11 results on '"John S. Werner"'
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2. Indikationsqualität bei zystischen Läsionen des Pankreas
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Matthias Ilmer, Jan G. D’Haese, John S. Werner, and Bernhard W. Renz
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Gynecology ,03 medical and health sciences ,medicine.medical_specialty ,0302 clinical medicine ,Transplant surgery ,business.industry ,030220 oncology & carcinogenesis ,medicine ,Surgery ,030230 surgery ,business ,Pancreatic surgery - Abstract
Im aktuellen klinischen Alltag haben zystische Pankreaslasionen (PCNs) einen zunehmend relevanten Stellenwert, da sie aufgrund der sich stetig verbessernden Bildgebung haufig als Zufallsbefund diagnostiziert werden. Man unterscheidet zwischen nichtneoplastischen und neoplastischen Pankreaszysten, wobei letztere in unterschiedlicher Auspragung zur malignen Entartung neigen und damit als Vorlauferlasionen des duktalen Adenokarzinoms des Pankreas (PDAC) gelten. Zur Differenzialdiagnose werden neben einer genauen Anamnese und Untersuchung vor allem bildgebende Verfahren wie die Computertomographie (CT) und Magnetresonanztomographie (MRT) sowie der endoskopische Ultraschall mit Feinnadelaspiration herangezogen. Die Indikationen zur chirurgischen Resektion dieser Lasionen richten sich nach den aktuellen europaischen Leitlinien, deren Inhalte sind jedoch nicht evidenzbasiert, sondern stutzen sich auf Erkenntnisse und Empfehlungen von Experten. Gemas den Konsensusempfehlungen kann die asymptomatische seros-zystische Neoplasie (SCN) als serose Lasion mit niedriger Tendenz zur Entartung beobachtet werden. Im Gegensatz dazu sollten alle muzinos-zystischen Neoplasien (MCN) >4 cm sowie alle solid-pseudopapillaren Neoplasien (SPN) reseziert werden. Intraduktal papillar-muzinose Neoplasien (IPMNs), die aufgrund ihres Bezugs zum Pankreasgangsystem in Haupt(MD)- oder Seitengang(BD)-IPMNs unterteilt werden, sollten als MD-IPMN und als Mixed-type(MT)-IPMN reseziert werden. Das Entartungsrisiko der BD-IPMN ist variabler und abhangig von Risikofaktoren, die klinisch und bildmorphologisch definiert werden. Das therapeutische Management erfolgt daher individuell nach Risikoabschatzung. Um die Indikationsqualitat bei PCNs quantifizieren zu konnen und damit auch zu einer optimierten Versorgung beizutragen, werden dringend prospektive Langzeitstudien benotigt.
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- 2020
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3. Implementierung neuer Technologien unter ökonomischen Gesichtspunkten im DRG-System
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W G R Sienel, T S Schiergens, and John S. Werner
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Gynecology ,03 medical and health sciences ,medicine.medical_specialty ,0302 clinical medicine ,Transplant surgery ,Cardiothoracic surgery ,business.industry ,030220 oncology & carcinogenesis ,medicine ,030211 gastroenterology & hepatology ,Surgery ,business ,Abdominal surgery - Abstract
Die Implementierung technologischer Innovationen in der Chirurgie wie roboterassistierte Eingriffe, neuartige Implantate, Navigation oder moderne Visualisierungstechniken stellen fur Klinken eine okonomische Herausforderung dar, da sie selten per se kostendeckend sind. Im deutschen DRG(„diagnosis related groups“)-System sind die Kosten zahlreicher neuartiger Technologien und Innovation in der Chirurgie kurzfristig und auch oft mittel- und langfristig nicht oder nicht ausreichend gedeckt. Dieser Ubersichtsartikel beschreibt die okonomischen Aspekte chirurgischer Innovationen und zeigt mogliche Wege fur Kliniken auf, die Kosten zu decken. In einem simulierten Fallbeispiel wird veranschaulicht, inwieweit das aktuelle deutsche DRG-Tarifsystem die Kosten minimal-invasiver Techniken (laparoskopisch, roboterassistiert) im Rahmen einer elektiven Sigmaresektion bei benigner Indikation widerspiegelt.
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- 2020
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4. Oligometastasierung bei neuroendokrinen Tumoren – Ausmaß der Chirurgie
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Florian Bösch, John S. Werner, Martin K. Angele, and Markus Guba
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medicine.medical_specialty ,Hormone activity ,business.industry ,medicine.medical_treatment ,Multimodal therapy ,030230 surgery ,Liver transplantation ,Neuroendocrine tumors ,Vascular surgery ,medicine.disease ,Surgery ,Tumor Debulking ,03 medical and health sciences ,0302 clinical medicine ,030220 oncology & carcinogenesis ,medicine ,Stage (cooking) ,business ,Carcinoid syndrome - Abstract
Neuroendocrine tumors (NETs) are rare neoplasms, which represent complex challenges in diagnosis and treatment. Even in the metastatic stage there are important differences in the type of tumor in comparison to gastrointestinal and pancreatic adenocarcinomas. Therefore, the disease courses are substantially different depending on the grade of differentiation. Even in the metastatic stage the 5‑year survival rates of G1 tumors is up to 83%. Approximately 20% of small intestine NETs additionally show hormone activity, which can compromise survival and the quality of life. For individual treatment decisions the special tumor biology of these tumors must be taken into consideration more so than for other tumor entities. Surgery always becomes important for these tumors when a R0 resection appears possible. Oligometastasis of the liver and the lymph drainage system can be meaningfully approached by surgical treatment. In selected patients with an isolated liver involvement, a liver transplantation can be considered; however, even tumor debulking can lead to improvement in the quality of life and survival, especially for hormone active tumors with a carcinoid syndrome which cannot be conservatively controlled. The aim of this review is to present the value of surgical treatment options in the case of (oligo)metastasized NETs.
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- 2018
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5. Aktuelle Therapiekonzepte für primär resektable und lokal fortgeschrittene Pankreaskarzinome
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John S. Werner, Claus Belka, Jan G. D’Haese, and Volker Heinemann
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Gynecology ,medicine.medical_specialty ,Oncology ,business.industry ,medicine ,Hematology ,business - Abstract
Hintergrund Das Pankreaskarzinom ist weiterhin mit einer sehr schlechten Prognose verbunden. Die chirurgische Resektion ist der einzige kurative Therapieansatz. Gleichwohl wurden in den letzten Jahren zunehmende Fortschritte im Bereich neuer onkologischer Therapiekonzepte gemacht, welche nachfolgend detailliert dargestellt werden sollen.
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- 2015
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6. Operative Therapie der abdominellen und retroperitonealen Sarkome
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Rolf D. Issels, Lars H. Lindner, Markus Albertsmeier, Martin K. Angele, John S. Werner, and Claus Belka
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Gynecology ,medicine.medical_specialty ,Transplant surgery ,business.industry ,Cardiothoracic surgery ,Medicine ,Surgery ,business ,Abdominal surgery - Abstract
Retroperitoneale Weichgewebssarkome neigen in hohem Mase zum Lokalrezidiv. Die komplette chirurgische Tumorresektion stellt die einzige potenziell kurative Therapieoption dar. Bei der systematischen abdominellen Kompartmentresektion wird der Tumor en bloc mit einem Saum von nicht infiltriertem Gewebe und Organen entfernt. Hierzu gehoren haufig eine Niere, ein Hemikolon, linksseitig der Pankreasschwanz sowie Anteile des Zwerchfells und des Musculus psoas. Weitere Organe und Gefase werden je nach Infiltration mitentfernt. Durch dieses aggressive Vorgehen konnen im Vergleich zu weniger radikalen Operationsverfahren haufiger histologisch tumorfreie Resektionsrander und letztlich eine geringere Lokalrezidivrate erreicht werden. Der Artikel beschreibt detailliert das chirurgische Vorgehen und die perioperative Behandlung der Patienten sowie die Ergebnisse der operativen Therapie. Ausfuhrlich werden die Einbindung in ein immer notwendiges onkologisches Therapiekonzept und die Bedeutung spezialisierter Zentren diskutiert.
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- 2014
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7. Detailed analysis of retinal function and morphology in a patient with autosomal recessive bestrophinopathy (ARB)
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John S. Werner, Robert J. Zawadzki, Christina Gerth, and Elise Héon
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Male ,medicine.medical_specialty ,genetic structures ,Fundus Oculi ,Genes, Recessive ,Retinal Pigment Epithelium ,Biology ,Retina ,Article ,chemistry.chemical_compound ,Retinal Diseases ,Optical coherence tomography ,Chloride Channels ,Physiology (medical) ,Ophthalmology ,Electroretinography ,medicine ,Humans ,Bestrophins ,Child ,Eye Proteins ,Alleles ,Vision, Ocular ,Retinal pigment epithelium ,Fourier Analysis ,medicine.diagnostic_test ,Retinal ,Electrooculography ,medicine.disease ,eye diseases ,Sensory Systems ,medicine.anatomical_structure ,chemistry ,Mutation ,sense organs ,Tomography, Optical Coherence ,Autosomal recessive bestrophinopathy ,Photoreceptor Cells, Vertebrate ,Retinopathy - Abstract
The objective of the paper is to study the retinal microstructure and function in a patient with autosomal recessive bestrophinopathy (ARB). Retinal function and morphology assessment in a patient diagnosed with a biallelic mutation in the BEST1 gene (heterozygote mutations: Leu88del17 and A195V) included: full-field electroretinogram (ffERG) and multifocal electroretinogram (mfERG), electro-oculogram (EOG) testing, and imaging with a high-resolution Fourier-domain optical coherence tomography (Fd-OCT) system (UC Davis Medical Center; axial resolution: 4.5 microm, acquisition speed: 9 frames/s, 1,000 A-scans/frame) combined with a flexible scanning head (Bioptigen Inc.). The 11-year old asymptomatic boy showed a well-demarcated retinopathy with deposits. Functional assessment revealed normal visual acuity, reduced central mfERG responses, delayed rod and rod-cone b-wave ffERG responses, and reduced light rise in the EOG. Fd-OCT demonstrated RPE deposits, photoreceptor detachment, elongated and thickened photoreceptor outer segments, but preserved inner retinal layers. In conclusion, ARB associated retinal dystrophy shows functional and morphological changes that overlap with classic Best disease. For the first time, high-resolution imaging provided in vivo evidence of RPE and photoreceptor involvement in ARB.
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- 2008
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8. Illusory Color & the Brain
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Lothar Spillmann, Baingio Pinna, and John S. Werner
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Brightness ,Multidisciplinary ,Property (philosophy) ,Color constancy ,business.industry ,media_common.quotation_subject ,Illusion ,General Medicine ,Art ,Object (philosophy) ,Optics ,Sky ,Perception ,Sensation ,Computer vision ,Artificial intelligence ,business ,media_common - Abstract
A world without color appears to be missing crucial elements. And indeed it is. Colors not only enable us to see the world more precisely, they also create emergent qualities that would not exist without them. The color photograph on the opposite page, for example, reveals autumnal leaves in the placid water of a fountain, along with the reflections of trees and of a dark-blue afternoon sky behind them. In a black-and-white picture of the same scene, the leaves are less distinct, the dark-blue sky is absent, the reflections of the light are weak, the water itself is hardly visible, and the difference in apparent depth among the sky, trees and floating leaves is all but gone. Yet this role for color, and even the true nature of color, is not well recognized. Many people believe that color is a defining and essential property of objects, one depending entirely on the specific wavelengths of light reflected from them. But this belief is mistaken. Color is a sensation created in the brain. If the colors we perceived depended only on the wavelength of reflected light, an object's color would appear to change dramatically with variations in illumination throughout the day and in shadows. Instead patterns of activity in the brain render an object's color relatively stable despite changes in its environment.
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- 2007
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9. Chromatic-Spatial Vision of the Aging Eye
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Peter B. Delahunt, John S. Werner, and Joseph L. Hardy
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genetic structures ,Spectral power distribution ,Color vision ,Contrast effect ,color appearance ,Color space ,Eye ,Article ,law.invention ,White point ,Optics ,Clinical Research ,law ,Chromatic scale ,Chromaticity ,Eye Disease and Disorders of Vision ,Physics ,business.industry ,aging ,Neurosciences ,photoreceptors ,Atomic and Molecular Physics, and Optics ,chromatic contrast sensitivity ,white point ,Achromatic lens ,ocular media ,sense organs ,business - Abstract
The human visual system undergoes continuous anatomical, physiological and functional changes throughout the life span. There is also continuous change in the spectral distribution and intensity of light reaching the retina from infancy through senescence, primarily due to changes in the absorption of short-wave light by the lens. Despite these changes in the retinal stimulus and the signals leaving the retina for perceptual analysis, color appearance is relatively stable during aging as measured by broadband reflective or self-luminous samples, the wavelengths of unique blue and yellow, and the achromatic locus. Measures of ocular media density for younger and older observers show, indeed, that color appearance is independent of ocular media density. This may be explained by a renormalization process that was demonstrated by measuring the chromaticity of the achromatic point before and after cataract surgery. There was a shift following cataract surgery (removal of a brunescent lens) that was initially toward yellow in color space, but over the course of months, drifted back in the direction of the achromatic point before surgery. The spatial characteristics of color mechanisms were quantified for younger and older observers in terms of chromatic perceptive fields and the chromatic contrast sensitivity functions. Younger and older observers differed with small spots or with chromatic spatial gratings near threshold, but there were no significant differences with larger spots or suprathreshold spatial gratings.
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- 2004
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10. Erratum zu: Operative Therapie der abdominellen und retroperitonealen Sarkome
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Martin K. Angele, Rolf D. Issels, John S. Werner, Claus Belka, Lars H. Lindner, and Markus Albertsmeier
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medicine.medical_specialty ,Transplant surgery ,business.industry ,Cardiothoracic surgery ,medicine ,Surgery ,Vascular surgery ,business ,Abdominal surgery - Abstract
In diesem Beitrag wurde die Quellen angabe von . Abb. 1 versehentlich nicht vollstandig angegeben. Wir bitten, die Quellenangabe zu be achten und den Fehler zu entschuldigen.
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- 2014
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11. Opponent chromatic response functions for an average observer
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John S. Werner and B. R. Wooten
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Computer Science::Computer Science and Game Theory ,Communication ,business.industry ,Color vision ,Experimental and Cognitive Psychology ,Observer (special relativity) ,Models, Psychological ,Sensory Systems ,Computer Science::Multiagent Systems ,Computer Science::Emerging Technologies ,Psychophysics ,Humans ,Photopigment ,Chromatic scale ,business ,Algorithm ,Color Perception ,General Psychology ,Mathematics - Abstract
Average opponent chromatic response functions are presented for use in quantitative models of color perception. Theoretical transformations of photopigment input are related to opponent channel activity. Opponent chromatic activity is, in turn, used to describe a theoretical huenaming curve for an average observer.
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- 1979
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