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Nummela P, Saarinen L, Leinonen H, Heiskanen A, Thiel A, Haglund C, Lepistö A, Satomaa T, Hautaniemi S, Ristimäki A. PO-465 N-glycans of pseudomyxoma peritonei present highly increased fucosylation and multifucosylation correlates with high-grade morphology. ESMO Open 2018. [DOI: 10.1136/esmoopen-2018-eacr25.972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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2
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Hemanth S, Caviglia C, Amato L, Anhoj TA, Heiskanen A, Emneus J, Keller SS. Pyrolytic 3D Carbon Microelectrodes for Electrochemistry. ACTA ACUST UNITED AC 2016. [DOI: 10.1149/07201.0117ecst] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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3
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Canali C, Mazzoni C, Larsen LB, Heiskanen A, Martinsen ØG, Wolff A, Dufva M, Emnéus J. An impedance method for spatial sensing of 3D cell constructs--towards applications in tissue engineering. Analyst 2016. [PMID: 26198701 DOI: 10.1039/c5an00987a] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We present the characterisation and validation of multiplexed 4-terminal (4T) impedance measurements as a method for sensing the spatial location of cell aggregates within large three-dimensional (3D) gelatin scaffolds. The measurements were performed using an array of four rectangular chambers, each having eight platinum needle electrodes for parallel analysis. The electrode positions for current injection and voltage measurements were optimised by means of finite element simulations to maximise the sensitivity field distribution and spatial resolution. Eight different 4T combinations were experimentally tested in terms of the spatial sensitivity. The simulated sensitivity fields were validated using objects (phantoms) with different conductivity and size placed in different positions inside the chamber. This provided the detection limit (volume sensitivity) of 16.5%, i.e. the smallest detectable volume with respect to the size of the measurement chamber. Furthermore, the possibility for quick single frequency analysis was demonstrated by finding a common frequency of 250 kHz for all the presented electrode combinations. As final proof of concept, a high density of human hepatoblastoma (HepG2) cells were encapsulated in gelatin to form artificial 3D cell constructs and detected when placed in different positions inside large gelatin scaffolds. Taken together, these results open new perspectives for impedance-based sensing technologies for non-invasive monitoring in tissue engineering applications providing spatial information of constructs within biologically relevant 3D environments.
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Affiliation(s)
- C Canali
- Department of Micro- and Nanotechnology, Technical University of Denmark, 2800, Kgs. Lyngby, Denmark.
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4
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Adesokan B, Quan X, Evgrafov A, Heiskanen A, Boisen A, Sørensen M. Experimentation and numerical modeling of cyclic voltammetry for electrochemical micro-sized sensors under the influence of electrolyte flow. J Electroanal Chem (Lausanne) 2016. [DOI: 10.1016/j.jelechem.2015.12.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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5
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Caviglia C, Zór K, Canepa S, Carminati M, Larsen LB, Raiteri R, Andresen TL, Heiskanen A, Emnéus J. Interdependence of initial cell density, drug concentration and exposure time revealed by real-time impedance spectroscopic cytotoxicity assay. Analyst 2015; 140:3623-9. [PMID: 25868456 DOI: 10.1039/c5an00097a] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We investigated the combined effect of the initial cell density (12,500, 35,000, 75,000, and 100,000 cells cm(-2)) and concentration of the anti-cancer drug doxorubicin on HeLa cells by performing time-dependent cytotoxicity assays using real-time electrochemical impedance spectroscopy. A correlation between the rate of cell death and the initial cell seeding density was found at 2.5 μM doxorubicin concentration, whereas this was not observed at 5 or 100 μM. By sensing the changes in the cell-substrate interaction using impedance spectroscopy under static conditions, the onset of cytotoxicity was observed 5 h earlier than when using a standard colorimetric end-point assay (MTS) which measures changes in the mitochondrial metabolism. Furthermore, with the MTS assay no cytotoxicity was observed after 15 h of incubation with 2.5 μM doxorubicin, whereas the impedance showed at this time point cell viability that was below 25%. These results indicate that impedance detection reveals cytotoxic events undetectable when using the MTS assay, highlighting the importance of combining impedance detection with traditional drug toxicity assays towards a more in depth understanding of the effect of anti-cancer drugs on in vitro assays. Moreover, the detection of doxorubicin induced toxicity determined with impedance under static conditions proved to be 6 times faster than in perfusion culture.
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Affiliation(s)
- C Caviglia
- Department of Micro- and Nanotechnology, Technical University of Denmark, Kgs. Lyngby, Denmark.
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6
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Zór K, Heiskanen A, Caviglia C, Vergani M, Landini E, Shah F, Carminati M, Martínez-Serrano A, Moreno TR, Kokaia M, Benayahu D, Keresztes Z, Papkovsky D, Wollenberger U, Svendsen WE, Dimaki M, Ferrari G, Raiteri R, Sampietro M, Dufva M, Emnéus J. A compact multifunctional microfluidic platform for exploring cellular dynamics in real-time using electrochemical detection. RSC Adv 2014. [DOI: 10.1039/c4ra12632g] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Dopamine detection from PC12 cell populations and monitoring of yeast redox metabolism demonstrate the multifunctionality of the compact microfluidic cell culture and electrochemical analysis platform with in-built fluid handling and detection unit.
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Affiliation(s)
- K. Zór
- Department of Micro- and Nanotechnology
- Technical University of Denmark
- DK-2800 Kgs. Lyngby, Denmark
| | - A. Heiskanen
- Department of Micro- and Nanotechnology
- Technical University of Denmark
- DK-2800 Kgs. Lyngby, Denmark
| | - C. Caviglia
- Department of Micro- and Nanotechnology
- Technical University of Denmark
- DK-2800 Kgs. Lyngby, Denmark
| | - M. Vergani
- Dipartimento di Elettronica
- Informazione e Bioingegneria
- Politecnico di Milano
- Milan, Italy
| | - E. Landini
- Department of Informatics, Bioengineering, Robotics, and System Engineering
- University of Genova
- Genova, Italy
| | - F. Shah
- Department of Micro- and Nanotechnology
- Technical University of Denmark
- DK-2800 Kgs. Lyngby, Denmark
| | - M. Carminati
- Dipartimento di Elettronica
- Informazione e Bioingegneria
- Politecnico di Milano
- Milan, Italy
| | - A. Martínez-Serrano
- Department of Molecular Biology and Center of Molecular Biology “Severo Ochoa”
- University Autónoma de Madrid
- Madrid, Spain
| | - T. Ramos Moreno
- Department of Molecular Biology and Center of Molecular Biology “Severo Ochoa”
- University Autónoma de Madrid
- Madrid, Spain
- Wallenberg Neuroscience Center
- Lund University
| | - M. Kokaia
- Wallenberg Neuroscience Center
- Lund University
- Lund, Sweden
| | - D. Benayahu
- Department of Cell and Developmental Biology
- Tel Aviv University
- Ramat Aviv, Israel
| | - Zs. Keresztes
- Research Center for Natural Sciences
- Hungarian Academy of Sciences
- Budapest, Hungary
| | - D. Papkovsky
- Department of Biochemistry and Cell Biology
- University College Cork
- Cork, Ireland
| | - U. Wollenberger
- Department of Molecular Enzymology
- University of Potsdam
- Potsdam (Golm), Germany
| | - W. E. Svendsen
- Department of Micro- and Nanotechnology
- Technical University of Denmark
- DK-2800 Kgs. Lyngby, Denmark
| | - M. Dimaki
- Department of Micro- and Nanotechnology
- Technical University of Denmark
- DK-2800 Kgs. Lyngby, Denmark
| | - G. Ferrari
- Dipartimento di Elettronica
- Informazione e Bioingegneria
- Politecnico di Milano
- Milan, Italy
| | - R. Raiteri
- Department of Informatics, Bioengineering, Robotics, and System Engineering
- University of Genova
- Genova, Italy
| | - M. Sampietro
- Dipartimento di Elettronica
- Informazione e Bioingegneria
- Politecnico di Milano
- Milan, Italy
| | - M. Dufva
- Department of Micro- and Nanotechnology
- Technical University of Denmark
- DK-2800 Kgs. Lyngby, Denmark
| | - J. Emnéus
- Department of Micro- and Nanotechnology
- Technical University of Denmark
- DK-2800 Kgs. Lyngby, Denmark
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7
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Caviglia C, Carminati M, Heiskanen A, Vergani M, Ferrari G, Sampietro M, Andresen TL, Emnéus J. Quantitative Label-Free Cell Proliferation Tracking with a Versatile Electrochemical Impedance Detection Platform. ACTA ACUST UNITED AC 2012. [DOI: 10.1088/1742-6596/407/1/012029] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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8
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Suila H, Pitkanen V, Hirvonen T, Heiskanen A, Anderson H, Laitinen A, Natunen S, Miller-Podraza H, Satomaa T, Natunen J, Laitinen S, Valmu L. Are globoseries glycosphingolipids SSEA-3 and -4 markers for stem cells derived from human umbilical cord blood? J Mol Cell Biol 2010; 3:99-107. [DOI: 10.1093/jmcb/mjq041] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
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9
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Heiskanen A. Amperometric monitoring of redox activity in living yeast cells: comparison of menadione and menadione sodium bisulfite as electron transfer mediators. Electrochem commun 2004. [DOI: 10.1016/j.elecom.2003.12.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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10
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Zhang F, Taipale M, Heiskanen A, Laiho M. Ectopic expression of Cdk6 circumvents transforming growth factor-beta mediated growth inhibition. Oncogene 2001; 20:5888-96. [PMID: 11593394 DOI: 10.1038/sj.onc.1204745] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2001] [Revised: 05/31/2001] [Accepted: 06/18/2001] [Indexed: 01/07/2023]
Abstract
Transforming growth factor-beta (TGF-beta) induced growth arrest of cells involves regulation of the activities of both D- and E-type cyclin kinase complexes thought to be mediated primarily by the regulation of p15(Ink4b) and p27(Kip1) cyclin kinase inhibitors. We show here that TGF-beta downregulates Cdk6 and that transient and stable expression of Cdk6 in Mv1Lu mink epithelial cells overrides TGF-beta mediated arrest. The main effect of the ectopic Cdk6 expression was to sequester TGF-beta induced p15(Ink4b) and to maintain more p27(Kip1) in cyclin D-complexes preventing the complete shift of p27(Kip1) to Cdk2 invoked by TGF-beta. This led to the presence of an active cyclinD-Cdk6-p27(Kip1) complex and partially active cyclin E-Cdk2 complex and resulted in the failure of TGF-beta to fully arrest Mv1Lu cell growth. Though dominant negative Cdk6, expressed similarly in the cells, sequestered both p15(Ink4b) and p27(Kip1), it lacks kinase activity and was unable to override the TGF-beta arrest. The results demonstrate that downregulation of Cdk6 kinase is required for the enforcement of the G(1)-phase arrest by TGF-beta and results in changes in association of the p15(Ink4b) and p27(Kip1) inhibitors with D- and E-type cyclin kinase complexes.
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Affiliation(s)
- F Zhang
- Haartman Institute, Department of Virology, University of Helsinki, FIN-00014 Helsinki, Finland
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11
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Taipale M, Tiihonen E, Heiskanen A, Laiho M. Accumulation of a form of p27(Kip1) not associated with Cdk-cyclin complexes in transforming growth factor-beta-arrested Mv1Lu cells. Exp Cell Res 2000; 259:107-16. [PMID: 10942583 DOI: 10.1006/excr.2000.4959] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The p27(Kip1) cyclin-dependent kinase inhibitor translocates in response to transforming growth factor-beta to a Cdk2-cyclin E complex inhibiting its catalytic activity, but the p27(Kip1) protein levels are unaffected [1]. We show here that transforming growth factor-beta induces the accumulation of a form of p27(Kip1) representing a subpopulation of total p27(Kip1) in growth-arrested Mv1Lu epithelial cells. The inducible p27(Kip1) is detectable only by a specific p27(Kip1) monoclonal antibody recognizing a native form of p27(Kip1). The increase in this subset of p27(Kip1) correlates with G(1) arrest and withdrawal of the cells from the cycle induced by transforming growth factor-beta, serum starvation, or contact inhibition. In contrast to the majority of p27(Kip1) in the cells, the transforming growth factor-beta-inducible p27(Kip1) is devoid of cyclin-dependent kinase/cyclin interactions. The results indicate that growth arresting treatments induce the accumulation of non-cyclin-dependent kinase-bound p27(Kip1), which may function as a reservoir for inhibition of Cdk2-cyclin E activities.
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Affiliation(s)
- M Taipale
- Department of Virology, University of Helsinki, Helsinki, FIN-00014, Finland
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12
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Haapajärvi T, Kivinen L, Heiskanen A, des Bordes C, Datto MB, Wang XF, Laiho M. UV radiation is a transcriptional inducer of p21(Cip1/Waf1) cyclin-kinase inhibitor in a p53-independent manner. Exp Cell Res 1999; 248:272-9. [PMID: 10094833 DOI: 10.1006/excr.1999.4403] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
p53 target genes p21(Cip1/Waf1) cyclin-kinase inhibitor (p21 CKI), GADD45, bax, and cyclin G and genes affecting the redox state of the cells are implicated in p53 damage control responses. In order to attribute their functions and dependency of p53 in UV-damaged cells we undertook an analysis of UVC responses of fibroblasts derived from p53 knock-out mice. UVC radiation efficiently and rapidly inhibited DNA replication in both p53 -/- and +/+ cells. The arrest was persistent in p53 -/- fibroblasts and cells underwent apoptosis, whereas p53 +/+ cells recovered and reentered the cycle. Protein and mRNA analyses of p21 expression showed that it was induced up to sixfold with similar kinetics both in the presence and in the absence of p53. However, high doses of UV abrogated the p21 response in p53 -/- cells, whereas it was maintained in cells with normal p53. UVC radiation transcriptionally activated p21 expression as demonstrated by luciferase reporter assays using deletion constructs of the p21 promoter. The promoter assays further confirmed the independency of p53-binding sites in the activation and linked UV-responsive transcriptional regulation of p21 to two Sp1 consensus binding sites within -61 bp of the transcription initiation site. A weaker regulation was mediated by elements between -1300 to -500 bp relative to the transcription initiation site. The results suggest that in fibroblasts UVC radiation is a rapid and efficient inducer of p21 expression also in a p53-independent manner.
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Affiliation(s)
- T Haapajärvi
- Department of Virology, University of Helsinki, Haartmaninkatu 3, Helsinki, FIN-00014, Finland
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13
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Paimela L, Heiskanen A, Kurki P, Helve T, Leirisalo-Repo M. Serum hyaluronate level as a predictor of radiologic progression in early rheumatoid arthritis. Arthritis Rheum 1991; 34:815-21. [PMID: 2059229 DOI: 10.1002/art.1780340706] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Increased serum levels of hyaluronate (HA) have been found in patients with rheumatoid arthritis (RA). This probably reflects increased leakage of HA from the inflamed joints into the circulation. In a prospective study of 40 patients with early RA, we evaluated the relationship of serum HA to clinical, laboratory, and radiologic parameters of disease activity. The patients were followed for 12 months; all had active disease at study entry. We confirmed the previous finding of higher serum HA concentrations in RA patients compared with healthy controls. At study entry, the patients' serum HA levels correlated positively with clinical and laboratory parameters of acute inflammation. Despite marked clinical improvement during therapy with second-line drugs, the serum HA levels increased during the followup period. At the end of 1 year, these levels correlated with the radiologic progression of joint lesions, whereas they showed a less pronounced correlation with clinical or laboratory parameters of inflammation. We conclude that, in early RA, serum HA levels may reflect ongoing joint destruction and may even predict subsequent joint damage.
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Affiliation(s)
- L Paimela
- Department of Rheumatology, Kivelä Hospital, Helsinki, Finland
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Riihimäki E, Heiskanen A, Tähti E. Theory of quantitative determination of intracardiac shunts by external detection. Ann Clin Res 1974; 6:45-9. [PMID: 4595065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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