Regulatory compliance and calibration issues to be addressed prior to SPECT data acquisition:
- SPECT analysis requires the use of at least 2 highly regulated experimental parameters, live animals and radionuclides, thus all regulatory issues must be examined and approved by the appropriate regulatory committee prior to initiation of an experimental protocol.
- A clear and concise protocol incorporating experimental design, radiation safety issues, and animal care issues must be generated and approved prior to any experimental work.
- The proposed isotope, chemical/physical form and quantity you may possess at any onetime, including waste must be approved by Radiation Safety and listed on the Authorized User's license.
- The SPECT Core Facility (UT 1330) must be listed on the investigator’s Authorized User’s license maintained by the Radiation Safety Office.
- Swiping the facility immediately after use and decontamination, if necessary, is the responsibility of the investigator/radiation worker. All survey results (including diagram with swipe locations, Quality Control standard count & decontamination results) must be retained by the investigator.
- The investigator/radiation worker is responsible for removal or arranging removal of radioactive waste generated by the investigator/radiation worker.
- If live animals are to be utilized for imaging, the room (UT1330) and CT/SPECT personnel associated with SPECT data acquisition must be approved and listed on the investigator’s IACUC protocol. Documented evidence of IACUC approval must be made available prior to any experimental work.
- For multiple data acquisitions, animals cannot remain in the CT/SPECT facility without IACUC approval, will need to be returned to an approved Comparative Medicine facility, and then brought to the SPECT facility at the appointed time of examination.
SPECT Evaluation of Cell Migration. SPECT has been utilized to evaluate trafficking of macrophages and lymphocytes in models of neuroinflammation and in normal animals [1-8]. To evaluate migration of peripheral mononuclear cells, bone marrow-derived monocytes (BMM) were labeled with 111In and transferred i.v. to naïve syngeneic recipients. (A) Trafficking of labeled cells was evaluated by SPECT after 6 hours and 1, 3, 5, and 7 days post-transfer. (B) Percent distribution of signal intensities from 111In labeled cells within lymphoid and non-lymphoid tissues.
SPECT Evaluation of Neuronal Receptors. To assess the loss of dopaminergic neuronal termini in a neurotoxicant (MPTP) model [9, 10], mice were injected i.v. with 500 m Ci of [123I]-(1r)-2b-carboxy-methoxy-3b-(4-iodophenyl)-tropane, ([123I]-b-CIT) to assess dopamine transporter (DAT) molecules 7 days post MPTP treatment . (A) Tomographic representation shows SPECT analysis of PBS- and MPTP-treated mice with intense signal in the eyes (yellow arrows) and striata (white arrows). Intensity of DAT binding in the striata is significantly (P=0.0006) diminished in MPTP treated mice . (B) Co-registration of SPECT with MRI images validated that beta CIT binding was within the striatum.
SPECT Evaluation of Drug Biodistribution and Binding. To assess the accession and retention of D-aspartic acid polymers in skeletal bone growing plates, we used SPECT to evaluate the biodistribution of the 1.2 kDa D-aspartic acid octapeptide (D-Asp8) polymer (A and D); the 24 kDa N-(2-Hydroxypropyl)-methacrylamide (HPMA) copolymer containing D-Asp8 (B); and the 46 kDa HPMA copolymer containing D-Asp8 (C). The planar images show D-Asp8 retained in knees, head, and lumbar region (A), the 24 kDa HPMA-D-Asp8 co-polymer retained primarily in the kidneys and bladder (B), and the 46 kDa HPMA-D-Asp8 retained primarily in the liver and bladder as well as the joints (C). Tomagraphic images of the knees show localization of D-Asp8 in the growth plates of the knees (D).
SPECT Evaluation of Spatial and Temporal Distribution of Anti-Tumor Radioimmuno-conjugates. Athymic mice, bearing subcutaneous xenografted LS174T tumors, were treated with PBS or the platelet-derived growth factor receptor-beta (PDGFr-beta ) antagonist, STI571 . Treated mice were injected iv with the 125I-labeled tumor-seeking antibody, B72.3. Temporal distribution of 125I-B72.3 in a STI571-treated mouse are shown for 24, 48, and 72 hours post-injection (A). Improved 125I-B72.3 uptake of of 125I-B72.3 in STI571-treated compared to PBS-treated mouse (B).
Data analysis, bioinformatics and statistical methods. Acquired data is reconstructed, filtered, and displayed in 3-dimensional movie format or as planar images. Software is available to provide image capture for movies (Camtasia, TechSmith) or planar (Snagit, TechSmith) images. The manufacturer’s digital analysis software allows setting upper and lower intensity thresholds and masking signals from background irradiation or removing excessively intense signals in irrelevant tissues (for instance iodine in thyroid). Radiation counts are obtained from regions of interest (ROI) and can be quantified by comparison to known activity in external fiducial markers.
- Dou H, Destache CJ, Morehead JR, Mosley RL, Boska MD, Kingsley J, Gorantla S, Poluektova L, Nelson JA, Chaubal M, Werling J, Kipp J, Rabinow BE, Gendelman HE. Development of a macrophage-based nanoparticle platform for antiretroviral drug delivery. Blood. 2006 Oct 15;108(8):2827-35. PubMed 16809617. Erratum in: Blood. 2007 Mar 1;109(5):1816.
- Gorantla S, Dou H, Boska M, Destache CJ, Nelson J, Poluektova L, Rabinow BE, Gendelman HE, Mosley RL. Quantitative magnetic resonance and SPECT imaging for macrophage tissue migration and nanoformulated drug delivery. J Leukoc Biol. 2006 Nov;80(5):1165-74. PMID: 16908517
- Wang D, Sima M, Mosley RL, Davda JP, Tietze N, Miller SC, Gwilt PR, Kopecková P, Kopecek J. Pharmacokinetic and biodistribution studies of a bone-targeting drug delivery system based on N-(2-hydroxypropyl)methacrylamide copolymers. Mol Pharm. 2006 Nov-Dec;3(6):717-25. PMID: 17140259
- Boska MD, Lewis TB, Destache CJ, Benner EJ, Nelson JA, Uberti M, Mosley RL, Gendelman HE. Quantitative 1H magnetic resonance spectroscopic imaging determines therapeutic immunization efficacy in an animal model of Parkinson's disease. J Neurosci, 2005. 25:1691-700. PMID: 15716405
- Baranowska-Kortylewicz J, Abe M, Pietras K, Kortylewicz ZP, Kurizaki T, Nearman J, Paulsson J, Mosley RL, Enke CA, Ostman A. Effect of platelet-derived growth factor receptor-beta inhibition with STI571 on radioimmunotherapy. Cancer Res, 2005. 65:7824-31. PMID: 16140951
- Mosley RL, Gorantla S, Dou H, Destache CJ, Nelson JA, Kingsley, Poluektova L, Boska M, Chaubal M, Werling J, Kipp K, Rabinow B, Gendelman HE, Macrophage tissue migration: A novel platform for anti-retroviral delivery, 2005, Abs 235, Keystone Symposium, Leukocyte Trafficking: Cellular and Molecular Mechanisms Keystone.
- Dou H, Destache CJ, Kingsley J, Mosley RL, Nelson JA, Morehead JR, Poluektova L, Boska M, Gorantla S, Chaubal M, Werling J, Kipp J, Rabinow BE, Gendelman HE. A novel platform for anti-retroviral delivery: Implications for HIV-1 associated dementia, 2005, Abs 338.19, Society for Neuroscience.
- Benner EJ, Mosley RL, Destache CJ, Lewis TB, Jackson-Lewis V, Gorantla S, Nemachek C, Green SR, Przedborski S, Gendelman HE. Therapeutic immunization protects dopaminergic neurons in a mouse model of Parkinson's disease. Proc Natl Acad Sci USA, 2004. 101:9435-40. PMID: 15197276
- Mosley RL, Zelivyanskaya ML, Dou H, Lewis TB, Poluektova LY, Uberti M, Mellon M, Nelson A, Boska MD, Gendelman HE, Measures of human lymphocyte transmigration in to brain in a murine model of HIV-1 encephalitis., 2004, 11thConference on Retroviruses and Opportunistic Infection
- Boska MD, Mosley RL, Nawab M, Nelson JA, Zelivyanskaya M, Poluetkova L, Uberti M, Dou H, Gendelman HE. Advances in neuroimaging for HIV-1 associated neurological dysfunction: Clues to the diagnosis, pathogenesis and therapy. Current HIV Res, 2004, 2:59-76. PMID: 150553341
- Gendelman HE, Destache CJ, Zelivyanskaya ML, Nelson JA, Boska MD, Biskup TM, McCarthy MK, Carlson KA, Nemechek C, Benner EJ, Mosley RL. Neuroimaging and proteomic tracking of neurodegeneration in MPTP-treated mice. Ann NY Acad Sci, 2003. 991:319-321.
- Zelivyanskaya ML, Poluektova LY, Mosley RL, Lewis T, Boska M, Gendelman HE, Modeling leukocyte egress into brain in murine HIV-1 encephalitis by single photon emission computed tomography and enhanced magnetic resonance imaging, 2003, p. 303, Vth International Conference in Cerebral Vascular Biology.
- Mosley RL, Zelivyanskaya ML, Dou H, Lewis TB, Mellon ML, Nelson JA, Boska MD, Poluetkova LY, Gendelman HE. Lymphocyte transendothelial brain migration in murine HIV-1 encephalitis: Tracking cell movement by single photon emission computed tomography. J. NeuroVirol. 2003, 9:124.