Photolysis of CF3CH2CHO in the presence of O2 at 248 and 266 nm: quantum yields, products, and mechanism.

Three different detection techniques, coupled to pulsed laser photolysis (PLP), have been employed to determine the quantum yields of CF3CH2CHO at 248 and 266 nm: CF3CH2CHO + hν → CF3CH2 + HCO (R1a), CF3CH2CHO + hν → CF3CH3 + CO (R1b), and CF3CH2CHO + hν → CF3CH2O + H (R1c). (a) In the presence of air, Fourier transform infrared (FTIR) spectroscopy was employed at a total pressure of 760 Torr to monitor and quantify the loss of CF3CH2CHO at both wavelengths as well as the build-up of formed products (CO, CF3CH3, CF3CHO, and CF3CH2OH) after various laser pulses. Cyclohexane was added as OH-scavenger in most experiments. CF3CH3 was observed and quantified at both wavelengths, confirming that channel R1b is occurring. Small amounts of HCOOH and COF2 were also detected. (b) Time-resolved cw-cavity ring down spectroscopy (cw-CRDS) at 40 Torr He coupled to photolysis at 248 nm was employed for the detection of HO2 radicals. Varying the O2 concentration allows distinguishing the origin of the HO2 radicals from either R1a or R1c. OH radicals were simultaneously detected by laser-induced fluorescence. (c) Time-resolved tunable diode laser absorption spectroscopy (TDLAS) at 30 Torr N2 coupled to photolysis at 266 nm was employed for the determination of the quantum yields of CO. By varying the O2 concentration, a distinction can be achieved between the yields of prompt CO R1b or decomposition of highly excited CF3CH2CO from R1c and HCO radicals R1a. Channel R1a has been identified as the major reaction path. The overall quantum yield, Φλ(CF3CH2CHO), at 248 nm was found as Φ248nm = (0.76 ± 0.14) and (0.73 ± 0.20) from cw-CRDS and FTIR experiments, respectively. At 266 nm, the overall quantum yield was found as Φ266nm = (0.55 ± 0.10) and (0.47 ± 0.10) from TDLAS and FTIR experiments, respectively.

The reduced osteogenic potential of Nf1-deficient osteoprogenitors is EGFR-independent.

Neurofibromatosis type 1 (NF1) is a common genetic disorder caused by mutations in the NF1 gene. Recalcitrant bone healing following fracture (i.e. pseudarthrosis) is one of the most problematic skeletal complications associated with NF1. The etiology of this condition is still unclear; thus, pharmacological options for clinical management are limited. Multiple studies have shown the reduced osteogenic potential of Nf1-deficient osteoprogenitors. A recent transcriptome profiling investigation revealed that EREG and EGFR, encoding epiregulin and its receptor Epidermal Growth Factor Receptor 1, respectively, were among the top over-expressed genes in cells of the NF1 pseudarthrosis site. Because EGFR stimulation is known to inhibit osteogenic differentiation, we hypothesized that increased EREG and EGFR expression in NF1-deficient skeletal progenitors may contribute to their reduced osteogenic differentiation potential. In this study, we first confirmed via single-cell mRNA sequencing that EREG over-expression was associated with NF1 second hit somatic mutations in human bone cells, whereas Transforming Growth Factor beta 1 (TGFß1) expression was unchanged. Second, using ex-vivo recombined Nf1-deficient mouse bone marrow stromal cells (mBMSCs), we show that this molecular signature is conserved between mice and humans, and that epiregulin generated by these cells is overexpressed and active, whereas soluble TGFß1 expression and activity are not affected. However, blocking either epiregulin function or EGFR signaling by EGFR1 or pan EGFR inhibition (using AG-1478 and Poziotinib respectively) did not correct the differentiation defect of Nf1-deficient mBMSCs, as measured by the expression of Alpl, Ibsp and alkaline phosphatase activity. These results suggest that clinically available drugs aimed at inhibiting EGFR signaling are unlikely to have a significant benefit for the management of bone non-union in children with NF1 PA.

[Is coronary artery spasm a disease specific to women?] / Spasme coronaire, une pathologie de la femme ?

Vasospastic angina is considered rare in Europe but with a prevalence probably underestimated and affects preferentially men in published studies, mostly involving Asian populations. Vasospastic angina in the female population have specificities in terms of pathophysiology, clinical presentation and prognosis, as well as diagnostic strategies currently recommended, that we describe from a clinical case. Although known for over 50years, vasospastic angina remains a disease still insufficiently researched, probably even less in women. This form of angina must not however be forgotten, and the appropriate diagnostic strategy must be known and used to improve prognosis.

Usefulness of pulmonary regurgitation Doppler tracings in predicting in-hospital and long-term outcome in patients with inferior wall acute myocardial infarction.

Right ventricular (RV) involvement is frequent during inferior wall acute myocardial infarction (AMI) and has been reported as a risk factor for in-hospital morbidity and mortality. The objectives of the present study were: (1) to evaluate in-hospital events in patients with and without RV involvement as diagnosed by abnormal flow characteristics derived from pulmonary regurgitation (PR) analysis (pressure half-time of PR, PHT(PR) < or = 150 ms and the lowest mid-diastolic to peak early diastolic velocity ratio, Vmin/Vmax < or = 0.5); and (2) to determine the influence of RV involvement in complications at long-term follow-up. Among 126 consecutively admitted patients with inferior wall AMI (mean age, 58 +/- 13 years), 101 had PR. We determined the prognostic significance of in-hospital and long-term events for the following variables: age > or = 65 years, ST-segment elevation > or = 1 mm in lead V4R, RV dilation, PHT of PR < or = 150 ms and Vmin/Vmax < or = 0.5, thrombolytic therapy, 3-vessel disease, and diabetes mellitus. We found that the PR derived Doppler index (PHT of PR < or = 150 ms and Vmin/Vmax < or = 0.5) was the only predictor of overall in-hospital clinical events (hazards ratio, 2.7, 95% confidence interval, 1.2 to 6.1, p = 0.016). At long-term follow-up (mean: 20 +/- 12 months, range 12 to 69), event-free survival analysis showed that age > or = 65 years was the only predictor of any event (relative risk, 3.7, 95% confidence interval, 2.1 to 6.3, p < 0.0001). Thus, RV involvement diagnosed with the use of PR flow-derived variables is an accurate and independent predictor of in-hospital complications. However, RV involvement does not influence long-term prognosis.

[Diagnostic strategy in acute myocarditis]. / Conduite diagnostique dans les myocardites aiguës.

Myocarditis is a focalised or diffuse disease of the myocardium. The principal causal agents are viruses in Europe and North America and a parasite in South America (Chagas' disease). The prevalence of acute myocarditis is variable, related to the periodic cycle of viral epidemics. The diagnosis is difficult to establish because the clinical presentation is variable, ranging from asymptomatic forms to rapidly fatal acute congestive heart failure. The diagnostic tools suffer from lack of sensitivity or specificity. Endomyocardial biopsy, despite its low sensitivity, remains the reference investigation as it provides histological proof of the myocarditis. Myocardial scintigraphy with antimyosin antibodies has the advantage of very good sensitivity but with less specificity. The authors discuss the critical indications and limitations of each investigation.

[Anaphylactic shock from an iodine contrast medium: role of the allergy check-up in one case]. / Choc anaphylactique à un produit de contraste iodé : intérêt du bilan allergologique à propos d'un cas.

Anaphylactoid reactions to iodine contrast media are rare but serious, possibly life-threatening and calling an appropriate and urgent care. The physiopathological mechanism of these reactions remains to be fully elucidated. This reaction is still mostly called "pseudoallergic" in the literature. However, recent papers emphasise that a true allergic process is more frequent than previously expected. They also insist on the interest of running allergy tests including skin testing. We report the case of an anaphylactic shock to iodine contrast media, occurring during coronary angiography. We performed an allergy check-up and found the culprit allergen. We also evidenced a cross-reaction to another contrast media from the similar group. On the other hand, there was no reaction to contrast media of other types. With these results, another coronary angiography could be performed without any adverse event. When hypersensitivity reactions to iodine contrast media occur, it is mandatory to perform a complete allergy check-up. This will help determine the precise mechanism of the reaction and find the culprit allergen.

[Variant angina: what to think in 2011?]. / Angor spastique : quel regard en 2011 ?

Spastic angina is considered rare but its prevalence is probably underestimated especially in case of atherosclerotic coronary lesions. Its diagnosis remains important due to its poor prognosis and therapeutic characteristics. We report three clinical cases illustrating two different clinical presentations and the problem of diagnosis of spastic angina. We performed a review of the literature essentially concerning commonly used diagnosis means and especially provocative testing for coronary spasm. This test needs to be adapted to the evolution of techniques and uses of coronary angiography in 2011, particularly the wide spread use of radial approach. Therefore new recommendations are needed, specifying the terms of provocative testing and establishing clear diagnosis criteria including clinical, electrocardiographic and angiographic data. Such guidelines would probably help to better diagnose and treat these patients in our practice.

Micronutrient distribution in 16-year-old maritime pine.

Concentrations and contents of the micronutrients Fe, Mn, Zn, Cu, and B were measured in various tree compartments of a 16-year-old stand of maritime pine (Pinus pinaster Soland in Ait.). The micronutrients were actively redistributed within the tree. The longer-lived aerial tissues, trunks and branches, constituted the major micronutrient reservoirs, with the exception of manganese which accumulated in the needles.

Pressure-Induced Frequency Lineshifts in the nu2 Band of Ammonia: An Experimental Test of the Rydberg-Ritz Principle.

Self-induced frequency lineshifts of NH3 in the nu2 band have been measured for low J and K values. By combination with lineshift parameters previously published for other frequency ranges, it is possible to consider several level manifolds connected by superabundant numbers of transitions. Using statistical tests, these results lead to a quite meaningful experimental confirmation of the nonadditivity of pressure lineshifts, that is, the Rydberg-Ritz combination principle cannot be extended to collisionally perturbed systems. Copyright 1999 Academic Press.

Rotational Analysis of the nu(7) Band in Furan (C(4)H(4)O).

We recorded and analyzed the absorption spectrum of the nu(7) fundamental band in furan, observed around 995 cm(-1). Fourier transform (FT) spectroscopy was used at ULB to record the spectrum under room-temperature conditions, at 0.01 cm(-1) instrumental resolution. Diode-laser (DL) spectroscopy in a supersonic jet was used to record some portions of the band at Lille, revealing the fine structure around the band center. Pure rotation (MMW) data in the upper state were also recorded at Lille. Some 5559 FT, 101 DL, and 23 MMW data were assigned in this work. We fitted, on one hand, the MMW and DL data together and, on the other hand, the MMW, DL, and FT data simultaneously using a weighted procedure, constraining the ground state constants to their value determined from the microwave data in the literature. The results from these fits are provided and the constants discussed. Ab initio calculations are also performed to provide a force field which is used to support the very strong increase with the vibrational excitation observed in the inertial defect determined from the experimental rotational constants. Copyright 1999 Academic Press.