The role of the deep femoral artery in the treatment of thigh claudication in case of hypogastric occlusion

BACKGROUND: This study evaluated the clinical and functional efficiency of deep femoral artery (DFA) revascularization in treating thigh claudication associated with ipsilateral internal iliac artery (IIA) occlusion. PATIENTS AND METHODS: The files of patients presenting with proximal claudication, ipsilateral IIA occlusion, and conventional surgical revascularization of DFA were retrospectively reviewed. Each patient benefited from preoperative and postoperative measurement of dynamic transcutaneous pressure of oxygen (TcPO2) and presented with preoperative proximal stress-related ischemia and with the clinical symptoms of buttock, thigh, or groin pain. RESULTS: Between May 2001 and December 2009, 23 DFA revascularizations were performed on 19 patients. Proximal stress-related pain disappeared in 17 lower limbs (74%). No postoperative thromboses were noted. Mean maximum walking distance (MWD) significantly improved (149+/-113 vs. 414+/-257 m; P<0.025), as did the ankle to arm systolic pressure index (0.71+/-0.17 vs. 0.90+/-0.19; P<0.005). Disappearance of proximal stress ischemia, revealed through postoperative dynamic TcPO2, measurement, occurred in 6 lower limbs (26%). Patency of ipsilateral superficial femoral artery, ipsilateral to the symptoms, seemed to be a predictive factor of MWD improvement (P<0.05). CONCLUSIONS: DFA revascularization is an efficient treatment for thigh claudication in case of IIA occlusion, even if the results are less satisfactory than those obtained through direct revascularizations of this artery

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

Design of a new multi-phase experimental simulation chamber for atmospheric photosmog, aerosol and cloud chemistry research

A new simulation chamber has been built at the Interuniversitary Laboratory of Atmospheric Systems (LISA). The CESAM chamber (French acronym for Experimental Multiphasic Atmospheric Simulation Chamber) is designed to allow research in multiphase atmospheric (photo-) chemistry which involves both gas phase and condensed phase processes including aerosol and cloud chemistry. CESAM has the potential to carry out variable temperature and pressure experiments under a very realistic artificial solar irradiation. It consists of a 4.2 m<sup>3</sup> stainless steel vessel equipped with three high pressure xenon arc lamps which provides a controlled and steady environment. Initial characterization results, all carried out at 290–297 K under dry conditions, concerning lighting homogeneity, mixing efficiency, ozone lifetime, radical sources, NO<sub>y</sub> wall reactivity, particle loss rates, background PM, aerosol formation and cloud generation are given. Photolysis frequencies of NO<sub>2</sub> and O<sub>3</sub> related to chamber radiation system were found equal to (4.2 × 10<sup>−3</sup> s<sup>−1</sup>) for <i>J</i><sub>NO<sub>2</sub></sub> and (1.4 × 10<sup>−5</sup> s<sup>−1</sup>) for <i>J</i><sub>O<sup>1</sup>D</sub> which is comparable to the solar radiation in the boundary layer. An auxiliary mechanism describing NO<sub>y</sub> wall reactions has been developed. Its inclusion in the Master Chemical Mechanism allowed us to adequately model the results of experiments on the photo-oxidation of propene-NO<sub>x</sub>-Air mixtures. Aerosol yields for the α-pinene + O<sub>3</sub> system chosen as a reference were determined and found in good agreement with previous studies. Particle lifetime in the chamber ranges from 10 h to 4 days depending on particle size distribution which indicates that the chamber can provide high quality data on aerosol aging processes and their effects. Being evacuable, it is possible to generate in this new chamber clouds by fast expansion or saturation with or without the presence of pre-existing particles, which will provide a multiphase environment for aerosol-droplet interaction

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

Exploring the potential of gold(iii) cyclometallated compounds as cytotoxic agents: variations on the C^N theme

A series of novel ((CN)-N-boolean AND) cyclometallated Au(III) complexes of general formula [Au(py(b)-H)(LL2)-L-1](n+) (py(b)-H = (CN)-N-boolean AND cyclometallated 2-benzylpyridine, L-1 and L-2 being chlorido, phosphane or glucosethiolato ligands, n = 0 or 1) have been synthesized and fully characterized using different techniques, including NMR, IR and far-IR, mass spectrometry, as well as elemental analysis. The crystal structure of one compound has been solved using X-ray diffraction methods. All compounds were tested in vitro in five human cancer cell lines including the lung, breast, colon and ovarian cancer cells. For comparison purposes, all compounds were also tested in a model of healthy human cells from the embryonic kidney. Notably, all new compounds were more toxic than their cyclometallated precursor bearing two chlorido ligands, and the derivative bearing one phosphane ligand presented the most promising toxicity profile in our in vitro screening, displaying a p53 dependent activity in colorectal cancer HCT116 cells. Finally, for the first time (CN)-N-boolean AND cyclometallated gold(III) complexes were shown to be potent inhibitors of the zinc finger protein PARP-1, involved in the mechanism of cisplatin resistance

Relating hygroscopicity and optical properties to chemical composition and structure of secondary organic aerosol particles generated from the ozonolysis of α-pinene

Secondary organic aerosol (SOA) were generated from the ozonolysis of α-pinene in the CESAM (French acronym for Experimental Multiphasic Atmospheric Simulation Chamber) simulation chamber. The SOA formation and aging were studied by following their optical, hygroscopic and chemical properties. The optical properties were investigated by determining the particle complex refractive index (CRI). The hygroscopicity was quantified by measuring the effect of relative humidity (RH) on the particle size (size growth factor, GF) and on the scattering coefficient (scattering growth factor, f(RH)). The oxygen to carbon atomic ratios (O : C) of the particle surface and bulk were used as a sensitive parameter to correlate the changes in hygroscopic and optical properties of the SOA composition during their formation and aging in CESAM. The real CRI at 525 nm wavelength decreased from 1.43–1.60 (±0.02) to 1.32–1.38 (±0.02) during the SOA formation. The decrease in the real CRI correlated to the O : C decrease from 0.68 (±0.20) to 0.55 (±0.16). In contrast, the GF remained roughly constant over the reaction time, with values of 1.02–1.07 (±0.02) at 90% (±4.2%) RH. Simultaneous measurements of O : C of the particle surface revealed that the SOA was not composed of a homogeneous mixture, but contained less oxidised species at the surface which may limit water absorption. In addition, an apparent change in both mobility diameter and scattering coefficient with increasing RH from 0 to 30% was observed for SOA after 14 h of reaction. We postulate that this change could be due to a change in the viscosity of the SOA from a predominantly glassy state to a predominantly liquid state

Lower Rate of Restenosis and Reinterventions With Covered vs Bare Metal Stents Following Innominate Artery Stenting

PURPOSE: To determine any difference between bare metal stents (BMS) and balloon-expandable covered stents in the treatment of innominate artery atheromatous lesions. MATERIALS AND METHODS: A multicenter retrospective study involving 13 university hospitals in France collected 93 patients (mean age 63.2±11.1 years; 57 men) treated over a 10-year period. All patients had systolic blood pressure asymmetry >15 mm Hg and were either asymptomatic (39, 42%) or had carotid (20, 22%), vertebrobasilar (24, 26%), and/or brachial (20, 22%) symptoms. Innominate artery stenosis ranged from 50% to 70% in 4 (4%) symptomatic cases and between 70% and 90% in 52 (56%) cases; 28 (30%) lesions were preocclusive and 8 (9%) were occluded. One (1%) severely symptomatic patient had a <50% stenosis. Demographic characteristics, operative indications, and procedure details were compared between the covered (36, 39%) and BMS (57, 61%) groups. Multivariate analysis was performed to determine relative risks of restenosis and reinterventions [reported with 95% confidence intervals (CI)]. RESULTS: The endovascular procedures were performed mainly via retrograde carotid access (75, 81%). Perioperative strokes occurred in 4 (4.3%) patients. During the mean 34.5±31.2-month follow-up, 30 (32%) restenoses were detected and 13 (20%) reinterventions were performed. Relative risks were 6.9 (95% CI 2.2 to 22.2, p=0.001) for restenosis and 14.6 (95% CI 1.8 to 120.8, p=0.004) for reinterventions between BMS and covered stents. The severity of the treated lesions had no influence on the results. CONCLUSION: Patients treated with BMS for innominate artery stenosis have more frequent restenoses and reinterventions than patients treated with covered stents

The Essential Role for Laboratory Studies in Atmospheric Chemistry

Laboratory studies of atmospheric chemistry characterize the nature of atmospherically relevant processes down to the molecular level, providing fundamental information used to assess how human activities drive environmental phenomena such as climate change, urban air pollution, ecosystem health, indoor air quality, and stratospheric ozone depletion. Laboratory studies have a central role in addressing the incomplete fundamental knowledge of atmospheric chemistry. This article highlights the evolving science needs for this community and emphasizes how our knowledge is far from complete, hindering our ability to predict the future state of our atmosphere and to respond to emerging global environmental change issues. Laboratory studies provide rich opportunities to expand our understanding of the atmosphere via collaborative research with the modeling and field measurement communities, and with neighboring disciplines