Due to methodologic difficulties, few investigations have been made on the blood flow velocity in the cerebral microcirculation. Using a newly developed video camera method, we simultaneously measured the blood flow velocity and diameter of pial arteries during hemorrhagic hypotension, after blood pressure recovery, and during CO2 inhalation in cats. When the mean arterial blood pressure was lo...

OBJECTIVE There is controversy about the effects of high plasma bicarbonate concentration ([HCO3(-)]) and the CO2 response test. We analyzed the relationship between [HCO3(-)] and the variation in hydrogen ion concentration (pH) for a given change in PaCO2, and its effects upon CO2 response. DESIGN A retrospective study was carried out. SETTING Two intensive care units. PATIENTS Subjects ...

Clavicular air sac pressure, arterial blood gases and pH, and rectal temperature were measured in treadmill-exercised cockerels breathing air, 10% O2 in N2 or a mixture of 10% O2/3% CO2 in N2. Air sac pressures were used to estimate changes in the rate and the relative depth of breathing. In air-breathing conditions exercise took place at two intensities corresponding to treadmill speeds of 3.2...

Spinal cord blood flow (SCBF) and the effect of end-tidal CO2 concentration (ETCO2) on SCBF (CO2 reactivity) were studied in the lumbar spinal cord of cats by means of the hydrogen-clearance technique Hydrogen gas was administered by inhalation, and its level in spinal cord tissue was estimated amperometrically with small (75 micrometers) platinum electrodes. The average SCBF's at normocapnia (...

BACKGROUND Positive self-bias is thought to be protective for mental health. We previously found that the degree of positive bias when learning self-referential social evaluation decreases with increasing social anxiety. It is unclear whether this reduction is driven by differences in state or trait anxiety, as both are elevated in social anxiety; therefore, we examined the effects on the state...

The aim of this investigation was to study noninvasively the effects of hypoxaemia, hyperoxaemia and hypercapnia on renal blood flow in normal subjects and renal allograft recipients, i.e. with denervated kidneys. By comparing these two groups, the influence of renal innervation on any resulting changes in renal blood flow could be ascertained. Nine normal and eight renal allograft recipients w...

rCBF was measured by 133Xenon inhalation technique in 39 patients with unilateral carotid artery occlusion in a subacute-chronic stage. Resting flow values (ISI) varied between 23.7 and 52.4 ml/100 g/min. An almost constant finding was interhemispheric asymmetry, the degree of which was correlated with the severity of the initial symptoms. An ischemic focus was an insignificant finding. The CO2...

Attenuating the strength of fearful memories could benefit people disabled by memories of past trauma. Pavlovian conditioning experiments indicate that a retrieval cue can return a conditioned aversive memory to a labile state. However, means to enhance retrieval and render a memory more labile are unknown. We hypothesized that augmenting synaptic signaling during retrieval would increase memor...