PDZ-scaffold protein, Tamalin promotes dendritic outgrowth and arborization in rat hippocampal neuron.

Tamalin is a scaffold protein known to regulate membrane trafficking through its interaction with cytohesin-2/ARNO, guanine nucleotide exchange factor (GEF) on ADP-ribosylation factor (Arf) 1/6, and induces actin reorganization. However, the neuronal function of Tamalin is not well understood. Here, we report that Tamalin participates in neurite development through the association with exchange factor for Arf6 (EFA6A)/Arf6 signaling. In immature hippocampal neuron, Tamalin knockdown markedly reduced the dendritic outgrowth, the number of dendritic tips and the levels of filamentous actin (F-actin) and microtubule-associated protein 2 (MAP2) in dendrites. In addition, Tamalin colocalized with EFA6A and Arf6 in the dendritic shaft. Tamalin knockdown reduced the number, size, and intensity of endogenous EFA6A cluster, whereas overexpression of Tamalin showed opposite effects compared with those of knockdown. These results suggest that Tamalin is responsible for neuronal dendritic development via regulation of EFA6A/Arf6-mediated cytoskeleton dynamics.

Pediatric cervical chordoma: report of two cases and a review of the current literature.

INTRODUCTION: The majority of chordomas occur between the fifth and seventh decades of life and are thus extremely rare in children, which account for less than 5% of all spinal chordoma cases. CASE REPORT: We report on the development of this rare condition in two boys aged 7 and 10 years. One patient presented with a palpable neck mass and dysphagia, while the other presented with posterior neck pain. Radiological studies revealed an extensive mass in the cervical vertebrae and paravertebral soft tissue of both patients. The tumors were subtotally removed in an attempt to improve the success of adjuvant proton beam radiotherapy. Pathological examination, which included immunohistochemical staining, revealed chordoma of the cervical spine in both patients. CONCLUSION: Although en bloc resection is the ideal modality for treatment of chordoma, such a procedure is often associated with a significant risk of surgical morbidity due to the tumor location. Therefore, piecemeal resection followed by postoperative adjuvant radiotherapy, including proton radiotherapy or radiosurgery, should be considered in such cases.

Cerebral toxoplasmosis combined with disseminated tuberculosis.

A 24-year-old man presented with mental change, fever, abdominal pain, tenderness and palpable mass on the lower abdomen. He was a non-Korean engineer and did not accompany a legal guardian, so medical history taking was difficult due to his mental status. Brain magnetic resonance imaging showed multiple rim-enhanced lesions of the brain, and abdominal computed tomography showed huge paraspinal abscess. Chest X-ray and computed tomography showed poorly defined nodular opacities. We initially thought that this patient was infected with toxoplasmosis with typical cerebral image finding and immunoglobulin laboratory finding of cerebrospinal fluid and serum study. The abdominal abscess was confirmed as tuberculosis through the pathologic finding of caseous necrosis. We used anti-tuberculosis medication and anti-toxoplasmosis medication for almost 4 months, and then his clinical state and radiological findings were considerably improved.

Changes in cervical range of motion and sagittal alignment in early and late phases after total disc replacement: radiographic follow-up exceeding 2 years.

OBJECT: This was a retrospective clinical study in which the follow-up period exceeded 2 years. The authors investigated the time course of radiographic changes in the cervical range of motion (ROM) and sagittal alignment after cervical total disc replacement involving the ProDisc-C artificial disc. METHODS: Eighteen patients who underwent C5-6 total disc replacement were followed for an average of 27 months. Cervical neutral and flexion-extension lateral radiographs were obtained before and at 1 and 3 months after surgery for early-phase observations and at the last follow-up for late-phase observation. Segmental ROM values in the treated, superior, and inferior adjacent segments were measured. For whole-neck motion, C2-7 ROM was also measured. The percentage contributions of ROM at functional and adjacent segments to whole-neck motion were calculated. For evaluating sagittal alignment, C2-7 and C5-6 Cobb angles were measured. All data from ProDisc-C arthroplasty were compared with the results obtained in 22 patients who underwent C5-6 interbody fusion in which a Solis cage was used and who were followed for an average of 25 months. RESULTS: In the ProDisc-C group, C2-7 and C5-6 ROM significantly decreased in the early phase after surgery and returned to preoperative levels in the late phase. Both superior and inferior adjacent segments showed significantly decreased ROM in the acute phase after surgery and returned to the preoperative values in the late phase. In terms of contributions to whole-neck motion, the ROM of the functional and adjacent segments did not change significantly compared with the preoperative ROM. In the cage group, C2-7 ROM was also significantly decreased in the early phase after surgery and returned to preoperative levels at the late phase. Both superior and inferior adjacent segments exhibited significantly increased ROM and percentage contributions to whole-neck motion in the early and late phases. Sagittal alignment of the whole cervical spine became significantly more lordotic in the late phase in the ProDisc-C group. The C5-6 Cobb angle became significantly lordotic in the ProDisc-C group, whereas there was no significant change in C5-6 Cobb angle in the cage group. CONCLUSIONS: In the early phase after ProDisc-C replacement, the ROM of the entire neck as well as functional and adjacent segments decreased but, at the late phase, they returned to the preoperative state. Contributions of functional and adjacent segments to whole-neck motion were not changed after ProDisc-C replacement. Adjacent-segmental motion could be saved by ProDisc-C replacement instead of interbody cage fusion. Segmental degenerative kyphosis was significantly corrected in patients who underwent ProDisc-C replacement.