Anatomical morphometric study of the cervical uncinate process and surrounding structures.

OBJECTIVE: The purpose of this study is to elucidate the anatomic relationships between the uncinate process and surrounding neurovascular structures to prevent possible complications in anterior cervical surgery. METHODS: Twenty-eight formalin-fixed cervical spines were removed from adult cadavers and were studied. The authors investigated the morphometric relationships between the uncinate process, vertebral artery and adjacent nerve roots. RESULTS: The height of the uncinate process was 5.6-7.5 mm and the width was 5.8-8.0 mm. The angle between the posterior tip of the uncinate process and vertebral artery was 32.2-42.4°. The distance from the upper tip of the uncinate process to the vertebral body immediately above was 2.1-3.3 mm, and this distance was narrowest at the fifth cervical vertebrae. The distance from the posterior tip of the uncinate process to the nerve root was 1.3-2.0 mm. The distance from the uncinate process to the vertebral artery was measured at three different points of the uncinate process : upper-posterior tip, lateral wall and the most antero-medial point of the uncinate process, and the distances were 3.6-6.1 mm, 1.7-2.8 mm, and 4.2-5.7 mm, respectively. The distance from the uncinate process tip to the vertebral artery and the angle between the uncinate process tip and vertebral artery were significantly different between the right and left side. CONCLUSION: These data provide guidelines for anterior cervical surgery, and will aid in reducing neurovascular injury during anterior cervical surgery, especially in anterior microforaminotomy.

Comparison of cell-labeling methods with ¹²4I-FIAU and 64Cu-PTSM for cell tracking using chronic myelogenous leukemia cells expressing HSV1-tk and firefly luciferase.

Cell-tracking methods with molecular-imaging modality can monitor the biodistribution of cells. In this study, the direct-labeling method with 64Cu-pyruvaldehyde-bis(N4-methylthiosemicarbazone) (64Cu-PTSM), indirect cell-labeling methods with herpes simplex virus type 1-thymidine kinase (HSV1-tk)-mediated ¹²4I-2'-fluoro-2'-deoxy-1-ß-D-arabinofuranosyl-5-iodouracil (¹²4I-FIAU) were comparatively investigated in vitro and in vivo for tracking of human chronic myelogenous leukemia cells. K562-TL was established by retroviral transduction of the HSV1-tk and firefly luciferase gene in the K562 cell. K562-TL cells were labeled with 64Cu-PTSM or ¹²4I-FIAU. Cell labeling efficiency, viability, and radiolabels retention were compared in vitro. The biodistribution of radiolabeled K562-TL cells with each radiolabel and small-animal positron emission tomography imaging were performed. Additionally, in vivo and ex vivo bioluminescence imaging (BLI) and tissue reverse transcriptase-polymerase chain reaction (RT-PCR) analysis were used for confirming those results. K562-TL cells were efficiently labeled with both radiolabels. The radiolabel retention (%) of ¹²4I-FIAU (95.2%±1.1%) was fourfold higher than 64Cu-PTSM (23.6%±0.7%) at 24 hours postlabeling. Viability of radiolabeled cells was statistically nonsignificant between ¹²4I-FIAU and 64Cu-PTSM. The radioactivity of each radiolabeled cells was predominantly accumulated in the lungs and liver at 2 hours. Both the radioactivity of 64Cu-PTSM- and ¹²4I-FIAU-labeled cells was highly accumulated in the liver at 24 hours. However, the radioactivity of ¹²4I-FIAU-labeled cells was markedly decreased from the body at 24 hours. The K562-TL cells were dominantly localized in the lungs and liver, which also verified by BLI and RT-PCR analysis at 2 and 24 hours postinjection. The 64Cu-PTSM-labeled cell-tracking method is more efficient than ¹²4I-FIAU-labeled cell tracking, because of markedly decrease of radioactivity and fast efflux of ¹²4I-FIAU in vivo. In spite of a high labeling yield and radiolabel retention of ¹²4I-FIAU in vitro, the in vivo cell-tracking method using 64Cu-PTSM could be a useful method to evaluate the distribution and targeting of various cell types, especially, stem cells and immune cells.

The Changes in Range of Motion after a Lumbar Spinal Arthroplasty with Charité in the Human Cadaveric Spine under Physiologic Compressive Follower Preload : A Comparative Study between Load Control Protocol and Hybrid Protocol.

OBJECTIVE: To compare two testing protocols for evaluating range of motion (ROM) changes in the preloaded cadaveric spines implanted with a mobile core type Charité lumbar artificial disc. METHODS: Using five human cadaveric lumbosacral spines (L2-S2), baseline ROMs were measured with a bending moment of 8 Nm for all motion modes (flexion/extension, lateral bending, and axial rotation) in intact spine. The ROM was tracked using a video-based motion-capturing system. After the Charité disc was implanted at the L4-L5 level, the measurement was repeated using two different methods : 1) loading up to 8 Nm with the compressive follower preload as in testing the intact spine (Load control protocol), 2) loading in displacement control until the total ROM of L2-S2 matches that when the intact spine was loaded under load control (Hybrid protocol). The comparison between the data of each protocol was performed. RESULTS: The ROMs of the L4-L5 arthroplasty level were increased in all test modalities (p < 0.05 in bending and rotation) under both load and hybrid protocols. At the adjacent segments, the ROMs were increased in all modes except flexion under load control protocol. Under hybrid protocol, the adjacent segments demonstrated decreased ROMs in all modalities except extension at the inferior segment. Statistical significance between load and hybrid protocols was observed during bending and rotation at the operative and adjacent levels (p < 0.05). CONCLUSION: In hybrid protocol, the Charité disc provided a relatively better restoration of ROM, than in the load control protocol, reproducing clinical observations in terms of motion following surgery.

Comparison of 18F-FDG, 18F-FET and 18F-FLT for differentiation between tumor and inflammation in rats.

INTRODUCTION: The goal of this study was to compare the glucose analog, 2-[18F]fluoro-2-deoxy-d-glucose ([18F]-FDG), the amino acid analog, o-(2-[18F]fluoroethyl)-l-tyrosine ([18F]-FET) and nucleoside analog, 3'-[18F]fluoro-3'-deoxythymidine ([18F]-FLT) with regard to their feasibility for differentiating tumors from inflammation. METHODS: In Fisher rat models bearing both 9L tumor and inflammation, the biodistributions and positron emission tomography (PET) images of [18F]-FDG, [18F]-FET and [18F]-FLT at 60 min post injection were compared. Pretreatment with thymidine phosphorylase before injection of [18F]-FLT was performed. RESULTS: The tumor-to-blood (T/B) and tumor-to-muscle (T/M) ratios of [18F]-FDG were significantly higher than those of [18F]-FET and [18F]-FLT (P<.01); however, the accumulation of [18F]-FDG [1.23+/-0.52 percent injected dose per gram of tissue (%ID/g)] in inflammation was also elevated. T/B and T/M ratios of [18F]-FET (2.3+/-0.5 and 2.2+/-0.5) were higher than those of [18F]-FLT (1.6+/-0.6 and 1.6+/-0.5), and inflammation uptake of those tracers was very low (0.63+/-0.19 and 0.27+/-0.16 %ID/g, respectively). [18F]-FET and [18F]-FLT showed higher selectivity indices (tumor-to-inflammation ratio corrected background) than [18F]-FDG. In PET images, [18F]-FDG was found to be accumulated in both tumor and inflammation, but [18F]-FET and [18F]-FLT selectively localized in tumor. CONCLUSION: Our data confirm the result of previous studies that [18F]-FET and [18F]-FLT are superior to [18F]-FDG in differentiating tumor from inflammation.

Synthesis and biologic evaluation of I-123-labeled porphyrin derivative as a potential tumor-imaging agent.

5-(3-(3-[(123)I]iodoallyloxy)phenyl)-10,15,20-tris-(3-carboxymethoxyphenyl)porphyrin ([ (123)I]2) was prepared for biologic evaluation in a B16-F10 tumor model to examine its potential as an imaging agent. The I-123-labeled porphyrin [(123)I]2 was purified by reverse-phase high-performance liquid chromatography (HPLC) to give a decay-corrected radiochemical yield of 8%-13% (n=9) and the radiochemical purity after HPLC purification was >95% and the overall radiolabeling time was 160 minutes. The in vitro cell uptake of [ (123)I]2 increased with time. Biodistribution in mice bearing the B16-F10 tumor, after an intravenous injection of [(123)I]2, also showed a time-dependent accumulation of the porphyrin in tumor tissue (10.35 %ID/g at 6 hours). The tumor-to-muscle ratio was 3.49, 3.38, 3.07, and 3.13 at 1, 2, 6, and 24 hours, respectively. The gamma-camera images of (123)I-porphyrin demonstrated a high focal accumulation of radioactivity in the B16-F10 melanoma tumor.

Synthesis and evaluation of cis-1-[4-(hydroxymethyl)-2-cyclopenten-1-yl]-5-[(124)I]iodouracil: a new potential PET imaging agent for HSV1-tk expression.

In our pursuit to find an appropriate reporter probe for herpes simplex virus type-1 thymidine kinase (HSV1-tk), a carbocyclic nucleoside analogue, cis-1-[4-(hydroxymethyl)-2-cyclopenten-1-yl]-5-[124I]iodouracil, has been efficiently synthesized. A Pd(0)-catalyzed coupling reaction together with organotin and exchange reactions for radiolabeling gave more than 80% radiochemical yield with greater than 95% radiochemical purity and 1.15 GBq/mumol specific activity. Biological data reveal that the analogue is stable in vitro, less toxic than ganciclovir (GCV), and selective to HSV1-tk-expressed cells based on micro positron emission tomography (microPET) image analyses. Thus, this new carbocyclic nucleoside, referred to in this paper as carbocyclic 2',3'-didehydro-2',3'-dideoxy-5-iodouridine (carbocyclic d4IU) is a potential imaging probe for HSV1-tk.

Syntheses of F-18 labeled fluoroalkyltyrosine derivatives and their biological evaluation in rat bearing 9L tumor.

We hereby report the synthesis of four fluorine-18 labeled tyrosine derivatives, 3-(2-[(18)F]fluoroethyl)tyrosine ([(18)F]1, [(18)F]ortho-FET), 3-(3-[(18)F]fluoropropyl)tyrosine ([(18)F]2, [(18)F]ortho-FPT) O-methyl-[3-(2-[(18)F]fluoroethyl)]tyrosine ([(18)F]3, [(18)F]MFET), and O-methyl-[3-(3-[(18)F]fluoropropyl)]tyrosine ([(18)F]4, [(18)F]MFPT). The fluorine-18 labeled tyrosine derivatives were prepared by the displacement reaction of the ethyl and propyl tosylates with K[(18)F]/K2.2.2 in acetonitrile under no-carrier-added (NCA) conditions, followed by hydrolysis with 4N HCl. The biological properties of labeled compounds were evaluated in rats bearing 9L tumor after an intravenous injection and PET image was obtained. The tumor/blood and tumor/brain ratios were 2.06, 2.92 for [(18)F]1, 2.25, 4.05 for [(18)F]2, 2.88, 1.90 for [(18)F]3, and 2.00, 2.60 for [(18)F]4 at 60 min post injection, respectively. The PET image showed localized accumulation of PET tracers in 9L glioma of the rat.