Personal Statement

The overall goal of Dr Paschalis’ research effort is to establish the contribution of the bone organic matrix to its mechanical performance, and to employ the resulting data so as to develop spectroscopic techniques as viable clinical diagnostic tools for musculoskeletal diseases.

Positions

• 2003-Present: Senior Scientist: Ludwig Boltzmann Institute for Osteology
• 2007-Present: a. Senior Scientist: National & Kapodistrian University of Athens, School of Medicine, 1st Dept. of Orthopaedic Surgery, University General Hospital “Attikon”
• 1999-2003: Director of IR Imaging Core: The Hospital for Special Surgery
• 4/2001-2003: Associate Scientist: The Hospital for Special Surgery
• 1997-2001: Assistant Scientist: The Hospital for Special Surgery
• 1993-1996: Postdoctoral Fellow: The Hospital for Special Surgery.

Professional Memberships

• American Society for Bone & Mineral Research
• Member of Austrian Society for Bone & Mineral Research

Editorial Board Service

• Calcified Tissue International
• Bone
• Journal for Bone and Mineral Research (2004 – 2010)

Ad hoc Reviewer

Honors

• Young Investigator Award: 5th International Conference on the Chemistry and Biology of Mineralized Tissues
• New Investigator Recognition Award; 44th Annual Meeting of the Orthopaedic Research Society, New Orleans, Louisiana, March 16-19, 1998.
• Young Investigator Award; 6th International Conference on the Chemistry and Biology of Mineralized Tissues, Oct. 1998.

Selected Publications (out of 137)

Bone Tissue Material Science

Material properties are important determinants of bone strength. In the following publications we developed spectroscopic parameters describing the spatial resolution of enzymatic collagen cross-links, and applied spectroscopic analyses to determine changes in bone material properties in premenopausal Type 2 diabetic women as a function of glycemic control, disease duration, and fragility fracture incidence. We also investigated changes in these bone properties due to menopause in healthy women, as well as differences in BMD-matched women that either sustain fragility fractures or not.

1. E. P. Paschalis, K. Verdelis, S. B. Doty, A. L. Boskey, R. Mendelsohn, M. Yamauchi
   Spectroscopic Characterization of Collagen Cross-Links in Bone. J of Bone and Mineral Research, 16 (10), 1821-8, 2001
2. Rokidi S, Andrade VFC, Borba V, Shane E, Cohen A, Zwerina J, Paschalis EP, Moreira CA.
   Bone tissue material composition is compromised in premenopausal women with Type 2 diabetes. Bone. 2020 Dec; 141:115634.
3. Gamsjaeger S, Brozek W, Recker R, Klaushofer K, Paschalis EP.
   Transmenopausal changes in trabecular bone quality. J Bone Miner Res., 29(3):608-17, 2014
4. Rokidi S, Paschalis EP, Klaushofer K, Vennin S, Desyatova A, Turner JA, Watson P, Lappe J, Akhter MP, Recker RR.
   Organic matrix quality discriminates between age- and BMD-matched fracturing versus non-fracturing post-menopausal women: A pilot study. Bone. 2019 Jun 21;127:207-214.

Bone tissue properties in Various Clinical Conditions

The following selected publications describe the interplay between mineral crystallite size and mineral content, an interaction that most likely confounds mineral content measuring techniques with the exception of thermogravimetric analysis, and appreciation of which may result in improvement of mineral content determination by either DXA or CT techniques. Impact Microindentation is a technique that may be applied in the clinical setting providing a measure of bone strength, beyond BMD considerations, yet its underlying principle is still to be fully elucidated. We have provided evidence of which bone material properties correlate with these clinical measurements.

1. Gamsjaeger S, Fratzl P, Paschalis EP.
   Interplay between Mineral Crystallinity and Mineral Accumulation in Health and Postmenopausal Osteoporosis. Acta Biomater. 2021 Feb 11:S1742-7061(21)00097-0.
2. Paschalis EP, Fratzl P, Gamsjaeger S, Hassler N, Brozek W, Eriksen EF, Rauch F, Glorieux FH, Shane E, Dempster D, Cohen A, Recker R, Klaushofer K.
   Aging Versus Postmenopausal Osteoporosis: Bone Composition and Maturation Kinetics at Actively-Forming Trabecular Surfaces of Female Subjects Aged 1 to 84 Years. J Bone Miner Res. 31(2):347-57, 2016
3. Rokidi S, Bravenboer N, Gamsjaeger S, Chavassieux P, Zwerina J, Paschalis E, Papapoulos S, Appelman-Dijkstra N.
   Impact Microindentation Measurements Correlate with Cortical Bone Material Properties Measured by Fourier Transform Infrared Imaging in Humans. Bone 2020, May 27;137:115437.
4. Rokidi S, Bravenboer N, Gamsjaeger S, Misof B, Blouin S, Chavassieux P, Klaushofer K, Paschalis E, Papapoulos S, Appelman-Dijkstra N.
   Impact microindentation assesses subperiosteal bone material properties in humans. Bone. 2020 Feb; 131:115110.

Treatment and Bone Tissue Properties

The following selected publications describe alterations in bone material properties due to various therapies in postmenopausal osteoporotic patients, as well as head-to-head comparisons.

1. Paschalis EP, Dempster DW, Chan-Diehl FW, Gamsjaeger S, Rokidi S, Hassler N, Brozek W, Klaushofer K, Taylor KA.
   Mineral and Organic Matrix Composition at Bone Forming Surfaces in Postmenopausal Women with Osteoporosis Treated with Either Teriparatide or Zoledronic Acid. Bone. 2021 Jan 13:115848.
2. Paschalis EP, Krege JH, Gamsjaeger S, Eriksen EF, Burr DB, Disch DP, Stepan JJ, Fahrleitner-Pammer A, Klaushofer K, Marin F, MD, Pavo I.
   Teriparatide treatment increases mineral content and volume in cortical and trabecular bone of iliac crest: a comparison of infrared imaging with X-ray-based bone assessment techniques. J Bone Miner Res., 33(12):2230-2235, 2018
3. Misof BM, Blouin S, Lueger S, Paschalis EP, Recker RR, Phipps R, Klaushofer K, Roschger P.
   Baseline mineralizing surface determines the magnitude of the bisphosphonate effect on cortical bone mineralization in postmenopausal osteoporotic patients. J Musculoskelet Neuronal Interact. Sep 1;17(3):183-191, 2017
4. Hofstetter B., Gamsjaeger S., Phipps RJ., Recker RR., Ebetino FH., Klaushofer K., Paschalis EP.
   Effects of Alendronate and Risedronate on Bone Material Properties in Actively Forming Trabecular Bone Surfaces. J of Bone and Mineral Research, 27(5):995-1003, 2012

Use of Novel Techniques in Analyses of Bone Tissue

1. Paschalis EP, Gamsjaeger S, Klaushofer K.
   Vibrational spectroscopic techniques to assess bone quality. Osteoporos. Int. 28(8), 2275-2291, 2017
2. Gamsjaeger S, Robins SP, Tatakis DN, Klaushofer K, Paschalis EP.
   Identification of pyridinoline trivalent collagen cross-links by Raman microspectroscopy. Calcified Tissue International, 100(6):565-574, 2017
3. Gamsjaeger S., Klaushofer K., Paschalis EP.
   Raman analysis of proteoglycans simultaneously in bone and cartilage. Journal of Raman Spectroscopy, 45(9): 794-800, 2014
4. C. Marcott, R.C. Reeder, E.P. Paschalis, D. N. Tatakis, A.L. Boskey, R. Mendelsohn;
   FT-IR Chemical Imaging of Biomineralized Tissues Using a Mercury-Cadmium-Telluride Focal-Plane Detector Cellular and Molecular Biology 44(1): 109-115, 1998