Citations

Object Intracranial monitoring for temporal lobe seizure localization to differentiate neocortical from mesial temporal onset seizures requires both neocortical subdural grids and hippocampal depth electrode implantation. There are 2 basic techniques for hippocampal depth electrode implantation. This first technique uses a stereotactically guided 8-contact depth electrode directed along the long axis of the hippocampus to the amygdala via an occipital bur hole. The second technique involves direct placement of 2 or 3 4-contact depth electrodes perpendicular to the temporal lobe through the middle temporal gyrus and overlying subdural grid. The purpose of this study was to determine whether one technique was superior to the other by examining monitoring success and complications. Methods Between 1997 and 2005, 41 patients underwent invasive seizure monitoring with both temporal subdural grids and depth electrodes placed in 2 ways. Patients in Group A underwent the first technique, and patients in Group B underwent the second technique. Results Group A consisted of 26 patients and Group B 15 patients. There were no statistically significant differences between Groups A and B regarding demographics, monitoring duration, seizure localization, or outcome (Engel classification). There was a statistically significant difference at the point in time at which these techniques were used: Group A represented more patients earlier in the series than Group B (p < 0.05). The complication rate attributable to the grids and depth electrodes was 0% in each group. It was more likely that the depth electrodes were placed through the grid if there was a prior resection and the patient was undergoing a new evaluation (p < 0.05). Furthermore, Group A procedures took significantly longer than Group B procedures. Conclusions In this patient series, there was no difference in efficacy of monitoring, complications, or outcome between hippocampal depth electrodes placed laterally through temporal grids or using an occipital bur hole stereotactic approach. Placement of the depth electrodes perpendicularly through the grids and middle temporal gyrus is technically more practical because multiple head positions and redraping are unnecessary, resulting in shorter operative times with comparable results.

ObjectiveTo identify major arteries in relationship to large pharyngeal tumors during transoral laser microsurgery.Study DesignCase series with planned data collection.SettingMayo Clinic, Jacksonville, Florida.Subjects and MethodsWe developed a new technique that combines three‐dimensional CT angiography and enhanced soft‐tissue neck CT for evaluation of pharyngeal tumors before transoral laser microsurgery. Data from CT angiography were used to create three‐dimensional images of the tumor and adjacent arterial branches to better orient the surgeon to the spatial relationships of major arteries and pharyngeal tumors. Included were selected patients who had large tumors involving the pharynx and who underwent transoral laser microsurgery.ResultsEighteen patients were studied from June 2008 through January 2009. Tumor enhancement was absent or modest in four of 18 patients. Three of these four patients had superficial squamous cell carcinomas and one had adenoid cystic carcinoma. The remaining 14 patients had good tumor enhancement. The tumor involved the lingual artery in three and displaced the lingual or facial artery in two of these 14 patients. One anomalous right inferior thyroid artery was identified. Compared with routine enhanced soft‐tissue neck CT, three‐dimensional CT angiography greatly enhanced the anatomical relationships of the major arteries. In one patient, the surgeon's approach was changed after three‐dimensional CT angiography demonstrated an encased lingual artery.ConclusionThree‐dimensional CT angiography was useful in identifying the anatomical orientation of major arteries and the planning of transoral laser microsurgery to treat tumors involving the pharynx.

Rationale : The large conductance Ca 2+ -activated K + (BK) channel, a key determinant of vascular tone, is regulated by angiotensin II (Ang II) type 1 receptor signaling. Upregulation of Ang II functions and downregulation of BK channel activities have been reported in diabetic vessels. However, the molecular mechanisms underlying Ang II-mediated BK channel modulation, especially in diabetes mellitus, have not been thoroughly examined. Objectives : The aim in this study was to determine whether caveolae-targeting facilitates BK channel dysfunction in diabetic vessels. Methods and Results : Using patch clamp techniques and molecular biological approaches, we found that BK channels, Ang II type 1 receptor, G αq/11 (G protein q/11 α subunit), nonphagocytic NAD(P)H oxidases (NOX-1), and c-Src kinases (c-Src) were colocalized in the caveolae of rat arterial smooth muscle cells and the integrity of caveolae in smooth muscle cells was critical for Ang II-mediated BK channel regulation. Most importantly, membrane microdomain targeting of these proteins was upregulated in the caveolae of streptozotocin-induced rat diabetic vessels, leading to enhanced Ang II-induced redox-mediated BK channel modification and causing BK channel and coronary dysfunction. The absence of caveolae abolished the effects of Ang II on vascular BK channel activity and preserved BK channel function in diabetes. Conclusions : These results identified a molecular scheme of receptor/enzyme/channel/caveolae microdomain complex that facilitates the development of vascular BK channel dysfunction in diabetes.

Abstract Background: Glomerular filtration rate (GFR) can be determined by measuring renal clearance of the radiocontrast agent iothalamate. Current analytic methods for quantifying iothalamate concentrations in plasma and urine using liquid chromatography or capillary electrophoresis have limitations such as long analysis times and susceptibility to interferences. We developed a liquid chromatography–tandem mass spectrometry (LC-MS/MS) method to overcome these limitations. Methods: Urine and plasma samples were deproteinized using acetonitrile and centrifugation. The supernatant was diluted in water and analyzed by LC-MS/MS using a water:methanol gradient. We monitored 4 multiple reaction monitoring transitions: m/z 614.8–487.0, 614.8–456.0, 614.8–361.1, and 614.8–177.1. We compared the results to those obtained via our standard capillary electrophoresis (CE-UV) on samples from 53 patients undergoing clinical GFR testing. Results: Mean recovery was 90%–110% in both urine and plasma matrices. Imprecision was ≤15% for the m/z 614.8–487.0 and 614.8–456.0 transitions over a 10-day period at 1 mg/L. Method comparison for 159 patient samples (53 clearances) provided the following Passing–Bablok regressions: plasma iothalamate LC-MS/MS (y) vs CE-UV (x), y = 0.99x + 0.36; urine iothalamate LC-MS/MS vs CE-UV, y = 1.01x + 0.31; corrected GFR LC-MS/MS vs CE-UV, y = 1.00x + 0.00. Interfering substances prevented accurate iothalamate quantification by CE-UV in 2 patients, whereas these samples could be analyzed by LC-MS/MS. Conclusions: Iothalamate can be quantified by LC-MS/MS for GFR measurement. This method circumvents potential problems with interfering substances that occasionally confound accurate GFR determinations.

Abstract Background Presacral tailgut cysts are uncommon and few data exist on the outcomes following surgery. Methods Patients undergoing tailgut cyst resection at the Mayo Clinic between 1985 and 2008 were analysed retrospectively. Demographic data, clinicopathological features, operative details, postoperative complications and recurrence were reviewed. Results Thirty-one patients were identified (28 women), with a median age of 52 years. Seventeen patients were symptomatic and 28 had a palpable mass on digital rectal examination. Median cyst diameter was 4·4 cm. Four patients had a fistula to the rectum. Complete cyst excision was achieved in all patients; eight underwent distal sacral resection or coccygectomy. Postoperative complications occurred in eight patients but without 30-day mortality. Malignant transformation was present in four patients: adenocarcinoma in three and carcinoid in one. The cyst recurred in one patient after surgery for a benign lesion. Conclusion Presacral tailgut cysts should be removed due to the risk of malignant transformation.

Background— Obstructive sleep apnea is highly prevalent in patients with cardiovascular disease and has detrimental effects on systolic and diastolic function of the ventricles. In this research, the changes in strain (S) and strain rate (SR) during the performance of the Mueller maneuver (MM) in an effort to better understand how negative intrathoracic pressures affect ventricular mechanics. Methods and Results— The MM was performed to maintain a target intrathoracic pressure of −40 mm Hg. Echocardiography was used to measure various parameters of cardiac structure and function. Myocardial deformation measurements were performed using tissue speckle tracking. Twenty-four healthy subjects (9 women; mean age, 30�6 years) were studied. Global left ventricular longitudinal S in systole and SR in early filling were significantly decreased during the MM (S: baseline, −17.0�1.6%; MM, −14.5�2.2%; P <0.0001, SR: baseline, 1.09�0.20 s −1 ; MM, 0.92�0.21 s −1 ; P =0.01). Global right ventricular longitudinal S was also significantly decreased during the MM (baseline, −22.0�3.1%; MM, −17.2�2.5%; P <0.0001), as was global right ventricular longitudinal systolic SR (baseline, −1.34�0.35 s −1 ; MM, −1.02�0.21 s −1 ; P =0.0006). Conclusions— Left ventricular and right ventricular longitudinal deformation are significantly reduced during the MM. These results suggest that negative intrathoracic pressure during apnea may contribute to changes in myocardial mechanics. These results could help explain the observed changes in left ventricular and right ventricular mechanics in patients with obstructive sleep apnea.