258 results on '"Witkowski T"'
Search Results
102. Depleted vagal tone and immune dysfunction are closely interrelated in chronic heart failure
- Author
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Jankowska, E. A., Witkowski, T., Zaczynska, E., Czarny, A., Anker, S. D., Banasiak, W., Poole-Wilson, P. A., and Piotr Ponikowski
103. Presence of oscillatory ventilation during exercise independently worsens prognosis in patients with stable chronic heart failure
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Witkowski, T., Nowak, K., Ewa A Jankowska, Grzeslo, A., Petruk-Kowalczyk, J., Banasiak, W., and Ponikowski, P.
104. Nocturnal breathing disorders are an independent predictor of cardiac death and of recurrent hospital admissions in chronic heart failure patients
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Pinna, G. D., Maestri, R., Capomolla, S., Johnson, P., Witkowski, T., Piotr Ponikowski, Andrews, D., Mortara, A., and Investigators, H. H. H.
105. Phase I Dose Escalation Study of Radiotherapy and Durvalumab (MEDI4736) in Relapsed/Refractory Diffuse Large B-Cell Lymphoma (DLBCL): The RaDD Study.
- Author
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Hawkes E.A., Manos K., Chong G., Palmer J., MacManus M., Keane C., Scott A., Shortt J., Ritchie D., Churilov L., Johnston L., Witkowski T., Barraclough A., Lee S.-T., Lin W., Koldej R., Khor R., Hawkes E.A., Manos K., Chong G., Palmer J., MacManus M., Keane C., Scott A., Shortt J., Ritchie D., Churilov L., Johnston L., Witkowski T., Barraclough A., Lee S.-T., Lin W., Koldej R., and Khor R.
- Abstract
Background: Although ~60% of patients with DLBCL are cured with frontline therapy, outcomes for those with relapsed/refractory disease remain poor. Tumour cells exploit immune checkpoint pathways, including the PD1/PDL1 axis, to evade and inhibit host anti-tumour immune responses. PD1/PDL1 expression and cytogenetic 9p24 alterations in some DLBCL subtypes provide additional rationale for PDL1 inhibition (PD-L1i) in DLBCL. Though single agent PD1i yields a disappointing ORR of 10-30% in heavily pre-treated DLBCL, some responses are durable.1 Radiotherapy (RT) is an established mechanism of stimulating anti-tumour immunity via increased circulating tumour antigen, immunogenic cell death and T-cell recruitment and activation in the tumour microenvironment. Synergy between concomitant immune checkpoint inhibition (ICI) and RT has been demonstrated in preclinical studies2 and solid tumours; a recent study in non-small cell lung cancer demonstrated an ORR of 36% with pembrolizumab + RT compared with 18% with pembrolizumab alone.3 RT hypofractionation appears critical to the abscopal effect when used with ICI,4 and concurrent RT and PD-L1i is more successful than sequential treatment.5 RT to multiple sites may broaden the spectrum of tumour antigen released and overcome clonal variation between disease sites; a dose-response relationship between RT and antigen release has yet to be established. This phase I study aims to determine the safety profile of escalating dose and number of sites of RT in combination with Durvalumab (MEDI4736), an anti-PD-L1 monoclonal antibody, in relapsed/refractory DLBCL, including primary refractory DLBCL and transformed follicular lymphoma. Study Design and Methods: RaDD (NCT03610061) includes eligible pts who have received >=1 prior line of therapy and are ineligible for or relapsed after autologous stem cell transplantation (SCT). Pts with active autoimmune disease, CNS involvement, prior allogeneic SCT or chronic steroid use are excluded. T
106. Phase I Dose Escalation Study of Radiotherapy and Durvalumab (MEDI4736) in Relapsed/Refractory Diffuse Large B-Cell Lymphoma (DLBCL): The RaDD Study.
- Author
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Hawkes E.A., Manos K., Chong G., Palmer J., MacManus M., Keane C., Scott A., Shortt J., Ritchie D., Churilov L., Johnston L., Witkowski T., Barraclough A., Lee S.-T., Lin W., Koldej R., Khor R., Hawkes E.A., Manos K., Chong G., Palmer J., MacManus M., Keane C., Scott A., Shortt J., Ritchie D., Churilov L., Johnston L., Witkowski T., Barraclough A., Lee S.-T., Lin W., Koldej R., and Khor R.
- Abstract
Background: Although ~60% of patients with DLBCL are cured with frontline therapy, outcomes for those with relapsed/refractory disease remain poor. Tumour cells exploit immune checkpoint pathways, including the PD1/PDL1 axis, to evade and inhibit host anti-tumour immune responses. PD1/PDL1 expression and cytogenetic 9p24 alterations in some DLBCL subtypes provide additional rationale for PDL1 inhibition (PD-L1i) in DLBCL. Though single agent PD1i yields a disappointing ORR of 10-30% in heavily pre-treated DLBCL, some responses are durable.1 Radiotherapy (RT) is an established mechanism of stimulating anti-tumour immunity via increased circulating tumour antigen, immunogenic cell death and T-cell recruitment and activation in the tumour microenvironment. Synergy between concomitant immune checkpoint inhibition (ICI) and RT has been demonstrated in preclinical studies2 and solid tumours; a recent study in non-small cell lung cancer demonstrated an ORR of 36% with pembrolizumab + RT compared with 18% with pembrolizumab alone.3 RT hypofractionation appears critical to the abscopal effect when used with ICI,4 and concurrent RT and PD-L1i is more successful than sequential treatment.5 RT to multiple sites may broaden the spectrum of tumour antigen released and overcome clonal variation between disease sites; a dose-response relationship between RT and antigen release has yet to be established. This phase I study aims to determine the safety profile of escalating dose and number of sites of RT in combination with Durvalumab (MEDI4736), an anti-PD-L1 monoclonal antibody, in relapsed/refractory DLBCL, including primary refractory DLBCL and transformed follicular lymphoma. Study Design and Methods: RaDD (NCT03610061) includes eligible pts who have received >=1 prior line of therapy and are ineligible for or relapsed after autologous stem cell transplantation (SCT). Pts with active autoimmune disease, CNS involvement, prior allogeneic SCT or chronic steroid use are excluded. T
107. Gedenktage: Ferdinand Liewehr 85 Jahre
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Witkowski, T., primary
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- 1982
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108. Glutamine and smooth muscle morphology of the gut in rats on total parenteral nutrition.
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Meritt, J, primary, Witkowski, T A, additional, Nagele, R, additional, Norcross, E D, additional, and Stein, T P, additional
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- 1989
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109. Mythologisch motivierte altpolabische Ortsnamen
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Witkowski, T., primary
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- 1970
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110. Zu einigen problematischen Ortsnamen des Kreises Stralsund
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Witkowski, T., primary
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- 1961
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111. Zu dem in den altpolabischen geographischen Namen enthaltenen appellativischen Wortschatz
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Witkowski, T., primary
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- 1973
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112. Robert Holsten 1862-1962
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Witkowski, T., primary
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- 1962
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113. Urslaw. *y und seine spätere Aussprache in den ehemaligen slawischen Dialekten Mecklenburgs und Vorpommerns
- Author
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Witkowski, T., primary
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- 1965
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114. II. Arbeitskonferenz der Internationalen Onomastischen Kommission beim Internationalen Slawistenkomitee in Berlin vom 17. bis 20. Oktober 1961
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Witkowski, T., primary
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- 1962
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115. Random and evolution algorithms of the tasks scheduling and of the production scheduling
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Witkowski, T., primary, Antczak, A., additional, and Antczak, P., additional
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116. The implementation of neural networks for the optimization of the production scheduling
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Witkowski, T., primary, Antczak, P., additional, and Strojny, G., additional
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117. Sensitive detection of TERTpromoter mutations reveals early acquisition and heterogeneity in cutaneous melanoma
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Colebatch, A.J., Witkowski, T., Waring, P.M., McArthur, G.A., Wong, S.Q., and Dobrovic, A.
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- 2017
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118. The implementation of neural networks for the optimization of the production scheduling.
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Witkowski, T., Antczak, P., and Strojny, G.
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- 2004
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119. Random and evolution algorithms of the tasks scheduling and of the production scheduling.
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Witkowski, T., Antczak, A., and Antczak, P.
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- 2004
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120. 358 Ergoreflex contribution to ventilatory response assessed during exercise of forearm and quadriceps muscles in patients with chronic heart failure
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Kaczmarek, A., Jankowska, E.A., Kus-Klinowska, A., Witkowski, T., Francis, D., Piepoli, M.F., Banasiak, W., and Ponikowski, P.
- Subjects
EXERCISE therapy ,HEART failure - Abstract
An abstract of the article "Ergoreflex Contribution to Ventilatory Response Assessed During Exercise of Forearm and Quadriceps Muscles in Patients With Chronic Heart Failure," by A. Kaczmarek and colleagues, is presented.
- Published
- 2004
121. A Comparison of Desflurane and Isoflurane in Prolonged Surgery
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Azad, S. S., Bartkowski, R. R., Witkowski, T. A., and Marr, A. T.
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- 1993
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122. Effect of intravenous iron sucrose on exercise tolerance in anemic and nonanemic patients with symptomatic chronic heart failure and iron deficiency FERRIC-HF: a randomized, controlled, observer-blinded trial.
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Okonko DO, Grzeslo A, Witkowski T, Mandal AK, Slater RM, Roughton M, Foldes G, Thum T, Majda J, Banasiak W, Missouris CG, Poole-Wilson PA, Anker SD, and Ponikowski P
- Published
- 2008
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123. Branched pegylated linker-auristatin to control hydrophobicity for the production of homogeneous minibody-drug conjugate against HER2-positive breast cancer.
- Author
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Douez E, Allard-Vannier E, Amar IAM, Jolivet L, Boursin F, Maisonial-Besset A, Witkowski T, Chezal JM, Colas C, Letast S, Auvert E, Denevault-Sabourin C, Aubrey N, and Joubert N
- Subjects
- United States, Mice, Humans, Animals, Female, Pharmaceutical Preparations, Tissue Distribution, Cell Line, Tumor, Ado-Trastuzumab Emtansine, Hydrophobic and Hydrophilic Interactions, Polyethylene Glycols, Breast Neoplasms drug therapy, Immunoconjugates therapeutic use, Oligopeptides, Aminobenzoates
- Abstract
Trastuzumab emtansine (Kadcyla®) was the first antibody-drug conjugate (ADC) approved by the Food and Drug Administration in 2013 against a solid tumor, and the first ADC to treat human epidermal growth factor receptor 2 positive (HER2+) breast cancer. However, this second generation ADC is burden by several limitations included heterogeneity, limited activity against heterogeneous tumor (regarding antigen expression) and suboptimal tumor penetration. To address this, different development strategies are oriented towards homogeneous conjugation, new drugs, optimized linkers and/or smaller antibody formats. To reach better developed next generation ADCs, a key parameter to consider is the management of the hydrophobicity associated with the linker-drug, increasing with and limiting the drug-to-antibody ratio (DAR) of the ADC. Here, an innovative branched pegylated linker was developed, to control the hydrophobicity of the monomethyl auristatin E (MMAE) and its cathepsin B-sensitive trigger. This branched pegylated linker-MMAE was then used for the efficient generation of internalizing homogeneous ADC of DAR 8 and minibody-drug conjugate of DAR 4, targeting HER2. Both immunoconjugates were then evaluated in vitro and in vivo on breast cancer models. Interestingly, this study highlighted that the minibody-MMAE conjugate of DAR 4 was the best immunoconjugate regarding in vitro cellular internalization and cytotoxicity, gamma imaging, ex vivo biodistribution profile in mice and efficient reduction of tumor size in vivo. These results are very promising and encourage us to explore further fragment-drug conjugate development., Competing Interests: Declaration of competing interest All authors have no relevant conflict of interest with the subject matter or materials discussed in the manuscript., (Copyright © 2023. Published by Elsevier B.V.)
- Published
- 2024
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124. Contribution of Somatic Ras/Raf/Mitogen-Activated Protein Kinase Variants in the Hippocampus in Drug-Resistant Mesial Temporal Lobe Epilepsy.
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Khoshkhoo S, Wang Y, Chahine Y, Erson-Omay EZ, Robert SM, Kiziltug E, Damisah EC, Nelson-Williams C, Zhu G, Kong W, Huang AY, Stronge E, Phillips HW, Chhouk BH, Bizzotto S, Chen MH, Adikari TN, Ye Z, Witkowski T, Lai D, Lee N, Lokan J, Scheffer IE, Berkovic SF, Haider S, Hildebrand MS, Yang E, Gunel M, Lifton RP, Richardson RM, Blümcke I, Alexandrescu S, Huttner A, Heinzen EL, Zhu J, Poduri A, DeLanerolle N, Spencer DD, Lee EA, Walsh CA, and Kahle KT
- Subjects
- Humans, Female, Adult, Middle Aged, Male, Mitogen-Activated Protein Kinases metabolism, Retrospective Studies, Hippocampus pathology, Epilepsy, Temporal Lobe surgery, Epilepsy pathology, Drug Resistant Epilepsy, Neocortex
- Abstract
Importance: Mesial temporal lobe epilepsy (MTLE) is the most common focal epilepsy subtype and is often refractory to antiseizure medications. While most patients with MTLE do not have pathogenic germline genetic variants, the contribution of postzygotic (ie, somatic) variants in the brain is unknown., Objective: To test the association between pathogenic somatic variants in the hippocampus and MTLE., Design, Setting, and Participants: This case-control genetic association study analyzed the DNA derived from hippocampal tissue of neurosurgically treated patients with MTLE and age-matched and sex-matched neurotypical controls. Participants treated at level 4 epilepsy centers were enrolled from 1988 through 2019, and clinical data were collected retrospectively. Whole-exome and gene-panel sequencing (each genomic region sequenced more than 500 times on average) were used to identify candidate pathogenic somatic variants. A subset of novel variants was functionally evaluated using cellular and molecular assays. Patients with nonlesional and lesional (mesial temporal sclerosis, focal cortical dysplasia, and low-grade epilepsy-associated tumors) drug-resistant MTLE who underwent anterior medial temporal lobectomy were eligible. All patients with available frozen tissue and appropriate consents were included. Control brain tissue was obtained from neurotypical donors at brain banks. Data were analyzed from June 2020 to August 2022., Exposures: Drug-resistant MTLE., Main Outcomes and Measures: Presence and abundance of pathogenic somatic variants in the hippocampus vs the unaffected temporal neocortex., Results: Of 105 included patients with MTLE, 53 (50.5%) were female, and the median (IQR) age was 32 (26-44) years; of 30 neurotypical controls, 11 (36.7%) were female, and the median (IQR) age was 37 (18-53) years. Eleven pathogenic somatic variants enriched in the hippocampus relative to the unaffected temporal neocortex (median [IQR] variant allele frequency, 1.92 [1.5-2.7] vs 0.3 [0-0.9]; P = .01) were detected in patients with MTLE but not in controls. Ten of these variants were in PTPN11, SOS1, KRAS, BRAF, and NF1, all predicted to constitutively activate Ras/Raf/mitogen-activated protein kinase (MAPK) signaling. Immunohistochemical studies of variant-positive hippocampal tissue demonstrated increased Erk1/2 phosphorylation, indicative of Ras/Raf/MAPK activation, predominantly in glial cells. Molecular assays showed abnormal liquid-liquid phase separation for the PTPN11 variants as a possible dominant gain-of-function mechanism., Conclusions and Relevance: Hippocampal somatic variants, particularly those activating Ras/Raf/MAPK signaling, may contribute to the pathogenesis of sporadic, drug-resistant MTLE. These findings may provide a novel genetic mechanism and highlight new therapeutic targets for this common indication for epilepsy surgery.
- Published
- 2023
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125. ALK-rearranged renal cell carcinoma with TPM3::ALK gene fusion and review of the literature.
- Author
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Galea LA, Hildebrand MS, Witkowski T, Joy C, McEvoy CR, Hanegbi U, and Aga A
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- Female, Humans, Gene Fusion, Gene Rearrangement, Immunohistochemistry, In Situ Hybridization, Fluorescence, Tropomyosin genetics, Aged, Carcinoma, Renal Cell pathology, Kidney Neoplasms pathology
- Abstract
ALK-rearranged renal cell carcinoma (ALK-RCC) is a very rare novel molecularly defined entity in the recently published fifth edition of the World Health Organization classification of tumours. We describe a case of ALK-RCC in a 76-year-old female. The tumour was composed of discohesive rhabdoid cells and pleomorphic, multinucleated cells (equivalent to ISUP/WHO grade 4). The tumour showed expression with PAX8, Keratin 7 and alpha methylacyl CoA racemase. ALK (D5F3 clone) was strongly and diffusely positive. ALK-FISH showed significant split signals of ALK, confirming the diagnosis. RNA sequencing showed TPM3::ALK rearrangement. Including the current case, there are 14 reported ALK-RCC cases with the same TPM3 fusion partner gene. Review of these published cases highlights their morphological heterogeneity and stresses the importance of running ALK immunohistochemistry on difficult cases to classify renal tumours. This is important while identification of ALK-RCC has clinical significance due to the availability of targeted therapy with ALK inhibitors., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
- Published
- 2023
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126. Synthesis and In Vitro Comparison of DOTA, NODAGA and 15-5 Macrocycles as Chelators for the 64 Cu-Labelling of Immunoconjugates.
- Author
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Maisonial-Besset A, Witkowski T, Quintana M, Besse S, Gaumet V, Cordonnier A, Alliot C, Vidal A, Denevault-Sabourin C, Tarrit S, Levesque S, Miot-Noirault E, and Chezal JM
- Subjects
- Humans, Animals, Mice, Chelating Agents chemistry, Azides, Antibodies, Monoclonal chemistry, Trastuzumab, Copper Radioisotopes chemistry, Positron-Emission Tomography methods, Copper, Immunoconjugates chemistry
- Abstract
The development of
64 Cu-based immuno-PET radiotracers requires the use of copper-specific bifunctional chelators (BFCs) that contain functional groups allowing both convenient bioconjugation and stable copper complexes to limit in vivo bioreduction, transmetallation and/or transchelation. The excellent in vivo kinetic inertness of the pentaazamacrocyclic [64 Cu]Cu-15-5 complex prompted us to investigate its potential for the64 Cu-labelling of monoclonal antibodies (mAbs), compared with the well-known NODAGA and DOTA chelators. To this end, three NODAGA, DOTA and 15-5-derived BFCs, containing a pendant azadibenzocyclooctyne moiety, were synthesised and a robust methodology was determined to form covalent bonds between them and azide-functionalised trastuzumab, an anti-HER2 mAb, using strain-promoted azide-alkyne cycloaddition. Unlike the DOTA derivative, the NODAGA- and 15-5-mAb conjugates were radiolabelled with64 Cu, obtaining excellent radiochemical yields, under mild conditions. Although all the radioimmunoconjugates showed excellent stability in PBS or mouse serum, [64 Cu]Cu-15-5- and [64 Cu]Cu-NODAGA-trastuzumab presented higher resistance to transchelation when challenged by EDTA. Finally, the immunoreactive fraction of the radioimmunoconjugates (88-94%) was determined in HER-2 positive BT474 human breast cancer cells, confirming that the bioconjugation and radiolabelling processes implemented had no significant impact on antigen recognition.- Published
- 2022
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127. Mosaicism in tuberous sclerosis complex: Lowering the threshold for clinical reporting.
- Author
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Ye Z, Lin S, Zhao X, Bennett MF, Brown NJ, Wallis M, Gao X, Sun L, Wu J, Vedururu R, Witkowski T, Gardiner F, Stutterd C, Duan J, Mullen SA, McGillivray G, Bodek S, Valente G, Reagan M, Yao Y, Li L, Chen L, Boys A, Adikari TN, Cao D, Hu Z, Beshay V, Zhang VW, Berkovic SF, Scheffer IE, Liao J, and Hildebrand MS
- Subjects
- Humans, Tuberous Sclerosis Complex 2 Protein genetics, Tuberous Sclerosis Complex 1 Protein genetics, Tumor Suppressor Proteins genetics, Mosaicism, Mutation, Tuberous Sclerosis diagnosis, Tuberous Sclerosis genetics, Tuberous Sclerosis pathology
- Abstract
Tuberous sclerosis complex (TSC) is a multi-system genetic disorder. Most patients have germline mutations in TSC1 or TSC2 but, 10%-15% patients do not have TSC1/TSC2 mutations detected on routine clinical genetic testing. We investigated the contribution of low-level mosaic TSC1/TSC2 mutations in unsolved sporadic patients and families with TSC. Thirty-one sporadic TSC patients negative on routine testing and eight families with suspected parental mosaicism were sequenced using deep panel sequencing followed by droplet digital polymerase chain reaction. Pathogenic variants were found in 22/31 (71%) unsolved sporadic patients, 16 were mosaic (median variant allele fraction [VAF] 6.8% in blood) and 6 had missed germline mutations. Parental mosaicism was detected in 5/8 families (median VAF 1% in blood). Clinical testing laboratories typically only report pathogenic variants with allele fractions above 10%. Our findings highlight the critical need to change laboratory practice by implementing higher sensitivity assays to improve diagnostic yield, inform patient management and guide reproductive counseling., (© 2022 The Authors. Human Mutation published by Wiley Periodicals LLC.)
- Published
- 2022
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128. A Convenient Route to New (Radio)Fluorinated and (Radio)Iodinated Cyclic Tyrosine Analogs.
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Chao MN, Chezal JM, Debiton E, Canitrot D, Witkowski T, Levesque S, Degoul F, Tarrit S, Wenzel B, Miot-Noirault E, Serre A, and Maisonial-Besset A
- Abstract
The use of radiolabeled non-natural amino acids can provide high contrast SPECT/PET metabolic imaging of solid tumors. Among them, radiohalogenated tyrosine analogs (i.e., [
123 I]IMT, [18 F]FET, [18 F]FDOPA, [123 I]8-iodo-L-TIC(OH), etc.) are of particular interest. While radioiodinated derivatives, such as [123 I]IMT, are easily available via electrophilic aromatic substitutions, the production of radiofluorinated aryl tyrosine analogs was a long-standing challenge for radiochemists before the development of innovative radiofluorination processes using arylboronate, arylstannane or iodoniums salts as precursors. Surprisingly, despite these methodological advances, no radiofluorinated analogs have been reported for [123 I]8-iodo-L-TIC(OH), a very promising radiotracer for SPECT imaging of prostatic tumors. This work describes a convenient synthetic pathway to obtain new radioiodinated and radiofluorinated derivatives of TIC(OH), as well as their non-radiolabeled counterparts. Using organotin compounds as key intermediates, [125 I]5-iodo-L-TIC(OH), [125 I]6-iodo-L-TIC(OH) and [125 I]8-iodo-L-TIC(OH) were efficiently prepared with good radiochemical yield (RCY, 51-78%), high radiochemical purity (RCP, >98%), molar activity (Am, >1.5-2.9 GBq/µmol) and enantiomeric excess (e.e. >99%). The corresponding [18 F]fluoro-L-TIC(OH) derivatives were also successfully obtained by radiofluorination of the organotin precursors in the presence of tetrakis(pyridine)copper(II) triflate and nucleophilic [18 F]F- with 19-28% RCY d.c., high RCP (>98.9%), Am (20-107 GBq/µmol) and e.e. (>99%).- Published
- 2022
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129. Synthesis and in vitro preliminary evaluation of prostate-specific membrane antigen targeted upconversion nanoparticles as a first step towards radio/fluorescence-guided surgery of prostate cancer.
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Cordonnier A, Boyer D, Besse S, Valleix R, Mahiou R, Quintana M, Briat A, Benbakkar M, Penault-Llorca F, Maisonial-Besset A, Maunit B, Tarrit S, Vivier M, Witkowski T, Mazuel L, Degoul F, Miot-Noirault E, and Chezal JM
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- Animals, Antigens, Surface chemistry, Cell Line, Tumor, Cell Survival drug effects, Coated Materials, Biocompatible metabolism, Coated Materials, Biocompatible pharmacology, Coated Materials, Biocompatible therapeutic use, Cycloaddition Reaction, Fluorides chemistry, Glutamate Carboxypeptidase II chemistry, Humans, Ligands, Magnetite Nanoparticles therapeutic use, Magnetite Nanoparticles toxicity, Male, Mice, Oleic Acids chemistry, Optical Imaging, Particle Size, Polyethylene Glycols chemistry, Prostatic Neoplasms diagnostic imaging, Prostatic Neoplasms drug therapy, Prostatic Neoplasms surgery, Thulium chemistry, Tissue Distribution, Ytterbium chemistry, Yttrium chemistry, Antigens, Surface metabolism, Coated Materials, Biocompatible chemistry, Glutamate Carboxypeptidase II metabolism, Magnetite Nanoparticles chemistry
- Abstract
Over the last decade, upconversion nanoparticles (UCNP) have been widely investigated in nanomedicine due to their high potential as imaging agents in the near-infrared (NIR) optical window of biological tissues. Here, we successfully develop active targeted UCNP as potential probes for dual NIR-NIR fluorescence and radioactive-guided surgery of prostate-specific membrane antigen (PSMA)(+) prostate cancers. We designed a one-pot thermolysis synthesis method to obtain oleic acid-coated spherical NaYF
4 :Yb,Tm@NaYF4 core/shell UCNP with narrow particle size distribution (30.0 ± 0.1 nm, as estimated by SAXS analysis) and efficient upconversion luminescence. Polyethylene glycol (PEG) ligands bearing different anchoring groups (phosphate, bis- and tetra-phosphonate-based) were synthesized and used to hydrophilize the UCNP. DLS studies led to the selection of a tetra-phosphonate PEG(2000) ligand affording water-dispersible UCNP with sustained colloidal stability in several aqueous media. PSMA-targeting ligands ( i.e. , glutamate-urea-lysine derivatives called KuEs) and fluorescent or radiolabelled prosthetic groups were grafted onto the UCNP surface by strain-promoted azide-alkyne cycloaddition (SPAAC). These UCNP, coated with 10 or 100% surface density of KuE ligands, did not induce cytotoxicity over 24 h incubation in LNCaP-Luc or PC3-Luc prostate cancer cell lines or in human fibroblasts for any of the concentrations evaluated. Competitive binding assays and flow cytometry demonstrated the excellent affinity of UCNP@KuE for PSMA-positive LNCaP-Luc cells compared with non-targeted UCNP@CO2 H. Furthermore, the binding of UCNP@KuE to prostate tumour cells was positively correlated with the surface density of PSMA-targeting ligands and maintained after125 I-radiolabelling. Finally, a preliminary biodistribution study in LNCaP-Luc-bearing mice demonstrated the radiochemical stability of non-targeted [125 I]UCNP paving the way for future in vivo assessments.- Published
- 2021
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130. Percutaneous closure of paravalvular leak (fistula) between aorta and left atrium using echocardiographic guidance.
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Kirsch JM, Witkowski T, Protasiewicz M, Brzozowski P, Reczuch K, and Kuliczkowski W
- Abstract
Competing Interests: The authors declare no conflict of interest.
- Published
- 2021
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131. A Synthetic DNA Construct to Evaluate the Recovery Efficiency of Cell-Free DNA Extraction and Bisulfite Modification.
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Goh SK, Cox DRA, Wong BKL, Musafer A, Witkowski T, Do H, Muralidharan V, and Dobrovic A
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- DNA genetics, Humans, Reproducibility of Results, Sulfites, Cell-Free Nucleic Acids genetics
- Abstract
Background: Despite improvements in the genetic and epigenetic analysis of cell-free DNA (cfDNA), there has been limited focus on assessing the preanalytical variables of recovery efficiency following cfDNA extraction and bisulfite modification. Quantification of recovery efficiency after these steps can facilitate quality assurance and improve reliability when comparing serial samples., Methods: We developed an exogenous DNA Construct to Evaluate the Recovery Efficiency of cfDNA extraction and BISulfite modification (CEREBIS) after cfDNA extraction and/or subsequent bisulfite modification from plasma. The strategic placement of cytosine bases in the 180 bp CEREBIS enabled PCR amplification of the construct by a single primer set both after plasma DNA extraction and following subsequent bisulfite modification., Results: Plasma samples derived from 8 organ transplant donors and 6 serial plasma samples derived from a liver transplant recipient were spiked with a known number of copies of CEREBIS. Recovery of CEREBIS after cfDNA extraction and bisulfite modification was quantified with high analytical accuracy by droplet digital PCR. The use of CEREBIS and quantification of its recovery was useful in identifying problematic extractions. Furthermore, its use was shown to be invaluable towards improving the reliability of the analysis of serial samples., Conclusions: CEREBIS can be used as a spike-in control to address the preanalytical variable of recovery efficiency both after cfDNA extraction from plasma and following bisulfite modification. Our approach can be readily implemented and its application may have significant benefits, especially in settings where longitudinal quantification of cfDNA for disease monitoring is necessary., (© American Association for Clinical Chemistry 2021. All rights reserved. For permissions, please email: journals.permissions@oup.com.)
- Published
- 2021
- Full Text
- View/download PDF
132. The Role of Hexokinase and Hexose Transporters in Preferential Use of Glucose over Fructose and Downstream Metabolic Pathways in the Yeast Yarrowia lipolytica .
- Author
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Hapeta P, Szczepańska P, Witkowski T, Nicaud JM, Crutz-Le Coq AM, and Lazar Z
- Subjects
- Fungal Proteins metabolism, Metabolic Networks and Pathways, Molasses, Yarrowia enzymology, Fructose metabolism, Glucose metabolism, Hexokinase metabolism, Monosaccharide Transport Proteins metabolism, Yarrowia metabolism
- Abstract
The development of efficient bioprocesses requires inexpensive and renewable substrates. Molasses, a by-product of the sugar industry, contains mostly sucrose, a disaccharide composed of glucose and fructose, both easily absorbed by microorganisms. Yarrowia lipolytica , a platform for the production of various chemicals, can be engineered for sucrose utilization by heterologous invertase expression, yet the problem of preferential use of glucose over fructose remains, as fructose consumption begins only after glucose depletion what significantly extends the bioprocesses. We investigated the role of hexose transporters and hexokinase (native and fructophilic) in this preference. Analysis of growth profiles and kinetics of monosaccharide utilization has proven that the glucose preference in Y. lipolytica depends primarily on the affinity of native hexokinase for glucose. Interestingly, combined overexpression of either hexokinase with hexose transporters significantly accelerated citric acid biosynthesis and enhanced pentose phosphate pathway leading to secretion of polyols (31.5 g/L vs. no polyols in the control strain). So far, polyol biosynthesis was efficient in glycerol-containing media. Moreover, overexpression of fructophilic hexokinase in combination with hexose transporters not only shortened this process to 48 h (84 h for the medium with glycerol) but also allowed to obtain 23% more polyols (40 g/L) compared to the glycerol medium (32.5 g/L).
- Published
- 2021
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133. PDCD1 Polymorphisms May Predict Response to Anti-PD-1 Blockade in Patients With Metastatic Melanoma.
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Parakh S, Musafer A, Paessler S, Witkowski T, Suen CSNLW, Tutuka CSA, Carlino MS, Menzies AM, Scolyer RA, Cebon J, Dobrovic A, Long GV, Klein O, and Behren A
- Subjects
- Adult, Aged, Aged, 80 and over, Female, Genotype, Humans, Male, Melanoma drug therapy, Melanoma mortality, Middle Aged, Polymorphism, Single Nucleotide, Progression-Free Survival, Retrospective Studies, Biomarkers, Tumor genetics, Drug Resistance, Neoplasm genetics, Immune Checkpoint Inhibitors therapeutic use, Melanoma genetics, Programmed Cell Death 1 Receptor genetics
- Abstract
A significant number of patients (pts) with metastatic melanoma do not respond to anti-programmed cell death 1 (PD1) therapies. Identifying predictive biomarkers therefore remains an urgent need. We retrospectively analyzed plasma DNA of pts with advanced melanoma treated with PD-1 antibodies, nivolumab or pembrolizumab, for five PD-1 genotype single nucleotide polymorphisms (SNPs): PD1.1 (rs36084323, G>A), PD1.3 (rs11568821, G>A), PD1.5 (rs2227981, C>T) PD1.6 (rs10204225, G>A) and PD1.9 (rs2227982, C>T). Clinico-pathological and treatment parameters were collected, and presence of SNPs correlated with response, progression free survival (PFS) and overall survival (OS). 115 patients were identified with a median follow up of 18.7 months (range 0.26 - 52.0 months). All were Caucasian; 27% BRAF V600 mutation positive. At PD-1 antibody commencement, 36% were treatment-naïve and 52% had prior ipilimumab. The overall response rate was 43%, 19% achieving a complete response. Overall median PFS was 11.0 months (95% CI 5.4 - 17.3) and median OS was 31.1 months (95% CI 23.2 - NA). Patients with the G/G genotype had more complete responses than with A/G genotype (16.5% vs. 2.6% respectively) and the G allele of PD1.3 rs11568821 was significantly associated with a longer median PFS than the AG allele, 14.1 vs. 7.0 months compared to the A allele (p=0.04; 95% CI 0.14 - 0.94). No significant association between the remaining SNPs and responses, PFS or OS were observed. Despite limitations in sample size, this is the first study to demonstrate an association of a germline PD-1 polymorphism and PFS in response to anti-PD-1 therapy in pts with metastatic melanoma. Extrinsic factors like host germline polymorphisms should be considered with tumor intrinsic factors as predictive biomarkers for immune checkpoint regulators., Competing Interests: MC has a consultant advisory role with BMS, MSD, Amgen, Novartis, Pierre Fabre, Roche, Sanofi, Merck and Co, Ideaya, Regeneron, Nektar, Eisai and Q biotics and OncoSec. AMM is a consultant advisor to BMS, MSD, Novartis, Roche, Pierre-Fabre, QBiotics. RAS has received fees for professional services from Qbiotics, Novartis, Merck Sharp & Dohme, NeraCare, AMGEN Inc., Bristol-Myers Squibb, Myriad Genetics, and GlaxoSmithKline. JC has sat on advisory boards for Novartis and GSK. GL is consultant advisor for Aduro Biotech Inc, Amgen Inc, Array Biopharma inc, Boehringer Ingelheim International GmbH, Bristol-Myers Squibb, Hexel AG, Highlight Therapeutics S.L., Merck Sharpe & Dohme, Novartis Pharma AG, OncoSec, Pierre Fabre, QBiotics Group Limited, Regeneron Pharmaceuticals Inc, SkylineDX B.V., and Specialised Therapeutics Australia Pty Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Parakh, Musafer, Paessler, Witkowski, Suen, Tutuka, Carlino, Menzies, Scolyer, Cebon, Dobrovic, Long, Klein and Behren.)
- Published
- 2021
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134. New insight into the role of ANXA1 in melanoma progression: involvement of stromal expression in dissemination.
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Delorme S, Privat M, Sonnier N, Rouanet J, Witkowski T, Kossai M, Mishellany F, Radosevic-Robin N, Juban G, Molnar I, Quintana M, and Degoul F
- Abstract
ANXA1, first described in the context of inflammation, appears to be deregulated in many cancers and increased in melanomas compared with melanocytes. To date, few studies have investigated the role of ANXA1 in melanoma progression. Furthermore, this protein is expressed by various cell types, including immune and endothelial cells. We therefore analyzed the specific roles of ANXA1 using melanoma and stromal cells in two human cell lines (A375-MA2 and SK-MEL-28) in vitro and in Anxa1 null C57Bl6/J mice bearing B16Bl6 tumors. We report decreased proliferation in both ANXA1 siRNA A375-MA2 and SK-MEL-28, but cell-dependent effects of ANXA1 in migration in vitro . However, we also observed a significant decrease of B16Bl6 tumor growth associated with a reduction of Ki-67 positive cells in Anxa1 null mice compared with wild-type mice. Interestingly, we also found a significant reduction of spontaneous metastases, which can be attributed to decreased angiogenesis concomitantly with greater immune cell presence in the Anxa1 null stromal context. This study highlights the pejorative role of ANXA1 in both tumor and stromal cells in melanoma, due to its involvement in proliferation and angiogenesis., Competing Interests: None., (AJCR Copyright © 2021.)
- Published
- 2021
135. Ropporin-1 and 1B Are Widely Expressed in Human Melanoma and Evoke Strong Humoral Immune Responses.
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Da Gama Duarte J, Woods K, Quigley LT, Deceneux C, Tutuka C, Witkowski T, Ostrouska S, Hudson C, Tsao SC, Pasam A, Dobrovic A, Blackburn JM, Cebon J, and Behren A
- Abstract
Antibodies that block immune regulatory checkpoints (programmed cell death 1, PD-1 and cytotoxic T-lymphocyte-associated antigen 4, CTLA-4) to mobilise immunity have shown unprecedented clinical efficacy against cancer, demonstrating the importance of antigen-specific tumour recognition. Despite this, many patients still fail to benefit from these treatments and additional approaches are being sought. These include mechanisms that boost antigen-specific immunity either by vaccination or adoptive transfer of effector cells. Other than neoantigens, epigenetically regulated and shared antigens such as NY-ESO-1 are attractive targets; however, tissue expression is often heterogeneous and weak. Therefore, peptide-specific therapies combining multiple antigens rationally selected to give additive anti-cancer benefits are necessary to achieve optimal outcomes. Here, we show that Ropporin-1 (ROPN1) and 1B (ROPN1B), cancer restricted antigens, are highly expressed and immunogenic, inducing humoral immunity in patients with advanced metastatic melanoma. By multispectral immunohistochemistry, 88.5% of melanoma patients tested ( n = 54/61) showed ROPN1B expression in at least 1 of 2/3 tumour cores in tissue microarrays. Antibody responses against ROPN1A and ROPN1B were detected in 71.2% of melanoma patients tested ( n = 74/104), with increased reactivity seen with more advanced disease stages. Thus, ROPN1A and ROPN1B may indeed be viable targets for cancer immunotherapy, alone or in combination with other cancer antigens, and could be combined with additional therapies such as immune checkpoint blockade.
- Published
- 2021
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136. Simultaneous placement of leadless pacemaker and dialysis catheter in patient with exhausted vasculature.
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Bednarczyk D, Kuliczkowski W, Letachowicz K, Dzidowski M, Witkowski T, Krajewska M, Kusztal M, Mysiak A, Ściborski K, and Mitkowski P
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- Device Removal, Humans, Male, Middle Aged, Prosthesis-Related Infections diagnosis, Prosthesis-Related Infections microbiology, Punctures, Treatment Outcome, Cardiac Pacing, Artificial, Catheterization, Central Venous instrumentation, Catheterization, Peripheral instrumentation, Catheters, Indwelling, Central Venous Catheters, Femoral Vein diagnostic imaging, Jugular Veins diagnostic imaging, Pacemaker, Artificial adverse effects, Prosthesis-Related Infections therapy, Renal Dialysis
- Abstract
The problem with limited venous access may occur in patients receiving long-term hemodialysis treatment with no possibility of arteriovenous access or in patients with cardiac implantable electronic device-related infection leading to the removal of cardiac implantable electronic device. We present a case report where both situations occur simultaneously. Using recent development in cardiac pacing-leadless cardiac pacemaker-we manage to overcome the vascular access problem. The described case emphasizes the necessity of multispecialty collaboration and gains of new pacing technology in patients who need placement of vascular access for hemodialysis and cardiac implantable electronic device where vascular access is scarce.
- Published
- 2021
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137. Hybrid percutaneous atrial septal defect closure with surgical occluder fixation.
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Przybylski R, Reczuch J, Bochenek M, Witkowski T, Reczuch K, and Kuliczkowski W
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- Humans, Heart Septal Defects, Atrial diagnostic imaging, Heart Septal Defects, Atrial surgery, Septal Occluder Device
- Published
- 2021
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138. Early reduced dopaminergic tone mediated by D3 receptor and dopamine transporter in absence epileptogenesis.
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Cavarec F, Krauss P, Witkowski T, Broisat A, Ghezzi C, De Gois S, Giros B, Depaulis A, and Deransart C
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- Animals, Behavior, Animal physiology, Brain diagnostic imaging, Corpus Striatum metabolism, Disease Models, Animal, Epilepsy, Absence diagnostic imaging, Rats, Tomography, Emission-Computed, Single-Photon, Yawning, Brain metabolism, Dopamine Plasma Membrane Transport Proteins metabolism, Epilepsy, Absence metabolism, Receptors, Dopamine D3 metabolism
- Abstract
Objective: In Genetic Absence Epilepsy Rats From Strasbourg (GAERSs), epileptogenesis takes place during brain maturation and correlates with increased mRNA expression of D3 dopamine receptors (D3R). Whether these alterations are the consequence of seizure repetition or contribute to the development of epilepsy remains to be clarified. Here, we addressed the involvement of the dopaminergic system in epilepsy onset in GAERSs., Methods: Experiments were performed using rats at different stages of brain maturation from three strains according to their increasing propensity to develop absence seizures: nonepileptic control rats (NECs), Wistar Hannover rats, and GAERSs. Changes in dopaminergic neurotransmission were investigated using different behavioral and neurochemical approaches: autoradiography of D3R and dopamine transporter, single photon emission computed tomographic imaging, acute and chronic drug effects on seizure recordings (dopaminergic agonists and antagonists), quinpirole-induced yawns and dopamine synaptosomal uptake, microdialysis, brain tissue monoamines, and brain-derived neurotrophic factor quantification., Results: Autoradiography revealed an increased expression of D3R in 14-day-old GAERSs, before absence seizure onset, that persists in adulthood, as compared to age-matched NECs. This was confirmed by increased yawns, a marker of D3R activity, and increased seizures when animals were injected with quinpirole at low doses to activate D3R. We also observed a concomitant increase in the expression and activity of the dopamine transporter in GAERSs before seizure onset, consistent with both lowered dopamine basal level and increased phasic responses., Significance: Our data show that the dopaminergic system is persistently altered in GAERSs, which may contribute not only to behavioral comorbidities but also as an etiopathogenic factor in the development of epilepsy. The data suggest that an imbalanced dopaminergic tone may contribute to absence epilepsy development and seizure onset, as its reversion by a chronic treatment with a dopamine stabilizer significantly suppressed epileptogenesis. Our data suggest a potential new target for antiepileptic therapies and/or improvement of quality of life of epileptic patients., (Wiley Periodicals, Inc. © 2019 International League Against Epilepsy.)
- Published
- 2019
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139. Molecular Genomic Profiling of Melanocytic Nevi.
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Colebatch AJ, Ferguson P, Newell F, Kazakoff SH, Witkowski T, Dobrovic A, Johansson PA, Saw RPM, Stretch JR, McArthur GA, Long GV, Thompson JF, Pearson JV, Mann GJ, Hayward NK, Waddell N, Scolyer RA, and Wilmott JS
- Subjects
- Adolescent, Adult, Child, Cohort Studies, DNA Mutational Analysis, Female, GTP Phosphohydrolases genetics, GTP Phosphohydrolases metabolism, Humans, Male, Membrane Proteins genetics, Membrane Proteins metabolism, Middle Aged, Mutation, Nevus, Pigmented congenital, Nevus, Pigmented pathology, Nevus, Pigmented surgery, Polymorphism, Single Nucleotide, Promoter Regions, Genetic genetics, Proto-Oncogene Proteins B-raf genetics, Proto-Oncogene Proteins B-raf metabolism, Skin pathology, Skin Neoplasms congenital, Skin Neoplasms pathology, Skin Neoplasms surgery, Telomerase genetics, Whole Genome Sequencing, Biomarkers, Tumor genetics, Gene Expression Regulation, Neoplastic, MAP Kinase Signaling System genetics, Nevus, Pigmented genetics, Skin Neoplasms genetics
- Abstract
The benign melanocytic nevus is the most common tumor in humans and rarely transforms into cutaneous melanoma. Elucidation of the nevus genome is required to better understand the molecular steps of progression to melanoma. We performed whole genome sequencing on a series of 14 benign melanocytic nevi consisting of both congenital and acquired types. All nevi had driver mutations in the MAPK signaling pathway, either BRAF V600E or NRAS Q61R/L. No additional definite driver mutations were identified. Somatic mutations in nevi with higher mutation loads showed a predominance of mutational signatures 7a and 7b, consistent with UVR exposure, whereas nevi with lower mutation loads (including all three congenital nevi) had a predominance of the ubiquitous signatures 1 and 5. Two nevi had mutations in promoter regions predicted to bind E26 transformation-specific family transcription factors, as well as subclonal mutations in the TERT promoter. This paper presents whole genome data from melanocytic nevi. We confirm that UVR is involved in the etiology of a subset of nevi. This study also establishes that TERT promoter mutations are present in morphologically benign skin nevi in subclonal populations, which has implications regarding the interpretation of this emerging biomarker in sensitive assays., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2019
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140. Genomic Analysis of Circulating Tumor DNA Using a Melanoma-Specific UltraSEEK Oncogene Panel.
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Gray ES, Witkowski T, Pereira M, Calapre L, Herron K, Irwin D, Chapman B, Khattak MA, Raleigh J, Hatzimihalis A, Cebon J, Sandhu S, McArthur GA, Millward M, Ziman M, Dobrovic A, and Wong SQ
- Subjects
- Humans, Mutation genetics, Proto-Oncogene Proteins B-raf genetics, Circulating Tumor DNA blood, Circulating Tumor DNA genetics, Genomics, Melanoma blood, Melanoma genetics, Oncogenes
- Abstract
The analysis of circulating tumor DNA provides a minimally invasive molecular interrogation that has the potential to guide treatment selection and disease monitoring. Here, the authors evaluated a custom UltraSEEK melanoma panel for the MassARRAY system, probing for 61 mutations over 13 genes. The analytical sensitivity and clinical accuracy of the UltraSEEK melanoma panel was compared with droplet digital PCR. The blinded analysis of 68 mutations detected in 48 plasma samples from stage IV melanoma patients revealed a concordance of 88% between the two platforms. Further comparison of both methods for the detection of BRAF V600E mutations in 77 plasma samples demonstrated a Cohen's κ of 0.826 (bias-corrected and accelerated 95% CI, 0.669-0.946). These results indicate that the UltraSEEK melanoma panel is as sensitive as droplet digital PCR for the detection of circulating tumor DNA in this cohort of patients but highlight the need for detected variants to be confirmed orthogonally to mitigate any false-positive results. The MassARRAY system enables rapid and sensitive genotyping for the detection of multiple melanoma-associated mutations in plasma., (Copyright © 2019 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2019
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141. Targeting the Tetraspanins with Monoclonal Antibodies in Oncology: Focus on Tspan8/Co-029.
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Bonnet M, Maisonial-Besset A, Zhu Y, Witkowski T, Roche G, Boucheix C, Greco C, and Degoul F
- Abstract
Tetraspanins are exposed at the surface of cellular membranes, which allows for the fixation of cognate antibodies. Developing specific antibodies in conjunction with genetic data would largely contribute to deciphering their biological behavior. In this short review, we summarize the main functions of Tspan8/Co-029 and its role in the biology of tumor cells. Based on data collected from recently reported studies, the possibilities of using antibodies to target Tspan8 in immunotherapy or radioimmunotherapy approaches are also discussed.
- Published
- 2019
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142. Optimizing Amplification of the GC-Rich TERT Promoter Region Using 7-Deaza-dGTP for Droplet Digital PCR Quantification of TERT Promoter Mutations.
- Author
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Colebatch AJ, Witkowski T, Waring PM, McArthur GA, Wong SQ, and Dobrovic A
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- Cell Line, Tumor, Humans, Deoxyguanine Nucleotides chemistry, Mutation, Polymerase Chain Reaction methods, Promoter Regions, Genetic, Telomerase genetics
- Published
- 2018
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143. Antibody PEGylation in bioorthogonal pretargeting with trans-cyclooctene/tetrazine cycloaddition: in vitro and in vivo evaluation in colorectal cancer models.
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Rondon A, Ty N, Bequignat JB, Quintana M, Briat A, Witkowski T, Bouchon B, Boucheix C, Miot-Noirault E, Pouget JP, Chezal JM, Navarro-Teulon I, Moreau E, and Degoul F
- Subjects
- Animals, Antibodies, Monoclonal pharmacology, Cell Line, Tumor, Colorectal Neoplasms pathology, Cycloaddition Reaction, Cyclooctanes chemistry, Cyclooctanes pharmacology, Cyclooctanes therapeutic use, Female, Humans, Immunoconjugates pharmacology, Mice, Peritoneal Neoplasms pathology, Peritoneal Neoplasms radiotherapy, Polyethylene Glycols chemistry, Polyethylene Glycols pharmacology, Polyethylene Glycols therapeutic use, Radioimmunotherapy, Antibodies, Monoclonal chemistry, Antibodies, Monoclonal therapeutic use, Colorectal Neoplasms radiotherapy, Immunoconjugates chemistry, Immunoconjugates therapeutic use
- Abstract
Bioorthogonal chemistry represents a challenging approach in pretargeted radioimmunotherapy (PRIT). We focus here on mAb modifications by grafting an increase amount of trans-cyclooctene (TCO) derivatives (0 to 30 equivalents with respect to mAb) bearing different polyethylene glycol (PEG) linkers between mAb and TCO (i.e. PEG
0 (1), PEG4 (2) and PEG12 (3)) and assessing their functionality. We used colorectal xenograft (HT29/Ts29.2) and peritoneal carcinomatosis (A431-CEA-Luc/35A7) as tumor cells/mAbs models and fluorescent tetrazines (TZ). MALDI-TOF MS shows that grafting with 2,3 increases significantly the number of TCO per mAb compared with no PEG. In vitro immunofluorescence showed that Ts29.2 and 35A7 labeling intensity is correlated with the number of TCO when using 1,3 while signals reach a maximum at 10 equivalents when using 2. Under 10 equivalents conditions, the capacity of resulting mAbs-1-3 for antigen recognition is similar when reported per grafted TCO and comparable to mAbs without TCO. In vivo, on both models, pretargeting with mAbs-2,3 followed by TZ injection induced a fluorescent signal two times lower than with mAbs-1. These findings suggest that while PEG linkers allow a better accessibility for TCO grafting, it might decrease the number of reactive TCO. In conclusion, mAb-1 represents the best candidate for PRIT.- Published
- 2017
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144. Tetraspanin 8 (TSPAN 8) as a potential target for radio-immunotherapy of colorectal cancer.
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Maisonial-Besset A, Witkowski T, Navarro-Teulon I, Berthier-Vergnes O, Fois G, Zhu Y, Besse S, Bawa O, Briat A, Quintana M, Pichard A, Bonnet M, Rubinstein E, Pouget JP, Opolon P, Maigne L, Miot-Noirault E, Chezal JM, Boucheix C, and Degoul F
- Subjects
- Animals, Antibodies, Monoclonal pharmacokinetics, Colorectal Neoplasms diagnostic imaging, Colorectal Neoplasms metabolism, Female, Humans, Immunoconjugates immunology, Indium Radioisotopes pharmacokinetics, Lutetium pharmacokinetics, Mice, Mice, Inbred BALB C, Mice, Nude, Molecular Targeted Therapy, Radiopharmaceuticals pharmacokinetics, Radiopharmaceuticals therapeutic use, Tissue Distribution, Xenograft Model Antitumor Assays, Antibodies, Monoclonal therapeutic use, Colorectal Neoplasms pathology, Colorectal Neoplasms therapy, Indium Radioisotopes therapeutic use, Lutetium therapeutic use, Radioimmunotherapy, Tetraspanins antagonists & inhibitors
- Abstract
Tetraspanin 8 (TSPAN8) overexpression is correlated with poor prognosis in human colorectal cancer (CRC). A murine mAb Ts29.2 specific for human TSPAN8 provided significant efficiency for immunotherapy in CRC pre-clinical models. We therefore evaluate the feasability of targeting TSPAN8 in CRC with radiolabeled Ts29.2. Staining of tissue micro-arrays with Ts29.2 revealed that TSPAN8 espression was restricted to a few human healthy tissues. DOTA-Ts29.2 was radiolabeled with 111In or 177Lu with radiochemical purities >95%, specific activity ranging from 300 to 600 MBq/mg, and radioimmunoreactive fractions >80%. The biodistribution of [111In]DOTA-Ts29.2 in nude mice bearing HT29 or SW480 CRC xenografts showed a high specificity of tumor localization with high tumor/blood ratios (HT29: 4.3; SW480-TSPAN8: 3.9 at 72h and 120h post injection respectively). Tumor-specific absorbed dose calculations for [177Lu]DOTA-Ts29.2 was 1.89 Gy/MBq, establishing the feasibility of using radioimmunotherapy of CRC with this radiolabeled antibody. A significant inhibition of tumor growth in HT29 tumor-bearing mice treated with [177Lu]DOTA-Ts29.2 was observed compared to control groups. Ex vivo experiments revealed specific DNA double strand breaks associated with cell apoptosis in [177Lu]DOTA-Ts29.2 treated tumors compared to controls. Overall, we provide a proof-of-concept for the use of [111In/177Lu]DOTA-Ts29.2 that specifically target in vivo aggressive TSPAN8-positive cells in CRC.
- Published
- 2017
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145. Tetraspanin 8 is a novel regulator of ILK-driven β1 integrin adhesion and signaling in invasive melanoma cells.
- Author
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El Kharbili M, Robert C, Witkowski T, Danty-Berger E, Barbollat-Boutrand L, Masse I, Gadot N, de la Fouchardière A, McDonald PC, Dedhar S, Le Naour F, Degoul F, and Berthier-Vergnes O
- Subjects
- Animals, Blotting, Western, Cell Adhesion genetics, Cell Line, Tumor, Cell Movement genetics, Gene Expression Regulation, Neoplastic, Humans, Integrin beta1 metabolism, Male, Melanoma metabolism, Melanoma pathology, Mice, Nude, Microscopy, Confocal, Mutation, Neoplasm Invasiveness, Phosphorylation, Protein Serine-Threonine Kinases metabolism, Proto-Oncogene Proteins c-akt metabolism, RNA Interference, Tetraspanins metabolism, Transplantation, Heterologous, Integrin beta1 genetics, Melanoma genetics, Protein Serine-Threonine Kinases genetics, Signal Transduction genetics, Tetraspanins genetics
- Abstract
Melanoma is well known for its propensity for lethal metastasis and resistance to most current therapies. Tumor progression and drug resistance depend to a large extent on the interplay between tumor cells and the surrounding matrix. We previously identified Tetraspanin 8 (Tspan8) as a critical mediator of melanoma invasion, whose expression is absent in healthy skin. The present study investigated whether Tspan8 may influence cell-matrix anchorage and regulate downstream molecular pathways leading to an aggressive behavior. Using silencing and ectopic expression strategies, we showed that Tspan8-mediated invasion of melanoma cells resulted from defects in cell-matrix anchorage by interacting with β1 integrins and by interfering with their clustering, without affecting their surface or global expression levels. These effects were associated with impaired phosphorylation of integrin-linked kinase (ILK) and its downstream target Akt-S473, but not FAK. Specific blockade of Akt or ILK activity strongly affected cell-matrix adhesion. Moreover, expression of a dominant-negative form of ILK reduced β1 integrin clustering and cell-matrix adhesion. Finally, we observed a tumor-promoting effect of Tspan8 in vivo and a mutually exclusive expression pattern between Tspan8 and phosphorylated ILK in melanoma xenografts and human melanocytic lesions. Altogether, the in vitro, in vivo and in situ data highlight a novel regulatory role for Tspan8 in melanoma progression by modulating cell-matrix interactions through β1 integrin-ILK axis and establish Tspan8 as a negative regulator of ILK activity. These findings emphasize the importance of targeting Tspan8 as a means of switching from low- to firm-adhesive states, mandatory to prevent tumor dissemination.
- Published
- 2017
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146. Comparison of 3 Methodologies for Genotyping of Small Deletion and Insertion Polymorphisms.
- Author
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Goh SK, Musafer A, Witkowski T, Muralidharan V, Christophi C, Do H, and Dobrovic A
- Subjects
- Alleles, Genotype, Humans, DNA genetics, Genotyping Techniques methods, Microfluidic Analytical Techniques, Mutagenesis, Insertional genetics, Polymerase Chain Reaction, Polymorphism, Single Nucleotide genetics, Sequence Deletion genetics
- Abstract
Background: The quantification of genomic chimerism is increasingly recognized for its clinical significance after transplantation. Before the measurement of chimerism, accurate genotyping of genetic polymorphisms for informative alleles that can distinguish donor DNA from recipient DNA is essential. The ease of allelic discrimination of small deletion and insertion polymorphisms (DIPs) makes DIPs attractive markers to track chimerism. Current methodologies for the genotyping of DIPs are largely based on "open-tube" approaches. "Closed-tube" approaches involving no or minimal post-PCR handling are preferred. We compared 3 distinct methodologies to determine an optimal platform for DIP genotyping., Methods: Genomic DNA from 19 normal individuals was genotyped for 6 small biallelic DIPs using high-resolution melting analysis (HRMA), probe-free droplet digital PCR (ddPCR), and microfluidic electrophoresis of PCR products. For HRMA, 3 different platforms were compared., Results: Our newly developed probe-free ddPCR approach allowed the genotype of each DIP to be determined by fluorescence intensity based on amplicon size. Microfluidic electrophoresis also allowed genotypes to be determined by amplicon size. HRMA assays allowed the genotype of each DIP to be determined by melting profile. Genotyping results were concordant between the 3 methodologies. HRMA was the most readily performed methodology and was robust across 3 separate HRMA-capable platforms., Conclusions: We demonstrated the effectiveness of probe-free ddPCR to accurately genotype small biallelic DIPs. Nevertheless, HRMA proved to be the optimal approach for genotyping small DIPs because closed-tube approaches are preferred owing to rapid and less laborious workflows and least risk of PCR contamination., (© 2016 American Association for Clinical Chemistry.)
- Published
- 2016
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147. Mitral valve geometry and hemodynamics after surgical mitral valve annuloplasty and implications for percutaneous treatment of patients with recurrent mitral regurgitation.
- Author
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Al Amri I, Debonnaire P, Witkowski T, van der Kley F, Palmen M, de Weger A, Klautz RJ, Bax JJ, Schalij MJ, Ajmone Marsan N, and Delgado V
- Subjects
- Aged, Aged, 80 and over, Cardiac Catheterization, Echocardiography, Female, Hemodynamics, Humans, Male, Middle Aged, Mitral Valve surgery, Mitral Valve Insufficiency diagnostic imaging, Mitral Valve Insufficiency mortality, Recurrence, Reoperation, Mitral Valve diagnostic imaging, Mitral Valve Annuloplasty methods, Mitral Valve Insufficiency surgery
- Abstract
The feasibility of transcatheter mitral valve therapy (edge-to-edge or valve-in-ring technique) in patients with significant mitral regurgitation (MR) recurrence after surgical restrictive mitral valve annuloplasty remains unknown. The aim of the present study was to investigate the eligibility for transcatheter mitral valve therapy of high-surgical-risk patients with significant MR recurrence after initial successful restrictive mitral valve annuloplasty. A total of 47 patients (age 67 ± 10 years, 47% men) with significant MR recurrence (effective regurgitant orifice area ≥20 mm², regurgitant volume ≥30 ml/beat, or vena contracta ≥3 mm) after restrictive mitral valve annuloplasty were identified. The long-term outcome of patients dichotomized according to the surgical risk was evaluated. The echocardiographic parameters of mitral valve geometry and hemodynamics at the moment of diagnosis of MR recurrence were assessed to evaluate the eligibility for transcatheter valve therapy. During a median follow-up of 3 years, 23 patients (48.9%) died. The patients with a high-surgical risk (logistic European System for Cardiac Operative Risk Evaluation score ≥20%) had significantly worse long-term survival than those with a low-surgical risk (logistic European System for Cardiac Operative Risk Evaluation score <20%; 50% and 88%, respectively; p = 0.002). All high-surgical-risk patients showed geometric mitral valve features that would allow transcatheter mitral valve therapy (mitral annular area 7 ± 2.0 cm², coaptation length 6 ± 1.6 mm, anterior and posterior mitral leaflet length 24 ± 2.8 mm and 15 ± 3.1 mm, respectively). In conclusion, patients with significant MR recurrence after initial successful restrictive mitral valve annuloplasty and a high risk of redo mitral valve surgery had lower long-term survival rates than patients who could undergo repeat surgery., (Copyright © 2013 Elsevier Inc. All rights reserved.)
- Published
- 2013
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148. Dynamics of the cognitive procedural learning in alcoholics with Korsakoff's syndrome.
- Author
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Beaunieux H, Pitel AL, Witkowski T, Vabret F, Viader F, and Eustache F
- Subjects
- Alcoholism physiopathology, Case-Control Studies, Female, Humans, Male, Middle Aged, Neuropsychological Tests, Alcohol Amnestic Disorder physiopathology, Learning physiology, Memory, Episodic, Memory, Short-Term physiology
- Abstract
Background: While procedures acquired before the development of amnesia are likely to be preserved in alcoholic patients with Korsakoff's syndrome, the ability of Korsakoff patients (KS) to learn new cognitive procedures is called in question. According to the Adaptive Control of Thoughts model, learning a new cognitive procedure requires highly controlled processes in the initial cognitive phase, which may be difficult for KS with episodic and working memory deficits. The goals of the present study were to examine the learning dynamics of KS compared with uncomplicated alcoholic patients (AL) and control subjects (CS) and to determine the contribution of episodic and working memory abilities in cognitive procedural learning performance., Methods: Fourteen KS, 15 AL, and 15 CS were submitted to 40 trials (4 daily learning sessions) of the Tower of Toronto task (disk-transfer task similar to the tower of Hanoi task) as well as episodic and working memory tasks., Results: The 10 KS who were able to perform the cognitive procedural learning task obtained lower results than both CS and AL. The cognitive phase was longer in the Korsakoff's syndrome group than in the other 2 groups but did not differ between the 3 groups any more when episodic memory abilities were controlled., Conclusions: Our results indicate that KS have impaired cognitive procedural learning abilities compared with both AL and CS. Episodic memory deficits observed in KS result in a delayed transition from the cognitive learning phase to more advanced learning phases and, as a consequence, in an absence of automation of the procedure within 40 trials., (Copyright © 2012 by the Research Society on Alcoholism.)
- Published
- 2013
- Full Text
- View/download PDF
149. Right ventricular function and survival following cardiac resynchronisation therapy.
- Author
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Leong DP, Höke U, Delgado V, Auger D, Witkowski T, Thijssen J, van Erven L, Bax JJ, Schalij MJ, and Marsan NA
- Subjects
- Aged, Echocardiography, Doppler, Female, Follow-Up Studies, Heart Failure physiopathology, Heart Failure therapy, Humans, Male, Middle Aged, Netherlands epidemiology, Prognosis, Retrospective Studies, Survival Rate trends, Cardiac Resynchronization Therapy methods, Heart Failure mortality, Ventricular Function, Right physiology
- Abstract
Objectives: Right ventricular (RV) function is an important prognostic marker in heart failure. However, its impact on all-cause mortality following cardiac resynchronisation therapy (CRT) independent of confounding factors has not been evaluated. Furthermore, evidence concerning the effect of CRT on RV function is limited. The study's aims were to: (1) assess the prognostic importance of RV function among CRT recipients, and (2) characterise RV functional change following CRT and its determinants., Design: Retrospective observational study., Setting: Single tertiary centre., Patients: A total of 848 CRT recipients (median age 65 years, 78% male, 60% ischaemic) underwent echocardiography before and 6 months after CRT. RV function was evaluated using tricuspid annular plane systolic excursion (TAPSE), with a ≤14 mm threshold indicating severe RV impairment. The primary endpoint was long-term all-cause mortality., Results: Significant baseline RV dysfunction was observed in 286 (34%) individuals. After a median 44 months, 288 deaths occurred. RV impairment was associated with a greater incidence of all-cause mortality (log-rank p<0.001). Independent predictors of this endpoint were functional class, ischaemic aetiology, diabetes, atrial fibrillation, renal dysfunction, bigger left ventricular (LV) end-systolic volume, less LV dyssynchrony and reduced TAPSE. Importantly, TAPSE added prognostic value to these recognised prognostic parameters (likelihood-ratio test p<0.001). Furthermore, improvement in RV function after CRT was independent of the improvement in LV systolic function but significantly associated with the improvement in LV diastolic function. Importantly, a favourable RV functional response to CRT was associated with superior survival., Conclusions: RV function is an independent predictor of long-term outcome following CRT.
- Published
- 2013
- Full Text
- View/download PDF
150. Percutaneous reduction of mitral valve regurgitation using the MitraClip system - immediate and 90-day follow-up of 3 cases.
- Author
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Kübler P, Kustrzycka-Kratochwil D, Telichowski A, Witkowski T, Banasiak W, Jankowska EA, Ponikowski P, and Reczuch K
- Abstract
Treatment of hemodynamically significant valvular heart diseases has been the domain of cardiac surgery for decades. However, a promising novel method is the MitraClip system, involving percutaneous connection of insufficient valve leaflets with special cobalt-chrome clips. Our study presents clinical characteristics, course of treatment with the MitraClip system, and immediate and 90-day clinical and echocardiographic follow-up of the first 3 patients treated in our institution. Subsequently, based on data from the literature and our own experience, the current position around the world, and the target group of patients who are most likely to benefit from treatment using the MitraClip system, are discussed.
- Published
- 2013
- Full Text
- View/download PDF
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