Cent Carbon Dioxide Research Articles

A method for quantitating blastogenesis by tuberculins in cultures of human blood lymphocytes.

A method for estimating the degree of lymphocyte transformation in vitro by incorporation of thymidine-3H was modified for studying reactions to tuberculins prepared from different groups of mycobacteria. The best results were obtained when cultures were grown in unsiliconized glass tubes sealed with corks for the first two days of incubation and then loosely capped and incubated in air during the last two days. A series of cultures grown in 2 per cent carbon dioxide gave comparable results. Because of the difficulty in distinguishing between reactors and nonreactors with the isotopic method, it was sometimes useful to include cultures for morphologic examination. Both methods gave similar patterns of reaction in individual donors except in cultures with very low rates of transformation. The tendency of blasts to occur in clumps made it difficult to estimate the relative effect of closely related antigens by morphologic examination, but it did not interfere with quantitation by the thymidine uptake method.

The Calculation of Cathode Current Efficiency and Metal Loss in a Small Alumina Reduction Cell

Experimental data from a small Hall cell were used to show the relationship between the cathode current efficiency and the carbon monoxide‐carbon dioxide content of the anodic gas. The equation, , was developed and shown to give reliable estimates of aluminum production. In this equation, the volume per cent of carbon dioxide is corrected for the Boudouard reaction which varies in amount with anode type and operating conditions. A second and equally effective equation is, , where Anode is based on the oxygen in the anodic gases and is metal efficiency loss resulting from solubility and vaporization. The minimum value of is the solubility of metal in the electrolyte, which in the small cell was estimated to be 0.12%. Calculations made with experimental and literature data show that under industrial conditions the Pearson and Waddington equation gives good estimates of cathode current efficiency, because the lower efficiency indicated by the excess carbon monoxide from the Boudouard reaction compensates for the factor.

METHODS OF ELEVATION OF PCO2 FOR RESTORATION OF SPONTANEOUS BREATHING AFTER ARTIFICIAL VENTILATION OF ANAESTHETIZED PATIENTS

SUMMARY Three methods for elevation of end-expiratory Pco 2 at the end of prolonged hyper-ventilation have been studied in 44 anaesthetized patients. The most rapid and repeatable method was the addition of 5 per cent carbon dioxide to the inspired gas for 5 minutes. This raised the end-expiratory Pco 2 from a mean value of 21.4 mm Hg to 41.8 mm Hg, and was associated with an onset of spontaneous respiration in a mean time of 2.2 min. Hypoventilation with a minute volume of 3 l./min for 5 minutes with a rebreathing circuit, without soda-lime, gave a slow rise of Pco 2 (mean rate 3 mm Hg/min) with a resumption of spontaneous respiration in a mean time of 4.5 min. Step reduction of minute volume from 10 to 5 l./min without rebreathing was a very slow and variable method of raising end-expiratory Pco 2 , with a mean time of 5.2 min before the restoration of spontaneous breathing.

Effects of Breathing 10 Per Cent Carbon Dioxide on the Pulmonary Circulation of Human Subjects

The effects on the pulmonary circulation of breathing 10% CO 2 for 10 to 20 min were studied in five eucapnic and 11 convalescing hypercapnic patients to recreate the CO 2 tensions which they had experienced during respiratory failure. Right heart catheterization permitted measurements of pulmonary arterial and wedge pressures and obtaining samples of mixed venous blood. Breathing CO 2 increased mean pulmonary arterial pressures from 33 to 50 mm Hg (52%); pulmonary arterial wedge pressures were unchanged, and cardiac output increased only 22%. In three hypercapnic and two eucapnic subjects reduction of blood hydrogen ion levels by rapid infusion of 120 to 135 mEq NaHCO 3 during CO 2 breathing did not lower pulmonary arterial pressure significantly, nor raise cardiac output. Neither vascular pressures nor cardiac outputs changed during oxygen breathing. Larger increases in cardiac output, which were produced by exercise, raised pulmonary artery pressure only half as much as breathing 10% CO 2 did. Therefore, pulmonary vascular resistance (PVR) that was elevated to an average of 4.8 mm Hg/L/min at rest while breathing air was increased to 6.5 mm Hg/L/min during CO 2 breathing ( P <0.01). In contrast, PVR was unchanged (4.6 mm Hg/L/min) during exercise. This difference between PVR while breathing CO 2 and during exercise was statistically significant ( P <0.02). Restoration of the pH of the blood toward normal by the infusion of bicarbonate during breathing of CO 2 raised the pulmonary arterial pressure. The five eucapnic subjects showed similar changes during CO 2 breathing and exercise, although their base-line values were significantly different. The differences were due, at least in part, to lower Paco 2 . This evidence suggests that CO 2 acts on pulmonary arterioles and capillaries that are exposed to alveolar gases to increase the pulmonary vascular impedance.

METHODS OF ELEVATION OF Pco2 FOR RESTORATION OF SPONTANEOUS BREATHING AFTER ARTIFICIAL VENTILATION OF ANAESTHETIZED PATIENTS

SUMMARY Three methods for elevation of end-expiratory Pco 2 at the end of prolonged hyper-ventilation have been studied in 44 anaesthetized patients. The most rapid and repeatable method was the addition of 5 per cent carbon dioxide to the inspired gas for 5 minutes. This raised the end-expiratory Pco 2 from a mean value of 21.4 mm Hg to 41.8 mm Hg, and was associated with an onset of spontaneous respiration in a mean time of 2.2 min. Hypoventilation with a minute volume of 3 l./min for 5 minutes with a rebreathing circuit, without soda-lime, gave a slow rise of Pco 2 (mean rate 3 mm Hg/min) with a resumption of spontaneous respiration in a mean time of 4.5 min. Step reduction of minute volume from 10 to 5 l./min without rebreathing was a very slow and variable method of raising end-expiratory Pco 2 , with a mean time of 5.2 min before the restoration of spontaneous breathing.

Electroencephalographic Recovery of Cerebrum after Hypoxia in Developing Chicks

Previous articleNext article No AccessElectroencephalographic Recovery of Cerebrum after Hypoxia in Developing ChicksJoseph J. Peters, John J. McDonough, and Alphonse R. VonderaheJoseph J. Peters Search for more articles by this author , John J. McDonough Search for more articles by this author , and Alphonse R. Vonderahe Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Volume 41, Number 4Oct., 1968 Article DOIhttps://doi.org/10.1086/physzool.41.4.30155484 Views: 2Total views on this site Citations: 5Citations are reported from Crossref Journal History This article was published in Physiological Zoology (1928-1998), which is continued by Physiological and Biochemical Zoology (1999-present). Copyright 1968 University of ChicagoPDF download Crossref reports the following articles citing this article:A.B. Mohan Raj, S.B. Wotton, P.E. Whittington Changes in the spontaneous and evoked electrical activity in the brain of hens during stunning with 30 per cent carbon dioxide in argon with 5 per cent residual oxygen, Research in Veterinary Science 53, no.11 (Jul 1992): 126–129.https://doi.org/10.1016/0034-5288(92)90097-LTAKANORI OOKAWA Behavioral and Electroencephalographic Manifestations of Avian Epilepsy: A Review of the Literature, Poultry Science 56, no.33 (May 1977): 773–792.https://doi.org/10.3382/ps.0560773Joseph J. Peters, Eric J. Hilgeford, Alphonse R. Vonderahe Ontogenesis of electroencephalographic seizure patterns in developing chick embryos during recovery from hypothermic hypoxia, Developmental Psychobiology 6, no.44 (Jul 1973): 337–348.https://doi.org/10.1002/dev.420060407Takanori Ookawa Notes on Abnormal Electroencephalograms in the Telencephalon of the Chicken and Pigeon, Poultry Science 52, no.11 (Jan 1973): 182–197.https://doi.org/10.3382/ps.0520182Jörgen Boëthius, Tomas Brundin, Nils-Åke Persson Effects of asphyxia on the electrocorticogram of newborn rabbits, Experimental Neurology 30, no.11 (Jan 1971): 116–122.https://doi.org/10.1016/0014-4886(71)90226-3

The protective action of anaesthetics against hypoxia.

On the basis of experimental examinations it has been possible to show that halothane and cyclopropane of the inhalation anaesthetics have a protective action on the brain against anoxia. A similar but even better effect could be obtained by most intravenous anaesthetics, particularly thiopentone. If thiopentone was combined with 5 per cent carbon dioxide, this effect was doubled.

A method of sampling human dental plaque for certain “caries-inducing” streptococci

A method is described which permits the identification of specific “caries-inducing” streptococci and the determination of their numbers in relation to other streptococci in dental plaque. Reproducible amounts of plaque were collected in calibrated stainless steel spoons and transferred to Möller's transport medium which preserved the viability of the micro-organisms. The plaques were mechanically dispersed with the aid of glass beads and serial dilutions were plated on Mitis-Salivarius agar. Incubation at 37 °C under 95 per cent nitrogen-5 per cent carbon dioxide for 18 hr was followed by aerobic storage at room temperature for 24 hr. The colonial morphology of known cariogenic streptococci is distinctive on this medium. Their numbers in relation to the other plaque streptococci which grow on this medium may be directly estimated. The cariogenicity of these strains may then be confirmed in the albino hamster test model. The transport medium preserves the viability of most plaque streptococci for several days at room temperature and permits the collection of samples in the field and subsequent plating in the laboratory. Preliminary studies have confirmed the usefulness of this method for the detection and enumeration of these caries-inducing streptococci in various human populations.

Mortality of stored-peanut insects exposed to mixtures of atmospheric gases at various temperatures

Tribolium castaneum (Herbst) adults and larvae and Plodia interpunctella (Hübner) larvae were exposed for 7 and 14 days to conditioned binary and ternary mixtures of nitrogen, oxygen, and carbon dioxide at 15·6, 26·7 and 37·8°C. The moth larvae were more susceptible to changes in the atmospheric gas concentrations and high temperatures than the beetle adults or larvae. In general, mortalities increased by extending the exposure from 7 to 14 days, increasing the temperature from 15·6 to 37·8°C, decreasing the oxygen concentration within binary or ternary mixture, or increasing the carbon dioxide concentration. Apparently, atmospheres lethal to the test insects can contain up to 15 per cent of oxygen if about 36 per cent of carbon dioxide is also present. In the absence of carbon dioxide, lethal atmospheres were obtained when the oxygen was reduced to about 1 per cent.

Effect of induced respiratory acidosis on the circulating blood volume in normal dogs

1. 1. The effect on the circulating blood volume of an acute increase in the fractional concentration of inspired carbon dioxide (respiratory acidosis) without a concomitant decrease of inspired concentration of oxygen was studied in anesthetized dogs. 2. 2. A gas mixture containing 5 per cent carbon dioxide and 21 to 23 per cent oxygen was administered to anesthetized dogs for four hours. Red blood cell volume, large vessel hematocrit, arterial pH, carbon dioxide pressure, oxygen pressure, and serum electrolytes were measured. 3. 3. Our results indicate that moderate to severe respiratory acidosis in the presence of normal oxygenation does not alter circulating blood volume significantly in anesthetized mongrel dogs.

Spectroscopic study of the gas-cap radiation intensity for simulated martian atmospheric probes

Measurements of radiation from the shock-heated stagnation zone of blunt models have been made in a high-temperature plasma tunnel using a gas mixture of 46 per cent carbon dioxide, 23 per cent nitrogen, and 31 per cent argon. The tests were designed to simulate the conditions expected for a probe launched into the Mars atmosphere to make spectral measurements. The velocity simulated ranged from 5 to 7 km/sec; and the density was maintained at low values of the order 10−8 g/cm3, consistent with ambient conditions prior to peak gas radiation during a Mars entry. Measurements of gas-cap radiation were made with non-ablating copper and ablating surface materials. The results of the tests showed that the plasma tunnel radiation measurements for non-ablating surfaces agree qualitatively with current theoretical predictions for equilibrium flow. Expected nonequilibrium radiation was not observed due to predissociation and freezing of the chemical species upstream in the plasma tunnel nozzle. Considerable enhancement of the gas-cap radiation can occur when ablative materials are employed for thermal protection during entry. Scaling laws are presented which estimate the effect of ablation vapor radiation.

Spectroscopic study of the gas-cap radiation intensity for simulated Martian atmospheric probes

Measurements of radiation from the shock-heated stagnation zone of blunt models have been made in a high-temperature plasma tunnel using a gas mixture of 46 per cent carbon dioxide, 23 per cent nitrogen, and 31 per cent argon. The tests were designed to simulate the conditions expected for a probe launched into the Mars atmosphere to make spectral measurements. The velocity simulated ranged from 5 to 7 km/sec; and the density was maintained at low values of the order 10 −8 g/cm 3, consistent with ambient conditions prior to peak gas radiation during a Mars entry. Measurements of gas-cap radiation were made with non-ablating copper and ablating surface materials. The results of the tests showed that the plasma tunnel radiation measurements for non-ablating surfaces agree qualitatively with current theoretical predictions for equilibrium flow. Expected nonequilibrium radiation was not observed due to predissociation and freezing of the chemical species upstream in the plasma tunnel nozzle. Considerable enhancement of the gas-cap radiation can occur when ablative materials are employed for thermal protection during entry. Scaling laws are presented which estimate the effect of ablation vapor radiation.

Breakdown and weight loss in Red Jonathan apples in controlled atmosphere storage

Red Jonathan apples were stored at 32�F in 5 per cent carbon dioxide and 16 per cent oxygen in the presence of calcium chloride. The incidence of breakdown decreased linearly as weight loss was increased. Thus carbon dioxide and oxygen levels, and weight loss may all affect the incidence of breakdown in apples in controlled atmospheres. Without information on weight loss to ensure that there is no confounding, conclusions about the effects of carbon dioxide and oxygen may be misleading,

SAFE REVERSAL (1): ATROPINE FOLLOWED BY NEOSTIGMINE: An Electrocardiographic Study

SUMMARY An electrocardiographic investigation was carried out in ten healthy adult patients anaesthetized using thiopentone, nitrous oxide and oxygen with tubocurarine. The arterial carbon dioxide tension was raised by adding 2.5 per cent carbon dioxide to the fresh gas flow whilst intermittent positive pressure ventilation was maintained throughout the whole period of anaesthesia and reversal. The Pco2 varied between 45 and 90 mm Hg and the pH values varied between 7.12 and 7.30. The intravenous injection of atropine 1.2 mg followed after 2 minutes by neostigmine 2.5 mg did not produce any serious cardiac arrhythmia provided adequate oxygenation was ensured throughout the whole period of reversal.

Role of carbon dioxide in erythropoiesis.

THE use of gas mixtures containing 5 per cent carbon dioxide gas has become a standard procedure for the cultivation of cells in vitro. In some systems, however, a higher concentration has proved essential1,2. In bone marrow cultures different concentrations of carbon dioxide have been used3,4, but the interest has centred on the role of oxygen and little attention has been paid to the function of the other gases in the mixtures. In the present system for the cultivation of rat bone marrow in vitro 30 per cent carbon dioxide (which is considerably higher than any concentration, previously reported) has been found to stimulate erythropoiesis5. This effect has now been investigated in detail.

Intestinal absorption of L-leucine in vitro in fish ( Stenotomus versicolor and Ictalurus nebulosus)

1. 1. In vitro everted intestinal sacs were made from two species of fish-scup, Stenotomus versicolor (marine), and the catfish, Ictalurus nebulosus (fresh water)—and were used to measure the transmural movement of L-leucine. 2. 2. With incubation for 30 min at 23 ± 1°C there was a unidirectional change in amino acid concentration showing uptake from the mucosal fluid and increased amounts in the serosal fluid. 3. 3. The absorption phenomenon appears to be oxygen dependent (95 per cent oxygen and 5 per cent carbon dioxide). Anaerobiotic conditions, with 100 per cent nitrogenn, resulted in an inhibition of the unidirectional transfer of amino acid.

A high-temperature, hydrogen-oxidizing bacterium--Hydrogenomonas thermophilus, n.sp.

WE have succeeded in isolating in pure culture from petroliferous soil a thermophilic bacterium which utilizes hydrogen. The isolation was accomplished by streaking material from a soil enrichment culture on to Repaske's mineral salts medium prepared by mixing equal volumes of a sterile 4 per cent agar solution in water and a sterile, double-strength solution of mineral salts containing ammonium chloride, MgSO4·7H2O, CaCl2·2H2O, potassium dihydrogen phosphate, sodium monohydrogen phosphate, and several trace elements. On cooling to about 50° C, 1 ml. of a solution of ferrous ammonium sulphate was added, the plates poured, allowed to solidify and immediately streaked. The plates were incubated in an atmosphere containing 70 per cent hydrogen, 20 per cent oxygen, and 10 per cent carbon dioxide at 50° C. By picking the minute, flat, smooth, translucent colonies into liquid mineral salts medium and incubating in the 70–20–10 gas mixture, a pure culture was obtained.

Effect of growth hormone on the isolated pancreatic islets of rat in vitro.

ISLETS of Langerhans were isolated by the technique of Kostianovsky and Lacy1 from the pancreases of intact rats, as well as from rats hypophysectomized 4 weeks previously, some of which were treated for the last 3 days with 2 mg bovine growth hormone/day. Following an equilibration period of 20 min in cold Krebs–Ringer bicarbonate buffer, pH 7.2, with 0.6 mg/ml. glucose, five or six islets were placed in each incubation flask with 0.5 ml. of the same buffer, and incubated at 37° C with continuous gassing, using a mixture of 95 per cent oxygen and 5 per cent carbon dioxide. After incubation for 15 min, the islets were transferred to a second incubation medium with either 0.6 or 3.0 mg/ml. glucose plus tritiated D,L-leucine (0.01 mc., 1.27 × 10−5 mmolar) and incubated for a further period of 15 min. At the end of the incubation, the islets were removed, washed with cold buffer containing 1 mg/ml. unlabelled D,L-leucine, and homogenized with 0.5 ml. of 10 per cent trichloroacetic acid in a tissue micro homogenizer. Insulin extraction from the islets homogenized with TCA was carried out according to the procedure described by Taylor2. Portions of the acid–alcohol extract were used for insulin determination and for counting the incorporation of tritium in the insulin–anti-insulin precipitate. The precipitate that remained after extraction with acid–alcohol was treated with chloroform–methanol–ether in order to remove the fat, and the protein content was determined by the micro-method of Lowry3. Release of insulin into the incubation media, and the insulin content in the extracted islets, were determined by the immunoassay method of Herbert4, in which the separation of free insulin and insulin bound to antibody is achieved by “instant dialysis” with ‘Dextran 80’ coated charcoal. Some twenty islets from each animal were studied; two sets were incubated with 0.6 mg/ml. glucose in the two cycles (baseline), while another two were submitted to glucose stimulation (3.0 mg/ml.) in the second cycle.

Pulmonary circulatory dynamics of hypercapnia, with reference to clinical and experimental study on its effect on cardiac output

The accumulation of carbon dioxide in the blood has often been observed in the patients with severe pulmonary disease. In these circumstances, an increased carbon dioxide might influence on the brain as well as heart and consequently cause oxygen deficiency in the brain associated with reduced cardiac out-put. The present studies were designed to test the pulmonary circulatory dynamics under the condition of acute induced hypercapnia in human subjects with pulmonary disease. On the other hand in animal experiment, the animals were examined under two times con-trolled hyperventilation than resting ventilation using a body respirator where their pulmonary circulatory dynamics were not influenced by the change of respiratory pattern. Method s 1) In human subjects Twenty patients with chronic obstructive pulmonary disease were examined for the pulmonary circulatory dynamics at 20 to 40 minutes after inhalation of 4.5 per cent of carbon dioxide. 2) In experimental animal Five healthy dogs were tested under two times controlled hyperventilation with air (hypocapnia), breathing 4 per cent of carbon dioxide (isocapnia), and 10 per cent of carbon dioxide (hypercapnia) in a body respirator of our design. Results A) In human subjects 1) There were no marked change in the wedge pressure of pulmonary artery by breath-ing 4.5 per cent of carbon dioxide with the exception of 3 cases. The mean pressure of pulmonary artery slightly increased from 17.1 to 19.2 mmHg, however, no cases rose as high as above threshold value of 40 mmHg. The pressure of the right ventricle increased in 18 patients, and inthe remaining 2 cases the pressure was unchanged. The mean value of end-diastolic pressure was increased by 2.8mmHg. 2) Before inhalation, the mean cardiac index of these patients was slightly higher than that of normal subjects, the average value being 4.05 l/min/m2. After inhalation, 12 of 19 patients showed decreased values. Almost all decreased cases already had hypercapnia before inhalation, otherwise showed hypercapnia after inhalation and a rise in end-diastolic pressure of the right ventricle was observed.

Changes in rhesus monkey amniotic fluid pH, pCO2, and bicarbonate concentration following maternal and fetal hypercarbia and fetal death in utero

Amniotic fluid pH, pCO2, and bicarbonate concentrations are reported in pregnant rhesus monkeys during periods of fetal distress secondary to: (1) maternal inhalation of 10 per cent carbon dioxide; (2) premature separation of the placenta; (3) prolonged intrauterine surgery; and (4) following fetal death in utero. Elevations in fetal plasma carbon dioxide tensions, secondary to stress situations, were quickly followed by a corresponding increase in pCO2 of amniotic fluid, and a decrease in its pH. Although fetal plasma bicarbonate concentrations decreased during periods of stress, similar changes in amniotic fluid bicarbonate were not observed. Fetal death in utero was accompanied by an increase in amniotic fluid pCO2 and a decrease in amniotic fluid bicarbonate concentration and pH.