478 research outputs found

    FORMULATION AND CHARACTERIZATION OF POLOXAMER 407 (R): THERMOREVERSIBLE GEL CONTAINING POLYMERIC MICROPARTICLES AND HYALURONIC ACID

    Full text link
    The influence of the composition and preparation method on the sol-gel transition temperature (Tsol-gel) and rheological response of poloxamer-based formulations was determined. Manual and more complex mechanical stirring were found to provide similar results. In addition, a linear dependence of Tsol-gel on the poloxamer content was observed in the range of concentrations analyzed, and a Poloxamer 407Âź concentration of 18% was selected. The addition of hyaluronic acid did not lead to significant changes in the Tsol-gel values. In contrast, the addition of microparticles caused a reduction in Tsol-gel without a significant reduction in gel strength, and pseudoplastic characteristics were observed, indicating that a thermoreversible gel was obtained with a rheology suitable for application in the treatment of burn wounds

    Acute bilateral simultaneous angle closure glaucoma after topiramate administration: a case report

    Get PDF
    <p>Abstract</p> <p>Introduction</p> <p>A case of severe acute bilateral angle closure glaucoma with complete visual loss after oral topiramate therapy.</p> <p>Case presentation</p> <p>A 34 year-old woman developed bilateral severe visual loss 2 days after doubling the dosage of topiramate. Her best-corrected visual acuity (BCVA) was counting fingers in both eyes (OU). Intraocular pressures were 49 mm and 51 mm of Hg in right and left eyes respectively, with conjunctival chemosis, corneal edema, shallow anterior chamber and closed angles on gonioscopy. B-scan ultrasound revealed annular peripheral choroidal effusions in both eyes.</p> <p>Conclusion</p> <p>Intraocular pressures and anterior chamber depth were normalized after discontinuation of topiramate and initiation of antiglaucoma therapy. Two weeks later, visual acuities improved to 20/25 in the right eye and 20/40 in the left eye. B-scan ultrasound showed resolution of choroidal effusion. Topiramate, an oral sulpha-derivative medication is known to cause ciliochoroidal effusions, which lead to forward rotation of the ciliary body and displacement of the lens-iris diaphragm, with resultant acute angle closure glaucoma and myopic shift.</p

    Higher-Spin Interactions: four-point functions and beyond

    Get PDF
    In this work we construct an infinite class of four-point functions for massless higher-spin fields in flat space that are consistent with the gauge symmetry. In the Lagrangian picture, these reflect themselves in a peculiar non-local nature of the corresponding non-abelian higher-spin couplings implied by the Noether procedure that starts from the fourth order. We also comment on the nature of the colored spin-2 excitation present both in the open string spectrum and in the Vasiliev system, highlighting how some aspects of String Theory appear to reflect key properties of Field Theory that go beyond its low energy limit. A generalization of these results to n-point functions, fermions and mixed-symmetry fields is also addressed.Comment: 66 pages, 10 figures, 1 table, LaTex. Several statements clarified. Final version to appear in JHE

    Interpretation of uniocular and binocular trials of glaucoma medications: an observational case series

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>To predict the effectiveness of topical glaucoma medications based on initial uniocular and binocular treatment. To test a traditional hypothesis that effectiveness following a uniocular trial is associated with the change in IOP in the initially treated eye minus the change in the initially untreated eye. To determine whether uniocular or binocular treatment trials are superior.</p> <p>Methods</p> <p>Based on a review of medical records, we identified 168 instances in 154 patients with bilateral primary open angle glaucoma of initial uniocular use of a topical glaucoma medication with well-documented intraocular pressure (IOP) readings at baseline (IOP<sub>A</sub>), during the trial (IOP<sub>B</sub>), and at follow-up (IOP<sub>C</sub>). Abstracted data included demographic data, IOP, and medication use. Predictors of the IOP following the trial (IOP<sub>C</sub>) in each eye were identified by multivariable linear regression. In 70 cases, the predictive ability of initial uniocular and binocular treatment could be directly compared.</p> <p>Results</p> <p>In a multivariable analysis, the follow-up pressure in the initially treated eye (IOP<sub>1C</sub>) was directly correlated with treated eye IOP during initial uniocular use (IOP<sub>1B</sub>, p < 0.001). In a multivariable analysis, the follow-up pressure in the initially untreated eye (IOP<sub>2C</sub>) was directly correlated with its baseline IOP<sub>2A </sub>(p < 0.001), and also tended to be associated with treated IOP<sub>1B </sub>(p = 0.07). The multivariable regression coefficient (b) for the IOP change in the initially untreated eye was generally not close to the value of -1 expected by the classic teaching (for eye 1, b = 0.04, p = 0.35; for eye 2, b = 0.07, p = 0.50). In 70 cases, the uniocular and binocular trials predicted a similar fraction of the variance in follow-up IOP<sub>1C </sub>(r<sup>2 </sup>= 0.56 and 0.57, respectively) and IOP<sub>2C </sub>(r<sup>2 </sup>= 0.39 and 0.38, respectively).</p> <p>Conclusion</p> <p>1) For uniocular trials, the IOP change in the untreated eye should not be subtracted from that in the treated eye. 2) Uniocular and binocular trials have similar predictive value when interpreted correctly. Either may be selected based on clinical circumstances.</p

    A new method for determining physician decision thresholds using empiric, uncertain recommendations

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The concept of risk thresholds has been studied in medical decision making for over 30 years. During that time, physicians have been shown to be poor at estimating the probabilities required to use this method. To better assess physician risk thresholds and to more closely model medical decision making, we set out to design and test a method that derives thresholds from actual physician treatment recommendations. Such an approach would avoid the need to ask physicians for estimates of patient risk when trying to determine individual thresholds for treatment. Assessments of physician decision making are increasingly relevant as new data are generated from clinical research. For example, recommendations made in the setting of ocular hypertension are of interest as a large clinical trial has identified new risk factors that should be considered by physicians. Precisely how physicians use this new information when making treatment recommendations has not yet been determined.</p> <p>Results</p> <p>We derived a new method for estimating treatment thresholds using ordinal logistic regression and tested it by asking ophthalmologists to review cases of ocular hypertension before expressing how likely they would be to recommend treatment. Fifty-eight physicians were recruited from the American Glaucoma Society. Demographic information was collected from the participating physicians and the treatment threshold for each physician was estimated. The method was validated by showing that while treatment thresholds varied over a wide range, the most common values were consistent with the 10-15% 5-year risk of glaucoma suggested by expert opinion and decision analysis.</p> <p>Conclusions</p> <p>This method has advantages over prior means of assessing treatment thresholds. It does not require physicians to explicitly estimate patient risk and it allows for uncertainty in the recommendations. These advantages will make it possible to use this method when assessing interventions intended to alter clinical decision making.</p

    Developing the specifications of an Open Angle Glaucoma screening intervention in the United Kingdom : a Delphi approach

    Get PDF
    PMID: 23216983 [PubMed - indexed for MEDLINE] PMCID: PMC3563574 Free PMC Article Acknowledgements We thank all the glaucoma specialists who took part in the Delphi process. We thank the Glaucoma screening Platform Study advisory panel including R Bativala, D Crabb, D Garway-Heath, M Griffiths, R Hitchings; S McPherson, A Tuulonen, A Viswanathan, H Waterman, R Wormald, D Wright for their guidance and contribution to the Delphi process and Luke Vale and Rodolfo Hernandez for their advice on development of the Delphi questionnaires. This paper was developed from the first phase of a project funded by the MRC (project reference G0701759) Developing the intervention & outcome components of a proposed randomized controlled trial of screening for open angle glaucoma. The Health Services Research Unit is core funded by the Chief Scientist Office of the Scottish Government Health Directorates. The views expressed in this report are those of the authors and not necessarily those of the funders.Peer reviewedPublisher PD
    • 

    corecore