Simultaneous recording of evoked potentials and T2*-weighted MR images during somatosensory stimulation of rat

Somatosensory evoked potentials (SEP) and T2*-weighted nuclear magnetic resonance (NMR) images were recorded simultaneously during somatosensory stimulation of rat to investigate the relationship between electrical activation of the brain tissue and the signal intensity change in functional NMR imaging. Electrical forepaw stimulation was performed in Wistar rats anesthetized with -chloralose. SEPs were recorded with calomel electrodes at stimulation frequencies of 1.5, 3, 4.5, and 6 Hz. At the same time, T2*-weighted imaging was performed, and the signal intensity increase during stimulation was correlated with the mean amplitude of the SEP. Both the stimulation-evoked signal intensity increase in T2*-weighted images and the amplitude of SEPs were dependent on the stimulation frequency, with the largest signals at a stimulation frequency of 1.5 Hz and decreasing activations with increasing frequencies. The feasibility of simultaneous, artifact-free recordings of T2*-weighted NMR images and of evoked potentials is proved. Furthermore, the study demonstrates - in the intact brain - the validity of functional magnetic resonance imaging for estimating the intensity of electrocortical activation

Time course of circulatory and metabolic recovery of cat brain after cardiac arrest assessed by perfusion- and diffusion-weighted imaging and MR-spectroscopy

Copyright 2003 ELSEVIER SCI IRELAND LT

Time course of circulatory and metabolic recovery of cat brain after cardiac arrest assessed by perfusion- and diffusion-weighted imaging and MR-spectroscopy

Copyright 2003 ELSEVIER SCI IRELAND LT

An automated CPR device compared with standard chest compressions for out-of-hospital resuscitation

Background: Effective cardiopulmonary resuscitation and increased coronary perfusion pressures have been linked to improved survival from cardiac arrest. This study aimed to compare the rates of survival between conventional cardiopulmonary resuscitation (C-CPR) and automated CPR (A-CPR) using AutoPulse™ in adults following out-of-hospital cardiac arrest (OHCA).Methods: This was a retrospective study using a matched case-control design across three regional study sites in Victoria, Australia. Each case was matched to at least two (maximum four) controls using age, gender, response time, presenting cardiac rhythm and bystander CPR, and analysed using conditional fixed-effects logistic regression.Results: During the period 1 October 2006 to 30 April 2010 there were 66 OHCA cases using A-CPR. These were matched to 220 cases of OHCA involving the administration of C-CPR only (controls). Survival to hospital was achieved in 26% (17/66) of cases receiving A-CPR compared with 20% (43/220) of controls receiving C-CPR and the propensity score adjusted odds ratio [AOR (95% CI)] was 1.69 (0.79, 3.63). Results were similar using only bystander witnessed OHCA cases with presumed cardiac aetiology. Survival to hospital was achieved for 29% (14/48) of cases receiving A-CPR compared with 18% (21/116) of those receiving C-CPR [AOR = 1.80 (0.78, 4.11)].Conclusions: The use of A-CPR resulted in a higher rate of survival to hospital compared with C-CPR, yet a tendency for a lower rate of survival to hospital discharge, however these associations did not reach statistical significance. Further research is warranted which is prospective in nature, involves randomisation and larger number of cases to investigate potential sub-group benefits of A-CPR including survival to hospital discharge

Cross Talk Between Plasma Membrane Na+/Ca2+ Exchanger-1 and TRPC/Orai-Containing Channels: Key Players in Arterial Hypertension

Arterial smooth muscle (ASM) Na(+)/Ca(2+) exchanger type 1 (NCX1) and TRPC/Orai-containing receptor/store-operated cation channels (ROC/SOC) are clustered with α2 Na(+) pumps in plasma membrane microdomains adjacent to the underlying junctional sarcoplasmic reticulum. This arrangement enables these transport proteins to function as integrated units to help regulate local Na(+) metabolism, Ca(2+) signaling and arterial tone. They thus influence vascular resistance and blood pressure (BP). For instance, up-regulation of NCX1 and TRPC6 has been implicated in the pathogenesis of high BP in several models of essential hypertension: ouabain-induced hypertensive rats, Milan hypertensive strain rats, and Dahl salt-sensitive hypertensive rats, which all have elevated plasma ouabain levels. Enhanced expression and function of arterial smooth muscle NCX1 and TRPC/Orai1-containing channels in experimental and clinical hypertension implies that these proteins are potential targets for pharmacological intervention