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Search Results: 1 - 10 of 14850 matches for " Christian Eckmann "
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Treatment of complicated skin and soft-tissue infections caused by resistant bacteria: value of linezolid, tigecycline, daptomycin and vancomycin
Christian Eckmann, Matthew Dryden
European Journal of Medical Research , 2010, DOI: 10.1186/2047-783x-15-12-554
Abstract: Tigecycline is an alternative in polymicrobial infections except by diabetic foot infections. Daptomycin might be a treatment option for cases of cSSTI with MRSA bacteremia. cSSTI caused by resistant Gram-negative bacteria are a matter of great concern. The development of new antibiotics in this area is an urgent priority to avoid the risk of a postantibiotic era with no antimicrobial treatment options. An individual approach for every single patient is mandatory to evaluate the optimal antimicrobial treatment regimen.Skin and soft tissue infections (SSTI) are amongst the most common bacterial infections in humans. They represent one of the most common indications for antibiotic treatment and represent about 10% of hospital admissions in the US [1]. Amongst the broad spectrum of skin and soft tissue infections treatment is mainly delivered out of hospital. SSTI have a broad range of aetiology, clinical manifestation and severity [2,3]. At one end of the spectrum the outcome may be spontaneous resolution without antibiotics, but at the other end it may present with sepsis with lethal outcome. SSTI at 10% is the third most frequent focus for severe sepsis or septic shock, after pneumonia (5560%) and abdominal infections (25%) [4].This review aims to discuss the currently available antibiotics active against resistant bacteria (primarily MRSA, VRE, ESBL-producing bacteria and carbapenem-resistant strains) in terms of mechanisms of action, eradication rates and most important clinical outcome.The classification of skin and soft tissue infections is often confusing. Specific SSTI can be sub-categorised according to the causative microbial agents, the main tissue layer affected (i.e. skin, subcutis, fascia and muscle) or according to clinical signs and symptoms. It is to be differentiated, whether the infection is localised or generalised. Useful classifications are those which differentiate SSTI according to urgency of surgical intervention [5,6]. Three categories can be
Impact of Fishing and Stocking Practices on Coregonid Diversity  [PDF]
Orlane Anneville, Emilien Lasne, Jean Guillard, Reiner Eckmann, Jason D. Stockwell, Christian Gillet, Daniel L. Yule
Food and Nutrition Sciences (FNS) , 2015, DOI: 10.4236/fns.2015.611108
Abstract: Fish species diversity can be lost through interacting stressors including habitat loss, stocking and overfishing. Although a multitude of stressors have played a role in the global decline of coregonid (Coregonus spp.) diversity, a number of contemporary studies have identified habitat loss stemming from eutrophication as the primary cause. Unfortunately, reconstructing the role of fishing and stocking practices can be difficult, because these records are incomplete or appear only in hard-to-access historic grey literature. Based on an illustrative set of historic and contemporary studies, we describe how fisheries management practices may have contributed to coregonid diversity loss in European and North American lakes. We provide case studies examining how fishing and stocking may reduce coregonid diversity through demographic decline and introgressive hybridization. In some lakes, fisheries management practices may have led to a loss of coregonid diversity well before issues with habitat degradation manifested. Our review suggests that fish conservation policies could beneficially consider the relative importance of all stressors, including management practices, as potential drivers of diversity loss.
mRNA: a complex(ed) life
Michaela Müller, Karla M Neugebauer, Christian Eckmann
Genome Biology , 2010, DOI: 10.1186/gb-2010-11-5-304
Abstract: An EMBL conference held recently in Heidelberg took on the daunting task of examining the life of mRNAs from start to finish. The assumption of the 'central dogma' is that mRNA production leads to protein expression. Yet cellular mRNA levels reflect a balance between the rates of gene transcription and mRNA degradation and translation is highly regulated. Therefore, the level of gene transcription in the cell does not necessarily correlate with encoded protein level. Throughout their lifetimes, all mRNAs exist in complexes with numerous proteins that regulate mRNA at the level of maturation, export, translation and decay. Thus, the life of each mRNA is complex(ed), enabling modulation of gene expression programs beyond promoters. This meeting provided a rare occasion to discuss both mRNA processing and translation regulation in one forum, thereby addressing the central tenets of gene expression in a holistic way. Here we present some of the highlights of the meeting.During processing in the nucleus, all eukaryotic mRNAs are modified at their 5' ends by the addition of a 7-methyl guanosine cap and are extended at their 3' ends by addition of a poly(A) tail. These features of mRNA termini are added by enzymatic reactions that are tightly coupled to transcription, ensuring the near universality of these signals, which are crucial for the life of mRNAs in the cytoplasm. Mechanisms of post-transcriptional mRNA regulation exploit the cap and poly(A) tail to control the mRNA's half-life and translational efficiency. Novel cytoplasmic regulatory mechanisms that operate through the poly(A) tail are now coming to light. Numerous microRNAs (miRNAs) repress translation in the context of Argonaute-containing RNA-silencing complexes. The conserved protein GW182 interacts with these RNA-silencing complexes and can trigger translational repression upon tethering to the mRNA. A mechanistic model of how GW182 elicits this response was proposed by Nahum Sonenberg (McGill University, M
GLS-1, a Novel P Granule Component, Modulates a Network of Conserved RNA Regulators to Influence Germ Cell Fate Decisions
Agata Rybarska,Martin Harterink,Britta Jedamzik,Adam P. Kupinski,Mark Schmid,Christian R. Eckmann
PLOS Genetics , 2009, DOI: 10.1371/journal.pgen.1000494
Abstract: Post-transcriptional regulatory mechanisms are widely used to influence cell fate decisions in germ cells, early embryos, and neurons. Many conserved cytoplasmic RNA regulatory proteins associate with each other and assemble on target mRNAs, forming ribonucleoprotein (RNP) complexes, to control the mRNAs translational output. How these RNA regulatory networks are orchestrated during development to regulate cell fate decisions remains elusive. We addressed this problem by focusing on Caenorhabditis elegans germline development, an exemplar of post-transcriptional control mechanisms. Here, we report the discovery of GLS-1, a new factor required for many aspects of germline development, including the oocyte cell fate in hermaphrodites and germline survival. We find that GLS-1 is a cytoplasmic protein that localizes in germ cells dynamically to germplasm (P) granules. Furthermore, its functions depend on its ability to form a protein complex with the RNA-binding Bicaudal-C ortholog GLD-3, a translational activator and P granule component important for similar germ cell fate decisions. Based on genetic epistasis experiments and in vitro competition experiments, we suggest that GLS-1 releases FBF/Pumilio from GLD-3 repression. This facilitates the sperm-to-oocyte switch, as liberated FBF represses the translation of mRNAs encoding spermatogenesis-promoting factors. Our proposed molecular mechanism is based on the GLS-1 protein acting as a molecular mimic of FBF/Pumilio. Furthermore, we suggest that a maternal GLS-1/GLD-3 complex in early embryos promotes the expression of mRNAs encoding germline survival factors. Our work identifies GLS-1 as a fundamental regulator of germline development. GLS-1 directs germ cell fate decisions by modulating the availability and activity of a single translational network component, GLD-3. Hence, the elucidation of the mechanisms underlying GLS-1 functions provides a new example of how conserved machinery can be developmentally manipulated to influence cell fate decisions and tissue development.
GLD-4-Mediated Translational Activation Regulates the Size of the Proliferative Germ Cell Pool in the Adult C. elegans Germ Line
Sophia Millonigg,Ryuji Minasaki equal contributor,Marco Nousch equal contributor,Christian R. Eckmann
PLOS Genetics , 2014, DOI: doi/10.1371/journal.pgen.1004647
Abstract: To avoid organ dysfunction as a consequence of tissue diminution or tumorous growth, a tight balance between cell proliferation and differentiation is maintained in metazoans. However, cell-intrinsic gene expression mechanisms controlling adult tissue homeostasis remain poorly understood. By focusing on the adult Caenorhabditis elegans reproductive tissue, we show that translational activation of mRNAs is a fundamental mechanism to maintain tissue homeostasis. Our genetic experiments identified the Trf4/5-type cytoplasmic poly(A) polymerase (cytoPAP) GLD-4 and its enzymatic activator GLS-1 to perform a dual role in regulating the size of the proliferative zone. Consistent with a ubiquitous expression of GLD-4 cytoPAP in proliferative germ cells, its genetic activity is required to maintain a robust proliferative adult germ cell pool, presumably by regulating many mRNA targets encoding proliferation-promoting factors. Based on translational reporters and endogenous protein expression analyses, we found that gld-4 activity promotes GLP-1/Notch receptor expression, an essential factor of continued germ cell proliferation. RNA-protein interaction assays documented also a physical association of the GLD-4/GLS-1 cytoPAP complex with glp-1 mRNA, and ribosomal fractionation studies established that GLD-4 cytoPAP activity facilitates translational efficiency of glp-1 mRNA. Moreover, we found that in proliferative cells the differentiation-promoting factor, GLD-2 cytoPAP, is translationally repressed by the stem cell factor and PUF-type RNA-binding protein, FBF. This suggests that cytoPAP-mediated translational activation of proliferation-promoting factors, paired with PUF-mediated translational repression of differentiation factors, forms a translational control circuit that expands the proliferative germ cell pool. Our additional genetic experiments uncovered that the GLD-4/GLS-1 cytoPAP complex promotes also differentiation, forming a redundant translational circuit with GLD-2 cytoPAP and the translational repressor GLD-1 to restrict proliferation. Together with previous findings, our combined data reveals two interconnected translational activation/repression circuitries of broadly conserved RNA regulators that maintain the balance between adult germ cell proliferation and differentiation.
Case Series of Methylene Blue Injections for the Treatment of Zygapophysial and Sacroiliac Joint Pain: Results of 5 Cases  [PDF]
Jay Parekh,Maxim Eckmann,Somayaji Ramamurthy
Open Journal of Anesthesiology (OJAnes) , 2013, DOI: 10.4236/ojanes.2013.36066
Abstract: Introduction: Shealy is credited with the use of fluoroscopy guided radiofrequency ablation (RFA) for denervation of the lumbar zygapophysial (L-Z) joint in the mid-1970’s. Peng and colleagues described the use of methylene blue (MB) injection for discogenic pain; MB may work through direct neurotoxicity or inhibition of nitric oxide synthesis. We present a retrospective case series of five patients with L-Z or SI joint pain where MB used as an alternative to RFA. Materials and Methods: This is a retrospective case series of five patients who received MB for the chemical neurolysis of either medial or/and lateral branch’s for zygapophysial or SI joint pain. All of the MB blocks were done under fluoroscopic guidance and performed in the same manner as diagnostic medial and lateral branch blocks but with care to consider the medication as neurotoxic in relation to spinal nerves. On average 1cc of 0.05% final concentration MB was injected per nerve or sacral foraminal level. Results: Four of the five patients had significant lasting pain relief. Discussion: Chemical neurolysis has potential to achieve technical success in these refractory cases of spine pain possibly due to spread over a broader area; for this same reason the procedure should be performed carefully under fluoroscopic guidance.
Case Series of Methylene Blue Injections for the Treatment of Zygapophysial and Sacroiliac Joint Pain: Results of 5 Cases  [PDF]
Jay Parekh, Maxim Eckmann, Somayaji Ramamurthy
Open Journal of Anesthesiology (OJAnes) , 2013, DOI: 10.4236/ojanes.2013.36066
Abstract:

Introduction: Shealy is credited with the use of fluoroscopy guided radiofrequency ablation (RFA) for denervation of the lumbar zygapophysial (L-Z) joint in the mid-1970’s. Peng and colleagues described the use of methylene blue (MB) injection for discogenic pain; MB may work through direct neurotoxicity or inhibition of nitric oxide synthesis. We present a retrospective case series of five patients with L-Z or SI joint pain where MB used as an alternative to RFA. Materials and Methods: This is a retrospective case series of five patients who received MB for the chemical neurolysis of either medial or/and lateral branch’s for zygapophysial or SI joint pain. All of the MB blocks were done under fluoroscopic guidance and performed in the same manner as diagnostic medial and lateral branch blocks but with care to consider the medication as neurotoxic in relation to spinal nerves. On average 1cc of 0.05% final concentration MB was injected per nerve or sacral foraminal level. Results: Four of the five patients had significant lasting pain relief. Discussion: Chemical neurolysis has potential to achieve technical success in these refractory cases of spine pain possibly due to spread over a broader area; for this same reason the procedure should be performed carefully under fluoroscopic guidance.

Non-equilibrium steady states
Jean-Pierre Eckmann
Physics , 2003,
Abstract: The mathematical physics of mechanical systems in thermal equilibrium is a well studied, and relatively easy, subject, because the Gibbs distribution is in general an adequate guess for the equilibrium state. On the other hand, the mathematical physics of {\em non-equilibrium} systems, such as that of a chain of masses connected with springs to two (infinite) heat reservoirs is more difficult, precisely because no such {\em a priori} guess exists. Recent work has, however, revealed that under quite general conditions, such states can not only be shown to exist, but are {\em unique}, using the H\"ormander conditions and controllability. Furthermore, interesting properties, such as energy flux, exponentially fast convergence to the unique state, and fluctuations of that state have been successfully studied. Finally, the ideas used in these studies can be extended to certain stochastic PDE's using Malliavin calculus to prove regularity of the process.
A Topological Glass
Jean-Pierre Eckmann
Physics , 2007, DOI: 10.1007/s10955-007-9387-9
Abstract: We propose and study a model with glassy behavior. The state space of the model is given by all triangulations of a sphere with $n$ nodes, half of which are red and half are blue. Red nodes want to have 5 neighbors while blue ones want 7. Energies of nodes with different numbers of neighbors are supposed to be positive. The dynamics is that of flipping the diagonal of two adjacent triangles, with a temperature dependent probability. We show that this system has an approach to a steady state which is exponentially slow, and show that the stationary state is unordered. We also study the local energy landscape and show that it has the hierarchical structure known from spin glasses. Finally, we show that the evolution can be described as that of a rarefied gas with spontaneous generation of particles and annihilating collisions.
Conflicting results of prenatal FISH with different probes for Down's Syndrome critical regions associated with mosaicism for a de novo del(21)(q22) characterised by molecular karyotyping: Case report
Christel Eckmann-Scholz, Stefan Gesk, Inga Nagel, Andrea Haake, Susanne Bens, Simone Heidemann, Monika Kautza, Christian Timke, Reiner Siebert, Almuth Caliebe
Molecular Cytogenetics , 2010, DOI: 10.1186/1755-8166-3-16
Abstract: Fluorescence in situ hybridisation (FISH) on uncultured amniotic fluid cells is a widely used means for the rapid prenatal diagnosis of common aneuploidies. Different commercial suppliers provide FISH assays for the detection of trisomies involving the Down syndrome critical regions (DSCR) in 21q22 which have been extensively validated in single institution series [1,2] and multicenter trials [3]. Interpretation of FISH results may be difficult if unexpected results are detected which for example can be caused by structural aberrations or mosaicism. Here we present a case in which rapid FISH screening with different commercial probes for the Down's syndrome critical regions yielded conflicting results with regard to a partial monosomy 21q. Moreover, by extensive conventional and molecular karyotyping we show this diagnostic problem to be caused by a de novo del(21)(q22) as part of a mosaic karyotype. Deletion of 21q is a rare chromosome disorder. In a recent review of 23 patients of whom reliable mapping data are available the variable phenotype depending on the deleted region became obvious [4]. Intrauterine growth retardation which was the initial presentation of the proband seems to be a constant finding.A 35-year-old woman presented at 24+0 weeks of gestation of her fourth pregnancy. She had suffered two early pregnancy losses. The third pregnancy ended in the delivery of a healthy boy. Medical and family history of the proposita and her partner were unremarkable. First trimester-screening including ultrasound and maternal serum biochemistry had been normal (adjusted risks +21 = 1:1839; +18 = 1:610; +13 = 1:3515). In the 25th week, ultrasound revealed symmetric foetal retardation with cerebral ventriculomegaly, partial agenesis of the corpus callosum, short nasal bone and hyperechogenic bowel. Therefore, amniocentesis was performed and foetal karyotyping initiated. For rapid screening for aneuploidies, FISH was performed according to standard methods on uncultur
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