peripheral arterial disease (PAD) group diagnosed with stage II chronic lower limb ischemia, according to Fontaine's classification, and 50-control group. The studies included an assessment of walking capacity using a six-minute walk test (6MWT) and measurement of force-velocity parameters (peak torque-PTQ, total work-TW, average power-AVGP) of the lower limbs obtained by means of a functional dynamometry under isokinetic conditions. The peripheral arterial disease group is characterized by significantly lower values of force-velocity parameters compared to the control group (p<0.005). Walking capacity in this group is significantly reduced due to significant differences in the distance covered (p<0.0001), walking speed (p<0.01), and its intensity (p<0.01). Further, a positive correlation was found between the maximum distance specified in the six-minute walk test and lower limb muscle strength in the isokinetic test. Mean values of all force-velocity parameters and walk distance were significantly higher in the control group than in the peripheral arterial disease group. In the PAD group, in both men and women, the value of the agonist/antagonist ratio of both lower limbs are lower in men and women comparing to the control group. A rehabilitation program for patients with intermittent claudication must consider exercises improving strength, exercise capacity, and endurance in patients with PAD. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Supervised Exercise Therapy for Intermittent Claudication Is Increasingly Endorsed by Dutch Vascular Surgeons.

PubMed

Hageman, David; Lauret, Gert-Jan; Gommans, Lindy N M; Koelemay, Mark J W; van Sambeek, Marc R H M; Scheltinga, Marc R M; Teijink, Joep A W

2018-02-01

Although supervised exercise therapy (SET) is generally accepted as an effective noninvasive treatment for intermittent claudication (IC), Dutch vascular surgeons were initially somewhat hesitant as reported by a 2011 questionnaire study. Later on, a nationwide multidisciplinary network for SET was introduced in the Netherlands. The aim of this questionnaire study was to determine possible trends in conceptions among Dutch vascular surgeons regarding the prescription of SET. In the year of 2015, Dutch vascular surgeons, fellows, and senior residents were asked to complete a 26-item questionnaire including issues that were considered relevant for prescribing SET such as patient selection criteria and comorbidity. Outcome was compared to the 2011 survey. Data of 124 respondents (82% males; mean age 46 years; 64% response rate) were analyzed. SET referral rate of new IC patients was not different over time (2015: 81% vs. 2011: 75%; P = 0.295). However, respondents were more willing to prescribe SET in IC patients with chronic obstructive pulmonary disease (2015: 86% vs. 2011: 69%; P = 0.002). Nevertheless, a smaller portion of respondents found that SET was also indicated for aortoiliac disease (2015: 63% vs. 2011: 76%; P = 0.049). Insufficient health insurance coverage and/or personal financial resources were the most important presumed barriers preventing patients from initiating SET (80% of respondents). Moreover, 94% of respondents judged that SET should be fully reimbursed by all Dutch basic health insurances. The concept of SET for IC is nowadays generally embraced by the vast majority of Dutch vascular surgeons. SET may have gained in popularity in IC patients with cardiopulmonary comorbidity. However, SET remains underutilized for aortoiliac disease. Reimbursement is considered crucial for a successful SET implementation. Copyright © 2017 Elsevier Inc. All rights reserved.

Evaluation of Cell Therapy on Exercise Performance and Limb Perfusion in Peripheral Artery Disease: The CCTRN Patients with Intermittent Claudication Injected with ALDH Bright Cells (PACE) Trial

PubMed Central

Perin, Emerson C.; Murphy, Michael P.; March, Keith L.; Bolli, Roberto; Loughran, John; Yang, Phillip C.; Leeper, Nicholas J.; Dalman, Ronald L.; Alexander, Jason; Henry, Timothy D.; Traverse, Jay H.; Pepine, Carl J.; Anderson, R. David; Berceli, Scott; Willerson, James T.; Muthupillai, Raja; Gahremanpour, Amir; Raveendran, Ganesh; Velasquez, Omaida; Hare, Joshua M.; Schulman, Ivonne Hernandez; Kasi, Vijaykumar S.; Hiatt, William R.; Ambale-Venkatesh, Bharath; Lima, João A.; Taylor, Doris A.; Resende, Micheline; Gee, Adrian P.; Durett, April G.; Bloom, Jeanette; Richman, Sara; G’Sell, Patricia; Williams, Shari; Khan, Fouzia; Ross, Elsie Gyang; Santoso, Michelle R.; Goldman, JoAnne; Leach, Dana; Handberg, Eileen; Cheong, Benjamin; Piece, Nichole; DiFede, Darcy; Bruhn-Ding, Barb; Caldwell, Emily; Bettencourt, Judy; Lai, Dejian; Piller, Linda; Simpson, Lara; Cohen, Michelle; Sayre, Shelly L.; Vojvodic, Rachel W.; Moyé, Lem; Ebert, Ray F.; Simari, Robert D.; Hirsch, Alan T.

2017-01-01

Background Atherosclerotic peripheral artery disease (PAD) affects 8–12% of Americans over 65 and is associated with a major decline in functional status, increased myocardial infarction and stroke rates, and increased risk of ischemic amputation. Current treatment strategies for claudication have limitations. PACE is an NHLBI-sponsored, randomized, double-blind, placebo-controlled phase 2, exploratory clinical trial designed to assess safety and efficacy of autologous bone marrow–derived aldehyde dehydrogenase bright (ALDHbr) cells in PAD patients and to explore associated claudication physiologic mechanisms. Methods All participants, randomized 1:1 to receive ALDHbr cells or placebo, underwent bone marrow aspiration and isolation of ALDHbr cells, followed by ten injections into the thigh and calf of the index leg. The co-primary endpoints were: change from baseline to six months in peak walking time (PWT), collateral count, peak hyperemic popliteal flow, and capillary perfusion measured by magnetic resonance imaging (MRI); as well as safety. Results A total of 82 patients with claudication and infra-inguinal PAD were randomized at nine sites, of which 78 had analyzable data (57 male, 21 female; mean age 66±9 years). The mean differences in the change over six months between study groups for PWT (mean ± standard error of the mean [SEM]) (0.9±0.8 minutes; 95% CI −0.6 to 2.5; p=0.238), collateral count (0.9±0.6 arteries; 95% CI −0.2 to 2.1; p=0.116), peak hyperemic popliteal flow (0.0±0.4 mL/sec; 95% CI −0.8 to 0.8; p=0.978), and capillary perfusion (−0.2±0.6%; 95% CI −1.3 to 0.9; p=0.752) were not significant. Additionally, there were no significant differences for the secondary endpoints, including quality of life measures. There were no adverse safety outcomes. Correlative relationships between MRI measures and PWT were not significant. A post-hoc exploratory analysis suggested that ALDHbr cell administration might be associated with an increase in the number of collateral arteries (1.5±0.7; 95% CI 0.1 to 2.9; p=0.047) in participants with completely occluded femoral arteries. Conclusions ALDHbr cell administration did not improve PWT or MR outcomes, and the changes in PWT were not associated with the anatomic or physiologic MRI endpoints. Future PAD cell therapy investigational trial design may be informed by new anatomic and perfusion insights. PMID:28209728

Five-year durability of stand-alone interspinous process decompression for lumbar spinal stenosis

PubMed Central

Nunley, Pierce D; Patel, Vikas V; Orndorff, Douglas G; Lavelle, William F; Block, Jon E; Geisler, Fred H

2017-01-01

Background Lumbar spinal stenosis is the most common indication for spine surgery in older adults. Interspinous process decompression (IPD) using a stand-alone spacer that functions as an extension blocker offers a minimally invasive treatment option for intermittent neurogenic claudication associated with spinal stenosis. Methods This study evaluated the 5-year clinical outcomes for IPD (Superion®) from a randomized controlled US Food and Drug Administration (FDA) noninferiority trial. Outcomes included Zurich Claudication Questionnaire (ZCQ) symptom severity (ss), physical function (pf), and patient satisfaction (ps) subdomains, leg and back pain visual analog scale (VAS), and Oswestry Disability Index (ODI). Results At 5 years, 84% of patients (74 of 88) demonstrated clinical success on at least two of three ZCQ domains. Individual ZCQ domain success rates were 75% (66 of 88), 81% (71 of 88), and 90% (79 of 88) for ZCQss, ZCQpf, and ZCQps, respectively. Leg and back pain success rates were 80% (68 of 85) and 65% (55 of 85), respectively, and the success rate for ODI was 65% (57 of 88). Percentage improvements over baseline were 42%, 39%, 75%, 66%, and 58% for ZCQss, ZCQpf, leg and back pain VAS, and ODI, respectively (all P<0.001). Within-group effect sizes were classified as very large for four of five clinical outcomes (ie, >1.0; all P<0.0001). Seventy-five percent of IPD patients were free from reoperation, revision, or supplemental fixation at their index level at 5 years. Conclusion After 5 years of follow-up, IPD with a stand-alone spacer provides sustained clinical benefit. PMID:28919727

Community walking programs for treatment of peripheral artery disease

PubMed Central

Mays, Ryan J.; Rogers, R. Kevin; Hiatt, William R.; Regensteiner, Judith G.

2013-01-01

Background Supervised walking programs offered at medical facilities for patients with peripheral artery disease (PAD) and intermittent claudication (IC), while effective, are often not utilized due to barriers including lack of reimbursement and the need to travel to specialized locations for the training intervention. Walking programs for PAD patients that occur in community settings, such as those outside of supervised settings, may be a viable treatment option, as they are convenient and potentially bypass the need for supervised walking. This review evaluated the various methodologies and outcomes of community walking programs for PAD. Methods A literature review using appropriate search terms was conducted within PubMed/Medline and the Cochrane databases to identify studies in the English language employing community walking programs to treat PAD patients with IC. Search results were reviewed, and relevant articles were identified that form the basis of this review. The primary outcome was peak walking performance on the treadmill. Results Randomized controlled trials (n=10) examining peak walking outcomes in 558 PAD patients demonstrated that supervised exercise programs were more effective than community walking studies that consisted of general recommendations for patients with IC to walk at home. Recent community trials that incorporated more advice and feedback for PAD patients in general resulted in similar outcomes with no differences in peak walking time compared to supervised walking exercise groups. Conclusions Unstructured recommendations for patients with symptomatic PAD to exercise in the community are not efficacious. Community walking programs with more feedback and monitoring offer improvements in walking performance for patients with claudication and may bypass some obstacles associated with facility-based exercise programs. PMID:24103409

Home-based exercise for elderly patients with intermittent claudication limited by osteoarticular disorders - feasibility and effectiveness of a low-intensity programme.

PubMed

Lamberti, Nicola; Straudi, Sofia; Lissia, Efisio; Cavazzini, Lorenza; Buja, Sergio; Manfredini, Roberto; Basaglia, Nino; Manfredini, Fabio

2018-04-01

Peripheral arterial disease (PAD) is a common cardiovascular pathology affecting mobility in elderly. Osteoarticular diseases (ODs), responsible for functional limitations and confounding leg symptoms, may interfere with exercise therapy. This study evaluates the feasibility and effectiveness of a structured home-based exercise programme on rehabilitative outcomes in a cohort of elderly PAD patients with and without coexisting ODs. Patients were enrolled from 2002 to 2016 in an exercise programme prescribed and controlled at the hospital and based on two daily 10-minute home walking sessions below the self-selected speed. The presence and localization of ODs at baseline were derived from consultation of medical documents. The ankle-brachial index and functional outcomes, defined as speed at the onset of claudication and attainable maximal speed by an incremental treadmill test, were assessed at baseline and discharge. Feasibility was determined according to dropout rate, number of visits, duration of the programme, and adherence. A total of 1,251 PAD patients were enrolled (931 men; 71 ± 9 years; 0.63 ± 0.19 ankle-brachial index). Eight hundred sixty-four patients were free of ODs (ODfree PAD , 69 %), whereas 387 were affected by ODs (OD PAD , 31 %), predominantly located in the spine (72 %). In the logistic regression models, the presence of ODs was associated with female sex, overweight, sedentary and/or driving professions. At discharge, OD PAD and ODfree PAD did not differ in dropout rates (12 % each), programme duration (378 ± 241 vs. 390 ± 260 days), number of visits (7 ± 3 each), and adherence (80 % each). Similar improvements for OD PAD and ODfree PAD were observed for the ankle-brachial index (0.06 ± 0.12 each), the speed at onset of claudication (0.7 ± 0.7 vs. 0.7 ± 0.8 kmh-1; p = 0.70), and maximal speed (0.4 ± 0.6 vs. 0.4 ± 0.6 kmh-1; p = 0.77). Equally satisfactory rehabilitative outcomes were observed in elderly patients with claudication limited by ODs who completed a well-tolerated, low-impact structured exercise programme.

Education and home based training for intermittent claudication: functional effects and quality of life.

PubMed

Prévost, Alain; Lafitte, Marianne; Pucheu, Yann; Couffinhal, Thierry

2015-03-01

Supervised exercise programs increase physical performance in patients with peripheral artery disease (PAD). However, there are a limited number of programs, and to date they have failed to provide evidence of long-term adherence to exercise or any meaningful effect on Quality of Life (QoL). We created a program of therapeutic education and a personalized program of reconditioning exercise for patients with PAD. Patients with an ankle-brachial index (ABI) below 0.9 in at least one limb, and an absolute claudication distance (ACD) ≤500 meters, were included in the study. Quality of Life (QoL) as measured by SF-36, cardiovascular risk factors and functional parameters were evaluated at 0, 3, 6 and 12 months. Forty-six patients completed the program. Cardiovascular risks were controlled and stabilized over time. SF-36 scores improved significantly and remained stable. Initial and absolute claudication distance (ICD and ACD) as well as other functional parameters improved significantly (6 months: +138 m or +203% ICD and +139 m or +84% ACD). Ten patients (22%) did not show improvement in ICD or ACD within the first 3 months, but their SF-36 score did increase at subsequent visits. Interestingly, these patients had a significantly lower ACD at baseline. This study measured beneficial effects of an educational therapeutic program for patients with PAD. The results demonstrate a significant improvement in functional and QoL parameters during the first 3 months of coaching, and long-term persistence of the results even when patients were no longer coached. © The European Society of Cardiology 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

A Three Month Home Exercise Programme Augmented with Nordic Poles for Patients with Intermittent Claudication Enhances Quality of Life and Continues to Improve Walking Distance and Compliance After One Year.

PubMed

Oakley, C; Spafford, C; Beard, J D

2017-05-01

The objective of this study was to collect 1 year follow-up information on walking distance, speed, compliance, and cost in patients with intermittent claudication who took part in a previously reported 12 week randomised clinical trial of a home exercise programme augmented with Nordic pole walking versus controls who walked normally. A second objective was to look at quality of life and ankle brachial pressure indices (ABPIs) after a 12 week augmented home exercise programme. Thirty-two of the 38 patients who completed the original trial were followed-up after 6 and 12 months. Frequency, duration, speed, and distance of walking were recorded using diaries and pedometers. A new observational cohort of 29 patients was recruited to the same augmented home exercise programme. ABPIs, walking improvement, and quality of life questionnaire were recorded at baseline and 12 weeks (end of the programme). Both groups in the follow-up study continued to improve their walking distance and speed over the following year. Compliance was excellent: 98% of the augmented group were still walking with poles at both 6 and 12 months, while 74% of the control group were still walking at the same point. The augmented group increased their mean walking distance to 17.5 km by 12 months, with a mean speed of 4.2 km/hour. The control group only increased their mean walking distance from 4.2 km to 5.6 km, and speed to 3.3 km/hour. Repeated ANOVA showed the results to be highly significant (p = .002). The 21/29 patients who completed the observational study showed a statistically significant increase in resting ABPIs from baseline (mean ± SD 0.75 ± 0.12) to week 12 (mean ± SD 0.85 ± 0.12) (t = (20) -8.89, p = .000 [two-tailed]). All their walking improvement and quality of life parameters improved significantly (p = .002 or less in the six categories) over the same period and their mean health scores improved by 79%. Following a 12 week augmented home exercise programme, most patients with intermittent claudication continued to significantly improve their walking distance and walking speed at 1 year compared with normal walking. Quality of life and ABPIs improved significantly after only 12 weeks and it is postulated that the improvement in ABPI was due to collateral development. These results justify the belief that an augmented home exercise programme will be as clinically effective as existing supervised exercise programmes, with the added benefits of lower cost and better compliance. Funding for a multicentre trial comparing an augmented home exercise programme with existing supervised exercise programme is now urgently required. Copyright © 2017 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Prognostic value of a low post-exercise ankle brachial index as assessed by primary care physicians.

PubMed

Diehm, Curt; Darius, Harald; Pittrow, David; Schwertfeger, Markus; Tepohl, Gerhart; Haberl, Roman L; Allenberg, Jens Rainer; Burghaus, Ina; Trampisch, Hans Joachim

2011-02-01

We aimed to investigate whether the post-exercise ankle brachial index (ABI) performed by primary care physicians offers useful information for the prediction of death or cardiovascular events, beyond the traditional resting ABI. An additional focus was on patients with intermittent claudication and normal resting ABI. Using data from the 5-year follow-up of 6468 elderly patients in the primary care setting in Germany (getABI study) we used multivariate Cox regression models adjusted for age, gender and conventional risk factors to determine the association of resting ABI and/or post-exercise ABI and all-cause mortality/morbidity. Mean post-exercise ABI in the total cohort was 0.977 and resting ABI was 1.034. For post-exercise ABI, a threshold value of 0.825 had nearly the same sensitivity (28.6%) and specificity (85.7%) as the conventionally used resting ABI with a cut-off value of 0.9 to predict death. Compared to patients with normal post-exercise ABI, a low post-exercise ABI was associated with an almost identical risk increase for mortality (hazard ratio [HR] 1.56, 95% confidence interval [CI] 1.30-1.86) as a low resting ABI (HR 1.65; CI 1.39-1.97) and/or myocardial infarction/stroke. Slight differences were observed for coronary/carotid revascularisation and peripheral revascularisation/amputation. In combined models it could not be shown that post-exercise ABI yielded relevant additional information for the prognosis of mortality and/or myocardial infarction/stroke, not even in the subgroup analysis of patients with intermittent claudication and normal resting ABI. It could not be shown that the post-exercise ABI is a useful tool for the prognosis of mortality and/or myocardial infarction/stroke beyond the resting ABI. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

True cadence and step accumulation are not equivalent: the effect of intermittent claudication on free-living cadence.

PubMed

Stansfield, B; Clarke, C; Dall, P; Godwin, J; Holdsworth, R; Granat, M

2015-02-01

'True cadence' is the rate of stepping during the period of stepping. 'Step accumulation' is the steps within an epoch of time (e.g. 1min). These terms have been used interchangeably in the literature. These outcomes are compared within a population with intermittent claudication (IC). Multiday, 24h stepping activity of those with IC (30) and controls (30) was measured objectively using the activPAL physical activity monitor. 'True cadence' and 'step accumulation' outcomes were calculated. Those with IC took fewer steps/d 6531±2712 than controls 8692±2945 (P=0.003). However, these steps were taken within approximately the same number of minute epochs (IC 301±100min/d; controls 300±70min/d, P=0.894) with only slightly lower true cadence (IC 69 (IQ 66,72) steps/min; controls 72 (IQ 68,76) steps/min, P=0.026), giving substantially lower step accumulation (IC 22 (IQ 19,24) steps/min; controls 30 (IQ 23,34) steps/min) (P<0.001). However, the true cadence of stepping within the blocks of the 1, 5, 20, 30 and 60min with the maximum number of steps accumulated was lower for those with IC than controls (P<0.05). Those with IC took 1300 steps fewer per day above a true cadence of 90 steps/min. True cadence and step accumulation outcomes were radically different for the outcomes examined. 'True cadence' and 'step accumulation' were not equivalent in those with IC or controls. The measurement of true cadence in the population of people with IC provides information about their stepping rate during the time they are stepping. True cadence should be used to correctly describe the rate of stepping as performed. Copyright © 2014 Elsevier B.V. All rights reserved.

Google Maps offers a new way to evaluate claudication.

PubMed

Khambati, Husain; Boles, Kim; Jetty, Prasad

2017-05-01

Accurate determination of walking capacity is important for the clinical diagnosis and management plan for patients with peripheral arterial disease. The current "gold standard" of measurement is walking distance on a treadmill. However, treadmill testing is not always reflective of the patient's natural walking conditions, and it may not be fully accessible in every vascular clinic. The objective of this study was to determine whether Google Maps, the readily available GPS-based mapping tool, offers an accurate and accessible method of evaluating walking distances in vascular claudication patients. Patients presenting to the outpatient vascular surgery clinic between November 2013 and April 2014 at the Ottawa Hospital with vasculogenic calf, buttock, and thigh claudication symptoms were identified and prospectively enrolled in our study. Onset of claudication symptoms and maximal walking distance (MWD) were evaluated using four tools: history; Walking Impairment Questionnaire (WIQ), a validated claudication survey; Google Maps distance calculator (patients were asked to report their daily walking routes on the Google Maps-based tool runningmap.com, and walking distances were calculated accordingly); and treadmill testing for onset of symptoms and MWD, recorded in a double-blinded fashion. Fifteen patients were recruited for the study. Determination of walking distances using Google Maps proved to be more accurate than by both clinical history and WIQ, correlating highly with the gold standard of treadmill testing for both claudication onset (r = .805; P < .001) and MWD (r = .928; P < .0001). In addition, distances were generally under-reported on history and WIQ. The Google Maps tool was also efficient, with reporting times averaging below 4 minutes. For vascular claudicants with no other walking limitations, Google Maps is a promising new tool that combines the objective strengths of the treadmill test and incorporates real-world walking environments. It offers an accurate, efficient, inexpensive, and readily accessible way to assess walking distances in patients with peripheral vascular disease. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

OXYGEN UPTAKE BEFORE AND AFTER THE ONSET OF CLAUDICATION DURING A 6-MINUTE WALK TEST

PubMed Central

Gardner, Andrew W.; Ritti-Dias, Raphael M.; Stoner, Julie A.; Montgomery, Polly S.; Khurana, Aman; Blevins, Steve M.

2011-01-01

Purposes To compare oxygen uptake before and after the onset of claudication in subjects with peripheral artery disease (PAD) during a 6-minute walk test, and to identify predictors of the change in oxygen uptake following the onset of claudication pain Methods Fifty subjects with PAD were studied, in which 33 experienced claudication (Pain Group) during a 6-minute walk test, and 17 were pain-free during this test (Pain-Free Group). Oxygen uptake and ambulatory cadence were primary outcomes obtained during the 6-minute walk test. Results The Pain Group experienced onset of claudication pain at 179 ± 45 meters (mean ± standard deviation) and continued to walk to achieve a 6-minute walk distance of 393 ± 74 meters, which was similar (p = 0.74) to the Pain-Free Group (401 ± 76 meters). Oxygen uptake increased (p < 0.0001) after the onset of pain in the Pain Group, and this change was greater (p = 0.025) than the increase in oxygen uptake from the second to fifth minute of walking in the Pain-Free Group. Furthermore, ambulatory cadence decreased after the onset of pain in the Pain Group (p = 0.0003). The change in oxygen uptake was associated with metabolic syndrome (p = 0.0023), 6-minute walk distance (p = 0.0037), age, (p = 0.0041), and the oxygen uptake during the second minute of the test (p = 0.012). Conclusion Claudication increases oxygen uptake of self-paced, over-ground ambulation despite a decrease in cadence. The pain-mediated increase in oxygen uptake was blunted in subjects with metabolic syndrome, suggesting that they have an impaired ability to increase oxygen uptake during ambulation. The clinical significance is that claudication increases metabolic cost of ambulation, thereby increasing the relative intensity of exercise and reducing the tolerance to sustain ambulation. PMID:21890308

Peripheral Vascular Disease: The Beneficial Effect of Exercise in Peripheral Vascular Diseases Based on Clinical Trials.

PubMed

Elnady, Basant M; Saeed, Ayman

2017-01-01

Intermittent claudication (IC) due to peripheral artery diseases (PAD) is one of the disabling disease that can affect quality of life (QOL) and functional status of capacity. It is characterized by cramping pain which develops with exercise and eliminated by rest secondary to decrease blood flow to the muscles. The annual incidence rate is increased with age. Exercise rehabilitation has a great impact in improving the functional capacity and prevent the functional disability. The available evidences from current studies have showed that exercise therapy is considered the primary treatment in PAD, which in consequently improves the QOL. In this chapter we will illustrate the current available evidences which support exercise benefit and outcomes in PAD with IC.

The impact of coronary artery disease and left ventricular ejection fraction on the prognosis of patients with peripheral artery disease.

PubMed

Tsujimura, Takuya; Iida, Osamu; Ishihara, Takayuki; Fujita, Masashi; Masuda, Masaharu; Okamoto, Shin; Nanto, Kiyonori; Kanda, Takashi; Sunaga, Akihiro; Takahara, Mitsuyoshi; Uematsu, Masaaki

2017-11-01

The impact of the severity of coronary artery disease (CAD) and left ventricular ejection fraction (LVEF) on the prognosis of patients with peripheral artery disease (PAD) has not been systematically studied. We retrospectively analysed 622 patients with PAD (intermittent claudication (IC): n = 446; critical limb ischaemia (CLI): n = 176). The association of SYNTAX score and LVEF with mortality was analysed using the Cox proportional hazard model. In patients with IC, a high SYNTAX score was significantly associated with mortality, whereas reduced LVEF was significantly associated with mortality in patients with CLI. The prognostic impact of CAD and LVEF appears different between patients with IC and CLI. © 2017 Royal Australasian College of Physicians.

Advances in targeting cyclic nucleotide phosphodiesterases

PubMed Central

Maurice, Donald H.; Ke, Hengming; Ahmad, Faiyaz; Wang, Yousheng; Chung, Jay; Manganiello, Vincent C.

2014-01-01

Cyclic nucleotide phosphodiesterases (PDEs) catalyse the hydrolysis of cyclic AMP and cyclic GMP, thereby regulating the intracellular concentrations of these cyclic nucleotides, their signalling pathways and, consequently, myriad biological responses in health and disease. Currently, a small number of PDE inhibitors are used clinically for treating the pathophysiological dysregulation of cyclic nucleotide signalling in several disorders, including erectile dysfunction, pulmonary hypertension, acute refractory cardiac failure, intermittent claudication and chronic obstructive pulmonary disease. However, pharmaceutical interest in PDEs has been reignited by the increasing understanding of the roles of individual PDEs in regulating the subcellular compartmentalization of specific cyclic nucleotide signalling pathways, by the structure-based design of novel specific inhibitors and by the development of more sophisticated strategies to target individual PDE variants. PMID:24687066

Achilles tendon reflex measuring system

NASA Astrophysics Data System (ADS)

Szebeszczyk, Janina; Straszecka, Joanna

1995-06-01

The examination of Achilles tendon reflex is widely used as a simple, noninvasive clinical test in diagnosis and pharmacological therapy monitoring in such diseases as: hypothyroidism, hyperthyroidism, diabetic neuropathy, the lower limbs obstructive angiopathies and intermittent claudication. Presented Achilles tendon reflect measuring system is based on the piezoresistive sensor connected with the cylinder-piston system. To determinate the moment of Achilles tendon stimulation a detecting circuit was used. The outputs of the measuring system are connected to the PC-based data acquisition board. Experimental results showed that the measurement accuracy and repeatability is good enough for diagnostics and therapy monitoring purposes. A user friendly, easy-to-operate measurement system fulfills all the requirements related to recording, presentation and storing of the patients' reflexograms.

Clinical Features and Endovascular Management of Iliac Artery Fibromuscular Dysplasia

PubMed Central

Ketha, Siva S.; Bjarnason, Haraldur; Oderich, Gustavo S.; Misra, Sanjay

2014-01-01

Purpose To identify the spectrum of clinical presentation of iliac artery fibromuscular dysplasia (FMD) and to evaluate the outcomes of endovascular management of iliac FMD for claudication. Methods and materials All patients in our institution with a diagnosis of FMD between January 1980 and December 2010 were identified. 14 patients were found to have FMD of the iliac arteries. Associated risk factors included hypertension (79%), hyperlipidemia (64%), smoking history (36%), coronary artery disease (21%), diabetes (0 %), and obesity (36%). Results Eight (57%) patients were incidentally found to have iliac FMD on imaging. 6 (43%) patients had life style limiting claudication involving one or both extremities. All 6 patients were reported as mild peripheral arterial disease (PAD) based on ankle brachial index (ABI) measurements (0.7 to 0.9). These six patients underwent 10 endovascular procedures for claudication including angioplasty (n=8) and self-expanding stent placement (n=2). Mean symptom free survival was 56.3 months. Conclusion Iliac FMD may be found incidentally or may present with disabling claudication that is amenable to endovascular treatment. PMID:24768236

Rocker-soled shoes and walking distance in patients with calf claudication.

PubMed

Richardson, J K

1991-07-01

Calf claudication is the major clinical manifestation of peripheral vascular occlusive disease in a significant number of patients. Although claudication causes substantial patient disability, most patients are treated conservatively because of the risks of surgical therapy and the uncertain efficacy of drug therapy. It was hypothesized that rocker-soled shoes would decrease the work of the plantar flexors and therefore increase walking distance in patients with calf claudication. To test this hypothesis, walking distances in patients with calf claudication using rocker-soled shoes and a placebo shoe insert were compared. Rocker-soled shoes significantly increased both the total distance walked and the distance at which patients were initially bothered by symptoms by 77m (37%, p less than .0005) and 89m (91%, p = .003), respectively. It was concluded that rocker-soled shoes may reduce disability in patients with calf claudication by increasing walking distance.

Photoacoustic tomography: applications for atherosclerosis imaging

NASA Astrophysics Data System (ADS)

Sangha, Gurneet S.; Goergen, Craig J.

2016-08-01

Atherosclerosis is a debilitating condition that increases a patient’s risk for intermittent claudication, limb amputation, myocardial infarction, and stroke, thereby causing approximately 50% of deaths in the western world. Current diagnostic imaging techniques, such as ultrasound, digital subtraction angiography, computed tomography angiography, magnetic resonance angiography, and optical imaging remain suboptimal for detecting development of early stage plaques. This is largely due to the lack of compositional information, penetration depth, and/or clinical efficiency of these traditional imaging techniques. Photoacoustic imaging has emerged as a promising modality that could address some of these limitations to improve the diagnosis and characterization of atherosclerosis-related diseases. Photoacoustic imaging uses near-infrared light to induce acoustic waves, which can be used to recreate compositional images of tissue. Recent developments in photoacoustic techniques show its potential in noninvasively characterizing atherosclerotic plaques deeper than traditional optical imaging approaches. In this review, we discuss the significance and development of atherosclerosis, current and novel clinical diagnostic methods, and recent works that highlight the potential of photoacoustic imaging for both experimental and clinical studies of atherosclerosis.

Evolution of surgical techniques for a progressive risk reduction.

PubMed

Amato, Bruno; Santoro, Mario; Izzo, Raffaele; Servillo, Giuseppe; Compagna, Rita; Di Domenico, Lorenza; Di Nardo, Veronica; Giugliano, Giuseppe

2017-07-18

Advanced age is a strong predictor of high perioperative mortality in surgical patients and patients aged 75 years and older have an elevated surgical risk, much higher than that of younger patients. Progressive advances in surgical techniques now make it possible to treat high-risk surgical patients with minimally invasive procedures. Endovascular techniques have revolutionized the treatment of several vascular diseases, in particular carotid stenosis, aortic pathologies, and severely incapacitating intermittent claudication or critical limb ischemia. The main advantages of the endovascular approach are the low complication rate, high rate of technical success and a good clinical outcome. Biliary stenting has improved the clinical status of severely ill patients with bile duct stricture before major surgery, and represents a good palliative therapy in the case of malignant biliary obstruction.

Transcutaneous calf-muscle electro-stimulation: A prospective treatment for diabetic claudicants?

PubMed

Ellul, Christian; Gatt, Alfred

2016-11-01

First-line therapy for claudicants with diabetes include supervised exercise programmes to improve walking distance. However, exercise comes with a number of barriers and may be contraindicated in certain conditions. The aim of this study was to evaluate whether calf-muscle electro-stimulation improves claudication distance. A prospective, one-group, pretest-posttest study design was employed on 40 participants living with type 2 diabetes mellitus, peripheral artery disease (ankle-brachial pressure index < 0.90) and calf-muscle claudication. Calf-muscle electro-stimulation of varying frequencies (1-250 Hz) was applied on both ischaemic limbs (N = 80) for 1 h per day for 12 consecutive weeks. The absolute claudication distance was measured at baseline and following the intervention. The cohort (n = 40; 30 males; mean age = 71 years; mean ankle-brachial pressure index = 0.70) registered a mean baseline absolute claudication distance of 333.71 m (standard deviation = 208). Following 91.68 days (standard deviation = 6.23) of electrical stimulation, a significant mean increase of 137 m (standard deviation = 136) in the absolute claudication distance was registered (p = 0.000, Wilcoxon signed rank test). Electrical stimulation of varying low to high frequencies on ischaemic calf muscles significantly increased the maximal walking capacity in claudicants with type 2 diabetes. This therapeutic approach may be considered in patients with impaired exercise tolerance or as an adjunct treatment modality. © The Author(s) 2016.

Cost-effectiveness of supervised exercise, stenting, and optimal medical care for claudication: results from the Claudication: Exercise Versus Endoluminal Revascularization (CLEVER) trial.

PubMed

Reynolds, Matthew R; Apruzzese, Patricia; Galper, Benjamin Z; Murphy, Timothy P; Hirsch, Alan T; Cutlip, Donald E; Mohler, Emile R; Regensteiner, Judith G; Cohen, David J

2014-11-11

Both supervised exercise (SE) and stenting (ST) improve functional status, symptoms, and quality of life compared with optimal medical care (OMC) in patients with claudication. The relative cost-effectiveness of these strategies is not well defined. The Claudication: Exercise Versus Endoluminal Revascularization (CLEVER) study randomized patients with claudication due to aortoiliac stenosis to a 6-month SE program, to ST, or to OMC. Participants who completed 6-month follow-up (n=98) were included in a health economic analysis through 18 months. Costs were assessed using resource-based methods and hospital billing data. Quality-adjusted life-years were estimated using the EQ-5D. Markov modeling based on the in-trial results was used to explore the impact of assumptions about the longer term durability of observed differences in quality of life. Through 18 months, mean healthcare costs were $5178, $9804, and $14 590 per patient for OMC, SE, and ST, respectively. Measured quality-adjusted life-years through 18 months were 1.04, 1.16, and 1.20. In our base case analysis, which assumed that observed differences in quality of life would dissipate after 5 years, the incremental cost-effectiveness ratios were $24 070 per quality-adjusted life-year gained for SE versus OMC, $41 376 for ST versus OMC, and $122 600 for ST versus SE. If the treatment effect of ST was assumed to be more durable than that of SE, the incremental cost-effectiveness ratio for ST versus SE became more favorable. Both SE and ST are economically attractive by US standards relative to OMC for the treatment of claudication in patients with aortoiliac disease. ST is more expensive than SE, with uncertain incremental benefit. www.clinicaltrials.gov, Unique identifier: NCT00132743. © 2014 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Significant savings with a stepped care model for treatment of patients with intermittent claudication.

PubMed

Fokkenrood, H J P; Scheltinga, M R M; Koelemay, M J W; Breek, J C; Hasaart, F; Vahl, A C; Teijink, J A W

2014-10-01

International guidelines recommend supervised exercise therapy (SET) as primary treatment for intermittent claudication (IC). The aim of this study was to calculate treatment costs in patients with IC and to estimate nationwide annual savings if a stepped care model (SCM, primary SET treatment followed by revascularization in case of SET failure) was followed. Invoice data of all patients with IC in 2009 were obtained from a Dutch health insurance company (3.4 million members). Patients were divided into three groups based on initial treatment after diagnosis (t0). The SET group received SET initiated at any time between 12 months before and up to 3 months after t0. The intervention group (INT) underwent endovascular or open revascularization between t0 and t+3 months. The third group (REST) received neither SET nor any intervention. All peripheral arterial disease related invoices were recorded during 2 years and average costs per patient were calculated. Savings following use of a SCM were calculated for three scenarios. Data on 4954 patients were analyzed. Initial treatment was SET (n = 701, 14.1%), INT (n = 1363, 27.5%), or REST (n = 2890, 58.3%). Within 2 years from t0, invasive revascularization in the SET group was performed in 45 patients (6.4%). Additional interventions (primary at other location and/or re-interventions) were performed in 480 INT patients (35.2%). Some 431 REST patients received additional SET (n = 299, 10.3%) or an intervention (n = 132, 4.5%). Mean total IC related costs per patient were €2,191, €9851 and €824 for SET, INT, and REST, respectively. Based on a hypothetical worst, moderate, and best case scenario, some 3.8, 20.6, or 33.0 million euros would have been saved per annum if SCM was implemented in the Dutch healthcare system. Implementation of a SCM treatment for patients with IC may lead to significant savings of health care resources. Copyright © 2014 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

The relationship of walking distances estimated by the patient, on the corridor and on a treadmill, and the Walking Impairment Questionnaire in intermittent claudication.

PubMed

Frans, Franceline Alkine; Zagers, Marjolein B; Jens, Sjoerd; Bipat, Shandra; Reekers, Jim A; Koelemay, Mark J W

2013-03-01

Physicians and patients consider the limited walking distance and perceived disability when they make decisions regarding (invasive) treatment of intermittent claudication (IC). We investigated the relationship between walking distances estimated by the patient, on the corridor and on a treadmill, and the Walking Impairment Questionnaire (WIQ) in patients with IC due to peripheral arterial disease. This was a single-center, prospective observational cohort study at a vascular laboratory in a university hospital in the Netherlands. The study consisted of 60 patients (41 male) with a median age of 64 years (range, 44-86 years) with IC and a walking distance ≤ 250 m on a standardized treadmill test. Main outcome measures were differences and Spearman rank correlations between pain-free walking distance, maximum walking distance (MWD) estimated by the patient, on the corridor and on a standardized treadmill test, and their correlation with the WIQ. The median patients' estimated, corridor, and treadmill MWD were 200, 200, and 123, respectively (P < .05). Although the median patients' estimated and corridor MWD were not significantly different, there was a difference on an individual basis. The correlation between the patients' estimated and corridor MWD was moderate (r = 0.61; 95% confidence interval [CI], 0.42-0.75). The correlation between patients' estimated and treadmill MWD was weak (r = 0.39; 95%, CI 0.15-0.58). Respective correlations for the pain-free walking distance were comparable. The patients' estimated MWD was moderately correlated with WIQ total score (r = 0.63; 95%, CI 0.45-0.76) and strongly correlated with WIQ distance score (r = 0.81; 95% CI, 0.69-0.88). The correlation between the corridor MWD and WIQ distance score was moderate (r = 0.59; 95% CI, 0.40-0.74). Patients' estimated walking distances and on a treadmill do not reflect walking distances in daily life. Instruments that take into account the perceived walking impairment, such as the WIQ, may help to better guide and evaluate treatment decisions. Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

One-Year Outcomes Following Directional Atherectomy of Popliteal Artery Lesions: Subgroup Analysis of the Prospective, Multicenter DEFINITIVE LE Trial.

PubMed

Rastan, Aljoscha; McKinsey, James F; Garcia, Lawrence A; Rocha-Singh, Krishna J; Jaff, Michael R; Harlin, Stuart; Kamat, Suraj; Janzer, Sean; Zeller, Thomas

2018-02-01

To report the effectiveness of directional atherectomy for the treatment of popliteal artery occlusive disease. This subset of the prospective, multicenter, single-arm DEFINITIVE LE trial included 158 patients (mean age 72.0±10.9 years; 82 men) who underwent directional atherectomy in 162 popliteal artery lesions between 2009 and 2011. Forty-eight (30.4%) patients were suffering from critical limb ischemia (CLI). The mean lesion length was 5.8±3.9 cm; 38 (23.5%) arteries were occluded. The primary outcome measure for patients with intermittent claudication (IC) was duplex ultrasound-defined primary patency at 1 year; the outcome for subjects with CLI was freedom from major amputation of the target limb at 1 year. Outcomes and adverse events were independently assessed. Procedure success (≤30% residual stenosis) was achieved in 84.4% of treated lesions; adjunctive stenting was required in 6 (3.7%) of the 162 lesions. The 1-year primary patency rate was 75.0% (IC patients 78.2% and CLI patients 67.5%, p=0.118). The freedom from major amputation in both cohorts was 100%. In both IC and CLI patients, significant improvements were demonstrated at 1 year in the Rutherford category, walking distance, and quality of life in comparison to baseline. This study indicates that directional atherectomy in popliteal arteries leads to favorable technical and clinical results at 1 year for claudicant as well as CLI patients.

Supervised exercise therapy: it does work, but how to set up a program?

PubMed

Hageman, David; van den Houten, Marijn M; Spruijt, Steffie; Gommans, Lindy N; Scheltinga, Marc R; Teijink, Joep A

2017-04-01

Intermittent claudication (IC) is a manifestation of peripheral arterial disease. IC has a high prevalence in the older population, is closely associated with other expressions of atherosclerotic disease and often co-exists in multimorbid patients. Treatment of IC should address reduction of cardiovascular risk and improvement of functional capacity and health-related quality of life (QoL). As recommended by contemporary international guidelines, the first-line treatment includes supervised exercise therapy (SET). In several randomized controlled trials and systematic reviews, SET is compared with usual care, placebo, walking advice and endovascular revascularization. The evidence supporting the efficacy of SET programs to alleviate claudication symptoms is robust. SET improves walking distance and health-related QoL and appears to be the most cost-effective treatment for IC. Nevertheless, only few of all newly diagnosed IC patients worldwide receive this safe, efficient and structured treatment. Worldwide implementation of structured SET programs is seriously impeded by outdated arguments favoring an invasive intervention, absence of a network of specialized physical therapists providing standardized SET and lack of awareness and/or knowledge of the importance of SET by referring physicians. Besides, misguiding financial incentives and lack of reimbursement hamper actual use of SET programs. In the Netherlands, a national integrated care network (ClaudicatioNet) was launched in 2011 to combat treatment shortcomings and stimulate cohesion and collaboration between stakeholders. This care intervention has resulted in optimized quality of care for all patients with IC.

Garlic: empiricism or science?

PubMed

Aviello, Gabriella; Abenavoli, Ludovico; Borrelli, Francesca; Capasso, Raffaele; Izzo, Angelo Antonio; Lembo, Francesca; Romano, Barbara; Capasso, Francesco

2009-12-01

Garlic (Allium sativum L. fam. Alliaceae) is one of the best-researched, best-selling herbal remedies and is also commonly used as a food and a spice. Garlic constituents include enzymes (for example, alliinase) and sulfur-containing compounds, including alliin, and compounds produced enzymatically from alliin (for example, allicin). Traditionally, it has been employed to treat infections, wounds, diarrhea, rheumatism, heart disease, diabetes, and many other disorders. Experimentally, it has been shown to exert antilipidemic, antihypertensive, antineoplastic, antibacterial, immunostimulant and hypoglycemic actions. Clinically, garlic has been evaluated for a number of conditions, including hypertension, hypercholesterolemia, intermittent claudication, diabetes, rheumatoid arthritis, common cold, as an insect repellent, and for the prevention of arteriosclerosis and cancer. Systematic reviews are available for the possible antilipidemic, antihypertensive, antithrombotic and chemopreventive effects. However, the clinical evidence is far from compelling. Garlic appears to be generally safe although allergic reactions may occur.

Fracture and Collapse of Balloon-Expandable Stents in the Bilateral Common Iliac Arteries Due to Shiatsu Massage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ichihashi, Shigeo, E-mail: shigeoichihashi@yahoo.co.jp; Higashiura, Wataru; Itoh, Hirofumi

2012-12-15

We report a case of stent fracture and collapse of balloon-expandable stents caused by shiatsu massage. A 76-year-old man presented with complaints of intermittent claudication of the right lower extremity. Stenoses of the bilateral common iliac arteries (CIAs) were detected. Balloon-expandable stents were deployed in both CIAs, resulting in resolution of symptoms. Five months later, pelvis x-ray showed collapse of both stents. Despite the stent collapse, the patient was asymptomatic, and his ankle brachial index values were within the normal range. Further history showed that the patient underwent daily shiatsu therapy in the umbilical region, which may have triggered collapsemore » of the stent. Physicians should advise patients to avoid compression of the abdominal wall after implantation of a stent in the iliac artery.« less

Plasma viscosity increase with progression of peripheral arterial atherosclerotic disease.

PubMed

Poredos, P; Zizek, B

1996-03-01

Increased blood and plasma viscosity has been described in patients with coronary and peripheral arterial disease. However, the relation of viscosity to the extent of arterial wall deterioration--the most important determinant of clinical manifestation and prognosis of the disease--is not well known. Therefore, the authors studied plasma viscosity as one of the major determinants of blood viscosity in patients with different stages of arterial disease of lower limbs (according to Fontaine) and its relation to the presence of some risk factors of atherosclerosis. The study encompassed four groups of subjects: 19 healthy volunteers (group A), 18 patients with intermittent claudication up to 200 m (stage II; group B), 15 patients with critical ischemia of lower limbs (stage III and IV; group C), and 16 patients with recanalization procedures on peripheral arteries. Venous blood samples were collected from an antecubital vein without stasis for the determination of plasma viscosity (with a rotational capillary microviscometer, PAAR), fibrinogen, total cholesterol, alpha-2-macroglobulin, and glucose concentrations. In patients with recanalization procedure local plasma viscosity was also determined from blood samples taken from a vein on the dorsum of the foot. Plasma viscosity was most significantly elevated in the patients with critical ischemia (1.78 mPa.sec) and was significantly higher than in the claudicants (1.68 mPa.sec), and the claudicants also had significantly higher viscosity than the controls (1.58 mPa.sec). In patients in whom a recanalization procedure was performed, no differences in systemic and local plasma viscosity were detected, neither before nor after recanalization of the diseased artery. In all groups plasma viscosity was correlated with fibrinogen concentration (r=0.70, P < 0.01) and total cholesterol concentration (r=0.24, P < 0.05), but in group C (critical ischemia) plasma viscosity was most closely linked to the concentration of alpha-2-macroglobulin (r=0.78, P < 0.01). These results indicate that in patients with peripheral arterial disease plasma viscosity increases with the progression of the atherosclerotic process and is correlated with the clinical stages of the disease.

Novel Method to Assess Arterial Insufficiency in Rodent Hindlimb

PubMed Central

Ziegler, Matthew A.; DiStasi, Matthew R.; Miller, Steven J.; Dalsing, Michael C.; Unthank, Joseph L.

2015-01-01

Background Lack of techniques to assess maximal blood flow capacity thwarts the use of rodent models of arterial insufficiency to evaluate therapies for intermittent claudication. We evaluated femoral vein outflow (VO) in combination with stimulated muscle contraction as a potential method to assess functional hindlimb arterial reserve and therapeutic efficacy in a rodent model of subcritical limb ischemia. Materials and methods VO was measured with perivascular flow probes at rest and during stimulated calf muscle contraction in young healthy rats (Wistar Kyoto, WKY; lean Zucker, LZR) and rats with cardiovascular risk factors (Spontaneously Hypertensive, SHR; Obese Zucker, OZR) with acute and/or chronic femoral arterial occlusion. Therapeutic efficacy was assessed by administration of Ramipril or Losartan to SHR after femoral artery excision. Results VO measurement in WKY demonstrated the utility of this method to assess hindlimb perfusion at rest and during calf muscle contraction. While application to diseased models (OZR, SHR) demonstrated normal resting perfusion compared to contralateral limbs, a significant reduction in reserve capacity was uncovered with muscle stimulation. Administration of Ramipril and Losartan demonstrated significant improvement in functional arterial reserve. Conclusion The results demonstrate that this novel method to assess distal limb perfusion in small rodents with subcritical limb ischemia is sufficient to unmask perfusion deficits not apparent at rest, detect impaired compensation in diseased animal models with risk factors, and assess therapeutic efficacy. The approach provides a significant advance in methods to investigate potential mechanisms and novel therapies for subcritical limb ischemia in pre-clinical rodent models. PMID:26850199

[Effect of supervised exercise training on walking speed, claudication distance and quality of life in peripheral arterial disease].

PubMed

Wenkstetten-Holub, Alfa; Kandioler-Honetz, Elisabeth; Kraus, Ingrid; Müller, Rudolf; Kurz, Robert Wolfgang

2012-08-01

Aim of the study was to evaluate the effects of supervised exercise training for peripheral arterial disease (PAD) on walking speed, claudication distance and quality of life. Ninety-four patients in stage IIa/IIb according to Fontaine underwent a six-month exercise training at the Center for Outpatient Rehabilitation Vienna (ZAW). Walking speed and Absolute Claudication Distance (ACD) improved significantly (p < 0,001 and p = 0,007 respectively). Increase of the Initial Claudication Distance (ICD) did not reach statistical significance (p = 0,14). Quality of life, as assessed by the questionnaire "PLC" manifested no significant change. The exercise training achieved considerable effects on walking speed and claudication distance. Despite these improvements, patient's quality of life revealed no relevant change. This outcome could be explained by the fact that aspects of physical functioning relevant to patients with claudicatio intermittens may be underrepresented in the PLC-questionnaire core module.

Gene therapy for therapeutic angiogenesis in peripheral arterial disease - a systematic review and meta-analysis of randomized, controlled trials.

PubMed

Hammer, Alexandra; Steiner, Sabine

2013-09-01

Beyond pharmacological, endovascular and surgical treatment strategies for peripheral arterial disease (PAD), therapeutic angiogenesis has been advocated to relieve symptoms and support limb salvage, in particular in patients with critical limb ischemia. We aimed to systematically review randomized controlled trials (RCTs) of gene therapy in PAD. A systematic search of electronic databases was performed to identify RCTs studying local administration of pro-angiogenic growth factors (VEGF, FGF, HGF, Del-1, HIF-1alpha) using plasmid or viral gene transfer by intra-arterial or intra-muscular injections. Outcomes of interest comprised all-cause mortality, amputations, ulcer healing, walking distance and ankle-brachial index. If feasible, standard meta-analysis should be performed with subgroup analysis for claudicants and patients with critical limb ischemia (CLI). The systematic search yielded 12 RCTs for analysis from 1163 citations. In total, 1494 patients (29 % females) were included with the majority suffering from CLI (64 %). Various endpoints were improved by single studies, but none by a majority of studies. Meta-analysis showed neither a significant benefit nor harm for gene therapy when synthesizing data for all-cause mortality (OR 0.88, 95 % CI 0.62 - 1.26) amputations (OR 0.64, 95 % CI 0.31 - 1.31) or ulcer healing (OR 1.79, 95 % CI 0.8 - 4.01). No differences were seen between patients with intermittent claudication or CLI. Despite promising results in single studies, no clear benefit could be identified for gene therapy in PAD patients, irrespective of disease severity.

Five-year durability of stand-alone interspinous process decompression for lumbar spinal stenosis.

PubMed

Nunley, Pierce D; Patel, Vikas V; Orndorff, Douglas G; Lavelle, William F; Block, Jon E; Geisler, Fred H

2017-01-01

Lumbar spinal stenosis is the most common indication for spine surgery in older adults. Interspinous process decompression (IPD) using a stand-alone spacer that functions as an extension blocker offers a minimally invasive treatment option for intermittent neurogenic claudication associated with spinal stenosis. This study evaluated the 5-year clinical outcomes for IPD (Superion ® ) from a randomized controlled US Food and Drug Administration (FDA) noninferiority trial. Outcomes included Zurich Claudication Questionnaire (ZCQ) symptom severity (ss), physical function (pf), and patient satisfaction (ps) subdomains, leg and back pain visual analog scale (VAS), and Oswestry Disability Index (ODI). At 5 years, 84% of patients (74 of 88) demonstrated clinical success on at least two of three ZCQ domains. Individual ZCQ domain success rates were 75% (66 of 88), 81% (71 of 88), and 90% (79 of 88) for ZCQss, ZCQpf, and ZCQps, respectively. Leg and back pain success rates were 80% (68 of 85) and 65% (55 of 85), respectively, and the success rate for ODI was 65% (57 of 88). Percentage improvements over baseline were 42%, 39%, 75%, 66%, and 58% for ZCQss, ZCQpf, leg and back pain VAS, and ODI, respectively (all P <0.001). Within-group effect sizes were classified as very large for four of five clinical outcomes (ie, >1.0; all P <0.0001). Seventy-five percent of IPD patients were free from reoperation, revision, or supplemental fixation at their index level at 5 years. After 5 years of follow-up, IPD with a stand-alone spacer provides sustained clinical benefit.

The effect of exercise on coagulation and fibrinolysis factors in patients with peripheral arterial disease.

PubMed

Patelis, Nikolaos; Karaolanis, Georgios; Kouvelos, Georgios N; Hart, Collin; Metheiken, Sean

2016-09-01

Peripheral arterial disease is a widely prevalent atherosclerotic occlusive disorder. Symptoms commence with exercise-induced pain in the lower extremities, known as claudication. Despite the fact that exercise has been shown to improve fibrinolytic profile some patients, the effect of exercise on coagulation and fibrinolysis cascades in claudicants has not been comprehensively defined. Literature search in English language yielded 13 studies of exercise on claudicants, including 420 patients. Claudicants tend to have a higher coagulation activity at rest compared to healthy individuals, a trend that persists even after exercise. Post-exercise coagulation activity of claudicants is increased when compared to their respective baseline levels, but it is so in a non-consistent manner. From the available data, it has been suggested that claudicants have a functional and effective fibrinolytic mechanism in place, operating continuously at a relatively higher activity level compared to healthy individuals. Fibrinolysis seems to be activated by exercise; a positive outcome with a prolonged effect as shown by a few of the studies. A final conclusion whether coagulation or fibrinolysis activity is affected mostly by exercise type and intensity in claudicants could not be answered. All conclusions regarding the effect of exercise on the coagulation and fibrinolysis mechanisms should be taken under cautious consideration, due to the limited number of studies, the small number of patients and the different exercise strategies employed in each study. Further randomized studies with similar exercise protocols could provide safer conclusions in the future. © 2016 by the Society for Experimental Biology and Medicine.

Wavelet analysis of skin perfusion to assess the effects of FREMS therapy before and after occlusive reactive hyperemia.

PubMed

Popa, Stefan Octavian; Ferrari, Myriam; Andreozzi, Giuseppe Maria; Martini, Romeo; Bagno, Andrea

2015-11-01

Laser Doppler Fluxmetry is used to evaluate the hemodynamics of skin microcirculation. Laser Doppler signals contain oscillations due to fluctuations of microvascular perfusion. By performing spectral analysis, six frequency intervals from 0.005 to 2 Hz have been identified and assigned to distinct cardiovascular structures: heart, respiration, vascular myocites, sympathetic terminations and endothelial cells (dependent and independent on nitric oxide). Transcutaneous electrical pulses are currently applied to treat several diseases, i.e. neuropathies and chronic painful leg ulcers. Recently, FREMS (Frequency Rhythmic Electrical Modulation System) has been applied to vasculopathic patients, too. In this study Laser Doppler signals of skin microcirculation were measured in five patients with intermittent claudication, before and after the FREMS therapy. Changes in vascular activities were assessed by wavelet transform analysis. Preliminary results demonstrate that FREMS induces alterations in vascular activities. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

[Treatment of severe intermittent claudication: ORACLE-PGE1 short term study. A randomised 40-week study. Evaluation of efficacy and costs].

PubMed

Cesarone, M R; Belcaro, G; Nicolaides, A N; Griffin, M; Geroulakos, G; Ramaswami, G; Cazaubon, M; Barsotti, A; Vasdekis, S; Christopoulos, D; Agus, G; Bavera, P; Mondani, P; Ippolito, E; Flenda, F

2002-12-01

The efficacy and cost of prostaglandin E1 (PGE1) in severe intermittent claudication was studied comparing a long-term protocol (LTP) with a short-term protocol (STP) in a randomised 40-week study. Phase 1 was a 2-week run-in phase (no treatment) for both protocols. In LTP, phase 2 was the main treatment phase. Treatment was performed with 2-hour infusions (60 micro g PGE1, 5 days each week for 4 weeks. In phase 3 (4-week interval period), PGE1 was administered twice a week (same dosage). In phase 4 (40 weeks), no PGE1 were used. In STP, phase 2 treatment was performed in two days by a 2-hour infusion (60 micro g PGE1 twice a day in 2 days). The same cycle was repeated every 4 weeks. A treadmill test was performed at inclusion, at the beginning of each phase and at the end of weeks 12, 16, 20 32 and 40. A progressive training plan (walking) and reduction in risk factors plan was used in both groups. Out of the 1276 included patients 1165 completed the study (606 in LTP group; 559 in the STP). Drop-outs were 111. The two groups were comparable in distribution, risk factors and smoking. Intention-to-treat analysis indicated an increase in pain free walking distance (PFWD). The absolute and percent increase in pain-free walking distance (PFWD) was comparable in both LTP and STP groups with a significative increase in TWD at 4 weeks. At 20 and 40 weeks increase was up to 219% in the LTP and 460% in the STP group (p<0.02). Comparable results concerning PFWD were obtained in the two groups. Both treatments were well tolerated. No side effect was observed. Local effects were observed in 8.5% of the treated subjects in the LTP and 4% in the STP. The average cost of the LTP protocol was 8786 Euro. For STP the costs was 946 (10.8% of LTP). For both protocols the cost of the infusion was 24% of the total for the LTP and 35% in the STP. Therefore 75% of the cost is not drug-related. In conclusion between-group-analysis favours STP considering walking distance and costs. Results indicate good efficacy and tolerability of PGE1 treatment particularly STP.

Primary Stenting of the Superficial Femoral Artery in Patients with Intermittent Claudication Has Durable Effects on Health-Related Quality of Life at 24 Months: Results of a Randomized Controlled Trial.

PubMed

Lindgren, Hans I V; Qvarfordt, Peter; Bergman, Stefan; Gottsäter, Anders

2018-06-01

Intermittent claudication (IC) is commonly caused by lesions in the superficial femoral artery (SFA), yet invasive treatment is still controversial and longer term patient-reported outcomes are lacking. This prospective randomized trial assessed the 24-month impact of primary stenting with nitinol self-expanding stents compared to best medical treatment (BMT) alone in patients with stable IC due to SFA disease on health-related quality of life (HRQoL). One hundred patients with stable IC due to SFA disease treated with BMT were randomized to either stent (n = 48) or control (n = 52) group. HRQoL assessed by Short Form 36 Health Survey (SF-36) and EuroQoL 5-dimensions (EQ5D) 24 months after treatment were primary outcome measures. Walking Impairment Questionnaire, ankle-brachial index (ABI), and walking distance were secondary outcomes. Significantly better SF-36 Physical Component Summary (P = 0.024) and physical domain scores such as Physical Function (P = 0.012), Bodily Pain (P = 0.002), General Health (P = 0.037), and EQ5D (P = 0.010) were reported in intergroup comparison between the stent and the control group. Both ABI (from 0.58 ± 0.11 to 0.85 ± 0.18; P < 0.001 in the stent group and from 0.63 ± 0.17 to 0.69 ± 0.18; P = 0.036 in the control group) and walking distance (from 170 ± 90 m to 616 ± 375 m; P < 0.001 in the stent group and from 209 ± 111 m to 331 ± 304 m; P = 0.006 in the control group) improved significantly in intragroup comparisons. In patients with IC caused by lesions in the SFA, primary stenting compared to BMT alone was associated with significant improvements in HRQoL, ABI, and walking distance durable up to 24 months of follow-up. Clinical Trial Registration http://www.clinicaltrials.gov . Unique Identifier: NCT01230229.

Systematic reviews of complementary therapies – an annotated bibliography. Part 2: Herbal medicine

PubMed Central

Linde, Klaus; ter Riet, Gerben; Hondras, Maria; Vickers, Andrew; Saller, Reinhard; Melchart, Dieter

2001-01-01

Background Complementary therapies are widespread but controversial. We aim to provide a comprehensive collection and a summary of systematic reviews of clinical trials in three major complementary therapies (acupuncture, herbal medicine, homeopathy). This article is dealing with herbal medicine. Potentially relevant reviews were searched through the register of the Cochrane Complementary Medicine Field, the Cochrane Library, Medline, and bibliographies of articles and books. To be included articles had to review prospective clinical trials of herbal medicines; had to describe review methods explicitly; had to be published; and had to focus on treatment effects. Information on conditions, interventions, methods, results and conclusions was extracted using a pre-tested form and summarized descriptively. Results From a total of 79 potentially relevant reviews pre-selected in the screening process 58 met the inclusion criteria. Thirty of the reports reviewed ginkgo (for dementia, intermittent claudication, tinnitus, and macular degeneration), hypericum (for depression) or garlic preparations (for cardiovascular risk factors and lower limb atherosclerosis). The quality of primary studies was criticized in the majority of the reviews. Most reviews judged the available evidence as promising but definitive conclusions were rarely possible. Conclusions Systematic reviews are available on a broad range of herbal preparations prescribed for defined conditions. There is very little evidence on the effectiveness of herbalism as practised by specialist herbalists who combine herbs and use unconventional diagnosis. PMID:11518548

Effectiveness of a Medical vs Revascularization Intervention for Intermittent Leg Claudication Based on Patient-Reported Outcomes.

PubMed

Devine, Emily B; Alfonso-Cristancho, Rafael; Yanez, N David; Edwards, Todd C; Patrick, Donald L; Armstrong, Cheryl A L; Devlin, Allison; Symons, Rebecca G; Meissner, Mark H; Derrick, Ellen L T; Lavallee, Danielle C; Kessler, Larry G; Flum, David R

2016-10-19

Intermittent claudication (IC) is the most common presentation of infrainguinal peripheral artery disease. Both medical and revascularization interventions for IC aim to increase walking comfort and distance, but there is inconclusive evidence of the comparative benefit of revascularization given the possible risk of limb loss. To compare the effectiveness of a medical (walking program, smoking cessation counseling, and medications) vs revascularization (endovascular or surgical) intervention for IC in the community, focusing on outcomes of greatest importance to patients. Longitudinal (12-month follow-up) prospective observational cohort study conducted between July 3, 2011, and November 5, 2014, at 15 clinics associated with 11 hospitals in Washington State. Participants were 21 years or older with newly diagnosed or established IC. Medical or revascularization interventions. Primary end points were 12-month change scores on the distance, speed, and stair-climb domains of the Walking Impairment Questionnaire (score range, 0-100). Secondary outcomes were change scores on the Walking Impairment Questionnaire pain domain (score range, 0-100), Vascular Quality of Life Questionnaire (VascuQol) (score range, 1-7), European Quality of Life-5 Dimension Questionnaire (EQ-5D) (score range, 0-1), and Claudication Symptom Instrument (CSI) (score range, 0-4). A total of 323 adults were enrolled, with 282 (87.3%) in the medical cohort. At baseline, the mean duration of disease was longer for participants in the medical cohort, while those in the revascularization cohort reported more severe disease. Other characteristics were well balanced. At 12 months, change scores in the medical cohort reached significance for the following 3 outcomes: speed (5.9; 95% CI, 0.5-11.3; P = .03), VascuQol (0.28; 95% CI, 0.08-0.49; P = .008), and EQ-5D (0.038; 95% CI, 0.011-0.066; P = .006). In the revascularization cohort, there were significant improvements in the following 7 outcomes: distance (19.5; 95% CI, 7.9-31.0; P = .001), speed (12.1; 95% CI, 1.4-22.8; P = .03), stair climb (11.4; 95% CI, 1.3-21.5; P = .03), pain (20.7; 95% CI, 11.0-30.4; P < .001), VascuQol (1.10; 95% CI, 0.80-1.41; P < .001), EQ-5D (0.113; 95% CI, 0.067-0.159; P < .001), and CSI (-0.63; 95% CI, -0.96 to -0.31; P < .001). Relative improvements (percentage changes) at 12 months in the revascularization cohort over the medical cohort were observed as follows: distance (39.1%), speed (15.6%), stair climb (9.7%), pain (116.9%), VascuQol (41%), EQ-5D (18%), and CSI (13.5%). Among patients with IC, those in the revascularization cohort had significantly improved function (Walking Impairment Questionnaire), better health-related quality of life (VascuQol and EQ-5D), and fewer symptoms (CSI) at 12 months compared with those in the medical cohort, providing important information to inform treatment strategies in the community.

Validation of the Edinburgh Claudication Questionnaire in 1st generation Black African-Caribbean and South Asian UK migrants: a sub-study to the Ethnic-Echocardiographic Heart of England Screening (E-ECHOES) study.

PubMed

Bennett, Philip C; Lip, Gregory Y H; Silverman, Stanley; Blann, Andrew D; Gill, Paramjit S

2011-06-03

We determined the diagnostic accuracy of the Edinburgh Claudication Questionnaire (ECQ) in 1st generation Black African-Caribbean UK migrants as previous diagnostic questionnaires have been found to be less accurate in this population. We also determined the diagnostic accuracy of translated versions of the ECQ in 1st generation South Asian UK migrants, as this has not been investigated before. Subjects were recruited from the Ethnic-Echocardiographic Heart of England Screening (E-ECHOES) study, a community based screening survey for heart failure in minority ethnic groups. Translated versions of the ECQ were prepared following a recognised protocol. All participants attending screening between October 2007 and February 2009 were asked to complete the ECQ in the language of their choice (English, Punjabi, Bengali, Urdu, Hindi or Gujarati). Subjects answering positively to experiencing leg pain or discomfort on walking were asked to return to have Ankle Brachial Pressure Index (ABPI) measured. 154 out of 2831 subjects participating in E-ECHOES (5.4%) were eligible to participate in this sub-study, for which 74.3% returned for ABPI assessment. Non-responders were younger than participants (59[9] vs. 65[11] years; p=0.015). Punjabi, English and Bengali questionnaires identified participants with Intermittent Claudication, so these questionnaires were assessed. The sensitivities (SN), specificities (SP), positive (PPV) and negative (NPV) predictive values were calculated. English: SN: 50%; SP: 68%; PPV: 43%; NPV: 74%. Punjabi: SN: 50%; SP: 87%; PPV: 43%; NPV: 90%. Bengali: SN: 33%; SP: 50%; PPV: 13%; NPV: 73%. There were significant differences in diagnostic accuracy between the 3 versions (Punjabi: 83.8%; Bengali: 45%; English: 62.2%; p<0.0001). No significant differences were found in sensitivity and specificity between illiterate and literate participants in any of the questionnaires and there was no significant different difference between those under and over 60 years of age. Our findings suggest that the ECQ is not as sensitive or specific a diagnostic tool in 1st generation Black African-Caribbean and South Asian UK migrants than in the Edinburgh Artery Study, reflecting the findings of other diagnostic questionnaires in these minority ethnic groups. However this study is limited by sample size so conclusions should be interpreted with caution.

Wearable Sensor Technology Efficacy in Peripheral Vascular Disease (wSTEP): A Randomized Controlled Trial.

PubMed

Normahani, Pasha; Kwasnicki, Richard; Bicknell, Colin; Allen, Louise; Jenkins, Mike P; Gibbs, Richard; Cheshire, Nicholas; Darzi, Ara; Riga, Celia

2017-05-11

To evaluate the effect of using wearable activity monitors (WAMs) in patients with intermittent claudication (IC) within a single-center randomized controlled trial. WAMs allow users to set daily activity targets and monitor their progress. They may offer an alternative treatment to supervised exercise programs (SEPs) for patients with IC. Thirty-seven patients with IC were recruited and randomized into intervention or control group. The intervention consisted of a feedback-enabled, wrist-worn activity monitor (WAM) in addition to access to SEP. The control group was given access to SEP only. The outcome measures were maximum walking distance (MWD), claudication distance (CD), and quality of life as measured by the VascuQol questionnaire. Participants were assessed upon recruitment, and at 3, 6, and 12 months. Patients in the WAM group showed significant improvement in MWD at 3 and 6 months (80-112 m, to 178 m; P < 0.001), which was sustained at 12 months. The WAM group also increased CD (40 vs 110 m; P < 0.001) and VascuQol score (4.7 vs 5.8; P = 0.004). The control group saw a temporary increase in VascuQol score at 6 months (4.5 vs 4.7; P = 0.028), but no other improvements in MWD or CD were observed. Significantly higher improvements in MWD were seen in the WAM group compared with that in the control group at 6 months (82 vs -5 m; P = 0.009, r = 0.47) and 12 months (69 vs 7.5 m; P = 0.011, r = 0.52). The study demonstrates the significant, sustained benefit of WAM-led technologies for patients with IC. This potentially resource-sparing intervention is likely to provide a valuable adjunct or alternative to SEP.

Percutaneous treatment of peripheral vascular disease: The role of diabetes and inflammation

PubMed Central

Nguyen, Louis L.

2010-01-01

Peripheral arterial disease (PAD) is a growing health problem for many Americans and often occurs along with other cardiovascular risk factors, including diabetes mellitus (DM), low-grade inflammation, hypertension, and lipid disorders. Intermittent claudication (IC), an early manifestation of PAD, commonly leads to reduced quality of life for patients who are limited in their ambulation. While recent wide adoption of percutaneous peripheral interventional (PPI) techniques has increased the number patients being aggressively treated for IC, the overall effectiveness of PPI for the treatment of IC is not well known, especially for DM patients who have both hemodynamic and functional obstacles to treatment success. This review is designed to illustrate how treatment outcomes for IC can be measured by different modalities and how diabetes and inflammation can influence those outcomes. In the setting of greater concern for health care resources and clinical accountability, better understanding of treatment outcomes and efficacy will help us manage these complex challenges. PMID:17544036

External-to-Internal Iliac Stent-Graft: Medium-Term Patency Following Exclusion of a Retrogradely Perfused Common Iliac Aneurysm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nicholls, Marcus John, E-mail: marcusnicholls@hotmail.co; McPherson, Simon

2010-08-15

Following complicated aortic aneurysm surgery a complete left iliac occlusion resulted in buttock claudication. A retrogradely perfused right common iliac aneurysm expanded. Exclusion was by external-to-internal iliac stent-graft. No deterioration in claudication occurred with medium-term stent-graft patency.

Ureter Injury as a Complication of Oblique Lumbar Interbody Fusion.

PubMed

Lee, Hyeong-Jin; Kim, Jin-Sung; Ryu, Kyeong-Sik; Park, Choon Keun

2017-06-01

Oblique lumbar interbody fusion is a commonly used surgical method of achieving lumbar interbody fusion. There have been some reports about complications of oblique lumbar interbody fusion at the L2-L3 level. However, to our knowledge, there have been no reports about ureter injury during oblique lumbar interbody fusion. We report a case of ureter injury during oblique lumbar interbody fusion to share our experience. A 78-year-old male patient presented with a history of lower back pain and neurogenic intermittent claudication. He was diagnosed with spinal stenosis at L2-L3, L4-L5 level and spondylolisthesis at L4-L5 level. Symptoms were not improved after several months of medical treatments. Then, oblique lumbar interbody fusion was performed at L2-L3, L4-L5 level. During the surgery, anesthesiologist noticed hematuria. A retrourethrogram was performed immediately by urologist, and ureter injury was found. Ureteroureterostomy and double-J catheter insertion were performed. The patient was discharged 2 weeks after surgery without urologic or neurologic complications. At 2 months after surgery, an intravenous pyelogram was performed, which showed an intact ureter. Our study shows that a low threshold of suspicion of ureter injury and careful manipulation of retroperitoneal fat can be helpful to prevent ureter injury during oblique lumbar interbody fusion at the upper level. Copyright © 2017 Elsevier Inc. All rights reserved.

Drug-Coated Balloon Treatment of Femoropopliteal Lesions for Patients With Intermittent Claudication and Ischemic Rest Pain: 2-Year Results From the IN.PACT Global Study.

PubMed

Micari, Antonio; Brodmann, Marianne; Keirse, Koen; Peeters, Patrick; Tepe, Gunnar; Frost, Martin; Wang, Hong; Zeller, Thomas

2018-05-28

The IN.PACT Global Study is the largest prospective, multicenter, independently adjudicated trial to evaluate a paclitaxel drug-coated balloon in patients with lifestyle-limiting claudication and/or ischemic rest pain due to atherosclerotic disease of the femoropopliteal artery and includes complex lesions beyond what are typically included in randomized controlled trials. Randomized controlled trials have demonstrated the safety and efficacy of drug-coated balloons for the treatment of Trans-Atlantic Inter-Society Consensus Document II A and B lesions, but there is a need for large-scale prospective studies to evaluate a broader range of lesions. The IN.PACT Global Study enrolled 1,535 subjects, and 1,406 (1,773 lesions) were included in the pre-defined clinical cohort analysis. Freedom from clinically driven target lesion revascularization was evaluated at 24 months. The safety composite endpoint was freedom from device- and procedure-related death through 30 days and freedom from target limb major amputation and clinically driven target vessel revascularization within 24 months. Mean lesion length was 12.1 cm, 35.5% were total occlusions, and 18.0% had in-stent restenosis. Freedom from clinically driven target lesion revascularization at 24 months was 83.3%, the composite safety endpoint was met in 81.7%, the 2-year all-cause mortality rate was 7.0%, and the major target limb amputation rate was 0.7%. Increased lesion length and the presence of de novo in-stent restenosis or coronary artery disease were associated with increased risk for clinically driven target lesion revascularization by 24 months. This real-world study of femoropopliteal artery disease treatment with drug-coated balloons confirmed positive findings reported from more strictly designed randomized controlled trials and showed that outcomes are durable in this population up to 2 years after treatment. (IN.PACT Global Clinical Study; NCT01609296). Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Successful percutaneous treatment of gluteal claudication secondary to isolated bilateral hypogastric stenoses.

PubMed

Chaer, Rabih A; Faries, Peter L; Lin, Stephanie; Dayal, Rajeev; McKinsey, James F; Kent, K Craig

2006-01-01

We report an unusual case of bilateral buttock claudication at ambulation of less than two blocks in a 57-year-old man with normal lower-extremity segmental pressure on noninvasive exercise testing. He was found to have bilateral high-grade internal iliac artery stenoses on arteriography. Both sides were successfully treated in a staged fashion via a contralateral approach with percutaneous transluminal angioplasty and a balloon-expandable stent, with complete symptom resolution. A clinical vascular examination with normal findings of the common iliac, external iliac, and common and superficial femoral arteries eliminates significant vascular obstruction as a cause of claudication. However, internal iliac occlusive disease may be suspected when symptoms are limited to the gluteal musculature and other causes are eliminated. Percutaneous interventions can be of diagnostic and therapeutic value.

[Clinical values of hemodynamics assessment by parametric color coding of digital subtraction angiography before and after endovascular therapy for critical limb ischaemia].

PubMed

Su, Haobo; Lou, Wensheng; Gu, Jianping

2015-10-06

To investigate the feasibility of parametric color coding of digital subtraction angiography (Syngo iFlow) for hemodynamics assessment in patients with critical limb ischemia in pre- and post-endovascular therapy. To explore the correlation between Syngo iFlow and the conventional techniques. from January 2013 to December 2014, Clinical data of 21 patients with TASC II type B and type C femoropopliteal arteriosclerotic occlusive disease who were treated by percutaneous transluminal angioplasty and/or primary stent implantation in Nanjing first hospital were analyzed retrospectively. Of these patients there were 10 males and 11 females with an average age of (72±6) years (range from 58-85 years). The treatment efficacy was assessed by the variation of a series of clinical symptoms indexes (such as pain score, cold sensation score and intermittent claudication score), ankle braehial index (ABI) and transcutaneous oxygen pressure (TcPO2). Angiography was performed with the same protocol before and after treatment and parametric color coding of digital subtraction angiography was created by Syngo iFlow software on a dedicated workstation. The time to peak (TTP) of artery and tissue perfusion selected at the same regions of foot and ankle were measured and analyzed to evaluate the improvement of microcirculation and hemodynamics of the ischemic limb. The correlations between Syngo iFlow and the traditional clinical evaluation methods were explored using the Spearman rank correlation test. All patients (21 limbs) underwent successful endovaseular therapy. The mean pain score, cold sensation score, intermittent claudication score, ABI and TcPO2 before treatment were (0.48±0.68), (2.71±0.72), (2.86±0.85), ABI (0.33±0.07), TcPO2 (26.83±3.41) mmHg. While 1 week after treatment all above indicators were (2.57±0.93), (0.33±0.48), (0.90±0.54), (0.69±0.11), TcPO2 (53.75±3.60) mmHg respectively. There were significant statistical differences between pre- and post-treatment (P<0.05). The pre- and post-operative TTP of artery and tissue perfusion were (14.07±1.77) vs (10.43±2.05) s, (18.75±2.72) vs (15.38±2.78) s. For assessment of hemodynamic changes during and after treatment, parametric color coding of digital subtraction angiography (Syngo iFlow) was assumed to show the limb blood flow and perfusion were improved and the differences were statistically significant. The Spearman rank correlation test showed the TTP of artery was positively correlated with ABI, TcPO2 (r=0.65, 0.73, P<0.05), the TTP of tissue perfusion was also positively correlated with ABI, TcPO2 (r=0.60, 0.60, P<0.05). Parametric color coding of digital subtraction angiography (Syngo iFlow) is a real-time, sensitive and quantitative tool that might provide additional support in the hemodynamics evaluation of endovascular treatment for patients with lower extremity peripheral arterial occlusion disease.

Stent-induced flow disturbances in the ipsilateral external carotid artery following internal carotid artery stenting: a temporary cause of jaw claudication.

PubMed

Giurgea, Georgiana-Aura; Haumer, Markus; Mlekusch, Irene; Sabeti-Sandor, Schila; Dick, Petra; Schillinger, Martin; Minar, Erich; Mlekusch, Wolfgang

2017-07-01

We hypothesize that stenting of the internal carotid artery can immediately impede blood flow to the external carotid artery by either plaque shift or stent coverage of the ostium, and thereby cause ischemic symptoms like ipsilateral jaw claudication. Thirty-three patients with high-grade asymptomatic stenosis of the internal carotid artery who underwent endovascular treatment were examined by ultrasound of the external carotid artery and performed an exercise test by chewing chewing gum synchronously to an electronic metronome for 3 min. Tests were performed before, the day after, and 1 week after the stenting procedure. Claudication time was defined as the timespan until occurrence of pain of the masseter muscle and/or chewing dyssynchrony to the metronome for more than 15 s. Ten patients with an isolated, atherosclerotic stenosis of the external carotid artery served as controls. A significantly reduced claudication time (in seconds) was recorded in patients who underwent carotid artery stenting compared to baseline values; median 89 (interquartile range, IQR, 57 to 124) vs. median 180 (IQR 153 to 180; p < 0.001). By categorization of the flow velocity at the external carotid artery into faster or slower as 200 cm/sec, the effect was even accentuated. Stenting values showed improvement 1 week after but did not return to baseline levels. No respective changes were found in controls. Stenting of the internal carotid artery lead to ipsilateral flow deterioration at the external carotid artery resulting in temporary jaw claudication. This impairment attenuated over the time and was significantly reduced after 1 week.

A Comparison of Clinical Outcomes for Diabetic and Nondiabetic Patients Following Directional Atherectomy in the DEFINITIVE LE Claudicant Cohort.

PubMed

Garcia, Lawrence A; Jaff, Michael R; Rocha-Singh, Krishna J; Zeller, Thomas; Bosarge, Christopher; Kamat, Suraj; McKinsey, James F

2015-10-01

To report a subset analysis that evaluated the hypothesis that directional atherectomy for peripheral artery disease in diabetic claudicants has noninferior primary patency at 12 months compared with nondiabetic claudicants. DEFINITIVE LE, a US/European multicenter study, assessed the effectiveness of directional atherectomy using SilverHawk/TurboHawk systems for treatment of peripheral artery disease in the superficial femoral, popliteal, and infrapopliteal arteries. Of the 800 patients enrolled in the study, only the 598 claudicant patients (mean age 69.5±10.4 years; 336 men) who were classified at baseline as Rutherford category 1-3 were eligible for this subset analysis. Of these, 46.8% (280/598) had diabetes. Follow-up to 12 months included duplex ultrasound examination, functional assessments, and adverse event evaluations. Independent angiographic and duplex ultrasound core laboratories assessed primary patency and secondary endpoints; a clinical events committee adjudicated adverse events. Although diabetics had significantly more baseline comorbidities, 12-month primary patency (77.0%) was no different than for nondiabetics (77.9%; superiority p=0.98; noninferiority p<0.001) across all anatomic territories treated. Freedom from clinically driven target lesion revascularization was no different between diabetics (83.8%) and nondiabetics (87.5%) overall (p=0.19) or by lesion locations. Secondary clinical outcomes (Rutherford category, ankle-brachial index, and walking impairment) improved at 12 months for both diabetics and nondiabetics. Noninferior 12-month patency rates demonstrate that directional atherectomy is an effective treatment in diabetic as well as nondiabetic claudicants. Directional atherectomy remains an attractive treatment option, improving luminal diameters without stents, which preserves future treatment options for both diabetic and nondiabetic patients with progressive, diffuse vascular disease. © The Author(s) 2015.

The limits of evidence in drug approval and availability: a case study of cilostazol and naftidrofuryl for the treatment of intermittent claudication.

PubMed

Hong, Haeyeon; Mackey, William C

2014-08-01

Despite numerous efforts to develop effective medications for the treatment of intermittent claudication (IC) over the past 4 decades, a gold standard medical management option has yet to be defined. Although not life-threatening, IC interferes with mobility and activities of daily living, significantly impairing quality of life and potentially causing depression. Cilostazol, the leading pharmacologic agent for IC in the United States, was approved by the US Food and Drug Administration (FDA) in 1999 based on controversial data. Meanwhile, naftidrofuryl, the first-line pharmacologic agent for IC in the United Kingdom and Europe, has never been approved by the FDA and therefore is not available in the United States. The clinical data for cilostazol and naftidrofuryl are plagued by flaws related to lack of protocol standardization, objective endpoints, and strict eligibility criteria in study subjects, making identification of a true treatment effect impossible. Furthermore, no prospective randomized trial comparing the efficacy of cilostazol and naftidrofuryl has been conducted, because the manufacturers of these agents have much to lose and little to gain from such a study. This article provides an overview of the pharmacology of cilostazol and naftidrofuryl, and the clinical studies leading to their approval and clinical acceptance. It further explores the possible sources of bias in analyzing these clinical trials, some of which have been brought to light by the National Institute for Health and Clinical Excellence (NICE) of the United Kingdom in its technology appraisal guidance. It also speculates the ways in which economic incentives may affect drug-marketing decisions. A literature review of pharmacology and clinical trials for cilostazol and naftidrofuryl was performed in PubMed. The majority of included clinical trials were initially identified through the most recent Cochrane review articles as well as the FDA's approval packet for cilostazol. The technology appraisal guidance of the National Institute for Health and Care Excellence of the United Kingdom and the manufacturer's response to this guidance document were located via an online search engine. The clinical data for cilostazol and naftidrofuryl are plagued by flaws related to lack of protocol standardization, objective endpoints, and strict eligibility criteria in study subjects, making identification of a true treatment effect difficult. Furthermore, no prospective randomized trial comparing the efficacy of cilostazol and naftidrofuryl has been conducted. The history of the evaluation, approval, and marketing of these drugs illustrates the limitations of data in the regulatory approval and marketing of agents whose benefit is subjective and difficult to quantify. Implementation of a standardized protocol with strict eligibility criteria, objective quantifiable measurement of drug effect, and validated endpoints will eventually allow development of an ideal pharmacotherapy for IC. Copyright © 2014 Elsevier HS Journals, Inc. All rights reserved.

[Usefulness of the ankle-arm index for detection of peripheral arterial disease in a working population of Junta de Andalucía at Málaga].

PubMed

Alonso, Inmaculada; Valdivielso, Pedro; Josefa Zamudio, María; Sánchez Chaparro, Miguel Angel; Pérez, Francisca; Ramos, Heliodoro; González Santos, Pedro

2009-01-17

Detection of asymptomatic peripheral arterial disease increases the risk of vascular morbibity and mortality. We aimed to estimate the prevalence of clinical and subclinical peripheral arterial disease using the ankle-arm index (AAI) as diagnostic tool in a working population. We included 450 workers, older than 50 years old, attending voluntary regular health check-up at Centro de Prevención de Riesgos Laborales de la Junta de Andalucía in Málaga (Spain). We recorded clinical and anthopometrical data. Blood samples were taken after an overnight fast. Vascular risk was calculated using Framinghan and SCORE scales. Every participant was asked for symptoms of intermittent claudicatio and AAI was measured. AAI was considered normal within 0.9-1.3 values. Most of our workers were at low- or moderate vascular risk. Only 48 (10.6%) of individuals had an abnormal AAI: 9 (2%) showed an AAI<0.9 and 39 (8.6%) showed an AAI>1.3. An AAI<0.9 was found in 19% of those with a SCORE risk > or = 5%, and in 11% of those having a Framinghan risk > or = 20%. Intermittent claudication was present in 4 out of 9 (44%) of those having an AAI<0.9 and in 7 out of 402 (1.7%) with a normal AAI. Systematic screening of peripheral arterial disease using the AAI is not recommended in active working population over 50 years-old of age. Thus, AAI measurement is indicated only for those individuals suffering from intermitent claudicatio and those who are at moderate- or high vascular risk.

Physical activity monitoring in patients with peripheral arterial disease: validation of an activity monitor.

PubMed

Fokkenrood, H J P; Verhofstad, N; van den Houten, M M L; Lauret, G J; Wittens, C; Scheltinga, M R M; Teijink, J A W

2014-08-01

The daily life physical activity (PA) of patients with peripheral arterial disease (PAD) may be severely hampered by intermittent claudication (IC). From a therapeutic, as well as research, point of view, it may be more relevant to determine improvement in PA as an outcome measure in IC. The aim of this study was to validate daily activities using a novel type of tri-axial accelerometer (Dynaport MoveMonitor) in patients with IC. Patients with IC were studied during a hospital visit. Standard activities (locomotion, lying, sitting, standing, shuffling, number of steps and "not worn" detection) were video recorded and compared with activities scored by the MoveMonitor. Inter-rater reliability (expressed in intraclass correlation coefficients [ICC]), sensitivity, specificity, and positive predictive values (PPV) were calculated for each activity. Twenty-eight hours of video observation were analysed (n = 21). Our video annotation method (the gold standard method) appeared to be accurate for most postures (ICC > 0.97), except for shuffling (ICC = 0.38). The MoveMonitor showed a high sensitivity (>86%), specificity (>91%), and PPV (>88%) for locomotion, lying, sitting, and "not worn" detection. Moderate accuracy was found for standing (46%), while shuffling appeared to be undetectable (18%). A strong correlation was found between video recordings and the MoveMonitor with regard to the calculation of the "number of steps" (ICC = 0.90). The MoveMonitor provides accurate information on a diverse set of postures, daily activities, and number of steps in IC patients. However, the detection of low amplitude movements, such as shuffling and "sitting to standing" transfers, is a matter of concern. This tool is useful in assessing the role of PA as a novel, clinically relevant outcome parameter in IC. Copyright © 2014 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Peripheral arterial disease, type 2 diabetes and postprandial lipidaemia: Is there a link?

PubMed Central

Valdivielso, Pedro; Ramírez-Bollero, José; Pérez-López, Carmen

2014-01-01

Peripheral arterial disease, manifested as intermittent claudication or critical ischaemia, or identified by an ankle/brachial index < 0.9, is present in at least one in every four patients with type 2 diabetes mellitus. Several reasons exist for peripheral arterial disease in diabetes. In addition to hyperglycaemia, smoking and hypertension, the dyslipidaemia that accompanies type 2 diabetes and is characterised by increased triglyceride levels and reduced high-density lipoprotein cholesterol concentrations also seems to contribute to this association. Recent years have witnessed an increased interest in postprandial lipidaemia, as a result of various prospective studies showing that non-fasting triglycerides predict the onset of arteriosclerotic cardiovascular disease better than fasting measurements do. Additionally, the use of certain specific postprandial particle markers, such as apolipoprotein B-48, makes it easier and more simple to approach the postprandial phenomenon. Despite this, only a few studies have evaluated the role of postprandial triglycerides in the development of peripheral arterial disease and type 2 diabetes. The purpose of this review is to examine the epidemiology and risk factors of peripheral arterial disease in type 2 diabetes, focusing on the role of postprandial triglycerides and particles. PMID:25317236

Bilateral hypogastric artery occlusion in endovascular repair of abdominal aortic aneurysms and its clinical significance.

PubMed

Zander, Tobias; Baldi, Sebastian; Rabellino, Martin; Rostagno, Roman; Isaza, Baltasar; Llorens, Rafael; Carreira, Jose M; Maynar, Manuel

2007-12-01

Endovascular treatment of aortoiliac aneurysms near or involving the hypogastric artery (HGA) requires HGA occlusion before endografting to avoid retrograde filling of the aneurysm. The purpose of this study is to evaluate clinical outcomes of bilateral HGA occlusion and determine if benefits gained by endovascular aneurysm repair (EVAR) outweigh the morbidity associated with the procedure. Between 1999 and 2004, 128 patients with abdominal aortic aneurysm (AAA) were treated with bifurcated endograft placement. Bilateral coverage or embolization of HGAs was performed in 14 patients (10.9%). Embolization was achieved by deployment of coils and coverage was accomplished by extending the endoprosthesis into the external iliac artery. Clinical follow-up and computed tomographic angiography were performed at 1, 3, 6, 9, and 12 months and annually thereafter to detect potential aneurysm growth and endoleaks. During follow-up (range, 1-72 months), buttock claudication was noted in four patients (28.6%), including unilateral claudication in two and bilateral claudication in two. One patient experienced claudication longer than 12 months, which resolved within 18 months. De novo erectile dysfunction was seen in one patient, and pelvic ischemia was not found in any patient. There was no evidence of endoleak, aneurysm enlargement, or death associated with HGA occlusion. In our series, complications of bilateral HGA occlusion before EVAR were moderate and resolved over time. The benefits gained from EVAR outweigh the clinical problems caused by bilateral HGA occlusion, as there are no technical complications added to the EVAR procedure.

Sciatica and claudication caused by ganglion cyst.

PubMed

Yang, Guang; Wen, Xiaoyu; Gong, Yubao; Yang, Chen

2013-12-15

Case report. We report a rare case that a ganglion cyst compressed the sciatic nerve and caused sciatica and claudication in a 51-year-old male. Sciatica and claudication commonly occurs in spinal stenosis. To our knowledge, only 4 cases have been reported on sciatica resulting from posterior ganglion cyst of hip. A 51-year-old male had a 2-month history of radiating pain on his right leg. He could only walk 20 to 30 m before stopping and standing to rest for 1 to 3 minutes. Interestingly, he was able to walk longer distances (about 200 m) when walking slowly in small steps, without any rest. He had been treated as a case of lumbar disc herniation, but conservative treatment was ineffective. On buttock examination, a round, hard, and fixative mass was palpated at the exit of the sciatic nerve. MR imaging of hip revealed a multilocular cystic mass located on the posterior aspect of the superior gemellus and obturator internus, compressing the sciatic nerve. On operation, we found that the cyst extended to the superior gemellus and the obturator internus, positioned right at the outlet of the sciatic nerve. At 18 months of follow-up, the patient continued to be symptom free. He returned to comprehensive physical activity with no limitations. For an extraspinal source, a direct compression on the sciatic nerve also resulted in sciatica and claudication. A meticulous physical examination is very important for the differential diagnosis of extraspinal sciatica from spinal sciatica.

The Effectiveness of Calf Muscle Electrostimulation on Vascular Perfusion and Walking Capacity in Patients Living With Type 2 Diabetes Mellitus and Peripheral Artery Disease.

PubMed

Ellul, Christian; Formosa, Cynthia; Gatt, Alfred; Hamadani, Auon Abbas; Armstrong, David G

2017-06-01

The aim of the study was to explore calf muscle electrostimulation on arterial inflow and walking capacity in claudicants with peripheral artery disease and diabetes mellitus. A prospective, 1-group, pretest-posttest study design was used on 40 high-risk participants (n = 40) who exhibited bilateral limb ischemia (ankle brachial pressure index [ABPI] <0.90), diabetes mellitus, and calf muscle claudication. A program of calf muscle electrical stimulation with varying frequency (1-250 Hz) was prescribed for 1 hour per day for 12 weeks. Spectral waveforms analysis, ABPI, absolute claudication distance (ACD), and thermographic temperature patterns across 4 specified regions of interest (hallux, medial forefoot, lateral forefoot, heel) at rest and after exercise, were recorded at baseline and following intervention to evaluate for therapeutic outcomes. A significant improvement in ACD and ABPI was registered following the intervention ( P = .000 and P = .001, respectively). Resting foot temperatures increased significantly ( P = .000) while the postexercise temperature drops were halved across all regions at follow-up, with hallux ( P = .005) and lateral forefoot ( P = .038) reaching statistical significance. Spectral Doppler waveforms were comparable ( P = .304) between both serial assessments. Electrical stimulation of varying frequency for 1 hour per day for 12 consecutive weeks registered statistically significant improvement in outcome measures that assess arterial inflow and walking capacity in claudicants with diabetes mellitus. These results favor the use of electrostimulation as a therapeutic measure in this high-risk population.

Presentation, diagnosis, and management of popliteal artery entrapment syndrome: 11 years of experience with 61 legs.

PubMed

Corneloup, L; Labanère, C; Chevalier, L; Jaussaud, J; Mignot, A; Gencel, L; Corneloup, O; Midy, D

2018-02-01

Popliteal artery entrapment syndrome (PAES) is still underdiagnosed yet it may significantly interfere with lifestyle, especially among young sportspeople, with symptoms like intermittent claudication. Although case reports and small case series are sometimes published, studies with larger populations are quite rare. This study summarizes our experience with PAES on 61 limbs (35 patients) over a period of 11 years, describing the demographics, the disease, and the diagnostic and therapeutic methods used with PAES patients. In a population of 327 consecutive explored symptomatic sportspersons, PAES was confirmed in 35 patients on 61 pathologic limbs. The median time with the symptoms before diagnosis was 34 months (range, 3-180 months). The mean age of patients was 30.5 years (range, 17-52 years) with 83% of males. The proportion of patients diagnosed with bilateral PAES was 74%. The main sports practiced were running (15 patients, 43%), soccer (nine patients, 26%), rugby (two patients), and athletics (two patients). Among 21 patients, intra-compartmental pressure measurements (ICP) found 18 (86%) to have an associated chronic exertional compartment syndrome (CECS). Among the patients followed up after PAES surgery, 80% were able to resume sport at a level comparable to that before the onset of pain. PAES could be sought earlier in young sportspeople who experience unexplained leg pain during exercise to diagnose the disease and avoid complications in a timely manner. Compartmental pressures should systematically be measured in the search for an associated CECS. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Limb Stress-Rest Perfusion Imaging With Contrast Ultrasound For The Assessment Of Peripheral Arterial Disease Severity

PubMed Central

Lindner, Jonathan R.; Womack, Lisa; Barrett, Eugene J.; Feltman, Judy; Price, Wendy; Harthun, Nancy L.; Kaul, Sanjiv; Patrie, James T.

2009-01-01

Objectives We hypothesized that lower extremity stress-rest perfusion imaging with contrast-enhanced ultrasound (CEU) could evaluate the severity of peripheral arterial disease (PAD). Background Perfusion imaging may provide valuable quantitative information on PAD, particularly in patients with diabetes in whom microvascular functional abnormalities are common. Methods Twenty-six control subjects and 39 patients with symptomatic PAD, 19 with type-2 diabetes mellitus, were studied. Claudication threshold was determined by a modified treadmill exercise test. Bilateral pulse-volume recordings, ankle-brachial index (ABI), and post-exercise ABI were performed. CEU perfusion imaging of the gastrocnemius and soleus was performed at rest and after 2 min of plantar-flexion exercise. Results During exercise, claudication occurred earlier in PAD patients with diabetes than without. Muscle blood flow during plantar-flexion exercise was lower (p<0.05) in patients with PAD (10.4±6.7) and PAD with diabetes (7.9±5.9) compared to control subjects (20.0±9.5). After adjusting for diabetes, the only diagnostic tests that predicted severity of disease defined by claudication threshold were CEU exercise blood flow (odds ratios: 0.67 [95% CI (0.51 to 0.88); p=0.003], and flow reserve (odds ratio: 0.64 [95% CI (0.46 to 0.89), p=0.008]). A multivariate model incorporating all non-invasive diagnostic tests indicated that the best models for predicting severity of disease were the combination of presence of diabetes and either exercise blood flow or flow reserve. Conclusions Limb microvascular perfusion imaging during exercise can be evaluated by CEU. Skeletal muscle blood flow during exercise and flow reserve are impaired in patients with PAD and correlate with the severity of symptoms. PMID:19356447

Lower extremity revascularization using directional atherectomy: 12-month prospective results of the DEFINITIVE LE study.

PubMed

McKinsey, James F; Zeller, Thomas; Rocha-Singh, Krishna J; Jaff, Michael R; Garcia, Lawrence A

2014-08-01

The aim of this study was to assess the safety and effectiveness of directional atherectomy (DA) for endovascular treatment of peripheral arterial disease (PAD) in infrainguinal arteries in patients with claudication or critical limb ischemia. To date, no prospective, multicenter, independently-adjudicated study has evaluated the effectiveness and durability of DA in the treatment of PAD. Previous DA studies have not been prospectively powered to evaluate any differences in outcomes in patients with and without diabetes. DEFINITIVE LE (Determination of EFfectiveness of the SilverHawk(®) PerIpheral Plaque ExcisioN System (SIlverHawk Device) for the Treatment of Infrainguinal VEssels / Lower Extremities) prospectively enrolled subjects at 47 multinational centers with an infrainguinal lesion length up to 20 cm. Primary endpoints were defined as primary patency at 12 months for claudicants and freedom from major unplanned amputation for critical limb ischemia (CLI) subjects. A pre-specified statistical hypothesis evaluated noninferiority of primary patency in diabetic versus nondiabetic claudicants. Independent angiographic and sonographic core laboratories assessed outcomes, and events were adjudicated by a clinical events committee. A total of 800 subjects were enrolled. The 12-month primary patency was 78% (95% confidence interval: 74.0% to 80.6%) in claudicants, with a 77% rate in the diabetic subgroup versus 78% in the nondiabetic subgroup (noninferior, p < 0.001). The rate of freedom from major unplanned amputation of the target limb at 12 months in CLI subjects was 95% (95% confidence interval: 90.7% to 97.4%). Periprocedural adverse events included embolization (3.8%), perforation (5.3%), and abrupt closure (2.0%). The bail-out stent rate was 3.2%. The DEFINITIVE LE study demonstrated that DA is a safe and effective treatment modality at 12 months for a diverse patient population with either claudication or CLI. Furthermore, DA was shown to be noninferior for treating PAD in patients with diabetes compared with those without diabetes. (Study of SilverHawk/TurboHawk in Lower Extremity Vessels [DEFINITIVE LE]; NCT00883246). Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Lumbar spinous process splitting decompression provides equivalent outcomes to conventional midline decompression in degenerative lumbar canal stenosis: a prospective, randomized controlled study of 51 patients.

PubMed

Rajasekaran, S; Thomas, Ashok; Kanna, Rishi M; Prasad Shetty, Ajoy

2013-09-15

Prospective, randomized controlled study. To compare the functional outcomes and extent of paraspinal muscle damage between 2 decompressive techniques for lumbar canal stenosis. Lumbar spinous process splitting decompression (LSPSD) preserves the muscular and liga-mentous attachments of the posterior elements of the spine. It can potentially avoid problems such as paraspinal muscle atrophy and trunk extensor weakness that can occur after conventional midline decompression. However, large series prospective randomized controlled studies are lacking. Patients with lumbar canal stenosis were randomly allocated into 2 groups: LSPSD (28 patients) and conventional midline decompression (23 patients). The differences in operative time, blood loss, time to comfortable mobilization, and hospital stay were studied. Paraspinal muscle damage was assessed by postoperative rise in creatine phosphokinase and C-reactive protein levels. Functional outcome was evaluated at 1 year by Japanese Orthopaedic Association score, neurogenic claudication outcome score, and visual analogue scale for back pain and neurogenic claudication. Fifty-one patients of mean age 56 years were followed-up for a mean 14.2 ± 2.9 months. There were no significant differences in the operative time, blood loss, and hospital stay. Both the groups showed significant improvement in the functional outcome scores at 1 year. Between the 2 groups, the Japanese Orthopaedic Association score, neurogenic claudication outcome score improvement, visual analogue scale for back pain, neurogenic claudication visual analogue scale, and the postoperative changes in serum C-reactive protein and creatine phosphokinase levels did not show any statistically significant difference. On the basis of the Japanese Orthopaedic Association recovery rate, it was found that 73.9% of conventional midline decompression group had good outcomes compared with only 60.7% after LSPSD. The functional outcome scores, back pain, and claudication pain in the immediate period and at the end of 1 year are similar in both the techniques. More patients had better functional outcomes after conventional decompression than the LSPSD technique. On the basis of this study, the superiority of one technique compared with the other is not established, mandating the need for further long-term studies. 2.

Comparison of two progressive treadmill tests in patients with peripheral arterial disease.

PubMed

Riebe, D; Patterson, R B; Braun, C M

2001-11-01

In a vascular rehabilitation program, 28% of our frail elderly patients are unable to be tested with traditional progressive exercise protocols at program entry due to the high (2.0 miles/h or 3.2 km/h) initial treadmill speeds. The purpose of this investigation was to compare a new progressive treadmill protocol which has a reduced initial speed (1.0 mile/h or 1.6 km/h) to an established protocol performed at 2.0 miles/h (3.2 km/h) to determine the comparability and reproducibility of the new protocol. Eleven patients with arterial claudication performed three symptom-limited exercise tests in random order. Two tests used the new protocol while the remaining trial used the established protocol. Claudication pain was measured using a 5-point scale. Oxygen consumption, heart rate, minute ventilation, respiratory exchange ratio and blood pressure at peak exercise were similar among the three trials. There were strong intraclass correlations for peak oxygen consumption (r = 0.97), onset of claudication (r = 0.96) and maximum walking time (r = 0.98) between the two trials using the new protocol. There was also a significant correlation between the new protocol and the established protocol for peak oxygen consumption (r = 0.90) and maximum walking time (r = 0.89). The new progressive treadmill protocol represents a valid, reliable protocol for patients with arterial claudication. This protocol may be useful for testing patients with a low functional capacity so that clinically appropriate exercise prescriptions can be established and the efficacy of treatments can be determined.

Sarcopenia in Peripheral Arterial Disease: Prevalence and Effect on Functional Status.

PubMed

Addison, Odessa; Prior, Steven J; Kundi, Rishi; Serra, Monica C; Katzel, Leslie I; Gardner, Andrew W; Ryan, Alice S

2018-04-01

(1) To determine the prevalence of sarcopenia in older men with peripheral arterial disease (PAD); (2) to compare a subgroup of the group with age-, race-, sex-, and body mass index (BMI)-matched non-PAD control counterparts, and (3) to compare the functional status of those with PAD with and without sarcopenia. Cohort study. Medical center. Sedentary community-dwelling men (N=108; age, >50y) with a confirmed diagnosis of PAD (44% blacks; BMI, 27.8±0.4kg/m 2 ; ankle-brachial index, .62±.01). Not applicable. Dual-energy x-ray absorptiometry scans were used to assess appendicular lean mass and determine the prevalence of sarcopenia by/height 2 . Treadmill tests were used to determine claudication onset time, peak walking time, and claudication recovery time. 6-Minute walk distance was also measured. Sarcopenia prevalence in our PAD cohort was 25%. The PAD subgroup (n=42) matched with control counterparts in terms of race, sex, age, and BMI had higher prevalence rates than did their non-PAD counterparts (23.8% vs 2.4%; P<.05). Individuals with sarcopenia (n=28) had a shorter 6-minute walk distance (326±18.8m vs 380±9.7m; P<.05) and higher claudication recovery time (592±98s vs 395±29s; P<.05) than did individuals with PAD but without sarcopenia (n=80). There was no difference in claudication onset time or peak walking time between the PAD groups. Men with PAD demonstrate a high prevalence of sarcopenia. Those with sarcopenia and PAD demonstrate decreased mobility function. Published by Elsevier Inc.

Revascularization of smokers with claudication is not predicted to limit quality of life despite a higher risk of late failure.

PubMed

Mixson, Joshua D; Brothers, Thomas E

2017-01-01

Tobacco smoking after lower extremity revascularization for claudication has repeatedly been shown to increase the risk of adverse events, such that many vascular specialists consider that refusal to abstain from smoking constitutes a major contraindication to open surgical bypass or endovascular intervention. A Markov decision analysis (DA) model was used to compare the options of direct revascularization vs medical therapy only in smokers with claudication. The primary outcome was calculated quality of life (cQoL), determined for each patient at follow-up based on the outcomes of the treatment received. Markov DA software was used to predict the QoL for each treatment option preoperatively based on smoking status. Among patients referred during a recent 64-month period with vasculogenic claudication, 94 were actively smoking compared with 217 who were not. The DA model predicted that if the patients who smoked were to discontinue smoking, the best therapy would be bypass surgery for 77% and endovascular intervention for 17%. However, despite at least doubling the risks with intervention in the patients who continue to smoke, the DA model still predicted that 78% and 9% would fare better with open surgical or endovascular intervention, respectively. Among actively smoking patients, open surgical (3%) or endovascular (4%) therapies were initially performed in few patients, whereas 93% were offered only medical therapy. Among initial nonsmokers, revascularization was performed by open (27%) or endovascular (42%) means. At 3 years, the median (interquartile range [IQR]) cQoL was lower in initial smokers than in nonsmokers (0.73 [IQR, 0.73-0.77] vs 0.82 [IQR, 0.75-0.86]; P < .0001), primarily because of a lack of revascularization for smokers. Among initial smokers who did undergo revascularization initially, because of progression of symptoms, or after smoking cessation, cQoL was similar to initial nonsmokers (0.77 [IQR, 0.73-0.84] vs 0.73 [IQR, 0.73-0.73]; P = .37). Although 26% of initial smokers had stopped by the time of their last follow-up, 10% of initially nonsmoking patients were smoking at follow-up. However, among all patients undergoing intervention, the cQoL of patients smoking at the time of last their follow-up was similar to nonsmokers (0.82 [IQR, 0.82-0.86] vs 0.83 [IQR, 0.73-0.86]; P = .99). Patients with claudication who smoke may be denied the symptom improvement associated with revascularization, yet recidivism for smoking also occurs among patients who have stopped smoking in order to receive revascularization. The strategy not to directly revascularize patients with claudication who continue to smoke does not appear to maximize patient midterm QoL. Published by Elsevier Inc.

Buttock Claudication and Erectile Dysfunction After Internal Iliac Artery Embolization in Patients Prior to Endovascular Aortic Aneurysm Repair

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rayt, H. S., E-mail: hsrayt@hotmail.com; Bown, M. J.; Lambert, K. V.

2008-07-15

Coil embolization of the internal iliac artery (IIA) is used to extend the application of endovascular aneurysm repair (EVAR) in cases of challenging iliac anatomy. Pelvic ischemia is a complication of the technique, but reports vary as to the rate and severity. This study reports our experience with IIA embolization and compares the results to those of other published series. The vascular unit database of the Leicester Royal Infirmary was used to identify patients who had undergone IIA coil embolization prior to EVAR. Data were collected from hospital case notes and by telephone interviews. Thirty-eight patients were identified; 29 ofmore » these were contactable by telephone. A literature search was performed for other studies of IIA embolization and the results were pooled. In this series buttock claudication occurred in 55% (16 of 29 patients) overall: in 52% of unilateral embolizations (11 of 21) and 63% of bilateral embolizations (5 of 8). New erectile dysfunction occurred in 46% (6 of 13 patients) overall: in 38% of unilateral embolizations (3 of 8) and 60% of bilateral embolizations (3 of 5). The literature review identified 18 relevant studies. The results were pooled with our results, to give 634 patients in total. Buttock claudication occurred in 28% overall (178 of 634 patients): in 31% of unilateral embolizations (99 of 322) and 35% of bilateral embolizations (34 of 98) (p = 0.46, Fisher's exact test). New erectile dysfunction occurred in 17% overall (27 of 159 patients): in 17% of unilateral embolizations (16 of 97) and 24% of bilateral embolizations (9 of 38) (p = 0.33). We conclude that buttock claudication and erectile dysfunction are frequent complications of IIA embolization and patients should be counseled accordingly.« less

Combined aspirin and cilostazol treatment is associated with reduced platelet aggregation and prevention of exercise-induced platelet activation.

PubMed

Cleanthis, M; Bhattacharya, V; Smout, J; Ashour, H; Stansby, G

2009-05-01

Cilostazol has proven efficacy in increasing walking distance in claudicants, but it has not been demonstrated to be more effective than placebo in secondary cardiovascular prevention. The direct effect of exercise on platelet function remains less well defined. We have investigated the effect of combination treatment with aspirin and cilostazol on platelet activity in claudicants subjected to repeated treadmill exercise. Nineteen claudicants completed a double-blind, randomised, controlled, cross-over trial. Each subject received a 2-week course of aspirin (75mg) and placebo and aspirin and cilostazol (100mg twice daily). Following each 2-week treatment period, patients participated in a standardised treadmill test (3.2kmh(-1), 10 degrees incline) walking to maximal claudication distance. The exercise was repeated thrice in total, and blood was sampled before and after exercise. Platelet activation was measured using free platelet counting aggregation, flow cytometry for surface markers of platelet activation and soluble P-selectin assay. Compared to aspirin and placebo, combination treatment with aspirin and cilostazol was associated with reduced arachidonic-acid-induced platelet aggregation (p<0.01, Wilcoxon signed-rank test). Aspirin and placebo treatment were associated with elevated P-selectin expression, platelet-monocyte aggregation and reduced CD42b expression (p<0.05, Wilcoxon signed-rank test) post-exercise. No difference was seen in spontaneous platelet aggregation whilst soluble P-selectin was reduced post-exercise with combination treatment with aspirin and cilostazol (p<0.05, Wilcoxon signed-rank test). Combination treatment with aspirin and cilostazol results in suppression of platelet activation and reduces the effect of exercise on platelets. The benefit seen may be a result of cilostazol enhancing the inhibitory effect of aspirin on the cyclo-oxygenase pathway.

Clinical observation of the application of autologous peripheral blood stem cell transplantation for the treatment of diabetic foot gangrene

PubMed Central

XU, SHI-MIN; LIANG, TING

2016-01-01

The aim of the present study was to investigate the optimal mobilization plan in autologous peripheral blood stem cell transplantation for the treatment of diabetic foot and to observe its clinical curative effect. A total of 127 patients with diabetic foot were treated with different doses of granulocyte colony stimulating factor (G-CSF) to mobilize their hematopoietic stem cells. Subsequently, the extracted stem cell suspension was injected into the ischemic lower extremities along the blood vessels in the areas presenting with pathological changes. Following the treatment, the intermittent claudication distance, skin temperature, ankle brachial index and pain scores of the patients were evaluated. In addition, the associations among the mobilization time, doses and peripheral blood CD34+ level were analyzed. The collection efficiency of the stem cells was associated with the dose of G-CSF and the mobilization time. Following the injection of the autologous peripheral blood stem cell suspension, the ischemic area of the patients was improved significantly. In conclusion, autologous peripheral blood stem cell transplantation can promote the establishment of collateral circulation in patients with diabetic foot, and the optimal time for gathering stem cells is closely correlated with the peripheral blood CD34+ level. PMID:26889255

Clinical impact of exercise in patients with peripheral arterial disease.

PubMed

Novakovic, Marko; Jug, Borut; Lenasi, Helena

2017-08-01

Increasing prevalence, high morbidity and mortality, and decreased health-related quality of life are hallmarks of peripheral arterial disease. About one-third of peripheral arterial disease patients have intermittent claudication with deleterious effects on everyday activities, such as walking. Exercise training improves peripheral arterial disease symptoms and is recommended as first line therapy for peripheral arterial disease. This review examines the effects of exercise training beyond improvements in walking distance, namely on vascular function, parameters of inflammation, activated hemostasis and oxidative stress, and quality of life. Exercise training not only increases walking distance and physiologic parameters in patients with peripheral arterial disease, but also improves the cardiovascular risk profile by helping patients achieve better control of hypertension, hyperglycemia, obesity and dyslipidemia, thus further reducing cardiovascular risk and the prevalence of coexistent atherosclerotic diseases. American guidelines suggest supervised exercise training, performed for a minimum of 30-45 min, at least three times per week, for at least 12 weeks. Walking is the most studied exercise modality and its efficacy in improving cardiovascular parameters in patients with peripheral arterial disease has been extensively proven. As studies have shown that supervised exercise training improves walking performance, cardiovascular parameters and quality of life in patients with peripheral arterial disease, it should be encouraged and more often prescribed.

Nutraceutical and functional scenario of wheat straw.

PubMed

Pasha, Imran; Saeed, Farhan; Waqas, Khalid; Anjum, Faqir Muhammad; Arshad, Muhammad Umair

2013-01-01

In the era of nutrition, much focus has been remunerated to functional and nutraceutical foodstuffs. The health endorsing potential of such provisions is attributed to affluent phytochemistry. These dynamic constituents have functional possessions that are imperative for cereal industry. The functional and nutraceutical significance of variety of foods is often accredited to their bioactive molecules. Numerous components have been considered but wheat straw and its diverse components are of prime consideration. In this comprehensive dissertation, efforts are directed to elaborate the functional and nutraceutical importance of wheat straw. Wheat straw is lignocellulosic materials including cellulose, hemicellulose and lignin. It hold various bioactive compounds such as policosanols, phytosterols, phenolics, and triterpenoids, having enormous nutraceutical properties like anti-allergenic, anti-artherogenic, anti-inflammatory, anti-microbial, antioxidant, anti-thrombotic, cardioprotective and vasodilatory effects, antiviral, and anticancer. These compounds are protecting against various ailments like hypercholesterolemia, intermittent claudication, benign prostatic hyperplasia and cardiovascular diseases. Additionally, wheat straw has demonstrated successfully, low cost, renewable, versatile, widely distributed, easily available source for the production of biogas, bioethanol, and biohydrogen in biorefineries to enhance the overall effectiveness of biomass consumption in protected and eco-friendly environment. Furthermore, its role in enhancing the quality and extending the shelf life of bakery products through reducing the progression of staling and retrogradation is limelight of the article.

Effects of a 6-month exercise program pilot study on walking economy, peak physiological characteristics, and walking performance in patients with peripheral arterial disease.

PubMed

Crowther, Robert G; Leicht, Anthony S; Spinks, Warwick L; Sangla, Kunwarjit; Quigley, Frank; Golledge, Jonathan

2012-01-01

The purpose of this study was to examine the effects of a 6-month exercise program on submaximal walking economy in individuals with peripheral arterial disease and intermittent claudication (PAD-IC). Participants (n = 16) were randomly allocated to either a control PAD-IC group (CPAD-IC, n = 6) which received standard medical therapy, or a treatment PAD-IC group (TPAD-IC; n = 10) which took part in a supervised exercise program. During a graded treadmill test, physiological responses, including oxygen consumption, were assessed to calculate walking economy during submaximal and maximal walking performance. Differences between groups at baseline and post-intervention were analyzed via Kruskal-Wallis tests. At baseline, CPAD-IC and TPAD-IC groups demonstrated similar walking performance and physiological responses. Postintervention, TPAD-IC patients demonstrated significantly lower oxygen consumption during the graded exercise test, and greater maximal walking performance compared to CPAD-IC. These preliminary results indicate that 6 months of regular exercise improves both submaximal walking economy and maximal walking performance, without significant changes in maximal walking economy. Enhanced walking economy may contribute to physiological efficiency, which in turn may improve walking performance as demonstrated by PAD-IC patients following regular exercise programs.

Protrusion of a rod into the spinal canal 10 years after segmental lumbar spine surgery.

PubMed

Cai, Siyi; Kong, Xiangyi; Yan, Chengrui; Wang, Yipeng; Wan, Xueshuai; Zhang, Jialu; Qiu, Guixing; Yu, Keyi

2017-03-01

The objective of this article is to report an unusual case of a spinal rod that protruded into the spinal canal after lumbar spine surgery.Only 4 cases of spinal rod migration with protrusion into the spinal canal have been reported. This is the first report of a case involving the use of posterior low lumbar segmental instrumentation with a screw-rod system. The left side of the rod gradually migrated and finally protruded into the canal and compressed the cord.A 60-year-old woman presented with pain and numbness of the posterior aspect of the left leg after a long-distance walk. Intermittent claudication became worse, and she developed pain and numbness in the perineal region. An x-ray showed that the left side of a spinal rod among the segmental spinal instruments that had been placed 10 years previously had protruded into the spinal canal.We removed the rod and decompressed the canal at the level of L5-S1. The patient became totally asymptomatic.Rods used as spinal instrumentation have the possibility of protruding into the spinal canal and endangering the nervous system. Long-term follow-up with radiological examinations should be conducted upon completion of spinal operations conducting using instrumentation.

Cyclic Nucleotide Phosphodiesterases: important signaling modulators and therapeutic targets

PubMed Central

Ahmad, Faiyaz; Murata, Taku; Simizu, Kasumi; Degerman, Eva; Maurice, Donald; Manganiello, Vincent

2014-01-01

By catalyzing hydrolysis of cAMP and cGMP, cyclic nucleotide phosphodiesterases are critical regulators of their intracellular concentrations and their biological effects. Since these intracellular second messengers control many cellular homeostatic processes, dysregulation of their signals and signaling pathways initiate or modulate pathophysiological pathways related to various disease states, including erectile dysfunction, pulmonary hypertension, acute refractory cardiac failure, intermittent claudication, chronic obstructive pulmonary disease, and psoriasis. Alterations in expression of PDEs and PDE-gene mutations (especially mutations in PDE6, PDE8B, PDE11A and PDE4) have been implicated in various diseases and cancer pathologies. PDEs also play important role in formation and function of multi-molecular signaling/regulatory complexes called signalosomes. At specific intracellular locations, individual PDEs, together with pathway-specific signaling molecules, regulators, and effectors, are incorporated into specific signalosomes, where they facilitate and regulate compartmentalization of cyclic nucleotide signaling pathways and specific cellular functions. Currently, only a limited number of PDE inhibitors (PDE3, PDE4, PDE5 inhibitors) are used in clinical practice. Future paths to novel drug discovery include the crystal structure-based design approach, which has resulted in generation of more effective family-selective inhibitors, as well as burgeoning development of strategies to alter compartmentalized cyclic nucleotide signaling pathways by selectively targeting individual PDEs and their signalosome partners. PMID:25056711

Surgical versus pharmacologic treatment of intraspinal gout.

PubMed

Chang, I-Chang

2005-04-01

A controversy between pharmacologic and surgical treatment of intraspinal gout exists in the literature. If gout is diagnosed timely, pharmacologic therapy may avert the need of surgery. The lack of readily available synovial fluid makes the diagnosis particularly difficult. The purpose of this study was to evaluate the clinical pictures and magnetic resonance imaging features in rapid differentiations of intraspinal gout. I retrospectively evaluated lumbar intraspinal tophaceous gout without the classic radiographic punched-out lesions. Four patients (average age, 65 years) had a history of hyperuricemia with multiple tophaceous deposits in the joints or visceral organs or both. The common presentations were low back pain with or without inflammatory reaction (fever, elevated C-reactive protein level, and mild leukocytosis). The patients also presented with intermittent claudication or radiculopathy of variable duration or both. The gouty tophi yielded homogeneous and hypointense masses on T1- and T2-weighted images, with multiple hypointense speckles. The masses were located in bilateral lumbar facet joints in all patients, with additional midline extension along the ligamentum flavum in three. All patients had uneventful outcomes after surgical decompression and pharmacologic treatment. Rapid deposition of tophi may aggravate nerve compression. If neurologic deficits are found, surgical decompression can provide a satisfactory outcome. Therapeutic study, Level IV. See the Guidelines for Authors for a complete description of levels of evidence.

Peripheral artery disease, redox signaling, oxidative stress - Basic and clinical aspects.

PubMed

Steven, Sebastian; Daiber, Andreas; Dopheide, Jörn F; Münzel, Thomas; Espinola-Klein, Christine

2017-08-01

Reactive oxygen and nitrogen species (ROS and RNS, e.g. H 2 O 2 , nitric oxide) confer redox regulation of essential cellular signaling pathways such as cell differentiation, proliferation, migration and apoptosis. At higher concentrations, ROS and RNS lead to oxidative stress and oxidative damage of biomolecules (e.g. via formation of peroxynitrite, fenton chemistry). Peripheral artery disease (PAD) is characterized by severe ischemic conditions in the periphery leading to intermittent claudication and critical limb ischemia (end stage). It is well known that redox biology and oxidative stress play an important role in this setting. We here discuss the major pathways of oxidative stress and redox signaling underlying the disease progression with special emphasis on the contribution of inflammatory processes. We also highlight therapeutic strategies comprising pharmacological (e.g. statins, angiotensin-converting enzyme inhibitors, phosphodiesterase inhibition) and non-pharmacological (e.g. exercise) interventions. Both of these strategies induce potent indirect antioxidant and anti-inflammatory mechanisms that may contribute to an improvement of PAD associated complications and disease progression by removing excess formation of ROS and RNS (e.g. by ameliorating primary complications such as hyperlipidemia and hypertension) as well as the normalization of the inflammatory phenotype suppressing the progression of atherosclerosis. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Unilateral repetitive tibial nerve stimulation improves neurogenic claudication and bilateral F-wave conduction in central lumbar spinal stenosis.

PubMed

Nakajima, Noritsuna; Tani, Toshikazu; Kiyasu, Katsuhito; Kumon, Masashi; Taniguchi, Shinichirou; Takemasa, Ryuichi; Tadokoro, Nobuaki; Nishida, Kazuya; Ikeuchi, Masahiko

2018-03-01

Repetitive electrical nerve stimulation of the lower limb may improve neurogenic claudication in patients with lumbar spinal stenosis (LSS) as originally described by Tamaki et al. We tested if this neuromodulation technique affects the F-wave conduction on both sides to explore the underlying physiologic mechanisms. We studied a total of 26 LSS patients, assigning 16 to a study group receiving repetitive tibial nerve stimulation at the ankle (RTNS) on one leg, and 10 to a group without RTNS. RTNS conditioning consisted of a 0.3-ms duration square-wave pulse with an intensity 20% above the motor threshold, delivered at a rate of 5 Hz for 5 min. All patients underwent the walking test and the F-wave and M-wave studies for the tibial nerve on both sides twice; once as the baseline, and once after either the 5-min RTNS or 5-min rest. Compared to the baselines, a 5-min RTNS increased claudication distance (176 ± 96 m vs 329 ± 133 m; p = 0.0004) and slightly but significantly shortened F-wave minimal onset latency (i.e., increased F-wave conduction velocity) not only on the side receiving RTNS (50.7 ± 4.0 ms vs 49.2 ± 4.2 ms; p = 0.00081) but also on the contralateral side (50.1 ± 4.6 ms vs 47.9 ± 4.2 ms; p = 0.011). A 5-min rest in the group not receiving RTNS neither had a significant change on claudication distance nor on any F-wave measurements. The M response remained unchanged in both groups. The present study verified a beneficial effect of unilaterally applied RTNS of a mild intensity on neurogenic claudication and bilateral F-wave conduction. Our F-wave data suggest that this type of neuromodulation could be best explained by an RTNS-induced widespread sympathetic tone reduction with vasodilation, which partially counters a walking-induced further decline in nerve blood flow in LSS patients who already have ischemic cauda equina. Copyright © 2017 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

Endovascular Management of the Arteria Profunda Femoralis: Long-Term Angiographic and Clinical Outcomes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karnabatidis, Dimitrios, E-mail: karnaby@med.upatras.gr; Spiliopoulos, Stavros; Pastromas, Georgios

2012-10-15

Purpose: This study was designed to investigate the long-term angiographic and clinical outcomes of percutaneous transluminal angioplasty (PTA) of the arteria profunda femoralis (PFA), in a series of patients suffering from critical limb ischemia (CLI) or severe intermittent claudication (IC). Methods: Our department's database was searched to identify patients who underwent PTA or bail-out stenting of the PFA. Among the study's inclusion criteria were Rutherford categories 3-6 and {>=}70% stenosis of the PFA. Only de novo stenotic lesions were assessed. Primary endpoints were technical success, angiographic lesion primary patency, angiographic binary in-lesion restenosis, and target lesion recanalization (TLR) rates. Secondarymore » endpoints included patient survival, limb salvage, and complication rates. Patient's baseline demographics, lesion, and procedural details were analyzed. Results: Between 2001 and 2011, 20 consecutive patients (17 males) with a mean age of 73 {+-} 9 (range 53-87) years underwent PTA or bail-out stenting in 23 PFA lesions. Critical limb ischemia was the indication in eight of 20 patients (40%). The mean lesion length was 31 {+-} 9.5 mm. The procedural technical success was 100% (23/23), whereas mean time angiographic and clinical follow-up was 26.8 {+-} 24.6 months. According to the Kaplan-Meier analysis, primary patency and binary restenosis rate were 95 and 86.1% respectively up to 8 years follow-up. No TLR procedures were performed. The 8-year patient survival and limb salvage rates were 87.5 and 84.7% respectively. Conclusions: PTA or stenting of focal, stenotic, PFA lesions, in patients suffering from CLI or IC, exhibit high long-term primary patency rates, as well as low binary restenosis and TLR rates. Large, multicenter studies are required to validate these results.« less

The NMatrix, a new method of presenting statistics, displays the characteristics of medicines with similar effects used in the treatment of lumbar spinal stenosis concisely and clearly, facilitating the selection of appropriate medications.

PubMed

Nakamura, Masao

2015-07-01

It is often difficult to compare the characteristics of a medicine with those of others based on common standards, whereas the application of rational standards would be expected to facilitate the comparison of medicines with similar effects. The present study was conducted to clarify the characteristics of individual medicines and to examine whether rational standards allow the most appropriate medicines to be chosen. Participants diagnosed with lumbar spinal stenosis (LSS) were assessed for QOL and ADL based on the Roland-Morris Disability Questionnaire, JOA score, VAS, and the presence of intermittent claudication (IC). Four medicines--beraprost sodium, ethyl icosapentate (EPA), sarpogrelate hydrochloride, and limaprost alfadex (PGE1)--were prescribed in a random manner. These four medicines were assessed independently in four studies using the same study design and size in each case. Using the NMatrix, the characteristics of the four medicines and the results of mutual comparisons could be displayed concisely and clearly in one matrix based on significance levels. This work involved analyzing pooled data from the four studies. All four medicines improved IC--one of the characteristic symptoms of LSS--by 12 weeks after administration. PGE1 required more time than the other medicines to affect IC. EPA appeared to almost significantly ameliorate some items at every point, though the evidence was insufficient. The NMatrix concisely and clearly displays the characteristics of "medicines with similar effects" for the treatment of lumbar spinal stenosis, and can help physicians to choose the optimal medicine based on rational criteria for individual patients, according to their symptoms and progress.

Clinical Correlates and Prognostic Significance of Change in Standardized Left Ventricular Mass in a Community‐Based Cohort of African Americans

PubMed Central

Fox, Ervin R.; Musani, Solomon K.; Samdarshi, Tandaw E.; Taylor, Jared K.; Beard, Walter L.; Sarpong, Daniel F.; Xanthakis, Vanessa; McClendon, Eric E.; Liebson, Philip R.; Skelton, Thomas N.; Butler, Kenneth R.; Mosley, Thomas H.; Taylor, Herman; Vasan, Ramachandran S.

2015-01-01

Background Though left ventricular mass (LVM) predicts cardiovascular events (CVD) and mortality in African Americans, limited data exists on factors contributing to change in LVM and its prognostic significance. We hypothesized that baseline blood pressure (BP) and body mass index (BMI) and change in these variables over time are associated with longitudinal increases in LVM and that such increase is associated with greater incidence of CVD. Methods and Results We investigated the clinical correlates of change in standardized logarithmically transformed‐LVM indexed to height2.7 (log‐LVMI) and its association with incident CVD in 606 African Americans (mean age 58±6 years, 66% women) who attended serial examinations 8 years apart. Log‐LVMI and clinical covariates were standardized within sex to obtain z scores for both visits. Standardized log‐LVMI was modeled using linear regression (correlates of change in standardized log‐LVMI) and Cox proportional hazards regression (incidence of CVD [defined as coronary heart disease, stroke, heart failure and intermittent claudication]). Baseline clinical correlates (standardized log‐LVM, BMI, systolic BP) and change in systolic BP over time were significantly associated with 8‐year change in standardized log‐LVMI. In prospective analysis, change in standardized LVM was significantly (P=0.0011) associated with incident CVD (hazards ratio per unit standard deviation change log‐LVMI 1.51, 95% CI 1.18 to 1.93). Conclusions In our community‐based sample of African Americans, baseline BMI and BP, and change in BP on follow‐up were key determinants of increase in standardized log‐LVMI, which in turn carried an adverse prognosis, underscoring the need for greater control of BP and weight in this group. PMID:25655570

Cost-effectiveness of superficial femoral artery endovascular interventions in the UK and Germany: a modelling study

PubMed Central

Kearns, Benjamin C; Thomas, Steven M

2017-01-01

Objectives To assess the lifetime costs and cost-effectiveness of 5 endovascular interventions to treat superficial femoral arterial disease. Design A model-based health economic evaluation. An existing decision analytical model was used, with updated effectiveness data taken from the literature, and updated costs based on purchasing prices. Setting UK and German healthcare perspectives were considered. Participants Patients with intermittent claudication of the femoropopliteal arteries eligible for endovascular treatment. Methods UK and German healthcare perspectives were considered, as were different strategies for re-intervention. Interventions Percutaneous transluminal angioplasty (PTA) with bail-out bare metal stenting (assumed to represent the existing standard of care, and 4 alternatives: primary bare metal stents, drug-eluting stents, drug-eluting balloons (DEBs) and biomimetic stents). Primary outcome measures The incremental cost-effectiveness ratio between 2 treatments, defined as the incremental costs divided by the incremental quality-adjusted life years (QALYs). Results Use of a biomimetic stent, BioMimics 3D, was always estimated to dominate the other interventions, having lower lifetime costs and greater effectiveness, as measured by QALYs. Of the remaining interventions, DEBs were always the most effective, and PTA the least effective. There was uncertainty in the cost-effectiveness results, with key drivers being the costs and effectiveness of the biomimetic stent along with the costs of DEBs. Conclusions All 4 of the alternatives to PTA were more effective, with the biomimetic stent being the most cost-effective. As there was uncertainty in the results, and all of the interventions have different mechanisms of action, all 4 may be considered to be alternatives to PTA. PMID:28087551

Drug-Coated Balloon Versus Standard Percutaneous Transluminal Angioplasty for the Treatment of Superficial Femoral and Popliteal Peripheral Artery Disease

PubMed Central

Tepe, Gunnar; Schneider, Peter; Brodmann, Marianne; Krishnan, Prakash; Micari, Antonio; Metzger, Christopher; Scheinert, Dierk; Zeller, Thomas; Cohen, David J.; Snead, David B.; Alexander, Beaux; Landini, Mario; Jaff, Michael R.

2015-01-01

Background— Drug-coated balloons (DCBs) have shown promise in improving the outcomes for patients with peripheral artery disease. We compared a paclitaxel-coated balloon with percutaneous transluminal angioplasty (PTA) for the treatment of symptomatic superficial femoral and popliteal artery disease. Methods and Results— The IN.PACT SFA Trial is a prospective, multicenter, single-blinded, randomized trial in which 331 patients with intermittent claudication or ischemic rest pain attributable to superficial femoral and popliteal peripheral artery disease were randomly assigned in a 2:1 ratio to treatment with DCB or PTA. The primary efficacy end point was primary patency, defined as freedom from restenosis or clinically driven target lesion revascularization at 12 months. Baseline characteristics were similar between the 2 groups. Mean lesion length and the percentage of total occlusions for the DCB and PTA arms were 8.94±4.89 and 8.81±5.12 cm (P=0.82) and 25.8% and 19.5% (P=0.22), respectively. DCB resulted in higher primary patency versus PTA (82.2% versus 52.4%; P<0.001). The rate of clinically driven target lesion revascularization was 2.4% in the DCB arm in comparison with 20.6% in the PTA arm (P<0.001). There was a low rate of vessel thrombosis in both arms (1.4% after DCB and 3.7% after PTA [P=0.10]). There were no device- or procedure-related deaths and no major amputations. Conclusions— In this prospective, multicenter, randomized trial, DCB was superior to PTA and had a favorable safety profile for the treatment of patients with symptomatic femoropopliteal peripheral artery disease. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique Identifiers: NCT01175850 and NCT01566461. PMID:25472980

Metabolic adaptations to repeated periods of contraction with reduced blood flow in canine skeletal muscle

PubMed Central

MacInnes, Alan; Timmons, James A

2005-01-01

Background Patients suffering from Intermittent Claudication (IC) experience repeated periods of muscle contraction with low blood flow, throughout the day and this may contribute to the hypothesised skeletal muscle abnormalities. However, no study has evaluated the consequences of intermittent contraction with low blood flow on skeletal muscle tissue. Our aim was to generate this basic physiological data, determining the 'normal' response of healthy skeletal muscle tissue. We specifically proposed that the metabolic responses to contraction would be modified under such circumstances, revealing endogenous strategies engaged to protect the muscle adenine nucleotide pool. Utilizing a canine gracilis model (n = 9), the muscle was stimulated to contract (5 Hz) for three 10 min periods (separated by 10 min rest) under low blood flow conditions (80% reduced), followed by 1 hr recovery and then a fourth period of 10 min stimulation. Muscle biopsies were obtained prior to and following the first and fourth contraction periods. Direct arterio-venous sampling allowed for the calculation of muscle metabolite efflux and oxygen consumption. Results During the first period of contraction, [ATP] was reduced by ~30%. During this period there was also a 10 fold increase in muscle lactate concentration and a substantial increase in muscle lactate and ammonia efflux. Subsequently, lactate efflux was similar during the first three periods, while ammonia efflux was reduced by the third period. Following 1 hr recovery, muscle lactate and phosphocreatine concentrations had returned to resting values, while muscle [ATP] remained 20% lower. During the fourth contraction period no ammonia efflux or change in muscle ATP content occured. Despite such contrasting metabolic responses, muscle tension and oxygen consumption were identical during all contraction periods from 3 to 10 min. Conclusion repeated periods of muscle contraction, with low blood flow, results in cessation of muscle ammonia production which is suggestive of a dramatic reduction in flux through AMP deaminase. PMID:16018808

Exercise in claudicants increase or decrease walking ability and the response relates to mitochondrial function.

PubMed

van Schaardenburgh, Michel; Wohlwend, Martin; Rognmo, Øivind; Mattsson, Erney J R

2017-06-07

Exercise of patients with intermittent claudication improves walking performance. Exercise does not usually increase blood flow, but seems to increase muscle mitochondrial enzyme activities. Although exercise is beneficial in most patients, it might be harmful in some. The mitochondrial response to exercise might therefore differ between patients. Our hypothesis was that changes in walking performance relate to changes in mitochondrial function after 8 weeks of exercise. At a subgroup level, negative responders decrease and positive responders increase mitochondrial capacity. Two types of exercise were studied, calf raising and walking (n = 28). We wanted to see whether there were negative and positive responders, independent of type of exercise. Measurements of walking performance, peripheral hemodynamics, mitochondrial respiration and content (citrate synthase activity) were obtained on each patient before and after the intervention period. Multiple linear regression was used to test whether changes in peak walking time relate to mitochondrial function. Subgroups of negative (n = 8) and positive responders (n = 8) were defined as those that either decreased or increased peak walking time following exercise. Paired t test and analysis of covariance was used to test changes within and between subgroups. Changes in peak walking time were related to changes in mitochondrial respiration supported by electron transferring flavoprotein (ETF + CI) P (p = 0.004), complex I (CI + ETF) P (p = 0.003), complex I + complex II (CI + CII + ETF) P (p = 0.037) and OXPHOS coupling efficiency (p = 0.046) in the whole group. Negative responders had more advanced peripheral arterial disease. Mitochondrial respiration supported by electron transferring flavoprotein (ETF + CI) P (p = 0.0013), complex I (CI + ETF) P (p = 0.0005), complex I + complex II (CI + CII + ETF) P (p = 0.011) and electron transfer system capacity (CI + CII + ETF) E (p = 0.021) and OXPHOS coupling efficiency decreased in negative responders (p = 0.0007) after exercise. Positive responders increased citrate synthase activity (p = 0.010). Changes in walking performance seem to relate to changes in mitochondrial function after exercise. Negative responders have more advanced peripheral arterial disease and decrease, while positive responders increase mitochondrial capacity. Trial registration ClinicalTrials.gov ID: NCT023110256.

Alternate energy source usage methods for in situ heat treatment processes

DOEpatents

Stone, Jr., Francis Marion; Goodwin, Charles R; Richard, Jr., James E

2014-10-14

Systems, methods, and heaters for treating a subsurface formation are described herein. At least one method for providing power to one or more subsurface heaters is described herein. The method may include monitoring one or more operating parameters of the heaters, the intermittent power source, and a transformer coupled to the intermittent power source that transforms power from the intermittent power source to power with appropriate operating parameters for the heaters; and controlling the power output of the transformer so that a constant voltage is provided to the heaters regardless of the load of the heaters and the power output provided by the intermittent power source.

Study of pentoxifylline effects on motility and viability of spermatozoa from infertile asthenozoospermic males

PubMed Central

Ghasemzadeh, Aliye; Karkon-Shayan, Farid; Yousefzadeh, Solmaz; Naghavi-Behzad, Mohammad; Hamdi, Kobra

2016-01-01

Background: The quality of semen is one of the major parameters in male infertility. Pentoxifylline, a methylxanthine derivative, is an agent primarily used in the treatment of intermittent claudication and other vascular disorders. Studies have shown that pentoxifylline enhances the quality and quantity of sperms. In this study, we have investigated the in vitro effects of pentoxifylline on viability and motility of spermatozoa in samples of infertile oligoasthenozoospermic males. Materials and Methods: In this observer-blinded clinical trial, semen samples of 25 infertile oligoasthenozoospermic males were collected in Alzahra Educational Medical Center of Tabriz University of Medical Sciences from August 2010 to August 2012. After the isolation of spermatozoa by the swim-up method, they were randomized into four groups in ISM1 environment: The controls treated normally: Group 1 treated by pentoxifylline at a dose of 50 μg/ml, Group 2 treated by pentoxifylline at a dose of 100 μg/ml, and Group 3 treated by pentoxifylline at a dose of 200 μg/ml. Sperm viability and motility were compared among the groups on 45 min, 24 h, 36 h, and 48 h intervals. Results: Mean percentages of live sperms were 98.40%, 51.40%, 20.60%, and 6.00% in control group and 98.40%, 69.20%, 38.60%, and 14.60% in Group 3 on the mentioned intervals, respectively. This mean percentage decrease of live sperms was significantly lower in Group 3 comparing with that of other groups (P = 0.01). Mean percentages of motile sperms were 54%, 8.40%, 2.80%, and 0% in control group; and 54%, 16%, 4.80%, and 1.40% in Group 3 on the mentioned intervals, respectively. There was not a significant difference between the four groups in this regard (P = 0.19). Conclusion: Pentoxifylline can enhance the viability of sperm of infertile oligoasthenozoospermic males with no significant effect on its motility. PMID:27942099

Home, automated office, and conventional office blood pressure as predictors of cardiovascular risk.

PubMed

Andreadis, Emmanuel A; Papademetriou, Vasilios; Geladari, Charalampia V; Kolyvas, George N; Angelopoulos, Epameinondas T; Aronis, Konstantinos N

2017-03-01

Automated office blood pressure (AOBP) has recently been shown to closely predict cardiovascular (CV) events in the elderly. Home blood pressure (HBP) has also been accepted as a valuable method in the prediction of CV disease. This study aimed to compare conventional office BP (OBP), HBP, and AOBP in order to evaluate their value in predicting CV events and deaths in hypertensives. We assessed 236 initially treatment naïve hypertensives, examined between 2009 and 2013. The end points were any CV and non-CV event including mortality, myocardial infarction, coronary heart disease, hospitalization for heart failure, severe arrhythmia, stroke, and intermittent claudication. We fitted proportional hazards models using the different modalities as predictors and evaluated their predictive performance using three metrics: time-dependent receiver operating characteristics curves, the Akaike's Information Criterion, and Harrell's C-index. After a mean follow-up of 7 years, 23 participants (39% women) had experienced ≥1 CV event. Conventional office systolic (hazard ratio [HR] per 1 mm Hg increase in BP, 1.028; 95% confidence interval [CI], 1.009-1.048), automated office systolic (HR per 1 mm Hg increase in BP, 1.031; 95% CI, 1.008-1.054), and home systolic (HR, 1.025; 95% CI, 1.003-1.047) were predictive of CV events. All systolic BP measurements were predictive after adjustment for other CV risk factors (P < .05). The predictive performance of the different modalities was similar. Conventional OBP was significantly higher than AOBP and average HBP. AOBP predicts equally well to OBP and HBP CV events. It appears to be comparable to HBP in the assessment of CV risk, and therefore, its introduction into guidelines and clinical practice as the reference method for assessing BP in the office seems reasonable after verification of these findings by randomized trials. Copyright © 2017 American Society of Hypertension. All rights reserved.

Practice-Based Evidence: Profiling the Safety of Cilostazol by Text-Mining of Clinical Notes

PubMed Central

Iyer, Srinivasan V.; LePendu, Paea; Olson, Cliff; Shah, Nigam H.

2013-01-01

Background Peripheral arterial disease (PAD) is a growing problem with few available therapies. Cilostazol is the only FDA-approved medication with a class I indication for intermittent claudication, but carries a black box warning due to concerns for increased cardiovascular mortality. To assess the validity of this black box warning, we employed a novel text-analytics pipeline to quantify the adverse events associated with Cilostazol use in a clinical setting, including patients with congestive heart failure (CHF). Methods and Results We analyzed the electronic medical records of 1.8 million subjects from the Stanford clinical data warehouse spanning 18 years using a novel text-mining/statistical analytics pipeline. We identified 232 PAD patients taking Cilostazol and created a control group of 1,160 PAD patients not taking this drug using 1∶5 propensity-score matching. Over a mean follow up of 4.2 years, we observed no association between Cilostazol use and any major adverse cardiovascular event including stroke (OR = 1.13, CI [0.82, 1.55]), myocardial infarction (OR = 1.00, CI [0.71, 1.39]), or death (OR = 0.86, CI [0.63, 1.18]). Cilostazol was not associated with an increase in any arrhythmic complication. We also identified a subset of CHF patients who were prescribed Cilostazol despite its black box warning, and found that it did not increase mortality in this high-risk group of patients. Conclusions This proof of principle study shows the potential of text-analytics to mine clinical data warehouses to uncover ‘natural experiments’ such as the use of Cilostazol in CHF patients. We envision this method will have broad applications for examining difficult to test clinical hypotheses and to aid in post-marketing drug safety surveillance. Moreover, our observations argue for a prospective study to examine the validity of a drug safety warning that may be unnecessarily limiting the use of an efficacious therapy. PMID:23717437

Selection of test paths for solder joint intermittent connection faults under DC stimulus

NASA Astrophysics Data System (ADS)

Huakang, Li; Kehong, Lv; Jing, Qiu; Guanjun, Liu; Bailiang, Chen

2018-06-01

The test path of solder joint intermittent connection faults under direct-current stimulus is examined in this paper. According to the physical structure of the circuit, a network model is established first. A network node is utilised to represent the test node. The path edge refers to the number of intermittent connection faults in the path. Then, the selection criteria of the test path based on the node degree index are proposed and the solder joint intermittent connection faults are covered using fewer test paths. Finally, three circuits are selected to verify the method. To test if the intermittent fault is covered by the test paths, the intermittent fault is simulated by a switch. The results show that the proposed method can detect the solder joint intermittent connection fault using fewer test paths. Additionally, the number of detection steps is greatly reduced without compromising fault coverage.

Perioperative outcomes of elective inflow revascularization for lower extremity claudication in the American College of Surgeons National Surgical Quality Improvement Program database.

PubMed

Madenci, Arin L; Ozaki, C Keith; Gupta, Naren; Raffetto, Joseph D; Belkin, Michael; McPhee, James T

2016-09-01

We compared the early postoperative morbidity and mortality rates of contemporary aortofemoral bypass (AFB) and other inflow procedures for claudication. We identified 1974 claudicants who underwent elective AFB (n = 566) or non-AFB (nonaortofemoral bypass [NAFB]; n = 1408) inflow reconstruction using the ACS-NSQIP database (2005 to 2012). Stent placement was not routinely captured. In propensity score-matched cohorts, we analyzed the association between type of inflow surgery and 30-day postoperative outcomes. Among 824 propensity score-matched patients (AFB, n = 412; NAFB, n = 412), the 30-day mortality rate was 2.7% for AFB and .0% for NAFB (P = .0008). NAFB conferred significantly lower rates of major cardiac (.2% vs 2.4%, P = .0063), respiratory (.7% vs 10.9%, P < .0001), renal (.2% vs 1.9%, P = .0380), and septic (.5% vs 3.6%, P = .0014) complications, and fewer returns to the operating room (4.6% vs 9.9%, P = .0032), compared with AFB. Rates of major venous thrombosis, wound complications, peripheral nerve injury, and graft failure were similar between the groups. This study reports a higher contemporary short-term complication rate with AFB compared to alternative inflow revascularization, against which future study of long-term durability may be weighed. Published by Elsevier Inc.

Clinical and Functional Impact of Hypogastric Artery Exclusion During EVAR.

PubMed

Mansour, Wassim; Capoccia, Laura; Sirignano, Pasqualino; Montelione, Nunzio; Pranteda, Chiara; Formiconi, Martina; Sbarigia, Enrico; Speziale, Francesco

2016-10-01

Hypogastric artery (HA) revascularization during endovascular aneurysm repair (EVAR) is still open to debate. Moreover, exclusion-related complication rates reported in literature are not negligible. The aim of this study is to present and analyze the outcomes in patients undergoing EVAR with exclusion of 1 or both HAs at our academic center. We retrospectively reviewed our results in patients submitted to EVAR and needing HA exclusion, in terms of perioperative (30-day) and follow-up rates of intestinal and spinal cord ischemia, buttock claudication, buttock skin necrosis, and sexual dysfunction. From January 2008 to December 2014, a total of 527 patients underwent elective standard infrarenal EVAR; among those 104 (19.7%) had iliac involvement needing HA exclusion. In 73 patients with unilateral iliac involvement (70.1%, group UH), many single HAs were excluded. Thirty-one patients (29.9%) had bilateral iliac involvement (group BH), of which 16 (51.6%) had 1 HA excluded with revascularization of the contralateral one (group BHR); in the remaining 15 patients (48.4%) both HAs were excluded (group BHE). No 30-day or follow-up aneurysm-related mortality, intestinal, or spinal cord ischemia were recorded. At 30 days, skin necrosis was observed in 2 patients. Buttock claudication and sexual dysfunction rates were significantly greater in group BHE than in group BHR (P < .05). At a mean 18.6 months follow-up (range: 4-47), buttock claudication and sexual dysfunction rates in group BHE were persistently higher than that in groups UH and BHR (P < .05); HA coil embolization was significantly associated with buttock claudication and sexual dysfunction (P < .05). Whenever anatomically feasible, at least 1 HA should be salvaged in case of bilateral involvement. In case of unilateral HA exclusion, the rate of complications is not negligible. Coil embolization is related to a higher complication rate. © The Author(s) 2016.

MiDAS ENCORE: Randomized Controlled Study Design and Protocol.

PubMed

Benyamin, Ramsin M; Staats, Peter S

2015-01-01

Epidural steroid injections (ESIs) are commonly used for treatment of symptomatic lumbar spinal stenosis (LSS). ESIs are generally administered after failure of conservative therapy. For LSS patients suffering from neurogenic claudication, the mild® procedure provides an alternative to ESIs via minimally invasive lumbar decompression. Both ESIs and mild offer interventional pain treatment options for LSS patients experiencing neurogenic claudication refractory to more conservative therapies. Prospective, multi-center, randomized controlled, clinical study. Twenty-six interventional pain management centers throughout the United States. To compare patient outcomes following treatment with either mild or ESIs in LSS patients with neurogenic claudication and having verified ligamentum flavum hypertrophy. Study participants include Medicare beneficiaries who meet study inclusion/exclusion criteria. Eligible patients will be randomized in a 1:1 ratio to one of 2 treatment arms, mild (treatment group) or ESI (control group). Each study group will include approximately 150 patients who have experienced neurogenic claudication symptoms for ≥ 3 months duration who have failed to respond to physical therapy, home exercise programs, and oral analgesics. Those randomized to mild are prohibited from receiving lumbar ESIs during the study period, while those randomized to ESI may receive ESIs up to 4 times per year. Patient assessments will occur at baseline, 6 months, and one year. An additional assessment will be conducted for the mild patient group at 2 years. The primary efficacy outcome measure is the proportion of Oswestry Disability Index (ODI) responders from baseline to one year follow-up in the treatment group (mild) versus the control group (ESI). ODI responders are defined as those patients achieving the validated Minimal Important Change (MIC) of ≥ 10 point improvement in ODI from baseline to follow-up as a clinically significant efficacy threshold. Secondary efficacy outcome measures include the proportion of Zurich Claudication Questionnaire (ZCQ) and Numeric Pain Rating Scale (NPRS) responders from baseline to follow-up using validated MIC thresholds. Improvement in ZCQ domains of ≥ 0.5 is considered significant, and a Patient Satisfaction score of at least 2.5 represents a satisfied patient. A reduction of ≥ 2 points in NPRS is considered significant pain relief. The primary safety outcome measure is the incidence of device- and/or procedure-related adverse events. Descriptive summaries will be presented by randomized group for all outcome measures at baseline and follow-up time points. Inferential statistical analysis will be conducted to determine significant differences related to functional improvement, pain relief, and safety outcomes. Primary study results will be presented based on one-year follow-up data, with an interim analysis report when 6-month follow-up data become available. Patients are not blinded due to significant differences in treatment protocols between study groups. Also, since neither study arm is focused on treatment of radicular pain, there may be a higher non-responder rate for both groups versus standard of care due to study restrictions on adjunctive pain therapies. This prospective, multi-center, randomized controlled study will provide Level I evidence of the safety and effectiveness of mild versus ESIs in managing neurogenic claudication symptoms in LSS patients.

MiDAS ENCORE: Randomized Controlled Clinical Trial Report of 6-Month Results.

PubMed

Staats, Peter S; Benyamin, Ramsin M

2016-02-01

Patients suffering from neurogenic claudication due to lumbar spinal stenosis (LSS) often experience moderate to severe pain and significant functional disability. Neurogenic claudication results from progressive degenerative changes in the spine, and most often affects the elderly. Both the MILD® procedure and epidural steroid injections (ESIs) offer interventional pain treatment options for LSS patients experiencing neurogenic claudication refractory to more conservative therapies. MILD provides an alternative to ESIs via minimally invasive lumbar decompression. Prospective, multi-center, randomized controlled clinical trial. Twenty-six US interventional pain management centers. To compare patient outcomes following treatment with either MILD (treatment group) or ESIs (active control group) in LSS patients with neurogenic claudication and verified ligamentum flavum hypertrophy. This prospective, multi-center, randomized controlled clinical trial includes 2 study arms with a 1-to-1 randomization ratio. A total of 302 patients were enrolled, with 149 randomized to MILD and 153 to the active control. Six-month follow-up has been completed and is presented in this report. In addition, one year follow-up will be conducted for patients in both study arms, and supplementary 2 year outcome data will be collected for patients in the MILD group only. Outcomes are assessed using the Oswestry Disability Index (ODI), numeric pain rating scale (NPRS) and Zurich Claudication Questionnaire (ZCQ). Primary efficacy is the proportion of ODI responders, tested for statistical superiority of the MILD group versus the active control group. ODI responders are defined as patients achieving the validated Minimal Important Change (MIC) of =10 point improvement in ODI from baseline to follow-up. Similarly, secondary efficacy includes proportion of NPRS and ZCQ responders using validated MIC thresholds. Primary safety is the incidence of device or procedure-related adverse events in each group. At 6 months, all primary and secondary efficacy results provided statistically significant evidence that MILD is superior to the active control. For primary efficacy, the proportion of ODI responders in the MILD group (62.2%) was statistically significantly higher than for the epidural steroid group (35.7%) (P < 0.001). Further, all secondary efficacy parameters demonstrated statistical superiority of MILD versus the active control. The primary safety endpoint was achieved, demonstrating that there is no difference in safety between MILD and ESIs (P = 1.00). Limitations include lack of patient blinding due to considerable differences in treatment protocols, and a potentially higher non-responder rate for both groups versus standard-of-care due to study restrictions on adjunctive pain therapies. Six month follow-up data from this trial demonstrate that the MILD procedure is statistically superior to epidural steroids, a known active treatment for LSS patients with neurogenic claudication and verified central stenosis due to ligamentum flavum hypertrophy. The results of all primary and secondary efficacy outcome measures achieved statistically superior outcomes in the MILD group versus ESIs. Further, there were no statistically significant differences in the safety profile between study groups. This prospective, multi-center, randomized controlled clinical trial provides strong evidence of the effectiveness of MILD versus epidural steroids in this patient population. NCT02093520.

Pathophysiology, diagnosis and treatment of intermittent claudication in patients with lumbar canal stenosis.

PubMed

Kobayashi, Shigeru

2014-04-18

Spinal nerve roots have a peculiar structure, different from the arrangements in the peripheral nerve. The nerve roots are devoid of lymphatic vessels but are immersed in the cerebrospinal fluid (CSF) within the subarachnoid space. The blood supply of nerve roots depends on the blood flow from both peripheral direction (ascending) and the spinal cord direction (descending). There is no hypovascular region in the nerve root, although there exists a so-called water-shed of the bloodstream in the radicular artery itself. Increased mechanical compression promotes the disturbance of CSF flow, circulatory disturbance starting from the venous congestion and intraradicular edema formation resulting from the breakdown of the blood-nerve barrier. Although this edema may diffuse into CSF when the subarachnoid space is preserved, the endoneurial fluid pressure may increase when the area is closed by increased compression. On the other hand, the nerve root tissue has already degenerated under the compression and the numerous macrophages releasing various chemical mediators, aggravating radicular symptoms that appear in the area of Wallerian degeneration. Prostaglandin E1 (PGE1) is a potent vasodilator as well as an inhibitor of platelet aggregation and has therefore attracted interest as a therapeutic drug for lumbar canal stenosis. However, investigations in the clinical setting have shown that PGE1 is effective in some patients but not in others, although the reason for this is unclear.

Pathophysiology, diagnosis and treatment of intermittent claudication in patients with lumbar canal stenosis

PubMed Central

Kobayashi, Shigeru

2014-01-01

Spinal nerve roots have a peculiar structure, different from the arrangements in the peripheral nerve. The nerve roots are devoid of lymphatic vessels but are immersed in the cerebrospinal fluid (CSF) within the subarachnoid space. The blood supply of nerve roots depends on the blood flow from both peripheral direction (ascending) and the spinal cord direction (descending). There is no hypovascular region in the nerve root, although there exists a so-called water-shed of the bloodstream in the radicular artery itself. Increased mechanical compression promotes the disturbance of CSF flow, circulatory disturbance starting from the venous congestion and intraradicular edema formation resulting from the breakdown of the blood-nerve barrier. Although this edema may diffuse into CSF when the subarachnoid space is preserved, the endoneurial fluid pressure may increase when the area is closed by increased compression. On the other hand, the nerve root tissue has already degenerated under the compression and the numerous macrophages releasing various chemical mediators, aggravating radicular symptoms that appear in the area of Wallerian degeneration. Prostaglandin E1 (PGE1) is a potent vasodilator as well as an inhibitor of platelet aggregation and has therefore attracted interest as a therapeutic drug for lumbar canal stenosis. However, investigations in the clinical setting have shown that PGE1 is effective in some patients but not in others, although the reason for this is unclear. PMID:24829876

Dynamic analysis with a fractional-order chaotic system for estimation of peripheral arterial disease in diabetic foot

NASA Astrophysics Data System (ADS)

Li, Chien-Ming; Du, Yi-Chun; Wu, Jian-Xing; Lin, Chia-Hung; Ho, Yueh-Ren; Chen, Tainsong

2013-08-01

Lower-extremity peripheral arterial disease (PAD) is caused by narrowing or occlusion of vessels in patients like type 2 diabetes mellitus, the elderly and smokers. Patients with PAD are mostly asymptomatic; typical early symptoms of this limb-threatening disorder are intermittent claudication and leg pain, suggesting the necessity for accurate diagnosis by invasive angiography and ankle-brachial pressure index. This index acts as a gold standard reference for PAD diagnosis and categorizes its severity into normal, low-grade and high-grade, with respective cut-off points of ≥0.9, 0.9-0.5 and <0.5. PAD can be assessed using photoplethysmography as a diagnostic screening tool, displaying changes in pulse transit time and shape, and dissimilarities of these changes between lower limbs. The present report proposed photoplethysmogram with fractional-order chaotic system to assess PAD in 14 diabetics and 11 healthy adults, with analysis of dynamic errors based on various butterfly motion patterns, and color relational analysis as classifier for pattern recognition. The results show that the classification of PAD severity among these testees was achieved with high accuracy and efficiency. This noninvasive methodology potentially provides timing and accessible feedback to patients with asymptomatic PAD and their physicians for further invasive diagnosis or strict management of risk factors to intervene in the disease progression.

The risk-benefit profile of commonly used herbal therapies: Ginkgo, St. John's Wort, Ginseng, Echinacea, Saw Palmetto, and Kava.

PubMed

Ernst, Edzard

2002-01-01

Because use of herbal remedies is increasing, a risk-benefit profile of commonly used herbs is needed. This article provides a clinically oriented overview of the efficacy and safety of ginkgo, St. John's wort, ginseng, echinacea, saw palmetto, and kava. Wherever possible, assessments are based on systematic reviews of randomized clinical trials. Encouraging data support the efficacy of some of these popular herbal medicinal products, and the potential for doing good seems greater than that for doing harm. The published evidence suggests that ginkgo is of questionable use for memory loss and tinnitus but has some effect on dementia and intermittent claudication. St. John's wort is efficacious for mild to moderate depression, but serious concerns exist about its interactions with several conventional drugs. Well-conducted clinical trials do not support the efficacy of ginseng to treat any condition. Echinacea may be helpful in the treatment or prevention of upper respiratory tract infections, but trial data are not fully convincing. Saw palmetto has been shown in short-term trials to be efficacious in reducing the symptoms of benign prostatic hyperplasia. Kava is an efficacious short-term treatment for anxiety. None of these herbal medicines is free of adverse effects. Because the evidence is incomplete, risk-benefit assessments are not completely reliable, and much knowledge is still lacking.

Claudication

MedlinePlus

... limbs are damaged, usually as a result of atherosclerosis. Atherosclerosis can develop in any of your arteries, especially those in your heart. When atherosclerosis affects your arms and legs, it's called peripheral ...

Unilateral iliofemoral occlusive disease: long-term results of the semi-closed endarterectomy with the ring-stripper.

PubMed

van den Dungen, J J; Boontje, A H; Kropveld, A

1991-11-01

Nowadays, fewer endarterectomies are performed for treatment of occlusive arterial disease; more often a bypass procedure is done. This study investigates whether the results of the semiclosed endarterectomy for unilateral iliofemoral occlusive disease indeed indicate a wider use of bypass procedures for such short obstructions. Ninety-four patients with an obstructed external iliac and common femoral artery, but with patent ipsilateral common iliac and contralateral iliac arteries, underwent 101 operations. Seven of these patients were operated on at a later stage for occlusive disease on the contralateral side. Ninety-three endarterectomies were performed, and an iliofemoral bypass graft was inserted eight times because an endarterectomy was not feasible. Sixty-two operations were performed for disabling claudication, and 39 operations were performed for limb-threatening ischemia. Eighty-five percent of the patients who underwent an endarterectomy for disabling claudication became asymptomatic. Eighty percent of the patients who underwent an endarterectomy for limb-threatening ischemia became asymptomatic or improved to claudication. After endarterectomy no deaths, false aneurysms, or infections occurred. The patency rates at 1, 5, and 10 years were 94%, 83%, and 65%, respectively. We conclude that the semiclosed endarterectomy with the ringstripper of a unilateral obstruction of one external iliac and common femoral artery can be performed with a low morbidity and without deaths and gives good long-term results.

[Doppler study of gluteal arteries. A useful tool for excluding gluteal arterial pathology snd an important adjunct to lower limb Doppler studies].

PubMed

Bruninx, G; Salame, H; Wery, D; Delcour, C

2002-02-01

1) To determine the negative predictive value (VPN) of duplex scan in patients complaining of buttock or hip pain and thereby to distinguish vascular claudication from other musculoskeletal or neurological diseases. 2) To show its complementarity in doppler investigation of lower limb arteries. Prospective study by duplex scan and arteriography of 60 gluteal arteries in 30 consecutive patients referred to check up for lower limb arteriopathy or sexual impotence. Duplex scan was performed by posterior approach. Correlation between doppler ultrasound and arteriography was studied. The study of normal arteries was possible in all cases and only one normal gluteal artery could not be detected in a diabetic overweight patient. On 60 arteries, sensitivity of duplex was 100 percent, specificity 96 percent and VPN 100 percent. Significant obstructive lesions were always associated with pathological velocimetric waveform or were not detected. Buttock claudication can appear like a typical vascular claudication or mimic neurological or musculoskeletal diseases. It is very useful to rule out a vascular causality responsible for buttock or hip pain by simple, non-invasive and cheap exploration. A normal doppler ultrasound of gluteal arteries can rule out vascular disease responsible for buttock or hip pain thereby avoiding arteriography. The strategy of diagnostic or therapy can be modified by such additional information as shown in two case reports.

Outer synchronization of complex networks with internal delay and coupling delay via aperiodically intermittent pinning control

NASA Astrophysics Data System (ADS)

Zhang, Chuan; Wang, Xingyuan; Wang, Chunpeng; Xia, Zhiqiu

This paper concerns the outer synchronization problem between two complex delayed networks via the method of aperiodically intermittent pinning control. Apart from previous works, internal delay and coupling delay are both involved in this model, and the designed intermittent controllers can be aperiodic. The main work in this paper can be summarized as follows: First, two cases of aperiodically intermittent control with constant gain and adaptive gain are implemented, respectively. The intermittent control and pinning control are combined to reduce consumptions further. Then, based on the Lyapunov stability theory, synchronization protocols are given by strict derivation. Especially, the designed controllers are indeed simple and valid in application of theory to practice. Finally, numerical examples put the proposed control methods to the test.

Pressure Autoregulation Measurement Techniques in Adult Traumatic Brain Injury, Part I: A Scoping Review of Intermittent/Semi-Intermittent Methods.

PubMed

Zeiler, Frederick A; Donnelly, Joseph; Calviello, Leanne; Menon, David K; Smielewski, Peter; Czosnyka, Marek

2017-12-01

The purpose of this study was to perform a systematic, scoping review of commonly described intermittent/semi-intermittent autoregulation measurement techniques in adult traumatic brain injury (TBI). Nine separate systematic reviews were conducted for each intermittent technique: computed tomographic perfusion (CTP)/Xenon-CT (Xe-CT), positron emission tomography (PET), magnetic resonance imaging (MRI), arteriovenous difference in oxygen (AVDO 2 ) technique, thigh cuff deflation technique (TCDT), transient hyperemic response test (THRT), orthostatic hypotension test (OHT), mean flow index (Mx), and transfer function autoregulation index (TF-ARI). MEDLINE ® , BIOSIS, EMBASE, Global Health, Scopus, Cochrane Library (inception to December 2016), and reference lists of relevant articles were searched. A two tier filter of references was conducted. The total number of articles utilizing each of the nine searched techniques for intermittent/semi-intermittent autoregulation techniques in adult TBI were: CTP/Xe-CT (10), PET (6), MRI (0), AVDO 2 (10), ARI-based TCDT (9), THRT (6), OHT (3), Mx (17), and TF-ARI (6). The premise behind all of the intermittent techniques is manipulation of systemic blood pressure/blood volume via either chemical (such as vasopressors) or mechanical (such as thigh cuffs or carotid compression) means. Exceptionally, Mx and TF-ARI are based on spontaneous fluctuations of cerebral perfusion pressure (CPP) or mean arterial pressure (MAP). The method for assessing the cerebral circulation during these manipulations varies, with both imaging-based techniques and TCD utilized. Despite the limited literature for intermittent/semi-intermittent techniques in adult TBI (minus Mx), it is important to acknowledge the availability of such tests. They have provided fundamental insight into human autoregulatory capacity, leading to the development of continuous and more commonly applied techniques in the intensive care unit (ICU). Numerous methods of intermittent/semi-intermittent pressure autoregulation assessment in adult TBI exist, including: CTP/Xe-CT, PET, AVDO 2 technique, TCDT-based ARI, THRT, OHT, Mx, and TF-ARI. MRI-based techniques in adult TBI are yet to be described, with the main focus of MRI techniques on metabolic-based cerebrovascular reactivity (CVR) and not pressure-based autoregulation.

MILD® Is an Effective Treatment for Lumbar Spinal Stenosis with Neurogenic Claudication: MiDAS ENCORE Randomized Controlled Trial.

PubMed

Benyamin, Ramsin M; Staats, Peter S; MiDAS Encore, Investigators

2016-05-01

Lumbar spinal stenosis (LSS) is a common degenerative condition of the spine, which is a major cause of pain and functional disability for the elderly. Neurogenic claudication symptoms are a hallmark of LSS, where patients develop low back or leg pain when walking or standing that is relieved by sitting or lumbar flexion. The treatment of LSS generally begins with conservative management such as physical therapy, home exercise programs, and oral analgesics. Once these therapies fail, patients commonly move forward with interventional pain treatment options such as epidural steroid injections (ESIs) or MILD® as the next step. To assess improvement of function and reduction in pain for Medicare beneficiaries following treatment with MILD (treatment group) in LSS patients with neurogenic claudication and verified ligamentum flavum hypertrophy and to compare to a control group receiving ESIs. Prospective, multi-center, randomized controlled clinical trial. Twenty-six US interventional pain management centers. Patients in this trial were randomized one to one into 2 study arms. A total of 302 patients were enrolled, with 149 randomized to MILD and 153 to the active control. Outcomes are assessed using the Oswestry Disability Index (ODI), Numeric Pain Rating Scale (NPRS) and Zurich Claudication Questionnaire (ZCQ). Primary efficacy is the proportion of ODI responders, tested for statistical superiority of the MILD group versus the ESI group. ODI responders are defined as patients achieving the validated Minimal Important Change (MIC) of = 10 point improvement in ODI from baseline to follow-up. Similarly, secondary efficacy is the proportion of NPRS and ZCQ responders using validated MIC thresholds. Primary safety is the incidence of device- or procedure-related adverse events in each group. This report presents safety and efficacy results at 1-year follow-up. Outcomes at 2 years will be collected and reported for patients in the MILD group only. At 1-year follow-up, ODI, NPRS, and all 3 ZCQ domains (Symptom Severity, Physical Function and Patient Satisfaction) demonstrated statistically significant superiority of MILD versus the active control. For primary efficacy, the 58.0% ODI responder rate in the MILD group was higher than the 27.1% responder rate in the epidural steroid group (P < 0.001). The primary safety endpoint was achieved, demonstrating that there is no difference in safety between MILD and ESIs (P = 1.00). There was a lack of patient blinding due to considerable differences in treatment protocols, and a potentially higher non-responder rate for both groups versus standard-of-care due to adjunctive pain therapy study restrictions. Study enrollment was not limited to patients that had never received ESI therapy. One-year results of this randomized controlled clinical trial demonstrate that MILD is statistically superior to ESIs in the treatment of LSS patients with neurogenic claudication and verified central stenosis due to ligamentum flavum hypertrophy. Primary and secondary efficacy outcome measures achieved statistical superiority in the MILD group compared to the control group. With 95% of patients in this study presenting with 5 or more LSS co-factors, it is important to note that patients with spinal co-morbidities also experienced statistically significant improved function that was durable through 1 year. MILD, minimally invasive lumbar decompression, interlaminar epidural steroid injections, ESI neurogenic claudication, ligamentum flavum, ENCORE, PILD, CED Study, LSS.

Peripheral artery bypass - leg

MedlinePlus

... nih.gov/pubmed/23473760 . Society for Vascular Surgery Lower Extremity Guidelines Writing Group; Conte MS, Pomposelli FB, et ... practice guidelines for atherosclerotic occlusive disease of the ... management of asymptomatic disease and claudication. J Vasc ...

COPART Risk Score, Endothelial Dysfunction, and Arterial Hypertension are Independent Risk Factors for Mortality in Claudicants.

PubMed

Hackl, G; Jud, P; Avian, A; Gary, T; Deutschmann, H; Seinost, G; Brodmann, M; Hafner, F

2016-08-01

The COPART risk score consists of six variables to assess the prognosis of PAOD patients. The flow mediated dilation (FMD) quantifies endothelial function. The aim of this study was to evaluate the mortality prediction of these two variables in a long-term observation of claudicants. 184 consecutive claudicants were included in a prospective observational study over a median observation period of 7.9 (IQR 7.2-8.7) years. The endothelial function was assessed on the day of study inclusion using brachial FMD. Three groups were assigned according to the COPART risk score: low risk (LR), n = 72 (39%); medium risk (MR), n = 59 (32%); and high risk (HR), n = 53 (29%). Overall survival rates differed among COPART risk score groups (p < .001, 5 year survival: LR group 83% [95% CI 74-92%]; MR group 73% [95% CI 62-84%]; HR group 57% [95% CI 43-70%]). Survivors had a significantly better median FMD than non-survivors (4.1% [IQR 1.2-6.4] vs. 1.3% [IQR 0.0-4.2]; p < .001). Also the FMD differed significantly among the three COPART risk groups (LR 4.0% [IQR 1.2-6.3], MR 2.3% [IQR 0.0-6.3], HR 1.7% [IQR 0.0-3.6]; p = .033). Finally, independent predictors for disease specific survival were COPART risk score (p = .033; MR group [HR 1.6], 95% CI 0.7-3.6; HR group [HR 2.7], 95% CI 1.2-5.8), FMD (p = .004; FMD ≤2.5 vs. >2.5, HR 2.6, 95% CI 1.4-4.9), and arterial hypertension (p = .039; HR 3.5, 95% CI 1.1-11.3). COPART risk score, FMD, and arterial hypertension are independent long-term mortality predictors in this group of claudicants. The best mortality assessment is provided by including all three predictors. Copyright © 2016 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

The efficacy of transcutaneous electrical nerve stimulation on the improvement of walking distance in patients with peripheral arterial disease with intermittent claudication: study protocol for a randomised controlled trial: the TENS-PAD study.

PubMed

Besnier, Florent; Sénard, Jean-Michel; Grémeaux, Vincent; Riédel, Mélanie; Garrigues, Damien; Guiraud, Thibaut; Labrunée, Marc

2017-08-10

In patients with peripheral arterial disease (PAD), walking improvements are often limited by early pain onset due to vascular claudication. It would thus appear interesting to develop noninvasive therapeutic strategies, such as transcutaneous electrical nerve stimulation (TENS), to improve the participation of PAD patients in rehabilitation programmes, and thus improve their quality of life. Our team recently tested the efficacy of a single 45-min session of 10-Hz TENS prior to walking. TENS significantly delayed pain onset and increased the pain-free walking distance in patients with class-II PAD. We now seek to assess the efficacy of a chronic intervention that includes the daily use of TENS for 3 weeks (5 days a week) on walking distance in Leriche-Fontaine stage-II PAD patients. This is a prospective, double-blind, multicentre, randomised, placebo-controlled trial. One hundred subjects with unilateral PAD (Leriche-Fontaine stage II) will be randomised into two groups (1:1). For the experimental group (TENS group): the treatment will consist of stimulation of the affected leg (at a biphasic frequency of 10 Hz, with a pulse width of 200 μs, maximal intensity below the motor threshold) for 45 min per day, in the morning before the exercise rehabilitation programme, for 3 weeks, 5 days per week. For the control group (SHAM group): the placebo stimulation will be delivered according to the same modalities as for the TENS group but with a voltage level automatically falling to zero after 10 s of stimulation. First outcome: walking distance without pain. transcutaneous oxygen pressure (TcPO 2 ) measured during a Strandness exercise test, peak oxygen uptake (VO 2 peak), endothelial function (EndoPAT®), Ankle-brachial Pressure Index, Body Mass Index, lipid profile (LDL-C, HDL-C, triglycerides), fasting glycaemia, HbA1c level, and the WELCH questionnaire. TENS-PAD is the first randomised controlled trial that uses transcutaneous electrical therapy as an adjuvant technique to improve vascular function in the treatment of PAD. If the results are confirmed, this technique could be incorporated into the routine care in cardiovascular rehabilitation centers and used in the long term by patients to improve their walking capacity. ClinicalTrials.gov, ID: NCT02678403 . Registered on 9 February 2016. Toulouse University Hospital.

Long-term safety of cilostazol in patients with peripheral artery disease: the CASTLE study (Cilostazol: A Study in Long-term Effects).

PubMed

Hiatt, William R; Money, Samuel R; Brass, Eric P

2008-02-01

Cilostazol, a phosphodiesterase III inhibitor, is indicated to treat the symptoms of intermittent claudication and increase walking distance in patients with peripheral arterial disease (PAD). At the time of approval, the United States Food and Drug Administration required an additional long-term safety study to evaluate the effect cilostazol on mortality. A total of 1899 subjects with a clinical diagnosis of PAD and symptoms of claudication were screened for participation in a randomized, double-blinded, placebo-controlled safety study of cilostazol. The intent-to-treat (ITT) population, which was the primary analysis (n = 1435), was defined as all randomized patients who received at least one dose of study medication and included patients who were followed up >30 days after discontinuation of study drug. A total of 717 patients received cilostazol and 718 received placebo. Cilostazol was administered at a primary dose of 100 mg twice daily. The dose could be reduced to 50 mg twice daily if patients experienced an adverse event that might have been drug related. Long-term adherence to study medication was poor, with >60% of participants discontinuing therapy by 36 months. The mortality analysis therefore focused on deaths during the period on-treatment, defined as the period during which the study drug was taken plus a 30-day follow-up period after dosing. Total patient-years of exposure were 1046 on-treatment for cilostazol and 1090 for placebo. On-treatment, there were 18 deaths on cilostazol and 19 deaths on placebo for a hazard ratio of 0.99 (95% confidence interval [CI], 0.52-1.88). Cardiovascular deaths on-treatment occurred in 14 patients on cilostazol and 14 on placebo. In the full ITT population at 36 months, there were 101 deaths, 49 on cilostazol and 52 on placebo, with hazard ratio of 0.94 (95% CI, 0.64-1.39). Thus, most deaths occurred >30 days after study drug discontinuation. Serious bleeding events affected 18 patients taking cilostazol in the on-treatment population and 22 taking placebo. The rates of bleeding events were similar in patients who used aspirin, aspirin plus clopidogrel, or anticoagulants at anytime during the course of the study This long-term study demonstrated no safety signal for cilostazol on all-cause or cardiovascular mortality. The study, however, was underpowered to detect a small adverse impact of cilostazol on mortality (hazard ratio upper bound of the 95% CI was 1.88 in the on-treatment population). Serious bleeding events appeared not to be increased by cilostazol.

Continuous nasogastric milk feeding versus intermittent bolus milk feeding for premature infants less than 1500 grams.

PubMed

Premji, Shahirose S; Chessell, Lorraine

2011-11-09

Milk feedings can be given via nasogastric tube either intermittently, typically over 10 to 20 minutes every two or three hours, or continuously, using an infusion pump. Although theoretical benefits and risks of each method have been proposed, effects on clinically important outcomes remain uncertain. To examine the evidence regarding the effectiveness of continuous versus intermittent bolus nasogastric milk feeding in premature infants less than 1500 grams. Searches were performed of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2011), MEDLINE, CINAHL and HealthSTAR up to July 2011. Randomised and quasi-randomised clinical trials comparing continuous versus intermittent bolus nasogastric milk feeding in premature infants less than 1500 grams. Two review authors independently assessed all trials for relevance and methodologic quality. The standard methods of the Cochrane Neonatal Review Group were used to extract data. Overall, the seven included trials, involving 511 infants, found no differences in time to achieve full enteral feeds between feeding methods (weighted mean difference (WMD) 2 days; 95% CI -0.3 to 3.9) . In the subgroup analysis of those studies comparing continuous nasogastric versus intermittent bolus nasogastric milk feedings the findings remained unchanged (WMD 2 days, 95% CI -0.4 to 4.1). There was no significant difference in somatic growth and incidence of NEC between feeding methods irrespective of tube placement. One study noted a trend toward more apneas during the study period in infants fed by the continuous tube feeding method compared to those fed by intermittent feedings delivered predominantly by orogastric tube placements [mean difference (MD) 14.0 apneas during study period; 95% CI -0.2 to 28.2]. In subgroup analysis based on weight groups, one study suggested that infants less than 1000 grams and 1000 to 1250 grams birth weight gained weight faster when fed by the continuous nasogastric tube feeding method compared to intermittent nasogastric tube feeding method (MD 2.0 g/day; 95% CI 0.5 to 3.5; MD 2.0 g/day; 95% CI 0.2 to 3.8, respectively). A trend toward earlier discharge for infants less than 1000 grams birth weight fed by the continuous tube feeding method compared to intermittent nasogastric tube feeding method (MD -11 days; 95% CI -21.8 to -0.2). Small sample sizes, methodologic limitations, inconsistencies in controlling variables that may affect outcomes, and conflicting results of the studies to date make it difficult to make universal recommendations regarding the best tube feeding method for premature infants less than 1500 grams. The clinical benefits and risks of continuous versus intermittent nasogastric tube milk feeding cannot be reliably discerned from the limited information available from randomised trials to date.

Peripheral Arterial Disease and Claudication

MedlinePlus

... Mental Health Sex and Birth Control Sex and Sexuality Birth Control Family Health Infants and Toddlers Kids ... Mental Health Sex and Birth Control Sex and Sexuality Birth Control Family Health Infants and Toddlers Kids ...

Synchronization of Hierarchical Time-Varying Neural Networks Based on Asynchronous and Intermittent Sampled-Data Control.

PubMed

Xiong, Wenjun; Patel, Ragini; Cao, Jinde; Zheng, Wei Xing

In this brief, our purpose is to apply asynchronous and intermittent sampled-data control methods to achieve the synchronization of hierarchical time-varying neural networks. The asynchronous and intermittent sampled-data controllers are proposed for two reasons: 1) the controllers may not transmit the control information simultaneously and 2) the controllers cannot always exist at any time . The synchronization is then discussed for a kind of hierarchical time-varying neural networks based on the asynchronous and intermittent sampled-data controllers. Finally, the simulation results are given to illustrate the usefulness of the developed criteria.In this brief, our purpose is to apply asynchronous and intermittent sampled-data control methods to achieve the synchronization of hierarchical time-varying neural networks. The asynchronous and intermittent sampled-data controllers are proposed for two reasons: 1) the controllers may not transmit the control information simultaneously and 2) the controllers cannot always exist at any time . The synchronization is then discussed for a kind of hierarchical time-varying neural networks based on the asynchronous and intermittent sampled-data controllers. Finally, the simulation results are given to illustrate the usefulness of the developed criteria.

Patient and Provider Assessment of Lipid Management Registry

ClinicalTrials.gov

2016-02-15

Hyperlipidemia; Hypercholesterolemia; Cardiovascular Disease; Diabetes; Chronic Kidney Disease (CKD); Hypertension; Smoking; Myocardial Infarction (MI); Unstable Angina; Angina; Coronary Artery Disease (CAD); Stroke; Transient Ischemic Attack (TIA); Carotid Stenosis; Peripheral Arterial Disease; Atherosclerosis; Claudication

Diurnal characteristics of turbulent intermittency in the Taklimakan Desert

NASA Astrophysics Data System (ADS)

Wei, Wei; Wang, Minzhong; Zhang, Hongsheng; He, Qing; Ali, Mamtimin; Wang, Yinjun

2017-12-01

A case study is performed to investigate the behavior of turbulent intermittency in the Taklimakan Desert using an intuitive, direct, and adaptive method, the arbitrary-order Hilbert spectral analysis (arbitrary-order HSA). Decomposed modes from the vertical wind speed series confirm the dyadic filter-bank essence of the empirical mode decomposition processes. Due to the larger eddies in the CBL, higher energy modes occur during the day. The second-order Hilbert spectra L2 (ω ) delineate the spectral gap separating fine-scale turbulence from large-scale motions. Both the values of kurtosis and the Hilbert-based scaling exponent ξ ( q ) reveal that the turbulence intermittency at night is much stronger than that during the day, and the stronger intermittency is associated with more stable stratification under clear-sky conditions. This study fills the gap in the characteristics of turbulence intermittency in the Taklimakan Desert area using a relatively new method.

Stability analysis of piecewise non-linear systems and its application to chaotic synchronisation with intermittent control

NASA Astrophysics Data System (ADS)

Wang, Qingzhi; Tan, Guanzheng; He, Yong; Wu, Min

2017-10-01

This paper considers a stability analysis issue of piecewise non-linear systems and applies it to intermittent synchronisation of chaotic systems. First, based on piecewise Lyapunov function methods, more general and less conservative stability criteria of piecewise non-linear systems in periodic and aperiodic cases are presented, respectively. Next, intermittent synchronisation conditions of chaotic systems are derived which extend existing results. Finally, Chua's circuit is taken as an example to verify the validity of our methods.

Assessing criticality in seismicity by entropy

NASA Astrophysics Data System (ADS)

Goltz, C.

2003-04-01

There is an ongoing discussion whether the Earth's crust is in a critical state and whether this state is permanent or intermittent. Intermittent criticality would allow specification of time-dependent hazard in principle. Analysis of a spatio-temporally evolving synthetic critical point phenomenon and of real seismicity using configurational entropy shows that the method is a suitable approach for the characterisation of critical point dynamics. Results obtained rather support the notion of intermittent criticality in earthquakes. Statistical significance of the findings is assessed by the method of surrogate data.

External intermittency prediction using AMR solutions of RANS turbulence and transported PDF models

NASA Astrophysics Data System (ADS)

Olivieri, D. A.; Fairweather, M.; Falle, S. A. E. G.

2011-12-01

External intermittency in turbulent round jets is predicted using a Reynolds-averaged Navier-Stokes modelling approach coupled to solutions of the transported probability density function (pdf) equation for scalar variables. Solutions to the descriptive equations are obtained using a finite-volume method, combined with an adaptive mesh refinement algorithm, applied in both physical and compositional space. This method contrasts with conventional approaches to solving the transported pdf equation which generally employ Monte Carlo techniques. Intermittency-modified eddy viscosity and second-moment turbulence closures are used to accommodate the effects of intermittency on the flow field, with the influence of intermittency also included, through modifications to the mixing model, in the transported pdf equation. Predictions of the overall model are compared with experimental data on the velocity and scalar fields in a round jet, as well as against measurements of intermittency profiles and scalar pdfs in a number of flows, with good agreement obtained. For the cases considered, predictions based on the second-moment turbulence closure are clearly superior, although both turbulence models give realistic predictions of the bimodal scalar pdfs observed experimentally.

Mid-term Results of Endovascular Treatment for Infrarenal Aortic Stenosis and Occlusion.

PubMed

Sohgawa, Etsuji; Sakai, Yukimasa; Nango, Mineyoshi; Cho, Hisayuki; Jogo, Atsushi; Hamamoto, Shinichi; Yamamoto, Akira; Miki, Yukio

2015-06-01

Focal stenosis or occlusion of the infrarenal aorta is rare, and treatment is usually conventional bypass or endarterectomy. However, endovascular treatment has advanced in recent years. The purpose of this retrospective study is to report the results of primary stenting for focal infrarenal aortic occlusive disease and clarify the usefulness of endovascular treatment. This study includes 6 consecutive patients (3 men, 3 women; mean age, 59.3 years) with infrarenal aortic stenosis or occlusion who underwent endovascular intervention at our hospital between April 2009 and February 2014. All patients had bilateral intermittent claudication. The mean preoperative ankle-brachial index (ABI) showed a slight to moderate decrease: right 0.668 and left 0.636. The mean lesion site length was 12.5 mm, the percent stenosis was 90.7%, and calcification was present in 3 patients. Primary stenting was performed in all patients. The stent selected was generally a self-expanding stent (SES). For patients with severe calcification, the stent selected was a balloon-expandable stent (BES). Four patients received an SES and two patients received a BES. The technical success rate was 100%, no complications occurred, and the mean pressure gradient disappeared or decreased. Symptoms resolved in all patients and the postoperative ABI improved: right 0.923 and left 0.968. During a mean follow-up period of 27 months, there were no recurrent symptoms and no restenosis on CT angiography. Endovascular treatment should be considered as a first line treatment for focal infrarenal aortic stenosis and occlusion.

Paclitaxel-Coated Balloons: Review of a Promising Interventional Approach to Preventing Restenosis in Femoropopliteal Arteries

PubMed Central

Teleb, Mohamed; Wardi, Miraie; Gosavi, Sucheta; Said, Sarmad; Mukherjee, Debabrata

2015-01-01

Peripheral arterial disease (PAD), a major cause of morbidity and mortality worldwide, is characterized by intermittent claudication and is associated with chronic diseases such as diabetes and hypertension. The goal of treatment is to address the underlying cause and to modify risk factors. Although medical management is the first-line treatment of PAD, some individuals may have severe symptoms and require revascularization with percutaneous transluminal angioplasty with or without stent placement or surgery. Interventional approaches may, however, be associated with high prevalence of restenosis and subsequent complications such as critical limb ischemia and amputation. Drug-eluting balloons (DEBs) are a new interventional technology with the primary goal of preventing restenosis. We review the clinical trials and studies that assessed the efficacy and safety profile of DEB and will focus on the restenosis rate in femoropopliteal arteries including target lesion revascularization (TLR) and late lumen lesion (LLL) using different modalities of intervention such as stents and DEB. Average data collected from the trials reported included restenosis rate of 25%, 0.3 mm LLL, and 14% reduction in TLR with DEB versus uncoated balloons. Below the knee (BTK) only intervention studies were excluded from this review as endovascular approach is usually reserved for critical limb ischemia for BTK disease. Interventional approach to treat PAD with DEB appears to be a promising technology. Additional larger studies are needed to further define safety, efficacy, and longer term outcome with this novel technology. PMID:27231422

Effects of orally administered OP-1206 alpha-CD with loxoprofen-Na on walking dysfunction in the rat neuropathic intermittent claudication model.

PubMed

Nakai, Katsuhiko; Takenobu, Yoshifumi; Takimizu, Hideyuki; Akimaru, Shinji; Ito, Hidenori; Maegawa, Hitoshi; Marsala, Martin; Katsube, Nobuo

2003-10-01

An orally active prostaglandin E1 analogue, OP-1206 alpha-CD improves walking dysfunction in the rat spinal stenosis model. Loxoprofen-Na, a non-steroidal anti-inflammatory drug, is used to relieve chronic pain in patients with lumbar spinal canal stenosis. To determine whether the OP-1206 alpha-CD in combination with loxoprofen-Na could induce a greater therapeutical effect on walking dysfunction and spinal cord blood flow (SCBF) than OP-1206 alpha-CD treatment alone after chronic spinal stenosis in the rat. Spinal stenosis was induced by placing two pieces of silicon rubber strips in the lumbar (L4 and L6) epidural space of rats. After surgery, walking function was measured using a treadmill apparatus and SCBF was measured using a laser-Doppler flow meter. Drugs were administered orally twice a day for 11 days from the day 3 post-surgery. OP-1206 alpha-CD elicited a significant improvement of walking dysfunction on days 7 and 14 post-surgery and significantly increased spinal cord blood flow on day 15, whereas walking dysfunction and SCBF of rats treated with loxoprofen-Na alone remained unchanged. Combined treatment of OP-1206 alpha-CD with loxoprofen-Na did not provide additive therapeutical effect. These results suggest that a significant improvement seen after OP-1206 alpha-CD treatment is primarily mediated by improvement of the local spinal cord blood flow. This effect is not ameliorated or potentiated by a combined treatment with loxoprofen-Na.

Pharmacological profile of sulodexide.

PubMed

Hoppensteadt, D A; Fareed, J

2014-06-01

Since its introduction, sulodexide has been used on and off for several indications. More recently this agent has become revitalized and tested in newer indications. Sulodexide is composed of glycosaminoglycan that includes a mixture of fast-moving heparin and dermatan sulfate. It exerts its anticoagulant and antithrombotic action through interactions with both AT and HCII. Sulodexide has been proven to have effects on the fibrinolytic system, platelets, endothelial cells, inflammation and more recently metalloproteases. The administration of sulodexide results in the release of lipoprotein lipase and has been shown to reduce the circulating level of lipids. It has also shown to decrease the viscosity of both whole blood and plasma. Sulodexide differs from heparin in its oral bioavailability and longer half-life. There is also less bleeding associated with sulodexide. In addition, oral administration of sulodexide does not interfere with the pharmacologic actions of commonly used agents. Similar to heparin, sulodexide releases TFPI which contributes to its antithrombotic effect and anti-inflammatory properties. Sulodexide has been proven to be effective in peripheral arterial thrombosis and venous thrombosis. It is also clinically active in the treatment of venous leg ulcers and intermittent claudication. More recent data suggest that sulodexide can be used in tinnitus and in vascular vertigo. Additional studies in these indications are required. Sulodexide was generally safe and well tolerated in the clinical trials, without any severe bleeding complications. Therefore sulodexide appears to be a good treatment for all arterial and venous diseases and for the prevention of progression of disease.

Imaging of cauda equina edema in lumbar canal stenosis by using gadolinium-enhanced MR imaging: experimental constriction injury.

PubMed

Kobayashi, S; Uchida, K; Takeno, K; Baba, H; Suzuki, Y; Hayakawa, K; Yoshizawa, H

2006-02-01

It has been reported that disturbance of blood flow arising from circumferential compression of the cauda equina by surrounding tissue plays a major role in the appearance of neurogenic intermittent claudication (NIC) associated with lumbar spinal canal stenosis (LSCS). We created a model of LSCS to clarify the mechanism of enhancement within the cauda equina on gadolinium-enhanced MR images from patients with LSCS. In 20 dogs, a lumbar laminectomy was performed by applying circumferential constriction to the cauda equina by using a silicon tube, to produce 30% stenosis of the circumferential diameter of the dural tube. After 1 and 3 weeks, gadolinium and Evans blue albumin were injected intravenously at the same time. The sections were used to investigate the status of the blood-nerve barrier function under a fluorescence microscope and we compared gadolinium-enhanced MR images with Evans blue albumin distribution in the nerve. The other sections were used for light and transmission electron microscopic study. In this model, histologic examination showed congestion and dilation in many of the intraradicular veins, as well as inflammatory cell infiltration. The intraradicular edema caused by venous congestion and Wallerian degeneration can also occur at sites that are not subject to mechanical compression. Enhanced MR imaging showed enhancement of the cauda equina at the stenosed region, demonstrating the presence of edema. Gadolinium-enhanced MR imaging may be a useful tool for the diagnosis of microcirculatory disorders of the cauda equina associated with LSCS.

Peripheral artery questionnaire improves ankle brachial index screening in symptomatic patients with peripheral artery disease.

PubMed

Kim, B-H; Cho, K-I; Spertus, J; Park, Y-H; Je, H-G; Shin, M-S; Lee, J-H; Jang, J-S

2014-12-01

The peripheral artery questionnaire (PAQ) is a disease-specific health status measure of patients with peripheral artery disease (PAD). Whether the PAQ scores are associated with a PAD diagnosis among patients with symptoms suspicious for PAD is unknown and could help increase the pretest probability of ankle brachial index (ABI) screening among patients with suspicious symptoms. The PAQ was completed by 567 patients evaluated for potential intermittent claudication at six tertiary centres. Demographics, medical history, physical examination findings and the PAQ domain scores were compared with ABI. A diagnostic threshold < 0.90 for a PAD diagnosis was assessed with a ROC of PAQ scores. The correlation between the PAQ Summary Score and ABI was also calculated. The PAQ Summary Score was significantly lower in patients with low ABI as compared with those having a normal ABI (37.6 ± 19.0 vs. 70.1 ± 22.7, p < 0.001). The PAQ Summary Score and ABI were highly correlated (r = 0.56, p < 0.001) and the optimal PAQ Summary Score for predicting low ABI was 50.3 (AUC = 0.86, sensitivity 80.3%, specificity 78.3%). The PAQ Summary Score was associated with an increased likelihood of PAD in patients with suspected PAD symptoms, and a low summary score (≤ 50.3) was an optimal threshold for predicting PAD among patients referred for ABI. © 2014 John Wiley & Sons Ltd.

UKPDS 59: hyperglycemia and other potentially modifiable risk factors for peripheral vascular disease in type 2 diabetes.

PubMed

Adler, Amanda I; Stevens, Richard J; Neil, Andrew; Stratton, Irene M; Boulton, Andrew J M; Holman, Rury R

2002-05-01

To determine the role of hyperglycemia in prospective analyses of peripheral vascular disease (PVD) in type 2 diabetes, taking into account other potential risk factors. Potential risk factors for the development of PVD were examined in 3,834 of 5,102 individuals enrolled in the U.K. Prospective Diabetes Study (UKPDS) without PVD at diagnosis of diabetes, followed for 6 years, and for whom relevant data were available. PVD was defined as two of the following: ankle-arm blood pressure index < 0.8, absence of both dorsalis pedis and posterior tibial pulses to palpation in one or both legs, and intermittent claudication. Logistic regression was used to estimate the association between potential risk factors measured 3-4 months after diagnosis of diabetes and incident PVD. The prevalence of PVD at 3-year intervals to 18 years was determined. Hyperglycemia, assessed as HbA(1c), was associated with an increased risk for incident PVD, independent of other risk factors including age, increased systolic blood pressure, reduced HDL cholesterol, smoking, prior cardiovascular disease, peripheral sensory neuropathy, and retinopathy. Each 1% increase in HbA(1c) was associated with a 28% increased risk of PVD (95% CI 12-46), and each 10-mmHg increase in systolic blood pressure with a 25% increase in risk (95% CI 10-43). Hyperglycemia, as well as smoking, dyslipidemia, and blood pressure are potentially modifiable risk factors for the development of PVD.

A Structured Review of Antithrombotic Therapy in Peripheral Artery Disease With a Focus on Revascularization: A TASC (InterSociety Consensus for the Management of Peripheral Artery Disease) Initiative.

PubMed

Hess, Connie N; Norgren, Lars; Ansel, Gary M; Capell, Warren H; Fletcher, John P; Fowkes, F Gerry R; Gottsäter, Anders; Hitos, Kerry; Jaff, Michael R; Nordanstig, Joakim; Hiatt, William R

2017-06-20

Peripheral artery disease affects >200 million people worldwide and is associated with significant limb and cardiovascular morbidity and mortality. Limb revascularization is recommended to improve function and quality of life for symptomatic patients with peripheral artery disease with intermittent claudication who have not responded to medical treatment. For patients with critical limb ischemia, the goals of revascularization are to relieve pain, help wound healing, and prevent limb loss. The baseline risk of cardiovascular and limb-related events demonstrated among patients with stable peripheral artery disease is elevated after revascularization and related to atherothrombosis and restenosis. Both of these processes involve platelet activation and the coagulation cascade, forming the basis for the use of antiplatelet and anticoagulant therapies to optimize procedural success and reduce postprocedural cardiovascular risk. Unfortunately, few high-quality, randomized data to support use of these therapies after peripheral artery disease revascularization exist, and much of the rationale for the use of antiplatelet agents after endovascular peripheral revascularization is extrapolated from percutaneous coronary intervention literature. Consequently, guideline recommendations for antithrombotic therapy after lower limb revascularization are inconsistent and not always evidence-based. In this context, the purpose of this structured review is to assess the available randomized data for antithrombotic therapy after peripheral arterial revascularization, with a focus on clinical trial design issues that may affect interpretation of study results, and highlight areas that require further investigation. © 2017 American Heart Association, Inc.

Improving interMediAte Risk management. MARK study

PubMed Central

2011-01-01

Background Cardiovascular risk functions fail to identify more than 50% of patients who develop cardiovascular disease. This is especially evident in the intermediate-risk patients in which clinical management becomes difficult. Our purpose is to analyze if ankle-brachial index (ABI), measures of arterial stiffness, postprandial glucose, glycosylated hemoglobin, self-measured blood pressure and presence of comorbidity are independently associated to incidence of vascular events and whether they can improve the predictive capacity of current risk equations in the intermediate-risk population. Methods/Design This project involves 3 groups belonging to REDIAPP (RETICS RD06/0018) from 3 Spanish regions. We will recruit a multicenter cohort of 2688 patients at intermediate risk (coronary risk between 5 and 15% or vascular death risk between 3-5% over 10 years) and no history of atherosclerotic disease, selected at random. We will record socio-demographic data, information on diet, physical activity, comorbidity and intermittent claudication. We will measure ABI, pulse wave velocity and cardio ankle vascular index at rest and after a light intensity exercise. Blood pressure and anthropometric data will be also recorded. We will also quantify lipids, glucose and glycosylated hemoglobin in a fasting blood sample and postprandial capillary glucose. Eighteen months after the recruitment, patients will be followed up to determine the incidence of vascular events (later follow-ups are planned at 5 and 10 years). We will analyze whether the new proposed risk factors contribute to improve the risk functions based on classic risk factors. Discussion Primary prevention of cardiovascular diseases is a priority in public health policy of developed and developing countries. The fundamental strategy consists in identifying people in a high risk situation in which preventive measures are effective and efficient. Improvement of these predictions in our country will have an immediate, clinical and welfare impact and a short term public health effect. Trial Registration Clinical Trials.gov Identifier: NCT01428934 PMID:21992621

[Cost and cost-effectiveness in the treatment of peripheral arterial occlusion disease - what is proven?].

PubMed

Torsello, G; Bisdas, T; Debus, S; Grundmann, R T

2015-02-01

This overview comments on the health-care relevance of peripheral arterial occlusive disease (PAOD) in patients with intermittent claudication (IC) and critical limb ischaemia (CLI). We evaluated different treatment modalities in terms of cost-effectiveness. For the literature review, the Medline database (PubMed) was searched under the key words "critical limb ischemia AND cost", "critical limb ischemia AND economy", "peripheral arterial disease AND cost", "peripheral arterial disease AND economy". In the years 2005 to 2009, the hospitalisations of patients with PAOD rose disproportionately in Germany by 20 %, to 483,961 hospital admissions. By comparison, hospital admissions altogether increased by only 8 %. The average in-patient costs were estimated to be approximately € 5000 per PAOD-patient - a rather conservative estimate. For the patient with IC the economic data position is clear, supervised exercise training is by far the most cost-effective treatment option, followed by percutaneous transluminal angioplasty (PTA) and finally the peripheral bypass. In accordance with the guidelines of the UK, the latter is therefore indicated only if PTA fails or is technically not possible. In patients with CLI, the situation is not obvious. Indeed, a short-term economic advantage can be calculated for the PTA, the long-term comparison of both methods, however, is impossible due to insufficient data. In addition, the risk factors for the patient have to be included in the calculation. This was indeed demonstrated in the short-term, but could not be analysed in the long-term follow-up. The issue of greater cost-effectiveness of open or endovascular treatment in patients with CLI is uncertain, the studies and patient populations are too heterogeneous. Further studies are urgently needed to structure the sequence of the various treatment options in guidelines and clinical pathways. Georg Thieme Verlag KG Stuttgart · New York.

Day-Case Treatment of Peripheral Arterial Disease: Results from a Multi-Center European Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spiliopoulos, Stavros, E-mail: stavspiliop@med.uoa.gr, E-mail: stavspiliop@upatras.gr; Karnabatidis, Dimitrios, E-mail: karnaby@med.upatras.gr; Katsanos, Konstantinos, E-mail: katsanos@med.upatras.gr

PurposeThe purpose of the study was to investigate safety and feasibility of day-case endovascular procedures for the management of peripheral arterial disease.Materials and MethodsThis was a multi-center, retrospective study including all patients treated over a 30-month period with endovascular angioplasty or stenting for intermittent claudication (IC) or critical limb ischemia (CLI) on a day-case basis, in Interventional Radiology (IR) departments of three European tertiary hospitals. Exclusion criteria were not related to the type of lesion and included unavailability of an adult able to take care of patient overnight; high bleeding risk and ASA score ≥4. Primary efficacy outcome was themore » rate of procedures performed on an outpatient basis requiring no further hospitalization and primary safety outcome was freedom from 30-day major complications’ rate.ResultsThe study included 652 patients (male 75 %; mean age 68 ± 10 years; range: 27–93), 24.6 % treated for CLI. In 53.3 % of the cases a 6Fr sheath was used. Technical success was 97.1 %. Haemostasis was obtained by manual compression in 52.4 % of the accesses. The primary efficacy outcome occurred in 95.4 % (622/652 patients) and primary safety outcome in 98.6 % (643/652 patients). Major complications included five (0.7 %) retroperitoneal hematomas requiring transfusion; one (0.1 %) common femoral artery pseudoaneurysm successfully treated with US-guided thrombin injection, two cases of intra-procedural distal embolization treated with catheter-directed local thrombolysis and one on-table cardiac arrest necessitating >24 h recovery. No major complication was noted after same-day discharge.ConclusionsDay-case endovascular procedures for the treatment of IC or CLI can be safely and efficiently performed in experienced IR departments of large tertiary hospitals.« less

Practice-based evidence: profiling the safety of cilostazol by text-mining of clinical notes.

PubMed

Leeper, Nicholas J; Bauer-Mehren, Anna; Iyer, Srinivasan V; Lependu, Paea; Olson, Cliff; Shah, Nigam H

2013-01-01

Peripheral arterial disease (PAD) is a growing problem with few available therapies. Cilostazol is the only FDA-approved medication with a class I indication for intermittent claudication, but carries a black box warning due to concerns for increased cardiovascular mortality. To assess the validity of this black box warning, we employed a novel text-analytics pipeline to quantify the adverse events associated with Cilostazol use in a clinical setting, including patients with congestive heart failure (CHF). We analyzed the electronic medical records of 1.8 million subjects from the Stanford clinical data warehouse spanning 18 years using a novel text-mining/statistical analytics pipeline. We identified 232 PAD patients taking Cilostazol and created a control group of 1,160 PAD patients not taking this drug using 1:5 propensity-score matching. Over a mean follow up of 4.2 years, we observed no association between Cilostazol use and any major adverse cardiovascular event including stroke (OR = 1.13, CI [0.82, 1.55]), myocardial infarction (OR = 1.00, CI [0.71, 1.39]), or death (OR = 0.86, CI [0.63, 1.18]). Cilostazol was not associated with an increase in any arrhythmic complication. We also identified a subset of CHF patients who were prescribed Cilostazol despite its black box warning, and found that it did not increase mortality in this high-risk group of patients. This proof of principle study shows the potential of text-analytics to mine clinical data warehouses to uncover 'natural experiments' such as the use of Cilostazol in CHF patients. We envision this method will have broad applications for examining difficult to test clinical hypotheses and to aid in post-marketing drug safety surveillance. Moreover, our observations argue for a prospective study to examine the validity of a drug safety warning that may be unnecessarily limiting the use of an efficacious therapy.

Systematic review of genuine versus spurious side-effects of beta-blockers in heart failure using placebo control: Recommendations for patient information☆☆☆

PubMed Central

Barron, Anthony J.; Zaman, Nabeela; Cole, Graham D.; Wensel, Roland; Okonko, Darlington O.; Francis, Darrel P.

2013-01-01

Background Patients trying life-preserving agents such as beta-blockers may be discouraged by listings of harmful effects provided in good faith by doctors, drug information sheets, and media. We systematically review the world experience of side-effect information in blinded, placebo-controlled beta-blockade in heart failure. We present information for a physician advising a patient experiencing an unwanted symptom and suspecting the drug. Methods We searched Medline for double-blinded randomized trials of beta-blocker versus placebo in heart failure reporting side-effects. We calculated, per 100 patients reporting the symptom on beta-blockade, how many would have experienced it on placebo: the “proportion of symptoms non-pharmacological”. Results 28 of the 33 classically-described side-effects are not significantly more common on beta-blockers than placebo. Of the 100 patients developing dizziness on beta-blockers, 81 (95% CI 73–89) would have developed it on placebo. For diarrhoea this proportion is 82/100 (70–95), and hyperglycaemia 83/100 (68–98). For only two side-effects is this under half (i.e. predominantly due to beta-blocker): bradycardia (33/100, CI 21–44) and intermittent claudication (41/100, 2–81). At least 6 so-called side-effects are less common on beta-blocker than placebo, including depression (reduced by 35%, p < 0.01) and insomnia (by 27%, p = 0.01). Conclusions Clinicians might reconsider whether it is scientifically and ethically correct to warn a patient that a drug might cause them a certain side-effect, when randomized controlled trials show no significant increase, or indeed a significant reduction. A better informed consultation could, in patients taking beta-blockers, alleviate suffering. In patients who might otherwise not take the drug, it might prevent deaths. PMID:23796325

Study of pentoxifylline effects on motility and viability of spermatozoa from infertile asthenozoospermic males.

PubMed

Ghasemzadeh, Aliye; Karkon-Shayan, Farid; Yousefzadeh, Solmaz; Naghavi-Behzad, Mohammad; Hamdi, Kobra

2016-01-01

The quality of semen is one of the major parameters in male infertility. Pentoxifylline, a methylxanthine derivative, is an agent primarily used in the treatment of intermittent claudication and other vascular disorders. Studies have shown that pentoxifylline enhances the quality and quantity of sperms. In this study, we have investigated the in vitro effects of pentoxifylline on viability and motility of spermatozoa in samples of infertile oligoasthenozoospermic males. In this observer-blinded clinical trial, semen samples of 25 infertile oligoasthenozoospermic males were collected in Alzahra Educational Medical Center of Tabriz University of Medical Sciences from August 2010 to August 2012. After the isolation of spermatozoa by the swim-up method, they were randomized into four groups in ISM1 environment: The controls treated normally: Group 1 treated by pentoxifylline at a dose of 50 μg/ml, Group 2 treated by pentoxifylline at a dose of 100 μg/ml, and Group 3 treated by pentoxifylline at a dose of 200 μg/ml. Sperm viability and motility were compared among the groups on 45 min, 24 h, 36 h, and 48 h intervals. Mean percentages of live sperms were 98.40%, 51.40%, 20.60%, and 6.00% in control group and 98.40%, 69.20%, 38.60%, and 14.60% in Group 3 on the mentioned intervals, respectively. This mean percentage decrease of live sperms was significantly lower in Group 3 comparing with that of other groups ( P = 0.01). Mean percentages of motile sperms were 54%, 8.40%, 2.80%, and 0% in control group; and 54%, 16%, 4.80%, and 1.40% in Group 3 on the mentioned intervals, respectively. There was not a significant difference between the four groups in this regard ( P = 0.19). Pentoxifylline can enhance the viability of sperm of infertile oligoasthenozoospermic males with no significant effect on its motility.

Cutting-Balloon Angioplasty Versus Balloon Angioplasty as Treatment for Short Atherosclerotic Lesions in the Superficial Femoral Artery: Randomized Controlled Trial

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poncyljusz, Wojciech, E-mail: wponcyl@poczta.onet.pl; Falkowski, Aleksander, E-mail: bakhis@hot.pl; Safranow, Krzysztof, E-mail: chrissaf@mp.pl

2013-12-15

Purpose: To evaluate the treatments of a short-segment atherosclerotic stenosis in the superficial femoral arteries with the cutting balloon angioplasty (CBA) versus conventional balloon angioplasty [percutaneous transluminal angioplasty (PTA)] in a randomized controlled trial. Material and Methods: The study group comprised 60 patients (33 men, 27 women; average age 64 years) with a short ({<=}5 cm) focal SFA de novo atherosclerotic stenosis associated with a history of intermittent claudication or rest pain. The primary end point of this study was the rate of binary restenosis in the treated segment 12 months after the intervention. All patients were evenly randomized tomore » either the PTA or CBA treatment arms. Follow-up angiograms and ankle-brachial index (ABI) measurements were performed after 12 months. The evaluation of the restenosis rates and factors influencing its occurrence were calculated by logistic regression analysis. Results: In the intention-to-treat analysis, restenosis rates after 2-month follow-up were 9 of 30 (30 %) in the PTA group and 4 of 30 (13 %) in the CBA group (p = 0.117). In the actual treatment analysis, after exclusion of patients who required nitinol stent placement for a suboptimal result after angioplasty alone (5 patients in the PTA group and none in the CBA group), restenosis rates were 9 of 25 (36 %) and 4 of 30 (13 %), respectively (p = 0.049). In the intention-to-treat analysis there were also significant differences in ABI values between the PTA and CBA groups at 0.77 {+-} 0.11 versus 0.82 {+-} 0.12, respectively (p = 0.039), at 12 months. Conclusion: Based on the presented results of the trial, CBA seems to be a safer and more effective than PTA for treatment of short atherosclerotic lesions in the superior femoral artery.« less

Assessment of Minimum Important Difference and Substantial Clinical Benefit with the Vascular Quality of Life Questionnaire-6 when Evaluating Revascularisation Procedures in Peripheral Arterial Disease.

PubMed

Nordanstig, J; Pettersson, M; Morgan, M; Falkenberg, M; Kumlien, C

2017-09-01

Patient reported outcomes are increasingly used to assess outcomes after peripheral arterial disease (PAD) interventions. VascuQoL-6 (VQ-6) is a PAD specific health-related quality of life (HRQoL) instrument for routine clinical practice and clinical research. This study assessed the minimum important difference for the VQ-6 and determined thresholds for the minimum important difference and substantial clinical benefit following PAD revascularisation. This was a population-based observational cohort study. VQ-6 data from the Swedvasc Registry (January 2014 to September 2016) was analysed for revascularised PAD patients. The minimum important difference was determined using a combination of a distribution based and an anchor-based method, while receiver operating characteristic curve analysis (ROC) was used to determine optimal thresholds for a substantial clinical benefit following revascularisation. A total of 3194 revascularised PAD patients with complete VQ-6 baseline recordings (intermittent claudication (IC) n = 1622 and critical limb ischaemia (CLI) n = 1572) were studied, of which 2996 had complete VQ-6 recordings 30 days and 1092 a year after the vascular intervention. The minimum important difference 1 year after revascularisation for IC patients ranged from 1.7 to 2.2 scale steps, depending on the method of analysis. Among CLI patients, the minimum important difference after 1 year was 1.9 scale steps. ROC analyses demonstrated that the VQ-6 discriminative properties for a substantial clinical benefit was excellent for IC patients (area under curve (AUC) 0.87, sensitivity 0.81, specificity 0.76) and acceptable in CLI (AUC 0.736, sensitivity 0.63, specificity 0.72). An optimal VQ-6 threshold for a substantial clinical benefit was determined at 3.5 scale steps among IC patients and 4.5 in CLI patients. The suggested thresholds for minimum important difference and substantial clinical benefit could be used when evaluating VQ-6 outcomes following different interventions in PAD and in the design of clinical trials. Copyright © 2017 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Persistent escalation of alcohol drinking in C57BL/6J mice with intermittent access to 20% ethanol

PubMed Central

Hwa, Lara S.; Chu, Adam; Levinson, Sally A.; Kayyali, Tala M.; DeBold, Joseph F.; Miczek, Klaus A.

2011-01-01

Background Intermittent access to drugs of abuse, as opposed to continuous access, is hypothesized to induce a kindling-type transition from moderate to escalated use, leading to dependence. Intermittent 24-hour cycles of ethanol access and deprivation can generate high levels of voluntary ethanol drinking in rats. Methods The current study uses C57BL/6J mice (B6) in an intermittent access to 20% ethanol protocol to escalate ethanol drinking levels. Adult male and female B6 mice were given intermittent access to 20% ethanol on alternating days of the week with water available ad libitum. Ethanol consumption during the initial 2 hours of access was compared to a short term, limited access “binge” drinking procedure, similar to drinking-in-the-dark (DID). B6 mice were also assessed for ethanol dependence with handling-induced convulsion (HIC), a reliable measure of withdrawal severity. Results After 3 weeks, male mice given intermittent access to ethanol achieved high stable levels of ethanol drinking in excess of 20 g/kg/24h, reaching above 100 mg/dl BEC, and showed a significantly higher ethanol preference than mice given continuous access to ethanol. Also, mice given intermittent access drank about twice as much as DID mice in the initial 2-hour access period. B6 mice that underwent the intermittent access protocol for longer periods of time displayed more severe signs of alcohol withdrawal. Additionally, female B6 mice were given intermittent access to ethanol and drank significantly more than males (ca. 30 g/kg/24h). Discussion The intermittent access method in B6 mice is advantageous because it induces escalated, voluntary, and preferential per os ethanol intake, behavior that may mimic a cardinal feature of human alcohol dependence, though the exact nature and site of ethanol acting in the brain and blood as a result of intermittent access has yet to be determined. PMID:21631540

The physical and psychological impact of neurogenic claudication: the patients' perspectives.

PubMed

Ammendolia, Carlo; Schneider, Michael; Williams, Kelly; Zickmund, Susan; Hamm, Megan; Stuber, Kent; Tomkins-Lane, Christy; Rampersaud, Y Raja

2017-03-01

The patient perspective regarding the impact of neurogenic claudication (NC) has not been well studied. The objectives of this study were to determine what is most bothersome among patients with NC and how it impacts their lives and expectations with surgical and non-surgical treatment. Semi-structured telephone interviews were conducted, audio recorded and transcribed verbatim. A thematic analysis categorized key findings based on relative importance and impact on participants. Twenty-eight individuals participated in this study. Participants were most bothered by the pain of NC, which dramatically impacted their lives. Inability to walk was the dominant functional limitation and this impacted the ability to engage in recreational and social activities. The most surprising finding was how frequently participants reported significant emotional effects of NC. From a patients' perspective NC has a significant multidimensional effects with pain, limited walking ability and emotional effects being most impactful to their lives.

Circadian rhythm of energy expenditure and oxygen consumption.

PubMed

Leuck, Marlene; Levandovski, Rosa; Harb, Ana; Quiles, Caroline; Hidalgo, Maria Paz

2014-02-01

This study aimed to evaluate the effect of continuous and intermittent methods of enteral nutrition (EN) administration on circadian rhythm. Thirty-four individuals, aged between 52 and 80 years, were fed through a nasoenteric tube. Fifteen individuals received a continuous infusion for 24 hours/d, and 19 received an intermittent infusion in comparable quantities, every 4 hours from 8:00 to 20:00. In each patient, 4 indirect calorimetric measurements were carried out over 24 hours (A: 7:30, B: 10:30, C: 14:30, and D: 21:30) for 3 days. Energy expenditure and oxygen consumption were significantly higher in the intermittent group than in the continuous group (1782 ± 862 vs 1478 ± 817 kcal/24 hours, P = .05; 257 125 vs 212 117 ml/min, P = .048, respectively). The intermittent group had higher levels of energy expenditure and oxygen consumption at all the measured time points compared with the continuous group. energy expenditure and oxygen consumption in both groups were significantly different throughout the day for 3 days. There is circadian rhythm variation of energy expenditure and oxygen consumption with continuous and intermittent infusion for EN. This suggests that only one indirect daily calorimetric measurement is not able to show the patient's true needs. Energy expenditure is higher at night with both food administration methods. Moreover, energy expenditure and oxygen consumption are higher with the intermittent administration method at all times.

Intermittent control of coexisting attractors.

PubMed

Liu, Yang; Wiercigroch, Marian; Ing, James; Pavlovskaia, Ekaterina

2013-06-28

This paper proposes a new control method applicable for a class of non-autonomous dynamical systems that naturally exhibit coexisting attractors. The central idea is based on knowledge of a system's basins of attraction, with control actions being applied intermittently in the time domain when the actual trajectory satisfies a proximity constraint with regards to the desired trajectory. This intermittent control uses an impulsive force to perturb one of the system attractors in order to switch the system response onto another attractor. This is carried out by bringing the perturbed state into the desired basin of attraction. The method has been applied to control both smooth and non-smooth systems, with the Duffing and impact oscillators used as examples. The strength of the intermittent control force is also considered, and a constrained intermittent control law is introduced to investigate the effect of limited control force on the efficiency of the controller. It is shown that increasing the duration of the control action and/or the number of control actuations allows one to successfully switch between the stable attractors using a lower control force. Numerical and experimental results are presented to demonstrate the effectiveness of the proposed method.

Combined Dietary Nitrate and Exercise Intervention in Peripheral Artery Disease: Protocol Rationale and Design

PubMed Central

Woessner, Mary N; VanBruggen, Mitch D; Pieper, Carl F; O'Reilly, Erin K; Kraus, William E

2017-01-01

Background Peripheral artery disease (PAD) is caused by atherosclerotic occlusions in the legs. It affects approximately 8-12 million people in the United States alone, one-third of whom suffer from intermittent claudication (IC), defined as ischemic leg pain that occurs with walking and improves with rest. Patients with IC suffer a markedly impaired quality of life and a high perception of disability. Improving pain-free walking time is a primary goal of rehabilitation in this population. Objective The nitric oxide (NO)-PAD trial is designed to compare the effects that 12 weeks of supervised exercise training, in combination with a high inorganic nitrate-content (beetroot [BR] juice) beverage or placebo (PL) beverage, has on clinical outcomes of exercise and functional capacity in two groups of PAD+IC patients: exercise training plus beetroot (EX+BR) and exercise training plus placebo (EX+PL). The primary aims of this randomized controlled, double-blind pilot study are to determine group differences following 12 weeks of EX+BR versus EX+PL in the changes for (1) exercise capacity: pain-free walking time (claudication onset time, COT), peak walk time (PWT), and maximal exercise capacity (peak oxygen uptake, VO2peak) during a maximal-graded cardiopulmonary exercise test (max CPX) and (2) functional capacity: 6-minute walk (6MW) distance. The secondary aims will provide mechanistic insights into the exercise outcome measures and will include (1) gastrocnemius muscle oxygenation during exercise via near-infrared spectroscopy (NIRS); (2) gastrocnemius muscle angiogenesis: capillaries per unit area and per muscle fiber, and relative fraction of type I, IIa, IIb, and IId/x fibers; and (3) vascular health/function via brachial artery flow-mediated dilation, lower-limb blood flow via plethysmography, and pulse wave velocity and reflection. Methods A total of 30 subjects between 40 and 80 years of age with PAD who are limited by IC will undergo exercise training 3 days per week for 12 weeks (ie, 36 sessions). They will be randomized to either the EX+BR or EX+PL group where participants will consume a beverage high in inorganic nitrate (4.2 mmol) or a low-nitrate placebo, respectively, 3 hours prior to each training session. Results Data collection from this study has been completed and is in the process of analysis and write-up. While the study is too underpowered—EX+BR, n=11; EX+PL, n=13—to determine between-group differences in the primary outcomes of COT, PWT, and 6MW, preliminary observations are promising with Cohen d effect sizes of medium to large. Conclusions Exercise training is currently the most effective therapy to increase functional capacity in PAD+IC. If the addition of inorganic nitrate to an exercise regimen elicits greater benefits, it may redefine the current standard of care for PAD+IC. Trial Registration ClinicalTrials.gov NCT01684930; https://clinicaltrials.gov/ct2/show/NCT01684930 (Archived by WebCite at http://www.webcitation.org/6raXFyEcP) PMID:28974486

High prevalence of known and unknown pulmonary diseases in patients with claudication during exercise oximetry: A retrospective analysis.

PubMed

Colas-Ribas, Christophe; Signolet, Isabelle; Henni, Samir; Feuillloy, Mathieu; Gagnadoux, Frédéric; Abraham, Pierre

2016-10-01

The prevalence of pulmonary disease in patients with peripheral artery disease (PAD) has not been extensively studied. Recent evidence has shown that ∼20% of the patients have an atypical chest transcutaneous oxygen pressure (TcpO2) pattern during exercise, which suggests walking-induced hypoxemia. The main objectives of this study were to: (1) describe in a retrospective way the characteristics of the patients suffering from claudication, who attended a treadmill testing in our laboratory, (2) assess the prevalence of known or unknown pulmonary disease. The second aim of this study was to evaluate the impact of the therapeutic interventions on the walking capacities, after treatment, of the eventually detected pulmonary disorders.We retrospectively analyzed 1482 exercise TcpO2 test results. Patients that had no history of pulmonary disease, but either reported severe dyspnea or showed atypical profiles on their chest exercise-TcpO2, were advised to refer to the department of pneumology for additional investigations.In addition to the 166 patients with a history of pulmonary disease, 158 patients were suspected of unknown pulmonary disease from the result of their TcpO2 test. Many patients (n = 99/158, 62.7%) did not attend a pulmonologist visit. A pulmonary disease was established in 55 (93.2%) of the other 59 patients. Obstructive sleep apnea syndrome (OSAS) was the one and only diagnosis retained in 42/59 patients (71.2%). Among the 47 patients who had a second evaluation of their walking capacity on treadmill, 38 had treatment of the pulmonary disease found, vascular surgery treatment or a severe restricted diet, 9 had no treatment. Only the "treated" group showed a significant improvement in the maximal walking distance on treadmill between the 2 evaluations, 313 ± 251 m to 433 ± 317 m (P = 0.03).This retrospective pilot study underlines the high prevalence of both known and unknown pulmonary disease in patients whose primary complaint was lower limb claudication. Systematic screening and treatment of pulmonary disease in patients with claudication might be justified, to improve walking ability of such patients and possibly reduce or delay the requirement for revascularization. Prospective studies are required to confirm these preliminary results.

Intermittent control: a computational theory of human control.

PubMed

Gawthrop, Peter; Loram, Ian; Lakie, Martin; Gollee, Henrik

2011-02-01

The paradigm of continuous control using internal models has advanced understanding of human motor control. However, this paradigm ignores some aspects of human control, including intermittent feedback, serial ballistic control, triggered responses and refractory periods. It is shown that event-driven intermittent control provides a framework to explain the behaviour of the human operator under a wider range of conditions than continuous control. Continuous control is included as a special case, but sampling, system matched hold, an intermittent predictor and an event trigger allow serial open-loop trajectories using intermittent feedback. The implementation here may be described as "continuous observation, intermittent action". Beyond explaining unimodal regulation distributions in common with continuous control, these features naturally explain refractoriness and bimodal stabilisation distributions observed in double stimulus tracking experiments and quiet standing, respectively. Moreover, given that human control systems contain significant time delays, a biological-cybernetic rationale favours intermittent over continuous control: intermittent predictive control is computationally less demanding than continuous predictive control. A standard continuous-time predictive control model of the human operator is used as the underlying design method for an event-driven intermittent controller. It is shown that when event thresholds are small and sampling is regular, the intermittent controller can masquerade as the underlying continuous-time controller and thus, under these conditions, the continuous-time and intermittent controller cannot be distinguished. This explains why the intermittent control hypothesis is consistent with the continuous control hypothesis for certain experimental conditions.

Velocity-intermittency structure for wake flow of the pitched single wind turbine under different inflow conditions

NASA Astrophysics Data System (ADS)

Crist, Ryan; Cal, Raul Bayoan; Ali, Naseem; Rockel, Stanislav; Peinke, Joachim; Hoelling, Michael

2017-11-01

The velocity-intermittency quadrant method is used to characterize the flow structure of the wake flow in the boundary layer of a wind turbine array. Multifractal framework presents the intermittency as a pointwise Hölder exponent. A 3×3 wind turbine array tested experimentally provided a velocity signal at a 21×9 downstream location, measured via hot-wire anemometry. The results show a negative correlation between the velocity and the intermittency at the hub height and bottom tip, whereas the top tip regions show a positive correlation. Sweep and ejection based on the velocity and intermittency are dominant downstream from the rotor. The pointwise results reflect large-scale organization of the flow and velocity-intermittency events corresponding to a foreshortened recirculation region near the hub height and the bottom tip.

Characterization of intermittency in renewal processes: Application to earthquakes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Akimoto, Takuma; Hasumi, Tomohiro; Aizawa, Yoji

2010-03-15

We construct a one-dimensional piecewise linear intermittent map from the interevent time distribution for a given renewal process. Then, we characterize intermittency by the asymptotic behavior near the indifferent fixed point in the piecewise linear intermittent map. Thus, we provide a framework to understand a unified characterization of intermittency and also present the Lyapunov exponent for renewal processes. This method is applied to the occurrence of earthquakes using the Japan Meteorological Agency and the National Earthquake Information Center catalog. By analyzing the return map of interevent times, we find that interevent times are not independent and identically distributed random variablesmore » but that the conditional probability distribution functions in the tail obey the Weibull distribution.« less

Robust, low-cost data loggers for stream temperature, flow intermittency, and relative conductivity monitoring

USGS Publications Warehouse

Chapin, Thomas; Todd, Andrew S.; Zeigler, Matthew P.

2014-01-01

Water temperature and streamflow intermittency are critical parameters influencing aquatic ecosystem health. Low-cost temperature loggers have made continuous water temperature monitoring relatively simple but determining streamflow timing and intermittency using temperature data alone requires significant and subjective data interpretation. Electrical resistance (ER) sensors have recently been developed to overcome the major limitations of temperature-based methods for the assessment of streamflow intermittency. This technical note introduces the STIC (Stream Temperature, Intermittency, and Conductivity logger); a robust, low-cost, simple to build instrument that provides long-duration, high-resolution monitoring of both relative conductivity (RC) and temperature. Simultaneously collected temperature and RC data provide unambiguous water temperature and streamflow intermittency information that is crucial for monitoring aquatic ecosystem health and assessing regulatory compliance. With proper calibration, the STIC relative conductivity data can be used to monitor specific conductivity.

Intermittent/transient fault phenomena in digital systems

NASA Technical Reports Server (NTRS)

Masson, G. M.

1977-01-01

An overview of the intermittent/transient (IT) fault study is presented. An interval survivability evaluation of digital systems for IT faults is discussed along with a method for detecting and diagnosing IT faults in digital systems.

Models of Intracavity Frequency Doubled Lasers

DTIC Science & Technology

1990-01-01

Intermittency; Intermittency Theory; Entropies and Dimension with Intermittency; Resonances, Frobenius - Perron Operators and Power Spectra; and Scaling and...to finding a measure is to approximate the Frobenius - Perron operator, whose domain is the set of measures on M (see, e.g., Li, 1976). An invariant...measure of the system is a fixed point of the Frobenius - Perron operator, and an iterative method using this operator can be shown to converge to an

Application of seemingly unrelated regression in medical data with intermittently observed time-dependent covariates.

PubMed

Keshavarzi, Sareh; Ayatollahi, Seyyed Mohammad Taghi; Zare, Najaf; Pakfetrat, Maryam

2012-01-01

BACKGROUND. In many studies with longitudinal data, time-dependent covariates can only be measured intermittently (not at all observation times), and this presents difficulties for standard statistical analyses. This situation is common in medical studies, and methods that deal with this challenge would be useful. METHODS. In this study, we performed the seemingly unrelated regression (SUR) based models, with respect to each observation time in longitudinal data with intermittently observed time-dependent covariates and further compared these models with mixed-effect regression models (MRMs) under three classic imputation procedures. Simulation studies were performed to compare the sample size properties of the estimated coefficients for different modeling choices. RESULTS. In general, the proposed models in the presence of intermittently observed time-dependent covariates showed a good performance. However, when we considered only the observed values of the covariate without any imputations, the resulted biases were greater. The performances of the proposed SUR-based models in comparison with MRM using classic imputation methods were nearly similar with approximately equal amounts of bias and MSE. CONCLUSION. The simulation study suggests that the SUR-based models work as efficiently as MRM in the case of intermittently observed time-dependent covariates. Thus, it can be used as an alternative to MRM.

Accelerated anaerobic hydrolysis rates under a combination of intermittent aeration and anaerobic conditions.

PubMed

Jensen, T R; Lastra Milone, T; Petersen, G; Andersen, H R

2017-04-01

Anaerobic hydrolysis in activated return sludge was investigated in laboratory scale experiments to find if intermittent aeration would accelerate anaerobic hydrolysis rates compared to anaerobic hydrolysis rates under strict anaerobic conditions. The intermittent reactors were set up in a 240 h experiment with intermittent aeration (3 h:3 h) in a period of 24 h followed by a subsequent anaerobic period of 24 h in a cycle of 48 h which was repeated five times during the experiment. The anaerobic reactors were kept under strict anaerobic conditions in the same period (240 h). Two methods for calculating hydrolysis rates based on soluble chemical oxygen demand were compared. Two-way analysis of variance with the Bonferroni post-test was performed in order to register any significant difference between reactors with intermittent aeration and strictly anaerobic conditions respectively. The experiment demonstrated a statistically significant difference in favor of the reactors with intermittent aeration showing a tendency towards accelerated anaerobic hydrolysis rates due to application of intermittent aeration. The conclusion of the work is thus that intermittent aeration applied in the activated return sludge process can improve the treatment capacity further in full scale applications.

Recent trends in morbidity and in-hospital outcomes of in-patients with peripheral arterial disease: a nationwide population-based analysis.

PubMed

Malyar, Nasser; Fürstenberg, Torsten; Wellmann, Jürgen; Meyborg, Matthias; Lüders, Florian; Gebauer, Katrin; Bunzemeier, Holger; Roeder, Norbert; Reinecke, Holger

2013-09-01

The prevalence of peripheral arterial disease (PAD) and especially of critical limb ischaemia (CLI) is announced to rise dramatically worldwide, with a considerable impact on the health care and socio-economic systems. We aimed to characterize the recent trends in morbidity and in-hospital outcome of PAD among all hospitalized patients in the entire German population between 2005 and 2009. Nationwide data of all hospitalizations in Germany in 2005, 2007, and 2009 were analysed regarding the prevalence of PAD, comorbidities, endovascular (EVR) and surgical revascularizations (SR), major and minor amputations, in-hospital mortality, and associated costs. From 2005 to 2009, total PAD cases increased by 20.7% (from 400 928 to 483 961), with an increase of CLI subset from 40.6 to 43.5%. Total EVR increased by 46%, while thromb-embolectomy, endarterectomy, and patch plastic increased by 67, 42, and 21%, respectively. Peripheral bypasses decreased by 2%. Major amputation decreased from 4.6 to 3.5%, while minor amputation slightly increased from 4.98 to 5.11%. The crude overall in-hospital mortality remained unchanged in claudicants (2.2%), while it decreased from 9.8 to 8.4% in CLI patients. However, mortality rate according to the Poisson model (n/1000 hospital residence days) increased significantly in claudicants (P < 0.001). Total reimbursement costs for PAD in-patient care increased by 21% with an average per case costs in 2009 of €4506 in a claudicant and €6791 in a CLI patient. This population-based analysis documents the significant rise of PAD, particularly of the CLI subset, and highlights the malign prognosis associated with PAD as indicated by high amputation and in-hospital mortality rates.

Microfibrillar-associated protein 4 variation in symptomatic peripheral artery disease.

PubMed

Hemstra, Line Ea; Schlosser, Anders; Lindholt, Jes Sanddal; Sorensen, Grith L

2018-06-08

Symptomatic peripheral artery disease (PAD) is an atherosclerotic occlusive disease affecting the lower extremities. The cause of symptomatic PAD is atherosclerosis, vascular dysfunctions, impaired angiogenesis and neointima formation. Microfibrillar-associated protein 4 (MFAP4) is an extracellular matrix protein, which is highly expressed in the heart and arteries and recently introduced as a potential mediator of pathological vascular remodeling and neointima formation. We aimed to investigate the relationship between serum MFAP4 (sMFAP4) and symptomatic PAD outcomes. A total of 286 PAD patients were analyzed if they had either intermittent claudication or critical lower-extremity ischemia (CLI) and followed for 7 years. The level of serum MFAP4 (sMFAP4) was measured by alphaLISA. Kaplan-Meier, Cox proportional hazard and logistic regression analysis were used to analyze the associations between upper tertile sMFAP4 and symptomatic PAD outcomes. Patients with upper tertile sMFAP4 had an odds ratio (OR) of 2.65 (p < 0.001) for having CLI diagnosis. Further analysis indicated that patients with upper tertile sMFAP4 had a hazard ratio (HR) of 1.97 (p = 0.04) for cardiovascular death during the 7-years follow-up. However, analysis of 2-year primary patency showed that patients with upper tertile sMFAP4 had decreased risk of vascular occlusion after reconstructive surgery with HR of 0.15 (p = 0.02). sMFAP4 has potential as a prognostic marker for cardiovascular death, primary patency of reconstructed vessels and CLI diagnosis in symptomatic PAD patients. Confirmation of observations in larger cohorts is warranted.

A Comparison of Cilostazol and Pentoxifylline for Treating Intermittent Claudication

NASA Technical Reports Server (NTRS)

Dawson, David L.; Cutler, Bruce S.; Hiatt, William R.; Hobson, Robert W., II; Martin, John D.; Bortey, Enoch B.; Forbes, William P.; Strandness, D. Eugene, Jr.; Homick, Jerry L. (Technical Monitor)

1999-01-01

A randomized, double-blind, placebo-controlled, parallel-group, phase III multicenter trial was performed to evaluate the relative efficacy and safety of cilostazol and pentoxifylline. The study included 54 outpatient vascular clinics, including sites at Air Force, Veterans Affairs, tertiary care, and university hospitals in the United States. Of 922 consenting patients, 698 met the inclusion criteria, were randomized, and received treatment with either cilostazol 100 mg P0 twice a day, pentoxifylline 400 mg PO 3 times a day, or placebo. Treatment was double-dummy to ensure study blindness. Efficacy was primarily established by maximal walking distance (MWD), measured with constant-speed, variable-grade treadmill testing, assessed at baseline and at 4, 8, 12, 16, 20, and 24 weeks. Mean MWD of cilostazol-treated patients (n=227) was significantly improved at every visit compared with patients who received pentoxifylline (n=232) or placebo (n=239). After 24 weeks of cilostazol, mean MWD increased 53.9% (107.3 m) from baseline, and the effect had not plateaued. This was better (P < 0.001) than the 30.4% (64.4 m) MWD improvement with pentoxifylline. MWD improvement with pentoxifylline was similar (P = 0.82) to that of placebo (64.7 m). Deaths and serious adverse event rates were similar in each group. Common side effects included headache (27.8% with cilostazol, 11.2% with pentoxifylline, 11.7% with placebo), palpitations (17.2% with cilostazol, 2.2% with pentoxifylllne, 1.3% with placebo), and abnormal stools. Cilostazol was significantly better than pentoxifylline or placebo for increasing walking distances; pentoxifylline was no better than placebo.

Hemorrhagic and ischemic strokes compared: stroke severity, mortality, and risk factors.

PubMed

Andersen, Klaus Kaae; Olsen, Tom Skyhøj; Dehlendorff, Christian; Kammersgaard, Lars Peter

2009-06-01

Stroke patients with hemorrhagic (HS) and ischemic strokes were compared with regard to stroke severity, mortality, and cardiovascular risk factors. A registry started in 2001, with the aim of registering all hospitalized stroke patients in Denmark, now holds information for 39,484 patients. The patients underwent an evaluation including stroke severity (Scandinavian Stroke Scale), CT, and cardiovascular risk factors. They were followed-up from admission until death or censoring in 2007. Independent predictors of death were identified by means of a survival model based on 25,123 individuals with a complete data set. Of the patients 3993 (10.1%) had HS. Stroke severity was almost linearly related to the probability of having HS (2% in patients with the mildest stroke and 30% in those with the most severe strokes). Factors favoring ischemic strokes vs HS were diabetes, atrial fibrillation, previous myocardial infarction, previous stroke, and intermittent arterial claudication. Smoking and alcohol consumption favored HS, whereas age, sex, and hypertension did not herald stroke type. Compared with ischemic strokes, HS was associated with an overall higher mortality risk (HR, 1.564; 95% CI, 1.441-1.696). The increased risk was, however, time-dependent; initially, risk was 4-fold, after 1 week it was 2.5-fold, and after 3 weeks it was 1.5-fold. After 3 months stroke type did not correlate to mortality. Strokes are generally more severe in patients with HS. Within the first 3 months after stroke, HS is associated with a considerable increase of mortality, which is specifically associated with the hemorrhagic nature of the lesion.

Connective Tissue Reflex Massage for Type 2 Diabetic Patients with Peripheral Arterial Disease: Randomized Controlled Trial

PubMed Central

Castro-Sánchez, Adelaida María; Moreno-Lorenzo, Carmen; Matarán-Peñarrocha, Guillermo A.; Feriche-Fernández-Castanys, Belen; Granados-Gámez, Genoveva; Quesada-Rubio, José Manuel

2011-01-01

The objective of this study was to evaluate the efficacy of connective tissue massage to improve blood circulation and intermittent claudication symptoms in type 2 diabetic patients. A randomized, placebo-controlled trial was undertaken. Ninety-eight type 2 diabetes patients with stage I or II-a peripheral arterial disease (PAD) (Leriche-Fontaine classification) were randomly assigned to a massage group or to a placebo group treated using disconnected magnetotherapy equipment. Peripheral arterial circulation was determined by measuring differential segmental arterial pressure, heart rate, skin temperature, oxygen saturation and skin blood flow. Measurements were taken before and at 30 min, 6 months and 1 year after the 15-week treatment. After the 15-week program, the groups differed (P < .05) in differential segmental arterial pressure in right lower limb (lower one-third of thigh, upper and lower one-third of leg) and left lower limb (lower one-third of thigh and upper and lower one-third of leg). A significant difference (P < .05) was also observed in skin blood flow in digits 1 and 4 of right foot and digits 2, 4 and 5 of left foot. ANOVA results were significant (P < .05) for right and left foot oxygen saturation but not for heart rate and temperature. At 6 months and 1 year, the groups differed in differential segmental arterial pressure in upper third of left and right legs. Connective tissue massage improves blood circulation in the lower limbs of type 2 diabetic patients at stage I or II-a and may be useful to slow the progression of PAD. PMID:19933770

Robust power spectral estimation for EEG data

PubMed Central

Melman, Tamar; Victor, Jonathan D.

2016-01-01

Background Typical electroencephalogram (EEG) recordings often contain substantial artifact. These artifacts, often large and intermittent, can interfere with quantification of the EEG via its power spectrum. To reduce the impact of artifact, EEG records are typically cleaned by a preprocessing stage that removes individual segments or components of the recording. However, such preprocessing can introduce bias, discard available signal, and be labor-intensive. With this motivation, we present a method that uses robust statistics to reduce dependence on preprocessing by minimizing the effect of large intermittent outliers on the spectral estimates. New method Using the multitaper method[1] as a starting point, we replaced the final step of the standard power spectrum calculation with a quantile-based estimator, and the Jackknife approach to confidence intervals with a Bayesian approach. The method is implemented in provided MATLAB modules, which extend the widely used Chronux toolbox. Results Using both simulated and human data, we show that in the presence of large intermittent outliers, the robust method produces improved estimates of the power spectrum, and that the Bayesian confidence intervals yield close-to-veridical coverage factors. Comparison to existing method The robust method, as compared to the standard method, is less affected by artifact: inclusion of outliers produces fewer changes in the shape of the power spectrum as well as in the coverage factor. Conclusion In the presence of large intermittent outliers, the robust method can reduce dependence on data preprocessing as compared to standard methods of spectral estimation. PMID:27102041

Lateral retroperitoneal transpsoas interbody fusion in a patient with achondroplastic dwarfism.

PubMed

Staub, Blake N; Holman, Paul J

2015-02-01

The authors present the first reported use of the lateral retroperitoneal transpsoas approach for interbody arthrodesis in a patient with achondroplastic dwarfism. The inherent anatomical abnormalities of the spine present in achondroplastic dwarfism predispose these patients to an increased incidence of spinal deformity as well as neurogenic claudication and potential radicular symptoms. The risks associated with prolonged general anesthesia and intolerance of significant blood loss in these patients makes them ideal candidates for minimally invasive spinal surgery. The patient in this case was a 51-year-old man with achondroplastic dwarfism who had a history of progressive claudication and radicular pain despite previous extensive lumbar laminectomies. The lateral retroperitoneal transpsoas approach was used for placement of interbody cages at L1/2, L2/3, L3/4, and L4/5, followed by posterior decompression and pedicle screw instrumentation. The patient tolerated the procedure well with no complications. Postoperatively his claudicatory and radicular symptoms resolved and a CT scan revealed solid arthrodesis with no periimplant lucencies.

Blood loss associated with Ring uncemented total knee replacement: comparison between continuous and intermittent suction drainage.

PubMed Central

Wittmann, F W; Ring, P A

1984-01-01

In a retrospective comparison of blood loss following uncemented total knee replacement, in which either continuous or intermittent suction drainage was used, measured blood loss was significantly greater with continuous drainage. However, a method of calculating actual blood loss demonstrated no significant difference. With intermittent drainage, more blood remains undetected around the knee joint; this technique should therefore be abandoned in favour of continuous suction drainage. PMID:6747978

Ophthalmic presentation of giant cell arteritis in African-Americans

PubMed Central

Garrity, S T; Pistilli, M; Vaphiades, M S; Richards, N Q; Subramanian, P S; Rosa, P R; Lam, B L; Osborne, B J; Liu, G T; Duncan, K E; Shin, R K; Volpe, N J; Shindler, K S; Lee, M S; Moster, M L; Tracey, E H; Cuprill-Nilson, S E; Tamhankar, M A

2017-01-01

Purpose To determine the differences in the presentation of ophthalmic giant cell arteritis between African-Americans and Caucasians. Methods This was a multicenter retrospective case series comparing African-American patients with ophthalmic GCA to a previously published Caucasian cohort. Neuro-ophthalmic centers across the United States were contacted to provide data on African-American patients with biopsy-proven ophthalmic giant cell arteritis. The differences between African-American and Caucasian patients with respect to multiple variables, including age, sex, systemic and ophthalmic signs and symptoms, ocular ischemic lesions, and laboratory results were studied. Results The Caucasian cohort was slightly older (mean=76.1 years) than the African-American cohort (mean=72.6 years, P=0.03), and there was no difference in sex distribution between the two cohorts. Headache, neck pain, and anemia were more frequent, while jaw claudication was less frequent in African-Americans (P<0.01, <0.001, 0.02, and 0.03 respectively). Acute vision loss was the most common presentation of giant cell arteritis in both groups, though it was less common in African-Americans (78 vs 98% of Caucasians, P<0.001). Eye pain was more common in African-Americans (28 vs 8% of Caucasians, P<0.01). Conclusions The presenting features of ophthalmic giant cell arteritis in African-Americans and Caucasians are not markedly different, although a few significant differences exist, including higher rates of headache, neck pain, anemia, and eye pain, and lower rates of jaw claudication and acute vision loss in African-Americans. Persons presenting with suspicious signs and symptoms should undergo evaluation for giant cell arteritis regardless of race. PMID:27636230

Stent-Graft Placement with Early Debridement and Antibiotic Treatment for Femoral Pseudoaneurysms in Intravenous Drug Addicts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fu, Qining, E-mail: cqmufqn@163.com; Meng, Xiyun, E-mail: 383274177@qq.com; Li, Fenghe, E-mail: lfh-cqmu@gmail.com

PurposeExplore the application of endovascular covered stent-graft (SG) placement in femoral pseudoaneurysms in intravenous drug addicts.Materials and MethodsWe evaluated a consecutive series of pseudoaneurysm in intravenous drug addicts treated with SGs from August 2010 to December 2013.Results15 patients with 16 arterial pseudoaneurysms were enrolled in this study. All were males with a mean age of 36.9 years. Hemorrhage was the most common reason (93.8 %) for seeking medical care, and 3 of these patients were in hemorrhagic shock at admission. All patients received broad-spectrum antibiotics, and debridement and drainage were implemented after SG placement. 7 of the 13 cases which had microbiologicmore » results showed mixed infections, while gram-negative bacteria were the major pathogens. Except for 2 patients, who were lost to follow-up, two new pseudoaneurysms formed due to delayed debridement, and one stent thrombosis occurred, none of the remaining cases had SG infection or developed claudication.ConclusionsSG placement controls massive hemorrhage rapidly, gives enough time for subsequent treatment for pseudoaneurysms due to intravenous drug abuse, and reduces the incidence of postoperative claudication. With appropriate broad-spectrum antibiotics and early debridement, the incidence of SG infection is relatively low. It is an effective alternative especially as temporary bridge measure for critical patients. However, the high cost, uncertain long-term prospects, high demand for medical adherence, and the risk of using the conduits for re-puncture call for a cautious selection of patients. More evidence is required for the application of this treatment.« less

Robust power spectral estimation for EEG data.

PubMed

Melman, Tamar; Victor, Jonathan D

2016-08-01

Typical electroencephalogram (EEG) recordings often contain substantial artifact. These artifacts, often large and intermittent, can interfere with quantification of the EEG via its power spectrum. To reduce the impact of artifact, EEG records are typically cleaned by a preprocessing stage that removes individual segments or components of the recording. However, such preprocessing can introduce bias, discard available signal, and be labor-intensive. With this motivation, we present a method that uses robust statistics to reduce dependence on preprocessing by minimizing the effect of large intermittent outliers on the spectral estimates. Using the multitaper method (Thomson, 1982) as a starting point, we replaced the final step of the standard power spectrum calculation with a quantile-based estimator, and the Jackknife approach to confidence intervals with a Bayesian approach. The method is implemented in provided MATLAB modules, which extend the widely used Chronux toolbox. Using both simulated and human data, we show that in the presence of large intermittent outliers, the robust method produces improved estimates of the power spectrum, and that the Bayesian confidence intervals yield close-to-veridical coverage factors. The robust method, as compared to the standard method, is less affected by artifact: inclusion of outliers produces fewer changes in the shape of the power spectrum as well as in the coverage factor. In the presence of large intermittent outliers, the robust method can reduce dependence on data preprocessing as compared to standard methods of spectral estimation. Copyright © 2016 Elsevier B.V. All rights reserved.

Intermittent Swimming with a Flexible Propulsor

NASA Astrophysics Data System (ADS)

Akoz, Emre; Moored, Keith

2017-11-01

Aquatic animals use a variety of swimming gaits to propel themselves efficiently through the oceans. One type of gait known as intermittent or burst-and-coast swimming is used by species such as saithe, cod and trout. Recent studies have shown that this gait can save up to 60% of a swimmer's energy by exploiting an inviscid Garrick mechanism. These detailed studies have examined the effects of an intermittent swimming gait on rigid propulsors, yet the caudal fins of intermittent swimmers are in fact highly flexible propulsors. In this respect, to gain a comprehensive understanding of intermittent swimming, the effect of elasticity on the swimming performance and wake flow of an intermittent swimmer is investigated. To accomplish this a torsional spring structural model is strongly coupled to a fast boundary element method solver that captures the fluid-structure interaction of a two-dimensional self-propelled intermittently pitching hydrofoil. It is shown that flexibility introduces extra vortices to the coasting phase of motion that can either promote or diminish thrust production depending upon the hydrofoil parameters. An optimal intermittent flexible swimmer is shown to increase its efficiency by as much as 28% when compared to an optimal continuous flexible swimmer. Supported by the Office of Naval Research under Program Director Dr. Bob Brizzolara, MURI Grant Number N00014-14-1-0533.

Scaling and intermittency of brain events as a manifestation of consciousness

NASA Astrophysics Data System (ADS)

Paradisi, P.; Allegrini, P.; Gemignani, A.; Laurino, M.; Menicucci, D.; Piarulli, A.

2013-01-01

We discuss the critical brain hypothesis and its relationship with intermittent renewal processes displaying power-law decay in the distribution of waiting times between two consecutive renewal events. In particular, studies on complex systems in a "critical" condition show that macroscopic variables, integrating the activities of many individual functional units, undergo fluctuations with an intermittent serial structure characterized by avalanches with inverse-power-law (scale-free) distribution densities of sizes and inter-event times. This condition, which is denoted as "fractal intermittency", was found in the electroencephalograms of subjects observed during a resting state wake condition. It remained unsolved whether fractal intermittency correlates with the stream of consciousness or with a non-task-driven default mode activity, also present in non-conscious states, like deep sleep. After reviewing a method of scaling analysis of intermittent systems based of eventdriven random walks, we show that during deep sleep fractal intermittency breaks down, and reestablishes during REM (Rapid Eye Movement) sleep, with essentially the same anomalous scaling of the pre-sleep wake condition. From the comparison of the pre-sleep wake, deep sleep and REM conditions we argue that the scaling features of intermittent brain events are related to the level of consciousness and, consequently, could be exploited as a possible indicator of consciousness in clinical applications.

Alternate energy source usage for in situ heat treatment processes

DOEpatents

Stone, Jr., Francis Marion; Goodwin, Charles R [League City, TX; Richard, Jr., James

2011-03-22

Systems, methods, and heaters for treating a subsurface formation are described herein. At least one system for providing power to one or more subsurface heaters is described herein. The system may include an intermittent power source; a transformer coupled to the intermittent power source, and a tap controller coupled to the transformer. The transformer may be configured to transform power from the intermittent power source to power with appropriate operating parameters for the heaters. The tap controller may be configured to monitor and control the transformer so that a constant voltage is provided to the heaters from the transformer regardless of the load of the heaters and the power output provided by the intermittent power source.

Patient selection and perioperative outcomes of bypass and endovascular intervention as first revascularization strategy for infrainguinal arterial disease.

PubMed

Bodewes, Thomas C F; Darling, Jeremy D; Deery, Sarah E; O'Donnell, Thomas F X; Pothof, Alexander B; Shean, Katie E; Moll, Frans L; Schermerhorn, Marc L

2018-01-01

The optimal initial revascularization strategy remains uncertain for patients with peripheral arterial disease. The purpose of this study was to evaluate current nationwide selection and perioperative outcomes of patients undergoing bypass or endovascular intervention for infrainguinal disease in those with no prior ipsilateral revascularization. Patients undergoing nonemergent first-time infrainguinal revascularization were identified in the Targeted Vascular module of the National Surgical Quality Improvement Program (NSQIP) for 2011 to 2014 and stratified by symptom status (chronic limb-threatening ischemia [CLTI] or claudication). Patients treated with endovascular intervention were compared with those who underwent bypass. Multivariable logistic regression was used to evaluate current selection of patients and to establish independent associations between first-time procedures and postoperative outcomes. Of 5998 first-time infrainguinal revascularizations performed, 3193 were bypass procedures (63% for CLTI) and 2805 were endovascular interventions (64% for CLTI). Current patient characteristics associated with an endovascular-first approach as opposed to bypass-first in CLTI patients were age ≥80 years, tissue loss, nonsmoking, functional dependence, diabetes, dialysis, and tibial lesions, whereas age ≥80 years, nonwhite race, nonsmoking, diabetes, and tibial lesions were associated with an endovascular approach for claudication. In comparing first-time endovascular intervention with bypass, there was no difference in 30-day mortality in CLTI patients (univariate: 2.1% vs 2.2%; adjusted: odds ratio [OR], 0.7; 95% confidence interval [CI], 0.4-1.1) or claudication patients (0.3% vs 0.6%). Among CLTI patients, endovascular-first intervention was associated with lower rates of major adverse cardiovascular event (3.6% vs 4.7%; OR, 0.6; 95% CI, 0.4-0.9), surgical site infection (0.9% vs 7.7%; OR, 0.1; 95% CI, 0.1-0.2), bleeding (8.5% vs 17%; OR, 0.4; 95% CI, 0.3-0.5), unplanned reoperation (13% vs 17%; OR, 0.7; 95% CI, 0.5-0.8), and unplanned readmission (17% vs 18%; OR, 0.8; 95% CI, 0.7-0.9). Patients with claudication undergoing endovascular-first intervention also had lower rates of major adverse cardiovascular event (0.8% vs 1.6%; OR, 0.4; 95% CI, 0.2-0.95), surgical site infection (0.7% vs 6.6%; OR, 0.1; 95% CI, 0.04-0.2), bleeding (2.3% vs 6.0%; OR, 0.3; 95% CI, 0.2-0.5), unplanned reoperation (4.3% vs 6.6%; OR, 0.6; 95% CI, 0.4-0.9), and unplanned readmission (5.9% vs 9.0%; OR, 0.6; 95% CI, 0.4-0.8). Conversely, endovascular-first intervention was associated with a higher rate of secondary revascularizations within 30 days for CLTI (4.3% vs 3.1%; OR, 1.6; 95% CI, 1.04-2.3) but not for claudication (2.6% vs 1.9%; OR, 1.7; 95% CI, 0.9-3.4). An endovascular-first approach as a revascularization strategy for infrainguinal disease was associated with substantially lower early morbidity but not mortality, at the cost of higher rates of postoperative secondary revascularizations. As a national representation of first-time revascularizations, this study highlights the early endovascular perioperative benefit, although more robust long-term data are needed to adopt either one strategy or the other in select patients with peripheral arterial disease. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Effects of intermittent traction therapy in an experimental spinal column model.

PubMed

Shin, Jeong-Hun; Jun, Seung-lyul; Lee, Young-Jun; Kim, Jae-Hyo; Hwang, Sung-Yeoun; Ahn, Seong-Hun

2014-04-01

Traction therapy, which is known to be a treatment method for scoliosis, one of many muscles disease, has been used since Hippocrates introduced it. However, the effects of traction therapy are still not clear. In addition, the meridian sinew theory, which is related to muscle treatment and is mentioned in the book on meridian sinews in the Miraculous Pivot of Huangdi's Internal Classic, has not been the subject of much study. For these reasons, experimental spinal models were made for this study to observe and analyze the lengths of vertebral interspaces after intermittent traction therapy, which is known to be excellent among muscle treatment methods, with various tensile forces. The results showed that the effects of intermittent traction therapy were unclear and that it might be harmful, especially when the pain was induced by muscle weakness. Because the results of this study on intermittent traction therapy were different from those expected from osteopathy or craniosacral theory, better studies of the subject are necessary. Copyright © 2014. Published by Elsevier B.V.

Comparison of various multifractal approaches to analyze the intermittent magnetic fluctuations observed in the Earth's magnetospheric cusp

NASA Astrophysics Data System (ADS)

Lamy, Hervé; Echim, Marius; Chang, Tom

2014-05-01

Several approaches exist to compute the multifractal characteristics of an intermittent set of fluctuations. First, the classical method based on the computation of the partition function uses the full set of fluctuations . Since it is dominated by the more numerous fluctuations of small amplitudes, this method can mask the fractal characteristics of minor fluctuations of much larger amplitude. To solve this issue, a new method was developed by Chang & Wu (2008) : the Rank-Ordered Multifractal Analysis (ROMA) The ROMA method offers a natural connection between the one-parameter monofractal scaling idea and the multifractal phenomenon of intermittency. The key-element in ROMA is to find s(Y), the spectrum of the scaling exponents, and Ps(Y), the scaled Probability Distribution Function (PDFs), from the raw PDFs of the variable X at various scales tau , P(X,tau), with the following scaling: P(X,tau) tau ^s(Y)=Ps(Y) with Y= X/tau ^s(Y) The first (direct) method is to use range-limited structure functions in a sufficiently small range of the scaled variable Y and search for the value of monofroctal exponent s(Y). A drawback of this approach is that the range of Y must be large enough to ensure that the statistics is meaningful. As a consequence, some cross-over behavior between fluctuations with different monofractal exponents can lead to an ambiguity with several solutions s(Y) for some ranges of Y. Also the multifractal spectrum produced is step-wise discontinuous. To overcome these difficulties, Wu & Chang (2011) have suggested a refined method where a value of the parameter s is assumed and the corresponding value of Y ensuring a collapse of the raw PDFs is searched for. The advantage of this latter approach is that s(Y) and Ps(Y) can be obtained for single values of Y. The two ROMA methods and the partition function method are used on a set of intermittent magnetic field fluctuations observed by the Cluster spacecraft in the Earth's magnetospheric cusp. Results are presented and discussed. Research supported by the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement no 313038/STORM. TC was also partially supported by the US National Science Foundation. T. Chang and C.C. Wu, Rank-Ordered Multifractal Spectrum for Intermittent Fluctuations, Phys. Rev. E77,045401(R), 2008 CC. Wu and T. Chang, Application of rank-ordered multifractal analysis (ROMA) to intermittent fluctuations in 3D turbulent flows, 2D MHD simulation and solar wind data, to be submitted to the special issue "Multifractals and Intermittent Turbulence in the Solar-Terrestrial System", Nonlinear Processes in Geophysics, 2011.

DEVELOPMENT OF BIOLOGICAL INDICATORS, METHODS AND ASSESSMENT TECHNIQUES FOR USE IN HEADWATER INTERMITTENT STREAMS

EPA Science Inventory

Despite representing the most abundant and widespread of our nation's surface waters, regions, states and tribes have received little guidance specific to headwater intermittent streams from the U.S. EPA. Headwater streams lie at the terrestrial-aquatic interface both spatially,...

On-off intermittency in time series of spontaneous paroxysmal activity in rats with genetic absence epilepsy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hramov, Alexander; Koronovskii, Alexey A.; Midzyanovskaya, I.S.

2006-12-15

In the present paper we consider the on-off intermittency phenomena observed in time series of spontaneous paroxysmal activity in rats with genetic absence epilepsy. The method to register and analyze the electroencephalogram with the help of continuous wavelet transform is also suggested.

Athermal laser treatment of the diabetic leg

NASA Astrophysics Data System (ADS)

Ignat, P.; Suteanu, S.; Brojbeanu, Gabriela; Vasiliu, Virgil V.

1995-03-01

This work shows the result obtained in the medical clinic of the `Dr. I. Cantacuzino Hospital' on a lot of 43 diabetic patients using the `LASSIS' devices composed of a He-Ne laser and 4 semiconductor lasers. The 43 patients showed various clinic pictures of a diabetic leg (diabetic arteriopathy and neuropathy) 16 of the lot showed an arteriopathy with claudication and a decrease of pulses oscillometrically measurements, 15 had ulceration and a beginning of gangrene and the other 12 showed a plantary boring ill. There has been achieved an amelioration of the oscillometric index of the claudication while walking the amelioration of local circulation, together with the limitation of the necrosis. For the boring ill, there has been achieved the acceleration of the granulating and epithelization process avoiding surgeries, suppuration and cutaneous plasties. The response to the laser treatment was compared to the response to the classic treatment (vasodilatation surgery unstrapping, antibiotherapy) on a proving lot. We appreciated that the cicatrization and local vasodilatation with athermal laser treatment should be a hope for the treatment of patients suffering of diabetic arteriopathy and neuropathy.

Organics removal, nitrogen removal and N2O emission in subsurface wastewater infiltration systems amended with/without biochar and sludge.

PubMed

Sun, Yafei; Qi, Shiyue; Zheng, Fanping; Huang, Linli; Pan, Jing; Jiang, Yingying; Hou, Wanyuan; Xiao, Lu

2018-02-01

Organics removal, nitrogen removal, N 2 O emission and nitrogen removal functional gene abundances in four subsurface wastewater infiltration systems (SWISs), named SWIS A (no intermittent aeration without biochar and sludge), SWIS B (no intermittent aeration with biochar and sludge), SWIS C (intermittent aeration without biochar and sludge), SWIS D (intermittent aeration with biochar and sludge) were investigated. Intermittent aeration enhanced chemical oxygen demand (COD), ammonia nitrogen (NH 4 + -N), total nitrogen (TN) removal and the abundances of nitrogen removal functional genes (amoA, nxrA, napA, narG, nirS, nirK, qnorB and nosZ) compared to non-aerated SWISs. High COD (95.4 ± 0.2%), NH 4 + -N (96.2 ± 0.6%), TN (86.4 ± 0.5%) removal efficiencies and low N 2 O emission rate (18.4 mg/(m 2  d)) were obtained simultaneously in intermittent aerated SWIS amended with biochar and sludge. The results suggested that intermittent aerated SWISs amended with biochar and sludge could be an effective and appropriate method for improving treatment performance and reducing N 2 O emission. Copyright © 2017 Elsevier Ltd. All rights reserved.

Combined Directional Atherectomy and Drug-Eluting Balloon Angioplasty for Isolated Popliteal Artery Lesions in Patients With Peripheral Artery Disease.

PubMed

Stavroulakis, Konstantinos; Bisdas, Theodosios; Torsello, Giovanni; Stachmann, Arne; Schwindt, Arne

2015-12-01

To evaluate the midterm results of combined directional atherectomy (DA) and drug-eluting balloon (DEB) angioplasty for atherosclerotic lesions of the popliteal artery. In a single-arm, prospective study, 21 patients (mean age 63±16 years; 16 men) with isolated popliteal artery lesions were enrolled and underwent treatment with combined DA and DEB angioplasty under filter protection between October 2009 and February 2014. The majority (18, 86%) presented with lifestyle-limiting intermittent claudication and 3 with critical limb ischemia. Fifteen (71%) target sites were de novo lesions; 4 were occlusions. The main outcome was primary patency; secondary outcomes were technical success, secondary patency, and early and midterm morbidity and mortality. The TurboHawk atherectomy device was used in 15 (71%) patients and the SilverHawk peripheral plaque excision system in the remaining 6 patients. The In.Pact Admiral/Pacific DEB was used in the majority of cases (15, 71%). The technical success rate was 90% (n=19). One flow-limiting dissection was treated with bailout stenting. Complications included a perforation of the popliteal artery and 2 puncture site hematomas; there was no distal embolic event. The mean follow-up was 18±12 months. Two restenoses were retreated successfully. Kaplan-Meier estimates of primary patency at 12 and 18 months were 95% and 90%, respectively; the secondary patency was 100%. One (5%) patient died in follow-up. None of the patients had an amputation. In this prospective single-arm study, the combined therapy of DA and DEB angioplasty for popliteal artery lesions showed promising midterm performance. The combination of DA and DEB may, in highly selected patients, overcome the challenges presented by the mobility of the knee joint. © The Author(s) 2015.

The course of peripheral vascular disease in non-insulin-dependent diabetes.

PubMed

Kreines, K; Johnson, E; Albrink, M; Knatterud, G L; Levin, M E; Lewitan, A; Newberry, W; Rose, F A

1985-01-01

The present report is an analysis of the course of peripheral vascular disease (PVD) in 619 patients with non-insulin-dependent diabetes (NIDDM) recruited within 1 yr of diagnosis and followed quarterly for up to 14 yr (X = 10.5 yr). At 13 yr duration, the actuarially determined cumulative risks for intermittent claudication (IC), nonpalpable dorsalis pedis pulse (NPUL), and arterial calcification (CALC) were, respectively, 37.9%, 34.5%, and 60.9% for men and 24.3%, 37.6%, and 32.2% for women. Major amputations (AMP) occurred in only 1.3% of the patients, equivalent to approximately one case per 1000 patients per year. The corresponding incidences of IC, NPUL, and CALC were, respectively, 29, 27, and 47 per 1000 men and 19, 27, and 25 per 1000 women per year. CALC and NPUL were strongly related to mortality. Baseline risk factors with probability levels that suggest a relationship to PVD were, in women, age versus CALC (P less than 0.01), age versus NPUL (P less than 0.05), weight versus NPUL (P less than 0.05), systolic BP versus CALC (P less than 0.01), summed glucose tolerance test versus CALC (P less than 0.01), and triglyceride level versus CALC (P less than 0.05). In men, the only significant risk factors were diminished vibration perception, which was related to NPUL (P less than 0.05), and the serum triglyceride level, which was related to IC (P less than 0.05). In patients who are carefully followed prospectively, IC is far more common, but AMP is far less common than has been generally appreciated. Further studies are needed to clarify the roles of the diverse risk factors that are possibly related.

Use of beta blockers in postinfarct prophylaxis: aspects on quality of life.

PubMed

Hjalmarson, A C

1987-07-01

The value of beta blockade after myocardial infarction is extremely well documented. Close to 50 randomized trials have been performed, involving about 40,000 patients with short- or long-term follow-up. Over 20,000 patients have been included in more than 20 placebo-controlled trials with a follow-up period of 3 months or more. In long-term follow-up studies, about 1 to 2 weeks to 1 year after myocardial infarction, mortality was reduced by 21% and reinfarction by 24% (about 20,000 patients in 24 trials). The trial medication was withdrawn in about 20% in both placebo and beta-blocker groups in the major trials. In addition to reduction of mortality and reinfarction rate, benefits have clearly been demonstrated on severity of chest pain, arrhythmias, and other thromboatherosclerotic complications, as well as on readmissions. Significantly more patients experienced congestive heart failure, hypotension, bradycardia, and cold hands with beta-blocker treatment, whereas no clear-cut difference was found for atrioventricular block, bronchial constriction, and intermittent claudication. Some studies have reported more tiredness, depression, and gastrointestinal disturbances. In the Stockholm metoprolol trial, analyses on quality of life have been performed. In this trial, 3 years of metoprolol treatment after myocardial infarction resulted in a prolongation of both survival and time spent completely asymptomatic, as well as in an optimal functional state. Furthermore, less time was spent disabled after serious atherosclerotic complications. Long-term beta blockade after myocardial infarction reduces mortality and morbidity but causes adverse reactions in some patients. With proper selection of patients and type and dosage of beta blocker, survival without atherosclerotic complications and side effects can be prolonged.

Intensive walking exercise for lower extremity peripheral arterial disease: A systematic review and meta-analysis.

PubMed

Lyu, Xiafei; Li, Sheyu; Peng, Shifeng; Cai, Huimin; Liu, Guanjian; Ran, Xingwu

2016-05-01

Supervised treadmill exercise is the recommended therapy for peripheral arterial disease (PAD) patients with intermittent claudication (IC). However, most PAD patients do not exhibit typical symptoms of IC. The aim of the present study was to explore the efficacy and safety of intensive walking exercise in PAD patients with and without IC. The PubMed, Embase and Cochrane Library databases were systematically searched. Randomized controlled trials comparing the effects of intensive walking exercise with usual care in patients with PAD were included for systematic review and meta-analysis. Eighteen trials with 1200 patients were eligible for the present analysis. Compared with usual care, intensive walking exercise significantly improved the maximal walking distance (MWD), pain-free walking distance, and the 6-min walking distance in patients with PAD (P < 0.00001 for all). Subgroup analyses indicated that a lesser improvement in MWD was observed in the subgroup with more diabetes patients, and that the subgroup with better baseline walking ability exhibited greater improvement in walking performance. In addition, similar improvements in walking performance were observed for exercise programs of different durations and modalities. No significant difference was found in adverse events between the intensive walking and usual care groups (relative risk 0.84; 95% confidence interval 0.51, 1.39; P = 0.50). Regardless of exercise length and modality, regularly intensive walking exercise improves walking ability in PAD patients more than usual care. The presence of diabetes may attenuate the improvements in walking performance in patients with PAD following exercise. © 2015 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd.

Development and use of sulodexide in vascular diseases: implications for treatment

PubMed Central

Coccheri, Sergio; Mannello, Ferdinando

2014-01-01

Sulodexide (SDX), a sulfated polysaccharide complex extracted from porcine intestinal mucosa, is a blend of two glycosaminoglycan (GAG) entities, namely a fast-moving heparin (HP) fraction and a dermatan sulfate (DS; 20%) component. The compound is unique among HP-like substances in that it is biologically active by both the parenteral and oral routes. A main feature of the agent is to undergo extensive absorption by the vascular endothelium. For this reason, in preclinical studies, SDX administered parenterally displays an antithrombotic action similar to that of HPs but associated with fewer alterations of the blood clotting mechanisms and tests, thus being much less conducive to bleeding risk than HPs. When given orally, SDX is associated with minimal changes in classic coagulation tests, but maintains a number of important effects on the structure and function of endothelial cells (EC), and the intercellular matrix. These activities include prevention or restoration of the integrity and permeability of EC, counteraction versus chemical, toxic or metabolic EC injury, regulation of EC–blood cell interactions, inhibition of microvascular inflammatory and proliferative changes, and other similar effects, thus allowing oral SDX to be considered as an endothelial-protecting agent. The best available clinical evidence of the efficacy of SDX administered orally with or without an initial parenteral phase is the following: alleviation of symptoms in chronic venous disease and especially acceleration of healing of venous leg ulcers; prevention of cardiovascular events in survivors after acute myocardial infarction; marked improvement of intermittent claudication in patients with peripheral occlusive arterial disease; and abatement of proteinuria in patients with diabetic nephropathy that may contribute to the amelioration or stabilization of kidney function. Although further clinical trials are warranted, SDX is presently widely accepted in many countries as an effective and safe long-term, endothelial-protecting drug. PMID:24391440

Stroke with polyvascular atherothrombotic disease.

PubMed

Blanco, Miguel; Sobrino, Tomás; Montaner, Joan; Medrano, Vicente; Jiménez, Carmen; Masjuán, Jaime; Gómez-Escalonilla, Carlos; de Luis, Pilar; Arboix, Adriá; Castillo, José

2010-02-01

To study the influence of polyvascular atherothrombotic disease on stroke patient prognosis, its relation with inflammatory markers, and to analyze the progression of atherothrombotic disease. MITICO is a multi-centered prospective observational study recruiting non-anticoagulated ischemic stroke patients. Blood samples were obtained at baseline and at one year follow-up for determination of high sensitivity C reactive protein (hs-CRP), interleukin 6 (IL-6), intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), matrix metalloproteinase 9 (MMP-9), and cellular fibronectin (c-Fn). Patients with polyvascular atherothrombotic disease were considered when presented a history of angina-myocardial infarction, intermittent claudication or ischemic limbs-amputation at inclusion. The sample consisted of 863 patients, 121 of them considered as polyvascular atherothrombotic disease (14.02%). Recurrence and vascular death were higher in patients with polyvascular atherothrombotic disease, as compared to patients with monovascular atherothrombotic disease (19.8% vs. 12.4%, p=0.022). Baseline plasma levels of IL-6 and VCAM-1 were higher in patients with polyvascular atherothrombotic disease. IL-6 and VCAM-1 levels were independently associated with a new vascular episode/vascular death. This association was stronger in the group of patients with polyvascular atherothrombotic disease. Baseline levels of IL-6, VCAM-1 and c-Fn were significantly higher in patients who developed progression of atherothrombotic disease. The increase from baseline in MMP-9 and c-Fn levels after one year follow-up was associated to progression of atherothrombotic disease. Stroke patients with polyvascular atherothrombotic disease showed higher rates of vascular recurrence and a stronger association with inflammatory markers. Progression of atherothrombotic disease was associated with inflammatory markers. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

A peripheral artery disease screening study in Puerto Rico.

PubMed

Delgado-Osorio, Héctor; Franqui-Rivera, Hilton; García-Palmieri, Mario R; Díaz-Santana, Mary V; Alvarez, Mario

2011-01-01

Peripheral artery disease (PAD) of the lower extremities is frequently underdiagnosed and undertreated. The results of screening for PAD in adults attending outpatient clinics at different sites in Puerto Rico from 2007 to 2010 are presented. A total of 33 outpatients screening clinics were conducted at different sites throughout the Island. Following the ACC/AHA Guideline recommendations, asymptomatic patients who qualified were screened for PAD using the ankle-brachial index (ABI). An ABI < 0.9 was considered positive for PAD. We estimated the prevalence of PAD in the study population and used logistic regression models to assess factors associated with a positive screening test for PAD. A total of 933 patients were screened for PAD. Out of the 933 patients, the ABI was < 0.9 in 390 (41.8%) of them. Bivariate analysis showed a significant difference in PAD screening results by gender (P = 0.004) and history of arterial hypertension (P = 0.004). Regarding clinical characteristics, leg edema 44.7% (P = 0.001), intermittent claudication 40.3% (P = 0.002), distal extremity coldness 29.0% (P = 0.012), and weak lower extremity pulses 67.5% (P < 0.001) were more prevalent on patients with an ABI < 0.9. In the multivariate analysis, male gender (OR = 1.92, 95% CI: 1.18, 3.11) and arterial hypertension (OR = 2.16, 95% CI: 1.28, 3.65) were significantly associated with PAD after adjusting for specific confounders. Arterial hypertension, cigarette smoking, diabetes mellitus, and dyslipidemia are known key factors in development of PAD. Practicing physicians must be aware of the importance of an early diagnosis of PAD, particularly in the asymptomatic patient, so as to institute preventive and management measures.

Surgical treatment of middle aortic syndrome with Takayasu arteritis or midaortic dysplastic syndrome.

PubMed

Kim, S M; Jung, I M; Han, A; Min, S-I; Lee, T; Ha, J; Kim, S J; Min, S-K

2015-08-01

Middle aortic syndrome (MAS) is a rare condition characterized by severe stenosis of the distal thoracic or abdominal aorta. The aims of this study are to define the anatomic characteristics of MAS and to review the various surgical methods and their outcomes in terms of long-term durability Ten adult patients were diagnosed with MAS caused by Takayasu arteritis (TA) or midaortic dysplastic syndrome and underwent surgical treatment between July 1992 and January 2013. The aortic lesions were mostly suprarenal (n = 7) and stenoses were commonly found in the celiac axis (n = 6), SMA (n = 7), and renal artery (n = 6). Indications for operation were uncontrolled hypertension in six patients and lower extremity claudication in four. Eight aortic bypasses, one supraceliac aortic interposition graft, and one bilateral aorto-renal bypass were performed. Adjunctive renal bypass with saphenous vein graft (n = 4) and IMA reimplantation (n = 2) were performed simultaneously. There was no post-operative mortality, and one complication of iliac dissection at the distal anastomosis site was detected and treated by stenting. Hypertension was cured or improved in five of the six patients, and lower extremity claudication improved in all of them. With a median follow up of 60 months (range, 12-263), all the aortic bypasses were patent and one adjunctive renal artery bypass graft with aortic bypass was occluded 29 months post-operatively. Aortic bypass for MAS is safe and shows excellent long-term durability. Considering the patients are relatively young with a long life expectancy, aggressive surgical treatment could be beneficial. Lifelong follow up to monitor complications and disease progression is necessary. Copyright © 2015 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Hybrid drive for motor vehicles with a preponderantly intermittent method of operation

NASA Technical Reports Server (NTRS)

Schreck, H.

1977-01-01

A flywheel hybrid propulsion system is compared with a conventional propulsion system in a test vehicle under intermittent operation. An energy balance is presented for the conventional propulsion system. Results so far indicate especially high energy conversion of the gyro component under dynamic operation along with favorable internal combustion engine conditions.

Impact of intermittent fasting on the lipid profile: Assessment associated with diet and weight loss.

PubMed

Santos, Heitor O; Macedo, Rodrigo C O

2018-04-01

Intermittent fasting, whose proposed benefits include the improvement of lipid profile and the body weight loss, has gained considerable scientific and popular repercussion. This review aimed to consolidate studies that analyzed the lipid profile in humans before and after intermittent fasting period through a detailed review; and to propose the physiological mechanism, considering the diet and the body weight loss. Normocaloric and hypocaloric intermittent fasting may be a dietary method to aid in the improvement of the lipid profile in healthy, obese and dyslipidemic men and women by reducing total cholesterol, LDL, triglycerides and increasing HDL levels. However, the majority of studies that analyze the intermittent fasting impacts on the lipid profile and body weight loss are observational based on Ramadan fasting, which lacks large sample and detailed information about diet. Randomized clinical trials with a larger sample size are needed to evaluate the IF effects mainly in patients with dyslipidemia. Copyright © 2018 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.

Clinical validity of a disease-specific health status questionnaire: the peripheral artery questionnaire.

PubMed

Hoeks, Sanne E; Smolderen, Kim G; Scholte Op Reimer, Wilma J M; Verhagen, Hence J M; Spertus, John A; Poldermans, Don

2009-02-01

Measuring patient-centered outcomes is becoming increasingly important in patients with peripheral arterial disease (PAD), both as a means of determining the benefits of treatment and as an aid for disease management. In order to monitor health status in a reliable and sensitive way, the disease-specific measure Peripheral Artery Questionnaire (PAQ) was developed. However, to date, its correlation with traditional clinical indices is unknown. The primary aim of this study was to better establish the clinical validity of the PAQ by examining its association with functional indices related to PAD. Furthermore, we hypothesized that the clinical validity of this disease-specific measure is better as compared with the EuroQol-5-dimensional (EQ-5D), a standardized generic instrument. Data on 711 consecutive PAD patients undergoing surgery were collected from 11 Dutch hospitals in 2004. At 3-year follow-up, questionnaires including the PAQ, EQ-5D, and EuroQol-Visual Analogue Scale (EQ VAS) were completed in 84% of survivors. The PAQ was analyzed according to three domains, as established by a factor analyses in the Dutch population, and the summary score. Baseline clinical indices included the presence and severity of claudication intermittent (CI) and the Lee Cardiac Risk Index. All three PAQ domains (Physical Function, Perceived Disability, and Treatment Satisfaction) were significantly associated with CI symptoms (P values < .001-.008). Patients with claudication had significant lower PAQ summary scores as compared with asymptomatic patients (58.6 +/- 27.8 vs 68.6 +/- 27.8, P = < .001). Furthermore, the PAQ summary score and the subscale scores for Physical Functioning and Perceived Disability demonstrated a clear dose-response relation for walking distance and the Lee Risk Index (P values < .001-.031). With respect to the generic EQ-5D, the summary EQ-5D index was associated with CI (0.81 +/- 0.20 vs 0.76 +/- 0.24, P = .031) but not with walking distance (P = .128) nor the Lee Risk Index (P = .154). The EQ VAS discriminated between the clinical indices (P values = .003-.008), although a clear dose-response relation was lacking. The clinical validity of the PAQ proved to be good as the PAQ subscales discriminated well between patients with or without symptomatic PAD and its severity as defined by walking distance. Furthermore, the PAQ subscales were directly proportional to the presence and number of risk factors relevant for PAD. For studying outcomes in PAD patients, the disease-specific PAQ is likely to be a more sensitive measure of treatment benefit as compared with the generic EQ VAS, although the latter may still be of value when comparing health status across different diseases. Regarding disease management, we advocate the use of the disease-specific PAQ as its greater sensitivity and validity will assist its translation into clinical practice.

Intermittent vs Continuous Androgen Deprivation Therapy for Prostate Cancer: A Systematic Review and Meta-analysis.

PubMed

Magnan, Sindy; Zarychanski, Ryan; Pilote, Laurie; Bernier, Laurence; Shemilt, Michèle; Vigneault, Eric; Fradet, Vincent; Turgeon, Alexis F

2015-12-01

Androgen deprivation is the standard therapy for patients with advanced or recurrent prostate cancer. However, this treatment causes adverse effects, alters quality of life, and may lead to castration-resistant disease. Intermittent androgen deprivation has been studied as an alternative. To conduct a systematic review and meta-analysis comparing the efficacy and tolerability of intermittent vs continuous androgen deprivation therapy in patients with prostate cancer. We searched Cochrane CENTRAL, Medline, Embase, Web of Science, Biosis, National Technical Information Service, OpenSIGLE, and Google Scholar from inception of each database through March 2014. References from published guidelines, reviews, and other relevant articles were also considered. We selected randomized clinical trials comparing intermittent vs continuous androgen deprivation therapy in patients with prostate cancer. Two reviewers performed study selection, data abstraction, and risk of bias assessment. We calculated hazard ratios (HRs) with the inverse variance method and risk ratios with the Mantel-Haenszel method, using random effect models. A noninferiority analysis was conducted for overall survival with a margin of 1.15 for the upper boundary of the HR. We assessed heterogeneity using the I2 index. Primary outcomes were overall survival and quality of life. Secondary outcomes were cancer-specific survival, progression-free survival, time to castration resistance, skeletal-related events, and adverse effects. From 10 510 references, we included 22 articles from 15 trials (6856 patients) published between 2000 and 2013. All but 1 study had an unclear or high risk of bias. We observed no significant difference between intermittent and continuous therapy for overall survival (HR, 1.02; 95% CI, 0.93-1.11; 8 trials, 5352 patients), cancer-specific survival (HR, 1.02; 95% CI, 0.87-1.19; 5 trials, 3613 patients), and progression-free survival (HR, 0.94; 95% CI, 0.84-1.05; 4 trials, 1774 patients). There was minimal difference in patients' self-reported quality of life between the 2 interventions. Most trials observed an improvement in physical and sexual functioning with intermittent therapy. Intermittent androgen deprivation was not inferior to continuous therapy with respect to the overall survival. Some quality-of-life criteria seemed improved with intermittent therapy. Intermittent androgen deprivation can be considered as an alternative option in patients with recurrent or metastatic prostate cancer.

Physical mechanisms in shock-induced turbulent separated flow

NASA Astrophysics Data System (ADS)

Dolling, D. S.

1987-12-01

It has been demonstrated that the flow downstream of the moving shock is separated and that the foot of the shock is effectively the instantaneous separation point. The shock induced turbulent separation is an intermittant process and the separation line indicated by surface tracer methods, such as kerosene-lampblack, is a downstream boundary of a region of intermittent separation.

A qualitative descriptive study of self-management issues in people with long-term intermittent urinary catheters.

PubMed

Wilde, Mary H; Brasch, Judith; Zhang, Yi

2011-06-01

The study was to identify and describe issues of intermittent urinary catheter users for future self-management research and/or training programmes. Limited studies were found of how people using clean intermittent catheterization manage their daily routines or troubleshoot problems. Self-management research related to intermittent catheterization could lead to improved compliance with the method and better quality of life. This qualitative descriptive study involved in-depth tape-recorded telephone interviews in 2008-2009 with 34 people in the United States of America using permanent intermittent catheterization, mostly individuals with spinal cord injury or multiple sclerosis. Recruitment was through Internet sites where individuals could link to the study website and then contact the researchers. The sample included 13 men and 21 women aged 21-72 years (mean 42 years). Content analysis for qualitative data involved iterative comparisons of transcripts, summaries and memos. Coding, key quotes and tables were developed to determine themes. Six major themes were identified: Knowing the Body, Practising Intermittent Catheterization, Limited Options in Catheters and Equipment, Inaccessible Bathrooms, Hassles, and Adjustment in Making Intermittent Catheterization a Part of Life. While some persons had choices in catheters, many did not because of insurance constraints. Some individuals developed knowledge of how to balance the procedure with fluid intake and activities. The lack of acceptable bathrooms can interfere with being able to go to work, travel or be with friends and family. All using intermittent catheterization should have adequate insurance coverage when this is needed. Research into training programmes could incorporate knowledge of experienced users. © 2011 Blackwell Publishing Ltd.

A complex-lamellar description of boundary layer transition

NASA Astrophysics Data System (ADS)

Kolla, Maureen Louise

Flow transition is important, in both practical and phenomenological terms. However, there is currently no method for identifying the spatial locations associated with transition, such as the start and end of intermittency. The concept of flow stability and experimental correlations have been used, however, flow stability only identifies the location where disturbances begin to grow in the laminar flow and experimental correlations can only give approximations as measuring the start and end of intermittency is difficult. Therefore, the focus of this work is to construct a method to identify the start and end of intermittency, for a natural boundary layer transition and a separated flow transition. We obtain these locations by deriving a complex-lamellar description of the velocity field that exists between a fully laminar and fully turbulent boundary condition. Mathematically, this complex-lamellar decomposition, which is constructed from the classical Darwin-Lighthill-Hawthorne drift function and the transport of enstrophy, describes the flow that exists between the fully laminar Pohlhausen equations and Prandtl's fully turbulent one seventh power law. We approximate the difference in enstrophy density between the boundary conditions using a power series. The slope of the power series is scaled by using the shape of the universal intermittency distribution within the intermittency region. We solve the complex-lamellar decomposition of the velocity field along with the slope of the difference in enstrophy density function to determine the location of the laminar and turbulent boundary conditions. Then from the difference in enstrophy density function we calculate the start and end of intermittency. We perform this calculation on a natural boundary layer transition over a flat plate for zero pressure gradient flow and for separated shear flow over a separation bubble. We compare these results to existing experimental results and verify the accuracy of our transition model.

A randomised trial of a contraceptive vaginal ring in women at risk of HIV infection in Rwanda: Safety of intermittent and continuous use

PubMed Central

Van Nuil, Jennifer Ilo; Uwineza, Mireille; Umulisa, Marie Michelle; Mwambarangwe, Lambert; Ndagijimana, Jean Claude; De Baetselier, Irith; Buyze, Jozefien; Delvaux, Thérèse; Crucitti, Tania; Jespers, Vicky

2018-01-01

Background Contraceptive vaginal rings could play a role in expanding the contraceptive method mix and in preparing communities for the introduction of HIV prevention and multipurpose rings. Methods We conducted an open label single-centre randomised clinical trial of intermittent versus continuous use of NuvaRing® in Kigali, Rwanda, in 2013–2014. We randomised 120 HIV-negative women 1:1 to intermittent use (three rings with a ring-free week in between rings) or continuous use (four rings without ring-free weeks). Women underwent an interview, counselling, and a speculum examination, and were tested for pregnancy, bacterial vaginosis (BV) by Nugent scoring, yeasts and trichomonads on wet mount, and sexually transmitted infections. Findings Only one woman withdrew early. Deliberate ring removals were rare, but spontaneous ring expulsions occurred during 14% of ring use periods. There were no incident pregnancies, serious adverse events, serious social harms, or early discontinuations for safety reasons. Systemic side effects were uncommon, and local side effects were not significantly differently distributed between groups except for lower abdominal pain (P = 0.013). The incidence of vaginal yeasts during ring use was high: 22% of intermittent users and 27% of continuous users had incident vaginal yeasts at one or multiple ring removal visits (P = 0.666), and symptomatic vaginal yeast cases were more common in the continuous than intermittent users (P = 0.031). In contrast, mean Nugent scores improved over time in both groups. Conclusions Intermittent and continuous NuvaRing® use were safe in Rwandan women and improved Nugent scores over time. However, attention should be paid to ring expulsions and to a potential increased risk of vaginal candidiasis. PMID:29856848

A wavelet-based intermittency detection technique from PIV investigations in transitional boundary layers

NASA Astrophysics Data System (ADS)

Simoni, Daniele; Lengani, Davide; Guida, Roberto

2016-09-01

The transition process of the boundary layer growing over a flat plate with pressure gradient simulating the suction side of a low-pressure turbine blade and elevated free-stream turbulence intensity level has been analyzed by means of PIV and hot-wire measurements. A detailed view of the instantaneous flow field in the wall-normal plane highlights the physics characterizing the complex process leading to the formation of large-scale coherent structures during breaking down of the ordered motion of the flow, thus generating randomized oscillations (i.e., turbulent spots). This analysis gives the basis for the development of a new procedure aimed at determining the intermittency function describing (statistically) the transition process. To this end, a wavelet-based method has been employed for the identification of the large-scale structures created during the transition process. Successively, a probability density function of these events has been defined so that an intermittency function is deduced. This latter strictly corresponds to the intermittency function of the transitional flow computed trough a classic procedure based on hot-wire data. The agreement between the two procedures in the intermittency shape and spot production rate proves the capability of the method in providing the statistical representation of the transition process. The main advantages of the procedure here proposed concern with its applicability to PIV data; it does not require a threshold level to discriminate first- and/or second-order time-derivative of hot-wire time traces (that makes the method not influenced by the operator); and it provides a clear evidence of the connection between the flow physics and the statistical representation of transition based on theory of turbulent spot propagation.

Assessing market uncertainty by means of a time-varying intermittency parameter for asset price fluctuations

NASA Astrophysics Data System (ADS)

Rypdal, Martin; Sirnes, Espen; Løvsletten, Ola; Rypdal, Kristoffer

2013-08-01

Maximum likelihood estimation techniques for multifractal processes are applied to high-frequency data in order to quantify intermittency in the fluctuations of asset prices. From time records as short as one month these methods permit extraction of a meaningful intermittency parameter λ characterising the degree of volatility clustering. We can therefore study the time evolution of volatility clustering and test the statistical significance of this variability. By analysing data from the Oslo Stock Exchange, and comparing the results with the investment grade spread, we find that the estimates of λ are lower at times of high market uncertainty.

[«Man-in-the-barrel» syndrome: atypical manifestation of giant cell arteritis].

PubMed

Calle-Lopez, Y; Fernandez-Ramirez, A F; Franco-Dager, E; Gomez-Lopera, J G; Vanegas-Garcia, A L

2018-06-01

«Man-in-the-barrel» syndrome refers to diplegia of the upper extremities in which mobility of the head and lower limbs is preserved. Brachial plexitis that presents as «man-in-the-barrel» syndrome is an unusual manifestation of giant cell arteritis. We report a case of C5-C6 plexitis as part of the clinical features of a patient with giant cell arteritis. A 70-year-old male with a two-month history of weight loss, headache, facial pain and jaw claudication, associated with a persistent elevation of acute phase reactants and bilateral brachial plexopathy, with no evidence of neck or brain injuries or occult neoplasm and with negative autoimmunity tests. Results of the biopsy study of the temporal artery were compatible with giant cell arteritis, and the positron emission tomography scan revealed extensive vascular involvement of the aorta and its branches. Although the typical clinical manifestations of giant cell arteritis are headache, jaw claudication, loss of sight, constitutional symptoms and polymyalgia rheumatica, its presence must be suspected in patients over the age of 50 who manifest alterations affecting the peripheral nerve, including brachial diplegia with no other demonstrable cause.

[A 65-year-old man with history of claudication, palpable purpura and livedo reticularis].

PubMed

Braun, N; Kimmel, M; Grabner, A; Ott, G; Alscher, M D

2010-04-01

A 65-year-old man was admitted with history of claudication symptoms and painful skin lesions of the lower legs. Physical examination showed palpable purpura of the lower legs and livedo reticularis, most marked at the forefoot and toes. Computed tomography (CT) showed an aortic mass 2 cm above the bifurcation. This was treated after angiography with a covered stent. Biopsy of the skin lesions showed no sign of vasculitis and no cholesterol crystals. The patient was discharged and remained symptom-free for 9 months. He was readmitted at that time with recurrent complaints. CT revealed a subtotal stenosis of the aortic stent. A skin biopsy showed CD31-positive tumor cells in small arteries. Biopsy of a new osteolytic lesion in the ileum confirmed the diagnosis of angiosarcoma of the aorta. The patient decided in favor of palliative care and was discharged from the hospital. Primary tumors of the aorta, although they are rare, should be considered in the presence of an intravascular mass with stenosis to blood flow. A skin biopsy is easy to conduct and often leads to the final diagnosis. Georg Thieme Verlag KG Stuttgart. New York.

Nonlinear system identification for prostate cancer and optimality of intermittent androgen suppression therapy.

PubMed

Suzuki, Taiji; Aihara, Kazuyuki

2013-09-01

These days prostate cancer is one of the most common types of malignant neoplasm in men. Androgen ablation therapy (hormone therapy) has been shown to be effective for advanced prostate cancer. However, continuous hormone therapy often causes recurrence. This results from the progression of androgen-dependent cancer cells to androgen-independent cancer cells during the continuous hormone therapy. One possible method to prevent the progression to the androgen-independent state is intermittent androgen suppression (IAS) therapy, which ceases dosing intermittently. In this paper, we propose two methods to estimate the dynamics of prostate cancer, and investigate the IAS therapy from the viewpoint of optimality. The two methods that we propose for dynamics estimation are a variational Bayesian method for a piecewise affine (PWA) system and a Gaussian process regression method. We apply the proposed methods to real clinical data and compare their predictive performances. Then, using the estimated dynamics of prostate cancer, we observe how prostate cancer behaves for various dosing schedules. It can be seen that the conventional IAS therapy is a way of imposing high cost for dosing while keeping the prostate cancer in a safe state. We would like to dedicate this paper to the memory of Professor Luigi M. Ricciardi. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

Intermittent patient suction system, self-contained control

DOEpatents

Lewis, Jay L.

1992-01-01

An intermittent patient suction system, a self-contained control device therefor and methods of making the same are provided, the self-contained control device having a housing that contains two restrictor units therein for respectively controlling the "on" time and "off" time that the control device applies a vacuum and does not apply a vacuum through the output of the control device to the patient.

Safety, Adherence and Acceptability of Intermittent Tenofovir/Emtricitabine as HIV Pre-Exposure Prophylaxis (PrEP) among HIV-Uninfected Ugandan Volunteers Living in HIV-Serodiscordant Relationships: A Randomized, Clinical Trial

PubMed Central

Kibengo, Freddie M.; Ruzagira, Eugene; Katende, David; Bwanika, Agnes N.; Bahemuka, Ubaldo; Haberer, Jessica E.; Bangsberg, David R.; Barin, Burc; Rooney, James F.; Mark, David; Chetty, Paramesh; Fast, Patricia; Kamali, Anatoli; Priddy, Frances H.

2013-01-01

Background Efficacy of oral pre-exposure prophylaxis (PrEP) in prevention of HIV acquisition has been evaluated using a daily regimen. However, adherence to long term daily medication is rarely perfect. Intermittent regimen may be a feasible alternative. Preclinical studies have demonstrated effectiveness of intermittent PrEP in SHIV prevention among animals. However, little is known about intermittent PrEP regimens. Design Seventy two HIV-uninfected volunteers in HIV serodiscordant couple relationships in Uganda were randomly assigned to receive daily oral Tenofovir/Emtricitabine (TDF/FTC-Truvada) or placebo, or intermittent (Monday, Friday and within 2 hours after sex, not to exceed one dose per day) oral TDF/FTC or placebo in a 2:1:2:1 ratio. Volunteers and study staff were blinded to drug assignment, but not to regimen assignment. Methods Volunteers were followed for 4 months after randomization, with monthly clinical and laboratory safety assessments and comprehensive HIV risk reduction services. Adherence was monitored using medication event monitoring system (MEMS) and self-report. Sexual activity data were collected via daily short text message (SMS) and self-report. HIV-specific immune responses were assessed by IFN-γ ELISPOT. Results Both daily and intermittent oral TDF/FTC regimens were well tolerated. Median MEMS adherence rates were 98% (IQR: 93-100) for daily PrEP regimen, 91% (IQR: 73-97) for fixed intermittent dosing and 45% (IQR: 20-63) for post-coital dosing. SMS response rate was 74%, but increased to 80% after excluding server outages; results may have been affected by the novelty of this measure. The majority of volunteers expressed willingness with no particular preference for either regimen. Conclusions Both daily and intermittent oral PrEP dosing regimens were safe. Adherence was high for daily and fixed intermittent dosing; post-coital dosing was associated with poor adherence. Fixed intermittent PrEP regimens may be feasible especially if a minimum effective drug concentration correlating with HIV prevention can be achieved with this dosing. Registration Clinicaltrials.gov number NCT00931346 PMID:24086333

Acoustic vibration test detects intermittent electrical discontinuities

NASA Technical Reports Server (NTRS)

Grieve, S. M.; Roberts, D. E.

1970-01-01

Nondestructive test method detects faulty electrical connections in inaccessible or hidden portions of electronic harness assemblies and connectors. Method employs readily available commercial equipment.

Intermittent Demand Forecasting in a Tertiary Pediatric Intensive Care Unit.

PubMed

Cheng, Chen-Yang; Chiang, Kuo-Liang; Chen, Meng-Yin

2016-10-01

Forecasts of the demand for medical supplies both directly and indirectly affect the operating costs and the quality of the care provided by health care institutions. Specifically, overestimating demand induces an inventory surplus, whereas underestimating demand possibly compromises patient safety. Uncertainty in forecasting the consumption of medical supplies generates intermittent demand events. The intermittent demand patterns for medical supplies are generally classified as lumpy, erratic, smooth, and slow-moving demand. This study was conducted with the purpose of advancing a tertiary pediatric intensive care unit's efforts to achieve a high level of accuracy in its forecasting of the demand for medical supplies. On this point, several demand forecasting methods were compared in terms of the forecast accuracy of each. The results confirm that applying Croston's method combined with a single exponential smoothing method yields the most accurate results for forecasting lumpy, erratic, and slow-moving demand, whereas the Simple Moving Average (SMA) method is the most suitable for forecasting smooth demand. In addition, when the classification of demand consumption patterns were combined with the demand forecasting models, the forecasting errors were minimized, indicating that this classification framework can play a role in improving patient safety and reducing inventory management costs in health care institutions.

Isolated popliteal artery occlusion in the young.

PubMed

Khoda, J; Lantsberg, L; Sebbag, G

1992-01-01

Three young patients with an isolated popliteal artery occlusion are presented, two with severe claudication and the third with a critical ischaemic foot. The work-up of these patients leads to certain aetiologic possibilities: microtrauma, smoking and contraceptive pills. Two of our patients underwent thromboembolectomy, the third managed conservatively. The follow-up was between six months and seven years and up to now all three patients remain well.

Determining the degree of synchronism for intermittent phase synchronization in human electroencephalography data

NASA Astrophysics Data System (ADS)

Koloskova, A. D.; Moskalenko, O. I.

2017-05-01

The phenomenon of intermittent phase synchronization during development of epileptic activity in human beings has been discovered based on EEG data. The presence of synchronous behavior phases has been detected both during spike-wave discharges and in the regions of background activity of the brain. The degree of synchronism in the intermittent phase-synchronization regime in both cases has been determined, and it has been established that spike-wave discharges are characterized by a higher degree of synchronism than exists in the regions of background activity of the brain. To determine the degree of synchronism, a modified method of evaluating zero conditional Lyapunov exponents from time series is proposed.

Predictors of improved quality of life and claudication in patients undergoing spinal cord stimulation for critical lower limb ischemia.

PubMed

Tshomba, Yamume; Psacharopulo, Daniele; Frezza, Serena; Marone, Enrico Maria; Astore, Domenico; Chiesa, Roberto

2014-04-01

The aim of this study was to determine predictors of improved quality of life and claudication in patients undergoing spinal cord stimulation (SCS) for critical lower limb ischemia. We retrospectively analyzed 101 consecutive patients with few meter claudication and nonhealing ulcer who underwent definitive SCS. These patients were selected among 274 SCS patients treated at our center from 1995 to 2012. All presented with non-reconstructable critical leg ischemia (NR-CLI) and underwent supervised exercise therapy, best medical care and regular ulcers standard or advanced medications for at least 1 month before SCS implantation. We measured self-perceived quality of life using the SF-36 questionnaire. Patients with an improved walking distance of at least 30 meters after SCS had significant improvement on SF-36 questionnaire scores. We considered 30 meters as the cut-off for clinically significant improvement in pain-free walking distance, and we defined this value as functional success. Logistic regression was applied to assess baseline and other patient variables as possible predictors of functional success. Neither perioperative mortality nor significant complications were found. At a median follow-up of 69 months (range 1-202 months), mortality, major amputation, and minor amputation were 8.9%, 5.9%, and 6.9%, respectively. Functional clinical success was reported in 25.7% of cases. Independent predictors of functional success at univariate analysis included delay between the onset of the ulcer and SCS (P < 0.001) and the pain-free walking distance before SCS (P < 0.002). The only predictive factor of functional success at multivariate analysis was the delay between the onset of ulcer and SCS (median delay in patients with and without functional success was 3 and 15 months, respectively). In particular, comparable to pain-free walking distance before SCS, the success rate decreased by 40% for each month elapsed from onset of ulcer to SCS. In our series of patients who underwent SCS, reduced delay between the onset of ulcer and SCS was associated with improved quality of life and walking distance. Larger series are required to confirm these data and to assess clinical implications. Copyright © 2014 Elsevier Inc. All rights reserved.

Shifting paradigms in the treatment of lower extremity vascular disease: a report of 1000 percutaneous interventions.

PubMed

DeRubertis, Brian G; Faries, Peter L; McKinsey, James F; Chaer, Rabih A; Pierce, Matthew; Karwowski, John; Weinberg, Alan; Nowygrod, Roman; Morrissey, Nicholas J; Bush, Harry L; Kent, K Craig

2007-09-01

Catheter-based revascularization has emerged as an alternative to surgical bypass for lower extremity vascular disease and is a frequently used tool in the armamentarium of the vascular surgeon. In this study we report contemporary outcomes of 1000 percutaneous infra-inguinal interventions performed by a single vascular surgery division. We evaluated a prospectively maintained database of 1000 consecutive percutaneous infra-inguinal interventions between 2001 and 2006 performed for claudication (46.3%) or limb-threatening ischemia (52.7%; rest pain in 27.7% and tissue loss in 72.3%). Treatments included angioplasty with or without stenting, laser angioplasty, and atherectomy of the femoral, popliteal, and tibial vessels. Mean age was 71.4 years and 57.3% were male; comorbidities included hypertension (84%), coronary artery disease (51%), diabetes (58%), tobacco use (52%), and chronic renal insufficiency (39%). Overall 30-day mortality was 0.5%. Two-year primary and secondary patencies and rate of amputation were 62.4%, 79.3%, and 0.5%, respectively, for patients with claudication. Two-year primary and secondary patencies and limb salvage rates were 37.4%, 55.4%, and 79.3% for patients with limb-threatening ischemia. By multivariable Cox PH modeling, limb-threat as procedural indication (P < 0.0001), diabetes (P = 0.003), hypercholesterolemia (P = 0.001), coronary artery disease (P = 0.047), and Transatlantic Inter-Society Consensus D lesion complexity (P = 0.050) were independent predictors of recurrent disease. For patients that developed recurrent disease, 7.5% required no further intervention, 60.3% underwent successful percutaneous reintervention, 11.7% underwent bypass and 20.5% underwent amputation. Patency rates were identical for the initial procedure and subsequent reinterventions (P = 0.97). Percutaneous therapy for peripheral vascular disease is associated with minimal mortality and can achieve 2-year secondary patency rates of nearly 80% in patients with claudication. Although patency is diminished in patients with limb-threat, limb-salvage rates remain reasonable at close to 80% at 2 years. Percutaneous infra-inguinal revascularization carries a low risk of morbidity and mortality, and should be considered first-line therapy in patients with chronic lower extremity ischemia.

Muscle protein metabolism in neonatal alloxan-administered rats: effects of continuous and intermittent swimming training

PubMed Central

2012-01-01

Background This study aimed to examine the effects of intermittent and continuous swimming training on muscle protein metabolism in neonatal alloxan-administered rats. Methods Wistar rats were used and divided into six groups: sedentary alloxan (SA), sedentary control (SC), continuous trained alloxan (CA), intermittent trained alloxan (IA), continuous trained control (CC) and intermittent trained control (IC). Alloxan (250 mg/kg body weight) was injected into newborn rats at 6 days of age. The continuous training protocol consisted of 12 weeks of swimming training in individual cylinder tanks while supporting a load that was 5% of body weight; uninterrupted swimming for 1 h/day, five days a week. The intermittent training protocol consisted of 12 weeks of swimming training in individual cylinder tanks while supporting a load that was 15% of body weight; 30 s of activity interrupted by 30 s of rest for a total of 20 min/day, five days a week. Results At 28 days, the alloxan animals displayed higher glycemia after glucose overload than the control animals. No differences in insulinemia among the groups were detected. At 120 days, no differences in serum albumin and total protein among the groups were observed. Compared to the other groups, DNA concentrations were higher in the alloxan animals that were subjected to continuous training, whereas the DNA/protein ratio was higher in the alloxan animals that were subjected to intermittent training. Conclusion It was concluded that continuous and intermittent training sessions were effective in altering muscle growth by hyperplasia and hypertrophy, respectively, in alloxan-administered animals. PMID:22309804

A classification scheme for turbulent flows based on their joint velocity-intermittency structure

NASA Astrophysics Data System (ADS)

Keylock, C. J.; Nishimura, K.; Peinke, J.

2011-12-01

Kolmogorov's classic theory for turbulence assumed an independence between velocity increments and the value for the velocity itself. However, this assumption is questionable, particularly in complex geophysical flows. Here we propose a framework for studying velocity-intermittency coupling that is similar in essence to the popular quadrant analysis method for studying near-wall flows. However, we study the dominant (longitudinal) velocity component along with a measure of the roughness of the signal, given mathematically by its series of Hölder exponents. Thus, we permit a possible dependence between velocity and intermittency. We compare boundary layer data obtained in a wind tunnel to turbulent jets and wake flows. These flow classes all have distinct velocity-intermittency characteristics, which cause them to be readily distinguished using our technique. Our method is much simpler and quicker to apply than approaches that condition the velocity increment statistics at some scale, r, on the increment statistics at a neighbouring, larger spatial scale, r+Δ, and the velocity itself. Classification of environmental flows is then possible based on their similarities to the idealised flow classes and we demonstrate this using laboratory data for flow in a parallel-channel confluence where the region of flow recirculation in the lee of the step is discriminated as a flow class distinct from boundary layer, jet and wake flows. Hence, using our method, it is possible to assign a flow classification to complex geophysical, turbulent flows depending upon which idealised flow class they most resemble.

The Impact of Natural Hazards such as Turbulent Wind Gusts on the Wind Energy Conversion Process

NASA Astrophysics Data System (ADS)

Wächter, M.; Hölling, M.; Milan, P.; Morales, A.; Peinke, J.

2012-12-01

Wind turbines operate in the atmospheric boundary layer, where they are exposed to wind gusts and other types of natural hazards. As the response time of wind turbines is typically in the range of seconds, they are affected by the small scale intermittent properties of the turbulent wind. We show evidence that basic features which are known for small-scale homogeneous isotropic turbulence, and in particular the well-known intermittency problem, have an important impact on the wind energy conversion process. Intermittent statistics include high probabilities of extreme events which can be related to wind gusts and other types of natural hazards. As a summarizing result we find that atmospheric turbulence imposes its intermittent features on the complete wind energy conversion process. Intermittent turbulence features are not only present in atmospheric wind, but are also dominant in the loads on the turbine, i.e. rotor torque and thrust, and in the electrical power output signal. We conclude that profound knowledge of turbulent statistics and the application of suitable numerical as well as experimental methods are necessary to grasp these unique features and quantify their effects on all stages of wind energy conversion.

Intermittent Versus Daily Pulmonary Tuberculosis Treatment Regimens: A Meta-Analysis

PubMed Central

Kasozi, Samuel; Clark, Justin; Doi, Suhail A. R.

2015-01-01

Background Several systematic reviews suggest that intermittent pulmonary tuberculosis (TB) chemotherapy is effective, but intensity (daily versus intermittent) and duration of rifampicin use (intensive phase only versus both phases) have not been distinguished. In addition, the various outcomes (success, failure, relapse, and default) have only selectively been evaluated. Methods We conducted a meta-analysis of proportions using all four outcomes as multi-category proportions to examine the effectiveness of WHO category 1 TB treatment regimens. Database searches of studies reporting treatment outcomes of HIV negative subjects were included and stratified by intensity of therapy and duration of rifampicin therapy. Using a bias-adjusted statistical model, we pooled proportions of the four treatment outcome categories using a method that handles multi-category proportions. Results A total of 27 studies comprising of 48 data sets with 10,624 participants were studied. Overall, treatment success was similar among patients treated with intermittent (I/I) (88%) (95% CI, 81–92) and daily (D/D) (90%) (95% CI, 84–95) regimens. Default was significantly less with I/I (0%) (95% CI, 0–2) compared to D/D regimens (5%) (95% CI, 1–9). Nevertheless, I/I relapse rates (7%) (95% CI, 3–11) were higher than D/D relapse rates (1%) (95% CI, 0–3). Conclusion Treatment regimens that are offered completely intermittently versus completely daily are associated with a trade-off between treatment relapse and treatment default. There is a possibility that I/I regimens can be improved by increasing treatment duration, and this needs to be urgently addressed by future studies. PMID:26056374

Evaluating the Effect of Three Water Management Techniques on Tomato Crop.

PubMed

Elnesr, Mohammad Nabil; Alazba, Abdurrahman Ali; Zein El-Abedein, Assem Ibrahim; El-Adl, Mahmoud Maher

2015-01-01

The effects of three water management techniques were evaluated on subsurface drip irrigated tomatoes. The three techniques were the intermittent flow (3 pulses), the dual-lateral drip system (two lateral lines per row, at 15 and 25 cm below soil surface), and the physical barrier (buried at 30 cm below soil surface). Field experiments were established for two successive seasons. Water movement in soil was monitored using continuously logging capacitance probes up to 60 cm depth. The results showed that the dual lateral technique positively increased the yield up to 50%, water use efficiency up to 54%, while the intermittent application improved some of the quality measures (fruit size, TSS, and Vitamin C), not the quantity of the yield that decreased in one season, and not affected in the other. The physical barrier has no significant effect on any of the important growth measures. The soil water patterns showed that the dual lateral method lead to uniform wetting pattern with depth up to 45 cm, the physical barrier appeared to increase lateral and upward water movement, while the intermittent application kept the wetting pattern at higher moisture level for longer time. The cost analysis showed also that the economic treatments were the dual lateral followed by the intermittent technique, while the physical barrier is not economical. The study recommends researching the effect of the dual lateral method on the root growth and performance. The intermittent application may be recommended to improve tomato quality but not quantity. The physical barrier is not recommended unless in high permeable soils.

A filter paper dry blood spot procedure for acute intermittent porphyria population screening by use of whole blood uroporphyrinogen-I-synthase assay.

PubMed

Johansson, L; Thunell, S; Wetterberg, L

1984-03-13

A filter paper dry blood spot procedure for the determination of whole blood uroporphyrinogen-I-synthase (UIS) activity is presented. The method is based on the concept of enzyme specific activity, the enzyme activity being related to the haemoglobin concentration of the assay sample. The diagnostic capacity with regard to the acute intermittent porphyria (AIP) gene carrier state is shown to be equivalent to that of a washed red cell reference method. On grounds of easy capillary blood sampling, uncomplicated and safe mail specimen transport and simple laboratory reception routines, the method is stated to be well adapted for use in AIP preadolescent population screening.

Intervention radiology for venous thrombosis: early thrombus removal using invasive methods.

PubMed

Casanegra, Ana I; McBane, Robert D; Bjarnason, Haraldur

2017-04-01

The post thrombotic syndrome is one of the most dreaded complications of proximal deep vein thrombosis. This syndrome leads to pain and suffering with leg swelling, recalcitrant ulceration and venous claudication which greatly impairs mobility and quality of life. The prevalence can be high in patients with iliofemoral venous involvement particularly in the setting of a proximal venous stenosis, such as occurs in May Thurner syndrome. Anticoagulation alone does not reduce the likelihood of this outcome. Compression therapy may be effective but garment discomfort limits its implementation. Pharmacomechanical thrombectomy, which combines catheter-directed thrombolysis with mechanical thrombus dissolution, provides an attractive treatment strategy for such patients. The rationale and delivery of pharmacomechanical thrombectomy, including patient selection and adjunctive antithrombotic therapy, will be reviewed in addition to tips and tricks for managing difficult patient scenarios. © 2017 John Wiley & Sons Ltd.

Synchronization of coupled stochastic complex-valued dynamical networks with time-varying delays via aperiodically intermittent adaptive control

NASA Astrophysics Data System (ADS)

Wang, Pengfei; Jin, Wei; Su, Huan

2018-04-01

This paper deals with the synchronization problem of a class of coupled stochastic complex-valued drive-response networks with time-varying delays via aperiodically intermittent adaptive control. Different from the previous works, the intermittent control is aperiodic and adaptive, and the restrictions on the control width and time delay are removed, which lead to a larger application scope for this control strategy. Then, based on the Lyapunov method and Kirchhoff's Matrix Tree Theorem as well as differential inequality techniques, several novel synchronization conditions are derived for the considered model. Specially, impulsive control is also considered, which can be seen as a special case of the aperiodically intermittent control when the control width tends to zero. And the corresponding synchronization criteria are given as well. As an application of the theoretical results, a class of stochastic complex-valued coupled oscillators with time-varying delays is studied, and the numerical simulations are also given to demonstrate the effectiveness of the control strategies.

Multivariate longitudinal data analysis with censored and intermittent missing responses.

PubMed

Lin, Tsung-I; Lachos, Victor H; Wang, Wan-Lun

2018-05-08

The multivariate linear mixed model (MLMM) has emerged as an important analytical tool for longitudinal data with multiple outcomes. However, the analysis of multivariate longitudinal data could be complicated by the presence of censored measurements because of a detection limit of the assay in combination with unavoidable missing values arising when subjects miss some of their scheduled visits intermittently. This paper presents a generalization of the MLMM approach, called the MLMM-CM, for a joint analysis of the multivariate longitudinal data with censored and intermittent missing responses. A computationally feasible expectation maximization-based procedure is developed to carry out maximum likelihood estimation within the MLMM-CM framework. Moreover, the asymptotic standard errors of fixed effects are explicitly obtained via the information-based method. We illustrate our methodology by using simulated data and a case study from an AIDS clinical trial. Experimental results reveal that the proposed method is able to provide more satisfactory performance as compared with the traditional MLMM approach. Copyright © 2018 John Wiley & Sons, Ltd.

Iatrogenic Aorto-Cisterna Chyli Fistula During Percutaneous Balloon Aortoplasty in a Patient with Takayasu's Arteritis: A Case Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hwang, Hye Sun; Shin, Sung Wook, E-mail: swshin@smc.samsung.co.kr; Kim, Eun Hui

2007-04-15

We present a case of iatrogenic aorto-cisterna chyli fistula that developed during percutaneous transluminal aortoplasty in a 16-year old girl with Takayasu's arteritis. The aorto-cisterna chyli fistula was angiographically confirmed and treated using a stent-graft, which successfully occluded the fistula. Her claudication then improved, although follow-up CT angiography at 10 months revealed mild recurrent aortic stenosis.

Genesis of Interplanetary Intermittent Turbulence: a Case Study of Rope-Rope Magnetic Reconnection

NASA Technical Reports Server (NTRS)

Chian, Abraham C.- L.; Feng, Heng Q.; Hu, Qiang; Loew, Murray H.; Miranda, Rodrigo A.; Munoz, Pablo R.; Sibeck, David G.; Wu, De J.

2016-01-01

In a recent paper, the relation between current sheet, magnetic reconnection, and turbulence at the leading edge of an interplanetary coronal mass ejection was studied. We report here the observation of magnetic reconnection at the interface region of two interplanetary magnetic flux ropes. The front and rear boundary layers of three interplanetary magnetic flux ropes are identified, and the structures of magnetic flux ropes are reconstructed by the Grad Shafranov method. A quantitative analysis of the reconnection condition and the degree of intermittency reveals that rope-rope magnetic reconnection is the most likely site for genesis of interplanetary intermittency turbulence in this event. The dynamic pressure pulse resulting from this reconnection triggers the onset of a geomagnetic storm.

One time quantitative PCR detection of Pseudomonas aeruginosa to discriminate intermittent from chronic infection in cystic fibrosis.

PubMed

Boutin, Sébastien; Weitnauer, Michael; Hassel, Selina; Graeber, Simon Y; Stahl, Mirjam; Dittrich, A Susanne; Mall, Marcus A; Dalpke, Alexander H

2018-05-01

Chronic airway infection with Pseudomonas aeruginosa is a major risk factor of progression of lung disease in patients with cystic fibrosis (CF). Chronic P. aeruginosa infection evolves from intermittent infection that is amenable to antibiotic eradication, whereas chronically adapted P. aeruginosa becomes resistant to antibiotic therapy. Discrimination of intermittent versus chronic infection is therefore of high therapeutic relevance, yet the available diagnostic methods are only partly satisfactory. The aim of the present study was, therefore, to evaluate the usage of quantitative PCR (qPCR) to measure pathogen abundance and to discriminate between intermittent and chronic Pseudomonas infection in patients with CF. Using an established qPCR protocol, we analyzed the abundance of P. aeruginosa in 141 throats swabs and 238 sputa from CF patients with intermittent or chronic infection with P. aeruginosa, as determined by standard culture based diagnostics. We observed a large increase of abundance of P. aeruginosa in throat swabs and sputum samples from patients with chronic compared to intermittent infections with P. aeruginosa. The data show that abundance of P. aeruginosa as measured by qPCR is a valuable tool to discriminate intermittent from chronic infection. Of note, P. aeruginosa burden seems more sensitive than mucoidity phenotype to discriminate chronic from intermittent strains. Furthermore we observed that molecular detection in throat swabs was linked to a viable culture in the sputum when sputum was available. This result is of special interest in young patients with cystic fibrosis that often cannot expectorate sputum. We also observed that qPCR in comparison to culture detected the infection earlier. The results suggest that qPCR detection and quantification of P. aeruginosa is a precious tool to be added to the diagnostic toolbox in cystic fibrosis. Copyright © 2018 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

[Activation of autophagy pathway in hippocampus and deterioration of learning and memory ability by intermittent hypoxia in rats after cerebral ischemia].

PubMed

Guo, Xiangfei; Zhao, Yaning; Li, Jianmin; Liu, Wenqian; Chen, Changxiang

2016-09-01

Objective To investigate the effects of different duration of intermittent hypoxia on the autophagy pathway in the hippocampus and the learning and memory ability after cerebral ischemia in rats. Methods 100 male Wistar rats were randomly divided into sham operation (SO) group, ischemia/reperfusion (I/R) group, intermittent hypoxia for 7 days combined with ischemia/reperfusion (IH7-I/R) group, intermittent hypoxia for 14 days combined with ischemia/reperfusion (IH14-I/R) group, intermittent hypoxia for 21 days combined with ischemia/reperfusion (IH21-I/R) group, n =20 in each group. The rats in IH7-I/R group, IH14-I/R group and IH21-I/R group were respectively subjected to intermittent hypoxia for 7, 14 and 21 days prior to I/R modeling by improved Pulsinelli four-vessel occlusion (4-VO). The morphological changes of nerve cells in the hippocampus of rat brain were detected by HE staining; the levels of mammalian target of rapamycin (mTOR) and beclin 1 mRNA in the hippocampus were determined by quantitative real-time PCR; the distribution of mTOR and beclin 1 in the hippocampus was observed by immunohistochemistry; the learning and memory ability of rats was assessed by the Morris water maze test. Results Compared with the SO group, the never cell morphology was damaged, the number of survival neurons in the hippocampus was reduced, the expressions of mTOR and beclin 1 in the hippocampus were strengthened, and the learning and memory ability declined in the I/R group. Compared with the I/R group, the never cell morphology was damaged seriously, the number of survival neurons in the hippocampus decreased, the expressions of mTOR and beclin 1 in the hippocampus increased, and the learning and memory ability dropped in the intermittent hypoxia groups. What's more, the above changes were dependent on the duration of intermittent hypoxia. Conclusion Intermittent hypoxia aggravates the dysfunction of learning and memory after cerebral ischemia and the damages increase with time passing, which are related to mTOR-beclin 1 activation and increasing neuronal cell death.

An integrative review: application of self-efficacy instruments for walking in populations with peripheral arterial disease.

PubMed

Caldieraro-Bentley, Angela J; Andrews, Jeannette O

2013-09-01

The study objective was to identify which self-efficacy measurement instruments are being used for walking in patients with peripheral arterial disease (PAD), the psychometrics of these instruments, and recommendations for use in research on patients with PAD. PAD is a common problem for individuals with similar risk factors as cardiovascular disease (CVD). Experts recommend a supervised walking program with incremental increases in speed and distance as an initial treatment for patients with intermittent claudication. Because patients may experience pain while walking, there is a tendency to be nonadherent with exercise therapy, and many limit or avoid walking all together, resulting in a sedentary lifestyle. Self-efficacy plays a role in determining a person's confidence in his or her ability to participate in an exercise program. Data sources for this study were PubMed, Cumulative Index of Nursing and Allied Health Literature, PsycINFO, and the Cochrane database. The integrative review method described by Wittemore and Knafl was used for this review (Wittemore R, Knafl K. The integrative review: updated methodology. J Adv Nurs 2005;52:546-53.). Publications were retrieved electronically and reviewed for inclusion on the basis of studies that measured self-efficacy for walking in populations with PAD, peripheral vascular disease, and CVD. The analysis consisted of 9 publications. Only 2 studies were specific to the population with PAD. The remaining studies addressed self-efficacy issues in CVD or congestive heart failure. The analysis identified 4 instruments based on Bandura's Social Cognitive Theory that were used to assess self-efficacy: (1) the Self-Efficacy Expectation Scale, (2) the Self-Efficacy for Managing Chronic Disease Scale, (3) the Performance-Based Efficacy Scale, and (4) the Barriers Self-Efficacy Scale. The Self-Efficacy Expectation Scale was most frequently used in these studies. The use of the Self-Efficacy Expectation Scale instruments for walking in patients with PAD is limited because reliability and validity have been demonstrated in an older, mostly white population with CVD and congestive heart failure. Instruments that encompass the key constructs of self-efficacy, including physical, personal, and environmental aspects, would allow full evaluation with identification of potential explanations for success or failure for the chosen outcome. This should be taken into consideration in future studies when using instruments of self-efficacy. Copyright © 2013 Society for Vascular Nursing, Inc. Published by Mosby, Inc. All rights reserved.

Peripheral Arterial Disease and Ankle-Brachial Pressure Index as Predictors of Mortality in Residents of Metlika County, Slovenia

PubMed Central

Mlačak, Blaž; Blinc, Aleš; Pohar, Maja; Stare, Janez

2006-01-01

Aim To test how the presence of peripheral arterial disease predicted mortality of middle-aged and elderly residents of Metlika county, a rural area in southeastern Slovenia. Methods In 1987, we interviewed and examined a representative cohort of 646 subjects aged 45-80 years at inclusion without overt coronary or cerebrovascular disease, for cardiovascular risk factors and measured the ankle-brachial pressure index (ABPI). Peripheral arterial disease was defined as ABPI<0.90. The subjects were followed up 15 years or until death. All-cause mortality and cardiovascular mortality were assessed and compared between subjects with and without peripheral arterial disease in a multivariate model. Results There were 580 subjects with normal ABPI and 66 subjects with peripheral arterial disease, among which 49 were asymptomatic and 17 had intermittent claudication. Because subjects with peripheral arterial disease were on average 10 years older than those without peripheral arterial disease, the mere presence of peripheral arterial disease was not an independent predictor of mortality. However, there was a significant interaction of peripheral arterial disease with age, with a more pronounced adverse prognostic effect of peripheral arterial disease in younger than in older age groups. For a 55-year-old subject with peripheral arterial disease, the hazard ratio of dying from any cause in the follow-up period was 2.44 (95% confidence interval [CI], 1.15-4.96) in comparison to an age-matched subject without peripheral arterial disease, but at 75 years of age, the hazard ratio decreased to only 0.71 (95% CI, 0.46-1.09). For cardiovascular mortality, the hazard ratio in the presence of peripheral arterial disease was 6.05 (95% CI, 1.87-16.27) at 55 years and 0.92 (95% CI, 0.54-1.52) at 75 years. Among patients with peripheral arterial disease, each decrement of ABPI at inclusion by 0.10 significantly increased the cardiovascular mortality after 15 years by 30% (P = 0.038). Conclusion Peripheral arterial disease, even asymptomatic, is an important predictor of adverse cardiovascular prognosis in relatively young patients. Reduced ABPI is a strong, independent predictor of cardiovascular mortality in all patients with peripheral arterial disease. PMID:16625701

EDTA-assisted leaching of Pb and Cd from contaminated soil.

PubMed

Qiao, Jiangbo; Sun, Huimin; Luo, Xiuhua; Zhang, Wang; Mathews, Shiny; Yin, Xianqiang

2017-01-01

Lead (Pb) and cadmium (Cd) contamination of soil and its harmful effects on human and environmental health have been one concern. In this study, batch and column leaching experiments were conducted to investigate the effects of two EDTA-assisted leaching methods, continuous and intermittent (dry-wet alternate), on the removal of Pb and Cd from contaminated soil. Total content and fractions of Pb and Cd at every 1 cm soil column depth were analyzed before and after the leaching. The results indicated that continuous leaching removed 75.43% of Pb (19.370 mg) and 53.21% of Cd (6.168 mg) and intermittent leaching removed 78.08% of Pb (20.051 mg) and 57.37% of Cd (6.650 mg), which showed intermittent leaching removed more Pb and Cd, but didn't differ significantly (P > 0.05) compared to the continuous leaching. In both leaching methods, total Pb and Cd content in all soil depths reduced after leaching. The two leaching methods made no significant differences in Pb and Cd distributions at different depths of the soil column. Copyright © 2016 Elsevier Ltd. All rights reserved.

Diagnosis of Magnetic Structures and Intermittency in Space Plasma Turbulence using the Method of Surrogate Data

NASA Technical Reports Server (NTRS)

Sahraoui, Fouad; Goldstein, Melvyn

2008-01-01

Several observations in space plasmas have reported the presence of coherent structures at different plasma scales. Structure formation is believed to be a direct consequence of nonlinear interactions between the plasma modes, which depend strongly on phase synchronization of those modes. Despite this important role of the phases in turbulence, very limited work has been however devoted to study the phases as a potential tracers of nonlinearities in comparison with the wealth of literature on power spectra of turbulence where phases are totally missed. We present a method based on surrogate data to systematically detect coherent structures in turbulent signals. The new method has been applied successfully to magnetosheath turbulence (Sahraoui, Phys. Rev. E, 2008, in press), where the relationship between the identified phase coherence and intermittency (classically identified as non Gaussian tails of the PDFs) as well as the energy cascade has been studied. Here we review the main results obtained in that study and show further applications to small scale solar wind turbulence. Implications of the results on theoretical modelling of space turbulence (applicability of weak/wave turbulence, its validity limits and its connection to intermittency) will be discussed.

Assessment of score- and Rasch-based methods for group comparison of longitudinal patient-reported outcomes with intermittent missing data (informative and non-informative).

PubMed

de Bock, Élodie; Hardouin, Jean-Benoit; Blanchin, Myriam; Le Neel, Tanguy; Kubis, Gildas; Sébille, Véronique

2015-01-01

The purpose of this study was to identify the most adequate strategy for group comparison of longitudinal patient-reported outcomes in the presence of possibly informative intermittent missing data. Models coming from classical test theory (CTT) and item response theory (IRT) were compared. Two groups of patients' responses to dichotomous items with three times of assessment were simulated. Different cases were considered: presence or absence of a group effect and/or a time effect, a total of 100 or 200 patients, 4 or 7 items and two different values for the correlation coefficient of the latent trait between two consecutive times (0.4 or 0.9). Cases including informative and non-informative intermittent missing data were compared at different rates (15, 30 %). These simulated data were analyzed with CTT using score and mixed model (SM) and with IRT using longitudinal Rasch mixed model (LRM). The type I error, the power and the bias of the group effect estimations were compared between the two methods. This study showed that LRM performs better than SM. When the rate of missing data rose to 30 %, estimations were biased with SM mainly for informative missing data. Otherwise, LRM and SM methods were comparable concerning biases. However, regardless of the rate of intermittent missing data, power of LRM was higher compared to power of SM. In conclusion, LRM should be favored when the rate of missing data is higher than 15 %. For other cases, SM and LRM provide similar results.

Local Inhibition of HSP90 to Prevent Intimal Hyperplasia after Balloon Injury

DTIC Science & Technology

2017-10-01

Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Peripheral arterial disease (PAD) remains a major threat to life and limb and represents a disabling and...Organizations…………… 5 1 1. INTRODUCTION: Peripheral arterial disease (PAD) is a significant health problem that affects the aging military and veteran...population, ranging from lifestyle limiting claudication to major amputation and death. Further, there is growing rate of disorders in Cardiovascular Health

GENESIS OF INTERPLANETARY INTERMITTENT TURBULENCE: A CASE STUDY OF ROPE–ROPE MAGNETIC RECONNECTION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chian, Abraham C.-L.; Loew, Murray H.; Feng, Heng Q.

In a recent paper, the relation between current sheet, magnetic reconnection, and turbulence at the leading edge of an interplanetary coronal mass ejection was studied. We report here the observation of magnetic reconnection at the interface region of two interplanetary magnetic flux ropes. The front and rear boundary layers of three interplanetary magnetic flux ropes are identified, and the structures of magnetic flux ropes are reconstructed by the Grad–Shafranov method. A quantitative analysis of the reconnection condition and the degree of intermittency reveals that rope–rope magnetic reconnection is the most likely site for genesis of interplanetary intermittency turbulence in this event.more » The dynamic pressure pulse resulting from this reconnection triggers the onset of a geomagnetic storm.« less

The effects of intermittency on statistical characteristics of turbulence and scale similarity of breakdown coefficients

NASA Astrophysics Data System (ADS)

Novikov, E. A.

1990-05-01

The influence of intermittency on turbulent diffusion is expressed in terms of the statistics of the dissipation field. The high-order moments of relative diffusion are obtained by using the concept of scale similarity of the breakdown coefficients (bdc). The method of bdc is useful for obtaining new models and general results, which then can be expressed in terms of multifractals. In particular, the concavity and other properties of spectral codimension are proved. Special attention is paid to the logarithmically periodic modulations. The parametrization of small-scale intermittent turbulence, which can be used for large-eddy simulation, is presented. The effect of molecular viscosity is taken into account in the spirit of the renorm group, but without spectral series, ɛ expansion, and fictitious random forces.

Comparison of the Calculations Results of Heat Exchange Between a Single-Family Building and the Ground Obtained with the Quasi-Stationary and 3-D Transient Models. Part 2: Intermittent and Reduced Heating Mode

NASA Astrophysics Data System (ADS)

Staszczuk, Anna

2017-03-01

The paper provides comparative results of calculations of heat exchange between ground and typical residential buildings using simplified (quasi-stationary) and more accurate (transient, three-dimensional) methods. Such characteristics as building's geometry, basement hollow and construction of ground touching assemblies were considered including intermittent and reduced heating mode. The calculations with simplified methods were conducted in accordance with currently valid norm: PN-EN ISO 13370:2008. Thermal performance of buildings. Heat transfer via the ground. Calculation methods. Comparative estimates concerning transient, 3-D, heat flow were performed with computer software WUFI®plus. The differences of heat exchange obtained using more exact and simplified methods have been specified as a result of the analysis.

A comparative study of percutaneous atherectomy for femoropopliteal arterial occlusive disease.

PubMed

Gu, Yongquan; Malas, Mahmoud B; Qi, Lixing; Guo, Lianrui; Guo, Jianming; Yu, Hengxi; Tong, Zhu; Gao, Xixiang; Zhang, Jian; Wang, Zhonggao

2017-08-01

SilverHawk™ directional atherectomy has been used to treat more than 300 thousand cases of lower extremity atherosclerotic occlusive disease in the world since it was approved by FDA in 2003. This study aimed to analyze the safety and effectiveness of symptomatic femoral popliteal atherosclerotic disease treated by directional atherectomy (DA). Clinical data of all consecutive patients treated with percutaneous atherectomy utilizing the SilverHawk™ plaque excision was retrospectively analyzed. The anatomic criteria of the atherosclerotic lesions were divided into four types: type I stenosis; type II occlusion; type III in-stent restenosis; type IV stent occlusion. There were 160 patients treated during the study period. Intermittent claudication in 75 patients (47%), rest pain in 55 patients (34.5%) and tissue loss in 30 patients (18.5%). The number of patients was 72, 15, 49 and 24 in type I, II, III and IV lesions, respectively. Technical success rate was 98.6%, 93.3%, 97.9% and 91.7% in type I, II, III and IV lesions, respectively. Debris of intimal plaque was captured by protection device in 92 patients (71.3%). The mean follow-up period was 23.5±10.4 months. Restenosis rate of type I to IV lesions was 21%, 36%, 36% and 40% respectively. Restenosis rate in type I lesion was significantly lower than that in type III and IV lesions (P<0.05). Patients with tissue loss responded to revascularization as follow: type I, 11/13 healed or reduced (84.6%), type II, 3/3 patients improved (100%), type III, 5/6 patients improved (83.3%) and type IV 4/4 healed (100%). In type IV group, four patients had in-stent thrombosis found by postoperative Duplex ultrasonography. They all underwent DA after catheter-directed thrombolysis with good angiographic results. Percutaneous DA is safe and effective for both de-novo atherosclerotic and in-stent stenotic or occlusive lesions. Thrombolysis before plaque excision is recommended in case of in-stenting thrombosis.

Matrix metalloproteinase 10 is associated with disease severity and mortality in patients with peripheral arterial disease.

PubMed

Martinez-Aguilar, Esther; Gomez-Rodriguez, Violeta; Orbe, Josune; Rodriguez, Jose A; Fernández-Alonso, Leopoldo; Roncal, Carmen; Páramo, Jose A

2015-02-01

Peripheral arterial disease (PAD) is associated with poor prognosis in terms of cardiovascular (CV) morbidity and mortality. Matrix metalloproteinases (MMPs) contribute to vascular remodeling by degrading extracellular matrix components and play a role in atherosclerosis as demonstrated for MMP-10 (stromelysin-2). This study analyzed MMP-10 levels in PAD patients according to disease severity and CV risk factors and evaluated the prognostic value of MMP-10 for CV events and mortality in lower limb arterial disease after a follow-up period of 2 years. MMP-10 was measured by enzyme-linked immunosorbent assay in 187 PAD patients and 200 sex-matched controls. PAD patients presented with increased levels of MMP-10 (702 ± 326 pg/mL control vs 946 ± 473 pg/mL PAD; P < .001) and decreased levels of tissue inhibitor of matrix metalloproteinase 1 (312 ± 117 ng/mL control vs 235 ± 110 ng/mL PAD; P < .001) compared with controls. Among PAD patients, those with critical limb ischemia (n = 88) showed higher levels of MMP-10 (1086 ± 478 pg/mL vs 822 ± 436 pg/mL; P < .001) compared with those with intermittent claudication (n = 99), whereas the MMP-10/tissue inhibitor of matrix metalloproteinase 1 ratio remained similar. The univariate analysis showed an association between MMP-10, age (P = .015), hypertension (P = .021), and ankle-brachial index (P = .006) in PAD patients that remained significantly associated with PAD severity after adjustment for other CV risk factors. Patients with the highest MMP-10 tertile had an increased incidence of all-cause mortality and CV mortality (P < .03). Our results suggest that MMP-10 is associated with severity and poor outcome in PAD. Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Herpes zoster as a risk factor for stroke and TIA: a retrospective cohort study in the UK.

PubMed

Breuer, Judith; Pacou, Maud; Gautier, Aline; Brown, Martin M

2014-07-08

Stroke and TIA are recognized complications of acute herpes zoster (HZ). Herein, we evaluate HZ as a risk factor for cerebrovascular disease (stroke and TIA) and myocardial infarction (MI) in a UK population cohort. A retrospective cohort of 106,601 HZ cases and 213,202 controls, matched for age, sex, and general practice, was identified from the THIN (The Health Improvement Network) general practice database. Cox proportional hazard models were used to examine the risks of stroke, TIA, and MI in cases and controls, adjusted for vascular risk factors, including body mass index >30 kg/m(2), smoking, cholesterol >6.2 mmol/L, hypertension, diabetes, ischemic heart disease, atrial fibrillation, intermittent arterial claudication, carotid stenosis, and valvular heart disease, over 24 (median 6.3) years after HZ infection. Risk factors for vascular disease were significantly increased in cases of HZ compared with controls. Adjusted hazard ratios for TIA and MI but not stroke were increased in all patients with HZ (adjusted hazard ratios [95% confidence intervals]: 1.15 [1.09-1.21] and 1.10 [1.05-1.16], respectively). However, stroke, TIA, and MI were increased in cases whose HZ occurred when they were younger than 40 years (adjusted hazard ratios [95% confidence intervals]: 1.74 [1.13-2.66], 2.42 [1.34-4.36], and 1.49 [1.04-2.15], respectively). Subjects younger than 40 years were significantly less likely to be asked about vascular risk factors compared with older patients (p < 0.001). HZ is an independent risk factor for vascular disease in the UK population, particularly for stroke, TIA, and MI in subjects affected before the age of 40 years. In older subjects, better ascertainment of vascular risk factors and earlier intervention may explain the reduction in risk of stroke after HZ infection. © 2014 American Academy of Neurology.

Angiotensin-converting enzyme inhibitors in patients with coronary artery disease and absence of heart failure or left ventricular systolic dysfunction: an overview of long-term randomized controlled trials.

PubMed

Danchin, Nicolas; Cucherat, Michel; Thuillez, Christian; Durand, Eric; Kadri, Zena; Steg, Philippe G

2006-04-10

Results of randomized trials of angiotensin-converting enzyme inhibitors in patients with coronary artery disease (CAD) and preserved left ventricular function are conflicting. We undertook this study to determine whether long-term prescription of angiotensin-converting enzyme inhibitors decreases major cardiovascular events and mortality in patients who have CAD and no evidence of left ventricular systolic dysfunction. We searched MEDLINE, EMBASE, and IPA databases, the Cochrane Controlled Trials Register (1990-2004), and reports from scientific meetings (2003-2004), and we reviewed secondary sources. Search terms included angiotensin-converting enzyme inhibitors, coronary artery disease, randomi(s)zed controlled trials, clinical trials, and myocardial infarction. Eligible studies included randomized controlled trials in patients who had CAD and no heart failure or left ventricular dysfunction, with follow-up omicronf 2 years or longer. Of 1146 publications screened, 7 met our selection criteria and included a total of 33 960 patients followed up for a mean of 4.4 years. Five trials included only patients with documented CAD. One trial included patients with documented CAD (80%) or patients who had diabetes mellitus and 1 or more additional risk factors, and another trial included patients who had CAD, a history of transient ischemic attack, or intermittent claudication. Treatment with angiotensin-converting enzyme inhibitors decreased overall mortality (odds ratio, 0.86; 95% confidence interval, 0.79-0.93), cardiovascular mortality (odds ratio, 0.81; 95% confidence interval, 0.73-0.90), myocardial infarction (odds ratio, 0.82; 95% confidence interval, 0.75-0.89), and stroke (odds ratio, 0.77; 95% confidence interval, 0.66-0.88). Other end points, including resuscitation after cardiac arrest, myocardial revascularization, and hospitalization because of heart failure, were also reduced. Angiotensin-converting enzyme inhibitors reduce total mortality and major cardiovascular end points in patients who have CAD and no left ventricular systolic dysfunction or heart failure.

Trial of a Paclitaxel-Coated Balloon for Femoropopliteal Artery Disease.

PubMed

Rosenfield, Kenneth; Jaff, Michael R; White, Christopher J; Rocha-Singh, Krishna; Mena-Hurtado, Carlos; Metzger, D Christopher; Brodmann, Marianne; Pilger, Ernst; Zeller, Thomas; Krishnan, Prakash; Gammon, Roger; Müller-Hülsbeck, Stefan; Nehler, Mark R; Benenati, James F; Scheinert, Dierk

2015-07-09

The treatment of peripheral artery disease with percutaneous transluminal angioplasty is limited by the occurrence of vessel recoil and restenosis. Drug-coated angioplasty balloons deliver antiproliferative agents directly to the artery, potentially improving vessel patency by reducing restenosis. In this single-blind, randomized trial conducted at 54 sites, we assigned, in a 2:1 ratio, 476 patients with symptomatic intermittent claudication or ischemic pain while at rest and angiographically significant atherosclerotic lesions to angioplasty with a paclitaxel-coated balloon or to standard angioplasty. The primary efficacy end point was primary patency of the target lesion at 12 months (defined as freedom from binary restenosis or from the need for target-lesion revascularization). The primary safety end point was a composite of freedom from perioperative death from any cause and freedom at 12 months from limb-related death (i.e., death from a medical complication related to a limb), amputation, and reintervention. The two groups were well matched at baseline; 42.9% of the patients had diabetes, and 34.7% were current smokers. At 12 months, the rate of primary patency among patients who had undergone angioplasty with the drug-coated balloon was superior to that among patients who had undergone conventional angioplasty (65.2% vs. 52.6%, P=0.02). The proportion of patients free from primary safety events was 83.9% with the drug-coated balloon and 79.0% with standard angioplasty (P=0.005 for noninferiority). There were no significant between-group differences in functional outcomes or in the rates of death, amputation, thrombosis, or reintervention. Among patients with symptomatic femoropopliteal peripheral artery disease, percutaneous transluminal angioplasty with a paclitaxel-coated balloon resulted in a rate of primary patency at 12 months that was higher than the rate with angioplasty with a standard balloon. The drug-coated balloon was noninferior to the standard balloon with respect to safety. (Funded by Lutonix-Bard; LEVANT 2 ClinicalTrials.gov number, NCT01412541.).

The coral reef aorta - a single centre experience in 70 patients.

PubMed

Grotemeyer, Dirk; Pourhassan, Siamak; Rehbein, Hermann; Voiculescu, Adina; Reinecke, Petra; Sandmann, Wilhelm

2007-01-01

Coral reef aorta (CRA) is described as rock-hard calcifications in the visceral part of the aorta. These heavily calcified plaques grow into the lumen and can cause significant stenoses, which may lead to malperfusion of the lower limbs, visceral ischemia or hypertension due to renal ischemia. From January 1984 to February 2007, 70 patients (24 men, 46 women, mean age 59.5 years, range 14 to 81 years) underwent treatment in the Department of Vascular Surgery and Renal Transplantation, University Hospital, Heinrich-Heine-University (Düsseldorf, Germany) for CRA. The present study is based on a review of patients' records and the prospective follow-up in the outpatient clinic. The most frequent finding was renovascular arterial hypertension (44.3%) causing headache, vertigo and visual symptoms. Intermittent claudication due to peripheral arterial occlusive disease was found in 28 patients (40.0%). Seventeen patients (24.3%) presented with chronic visceral ischemia causing diarrhea, weight loss and abdominal pain. Sixty-nine of the 70 patients (98.6%) underwent surgery; in 57 patients, aortic reconstruction was achieved with thromboendarterectomy, performed on an isolated suprarenal segment in six cases (8.7%), an infrarenal segment in 15 cases (21.7%), and the supra- and infrarenal aorta in 43 cases (62.3%). Eight patients (11.6%) died during or soon after surgery. Postoperative complications requiring corrective surgery occurred in 11 patients (15.9%). Almost one-third of the patients (n=19, 27.5%) returned for follow-up after a mean of 52.6 months (range six to 215 months). Of the 19 patients, there was significant clinical and diagnostic improvement in 16 patients (84.2%) and three patients (15.8%) were unchanged. Impairment was not observed. Despite the existing and improving surgical techniques for the treatment of CRA, its pathophysiological basis and genesis is not yet understood.

Validity and reliability of the session-RPE method for quantifying training in Australian football: a comparison of the CR10 and CR100 scales.

PubMed

Scott, Tannath J; Black, Cameron R; Quinn, John; Coutts, Aaron J

2013-01-01

The purpose of this study was to examine and compare the criterion validity and test-retest reliability of the CR10 and CR100 rating of perceived exertion (RPE) scales for team sport athletes that undertake high-intensity, intermittent exercise. Twenty-one male Australian football (AF) players (age: 19.0 ± 1.8 years, body mass: 83.92 ± 7.88 kg) participated the first part (part A) of this study, which examined the construct validity of the session-RPE (sRPE) method for quantifying training load in AF. Ten male athletes (age: 16.1 ± 0.5 years) participated in the second part of the study (part B), which compared the test-retest reliability of the CR10 and CR100 RPE scales. In part A, the validity of the sRPE method was assessed by examining the relationships between sRPE, and objective measures of internal (i.e., heart rate) and external training load (i.e., distance traveled), collected from AF training sessions. Part B of the study assessed the reliability of sRPE through examining the test-retest reliability of sRPE during 3 different intensities of controlled intermittent running (10, 11.5, and 13 km·h(-1)). Results from part A demonstrated strong correlations for CR10- and CR100-derived sRPE with measures of internal training load (Banisters TRIMP and Edwards TRIMP) (CR10: r = 0.83 and 0.83, and CR100: r = 0.80 and 0.81, p < 0.05). Correlations between sRPE and external training load (distance, higher speed running and player load) for both the CR10 (r = 0.81, 0.71, and 0.83) and CR100 (r = 0.78, 0.69, and 0.80) were significant (p < 0.05). Results from part B demonstrated poor reliability for both the CR10 (31.9% CV) and CR100 (38.6% CV) RPE scales after short bouts of intermittent running. Collectively, these results suggest both CR10- and CR100-derived sRPE methods have good construct validity for assessing training load in AF. The poor levels of reliability revealed under field testing indicate that the sRPE method may not be sensible to detecting small changes in exercise intensity during brief intermittent running bouts. Despite this limitation, the sRPE remains a valid method to quantify training loads in high-intensity, intermittent team sport.

Effects of intermittent fasting and chronic swimming exercise on body composition and lipid metabolism.

PubMed

Moraes, Ruan Carlos Macedo de; Portari, Guilherme Vannucchi; Ferraz, Alex Soares Marreiros; da Silva, Tiago Eugênio Oliveira; Marocolo, Moacir

2017-12-01

Intermittent fasting protocol (IFP) has been suggested as a strategy to change body metabolism and improve health. The effects of IFP seem to be similar to aerobic exercise, having a hormetic adaptation according to intensity and frequency. However, the effects of combining both interventions are still unknown. Therefore, the aim of the present study was to evaluate the effects of IFP with and without endurance-exercise training on body composition, food behavior, and lipid metabolism. Twenty-week-old Wistar rats were kept under an inverted circadian cycle of 12 h with water ad libitum and assigned to 4 different groups: control group (ad libitum feeding and sedentary), exercise group (ad libitum feeding and endurance training), intermittent fasting group (IF; intermittent fasting and sedentary), and intermittent fasting and exercise group (IFEX; intermittent fasting and endurance training). After 6 weeks, the body weight of IF and IFEX animals decreased without changes in food consumption. Yet, the body composition between the 2 groups was different, with the IFEX animals containing higher total protein and lower total fat content than the IF animals. The IFEX group also showed increases in total high-density lipoprotein cholesterol and increased intramuscular lipid content. The amount of brown adipose tissue was higher in IF and IFEX groups; however, the IFEX group showed higher expression levels of uncoupling protein 1 in this tissue, indicating a greater thermogenesis. The IFP combined with endurance training is an efficient method for decreasing body mass and altering fat metabolism, without inflicting losses in protein content.

Hybrid optimal scheduling for intermittent androgen suppression of prostate cancer

NASA Astrophysics Data System (ADS)

Hirata, Yoshito; di Bernardo, Mario; Bruchovsky, Nicholas; Aihara, Kazuyuki

2010-12-01

We propose a method for achieving an optimal protocol of intermittent androgen suppression for the treatment of prostate cancer. Since the model that reproduces the dynamical behavior of the surrogate tumor marker, prostate specific antigen, is piecewise linear, we can obtain an analytical solution for the model. Based on this, we derive conditions for either stopping or delaying recurrent disease. The solution also provides a design principle for the most favorable schedule of treatment that minimizes the rate of expansion of the malignant cell population.

Optimization of continuous and intermittent microwave extraction of pectin from banana peels.

PubMed

Swamy, Gabriela John; Muthukumarappan, Kasiviswanathan

2017-04-01

Continuous and intermittent microwave-assisted extractions were used to extract pectin from banana peels. Extraction parameters which were employed in the continuous process were microwave power (300-900W), time (100-300s), pH (1-3) and in the intermittent process were microwave power (300-900W), pulse ratio (0.5-1), pH (1-3). The independent factors were optimized with the Box-Behnken response surface design (BBD) (three factor three level) with the desirability function methodology. Results indicate that the independent factors have substantial effect on the pectin yield. Optimized solutions for highest pectin yield (2.18%) from banana peels were obtained with microwave power of 900W, time 100s and pH 3.00 in the continuous method while the intermittent process yielded the highest pectin content (2.58%) at microwave power of 900W, pulse ratio of 0.5 and pH of 3.00. The optimized conditions were validated and close agreement was observed with the validation experiment and predicted value. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ultrastructure of medial rectus muscles in patients with intermittent exotropia.

PubMed

Yao, J; Wang, X; Ren, H; Liu, G; Lu, P

2016-01-01

PURPOSE To study the ultrastructure of the medial rectus in patients with intermittent exotropia at different ages.PATIENTS AND METHODS The medial recti were harvested surgically from 20 patients with intermittent exotropia. Patients were divided into adolescent (age<18 years, n=10) and adult groups (age >18 years, n=10). The normal control group included five patients without strabismus and undergoing eye enucleation. Hematoxylin and eosin staining and transmission electron microscopy were used to visualize the medial recti. Western blot was used to determine the levels of myosin and actin.RESULTS Varying fiber thickness, atrophy, and misalignment of the medial recti were visualized under optical microscope in patients with exotropia. Electron microscopy revealed sarcomere destruction, myofilament disintegration, unclear dark and light bands, collagen proliferation, and fibrosis. The adolescent group manifested significantly higher levels of myosin and actin than the adult group (P<0.05).CONCLUSION Younger patients with intermittent exotropia show stronger contraction of the medial recti compared with older patients. Our findings suggest that childhood was the appropriate time for surgery as the benefit of the intervention was better than in adulthood.

Intelligent Structured Intermittent Auscultation (ISIA): evaluation of a decision-making framework for fetal heart monitoring of low-risk women

PubMed Central

2014-01-01

Background Research-informed fetal monitoring guidelines recommend intermittent auscultation (IA) for fetal heart monitoring for low-risk women. However, the use of cardiotocography (CTG) continues to dominate many institutional maternity settings. Methods A mixed methods intervention study with before and after measurement was undertaken in one secondary level health service to facilitate the implementation of an initiative to encourage the use of IA. The intervention initiative was a decision-making framework called Intelligent Structured Intermittent Auscultation (ISIA) introduced through an education session. Results Following the intervention, medical records review revealed an increase in the use of IA during labour represented by a relative change of 12%, with improved documentation of clinical findings from assessments, and a significant reduction in the risk of receiving an admission CTG (RR 0.75, 95% CI, 0.60 – 0.95, p = 0.016). Conclusion The ISIA informed decision-making framework transformed the practice of IA and provided a mechanism for knowledge translation that enabled midwives to implement evidence-based fetal heart monitoring for low risk women. PMID:24884597

Hybrid Endovascular Aortic Aneurysm Repair: Preservation of Pelvic Perfusion with External to Internal Iliac Artery Bypass.

PubMed

Mansukhani, Neel A; Havelka, George E; Helenowski, Irene B; Rodriguez, Heron E; Hoel, Andrew W; Eskandari, Mark K

2017-07-01

Diminished pelvic arterial flow as a result of intentional coverage/embolization of internal iliac arteries (IIA) during isolated endovascular common iliac artery aneurysm (CIAA) repair or endovascular repair of abdominal aortic aneurysms (EVAR) may result in symptomatic pelvic ischemia. Although generally well tolerated, in severe cases, pelvic ischemia may manifest as recalcitrant buttock claudication, vasculogenic impotence, or perineal, vesicle, rectal, and/or spinal cord ischemia. Branched graft technology has recently become available; however, many patients are not candidates for endovascular repair with these devices. Therefore, techniques to preserve pelvic arterial flow are needed. We reviewed our outcomes of isolated endovascular CIAA repair or EVAR in conjunction with unilateral external-internal iliac artery bypass. Single-center, retrospective review of 10 consecutive patients who underwent hybrid endovascular abdominal aortic aneurysm (AAA) or CIAA repair with concomitant external-internal iliac artery bypass between 2006 and 2015. Demographics, index procedural details, postoperative symptoms, hospital length of stay (LOS), follow-up imaging, and bypass patency were recorded. The cohort of 10 patients was all men with a mean age of 71 years (range: 56-84). Hybrid repair consisted of contralateral IIA coil embolization followed by EVAR with external iliac artery-internal iliac artery (EIA-IIA) bypass. All EIA-IIA bypasses were performed via a standard lower quadrant retroperitoneal approach with a prosthetic bypass graft. Technical success was 100%, and there were no perioperative deaths. One patient developed transient paraplegia, 1 patient had buttock claudication on the side of his hypogastric embolization contralateral to his iliac bypass, and 1 developed postoperative impotence. 20% of patients sustained long-term complications (buttock claudication and postoperative impotence). Mean LOS was 2.8 days (range: 1-9 days). Postoperative imaging was obtained in 90% of patients, and mean follow-up was 10.8 months (range: 0.5-36 months). All bypasses remained patent. Although branched graft technology continues to evolve, strategies to maintain adequate pelvic circulation are necessary to avoid the devastating complications of pelvic ischemia. We have demonstrated that a hybrid approach combining EVAR or isolated endovascular common iliac artery exclusion with a unilateral external-internal iliac bypass via a retroperitoneal approach is well tolerated with a short LOS and excellent patency rates. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of aeration method and aeration rate on greenhouse gas emissions during composting of pig feces in pilot scale.

PubMed

Jiang, Tao; Li, Guoxue; Tang, Qiong; Ma, Xuguang; Wang, Gang; Schuchardt, Frank

2015-05-01

The aim of this study was to uncover ways to mitigate greenhouse gas (GHG) emissions and reduce energy consumption during the composting process. We assessed the effects of different aeration rates (0, 0.18, 0.36, and 0.54 L/(kg dry matter (dm)·min)) and methods (continuous and intermittent) on GHG emissions. Pig feces and corn stalks were mixed at a ratio of 7:1. The composting process lasted for 10 weeks, and the compost was turned approximately every 2 weeks. Results showed that both aeration rate and method significantly affected GHG emissions. Higher aeration rates increased NH3 and N2O losses, but reduced CH4 emissions. The exception is that the CH4 emission of the passive aeration treatment was lower than that of the low aeration rate treatment. Without forced aeration, the CH4 diffusion rates in the center of the piles were very low and part of the CH4 was oxidized in the surface layer. Intermittent aeration reduced NH3 and CH4 losses, but significantly increased N2O production during the maturing periods. Intermittent aeration increased the nitrification/denitrification alternation and thus enhanced the N2O production. Forced aeration treatments had higher GHG emission rates than the passive aeration treatment. Forced aeration accelerated the maturing process, but could not improve the quality of the end product. Compared with continuous aeration, intermittent aeration could increase the O2 supply efficiency and reduced the total GHG emission by 17.8%, and this reduction increased to 47.4% when composting was ended after 36 days. Copyright © 2015. Published by Elsevier B.V.

Macroinvertebrate biomonitoring in intermittent coastal plain streams impacted by animal agriculture.

PubMed

Davis, Stephanie; Golladay, Stephen W; Vellidis, George; Pringle, Catherine M

2003-01-01

Little attention has been given to the ecology of intermittent coastal plain streams in the southeastern United States, and it is not known whether available macroinvertebrate biomonitoring methods reliably detect degradation in these streams. This study compared differences in biomonitoring metrics between reference and agricultural streams, and between the flow period (January-April) and the intermittent flow period (May-December). Percentages of crustaceans, isopods, and Ephemeroptera-Plecoptera-Trichoptera (EPT) were significantly higher at the reference site than the two most impacted sites during the flow period, probably resulting from the abundance of leaf litter and lower temperatures. During this same period, the agriculturally impacted sites had a significantly higher percentage of dipterans--a group that thrives in the silty, nutrient-rich waters. Four metrics (percent Crustacea, Isopoda, Diptera, and EPT) had no overlap between values for the most impacted and the least impacted sites during the flow period, but no metrics were able to detect more discrete differences among sites. Sites were physically and biologically similar during the intermittent period when natural stresses (i.e., stagnant water, high temperatures, low dissolved oxygen) were high, with many metrics, such as percentages of dominant family, burrowers, chironomids, and dipterans becoming similar at all sites. Our findings indicate that development of a better understanding of invertebrate fauna in reference conditions and of the natural variation in intermittent streams is necessary to develop effective biomonitoring programs for these systems.

The role of sacroiliac joint dysfunction in the genesis of low back pain: the obvious is not always right.

PubMed

Weksler, Natan; Velan, Gad J; Semionov, Michael; Gurevitch, Boris; Klein, Moti; Rozentsveig, Vsevolod; Rudich, Tzvia

2007-12-01

It is a common practice to the link low back pain with protruding disc even when neurological signs are absent. Because pain caused by sacroiliac joint dysfunction can mimic discogenic or radicular low back pain, we assumed that the diagnosis of sacroiliac joint dysfunction is frequently overlooked. To assess the incidence of sacroiliac joint dysfunction in patients with low back pain and positive disc findings on CT scan or MRI, but without claudication or objective neurological deficits. Fifty patients with low back pain and disc herniation, without claudication or neurological abnormalities such as decreased motor strength, sensory alterations or sphincter incontinence and with positive pain provocation tests for sacroiliac joint dysfunction were submitted to fluoroscopic diagnostic sacroiliac joint infiltration. The mean baseline VAS pain score was 7.8 +/- 1.77 (range 5-10). Thirty minutes after infiltration, the mean VAS score was 1.3 +/- 1.76 (median 0.000E+00 with an average deviation from median = 1.30) (P = 0.0002). Forty-six patients had a VAS score ranging from 0 to 3, 8 weeks after the fluoroscopic guided infiltration. There were no serious complications after treatment. An unanticipated motor block that required hospitalization was seen in four patients, lasting from 12 to 36 h. Sacroiliac joint dysfunction should be considered strongly in the differential diagnosis of low back pain in this group of patients.

Effects of walking with a shopping trolley on spinal posture and loading in subjects with neurogenic claudication.

PubMed

Comer, Christine M; White, Derrick; Conaghan, Philip G; Bird, Howard A; Redmond, Anthony C

2010-10-01

To explore possible mechanisms underpinning symptom relief and improved walking tolerance in patients with neurogenic claudication (NC) when pushing a shopping trolley by evaluating the effects of a shopping trolley on spinal posture and loading patterns. An exploratory study of kinematic and kinetic changes in walking with and without pushing a shopping trolley in persons with NC symptoms and a comparison with asymptomatic control subjects. A primary care-based musculoskeletal service. Participants (n=8) with NC symptoms who have anecdotally reported symptomatic improvement when walking with a shopping trolley and a control group of asymptomatic persons (n=8). Shopping trolley. Changes in lumbar spinal sagittal posture and ground reaction force. Subjects with NC and asymptomatic controls walked with significantly more flexed spinal posture (increase in flexion, 3.40°; z=3.516; P<.001) and reduced mean ground reaction forces (-6.9% of body weight; z=-3.46; P=.001) when walking with a shopping trolley. However, at the midstance point of the gait cycle, controls showed minimal reliance on the trolley, whereas, people with NC showed continued offloading. Both posture and loading are affected by pushing a shopping trolley; however, patients with NC were found to offload the spine throughout the stance phase of gait, whereas asymptomatic controls did not. Copyright © 2010 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Clinical utility of colour flow Doppler ultrasonography in planning anterolateral thigh flap harvest.

PubMed

Patel, Rajan S; Higgins, Kevin M; Enepekides, Danny J; Hamilton, Paul A

2010-10-01

The anatomic variability of cutaneous perforators contributes to the technical challenges of anterolateral thigh (ALT) free flap harvest. The objective of this study was to assess the accuracy and clinical utility of preoperative colour flow Doppler (CFD) ultrasonography in evaluating planned ALT flap donor sites. A prospective study of the infrainguinal vasculature (profunda femoris and lateral circumflex femoral arteries) in 16 consecutive patients scheduled for ALT free flap transfer for reconstruction of head and neck surgical defects was undertaken. All patients underwent CFD ultrasonography. The location of perforators and the thigh thickness determined by CFD ultrasonography were correlated with the actual intraoperative findings using a scatter plot and paired t-test. Two patients were diagnosed with bilateral silent infrainguinal claudication, which precluded safe use of the ALT donor site. In two other patients, the planned ALT donor site ipsilateral to the defect was not used because of silent infrainguinal claudication diagnosed by CFD ultrasonography. In the 14 patients who underwent ALT flap harvest, CFD ultrasonography identified 48 perforators, which coincided with 43 actual perforators found intraoperatively. CFD ultrasonography demonstrated a statistically significant correlation with the actual perforator locations (Spearman coefficient .76; p = .55). Although CFD ultrasonography tended to underestimate flap thickness, there was a statistically significant correlation (Spearman coefficient .94; p ≤ .0001) with the actual flap thickness. CFD ultrasonography has clinical utility in facilitating decision making and planning ALT flap harvest.

Statistical analysis and modeling of intermittent transport events in the tokamak scrape-off layer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, Johan, E-mail: anderson.johan@gmail.com; Halpern, Federico D.; Ricci, Paolo

The turbulence observed in the scrape-off-layer of a tokamak is often characterized by intermittent events of bursty nature, a feature which raises concerns about the prediction of heat loads on the physical boundaries of the device. It appears thus necessary to delve into the statistical properties of turbulent physical fields such as density, electrostatic potential, and temperature, focusing on the mathematical expression of tails of the probability distribution functions. The method followed here is to generate statistical information from time-traces of the plasma density stemming from Braginskii-type fluid simulations and check this against a first-principles theoretical model. The analysis ofmore » the numerical simulations indicates that the probability distribution function of the intermittent process contains strong exponential tails, as predicted by the analytical theory.« less

Methoxyflurane and Nitrous Oxide as Obstetric Analgesics. II.—A Comparison by Self-administered Intermittent Inhalation

PubMed Central

Jones, Peter L.; Rosen, M.; Mushin, W. W.; Jones, E. V.

1969-01-01

Methoxyflurane (0·35%) in air and nitrous oxide/oxygen (50%/50%) self-administered intermittently in the usual way have been compared as analgesics for labour. There were 25 patients in each group. Objective assessment by an anaesthetist showed that methoxyflurane is the more effective analgesic, and this was supported by the opinion of the multiparae. Nausea and vomiting were significantly less with methoxyflurane. Fifty per cent. nitrous oxide in oxygen given intermittently does not appear to be the best analgesic concentration. Nevertheless, since a considerable variation in sensitivity exists, it would probably be unwise to consider the introduction of higher concentrations for use by unsupervised midwives. This trial confirms the predictions made by us using a method for screening inhalational analgesics, in which methoxyflurane and nitrous oxide were given continuously. PMID:4895339

Methoxyflurane and nitrous oxide as obstetric analgesics. II. A comparison by self-administered intermittent inhalation.

PubMed

Jones, P L; Rosen, M; Mushin, W W; Jones, E V

1969-08-02

Methoxyflurane (0.35%) in air and nitrous oxide/oxygen (50%/50%) self-administered intermittently in the usual way have been compared as analgesics for labour. There were 25 patients in each group. Objective assessment by an anaesthetist showed that methoxyflurane is the more effective analgesic, and this was supported by the opinion of the multiparae. Nausea and vomiting were significantly less with methoxyflurane. Fifty per cent. nitrous oxide in oxygen given intermittently does not appear to be the best analgesic concentration. Nevertheless, since a considerable variation in sensitivity exists, it would probably be unwise to consider the introduction of higher concentrations for use by unsupervised midwives.This trial confirms the predictions made by us using a method for screening inhalational analgesics, in which methoxyflurane and nitrous oxide were given continuously.

Influence of Vancomycin Infusion Methods on Endothelial Cell Toxicity

PubMed Central

Drouet, Maryline; Chai, Feng; Barthélémy, Christine; Lebuffe, Gilles; Debaene, Bertrand; Odou, Pascal

2014-01-01

Peripheral intravenous therapy is frequently used in routine hospital practice and, due to various factors, its most common side effect is phlebitis. The infusion of vancomycin is particularly associated with phlebitis despite its widespread use. French guidelines recommend central intravenous infusion for high concentrations of vancomycin, but peripheral intravenous therapy is often preferred in intensive care units. Methods of vancomycin infusion are either intermittent infusion or continuous infusion. A comparison of these methods under in vitro conditions simulating clinical use could result in better infusion efficacy. Human umbilical vein endothelial cells (HUVECs) were therefore challenged with clinical doses of vancomycin over a 24- to 72-h period using these infusion methods. Cell death was measured with the alamarBlue test. Concentration-dependent and time-dependent vancomycin toxicity on HUVECs was noted with a 50% lethal dose at 5 mg/ml after 24 h, reaching 2.5 mg/ml after 72 h of infusion, simulating long-term infusion. This toxicity does not seem to be induced by acidic pH. In comparing infusion methods, we observed that continuous infusion induced greater cell toxicity than intermittent infusion at doses higher than 1 g/day. The increasing use of vancomycin means that new guidelines are required to avoid phlebitis. If peripheral intravenous therapy is used to reduce infusion time, along with intermittent infusion, vein irritation and localized phlebitis may be reduced. Further studies have to be carried out to explore the causes of vancomycin endothelial toxicity. PMID:25421476

Safety and adherence to intermittent pre-exposure prophylaxis (PrEP) for HIV-1 in African men who have sex with men and female sex workers.

PubMed

Mutua, Gaudensia; Sanders, Eduard; Mugo, Peter; Anzala, Omu; Haberer, Jessica E; Bangsberg, David; Barin, Burc; Rooney, James F; Mark, David; Chetty, Paramesh; Fast, Patricia; Priddy, Frances H

2012-01-01

Little is known about safety of and adherence to intermittent HIV PrEP regimens, which may be more feasible than daily dosing in some settings. We present safety and adherence data from the first trial of an intermittent PrEP regimen among Kenyan men who have sex with men (MSM) and female sex workers (FSW). MSM and FSW were randomized to daily oral FTC/TDF or placebo, or intermittent (Monday, Friday and within 2 hours after sex, not to exceed one dose per day) oral FTC/TDF or placebo in a 2:1:2:1 ratio; volunteers were followed monthly for 4 months. Adherence was assessed with the medication event monitoring system (MEMS). Sexual activity data were collected via daily text message (SMS) queries and timeline followback interviews with a one-month recall period. Sixty-seven men and 5 women were randomized into the study. Safety was similar among all groups. Median MEMS adherence rates were 83% [IQR: 63-92] for daily dosing and 55% [IQR:28-78] for fixed intermittent dosing (p = 0.003), while adherence to any post-coital doses was 26% [IQR:14-50]. SMS response rates were low, which may have impaired measurement of post-coital dosing adherence. Acceptability of PrEP was high, regardless of dosing regimen. Adherence to intermittent dosing regimens, fixed doses, and in particular coitally-dependent doses, may be more difficult than adherence to daily dosing. However, intermittent dosing may still be appropriate for PrEP if intracellular drug levels, which correlate with prevention of HIV acquisition, can be attained with less than daily dosing and if barriers to adherence can be addressed. Additional drug level data, qualitative data on adherence barriers, and better methods to measure sexual activity are necessary to determine whether adherence to post-coital PrEP could be comparable to more standard regimens. ClinicalTrials.gov NCT00971230.

In situ measurements of wind and current speed and relationship between output power and turbulence

NASA Astrophysics Data System (ADS)

Duran Medina, Olmo; Schmitt, François G.; Sentchev, Alexei; Calif, Rudy

2015-04-01

In a context of energy transition, wind and tidal energy are sources of clean energy with the potential of partially satisfying the growing demand. The main problem of this type of energy, and other types of renewable energy remains the discontinuity of the electric power produced in different scales, inducing large fluctuations also called intermittency. This intermittency of wind and tidal energy is inherent to the turbulent nature of wind and marine currents. We consider this intermittent power production in strong relation with the turbulent intermittency of the resource. The turbulence theory is multifractal energy cascades models, a classic in physics of turbulence. From earlier studies in atmospheric sciences, we learn that wind speed and the aggregate power output are intermittent and multifractal over a wide range of scales [Calif and Schmitt 2014]. We want to extend this study to a marine current turbine and compare the scaling properties for those renewable energy sources. We consider here coupling between simultaneous velocity time series and output power from a wind turbine and a marine current turbine. Wind turbine data were obtained from Denmark and marine current data from Western Scheldt, Belgium where a prototype of a vertical and horizontal marine current turbines are tested. After an estimation of their Fourier density power spectra, we study their scaling properties in Kolmogorov's theory and the framework of fully developed turbulence. Hence, we employ a Hilbert-based methodology, namely arbitrary-order Hilbert spectral analysis [Calif et al. 2013a, 2013b] to characterize the intermittent property of the wind and marine current velocity in order to characterize the intermittent nature of the fluid. This method is used in order to obtain the spectrum and the corresponding power law for non-linear and non-stationary time series. The goal is to study the non-linear transfer characteristics in a multi-scale and multi-intensity framework.

How is overland flow produced under intermittent rain? An analysis using plot-scale rainfall simulation on dryland soils

NASA Astrophysics Data System (ADS)

Dunkerley, David

2018-01-01

The characteristic intermittency of rainfall includes temporary cessations (hiatuses), as well as periods of very low intensity within more intense events. To understand how these characteristics of rainfall affect overland flow production, rainfall simulations involving repeated cycles of on-off intermittency were carried out on dryland soils in arid western New South Wales, Australia. Periods of rain (10 mm/h) and no-rain were applied in alternation with cycle times from 3 min to 25 min, in experiments lasting 1-1.5 h. Results showed that intermittency could delay the onset of runoff by more than 30 min, reduce the runoff ratio, reduce the peak runoff rate, and reduce the apparent event infiltration rate by 30-45%. When hiatuses in rainfall were longer than 15-20 min, runoff that had resulted from prior rain ceased completely before the recommencement of rain. Results demonstrate that if rainfall intermittency is not accounted for, estimates of infiltrability based on runoff plot data can be systematically in error. Despite the use of intermittent rain, the episodic occurrence of runoff could be predicted successfully by fitting multiple affine Horton infiltration equations, whose changing f0 and Kf coefficients, but uniform values of fc, reflected the redistribution of soil moisture and the change in the infiltrability f during hiatuses in rainfall. The value of fc varied little among the fitted equations, so constituting an affine set of relationships. This new approach provides an alternative to the use of steady-state methods that are common in rainfall simulation experiments and which typically yield only an estimate of fc. The new field results confirm that intermittency affects infiltration and runoff depths and timing at plot scale and on intra-event timescales. Additional work on other soil types, and at other spatial and temporal scales, is needed to test the generality of these findings.

Method for estimating spatially variable seepage loss and hydraulic conductivity in intermittent and ephemeral streams

USGS Publications Warehouse

Niswonger, R.G.; Prudic, David E.; Fogg, G.E.; Stonestrom, David A.; Buckland, E.M.

2008-01-01

A method is presented for estimating seepage loss and streambed hydraulic conductivity along intermittent and ephemeral streams using streamflow front velocities in initially dry channels. The method uses the kinematic wave equation for routing streamflow in channels coupled to Philip's equation for infiltration. The coupled model considers variations in seepage loss both across and along the channel. Water redistribution in the unsaturated zone is also represented in the model. Sensitivity of the streamflow front velocity to parameters used for calculating seepage loss and for routing streamflow shows that the streambed hydraulic conductivity has the greatest sensitivity for moderate to large seepage loss rates. Channel roughness, geometry, and slope are most important for low seepage loss rates; however, streambed hydraulic conductivity is still important for values greater than 0.008 m/d. Two example applications are presented to demonstrate the utility of the method.

Comparison of High-Protein, Intermittent Fasting Low-Calorie Diet and Heart Healthy Diet for Vascular Health of the Obese

PubMed Central

Zuo, Li; He, Feng; Tinsley, Grant M.; Pannell, Benjamin K.; Ward, Emery; Arciero, Paul J.

2016-01-01

Aim: It has been debated whether different diets are more or less effective in long-term weight loss success and cardiovascular disease prevention among men and women. To further explore these questions, the present study evaluated the combined effects of a high-protein, intermittent fasting, low-calorie diet plan compared with a heart healthy diet plan during weight loss, and weight loss maintenance on blood lipids and vascular compliance of obese individuals. Methods: The experiment involved 40 obese adults (men, n = 21; women, n = 19) and was divided into two phases: (a) 12-week high-protein, intermittent fasting, low-calorie weight loss diet comparing men and women (Phase 1) and (b) a 1-year weight maintenance phase comparing high-protein, intermittent fasting with a heart healthy diet (Phase 2). Body weight, body mass index (BMI), blood lipids, and arterial compliance outcomes were assessed at weeks 1 (baseline control), 12 (weight loss), and 64 (12 + 52 week; weight loss maintenance). Results: At the end of weight loss intervention, concomitant reductions in body weight, BMI and blood lipids were observed, as well as enhanced arterial compliance. No sex-specific differences in responses were observed. During phase 2, the high-protein, intermittent fasting group demonstrated a trend for less regain in BMI, low-density lipoprotein (LDL), and aortic pulse wave velocity than the heart healthy group. Conclusion: Our results suggest that a high-protein, intermittent fasting and low-calorie diet is associated with similar reductions in BMI and blood lipids in obese men and women. This diet also demonstrated an advantage in minimizing weight regain as well as enhancing arterial compliance as compared to a heart healthy diet after 1 year. PMID:27621707

Stream permanence influences crayfish occupancy and abundance in the Ozark Highlands, USA

USGS Publications Warehouse

Yarra, Allyson N.; Magoulick, Daniel D.

2018-01-01

Crayfish use of intermittent streams is especially important to understand in the face of global climate change. We examined the influence of stream permanence and local habitat on crayfish occupancy and species densities in the Ozark Highlands, USA. We sampled in June and July 2014 and 2015. We used a quantitative kick–seine method to sample crayfish presence and abundance at 20 stream sites with 32 surveys/site in the Upper White River drainage, and we measured associated local environmental variables each year. We modeled site occupancy and detection probabilities with the software PRESENCE, and we used multiple linear regressions to identify relationships between crayfish species densities and environmental variables. Occupancy of all crayfish species was related to stream permanence. Faxonius meeki was found exclusively in intermittent streams, whereas Faxonius neglectus and Faxonius luteushad higher occupancy and detection probability in permanent than in intermittent streams, and Faxonius williamsi was associated with intermittent streams. Estimates of detection probability ranged from 0.56 to 1, which is high relative to values found by other investigators. With the exception of F. williamsi, species densities were largely related to stream permanence rather than local habitat. Species densities did not differ by year, but total crayfish densities were significantly lower in 2015 than 2014. Increased precipitation and discharge in 2015 probably led to the lower crayfish densities observed during this year. Our study demonstrates that crayfish distribution and abundance is strongly influenced by stream permanence. Some species, including those of conservation concern (i.e., F. williamsi, F. meeki), appear dependent on intermittent streams, and conservation efforts should include consideration of intermittent streams as an important component of freshwater biodiversity.

Determinants of Light and Intermittent Smoking in the U.S.: Results from Three Pooled National Health Surveys

PubMed Central

Reyes-Guzman, Carolyn M.; Pfeiffer, Ruth M.; Lubin, Jay; Freedman, Neal D.; Cleary, Sean D.; Levine, Paul H.; Caporaso, Neil E.

2016-01-01

Background Light and/or intermittent smokers have been the fastest growing segment of cigarette smokers in the U.S. over the past two decades. Defining their behavioral characteristics is a critical public health priority. Materials and Methods Our sample included 78,229 U.S. adults from three pooled contemporary population-based surveys: the 2012 NHIS, 2012 NSDUH, and 2011-2012 NHANES. We classified current smokers into four categories (light and intermittent [LITS], light-daily, heavier-intermittent and heavier-daily) and assessed smoking behaviors, illicit drug use, and mental health indicators using weighted analyses. Results Analyses associated smoking categories with nicotine dependence, age of smoking initiation, race/ethnicity and other demographic and behavioral factors. Compared to heavier-daily smokers, smokers who were LITS were most likely to have mild or no nicotine dependence (weighted odds ratio [OR] = 16.92, 95% confidence interval [CI] 13.10-21.85), to start smoking cigarettes regularly after age 21 (OR = 3.42, 95% CI 2.84-4.12), and to be Hispanic (OR = 5.38, 95% CI 4.38-6.61). Additional significant results were found for other categories of smokers. Conclusion Based on pooled data from three large national surveys, light and/or intermittent smokers differed in smoking, drug use and mental health behaviors from heavier-daily, former and never smokers. Notable differences by level of smoking frequency and intensity were observed for nicotine dependence, age of smoking initiation and race/ethnicity. Impact Our results may help focus preventive measures and policies for the growing number of light and/or intermittent smokers in the U.S. because smoking patterns vary by behavioral and socioeconomic factors. PMID:27760782

Streamflow Duration Assessment Method for the Pacific Northwest

EPA Pesticide Factsheets

The Streamflow Duration Assessment Method for the Pacific Northwest is a scientific tool developed by EPA and the U.S. Army Corps of Engineers to provide a rapid assessment framework to distinguish between ephemeral, intermittent and perennial streams.

Device and method for imaging of non-linear and linear properties of formations surrounding a borehole

DOEpatents

Johnson, Paul A; Tencate, James A; Le Bas, Pierre-Yves; Guyer, Robert; Vu, Cung Khac; Skelt, Christopher

2013-10-08

In some aspects of the disclosure, a method and an apparatus is disclosed for investigating material surrounding the borehole. The method includes generating within a borehole an intermittent low frequency vibration that propagates as a tube wave longitudinally to the borehole and induces a nonlinear response in one or more features in the material that are substantially perpendicular to a longitudinal axis of the borehole; generating within the borehole a sequence of high frequency pulses directed such that they travel longitudinally to the borehole within the surrounding material; and receiving, at one or more receivers positionable in the borehole, a signal that includes components from the low frequency vibration and the sequence of high frequency pulses during intermittent generation of the low frequency vibration, to investigate the material surrounding the borehole.

Finite-time hybrid projective synchronization of the drive-response complex networks with distributed-delay via adaptive intermittent control

NASA Astrophysics Data System (ADS)

Cheng, Lin; Yang, Yongqing; Li, Li; Sui, Xin

2018-06-01

This paper studies the finite-time hybrid projective synchronization of the drive-response complex networks. In the model, general transmission delays and distributed delays are also considered. By designing the adaptive intermittent controllers, the response network can achieve hybrid projective synchronization with the drive system in finite time. Based on finite-time stability theory and several differential inequalities, some simple finite-time hybrid projective synchronization criteria are derived. Two numerical examples are given to illustrate the effectiveness of the proposed method.

Intermittent fasting protects against the deterioration of cognitive function, energy metabolism and dyslipidemia in Alzheimer's disease-induced estrogen deficient rats.

PubMed

Shin, Bae Kun; Kang, Suna; Kim, Da Sol; Park, Sunmin

2018-02-01

Intermittent fasting may be an effective intervention to protect against age-related metabolic disturbances, although it is still controversial. Here, we investigated the effect of intermittent fasting on the deterioration of the metabolism and cognitive functions in rats with estrogen deficiency and its mechanism was also explored. Ovariectomized rats were infused with β-amyloid (25-35; Alzheimer's disease) or β-amyloid (35-25, Non-Alzheimer's disease; normal cognitive function) into the hippocampus. Each group was randomly divided into two sub-groups: one with intermittent fasting and the other fed ad libitum: Alzheimer's disease-ad libitum, Alzheimer's disease-intermittent fasting, Non-Alzheimer's disease-ad libitum, and Non-Alzheimer's disease-intermittent fasting. Rats in the intermittent fasting groups had a restriction of food consumption to a 3-h period every day. Each group included 10 rats and all rats fed a high-fat diet for four weeks. Interestingly, Alzheimer's disease increased tail skin temperature more than Non-Alzheimer's disease and intermittent fasting prevented the increase. Alzheimer's disease reduced bone mineral density in the spine and femur compared to the Non-Alzheimer's disease, whereas bone mineral density in the hip and leg was reduced by intermittent fasting. Fat mass only in the abdomen was decreased by intermittent fasting. Intermittent fasting decreased food intake without changing energy expenditure. Alzheimer's disease increased glucose oxidation, whereas intermittent fasting elevated fat oxidation as a fuel source. Alzheimer's disease and intermittent fasting deteriorated insulin resistance in the fasting state but intermittent fasting decreased serum glucose levels after oral glucose challenge by increasing insulin secretion. Alzheimer's disease deteriorated short and spatial memory function compared to the Non-Alzheimer's disease, whereas intermittent fasting prevented memory loss in comparison to ad libitum. Unexpectedly, cortisol levels were increased by Alzheimer's disease but decreased by intermittent fasting. Intermittent fasting improved dyslipidemia and liver damage index compared to ad libitum. Alzheimer's disease lowered low-density lipoprotein cholesterol and serum triglyceride levels compared to Non-Alzheimer's disease. In conclusion, Alzheimer's disease impaired not only cognitive function but also disturbed energy, glucose, lipid, and bone metabolism in ovariectomized rats. Intermittent fasting protected against the deterioration of these metabolic parameters, but it exacerbated bone mineral density loss and insulin resistance at fasting in Alzheimer's disease-induced estrogen-deficient rats. Impact statement Intermittent fasting was evaluated for its effects on cognitive function and metabolic disturbances in a rat model of menopause and Alzheimer's disease. Intermittent fasting decreased skin temperature and fat mass, and improved glucose tolerance with decreasing food intake. Intermittent fasting also prevented memory loss: short-term and special memory loss. Therefore, intermittent fasting may prevent some of the metabolic pathologies associated with menopause and protect against age-related memory decline.

Classification of ephemeral, intermittent, and perennial stream reaches using a TOPMODEL-based approach

USGS Publications Warehouse

Williamson, Tanja N.; Agouridis, Carmen T.; Barton, Christopher D.; Villines, Jonathan A.; Lant, Jeremiah G.

2015-01-01

Whether a waterway is temporary or permanent influences regulatory protection guidelines, however, classification can be subjective due to a combination of factors, including time of year, antecedent moisture conditions, and previous experience of the field investigator. Our objective was to develop a standardized protocol using publically available spatial information to classify ephemeral, intermittent, and perennial streams. Our hypothesis was that field observations of flow along the stream channel could be compared to results from a hydrologic model, providing an objective method of how these stream reaches can be identified. Flow-state sensors were placed at ephemeral, intermittent, and perennial stream reaches from May to December 2011 in the Appalachian coal basin of eastern Kentucky. This observed flow record was then used to calibrate the simulated saturation deficit in each channel reach based on the topographic wetness index used by TOPMODEL. Saturation deficit values were categorized as flow or no-flow days, and the simulated record of streamflow was compared to the observed record. The hydrologic model was more accurate for simulating flow during the spring and fall seasons. However, the model effectively identified stream reaches as intermittent and perennial in each of the two basins.

The use of intermittent and continuous recordings of jugular venous bulb oxygen saturation in the unconscious patient.

PubMed

Garlick, R; Bihari, D

1987-01-01

Monitoring clinical signs in unconscious patients provides only late information about cerebral deterioration. Ischaemia and hypoxia are the mechanisms of much of the damage. Cerebral blood flow (CBF) measurements provide direct evidence of ischaemia but are intermittent values for what may be an unstable situation. Continuous recordings of CBF and oxygenation are more likely to reveal harmful tendencies to ischaemia and hypoxia at an early stage than intermittent readings. We report our experience with intermittent and also continuous recording of the jugular venous bulb oxygen saturation (JVO2Sat) obtained by fibreoptic oximetry in a group of 10 head injured and 7 septic patients. Simultaneous measurements of CBF by an isotopic xenon clearance method were also made. The JVO2Sat has been suggested to be a reliable indicator of cerebral oxygenation, a low value being indicative of ischaemia. We discuss whether our findings support this statement. There are also variations in JVO2Sat with mean arterial blood pressure and intracranial pressure. These variations have important implications in the interpretation that can be made of one single value of JVO2Sat.

Cross-Sectional Imaging in a Case of Adventitial Cystic Disease of the Popliteal Artery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ricci, Paolo; Panzetti, Claudio; Mastantuono, Marco

1999-01-15

Adventitial cystic disease of the popliteal artery is an unusual condition of uncertain etiology, in which a mucin-containing cyst forms in the wall of the artery and produces lower extremity claudication, typically in young and middle-aged men. A diagnosis of adventitial cystic disease of the popliteal artery was made preoperatively in a 47-year-old man by means of several imaging modalities, including angiography, magnetic resonance imaging, and ultrasound. The pathological findings confirmed the suggested diagnosis.

Distributed Position-Based Consensus of Second-Order Multiagent Systems With Continuous/Intermittent Communication.

PubMed

Song, Qiang; Liu, Fang; Wen, Guanghui; Cao, Jinde; Yang, Xinsong

2017-04-24

This paper considers the position-based consensus in a network of agents with double-integrator dynamics and directed topology. Two types of distributed observer algorithms are proposed to solve the consensus problem by utilizing continuous and intermittent position measurements, respectively, where each observer does not interact with any other observers. For the case of continuous communication between network agents, some convergence conditions are derived for reaching consensus in the network with a single constant delay or multiple time-varying delays on the basis of the eigenvalue analysis and the descriptor method. When the network agents can only obtain intermittent position data from local neighbors at discrete time instants, the consensus in the network without time delay or with nonuniform delays is investigated by using the Wirtinger's inequality and the delayed-input approach. Numerical examples are given to illustrate the theoretical analysis.

A smart, intermittent driven particle sensor with an airflow change trigger using a lead zirconate titanate (PZT) cantilever

NASA Astrophysics Data System (ADS)

Takahashi, Hidetoshi; Tomimatsu, Yutaka; Kobayashi, Takeshi; Isozaki, Akihiro; Itoh, Toshihiro; Maeda, Ryutaro; Matsumoto, Kiyoshi; Shimoyama, Isao

2014-02-01

This paper reports on a smart, intermittent driven particle sensor with an airflow trigger. A lead zirconate titanate cantilever functions as the trigger, which detects an airflow change without requiring a power supply to drive the sensing element. Because an airflow change indicates that the particle concentration has changed, the trigger switches the optical particle counter from sleep mode to active mode only when the particle concentration surrounding the sensor changes. The sensor power consumption in sleep mode is 100 times less than that in the active mode. Thus, this intermittent driven method significantly reduces the total power consumption of the particle sensor. In this paper, we fabricate a prototype of the particle sensor and demonstrate that the optical particle counter can be switched on by the fabricated trigger and thus that the particle concentration can be measured.

Lack of difference between continuous versus intermittent heparin infusion on maintenance of intra-arterial catheter in postoperative pediatric surgery: a randomized controlled study

PubMed Central

Witkowski, Maria Carolina; de Moraes, Maria Antonieta P.; Firpo, Cora Maria F.

2013-01-01

OBJECTIVE: To compare two systems of arterial catheters maintenance in postoperative pediatric surgery using intermittent or continuous infusion of heparin solution and to analyze adverse events related to the site of catheter insertion and the volume of infused heparin solution. METHODS: Randomized control trial with 140 patients selected for continuous infusion group (CIG) and intermittent infusion group (IIG). The variables analyzed were: type of heart disease, permanence time and size of the catheter, insertion site, technique used, volume of heparin solution and adverse events. The descriptive variables were analyzed by Student's t-test and the categorical variables, by chi-square test, being significant p<0.05. RESULTS: The median age was 11 (0-22) months, and 77 (55%) were females. No significant differences between studied variables were found, except for the volume used in CIG (12.0±1.2mL/24 hours) when compared to IIG (5.3±3.5mL/24 hours) with p<0.0003. CONCLUSIONS: The continuous infusion system and the intermittent infusion of heparin solution can be used for intra-arterial catheters maintenance in postoperative pediatric surgery, regardless of patient's clinical and demographic characteristics. Adverse events up to the third postoperative day occurred similarly in both groups. However, the intermittent infusion system usage in underweight children should be considered, due to the lower volume of infused heparin solution [ClinicalTrials.gov Identifier: NCT01097031]. PMID:24473958

Cryotherapy for acute ankle sprains: a randomised controlled study of two different icing protocols

PubMed Central

Bleakley, C M; McDonough, S M; MacAuley, D C

2006-01-01

Background The use of cryotherapy in the management of acute soft tissue injury is largely based on anecdotal evidence. Preliminary evidence suggests that intermittent cryotherapy applications are most effective at reducing tissue temperature to optimal therapeutic levels. However, its efficacy in treating injured human subjects is not yet known. Objective : To compare the efficacy of an intermittent cryotherapy treatment protocol with a standard cryotherapy treatment protocol in the management of acute ankle sprains. Subjects Sportsmen (n  =  44) and members of the general public (n  =  45) with mild/moderate acute ankle sprains. Methods Subjects were randomly allocated, under strictly controlled double blind conditions, to one of two treatment groups: standard ice application (n  =  46) or intermittent ice application (n  =  43). The mode of cryotherapy was standardised across groups and consisted of melting iced water (0°C) in a standardised pack. Function, pain, and swelling were recorded at baseline and one, two, three, four, and six weeks after injury. Results Subjects treated with the intermittent protocol had significantly (p<0.05) less ankle pain on activity than those using a standard 20 minute protocol; however, one week after ankle injury, there were no significant differences between groups in terms of function, swelling, or pain at rest. Conclusion Intermittent applications may enhance the therapeutic effect of ice in pain relief after acute soft tissue injury. PMID:16611722

Intermittent versus continuous exercise training in chronic heart failure: a meta-analysis.

PubMed

Smart, Neil A; Dieberg, Gudrun; Giallauria, Francesco

2013-06-20

We conducted a meta-analysis of randomized, controlled trials of combined strength and intermittent aerobic training, intermittent aerobic training only and continuous exercise training in heart failure patients. A systematic search was conducted of Medline (Ovid) (1950-September 2011), Embase.com (1974-September 2011), Cochrane Central Register of Controlled Trials and CINAHL (1981-September 19 2011). The search strategy included a mix of MeSH and free text terms for the key concepts heart failure, exercise training, interval training and intermittent exercise training. The included studies contained an aggregate of 446 patients, 212 completed intermittent exercise training, 66 only continuous exercise training, 59 completed combined intermittent and strength training and 109 sedentary controls. Weighted mean difference (MD) in Peak VO2 was 1.04mlkg(-1)min(-1) and (95% C.I.) was 0.42-1.66 (p=0.0009) in intermittent versus continuous exercise training respectively. Weighted mean difference in Peak VO2 was -1.10mlkg(-1)min(-1) (95% C.I.) was -1.83-0.37 p=0.003 for intermittent only versus intermittent and strength (combined) training respectively. In studies reporting VE/VCO2 for intermittent versus control groups, MD was -1.50 [(95% C.I. -2.64, -0.37), p=0.01] and for intermittent versus continuous exercise training MD was -1.35 [(95% C.I. -2.15, -0.55), p=0.001]. Change in peak VO2 was positively correlated with weekly exercise energy expenditure for intermittent exercise groups (r=0.48, p=0.05). Combined strength and intermittent exercise appears superior for peak VO2 changes when compared to intermittent exercise of similar exercise energy expenditure. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Transmission losses, infiltration and groundwater recharge through ephemeral and intermittent streambeds: A review of applied methods

NASA Astrophysics Data System (ADS)

Shanafield, Margaret; Cook, Peter G.

2014-04-01

Aquifer recharge through ephemeral streambeds is believed to be a major source of groundwater recharge in arid areas; however, comparatively few studies quantify this streamflow recharge. This review synthesizes the available field-based aquifer recharge literature from arid regions around the world. Seven methods for quantifying ephemeral and intermittent stream infiltration and aquifer recharge are reviewed; controlled infiltration experiments, monitoring changes in water content, heat as a tracer of infiltration, reach length water balances, floodwave front tracking, groundwater mounding, and groundwater dating. The pertinent temporal and spatial scales, as well as the advantages and limitations of each method are illustrated with examples from the literature. Comparisons between the methods are used to highlight appropriate uses of each field method, with emphasis on the advantages of using multiple methods within a study in order to avoid the potential drawbacks inherent in any single method. Research needs are identified, including: quantitative uncertainty analysis, long-term data collection and analysis, understanding of the role of riparian vegetation, and reconciliation of transmission losses and infiltration estimates with actual aquifer recharge.

Coho salmon dependence on intermittent streams.

Treesearch

P.J. Wigington; J.L. Ebersole; M.E. Colvin; S.G. Leibowitz; B. Miller; B. Hansen; H. Lavigne; D. White; J.P. Baker; M.R. Church; J.R. Brooks; M.A. Cairns; J.E. Compton

2006-01-01

In this paper, we quantify the contributions of intermittent streams to coho salmon production in an Oregon coastal watershed. We provide estimates of (1) proportion of spawning that occurred in intermittent streams, (2) movement of juveniles into intermittent streams, (3) juvenile survival in intermittent and perennial streams during winter, and (4) relative size of...

A revised logistic regression equation and an automated procedure for mapping the probability of a stream flowing perennially in Massachusetts

USGS Publications Warehouse

Bent, Gardner C.; Steeves, Peter A.

2006-01-01

A revised logistic regression equation and an automated procedure were developed for mapping the probability of a stream flowing perennially in Massachusetts. The equation provides city and town conservation commissions and the Massachusetts Department of Environmental Protection a method for assessing whether streams are intermittent or perennial at a specific site in Massachusetts by estimating the probability of a stream flowing perennially at that site. This information could assist the environmental agencies who administer the Commonwealth of Massachusetts Rivers Protection Act of 1996, which establishes a 200-foot-wide protected riverfront area extending from the mean annual high-water line along each side of a perennial stream, with exceptions for some urban areas. The equation was developed by relating the observed intermittent or perennial status of a stream site to selected basin characteristics of naturally flowing streams (defined as having no regulation by dams, surface-water withdrawals, ground-water withdrawals, diversion, wastewater discharge, and so forth) in Massachusetts. This revised equation differs from the equation developed in a previous U.S. Geological Survey study in that it is solely based on visual observations of the intermittent or perennial status of stream sites across Massachusetts and on the evaluation of several additional basin and land-use characteristics as potential explanatory variables in the logistic regression analysis. The revised equation estimated more accurately the intermittent or perennial status of the observed stream sites than the equation from the previous study. Stream sites used in the analysis were identified as intermittent or perennial based on visual observation during low-flow periods from late July through early September 2001. The database of intermittent and perennial streams included a total of 351 naturally flowing (no regulation) sites, of which 85 were observed to be intermittent and 266 perennial. Stream sites included in the database had drainage areas that ranged from 0.04 to 10.96 square miles. Of the 66 stream sites with drainage areas greater than 2.00 square miles, 2 sites were intermittent and 64 sites were perennial. Thus, stream sites with drainage areas greater than 2.00 square miles were assumed to flow perennially, and the database used to develop the logistic regression equation included only those stream sites with drainage areas less than 2.00 square miles. The database for the equation included 285 stream sites that had drainage areas less than 2.00 square miles, of which 83 sites were intermittent and 202 sites were perennial. Results of the logistic regression analysis indicate that the probability of a stream flowing perennially at a specific site in Massachusetts can be estimated as a function of four explanatory variables: (1) drainage area (natural logarithm), (2) areal percentage of sand and gravel deposits, (3) areal percentage of forest land, and (4) region of the state (eastern region or western region). Although the equation provides an objective means of determining the probability of a stream flowing perennially at a specific site, the reliability of the equation is constrained by the data used in its development. The equation is not recommended for (1) losing stream reaches or (2) streams whose ground-water contributing areas do not coincide with their surface-water drainage areas, such as many streams draining the Southeast Coastal Region-the southern part of the South Coastal Basin, the eastern part of the Buzzards Bay Basin, and the entire area of the Cape Cod and the Islands Basins. If the equation were used on a regulated stream site, the estimated intermittent or perennial status would reflect the natural flow conditions for that site. An automated mapping procedure was developed to determine the intermittent or perennial status of stream sites along reaches throughout a basin. The procedure delineates the drainage area boundaries, determines values for the four explanatory variables, and solves the equation for estimating the probability of a stream flowing perennially at two locations on a headwater (first-order) stream reach-one near its confluence or end point and one near its headwaters or start point. The automated procedure then determines the intermittent or perennial status of the reach on the basis of the calculated probability values and a probability cutpoint (a stream is considered to flow perennially at a cutpoint of 0.56 or greater for this study) for the two locations or continues to loop upstream or downstream between locations less than and greater than the cutpoint of 0.56 to determine the transition point from an intermittent to a perennial stream. If the first-order stream reach is determined to be intermittent, the procedure moves to the next downstream reach and repeats the same process. The automated procedure then moves to the next first-order stream and repeats the process until the entire basin is mapped. A map of the intermittent and perennial stream reaches in the Shawsheen River Basin is provided on a CD-ROM that accompanies this report. The CD-ROM also contains ArcReader 9.0, a freeware product, that allows a user to zoom in and out, set a scale, pan, turn on and off map layers (such as a USGS topographic map), and print a map of the stream site with a scale bar. Maps of the intermittent and perennial stream reaches in Massachusetts will provide city and town conservation commissions and the Massachusetts Department of Environmental Protection with an additional method for assessing the intermittent or perennial status of stream sites.

Parameter motivated mutual correlation analysis: Application to the study of currency exchange rates based on intermittency parameter and Hurst exponent

NASA Astrophysics Data System (ADS)

Cristescu, Constantin P.; Stan, Cristina; Scarlat, Eugen I.; Minea, Teofil; Cristescu, Cristina M.

2012-04-01

We present a novel method for the parameter oriented analysis of mutual correlation between independent time series or between equivalent structures such as ordered data sets. The proposed method is based on the sliding window technique, defines a new type of correlation measure and can be applied to time series from all domains of science and technology, experimental or simulated. A specific parameter that can characterize the time series is computed for each window and a cross correlation analysis is carried out on the set of values obtained for the time series under investigation. We apply this method to the study of some currency daily exchange rates from the point of view of the Hurst exponent and the intermittency parameter. Interesting correlation relationships are revealed and a tentative crisis prediction is presented.

Current management of peripheral arterial occlusive disease: a review of pharmacologic agents and other interventions.

PubMed

Mannava, Krishna; Money, Samuel R

2007-01-01

Peripheral arterial occlusive disease (PAOD) of the lower extremities is becoming more prevalent worldwide. Nonsurgical treatment options provide the foundation for management. Lifestyle and risk factor modification should be emphasized in this patient population because of the associated adverse cardiovascular events. This includes implementation of a regular walking and smoking-cessation programs, aggressive control of hyperlipidemia, hypertension and diabetes mellitus, and treatment of hyperhomocysteinemia. Antiplatelet agents such as aspirin (acetylsalicylic acid) or clopidogrel are not specifically indicated for claudication but these drugs should be used in all patients with PAOD to prevent secondary ischemic events. Currently, cilostazol is the only US FDA approved agent that appears effective for the treatment of claudication symptoms. Several agents have been used with success outside of the US and others are still undergoing testing. Definitive recommendations cannot be made on the use of these drugs until further evaluation is completed. Ongoing research with new strategies for angiogenesis and the use of progenitor cells has yielded encouraging results, particularly for patients with critical limb ischemia and limited options. Advances in endovascular technology over the last several years have greatly enhanced the ability to diagnose and treat specific anatomic lesions that previously would have required open surgical correction. The use of percutaneous transluminal angioplasty and stents in the lower extremities has had considerable success when following specific guidelines such as those set forth by the TransAtlantic Inter-Society Consensus Working Group.

Relationship Between Central and Peripheral Atherosclerosis and Left Ventricular Dysfunction in a Community Population

PubMed Central

Tsao, Connie W.; Gona, Philimon; Salton, Carol; Murabito, Joanne M.; Oyama, Noriko; Danias, Peter G.; O’Donnell, Christopher J.; Manning, Warren J.; Yeon, Susan B.

2011-01-01

We aimed to determine the relationships between resting left ventricular (LV) wall motion abnormalities (WMAs), aortic plaque, and PAD in a community cohort. 1726 Framingham Heart Study Offspring Cohort participants (806 males, 65±9 years) underwent cardiovascular magnetic resonance with quantification of aortic plaque volume and assessment of regional LV systolic function. Claudication, lower extremity revascularization, and ankle-brachial index (ABI) were recorded at Examination 7. WMAs were associated with greater aortic plaque burden, decreased ABI, and claudication in age- and sex-adjusted analyses (all p<0.001), which were not significant after adjustment for cardiovascular risk factors. In age- and sex-adjusted analyses, both the presence (p<0.001) and volume of aortic plaque were associated with decreased ABI (p<0.001). After multivariable adjustment, ABI≤0.9 or prior revascularization was associated with a three-fold odds of aortic plaque (p=0.0083). Plaque volume significantly increased with decreasing ABI in multivariable-adjusted analyses (p<0.0001). In this free-living population, associations of WMAs with aortic plaque burden and clinical measures of PAD were attenuated after adjustment for coronary heart disease risk factors. Aortic plaque volume and ABI remained strongly negatively correlated after multivariable adjustment. Our findings suggest that the association between coronary heart disease and non-coronary atherosclerosis is explained by cardiovascular risk factors. Aortic atherosclerosis and PAD remain strongly associated after multivariable adjustment suggesting shared mechanisms beyond those captured by traditional risk factors. PMID:21708875

A small-bolt method for screening tree protectants against bark beetles (coleoptera: curculionidae)

Treesearch

B.L. Strom; L.M. Roton

2009-01-01

A simple, small-bolt method was developed and refi ned for evaluating and screening treatments being considered as prophylactics against bark beetles (Coleoptera: Curculionidae: Scolytinae). Using this method, 4 insecticide products (3 active ingredients) were evaluated against the southern pine beetle, Dendroctonus frontalis Zimmermann, intermittently during a period...

[Effect of treatment of idiopathic hypogonadotropic hypogonadism with an LHRH infusion pump].

PubMed

Goicolea Opacua, I; Cortázar Galarza, A; Cacho García, L; Guimón Bardesi, M; Vázquez García, J A

1989-01-01

Treatment of idiopathic hypogonadotropic hypogonadism with an intermittent LHRH infusion pump is more physiologic than the repeated injections of gonadotropin previously used. The results of treating 7 patients, 5 males and 2 females, with this new method are presented. A better FSH and LH response to the LHRH is achieved during treatment which results in a increase in testosterone production but not so of estradiol. The size of the testicles as well as the amount of pubic hair increased in all cases, although fertility was only achieved in one patient, who also showed the best testicular response. We may conclude that treatment with intermittent infusion of LHRH is an important innovation although only partially successful since there are resistant cases and the final outcome is not better than with other methods.

Stochastic modelling of intermittency.

PubMed

Stemler, Thomas; Werner, Johannes P; Benner, Hartmut; Just, Wolfram

2010-01-13

Recently, methods have been developed to model low-dimensional chaotic systems in terms of stochastic differential equations. We tested such methods in an electronic circuit experiment. We aimed to obtain reliable drift and diffusion coefficients even without a pronounced time-scale separation of the chaotic dynamics. By comparing the analytical solutions of the corresponding Fokker-Planck equation with experimental data, we show here that crisis-induced intermittency can be described in terms of a stochastic model which is dominated by state-space-dependent diffusion. Further on, we demonstrate and discuss some limits of these modelling approaches using numerical simulations. This enables us to state a criterion that can be used to decide whether a stochastic model will capture the essential features of a given time series. This journal is © 2010 The Royal Society

Multi-phase imaging of intermittency at steady state using differential imaging method by X-ray micro-tomography

NASA Astrophysics Data System (ADS)

Gao, Y.; Lin, Q.; Bijeljic, B.; Blunt, M. J.

2017-12-01

To observe intermittency in consolidated rock, we image a steady state flow of brine and decane in Bentheimer sandstone. We devise an experimental method based on X-ray differential imaging method to examine how changes in flow rate impact the pore-scale distribution of fluids during co-injection flow under dynamic flow conditions at steady state. This helps us elucidate the diverse flow regimes (connected, intermittent break-up, or continual break-up of the non-wetting phase pathways) for two capillary numbers. Also, relative permeability curves under both capillary and viscous limited conditions could be measured. We have performed imbibition sample floods using oil-brine and measured steady state relative permeability on a sandstone rock core in order to fully characterize the flow behaviour at low and high Ca. Two sets of experiments at high and low flow rates are provided to explore the time-evolution of the non-wetting phase clusters distribution under different flow conditions. The high flow rate is 0.5 mL/min, whose corresponding capillary number is 7.7×10-6. The low flow rate is 0.02 mL/min, whose capillary number is 3.1×10-7. A procedure based on using high-salinity brine as the contrast phase and applying differential imaging between the dry scan and that of the sample saturation with a 30 wt% Potassium iodide (KI) doped brine help to make sure there is no non-wetting phase in micro-pores. Then the intermittent phase in multiphase flow image at high Ca can be quantified by obtaining the differential image between the 30 wt% KI brine image and the scans that taken at each fixed fractional flow. By using the grey scale histogram distribution of the raw images at each condition, the oil proportion in the intermittent phase can be calculated. The pressure drops at each fractional flow at low and high Ca can be measured by high-precision pressure differential sensors and utilized to calculate to the relative permeability at pore scale. The relative permeability data and fw-Sw relationship obtained by our experiment at pore scale are compared with the data collected from experiments which were conducted at core scale, and they match well.

Intermittency in a single event

NASA Astrophysics Data System (ADS)

Bialas, A.; Ziaja, B.

1996-02-01

The possibility to study intermittency in a single event of high multiplicity is investigated in the framework of the α-model. It is found that, for cascade long enough, the dispersion of intermittency exponents obtained from individual events is fairly small. This fact opens the possibility to study the distribution of the intermittency parameters characterizing the cascades seen (by observing intermittency) in particle spectra.

Control of off-gassing rates of methyl isothiocyanate from the application of metam-sodium by chemigation and shank injection

NASA Astrophysics Data System (ADS)

Sullivan, D. A.; Holdsworth, M. T.; Hlinka, D. J.

Fumigants are used to enhance the yield and quality of agricultural produce, which is critical to the maintenance of the production levels of carrots, potatoes, tomatoes, strawberries, melons, and many other crops grown in the US and throughout much of the world. With the worldwide phase-out of methyl bromide in progress, the continued availability of the remaining alternatives, such as metam-sodium, 1,3-dichloropropene, and chloropicrin, is becoming increasingly important. Metam-sodium has been used for over 40 years and is the second most widely used fumigant in the United States. Reduction in off-gassing rates of fumigants can promote health and safety benefits and an increased dose in the treatment zone, thereby increasing the potential efficacy of these products. On this basis, there is a need to evaluate off-gassing rates as a function of application and sealing methods. This paper summarizes recent research into the volatilization of the principal transformation product of metam-sodium, i.e., methyl isothiocyanate (MITC), into the atmosphere as a function of application and sealing methods. Seven field studies were conducted from 1999-2001 to evaluate the off-gassing rates of MITC from applications of metam-sodium by shank injection and chemigation using two different water sealing methods, i.e., standard water sealing and intermittent water sealing. MITC is slightly soluble in water. Irrigation of a field following an application helps to retain the compound in the soil, minimizing off-gassing while increasing the dose to the target pests. Intermittent water sealing involves applying water on an intermittent basis to minimize off-gassing rates during nighttime periods when relatively poor atmospheric dispersion conditions often occur. Research conducted by the Metam-Sodium TASK Force indicates that intermittent water sealing significantly reduces off-gassing rates both for shank injection and chemigation applications when compared with standard water sealing practices.

A reduced-order model-based study on the effect of intermittent pneumatic compression of limbs on the cardiovascular system.

PubMed

Maffiodo, Daniela; De Nisco, Giuseppe; Gallo, Diego; Audenino, Alberto; Morbiducci, Umberto; Ferraresi, Carlo

2016-04-01

This work investigates the effect that the application of intermittent pneumatic compression to lower limbs has on the cardiovascular system. Intermittent pneumatic compression can be applied to subjects with reduced or null mobility and can be useful for therapeutic purposes in sports recovery, deep vein thrombosis prevention and lymphedema drainage. However, intermittent pneumatic compression performance and the effectiveness are often difficult to predict. This study presents a reduced-order numerical model of the interaction between the cardiovascular system and the intermittent pneumatic compression device. The effect that different intermittent pneumatic compression operating conditions have on the overall circulation is investigated. Our findings confirm (1) that an overall positive effect on hemodynamics can be obtained by properly applying the intermittent pneumatic compression device and (2) that using intermittent pneumatic compression for cardiocirculatory recovery is feasible in subjects affected by lower limb disease. © IMechE 2016.

Long-term Durability of Infrainguinal Endovascular and Open Revascularization for Disabling Claudication.

PubMed

Khan, Sikandar Z; Rivero, Mariel; Cherr, Gregory S; Harris, Linda M; Dryjski, Maciej L; Dosluoglu, Hasan H

2018-05-15

Infrainguinal revascularization for disabling claudication (DC) is frequently performed, but long-term results are still unknown. In this study, we compared clinical outcomes of infrainguinal endovascular (EV) and open interventions for DC after the failure of medical management. One hundred ninety-four patients with DC (Rutherford category 3) who had open (n = 53) or EV (n = 141) interventions were grouped as open-great saphenous vein (GSV) (n = 21), open-prosthetic (n = 32), EV-Trans-Atlantic Inter-Society Consensus II (TASC II) A and B (AB) (n = 48), and EV-TASC II C and D (CD) (n = 93). Patency, primary clinical success (PCS; sustained improvement in symptoms without reintervention), and secondary clinical success (SCS; sustained improvement in symptoms with reintervention) rates were compared. Mean follow-up was 57 ± 33 months. Five-year primary patency was 58% in open-GSV, 40% in open-prosthetic, 72% in EV-AB, and 38% in EV-CD (P < 0.001). Five-year secondary patency was 77% in open-GSV, 50% in open-prosthetic, 96% in EV-AB, and 61% in EV-CD (P < 0.001). Freedom from major adverse limb events was 73% in open-GSV, 77% in EV-AB, 70% in EV-CD, and 67% in open-prosthetic (P = 0.279). Five-year PCS was 46% in open-GSV, 40% in open-prosthetic, 57% in EV-AB, and 44% in EV-CD (P = 0.02). Five-year SCS was 78% in open-GSV, 78% in open-prosthetic, 85% in EV-AB, and 84% in EV-CD (P = 0.732). A total of 116 reinterventions were performed, 10 in 6 limbs (27%) in open-GSV, 18 in 12 limbs (36%) in open-prosthetic, 26 in 15 limbs (24%) in EV-AB, and 62 in 39 limbs (36%) in EV-CD. Reinterventions included 71 (61%) EV and 45 (39%) open procedures. Durability of infrainguinal interventions in claudicants depends mainly on anatomic complexity of disease. Good long-term clinical success can be achieved with both open and EV interventions, albeit with high reintervention rates, especially in patients with TASC II C and D disease. A considerable subset of EV patients will eventually require surgical revascularization to maintain clinical benefit. In this study, almost 20% of patients undergoing EV for TASC II C and D disease eventually required surgical bypass. Copyright © 2018 Elsevier Inc. All rights reserved.

Intermittent hypercapnic hypoxia during sleep does not induce ventilatory long-term facilitation in healthy males.

PubMed

Deacon, Naomi L; McEvoy, R Doug; Stadler, Daniel L; Catcheside, Peter G

2017-09-01

Intermittent hypoxia-induced ventilatory neuroplasticity is likely important in obstructive sleep apnea pathophysiology. Although concomitant CO 2 levels and arousal state critically influence neuroplastic effects of intermittent hypoxia, no studies have investigated intermittent hypercapnic hypoxia effects during sleep in humans. Thus the purpose of this study was to investigate if intermittent hypercapnic hypoxia during sleep induces neuroplasticity (ventilatory long-term facilitation and increased chemoreflex responsiveness) in humans. Twelve healthy males were exposed to intermittent hypercapnic hypoxia (24 × 30 s episodes of 3% CO 2 and 3.0 ± 0.2% O 2 ) and intermittent medical air during sleep after 2 wk washout period in a randomized crossover study design. Minute ventilation, end-tidal CO 2 , O 2 saturation, breath timing, upper airway resistance, and genioglossal and diaphragm electromyograms were examined during 10 min of stable stage 2 sleep preceding gas exposure, during gas and intervening room air periods, and throughout 1 h of room air recovery. There were no significant differences between conditions across time to indicate long-term facilitation of ventilation, genioglossal or diaphragm electromyogram activity, and no change in ventilatory response from the first to last gas exposure to suggest any change in chemoreflex responsiveness. These findings contrast with previous intermittent hypoxia studies without intermittent hypercapnia and suggest that the more relevant gas disturbance stimulus of concomitant intermittent hypercapnia frequently occurring in sleep apnea influences acute neuroplastic effects of intermittent hypoxia. These findings highlight the need for further studies of intermittent hypercapnic hypoxia during sleep to clarify the role of ventilatory neuroplasticity in the pathophysiology of sleep apnea. NEW & NOTEWORTHY Both arousal state and concomitant CO 2 levels are known modulators of the effects of intermittent hypoxia on ventilatory neuroplasticity. This is the first study to investigate the effects of combined intermittent hypercapnic hypoxia during sleep in humans. The lack of neuroplastic effects suggests a need for further studies more closely replicating obstructive sleep apnea to determine the pathophysiological relevance of intermittent hypoxia-induced ventilatory neuroplasticity. Copyright © 2017 the American Physiological Society.

A theoretically consistent stochastic cascade for temporal disaggregation of intermittent rainfall

NASA Astrophysics Data System (ADS)

Lombardo, F.; Volpi, E.; Koutsoyiannis, D.; Serinaldi, F.

2017-06-01

Generating fine-scale time series of intermittent rainfall that are fully consistent with any given coarse-scale totals is a key and open issue in many hydrological problems. We propose a stationary disaggregation method that simulates rainfall time series with given dependence structure, wet/dry probability, and marginal distribution at a target finer (lower-level) time scale, preserving full consistency with variables at a parent coarser (higher-level) time scale. We account for the intermittent character of rainfall at fine time scales by merging a discrete stochastic representation of intermittency and a continuous one of rainfall depths. This approach yields a unique and parsimonious mathematical framework providing general analytical formulations of mean, variance, and autocorrelation function (ACF) for a mixed-type stochastic process in terms of mean, variance, and ACFs of both continuous and discrete components, respectively. To achieve the full consistency between variables at finer and coarser time scales in terms of marginal distribution and coarse-scale totals, the generated lower-level series are adjusted according to a procedure that does not affect the stochastic structure implied by the original model. To assess model performance, we study rainfall process as intermittent with both independent and dependent occurrences, where dependence is quantified by the probability that two consecutive time intervals are dry. In either case, we provide analytical formulations of main statistics of our mixed-type disaggregation model and show their clear accordance with Monte Carlo simulations. An application to rainfall time series from real world is shown as a proof of concept.

Seizure tests distinguish intermittent fasting from the ketogenic diet

PubMed Central

Hartman, Adam L.; Zheng, Xiangrong; Bergbower, Emily; Kennedy, Michiko; Hardwick, J. Marie

2010-01-01

Summary Purpose Calorie restriction can be anticonvulsant in animal models. The ketogenic diet was designed to mimic calorie restriction and has been assumed to work by the same mechanisms. We challenged this assumption by profiling the effects of these dietary regimens in mice subjected to a battery of acute seizure tests. Methods Juvenile male NIH Swiss mice received ketogenic diet or a normal diet fed in restricted quantities (continuously or intermittently) for ~ 12 days, starting at 3–4 weeks of age. Seizures were induced by the 6 Hz test, kainic acid, maximal electroshock, or pentylenetetrazol. Results The ketogenic and calorie-restricted diets often had opposite effects depending on the seizure test. The ketogenic diet protected from 6 Hz–induced seizures, whereas calorie restriction (daily and intermittent) increased seizure activity. Conversely, calorie restriction protected juvenile mice against seizures induced by kainic acid, whereas the ketogenic diet failed to protect. Intermittent caloric restriction worsened seizures induced by maximal electroshock but had no effect on those induced by pentylenetetrazol. Discussion In contrast to a longstanding hypothesis, calorie restriction and the ketogenic diet differ in their acute seizure test profiles, suggesting that they have different underlying anticonvulsant mechanisms. These findings highlight the importance of the 6 Hz test and its ability to reflect the benefits of ketosis and fat consumption. PMID:20477852

Relationship between Aerobic Capacity and Yo-Yo IR1 Performance in Brazilian Professional Futsal Players

PubMed Central

Boullosa, Daniel A.; Tonello, Lais; Ramos, Isabela; Silva, Alessandro de Oliveira; Simoes, Herbert G.; Nakamura, Fabio Y.

2013-01-01

Purpose To evaluate the relationship between aerobic and intermittent capacities in a team of professional futsal players. Methods Fifteen futsal players from Brazilian first division (age: 25.9±5.1 yrs; height: 1.77±0.04 m, body mass: 74.37±6.02 kg) performed in random order a ramp test and the Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1) at the start of the season for determination of maximum oxygen consumption (VO2max), peak running speed (Speak), and intermittent running ability. Results Mean VO2max was of 57.25±6.35 ml·kg-1min-1 with a Speak of 17.69±1.88 km·h-1. Yo-Yo IR1 performance was of 1,226±282 m. There was no correlation between VO2max and Yo-Yo performance while Speak and Yo-Yo IR1 performance were correlated (r=0.641; P=0.007). Conclusion From the current results, it may be suggested that both continuous and intermittent physical evaluations are necessary for obtaining a complete fitness profile of futsal players. The low Yo-Yo IR1 performance of Brazilian futsal players when compared to other elite team sport athletes warrants further investigation. PMID:24427483

The effect of intermittent hypobaric-hypoxia treatments on renal glutathione peroxidase activity of rats

NASA Astrophysics Data System (ADS)

Paramita, I. A.; Jusman, S. W. A.

2017-08-01

Many people living at high altitudes experiencing a condition called intermittent hypobaric hypoxia (IHH). Some people even create IHH condition as an exercise for pilots, athletes, and mountaineers. In this experiment, we aimed to determine whether the protective effect of IHH is mediated through glutathione peroxidase (GPX) enzyme. The experiment’s sample is two-month-old healthy Sprague-Dawley rat kidneys weighing 200-250 g. Intermittent hypobaric hypoxia treatment is done using a Hypobaric Chamber type I that can mimic air pressure at certain altitudes: 35,000 (one minute), 30,000 (three minutes), 25,000 (five minutes), and 18,000 (30 minutes) feet. The rats were divided into five treatment groups, including a control group, hypobaric-hypoxia group, and intermittent hypobaric-hypoxia 1x, 2x, and 3x groups with each group consisting of three rats. The specific activity of GPX was measured using RANDOX and RANSEL methods. The statistical analysis of one way-ANOVA did not show significant differences between the groups (p > 0.05), although specific activities of the renal GPX of rats exposed to hypobaric-hypoxia were higher than the control group. This may be caused by the other antioxidants’ activities. In conclusion, the IHH treatment did not affect GPX activity in the rat kidneys.

A variational approach to probing extreme events in turbulent dynamical systems

PubMed Central

Farazmand, Mohammad; Sapsis, Themistoklis P.

2017-01-01

Extreme events are ubiquitous in a wide range of dynamical systems, including turbulent fluid flows, nonlinear waves, large-scale networks, and biological systems. We propose a variational framework for probing conditions that trigger intermittent extreme events in high-dimensional nonlinear dynamical systems. We seek the triggers as the probabilistically feasible solutions of an appropriately constrained optimization problem, where the function to be maximized is a system observable exhibiting intermittent extreme bursts. The constraints are imposed to ensure the physical admissibility of the optimal solutions, that is, significant probability for their occurrence under the natural flow of the dynamical system. We apply the method to a body-forced incompressible Navier-Stokes equation, known as the Kolmogorov flow. We find that the intermittent bursts of the energy dissipation are independent of the external forcing and are instead caused by the spontaneous transfer of energy from large scales to the mean flow via nonlinear triad interactions. The global maximizer of the corresponding variational problem identifies the responsible triad, hence providing a precursor for the occurrence of extreme dissipation events. Specifically, monitoring the energy transfers within this triad allows us to develop a data-driven short-term predictor for the intermittent bursts of energy dissipation. We assess the performance of this predictor through direct numerical simulations. PMID:28948226

Effect of different disinfection protocols on microbial and biofilm contamination of dental unit waterlines in community dental practices.

PubMed

Dallolio, Laura; Scuderi, Amalia; Rini, Maria S; Valente, Sabrina; Farruggia, Patrizia; Sabattini, Maria A Bucci; Pasquinelli, Gianandrea; Acacci, Anna; Roncarati, Greta; Leoni, Erica

2014-02-18

Output water from dental unit waterlines (DUWLs) may be a potential source of infection for both dental healthcare staff and patients. This study compared the efficacy of different disinfection methods with regard to the water quality and the presence of biofilm in DUWLs. Five dental units operating in a public dental health care setting were selected. The control dental unit had no disinfection system; two were disinfected intermittently with peracetic acid/hydrogen peroxide 0.26% and two underwent continuous disinfection with hydrogen peroxide/silver ions (0.02%) and stabilized chlorine dioxide (0.22%), respectively. After three months of applying the disinfection protocols, continuous disinfection systems were more effective than intermittent systems in reducing the microbial contamination of the water, allowing compliance with the CDC guidelines and the European Council regulatory thresholds for drinking water. P. aeruginosa, Legionella spp, sulphite-reducing Clostridium spores, S. aureus and β-haemolytic streptococci were also absent from units treated with continuous disinfection. The biofilm covering the DUWLs was more extensive, thicker and more friable in the intermittent disinfection dental units than in those with continuous disinfection. Overall, the findings showed that the products used for continuous disinfection of dental unit waterlines showed statistically better results than the intermittent treatment products under the study conditions.

Intermittent targeted therapies and stochastic evolution in patients affected by chronic myeloid leukemia

NASA Astrophysics Data System (ADS)

Pizzolato, N.; Persano Adorno, D.; Valenti, D.; Spagnolo, B.

2016-05-01

Front line therapy for the treatment of patients affected by chronic myeloid leukemia (CML) is based on the administration of tyrosine kinase inhibitors, namely imatinib or, more recently, axitinib. Although imatinib is highly effective and represents an example of a successful molecular targeted therapy, the appearance of resistance is observed in a proportion of patients, especially those in advanced stages. In this work, we investigate the appearance of resistance in patients affected by CML, by modeling the evolutionary dynamics of cancerous cell populations in a simulated patient treated by an intermittent targeted therapy. We simulate, with the Monte Carlo method, the stochastic evolution of initially healthy cells to leukemic clones, due to genetic mutations and changes in their reproductive behavior. We first present the model and its validation with experimental data by considering a continuous therapy. Then, we investigate how fluctuations in the number of leukemic cells affect patient response to the therapy when the drug is administered with an intermittent time scheduling. Here we show that an intermittent therapy (IT) represents a valid choice in patients with high risk of toxicity, despite an associated delay to the complete restoration of healthy cells. Moreover, a suitably tuned IT can reduce the probability of developing resistance.

Effect of Different Disinfection Protocols on Microbial and Biofilm Contamination of Dental Unit Waterlines in Community Dental Practices

PubMed Central

Dallolio, Laura; Scuderi, Amalia; Rini, Maria S.; Valente, Sabrina; Farruggia, Patrizia; Bucci Sabattini, Maria A.; Pasquinelli, Gianandrea; Acacci, Anna; Roncarati, Greta; Leoni, Erica

2014-01-01

Output water from dental unit waterlines (DUWLs) may be a potential source of infection for both dental healthcare staff and patients. This study compared the efficacy of different disinfection methods with regard to the water quality and the presence of biofilm in DUWLs. Five dental units operating in a public dental health care setting were selected. The control dental unit had no disinfection system; two were disinfected intermittently with peracetic acid/hydrogen peroxide 0.26% and two underwent continuous disinfection with hydrogen peroxide/silver ions (0.02%) and stabilized chlorine dioxide (0.22%), respectively. After three months of applying the disinfection protocols, continuous disinfection systems were more effective than intermittent systems in reducing the microbial contamination of the water, allowing compliance with the CDC guidelines and the European Council regulatory thresholds for drinking water. P. aeruginosa, Legionella spp, sulphite-reducing Clostridium spores, S. aureus and β-haemolytic streptococci were also absent from units treated with continuous disinfection. The biofilm covering the DUWLs was more extensive, thicker and more friable in the intermittent disinfection dental units than in those with continuous disinfection. Overall, the findings showed that the products used for continuous disinfection of dental unit waterlines showed statistically better results than the intermittent treatment products under the study conditions. PMID:24552789

Predictions of Separated and Transitional Boundary Layers Under Low-Pressure Turbine Airfoil Conditions Using an Intermittency Transport Equation

NASA Technical Reports Server (NTRS)

Suzen, Y. Bora; Huang, P. G.; Hultgren, Lennart S.; Ashpis, David E.

2001-01-01

A new transport equation for the intermittency factor was proposed to predict separated and transitional boundary layers under low-pressure turbine airfoil conditions. The intermittent behavior of the transitional flows is taken into account and incorporated into computations by modifying the eddy viscosity, mu(sub t), with the intermittency factor, gamma. Turbulent quantities are predicted by using Menter's two-equation turbulence model (SST). The intermittency factor is obtained from a transport equation model, which not only can reproduce the experimentally observed streamwise variation of the intermittency in the transition zone, but also can provide a realistic cross-stream variation of the intermittency profile. In this paper, the intermittency model is used to predict a recent separated and transitional boundary layer experiment under low pressure turbine airfoil conditions. The experiment provides detailed measurements of velocity, turbulent kinetic energy and intermittency profiles for a number of Reynolds numbers and freestream turbulent intensity conditions and is suitable for validation purposes. Detailed comparisons of computational results with experimental data are presented and good agreements between the experiments and predictions are obtained.

Predictions of Separated and Transitional Boundary Layers Under Low-Pressure Turbine Airfoil Conditions Using an Intermittency Transport Equation

NASA Technical Reports Server (NTRS)

Suzen, Y. B.; Huang, P. G.; Hultgren, Lennart S.; Ashpis, David E.

2003-01-01

A new transport equation for the intermittency factor was proposed to predict separated and transitional boundary layers under low-pressure turbine airfoil conditions. The intermittent behavior of the transitional flows is taken into account and incorporated into computations by modifying the eddy viscosity, t , with the intermittency factor, y. Turbulent quantities are predicted by using Menter s two-equation turbulence model (SST). The intermittency factor is obtained from a transport equation model, which not only can reproduce the experimentally observed streamwise variation of the intermittency in the transition zone, but also can provide a realistic cross-stream variation of the intermittency profile. In this paper, the intermittency model is used to predict a recent separated and transitional boundary layer experiment under low pressure turbine airfoil conditions. The experiment provides detailed measurements of velocity, turbulent kinetic energy and intermittency profiles for a number of Reynolds numbers and freestream turbulent intensity conditions and is suitable for validation purposes. Detailed comparisons of computational results with experimental data are presented and good agreements between the experiments and predictions are obtained.

40 CFR 799.9410 - TSCA chronic toxicity.

Code of Federal Regulations, 2012 CFR

2012-07-01

... should be used, if possible, throughout the duration of the study, and the research sample should be... continuously or intermittently depending on the method of analysis. Chamber concentration may be measured using gravimetric or analytical methods, as appropriate. If trial run measurements are reasonably consistent (±10...

40 CFR 799.9410 - TSCA chronic toxicity.

Code of Federal Regulations, 2011 CFR

2011-07-01

... should be used, if possible, throughout the duration of the study, and the research sample should be... continuously or intermittently depending on the method of analysis. Chamber concentration may be measured using gravimetric or analytical methods, as appropriate. If trial run measurements are reasonably consistent (±10...

40 CFR 799.9410 - TSCA chronic toxicity.

Code of Federal Regulations, 2010 CFR

2010-07-01

... should be used, if possible, throughout the duration of the study, and the research sample should be... continuously or intermittently depending on the method of analysis. Chamber concentration may be measured using gravimetric or analytical methods, as appropriate. If trial run measurements are reasonably consistent (±10...

40 CFR 799.9410 - TSCA chronic toxicity.

Code of Federal Regulations, 2014 CFR

2014-07-01

... should be used, if possible, throughout the duration of the study, and the research sample should be... continuously or intermittently depending on the method of analysis. Chamber concentration may be measured using gravimetric or analytical methods, as appropriate. If trial run measurements are reasonably consistent (±10...

40 CFR 799.9410 - TSCA chronic toxicity.

Code of Federal Regulations, 2013 CFR

2013-07-01

... should be used, if possible, throughout the duration of the study, and the research sample should be... continuously or intermittently depending on the method of analysis. Chamber concentration may be measured using gravimetric or analytical methods, as appropriate. If trial run measurements are reasonably consistent (±10...

Factors influencing uptake of intermittent preventive treatment of malaria in pregnancy using sulphadoxine pyrimethamine in Sunyani Municipality, Ghana.

PubMed

Ibrahim, Hajira; Maya, Ernest Tei; Issah, Kofi; Apanga, Paschal Awingura; Bachan, Emmanuel George; Noora, Charles Lwanga

2017-01-01

Malaria continues to pose a public health challenge in Ghana particularly in pregnant women. Ghana adopted intermittent preventive treatment of malaria in pregnancy policy using sulphadoxine pyrimethamine. Despite its implementation, its coverage still remains low. This study sought to investigate factors that influence the uptake of intermittent preventive treatment of malaria in pregnancy in the Sunyani Municipality. This was a cross sectional study which employed a quantitative method. The study was conducted in five selected facilities in the Sunyani Municipality within the period of January to June 2015. Structured questionnaires were administered to 400 pregnant women randomly sampled from antenatal clinics of selected health facilities. Descriptive, bivariate and multivariate analysis of quantitative data was done using Stata12. A total of 400 pregnant women at 36 weeks or more gestational age were studied. The study revealed that 98.5% of the pregnant women received at least one (1) dose of sulphadoxine pyrimethamine during the current pregnancy with 71% receiving optimal (at least 3 doses) doses of sulphadoxine pyrimethamine for intermittent preventive treatment of malaria in pregnancy at the time of study. The study revealed that women who attended ANC ≥4 times (Adjusted OR = 4.7, 95% CI 1.31-17.2), knowledge of malaria in pregnancy (Adjusted OR = 2.2, 95% CI 1.03-4.62) and knowledge of intermittent preventive treatment for malaria in pregnancy (Adjusted OR = 1.8, 95% CI 1.15-2.96) were found to be positively associated with the uptake of optimal doses of sulphadoxine pyrimethamine. This study has demonstrated that having a good knowledge of malaria in pregnancy and intermittent preventive treatment of malaria in pregnancy can significantly influence the uptake of optimal doses of sulphadoxine pyrimethamine. Encouraging women to attend antenatal care regularly (at least four visits) could also increase the optimal uptake of sulphadoxine pyrimethamine.

Relationship Between Internal Load Indicators and Changes on Intermittent Performance After the Preseason in Professional Soccer Players.

PubMed

Campos-Vazquez, Miguel A; Toscano-Bendala, Francisco J; Mora-Ferrera, José C; Suarez-Arrones, Luis J

2017-06-01

The aim of this study was to examine the effects of accumulated internal training load (ITL) during the preseason (4 weeks) on changes in the intermittent performance, in a professional soccer team. Twelve professionals soccer players (Mean ± SD age: 27.7 ± 4.3 years; height: 177.1 ± 6.2 cm; body mass: 73.1 ± 5.2 kg; % body fat [Faulkner]: 10.2 ± 1.2) belonging to a Spanish second division team (2013-2014) participated in this study. The 30-15 intermittent fitness test was performed before and after the preseason, and the speed for the last period completed by each player was recorded (VIFT). During the preseason, the team alternated practice of training sessions (TRNs) with friendly matches (FMs). Session rating of perceived exertion (sRPE), heart rate (HR), and HR reserve were analyzed every TRN and FM to calculate ITL (ITL: sRPE-TL, Edward's-TL and Edward's-TLres). The players' VIFT substantially increased after the preseason period (20.1 ± 0.8 vs. 21.1 ± 0.8 km·h; effect size [ES] = 1.15 ± 0.25; almost certainly). The average value of sRPE throughout FMs was substantially greater than the value of the TRNs (7.4 ± 0.9 vs. 5.25 ± 0.2; ES = 2.31 ± 2.45; almost certainly). sRPE-TL, practice volume, and sum of RPE during the preseason were positively and largely correlated (r = 0.70-0.75) with changes on intermittent performance. No relationships were found between HR-derived measures of exercise load and changes on intermittent fitness. The present results suggest that practice volume and subjective measures of TL, related better than HR-based TL methods to changes on intermittent performance after the preseason, in professional soccer players.

Multistate intermittency on the route to chaos of a semiconductor laser subjected to optical feedback from a long external cavity.

PubMed

Choi, Daeyoung; Wishon, Michael J; Chang, C Y; Citrin, D S; Locquet, A

2018-01-01

We observe experimentally two regimes of intermittency on the route to chaos of a semiconductor laser subjected to optical feedback from a long external cavity as the feedback level is increased. The first regime encountered corresponds to multistate intermittency involving two or three states composed of several combinations of periodic, quasiperiodic, and subharmonic dynamics. The second regime is observed for larger feedback levels and involves intermittency between period-doubled and chaotic regimes. This latter type of intermittency displays statistical properties similar to those of on-off intermittency.

Long term and transitional intermittent smokers: a longitudinal study

PubMed Central

Lindstrom, M; Isacsson, S

2002-01-01

Objective: To investigate differences in snuff consumption, sociodemographic and psychosocial characteristics between baseline intermittent smokers that had become daily smokers, stopped smoking or remained intermittent smokers at the one year follow up. Design/setting/participants/measurements: A population of 12 507 individuals interviewed at baseline in 1992-94 and at a one year follow up, aged 45–69 years, was investigated in a longitudinal study. The three groups of baseline intermittent smokers were compared to the reference population (all others) according to sociodemographic, psychosocial, and snuff consumption characteristics. A multivariate logistic regression model was used to assess differences in psychosocial conditions, adjusting for age, sex, country of origin, marital status, education, and snuff consumption. Results: 60% of all baseline intermittent smokers had remained intermittent smokers, 16% had become daily smokers, and 24% had stopped smoking at the one year follow up. The long term intermittent smokers and those who had stopped smoking were young, unmarried, highly educated, and snuff consumers to a higher extent than the reference population. They also had more psychosocial resources than the reference population, while the psychosocial resources of those who had become daily smokers were poorer. Conclusions: The majority of intermittent smokers are long term intermittent smokers. The results suggest that long term intermittent smokers have other psychosocial characteristics than daily smokers. PMID:11891370

5 CFR 340.403 - Intermittent employment.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 340.403 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS OTHER THAN FULL-TIME CAREER EMPLOYMENT (PART-TIME, SEASONAL, ON-CALL, AND INTERMITTENT) Seasonal and intermittent... has an obligation to document the change in work schedule from intermittent to part-time or full-time...

The use of the color Doppler ultrasonography in the diagnosis and monitoring of an atypical case of giant-cell arteritis.

PubMed

Martins, N; Polido-Pereira, J; Rodrigues, A M; Soares, F; Batista, P; Pereira da Silva, J A

2016-01-01

Giant Cell Arteritis (GCA) is a large vessels vasculitis that is typically characterised by headache, scalp tenderness, jaw claudication and visual disturbances. Temporal arteries color Doppler ultrasonography (CDUS) is a sensitive and non-invasive image technique used in the diagnosis of this disease. This work highlights the importance of CDUS in the diagnostic workup of GCA and also demonstrates it´s usefullness in the evaluation and documentation of the response to corticosteroids therapy in an atypical case of ACG.

Management of bladder dysfunction and satisfaction of life after spinal cord injury in Norway

PubMed Central

Hagen, Ellen Merete; Rekand, Tiina

2014-01-01

Background There is limited knowledge about bladder dysfunction and bladder management in persons with spinal cord injury (SCI) after discharge from the hospital in Norway. The impact of bladder dysfunction on satisfaction of life has been rarely explored. Setting Community-based survey from Norway. Methods An anonymous cross-sectional postal survey. A questionnaire was sent to the registered members of the Norwegian Spinal Cord Injuries Association. A total of 400 participants, with traumatic or non-traumatic SCI, received the questionnaire. Results A total of 248 subjects (62%), 180 men and 68 women, answered the questionnaire. Mean age was 54 years and mean time since injury 13.4 years. A total of 164 participants (66.1%) used intermittent catheterization for bladder emptying (48.5% women versus 72.8% men); more paraplegics than tetraplegics (77.2% versus 55.7%). Recommendations given at the Spinal Cord Units were thoroughly followed by persons who had used catheters more than 5 years. Use of incontinence pads were associated with reduced satisfaction of life. Conclusions The most common method of management of bladder dysfunction is clean intermittent catheterization in Norway. Recommendations were followed more thoroughly by persons who have used intermittent catheterization for more than 5 years. Spinal Cord Units are important source for information and guidance. PMID:24621024

Visual Method for Detecting Contaminant on Dried Nutmeg Using Fluorescence Imaging

NASA Astrophysics Data System (ADS)

Dahlan, S. A.; Ahmad, U.; Subrata, I. D. M.

2018-05-01

Traditional practice of nutmeg sun-drying causes some fungi such as Aspergillus flavus to grow. One of the secondary metabolites of A. flavus named aflatoxin (AFs) is known to be carcinogenic, so the dried nutmeg kernel must be aflatoxin-free in the trading. Aflatoxin detection requires time and costly, make it difficult to conduct at the farmers level. This study aims to develop a simple and low-cost method to detect aflatoxin at the farmer level. Fresh nutmeg seeds were dried in two ways; sundried everyday (continuous), and sundried every two days (intermittent), both for around 18 days. The dried nutmeg seeds are then stored in a rice sack under normal conditions until the fungi grow, then they were opened and the images of kernels were captured using a CCD camera, with normal light and UV light sources. Visual observation on images captured in normal light source was able to detect the presence of fungi on dried kernels, by 28.0% for continuous and 26.2% for intermittent sun-drying. Visual observation on images captured in UV light source was able to detect the presence of aflatoxin on dried kernels, indicated by blue luminance on kernel, by 10.4% and 13.4% for continuous and intermittent sun-drying.

[Intermittent hypoxia due to sleep apnea syndrome in patients with type 2 diabetes mellitus].

PubMed

Burchakov, D I; Mayorov, A Yu

To evaluate the possible association between intermittent hypoxia (IH) and HbA1c in patients with insufficient control type of 2 diabetes mellitus (T2DM). In this cross-sectional study 183 patients with HbAc1≥7% underwent three-channel overnight monitoring (ApneaLink) and completed Berlin Questionnaire, Epworth Sleepiness Scale and Pittsburgh Sleep Quality Index. Patients were divided in two groups, based on the cut-off value of oxygen desaturation index≥15. There were 79 (43%) patients with intermittent hypoxia, which was associated with poorer glycaemic control, defined as HbA1c>8.7% (sample median) in the univariate analysis and after adjustment for body mass index OR 2,40 (CI 1.21-4.95, p=0.021). Neither of three questionnaires yielded satisfactory results as a screening method in patients with T2DM. There is a need to implement instrumental screening of sleep-disordered breathing in this population and to study the effects of CPAP-therapy on glycaemic control and carbohydrate metabolism.

Intermittent turbulence in flowing bacterial suspensions

PubMed Central

Secchi, Eleonora; Rusconi, Roberto; Buzzaccaro, Stefano; Salek, M. Mehdi; Smriga, Steven; Piazza, Roberto; Stocker, Roman

2016-01-01

Dense suspensions of motile bacteria, possibly including the human gut microbiome, exhibit collective dynamics akin to those observed in classic, high Reynolds number turbulence with important implications for chemical and biological transport, yet this analogy has remained primarily qualitative. Here, we present experiments in which a dense suspension of Bacillus subtilis bacteria was flowed through microchannels and the velocity statistics of the flowing suspension were quantified using a recently developed velocimetry technique coupled with vortex identification methods. Observations revealed a robust intermittency phenomenon, whereby the average velocity profile of the suspension fluctuated between a plug-like flow and a parabolic flow profile. This intermittency is a hallmark of the onset of classic turbulence and Lagrangian tracking revealed that it here originates from the presence of transient vortices in the active, collective motion of the bacteria locally reinforcing the externally imposed flow. These results link together two entirely different manifestations of turbulence and show the potential of the microfluidic approach to mimic the environment characteristic of certain niches of the human microbiome. PMID:27307513

Intermittent turbulence in flowing bacterial suspensions.

PubMed

Secchi, Eleonora; Rusconi, Roberto; Buzzaccaro, Stefano; Salek, M Mehdi; Smriga, Steven; Piazza, Roberto; Stocker, Roman

2016-06-01

Dense suspensions of motile bacteria, possibly including the human gut microbiome, exhibit collective dynamics akin to those observed in classic, high Reynolds number turbulence with important implications for chemical and biological transport, yet this analogy has remained primarily qualitative. Here, we present experiments in which a dense suspension of Bacillus subtilis bacteria was flowed through microchannels and the velocity statistics of the flowing suspension were quantified using a recently developed velocimetry technique coupled with vortex identification methods. Observations revealed a robust intermittency phenomenon, whereby the average velocity profile of the suspension fluctuated between a plug-like flow and a parabolic flow profile. This intermittency is a hallmark of the onset of classic turbulence and Lagrangian tracking revealed that it here originates from the presence of transient vortices in the active, collective motion of the bacteria locally reinforcing the externally imposed flow. These results link together two entirely different manifestations of turbulence and show the potential of the microfluidic approach to mimic the environment characteristic of certain niches of the human microbiome. © 2016 The Author(s).

[Effects of Water and Nitrogenous Fertilizer Coupling on CH4 and N2O Emission from Double-Season Rice Paddy Field].

PubMed

Fu, Zhi-qiang; Long, Pan; Liu, Yi-yi; Zhong, Juan; Long, Wen-fei

2015-09-01

To provide support for the efficient use of water and fertilizer technology to double-season rice cultivation, water and fertilizer coupling mode was applied in this research, including two irrigation methods and four N levels. The irrigation methods were flood irrigation and intermittent irrigation, while four N levels were high-N, middle-N, low-N and none-N. Field experiment was conducted to study the effect of water and fertilizer coupling mode on CH4 and N2O emission. The results showed that the accumulated CH4 emissions were significantly reduced by intermittent irrigation, in comparison with flood irrigation, the reduction in early rice season were from 13. 18 kg.hm-2 to 87. 90 kg.hm-2, and were from 74. 48 kg.hm-2 to 131. 07 kg.hm-2 in late rice season, with a rate of 24. 4% -67. 4% and 42. 5% -65. 5% respectively; whereas the accumulated N20 emissions were increased, the increment were from 0. 03 kg.hm-2 to 0. 24 kg.hm-2 in early rice season and from 0. 35 kg.hm-2 to 1. 53 kg.hm-2 in late rice season when compared flood irrigation, increased by 6.2% -18. 3% and 40.2% - 80.9% respectively. On the whole, intermittent irrigation reduces the warming potential of greenhouse gases (GWP), which were decreased by 18. 8% to 58. 6% in early rice season and by 34. 4% to 60. 1% in late rice season, and the reduction of total GWP were from 2 388 to 4 151 kg. hm-2 (CO2 eq), with a rate of 41% -54% . Through correlation analysis it found that CH4 emissions from soil were significantly related with soil solution Eh and solution CH4 concentration. In comparison with the flood irrigation, the application of intermittent irrigation in double-season rice cultivation was conducive to CH4 reduction, though the increase came in N2O, but the GWPs were significantly reduced. Comprehensively, intermittent irrigation matching with middle-N is more benefit to double-season rice cultivation.

Quantifying spatial and temporal patterns of flow intermittency using spatially contiguous runoff data

NASA Astrophysics Data System (ADS)

Yu (于松延), Songyan; Bond, Nick R.; Bunn, Stuart E.; Xu, Zongxue; Kennard, Mark J.

2018-04-01

River channel drying caused by intermittent stream flow is a widely-recognized factor shaping stream ecosystems. There is a strong need to quantify the distribution of intermittent streams across catchments to inform management. However, observational gauge networks provide only point estimates of streamflow variation. Increasingly, this limitation is being overcome through the use of spatially contiguous estimates of the terrestrial water-balance, which can also assist in estimating runoff and streamflow at large-spatial scales. Here we proposed an approach to quantifying spatial and temporal variation in monthly flow intermittency throughout river networks in eastern Australia. We aggregated gridded (5 × 5 km) monthly water-balance data with a hierarchically nested catchment dataset to simulate catchment runoff accumulation throughout river networks from 1900 to 2016. We also predicted zero flow duration for the entire river network by developing a robust predictive model relating measured zero flow duration (% months) to environmental predictor variables (based on 43 stream gauges). We then combined these datasets by using the predicted zero flow duration from the regression model to determine appropriate 'zero' flow thresholds for the modelled discharge data, which varied spatially across the catchments examined. Finally, based on modelled discharge data and identified actual zero flow thresholds, we derived summary metrics describing flow intermittency across the catchment (mean flow duration and coefficient-of-variation in flow permanence from 1900 to 2016). We also classified the relative degree of flow intermittency annually to characterise temporal variation in flow intermittency. Results showed that the degree of flow intermittency varied substantially across streams in eastern Australia, ranging from perennial streams flowing permanently (11-12 months) to strongly intermittent streams flowing 4 months or less of year. Results also showed that the temporal extent of flow intermittency varied dramatically inter-annually from 1900 to 2016, with the proportion of intermittent (weakly and strongly intermittent) streams ranging in length from 3% to nearly 100% of the river network, but there was no evidence of an increasing trend towards flow intermittency over this period. Our approach to generating spatially explicit and catchment-wide estimates of streamflow intermittency can facilitate improved ecological understanding and management of intermittent streams in Australia and around the world.

Intermittent search strategies

NASA Astrophysics Data System (ADS)

Bénichou, O.; Loverdo, C.; Moreau, M.; Voituriez, R.

2011-01-01

This review examines intermittent target search strategies, which combine phases of slow motion, allowing the searcher to detect the target, and phases of fast motion during which targets cannot be detected. It is first shown that intermittent search strategies are actually widely observed at various scales. At the macroscopic scale, this is, for example, the case of animals looking for food; at the microscopic scale, intermittent transport patterns are involved in a reaction pathway of DNA-binding proteins as well as in intracellular transport. Second, generic stochastic models are introduced, which show that intermittent strategies are efficient strategies that enable the minimization of search time. This suggests that the intrinsic efficiency of intermittent search strategies could justify their frequent observation in nature. Last, beyond these modeling aspects, it is proposed that intermittent strategies could also be used in a broader context to design and accelerate search processes.

'For me it's about not feeling like I'm on a diet': a thematic analysis of women's experiences of an intermittent energy restricted diet to reduce breast cancer risk.

PubMed

Donnelly, L S; Shaw, R L; Pegington, M; Armitage, C J; Evans, D G; Howell, A; Harvie, M N

2018-06-21

Weight-loss programmes requiring intermittent energy restriction offer an alternative to continuous energy restriction programmes that typically have low adherence. We reported greater weight loss, better adherence and spontaneous reduced energy intake on healthy eating days with intermittent as opposed to continuous energy restriction. The present study aims to explore why intermittent energy restriction diets exert these positive effects. Semi-structured interviews were carried out with 13 women aged 39-62 years, who followed a 4-month intermittent energy restriction (2 days of low energy/low carbohydrate, 5 days of healthy eating). Nine of the 13 women successfully lost >5% of their total body weight. Data were analysed using thematic analysis. The intermittent regimen redefined the meaning of dieting and normal eating. Women reconceptualised dieting as only two low energy days per week, even though this often differed from their pre-diet eating patterns. Women reported that they could adhere more closely to the rules of the intermittent diet compared to previously attempted continuous diets. They found that the intermittent diet was less cognitively demanding because the restrictive and clear rules of the intermittent diet were easier to understand and easier to follow than with continuous dieting. Many participants found intermittent dieting preferable to previous experiences of continuous dieting. The findings provide some insight into the ways in which intermittent dieting is successful, and why it could be considered a viable alternative to continuous energy restriction for weight loss. © 2018 The British Dietetic Association Ltd.

Intermittency of intermittencies

NASA Astrophysics Data System (ADS)

Hramov, Alexander E.; Koronovskii, Alexey A.; Moskalenko, Olga I.; Zhuravlev, Maxim O.; Ponomarenko, Vladimir I.; Prokhorov, Mikhail D.

2013-09-01

A phenomenon of intermittency of intermittencies is discovered in the temporal behavior of two coupled complex systems. We observe for the first time the coexistence of two types of intermittent behavior taking place simultaneously near the boundary of the synchronization regime of coupled chaotic oscillators. This phenomenon is found both in the numerical and physiological experiments. The laws for both the distribution and mean length of laminar phases versus the control parameter values are analytically deduced. A very good agreement between the theoretical results and simulation is shown.

The influence of intermittent fasting on the circadian pattern of melatonin while controlling for caloric intake, energy expenditure, light exposure, and sleep schedules: A preliminary report

PubMed Central

Almeneessier, Aljohara S.; Bahammam, Ahmed S.; Sharif, Munir M.; Bahammam, Salman A.; Nashwan, Samar Z.; Pandi Perumal, Seithikurippu R.; Cardinali, Daniel P.; Alzoghaibi, Mohammad

2017-01-01

AIMS: We hypothesized that if we control for food composition, caloric intake, light exposure, sleep schedule, and exercise, intermittent fasting would not influence the circadian pattern of melatonin. Therefore, we designed this study to assess the effect of intermittent fasting on the circadian pattern of melatonin. METHODS: Eight healthy volunteers with a mean age of 26.6 ± 4.9 years and body mass index of 23.7 ± 3.5 kg/m2 reported to the Sleep Disorders Center (the laboratory) on four occasions: (1) adaptation, (2) 4 weeks before Ramadan while performing Islamic intermittent fasting for 1 week (fasting outside Ramadan [FOR]), (3) 1 week before Ramadan (nonfasting baseline [BL]), and (4) during the 2nd week of Ramadan while fasting (Ramadan). The plasma levels of melatonin were measured using enzyme-linked immunoassays at 22:00, 02:00, 04:00, 06:00, and 11:00 h. The light exposure, meal composition, energy expenditure, and sleep schedules remained the same while the participants stayed at the laboratory. RESULTS: The melatonin levels followed the same circadian pattern during the three monitoring periods (BL, FOR, and Ramadan). The peak melatonin level was at 02:00 h and the trough level was at 11:00 h in all studied periods. Lower melatonin levels at 22:00 h were found during fasting compared to BL. Cosinor analysis revealed no significant changes in the acrophase of melatonin levels. CONCLUSIONS: In this preliminary report, under controlled conditions of light exposure, meal composition, energy expenditure, and sleep-wake schedules, intermittent fasting has no significant influence on the circadian pattern of melatonin. PMID:28808490

[Counteracting effects of intermittent head-up tilt on simulated-weightlessness induced atrophy of anti-gravity muscles].

PubMed

Liu, C; Zhang, L F; Zhang, L N; Ni, H Y; Zhang, Y Q; Sun, L

2000-12-01

Objective. To study the efficacy of intermittent + Gz (45 degrees head-up tilt, HUT) exposures in preventing or alleviating atrophic changes in hind limb muscles induced by simulated weightlessness. Method. Male Sprague-Dawley (SD) rats were assigned randomly to one of three groups: simultaneous control (CON), simulated weightlessness (SUS), and SUS plus 6 h/d HUT (SUS + HUT). Muscles examined included soleus (SOL), medial gastrocnemius (correction from grastrocnemius) (MG), lateral gastrocnemius (LG) and extensor digitorum longus (EDL). Sections were treated with an adenosinetriphosphatase (ATPase) stain or alkaline phosphatase stain. The cross-sectional areas (CSA) of fibers, the relative proportion of type I fiber and the ratio of capillaries/fibers (C/F) were measured using Leica image analysis system. Result. Compared with CON, the wet weight of hind limb muscles in SUS were significantly reduced. The changes of wet weight in different groups were various. The C/F ratios of all muscles were significantly reduced. SUS + HUT rats showed significant increases in SOL and MG wet weight, and the relative counter-effects of intermittent HUT were 93.4% and 34.8%, respectively. In SUS + HUT group, the CSA of both type I and II fibers and relative proportion of type I fibers were completely recovered in SOL, and partially recovered in MG, while the counter-effects were much less obvious in the fibers of LG and EDL. However, HUT resulted in a significant recovery of the C/F ratios in all muscles. Conclusion. The present study demonstrated that intermittent HUT is effective in counteracting the atrophy induced by simulated weightlessness. The result that reactivity to HUT varied among different muscles suggests that the intermittent artificial gravity should be complemented with other countermeasures.

The stochastic dynamics of intermittent porescale particle motion

NASA Astrophysics Data System (ADS)

Dentz, Marco; Morales, Veronica; Puyguiraud, Alexandre; Gouze, Philippe; Willmann, Matthias; Holzner, Markus

2017-04-01

Numerical and experimental data for porescale particle dynamics show intermittent patterns in Lagrangian velocities and accelerations, which manifest in long time intervals of low and short durations of high velocities [1, 2]. This phenomenon is due to the spatial persistence of particle velocities on characteristic heterogeneity length scales. In order to systematically quantify these behaviors and extract the stochastic dynamics of particle motion, we focus on the analysis of Lagrangian velocities sampled equidistantly along trajectories [3]. This method removes the intermittency observed under isochrone sampling. The space-Lagrangian velocity series can be quantified by a Markov process that is continuous in distance along streamline. It is fully parameterized in terms of the flux-weighted Eulerian velocity PDF and the characteristic pore-length. The resulting stochastic particle motion describes a continuous time random walk (CTRW). This approach allows for the process based interpretation of experimental and numerical porescale velocity, acceleration and displacement data. It provides a framework for the characterization and upscaling of particle transport and dispersion from the pore to the Darcy-scale based on the medium geometry and Eulerian flow attributes. [1] P. De Anna, T. Le Borgne, M. Dentz, A.M. Tartakovsky, D. Bolster, and P. Davy, "Flow intermittency, dispersion, and correlated continuous time random walks in porous media," Phys. Rev. Lett. 110, 184502 (2013). [2] M. Holzner, V. L. Morales, M. Willmann, and M. Dentz, "Intermittent Lagrangian velocities and accelerations in three- dimensional porous medium flow," Phys. Rev. E 92, 013015 (2015). [3] M. Dentz, P. K. Kang, A. Comolli, T. Le Borgne, and D. R. Lester, "Continuous time random walks for the evolution of Lagrangian velocities," Phys. Rev. Fluids (2016).

A novel implantable catheter system with transcutaneous port for intermittent convection-enhanced delivery of carboplatin for recurrent glioblastoma.

PubMed

Barua, Neil U; Hopkins, Kirsten; Woolley, Max; O'Sullivan, Stephen; Harrison, Rob; Edwards, Richard J; Bienemann, Alison S; Wyatt, Marcella J; Arshad, Azeem; Gill, Steven S

2016-01-01

Inadequate penetration of the blood-brain barrier (BBB) by systemically administered chemotherapies including carboplatin is implicated in their failure to improve prognosis for patients with glioblastoma. Convection-enhanced delivery (CED) of carboplatin has the potential to improve outcomes by facilitating bypass of the BBB. We report the first use of an implantable CED system incorporating a novel transcutaneous bone-anchored port (TBAP) for intermittent CED of carboplatin in a patient with recurrent glioblastoma. The CED catheter system was implanted using a robot-assisted surgical method. Catheter targeting accuracy was verified by performing intra-operative O-arm imaging. The TBAP was implanted using a skin-flap dermatome technique modeled on bone-anchored hearing aid surgery. Repeated infusions were performed by attaching a needle administration set to the TBAP. Drug distribution was monitored with serial real-time T2-weighted magnetic resonance imaging (MRI). All catheters were implanted to within 1.5 mm of their planned target. Intermittent infusions of carboplatin were performed on three consecutive days and repeated after one month without the need for further surgical intervention. Infused volumes of 27.9 ml per day were well tolerated, with the exception of a single seizure episode. Follow-up MRI at eight weeks demonstrated a significant reduction in the volume of tumor enhancement from 42.6 ml to 24.6 ml, and was associated with stability of the patient's clinical condition. Reduction in the volume of tumor enhancement indicates that intermittent CED of carboplatin has the potential to improve outcomes in glioblastoma. The novel technology described in this report make intermittent CED infusion regimes an achievable treatment strategy.

[Reassessment of a combination of cerebrospinal fluid scintigraphy and nasal pledget counts in patients with suspected rhinorrhea].

PubMed

Kosuda, S; Arai, S; Hohshito, Y; Tokumitsu, H; Kusano, S; Ishihara, S; Shima, K

1998-07-01

A combination study of cerebrospinal fluid scintigraphy and nasal pledget counts was performed using 37 MBq of 111In-DTPA in 12 patients with suspected rhinorrhea. A pledget was inserted and dwelled in each nasal cavity for 6 hours, with the patient prone during at least 30 minutes. A total of 18 studies was implemented and nasal pledget counting method successfully diagnosed all of CSF rhinorrhea. Diagnosis was possible when pledget counts were greater than 1 kcpm. In patients with persistent, intermittent and occult/no nasal discharge, rhinorrhea was found in 100% (5/5), 60% (3/5), 25% (2/8), respectively. Two cases only exhibited positive scintigraphy. MRI or CT cisternography should be first performed in patients with persistent discharge, but in patients with intermittent/occult discharge pledget counting method might take priority of other diagnostic modalities. In conclusion, nasal pledget counting method is a simple and useful tool for detecting rhinorrhea.

Intermittent changing axis deviation with intermittent left anterior hemiblock during atrial flutter with subclinical hyperthyroidism.

PubMed

Patanè, Salvatore; Marte, Filippo

2009-06-26

Subclinical hyperthyroidism is an increasingly recognized entity that is defined as a normal serum free thyroxine and free triiodothyronine levels with a thyroid-stimulating hormone level suppressed below the normal range and usually undetectable. It has been reported that subclinical hyperthyroidism is not associated with CHD or mortality from cardiovascular causes but it is usually associated with a higher heart rate and a higher risk of supraventricular arrhythmias including atrial fibrillation and atrial flutter. Intermittent changing axis deviation during atrial fibrillation has also rarely been reported. We present a case of intermittent changing axis deviation with intermittent left anterior hemiblock in a 59-year-old Italian man with atrial flutter and subclinical hyperthyroidism. To our knowledge, this is the first report of intermittent changing axis deviation with intermittent left anterior hemiblock in a patient with atrial flutter.

40 CFR 51.119 - Intermittent control systems.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., 1970, and was operated as specified by the operating system of the ICS before December 31, 1970. (3... 40 Protection of Environment 2 2014-07-01 2014-07-01 false Intermittent control systems. 51.119... Intermittent control systems. (a) The use of an intermittent control system (ICS) may be taken into account in...

40 CFR 51.119 - Intermittent control systems.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., 1970, and was operated as specified by the operating system of the ICS before December 31, 1970. (3... 40 Protection of Environment 2 2011-07-01 2011-07-01 false Intermittent control systems. 51.119... Intermittent control systems. (a) The use of an intermittent control system (ICS) may be taken into account in...

40 CFR 51.119 - Intermittent control systems.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., 1970, and was operated as specified by the operating system of the ICS before December 31, 1970. (3... 40 Protection of Environment 2 2012-07-01 2012-07-01 false Intermittent control systems. 51.119... Intermittent control systems. (a) The use of an intermittent control system (ICS) may be taken into account in...

40 CFR 51.119 - Intermittent control systems.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., 1970, and was operated as specified by the operating system of the ICS before December 31, 1970. (3... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Intermittent control systems. 51.119... Intermittent control systems. (a) The use of an intermittent control system (ICS) may be taken into account in...

40 CFR 51.119 - Intermittent control systems.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., 1970, and was operated as specified by the operating system of the ICS before December 31, 1970. (3... 40 Protection of Environment 2 2013-07-01 2013-07-01 false Intermittent control systems. 51.119... Intermittent control systems. (a) The use of an intermittent control system (ICS) may be taken into account in...

Comparing cost-effectiveness of X-Stop with minimally invasive decompression in lumbar spinal stenosis: a randomized controlled trial.

PubMed

Lønne, Greger; Johnsen, Lars Gunnar; Aas, Eline; Lydersen, Stian; Andresen, Hege; Rønning, Roar; Nygaard, Øystein P

2015-04-15

Randomized clinical trial with 2-year follow-up. To compare the cost-effectiveness of X-stop to minimally invasive decompression in patients with symptomatic lumbar spinal stenosis. Lumbar spinal stenosis is the most common indication for operative treatment in elderly. Although surgery is more costly than nonoperative treatment, health outcomes for more than 2 years were shown to be significantly better. Surgical treatment with minimally invasive decompression is widely used. X-stop is introduced as another minimally invasive technique showing good results compared with nonoperative treatment. We enrolled 96 patients aged 50 to 85 years, with symptoms of neurogenic intermittent claudication within 250-m walking distance and 1- or 2-level lumbar spinal stenosis, randomized to either minimally invasive decompression or X-stop. Quality-adjusted life-years were based on EuroQol EQ-5D. The hospital unit costs were estimated by means of the top-down approach. Each cost unit was converted into a monetary value by dividing the overall cost by the amount of cost units produced. The analysis of costs and health outcomes is presented by the incremental cost-effectiveness ratio. The study was terminated after a midway interim analysis because of significantly higher reoperation rate in the X-stop group (33%). The incremental cost for X-stop compared with minimally invasive decompression was &OV0556;2832 (95% confidence interval: 1886-3778), whereas the incremental health gain was 0.11 quality-adjusted life-year (95% confidence interval: -0.01 to 0.23). Based on the incremental cost and effect, the incremental cost-effectiveness ratio was &OV0556;25,700. The majority of the bootstrap samples displayed in the northeast corner of the cost-effectiveness plane, giving a 50% likelihood that X-stop is cost-effective at the extra cost of &OV0556;25,700 (incremental cost-effectiveness ratio) for a quality-adjusted life-year. The significantly higher cost of X-stop is mainly due to implant cost and the significantly higher reoperation rate. 2.

Design of the Revascularization With Open Bypass vs Angioplasty and Stenting of the Lower Extremity Trial (ROBUST): a randomized clinical trial.

PubMed

Malas, Mahmoud B; Qazi, Umair; Glebova, Natalia; Arhuidese, Isibor; Reifsnyder, Thomas; Black, James; Perler, Bruce A; Freischlag, Julie A

2014-12-01

To our knowledge, there is no level 1 evidence comparing open bypass with angioplasty and stenting in TransAtlantic Inter-Society Consensus (TASC II) B and C superficial femoral artery lesions. The Revascularization With Open Bypass vs Angioplasty and Stenting of the Lower Extremity Trial (ROBUST) is the first prospective randomized clinical trial comparing both treatments. To report the design of the ROBUST trial. The primary aim of the trial is to compare (1) the patency rate (primary, primary assisted, and secondary patency at 6 and 12 months), (2) improvement of quality of life, (3) clinical improvement (at least 1 Rutherford category), and (4) wound healing and limb salvage in patients presenting with critical limb ischemia; secondary aims include (1) cost-effectiveness by factoring procedure and hospital admission costs including rehabilitation, readmission, and reintervention costs, (2) amputation-free survival, (3) reintervention rate, and (4) 30-day operative mortality, morbidity, and wound and access complications. ROBUST is a prospective randomized clinical trial with the aim to enroll 320 patients with intermittent claudication that does not respond to medical management and patients with critical limb ischemia. The maximum level of medical therapy will be administered using antiplatelet agents and statins, as well as measures to control hypertension and diabetes mellitus. Patients with TASC II B or C lesions are prospectively randomized to receive either femoropopliteal bypass or percutaneous transluminal angioplasty and stenting; patients with TASC II A and D lesions are not randomized and receive percutaneous transluminal angioplasty and stenting or femoropopliteal bypass, respectively. All patients will be evaluated at 1, 6, and 12 months postoperatively with physical examination, ankle brachial index, duplex, and a quality-of-life questionnaire. The trial is actively enrolling participants. At the time of writing, 29 patients have been enrolled; most are male (60%) and white (65%). Providing level 1 evidence, ROBUST may help to establish guidelines for the treatment of superficial femoral artery lesions, eliminate unnecessary procedures, and reduce health care costs. clinicaltrials.gov Identifier: NCT01602159.

Efficacy and safety of rivaroxaban compared with warfarin in patients with peripheral artery disease and non-valvular atrial fibrillation: insights from ROCKET AF.

PubMed

Jones, William Schuyler; Hellkamp, Anne S; Halperin, Jonathan; Piccini, Jonathan P; Breithardt, Gunter; Singer, Daniel E; Fox, Keith A A; Hankey, Graeme J; Mahaffey, Kenneth W; Califf, Robert M; Patel, Manesh R

2014-01-01

Vascular disease is included in a risk scoring system to predict stroke in patients with non-valvular atrial fibrillation (AF). This post hoc analysis of ROCKET AF aimed to determine the absolute rates of stroke and bleeding, and the relative effectiveness and safety of rivaroxaban vs. warfarin in patients with and without peripheral artery disease (PAD). Peripheral artery disease was defined on the case-report form as the presences of intermittent claudication, amputation for arterial insufficiency, vascular reconstruction, bypass surgery, or percutaneous intervention to the extremities, or previously documented abdominal aortic aneurysm. ROCKET AF was a double-blind, double-dummy, randomized-controlled trial comparing rivaroxaban and warfarin for the prevention of stroke or systemic embolism. A total of 839 (5.9%) patients in ROCKET AF had PAD. Patients with and without PAD had similar rates of stroke or systemic embolism [HR: 1.04, 95% CI (0.72, 1.50), P = 0.84] and major or non-major clinically relevant (NMCR) bleeding [HR: 1.11, 95% CI (0.96, 1.28), P = 0.17], respectively. The efficacy of rivaroxaban when compared with warfarin for the prevention of stroke or systemic embolism was similar in patients with PAD (HR: 1.19, 95% CI: 0.63-2.22) and without PAD (HR: 0.86, 95% CI: 0.73-1.02; interaction P = 0.34). There was a significant interaction for major or NMCR bleeding in patients with PAD treated with rivaroxaban compared with warfarin (HR: 1.40, 95% CI: 1.06-1.86) compared with those without PAD (HR: 1.03, 95% CI: 0.95-1.11; interaction P = 0.037). Patients with PAD in ROCKET AF did not have a statistically significant higher risk of stroke or systemic embolism than patients without PAD, and there were similar efficacy outcomes in patients treated with rivaroxaban and warfarin. In PAD patients, there was a higher risk of major bleeding or NMCR bleeding with rivaroxaban when compared with warfarin (interaction P = 0.037). Further investigation is warranted to validate this subgroup analysis and determine the optimal treatment in this high-risk cohort of AF patients with PAD.

[Stroke in young adults: incidence and clinical picture in 280 patients according to their aetiological subtype].

PubMed

Arboix, Adrià; Massons, Joan; García-Eroles, Luís; Oliveres, Montserrat

2016-03-04

To assess the clinical features and incidence rate of stroke in young adults (less than 55 years of age). Hospital-based descriptive study of 280 young inpatients consecutively admitted for stroke over a period of 24 years. We conducted a comparison with the remaining 4,312 patients admitted for stroke. Stroke in young adults represented 6.1% of all strokes, 5.7% of transient ischaemic attacks, 5.8% of cerebral infarctions and 8.4% of brain haemorrhages. However, reported minimal frequency of cardioembolic (2.1%) and atherothrombotic (3.4%) infarctions, accounted for 5.9% of lacunar and for 10.7% of essential infarctions and showed a maximum frequency in those infarctions of unusual aetiology (36%). Factors independently associated with stroke in young adults were cigarette smoking (OR 4.23; 95% CI 3.02-5.93; P=.000), unusual aetiology (OR 4.97; 95% CI 3.15-7.84; P=.000), headache (OR 4.57; 95% CI 2.59-8.07; P=.000), alcohol abuse (OR 3.93; 95% CI 2.46-6.29; P=.000), oral contraceptives (OR 14.07; 95% CI 2.37-83.40; P=.004), atrial fibrillation (OR 0.15; 95% CI 0.08-0.28; P=.000), arterial hypertension (OR 0.43; 95% CI 0.33-0.57; P=.000), COPD (OR 0.20; 95% CI 0.09-0.44; P=.000), atherothrombotic infarction (OR 0.51; 95% CI 0.34-0.77; P=.001), female sex (OR 0.71; 95% CI 0.52-0.97; P=.029), diabetes mellitus (OR 0.66; 95% CI 0.46-0.98; P=.030), ischaemic heart disease (OR 0.56; 95% CI 0.33-0.95; P=.032) and intermittent claudication (OR 0.48; 95% CI 0.24-0.94; P=.033). Stroke in young adults is infrequent (6.1% of the total), but represents the highest frequency of cerebral infarcts of unusual aetiology (36%). We conclude that stroke in younger patients presents its own and differentiated clinical profile. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

Intermittent Withdrawal of Oxaliplatin for Alleviating Neurotoxicity during Oxaliplatin-Based Chemotherapy for Japanese Patients with Inoperable or Metastatic Colorectal Cancer: A Phase 2 Multicenter Study.

PubMed

Kato, Shunsuke; Imai, Hiroo; Gamoh, Makio; Takahata, Takenori; Ohori, Hisatsugu; Yasuda, Katsuhiro; Niitani, Tomohito; Murakawa, Yasuko; Amagai, Kenji; Isobe, Hideki; Shindo, Yoshiaki; Kuroki, Michio; Sakamoto, Yasuhiro; Shimodaira, Hideki; Yoshioka, Takashi; Ishioka, Chikashi

2018-05-01

Oxaliplatin-based chemotherapy is a well-established regimen for patients with inoperable and metastatic colorectal cancer. However, one of the major limitations of oxaliplatin-based chemotherapy is sensory neuropathy. It was previously reported that introduction of intermittent oxaliplatin treatment to an oxaliplatin-based regimen has a significant benefit on efficacy or safety. Here, we prospectively assessed whether efficacy and safety of first-line chemotherapy for advanced colorectal cancer are achieved by introduction of withdrawal of oxaliplatin treatment for a certain period (intermittent oxaliplatin treatment). The primary endpoint of the present study is to assess the progression free survival time on patients treated with chemotherapy (mFOLFOX6 (levofolinate, 5-fluorouracil and oxaliplatin combination therapy) plus bevacizumab or CapeOX (oxaliplatin and capecitabine combination therapy) plus bevacizumab) with intermittent oxaliplatin treatment. Bevacizumab is a humanized anti-vascular endothelial growth factor antibody. Median progression-free survival by the mFOLFOX6 plus bevacizumab with intermittent oxaliplatin treatment or the CapeOX plus bevacizumab with intermittent oxaliplatin treatment were 10.6 months (95% confidential interval [CI], 8.3-13.4 months) or 8.0 months (95% CI, 4.2-16.8 months), respectively. Overall response rate by the mFOLFOX6 plus bevacizumab with intermittent oxaliplatin treatment or CapeOX plus bevacizumab with intermittent oxaliplatin treatment was 55.1% or 42.1%, respectively. Grade 3 or 4 neuropathy was observed in 4.1% or 10.5% of patients treated with mFOLFOX6 plus bevacizumab with intermittent oxaliplatin treatment or CapeOX plus bevacizumab with intermittent oxaliplatin treatment, respectively. Introduction of intermittent oxaliplatin treatment has improved severe neuropathy in mFOLFOX6 plus bevacizumab regimen without reducing treatment efficacy.

Stroke with intermittent atrial fibrillation: incidence and predictors during aspirin therapy. Stroke Prevention in Atrial Fibrillation Investigators.

PubMed

Hart, R G; Pearce, L A; Rothbart, R M; McAnulty, J H; Asinger, R W; Halperin, J L

2000-01-01

This study was performed to characterize the risk of stroke in elderly patients with recurrent intermittent atrial fibrillation (AF). Although intermittent AF is common, relatively little is known about the attendant risk of stroke. A longitudinal cohort study was performed comparing 460 participants with intermittent AF with 1,552 with sustained AF treated with aspirin in the Stroke Prevention in Atrial Fibrillation studies and followed for a mean of two years. Independent risk factors for ischemic stroke were identified by multivariate analysis. Patients with intermittent AF were, on average, younger (66 vs. 70 years, p < 0.001), were more often women (37% vs. 26% p < 0.001) and less often had heart failure (11% vs. 21%, p < 0.001) than those with sustained AF. The annualized rate of ischemic stroke was similar for those with intermittent (3.2%) and sustained AF (3.3%). In patients with intermittent AF, independent predictors of ischemic stroke were advancing age (relative risk [RR] = 2.1 per decade, p < 0.001), hypertension (RR = 3.4, p = 0.003) and prior stroke (RR = 4.1, p = 0.01). Of those with intermittent AF predicted to be high risk (24%), the observed stroke rate was 7.8% per year (95% confidence interval 4.5 to 14). In this large cohort of AF patients given aspirin, those with intermittent AF had stroke rates similar to patients with sustained AF and similar stroke risk factors. Many elderly patients with recurrent intermittent AF have substantial rates of stroke and likely benefit from anticoagulation. High-risk patients with intermittent AF can be identified using the same clinical criteria that apply to patients with sustained AF.

Relationship between central and peripheral atherosclerosis and left ventricular dysfunction in a community population.

PubMed

Tsao, Connie W; Gona, Philimon; Salton, Carol; Murabito, Joanne M; Oyama, Noriko; Danias, Peter G; O'Donnell, Christopher J; Manning, Warren J; Yeon, Susan B

2011-08-01

We aimed to determine the relationships between resting left ventricular (LV) wall motion abnormalities (WMAs), aortic plaque, and peripheral artery disease (PAD) in a community cohort. A total of 1726 Framingham Heart Study Offspring Cohort participants (806 males, 65 ± 9 years) underwent cardiovascular magnetic resonance with quantification of aortic plaque volume and assessment of regional left ventricular systolic function. Claudication, lower extremity revascularization, and ankle-brachial index (ABI) were recorded at the most contemporaneous examination visit. WMAs were associated with greater aortic plaque burden, decreased ABI, and claudication in age- and sex-adjusted analyses (all p < 0.001), which were not significant after adjustment for cardiovascular risk factors. In age- and sex-adjusted analyses, both the presence (p < 0.001) and volume of aortic plaque were associated with decreased ABI (p < 0.001). After multivariable adjustment, an ABI ≤ 0.9 or prior revascularization was associated with a threefold odds of aortic plaque (p = 0.0083). Plaque volume significantly increased with decreasing ABI in multivariable-adjusted analyses (p < 0.0001). In this free-living population, associations of WMAs with aortic plaque burden and clinical measures of PAD were attenuated after adjustment for coronary heart disease risk factors. Aortic plaque volume and ABI remained strongly negatively correlated after multivariable adjustment. Our findings suggest that the association between coronary heart disease and non-coronary atherosclerosis is explained by cardiovascular risk factors. Aortic atherosclerosis and PAD remain strongly associated after multivariable adjustment, suggesting shared mechanisms beyond those captured by traditional risk factors.

Report from a quality assurance program on patients undergoing the MILD procedure.

PubMed

Durkin, Brian; Romeiser, Jamie; Shroyer, A Laurie W; Schiller, Robin; Bae, Jin; Davis, Raphael P; Peyster, Robert; Benveniste, Helene

2013-05-01

To characterize trends in pain and functional outcomes and identify risk factors in patients with lumbar spinal stenosis (LSS) and neurogenic claudication undergoing the "Minimally Invasive Lumbar Decompression" (MILD) procedure. Retrospective observational cohort study. Academic multidisciplinary pain center at Stony Brook Medicine. Patients undergoing the MILD procedure from October 2010 to November 2012. De-identified perioperative, pain and function related data for 50 patients undergoing MILD were extracted from the Center for Pain Management's quality assessment database. Data included numerical rating scale (NRS), symptom severity and physical function (Zurich Claudication Questionnaire), functional status (Oswestry Disability Index [ODI]), pain interference scores (National Institutes of Health Patient-Reported Outcomes Measurement Information System [PROMIS]), and patients' self-reported low back and lower extremity pain distribution. No MILD patient incurred procedure-related complications. Average NRS scores decreased postoperatively and 64.3% of patients reported less pain at 3 months. Clinically meaningful functional ODI improvements of at least 20% from baseline were present in 25% of the patients at 6 months. Preliminary analysis of changes in PROMIS scores at 3 months revealed that pre-MILD "severe" lumbar canal stenosis may be associated with high risk of "no improvement." No such impact was observed for NRS or ODI outcomes. Overall, pain is reduced and functional status improved in LSS patients following the MILD procedure at 3 and 6 months. Given the small sample size, it is not yet possible to identify patient subgroups at risk for "no improvement." Continued follow-up of longer-term outcomes appears warranted to develop evidence-based patient selection criteria. Wiley Periodicals, Inc.

Acute Effects of Carbohydrate Supplementation on Intermittent Sports Performance

PubMed Central

Baker, Lindsay B.; Rollo, Ian; Stein, Kimberly W.; Jeukendrup, Asker E.

2015-01-01

Intermittent sports (e.g., team sports) are diverse in their rules and regulations but similar in the pattern of play; that is, intermittent high-intensity movements and the execution of sport-specific skills over a prolonged period of time (~1–2 h). Performance during intermittent sports is dependent upon a combination of anaerobic and aerobic energy systems, both of which rely on muscle glycogen and/or blood glucose as an important substrate for energy production. The aims of this paper are to review: (1) potential biological mechanisms by which carbohydrate may impact intermittent sport performance; (2) the acute effects of carbohydrate ingestion on intermittent sport performance, including intermittent high-intensity exercise capacity, sprinting, jumping, skill, change of direction speed, and cognition; and (3) what recommendations can be derived for carbohydrate intake before/during exercise in intermittent sports based on the available evidence. The most researched intermittent sport is soccer but some sport-specific studies have also been conducted in other sports (e.g., rugby, field hockey, basketball, American football, and racquet sports). Carbohydrate ingestion before/during exercise has been shown in most studies to enhance intermittent high-intensity exercise capacity. However, studies have shown mixed results with regards to the acute effects of carbohydrate intake on sprinting, jumping, skill, change of direction speed, and cognition. In most of these studies the amount of carbohydrate consumed was ~30–60 g/h in the form of a 6%–7% carbohydrate solution comprised of sucrose, glucose, and/or maltodextrin. The magnitude of the impact that carbohydrate ingestion has on intermittent sport performance is likely dependent on the carbohydrate status of the individual; that is, carbohydrate ingestion has the greatest impact on performance under circumstances eliciting fatigue and/or hypoglycemia. Accordingly, carbohydrate ingestion before and during a game seems to have the greatest impact on intermittent sports performance towards the end of the game. PMID:26184303

Acute Effects of Carbohydrate Supplementation on Intermittent Sports Performance.

PubMed

Baker, Lindsay B; Rollo, Ian; Stein, Kimberly W; Jeukendrup, Asker E

2015-07-14

Intermittent sports (e.g., team sports) are diverse in their rules and regulations but similar in the pattern of play; that is, intermittent high-intensity movements and the execution of sport-specific skills over a prolonged period of time (~1-2 h). Performance during intermittent sports is dependent upon a combination of anaerobic and aerobic energy systems, both of which rely on muscle glycogen and/or blood glucose as an important substrate for energy production. The aims of this paper are to review: (1) potential biological mechanisms by which carbohydrate may impact intermittent sport performance; (2) the acute effects of carbohydrate ingestion on intermittent sport performance, including intermittent high-intensity exercise capacity, sprinting, jumping, skill, change of direction speed, and cognition; and (3) what recommendations can be derived for carbohydrate intake before/during exercise in intermittent sports based on the available evidence. The most researched intermittent sport is soccer but some sport-specific studies have also been conducted in other sports (e.g., rugby, field hockey, basketball, American football, and racquet sports). Carbohydrate ingestion before/during exercise has been shown in most studies to enhance intermittent high-intensity exercise capacity. However, studies have shown mixed results with regards to the acute effects of carbohydrate intake on sprinting, jumping, skill, change of direction speed, and cognition. In most of these studies the amount of carbohydrate consumed was ~30-60 g/h in the form of a 6%-7% carbohydrate solution comprised of sucrose, glucose, and/or maltodextrin. The magnitude of the impact that carbohydrate ingestion has on intermittent sport performance is likely dependent on the carbohydrate status of the individual; that is, carbohydrate ingestion has the greatest impact on performance under circumstances eliciting fatigue and/or hypoglycemia. Accordingly, carbohydrate ingestion before and during a game seems to have the greatest impact on intermittent sports performance towards the end of the game.

Extrapolating regional probability of drying of headwater streams using discrete observations and gauging networks

NASA Astrophysics Data System (ADS)

Beaufort, Aurélien; Lamouroux, Nicolas; Pella, Hervé; Datry, Thibault; Sauquet, Eric

2018-05-01

Headwater streams represent a substantial proportion of river systems and many of them have intermittent flows due to their upstream position in the network. These intermittent rivers and ephemeral streams have recently seen a marked increase in interest, especially to assess the impact of drying on aquatic ecosystems. The objective of this paper is to quantify how discrete (in space and time) field observations of flow intermittence help to extrapolate over time the daily probability of drying (defined at the regional scale). Two empirical models based on linear or logistic regressions have been developed to predict the daily probability of intermittence at the regional scale across France. Explanatory variables were derived from available daily discharge and groundwater-level data of a dense gauging/piezometer network, and models were calibrated using discrete series of field observations of flow intermittence. The robustness of the models was tested using an independent, dense regional dataset of intermittence observations and observations of the year 2017 excluded from the calibration. The resulting models were used to extrapolate the daily regional probability of drying in France: (i) over the period 2011-2017 to identify the regions most affected by flow intermittence; (ii) over the period 1989-2017, using a reduced input dataset, to analyse temporal variability of flow intermittence at the national level. The two empirical regression models performed equally well between 2011 and 2017. The accuracy of predictions depended on the number of continuous gauging/piezometer stations and intermittence observations available to calibrate the regressions. Regions with the highest performance were located in sedimentary plains, where the monitoring network was dense and where the regional probability of drying was the highest. Conversely, the worst performances were obtained in mountainous regions. Finally, temporal projections (1989-2016) suggested the highest probabilities of intermittence (> 35 %) in 1989-1991, 2003 and 2005. A high density of intermittence observations improved the information provided by gauging stations and piezometers to extrapolate the temporal variability of intermittent rivers and ephemeral streams.

Knockdown of angiopoietin-like 2 mimics the benefits of intermittent fasting on insulin responsiveness and weight loss.

PubMed

Martel, Cécile; Pinçon, Anthony; Bélanger, Alexandre Maxime; Luo, Xiaoyan; Gillis, Marc-Antoine; de Montgolfier, Olivia; Thorin-Trescases, Nathalie; Thorin, Éric

2018-01-01

Angiopoietin-like 2 (ANGPTL2) is an inflammatory adipokine linking obesity to insulin resistance. Intermittent fasting, on the other hand, is a lifestyle intervention able to prevent obesity and diabetes but difficult to implement and maintain. Our objectives were to characterize a link between ANGPTL2 and intermittent fasting and to investigate whether the knockdown of ANGPTL2 reproduces the benefits of intermittent fasting on weight gain and insulin responsiveness in knockdown and wild-type littermates mice. Intermittent fasting, access to food ad libitum once every other day, was initiated at the age of three months and maintained for four months. Intermittent fasting decreased by 63% (p < 0.05) gene expression of angptl2 in adipose tissue of wild-type mice. As expected, intermittent fasting improved insulin sensitivity (p < 0.05) and limited weight gain (p < 0.05) in wild-type mice. Knockdown mice fed ad libitum, however, were comparable to wild-type mice following the intermittent fasting regimen: insulin sensitivity and weight gain were identical, while intermittent fasting had no additional impact on these parameters in knockdown mice. Energy intake was similar between both wild-type fed intermittent fasting and ANGPTL2 knockdown mice fed ad libitum, suggesting that intermittent fasting and knockdown of ANGPTL2 equally lower feeding efficiency. These results suggest that the reduction of ANGPTL2 could be a useful and promising strategy to prevent obesity and insulin resistance, although further investigation of the mechanisms linking ANGPTL2 and intermittent fasting is warranted. Impact statement Intermittent fasting is an efficient diet pattern to prevent weight gain and improve insulin sensitivity. It is, however, a difficult regimen to follow and compliance is expected to be very low. In this work, we demonstrate that knockdown of ANGPTL2 in mice fed ad libitum mimics the beneficial effects of intermittent fasting on weight gain and insulin sensitivity in wild-type mice. ANGPTL2 is a cytokine positively associated with fat mass in humans, which inactivation in mice improves resistance to a high-fat metabolic challenge. This study provides a novel pathway by which IF acts to limit obesity despite equivalent energy intake. The development of a pharmacological ANGPTL2 antagonist could provide an efficient tool to reduce the burden of obesity.

Mature Results of the Ottawa Phase II Study of Intermittent Androgen-Suppression Therapy in Prostate Cancer: Clinical Predictors of Outcome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malone, Shawn; Perry, Gad; Eapen, Libni

2007-07-01

Purpose: To present the mature experience of a phase II trial of intermittent androgen suppression (IAS). Methods and Materials: Intermittent androgen-suppression therapy was initiated in prostate-cancer patients to delay hormone resistance and minimize potential side effects of androgen-deprivation therapy (ADT). Patients received cyclical periods of ADT and observation (off-treatment interval [OTI]). Androgen-deprivation therapy was reinitiated when the level of prostate-specific antigen (PSA) rose above 10 ng/ml, or for disease progression. Associations between clinical factors and eligibility for OTI were measured. Kaplan-Meier and Cox regression analyses were used to determine factors predicting the duration of OTIs. Results: Ninety-five patients completed 187more » cycles of treatment. The median duration of OTIs was 8.5 months. Patients with higher PSA and metastatic disease were less likely to be eligible for the first OTI (p < 0.01). In multivariate analysis, patients with higher PSA and local relapse had significantly longer OTIs (p < 0.01) compared with metastatic patients. The median time to withdrawal from the study was 37 months. Conclusions: Intermittent androgen suppression appears to be a favorable treatment option for patients with biochemically (according to level of PSA) or locally recurrent prostate cancer with favorable long-term survival, a high probability of eligibility for OTIs, and durable OTIs.« less

Phase I study of afatinib combined with nintedanib in patients with advanced solid tumours

PubMed Central

Bahleda, Rastislav; Hollebecque, Antoine; Varga, Andrea; Gazzah, Anas; Massard, Christophe; Deutsch, Eric; Amellal, Nadia; Farace, Françoise; Ould-Kaci, Mahmoud; Roux, Flavien; Marzin, Kristell; Soria, Jean-Charles

2015-01-01

Background: This Phase I study evaluated continuous- and intermittent-dosing (every other week) of afatinib plus nintedanib in patients with advanced solid tumours. Methods: In the dose-escalation phase (n=45), maximum tolerated doses (MTDs) were determined for continuous/intermittent afatinib 10, 20, 30 or 40 mg once daily plus continuous nintedanib 150 or 200 mg twice daily. Secondary objectives included safety and efficacy. Clinical activity of continuous afatinib plus nintedanib at the MTD was further evaluated in an expansion phase (n=25). Results: The most frequent dose-limiting toxicities were diarrhoea (11%) and transaminase elevations (7%). Maximum tolerated doses were afatinib 30 mg continuously plus nintedanib 150 mg, and afatinib 40 mg intermittently plus nintedanib 150 mg. Treatment-related adverse events (mostly Grade ⩽3) included diarrhoea (98%), asthenia (64%), nausea (62%) and vomiting (60%). In the dose-escalation phase, two patients had partial responses (PRs) and 27 (60%) had stable disease (SD). In the expansion phase, one complete response and three PRs were observed (all non-small cell lung cancer), with SD in 13 (52%) patients. No pharmacokinetic interactions were observed. Conclusions: MTDs of continuous or intermittent afatinib plus nintedanib demonstrated a manageable safety profile with proactive management of diarrhoea. Antitumour activity was observed in patients with solid tumours. PMID:26512876

Durability of treatment response to zolpidem with three different maintenance regimens: a preliminary study

PubMed Central

Perlis, Michael; Grandner, Michael; Zee, Jarcy; Bremer, Erin; Whinnery, Julia; Barilla, Holly; Andalia, Priscilla; Gehrman, Phil; Morales, Knashawn; Thase, Michael; Bootzin, Richard; Ader, Robert

2015-01-01

Background and aim At present, there is no consensus regarding how to medically manage chronic insomnia in the long term. The unstated standard of practice is for patients to use hypnotics intermittently. The present study aimed to compare a partial reinforcement strategy with nightly and intermittent dosing strategies for its potential as a maintenance therapy. Methods A mixed model was used in the study. One between-subjects factor: group (n = 4). One repeated-measures factor: time (12 weekly assessments). A total of 74 subjects with chronic Insomnia were treated with 10 mg zolpidem for 4 weeks. Treatment respondents were randomized to nightly dosing with 10 mg or 5 mg (QHS-10 and QHS-5), intermittent dosing with 10 mg (IDS-10 [3–5 days weekly]), or partial reinforcement dosing with 10 mg (PRS-10 [nightly pill use with 50% active medication and 50% placebos]) for 12 weeks. Results It was found, in compliant subjects (n = 55), that all four strategies evaluated maintained treatment response over time (ie, prevented or delayed relapse). For the subjects that remained in remission, the subjects in the intermittent dosing group (IDS-10) group exhibited poorer sleep continuity. Conclusions While best considered a preliminary study, the present findings suggest that the partial reinforcement strategy may be a viable means toward maintaining treatment gains over time with less active medication. PMID:26298795

High acceptability of HIV pre-exposure prophylaxis but challenges in adherence and use: qualitative insights from a phase I trial of intermittent and daily PrEP in at-risk populations in Kenya.

PubMed

Van der Elst, Elisabeth Maria; Mbogua, Judie; Operario, Don; Mutua, Gaudensia; Kuo, Caroline; Mugo, Peter; Kanungi, Jennifer; Singh, Sagri; Haberer, Jessica; Priddy, Frances; Sanders, Eduard Joachim

2013-07-01

This paper used qualitative methods to explore experiences of men who have sex with men and female sex workers in Nairobi and Mtwapa, Kenya, who used oral pre-exposure prophylaxis (PrEP) for HIV prevention as part of a four-month trial of safety, acceptability and adherence. Fifty-one of 72 volunteers who took part in a randomized, placebo-controlled, blinded trial that compared daily and intermittent dosage of PrEP underwent qualitative assessments after completing the trial. Analyses identified three themes: (i) acceptability of PrEP was high, i.e. side effects were experienced early in the study but diminished over time, however characteristics of pills could improve comfort and use; (ii) social impacts such as stigma, rumors, and relationship difficulties due to being perceived as HIV positive were prevalent; (iii) adherence was challenged by complexities of daily life, in particular post-coital dosing adherence suffered from alcohol use around time of sex, mobile populations, and transactional sex work. These themes resonated across dosing regimens and gender, and while most participants favored the intermittent dosing schedule, those in the intermittent group noted particular challenges in adhering to the post-coital dose. Culturally appropriate and consistent counseling addressing these issues may be critical for PrEP effectiveness.

A stochastic estimation procedure for intermittently-observed semi-Markov multistate models with back transitions.

PubMed

Aralis, Hilary; Brookmeyer, Ron

2017-01-01

Multistate models provide an important method for analyzing a wide range of life history processes including disease progression and patient recovery following medical intervention. Panel data consisting of the states occupied by an individual at a series of discrete time points are often used to estimate transition intensities of the underlying continuous-time process. When transition intensities depend on the time elapsed in the current state and back transitions between states are possible, this intermittent observation process presents difficulties in estimation due to intractability of the likelihood function. In this manuscript, we present an iterative stochastic expectation-maximization algorithm that relies on a simulation-based approximation to the likelihood function and implement this algorithm using rejection sampling. In a simulation study, we demonstrate the feasibility and performance of the proposed procedure. We then demonstrate application of the algorithm to a study of dementia, the Nun Study, consisting of intermittently-observed elderly subjects in one of four possible states corresponding to intact cognition, impaired cognition, dementia, and death. We show that the proposed stochastic expectation-maximization algorithm substantially reduces bias in model parameter estimates compared to an alternative approach used in the literature, minimal path estimation. We conclude that in estimating intermittently observed semi-Markov models, the proposed approach is a computationally feasible and accurate estimation procedure that leads to substantial improvements in back transition estimates.

Ecological research and management of intermittent rivers: an ...

EPA Pesticide Factsheets

Rivers and streams that do not flow permanently (herein intermittent rivers; IRs) make up a large proportion of the world's inland waters and are gaining widespread attention. We review the research on IRs from its early focus on natural history through to current application in management and policy.The few early studies of the ecology of IRs were largely descriptive. Nevertheless, in the 1970s, synthesis of this sparse research complemented work on temporary standing waters to found a powerful framework for much of the subsequent research on IRs.Research on the ecology and biogeochemistry of IRs continues to fuel our understanding of resistance and resilience to drying and flooding as disturbances. Syntheses of the growing literature, including cross-continental and cross-climate comparisons, are revealing the generality and individuality of ecological and ecosystem responses to flow cessation and surface water loss. Meanwhile, increasing numbers of experiments test the causality of these responses.Much of the increased consideration of IRs in research, management and policy is driven by the observed and projected shifts in flow regimes from perennial to intermittent associated with changes in land and water use and climate, superimposed on the high incidence of natural intermittency. The need to protect and better manage IRs is prompting researchers to develop new or modified methods to monitor flow status and assess the ecological condition of these systems.

Intermittent screening and treatment or intermittent preventive treatment with dihydroartemisinin-piperaquine versus intermittent preventive treatment with sulfadoxine-pyrimethamine for the control of malaria during pregnancy in western Kenya: an open-label, three-group, randomised controlled superiority trial.

PubMed

Desai, Meghna; Gutman, Julie; L'lanziva, Anne; Otieno, Kephas; Juma, Elizabeth; Kariuki, Simon; Ouma, Peter; Were, Vincent; Laserson, Kayla; Katana, Abraham; Williamson, John; ter Kuile, Feiko O

2015-12-19

Every year, more than 32 million pregnancies in sub-Saharan Africa are at risk of malaria infection and its adverse consequences. The effectiveness of the intermittent preventive treatment with sulfadoxine-pyrimethamine strategy recommended by WHO is threatened by high levels of parasite resistance. We aimed to assess the efficacy and safety of two alternative strategies: intermittent screening with malaria rapid diagnostic tests and treatment of women who test positive with dihydroartemisinin-piperaquine, and intermittent preventive treatment with dihydroartemisinin-piperaquine. We did this open-label, three-group, randomised controlled superiority trial at four sites in western Kenya with high malaria transmission and sulfadoxine-pyrimethamine resistance. HIV-negative pregnant women between 16 and 32 weeks' gestation were randomly assigned (1:1:1), via computer-generated permuted-block randomisation (block sizes of three, six, and nine), to receive intermittent screening and treatment with dihydroartemisinin-piperaquine, intermittent preventive treatment with dihydroartemisinin-piperaquine, or intermittent preventive treatment with sulfadoxine-pyrimethamine. Study participants, study clinic nurses, and the study coordinator were aware of treatment allocation, but allocation was concealed from study investigators, delivery unit nurses, and laboratory staff. The primary outcome was malaria infection at delivery, defined as a composite of peripheral or placental parasitaemia detected by placental histology, microscopy, or rapid diagnostic test. The primary analysis was by modified intention to treat. This study is registered with ClinicalTrials.gov, number NCT01669941. Between Aug 21, 2012, and June 19, 2014, we randomly assigned 1546 women to receive intermittent screening and treatment with dihydroartemisinin-piperaquine (n=515), intermittent preventive treatment with dihydroartemisinin-piperaquine (n=516), or intermittent preventive treatment with sulfadoxine-pyrimethamine (n=515); 1368 (88%) women comprised the intention-to-treat population for the primary endpoint. Prevalence of malaria infection at delivery was lower in the intermittent preventive treatment with dihydroartemisinin-piperaquine group than in the intermittent preventive treatment with sulfadoxine-pyrimethamine group (15 [3%] of 457 women vs 47 [10%] of 459 women; relative risk 0·32, 95% CI 0·18-0·56; p<0·0001), but not in the intermittent screening and treatment with dihydroartemisinin-piperaquine group (57 [13%] of 452 women; 1·23, 0·86-1·77; p=0·26). Compared with intermittent preventive treatment with sulfadoxine-pyrimethamine, intermittent preventive treatment with dihydroartemisinin-piperaquine was associated with a lower incidence of malaria infection during pregnancy (192·0 vs 54·4 events per 100 person-years; incidence rate ratio [IRR] 0·28, 95% CI 0·22-0·36; p<0·0001) and clinical malaria during pregnancy (37·9 vs 6·1 events; 0·16, 0·08-0·33; p<0·0001), whereas intermittent screening and treatment with dihydroartemisinin-piperaquine was associated with a higher incidence of malaria infection (232·0 events; 1·21, 1·03-1·41; p=0·0177) and clinical malaria (53·4 events; 1·41, 1·00-1·98; p=0·0475). We recorded 303 maternal and infant serious adverse events, which were least frequent in the intermittent preventive treatment with dihydroartemisinin-piperaquine group. At current levels of rapid diagnostic test sensitivity, intermittent screening and treatment is not a suitable alternative to intermittent preventive treatment with sulfadoxine-pyrimethamine in the context of high sulfadoxine-pyrimethamine resistance and malaria transmission. However, dihydroartemisinin-piperaquine is a promising alternative drug to replace sulfadoxine-pyrimethamine for intermittent preventive treatment. Future studies should investigate the efficacy, safety, operational feasibility, and cost-effectiveness of intermittent preventive treatment with dihydroartemisinin-piperaquine. The Malaria in Pregnancy Consortium, which is funded through a grant from the Bill & Melinda Gates Foundation to the Liverpool School of Tropical Medicine. Copyright © 2015 Elsevier Ltd. All rights reserved.

5 CFR 630.1205 - Intermittent leave or reduced leave schedule.

Code of Federal Regulations, 2013 CFR

2013-01-01

... REGULATIONS ABSENCE AND LEAVE Family and Medical Leave § 630.1205 Intermittent leave or reduced leave schedule. (a) Leave under § 630.1203(a) (1) or (2) of this part shall not be taken intermittently or on a... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Intermittent leave or reduced leave...

5 CFR 630.1205 - Intermittent leave or reduced leave schedule.

Code of Federal Regulations, 2012 CFR

2012-01-01

... REGULATIONS ABSENCE AND LEAVE Family and Medical Leave § 630.1205 Intermittent leave or reduced leave schedule. (a) Leave under § 630.1203(a) (1) or (2) of this part shall not be taken intermittently or on a... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Intermittent leave or reduced leave...

5 CFR 630.1204 - Intermittent leave or reduced leave schedule.

Code of Federal Regulations, 2011 CFR

2011-01-01

... REGULATIONS ABSENCE AND LEAVE Family and Medical Leave § 630.1204 Intermittent leave or reduced leave schedule. (a) Leave under § 630.1203(a) (1) or (2) of this part shall not be taken intermittently or on a... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Intermittent leave or reduced leave...

5 CFR 630.1205 - Intermittent leave or reduced leave schedule.

Code of Federal Regulations, 2014 CFR

2014-01-01

... REGULATIONS ABSENCE AND LEAVE Family and Medical Leave § 630.1205 Intermittent leave or reduced leave schedule. (a) Leave under § 630.1203(a) (1) or (2) of this part shall not be taken intermittently or on a... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Intermittent leave or reduced leave...

Cosmic Rays in Intermittent Magnetic Fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shukurov, Anvar; Seta, Amit; Bushby, Paul J.

The propagation of cosmic rays in turbulent magnetic fields is a diffusive process driven by the scattering of the charged particles by random magnetic fluctuations. Such fields are usually highly intermittent, consisting of intense magnetic filaments and ribbons surrounded by weaker, unstructured fluctuations. Studies of cosmic-ray propagation have largely overlooked intermittency, instead adopting Gaussian random magnetic fields. Using test particle simulations, we calculate cosmic-ray diffusivity in intermittent, dynamo-generated magnetic fields. The results are compared with those obtained from non-intermittent magnetic fields having identical power spectra. The presence of magnetic intermittency significantly enhances cosmic-ray diffusion over a wide range of particlemore » energies. We demonstrate that the results can be interpreted in terms of a correlated random walk.« less

Coexistence of intermittencies in the neuronal network of the epileptic brain

NASA Astrophysics Data System (ADS)

Koronovskii, Alexey A.; Hramov, Alexander E.; Grubov, Vadim V.; Moskalenko, Olga I.; Sitnikova, Evgenia; Pavlov, Alexey N.

2016-03-01

Intermittent behavior occurs widely in nature. At present, several types of intermittencies are known and well-studied. However, consideration of intermittency has usually been limited to the analysis of cases when only one certain type of intermittency takes place. In this paper, we report on the temporal behavior of the complex neuronal network in the epileptic brain, when two types of intermittent behavior coexist and alternate with each other. We prove the presence of this phenomenon in physiological experiments with WAG/Rij rats being the model living system of absence epilepsy. In our paper, the deduced theoretical law for distributions of the lengths of laminar phases prescribing the power law with a degree of -2 agrees well with the experimental neurophysiological data.

NOTE: Acceleration of Monte Carlo-based scatter compensation for cardiac SPECT

NASA Astrophysics Data System (ADS)

Sohlberg, A.; Watabe, H.; Iida, H.

2008-07-01

Single proton emission computed tomography (SPECT) images are degraded by photon scatter making scatter compensation essential for accurate reconstruction. Reconstruction-based scatter compensation with Monte Carlo (MC) modelling of scatter shows promise for accurate scatter correction, but it is normally hampered by long computation times. The aim of this work was to accelerate the MC-based scatter compensation using coarse grid and intermittent scatter modelling. The acceleration methods were compared to un-accelerated implementation using MC-simulated projection data of the mathematical cardiac torso (MCAT) phantom modelling 99mTc uptake and clinical myocardial perfusion studies. The results showed that when combined the acceleration methods reduced the reconstruction time for 10 ordered subset expectation maximization (OS-EM) iterations from 56 to 11 min without a significant reduction in image quality indicating that the coarse grid and intermittent scatter modelling are suitable for MC-based scatter compensation in cardiac SPECT.

High-Capacity Hydrogen-Based Green-Energy Storage Solutions For The Grid Balancing

NASA Astrophysics Data System (ADS)

D'Errico, F.; Screnci, A.

One of the current main challenges in green-power storage and smart grids is the lack of effective solutions for accommodating the unbalance between renewable energy sources, that offer intermittent electricity supply, and a variable electricity demand. Energy management systems have to be foreseen for the near future, while they still represent a major challenge. Integrating intermittent renewable energy sources, by safe and cost-effective energy storage systems based on solid state hydrogen is today achievable thanks to recently some technology breakthroughs. Optimized solid storage method made of magnesium-based hydrides guarantees a very rapid absorption and desorption kinetics. Coupled with electrolyzer technology, high-capacity storage of green-hydrogen is therefore practicable. Besides these aspects, magnesium has been emerging as environmentally friend energy storage method to sustain integration, monitoring and control of large quantity of GWh from high capacity renewable generation in the EU.

High-Capacity Hydrogen-Based Green-Energy Storage Solutions for the Grid Balancing

NASA Astrophysics Data System (ADS)

D'Errico, F.; Screnci, A.

One of the current main challenges in green-power storage and smart grids is the lack of effective solutions for accommodating the unbalance between renewable energy sources, that offer intermittent electricity supply, and a variable electricity demand. Energy management systems have to be foreseen for the near future, while they still represent a major challenge. Integrating intermittent renewable energy sources, by safe and cost-effective energy storage systems based on solid state hydrogen is today achievable thanks to recently some technology breakthroughs. Optimized solid storage method made of magnesium-based hydrides guarantees a very rapid absorption and desorption kinetics. Coupled with electrolyzer technology, high-capacity storage of green-hydrogen is therefore practicable. Besides these aspects, magnesium has been emerging as environmentally friend energy storage method to sustain integration, monitoring and control of large quantity of GWh from high capacity renewable generation in the EU.

Comprehensive Validation of an Intermittency Transport Model for Transitional Low-Pressure Turbine Flows

NASA Technical Reports Server (NTRS)

Suzen, Y. B.; Huang, P. G.

2005-01-01

A transport equation for the intermittency factor is employed to predict transitional flows under the effects of pressure gradients, freestream turbulence intensities, Reynolds number variations, flow separation and reattachment. and unsteady wake-blade interactions representing diverse operating conditions encountered in low-pressure turbines. The intermittent behaviour of the transitional flows is taken into account and incorporated into computations by modifying the eddy viscosity, Mu(sub t), with the intermittency factor, gamma. Turbulent quantities are predicted by using Menter's two-equation turbulence model (SST). The onset location of transition is obtained from correlations based on boundary-layer momentum thickness, acceleration parameter, and turbulence intensity. The intermittency factor is obtained from a transport model which can produce both the experimentally observed streamwise variation of intermittency and a realistic profile in the cross stream direction. The intermittency transport model is tested and validated against several well documented low pressure turbine experiments ranging from flat plate cases to unsteady wake-blade interaction experiments. Overall, good agreement between the experimental data and computational results is obtained illustrating the predicting capabilities of the model and the current intermittency transport modelling approach for transitional flow simulations.

Putting intelligent structured intermittent auscultation (ISIA) into practice.

PubMed

Maude, Robyn M; Skinner, Joan P; Foureur, Maralyn J

2016-06-01

Fetal monitoring guidelines recommend intermittent auscultation for the monitoring of fetal wellbeing during labour for low-risk women. However, these guidelines are not being translated into practice and low-risk women birthing in institutional maternity units are increasingly exposed to continuous cardiotocographic monitoring, both on admission to hospital and during labour. When continuous fetal monitoring becomes routinised, midwives and obstetricians lose practical skills around intermittent auscultation. To support clinical practice and decision-making around auscultation modality, the intelligent structured intermittent auscultation (ISIA) framework was developed. The purpose of this discussion paper is to describe the application of intelligent structured intermittent auscultation in practice. The intelligent structured intermittent auscultation decision-making framework is a knowledge translation tool that supports the implementation of evidence into practice around the use of intermittent auscultation for fetal heart monitoring for low-risk women during labour. An understanding of the physiology of the materno-utero-placental unit and control of the fetal heart underpin the development of the framework. Intelligent structured intermittent auscultation provides midwives with a robust means of demonstrating their critical thinking and clinical reasoning and supports their understanding of normal physiological birth. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Intermittent Hypoxia Alters Gene Expression in Peripheral Blood Mononuclear Cells of Healthy Volunteers.

PubMed

Polotsky, Vsevolod Y; Bevans-Fonti, Shannon; Grigoryev, Dmitry N; Punjabi, Naresh M

2015-01-01

Obstructive sleep apnea is associated with high cardiovascular morbidity and mortality. Intermittent hypoxia of obstructive sleep apnea is implicated in the development and progression of insulin resistance and atherosclerosis, which have been attributed to systemic inflammation. Intermittent hypoxia leads to pro-inflammatory gene up-regulation in cell culture, but the effects of intermittent hypoxia on gene expression in humans have not been elucidated. A cross-over study was performed exposing eight healthy men to intermittent hypoxia or control conditions for five hours with peripheral blood mononuclear cell isolation before and after exposures. Total RNA was isolated followed by gene microarrays and confirmatory real time reverse transcriptase PCR. Intermittent hypoxia led to greater than two fold up-regulation of the pro-inflammatory gene toll receptor 2 (TLR2), which was not increased in the control exposure. We hypothesize that up-regulation of TLR2 by intermittent hypoxia may lead to systemic inflammation, insulin resistance and atherosclerosis in patients with obstructive sleep apnea.

Timing of intermittent torque control with wire-driven gait training robot lifting toe trajectory for trip avoidance.

PubMed

Miyake, Tamon; Kobayashi, Yo; Fujie, Masakatsu G; Sugano, Shigeki

2017-07-01

Gait training robots are useful for changing gait patterns and decreasing risk of trip. Previous research has reported that decreasing duration of the assistance or guidance of the robot is beneficial for efficient gait training. Although robotic intermittent control method for assisting joint motion has been established, the effect of the robot intervention timing on change of toe clearance is unclear. In this paper, we tested different timings of applying torque to the knee, employing the intermittent control of a gait training robot to increase toe clearance throughout the swing phase. We focused on knee flexion motion and designed a gait training robot that can apply flexion torque to the knee with a wire-driven system. We used a method of timing detecting for the robot conducting torque control based on information from the hip, knee, and ankle angles to establish a non-time dependent parameter that can be used to adapt to gait change, such as gait speed. We carried out an experiment in which the conditions were four time points: starting the swing phase, lifting the foot, maintaining knee flexion, and finishing knee flexion. The results show that applying flexion torque to the knee at the time point when people start lifting their toe is effective for increasing toe clearance in the whole swing phase.

Observation of Turbulent Intermittency Scaling with Magnetic Helicity in an MHD Plasma Wind Tunnel

NASA Astrophysics Data System (ADS)

Schaffner, D. A.; Wan, A.; Brown, M. R.

2014-04-01

The intermittency in turbulent magnetic field fluctuations has been observed to scale with the amount of magnetic helicity injected into a laboratory plasma. An unstable spheromak injected into the MHD wind tunnel of the Swarthmore Spheromak Experiment displays turbulent magnetic and plasma fluctuations as it relaxes into a Taylor state. The level of intermittency of this turbulence is determined by finding the flatness of the probability distribution function of increments for magnetic pickup coil fluctuations B˙(t). The intermittency increases with the injected helicity, but spectral indices are unaffected by this variation. While evidence is provided which supports the hypothesis that current sheets and reconnection sites are related to the generation of this intermittent signal, the true nature of the observed intermittency remains unknown.

Exponential stabilization and synchronization for fuzzy model of memristive neural networks by periodically intermittent control.

PubMed

Yang, Shiju; Li, Chuandong; Huang, Tingwen

2016-03-01

The problem of exponential stabilization and synchronization for fuzzy model of memristive neural networks (MNNs) is investigated by using periodically intermittent control in this paper. Based on the knowledge of memristor and recurrent neural network, the model of MNNs is formulated. Some novel and useful stabilization criteria and synchronization conditions are then derived by using the Lyapunov functional and differential inequality techniques. It is worth noting that the methods used in this paper are also applied to fuzzy model for complex networks and general neural networks. Numerical simulations are also provided to verify the effectiveness of theoretical results. Copyright © 2015 Elsevier Ltd. All rights reserved.

SU-E-I-34: Intermittent Low- and High-Dose Ethanol Exposure Alters Neurochemical Responses in Adult Rat Brain: An Ex Vivo 1H NMR Spectroscopy at 11.7 T

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Do-Wan; Kim, Sang-Young; Song, Kyu-Ho

Purpose: The first goal of this study was to determine the influence of the dose-dependent effects of intermittent ethanol intoxication on cerebral neurochemical responses among sham controls and low- and high-dose-ethanol-exposed rats with ex vivo high-resolution spectra. The second goal of this study was to determine the correlations between the metabolite-metabolite levels (pairs-of-metabolite levels) from all of the individual data from the frontal cortex of the intermittent ethanol-intoxicated rats. Methods: Eight-week-old male Wistar rats were divided into 3 groups. Twenty rats in the LDE (n = 10) and the HDE (n = 10) groups received ethanol doses of 1.5 g/kgmore » and 2.5 g/kg, respectively, through oral gavage every 8-h for 4 days. At the end of the 4-day intermittent ethanol exposure, one-dimensional ex vivo 500-MHz proton nuclear magnetic resonance spectra were acquired from 30 samples of the frontal cortex region (from the 3 groups). Results: Normalized total-N-acetylaspartate (tNAA: NAA + NAAG [N-acetylaspartyl-glutamate]), gamma-aminobutyric acid (GABA), and glutathione (GSH) levels were significantly lower in the frontal cortex of the HDE-exposed rats than that of the LDE-exposed rats. Moreover, compared to the CNTL group, the LDE rats exhibited significantly higher normalized GABA levels. The 6 pairs of normalized metabolite levels were positively (+) or negatively (−) correlated in the rat frontal cortex as follows: tNAA and GABA (+), tNAA and Aspartate (Asp) (−), myo-Inositol (mIns) and Asp (−), mIns and Alanine (+), mIns and Taurine (+), and mIns and tNAA (−). Conclusion: Our results suggested that repeated intermittent ethanol intoxication might result in neuronal degeneration and dysfunction, changes in the rate of GABA synthesis, and oxidative stress in the rat frontal cortex. Our ex vivo 1H high-resolution-magic angle spinning nuclear magnetic resonance spectroscopy results suggested some novel metabolic markers for the dose-dependent influence of repeated intermittent ethanol intoxication in the frontal cortex.« less

A Randomized Trial Comparing Part-time Patching with Observation for Children 3–10 Years Old with Intermittent Exotropia

PubMed Central

Cotter, Susan A.; Mohney, Brian G.; Chandler, Danielle L.; Holmes, Jonathan M.; Repka, Michael X.; Melia, Michele; Wallace, David K.; Beck, Roy W.; Birch, Eileen E.; Kraker, Raymond T.; Tamkins, Susanna M.; Miller, Aaron M.; Sala, Nicholas A.; Glaser, Stephen R.

2014-01-01

Objective To determine the effectiveness of prescribed part-time patching for treatment of intermittent exotropia in children Design Multicenter, randomized clinical trial Participants Three hundred fifty-eight children aged 3 to < 11 years old with previously untreated (except for refractive correction) intermittent exotropia (IXT) and near stereoacuity of 400 arcsec or better were enrolled. Intermittent exotropia met the following criteria: 1) constant or intermittent exotropia at distance and either intermittent exotropia or exophoria at near; 2) exodeviation (tropia or phoria) of at least 15 prism diopters (Δ) at distance or near by prism and alternate cover test (PACT); and 3) exodeviation of at least 10Δ at distance by PACT. Methods Participants were randomly assigned to either observation (no treatment for 6 months) or patching for 3 hours per day for 5 months, with a 1-month washout period of no patching before the 6-month primary outcome exam. Main Outcome Measure The primary outcome was deterioration at either the 3-month or the 6-month follow-up visit, defined as: 1) constant exotropia measuring at least 10Δ at distance and near by simultaneous prism and cover test, and/or 2) near stereoacuity decreased by at least 2 octaves from baseline, both assessed by a masked examiner and confirmed by a retest. Participants who were prescribed any non-randomized treatment without first meeting either deterioration criteria were also counted as having deteriorated. Results Of the 324 (91%) participants completing the 6-month primary outcome exam, deterioration occurred in 10 (6.1%) of the 165 participants in the observation group (3 of these 10 started treatment without meeting deterioration criteria) and in 1 (0.6%) of the 159 participants in the part-time patching group (difference = 5.4%, lower limit of one-sided exact 95% confidence interval = 2.0%; p value from one-sided hypothesis test = 0.004). Conclusion Deterioration of previously untreated childhood IXT over a 6-month period is uncommon with or without patching treatment. Although there is a slightly lower deterioration rate with patching, both management approaches are reasonable for treating 3 to 10 year olds with IXT. PMID:25234012

An integrative treatment approach of a patient with cervical radiculitis: A case report

PubMed Central

Apfelbeck, Leanne

2005-01-01

Abstract Objective To describe a case report of the use of 3 treatment methods for treatment of cervical radiculitis; manual intermittent traction, instrumental chiropractic spinal manipulation, and interferential therapy. Clinical Features A 54-year-old man experienced neck and left arm pain with positive orthopedic tests indicating cervical spinal nerve root involvement; he was diagnosed with cervical radiculitis Intervention and Outcome The patient received 10 treatments over a period of 8 weeks. Instrumental spinal manipulation, manual intermittent traction, and interferential therapy were integrated as a treatment plan for the patient. The patient's condition appeared to resolve. Outcome measures were evaluated at baseline, weeks 3, 5, and 8. Neck Disability Index scores were 32%, 14%, 8%, and 4% respectively, and the Visual Analog Scales were 8.5/10, 2.0/10, 1.0/10, and 0.5/10. The symptoms of cervical radiculitis was resolved in an 8 week period after 10 treatments. Conclusion The integration of instrumental spinal manipulation, manual intermittent traction, and interferential may work well together for patients with similar signs and symptoms as presented in this case. PMID:19674652

Femorofemoral bypass grafting in high-risk patients.

PubMed

Deruyter, L; Caes, F; Van den Brande, P; Cham, B; Welch, W

1986-01-01

A total of 37 extra-anatomic femorofemoral bypasses were inserted for severe unilateral iliac artery stenosis or a thrombosed graft limb of an aorto-bifemoral bifurcation graft. All patients were severely debilitated and at high risk for direct aorto-iliac reconstruction. 30% suffered severe claudication; 70% had ischemic restpain or trophic lesions. 43% died during a mean follow-up period of 17 months. This study demonstrates that the extra-anatomic femoro-femoral bypass procedure is an effective alternative therapeutic modality for high-risk patients with an acceptable operative mortality (5.4%) and morbidity to improve the quality of life.

Prospective, multicenter study of endovascular repair of aortoiliac and iliac aneurysms using the Gore Iliac Branch Endoprosthesis.

PubMed

Schneider, Darren B; Matsumura, Jon S; Lee, Jason T; Peterson, Brian G; Chaer, Rabih A; Oderich, Gustavo S

2017-09-01

The GORE EXCLUDER Iliac Branch Endoprosthesis (IBE; W. L. Gore and Associates, Flagstaff, Ariz) is an iliac branch stent graft system designed to preserve internal iliac artery perfusion during endovascular repair of aortoiliac aneurysms (AIAs) and common iliac artery (CIA) aneurysms (CIAAs). We report the 6-month primary end point results of the IBE 12-04 United States pivotal trial for endovascular treatment of AIAs and CIAAs using the IBE device. The trial prospectively enrolled 63 patients with AIA or CIAA who underwent implantation of the IBE device at 28 centers in the United States from 2013 to 2015. All patients underwent placement of a single IBE device. Twenty-two patients (34.9%) with bilateral CIAs were enrolled after undergoing staged coil or plug embolization (21 of 22) or surgical revascularization (1 of 22) of the contralateral internal iliac artery. Follow-up at 30 days and 6 months included clinical assessment and computed tomography angiography evaluation as assessed by an independent core laboratory. The primary effectiveness end point was freedom from IBE limb occlusion and reintervention for type I or III endoleak and ≥60% stenosis at 6 months, and the secondary effectiveness end point was freedom from new onset of buttock claudication on the IBE side at 6 months. Mean CIA diameter on the IBE side was 41.0 ± 11.4 mm (range, 25.2-76.3 mm). There were no procedural deaths, and technical success, defined as successful deployment and patency of all IBE components and freedom from type I or III endoleak, was 95.2% (60 of 63). Data for 61 patients were available for primary and secondary effectiveness end point analysis. Internal iliac limb patency was 95.1% (58 of 61), and no new type I or III endoleaks or device migrations were observed at 6 months. The three patients with loss of internal iliac limb patency were asymptomatic, and freedom from new-onset buttock claudication on the IBE side was 100% at 6 months. New-onset buttock claudication occurred on the non-IBE treatment side in six of 21 patients (28.6%) who underwent staged internal iliac artery coil embolization. These results confirm that the IBE device is effective at treating CIAAs and AIAs, maintaining blood flow into the internal iliac artery, and avoiding complications associated with internal iliac artery sacrifice. Follow-up will be continued for 5 years to establish the long-term durability of iliac aneurysm repair with the IBE device. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

A functional murine model of hindlimb demand ischemia.

PubMed

Peck, Michael A; Crawford, Robert S; Abularrage, Christopher J; Patel, Virendra I; Conrad, Mark F; Yoo, Jin Hyung; Watkins, Michael T; Albadawi, Hassan

2010-05-01

To date, murine models of treadmill exercise have been used to study general exercise physiology and angiogenesis in ischemic hindlimbs. The purpose of these experiments was to develop a murine model of demand ischemia in an ischemic limb to mimic claudication in humans. The primary goal was to determine whether treadmill exercise reflected a hemodynamic picture which might be consistent with the hyperemic response observed in humans. Aged hypercholesterolemic ApoE null mice (ApoE(-/-), n = 13) were subjected to femoral artery ligation (FAL) and allowed to recover from the acute ischemic response. Peripheral perfusion of the hindlimbs at rest was determined by serial evaluation using laser Doppler imaging (LDI) on days 0, 7, and 14 following FAL. During the experiments, mice were also assessed on an established five-point clinical ischemic score, which assessed the degree of digital amputation, necrosis, and cyanosis compared to the nonischemic contralateral limb. After stabilization of the LDI ratio (ischemic limb flux/contralateral nonischemic limb flux) and clinical ischemic score, mice underwent 2 days of treadmill training (10 min at 10 m/min, incline of 10 degrees ) followed by 60 min of daily treadmill exercise (13 m/min, incline of 10 degrees ) through day 25. An evaluation of preexercise and postexercise perfusion using LDI was performed on two separate occasions following the onset of daily exercise. During the immediate 15 min postexercise evaluation, LDI scanning was obtained in quadruplicate, to allow identification of peak flux ratios. Statistical analysis included unpaired t-tests and analysis of variance. After FAL, the LDI flux ratio reached a nadir between days 1 and 2, then stabilized by day 14 and remained stable through day 25. The clinical ischemic score stabilized at day 7 and remained stable throughout the rest of the experiment. Based on stabilization of both the clinical ischemic score and LDI ratio, exercise training began on day 15. The peak 15 min postexercise LDI ratio increased significantly compared to the preexercise ratio on day 17 (0.48 +/- 0.04 vs. 0.34 +/- 0.04, p < 0.05) and day 25 (0.37 +/- 0.03 vs. 0.27 +/- 0.03, p < 0.01). Within 2 hr of exercise, the LDI ratio returned to preexercise levels on both days 17 and 25. Clinical and hemodynamic stabilization of limb perfusion is evident by 14 days after FAL. FAL followed by demand ischemia results in a reversible relative hyperemic response similar to that observed in exercising human claudicants. A murine model of FAL associated with demand ischemia may be useful to evaluate the metabolic, inflammatory, and flow-related changes associated with claudication in humans. Copyright 2010 Annals of Vascular Surgery Inc. All rights reserved.

Nocturnal intermittent hypoxia and C reactive protein among middle-aged community residents: a cross-sectional survey.

PubMed

Muraki, Isao; Tanigawa, Takeshi; Yamagishi, Kazumasa; Sakurai, Susumu; Ohira, Tetsuya; Imano, Hironori; Kitamura, Akihiko; Kiyama, Masahiko; Sato, Shinichi; Shimamoto, Takashi; Konishi, Masamitsu; Iso, Hiroyasu

2010-06-01

There are conflicting results for the association between obstructive sleep apnoea and raised C reactive protein (CRP) levels. A study was undertaken to investigate whether nocturnal intermittent hypoxia, a surrogate marker for obstructive sleep apnoea, was associated with CRP levels among a community-dwelling Japanese population. Among participants in the Circulatory Risk in Communities Study (CIRCS), 1422 male and 2466 female community residents aged 40-69 years were tested during sleep. No nocturnal intermittent hypoxia, mild nocturnal intermittent hypoxia and moderate to severe nocturnal intermittent hypoxia were defined using 3% oxygen desaturation index cut-off points at 5 and 15 events/h, respectively. High-sensitivity CRP levels were measured using a latex particle-enhanced immunonephelometric assay. Multivariate analysis was adjusted for age, sex, body mass index, smoking status, current alcohol intake, hypertension, hypercholesterolaemia, diabetes mellitus and menopausal status for women. Multivariable-adjusted mean CRP levels among men were 0.70 mg/l (95% CI 0.65 to 0.75) for no nocturnal intermittent hypoxia, 0.82 mg/l (95% CI 0.74 to 0.89) for mild nocturnal intermittent hypoxia and 0.84 mg/l (95% CI 0.70 to 1.00) for moderate to severe nocturnal intermittent hypoxia (p for trend=0.03). The values for women were 0.59 mg/l (95% CI 0.57 to 0.62), 0.66 mg/l (95% CI 0.59 to 0.73) and 0.82 mg/l (95% CI 0.62 to 1.03), respectively (p for trend=0.008). Compared with no nocturnal intermittent hypoxia, the prevalence of a high CRP level (>or=1.0 mg/l) was 1.4-1.7-fold higher for mild to severe nocturnal intermittent hypoxia in both sexes. Nocturnal intermittent hypoxia is associated with raised serum CRP levels among middle-aged Japanese subjects.

Intermittent Hypoxia Impairs Glucose Homeostasis in C57BL6/J Mice: Partial Improvement with Cessation of the Exposure

PubMed Central

Polak, Jan; Shimoda, Larissa A.; Drager, Luciano F.; Undem, Clark; McHugh, Holly; Polotsky, Vsevolod Y.; Punjabi, Naresh M.

2013-01-01

Objectives: Obstructive sleep apnea is associated with insulin resistance, glucose intolerance, and type 2 diabetes mellitus. Although several studies have suggested that intermittent hypoxia in obstructive sleep apnea may induce abnormalities in glucose homeostasis, it remains to be determined whether these abnormalities improve after discontinuation of the exposure. The objective of this study was to delineate the effects of intermittent hypoxia on glucose homeostasis, beta cell function, and liver glucose metabolism and to investigate whether the impairments improve after the hypoxic exposure is discontinued. Interventions: C57BL6/J mice were exposed to 14 days of intermittent hypoxia, 14 days of intermittent air, or 7 days of intermittent hypoxia followed by 7 days of intermittent air (recovery paradigm). Glucose and insulin tolerance tests were performed to estimate whole-body insulin sensitivity and calculate measures of beta cell function. Oxidative stress in pancreatic tissue and glucose output from isolated hepatocytes were also assessed. Results: Intermittent hypoxia increased fasting glucose levels and worsened glucose tolerance by 67% and 27%, respectively. Furthermore, intermittent hypoxia exposure was associated with impairments in insulin sensitivity and beta cell function, an increase in liver glycogen, higher hepatocyte glucose output, and an increase in oxidative stress in the pancreas. While fasting glucose levels and hepatic glucose output normalized after discontinuation of the hypoxic exposure, glucose intolerance, insulin resistance, and impairments in beta cell function persisted. Conclusions: Intermittent hypoxia induces insulin resistance, impairs beta cell function, enhances hepatocyte glucose output, and increases oxidative stress in the pancreas. Cessation of the hypoxic exposure does not fully reverse the observed changes in glucose metabolism. Citation: Polak J; Shimoda LA; Drager LF; Undem C; McHugh H; Polotsky VY; Punjabi NM. Intermittent hypoxia impairs glucose homeostasis in C57BL6/J mice: partial improvement with cessation of the exposure. SLEEP 2013;36(10):1483-1490. PMID:24082307

The influence of job stress, social support and health status on intermittent and chronic sleep disturbance: an 8-year longitudinal analysis.

PubMed

Gosling, John A; Batterham, Philip J; Glozier, Nick; Christensen, Helen

2014-08-01

To determine the role of health status and social support in the relationship between job stress and sleep disturbance, for both intermittent and chronic sleep disturbance. A total of 1946 mid-life adults completed three questionnaires spanning an 8-year time frame. Sleep disturbance was assessed at each time point, and participants were classified as experiencing intermittent, chronic or no sleep disturbance across this 8-year period. Independent variables included a range of job stress measures, social support, physical and mental health, and demographic characteristics. After controlling for physical and mental health, perceived lack of job marketability increased risk of intermittent sleep disturbance (odds ratio (OR)=1.33, p=0.012). No other job stress measures were associated with either intermittent or chronic sleep disturbance after adjusting for years of education, social support, and employment status. Poorer mental and physical health status, although significantly increasing odds for intermittent sleep disturbance, represented a significantly greater increase in the odds for chronic sleep disturbance over and above intermittent disturbance (OR=0.96, p<0.001 for both SF-12 mental and physical health). This population-based cohort study found little evidence that job stress had an independent effect on chronic or intermittent sleep disturbance independent of health, social support, and education. Risk profiles for intermittent and chronic sleep disturbance did not differ with regard to job stress; however, various demographic and social support factors were distinguishing factors. Health status, both physical and mental, also showed a significantly greater impact on chronic sleep disturbance than intermittent sleep disturbance. Karasek's model of job strain had little value in predicting sleep disturbance outcomes. Copyright © 2014 Elsevier B.V. All rights reserved.

Comparing microbial water quality in an intermittent and continuous piped water supply.

PubMed

Kumpel, Emily; Nelson, Kara L

2013-09-15

Supplying piped water intermittently is a common practice throughout the world that increases the risk of microbial contamination through multiple mechanisms. Converting an intermittent supply to a continuous supply has the potential to improve the quality of water delivered to consumers. To understand the effects of this upgrade on water quality, we tested samples from reservoirs, consumer taps, and drinking water provided by households (e.g. from storage containers) from an intermittent and continuous supply in Hubli-Dharwad, India, over one year. Water samples were tested for total coliform, Escherichia coli, turbidity, free chlorine, and combined chlorine. While water quality was similar at service reservoirs supplying the continuous and intermittent sections of the network, indicator bacteria were detected more frequently and at higher concentrations in samples from taps supplied intermittently compared to those supplied continuously (p < 0.01). Detection of E. coli was rare in continuous supply, with 0.7% of tap samples positive compared to 31.7% of intermittent water supply tap samples positive for E. coli. In samples from both continuously and intermittently supplied taps, higher concentrations of total coliform were measured after rainfall events. While source water quality declined slightly during the rainy season, only tap water from intermittent supply had significantly more indicator bacteria throughout the rainy season compared to the dry season. Drinking water samples provided by households in both continuous and intermittent supplies had higher concentrations of indicator bacteria than samples collected directly from taps. Most households with continuous supply continued to store water for drinking, resulting in re-contamination, which may reduce the benefits to water quality of converting to continuous supply. Copyright © 2013 Elsevier Ltd. All rights reserved.

5 CFR 340.403 - Intermittent employment.

Code of Federal Regulations, 2011 CFR

2011-01-01

... FULL-TIME CAREER EMPLOYMENT (PART-TIME, SEASONAL, ON-CALL, AND INTERMITTENT) Seasonal and intermittent... appropriate only when the nature of the work is sporadic and unpredictable so that a tour of duty cannot be...

Intermittent Explosive Disorder amongst Women in Conflict Affected Timor-Leste: Associations with Human Rights Trauma, Ongoing Violence, Poverty, and Injustice

PubMed Central

Rees, Susan; Silove, Derrick; Verdial, Teresa; Tam, Natalino; Savio, Elisa; Fonseca, Zulmira; Thorpe, Rosamund; Liddell, Belinda; Zwi, Anthony; Tay, Kuowei; Brooks, Robert; Steel, Zachary

2013-01-01

Introduction Women in conflict-affected countries are at risk of mental disorders such as posttraumatic stress disorder and depression. No studies have investigated the association between experiences of abuse and injustice and explosive anger amongst women in these settings, and the impact of anger on women's health, family relationships and ability to participate in development. Methods A mixed methods study including an epidemiological survey (n = 1513, 92.6% response) and qualitative interviews (n = 77) was conducted in Timor-Leste. The indices measured included Intermittent Explosive Disorder, posttraumatic stress disorder; severe distress; days out of role (the number of days that the person was unable to undertake normal activities); gender-specific trauma; conflict/violence; poverty; and preoccupations with injustice. Results Women with Intermittent Explosive Disorder (n = 184, 12.2%) were more disabled than those without the disorder (for >5 days out of role, 40.8% versus 31.5%, X2 (2)  = 12.93 p = 0.0016). Multivariable associations with Intermittent Explosive Disorder, controlling for the presence of PTSD, psychological distress and other predictors in the model, included the sense of being sick (OR 1.73; 95% CI 1.08–2.77); victimization as a result of helping the resistance movement (OR 2.33, 95% CI 1.48–3.68); war-related trauma specific to being a woman (OR 1.95, 95%, CI 1.09–3.50); ongoing family violence and community conflict (OR 1.88, 95% CI 1.27–2.77); extreme poverty (OR 1.23, 95%, CI 1.08–1.39); and distressing preoccupations with injustice (relating to 2/3 historical periods, OR 2.10, 95% CI 1.35–3.28). In the qualitative study, women elaborated on the determinants of anger and its impact on their health, family and community functioning, child-rearing, and capacity to engage in development. Women reflected on the strategies that might help them overcome their anger. Conclusions Intermittent Explosive Disorder is prevalent and disabling amongst women in conflict-affected Timor-Leste, impacting on their health, child-rearing and ability to participate fully in socio-economic development. PMID:23950885

Intermittent fasting and cardiovascular disease: current evidence and unresolved questions.

PubMed

Tinsley, Grant M; Horne, Benjamin D

2018-01-01

Intermittent fasting has produced a variety of beneficial health effects in animal models, although high-quality research in humans has been limited. This special report examines current evidences for intermittent fasting in humans, discusses issues that require further examination, and recommends new research that can improve the knowledge base in this emerging research area. While potentially useful for health improvement, intermittent fasting requires further study prior to widespread implementation for health purposes. Randomized, longer-term studies are needed to determine whether using intermittent fasting as a lifestyle rather than a diet is feasible and beneficial for the health of some members of the human population.

Intermittent, noncyclic dysfunction of a mechanical aortic prosthesis by pannus formation.

PubMed

Giroux, Sylvie K; Labinaz, Marino X; Grisoli, Dominique; Klug, Andrew P; Veinot, John P; Burwash, Ian G

2010-01-01

Mechanical aortic prosthesis dysfunction can result from thrombosis or pannus formation. Pannus formation usually restricts systolic excursion of the occluding disk, resulting in progressive stenosis of the aortic prosthesis. Intermittent dysfunction of a mechanical aortic prosthesis is usually ascribed to thrombus formation. We describe an unusual case of intermittent, noncyclic dysfunction of a mechanical aortic prosthesis due to pannus formation in the absence of systolic restriction of disk excursion that presented with intermittent massive aortic regurgitation, severe ischemia, and shock. Pannus formation should be considered as a potential cause of acute intermittent severe aortic regurgitation in a patient with a mechanical aortic prosthesis.

Clustering-based Filtering to Detect Isolated and Intermittent Pulses in Radio Astronomy Data

NASA Astrophysics Data System (ADS)

Wagstaff, Kiri; Tang, B.; Lazio, T. J.; Spolaor, S.

2013-01-01

Radio-emitting neutron stars (pulsars) produce a series of periodic pulses at radio frequencies. Dispersion, caused by propagation through the interstellar medium, delays signals at lower frequencies more than higher frequencies. This well understood effect can be reversed though de-dispersion at the appropriate dispersion measure (DM). The periodic nature of a pulsar provides multiple samples of signals at the same DM, increasing the reliability of any candidate detection. However, existing methods for pulsar detection are ineffective for many pulse-emitting phenomena now being discovered. Sources exhibit a wide range of pulse repetition rates, from highly regular canonical pulsars to intermittent and nulling pulsars to rotating radio transients (RRATs) that may emit only a few pulses per hour. Other source types may emit only a few pulses, or even only a single pulse. We seek to broaden the scope of radio signal analysis to enable the detection of isolated and intermittent pulses. Without a requirement that detected sources be periodic, we find that a typical de-dispersion search yields results that are often dominated by spurious detections from radio frequency interference (RFI). These occur across the DM range, so filtering out DM-0 signals is insufficient. We employ DBSCAN data clustering to identify groups within the de-dispersion results, using information for each candidate about time, DM, SNR, and pulse width. DBSCAN is a density-based clustering algorithm that offers two advantages over other clustering methods: 1) the number of clusters need not to be specified, and 2) there is no model of expected cluster shape (such as the Gaussian assumption behind EM clustering). Each data cluster can be selectively masked or investigated to facilitate the process of sifting through hundreds of thousands of detections to focus on those of true interest. Using data obtained by the Byrd Green Bank Telescope (GBT), we show how this approach can help separate RFI from difficult to find single and intermittent pulses.

Scalings of intermittent structures in magnetohydrodynamic turbulence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhdankin, Vladimir, E-mail: zhdankin@jila.colorado.edu; Boldyrev, Stanislav; Space Science Institute, Boulder, Colorado 80301

Turbulence is ubiquitous in plasmas, leading to rich dynamics characterized by irregularity, irreversibility, energy fluctuations across many scales, and energy transfer across many scales. Another fundamental and generic feature of turbulence, although sometimes overlooked, is the inhomogeneous dissipation of energy in space and in time. This is a consequence of intermittency, the scale-dependent inhomogeneity of dynamics caused by fluctuations in the turbulent cascade. Intermittency causes turbulent plasmas to self-organize into coherent dissipative structures, which may govern heating, diffusion, particle acceleration, and radiation emissions. In this paper, we present recent progress on understanding intermittency in incompressible magnetohydrodynamic turbulence with a strongmore » guide field. We focus on the statistical analysis of intermittent dissipative structures, which occupy a small fraction of the volume but arguably account for the majority of energy dissipation. We show that, in our numerical simulations, intermittent structures in the current density, vorticity, and Elsässer vorticities all have nearly identical statistical properties. We propose phenomenological explanations for the scalings based on general considerations of Elsässer vorticity structures. Finally, we examine the broader implications of intermittency for astrophysical systems.« less

Comparison of groundwater recharge estimation techniques in an alluvial aquifer system with an intermittent/ephemeral stream (Queensland, Australia)

NASA Astrophysics Data System (ADS)

King, Adam C.; Raiber, Matthias; Cox, Malcolm E.; Cendón, Dioni I.

2017-09-01

This study demonstrates the importance of the conceptual hydrogeological model for the estimation of groundwater recharge rates in an alluvial system interconnected with an ephemeral or intermittent stream in south-east Queensland, Australia. The losing/gaining condition of these streams is typically subject to temporal and spatial variability, and knowledge of these hydrological processes is critical for the interpretation of recharge estimates. Recharge rate estimates of 76-182 mm/year were determined using the water budget method. The water budget method provides useful broad approximations of recharge and discharge fluxes. The chloride mass balance (CMB) method and the tritium method were used on 17 and 13 sites respectively, yielding recharge rates of 1-43 mm/year (CMB) and 4-553 mm/year (tritium method). However, the conceptual hydrogeological model confirms that the results from the CMB method at some sites are not applicable in this setting because of overland flow and channel leakage. The tritium method was appropriate here and could be applied to other alluvial systems, provided that channel leakage and diffuse infiltration of rainfall can be accurately estimated. The water-table fluctuation (WTF) method was also applied to data from 16 bores; recharge estimates ranged from 0 to 721 mm/year. The WTF method was not suitable where bank storage processes occurred.

Experimental Analysis of Temperature Differences During Implant Site Preparation: Continuous Drilling Technique Versus Intermittent Drilling Technique.

PubMed

Di Fiore, Adolfo; Sivolella, Stefano; Stocco, Elena; Favero, Vittorio; Stellini, Edoardo

2018-02-01

Implant site preparation through drilling procedures may cause bone thermonecrosis. The aim of this in vitro study was to evaluate, using a thermal probe, overheating at implant sites during osteotomies through 2 different drilling methods (continuous drilling technique versus intermittent drilling technique) using irrigation at different temperatures. Five implant sites 13 mm in length were performed on 16 blocks (fresh bovine ribs), for a total of 80 implant sites. The PT-100 thermal probe was positioned 5 mm from each site. Two physiological refrigerant solutions were used: one at 23.7°C and one at 6.0°C. Four experimental groups were considered: group A (continuous drilling with physiological solution at 23.7°C), group B (intermittent drilling with physiological solution at 23.7°C), group C (continuous drilling with physiological solution at 6.0°C), and group D (intermittent drilling with physiological solution at 6.0°C). The Wilcoxon rank-sum test (2-tailed) was used to compare groups. While there was no difference between group A and group B (W = 86; P = .45), statistically significant differences were observed between experimental groups A and C (W = 0; P =.0001), B and D (W = 45; P =.0005), and C and D (W = 41; P = .003). Implant site preparation did not affect the overheating of the bone. Statistically significant differences were found with the refrigerant solutions. Using both irrigating solutions, bone temperature did not exceed 47°C.

Response of Preterm Infants to 2 Noninvasive Ventilatory Support Systems: Nasal CPAP and Nasal Intermittent Positive-Pressure Ventilation.

PubMed

Silveira, Carmen Salum Thomé; Leonardi, Kamila Maia; Melo, Ana Paula Carvalho Freire; Zaia, José Eduardo; Brunherotti, Marisa Afonso Andrade

2015-12-01

Noninvasive ventilation (NIV) in preterm infants is currently applied using intermittent positive pressure (2 positive-pressure levels) or in a conventional manner (one pressure level). However, there are no studies in the literature comparing the chances of failure of these NIV methods. The aim of this study was to evaluate the occurrence of failure of 2 noninvasive ventilatory support systems in preterm neonates over a period of 48 h. A randomized, prospective, clinical study was conducted on 80 newborns (gestational age < 37 weeks, birthweight < 2,500 g). The infants were randomized into 2 groups: 40 infants were treated with nasal CPAP and 40 infants with nasal intermittent positive-pressure ventilation (NIPPV). The occurrence of apnea, progression of respiratory distress, nose bleeding, and agitation was defined as ventilation failure. The need for intubation and re-intubation after failure was also observed. There were no significant differences in birth characteristics between groups. Ventilatory support failure was observed in 25 (62.5%) newborns treated with nasal CPAP and in 12 (30%) newborns treated with NIPPV, indicating an association between NIV failure and the absence of intermittent positive pressure (odds ratio [OR] 1.22, P < .05). Apnea (32.5%) was the main reason for nasal CPAP failure. After failure, 25% (OR 0.33) of the newborns receiving nasal CPAP and 12.5% (OR 0.14) receiving NIPPV required invasive mechanical ventilation. Ventilatory support failure was significantly more frequent when nasal CPAP was used. Copyright © 2015 by Daedalus Enterprises.

Intermittency of principal stress directions within Arctic sea ice.

PubMed

Weiss, Jérôme

2008-05-01

The brittle deformation of Arctic sea ice is not only characterized by strong spatial heterogeneity as well as intermittency of stress and strain-rate amplitudes, but also by an intermittency of principal stress directions, with power law statistics of angular fluctuations, long-range correlations in time, and multifractal scaling. This intermittency is much more pronounced than that of wind directions, i.e., is not a direct inheritance of the turbulent forcing.

Metabolic Effects of Intermittent Fasting.

PubMed

Patterson, Ruth E; Sears, Dorothy D

2017-08-21

The objective of this review is to provide an overview of intermittent fasting regimens, summarize the evidence on the health benefits of intermittent fasting, and discuss physiological mechanisms by which intermittent fasting might lead to improved health outcomes. A MEDLINE search was performed using PubMed and the terms "intermittent fasting," "fasting," "time-restricted feeding," and "food timing." Modified fasting regimens appear to promote weight loss and may improve metabolic health. Several lines of evidence also support the hypothesis that eating patterns that reduce or eliminate nighttime eating and prolong nightly fasting intervals may result in sustained improvements in human health. Intermittent fasting regimens are hypothesized to influence metabolic regulation via effects on (a) circadian biology, (b) the gut microbiome, and (c) modifiable lifestyle behaviors, such as sleep. If proven to be efficacious, these eating regimens offer promising nonpharmacological approaches to improving health at the population level, with multiple public health benefits.

Intermittency, nonlinear dynamics and dissipation in the solar wind and astrophysical plasmas

PubMed Central

Matthaeus, W. H.; Wan, Minping; Servidio, S.; Greco, A.; Osman, K. T.; Oughton, S.; Dmitruk, P.

2015-01-01

An overview is given of important properties of spatial and temporal intermittency, including evidence of its appearance in fluids, magnetofluids and plasmas, and its implications for understanding of heliospheric plasmas. Spatial intermittency is generally associated with formation of sharp gradients and coherent structures. The basic physics of structure generation is ideal, but when dissipation is present it is usually concentrated in regions of strong gradients. This essential feature of spatial intermittency in fluids has been shown recently to carry over to the realm of kinetic plasma, where the dissipation function is not known from first principles. Spatial structures produced in intermittent plasma influence dissipation, heating, and transport and acceleration of charged particles. Temporal intermittency can give rise to very long time correlations or a delayed approach to steady-state conditions, and has been associated with inverse cascade or quasi-inverse cascade systems, with possible implications for heliospheric prediction. PMID:25848085

Dynamic resetting of the human circadian pacemaker by intermittent bright light

NASA Technical Reports Server (NTRS)

Rimmer, D. W.; Boivin, D. B.; Shanahan, T. L.; Kronauer, R. E.; Duffy, J. F.; Czeisler, C. A.

2000-01-01

In humans, experimental studies of circadian resetting typically have been limited to lengthy episodes of exposure to continuous bright light. To evaluate the time course of the human endogenous circadian pacemaker's resetting response to brief episodes of intermittent bright light, we studied 16 subjects assigned to one of two intermittent lighting conditions in which the subjects were presented with intermittent episodes of bright-light exposure at 25- or 90-min intervals. The effective duration of bright-light exposure was 31% or 63% compared with a continuous 5-h bright-light stimulus. Exposure to intermittent bright light elicited almost as great a resetting response compared with 5 h of continuous bright light. We conclude that exposure to intermittent bright light produces robust phase shifts of the endogenous circadian pacemaker. Furthermore, these results demonstrate that humans, like other species, exhibit an enhanced sensitivity to the initial minutes of bright-light exposure.

Development of Ethanol Withdrawal-Related Sensitization and Relapse Drinking in Mice Selected for High or Low Ethanol Preference

PubMed Central

Lopez, Marcelo F.; Grahame, Nicholas J.; Becker, Howard C.

2010-01-01

Background Previous studies have shown that high alcohol consumption is associated with low withdrawal susceptiblility, while at the same time, other studies have shown that exposure to ethanol vapor increases alcohol drinking in rats and mice. In the present studies, we sought to shed light on this seeming contradiction by using mice selectively bred for High- (HAP) and Low- (LAP) Alcohol Preference, first, assessing these lines for differences in signs of ethanol withdrawal and second, for differences in the efficacy of intermittent alcohol vapor exposure on elevating subsequent ethanol intake. Methods Experiment 1 examined whether these lines of mice differed in ethanol withdrawal-induced CNS hyperexcitability and the development of sensitization to this effect following intermittent ethanol vapor exposure. Adult HAP and LAP lines (replicates 1 and 2), and the C3H/HeNcr inbred strain (included as a control genotype for comparison purposes) received intermittent exposure to ethanol vapor and were evaluated for ethanol withdrawal-induced seizures assessed by scoring handling-induced convulsions (HIC). Experiment 2 examined the influence of chronic intermittent ethanol exposure on voluntary ethanol drinking. Adult male and female HAP-2 and LAP-2 mice, along with male C57BL/6J (included as comparative controls) were trained to drink 10% ethanol using a limited access (2 hr/day) 2-bottle choice paradigm. After stable baseline daily intake was established, mice received chronic intermittent ethanol vapor exposure in inhalation chambers. Ethanol intake sessions resumed 72 hr after final ethanol (or air) exposure for 5 consecutive days. Results Following chronic ethanol treatment, LAP mice exhibited overall greater withdrawal seizure activity compared to HAP mice. In Experiment 2, chronic ethanol exposure/withdrawal resulted in a significant increase in ethanol intake in male C57BL/6J, and modestly elevated intake in HAP-2 male mice. Ethanol intake for male control mice did not change from baseline levels of intake. In contrast, HAP-2 females and LAP-2 mice of both sexes did not show changes in ethanol intake as a consequence of intermittent ethanol exposure. Conclusions Overall, these results indicate that the magnitude of ethanol withdrawal-related seizures is inversely related to inherited ethanol intake preference. Additionally, intermittent ethanol vapor exposure appears more likely to affect high-drinking mice (C57BL/6J and HAP-2) than low drinkers, even though these animals are less affected by ethanol withdrawal. PMID:21314693

Prediction of Transitional Flows in the Low Pressure Turbine

NASA Technical Reports Server (NTRS)

Huang, George; Xiong, Guohua

1998-01-01

Current turbulence models tend to give too early and too short a length of flow transition to turbulence, and hence fail to predict flow separation induced by the adverse pressure gradients and streamline flow curvatures. Our discussion will focus on the development and validation of transition models. The baseline data for model comparisons are the T3 series, which include a range of free-stream turbulence intensity and cover zero-pressure gradient to aft-loaded turbine pressure gradient flows. The method will be based on the conditioned N-S equations and a transport equation for the intermittency factor. First, several of the most popular 2-equation models in predicting flow transition are examined: k-e [Launder-Sharina], k-w [Wilcox], Lien-Leschiziner and SST [Menter] models. All models fail to predict the onset and the length of transition, even for the simplest flat plate with zero-pressure gradient(T3A). Although the predicted onset position of transition can be varied by providing different inlet turbulent energy dissipation rates, the appropriate inlet conditions for turbulence quantities should be adjusted to match the decay of the free-stream turbulence. Arguably, one may adjust the low-Reynolds-number part of the model to predict transition. This approach has so far not been very successful. However, we have found that the low-Reynolds-number model of Launder and Sharma [1974], which is an improved version of Jones and Launder [1972] gave the best overall performance. The Launder and Sharma model was designed to capture flow re-laminarization (a reverse of flow transition), but tends to give rise to a too early and too fast transition in comparison with the physical transition. The three test cases were for flows with zero pressure gradient but with different free-stream turbulent intensities. The same can be said about the model when considering flows subject to pressure gradient(T3C1). To capture the effects of transition using existing turbulence models, one approach is to make use of the concept of the intermittency to predict the flow transition. It was originally based on the intermittency distribution of Narasimha [1957], and then gradually evolved into a transport equation for the intermittency factor. Gostelow and associates [1994,1995] have made some improvements to Narasimha's method in an attempt to account for both favorable and adverse pressure gradients. Their approach is based on a linear, explicit combination of laminar and turbulent solutions. This approach fails to predict the overshoot of the skin friction on a flat plate near the end of transition zone, even though the length of transition is well predicted. The major flaw of Gostelow's approach is that it assumes the non-turbulent part being the laminar solution and the turbulent part being the turbulent solution and they do not interact across the transitional region. The technique in condition averaging the flow equations in intermittent flows was first introduced by Libby [1975] and Dopazo [1977] and further refined by Dick and associates [1988, 1996]. This approach employs two sets of transport equations for the non-turbulent part and the other for the turbulent part. The advantage of this approach is that it allows the interaction of non-turbulent and turbulent velocities through the introduction of additional source terms in the continuity and momentum equations for the non-turbulent and turbulent velocities. However, the strong coupling of the two sets of equations has caused some numerical difficulties, which requires special attention. The prediction of the skin friction can be improved by this approach via the implicit coupling of non-turbulent and turbulent velocity flelds. Another improvement of the interrmittency model can be further made by allowing the intermittency to vary in the cross-stream direction. This is one step prior to testing any proposal for the transport equation for the intermittency factor. Instead of solving the transport equation for the intermittency factor, the distribution for the intermittency factor is prescribed by Klebanoff's empirical formula [1955]. The skin friction is very well predicted by this new modification, including the overshoot of the profile near the end of the transition zone. The outcome of this study is very encouraging since it indicates that the proper description of the intermittency distribution is the key to the success of the model prediction. This study will be used to guide us on the modelling of the intermittency transport equation.

Development of the Nonstationary Incremental Analysis Update Algorithm for Sequential Data Assimilation System

NASA Astrophysics Data System (ADS)

Ham, Yoo-Geun; Song, Hyo-Jong; Jung, Jaehee; Lim, Gyu-Ho

2017-04-01

This study introduces a altered version of the incremental analysis updates (IAU), called the nonstationary IAU (NIAU) method, to enhance the assimilation accuracy of the IAU while retaining the continuity of the analysis. Analogous to the IAU, the NIAU is designed to add analysis increments at every model time step to improve the continuity in the intermittent data assimilation. Still, unlike the IAU, the NIAU method applies time-evolved forcing employing the forward operator as rectifications to the model. The solution of the NIAU is better than that of the IAU, of which analysis is performed at the start of the time window for adding the IAU forcing, in terms of the accuracy of the analysis field. It is because, in the linear systems, the NIAU solution equals that in an intermittent data assimilation method at the end of the assimilation interval. To have the filtering property in the NIAU, a forward operator to propagate the increment is reconstructed with only dominant singular vectors. An illustration of those advantages of the NIAU is given using the simple 40-variable Lorenz model.

Effects of gamma irradiation on the performance of Jatropha (Jatropha curcas L.) accessions

NASA Astrophysics Data System (ADS)

Surahman, M.; Santosa, E.; Agusta, H.; Aisyah, S. I.; Nisya, F. N.

2018-03-01

This study aimed to assess the effects of mutation by using gamma ray on the performance of jatropha plants. The study was conducted at PAIR BATAN. Jatropha seeds obtained from the collection farm of SBRC LPPM IPB and PT Indocement Tunggal Prakarsa Tbk in Gunung Putri, Bogor, were irradiated. The irradiated seeds were grown in Jonggol Trial Farm of IPB. Gamma irradiation was conducted by using a GCM 4000A device. Treatments consisted of irradiation doses, irradiation methods, and accessions. Irradiation doses given were 175, 200, 225 Gy, and no irradiation (control). Irradiation methods consisted of acute, intermittent, and split-dose. Accessions used in this study were Dompu, Medan, Bima, Lombok, ITP II, IP2P, and Thailand. Results of the study were analysed until 5 months after planting showed that gamma ray mutation gave stimulating and inhibiting effects on similar traits. Irradiation dose of 225 Gy was good to be given in acute, intermittent, and split-dose methods. Irradiation effects were found to be significant in jatropha accessions. Effects of irradiation on production will be published soon.

Trajectory Adjustments Underlying Task-Specific Intermittent Force Behaviors and Muscular Rhythms

PubMed Central

Chen, Yi-Ching; Lin, Yen-Ting; Huang, Chien-Ting; Shih, Chia-Li; Yang, Zong-Ru; Hwang, Ing-Shiou

2013-01-01

Force intermittency is one of the major causes of motor variability. Focusing on the dynamics of force intermittency, this study was undertaken to investigate how force trajectory is fine-tuned for static and dynamic force-tracking of a comparable physical load. Twenty-two healthy adults performed two unilateral resistance protocols (static force-tracking at 75% maximal effort and dynamic force-tracking in the range of 50%–100% maximal effort) using the left hand. The electromyographic activity and force profile of the designated hand were monitored. Gripping force was off-line decomposed into a primary movement spectrally identical to the target motion and a force intermittency profile containing numerous force pulses. The results showed that dynamic force-tracking exhibited greater intermittency amplitude and force pulse but a smaller amplitude ratio of primary movement to force intermittency than static force-tracking. Multi-scale entropy analysis revealed that force intermittency during dynamic force-tracking was more complex on a low time scale but more regular on a high time scale than that of static force-tracking. Together with task-dependent force intermittency properties, dynamic force-tracking exhibited a smaller 8–12 Hz muscular oscillation but a more potentiated muscular oscillation at 35–50 Hz than static force-tracking. In conclusion, force intermittency reflects differing trajectory controls for static and dynamic force-tracking. The target goal of dynamic tracking is achieved through trajectory adjustments that are more intricate and more frequent than those of static tracking, pertaining to differing organizations and functioning of muscular oscillations in the alpha and gamma bands. PMID:24098640

Mental Fatigue Impairs Intermittent Running Performance.

PubMed

Smith, Mitchell R; Marcora, Samuele M; Coutts, Aaron J

2015-08-01

The purpose of the study was to investigate the effects of mental fatigue on intermittent running performance. Ten male intermittent team sports players performed two identical self-paced, intermittent running protocols. The two trials were separated by 7 d and preceded, in a randomized-counterbalanced order, by 90 min of either emotionally neutral documentaries (control) or the AX-continuous performance test (AX-CPT; mental fatigue). Subjective ratings of fatigue and vigor were measured before and after these treatments, and motivation was recorded before the intermittent running protocol. Velocity, heart rate, oxygen consumption, blood glucose and lactate concentrations, and ratings of perceived exertion (RPE) were measured throughout the 45-min intermittent running protocol. Session RPE was recorded 30 min after the intermittent running protocol. Subjective ratings of fatigue were higher after the AX-CPT (P = 0.005). This mental fatigue significantly reduced velocity at low intensities (1.28 ± 0.18 m·s vs 1.31 ± 0.17 m·s; P = 0.037), whereas high-intensity running and peak velocities were not significantly affected. Running velocity at all intensities significantly declined over time in both conditions (P < 0.001). Oxygen consumption was significantly lower in the mental fatigue condition (P = 0.007). Other physiological variables, vigor and motivation, were not significantly affected. Ratings of perceived exertion during the intermittent running protocol were not significantly different between conditions despite lower overall velocity in the mental fatigue condition. Session RPE was significantly higher in the mental fatigue condition (P = 0.013). Mental fatigue impairs intermittent running performance. This negative effect of mental fatigue seems to be mediated by higher perception of effort.

Prognostic impact of subclinical or manifest extracoronary artery diseases after acute myocardial infarction.

PubMed

Eriksson Östman, Maja; Calais, Fredrik; Rosenblad, Andreas; Fröbert, Ole; Leppert, Jerzy; Hedberg, Pär

2017-08-01

In patients with coronary artery disease (CAD), clinically overt extracoronary artery diseases (ECADs), including claudication or previous strokes, are associated with poor outcomes. Subclinical ECADs detected by screening are common among such patients. We aimed to evaluate the prognostic impact of subclinical versus symptomatic ECADs in patients with acute myocardial infarction (AMI). In a prospective observational study, 654 consecutive patients diagnosed with AMI underwent ankle brachial index (ABI) measurements and ultrasonographic screening of the carotid arteries and abdominal aorta. Clinical ECADs were defined as prior strokes, claudication, or extracoronary artery intervention. Subclinical ECADs were defined as the absence of a clinical ECAD in combination with an ABI ≤0.9 or >1.4, carotid artery stenosis, or an abdominal aortic aneurysm. At baseline, subclinical and clinical ECADs were prevalent in 21.6% and 14.4% of the patients, respectively. Patients with ECADs received evidence-based medication more often at admission but similar medications at discharge compared with patients without ECADs. During a median follow-up of 5.2 years, 166 patients experienced endpoints of hospitalization for AMI, heart failure, stroke, or cardiovascular death. With ECAD-free cases as reference and after adjustment for risk factors, a clinical ECAD (hazard ratio [HR] 2.10, 95% confidence interval [CI] 1.34-3.27, p=0.001), but not a subclinical ECAD (HR 1.35, 95% CI 0.89-2.05, p=0.164), was significantly associated with worse outcomes. Despite receiving similar evidence-based medication at discharge, patients with clinical ECAD, but not patients with a subclinical ECAD, had worse long-term prognosis than patients without an ECAD after AMI. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Spondylectomy and lateral lumbar interbody fusion for thoracolumbar kyphosis in an adult with achondroplasia: A case report.

PubMed

Miyazaki, Masashi; Kanezaki, Shozo; Notani, Naoki; Ishihara, Toshinobu; Tsumura, Hiroshi

2017-12-01

Fixed thoracolumbar kyphosis with spinal stenosis in adult patients with achondroplasia presents a challenging issue. We describe the first case in which spondylectomy and minimally invasive lateral access interbody arthrodesis were used for the treatment of fixed severe thoracolumbar kyphosis and lumbar spinal canal stenosis in an adult with achondroplasia. A 61-year-old man with a history of achondroplastic dwarfism presented with low back pain and radiculopathy and neurogenic claudication. Plain radiographs revealed a high-grade thoracolumbar kyphotic deformity with diffuse degenerative changes in the lumbar spine. The apex was located at L2, the local kyphotic angle from L1 to L3 was 105°, and the anterior area was fused from the L1 to L3 vertebrae. MRI revealed significant canal and lateral recess stenosis secondary to facet hypertrophy. We planned a front-back correction of the anterior and posterior spinal elements. We first performed anterior release at the fused part from L1 to L3 and XLIF at L3/4 and L4/5. Next, the patient was placed in the prone position. Spondylectomy at the L2 vertebra and posterior fusion from T10 to L5 were performed. Postoperative radiographs revealed L1 to L3 kyphosis of 32°. No complications occurred during or after surgery. Postoperatively, the patient's low back pain and neurological claudication were resolved. No worsening of kyphosis was observed 24 months postoperatively. Circumferential decompression of the spinal cord at the apical vertebral level and decompression of lumbar canal stenosis were necessary. Front-back correction of the anterior and posterior spinal elements via spondylectomy and lateral lumbar interbody fusion is a reasonable surgical option for thoracolumbar kyphosis and developmental canal stenosis in patients with achondroplasia.

PoleStriding exercise and vitamin E for management of peripheral vascular disease.

PubMed

Collins, Eileen G; Edwin Langbein, W; Orebaugh, Cynthia; Bammert, Christine; Hanson, Karla; Reda, Domenic; Edwards, Lonnie C; Littooy, Fred N

2003-03-01

The purpose of this investigation was to evaluate the efficacy of PoleStriding exercise (a form of walking that uses muscles of the upper and lower body in a continuous movement similar to cross-country skiing) and vitamin E (alpha-tocopherol) to improve walking ability and perceived quality of life (QOL) of patients with claudication pain secondary to peripheral arterial disease (PAD). Fifty-two subjects were randomized into four groups: PoleStriding with vitamin E (N = 13), PoleStriding with placebo (N= 14), vitamin E without exercise (N= 13), and placebo without exercise (N = 12). The dose of vitamin E was 400 IU daily. Only the PoleStriding with vitamin E and PoleStriding with placebo groups received PoleStriding instruction and training. Assignment to vitamin E or placebo was double blind. Subjects trained three times weekly for 30-45 min (rest time excluded). Individuals in vitamin E and placebo groups came to the laboratory biweekly for ankle blood-pressure measurements. Results of this randomized clinical trial provide strong evidence that PoleStriding significantly (P< 0.001) improved exercise tolerance on the constant work-rate and incremental treadmill tests. Ratings of perceived claudication pain were significantly less after the PoleStriding training program (P= 0.02). In contrast, vitamin E did not have a statistically significant effect on the subjects' ratings of perceived leg pain (P= 0.35) or treadmill walking duration ( P= 0.36). Perceived distance and walking speed (Walking Impairment Questionnaire) and perceived physical function (Rand Short Form-36) improved in the PoleStriding trained group only (P< 0.001, 0.022 and 0.003, respectively). PoleStriding effectively improved the exercise tolerance and perceived QOL of patients with PAD. Little additional benefit to exercise capacity was realized from vitamin E supplementation.

Spinal case of the month with short perspective: How would you treat this L3-L4 synovial cyst?

PubMed

Epstein, Nancy E

2018-01-01

In this new section, Case of the Month with Short Perspective from Surgical Neurology International, we want to see how various spine surgeons would approach different spinal pathologies. In this first case, an elderly male presented with 3 years of lower back pain and progressive neurogenic claudication with bilateral radiculopathy that had exacerbated over the prior 6 months. An outside physician performed a magnetic resonance (MR) study of the lumbar spine that showed a massive synovial cyst filling the spinal canal (e.g., large bilateral cysts) at the L3-L4 level with grade I spondylolisthesis. The MR and CT studies also both demonstrated moderate L2-L3, and severe L3-L4 stenosis. Despite the massive synovial cyst filling the spinal canal at the L3-L4 level, pain management (anesthesia training) spent 3 months performing three successive epidural steroid injections accompanied by attempts at percutaneous synovial cyst aspiration/rupture. By the time the patient presented to neurosurgery, he had developed severe neurogenic claudication, radiculopathy, myelopathy, and a cauda equina syndrome. Dynamic X-rays revealed a mild grade I degenerative spondylolisthesis at the L3-L4 level without active motion, while both computed tomography (CT) and MR studies confirmed moderate stenosis stenosis/ossification of the yellow ligament at the L2-L3 level, severe stenosis at L3-L4 level with spondylolisthesis, and massive bilateral synovial cysts at the L3-L4 level filling the spinal canal. Following an L2-L4 decompressive laminectomy without fusion (note the absence of motion intraoperatively at the L3-L4 level), the patient's symptoms resolved, and he regained normal function. How would you have managed this patient?

Calf Muscle Oxygen Saturation During Six-Minute Walk Test And Its Relationship With Walking Impairment In Symptomatic Peripheral Artery Disease.

PubMed

Andrade-Lima, Aluísio; Cucato, Gabriel G; Domingues, Wagner J R; Germano-Soares, Antônio H; Cavalcante, Bruno R; Correia, Marilia A; Saes, Glauco F; Wolosker, Nelson; Gardner, Andrew W; Zerati, Antônio E; Ritti-Dias, Raphael M

2018-05-21

Impaired microcirculation is associated with poor walking capacity in symptomatic peripheral artery disease (PAD) patients during treadmill test, however, this test does not simulate the efforts of daily walking of these patients. Thus, the aim of the study was to describe the microcirculation responses during six-minute walk test (6MWT) and to analyze the relationship between microcirculation indicators and walking impairment in symptomatic PAD patients. Thirty-four patients were included (mean age = 67.6 ± 11.2). The clinical characteristics were collected and they performed a 6MWT in which initial claudication distance (ICD) and total walking distance (TWD) were recorded. During and after the 6MWT, calf muscle oxygen saturation (StO 2 ) parameters were monitored continuously to measure microcirculation behavior. The association between calf muscle StO 2 parameters and walking impairment was analyzed by Pearson or Spearman correlations. Walking impairment was not associated with any StO 2 parameters during exercise. In contrast, after 6MWT, recovery time of StO 2 (r = -0.472, P = .008) and recovery time to maximal StO 2 (r= -0.402, P = .019) were negatively correlated with ICD. Furthermore, the distance walked under claudication symptoms (ΔTWD - ICD) was positively correlated with recovery time to maximal StO 2 (r = 0.347, P = .048). In symptomatic PAD patients, shorter ICD values during a 6MWT are associated with a delayed recovery in calf muscle StO 2 after exercise. Calf muscle StO 2 parameters decrease subtly during 6MWT, suggesting that the degree of ischemia in the calf muscle during ground walking, simulating efforts of the daily walking, is relatively low. Copyright © 2018 Elsevier Inc. All rights reserved.

Global Positioning System Use in the Community to Evaluate Improvements in Walking After Revascularization

PubMed Central

Gernigon, Marie; Le Faucheur, Alexis; Fradin, Dominique; Noury-Desvaux, Bénédicte; Landron, Cédric; Mahe, Guillaume; Abraham, Pierre

2015-01-01

Abstract Revascularization aims at improving walking ability in patients with arterial claudication. The highest measured distance between 2 stops (highest-MDCW), the average walking speed (average-WSCW), and the average stop duration (average-DSCW) can be measured by global positioning system, but their evolution after revascularization is unknown. We included 251 peripheral artery diseased patients with self-reported limiting claudication. The patients performed a 1-hour stroll, recorded by a global positioning system receiver. Patients (n = 172) with confirmed limitation (highest-MDCW <2000m) at inclusion were reevaluated after 6 months. Patients revascularized during the follow-up period were compared with reference patients (ie, with unchanged lifestyle medical or surgical status). Other patients (lost to follow-up or treatment change) were excluded (n = 89). We studied 44 revascularized and 39 reference patients. Changes in highest-MDCW (+442 vs. +13 m) and average-WSCW (+0.3 vs. −0.2 km h−1) were greater in revascularized than in reference patients (both P < 0.01). In contrast, no significant difference in average-DSCW changes was found between the groups. Among the revascularized patients, 13 (29.5%) had a change in average-WSCW, but not in highest-MDCW, greater than the mean + 1 standard deviation of the change observed for reference patients. Revascularization may improve highest-MDCW and/or average-WSCW. This first report of changes in community walking ability in revascularized patients suggests that, beyond measuring walking distances, average-WSCW measurement is essential to monitor these changes. Applicability to other surgical populations remains to be evaluated. Registration: http://www.clinicaltrials.gov/ct2/show/NCT01141361 PMID:25950694

Global positioning system use in the community to evaluate improvements in walking after revascularization: a prospective multicenter study with 6-month follow-up in patients with peripheral arterial disease.

PubMed

Gernigon, Marie; Le Faucheur, Alexis; Fradin, Dominique; Noury-Desvaux, Bénédicte; Landron, Cédric; Mahe, Guillaume; Abraham, Pierre

2015-05-01

Revascularization aims at improving walking ability in patients with arterial claudication. The highest measured distance between 2 stops (highest-MDCW), the average walking speed (average-WSCW), and the average stop duration (average-DSCW) can be measured by global positioning system, but their evolution after revascularization is unknown.We included 251 peripheral artery diseased patients with self-reported limiting claudication. The patients performed a 1-hour stroll, recorded by a global positioning system receiver. Patients (n = 172) with confirmed limitation (highest-MDCW <2000m) at inclusion were reevaluated after 6 months. Patients revascularized during the follow-up period were compared with reference patients (ie, with unchanged lifestyle medical or surgical status). Other patients (lost to follow-up or treatment change) were excluded (n = 89).We studied 44 revascularized and 39 reference patients. Changes in highest-MDCW (+442 vs. +13 m) and average-WSCW (+0.3 vs. -0.2 km h) were greater in revascularized than in reference patients (both P < 0.01). In contrast, no significant difference in average-DSCW changes was found between the groups. Among the revascularized patients, 13 (29.5%) had a change in average-WSCW, but not in highest-MDCW, greater than the mean + 1 standard deviation of the change observed for reference patients.Revascularization may improve highest-MDCW and/or average-WSCW. This first report of changes in community walking ability in revascularized patients suggests that, beyond measuring walking distances, average-WSCW measurement is essential to monitor these changes. Applicability to other surgical populations remains to be evaluated. http://www.clinicaltrials.gov/ct2/show/NCT01141361.

Adolescent Alcohol Exposure-Induced Changes in Alpha-Melanocyte Stimulating Hormone and Neuropeptide Y Pathways via Histone Acetylation in the Brain During Adulthood.

PubMed

Kokare, Dadasaheb M; Kyzar, Evan J; Zhang, Huaibo; Sakharkar, Amul J; Pandey, Subhash C

2017-09-01

Adolescent intermittent ethanol exposure causes long-lasting alterations in brain epigenetic mechanisms. Melanocortin and neuropeptide Y signaling interact and are affected by ethanol exposure in the brain. Here, the persistent effects of adolescent intermittent ethanol on alpha-melanocyte stimulating hormone, melanocortin 4 receptor, and neuropeptide Y expression and their regulation by histone acetylation mechanisms were investigated in adulthood. Male rats were exposed to adolescent intermittent ethanol (2 g/kg, i.p.) or volume-matched adolescent intermittent saline from postnatal days 28 to 41 and allowed to grow to postnatal day 92. Anxiety-like behaviors were measured by the elevated plus-maze test. Brain regions from adult rats were used to examine changes in alpha-melanocyte stimulating hormone, melanocortin 4 receptor, and neuropeptide Y expression and the histone acetylation status of their promoters. Adolescent intermittent ethanol-exposed adult rats displayed anxiety-like behaviors and showed increased pro-opiomelanocortin mRNA levels in the hypothalamus and increased melanocortin 4 receptor mRNA levels in both the amygdala and hypothalamus compared with adolescent intermittent saline-exposed adult rats. The alpha-Melanocyte stimulating hormone and melanocortin 4 receptor protein levels were increased in the central and medial nucleus of the amygdala, paraventricular nucleus, and arcuate nucleus of the hypothalamus in adolescent intermittent ethanol-exposed compared with adolescent intermittent saline-exposed adult rats. Neuropeptide Y protein levels were decreased in the central and medial nucleus of the amygdala of adolescent intermittent ethanol-exposed compared with adolescent intermittent saline-exposed adult rats. Histone H3K9/14 acetylation was decreased in the neuropeptide Y promoter in the amygdala but increased in the melanocortin 4 receptor gene promoter in the amygdala and the melanocortin 4 receptor and pro-opiomelanocortin promoters in the hypothalamus of adolescent intermittent ethanol-exposed adult rats compared with controls. Increased melanocortin and decreased neuropeptide Y activity due to changes in histone acetylation in emotional brain circuitry may play a role in adolescent intermittent ethanol-induced anxiety phenotypes in adulthood. Published by Oxford University Press on behalf of CINP 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

The Effect of Solar Radiation Pressure on the Motion of an Artificial Satellite

NASA Technical Reports Server (NTRS)

Bryant, Robert W.

1961-01-01

The effects of solar radiation pressure on the motion of an artificial satellite are obtained, including the effects of the intermittent acceleration which results from the eclipsing of the satellite by the earth. Vectorial methods have been utilized to obtain the nonlinear equations describing the motion, and the method of Kryloff-Bogoliuboff has been applied in their solution.

Delivery Device and Method for Forming the Same

NASA Technical Reports Server (NTRS)

Liu, Xiaohua (Inventor); Ma, Peter X. (Inventor); McCauley, Laurie (Inventor)

2014-01-01

A delivery device includes a hollow container, and a plurality of biodegradable and/or erodible polymeric layers established in the container. A layer including a predetermined substance is established between each of the plurality of polymeric layers, whereby degradation of the polymeric layer and release of the predetermined substance occur intermittently. Methods for forming the device are also disclosed herein.

9 CFR 3.116 - Care in transit.

Code of Federal Regulations, 2010 CFR

2010-01-01

... such methods as intermittent spraying of water or application of a nontoxic emollient; (2) Assuring... related stress; and (5) Calming the marine mammals to avoid struggling, thrashing, and other unnecessary.../or warmed sufficiently to prevent overheating, hypothermia, or temperature related stress; and (2...

9 CFR 3.116 - Care in transit.

Code of Federal Regulations, 2011 CFR

2011-01-01

... such methods as intermittent spraying of water or application of a nontoxic emollient; (2) Assuring... related stress; and (5) Calming the marine mammals to avoid struggling, thrashing, and other unnecessary.../or warmed sufficiently to prevent overheating, hypothermia, or temperature related stress; and (2...

Intermittent fasting: A “new” historical strategy for controlling seizures?

PubMed Central

Hartman, Adam L.; Rubenstein, James E.; Kossoff, Eric H.

2013-01-01

Summary In antiquity, fasting was a treatment for epilepsy and a rationale for the ketogenic diet (KD). Preclinical data indicate the KD and intermittent fasting do not share identical anticonvulsant mechanisms. We implemented an intermittent fasting regimen in six children with an incomplete response to a KD. Three patients adhered to the combined intermittent fasting/KD regimen for 2 months and four had transient improvement in seizure control, albeit with some hunger-related adverse reactions. PMID:23206889

Decomposing an urban soundscape to reveal patterns and drivers of variation in anthropogenic noise.

PubMed

Gill, Sharon A; Grabarczyk, Erin E; Baker, Kathleen M; Naghshineh, Koorosh; Vonhof, Maarten J

2017-12-01

Continuous and intermittent noise may have different effects on humans and wildlife, therefore distinguishing temporal patterns of noise and their drivers is important for policy regarding both public health and wildlife management. We visualized patterns and explored land-use drivers of continuous and high-amplitude intermittent sound pressure levels (SPLs) on an urban campus in Michigan, U.S.A. To visualize patterns of SPLs, we introduce decibel duration curves (DDCs), which show the cumulative frequency distribution of SPLs and aid in the interpretation of statistical SPLs (L n values) that reflect continuous versus intermittent sounds. DDCs and L n values reveal that our 24 recording locations varied in the intensity of both continuous and intermittent noise, with intermittent high-amplitude sound events in particular contributing to variability in SPLs over the study site. Time of day influenced both continuous and intermittent SPLs, as locations relatively close to manmade structures (buildings, roads and parking lots) experienced higher SPLs as the day progressed. Continuous SPLs increased with decreasing distance to manmade structures, whereas intermittent SPLs increased with decreasing distance to roads and increasing distance to buildings. Thus, different land-use factors influenced patterns of continuous and intermittent noise, which suggests that different policy and strategies may be needed to ameliorate their effects on the public and wildlife. Copyright © 2017 Elsevier B.V. All rights reserved.

Transport of cosmic-ray protons in intermittent heliospheric turbulence: Model and simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alouani-Bibi, Fathallah; Le Roux, Jakobus A., E-mail: fb0006@uah.edu

The transport of charged energetic particles in the presence of strong intermittent heliospheric turbulence is computationally analyzed based on known properties of the interplanetary magnetic field and solar wind plasma at 1 astronomical unit. The turbulence is assumed to be static, composite, and quasi-three-dimensional with a varying energy distribution between a one-dimensional Alfvénic (slab) and a structured two-dimensional component. The spatial fluctuations of the turbulent magnetic field are modeled either as homogeneous with a Gaussian probability distribution function (PDF), or as intermittent on large and small scales with a q-Gaussian PDF. Simulations showed that energetic particle diffusion coefficients both parallelmore » and perpendicular to the background magnetic field are significantly affected by intermittency in the turbulence. This effect is especially strong for parallel transport where for large-scale intermittency results show an extended phase of subdiffusive parallel transport during which cross-field transport diffusion dominates. The effects of intermittency are found to depend on particle rigidity and the fraction of slab energy in the turbulence, yielding a perpendicular to parallel mean free path ratio close to 1 for large-scale intermittency. Investigation of higher order transport moments (kurtosis) indicates that non-Gaussian statistical properties of the intermittent turbulent magnetic field are present in the parallel transport, especially for low rigidity particles at all times.« less

Efficacy of continuous versus intermittent subglottic secretion drainage in preventing ventilator-associated pneumonia in patients requiring mechanical ventilation: A single-center randomized controlled trial.

PubMed

Fujimoto, Hiroko; Yamaguchi, Osamu; Hayami, Hajime; Shimosaka, Mika; Tsuboi, Sayaka; Sato, Mitsunori; Takebayashi, Shigeo; Morita, Satoshi; Saito, Mari; Goto, Takahisa; Kurahashi, Kiyoyasu

2018-03-23

Aspiration of subglottic secretion is a widely used intervention to prevent ventilator-associated pneumonia (VAP). This study aimed to compare the efficacy of continuous and intermittent subglottic secretion drainage (SSD) in preventing VAP. A single-center randomized controlled trial was conducted on adult postoperative patients who were expected to undergo mechanical ventilation for more than 48 hours. Primary outcome measure was incidence of VAP and secondary outcome measures were length of mechanical ventilation and intensive-care unit (ICU) stay. Fifty-nine patients received continuous SSD, while 60 patients received intermittent SSD. Of these 119 patients, 88 (74%) were excluded and 15 and 16 patients were allocated to receive continuous and intermittent SSD, respectively. VAP was detected in 4 (26.7%) and 7 (43.8%) patients in the continuous and intermittent groups, respectively, (p=0.320). The length of mechanical ventilation was significantly shorter (p=0.034) in the continuous group (99.5±47.1 h) than in the intermittent group (159.9±94.5 h). The length of ICU stay was also shorter (p=0.0097) in the continuous group (6.3±2.1 days) than the intermittent group (9.8±4.8 days). Although continuous SSD did not reduce the incidence of VAP, it reduced the length of mechanical ventilation and ICU stay when compared to intermittent SSD.

EVOLUTION OF INTERMITTENCY IN THE SLOW AND FAST SOLAR WIND BEYOND THE ECLIPTIC PLANE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wawrzaszek, A.; Macek, W. M.; Echim, M.

2015-12-01

We study intermittency as a departure from self-similarity of the solar wind magnetic turbulence and investigate the evolution with the heliocentric distance and latitude. We use data from the Ulysses spacecraft measured during two solar minima (1997–1998 and 2007–2008) and one solar maximum (1999–2001). In particular, by modeling a multifractal spectrum, we revealed the intermittent character of turbulence in the small-scale fluctuations of the magnetic field embedded in the slow and fast solar wind. Generally, at small distances from the Sun, in both the slow and fast solar wind, we observe the high degree of multifractality (intermittency) that decreases somewhatmore » slowly with distance and slowly with latitude. The obtained results seem to suggest that generally intermittency in the solar wind has a solar origin. However, the fast and slow streams, shocks, and other nonlinear interactions can only be considered as the drivers of the intermittent turbulence. It seems that analysis shows that turbulence beyond the ecliptic plane evolves too slowly to maintain the intermittency with the distance and latitude. Moreover, we confirm that the multifractality and intermittency are at a lower level than in the ecliptic, as well as the existence of symmetry with respect to the ecliptic plane, suggesting that there are similar turbulent properties observed in the two hemispheres.« less

Detection and control of combustion instability based on the concept of dynamical system theory.

PubMed

Gotoda, Hiroshi; Shinoda, Yuta; Kobayashi, Masaki; Okuno, Yuta; Tachibana, Shigeru

2014-02-01

We propose an online method of detecting combustion instability based on the concept of dynamical system theory, including the characterization of the dynamic behavior of combustion instability. As an important case study relevant to combustion instability encountered in fundamental and practical combustion systems, we deal with the combustion dynamics close to lean blowout (LBO) in a premixed gas-turbine model combustor. The relatively regular pressure fluctuations generated by thermoacoustic oscillations transit to low-dimensional intermittent chaos owing to the intermittent appearance of burst with decreasing equivalence ratio. The translation error, which is characterized by quantifying the degree of parallelism of trajectories in the phase space, can be used as a control variable to prevent LBO.

Acoustic Emission during Intermittent Creep in an Aluminum-Magnesium Alloy

NASA Astrophysics Data System (ADS)

Shibkov, A. A.; Zheltov, M. A.; Gasanov, M. F.; Zolotov, A. E.

2018-01-01

The use of high-speed methods to measure deformation, load, and the dynamics of deformation bands, as well as the correlation between the intermittent creep characteristics of the AlMg6 aluminum-magnesium alloy and the parameters of the acoustic emission signals, has been studied experimentally. It has been established that the emergence and rapid expansion of the primary deformation band, which generates a characteristic acoustic emission signal in the frequency range of 10-1000 Hz, is a trigger for the development of a deformation step in the creep curve. The results confirm the accuracy of the mechanism of generating an acoustic signal associated with the emergence of a dislocation band on the external surface of the specimen.

Detection and control of combustion instability based on the concept of dynamical system theory

NASA Astrophysics Data System (ADS)

Gotoda, Hiroshi; Shinoda, Yuta; Kobayashi, Masaki; Okuno, Yuta; Tachibana, Shigeru

2014-02-01

We propose an online method of detecting combustion instability based on the concept of dynamical system theory, including the characterization of the dynamic behavior of combustion instability. As an important case study relevant to combustion instability encountered in fundamental and practical combustion systems, we deal with the combustion dynamics close to lean blowout (LBO) in a premixed gas-turbine model combustor. The relatively regular pressure fluctuations generated by thermoacoustic oscillations transit to low-dimensional intermittent chaos owing to the intermittent appearance of burst with decreasing equivalence ratio. The translation error, which is characterized by quantifying the degree of parallelism of trajectories in the phase space, can be used as a control variable to prevent LBO.

Effect of Intermittent Kangaroo Mother Care on Weight Gain of Low Birth Weight Neonates With Delayed Weight Gain

PubMed Central

Samra, Nashwa M.; Taweel, Amal El; Cadwell, Karin

2013-01-01

Objective: To evaluate intermittent Kangaroo Mother Care (KMC) with additional opportunities to breastfeed on weight gain of low birth weight (LBW) neonates with delayed weight gain. Methods: 40 LBW neonates were followed to see whether KMC with additional opportunities to breastfeed improved weight gain. Results: In the KMC group, the mean age of regaining birth weight was significantly less (15.68 vs. 24.56 days) and the average daily weight gain was significantly higher (22.09 vs. 10.39 g, p < .001) than controls. Conclusion: KMC with additional opportunities to breastfeed was found to be an effective intervention for LBWs with delayed weight gain and should be considered to be an effective strategy. PMID:24868132

Predicting and generalizing the refuge function of intermittent and ephemeral streams

EPA Science Inventory

Intermittent and ephemeral streams can provide important functions within stream networks. For fish, intermittent and ephemeral streams can contribute energy and materials to downstream perennial waters, serve as seasonal habitats, and/or provide refuge functions. Understanding t...

Southwestern Intermittent and Ephemeral Stream Connectivity

EPA Science Inventory

Ephemeral and intermittent streams are abundant in the arid and semiarid landscapes of the Western and Southwestern United States (U.S.). Connectivity of ephemeral and intermittent streams to the relatively few perennial reaches through runoff is a major driver of the ecohydrolog...

Reliability, Validity and Usefulness of 30–15 Intermittent Fitness Test in Female Soccer Players

PubMed Central

Čović, Nedim; Jelešković, Eldin; Alić, Haris; Rađo, Izet; Kafedžić, Erduan; Sporiš, Goran; McMaster, Daniel T.; Milanović, Zoran

2016-01-01

PURPOSE: The aim of this study was to examine the reliability, validity and usefulness of the 30–15IFT in competitive female soccer players. METHODS: Seventeen elite female soccer players participated in the study. A within subject test-retest study design was utilized to assess the reliability of the 30–15 intermittent fitness test (IFT). Seven days prior to 30–15IFT, subjects performed a continuous aerobic running test (CT) under laboratory conditions to assess the criterion validity of the 30–15IFT. End running velocity (VCT and VIFT), peak heart rate (HRpeak) and maximal oxygen consumption (VO2max) were collected and/or estimated for both tests. RESULTS: VIFT (ICC = 0.91; CV = 1.8%), HRpeak (ICC = 0.94; CV = 1.2%), and VO2max (ICC = 0.94; CV = 1.6%) obtained from the 30–15IFT were all deemed highly reliable (p > 0.05). Pearson product moment correlations between the CT and 30–15IFT for VO2max, HRpeak and end running velocity were large (r = 0.67, p = 0.013), very large (r = 0.77, p = 0.02) and large (r = 0.57, p = 0.042), respectively. CONCLUSION: Current findings suggest that the 30–15IFT is a valid and reliable intermittent aerobic fitness test of elite female soccer players. The findings have also provided practitioners with evidence to support the accurate detection of meaningful individual changes in VIFT of 0.5 km/h (1 stage) and HRpeak of 2 bpm. This information may assist coaches in monitoring “real” aerobic fitness changes to better inform training of female intermittent team sport athletes. Lastly, coaches could use the 30–15IFT as a practical alternative to laboratory based assessments to assess and monitor intermittent aerobic fitness changes in their athletes. PMID:27909408

Study of intermittent dynamics in the terrestrial foreshock using the Cluster spacecraft records

NASA Astrophysics Data System (ADS)

Kovács, Péter; Vadász, Gergely; Koppán, András; Vörös, Zoltán

2014-05-01

The paper concerns with the statistical investigation of the intermittent dynamics in the terrestrial foreshock. We use the 22.5 Hz FGM magnetic data of the four spacecraft of the Cluster mission from periods when the mission orbit traversed the solar wind (January-April in the years of 2001-2010). Intermittency is studied in terms of space and time through a sliding-window probability density function (PDF) analysis of the records. The spatial dependence of the appearance of intermittent fluctuations is monitored according to the distance from the bow shock (BS) and the angle measured between the BS normal and the IMF direction (quasi parallel and perpendicular conditions). Beside the intermittent turbulent fluctuations, the foreshock dynamics is dominated by various wave phenomena, that are, in most cases, more energetic than the turbulent activity. For this reason, a high-pass wavelet filtering is carried out on the time-series for extracting the small-amplitude intermittent fluctuations at high-frequencies. The level of intermittent fluctuations is measured through the deviation of the fourth statistical moments of the time-series increments (i.e. the flatness) from the Gaussian value, 3. Instead of temporal increments, the PDF analysis is also carried out with spatial differences among the records of the four Cluster spacecraft. In this case the Taylor hypothesis has not to be invoked in the interpretation of the obtained results. It is shown that the intermittency level measured by spatial differences decreases logarithmically with the inter-spacecraft distance. The level of intermittent fluctuations in the foreshock is studied in terms of different solar wind conditions. The strongest correlation turns out to be between the intensity of intermittent foreshock dynamics and the solar wind bulk velocity and Alfvén Mach number. The research leading to these results has received funding from the European Community's Seventh Framework Programme ([FP7/2007-2013]) under grant agreement n° 313038/STORM.

Effects of acute intermittent hypoxia on glucose metabolism in awake healthy volunteers

PubMed Central

Louis, Mariam; Punjabi, Naresh M.

2009-01-01

Accumulating evidence suggests that obstructive sleep apnea is associated with alterations in glucose metabolism. Although the pathophysiology of metabolic dysfunction in obstructive sleep apnea is not well understood, studies of murine models indicate that intermittent hypoxemia has an important contribution. However, corroborating data on the metabolic effects of intermittent hypoxia on glucose metabolism in humans are not available. Thus the primary aim of this study was to characterize the acute effects of intermittent hypoxia on glucose metabolism. Thirteen healthy volunteers were subjected to 5 h of intermittent hypoxia or normoxia during wakefulness in a randomized order on two separate days. The intravenous glucose tolerance test (IVGTT) was used to assess insulin-dependent and insulin-independent measures of glucose disposal. The IVGTT data were analyzed using the minimal model to determine insulin sensitivity (SI) and glucose effectiveness (SG). Drops in oxyhemoglobin saturation were induced during wakefulness at an average rate of 24.3 events/h. Compared with the normoxia condition, intermittent hypoxia was associated with a decrease in SI [4.1 vs. 3.4 (mU/l)−1·min−1; P = 0.0179] and SG (1.9 vs. 1.3 min−1×10−2, P = 0.0065). Despite worsening insulin sensitivity with intermittent hypoxia, pancreatic insulin secretion was comparable between the two conditions. Heart rate variability analysis showed the intermittent hypoxia was associated with a shift in sympathovagal balance toward an increase in sympathetic nervous system activity. The average R-R interval on the electrocardiogram was 919.0 ms during the normoxia condition and 874.4 ms during the intermittent hypoxia condition (P < 0.04). Serum cortisol levels after intermittent hypoxia and normoxia were similar. Hypoxic stress in obstructive sleep apnea may increase the predisposition for metabolic dysfunction by impairing insulin sensitivity, glucose effectiveness, and insulin secretion. PMID:19265062

Intermittent energy restriction in type 2 diabetes: A short discussion of medication management.

PubMed

Carter, Sharayah; Clifton, Peter M; Keogh, Jennifer B

2016-12-15

To discuss type 2 diabetes mellitus (T2DM) medication changes required during the popular 5:2 intermittent energy restriction (IER) diet. A search was conducted in MEDLINE, EMBASE, AMED, CINAHL and Cochrane library for original research articles investigating the use of very low calorie diets (VLCD) in people with T2DM. The search terms used included "VLCD" or "very low energy diet" or "very low energy restriction" or "IER" or "intermittent fasting" or "calorie restriction" or "diabetes mellitus type 2" and "type 2 diabetes". Reference lists of selected articles were also screened for relevant publications. Only research articles written in English, which also included an explanation of medication changes were included. A recent pilot trial using the 5:2 IER method, conducted by our research group, will also be summarized. A total of 8 studies were found that investigated the use of VLCD in T2DM and discussed medication management. Overall these studies indicate that the use of a VLCD for people with T2DM usually require the cessation of medication to prevent hypoglycemia. Therefore, the 5:2 IER method will also require medication changes, but as seen in our pilot trial, may not require total cessation of medication, rather a cessation on the 2 IER days only. Guidelines outlined here can be used in the initial stages of a 2-d IER diet, but extensive blood glucose monitoring is still required to make the necessary individual reductions to medications in response to weight loss.

A classification scheme for turbulence based on the velocity-intermittency structure with an application to near-wall flow and with implications for bed load transport

NASA Astrophysics Data System (ADS)

Keylock, C. J.; Nishimura, K.; Peinke, J.

2012-03-01

Kolmogorov's classic theory for turbulence assumed an independence between velocity increments and the value for the velocity itself. However, recent work has called this assumption in to question, which has implications for the structure of atmospheric, oceanic and fluvial flows. Here we propose a conceptually simple analytical framework for studying velocity-intermittency coupling that is similar in essence to the popular quadrant analysis method for studying near-wall flows. However, we study the dominant (longitudinal) velocity component along with a measure of the roughness of the signal, given mathematically by its series of Hölder exponents. Thus, we permit a possible dependence between velocity and intermittency. We compare boundary layer data obtained in a wind tunnel to turbulent jets and wake flows. These flow classes all have distinct characteristics, which cause them to be readily distinguished using our technique and the results are robust to changes in flow Reynolds numbers. Classification of environmental flows is then possible based on their similarities to the idealized flow classes and we demonstrate this using laboratory data for flow in a parallel-channel confluence. Our results have clear implications for sediment transport in a range of geophysical applications as they suggest that the recently proposed impulse-based methods for studying bed load transport are particularly relevant in domains such as gravel bed river flows where the boundary layer is disrupted and wake interactions predominate.

Modeling of Flow Transition Using an Intermittency Transport Equation

NASA Technical Reports Server (NTRS)

Suzen, Y. B.; Huang, P. G.

1999-01-01

A new transport equation for intermittency factor is proposed to model transitional flows. The intermittent behavior of the transitional flows is incorporated into the computations by modifying the eddy viscosity, mu(sub t), obtainable from a turbulence model, with the intermittency factor, gamma: mu(sub t, sup *) = gamma.mu(sub t). In this paper, Menter's SST model (Menter, 1994) is employed to compute mu(sub t) and other turbulent quantities. The proposed intermittency transport equation can be considered as a blending of two models - Steelant and Dick (1996) and Cho and Chung (1992). The former was proposed for near-wall flows and was designed to reproduce the streamwise variation of the intermittency factor in the transition zone following Dhawan and Narasimha correlation (Dhawan and Narasimha, 1958) and the latter was proposed for free shear flows and was used to provide a realistic cross-stream variation of the intermittency profile. The new model was used to predict the T3 series experiments assembled by Savill (1993a, 1993b) including flows with different freestream turbulence intensities and two pressure-gradient cases. For all test cases good agreements between the computed results and the experimental data are observed.

Intermittent granulocyte and monocyte apheresis versus mercaptopurine for maintaining remission of ulcerative colitis: a pilot study.

PubMed

Sakuraba, Atsushi; Sato, Toshiro; Morohoshi, Yuichi; Matsuoka, Katsuyoshi; Okamoto, Susumu; Inoue, Nagamu; Takaishi, Hiromasa; Ogata, Haruhiko; Iwao, Yasushi; Hibi, Toshifumi

2012-06-01

The effect of granulocyte and monocyte adsorption apheresis (GMA) on prevention of relapse of ulcerative colitis (UC) is not clear. This was a pilot open-labeled, prospective, randomized, unblinded study to compare the tolerability and efficacy of intermittent GMA (once every 2 weeks) with mercaptopurine to maintain remission of UC. Twenty-one patients with UC, who had achieved remission by induction therapies were randomly assigned to receive either intermittent GMA (N = 10) or oral mercaptopurine (0.5 mg/kg per day; N = 11). The study period was 24 months. The rate of the patients maintaining remission and the incidences of adverse effects were compared between the two groups. At 24 months, seven of 10 patients (70.0%) on intermittent GMA and seven of 11 patients (63.6%, P = 1.00) on oral mercaptopurine were still in remission. Three patients relapsed in each group. One patient taking mercaptopurine, but none receiving intermittent GMA, dropped out because of adverse effects. Intermittent therapy with GMA was well tolerated and a substantial proportion of patients maintained remission. Intermittent GMA therapy in maintaining remission of UC merits further investigation. © 2012 The Authors. Therapeutic Apheresis and Dialysis © 2012 International Society for Apheresis.

Intermittency in 2D soap film turbulence

NASA Astrophysics Data System (ADS)

Cerbus, R. T.; Goldburg, W. I.

2013-10-01

The Reynolds number dependency of intermittency for 2D turbulence is studied in a flowing soap film. The Reynolds number used here is the Taylor microscale Reynolds number Rλ, which ranges from 20 to 800. Strong intermittency is found for both the inverse energy and direct enstrophy cascades as measured by (a) the pdf of velocity differences P(δu(r)) at inertial scales r, (b) the kurtosis of P(∂xu), and (c) the scaling of the so-called intermittency exponent μ, which is zero if intermittency is absent. Measures (b) and (c) are quantitative, while (a) is qualitative. These measurements are in disagreement with some previous results but not all. The velocity derivatives are nongaussian at all Rλ but show signs of becoming gaussian as Rλ increases beyond the largest values that could be reached. The kurtosis of P(δu(r)) at various r indicates that the intermittency is scale dependent. The structure function scaling exponents also deviate strongly from the Kraichnan prediction. For the enstrophy cascade, the intermittency decreases as a power law in Rλ. This study suggests the need for a new look at the statistics of 2D turbulence.

Intermittent atrial tachycardia promotes repolarization alternans and conduction slowing during rapid rates, and increases susceptibility to atrial fibrillation in a free-behaving sheep model.

PubMed

Monigatti-Tenkorang, Joanna; Jousset, Florian; Pascale, Patrizio; Vesin, Jean-Marc; Ruchat, Patrick; Fromer, Martin; Narayan, Sanjiv M; Pruvot, Etienne

2014-04-01

Paroxysmal atrial fibrillation (AF) may be triggered by intermittent atrial tachycardia, and ultimately lead to persistent AF. However, the mechanisms by which intermittent atrial tachycardia promotes sustained AF are not well understood. Eight sheep were chronically implanted with 2 pacemakers for the recording of broadband right atrial unipolar electrograms, and for the delivery of electrophysiological stimulation protocols and intermittent right atrial tachycardia. Right atrial kinetics of activation recovery interval (ARI) as a surrogate for action potential duration, of conduction time and velocity, and of repolarization alternans were analyzed at incremental pacing rates during the remodeling process induced by weeks of intermittent atrial tachycardia until the development of sustained AF. Intermittent atrial tachycardia decreased ARI and blunted its rate adaptation, facilitated atrial capture, and slowed conduction at high rates, and increased susceptibility to pacing-induced AF. In spite of blunted ARI rate adaptation, right atrial repolarization alternans was maintained during remodeling, and further increased in magnitude just before rapid pacing-induced AF. This study suggests that weeks of intermittent right atrial tachycardia result in a gradual electrical remodeling favorable for wavebreaks and reentry that may facilitate fibrillation. © 2014 Wiley Periodicals, Inc.

INTERMITTENT AND PERENNIAL STREAM MACROINVERTEBRATE COMMUNITY RESPONSE TO IMPERVIOUS COVER: THRESHOLD INDICATOR TAXA ANALYSIS AND PERMUTATIONS

EPA Science Inventory

The urban stream syndrome and the impact of impervious cover on macroinvertebrate communities is well-documented, but many exclude intermittent streams despite their prevalence. This study investigated macroinvertebrate communities of intermittent and perennial streams separately...

Intermittent Control Systems

ERIC Educational Resources Information Center

Montgomery, Thomas L.; And Others

1975-01-01

The technique of intermittent control systems for air quality control as developed and used by the Tennessee Valley Authority is investigated. Although controversial, all Tennessee Valley Authority sulfur dioxide elimination programs are scheduled to be operational this year. Existing or anticipated intermittent control systems are identified. (BT)

COHO SALMON DEPENDENCE ON INTERMITTENT STREAMS

EPA Science Inventory

In February 2006, the US Supreme Court heard cases that may affect whether intermittent streams are jurisdictional waters under the Clean Water Act. In June 2006, however, the cases were remanded to the circuit court, leaving the status of intermittent streams uncertain once agai...

Impacts of Urbanization and Intermittent Flow on Macroinvertebrates in Headwater Stream

EPA Science Inventory

Recent Supreme Court cases have brought increased attention to the contribution of intermittent waters to the health of downstream ecosystems. However, there is still limited knowledge on what factors are shaping these frequently disturbed intermittent stream communities. The obj...

Intermittent fasting: a "new" historical strategy for controlling seizures?

PubMed

Hartman, Adam L; Rubenstein, James E; Kossoff, Eric H

2013-05-01

In antiquity, fasting was a treatment for epilepsy and a rationale for the ketogenic diet (KD). Preclinical data indicate the KD and intermittent fasting do not share identical anticonvulsant mechanisms. We implemented an intermittent fasting regimen in six children with an incomplete response to a KD. Three patients adhered to the combined intermittent fasting/KD regimen for 2 months and four had transient improvement in seizure control, albeit with some hunger-related adverse reactions. Copyright © 2012 Elsevier B.V. All rights reserved.

Intermittent nature of acceleration in near wall turbulence.

PubMed

Lee, Changhoon; Yeo, Kyongmin; Choi, Jung-Il

2004-04-09

Using direct numerical simulation of a fully developed turbulent channel flow, we investigate the behavior of acceleration near a solid wall. We find that acceleration near the wall is highly intermittent and the intermittency is in large part associated with the near wall organized coherent turbulence structures. We also find that acceleration of large magnitude is mostly directed towards the rotation axis of the coherent vortical structures, indicating that the source of the intermittent acceleration is the rotational motion associated with the vortices that causes centripetal acceleration.

Environments predicting intermittent shortening access reduce operant performance but not home cage binge size in rats

PubMed Central

Wojnicki, F.H.E.; Babbs, R.K.; Corwin, R.L.W

2013-01-01

When non-food-deprived rats are given brief access to vegetable shortening (a semi-solid fat used in baked products) on an intermittent basis (Monday, Wednesday, Friday), they consume significantly more and emit more operant responses for shortening than a separate group of rats given brief access to shortening every day. Since both groups are traditionally housed in the same room, it is possible that the environmental cues associated with placing shortening in the cages (e.g., investigator in room, cages opening and closing, etc.) provide predictable cues to the daily group, but unpredictable cues to the intermittent group. The present study examined the effects of providing predictable environmental cues to an isolated intermittent group in order to examine the independent contributions of intermittency and predictability on intake and operant performance. Two groups of rats were housed in the same room, with one group provided 30-min intermittent (INT) access and the second group provided 30-min daily access (D) to shortening. A third group (ISO) of rats was housed in a room by themselves in which all environmental cues associated with intermittent shortening availability were highly predictable. After five weeks of home cage shortening access, all rats were then exposed to several different operant schedules of reinforcement. The INT and ISO groups consumed significantly more shortening in the home cage than the D group. In contrast, the INT group earned significantly more reinforcers than both the ISO and D groups under all but one of the reinforcement schedules, while ISO and D did not differ. These data indicate that intermittent access will generate binge-type eating in the home cage independent of cue predictability. However, predictable cues in the home cage reduce operant responding independent of intermittent access. PMID:23535243

Intermittent maple syrup urine disease: two case reports.

PubMed

Axler, Olof; Holmquist, Peter

2014-02-01

The presenting symptoms and clinical course of 2 cases of intermittent maple syrup urine disease (MSUD) are described. Intermittent MSUD is a potentially life-threatening metabolic disorder caused by a deficiency of branched-chain α-keto acid dehydrogenase, the enzyme complex that decarboxylates the 3 branched-chain amino acids. In contrast to classic MSUD, children with the intermittent form show normal development with normal intelligence and, when asymptomatic, normal levels of branched-chain amino acids. Symptoms usually appear between 5 months and 2 years of age, when a trivial infection such as otitis media or viral gastroenteritis triggers catabolism of muscle protein. Intermittent MSUD should be suspected in cases of common infections with a clinically atypical course, especially in children displaying ataxia or marked drowsiness.

Basic and Applied Algal Life Support System Research on Board the Deep Space Gateway

NASA Astrophysics Data System (ADS)

Niederwieser, T.; Zea, L.; Anthony, J.; Stodieck, L.

2018-02-01

We study the effect of long-term preservation methods on DNA damage of algal cultures for BLSS applications. In a secondary step, the Deep Space Gateway serves as a technology demonstration platform for algal photobioreactors in intermittently occupied habitats.

Bayesian analysis of longitudinal dyadic data with informative missing data using a dyadic shared-parameter model.

PubMed

Ahn, Jaeil; Morita, Satoshi; Wang, Wenyi; Yuan, Ying

2017-01-01

Analyzing longitudinal dyadic data is a challenging task due to the complicated correlations from repeated measurements and within-dyad interdependence, as well as potentially informative (or non-ignorable) missing data. We propose a dyadic shared-parameter model to analyze longitudinal dyadic data with ordinal outcomes and informative intermittent missing data and dropouts. We model the longitudinal measurement process using a proportional odds model, which accommodates the within-dyad interdependence using the concept of the actor-partner interdependence effects, as well as dyad-specific random effects. We model informative dropouts and intermittent missing data using a transition model, which shares the same set of random effects as the longitudinal measurement model. We evaluate the performance of the proposed method through extensive simulation studies. As our approach relies on some untestable assumptions on the missing data mechanism, we perform sensitivity analyses to evaluate how the analysis results change when the missing data mechanism is misspecified. We demonstrate our method using a longitudinal dyadic study of metastatic breast cancer.