18 research outputs found
Designed Azolopyridinium Salts Block Protective Antigen Pores In Vitro and Protect Cells from Anthrax Toxin
Background:Several intracellular acting bacterial protein toxins of the AB-type, which are known to enter cells by endocytosis, are shown to produce channels. This holds true for protective antigen (PA), the binding component of the tripartite anthrax-toxin of Bacillus anthracis. Evidence has been presented that translocation of the enzymatic components of anthrax-toxin across the endosomal membrane of target cells and channel formation by the heptameric/octameric PA63 binding/translocation component are related phenomena. Chloroquine and some 4-aminoquinolones, known as potent drugs against Plasmodium falciparium infection of humans, block efficiently the PA63-channel in a dose dependent way.Methodology/Principal Findings:Here we demonstrate that related positively charged heterocyclic azolopyridinium salts block the PA63-channel in the μM range, when both, inhibitor and PA63 are added to the same side of the membrane, the cis-side, which corresponds to the lumen of acidified endosomal vesicles of target cells. Noise-analysis allowed the study of the kinetics of the plug formation by the heterocycles. In vivo experiments using J774A.1 macrophages demonstrated that the inhibitors of PA63-channel function also efficiently block intoxication of the cells by the combination lethal factor and PA63 in the same concentration range as they block the channels in vitro.Conclusions/Significance:These results strongly argue in favor of a transport of lethal factor through the PA63-channel and suggest that the heterocycles used in this study could represent attractive candidates for development of novel therapeutic strategies against anthrax. © 2013 Beitzinger et al
ISRCTN12125882 - Influence of topical anti-VEGF (Ranibizumab) on the outcome of filtration surgery for glaucoma - Study Protocol
<p>Abstract</p> <p>Background</p> <p>Excessive wound healing, with scarring of the episcleral tissue or encapsulation of the filtering bleb is the main reason for failure in trabeculectomy. Ranibizumab, an inhibitor of the Vascular Endothelial Growth Factor (VEGF), is seen as a promising candidate to prevent or treat extensive wound healing. We describe the design of a two phased study, i) assessing the local tolerability and safety of topical ranibizumab and ii) assessing the efficacy of topical ranibizumab against placebo in patients who underwent trabeculectomy with mitomycin C combined with phacoemulsification and intra ocular lens (IOL) implantation.</p> <p>Methods/Design</p> <p>In the first phase five patients that had trabeculectomy with mitomycin C combined with phacoemulsification and IOL implantation will be treated with topical ranibizumab (Lucentis<sup>®</sup>) eye drops (2 mg/ml) four times daily for one month. The treatment will be started at the first postoperative day. Patients will be assessed for local and systemic side effects using a standardised schedule. In the second phase, after successful completion of phase 1, consenting eligible patients who underwent trabeculectomy with mitomycin C combined with phacoemulsification and IOL implantation will be randomised to either receive topical ranibizumab eye drops (2 mg/ml) four times daily for 1 month or placebo (BSS 4x/d for 1 month). Patients will be reviewed weekly for 4 weeks until conjunctival sutures are removed. Further follow up examinations are planned after 3 and six months. Assessment of differences in the intraocular eye pressure will be considered primary, and bleb appearance/vascularisation using a standardized photography and the Moorfields bleb grading system, postoperative intraocular pressure and conjunctival wound healing problems will be considered secondary outcome parameters.</p> <p>Discussion</p> <p>Anti-VEGF-antibodies might be more effective in preventing scaring and might have fewer toxic side effects than the currently used anti-metabolites and may replace them in the long term.</p> <p>Trial Registration</p> <p>ISRCTN: <a href="http://www.controlled-trials.com/ISRCTN12125882">ISRCTN12125882</a></p
Ki-67 as a prognostic marker in mantle cell lymphoma—consensus guidelines of the pathology panel of the European MCL Network
Mantle cell lymphoma (MCL) has a heterogeneous clinical course and is mainly an aggressive B cell non-Hodgkin lymphoma; however, there are some indolent cases The Ki-67 index, defined by the percentage of Ki-67-positive lymphoma cells on histopathological slides, has been shown to be a very powerful prognostic biomarker. The pathology panel of the European MCL Network evaluated methods to assess the Ki-67 index including stringent counting, digital image analysis, and estimation by eyeballing. Counting of 2 × 500 lymphoma cells is the gold standard to assess the Ki-67 index since this value has been shown to predict survival in prospective randomized trials of the European MCL Network. Estimation by eyeballing and digital image analysis showed a poor concordance with the gold standard (concordance correlation coefficients [CCC] between 0.29 and 0.61 for eyeballing and CCC of 0.24 and 0.37 for two methods of digital image analysis, respectively). Counting a reduced number of lymphoma cells (2 × 100 cells) showed high interobserver agreement (CCC = 0.74). Pitfalls of the Ki-67 index are discussed and guidelines and recommendations for assessing the Ki-67 index in MCL are given
Complex refractive indices of Spiro-TTB and C60
Combining spectrophotometry, variable angle spectroscopic ellipsometry, and X-ray reflectometry with an algorithm that simultaneously fits all available spectra we determine the complex refractive index of evaporated Spiro-TTB and C60 layer
Cost Utility for Penetrating Keratoplasty in Patients with Poor Binocular Vision
PURPOSE:
Cost-utility and cost-effectiveness analyses are of increasing importance to clinicians and health policy experts. This study determines the costs in Germany and other countries in relation to gain of utility for patients with bilateral poor vision owing to corneal disease undergoing penetrating keratoplasty (PK) in 1 eye.
DESIGN:
A cost-utility analysis was performed using retrospective clinical data and high-level evidence-based data.
PARTICIPANTS:
Sixty patients (mean age, 46.3 years) with bilateral poor vision who underwent PK for corneal disease.
METHODS:
Visual acuity and utility values were obtained before and 1 year after PK and after suture removal. A 10-year graft survival rate of 80% was assumed. Expenses included costs for the corneal transplant and surgery, medication, and optical rehabilitation. A discount rate of 5% was applied for costs and quality-adjusted life years (QALYs). Cost-utility analysis encompassed a 10-year period after surgery.
MAIN OUTCOME MEASURES:
The number of QALYs was calculated for the study group undergoing PK. This was divided into the cost of the procedure to get the number of euros spent per QALY gained. RESULTS: Median binocular preoperative visual acuity was -log mean angle of resolution (-logMAR) 0.91+/-0.53 (Snellen equivalent 20/160) yielding a utility value of 0.67. After suture removal and optical rehabilitation, binocular visual acuity increased to median -logMAR 0.36+/-0.36 (20/46) with a utility value of 0.79. Over the 10 years after surgery and considering graft survival and discounting, a cost utility of 9551 euros per QALY was gained (equivalent to US11,557 dollars). One-way sensitivity analysis yielded a range from 7706 euros to 12874 euros per QALY, highlighting the robustness of the model.
CONCLUSIONS:
Although an expensive procedure, PK is cost effective in patients with bilateral poor vision
714-4 What is the Optimal Pulse Duration for Defibrillation? Insights from a Porcine Animal Model
We investigated the effect of modifying total biphasic shock duration (SDur) in 7 anesthesized pigs while keeping pulse 1/pulse 2 duration ratio constant (60%/40%; pulse 1=first part, pulse 2=second part of biphasic shock). Different SDurs of 10.8ms (pulse 1: 6 ms(Interpulse delay: 0.8ms/pulse 2: 4ms), 7.1ms (3.8/0.8/2.5ms) and 3.6 ms (1,7/0.8/1.1 ms) generated by an external capacitor (Medtronic 2349®) were tested in a randomized protocol against a SDur of 14.3 ms (8.1/0.8/5.4 ms) used by a currently available defibrillator system (CPI ECD®). 5 shocks were delivered at each energy level between 5 and 40 Joules (J) in 5 J steps through a transvenous/subcutaneous lead system (CPI Endotak C®/SubQ®). Voltage and current were recorded on an oscilloscope and impedance calculated as voltage divided by current.ResultsCumulative success at all energy levels was higher with 7.1 ms SDur (70%) than with 10.8 ms (56%, p<0.01). 14.3 ms (37%, p<0.001) and 3.6 ms (48%, p<0.001). SOur of 10.8 ms were significantly more successful than 14.3 ms (p<0.001; x2-test). Shocks of 14.3 ms had a significantly lower impedance at the trailing edge of pulse 2 compared to shorter SDur (31.6±9.3rl vs. 37±7.9rl/l0.8 ms, 36.2±7Ω/7.1 ms and 35±9Ω/3.6 ms).Conclusions1) In analogy to chronaxy in electrostimulation there is an optirnal SDur for defibrillation. 2) In this animal model the optimal SDur for biphasic shocks is considerably shorter than the one used with currently available defibrillator systems. 3) This may be due to a significantly lower impedance at the trailing edge of pulse 2 for longer SDur possibly leading to refibrillation. 4) Shorter SDurs may allow the use of smaller capacitors in future clinical devices
Blue diversion: A new approach to sanitation in informal settlements
The sanitation concept Blue Diversion (www.bluediversiontoilet.com) was developed as a possible answer to the sanitation crisis in urban slums. It is based on two main elements: (1) diversion of urine, feces, and water at the source as the basis for efficient resource recovery, and (2) linking different scales (family toilets and semi-centralized resource recovery). Our objective was to develop an attractive grid-free (i.e. functioning without piped water, sewer, and electrical grid) dry urine-diverting toilet, which provides water (through recycling on-site) for flushing, personal hygiene (anal cleansing and menstrual hygiene), and hand washing. This service, including the entire sanitation value chain, should eventually be made available as a profitable business with total user fees of 5 ¢/p/d. The results presented in this paper are (1) a toilet design model, (2) the development of a new type of membrane bioreactor for treating flush and wash water, (3) main results of a geographic information system-based stochastic service model to link the family-scale toilet to a community-scale Resource Recovery Plant, and (4) a business model that yields maximum profit for the local community. We conclude that the approach is feasible, but challenging from a technical as well as an organizational point of view. A firm's competitive advantage originates increasingly from absorbing external knowledge. Absorbing external knowledge and the underlying learning processes are referred to as a company's absorptive capacity. In this article, we outline research trends on absorptive capacity. We apply a bibliometric analysis to describe the concept's historical development, define the intellectual core of the absorptive capacity concept, and discuss recent conceptualizations. Then, we identify two prominent streams in the absorptive capacity literature and provide a new approach on how to integrate them. Finally, we provide an outlook on possible themes in future research on absorptive capacity