Preoperative identification of subthalamic nucleus for deep brain stimulation using three-dimensional phase sensitive inversion recovery technique.

PURPOSE: We assessed the feasibility of utilizing three-dimensional (3D) phase sensitive inversion recovery (IR) images for preoperatively determining deep brain stimulator position. METHODS: We measured geometric distortion with a grid phantom and evaluated images of 3 volunteers to determine optimum imaging parameters for 3D phase sensitive IR. RESULTS: Geometric distortion measured less than 1.0%. Respective inversion and recovery times, which provided high T(1) contrast between the subthalamic nucleus and adjacent tissue, were 200 and 4000 ms. In studies of 3 volunteers and 2 patients, the subthalamic nucleus was clearly depicted in 3D phase sensitive IR images. The measured coordinates of the subthalamic nucleus agreed well with those calculated by conventional estimation from midpoint of the anterior and posterior commissure. CONCLUSION: Three-dimensional phase sensitive inversion recovery was useful in visualizing the subthalamic nucleus for effective deep brain stimulation.     

Reversible Verbal and Visual Memory Deficits after Left Retrosplenial Infarction

The retrosplenial cortex is a cytoarchitecturally distinct brain structure located in the posterior cingulate gyrus and bordering the splenium, precuneus, and calcarine fissure. Functional imaging suggests that the retrosplenium is involved in memory, visuospatial processing, proprioception, and emotion.We report on a patient who developed reversible verbal and visual memory deficits following a stroke. Neuropsychological testing revealed both anterograde and retrograde memory deficits in verbal and visual modalities. Brain diffusion-weighted and T2-weighted magnetic resonance imaging (MRI) demonstrated an acute infarction of the left retrosplenium.     

Poxvirus-based vaccine therapy for patients with advanced pancreatic cancer

Purpose  

An open-label Phase 1 study of recombinant prime-boost poxviruses targeting CEA and MUC-1 in patients with advanced pancreatic cancer was conducted to determine safety, tolerability and obtain preliminary data on immune response and survival.     

Cysteine Conjugate beta-Lyase-Dependent Metabolism of Compound A (2-[fluoromethoxy]-1,1,3,3,3-pentafluoro-1-propene) in Human Subjects Anesthetized with Sevoflurane and in Rats Given Compound A

Background: Sevoflurane undergoes Baralyme- or soda lime-catalyzed degradation in the anesthesia circuit to yield compound A (2-[fluoromethoxy]-1,1,3,3,3-pentafluoro-1-propene), which is nephrotoxic in rats and undergoes metabolism via the cysteine conjugate beta-lyase pathway in those animals. The objective of these experiments was to test the hypothesis that compound A undergoes beta-lyase-dependent metabolism in humans.

Methods: Human volunteers were anesthetized with sevoflurane (1.25 minimum alveolar concentration, 3%, 2 l/min, 8 h) and thereby exposed to compound A. Urine was collected at 24-h intervals for 72 h after anesthesia. Rats, which served as a positive control, were given compound A intraperitoneally, and urine was collected for 24 h afterward. Human and rat urine samples were analyzed by19 F nuclear magnetic resonance spectroscopy and gas chromatography-mass spectrometry for the presence of compound A metabolites.

Results: Analysis of human and rat urine showed the presence of the compound A metabolites [S-[2-(fluoromethoxy)-1,1,3,3,3-pentafluoropropyl]-N-acetyl-L-cysteine, (E)- and (Z)-S-[2-(fluoromethoxy)-1,3,3,3-tetrafluoro-1-propenyl]-N-acetyl-L-cyst eine, 2-(fluoromethoxy)-3,3,3-trifluoropropanoic acid, 3,3,3-trifluorolactic acid, and inorganic fluoride. The presence of 2-(fluoromethoxy)-3,3,3-trifluoropropanoic acid and 3,3,3-trifluorolactic acid in human urine was confirmed by gas chromatography-mass spectrometry.     

Experimental transplantation gliomas in the adult cat brain

Summary In adult cats experimental brain tumours were produced by stereotactical xenotransplantation of the rat glioma clone F 98 into the internal capsule of the left hemisphere. Two to four weeks after transplantation tumours and peritumoural oedema were investigated by magnetic resonance imaging (MRI), electrophysiological recording and analysis of tissue content of water, electrolytes and extravasated serum proteins.Spherical tumours with a diameter of about 10 mm developed at the injection site and were surrounded by massive white matter oedema. Water content in peritumoural white matter increased from 2.63 ± 0.17 to 3.65 ± 0.19 ml/g d.w. (means ± SD), sodium from 187±11 to 351±55 eq/g d.w. and calcium from 7.4±1.1 to 13.3 ± 1.3 ± 1.3 eq/g d.w. Potassium and magnesium did not change. Oedema development was associated with the extravasation of 18.0 ± 16.8mg/g d.w. albumin and 15.8 ± 12.2 mg/g d.w. immunoglobulin. The calculated electrolyte content of oedema fluid approximated that of plasma but the serum protein content was about 40% lower. The ratio of low (albumin) to high (immunoglobulin) molecular weight proteins was the same in blood and oedema fluid. It is, therefore, concluded that peritumoural oedema consist of two components,a whole plasma extravasate and a protein-free ultra-filtrate.Peritumoural oedema could be clearly detected by MRI but differentiation between tumour and oedema was only possible after contrast enhancement with gadolinium-DTPA. The ratios of the intensities of the MR signal correlated linearly with the water content within white matter. MRI, in consequence, allows quantification of oedema provided a reference area with normal water content is present.