Our aim was to determine the effects of focal acidification in the raphe obscurus (RO) and raphe pallidus (RP) on ventilation and other physiological variables in both the awake and sleep states in adult goats. Through chronically implanted microtubules, 1) a focal acidosis was created by microdialysis of mock cerebrospinal fluid (mCSF), equilibrated with various levels of CO2, and 2) medullary...

We investigated if hemodynamic variability, cerebral blood flow (CBF) regulation, and their interrelationships differ between patients with transient ischemic attack (TIA) and controls. We recorded blood pressure (BP) and bilateral middle cerebral artery flow velocity (MCAv) in a cohort of TIA patients (n = 17), and age-matched controls (n = 15). Spontaneous fluctuations in BP and MCAv were cha...

INTRODUCTION: Cerebrovascular reactivity (CVR), referring to the ability of blood vessels to dilate upon stimulation, is an important marker of brain’s vascular function (1). During the past few years, there has been a surging interest in quantitative mapping of CVR using BOLD MRI in combination with hypercapnia challenge (2-5) and to use this technique in cerebrovascular diseases (3,4) and nor...

• Research has provided ample evidence that the cerebral vascular system possesses a marked degree of autonomy and is largely unaffected by changes in the systemic circulation. This autonomy is made possible, first of all, by minimal effect on cerebral vessels of those factors which act on the general circulation, such as the autonomic innervation and, second, by the extreme sensitivity of cere...

1. In closed-chest dogs anaesthetized with trichlorethylene, the inhalation of carbon dioxide sufficient to increase the arterial P(CO2) from 40 to about 100 mm Hg, increased myocardial blood flow (measured using a (133)Xe clearance technique) and right atrial pressure. There were no consistent changes in mean arterial blood pressure, heart rate or cardiac output.2. The effect of hypercapnia on...

Transcutaneous carbon dioxide and oxygen tensions (tc-pCO2 and tc-pO2) were measured in seven healthy adult volunteers during hyperventilation in atmospheric air and during CO2 inhalation. Three skin sensors were applied to each subject: an O2 electrode, a CO2 electrode, and a combined O2-CO2 electrode, each heated to 44 degrees C. We observed close correlation between tc-pCO2 and capillary-pCO...

BACKGROUND AND PURPOSE Analysis of dynamic cerebral autoregulation (DCA) from spontaneous blood pressure fluctuations might contribute to prognosis of severe internal carotid artery stenosis, but its response to carotid recanalization has not been investigated so far. This study investigates the effect of carotid endarterectomy or stenting on various DCA parameters. METHODS In 58 patients wit...

The effect of the basal cerebral blood flow (CBF) on both the magnitude and dynamics of the functional hemodynamic response in humans has not been fully investigated. Thus, the hemodynamic response to visual stimulation was measured using blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) in human subjects in a 7-T magnetic field under different basal conditio...

We would like to raise a number of concerns with regard to the recent paper by Gerritzen et al., entitled ‘Castration of piglets under CO2-gas anaesthesia’ (Animal, 2008, 2(11), 1666–1673). While we endorse the motivation of the authors in addressing the welfare problems created by castration of piglets without anaesthesia, especially in light of recent Dutch legislation, we believe that taking...

Two isostructural 1D compounds {[M3(hpdc)2(H2O)6] 2H2O}n (M = Mn, Co; H3hpde = 2-hydroxypyrimidine-4,6-dicarboxylic acid) were synthesized by the in situ hydrothermal reactions of 2-chloropyrimidine-4,6-dicarboxylic acid with MCl2 (M = Mn, Co) and NaOH; the MnII compound shows spin-canted antiferromagnetism, whereas the CoII compound exhibits the coexistence of spin-canting and a two-step field...