44 results on '"Zietemann V"'
Search Results
2. POS0362 SEX-RELATED DIFFERENCES IN CHARACTERISTICS AND MORTALITY OF PATIENTS WITH RHEUMATOID ARTHRITIS AND CONCOMITANT HEART FAILURE
- Author
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Rudi, T., primary, Zietemann, V., additional, Meissner, Y., additional, Schneider, M., additional, Worsch, M., additional, and Strangfeld, A., additional
- Published
- 2023
- Full Text
- View/download PDF
3. Kontinuität der DMARD-Therapie und Sterblichkeit von Patienten mit rheumatoider Arthritis und prävalenter interstitieller Lungenerkrankung
- Author
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Rudi, T, Zietemann, V, Schäfer, M, Meissner, Y, Zink, A, Kneitz, C, Krause, A, Strangfeld, A, Rudi, T, Zietemann, V, Schäfer, M, Meissner, Y, Zink, A, Kneitz, C, Krause, A, and Strangfeld, A
- Published
- 2023
4. Charakterisierung geschlechtsspezifischer Unterschiede bei Patienten mit rheumatoider Arthritis und bestehender Herzinsuffizienz sowie deren Einfluss auf die Mortalität
- Author
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Rudi, T, Zietemann, V, Meissner, Y, Schneider, M, Klopsch, T, Worsch, ME, Strangfeld, A, Rudi, T, Zietemann, V, Meissner, Y, Schneider, M, Klopsch, T, Worsch, ME, and Strangfeld, A
- Published
- 2023
5. Every-day clinical practice in patients with advanced non-small-cell lung cancer
- Author
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Zietemann, V. and Duell, T.
- Published
- 2010
- Full Text
- View/download PDF
6. Depressionshäufigkeit in Abhängigkeit von verschiedenen Erkrankungen bei geriatrischen Patienten
- Author
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Zietemann, V., Zietemann, P., Weitkunat, R., and Kwetkat, A.
- Published
- 2007
- Full Text
- View/download PDF
7. METACOHORTS for the study of vascular disease and its contribution to cognitive decline and neurodegeneration: An initiative of the Joint Programme for Neurodegenerative Disease Research
- Author
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Dichgans, M., Wardlaw, J., Smith, E., Zietemann, V., Seshadri, S., Sachdev, P., Biessels, G.J., Fazekas, F., Benavente, O., Pantoni, L., Leeuw, F. de, Norrving, B., Matthews, P., Chen, C., Mok, V., During, M., Whiteley, W., Shuler, K., Alonso, A., Black, S.E., Brayne, C., Chabriat, H., Cordonnier, C., Doubal, F., Duzel, E., Ewers, M., Frayne, R., Hachinski, V., Ikram, M.A., Jessen, F., Jouvent, E., Linn, J., O'Brien, J., Oostenbrugge, R. van, Malik, R., Mazoyer, B., Schmidt, R., Sposato, L.A., Stephan, B., Swartz, R.H., Vernooij, M., Viswanathan, A., Werring, D., Abe, K., Allan, L., Arba, F., Bae, H.J., Bath, P.M.W., Bordet, R., Breteler, M., Choi, S., Deary, I., DeCarli, C., Ebmeier, K., Feng, L., Greenberg, S.M., Ihara, M., Kalaria, R., Kim, S., Lim, J.S., Lindley, R.I., Mead, G., Murray, A., Quinn, T., Ritchie, C., Sacco, R., Salman, R.A., Sprigg, N., Sudlow, C., Thomas, A., Boxtel, M. van, Grond, J. van der, Lugt, A. van der, Yang, Y.H., VISTA Collaboration, and METACOHORTS Consortiums
- Subjects
Dementia ,Neurodegeneration ,Cerebrovascular disease ,Survey ,Cohorts ,Small vessel disease - Published
- 2016
8. METACOHORTS for the study of vascular disease and its contribution to cognitive decline and neurodegeneration: An initiative of the Joint Programme for Neurodegenerative Disease Research
- Author
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Dichgans, M, Wardlaw, J, Smith, E, Zietemann, V, Seshadri, S, Sachdev, P, Biessels, GJ, Fazekas, F, Benavente, O, Pantoni, L, van der Leeuw, F, Norrving, B, Matthews, P, Chen, C (Christopher Li Hsian), Mok, V, During, M, Whiteley, W, Shuler, K, Alonso, A, Black, SE, Brayne, C, Chabriat, H, Cordonnier, C, Doubal, F, Duzel, E, Ewers, M, Frayne, R, Hachinski, V, Ikram, Arfan, Jessen, F, Jouvent, E, Linn, J, O'Brien, J, van Oostenbrugge, R, Malik, R, Mazoyer, B, Schmidt, R, Sposato, LA, Stephan, B, Swartz, RH, Vernooij, Meike, Viswanathan, A, Werring, D, Abe, K, Allan, L, Arba, F, Bae, H J, Bath, P M W, Bordet, R, Breteler, M, Choi, S, Deary, I, DeCarli, C, Ebmeier, K, Feng, L, Greenberg, SM, Ihara, M, Kalaria, R, Kim, S, Lim, J S, Lindley, RI, Mead, G, Murray, A, Quinn, T, Ritchie, C, Sacco, R, Salman, RA, Sprigg, N, Sudlow, C, Thomas, A, van Boxtel, M, van der Grond, J, van der Lugt, Aad, Yang, Y H, MUMC+: MA Neurologie (3), Klinische Neurowetenschappen, Section Neuropsychology, Psychiatrie & Neuropsychologie, RS: FPN NPPP I, Epidemiology, Neurology, and Radiology & Nuclear Medicine
- Subjects
Male ,LACUNAR STROKE ,Clinical Neurology ,SMALL-VESSEL DISEASE ,METACOHORTS Consortium. Electronic address: joanna.wardlaw@ed.ac.uk ,Cohort Studies ,Risk Factors ,Surveys and Questionnaires ,WHITE-MATTER HYPERINTENSITIES ,Prevalence ,Humans ,Cognitive Dysfunction ,Neurodegeneration ,METACOHORTS Consortium ,Cerebrovascular disease ,Survey ,Aged ,Science & Technology ,Dementia, Vascular ,Incidence ,STROKE SURVIVORS ,Neurodegenerative Diseases ,1103 Clinical Sciences ,IMPAIRMENT ,Neurodegeneration, Cohorts, Survey ,Small vessel disease ,ALZHEIMERS-DISEASE ,Cerebrovascular Disorders ,GAIT DISORDERS ,Geriatrics ,Female ,Dementia ,Neurosciences & Neurology ,STRUCTURAL NETWORK EFFICIENCY ,1109 Neurosciences ,Life Sciences & Biomedicine ,PARKINSONIAN SIGNS ,Cohorts - Abstract
Dementia is a global problem and major target for health care providers. Although up to 45% of cases are primarily or partly due to cerebrovascular disease, little is known of these mechanisms or treatments because most dementia research still focuses on pure Alzheimer's disease. An improved understanding of the vascular contributions to neurodegeneration and dementia, particularly by small vessel disease, is hampered by imprecise data, including the incidence and prevalence of symptomatic and clinically “silent” cerebrovascular disease, long-term outcomes (cognitive, stroke, or functional), and risk factors. New large collaborative studies with long follow-up are expensive and time consuming, yet substantial data to advance the field are available. In an initiative funded by the Joint Programme for Neurodegenerative Disease Research, 55 international experts surveyed and assessed available data, starting with European cohorts, to promote data sharing to advance understanding of how vascular disease affects brain structure and function, optimize methods for cerebrovascular disease in neurodegeneration research, and focus future research on gaps in knowledge. Here, we summarize the results and recommendations from this initiative. We identified data from over 90 studies, including over 660,000 participants, many being additional to neurodegeneration data initiatives. The enthusiastic response means that cohorts from North America, Australasia, and the Asia Pacific Region are included, creating a truly global, collaborative, data sharing platform, linked to major national dementia initiatives. Furthermore, the revised World Health Organization International Classification of Diseases version 11 should facilitate recognition of vascular-related brain damage by creating one category for all cerebrovascular disease presentations and thus accelerate identification of targets for dementia prevention.
- Published
- 2016
9. STROKOG (stroke and cognition consortium): An international consortium to examine the epidemiology, diagnosis, and treatment of neurocognitive disorders in relation to cerebrovascular disease.
- Author
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Sachdev, PS, Lo, JW, Crawford, JD, Mellon, L, Hickey, A, Williams, D, Bordet, R, Mendyk, A-M, Gelé, P, Deplanque, D, Bae, H-J, Lim, J-S, Brodtmann, A, Werden, E, Cumming, T, Köhler, S, Verhey, FRJ, Dong, Y-H, Tan, HH, Chen, C, Xin, X, Kalaria, RN, Allan, LM, Akinyemi, RO, Ogunniyi, A, Klimkowicz-Mrowiec, A, Dichgans, M, Wollenweber, FA, Zietemann, V, Hoffmann, M, Desmond, DW, Linden, T, Blomstrand, C, Fagerberg, B, Skoog, I, Godefroy, O, Barbay, M, Roussel, M, Lee, B-C, Yu, K-H, Wardlaw, J, Makin, SJ, Doubal, FN, Chappell, FM, Srikanth, VK, Thrift, AG, Donnan, GA, Kandiah, N, Chander, RJ, Lin, X, Cordonnier, C, Moulin, S, Rossi, C, Sabayan, B, Stott, DJ, Jukema, JW, Melkas, S, Jokinen, H, Erkinjuntti, T, Mok, VCT, Wong, A, Lam, BYK, Leys, D, Hénon, H, Bombois, S, Lipnicki, DM, Kochan, NA, STROKOG, Sachdev, PS, Lo, JW, Crawford, JD, Mellon, L, Hickey, A, Williams, D, Bordet, R, Mendyk, A-M, Gelé, P, Deplanque, D, Bae, H-J, Lim, J-S, Brodtmann, A, Werden, E, Cumming, T, Köhler, S, Verhey, FRJ, Dong, Y-H, Tan, HH, Chen, C, Xin, X, Kalaria, RN, Allan, LM, Akinyemi, RO, Ogunniyi, A, Klimkowicz-Mrowiec, A, Dichgans, M, Wollenweber, FA, Zietemann, V, Hoffmann, M, Desmond, DW, Linden, T, Blomstrand, C, Fagerberg, B, Skoog, I, Godefroy, O, Barbay, M, Roussel, M, Lee, B-C, Yu, K-H, Wardlaw, J, Makin, SJ, Doubal, FN, Chappell, FM, Srikanth, VK, Thrift, AG, Donnan, GA, Kandiah, N, Chander, RJ, Lin, X, Cordonnier, C, Moulin, S, Rossi, C, Sabayan, B, Stott, DJ, Jukema, JW, Melkas, S, Jokinen, H, Erkinjuntti, T, Mok, VCT, Wong, A, Lam, BYK, Leys, D, Hénon, H, Bombois, S, Lipnicki, DM, Kochan, NA, and STROKOG
- Abstract
INTRODUCTION: The Stroke and Cognition consortium (STROKOG) aims to facilitate a better understanding of the determinants of vascular contributions to cognitive disorders and help improve the diagnosis and treatment of vascular cognitive disorders (VCD). METHODS: Longitudinal studies with ≥75 participants who had suffered or were at risk of stroke or TIA and which evaluated cognitive function were invited to join STROKOG. The consortium will facilitate projects investigating rates and patterns of cognitive decline, risk factors for VCD, and biomarkers of vascular dementia. RESULTS: Currently, STROKOG includes 25 (21 published) studies, with 12,092 participants from five continents. The duration of follow-up ranges from 3 months to 21 years. DISCUSSION: Although data harmonization will be a key challenge, STROKOG is in a unique position to reuse and combine international cohort data and fully explore patient level characteristics and outcomes. STROKOG could potentially transform our understanding of VCD and have a worldwide impact on promoting better vascular cognitive outcomes.
- Published
- 2017
10. SEX-RELATED DIFFERENCES IN CHARACTERISTICS AND MORTALITY OF PATIENTS WITH RHEUMATOID ARTHRITIS AND CONCOMITANT HEART FAILURE.
- Author
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Rudi, T., Zietemann, V., Meissner, Y., Schneider, M., Worsch, M., and Strangfeld, A.
- Published
- 2023
- Full Text
- View/download PDF
11. THE IMPACT OF DIFFERENT DMARDS ON MORTALITY IN PATIENTS WITH RHEUMATOID ARTHRITIS AND PREVALENT INTERSTITIAL LUNG DISEASE.
- Author
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Rudi, T., Zietemann, V., Schaefer, M., Meissner, Y., Zink, A., Krause, A., and Strangfeld, A.
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- 2023
- Full Text
- View/download PDF
12. Acute infarcts cause focal thinning in remote cortex via degeneration of connecting fiber tracts
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Duering, M., primary, Righart, R., additional, Wollenweber, F. A., additional, Zietemann, V., additional, Gesierich, B., additional, and Dichgans, M., additional
- Published
- 2015
- Full Text
- View/download PDF
13. Prevalence and risk factors of brain metastases in patients with newly diagnosed advanced non-small-cell lung cancer
- Author
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Duell, T., primary, Kappler, S., additional, Knöferl, B., additional, Schuster, T., additional, Hochhaus, J., additional, Morresi-Hauf, A., additional, Huber, RM., additional, Tufman, A., additional, and Zietemann, V., additional
- Published
- 2015
- Full Text
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14. Pharmacogenomics Bias - Systematic distortion of study results by genetic heterogeneity
- Author
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Siebert, U, Sroczynski, G, and Zietemann, V
- Subjects
DECISION ANALYSIS ,KORONARKRANKHEIT ,PATIENTENSIMULATION ,PHARMACOGENETICS ,BIAS ,ddc: 610 ,PHARMACOGENOMICS ,PATIENT SIMULATION ,CORONARY HEART DISEASE ,PHARMAKOGENETIK ,BIAS (EPIDEMIOLOGIE) ,ENTSCHEIDUNGSUNTERSTÜTZENDE TECHNIKEN - Abstract
Background Decision analyses of drug treatments in chronic diseases require modeling the progression of disease and treatment response beyond the time horizon of clinical or epidemiological studies. In many such models, progression and drug effect have been applied uniformly to all patients; heterogeneity in progression, including pharmacogenomic effects, has been ignored. Objective We sought to systematically evaluate the existence, direction and relative magnitude of a pharmacogenomics bias (PGX-Bias) resulting from failure to adjust for genetic heterogeneity in both treatment response (HT) and heterogeneity in progression of disease (HP) in decision-analytic studies based on clinical study data. Methods We performed a systematic literature search in electronic databases for studies regarding the effect of genetic heterogeneity on the validity of study results. Included studies have been summarized in evidence tables. In the case of lacking evidence from published studies we sought to perform our own simulation considering both HT and HP. We constructed two simple Markov models with three basic health states (early-stage disease, late-stage disease, dead), one adjusting and the other not adjusting for genetic heterogeneity. Adjustment was done by creating different disease states for presence (G+) and absence (G-) of a dichotomous genetic factor. We compared the life expectancy gains attributable to treatment resulting from both models and defined pharmacogenomics bias as percent deviation of treatment-related life expectancy gains in the unadjusted model from those in the adjusted model. We calculated the bias as a function of underlying model parameters to create generic results. We then applied our model to lipid-lowering therapy with pravastatin in patients with coronary atherosclerosis, incorporating the influence of two TaqIB polymorphism variants (B1 and B2) on progression and drug efficacy as reported in the DNA substudy of the REGRESS trial. Results We found four studies that systematically evaluated heterogeneity bias. All of them indicated that there is a potential of heterogeneity bias. However, none of these studies explicitly investigated the effect of genetic heterogeneity. Therefore, we performed our own simulation study. Our generic simulation showed that a purely HT-related bias is negative (conservative) and a purely HP-related bias is positive (liberal). For many typical scenarios, the absolute bias is smaller than 10%. In case of joint HP and HT, the overall bias is likely triggered by the HP component and reaches positive values >100% if fractions of "fast progressors" and "strong treatment responders" are low. In the clinical example with pravastatin therapy, the unadjusted model overestimated the true life-years gained (LYG) by 5.5% (1.07 LYG vs. 0.99 LYG for 56-year-old men). Conclusions We have been able to predict the pharmacogenomics bias jointly caused by heterogeneity in progression of disease and heterogeneity in treatment response as a function of characteristics of patients, chronic disease, and treatment. In the case of joint presence of both types of heterogeneity, models ignoring this heterogeneity may generate results that overestimate the treatment benefit. Hintergrund Pharmakogenomik ist die Wissenschaft, die sich mit germinalen genetischen Variationen und mit deren Einfluss auf das Antwortverhalten auf pharmakologische Substanzen beschäftigt. In Entscheidungsanalysen zu Arzneimitteltherapien chronischer Erkrankungen müssen die Krankheitsprogression und Behandlungsresponse über den Zeithorizont klinischer oder epidemiologischer Studien hinaus modelliert werden. In vielen dieser Modelle wurde die Progression und Arzneimitteleffekt uniform für alle Patienten angesetzt und eine Heterogenität in der Progression und pharmakogenomische Effekte wurden häufig nicht berücksichtigt. Ziel Ziel dieses HTA-Berichts ist eine systematische Evaluation des Pharmacogenomics-Bias (PGX-Bias). Insbesondere sollen Existenz, Richtung und Größe einer Verzerrung in entscheidungsanalytischen Modellierungen basierend auf klinischen Studien bewertet werden. Methoden Es wurde eine systematische Literaturrecherche in den einschlägigen Datenbanken zum Einfluss genetischer Heterogenität auf die Validität von Studienergebnissen bzw. das Vorliegen eines PGX-Bias durchgeführt. Die eingeschlossenen Studien wurden in systematischen Kurzbeschreibungen und Evidenztabellen zusammengefasst. Zur validen Untersuchung eines PGX-Bias sollte bei Mangel an publizierten Studienergebnissen eine eigene entscheidungsanalytische Simulation durchgeführt werden, die sowohl die genetisch bedingte Heterogenität in der natürlichen Krankheitsprogression (HP) als auch die genetische bedingte Heterogenität in der Behandlungswirksamkeit (HW) untersucht. Es wurden zwei einfache Markov-Modelle entwickelt, von denen eines für die genetische Heterogenität adjustiert und das andere nicht. Der PGX-Bias wurde als prozentuale Abweichung der behandlungsbedingten zusätzlichen Lebensjahre (LYG) im nicht-adjustierten Modell vom adjustierten Modell definiert. In einem klinischen Beispiel wurde der PGX-Bias für die lipidsenkende Therapie mit Pravastin bei Patienten mit koronarer Atherosklerose ermittelt und dazu der Einfluss des TaqIB-Polymorphismus auf die Progression und Behandlungswahrscheinlichkeit basierend auf den Ergebnissen der REGRESS-DNA-Substudie ins Modell integriert. Ergebnisse Es wurden vier publizierte Studien identifiziert, die sich systematisch mit einem Heterogenitätsbias beschäftigen. Alle vier Studien deuten übereinstimmend auf das Potenzial eines Heterogenitätsbias hin, jedoch untersuchte keine dieser Studien explizit den Effekt von genetischer Heterogenität. Aus diesem Grund erfolgte eine eigene Simulationsstudie für diese Fragestellung. Die im Rahmen dieses HTA-Berichts eigens durchgeführte Simulation zeigt, dass ein rein HW-basierter Bias negativ (konservativ) ist und ein rein HP-basierter Bias positiv (liberal) ist. Für viele typische Szenarien ist der PGX-Bias kleiner als 10%. Im Fall einer kombinierten Heterogenität (HP und HW), ist es wahrscheinlich, dass der Gesamtbias durch die HP-Komponente bestimmt wird. Der PGX-Bias erreicht positive Werte von über 100%, wenn der Anteil der schnell progredierenden Patienten und starken Behandlungsrespondern niedrig ist. Im klinischen KHK-Beispiel (KHK=Koronare Herzkrankheit) mit Pravastinbehandlung überschätzte das nicht-adjustierte Modell den wahren Effekt der Pravastatinbehandlung in gewonnenen Lebensjahren um + 5,5% (1,07 LYG vs. 0,99 LYG für 56 Jahre alte Männer). Schlussfolgerungen In diesem HTA-Bericht konnte der PGX-Bias, der durch die Heterogenität in der Behandlungswahrscheinlichkeit und die Heterogenität in der Progression verursacht ist, als Funktion der Charakteristika von Patienten, chronischer Krankheit und Therapie dargestellt werden. Liegen beide Heterogenitätskomponenten vor, was in den meisten realistischen Situationen der Fall sein wird, so führt die Nichtberücksichtigung dieser Heterogenität zur Überschätzung des Behandlungseffekts.
- Published
- 2008
15. Collaborative case-control study of genetic susceptibility in early onset lung cancer
- Author
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Sauter, W, Timofeeva, M, Rosenberger, A, Mittelstrass, K, Illig, T, Zietemann, V, Meese, E, Sybrecht, G, Kronenberg, F, Dienemann, H, Chang-Claude, J, Wichmann, HE, Bickeböller, H, and Risch, A
- Subjects
ddc: 610 - Published
- 2007
16. Cisplatin versus Carboplatin bei der Behandlung von nichtkleinzelligem Lungenkrebs (NSCLC) im fortgeschrittenem Stadium
- Author
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Zietemann, V, Siebert, U, and Duell, T
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ddc: 610 - Published
- 2006
17. Pharmacogenomics-Bias - Systematische Verzerrungen in Studienergebnissen durch genetische Heterogenität
- Author
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Siebert, U, Sroczynski, G, Zietemann, V, Siebert, U, Sroczynski, G, and Zietemann, V
- Abstract
Background Decision analyses of drug treatments in chronic diseases require modeling the progression of disease and treatment response beyond the time horizon of clinical or epidemiological studies. In many such models, progression and drug effect have been applied uniformly to all patients; heterogeneity in progression, including pharmacogenomic effects, has been ignored. Objective We sought to systematically evaluate the existence, direction and relative magnitude of a pharmacogenomics bias (PGX-Bias) resulting from failure to adjust for genetic heterogeneity in both treatment response (HT) and heterogeneity in progression of disease (HP) in decision-analytic studies based on clinical study data. Methods We performed a systematic literature search in electronic databases for studies regarding the effect of genetic heterogeneity on the validity of study results. Included studies have been summarized in evidence tables. In the case of lacking evidence from published studies we sought to perform our own simulation considering both HT and HP. We constructed two simple Markov models with three basic health states (early-stage disease, late-stage disease, dead), one adjusting and the other not adjusting for genetic heterogeneity. Adjustment was done by creating different disease states for presence (G+) and absence (G-) of a dichotomous genetic factor. We compared the life expectancy gains attributable to treatment resulting from both models and defined pharmacogenomics bias as percent deviation of treatment-related life expectancy gains in the unadjusted model from those in the adjusted model. We calculated the bias as a function of underlying model parameters to create generic results. We then applied our model to lipid-lowering therapy with pravastatin in patients with coronary atherosclerosis, incorporating the influence of two TaqIB polymorphism variants (B1 and B2) on progression and drug efficacy as reported in the DNA substudy of the REGRESS trial. Results We fo, Hintergrund Pharmakogenomik ist die Wissenschaft, die sich mit germinalen genetischen Variationen und mit deren Einfluss auf das Antwortverhalten auf pharmakologische Substanzen beschäftigt. In Entscheidungsanalysen zu Arzneimitteltherapien chronischer Erkrankungen müssen die Krankheitsprogression und Behandlungsresponse über den Zeithorizont klinischer oder epidemiologischer Studien hinaus modelliert werden. In vielen dieser Modelle wurde die Progression und Arzneimitteleffekt uniform für alle Patienten angesetzt und eine Heterogenität in der Progression und pharmakogenomische Effekte wurden häufig nicht berücksichtigt. Ziel Ziel dieses HTA-Berichts ist eine systematische Evaluation des Pharmacogenomics-Bias (PGX-Bias). Insbesondere sollen Existenz, Richtung und Größe einer Verzerrung in entscheidungsanalytischen Modellierungen basierend auf klinischen Studien bewertet werden. Methoden Es wurde eine systematische Literaturrecherche in den einschlägigen Datenbanken zum Einfluss genetischer Heterogenität auf die Validität von Studienergebnissen bzw. das Vorliegen eines PGX-Bias durchgeführt. Die eingeschlossenen Studien wurden in systematischen Kurzbeschreibungen und Evidenztabellen zusammengefasst. Zur validen Untersuchung eines PGX-Bias sollte bei Mangel an publizierten Studienergebnissen eine eigene entscheidungsanalytische Simulation durchgeführt werden, die sowohl die genetisch bedingte Heterogenität in der natürlichen Krankheitsprogression (HP) als auch die genetische bedingte Heterogenität in der Behandlungswirksamkeit (HW) untersucht. Es wurden zwei einfache Markov-Modelle entwickelt, von denen eines für die genetische Heterogenität adjustiert und das andere nicht. Der PGX-Bias wurde als prozentuale Abweichung der behandlungsbedingten zusätzlichen Lebensjahre (LYG) im nicht-adjustierten Modell vom adjustierten Modell definiert. In einem klinischen Beispiel wurde der PGX-Bias für die lipidsenkende Therapie mit Pravastin bei Patienten mit koronarer Atherosklero
- Published
- 2008
18. Verzerrte Schätzung von Behandlungseffekten in randomisierten Studien mit multimodalem Behandlungsprozess – Darstellung des Problems zeitabhängiger Störvariablen anhand kausaler Graphen
- Author
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Zietemann, V., additional, Schuster, T., additional, and Duell, T., additional
- Published
- 2013
- Full Text
- View/download PDF
19. Prevalence and effectiveness of first-, second-, and third-line systemic therapy in a cohort of unselected patients with advanced non-small cell lung cancer
- Author
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Zietemann, V., primary and Duell, T., additional
- Published
- 2011
- Full Text
- View/download PDF
20. Omega-3-Fettsäuren bei Psoriasis
- Author
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Maringer, B., primary, Zietemann, V., additional, Ratzinger, G., additional, and Siebert, U., additional
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- 2009
- Full Text
- View/download PDF
21. PCN63 META-ANALYTIC, TRIAL-LEVEL APPROACH TO VALIDATION OF PROGRESSION-FREE SURVIVAL AS A SURROGATE ENDPOINT IN ADVANCED BREAST CANCER
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Miksad, R, primary, Zietemann, V, additional, Mattheucci Gothe, R, additional, Schwarzer, R, additional, Conrads-Frank, A, additional, Schnell-lnderst, P, additional, Stollenwerk, B, additional, Plieschnegger, P, additional, Esteban, E, additional, and Siebert, U, additional
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- 2007
- Full Text
- View/download PDF
22. Soziale Kontakte und Depression bei geriatrischen Patienten: Gibt es einen Einfluss von Geschlecht?
- Author
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Zietemann, V., primary, Machens, P., additional, Mielck, A., additional, and Kwetkat, A., additional
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- 2007
- Full Text
- View/download PDF
23. Verzerrte Schätzung von Behandlungseff ekten in randomisierten Studien mit multimodalem Behandlungsprozess -- Darstellung des Problems zeitabhängiger Störvariablen anhand kausaler Graphen.
- Author
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Zietemann, V. D., Schuster, T., and Duell, T. H. G.
- Published
- 2015
- Full Text
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24. Do genetic factors protect for early onset lung cancer? A case control study before the age of 50 years
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Jilge Bettina, Höffken Gerd, Häußinger Karl, Kreymborg Karsten, Konietzko Nikolaus, Gröschel Andreas, Drings Peter, Degen Maria, Cebulla Matthias, Kronenberg Florian, Sybrecht Gerhard, Meese Eckart, Wölke Gabi, Zietemann Vera, Klopp Norman, Korb Katrin, Illig Thomas, Rosenberger Albert, Ko You-Dschun, Morr Harald, Schmidt Christine, Schmidt E-Wilhelm, Täuscher Dagmar, Bickeböller Heike, and Wichmann H-Erich
- Subjects
Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Background Early onset lung cancer shows some familial aggregation, pointing to a genetic predisposition. This study was set up to investigate the role of candidate genes in the susceptibility to lung cancer patients younger than 51 years at diagnosis. Methods 246 patients with a primary, histologically or cytologically confirmed neoplasm, recruited from 2000 to 2003 in major lung clinics across Germany, were matched to 223 unrelated healthy controls. 11 single nucleotide polymorphisms of genes with reported associations to lung cancer have been genotyped. Results Genetic associations or gene-smoking interactions was found for GPX1(Pro200Leu) and EPHX1(His113Tyr). Carriers of the Leu-allele of GPX1(Pro200Leu) showed a significant risk reduction of OR = 0.6 (95% CI: 0.4–0.8, p = 0.002) in general and of OR = 0.3 (95% CI:0.1–0.8, p = 0.012) within heavy smokers. We could also find a risk decreasing genetic effect for His-carriers of EPHX1(His113Tyr) for moderate smokers (OR = 0.2, 95% CI:0.1–0.7, p = 0.012). Considered both variants together, a monotone decrease of the OR was found for smokers (OR of 0.20; 95% CI: 0.07–0.60) for each protective allele. Conclusion Smoking is the most important risk factor for young lung cancer patients. However, this study provides some support for the T-Allel of GPX1(Pro200Leu) and the C-Allele of EPHX1(His113Tyr) to play a protective role in early onset lung cancer susceptibility.
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- 2008
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25. Do genetic factors protect for early onset lung cancer? A case control study before the age of 50 years.
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Rosenberger A, Illig T, Korb K, Klopp N, Zietemann V, Wölke G, Meese E, Sybrecht G, Kronenberg F, Cebulla M, Degen M, Drings P, Gröschel A, Konietzko N, Kreymborg KG, Häussinger K, Höffken G, Jilge B, Ko YD, and Morr H
- Abstract
Background: Early onset lung cancer shows some familial aggregation, pointing to a genetic predisposition. This study was set up to investigate the role of candidate genes in the susceptibility to lung cancer patients younger than 51 years at diagnosis.Methods: 246 patients with a primary, histologically or cytologically confirmed neoplasm, recruited from 2000 to 2003 in major lung clinics across Germany, were matched to 223 unrelated healthy controls. 11 single nucleotide polymorphisms of genes with reported associations to lung cancer have been genotyped.Results: Genetic associations or gene-smoking interactions was found for GPX1(Pro200Leu) and EPHX1(His113Tyr). Carriers of the Leu-allele of GPX1(Pro200Leu) showed a significant risk reduction of OR = 0.6 (95% CI: 0.4-0.8, p = 0.002) in general and of OR = 0.3 (95% CI:0.1-0.8, p = 0.012) within heavy smokers. We could also find a risk decreasing genetic effect for His-carriers of EPHX1(His113Tyr) for moderate smokers (OR = 0.2, 95% CI:0.1-0.7, p = 0.012). Considered both variants together, a monotone decrease of the OR was found for smokers (OR of 0.20; 95% CI: 0.07-0.60) for each protective allele.Conclusion: Smoking is the most important risk factor for young lung cancer patients. However, this study provides some support for the T-Allel of GPX1(Pro200Leu) and the C-Allele of EPHX1(His113Tyr) to play a protective role in early onset lung cancer susceptibility. [ABSTRACT FROM AUTHOR]- Published
- 2008
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26. Impact of DMARD treatment and systemic inflammation on all-cause mortality in patients with rheumatoid arthritis and interstitial lung disease: a cohort study from the German RABBIT register.
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Rudi T, Zietemann V, Meissner Y, Zink A, Krause A, Lorenz HM, Kneitz C, Schaefer M, and Strangfeld A
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- Humans, Cohort Studies, Tumor Necrosis Factor-alpha, Inflammation drug therapy, Biological Factors therapeutic use, Biomarkers, Antirheumatic Agents adverse effects, Arthritis, Rheumatoid complications, Arthritis, Rheumatoid drug therapy, Arthritis, Rheumatoid chemically induced, Lung Diseases, Interstitial complications, Lung Diseases, Interstitial drug therapy, Biological Products therapeutic use
- Abstract
Objectives: To investigate the impact of disease activity and treatment with disease-modifying antirheumatic drugs (DMARDs) on all-cause mortality in patients with rheumatoid arthritis and prevalent interstitial lung disease (RA-ILD)., Methods: Patients with RA-ILD were selected from the biologics register Rheumatoid Arthritis: Observation of Biologic Therapy (RABBIT). Using time-varying Cox regression, the association between clinical measures and mortality was investigated. The impact of DMARDs was analysed by (1) Cox regression considering cumulative exposure (ie, treatment months divided by total months) and (2) time-varying Cox regression as main approach (treatment exposures at monthly level)., Results: Out of 15 566 participants, 381 were identified as RA-ILD cases with 1258 person-years of observation and 2.6 years median length of follow-up. Ninety-seven patients (25.5%) died and 34 (35.1%) of these were not receiving DMARD therapy at the time of death. Higher inflammatory biomarkers but not swollen and tender joint count were significantly associated with mortality. Compared with tumour necrosis factor inhibitors (TNFi), non-TNFi biologic DMARDs (bDMARDs) exhibited adjusted HRs (aHRs) for mortality below 1, lacking statistical significance. This finding was stable in various sensitivity analyses. Joint aHR for non-TNFi biologics and JAKi versus TNFi was 0.56 (95% CI 0.33 to 0.97). Receiving no DMARD treatment was associated with a twofold higher mortality risk compared with receiving any DMARD treatment, aHR 2.03 (95% CI 1.23 to 3.35)., Conclusions: Inflammatory biomarkers and absence of DMARD treatment were associated with increased risk of mortality in patients with RA-ILD. Non-TNFi bDMARDs may confer enhanced therapeutic benefits in patients with RA-ILD., Competing Interests: Competing interests: AK: consulting fees: AbbVie, Gilead, Boehringer Ingelheim, Novartis, Janssen, UCB, Lilly and payment for lectures, presentations: AbbVie, Gilead, Boehringer Ingelheim, Roche, Novartis, Janssen, UCB, Lilly and support for attending meetings and/or travel: AbbVie, Boehringer Ingelheim and participation on a Data Safety Monitoring Board or Advisory Board: Pfizer and leadership or fiduciary role in other board, society, commitee or advocacy group, paid or unpaid: German Society for Rheumatology. CK: payment for lectures, presentations: AbbVie, AstraZeneca, BMS, Boehringer Ingelheim, Celltrion, Galapagos, GSK, Hexal, Janssen, Lilly, Medical School Hamburg, MSD, Novartis, Pfizer, Roche, Sanofi, UCB and participation on a Data Safety Monitoring Board or Advisory Board: Boehringer Ingelheim, Novartis. H-ML: grants or contracts from any entity: Pfizer, Novartis and consulting fees: AbbVie, AstraZeneca, Actelion, Amgen, Bayer Vital, Boehringer Ingelheim, BMS, Celgene, GSK, Gilead/Galapagos, Janssen, Lilly, Medac, MSD, Novartis, Pfizer, Roche/Chugai, Sanofi, UCB and payment for lectures, presentations: AbbVie, AstraZeneca, Actelion, Amgen, Bayer Vital, Boehringer Ingelheim, BMS, Celgene, GSK, Gilead/Galapagos, Janssen, Lilly, Medac, MSD, Novartis, Pfizer, Roche/Chugai, Sanofi, UCB and support for attending meetings and/or travel: AbbVie, AstraZeneca, Boehringer Ingelheim, BMS, Celgene, GSK, Gilead/Galapagos, Janssen, Lilly, MSD, Novartis, Pfizer, Roche/Chugai, Sanofi, USB and participation on a Data Safety Monitoring Board or Advisory Board: AbbVie, AstraZeneca, Amgen, Boehringer Ingelheim, BMS, Celgene, GSK, Gilead/Galapagos, Janssen, Lilly, Medac, MSD, Novartis, Pfizer, Roche/Chugai, Sanofi, UCB. AS: lecture honoraria from AbbVie, Amgen, BMS, Celltrion, MSD, Lilly, Pfizer, Roche, UCB., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)
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- 2024
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27. Early MoCA predicts long-term cognitive and functional outcome and mortality after stroke.
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Zietemann V, Georgakis MK, Dondaine T, Müller C, Mendyk AM, Kopczak A, Hénon H, Bombois S, Wollenweber FA, Bordet R, and Dichgans M
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- Aged, Cognitive Dysfunction etiology, Female, Humans, Male, Middle Aged, Predictive Value of Tests, Prospective Studies, Recovery of Function, Cognitive Dysfunction diagnosis, Mental Status and Dementia Tests, Stroke complications, Stroke mortality
- Abstract
Objective: To examine whether the Montreal Cognitive Assessment (MoCA) administered within 7 days after stroke predicts long-term cognitive impairment, functional impairment, and mortality., Methods: MoCA was administered to 274 patients from 2 prospective hospital-based cohort studies in Germany (n = 125) and France (n = 149). Cognitive and functional outcomes were assessed at 6, 12, and 36 months after stroke by comprehensive neuropsychological testing, the Clinical Dementia Rating (CDR) scale, the modified Rankin Scale (mRS), and Instrumental Activities of Daily Living (IADL) and analyzed with generalized estimating equations. All-cause mortality was investigated by Cox proportional hazard models. Analyses were adjusted for demographic variables, education, vascular risk factors, premorbid cognitive status, and NIH Stroke Scale scores. The additive predictive value of MoCA was examined with receiver operating characteristic curves., Results: In pooled analyses, a baseline MoCA score <26 was associated with cognitive impairment, defined by neuropsychological testing (odds ratio [OR] 5.30, 95% confidence interval [CI] 2.75-10.22) and by CDR score ≥0.5 (OR 2.53, 95% CI 1.53-4.18); functional impairment, defined by mRS score >2 (OR 5.03, 95% CI 2.20-11.51) and by IADL score <8 (OR 2.48, 95% CI 1.40-4.38); and mortality (hazard ratio 7.24, 95% CI 1.99-26.35) across the 3-year follow-up. Patients with MoCA score <26 performed worse across all prespecified cognitive domains (executive function/attention, memory, language, visuospatial ability). MoCA increased the area under the curve for predicting cognitive impairment (neuropsychological testing 0.81 vs 0.72, p = 0.01) and functional impairment (mRS score >2, 0.88 vs 0.84, p = 0.047)., Conclusion: Early cognitive testing by MoCA predicts long-term cognitive outcome, functional outcome, and mortality after stroke. Our results support routine use of the MoCA in stroke patients., (© 2018 American Academy of Neurology.)
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- 2018
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28. Validation of the Telephone Interview of Cognitive Status and Telephone Montreal Cognitive Assessment Against Detailed Cognitive Testing and Clinical Diagnosis of Mild Cognitive Impairment After Stroke.
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Zietemann V, Kopczak A, Müller C, Wollenweber FA, and Dichgans M
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- Aged, Aged, 80 and over, Cognitive Dysfunction etiology, Follow-Up Studies, Humans, Middle Aged, Prospective Studies, Stroke therapy, Cognition, Cognitive Dysfunction diagnosis, Interviews as Topic, Stroke complications
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Background and Purpose: Assessment of cognitive status poststroke is recommended by guidelines but follow-up can often not be done in person. The Telephone Interview of Cognitive Status (TICS) and the Telephone Montreal Cognitive Assessment (T-MoCA) are considered useful screening instruments. Yet, evidence to define optimal cut-offs for mild cognitive impairment (MCI) after stroke is limited., Methods: We studied 105 patients enrolled in the prospective DEDEMAS study (Determinants of Dementia After Stroke; NCT01334749). Follow-up visits at 6, 12, 36, and 60 months included comprehensive neuropsychological testing and the Clinical Dementia Rating scale, both of which served as reference standards. The original TICS and T-MoCA were obtained in 2 separate telephone interviews each separated from the personal visits by 1 week (1 before and 1 after the visit) with the order of interviews (TICS versus T-MoCA) alternating between subjects. Area under the receiver-operating characteristic curves was determined., Results: Ninety-six patients completed both the face-to-face visits and the 2 interviews. Area under the receiver-operating characteristic curves ranged between 0.76 and 0.83 for TICS and between 0.73 and 0.94 for T-MoCA depending on MCI definition. For multidomain MCI defined by multiple-tests definition derived from comprehensive neuropsychological testing optimal sensitivities and specificities were achieved at cut-offs <36 (TICS) and <18 (T-MoCA). Validity was lower using single-test definition, and cut-offs were higher compared with multiple-test definitions. Using Clinical Dementia Rating as the reference, optimal cut-offs for MCI were <36 (TICS) and approximately 19 (T-MoCA)., Conclusions: Both the TICS and T-MoCA are valid screening tools poststroke, particularly for multidomain MCI using multiple-test definition., (© 2017 American Heart Association, Inc.)
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- 2017
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29. STROKOG (stroke and cognition consortium): An international consortium to examine the epidemiology, diagnosis, and treatment of neurocognitive disorders in relation to cerebrovascular disease.
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Sachdev PS, Lo JW, Crawford JD, Mellon L, Hickey A, Williams D, Bordet R, Mendyk AM, Gelé P, Deplanque D, Bae HJ, Lim JS, Brodtmann A, Werden E, Cumming T, Köhler S, Verhey FR, Dong YH, Tan HH, Chen C, Xin X, Kalaria RN, Allan LM, Akinyemi RO, Ogunniyi A, Klimkowicz-Mrowiec A, Dichgans M, Wollenweber FA, Zietemann V, Hoffmann M, Desmond DW, Linden T, Blomstrand C, Fagerberg B, Skoog I, Godefroy O, Barbay M, Roussel M, Lee BC, Yu KH, Wardlaw J, Makin SJ, Doubal FN, Chappell FM, Srikanth VK, Thrift AG, Donnan GA, Kandiah N, Chander RJ, Lin X, Cordonnier C, Moulin S, Rossi C, Sabayan B, Stott DJ, Jukema JW, Melkas S, Jokinen H, Erkinjuntti T, Mok VC, Wong A, Lam BY, Leys D, Hénon H, Bombois S, Lipnicki DM, and Kochan NA
- Abstract
Introduction: The Stroke and Cognition consortium (STROKOG) aims to facilitate a better understanding of the determinants of vascular contributions to cognitive disorders and help improve the diagnosis and treatment of vascular cognitive disorders (VCD)., Methods: Longitudinal studies with ≥75 participants who had suffered or were at risk of stroke or TIA and which evaluated cognitive function were invited to join STROKOG. The consortium will facilitate projects investigating rates and patterns of cognitive decline, risk factors for VCD, and biomarkers of vascular dementia., Results: Currently, STROKOG includes 25 (21 published) studies, with 12,092 participants from five continents. The duration of follow-up ranges from 3 months to 21 years., Discussion: Although data harmonization will be a key challenge, STROKOG is in a unique position to reuse and combine international cohort data and fully explore patient level characteristics and outcomes. STROKOG could potentially transform our understanding of VCD and have a worldwide impact on promoting better vascular cognitive outcomes.
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- 2016
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30. Prevalence of Amyloid Positron Emission Tomographic Positivity in Poststroke Mild Cognitive Impairment.
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Wollenweber FA, Därr S, Müller C, Duering M, Buerger K, Zietemann V, Malik R, Brendel M, Ertl-Wagner B, Bartenstein P, Rominger A, and Dichgans M
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- Aged, Aged, 80 and over, Amyloid beta-Peptides, Cognitive Dysfunction etiology, Female, Humans, Magnetic Resonance Imaging, Male, Memory physiology, Neuropsychological Tests, Positron-Emission Tomography, Prospective Studies, Stroke complications, Amyloid, Brain diagnostic imaging, Cognitive Dysfunction diagnostic imaging, Stroke diagnostic imaging
- Abstract
Background and Purpose: Mild cognitive impairment (MCI) is common after stroke and associated with poor outcome. However, the mechanisms underlying poststroke MCI (PS-MCI) are insufficiently understood. We performed amyloid-β positron emission tomography (PET) in a prospective cohort of stroke survivors to determine the role of amyloid pathology in PS-MCI., Methods: We studied 178 consecutive patients enrolled into the prospective DEDEMAS study (Determinants of Dementia After Stroke). Follow-up visits 6 months post stroke included detailed cognitive testing, standardized magnetic resonance imaging, and amyloid-β imaging using flutemetamol ((18)F) PET. MCI was defined by the modified Petersen criteria. Amyloid-positivity was assessed visually and quantitatively. Fifty-six (31%) patients agreed to undergo PET imaging., Results: Thirty-eight (68%) patients who consented to PET imaging had PS-MCI. Visual assessment revealed amyloid PET positivity in 2 (5%) of the 38 PS-MCI patients and in 2 (11%) of the 18 cognitively healthy stroke survivors. There was no correlation between flutemetamol ((18)F) standardized uptake value ratios and cognitive scores in the 56 patients. PS-MCI patients had significant cognitive impairments on executive function (P<0.01) and memory tests (P<0.01) when compared with cognitively healthy stroke survivors (P<0.01)., Conclusions: The prevalence of amyloid-pathology in patients with PS-MCI is not increased when compared with cognitively healthy stroke survivors and to recent estimates for cognitively healthy elderly subjects. Factors other than amyloid-pathology likely contribute to the development of PS-MCI., Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01334749., (© 2016 American Heart Association, Inc.)
- Published
- 2016
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31. Peripheral glucose levels and cognitive outcome after ischemic stroke-Results from the Munich Stroke Cohort.
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Zietemann V, Wollenweber FA, Bayer-Karpinska A, Biessels GJ, and Dichgans M
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Introduction: The relationship between glucose metabolism and stroke outcome is likely to be complex. We examined whether there is a linear or non-linear relationship between glucose measures in the acute phase of stroke and post-stroke cognition, and whether altered glucose metabolism at different time intervals (long- and short-term before stroke, acute phase) is associated with cognitive outcome., Patients and Methods: In all, 664 consecutively recruited patients with acute ischemic stroke and without pre-stroke dementia were included in this prospective observational study. Blood samples were taken at admission and fasting on the first morning after stroke. Duration of diabetes was assessed by interview. Cognitive outcome was assessed by the Telephone Interview for Cognitive Status 3 months post-stroke. Dose-response analyses were used to investigate non-linearity. Regression analyses were stratified by diabetes status and adjusted for relevant confounders., Results: Cognitive status was testable in 422 patients (81 with diabetes). There was a non-linear relationship between both admission and fasting glucose levels and cognitive outcome. Lower glucose values were significantly associated with lower Telephone Interview for Cognitive Status scores 3 months post-stroke in patients without diabetes with a similar trend in diabetic patients. There was an inverse association between duration of diabetes and Telephone Interview for Cognitive Status scores (linear regression: -0.10 (95% confidence interval: -0.17 to -0.02) per year increase of diabetes duration), whereas HbA
1c was not related to cognitive outcome. Results were supported by sensitivity analyses accounting for attrition., Conclusion: Lower glucose levels in the acute phase of stroke are associated with worse cognitive outcome but the relationship is non-linear. Long-term abnormalities in glucose metabolism are also related to poor outcome but this is not the case for shorter term abnormalities. Altered glucose levels at different stages of stroke may affect stroke outcome through different pathways., Competing Interests: The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: GJB consults for and receives research support from Boehringer Ingelheim and consults for Takeda Pharmaceuticals. Compensation for these services is transferred to his employer, the UMC Utrecht.- Published
- 2016
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32. [Time-dependent confounding in the estimation of treatment effects in randomised trials with multimodal therapies--an illustration of the problem of time-dependent confounding by causal graphs].
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Zietemann VD, Schuster T, and Duell TH
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- Computer Simulation, Humans, Outcome Assessment, Health Care statistics & numerical data, Reproducibility of Results, Sensitivity and Specificity, Time Factors, Combined Modality Therapy statistics & numerical data, Confounding Factors, Epidemiologic, Data Interpretation, Statistical, Models, Statistical, Outcome Assessment, Health Care methods, Randomized Controlled Trials as Topic statistics & numerical data
- Abstract
Biased effect estimates induced by unconsidered confounding variables are a known problem in observational studies. Selection bias, resulting from non-random sampling of study participants, is widely recognised as a problem in case-control and cross-sectional studies. In contrast, possible bias in randomised controlled trials (RCTs) is mostly ignored. This paper illustrates, by applying directed acyclic graphs (DAGs), possible bias in the effect estimates of first-line therapy, caused by subsequent changes in therapy (time-dependent confounding). Possible selection bias, induced by not only random loss to follow-up, will be explained as well using DAGs. Underlying assumptions of standard methods usually used to analyse RCTs (like intention-to-treat, per-protocol) are shown and it is explained why effect estimates may be biased in RCTs, if only these conventional methods are used. Adequate statistical methods (causal inference models as marginal structural models and structural nested models) exist. Higher documentary efforts, however, are necessary, because any changes in medication, loss to follow-up as well as reasons for such changes need to be documented in detail as required by these advanced statistical methods. Nevertheless, causal inference models should become standard along side the currently applied standard methods, especially in studies with high non-compliance due to changes in therapy and substantial loss to follow-up. Possible bias cannot be excluded if similar results are obtained from both methods. However, study results should be interpreted with caution if they differ between both approaches., (© Georg Thieme Verlag KG Stuttgart · New York.)
- Published
- 2015
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33. The Determinants of Dementia After Stroke (DEDEMAS) Study: protocol and pilot data.
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Wollenweber FA, Zietemann V, Rominger A, Opherk C, Bayer-Karpinska A, Gschwendtner A, Coloma Andrews L, Bürger K, Duering M, and Dichgans M
- Subjects
- Aged, Amyloid metabolism, Ankle Brachial Index, Carotid Intima-Media Thickness, Cohort Studies, Dementia therapy, Female, Fluorodeoxyglucose F18, Humans, Magnetic Resonance Imaging, Male, Neurologic Examination, Neuropsychological Tests, Pilot Projects, Positron-Emission Tomography, Retina pathology, Treatment Outcome, Waist-Hip Ratio, Dementia diagnosis, Dementia etiology, Stroke complications
- Abstract
Rationale: About 20% of stroke patients develop dementia within a few months after their event, but the determinants and mechanisms of poststroke dementia are insufficiently understood., Aims: To identify and characterize the determinants of cognitive impairment poststroke., Design: Observational prospective study in patients with acute stroke and no prior dementia. Six hundred subjects will be characterized by detailed interview, standardized clinical examinations, biometric measures (intima-media thickness, waist-hip ratio, and ankle-brachial index), multimodal imaging (magnetic resonance imaging, fluorodeoxyglucose-positron emission tomography (FDG-PET), amyloid-positron emission tomography (amyloid-PET), and retinal imaging), analysis of biomarkers derived from blood and cerebrospinal fluid, and detailed cognitive testing at repeat time points. Patients will be followed for five-years with a total of five personal visits and three telephone interviews., Study Outcomes: Primary end-point is the occurrence of poststroke dementia. Secondary end-points include poststroke cognitive impairment-no dementia, stroke recurrence, and death. Predictive factors for poststroke dementia will be identified by multiple Cox proportional-hazards model., Results: Baseline characteristics of the first 71 patients (study inclusion between May 2011 and August 2012) are as follows: median age, 70 years (interquartile range, 65-75); female gender, 25 (35%); median National Institutes of Health Stroke Scale at admission, 2 (1-4); and etiological stroke subtypes according to TOAST classification, 15% large artery disease, 18% small vessel disease, 35% cardioembolic, and 32% undetermined or multiple competing etiologies., Discussion: This study will provide insights into the mechanisms of poststroke dementia and hold the potential to identify novel diagnostic markers and targets for preventive therapies. The study is registered at http://www.clinicaltrials.gov (NCT01334749) and will be extended as a multicenter study starting 2013., (© 2013 The Authors. International Journal of Stroke © 2013 World Stroke Organization.)
- Published
- 2014
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34. Prediction of vascular risk after stroke - protocol and pilot data of the Prospective Cohort with Incident Stroke (PROSCIS).
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Liman TG, Zietemann V, Wiedmann S, Jungehuelsing GJ, Endres M, Wollenweber FA, Wellwood I, Dichgans M, and Heuschmann PU
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- Adult, Aged, Aged, 80 and over, Clinical Protocols, Cohort Studies, Female, Humans, Male, Middle Aged, Myocardial Infarction epidemiology, Pilot Projects, Prognosis, Research Design, Risk Factors, Vascular Diseases epidemiology, Young Adult, Models, Statistical, Risk Assessment methods, Stroke complications, Stroke mortality
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Rationale: Long-term risk of vascular disease is substantially increased after stroke with several models proposed to predict subsequent stroke and other vascular events after an index event. However, recent validation studies demonstrate limited predictive properties of available prognostic models., Aims: We aim to determine prediction models of different complexity for the combined vascular end-point of stroke, myocardial infarction, and vascular death at three-years after first-ever stroke. An independent external validation of the developed models will be performed., Design: Prospective observational hospital-based cohort study of patients after first-ever stroke., Methods: The new predictive models will be developed using the following steps: (1) Development of a basic score based on clinical history data (e.g. hypertension, myocardial infarction, and atrial fibrillation); (2) Development of an advanced score including additional factors such as blood-based biomarkers and results of vascular imaging; (3) Comparing the models fit using different methods (discrimination, calibration); (4) Assessment of clinical utility of an advanced score using methods based on reclassification tables (e.g. net reclassification improvement, integrated discrimination improvement, decision curve analysis); and (5) Investigation of external validity., Outcomes: Primary outcome is a combined vascular end-point composed of stroke, myocardial infarction, and vascular death at three-years after stroke. Furthermore, each component of the composite end-point will be investigated individually and the patterns and time points of risk transitions between vascular end-points and stroke sub-types will be determined., (© 2012 The Authors. International Journal of Stroke © 2012 World Stroke Organization.)
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- 2013
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35. Subclinical hyperthyroidism is a risk factor for poor functional outcome after ischemic stroke.
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Wollenweber FA, Zietemann V, Gschwendtner A, Opherk C, and Dichgans M
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- Aged, Aged, 80 and over, Brain Ischemia blood, Brain Ischemia physiopathology, Female, Humans, Hyperthyroidism blood, Hyperthyroidism physiopathology, Male, Middle Aged, Prognosis, Prospective Studies, Risk Factors, Stroke blood, Stroke physiopathology, Thyrotropin blood, Brain Ischemia complications, Hyperthyroidism complications, Stroke complications
- Abstract
Background and Purpose: Subclinical hyperthyroidism is associated with adverse cardiovascular events, including stroke and atrial fibrillation. However, its impact on functional outcome after stroke remains unexplored., Methods: A total of 165 consecutively recruited patients admitted for ischemic stroke were included in this observational prospective study. Blood samples were taken in the morning within 3 days after symptom onset, and patients were divided into the following 3 groups: subclinical hyperthyroidism (0.1< thyroid-stimulating hormone ≤ 0.44 μU/mL), subclinical hypothyroidism (2.5 ≤ thyroid-stimulating hormone <20 μU/mL), and euthyroid state (0.44< thyroid-stimulating hormone <2.5 μU/mL). Patients with overt thyroid dysfunction were excluded. Follow-up took place 3 months after stroke. Primary outcome was functional disability (modified Rankin Scale), and secondary outcome was level of dependency (Barthel Index). Ordinal logistic regression analysis was used to adjust for possible confounders. Variables previously reported to be affected by thyroid function, such as atrial fibrillation, total cholesterol, or body mass index, were included in an additional model., Results: Nineteen patients (11.5%) had subclinical hyperthyroidism, and 23 patients (13.9%) had subclinical hypothyroidism. Patients with subclinical hyperthyroidism had a substantially increased risk of functional disability 3 months after stroke compared with subjects with euthyroid state (odds ratio, 2.63; 95% confidence interval, 1.02-6.82, adjusted for age, sex, smoking status, and time of blood sampling). The association remained significant, when including the baseline NIHSS, TIA, serum CRP, atrial fibrillation, body mass index, and total cholesterol as additional variables (odds ratio, 3.95; 95% confidence interval, 1.25-12.47), and was confirmed by the secondary outcome (Barthel Index: odds ratio, 9.12; 95% confidence interval, 2.08-39.89)., Conclusions: Subclinical hyperthyroidism is a risk factor for poor outcome 3 months after ischemic stroke.
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- 2013
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36. Prevention of vascular cognitive impairment.
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Dichgans M and Zietemann V
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- Humans, Cerebrovascular Disorders complications, Cognition Disorders etiology, Cognition Disorders prevention & control
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- 2012
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37. Erythrocyte membrane phospholipid polyunsaturated fatty acids are related to plasma C-reactive protein and adiponectin in middle-aged German women and men.
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Enzenbach C, Kröger J, Zietemann V, Jansen EH, Fritsche A, Döring F, Boeing H, and Schulze MB
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- Adult, Biomarkers, Cross-Sectional Studies, Female, Germany, Humans, Male, Middle Aged, PPAR gamma genetics, PPAR gamma metabolism, Polymorphism, Genetic, Risk Factors, White People, 8,11,14-Eicosatrienoic Acid blood, Adiponectin blood, C-Reactive Protein metabolism, Erythrocyte Membrane chemistry, Phospholipids blood, gamma-Linolenic Acid blood
- Abstract
Purpose: Modulation of circulating inflammatory markers and adiponectin may link PUFA to risk of diabetes and cardiovascular diseases. We investigated erythrocyte n-6 and n-3 PUFA in relation to plasma C-reactive protein (CRP) and adiponectin, and whether the Pro12Ala polymorphism in the PPARγ2 gene (PPARG2) modified these associations., Methods: We conducted a cross-sectional analysis among 1,222 women and 758 men participating in the EPIC-Potsdam study., Results: Most notably, in both sexes, higher linoleic acid (LA) was related to lower CRP (geometric mean outcome [mg/L], quintile 1, quintile 5, p for trend ≤ 0.01 unless otherwise stated: 0.95, 0.61 [women], 0.67, 0.51 [men]) and higher adiponectin (7.9, 9.1 [women], 5.3, 6.1 [men]), whereas higher γ-linolenic acid (GLA) and dihomo-γ-linolenic acid (DGLA) were related to higher CRP (GLA: 0.63, 0.92 [women], 0.55, 0.70, p = 0.08 [men], DGLA: 0.55, 1.07 [women], 0.52, 0.76 [men]) and lower adiponectin (GLA: 8.6, 8.0 [women], 5.8, 5.4, p = 0.08 [men], DGLA: 9.2, 7.9 [women], 5.9, 5.4, p = 0.08 [men]) adjusting for age and lifestyle. The associations mostly did neither strongly nor significantly vary by PPARG2 genotype. In women, Pro12Ala appeared to interact with arachidonic acid on CRP (p = 0.04), as well as with docosatetraenoic acid on CRP (p = 0.08) and adiponectin (p = 0.02)., Conclusions: Our findings suggest that erythrocyte PUFA, particularly LA and n-6 higher unsaturated fatty acids, are related to circulating CRP and adiponectin. They do not indicate that PUFA strongly interact with the PPARG2 Pro12Ala variant on these risk markers.
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- 2011
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38. Erythrocyte membrane phospholipid fatty acids, desaturase activity, and dietary fatty acids in relation to risk of type 2 diabetes in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam Study.
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Kröger J, Zietemann V, Enzenbach C, Weikert C, Jansen EH, Döring F, Joost HG, Boeing H, and Schulze MB
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- Adult, Aged, Case-Control Studies, Delta-5 Fatty Acid Desaturase, Fatty Acid Desaturases genetics, Fatty Acids administration & dosage, Female, Genotype, Humans, Male, Mendelian Randomization Analysis, Middle Aged, Prospective Studies, Stearoyl-CoA Desaturase metabolism, Diabetes Mellitus, Type 2 etiology, Dietary Fats administration & dosage, Erythrocyte Membrane chemistry, Fatty Acid Desaturases metabolism, Fatty Acids blood, Phospholipids blood
- Abstract
Background: The long-term role of fatty acids (FAs) in the cause of diabetes remains largely unclear., Objective: We aimed to investigate erythrocyte membrane FAs, desaturase activity, and dietary FAs in relation to the incidence of type 2 diabetes., Design: We applied a nested case-cohort design (n = 2724, including 673 incident diabetes cases) within the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam Study, which involves 27,548 middle-aged subjects. Thirty erythrocyte membrane FAs (percentage of total FAs) and FA intake (percentage of total fat) were measured at baseline, and physician-confirmed incident diabetes was assessed during a mean follow-up of 7.0 y. We evaluated Δ⁵ desaturase (D5D) and Δ⁶ desaturase (D6D) activity by using FA product-to-precursor ratios (traditional approach) and by investigating variants in FADS1 and FADS2 genes that encode these desaturases (Mendelian randomization approach)., Results: As a main finding, erythrocyte 16:1n-7 and 18:3n-6 and FA ratios, which reflect stearoyl coenzyme A desaturase (SCD) and D6D activity, were directly related to diabetes risk in multivariable-adjusted models [relative risks (95% CIs) comparing extreme quintiles: 16:1n-7, 2.11 (1.46, 3.05); 18:3n-6, 2.00 (1.38, 2.88); SCD, 2.61 (1.75, 3.89); and D6D, 2.46 (1.67, 3.63)], whereas the FA ratio that reflects D5D activity was inversely associated with risk [0.46 (0.31, 0.70)]. The Mendelian randomization approach corroborated the direct relation for D6D activity and tended to support the inverse relation for D5D activity. Proportions of dietary FAs showed only modest to low correlations with erythrocyte FAs and were not significantly associated with risk., Conclusion: The FA profile of erythrocyte membrane phospholipids and activity of desaturase enzymes are strongly linked to the incidence of type 2 diabetes.
- Published
- 2011
- Full Text
- View/download PDF
39. Genetic variation of the FADS1 FADS2 gene cluster and n-6 PUFA composition in erythrocyte membranes in the European Prospective Investigation into Cancer and Nutrition-Potsdam study.
- Author
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Zietemann V, Kröger J, Enzenbach C, Jansen E, Fritsche A, Weikert C, Boeing H, and Schulze MB
- Subjects
- Adult, Aged, Delta-5 Fatty Acid Desaturase, Fatty Acids, Omega-6 chemistry, Female, Gene Expression Regulation physiology, Genotype, Humans, Linoleoyl-CoA Desaturase metabolism, Male, Middle Aged, Multigene Family, Neoplasms, Nutritional Physiological Phenomena, Erythrocyte Membrane chemistry, Fatty Acid Desaturases genetics, Fatty Acids, Omega-6 blood, Polymorphism, Single Nucleotide
- Abstract
Delta-5 (D5D) and delta-6 (D6D) desaturases are key enzymes in PUFA metabolism. Several factors (e.g. hyperglycaemia, hypertension, blood lipids, statins and fatty acids in diet and biological tissues) may influence desaturase activity. The goals were to evaluate the associations between variation in genes encoding these desaturases (FADS1 and FADS2) and blood concentrations of n-6 PUFA and estimated D5D and D6D activities (evaluated as product/precursor ratio), and to investigate whether other factors influencing the activity of desaturases modify these associations. A random sample of 2066 participants from the European Prospective Investigation into Cancer and Nutrition-Potsdam study (n 27 548) was utilised in the analyses. Crude and adjusted associations between rs174546 genotypes (reflecting genetic variation in the FADS1 FADS2 gene cluster), n-6 PUFA in erythrocytes and estimated desaturase activities were evaluated using multiple linear regression. Potential effect modification was determined by performing stratified analyses and evaluating interaction terms. We found rs174546 genotypes to be related to linoleic (r² 0·060), γ-linolenic (r² 0·041), eicosadienoic (r² 0·034), arachidonic (r² 0·026), docosatetraenoic acids (r² 0·028), estimated D6D activity (r² 0·052) and particularly strongly to dihomo-γ-linolenic acid (DGLA, r² 0·182) and D5D activity (r² 0·231). We did not observe effect modifications with regard to the estimated D5D activity, DGLA and arachidonic acid (AA) for most of the factors evaluated; however, the genetic effect on D5D activity and DGLA may be modified by the dietary n-6:n-3-ratio (P-values for interaction: 0·008 and 0·002), and the genetic effect on DGLA and AA may be modified by lipid-lowering medication (P-values for interaction: 0·0004 and 0·006). In conclusion, genetic variation in the FADS1 FADS2 gene cluster affects n-6 PUFA profiles in erythrocytes reflecting altered D5D activity.
- Published
- 2010
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40. Progression-free survival as a surrogate endpoint in advanced breast cancer.
- Author
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Miksad RA, Zietemann V, Gothe R, Schwarzer R, Conrads-Frank A, Schnell-Inderst P, Stollenwerk B, and Siebert U
- Subjects
- Disease-Free Survival, Female, Humans, Proportional Hazards Models, Randomized Controlled Trials as Topic, Sensitivity and Specificity, Survival Analysis, Anthracyclines therapeutic use, Antineoplastic Agents therapeutic use, Breast Neoplasms drug therapy, Taxoids therapeutic use
- Abstract
Objectives: Progression-free survival (PFS) has not been validated as a surrogate endpoint for overall survival (OS) for anthracycline (A) and taxane-based (T) chemotherapy in advanced breast cancer (ABC). Using trial-level, meta-analytic approaches, we evaluated PFS as a surrogate endpoint., Methods: A literature review identified randomized, controlled A and T trials for ABC. Progression-based endpoints were classified by prospective definitions. Treatment effects were derived as hazard ratios for PFS (HRPFS) and OS (HROS). Kappa statistic assessed overall agreement. A fixed-effects regression model was used to predict HROS from observed HRPFS. Cross-validation was performed. Sensitivity and subgroup analyses were performed for PFS definition, year of last patient recruitment, line of treatment, and constant rate assumption., Results: Sixteen A and fifteen T trials met inclusion criteria, producing seventeen A (n = 4,323) and seventeen T (n = 5,893) trial-arm pairs. Agreement (kappa statistic) between the direction of HROS and HRPFS was 0.71 for A (p = .0029) and 0.75 for T (p = .0028). While HRPFS was a statistically significant predictor of HROS for both A (p = .0019) and T (p = .012), the explained variances were 0.49 (A) and 0.35 (T). In cross-validation, 97 percent of the 95 percent prediction intervals crossed the equivalence line, and the direction of predicted HROS agreed with observed HROS in 82 percent (A) and 76 percent (T). Results were robust in sensitivity and subgroup analyses., Conclusions: This meta-analysis suggests that the trial-level treatment effect on PFS is significantly associated with the trial-level treatment effect on OS. However, prediction of OS based on PFS is surrounded with uncertainty.
- Published
- 2008
- Full Text
- View/download PDF
41. [Relation between certain diseases and frequency of depression in geriatric patients].
- Author
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Zietemann V, Zietemann P, Weitkunat R, and Kwetkat A
- Subjects
- Activities of Daily Living psychology, Aged, Aged, 80 and over, Chronic Disease epidemiology, Comorbidity, Depressive Disorder psychology, Female, Geriatric Assessment, Germany, Humans, Male, Pain psychology, Risk Factors, Statistics as Topic, Chronic Disease psychology, Depressive Disorder epidemiology
- Abstract
The higher prevalence of depression in specific diseases and older persons is discussed. This prevalence varies greatly according to the method used to collect data. A risk group can only be defined if information on diseases and other influencing factors are collected uniformly. The target diagnoses Parkinson's disease, stroke, myocardial infarction, cancer, diabetes mellitus, chronic pain, multiple infarct syndrome, Alzheimer's and other dementia were recorded from 1208 geriatric patients of the ZAGF municipal hospital in Munich, Germany. Logistic regression was used to identify chronic pain as the main cofactor for an association with depression (clinical diagnoses by ICD-10) and depressive symptoms (via GDS [Geriatric Depression Scale]). This association was also found for multimorbid patients with chronic pain. Impairment of the activities of daily living and the clinical setting were important additional cofactors. Pain patients are therefore at higher risk for depression.
- Published
- 2007
- Full Text
- View/download PDF
42. [Social contact and depression in geriatric patients: is there an influence of gender?].
- Author
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Zietemann V, Machens P, Mielck A, and Kwetkat A
- Subjects
- Aged, Aged, 80 and over, Female, Germany epidemiology, Humans, Male, Prevalence, Risk Factors, Sex Distribution, Sex Factors, Depression epidemiology, Risk Assessment methods, Social Behavior, Social Support
- Abstract
Depression is one of the most common affective illnesses. The investigation of changeable factors that are associated with depression is an important condition for the establishment of preventive measures. In a cross-sectional study, data on social factors were recorded from 580 geriatric patients of the municipal hospital in Munich. Ordinal logistic regression was used to analyse their association with depression (clinical diagnoses by ICD-10) and depressive symptoms (GDS). The results indicate that the occurrence of depressive symptoms and of depression was associated with less social contacts and less support, even after adjustment for other risk factors (for example, physical and cognitive impairment). This association was more distinct for women (for example, depressive symptoms: moderate versus much contact: OR=2.7; 95% CI: 1.8-4.1) than for men (OR=1.3; 95% CI: 0.7-2.4). Further research is needed to investigate whether women could benefit more than men from programmes promoting social support.
- Published
- 2007
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- View/download PDF
43. Sympatric mouse lemurs in north-west Madagascar: a new rufous mouse lemur species (Microcebus ravelobensis).
- Author
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Zimmermann E, Cepok S, Rakotoarison N, Zietemann V, and Radespiel U
- Subjects
- Analysis of Variance, Animals, Body Constitution, Cheirogaleidae anatomy & histology, Hair Color, Madagascar, Phylogeny, Species Specificity, Cheirogaleidae classification
- Published
- 1998
- Full Text
- View/download PDF
44. Sex-specific usage patterns of sleeping sites in grey mouse lemurs (Microcebus murinus) in northwestern Madagascar.
- Author
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Radespiel U, Cepok S, Zietemann V, and Zimmermann E
- Subjects
- Animals, Female, Hot Temperature, Madagascar, Male, Risk Factors, Seasons, Sex Factors, Trees, Cheirogaleidae psychology, Competitive Behavior, Homing Behavior, Sleep, Social Behavior
- Abstract
Sleeping sites are a potentially important resource for grey mouse lemurs since they are confronted with high daily temperature fluctuations and a high predation pressure. In order to determine the existence and degree of resource competition, sleeping site characteristics, locations, and usage patterns as well as sleeping group compositions were investigated in a 3 month field study in a dry deciduous forest of northwestern Madagascar. The daily sleeping sites of females were on average better insulated and safer than those of males. Males used more sleeping sites and changed the site more often than females. During the whole study, males slept alone, whereas the females formed stable sleeping groups in on average 83.7% of the days. Sex-specific differences in usage patterns might be explained by intersexual resource competition and female dominance and could possibly be related to differential parental investment of the sexes. The underlying study indicates that sleeping sites may be a restricted and defendable resource for grey mouse lemurs. The investigation gives new insights into the distribution patterns and social organization of this species.
- Published
- 1998
- Full Text
- View/download PDF
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