Comparison of Monopolar Review to Fixed Parameter Fractionation in Deep Brain Stimulation.

Background: Technological advancements in deep brain stimulation (DBS) require methodological changes in programming. Fractionalization poses significant practical challenges for the most common approach for assessing DBS efficacy, monopolar review (MR). Objectives: Two DBS programming methods: MR and fixed parameter vertical and horizontal fractionalization (FPF) were compared. Methods: A two-phase process of vertical and horizontal FPF was performed. MR was conducted thereafter. After a short wash-out period, both optimal configurations determined by MR and FPF were tested in a double-blind randomized manner. Results: Seven PD patients were enrolled, providing 11 hemispheres to compare the two conditions. In all subjects, the blinded examiner selected a directional or fractionalization configuration. There was no significant difference in clinical benefits between MR and FPF. FPF was the preferred method for initial programming as selected by subject and clinician. Conclusions: FPF programming is a viable and efficient methodology that may be incorporated into clinical practice.

Using a Robotic-Assisted Approach for Stereotactic Laser Ablation Corpus Callosotomy: A Technical Report.

BACKGROUND: Corpus callosotomy for medically intractable epilepsy is an effective ablative procedure traditionally achieved using either standard open craniotomy or with less-invasive approaches. Advances in robotic-assisted stereotactic guidance for neurosurgery can be applied for LITT for corpus callosotomy. CLINICAL PRESENTATIONS: Two patients were included in this study. One was a 25-year-old female patient with extensive bi-hemispheric malformations of cortical development and medically refractory epilepsy, and the other was an 18-year-old male with medically refractory epilepsy and atonic seizures, who underwent a complete corpus callosotomy using robotic-assisted stereotactic guidance for LITT. RESULTS: Both patients underwent successful intended corpus callosotomy with volumetric analysis demonstrating a length disconnection of 74% and a volume disconnection of 55% for patient 1 and a length disconnection of 83% and a volume disconnection of 33% for patient 2. Postoperatively, both patients had clinical reductions in seizure. CONCLUSION: Our experience demonstrates that robotic guidance systems can safely and effectively be adapted for minimally invasive LITT corpus callosotomy.

Intracellular localization and interaction of mRNA binding proteins as detected by FRET.

BACKGROUND: A number of RNA binding proteins (BPs) bind to A+U rich elements (AREs), commonly present within 3'UTRs of highly regulated RNAs. Individual RNA-BPs proteins can modulate RNA stability, RNA localization, and/or translational efficiency. Although biochemical studies have demonstrated selectivity of ARE-BPs for individual RNAs, less certain is the in vivo composition of RNA-BP multiprotein complexes and how their composition is affected by signaling events and intracellular localization. Using FRET, we previously demonstrated that two ARE-BPs, HuR and AUF1, form stable homomeric and heteromeric associations in the nucleus and cytoplasm. In the current study, we use immuno-FRET of endogenous proteins to examine the intracellular localization and interactions of HuR and AUF1 as well as KSRP, TIA-1, and Hedls. These results were compared to those obtained with their exogenously expressed, fluorescently labeled counterparts. RESULTS: All ARE-BPs examined were found to colocalize and to form stable associations with selected other RNA-BPs in one or more cellular locations variably including the nucleus, cytoplasm (in general), or in stress granules or P bodies. Interestingly, FRET based interaction of the translational suppressor, TIA-1, and the decapping protein, Hedls, was found to occur at the interface of stress granules and P bodies, dynamic sites of intracellular RNA storage and/or turnover. To explore the physical interactions of RNA-BPs with ARE containing RNAs, in vitro transcribed Cy3-labeled RNA was transfected into cells. Interestingly, Cy3-RNA was found to coalesce in P body like punctate structures and, by FRET, was found to interact with the RNA decapping proteins, Hedls and Dcp1. CONCLUSIONS: Biochemical methodologies, such as co-immunoprecipitation, and cell biological approaches such as standard confocal microscopy are useful in demonstrating the possibility of proteins and/or proteins and RNAs interacting. However, as demonstrated herein, colocalization of proteins and proteins and RNA is not always indicative of interaction. To this point, using FRET and immuno-FRET, we have demonstrated that RNA-BPs can visually colocalize without producing a FRET signal. In contrast, proteins that appear to be delimited to one or another intracellular compartment can be shown to interact when those compartments are juxtaposed.