Stefan Judex 

Associate Professor
Director, Integrative Skeletal Adaptation and Genetics Laboratory

Research Focus

Research in the Integrative Skeletal Adaptation and Genetics Laboratory focuses on how organ systems, such as the skeleton, respond to altered functional demand. Specifically, we are combining genetic, molecular, and biomechanical approaches to elucidate how bone regulates its quantity and quality and how mechanical stimuli may perturb this regulation. An improved understanding of how external signals are translated into a biological response require the rigorous integration of engineering with biology, from the genome to the molecular, cellular, and tissue level. This understanding will, ultimately, lead to the design of pharmacological and non-pharmacological (e.g., mechanical or nutritional) interventions that will enhance tissue strength in young adults and prevent the loss of tissue quantity and quality during osteoporosis, aging, or space flight. To this end, genetic (e.g., QTL) and molecular (e.g., RT-PCR, immunocytochemistry, or microarrays) assays are used to relate specific loci on chromosomes and the expression level of corresponding genes to traits at the level of the tissue. These traits are rigorously defined by their chemical, morphological, and mechanical properties by cutting edge technology such as MRI, high resolution computed tomographic imaging, in situ infrared spectroscopy, or finite element modeling.

Micro-computed tomography images of the distal femur of three mice with distinct genotypes. The differences in trabecular and cortical bone structure between (a.) "low bone mineral density" C57BL/6J mice, (b.) "medium bone mineral density" BALB/cByJ, mice, and (c.) "high bone mineral density" C3H/HeJ mouse are striking. Intriguingly, the differential genotype is also associated with a differential skeletal plasticity to both increased or decreased mechanical demand.

Education & Training

• 1999-2001 Post-doctoral Research Fellow, Department of Biomedical Engineering (Molecular Biology), SUNY Stony Brook, NY
• 1999 Ph.D., Mechanical Engineering (Biomechanics), University of Calgary, Canada
• 1993 Diplom Ingenieur Universität (Master of Science), Mechanical Engineering, Technical University Munich, Munich, Germany
   

Academic Appointments

• 2006 – present Associate Professor, Department of Biomedical Engineering, State University of New York (SUNY), Stony Brook, NY
• 2004 – present Adjunct Assistant Professor, Department of Preventive Medicine and Community Health, The University of Texas Medical Branch
• 2001 - 2006 Assistant Professor, Department of Biomedical Engineering, SUNY Stony Brook, NY
   

Awards
               

Professional Affiliations

• Advances in Mineral Metabolism
• American Association for the Advancement of Science
• American Society for Bone and Mineral Research
• American Society for Engineering Education
• International Society of Biomechanics
• Orthopaedic Research Society

Funding Sources

• NASA
• NSF
• NIH
• NSBRI
• SUNY-BNL Seed Grant
• Stony Brook School of Medicine
• The Coulter Foundation
• The Whitaker Foundation
• US Army

Recent Publications

Click here to search Stefan Judex's PubMed listings

Recent Refereed Journal Papers:

• Rubin, C.T., Judex, S., Qin, Y.X. (2006) Low-level mechanical signals and their potential as a non-pharmacologic intervention for osteoporosis. Age and Ageing 35 (S2), ii32-ii36.

• Xie, L.Q., Jacobson, J., Choi, E., Busa, B., Donahue, L.R, Rubin, C.T., Miller, L.M., Judex, S. (2006). Low-level mechanical vibrations can influence bone resorption and bone formation in the growing skeleton. Bone 39(5), 1059-1066.\

• Gilsanz, V., Wren, T.A., Sanchez, M., Dorey, S., Judex, S., Rubin, C.T (2006) Low level, high frequency mechanical signals enhance musculoskeletal development of young women with low bone density. Journal of Bone and Mineral Research 21(9), 1464-1474.

• Judex, S., Lei, X., Han, D., Rubin, C. (2007) Low-magnitude mechanical signals that stimulate bone formation in the ovariectomized rat are dependent on the applied frequency but not on the strain magnitude. Journal of Biomechanics 40, 1333–1339.

• Garman, R.A., Gaudette, G., Donahue, L.R, Rubin, C.T., Judex, S. (2007) Low-level accelerations applied in the absence of weight bearing can enhance trabecular bone formation. Journal of Orthopaedic Research 25(6), 732-740.

• Bastie, C., Zong, H., Xu, J., Busa, B., Judex, S., Kurland, I.J., Pessin, J.E. (2007) The Src family member fyn suppresses peripheral tissue fatty acid oxidation through tonic inhibition of AMP kinase signaling. Cell Metabolism 5(5), 371-381.

• Miller, L.M, Little, W.B., Schirmer, A., Busa, B., Judex, S. (2007) Accretion of bone quantity and quality in the developing mouse skeleton. Journal of Bone and Mineral Research 22(7), 1037-1045.

• Garman, R., Rubin, C., Judex, S. (2007) Small oscillatory accelerations, independent of matrix deformations, increase osteoblast activity and enhance bone morphology. PLoS ONE 2(7), e653. doi:10.1371/journal.pone.0000653.

• Ozcivici, E., Garman, R., Judex, S. (2007) High-frequency oscillatory motions enhance the simulated mechanical properties of non-weight bearing trabecular bone. Journal of Biomechanics 40(15), 3404-3011.

• Karlson, K.J., Judex. S. (2007) Increased non-linear locomotion alters diaphyseal bone shape. The Journal of Experimental Biology 210, 3117-3125.

• Lublinsky, S., Ozcivici, E., Judex. S. (2007) An automated algorithm to detect the trabecular-cortical bone interface in microCT images.  Calcified Tissue International 81(4), 285-293.

• Rubin, C.T., Capilla, E., Luu, Y.K., Busa, B., Crawford, H., Nolan, D.J., Mittal, V., Rosen, C., Pessin, J.E., Judex, S. (2007) Adipogenesis is inhibited by brief, daily exposure to high-frequency, extremely low-magnitude mechanical signals. Proceedings of the National Academy of Sciences 104(45), 17879–17884.

• Chen, X., Nasiri, A., Judex, S., Broadus, A.E. (2007) Mechanical regulation of PTHrP expression in entheses. Bone 41(5), 752-759.

• Squire, M., Brazin, A., Keng, Y., Judex, S. (2007) The influence of baseline bone morphometry on the gender- and site-specific dependency of disuse osteopenia. Bone doi:10.1016/j.bone.2007.09.052. 

Recent Book Chapters:

• Zernicke, R.F., Judex S., Lorincz, C. (in press) Adaptation of biological materials to exercise, disuse, and aging. In: Biomechanics of the Musculo-skeletal System (2nd Edition). Nigg, B.M, Herzog, W. (eds.). John Wiley & Sons Ltd, U.K.

• Judex, S., Whiting, W.C., Olender, G., Zernicke, R.F. (in press) Bone biomechanics and fracture. In: Biomechanics in Ergonomics (2nd Edition). Kumar, S. (ed.). Taylor & Francis, London, U.K.

• Ozcivici, E., Ferreri, S., Qin, Y.X., Judex, S. (in press) Determination of bone’s mechanical matrix properties by nanoindentation.  In: Molecular Methods in Medicine: Osteoporosis. Westendorf, J. (ed.). The Humana Press, Totowa, NJ.

• Rubin, C.T., Judex, S., Rubin, J., Qin, Y.X. (in press) Inhibition of osteoporosis by biophysical intervention. In: Osteoporosis. Marcus, R., Feldman, D., Nelson, D., Rosen, C. (eds.) 3rd edition, Elsevier Inc., San Diego, CA.

• Ozcivici, E., Luu, Y.K., Rubin, C., Judex, S. (in press) High-resolution imaging of organs and tissues by in vivo micro-computed tomography. In: The Protocols in Musculoskeletal Research: A Practical Manual for Laboratory Techniques. Qin, Y.X (ed.). The Humana Press, Totowa, NJ.

• Judex, S., Rubin, J., Rubin, C. (in press) Mechanisms of exercise effects on bone quantity and quality. In: Principles of Bone Biology. Bilezikian, J.P., Raisz, L.G., Martin, J. (eds.) 3rd edition. Academic Press, San Diego, CA.

Recent Invited Presentations and Lectures

• Gordon Research Conference on Musculoskeletal Biology and Bioengineering, Andover, NH, 2008, Invited Speaker, High frequency physical signals in the musculoskeleton.

• Conference on Orthodontic Advances in Science and Technology (COAST), Asilomar, CA, 2008, Keynote Lecture, Mechano-regulation of bone modeling and remodeling.

• Endocrinology Research Conference, Department of Endocrinology and Metabolism, SUNY Stony Brook, NY, 2008.  Invited Speaker, Regulation of high-frequency mechanical signals: from bone to fat.

• Canadian Society for Exercise Physiology, London, ON, Canada, 2007, Invited Speaker: Sensitivity of the musculoskeleton to very small magnitude vibrations.

• City College of New York, Department of Biomedical Engineering, 2007, Invited Seminar: Genetic and epigenetic regulation of bone quality and quantiy.

• International Symposium on Vibration Therapy, Hong Kong, 2006, Invited Lecture: Genetic and molecular modulation of bone's sensitivity to vibrations.

• International Symposium on Vibration Therapy, Hong Kong, 2006, Invited Lecture: What parameters define the efficacy of low magnitude vibrations?

Courses

• BME 212 BME Research Fundamentals
• BME 475 Undergraduate Teaching Practicum
• BME 449 Research in Biomedical Engineering
• BME 508 Molecular and Cellular Biomechanics