Functional analysis of genes involved in the biosynthesis of isoprene in Bacillus subtilis

In comparison to other bacteria Bacillus subtilis emits the volatile compound isoprene in high concentrations. Isoprene is the smallest representative of the natural product group of terpenoids. A search in the genome of B. subtilis resulted in a set of genes with yet unknown function, but putatively involved in the methylerythritol phosphate (MEP) pathway to isoprene. Further identification of these genes would give the possibility to engineer B. subtilis as a host cell for the production of terpenoids like the valuable plant-produced drugs artemisinin and paclitaxel. Conditional knock-out strains of putative genes were analyzed for the amount of isoprene emitted. Differences in isoprene emission were used to identify the function of the enzymes and of the corresponding selected genes in the MEP pathway. We give proof on a biochemical level that several of these selected genes from this species are involved in isoprene biosynthesis. This opens the possibilities to investigate the physiological function of isoprene emission and to increase the endogenous flux to the terpenoid precursors, isopentenyl diphosphate and dimethylallyl diphosphate, for the heterologous production of more complex terpenoids in B. subtilis

Using 4D CAD to visualize the impacts of highway construction on the public

Highway construction activities have a multitude of impacts on the public that change over time and with location. In devising strategies to manage and minimize these impacts, gaining an in-depth understanding about timing and spatial extents of them is crucial. However, in practice gaining such understanding is difficult due to the complex and varying nature of the impacts. To support project planners with understanding a highway construction project's impacts upfront, we developed a 4D modeling method that visualizes the most important attributes of the impacts on the public, namely their spatial extents and their progression over time. By applying the method to support a Dutch highway expansion project, we show that, compared to 2D methods, the proposed 4D modeling method provides an integral perspective of the spatial changes of the project impacts over time that allows for the evaluation of various scenarios with relative ease

Flow-volumes indices as means to discriminate between intra- and extrapulmonary restrictive disease.

Contains fulltext : 47863.pdf (publisher's version ) (Closed access)Restrictive lung disease comes in two major categories: (1) intrapulmonary (= parenchymal) disease caused by fibrotic reactions or (2) extrapulmonary (= compression), like in heart failure. In the first category the conducting airways, tethered in stiffened structures, are less likely to be compressed during forceful expiration and expiratory flows hence are expected to remain high. This could serve as a cheap and easy diagnostic, avoiding more complicated measures. A database was build containing 624 patients suffering from either intra- and extrapulmonary disease. The flow-volume curve indices of restrictive patients (with a total lung capacity 0.05). The area under the ROC to discriminate extra- from intrapulmonary disease was a low 0.607 and 0.606 for the PEF and MEF75, respectively. For the peakflow an optimal cut-off point was found at 65.8% of the reference value. The positive/negative predictive value of a peakflow < 65.8% to detect extrapulmonary disease was 30.1% and 82.2%, respectively

Urinary pharmacokinetic methodology to determine the relative lung availability of inhaled beclometasone

Background: Urinary pharmacokinetic methods have been identified to determine the relative lung and systemic bioavailability after an inhalation. We have extended this methodology to inhaled beclometasone dipropionate (BDP). Methods: Ethical approval was obtained and all subjects gave consent. Twelve healthy- volunteers received randomised doses, separated by >7 days, of 2000µg BDP solution with (OralC) and without (Oral) 5g oral charcoal, ten 100µg inhalations from a Qvar® Easibreathe metered dose inhaler (pMDI) with (QvarC) and without (Qvar) oral charcoal and eight 250µg inhalations from a Clenil® pMDI (Clenil). Subjects provided urine samples at 0, 0.5, 1, 2, 3, 5, 8, 12, and 24 hours post study dose.Urinary concentrations of BDP and its metabolites, beclometasone -17- monopropionate (BMP) and beclometasone (BOH) were measured. Results: No BDP, BMP, or BOH was detected in any samples post OralC dosing. Post oral dosing no BDP was detected in all urine samples and no BMP or BOH was excreted in the first 30 minutes. Significantly more (p < 0.001) BDP, BMP and BOH was excreted in the first 30 minutes and cumulative 24 urinary excretions post Qvar and Clenil compared to Oral. Using 30 minute urinary excretion the mean ratio (90% confidence interval) for Qvar compared to Clenil was 231.4 (209.6, 255.7). Conclusions: The urinary pharmacokinetic methodology to determine the relative lung and systemic bioavailability post inhalation, using 30 minute and pooled 24 hour post inhalation samples, applies to BDP. The ratio between Qvar and Clenil is consistent with related clinical and gamma scintigraphy lung deposition studies