The aim of the present study was to examine the relationships between the responses to progressive isocapnic hypoxia and hypoxic withdrawal test in patients with obstructive sleep apnoea-hypopnoea syndrome (OSAHS) and to analyse the determinants of carotid body sensitivity in OSAHS. Nineteen consecutive OSAHS patients and 13 healthy subjects were selected. Ventilatory (delta V'I/Sa,O2/BSA) and ...

Oxygen saturation of arterial blood (SaO2) was assessed in children after discontinuing N2O/O2 sedation for dental procedures. Two post-treatment methods were used: breathing 100% O2 for 5 min after the procedure, and breathing room air for 5 min. Participants were 24 healthy children ages 41 to 113 months. Each child was treated twice and a crossover design was used. The mean length of procedu...

This paper shows for the first time that the spectral features of the ternary complex of tyrosinase/O2/phenol, trapped at low temperature using the very slow substrate 3,5-difluorophenol, are those of a mu-eta2:eta2-peroxidodicopper(II) species, and that this remains the only enzyme species under turnover and substrate saturation conditions.

Moderate and severe levels of experimental valvular aortic stenosis (VAS) were produced in anesthetized, open-chest dogs to determine the effects of VAS on subepicardial (EPI) and subendocardial (ENDO) blood flow, O2 extraction, and O2 consumption (MVO2). Regional flow was determined by microspheres, and O2 saturation and extraction were analyzed by a three-wavelength absorbance microspectropho...

A method for noninvasive measurement of Hb O2 saturation (SO2) in retinal blood vessels by digital imaging was developed and tested. Images of vessels were recorded at O2-sensitive and O2-insensitive wavelengths (600 and 569 nm, respectively) by using a modified fundus camera with an image splitter coupled to an 18-bit digital camera. Retinal arterial SO2 was varied experimentally by having sub...

The activation of cardiovascular reflexes for postural adaptation questions whether, in healthy humans, the central blood volume is optimised to support the upright position. A functional definition of an 'optimal circulating volume' that provides the heart with enough central blood volume to establish a maximal cardiac output (CO) and mixed venous oxygen saturation (S(v,O2)) at rest was evalua...

Moderate and severe levels of experimental valvular aortic stenosis (VAS) were produced in anesthetized, open-chest dogs to determine the effects of VAS on subepicardial (EPI) and subendocardial (ENDO) blood flow, O2 extraction, and O2 consumption (MVO2). Regional flow was determined by microspheres, and O2 saturation and extraction were analyzed by a three-wavelength absorbance microspectropho...

We report room-temperature ferromagnetism of graphitic petal arrays grown on Si substrates by microwave plasma chemical vapor deposition without catalyst. The samples have been characterized by Raman and X-ray photoelectron spectroscopy to confirm the absence of possible ferromagnetic impurities. The petals exhibit ferromagnetic hysteresis with saturation magnetization of ∼4.67 emu cm(-3) and c...

The delivery of oxygen by arterial blood to the tissues of the body has a number of critical determinants including blood oxygen concentration (content), saturation (S O2 ) and partial pressure, haemoglobin concentration and cardiac output, including its distribution. The haemoglobin-oxygen dissociation curve, a graphical representation of the relationship between oxygen satur-ation and oxygen ...

Objectives:Objective measures of morbidity will be required to establish the radial artery (RA) as a viable long term alternative to saphenous vein. The RA is the dominant arterial supply to the thenar musculature. We hypothesised that RA harvest should decrease O2 saturation and thenar muscle power. Methods: RA was harvested from non-dominant (ND) limbs only (left n ˆ 58, right n ˆ 21). Oximet...