ABSTRACT
INTRODUCTION: Quality management (QM) is a control tool for the implementation of a wide range of organizational measures aimed at achieving process orientation and process optimization. The organizational framework for these measures can be structured to fulfill the requirements of certification to the DIN EN ISO 9001 standard. The objective was to implement this tool within a university otorhinolaryngology department. MATERIAL AND METHOD: After drawing up a project plan, the measures required to fulfill the audit requirements were put into practice by a QM core team, which included employees from four areas: healthcare, research, nursing and teaching. RESULTS: The measures carried out resulted in the achievement of certification, provided that annual surveillance audits are performed. DISCUSSION: The attainment of the certificate requires continuous fulfillment of the required standards. Future requirements, such as the demands placed on knowledge management, necessitate further appropriate measures.
Subject(s)
Certification , Otolaryngology , Otolaryngology/standardsABSTRACT
BACKGROUND: Optimal treatment of polyomavirus-induced allograft nephropathy (PVAN) with immunosuppressive and antiviral therapy is uncertain at present. Reduced immunosuppression is accompanied by increased risk of rejection, and antiviral agents are nephrotoxic. Leflunomide has immunosuppressive and antiviral properties and may be an alternative treatment agent. We report a two-center experience with use of leflunomide for treatment of PVAN. PATIENTS AND METHODS: Thirteen renal allograft recipients were diagnosed with biopsy-proven PVAN. Treatment consisted of lowering the calcineurin-inhibitor trough level, discontinuing mycophenolate mofetil therapy, and initiating leflunomide therapy. In 8 of the 13 patients, the serum concentration of the leflunomide active metabolite A771726 was monitored. RESULTS: Exchange of mycophenolate mofetil with leflunomide in patients with PVAN was well tolerated and safe, with no serious adverse effects or episodes of graft rejection. Mean follow-up after transplantation was 717 days, and after initiation of leflunomide therapy was 465 days. With the modified therapy, 12 patients cleared the virus at a mean of 109 days. One graft was lost due to refractory rejection accompanied by a decreasing viral load. In the other 12 patients, graft function stabilized or improved (mean [median] creatinine concentration at diagnosis, 2.39 [2.5] mg/mL, vs 2.27 [2.0] mg/dL at follow-up). Leflunomide concentration did not correlate with treatment efficiency. CONCLUSIONS: Treatment of PVAN with leflunomide, a low-dose calcineurin inhibitor, and prednisone seems to reduce viral load and stabilize renal graft function without increasing the risk of rejection. Even low serum concentrations of leflunomide support viral elimination and prevention of graft rejection.
Subject(s)
Antiviral Agents/therapeutic use , BK Virus/drug effects , Isoxazoles/therapeutic use , Kidney Transplantation/adverse effects , Polyomavirus Infections/prevention & control , Biopsy , Dose-Response Relationship, Drug , Drug Monitoring/methods , Graft Rejection/epidemiology , Humans , Immunosuppressive Agents/therapeutic use , Isoxazoles/blood , Kidney Transplantation/pathology , Leflunomide , Mycophenolic Acid/analogs & derivatives , Mycophenolic Acid/therapeutic use , Risk Factors , Viral LoadABSTRACT
PURPOSE: To evaluate a new angiographic technique that offers three-dimensional imaging of chorioretinal vascular diseases. METHODS: Fluorescein (FA) and indocyanine green angiography (ICGA) were performed using a confocal scanning laser ophthalmoscope. Tomographic series with 32 images per set were taken over a depth of 4 mm at an image frequency of 20 Hz. An axial analysis was performed for each x/y position to determine the fluorescence distribution along the z-axis. The location of the onset of fluorescence at a defined threshold intensity was identified and a depth profile was generated. The overall results of fluorescence topography were displayed in a gray scale-coded image and three-dimensional relief. RESULTS: Topographic angiography delineated the choriocapillary surface covering the posterior pole with exposed larger retinal vessels. Superficial masking of fluorescence by hemorrhage or absorbing fluid did not preclude detection of underlying diseases. Choroidal neovascularization (CNV) appeared as a vascular formation with distinct configuration and prominence. Chorioretinal infiltrates exhibited perfusion defects with dye pooling. Retinal pigment epithelium detachments (PEDs) demonstrated dynamic filling mechanisms. Intraretinal extravasation in retinal vascular disease was detected within a well-demarcated area with prominent retinal thickening. CONCLUSIONS: Confocal topographic angiography allows high-resolution three-dimensional imaging of chorioretinal vascular and exudative diseases. Structural vascular changes (e.g., proliferation) are detected in respect to location and size. Dynamic processes (e.g., perfusion defects, extravasation, and barrier dysfunction) are clearly identified and may be quantified. Topographic angiography is a promising technique in the diagnosis, therapeutic evaluation, and pathophysiological evaluation of macular disease.
Subject(s)
Choroidal Neovascularization/diagnosis , Fluorescein Angiography/methods , Indocyanine Green , Retinal Detachment/diagnosis , Retinal Hemorrhage/diagnosis , Retinal Vein Occlusion/diagnosis , Choroid/blood supply , Disease Progression , Humans , Imaging, Three-Dimensional , Retinal Vessels/pathologyABSTRACT
Three-dimensional topography of perfused vascular structures is possible via confocal laser scanning of intravascular fluorescence. The lateral resolution is given by the spot size of the scanning laser beam (optimally 10 microm at the retina). The axial resolution, however, depends on the accuracy of detection of the surface of the fluorescent structure, which is typically one order of magnitude higher (30 microm at the retina) than the confocal resolution. The vascular structure is stained with an appropriate fluorescent dye prior to the investigation using standard systemic dye injection. Confocal scanning of the fluorescence in planes of different depths within the vascular structure under investigation leads to a three-dimensional data set. Signal processing includes passive eye tracking, lateral averaging and axial determination of the surface of the fluorescent structure. The potential of this new technique is demonstrated by showing the topography of physiological vessel structures as well as of selected vascular diseases such as cone dystrophy, RPE detachment, choroidal haemangioma and retinal laser coagulation. Confocal laser angioscopic fluorescence topography (CLAFT) measures the three-dimensional surface structure of functional (perfused) vasculature and surrounding leakage. CLAFT may help to diagnose and quantify status and time course of vascular diseases.
Subject(s)
Diagnostic Techniques, Ophthalmological , Fluorescein Angiography/methods , Image Processing, Computer-Assisted , Lasers , Retinal Diseases/diagnosis , Retinal Vessels/pathology , Contrast Media/administration & dosage , Fluorescein/administration & dosage , Fundus Oculi , Humans , Injections, Intravenous , Reproducibility of Results , Retina/pathology , Sensitivity and SpecificityABSTRACT
BACKGROUND: Confocal indocyanin green angiography (ICGA) offers detailed two-dimensional imaging of choroidal pathologies. However, the spatial extension of lesions is not reproduced. We developed a novel method for three-dimensional documentation of choroidal vascular abnormalities. METHODS: Focal series were performed using a laser scanning ophthalmoscope (Heidelberg Retina Angiograph). Thirty-two images within a distance of 4 mm were taken at a frequency of 20 Hz. Following correction of dislocation, a surface of normalized fluorescence intensity was determined and displayed topographically. RESULTS: In physiological eyes three-dimensional ICGA demonstrates the homogeneous concavity of the choroid with prominent overlay of retinal vessels. Classic choroidal neovascularization (CNV) imposes as substantial elevation. Occult CNV are demarcated despite negative conventional ICGA due to reduction of blocking phenomena. Therapeutic interventions such as photocoagulation, photodynamic therapy and surgery induce a resolution of CNV with or without residual defects within the choroidal pattern. CONCLUSION: Topographic ICGA allows for the first time in-vivo representation of prominence and depth of vascularized pathologies and provides a tool for improved diagnostic and therapeutic evaluation.
Subject(s)
Choroidal Neovascularization/diagnosis , Fluorescein Angiography , Image Processing, Computer-Assisted , Indocyanine Green , Microscopy, Confocal , Ophthalmoscopes , Humans , Macular Degeneration/diagnosis , Sensitivity and SpecificityABSTRACT
Brief ischemic episodes confer marked protection against myocardial stunning 1-3 d later (late preconditioning [PC] against stunning). The mechanism of this powerful protective effect is poorly understood. Although protein kinase C (PKC) has been implicated in PC against infarction, it is unknown whether it triggers late PC against stunning. In addition, the entire PKC hypothesis of ischemic PC remains controversial, possibly because the effects of PKC inhibitors on PC protection have not been correlated with their effects on PKC activity and/or translocation in vivo. Thus, conscious rabbits underwent a sequence of six 4-min coronary occlusion (O)/4-min reperfusion (R) cycles for three consecutive days (days 1, 2, and 3). In the control group (group I, n = 7), the recovery of systolic wall thickening after the six O/R cycles was markedly improved on days 2 and 3 compared with day 1, indicating the development of late PC against stunning. Administration of the PKC inhibitor chelerythrine at a dose of 5 mg/kg before the first O on day 1 (group II, n = 10) abrogated the late PC effect against stunning, whereas a 10-fold lower dose (0.5 mg/kg; group III, n = 7) did not. Administration of 5 mg/kg of chelerythrine 10 min after the sixth reperfusion on day 1 (group IV, n = 6) failed to block late PC against stunning. When rabbits were given 5 mg/kg of chelerythrine in the absence of O/R (group V, n = 5), the severity of myocardial stunning 24 h later was not modified. Pretreatment with phorbol 12-myristate 13-acetate (4 microg/kg) on day 1 without ischemia (group VI, n = 11) induced late PC against stunning on day 2 and the magnitude of this effect was equivalent to that observed after ischemic PC. In vehicle-treated rabbits (group VIII, n = 5), the six O/R cycles caused translocation of PKC isoforms epsilon and eta from the cytosolic to the particulate fraction without significant changes in total PKC activity, in the subcellular distribution of total PKC activity, or in the subcellular distribution of the alpha, beta1, beta2, gamma, delta, zeta, iota, lambda, and mu isoforms. The higher dose of chelerythrine (5 mg/kg; group X, n = 5) prevented the translocation of both PKC epsilon and eta induced by ischemic PC, whereas the lower dose (0.5 mg/kg; group XI, n = 5) prevented the translocation of PKC eta but not that of epsilon, indicating that the activation of epsilon is necessary for late PC to occur whereas that of eta is not. To our knowledge, this is the first demonstration that a PKC inhibitor actually prevents the translocation of PKC induced by ischemic PC in vivo, and that this inhibition of PKC translocation results in loss of PC protection. Taken together, the results demonstrate that the mechanism of late PC against myocardial stunning in conscious rabbits involves a PKC-mediated signaling pathway, and implicate epsilon as the specific PKC isoform responsible for the development of this cardioprotective phenomenon.
Subject(s)
Ischemic Preconditioning, Myocardial , Isoenzymes/analysis , Myocardial Stunning/physiopathology , Protein Kinases/physiology , Alkaloids , Animals , Benzophenanthridines , Cardiomegaly/physiopathology , Cell Fractionation , Coronary Disease/physiopathology , Enzyme Activation/drug effects , Enzyme Inhibitors/pharmacology , Heart Rate/physiology , Ischemia/physiopathology , Male , Phenanthridines/pharmacology , Protein Kinase Inhibitors , Rabbits , Reperfusion , Signal Transduction/physiology , Tetradecanoylphorbol Acetate/pharmacologyABSTRACT
To examine the cardioprotective role of A3 adenosine receptors during myocardial ischemia/reperfusion injury, we tested the effect of N6-(3-iodobenzyl)adenosine-5'-N-methyluronamide (IB-MECA), a potent and selective A3 adenosine receptor agonist, in models of myocardial stunning and infarction in chronically instrumented conscious rabbits. In phase I (studies of myocardial stunning), rabbits were subjected to six 4-minute coronary occlusions, each separated by 4-minute reperfusion periods, after which the recovery of systolic wall thickening was measured (ultrasonic crystals). In phase II (studies of myocardial infarction), rabbits were subjected to a 30-minute coronary occlusion followed by 3 days of reperfusion. In both phases, IB-MECA was administered as an intravenous bolus (100 micrograms/kg) 10 minutes before the first coronary occlusion. This dose of IB-MECA was determined in pilot studies to have no effect on heart rate, arterial blood pressure, or plasma histamine concentration in rabbits. In phase I, IB-MECA markedly improved the recovery of wall thickening after the six occlusion/reperfusion cycles, and this effect was sustained throughout the 5-hour observation period; the total deficit of wall thickening (a measure of the overall severity of myocardial stunning) was reduced by 68% (control, 129 +/- 16 arbitrary units, n = 7; IB-MECA, 41 +/- 6 arbitrary units, n = 6; P < .01). The protective effects of IB-MECA against stunning were completely blocked by pretreatment with the nonselective adenosine receptor antagonist 8-p-sulfophenyl theophylline or the specific protein kinase C inhibitor chelerythrine. In phase II, IB-MECA reduced myocardial infarct size by 61%; infarct size (tetrazolium staining) was 41 +/- 4% of the risk region in control animals (n = 8) and 16 +/- 6% in IB-MECA-treated animals (n = 8, P < .01). These results demonstrate that in conscious rabbits the A3 adenosine receptor agonist IB-MECA confers a powerful protection against both reversible (stunning) and irreversible (infarction) injury during acute myocardial ischemia and reperfusion by a protein kinase C-mediated pathway, suggesting that selective activation of A3 receptors is an effective means of protecting the ischemic myocardium without hemodynamic changes.