Intracellular metabolites in the primate brain are primarily localized in long fibers rather than in cell bodies, as shown by diffusion-weighted magnetic resonance spectroscopy.

Due to their pure intracellular compartmentation, the translational diffusion of brain metabolites in vivo depends on the intracellular environment, including viscosity, molecular crowding and subcellular structures. However, as the diffusion time is increased, metabolites have enough time to significantly encounter cell boundaries, so that cell size and geometry are expected to strongly determine metabolite diffusion path. In the present work, diffusion-weighted nuclear magnetic resonance spectroscopy was used to investigate brain metabolite diffusion in vivo, at long and ultra-long diffusion times (from ~80 ms to more than 1 s), in a voxel with equal proportions of white and grey matter in macaque monkeys.

An algorithm for difficult airway management, modified for modern optical devices (Airtraq laryngoscope; LMA CTrach™): a 2-year prospective validation in patients for elective abdominal, gynecologic, and thyroid surgery.

Background: Because algorithms for difficult airway management, including the use of new optical tracheal intubation devices, require prospective evaluation in routine practice, we prospectively assessed an algorithm for difficult airway management that included two new airway devices.

Methods: After 6 months of instruction, training, and clinical testing, 15 senior anesthesiologists were asked to use an established algorithm for difficult airway management in anesthetized and paralyzed patients. Abdominal, gynecologic, and thyroid surgery patients were enrolled.

LMA supreme versus facemask ventilation performed by novices: a comparative study in morbidly obese patients showing difficult ventilation predictors.

Background: We designed a study to compare ventilation characteristics performed in morbidly obese patients by medical students via the facemask to that via the LMA Supreme.

Methods: This prospective, randomized, crossover study included 31 ASA I-III morbidly patients showing difficult mask ventilation predictors. After induction of anesthesia, ten medical students with no previous clinical experience in airway management, clinically educated to facemask ventilation maneuvers, and theoretically educated to laryngeal mask use were supervised by a senior anesthesiologist during performance of 60 s facemask and LMA Supreme ventilation in a randomly assigned order.

NMR measurement of brain oxidative metabolism in monkeys using 13C-labeled glucose without a 13C radiofrequency channel.

We detected glutamate C4 and C3 labeling in the monkey brain during an infusion of [U-13C6]glucose, using a simple 1H PRESS sequence without 13C editing or decoupling. Point-resolved spectroscopy (PRESS) spectra revealed decreases in 12C-bonded protons, and increases in 13C-bonded protons of glutamate. To take full advantage of the simultaneous detection of 12C- and 13C-bonded protons, we implemented a quantitation procedure to properly measure both glutamate C4 and C3 enrichments.

Systolic blood pressure, not BIS, is associated with movement during laryngoscopy and intubation.

Objective: To compare bispectral index (BIS) values to hemodynamic variations, in order to evaluate adequacy of anesthesia during orotracheal intubation with muscle relaxants.

Methods: Forty-one patients ASA I-II, scheduled for elective peripheral surgery under general anesthesia with tracheal intubation were enrolled in the study. Fentanyl/thiopental followed by vecuronium were used for induction.