Moon Chan Kim

Anatomy of Neurovascular Structures Around the Carpal Tunnel During Dynamic Wrist Motion for Endoscopic Carpal Tunnel Release

OBJECTIVE: The purpose of this study is to investigate the anatomic relationship between neurovascular structures and the transverse carpal ligament (TCL) so as to avoid complications during an endoscopic carpal tunnel release procedure. METHODS: Fresh cadaver hands from seven men and 12 women (age range, 48–74 yr) were used. The neurovascular structures just over and under the TCL were meticulously dissected under loupe magnification. Several anatomic landmarks were calculated (average length of the TCL; average distance between the TCL distal margin and the neurovascular structures; and average lengths of the superficial palmar arch, ramus communicantes, recurrent motor branch, and palmar cutaneous branch of the median nerve). The ulnar neurovascular structure was studied with the wrist positioned in neutral, ulnar flexion, and radial flexion. RESULTS: The anatomic relationships between the TCL and vascular and neural structures were measured. The ulnar neurovascular structures usually passed just over ulnar to the superior portion of the hook of the hamate. However, in 11 hands, a looped ulnar artery coursed 1 to 4 mm radial to the hook of the hamate and continued to the superficial palmar arch. The looped ulnar artery migrates on the ulnar side of Guyons canal (-2–2 mm radial to the hook of the hamate) with the wrist in radial flexion (of the wrist). During ulnar flexion of the wrist, the ulnar artery shifts more radially beyond the hook of the hamate (2–7 mm). CONCLUSION: It is appropriate to transect the ligament over 4 mm apart from the lateral margin of the hook of the hamate without placing the edge of the scalpel toward the ulnar side. We would also recommend not transecting the TCL in the ulnar flexed wrist position to protect the ulnar neurovascular structure. The proximal portal could be made just ulnar to the palmaris longus tendon to spare the neurovascular structures in the proximal portion of the TCL.

Cytotoxicity of rat marrow stromal cells against malignant glioma cells

ObjectsMarrow stromal cells (MSCs) have been shown to have the capacity of orthodox and unorthodox plasticity. In this study, the authors tried to access in vitro cytotoxicity of MSCs from rat and also to differentiate MSCs into immune effector cell.MethodsRat MSCs (rMSCs) were isolated by standard methodology and were activated by interleukin-2 (IL-2), interleukin-15 (IL-15), granulocyte macrophage colony stimulating factor, and combinations, which were effector cells. Cytotoxicity of rMSCs and activated rMSCs against the target cells (9L rat glioma cell line) was estimated using visual survival cell assay. Phenotypes of these various activated cells were determined using flow cytometry. The secreted protein from effector cells was estimated by enzyme-linked immunosorbent assay. The expression of immune response-related genes in activated cells was measured.ResultsThere was a significant cytotoxicity of rMSCs activated with various cytokine combinations. After various cytokine activations of rMSCs, the population of immune effector cells (CD8, CD161a) and immune reaction-related proteins (IL-4, γ-INF) might increase. Apoptosis may be one of the lysis mechanisms of target cells by activated rMSCs. The contributing genes could be γ-INF, FasL, and perforin.ConclusionThis study suggests that rMSC may be used as adoptive transfer therapy in patients suffering from malignant brain tumor, but we have to investigate orthotopic animal study for the proper translation.

Lymphokine activated killer cells from umbilical cord blood show higher antitumor effect against anaplastic astrocytoma cell line (U87) and medulloblastoma cell line (TE671) than lymphokine activated killer cells from peripheral blood

ObjectsThe aims of this study were to assess the cytotoxic capability of lymphokine-activated killer (LAK) cells from umbilical cord blood (UCB), to compare them with those of peripheral blood (PB)-derived cells against anaplastic astrocytoma cell line (U87) and medulloblastoma cell line (TE671), and to identify which mechanism and genes were involved in cytotoxicity.MethodsThe effector cells were generated by interleukin-2 from UCB and PB. The antitumor property of effector cells against the target cells (U87, TE671) were estimated using a visual survival cell assay. The mixed target and effector (UCB) cells were analyzed for whether DNA fragmentation was present or not. Reverse transcription polymerase chain reaction analysis was then performed to estimate the statement of the perforin and FasL genes in activated and inactivated cells from UCB.ResultsThe higher in vitro antitumor properties of the LAK cells from UCB were observed in comparison to the LAK cells from PB against the U87 and the TE671 (p<0.05). Apoptosis may be one of the lysis mechanisms of target cells by the LAK cells from UCB. The contributing genes could be FasL and perforin.ConclusionsThis study suggests that UCB may be used as a source of LAK cells in adults and children suffering from anaplastic astrocytoma or medulloblastoma.

Evaluation of the Accuracy of the CyberKnife

The use of stereotactic radiosurgical systems to treat intracranial and extracranial tumors and other lesions requires a high degree of accuracy in target identification and localization. CyberKnife can deliver, with a high degree of precision, a single or several fractions of radiation dose to a well-defined small intracranial or extracranial target. The accuracy of the output factor directly affects the accuracy of dose delivery in CyberKnife system. The purpose of this study was to evaluation the total system accuracy of the CyberKnife and also to estimate an output factor for CyberKnife using the several detectors. Accuracy of target localization was measured in anthropomorphic head phantom containing a spherical target, fiducial markers, and two pieces of film. The accuracy measured is the displacement of the dose contours from the treatment plan to that measured in the exposed phantom. All measurements of the output factors for collimators were performed by six different detectors: diode detector, X-Omat V film, Gafchromic EBT film, 0.015, 0.125 and 0.6 cc ionization chamber. Each collimator normalized with respect to the output factor of the largest collimator. We performed the E2E test and the general film dosimetry for estimation target localization in CyberKnife. The targeting error of the skull tracking mode and fiducial tracking mode were 0.956 mm and 0.923 mm. We could confirm the accuracy of total system is less than the 1 mm. For larger collimators, the output factors from six detectors showed a good agreement. For the collimators less than 15 mm, there were substantial differences in the output factors among different detectors. That is, the value of output factor for the 5 mm collimator of a diode and Gafchromic film was each 0.656 and 0.777. The Gafchromic EBT film was considered more accurate than the others detectors.