Self-reported estimation of usual walking speed improves the performance of questionnaires estimating walking capacity in patients with vascular-type claudication

OBJECTIVE: Most questionnaires do not estimate the usual walking speed of the patient, although it is well known that patients may experience apparently different walking capacities if walking slow or fast. We hypothesized that correcting the self-reported estimated walking capacity by a coefficient issued from the self-reported estimation of usual walking speed would significantly improve the correlation between questionnaire-estimated and treadmill-measured walking capacity. METHODS: Three hundred ten consecutive patients complaining of vascular-type claudication were asked to estimate their usual walking speed in comparison to people of their age (or friends or relatives) with ratings ranging from much slower (1 pt) to much faster (5 pts), in addition to the filling out of the walking impairment questionnaire (WIQ) and the estimated ambulatory capacity by history questionnaire (EACH-Q). Corrected WIQ (WIQc) and corrected EACH-Q (EACH-Qc) scores were obtained by multiplying the scores of each questionnaire by the "usual-speed" coefficient and dividing by 5. Results for questionnaire scores were compared to maximal walking time (MWT) on a treadmill. RESULTS: All but four patients self-completed the usual-speed question. Median scores (25-75 centiles) were 41% (26-59) for the WIQ and 24% (11-41) for the EACH-Q. Coefficients of correlation of the three WIQ subscales and of the EACH-Q with treadmill results were significantly improved after correction by the "usual-speed" question. Overall, WIQ (mean of the three WIQ subscales) tended to improve but did not reach significance. CONCLUSION: Correcting the self-reported estimation of walking capacity by a self-reported estimation of usual walking pace significantly improves the correlation of all WIQ subscale scores and of the EACH-Q score with treadmill measurements of capacity. This confirms the interest of speed estimation in patients with peripheral arterial occlusive disease and claudication

Patency of direct revascularisation of the hypogastric arteries in patients with aortoiliac occlusive disease

OBJECTIVES: Various indications for internal iliac artery (IIA) revascularisation have been reported. Revascularisations for gluteal ischaemia and buttock claudication remain controversial and uncommon. The objective of the study was to assess the patency of direct conventional revascularisations (CRs) of the IIA in patients with aortoiliac occlusive disease because few studies have focussed on this specific topic. MATERIALS AND METHODS: The charts of all patients who underwent CR of the IIA, between August 2000 and January 2009, were retrospectively reviewed. We recorded for each patient preoperative vascular work-up. All patients were tested for patency on January 2009. A computed tomography (CT) scan was requested if the duplex scan casts any doubt with regard to patency. If non-patent, the last date for confirmed patency was kept for the analysis. Functional outcomes at the proximal level were also collected. RESULTS: We studied 40 patients with occlusive disease. Buttock claudication was observed in 27 patients (66%), including eight (20%) in whom these symptoms were isolated. The 13 other patients had distal claudication or rest pain and documented proximal ischaemia, justifying the IIA revascularisations. We performed 44 conventional direct revascularisations of the IIA concomitant to aorto- or iliofemoral bypasses in these patients. The overall postoperative patency rate was 89%. Five early occlusions of the IIA remained asymptomatic. The median duration of follow-up was 39 months (3-86 months). The survival rate was 95% at 1 year and 86% at 5 years. The primary patency rate of the IIA was 89% at 1 year and 72.5% at 5 years. Buttock claudication disappeared in 23 of the 27 patients (85%), who were symptomatic at the proximal level prior to surgery. CONCLUSION: Direct IIA concomitant revascularisation has an acceptable patency rate in patients undergoing aorto- or iliofemoral bypasses for occlusive disease. When feasible, this technique appears to be safe for the treatment and prevention of buttock claudication

Functional outcome of hypogastric revascularisation for prevention of buttock claudication in patients with peripheral artery occlusive disease

We have defined proximal lower limb ischaemia as a decrease in Exercise-transcutaneous oxygen pressure (TcPO(2)) lower than minus 15mmHg at the buttock level in patients with peripheral artery occlusive disease. The purpose of this study was to objectively evaluate the benefits of direct versus indirect revascularisation of internal iliac arteries (IIAs) for prevention of buttock claudication in this population. We retrospectively reviewed the charts of proximal ischaemia patients who underwent revascularisation and both preoperative and postoperative stress TcPO(2) testing. Revascularisation procedures were classified as either direct revascularisation, including percutaneous transluminal angioplasty and internal iliac artery bypass, resulting in a direct inflow in a patent IIA (group 1) or indirect revascularisation, including aortobifemoral bypass and recanalisation of the femoral junction on the ischaemic side, resulting in indirect inflow from collateral arteries in the hypogastric territory (group 2). Patency was checked 3 months after revascularisation in all cases. Treadmill exercise stress tests were performed before and after revascularisation using the same protocol designed to assess pain, determine maximum walking distance (MWD) and measure TcPO(2) during exercise. In addition, ankle-brachial indices (ABIs) were calculated. Between May 2001 and March 2008, a total of 93 patients with objectively documented proximal ischaemia underwent 145 proximal revascularisation procedures using conventional open techniques in 109 cases and endovascular techniques in 36. Direct revascularisation was performed on 50 limbs (35%) (group 1) and indirect revascularisation on 95 limbs (65%) (group 2). The mean interval between revascularisation and stress testing was 60+/-74 days preoperatively and 149+/-142 days postoperatively. No postoperative thrombosis was observed. Buttock claudication following revascularisation was more common in group 2 (p<0.001). No difference was observed between the two groups with regard to improvement in MWD (365 / 294 m) and ABI (0.20/0.22). Disappearance of proximal ischaemia was more common after direct revascularisation (p<0.01). The extent of lesions graded according to the TASC II classification appeared not to be predictive of improvement in assessment criteria following revascularisation. Conversely, patency of the superficial femoral artery was correlated with improvement (p<0.01). This study indicates that direct revascularisation, if feasible, provides the best functional outcome for prevention of buttock claudication

Dissolved matter fluxes in the inner delta of the River Niger

Abstract This study is part of the EQUANIS programme, the objectives of which are (a) estimating inputs from the River Niger to the inner Delta; (b) computing the hydrological balance; and (c) monitoring the quality of water in the central lacustrine basin. Eleven sampling locations were selected near gauging stations, both on the Niger River and its main tributary, the Bani River. Those sites have been sampled weekly since July 1990. The inner delta of the Niger River is a system particularly subject to sahelian and sub-desert climatic conditions and characterized by large flood plains. Time series of input water volumes in the inner delta, and of the water losses within it, show that the water losses are high, due to the intense evaporation, and vary from 6 to 40 km3. The water .losses reach their maximum during the wettest years-up to 47%, and minimum during the driest years-only 32%, due to the reduction of the flooded area. The surface of the flooded area is inferred from the hydrological balance. The preliminary results of this study indicate that the Niger and Bani rivers have low levels of dissolved element concentrations. The mean conductivity values, ranging from 50-80 pS cm-', increase regularly during the low water stage and decrease drastically with rising water. The pH values are slightly basic, ranging from 7.1 to 8. Silica and bicarbonates are the main dissolved species; they always represent more than 75% of TDS. In May, when the rising water stage begins, the waters are poorly mineralized at the input of the delta, while they have been enriched during the dry season in the delta. A good mass balance is found between inputs and outputs through the delta. However, a disequilibrium appears at the sampling sites within the basin, which could be partially linked to poor mixing between the Niger and Bani river waters. The first results from the upper basin and below the inner delta, show low concentrations of matter. The specific dissolved loads vary between 10-12 t km-' year-' for the Niger River and 2.5 t km-2 year-' for the Bani River. The annual input in the inner delta was about 2.2 X lo6 t in 1992-1993. Chemical budgets show a saline deposit of 0.3 x lo6 t in the inner delta. Seasonal variations of the dissolved matter fluxes are very different between the upper and lower parts of the inner delta, due to the breaking of the annual flood and to the more important flood plains in the upper delta. Los flujos de materiales disueltos en el delta inerior del Niger Resumen Es presente estudio forma parte del programa EQUANIS, cuyos objetivos son (a) estimación de los aportes del río Niger al delta interior, (b) cómputo del balance gídrico, y (c) monitoreo de la calidad del agua en la cuenca lacustre central. Se seleccionaron once sitios de muestre0 próximos a las estaciones de aforo tanto en el Niger como en su principal afluente, el Bani. Desde julio de 1990 se llevaron a cabo allí muestreos semanales. EI delta interior del Niger is us sistema particular sometido a condiciones interior, y de pérdidas de agua en is mismo, muestran que las pérdidas son elevadas debido a la evaporación intensa, y fluctúan entre 40 y 6 km3. Las pérdidas de agua son máximas durante los años más húmedos (hasta un 47%) y mínimas durante los años más socos (solo 32%) debido a la reducción de las Breas inundadas. La superficie inundada se deduce del balance hídrico. Los resultados preliminares del estudio indican que los ríos Niger y Bani tienen un bajo nivel de concentración de elementos en disolución. Los valores medios de conductividad que van de 50 a 80 pS cm" se incrementan regularmente durante el período de estiaje y disminuyen drásticamente en períodos de avenidas y variacíon de niveles. Los valores de pH son ligeramente básicos, de 7.1 a 8. Los principales materiales dusueltos son el sílice y los bicarbonatos; siempre representan más del 75% del TDS. En mayo, cuando se inicia el período de crecida, las aguas contienen pocos minerales en la entrada del delta mientras que se han concentrado durante la estación seca del delta. Se observa un buen balance de masa en el delta entre los aportes y descargas, pero aparece un desequilibrio en los sitios de muestre0 dentro de la cuenca, que puede atribuirse parcialmente a una mala mezcla entre las aguals del Niger y del Bani. Los primeros resultados en la cuenca superior y baja del delta interior muestran bajas concentraciones de material. Las cargas disueltas específicas fluctúan entre 10 y 12 t km-2 año-' para el río Niger y 2.5 t km-* año-' para el río Bani. El aporte anual en el delta interior fue de unos 2.2 X lo6 t en 1992-1993. Los balances químicos presentan un depósito salino de 0.3 X lo6 t en el delta interior. Las variaciones estacionales de los flujos de materiales son muy diferentes entre las partes alta y baja del delta interior, debido al inicio de la crecida anual y a las más importantes planicies de inundación en la parte superior del delta

Measurement of finite-frequency current statistics in a single-electron transistor

Electron transport in nano-scale structures is strongly influenced by the Coulomb interaction which gives rise to correlations in the stream of charges and leaves clear fingerprints in the fluctuations of the electrical current. A complete understanding of the underlying physical processes requires measurements of the electrical fluctuations on all time and frequency scales, but experiments have so far been restricted to fixed frequency ranges as broadband detection of current fluctuations is an inherently difficult experimental procedure. Here we demonstrate that the electrical fluctuations in a single electron transistor (SET) can be accurately measured on all relevant frequencies using a nearby quantum point contact for on-chip real-time detection of the current pulses in the SET. We have directly measured the frequency-dependent current statistics and hereby fully characterized the fundamental tunneling processes in the SET. Our experiment paves the way for future investigations of interaction and coherence induced correlation effects in quantum transport.Comment: 7 pages, 3 figures, published in Nature Communications (open access

Antitumour necrosis factor-α therapy for hidradenitis suppurativa: results from a national cohort study between 2000 and 2013

International audienceHidradenitis suppurativa (HS) is a frequent chronic inflammatory skin disease typically characterized by recurrent painful, deep inflammatory nodules of the axillary, breast, groin and gluteal areas. European recommendations are mainly based on expert opinion. Drug treatments are heterogenous (e.g., antibiotics, corticosteroids, retinoids) and lack consensus among expert centres. The most severe disease forms or those failing to respond to conventional drugs may be associated with worsened functional prognosis. Anti-tumor necrosis factor α (anti-TNFα) drugs have been prescribed in these cases. The results of randomized controlled trials (RCTs) are discordant. Three RCTs concluded to the efficacy of adalimumab (ADA), and two others did not detect any difference between infliximab (IFX) or etanercept (ETA) and placebo. Finally, data from the literature and reported experiences do not conclude on the efficacy of anti-TNFα drugs for HS. This article is protected by copyright. All rights reserve

The economic and ecological effects of water management choices in the upper Niger river: Development of decision support methods

One million people in the Inner Niger Delta make a living from arable farming, fisheries and livestock. Upstream dams (one built for electricity generation and one for irrigation) affect this downstream multifunctional use of water. Additionally, the Inner Niger Delta, which is one of the largest Ramsar sites in the world, is a hotspot of biodiversity and accommodates two of the largest known breeding colonies of large wading birds in Africa and in addition, is a vital part of the eco-regional network, supporting up to 3 to 4 million staging waterbirds, residents and migrants from all over Europe and western Asia. The hydrological and related ecological conditions in the Inner Delta largely determine the population size of these waterbird species. The major aim of the three-year study was to develop a decision-support system for river management in the Upper Niger, in which ecological and socio-economical impacts and benefits of dams and irrigation systems can be analysed in relation to different water management scenarios. The study involves various components: hydrology, arable farming, livestock, fisheries, ecology and socio-economics. An economic analysis has been conducted to determine the role of dams in the economy of the Inner Niger Delta and the Upper Niger region. By innovatively combining the above information on hydrology, ecology, fisheries, and agriculture, the study shows that building new dams is not an efficient way to increase economic growth and reduce poverty in the region. In fact, such efforts are counter-effective. Instead, development efforts should be aimed at improving the efficiency of the existing infrastructure, as well as of current economic activities in the Inner Niger Delta itself. This approach will also provide greater certainty for the essential eco-regional network functioning of the Inner Delta. © 2006 Taylor & Francis