827 research outputs found
Management of an extended clivus fracture: a case report
Background: Clivus fractures are highly uncommon. The classification by Corradino et al. divides the different lesions in longitudinal, transverse and oblique fractures. Longitudinal types are associated with the highest mortality rate between 67 – 80%. Clivus fractures are often found after high velocity trauma, especially traffic accidents and falls. The risk of neurologic lesions is high, because of the anatomic proximity to neurovascular structures like the brainstem, the vertebrobasilar artery, and the cranial nerves. Longitudinal clivus fractures have a special risk of causing entrapment of the basilar artery and thus ischemia of the brainstem. Case presentation: This lesion in our patient was a combination-fracture of the craniocervical junction with a transverse clivus fracture. In this case, the primary closed reduction of the clivus fracture and the immobilization with a halo device was the therapy of choice and led to consolidation of the fracture. Conclusion: Therapy advices and examples in the literature are scarce. We present a patient with a clivus fracture, who could be well treated by a halo device. Through detailed research of the literature a therapy algorithm has been developed.<br
Leaving colorectal polyps in place can be achieved with high accuracy using blue light imaging (BLI)
Objectives:
A negative predictive value of more than 90% is proposed by the American Society of Gastrointestinal Endoscopy Preservation and Incorporation of Valuable Endoscopic Innovations (PIVI) statement for a new technology in order to leave distal diminutive colorectal polyps in place without resection. To our knowledge, no prior prospective study has yet evaluated the feasibility of the most recently introduced blue light imaging (BLI) system for real-time endoscopic prediction of polyp histology for the specific endpoint of leaving hyperplastic polyps in place.
Aims:
Prospective assessment of real-time prediction of colorectal polyps by using BLI.
Material and methods:
In total, 177 consecutive patients undergoing screening or surveillance colonoscopy were included. Colorectal polyps were evaluated in real-time by using high-definition endoscopy and the BLI technology without optical magnification. Before resection, the endoscopist described each polyp according to size, shape and surface characteristics (pit and vascular pattern, colour and depression), and histology was predicted with a level of confidence (high or low).
Results:
Histology was predicted with high confidence in 92.5% of polyps. Sensitivity of BLI for prediction of adenomatous histology was 92.68%, with a specificity and accuracy of 94.87 and 93.75%, respectively. Following the recommendation of the PIVI statement, positive and negative predictive values were calculated with values of 95 and 92.5%, respectively. Prediction of surveillance based on both US and European guidelines was correctly predicted in 91% of patients.
Conclusion:
The most recently introduced BLI technology is accurate enough to leave distal colorectal polyps in place without resection. BLI also allowed for assignment of postpolypectomy surveillance intervals. This approach therefore has the potential to reduce costs and risks associated with the redundant removal of diminutive colorectal polyps
High-definition endoscopy with digital chromoendoscopy for histologic prediction of distal colorectal polyps
Background: Distal diminutive colorectal polyps are common and accurate endoscopic prediction of hyperplastic or adenomatous polyp histology could reduce procedural time, costs and potential risks associated with the resection. Within this study we assessed whether digital chromoendoscopy can accurately predict the histology of distal diminutive colorectal polyps according to the ASGE PIVI statement.
Methods: In this prospective cohort study, 224 consecutive patients undergoing screening or surveillance colonoscopy were included. Real time histology of 121 diminutive distal colorectal polyps was evaluated using high-definition endoscopy with digital chromoendoscopy and the accuracy of predicting histology with digital chromoendoscopy was assessed.
Results: The overall accuracy of digital chromoendoscopy for prediction of adenomatous polyp histology was 90.1 %. Sensitivity, specificity, positive and negative predictive values were 93.3, 88.7, 88.7, and 93.2 %, respectively. In high-confidence predictions, the accuracy increased to 96.3 % while sensitivity, specificity, positive and negative predictive values were calculated as 98.1, 94.4, 94.5, and 98.1 %, respectively. Surveillance intervals with digital chromoendoscopy were correctly predicted with >90 % accuracy.
Conclusions: High-definition endoscopy in combination with digital chromoendoscopy allowed real-time in vivo prediction of distal colorectal polyp histology and is accurate enough to leave distal colorectal polyps in place without resection or to resect and discard them without pathologic assessment. This approach has the potential to reduce costs and risks associated with the redundant removal of diminutive colorectal polyps
Dynamic nuclear polarization at high magnetic fields in liquids
High field dynamic nuclear polarization spectrometer for liquid samples have
been constructed. ► The field dependence of the Overhauser DNP efficiency has
been measured for the first time up to 9.2 T. ► High DNP enhancements for
liquid samples have been observed at high magnetic fields. ► The enhancements
have been compared with results from NMRD, MD and theoretical models. ►
Coherent and relaxation effects within fast magnetic field changes have been
analyzed
Randomized trial of daily high-dose vitamin D3 in patients with RRMS receiving subcutaneous interferon β-1a
OBJECTIVE: In the phase II, randomized, double-blind, placebo-controlled Supplementation of Vigantol Oil versus Placebo Add-on in Patients with Relapsing-Remitting Multiple Sclerosis (RRMS) Receiving Rebif Treatment (SOLAR) study (NCT01285401), we assessed the efficacy and safety of add-on vitamin D3 in patients with RRMS. METHODS: Eligible patients with RRMS treated with SC interferon-β-1a (IFN-β-1a) 44 μg 3 times weekly and serum 25(OH)D levels <150 nmol/L were included. From February 15, 2011, to May 11, 2015, 229 patients were included and randomized 1:1 to receive SC IFN-β-1a plus placebo (n = 116) or SC IFN-β-1a plus oral high-dose vitamin D3 14,007 IU/d (n = 113). The revised primary outcome was the proportion of patients with no evidence of disease activity (NEDA-3) at week 48. RESULTS: At 48 weeks, 36.3% of patients who received high-dose vitamin D3 had NEDA-3, without a statistically significant difference in NEDA-3 status between groups (placebo 35.3%; odds ratio 0.93; 95% confidence interval [CI] 0.53-1.63; p = 0.80). Compared with placebo, the high-dose vitamin D3 group had better MRI outcomes for combined unique active lesions (incidence rate ratio 0.68; 95% CI 0.52-0.89; p = 0.0045) and change from baseline in total volume of T2 lesions (difference in mean ranks: -0.074; p = 0.035). CONCLUSIONS: SOLAR did not establish a benefit for high-dose vitamin D3 as add-on to IFN-β-1a, based on the primary outcome of NEDA-3, but findings from exploratory outcomes suggest protective effects on development of new MRI lesions in patients with RRMS. CLINICALTRIALSGOV IDENTIFIER: NCT01285401. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that for patients with RRMS treated with SC IFN-β-1a, 48 weeks of cholecalciferol supplementation did not promote NEDA-3 status
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Proceedings of the Rank Forum on Vitamin D
The Rank Forum on Vitamin D was held on 2nd and 3rd July 2009 at the University of Surrey, Guildford, UK. The workshop consisted of a series of scene-setting presentations to address the current issues and challenges concerning vitamin D and health, and included an open discussion focusing on the identification of the concentrations of serum 25-hydroxyvitamin D (25(OH)D) (a marker of vitamin D status) that may be regarded as optimal, and the implications this process may have in the setting of future dietary reference values for vitamin D in the UK. The Forum was in agreement with the fact that it is desirable for all of the population to have a serum 25(OH)D concentration above 25 nmol/l, but it discussed some uncertainty about the strength of evidence for the need to aim for substantially higher concentrations (25(OH)D concentrations . 75 nmol/l). Any discussion of ‘optimal’ concentration of serum 25(OH)D needs to define ‘optimal’ with care since it is important to consider the normal distribution of requirements and the vitamin D needs for a wide range of outcomes. Current UK reference values concentrate on the requirements of particular subgroups of the population; this differs from the approaches used in other European countries where a wider range of age groups tend to be covered. With the re-emergence of rickets and the public health burden of low vitamin D status being already apparent, there is a need for urgent action from policy makers and risk managers. The Forum highlighted
concerns regarding the failure of implementation of existing strategies in the UK for achieving current vitamin D recommendations
Radial distribution of dilated intercellular spaces of the esophageal squamous epithelium in patients with reflux disease exhibiting discrete endoscopic lesions
Introduction: Dilatation of intercellular spaces of the esophageal squamous epithelium has been suggested as a marker of early acid reflux-induced damage. This change is a potentially useful addition to histomorphological changes that represent so called minimal endoscopic lesions. We have assessed dilatation of intercellular spaces with regard to: (1) interobserver variability, and (2) whether the incidence of this varies between 'red streaks' and the adjacent normal looking squamous epithelium. Methods: Esophageal biopsies from 44 patients with chronic gastro-esophageal reflux (GERD) were evaluated. At endoscopy, these patients had one or more red streaks on the tops of the mucosal folds in the distal esophagus. Biopsies were taken from the red streaks and from the normal-appearing mucosa 1 cm lateral to the red streaks. Biopsies were assessed in a blinded fashion by two independent pathologists (MV & RF). Criteria for assessing intercellular space dilatation were evaluated and agreed on prior to the study. Results: Good interobserver agreement was recorded (kappa = 0.82 at the streaks and 0.77 for the control tissues) for absence/presence of intercellular space dilatation. Red streak and control biopsies differed significantly (p = 0.0001), with respect to presence of dilated intercellular spaces, with 90.5 % of the former demonstrating this as present compared to 56.1% in the controls. Conclusion: This study supports the concept that esophageal mucosal minimal changes due to reflux is localised and that dilatation of intercellular spaces is an early sign of reflux-induced epithelial damage. The low interobserver variability in the assessment of intercellular space dilatation suggests that this may be a useful variable for assessment of early signs of acid-reflux induced damage to the squamous epithelium of the esophagus by use of light microscopy. Copyrigh
Prediction of specificity-determining residues for small-molecule kinase inhibitors
<p>Abstract</p> <p>Background</p> <p>Designing small-molecule kinase inhibitors with desirable selectivity profiles is a major challenge in drug discovery. A high-throughput screen for inhibitors of a given kinase will typically yield many compounds that inhibit more than one kinase. A series of chemical modifications are usually required before a compound exhibits an acceptable selectivity profile. Rationalizing the selectivity profile for a small-molecule inhibitor in terms of the specificity-determining kinase residues for that molecule can be an important step toward the goal of developing selective kinase inhibitors.</p> <p>Results</p> <p>Here we describe S-Filter, a method that combines sequence and structural information to predict specificity-determining residues for a small molecule and its kinase selectivity profile. Analysis was performed on seven selective kinase inhibitors where a structural basis for selectivity is known. S-Filter correctly predicts specificity determinants that were described by independent groups. S-Filter also predicts a number of novel specificity determinants that can often be justified by further structural comparison.</p> <p>Conclusion</p> <p>S-Filter is a valuable tool for analyzing kinase selectivity profiles. The method identifies potential specificity determinants that are not readily apparent, and provokes further investigation at the structural level.</p
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