Dexmedetomidine Oral Mucosa Patch for Sedation Suppresses Apoptosis in Hippocampus of Normal Rats / 대한배뇨장애요실금학회지

PURPOSE: Dexmedetomidine, an α2-adrenergic agonist, provides sedative and analgesic effects without significant respiratory depression. Dexmedetomidine has been suggested to have an antiapoptotic effect in response to various brain insults. We developed an oral mucosa patch using dexmedetomidine for sedation. The effects of the dexmedetomidine oral mucosa patch on cell proliferation and apoptosis in the hippocampus were evaluated. METHODS: A hydrogel oral mucosa patch was adhered onto the oral cavity of physiologically normal rats, and was attached for 2 hours, 6 hours, 12 hours, or 24 hours. Plasma dexmedetomidine concentrations were determined by liquid chromatography– electrospray ionization–tandem mass spectrometry–multiple-ion reaction monitoring (LC-ESI-MS/MS-MRM). Cell proliferation in the hippocampus was detected by Ki-67 immunohistochemistry. Caspase-3 immunohistochemistry, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining, and Western blotting for Bax and Bcl-2 were performed to detect hippocampal apoptosis. The levels of brain-derived neurotrophic factor (BDNF) and tyrosine kinase B (TrkB) in the hippocampus were also measured by Western blotting. RESULTS: Plasma dexmedetomidine concentration increased according to the attachment time of the dexmedetomidine oral mucosa patch. Hippocampal cell proliferation did not change due to the dexmedetomidine oral mucosa patch, and the dexmedetomidine oral mucosa patch exerted no significant effect on BDNF or TrkB expression. In contrast, the dexmedetomidine oral mucosa patch exerted an antiapoptotic effect depending on the attachment time of the dexmedetomidine oral mucosa patch. CONCLUSIONS: A dexmedetomidine oral mucosa patch can be used as a convenient tool for sedation, and is of therapeutic value due to its antiapoptotic effects under normal conditions.

Stereotactic Surgery in the Management of Hypertensive Intracerebral Hemorrhage: Evaluation of the Efficacy Using Continuous Intracranial Pressure Monitoring

Persistently elevated intracranial pressure(ICP) has been associated with poor clinical outcome after intracerebral hemorrhage(ICH). Increased ICP is one of the main target of treatment in hypertensive ICH. To evaluate the efficacy of stereotactic surgery for the patients with hypertensive ICH, continuous ICP monitoring was done in these patients. This study is based on 30 patients(39-75 years of age, with a mean age of 59.4 years) between January 1996 and December 1997, who had suffered hypertensive supratentorial ICH. All patients underwent partial removal of the hematoma(mean 11.8cc in volume) through the stereotactically placed catheters and the residual hematoma was drained by urokinase irrigation for average of 3.4 days. ICP was monitored in all cases starting before the surgery and continuously until two days after the surgery. Patients were assigned into three categories(Category A; less than 20mmHg, Category B; 20-30mmHg, and Category C; above 30mmHg) according to the initial(preoperative) ICP. Ten patients(39.5cc in average volume of hematoma) were defined to category A, six(45cc) to category B, and fourteen(62.4cc) to category C. After partial removal of the hematoma, there was statistically significant difference in drop of ICP(average 8.4mmHg in category A, 16mmHg in category B, and 36.7mmHg in category C)(p<0.001) and postoperative ICP was maintained under 20mmHg in all patients by urokinase irrigation and external drainage through the stereotactically placed catheters. Cerebral perfusion pressure(CPP) was maintained more than 90mmHg after partial removal of hematoma in all patients. This study demonstrates that ICP was controlled effectively by stereotactic external drainage with intermittent mannitol infusion under the continuous ICP monitoring without large decompressive surgery under general anesthesia for patients whose ICH volume was more than 60cc. Exception to this would be those with rapid progression of neurologic deterioration.

Solitary Osteochondroma of the Thoracic Spine Presenting as Spinal Cord Compression: Case Report

Osteochondroma is the most common type of benign bone tumor, but it is unusual in the spine and they rarely present with compression of the spinal cord. We treated a male patient with a solitary osteochondroma of the thoracic spine that caused spinal cord compression. Computed tomography and magnetic resonance images demonstrated a mass arising from the T5 vertebrae, projecting into the spinal canal compressing the spinal cord. Diagnosis was confirmed by surgery and histological study of the resected specimen.