A colorimetric nanosensor based on a selective target-responsive aptamer kissing complex.

Herein, we report a novel approach for the design of a colorimetric aptasensor based on functionalized gold nanoparticle probes. This approach relies on the conjugation of nanoparticles by two functional DNA and RNA hairpins that engage specific kissing (loop-loop) interactions in response to the addition of a small analyte ligand, leading to particle aggregation and then red-to-purple colour change of the colloidal solution.

One-year clinical outcome after primary stenting for Trans-Atlantic Inter-Society Consensus (TASC) C and D femoropopliteal lesions (the STELLA "STEnting Long de L'Artère fémorale superficielle" cohort).

OBJECTIVE: The study aims to evaluate the safety and the efficacy of primary stenting for Trans-Atlantic Inter-Society Consensus Document II on Management of Peripheral Arterial Disease (TASC) C and D femoropopliteal lesions. DESIGN: Prospective cohort study. METHODS: Patients with TASC C and D de novo femoropopliteal lesions were treated with the same endovascular technique by implanting a primary nitinol self-expanding stent (LifeStent(®), Bard Peripheral Vascular, Tempe, AZ, USA). Patients were included in a single-centre registry and prospectively followed up. The primary end point was primary sustained clinical improvement after 12 months. Secondary end points were secondary sustained clinical improvement, primary and secondary patency rates, freedom from target lesion revascularisation (TLR), freedom from target extremity revascularisation (TER) and stent fracture rate. RESULTS: We enrolled 58 patients (62 limbs) suffering from either claudication (40.3%) or critical limb ischaemia (59.7%). Lesions were either TASC C (62.9%) or TASC D (37.1%). Median length of the treated segment was 220 ± 160 mm. The mean number of stents was 2.2. Mean follow-up was 17 months, with one patient lost to follow-up. At 1 year, the primary end point was 68.6% while secondary sustained clinical improvement was 82.6%. Freedom from TLR and TER rates were 81.1% and 96.3%. Primary and secondary patencies were 66% and 80.9%. One-year primary and secondary sustained clinical improvement rates were 76.7% ± 7.2 for TASC C and 46.3% ± 11.1 for TASC D (p = 0.03) and 87.6% ± 5.9 for TASC C and 67.3% ± 11.3 for TASC D (p = 0.09), respectively. The ankle-brachial pressure index increased from 0.58 to 0.94 (p = 0.001) at 1 year and the incidence of in-stent restenosis (ISR) was 19.3%. Stent fracture and disconnection rate was 17.7%. CONCLUSIONS: Primary stenting of TASC C and D lesions appears to be safe and efficient given the high-sustained clinical improvement and the low rate of ISR observed in our study. Endovascular treatment of such long and severe lesions exposes to high rate of stent fractures, which should not be a concern given their low clinical impact.

Endovascular repair of common femoral artery and concomitant arterial lesions.

OBJECTIVE: The common femoral artery (CFA) is an unusual location for endovascular repair (ER). We report the early results after ER of the CFA in a single centre. DESIGN: This is a cohort study. MATERIALS/METHODS: From 2006 to 2008, ER of the CFA was proposed to 36 patients (mean age 67.9, range 51-92). CFA lesions were classified into four types: in type I, lesions were located at the iliac external artery and were extended to the CFA; in type II, lesions were limited to the CFA; in type III, lesions were located at the CFA and its bifurcation; type IV represents restenosis bypass anastomosis. All patients were treated by stenting. RESULTS: Indications for ER of the CFA included 25 patients (70%) for claudication and 11 patients (30%) for critical limb ischaemia. Forty-three stents were implanted. The mean follow-up was 22 months (range, 12-42). At 1 year, primary and secondary sustained clinical improvements were 80% and 90%; target lesion revascularisation and target extremity revascularisation free cumulative survival were 85% and 80%, respectively, and in-stent restenosis rate was 20%. One stent fracture was noted. CONCLUSIONS: ER of CFA and concomitant arterial lesions seems to be a safe technique with acceptable clinical outcome at 1 year.

Does phosphoryl protonation occurs in aqueous phosphoesters solutions.

Ionisation of trimethylphosphate (TMP), dimethylphosphate (DMP) and diethylphosphate (DEP) is investigated by acidic titration in water by Raman (R), Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopies. The vibrational frequencies of the PO(2)(-) ionic form and the neutral form were found in accord with the literature. While increasing further H(+) concentration, the PO band disappears in the benefit of new ones. These results, together with deuteration experiments indicate the presence of a new ionic form positively charged with general formula R(1)R(2)R(3)P(OH)(+) or R(1)R(2)P(OH)(+)(2). The pK of this phosphonium entities is lying in the range -2, -4. These results were confirmed by (31)P NMR titration. The occurrence of such a phosphonium ion in aqueous solutions might be of crucial importance for biochemical reactions and interactions, owing to the large spread of phosphoryl group in biomolecules and keeping in mind that intracellular compartments are more likely concentrated media with little free water than real aqueous solutions. Furthermore, pK's can be shifted by physical-chemical parameters like dielectric constant and electric field. This may involve at least fractional positive charge apparition that might be important in biochemical regulation by charge-charge and charge-dipole interactions. This finding will gain to be further explored on more complex molecules like phospholipids, nucleic acids and proteins.

Chemical and enzymatic synthesis of fructose analogues as probes for import studies by the hexose transporter in parasites.

Various D-fructose analogues modified at C-1 or C-6 positions were synthesized from D-glucose by taking advantage of the Amadori rearrangement or using the aldol condensation between dihydroxyacetone phosphate and appropriate aldehyde catalyzed by fructose 1,6-diphosphate aldolase from rabbit muscle. The affinities of the analogues for the glucose transporter expressed in the mammalian form of Trypanosoma brucei were determined by inhibition of radiolabelled 2-deoxy-D-glucose (2-DOG) transport using zero-trans kinetic analysis. Interestingly, the analogues bearing an aromatic group (i.e. a fluorescence marker) at C-1 or C-6 positions present comparable apparent affinities to D-fructose for the transporter. This result could find applications for hexose transport studies and also provides criteria for the design of glucose import inhibitors.

An easy stereospecific synthesis of 1-amino-2,5-anhydro-1-deoxy-D-mannitol and arylamino derivatives.

1-Amino-2,5-anhydro-1-deoxy-D-mannitol and a series of arylamino derivatives were prepared by nitrous acid deamination of 2-amino-2-deoxy-D-glucose and subsequent reductive amination of the resulting 2,5-anhydro-D-mannose. Some of these compounds showed an enhanced affinity for the hexose transporter of Trypanosoma brucei as compared to D-fructose.