The incorporation of platinum disk microelectrodes of various radii (2.5-50 microns) in a well-jet flow cell offers reduced limits of detection for the determination of copper in urine by flow injection analysis compared with standard methods based on a conventional sized glassy carbon disk macroelectrode (radius 1.5 mm), in a ...

Rapid scanning near infrared spectroscopy (730-960 nm) was utilized to determine cat brain cytochrome-c-oxidase after blood-perfluorocarbon (FC-43) exchange. Spectra were carried out before, during, and after the exchange transfusion on cats with preserved somatosensory evoked potentials and microsphere determined cerebral blood flow (CBF). Carbon dioxide (8%) did not produce an ...

In two murder cases involving burning, both victims had been set on fire in the open air after being drenched with kerosene. In the first case, carbon monoxide hemoglobin (COHb) saturation was found to be 2.1% in the left heart blood and 0.8% in the right heart blood, a ratio ...

Ninety-seven people died from a fire that occurred in the Dupont Plaza Hotel in Puerto Rico on 31 Dec. 1986. All, except four who died later in the hospital, were found dead at the scene. All of the fatalities at the hotel (except for eight) were burned beyond recognition. Blood ...

This study investigated effects of increased arterial carbon dioxide on the brain capillary perfusion pattern. Conscious rats were exposed to a 0%, 8% or 12% CO2 in air gas mixture. Arterial blood pressure, heart rate, arterial blood gases and pH were recorded, and either regional cerebral blood flow or the ...

The use of radioactive isotopes limits clinical applications of blood volume measurement in the ICU. We measured red cell volumes with carbon monoxide-labeled RBC in six dogs and five human volunteers. The measured values obtained on the dogs were compared with the simultaneous measurements with the 51Cr method; the ratio ...

A reference method for tonometry of blood is described. The document covers the theory of tonometry, the materials and equipment needed, and essential aspects of the tonometry procedure for blood. The partial pressures of oxygen and carbon dioxide in tonometered blood are accurately known and therefore this blood is recommended ...

The reaction of cerebral blood flow to acute changes in arterial carbon dioxide pressure (PaCO2) and mean arterial blood pressure was determined in 57 preterm infants supported by mechanical ventilation (mean gestational age 30.1 weeks) during the first 48 hours of life. All infants had normal brain sonograms at the ...

Blood gas analysis is crucial for the proper evaluation of systemic acid-base disorders, but several reports have been critical of the current approach which relies on the Henderson-Hasselbalch equation and other possibly erroneous assumptions about the bicarbonate-carbonic acid buffer system of blood. This report studied renal failure patients receiving dialysis ...

A variety of industrial agents to which large segments of the population are exposed have been linked to the development of cardiovascular disease. These toxic agents, which include carbon monoxide, carbon disulphide, lead, and cadmium, are produced by a wide variety of industrial processes and so are ubiquitous in the ...

Haemolysis of human blood has been examined in vitro as a function of pH in the range 7.2-8.0. The hydrogen ion concentration of freshly donated blood from 11 donors was manipulated in 42 experiments, entirely by altering the carbon dioxide fraction of air with which the blood was equilibrated using ...

Determinations of blood cyanide and carboxyhemoglobin concentrations were performed in 18 victims found dead in buildings after fires during a 2-year period. The results indicated that 50% of the victims had been exposed to toxic levels of hydrogen cyanide and 90% to toxic levels of carbon monoxide. Lethal concentrations of ...

We studied the effects of prolonged (6 hours) hypocapnia and the abrupt termination thereof on cerebral blood flow and metabolism in six paralyzed, sedated (but not anesthetized) newborn lambs. Thirty minutes after institution of hyperventilation to an arterial carbon dioxide pressure of 15 +/- 2 torr, hyperventilation, cerebral blood flow ...

To test the relationship pK' = 6.103 + log[HCO3calc] - log[HCO3meas], we used a Corning 168 blood-gas analyzer to analyze 500 blood samples for pH and PCO2, from which we calculated a value for bicarbonate. We also analyzed 500 venous blood samples, collected simultaneously, for potentiometric total carbon dioxide with ...

In order to examine the usefulness of blood cyanide concentrations as an indicator of whether or not a victim was alive at the start of a fire, blood cyanide concentrations were measured in the bodies that we autopsied in our institute between January 1986 and March, 1987. In the present ...

Twenty-two women were studied during laparoscopy with abdominal insufflation of carbon dioxide. A bain anaesthetic breathing circuit was used with a fresh gas flow (VFG) of 110 ml.min-1.kg-1, and controlled ventilation was applied with a minute ventilation (VE) of 175 ml.min-1.kg-1. Arterial blood gases were analysed at the end of ...

A reference method for tonometry of blood is described. The document covers the theory of tonometry, the materials and equipment needed, and essential aspects of the tonometry procedure for blood. The partial pressures of oxygen and carbon dioxide in tonometered blood are accurately known and therefore this blood is recommended ...

Ventilatory characteristics during isoflurane anaesthesia and spontaneous breathing were studied in ten adults during surgery. After premedication with diazepam and induction with thiopental sodium and suxamethonium, 1.2% isoflurane in a 50% mixture of nitrous oxide in oxygen was introduced via a non-rebreathing circuit. Respiratory flow was measured by means of ...

Interest in combined noninvasive respiratory monitors is increasing. The combination of a pulse oximeter and an end-tidal CO2 monitor in one unit reduces space requirements and, potentially, production costs. One such unit (POET, Criticare Systems, Inc.) was tested for accuracy in 15 healthy nonsmoking adult volunteers. Each patient was subjected ...

1. The ventilatory response to changes in end-tidal carbon dioxide tension during hyperoxia, obtained with Read's rebreathing method and a steady-state technique, were compared. 2. In ten young male subjects, forty successful rebreathing and thirteen steady-state experiments were performed on thirteen different morning sessions. 3. In all subjects the ventilatory ...

We measured cerebrovascular reactivity to carbon dioxide in the cerebral cortex and the subcortical white matter of 12 healthy adult volunteers (four young subjects aged 21-24, four middle-aged subjects aged 34-40, and four elderly subjects aged 62-85 years). Blood flow was computed from the concentration history of xenon-133 in the ...

The purpose of the present study was to examine whether there were some differences between metabolic responses induced by carbon monoxide (CO) poisoning and those by hypoxic hypoxia. Significant decrease in cytochrome oxidase (COX) activity in heart and liver was observed during acute exposure, while no change was observed in ...

A female patient born in 1941, who suffers from affective psychosis and Addison's disease, first received lithium carbonate in 1983 during a severe, therapy-resistent depression. With lithium treatment she showed a considerable improvement. In the following months, with a daily dosage of 24.4 mmol, the blood lithium levels were between ...

The Magill and Lack anaesthetic breathing systems were compared by measuring inspired and expired carbon dioxide concentrations and expired minute volumes in lightly anaesthetized, unstimulated subjects. There were no significant differences between the two breathing systems at fresh gas flow rates of approximately 50 and 70 ml kg-1 min-1. Inspired ...

The single-breath method was originally proposed by Kim et al. [1] for estimating the blood carbon dioxide tension and cardiac output. Its reliability has not been proven. The present study was undertaken, using dogs, to compare the mixed venous carbon dioxide tension (PVCO2) calculated by the single-breath method with the ...

A general construction procedure for conventional shape ion-selective electrodes based on a conductive support prepared with a mixture of a non-conductive epoxy and graphite was used in the preparation of a flow-through benzoate electrode to be used as potentiometric detector in flow injection analysis manifolds. The membranes were prepared from ...

Carbon monoxide intoxication continues to be a commonly encountered cause of death in most areas of Canada. The forensic nature of the samples in these cases presents special problems that are not normally encountered in clinical determinations. A study was undertaken to assess various methods of determining the percent carboxyhemoglobin ...

A compartmental model is formulated for oxygen transport in the cerebrovascular bed of the brain. The model considers the arteriolar, capillary and venular vessels. The vascular bed is represented as a series of compartments on the basis of blood vessel diameter. The formulation takes into account such parameters as hematocrit, ...

Changes in regional cerebral blood flow and behavioral and physiological indices were monitored after intravenous administration of d-amphetamine sulfate and placebo in groups of patients with schizophrenia and normal volunteers. Amphetamine administration was associated with decreased anxiety, emotional withdrawal, depressed mood, blunted affect and increased excitement in the patients. Subjects ...

1. Early chick embryos (up to 7 days) survive longer in 1% CO than older ones. As shown by the partition constants of the oxygen-carbon monoxide equilibrium, such a behavior cannot be related to the different hemoglobin patrimonies. 2. In vivo, early embryo hemoglobin is completely turned into its CO ...

1. The rise ('boost') in carboxyhaemoglobin (HbCO) on smoking has been studied with alveolar carbon monoxide measurements before and after smoking a cigarette. We re-examined this in 28 subjects with HbCO values compared with rebreathing carbon monoxide [FACO(Rb)] and breath-hold alveolar carbon monoxide and oxygen concentrations, obtained after a 20 ...

In order to evaluate potential applications of non-invasive fiberoptic conjunctival carbon dioxide (Pcj,CO2) and polarographic oxygen (Pcj,O2) sensors, we studied the effects of graded hyper- and hypoventilation on Pcj,CO2 and Pcj,O2 values in dogs. Pcj,CO2 values correlated well with Pa,CO2 (r = 0.95, n = 114); the mean Pcj,CO2--Pa,CO2 gradient ...

The effect of adding CO2 to inhaled air in six subjects with acute mountain sickness was investigated during a medical expedition to 5400 m.3% CO2 in ambient air increased ventilation and resulted in a rise in PaO2 of between 24% and 40%. There was a 9-28% increase in PaCO2 and ...

Two new cases of aplastic anemia possibly associated with Neptazane (methazolamide) are reported. Several previous authors, as well as the manufacturer of Diamox (acetazolamide) and Neptazane, have recommended routine blood counts for patients on carbonic anhydrase inhibitors. Four surveys are presented of current practices with regard to blood monitoring. These ...

Ten patients undergoing elective cataract surgery with local anesthesia were evaluated for rebreathing using mass spectrometry and arterial blood gas analysis. Results showed a 10 or 51 oxygen-air mixture with an inspired oxygen concentration of 50% (FIO2) administered via a face tent maintained normal blood gases and a satisfactorily low ...

The dynamics of the enthalpy and volume changes produced in the photodissociation of carbon monoxide from sperm whale myoglobin is investigated by time-resolved photoacoustic calorimetry. The enthalpy and volume changes for the formation of the geminate pair, which occurs within 50 ns of photolysis, are delta H = -2.2 +/- ...

The ability of fluorophotometry to measure the time course of changes in aqueous humor flow in rabbits was evaluated by measuring the effect of intravenous carbonic anhydrase inhibitors on aqueous humor flow determinations. The abrupt changes in aqueous humor flow which were found by fluorophotometry agreed well with the expected ...

We evaluated the rate of bilirubin production in vivo in newborns whose mothers received an epidural block with bupivacaine hydrochloride during labor and delivery. Bilirubin production was estimated in 23 full-term newborns whose mothers were treated with bupivacaine and in 20 controls by determining the end-tidal carbon monoxide concentration and ...

The case of a patient with elevated carboxyhemoglobin saturation, prolonged carboxyhemoglobin half-life, and Waldenström's macroglobulinemia is presented. In vitro studies on the patient's blood showed that the half-life of carboxyhemoglobin in the macroglobulinemic blood was about three times longer than in a normal blood sample. Similar experiments using normal and ...

Neurohypophyseal blood flow was studied using radiolabelled microspheres in 13 dogs. Hypoxic hypoxia and carbon monoxide hypoxia with similar arterial oxygen contents (CaO2, approximately 8 vol %) were produced. Under conditions of hypoxic hypoxia, 100-200% increases in blood flow in caudate nucleus, white matter, neurohypophysis, and all other brain regions ...

We developed a miniature mixing chamber, the bymixer, that aids in the measurement of respiratory gas metabolism and inhalation anesthetic uptake. A small fraction of total respiratory gas flow is bypassed from the inspiratory or expiratory limb of the breathing circuit to the bymixer. We tested the relationship between total ...

The pionic carbon/oxygen capture ratio for the blood and muscle tissue of a pig was measured using an intrinsic Ge detector in order to investigate possible explanations for an enhanced lesion observed in the autopsy of pion-irradiated patients. Pure iron was also irradiated in order to determine the energies and ...

We performed a series of five baboon experiments to compare cerebral blood flow measured with an improved stable xenon/CT method and the radiolabelled microsphere technique at a PaCO2 of 40 mm Hg. The xenon/CT method was implemented by fitting the arterial xenon uptake with a double exponential function, by measuring ...

Nitrogen dioxide induced SOS functions in Salmonella typhimurium and Escherichia coli K-12 and was mutagenic in Escherichia coli WP2. When a rabbit was administered aminopyrine intravenously and administered nitrogen dioxide by inhalation, N-nitrosodimethylamine was detected in its blood. Analysis was conducted with 15N-nitrosodimethylamine as an internal standard by a combination ...

The oxygen-15 steady-state technique to measure the regional cerebral metabolic rate for oxygen requires a correction for the nonextracted intravascular molecular oxygen-15. To perform this correction, an additional procedure is carried out using RBCs labeled with 11CO or C15O. The previously reported correction method, however, required knowledge of the regional ...

Acid-base status of umbilical artery and vein blood was measured immediately after delivery in 300 cases. A slight acidosis of mixed respiratory/metabolic type was found in newborns delivered following a second stage of 10-30 min duration. After a second stage of more than 30 min the metabolic contribution to the ...

Acetazolamide, a carbonic anhydrase (CA) inhibitor, was used to normalize metabolic alkalemia. A dosage of acetazolamide for normalizing metabolic alkalemia has not yet been experimentally determined. The dosage of acetazolamide for this purpose is experimentally calculated in this paper. The correlation between various concentration of acetazolamide mixed with blood and ...

We measured the oxygen consumption, carbon dioxide production, and respiratory quotient during the combustion of a known mass of anhydrous ethanol and methanol to assess the accuracy of an open-circuit flow-through system. Continuous measurements were made of the mass of alcohol burned, the velocity of gas flow through the apparatus, ...

The belief that the cochlea is particularly vulnerable to a reduction in oxygen availability comes predominantly from studies reporting the disruption of electrophysiological measures, such as the compound action potential, endocochlear potential, inner hair cell intracellular potentials or afferent nerve fiber responses by asphyxiation. Because hypoxia has frequently been suggested ...

An improved gas chromatographic method for HCN in blood with acetonitrile as an internal standard has been developed. The necessity to test for cyanide on samples from air accident fire victims is discussed in view of the fact that carbon monoxide measurements usually do not correlate with cyanide findings. Nine ...