337 research outputs found

    Midline Catheter Use in the Newborn Intensive Care Unit

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    Ongoing evaluation of current practice and incorporation of evidence based research into guidelines and protocols is a requirement for the provision of high quality, cost efficient care. Despite some literature describing observational data, midline catheters (MCs) are not an appropriate vascular access device for Newborn Intensive Care Unit (NICU) patients due to insufficient high level evidence demonstrating safety and efficacy. In addition, national guidelines for MC use in neonatal and infant patients lacks sufficient information for safe and effective use of MCs. The results of this small, online survey indicate that while some neonatal nurses and Nurse Practitioners report the use of MC use in the NICU, there is a wide range of practice pertaining to MC unit-specific protocols, competencies, success with placement, and clinician agreement of appropriate use for this vascular access device (VAD). Multicenter, randomized control trials are needed to evaluate current MC practice in the NICU, and institutions must incorporates current, evidence based practice into policies, procedures, and guidelines

    Substituent effects on the pairing and polymerase recognition of simple unnatural base pairs

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    As part of an effort to develop stable and replicable unnatural base pairs, we have evaluated a large number of unnatural nucleotides with predominantly hydrophobic nucleobases. Despite its limited aromatic surface area, a nucleobase analog scaffold that has emerged as being especially promising is the simple phenyl ring. Modifications of this scaffold with methyl and fluoro groups have been shown to impact base pair stability and polymerase recognition, suggesting that nucleobase shape, hydrophobicity and electrostatics are important. To further explore the impact of heteroatom substitution within this nucleobase scaffold, we report the synthesis, stability and polymerase recognition of nucleoside analogs bearing single bromo- or cyano-derivatized phenyl rings. Both modifications are found to generally stabilize base pair formation to a greater extent than methyl or fluoro substitution. Moreover, polymerase recognition of the unnatural base pairs is found to be very sensitive to both the position and nature of the heteroatom substituent. The results help identify the determinants of base pair stability and efficient replication and should contribute to the effort to develop stable and replicable unnatural base pairs

    Tus, an E. coli Protein, Contains Mammalian Nuclear Targeting and Exporting Signals

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    Shuttling of proteins between nucleus and cytoplasm in mammalian cells is facilitated by the presence of nuclear localization signals (NLS) and nuclear export signals (NES), respectively. However, we have found that Tus, an E. coli replication fork arresting protein, contains separate sequences that function efficiently as NLS and NES in mammalian cell lines, as judged by cellular location of GFP-fusion proteins. The NLS was localized to a short stretch of 9 amino acids in the carboxy-terminus of Tus protein. Alterations of any of these basic amino acids almost completely abolished the nuclear targeting. The NES comprises a cluster of leucine/hydrophobic residues located within 21 amino acids at the amino terminus of Tus. Finally, we have shown that purified GFP-Tus fusion protein or GFP-Tus NLS fusion protein, when added to the culture media, was internalized very efficiently into mammalian cells. Thus, Tus is perhaps the first reported bacterial protein to possess both NLS and NES, and has the capability to transduce protein into mammalian cells

    Operative Management of Symptomatic, Metachronous Carotid Body Tumors Involving the Skull Base and Its Neurological Sequelae

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    A 44-year-old morbidly obese woman with a history of right carotid body tumor (CBT) resection presented with a symptomatic, nonfunctional, left Shamblin-III CBT. Abutment of the skull base precluded distal internal carotid artery control for arterial reconstruction, favoring parent vessel sacrifice after an asymptomatic provocative test. She underwent CBT resection with anticipated sacrifice of cranial nerves X and XII and the common carotid artery and its branches, developing baroreceptor failure syndrome and sequelae of cranial nerve sacrifice. When facing a symptomatic, metachronous CBT abutting the skull base, upfront operative intervention with adjuvant radiation for residual tumor optimizes curative resection

    Assessing the Emergence of Resistance: The Absence of Biological Cost In Vivo May Compromise Fosfomycin Treatments for P. aeruginosa Infections

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    BACKGROUND: Fosfomycin is a cell wall inhibitor used efficiently to treat uncomplicated urinary tract and gastrointestinal infections. A very convenient feature of fosfomycin, among others, is that although the expected frequency of resistant mutants is high, the biological cost associated with mutation impedes an effective growth rate, and bacteria cannot offset the obstacles posed by host defenses or compete with sensitive bacteria. Due to the current scarcity of new antibiotics, fosfomycin has been proposed as an alternative treatment for other infections caused by a wide variety of bacteria, particularly Pseudomonas aeruginosa. However, whether fosfomycin resistance in P. aeruginosa provides a fitness cost still remains unknown. PRINCIPAL FINDINGS: We herein present experimental evidence to show that fosfomycin resistance cannot only emerge easily during treatment, but that it is also cost-free for P. aeruginosa. We also tested if, as has been reported for other species such as Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis, fosfomycin resistant strains are somewhat compromised in their virulence. As concerns colonization, persistence, lung damage, and lethality, we found no differences between the fosfomycin resistant mutant and its sensitive parental strain. The probability of acquisition in vitro of resistance to the combination of fosfomycin with other antibiotics (tobramycin and imipenem) has also been studied. While the combination of fosfomycin with tobramycin makes improbable the emergence of resistance to both antibiotics when administered together, the combination of fosfomycin plus imipenem does not avoid the appearance of mutants resistant to both antibiotics. CONCLUSIONS: We have reached the conclusion that the use of fosfomycin for P. aeruginosa infections, even in combined therapy, might not be as promising as expected. This study should encourage the scientific community to assess the in vivo cost of resistance for specific antibiotic-bacterial species combinations, and therefore avoid reaching universal conclusions from single model organisms

    Heterogenisation of ketone catalysts within mesoporous supports for asymmetric epoxidation

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    The synthesis of the first mesoporous silica (150 Γ…) anchored carbohydrate-derived chiral ketone is described. This new heterogeneous catalyst has been shown to be effective in the asymmetric epoxidation of olefins by oxone. The heterogeneous ketone catalyst has comparable activity to that of its homogeneous counterpart and returned enantioselectivities up to 90% e.e

    A hetero-alkali-metal version of the utility amide LDA : lithium-potassium diisopropylamide

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    Designed to extend the synthetically important alkali-metal diisopropylamide [(NPr2)-Pr-i; DA] class of compounds, the first example of a hetero-alkali-metallic complex of DA has been prepared as a partial TMEDA solvate. Revealed by an X-ray crystallographic study, its structure exists as a discrete lithium-rich trinuclear Li2KN3 heterocycle, with TMEDA only solvating the largest of the alkali-metals, with the two-coordinate lithium atoms being close to linearity [161.9(2)degrees]. A variety of NMR spectroscopic studies, including variable temperature and DOSY NMR experiments, suggests that this new form of LDA maintains its integrity in non-polar hydrocarbon solution. This complex thus represents a rare example of a KDA molecule which is soluble in non-polar medium without the need for excessive amounts of solubilizing Lewis donor being added

    The Obligation of Physicians to Medical Outliers: A Kantian and Hegelian Synthesis

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    Background Patients who present to medical practices without health insurance or with serious co-morbidities can become fiscal disasters to those who care for them. Their consumption of scarce resources has caused consternation among providers and institutions, especially as it concerns the amount and type of care they should receive. In fact, some providers may try to avoid caring for them altogether, or at least try to limit their institutional or practice exposure to them. Discussion We present a philosophical discourse, with emphasis on the writings of Immanuel Kant and G.F.W. Hegel, as to why physicians have the moral imperative to give such outliers considerate and thoughtful care. Outliers are defined and the ideals of morality, responsibility, good will, duty, and principle are applied to the care of patients whose financial means are meager and to those whose care is physiologically futile. Actions of moral worth, unconditional good will, and doing what is right are examined. Summary Outliers are a legitimate economic concern to individual practitioners and institutions, however this should not lead to an evasion of care. These patients should be identified early in their course of care, but such identification should be preceded by a well-planned recognition of this burden and appropriate staffing and funding should be secured. A thoughtful team approach by medical practices and their institutions, involving both clinicians and non-clinicians, should be pursued

    Mesofluidic Devices for DNA-Programmed Combinatorial Chemistry

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    Hybrid combinatorial chemistry strategies that use DNA as an information-carrying medium are proving to be powerful tools for molecular discovery. In order to extend these efforts, we present a highly parallel format for DNA-programmed chemical library synthesis. The new format uses a standard microwell plate footprint and is compatible with commercially available automation technology. It can accommodate a wide variety of combinatorial synthetic schemes with up to 384 different building blocks per chemical step. We demonstrate that fluidic routing of DNA populations in the highly parallel format occurs with excellent specificity, and that chemistry on DNA arrayed into 384 well plates proceeds robustly, two requirements for the high-fidelity translation and efficient in vitro evolution of small molecules
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