Air- and water-stable Lewis acids: synthesis and reactivity of P-trifluoromethyl electrophilic phosphonium cations.

A new class of electrophilic phosphonium cations (EPCs) containing a -CF3 group attached to the phosphorus(v) center is readily accessible in high yields, via a scalable process. These species are stable to air, water, alcohol and strong Brønsted acid, even at raised temperatures. Thus, P-CF3 EPCs are more robust than previously reported EPCs containing P-X moieties (X = F, Cl, OR), and despite their reduced Lewis acidity they function as Lewis acid catalysts without requiring anhydrous reaction conditions.

[Indoor air quality and adult asthma]. / Pollution de l'air intérieur et asthme chez l'adulte.

INTRODUCTION: Asthma is a chronic inflammatory disease of the airways. The recent increase in its global prevalence suggests a possible role of environmental factors such as indoor air pollution. In 2000, according to the Institute Of Medicine, there was insufficient evidence to determine whether or not an association existed between high priority indoor air pollutants, listed by the French Indoor Air Quality Observatory, and asthma. The objective of this paper is to describe the current state of knowledge on the links between exposure to high priority indoor air pollutants and exacerbations of adult asthma. METHOD: A review of the Medline database has been undertaken of the following pollutants: formaldehyde, benzene, acetaldehyde, volatile organic compounds, particles (PM2.5, PM10) and diethylhexyl-phthalate. The studies were classified by type and source of pollutant. RESULTS: Twenty-three studies were included in the analysis. Most of the observational studies have shown an association between pollutants (by type and source) and adult asthma. The best documented pollutants were formaldehyde and volatile organic compounds. No studies were found on acetaldehyde and diethylhexyl-phthalate. CONCLUSION: The analysis of the literature is complicated on account of the difficulty of comparing different studies. However, since the synthesis performed in 2000, the existence of a link between chemical indoor air pollutants and increased respiratory symptoms appears to be reinforced. It seems necessary to adopt preventive health measures while pursuing scientific research on this topic.

Renal vascular effects of stroma and stroma-free hemoglobin.

To assess the renal effects of hemoglobulin infusion, intrarenal hemodynamics were studied in 14 dogs using radioactive microspheres following the infusion of hemoglobin and stroma. Fractional renal microsphere distribution in the outer cortex remained at control levels following the infusion of hemoglobin. When the infusion of stroma followed, there was a 4.3 per cent, p less than 0.01, increase in the outer cortex microsphere distribution at the expense of the inner cortex, p less than 0.05. When the order was reversed, the stroma suspension being infused first, again there was a significant increase in the outer cortex distribution--6.1 per cent; p less than 0.01. When the infusion of hemoglobin followed, the outer cortex microsphere trapping reverted to control levels. These data revealed no effect upon intrarenal blood flow following the infusion of hemoglobin. The previously reported renal toxicity of hemoglobin infusion is, therefore, probably secondary to contamination with stroma. Hemoglobin should be further investigated for use as an ideal resuscitation fluid.

Changes in intrarenal blood flow during sepsis.

The intrarenal hemodynamics of nine dogs were studied using 15 micron diameter plastic radioactive microspheres labeled with either 85Sr or 141Ce injected before and with the alternative isotope injected 30 minutes after the induction of sepsis. Total renal microsphere trapping increased by 30.6 per cent, p less than 0.01, after the induction of sepsis. The glomerular filtration rate was unchanged. Microsphere trapping in the outer and inner cortex increased by 36.9 per cent, p less than 0.005, and by 20.3 per cent, p less than 0.05, respectively, reflecting increased renal blood flow. Fractional renal microsphere distribution in the outer cortex increased from 70.0 to 73.4 per cent, p less than 0.01, following the induction of sepsis. These data confirm that sepsis results in renal vasodilatation. In addition, a shift in intrarenal blood flow to the outer cortex was demonstrated. Since the outer cortex is perfused with blood which first passes through the inner cortex, it can be hypothesized that renal blood flow in septic states may be passing through dilated glomerular vessels unable to trap microspheres in the inner cortex or passing through precapillary open arteriovenous shunts, or both, thereby bypassing inner cortical functioning glomeruli. This may partly explain the decreased renal function associated with increased renal blood flow in septic states.