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We investigated consequences of resistance acquisition in Escherichia coli clinical isolates during anaerobic (continuous culture) growth and examined their sensitivity to butyrate, a hallmark metabolite of healthy gut microbiota. Strains were stratified based on carrying either a carbapenemase (CARB) or displaying porin malfunctioning (POR). POR displayed markedly altered growth efficiencies, lower membrane stability and increased sensitivity to butyrate compared with CARB. Major differences in global gene expression between the two groups during anaerobic growth were revealed involving increased expression of alternative substrate influx routes, the stringent response and iron acquisition together with lower expression of various stress response systems in POR. Longitudinal analyses during butyrate wash-in showed common responses for all strains as well as specific features of POR that displayed strong initial "overshoot" reactions affecting various stress responses that balanced out over time. Results were partly reproduced in a mutant strain verifying porin deficiencies as the major underlying mechanism for results observed in clinical isolates. Furthermore, direct competition experiments confirmed butyrate as key for amplifying fitness disadvantages based on porin malfunctioning. Results provide new (molecular) insights into ecological consequences of resistance acquisition and can assist in developing measures to prevent colonization and infection based on the underlying resistance mechanism.

Background: Every encounter a healthcare professional has with new or expecting parents offers an opportunity for addressing improved early nutrition and lifestyle. Evidence-based qualification programmes via e-learning offer valuable tools for attenuating the world's huge double burden of both under- and overnutrition in early childhood. We evaluated use and learner satisfaction of a global e-learning programme on early nutrition and lifestyle addressing international healthcare professionals., Methods: We implemented the Early Nutrition Specialist Programme (ENS) with six interactive e-learning courses on early nutrition building on more than ten years of experience with global e-learning platforms, expert knowledge and an international network in the subject field. We collected descriptive and explorative evaluation data on usage and learner satisfaction with a questionnaire and log data over three years among 4003 learners from 48 countries., Results: Results show high completion of the ENS programme, with 85.5% of learners finalizing the programme after enrollment into the first of six courses. Very good results were provided for learner satisfaction with the courses (96.7% of users), for increasing understanding of the topic (97.4%) and matching the indicated time investment (94.4%). Most predominant themes in the open text fields of user feedback questionnaires were "Increase interactivity or number of audio-visuals", "Content suggestions or more examples" and "Technical (quality) issues or navigation problems"., Conclusions: The ENS programme evaluation shows high completion rates and level of satisfaction by learners from numerous countries. The different needs for Continuing Medical Education (CME) of healthcare professionals in diverse healthcare system settings can be met by a joint e-learning qualification programme. Further optimizations will be implemented based on user feedback. More research with a learning analytics approach may help to further identify the most effective and efficient didactic and pedagogic elements of e-learning.

Objective: The purpose of the study was to test the ability of oculomotor, vestibular, and reaction time (OVRT) metrics to serve as a concussion assessment or diagnostic tool for general clinical use., Setting and Participants: Patients with concussion were high school-aged athletes clinically diagnosed in a hospital setting with a sports-related concussion (n = 50). Control subjects were previously recruited male and female high school student athletes from 3 local high schools (n = 170)., Design: Video-oculography was used to acquire eye movement metrics during OVRT tasks, combined with other measures. Measures were compared between groups, and a subset was incorporated into linear regression models that could serve as indicators of concussion., Measures: The OVRT test battery included multiple metrics of saccades, smooth pursuit tracking, nystagmoid movements, vestibular function, and reaction time latencies., Results: Some OVRT metrics were significantly different between groups. Linear regression models distinguished control subjects from concussion subjects with high accuracy. Metrics included changes in smooth pursuit tracking, increased reaction time and reduced saccade velocity in a complex motor task, and decreased optokinetic nystagmus (OKN) gain. In addition, optokinetic gain was reduced and more variable in subjects assessed 22 or more days after injury., Conclusion: These results indicate that OVRT tests can be used as a reliable adjunctive tool in the assessment of concussion and that OKN results appear to be associated with a prolonged expression of concussion symptoms.

Background and Purpose  The transpalpebral "eyelid" approach is a novel alternative to the traditional ciliary or supraciliary incision for supraorbital frontal craniotomy and access to the anterior cranial fossa. Though a prior publication from our institution has described the surgical approach in detail along with cosmetic and clinical outcomes, postoperative imaging findings have not yet been described. As this surgical technique becomes more widely practiced, it is essential for neuroradiologists, oculoplastic surgeons, and skull base neurosurgeons to be familiar with the expected postoperative imaging findings, especially those that prompt subsequent intervention. Materials and Methods  A retrospective, institutional review board approved review was performed of 102 patients who underwent transpalpebral surgical approach at Allegheny General Hospital from June 2007 through May 2015. Operative reports, pathology reports, preoperative imaging, postoperative imaging, and postoperative clinical documentation were reviewed. Results  Forty-nine percent of patients had solely benign expected postoperative imaging findings, 37% had various atypical findings not requiring further intervention (most commonly asymmetric globe protrusion and bone cement in a paranasal sinus), 6% had findings prompting minimally invasive bedside procedures (most commonly pseudomeningocele), and 8% had findings requiring surgical intervention. Conclusion  The majority of imaging following the transpalpebral approach showed typical, benign findings, such as minimal pneumocephalus and asymmetric globe protrusion. Nonetheless, members of the clinical team should be aware of the small number of findings requiring intervention, especially pseudomeningocele.

We conduct a rigorous analysis of the (1+1) evolutionary algorithm for the single source shortest path problem proposed by Scharnow, Tinnefeld, and Wegener (The analyses of evolutionary algorithms on sorting and shortest paths problems, 2004, Journal of Mathematical Modelling and Algorithms, 3(4):349-366). We prove that with high probability, the optimization time is O(n2 max{ℓ, log(n)}), where ℓ is the smallest integer such that any vertex can be reached from the source via a shortest path having at most ℓ edges. This bound is tight. For all values of n and ℓ we provide a graph with edge weights such that, with high probability, the optimization time is of order Ω(n2 max{ℓ, log(n)}). To obtain such sharp bounds, we develop a new technique that overcomes the coupon collector behavior of previously used arguments. Also, we exhibit a simple Chernoff type inequality for sums of independent geometrically distributed random variables, and one for sequences of random variables that are not independent, but show a desired behavior independent of the outcomes of the previous random variables. We are optimistic that these tools find further applications in the analysis of evolutionary algorithms.

Background: Supra orbital frontal minicraniotomy is one of the most commonly used minimally invasive approaches for anterior cranial fossa lesions., Objective: To describe our experience with the transpalpebral "eyelid" incision to obtain access to the anterior cranial fossa., Methods: We describe the approach and technique of the transpalpebral eyelid incision in a step-by-step fashion and discuss the results of 40 cases for which the eyelid incision was used. We retrospectively reviewed the charts of these patients to analyze outcomes with regard to opening and closing time, length of hospital stay, residual aneurysm or Simpson grade for resection, complications, and cosmetic result., Results: We treated 31 anterior circulation aneurysms (28 unruptured and 3 ruptured), 7 anterior skull base meningiomas, 1 frontal low-grade glioma, and 1 frontal cavernoma using the transpalpebral incision. Opening time was about 45 to 60 minutes, and closure time from dura to skin was about 45 to 60 minutes. The hospital length of stay was similar to that in our open craniotomy cases. No residual aneurysm was demonstrated in the follow-up studies of all 31 aneurysms. Simpson grade I resection was achieved in 6 meningiomas. Complications included 1 postoperative eyelid hematoma, 2 postoperative infections, and a subclinical stroke discovered on postoperative imaging. Excellent cosmetic outcome was accomplished in 39 of 40 patients., Conclusion: The transpalpebral approach provides dissection in natural anatomical planes, affords preservation of the frontalis muscle, avoids injury to nerve VII branches, and results in an excellent cosmetic outcome.

Pressure ulcers represent a significant impact on utilization of healthcare beds, cost for the insurer, and adverse emotional impact for the family. With this in mind, one must address in an effective fashion a method of objective assessment using the current methodology to deal with risk factors in mobility, disease states, and nutrition, as well as give significant attention to prevention protocols. One should adhere to a schedule of turning the patient, sleep surfaces, and appropriate skin care while recognizing the impact of each. Finally, treatment modalities should be undertaken, not only with cost-effective issues in mind, but with ease and convenience for the healthcare provider and the least discomfort for the patient as well. One can focus on debridement by way of enzymatic, autolytic, or surgical methods, recognizing surgery as the least effective for our goals in the management of this patient. Assessment and, finally, reassessment using the available scales will allow us to provide effective healthcare in a therapeutic fashion.

A new synthetic approach to the title compounds is reported. It is based on the phosphotriester methodology and uses a unique combination of protecting groups (Fmoc and Ph for the aglycons; DMT, CPTr and Mthp for the carbohydrate hydroxy functions; 2-CIPh for the phosphodiester bonds; BPOC for amino acid). This enables selective deprotection of the blocked oligonucleotide intermediates in two steps (oximate and acid treatments) to yield the 2'(3')-O-aminoacyl oligoribonucleotides suitable for biochemical investigations.

The solution structure of the self-complementary hexamer 5'r(GCAUGC)2 is investigated by means of nuclear magnetic resonance spectroscopy and restrained molecular dynamics. The proton resonances are assigned in a sequential manner, and a set of 110 approximate interproton distance restraints are derived from the two-dimensional nuclear Overhauser enhancement spectra. These distances are used as the basis of a structure refinement by restrained molecular dynamics in which the experimental restraints are incorporated into the total energy function of the system in the form of effective potentials. Eight restrained molecular dynamics simulations are carried out, four starting from a structure with regular A-type geometry and four from one with regular B-type geometry. The atomic root mean square (rms) difference between the initial structures is 3.2 A. In the case of all eight simulations, convergence is achieved both globally and locally to a set of very similar A-type structures with an average atomic rms difference between them of 0.8 +/- 0.2 A. Further, the atomic rms differences between the restrained dynamics structures obtained by starting out from the same initial structures but with different random number seeds for the assignment of the initial velocities are the same as those between the restrained dynamics structures starting out from the two different initial structures. These results suggest that the restrained dynamics structures represent good approximations of the solution structure. The converged structures exhibit clear sequence-dependent variation in some of the helical parameters, in particular helix twist, roll, slide, and propellor twist.(ABSTRACT TRUNCATED AT 250 WORDS)

The solution structure of the self-complementary dodecamer 5'd(CGCGPATTCGCG)2, containing a purine-thymine base pair within the hexameric canonical recognition site GAATTC for the restriction endonuclease EcoRI, is investigated by nuclear magnetic resonance spectroscopy and restrained molecular dynamics. Nonexchangeable and exchangeable protons are assigned in a sequential manner. A set of 228 approximate interproton distance restraints are derived from two-dimensional nuclear Overhauser enhancement spectra recorded at short mixing times. These distances are used as the basis for refinement using restrained molecular dynamics in which the interproton distance restraints are incorporated into the total energy function of the system in the form of effective potentials. Eight calculations are carried out, four starting from classical A-DNA and four from classical B-DNA. In all cases convergence to very similar B-type structures is achieved with an average atomic root mean square (rms) difference between the eight converged structures of 0.7 +/- 0.2 A, compared to a value of 6.5 A for that between the two starting structures. It is shown that the introduction of the purine-thymine mismatch does not result in any significant distortion of the structure. The variations in the helical parameters display a clear sequence dependence. The variation in helix twist and propeller twist follows Calladine's rules and can be attributed to the relief of interstrand purine-purine clash at adjacent base pairs. Overall the structure is straight. Closer examination, however, reveals that the central 5 base pair steps describe a smooth bend directed toward the major groove with a radius of curvature of approximately 38 A, which is compensated by two smaller kinks in the direction of the minor groove at base pair steps 3 and 9. These features can be explained in terms of the observed variation in roll and slide.

Specific syntheses of 2'(3')-O-aminoacyl oligoribonucleotides C-C-A-Gly (12), C-C-A(AcGly) (7), U-C-C-A-Gly (17), and C-U-C-C-A-Gly (19), which are the 3'-terminal sequences of Escherichia coli Gly-tRNA (or AcGly-tRNA, respectively) are described. Compounds 12, 17, and 19 were synthesized by employing the benzotriazolyl phosphotriester approach with the following protection groups on the components: benzoyl for the heterocyclic amino groups, 2-chlorophenyl group for internucleotide phosphate protection, dimethoxytrityl and levulinoyl groups for blocking of the 5'-hydroxyl, methoxytetrahydropyranyl group for protection of the 2'-hydroxyl functions, and N-(benzyloxycarbonyl)orthoglycinate as the masked aminoacyl group simultaneously protecting the 2',3'-cis diol group of the 3'-terminal adenosine moiety. The fully protected tri-, tetra-, and pentanucleotides were obtained via 5'-extension of di- and trinucleotide blocks after prior selective removal of the 5'-O-levulinoyl group with hydrazine. The blocked derivatives 11, 16, and 18 were totally deprotected by reactions with NH4OH, H+, and H2/Pd to yield the target compounds 12, 17, and 19 in good yields. C-C-A(AcGly) (7) was synthesized according to a stepwise procedure via activation of preformed diesters with (mesitylenesulfonyl)tetrazole. C-C-A-Gly (12), U-C-C-A-Gly (17), and C-U-C-C-A-Gly (19) were all acceptor substrates in the peptidyltransferase reaction with the Ac-Phe-tRNA-70S ribosome-poly(U) system. All three models also promoted EF-Tu-70S ribosome GTP hydrolysis.(ABSTRACT TRUNCATED AT 250 WORDS)