Continuous monitoring of the bronchial epithelial lining fluid by microdialysis

<p>Abstract</p> <p>Background</p> <p>Contents of the epithelial lining fluid (ELF) of the bronchi are of central interest in lung diseases, acute lung injury and pharmacology. The most commonly used technique broncheoalveolar lavage is invasive and may cause lung injury. Microdialysis (MD) is a method for continuous sampling of extracellular molecules in the immediate surroundings of the catheter. Urea is used as an endogenous marker of dilution in samples collected from the ELF. The aim of this study was to evaluate bronchial MD as a continuous monitor of the ELF.</p> <p>Methods</p> <p>Microdialysis catheters were introduced into the right main stem bronchus and into the right subclavian artery of five anesthetized and normoventilated pigs. The flowrate was 2 μl/min and the sampling interval was 60 minutes. Lactate and fluorescein-isothiocyanate-dextran 4 kDa (FD-4) infusions were performed to obtain two levels of steady-state concentrations in blood. Accuracy was defined as [bronchial-MD] divided by [arterial-MD] in percent. Data presented as mean ± 95 percent confidence interval.</p> <p>Results</p> <p>The accuracy of bronchial MD was calculated with and without correction by the arteriobronchial urea gradient. The arteriobronchial lactate gradient was 1.2 ± 0.1 and FD-4 gradient was 4.0 ± 1.2. Accuracy of bronchial MD with a continuous lactate infusion was mean 25.5% (range 5.7–59.6%) with a coefficient of variation (CV) of 62.6%. With correction by the arteriobronchial urea gradient accuracy was mean 79.0% (57.3–108.1%) with a CV of 17.0%.</p> <p>Conclusion</p> <p>Urea as a marker of catheter functioning enhances bronchial MD and makes it useful for monitoring substantial changes in the composition of the ELF.</p

El primado de la categoría de la sustancia en el programa de la "lógica trascendental" de Kant

Kant; filosofía moderna; filosofía crítica; filosofía trascendental; categorías; analítica trascendental

Milton, Leibniz, and the Measure of Motion

Milton’s description of the “high capital / Of Satan and his peers,” the aptly named Pan-daemonium, leads to a memorable account of its architect’s expulsion from heaven: Men called him Mulciber; and how he fell From heaven, they fabled, thrown by angry Jove Sheer o’er the Crystal Battlements; from morn To noon he fell, from noon to dewy eve, A summer’s day; and with the setting Sun Dropped from the zenith like a falling Star, On Lemnos the Aegaean Isle: thus they relate, Erring; for he with this rebellious rout Fell long before; nor aught availed him now To have built in heaven high towers; nor did he scape By all his engines, but was headlong sent With his industrious crew to build in hell. (I: 740-751) Here, as often in Milton’s epic, time provides the measure of motion – recall, for instance, the war in heaven, which concludes with the anarchic descent of the defeated angels: “Nine days they fell; confounded Chaos roared, / And felt tenfold confusion in their fall” (VI: 871-72). Elsewhere space provides the measure of both time and stasis, as in an earlier, parallel description of the aftermath of this defeat: “Nine times the space that measures day and night / To mortal men, he with his horrid crew / Lay vanquished (I: 50-52). In these examples, falling – a continuous change in location over a duration – is measured by time’s succession, whereas the duration of immobility is imagined as spatial extension,the “space” that the fallen “lay vanquished.” Such shifting articulations of time and spaceare not surprising, since at stake are precisely motion and stasis, both of which necessarily demand relating the spatial to the temporal

Phyllosphere microbial associations improve plant reproductive success

The above-ground (phyllosphere) plant microbiome is increasingly recognized as an important component of plant health. We hypothesized that phyllosphere bacterial recruitment may be disrupted in a greenhouse setting, and that adding a bacterial amendment would therefore benefit the health and growth of host plants. Using a newly developed synthetic phyllosphere bacterial microbiome for tomato (Solanum lycopersicum), we tested this hypothesis across multiple trials by manipulating microbial inoculation of leaves and measuring subsequent plant growth and reproductive success, comparing results from plants grown in both greenhouse and field settings. We confirmed that greenhouse-grown plants have a relatively depauperate phyllosphere bacterial microbiome, which both makes them an ideal system for testing the impact of phyllosphere communities on plant health and important targets for microbial amendments as we move towards increased agricultural sustainability. We find that the addition of the synthetic microbial community early in greenhouse growth leads to an increase in fruit production in this setting, implicating the phyllosphere microbiome as a key component of plant fitness and emphasizing the role that these bacterial microbiomes likely play in the ecology and evolution of plant communities