Search

IntroductionThe purpose of this study was to determine the earliest timing of inguinal hernia repair under general anesthesia with minimized risk for respiratory complications during postoperative course.MethodsWe performed a monocentric analysis of patient records of premature and full-term infants undergoing inguinal hernia repair between 2009 and 2016. In addition to demographic and medical parameters, preexisting conditions and the perioperative course were recorded.ResultsThe study included 499 infants (preterm n = 285; full term n = 214). The number of subsequently ventilated patients was particularly high among preterm infants with bronchopulmonary dysplasia, up to 45.3% (p < 0.001). Less than 10% of subsequent ventilation occurred in preterm infants after 45 weeks of postmenstrual age at the time of surgery or in patients with a body weight of more than 4,100 g. Preterm infants with a bronchopulmonary dysplasia had an increased risk of apneas (p < 0.05). Only 10% of the preterm babies with postoperative apneas weighed more than 3,600 g at the time of surgery or were older than 44 weeks of postmenstrual age.ConclusionOur data indicate that after the 45th week of postmenstrual age and a weight above 4,100 g, the risk for respiratory failure after general anesthesia seems to be significantly decreased in preterm infants.

We report on the presence of a functional hydroxyectoine biosynthesis gene cluster, ectABCD-ask , in Pseudomonas stutzeri DSM5190 T and evaluate the suitability of P. stutzeri DSM5190 T for hydroxyectoine production. Furthermore, we present information on heterologous de novo production of the compatible solute hydroxyectoine in Escherichia coli . In this host, the P. stutzeri gene cluster remained under the control of its salt-induced native promoters. We also noted the absence of trehalose when hydroxyectoine genes were expressed, as well as a remarkable inhibitory effect of externally applied betaine on hydroxyectoine synthesis. The specific heterologous production rate in E. coli under the conditions employed exceeded that of the natural producer Pseudomonas stutzeri and, for the first time, enabled effective hydroxyectoine production at low salinity (2%), with the added advantage of simple product processing due to the absence of other cosolutes.

The foliar pathogen Pseudomonas syringae pv. syringae exhibits an exceptional ability to survive on asymptomatic plants as an epiphyte. Intermittent wetting events on plants lead to osmotic and matric stresses which must be tolerated for survival as an epiphyte. In this study, we have applied bioinformatic, genetic, and biochemical approaches to address water stress tolerance in P. syringae pv. syringae strain B728a, for which a complete genome sequence is available. P. syringae pv. syringae B728a is able to produce the compatible solutes betaine, ectoine, N -acetylglutaminylglutamine amide (NAGGN), and trehalose. Analysis of osmolyte profiles of P. syringae pv. syringae B728a under a variety of in vitro and in planta conditions reveals that the osmolytes differentially contribute to water stress tolerance in this species and that they interact at the level of transcription to yield a hierarchy of expression. While the interruption of a putative gene cluster coding for NAGGN biosynthesis provided the first experimental evidence of the NAGGN biosynthetic pathway, application of this knockout strain and also a gfp reporter gene fusion strain demonstrated the small contribution of NAGGN to cell survival and desiccation tolerance of P. syringae pv. syringae B728a under in planta conditions. Additionally, detailed investigation of ectC , an orphan of the ectoine cluster (lacking the ectA and ectB homologs), revealed its functionality and that ectoine production could be detected in NaCl-amended cultures of P. syringae pv. syringae B728a to which sterilized leaves of Syringa vulgaris had been added.

Successful companies use business processes for the transfer of long-term strategies in operational workflows. The modeling approach presented in this chapter shows how strategic objectives of a company can be combined with the S-BPM modeling notation. The new modeling approach is used in two case studies. First, redesign rules for the strategic optimization of workflow models are demonstrated in the case of the customer support processes of an international enterprise. A second case study introduces a company-wide monitoring system through the example of the product development process of a multinational company from Germany.

Background Sodium/proton-antiporters (Nha) are known to play an important role in pH- and Na+-homeostasis. In microorganisms several types with different capacity, affinity and selectivity for Na+ and Li+ exist. The homeostasis system of E. coli, NhaA and NhaB, is well researched, but the function of other types of Na+/H+-antiporters like NhaD is yet to be fully understood. Since several antiporters play an important role at various points in the physiology of higher organisms, one can speculate that the main functions of some of those procaryotic antiporters differ from pH- and Na+-homeostasis. Results This study investigates the function and regulation of a gene encoding for a NhaD type antiporter which was discovered in the halophilic eubacterium Halomonas elongata. The deduced primary amino acid sequence of the abovementioned gene showed more than 60% identity to known antiporters of the NhaD type from Alkalimonas amylolytica, Shewanella oneidensis and several other marine organisms of the γ-Proteobacteria. Evidence was found for a dual regulation of H. elongata NhaD expression. The gene was cloned and expressed in E. coli. Antiporter deficient NaCl and LiCl sensitive E. coli mutants EP432 and KNabc were partially complemented by a plasmid carrying the H. elongata nhaD gene. Surprisingly the LiCl sensitivity of E. coli strain DH5α having a complete homeostasis system was increased when NhaD was co-expressed. Conclusion Since NhaD is an antiporter known so far only from halophilic or haloalcaliphilic Proteobacteria one can speculate that this type of antiporter provides a special mechanism for adaptation to marine habitats. As was already speculated – though without supporting data – and substantiated in this study this might be active Na+-import for osmoregulatory purposes.

Compatible solutes are small organic osmolytes including but not limited to sugars, polyols, amino acids, and their derivatives. They are compatible with cell metabolism even at molar concentrations. A variety of organisms synthesize or take up compatible solutes for adaptation to extreme environments. In addition to their protective action on whole cells, compatible solutes display significant effects on biomolecules in vitro. These include stabilization of native protein and nucleic acid structures. They are used as additives in polymerase chain reactions to increase product yield and specificity, but also in other nucleic acid and protein applications. Interactions of compatible solutes with nucleic acids and protein-nucleic acid complexes are much less understood than the corresponding interactions of compatible solutes with proteins. Although we may begin to understand solute/nucleic acid interactions there are only few answers to the many questions we have. I summarize here the current state of knowledge and discuss possible molecular mechanisms and thermodynamics.

Background Sodium/proton-antiporters (Nha) are known to play an important role in pH- and Na+-homeostasis. In microorganisms several types with different capacity, affinity and selectivity for Na+ and Li+ exist. The homeostasis system of E. coli, NhaA and NhaB, is well researched, but the function of other types of Na+/H+-antiporters like NhaD is yet to be fully understood. Since several antiporters play an important role at various points in the physiology of higher organisms, one can speculate that the main functions of some of those procaryotic antiporters differ from pH- and Na+-homeostasis.

The sensitivity of a nitroxide spin label to the polarity of its environment has been used to estimate the hydrophobic barrier of the proton channel of the transmembrane proton pump bacteriorhodopsin. By means of site-specific mutagenesis, single cysteine residues were introduced at 10 positions located at the protein surface, in the protein interior, and along the proton pathway. After reaction with a methanethiosulfonate spin label, the principle values of the hyperfine tensor A and the g-tensor were determined from electron paramagnetic resonance spectra measured at 170K. The shape of the hydrophobic barrier of the proton channel is characterized in terms of a polarity index, ΔA, determined from the variation of the hyperfine coupling constant Azz. The maximum of the hydrophobic barrier is found to be close to the retinal chromophore in the proton uptake pathway. The effect of the asymmetric distribution of charged and polar residues in the proton release and uptake pathways is clearly reflected in the behavior of the hydrophobic barrier. The presence of azide reduces the barrier height of both the cytoplasmic and extracellular channels. This finding supports the view of azide and other weakly acidic anions as catalysts for the formation of hydrogen-bonded networks in proton pathways of proteins.