scholarly journals Evaluation of a fully automated end-tidal carbon monoxide instrument for breath analysis

1996 ◽  
Vol 42 (1) ◽  
pp. 50-56 ◽  
Author(s):  
H J Vreman ◽  
L M Baxter ◽  
R T Stone ◽  
D K Stevenson
Keyword(s):  
Carbon Monoxide ◽  
Sampling Efficiency ◽  
Excellent Correlation ◽  
Breath Sampling ◽  
Total Hemoglobin ◽  
In Vivo Tests ◽  
Term Newborns ◽  
The Mean ◽  
End Tidal

Abstract We evaluated a novel, portable breath sampler/CO-quantifying instrument [Baby's Breath Carbon Monoxide Analyzer (BB); Natus Medical], developed for use at the bedside or with gas samples collected into bags. Bench tests demonstrated that the CO measurements were linear, accurate, and precise when compared with gas chromatography (GC) results. In vivo tests (n = 30) performed with adults showed excellent correlation between end-tidal breath CO measurements (ETCO) corrected for inhaled CO (ETCOc) as determined by BB and GC. Breath sampling efficiency was 96%. ETCOc measurements and blood carboxyhemoglobin fractions (% of total hemoglobin) corrected for inhaled CO (COHbc) correlated strongly: COHbc = 0.25 ETCOc--0.01 microL/L CO (r2 = 0.97, Sy/x = 0.47, SE slope = 0.01, n = 30). The imprecision, assessed by the mean of the population's CV for triplicate determinations, was 11%. Measurements with healthy and hemolytic term newborns showed that ETCOc values of > 3 microL/L correlated with known hemolytic conditions. We conclude that this instrument is clinically reliable and can be used to noninvasively measure ETCO in neonates and adults.

scholarly journals Baseline Sensitivities of Venturia inaequalis Populations to the Strobilurin Fungicide Kresoxim-methyl

Plant Disease ◽  
1999 ◽  
Vol 83 (3) ◽  
pp. 274-278 ◽  
Author(s):  
Gilberto Olaya ◽  
Wolfram Köller
Keyword(s):  
Venturia Inaequalis ◽  
Resistance Development ◽  
Additional Tool ◽  
Apple Leaves ◽  
Scab Control ◽  
In Vivo Tests ◽  
Strobilurin Fungicide ◽  
The Mean

The efficacies of the new strobilurin fungicide kresoxim-methyl for the protection of apple leaves from infection by baseline populations of Venturia inaequalis were uniform across five major apple growing regions in North America. The mean ED50 value determined for 25 populations was 0.35 μg ml-1, with values ranging from 0.11 μg ml-1 to 0.75 μg ml-1. The mean level of scab control achieved at the kresoxim-methyl dose of 4 μg ml-1 was 93%. For one of the five orchards sampled in each region, kresoxim-methyl sensitivities of germinating conidia were determined. Sensitivities of 250 isolates were broadly distributed, with ED50 values ranging from 0.003 μg ml-1 to 0.14 μg ml-1 and a mean of 0.02 μg ml-1. This broad range of in vitro sensitivities was not reflected for the in vivo efficacy of kresoxim-methyl in the protection of apple leaves from scab infections. The discrepancy between in vivo and in vitro sensitivities implies that in vivo tests are more useful for the monitoring of kresoxim-methyl sensitivities of orchard populations. Because it can be expected that only isolates resistant under both test conditions will be prone to future selection, such isolates will contribute to increased frequencies of the least sensitive isolates described in this baseline study. Testing of in vitro isolate sensitivities will, therefore, provide an additional tool in the monitoring of kresoxim-methyl resistance development.

Alveolar carbon monoxide: A comparison of methods of measurement and a study of the effect of change in body posture

1988 ◽  
Vol 74 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Andrew J. T. Kirkham ◽  
Andrew R. Guyatt ◽  
Gordon Cumming
Keyword(s):  
Carbon Monoxide ◽  
Linear Models ◽  
Body Posture ◽  
Breath Hold ◽  
Erect Posture ◽  
Indirect Measures ◽  
The Mean ◽  
The Difference ◽  
End Tidal ◽  
Inspired Oxygen

1. We have compared rebreathing, breath-hold and mean alveolar methods of measuring alveolar carbon monoxide (CO), at levels similar to those found in smokers, as a preliminary to using them as indirect measures of carboxyhaemoglobin levels. In the present study alveolar CO levels were raised by rebreathing a 2% CO mixture. 2. Breath-hold CO was measured after breath-hold times of 0–35 s in 5 s increments. Using generalized linear models, the maximum value for breath-hold CO was estimated to occur at 23 s. Breath-hold CO after a 20 and 25 s breath-hold were similar to and significantly greater than those of less than 20 s or greater than 25 s. 3. As expired CO increased, the difference between breath-hold and mean alveolar CO became proportionally larger. On average, breath-hold CO was 24% larger than mean alveolar CO. 4. Rebreathing, breath-hold and mean alveolar CO were compared at four different inspired oxygen concentrations. Expired CO increased significantly with increasing oxygen for all three methods. At end-tidal oxygen levels of less than 25%, breath-hold and rebreathing CO were similar, however, the overall mean difference between the three methods was significant. 5. While rebreathing CO was unaffected by changes in ventilation/perfusion of the lung, induced by change in body posture, both breath-hold and mean alveolar CO showed a significant fall with change from the supine to erect posture. 6. We conclude that under normoxic conditions, rebreathing and breath-hold CO (20 or 25 s breath-hold) were similar, whereas the mean alveolar method produced significantly lower values, presumably due to lack of equilibration. Altering ventilation/perfusion of the lung caused no mean change in the measurement of rebreathing CO but did affect the other methods.

The partial pressure of carbon monoxide in human tissues calculated using a parallel capillary-tissue cylinder model

2018 ◽  
Vol 124 (3) ◽  
pp. 761-768 ◽  
Author(s):  
Ronald F. Coburn
Keyword(s):  
Carbon Monoxide ◽  
Heme Proteins ◽  
Toxic Effects ◽  
Human Tissues ◽  
Co Poisoning ◽  
Tissue Model ◽  
Future Studies ◽  
Cylinder Model ◽  
The Mean

Tissue PCOvalues have not been previously estimated under conditions where the blood carboxyhemoglobin % saturation ([COHb]) is at a normal level or increased. Tissue PCOvalues are not known for conditions when [COHb] is increased during CO therapy or during CO poisoning. Using a modified Krogh parallel capillary-tissue model, mean tissue PCOwas calculated for when [COHb] was 1, 5, 10, and 15% saturation, relevant to CO therapy, and 20, 30, and 40% saturation, relevant to CO poisoning. Calculations were made for the time during which CO was being inhaled, after cessation of CO uptake, and for different O2extractions from blood flowing in the model capillary. The T1/2of relevant CO reactions was used in these calculations. When the [COHb] increased to 5 to 10% saturation, mean tissue PCOvalues increased to 500 to 1,100% of values when the [COHb] was 1% saturation. When the [COHb] increased to 20 to 40% saturation, mean tissue PCOvalues increased to 2,300 to 5,700% of the 1% saturation value. Results indicate the utility of the modified Krogh model in furthering understanding the physiology of determinants of tissue PCOand should facilitate future studies of in vivo CO binding to different extravascular heme proteins during CO therapy and during CO poisoning.NEW & NOTEWORTHY Tissue PCOlevels resulting from carboxyhemoglobin concentrations achieved during CO therapy or during CO poisoning have not been previously estimated. Results published here show that at carboxyhemoglobin levels achieved during CO therapy there are 500 to 1,100% increases in mean tissue PCOvalues. With carboxyhemoglobin increases associated with toxic effects, there are 2,300 to 5,700% increases in the mean tissue PCO. These differences suggest a basis for understanding the therapeutic and toxic effects of CO.

scholarly journals Elevated End-Tidal Carbon Monoxide Concentration in Children with Sickle Cell Anemia

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1390-1390
Author(s):  
Ashutosh Lal ◽  
Kristen Yen ◽  
Lasandra Patterson ◽  
Alisa Goldrich ◽  
Anne M Marsh ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Young Children ◽  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Second Hand Smoke ◽  
Control Group ◽  
Exhaled Breath ◽  
Healthy Children ◽  
The Mean ◽  
End Tidal

Abstract Background: Carbon monoxide (CO) produced during oxygen-dependent cleavage of porphyrin ring of heme is excreted in exhaled breath. The catabolism of heme is increased when red blood cells are destroyed at an accelerated rate. Thus, quantifying CO in exhaled breath could serve as an indicator of hemolysis. However, the requirement for forced breath sample has limited the measurement of exhaled CO in young children. Objective: To assess end-tidal CO concentration (ETCOc) in children with sickle cell anemia (SCA). Design/Methods: ETCOc was measured using the CoSense ETCO Monitor (Capnia Inc. Palo Alto, CA). Children between 5-14 years with SCA (Hb SS) who were not on chronic transfusions were eligible. Healthy children served as age-matched controls. Children with exposure to second-hand smoke, acute respiratory infection or symptomatic asthma were excluded. End-tidal breath samples were collected by placing the tip of a nasal cannula 5 mm into the nares. Up to 3 measurements were taken for each subject and the highest ETCOc value was used for analysis. (ClinicalTrials.gov: NCT01848691) Results: The mean (range) age of 16 children with SCA and 16 controls was 9.7 years (5-14 years) and 9.9 years (5-14 years), respectively. The mean (± s.d.) ETCOc for SCA was 4.85 ± 2.24 ppm versus 0.96 ± 0.54 ppm for control group (p<0.001). The ETCOc in the control group ranged from 0.2 to 2.3 ppm, but was ≤1.2 ppm in 14/16, which is suggested as the upper limit of normal for healthy children. In the SCA group, the ETCOc range was 1.8 to 9.7 ppm, with values ≥2.4 ppm in 15/16 subjects. A threshold ETCOc value of >2.1 ppm provided both sensitivity and specificity equal to 93.8% (69.8-99.8%) for distinguishing SCA from healthy children. Children with SCA who had higher absolute reticulocyte count also demonstrated higher ETCOc (r=0.62, p=0.011). Patients with severe anemia (hemoglobin <8 g/dL) had a higher mean ETCOc (5.43 ppm) than the rest (4.40 ppm) but the difference was not significant. ETCOc level tended to increase with age in SCA (r=0.45, p=0.08). Conclusions: Carbon monoxide in exhaled breath can be measured in young children in the clinic using a portable monitor. ETCOc may be a valuable tool for non-invasive monitoring of the severity of hemolysis in SCA. The mean ETCOc was 5-fold higher in SCA compared with controls, with little overlap seen between the groups. This suggests a potential use for ETCOc as a point-of-care screening test for SCA in children. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures Lal: Capnia, Inc: Research Funding. Yen:Capnia, Inc. : Employment. Bhatnagar:Capnia, Inc: Employment.

Chronic carbon monoxide inhalation during pregnancy augments uterine artery blood flow and uteroplacental vascular growth in mice

2013 ◽  
Vol 305 (8) ◽  
pp. R939-R948 ◽  
Author(s):  
Carolina C. Venditti ◽  
Richard Casselman ◽  
Malia S. Q. Murphy ◽  
S. Lee Adamson ◽  
John G. Sled ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Blood Flow ◽  
Uterine Artery ◽  
Subsequent Development ◽  
Artery Blood Flow ◽  
Vascular Effects ◽  
Smoking During Pregnancy ◽  
Vascular Growth ◽  
End Tidal

End-tidal breath carbon monoxide (CO) is abnormally low in women with preeclampsia (PE), while women smoking during pregnancy have shown an increase in CO levels and a 33% lower incidence of PE. This effect may be, in part, due to lowered sFLT1 plasma levels in smokers, and perhaps low-level CO inhalation can attenuate the development of PE in high-risk women. Our previous work showed maternal chronic CO exposure (<300 ppm) throughout gestation had no maternal or fetal deleterious effects in mice. Our current study evaluated the uteroplacental vascular effects in CD-1 maternal mice that inhaled CO (250 ppm) both chronically, gestation day (GD) 0.5 to 18.5, and acutely, 2.5 h on each of GD 10.5 and 14.5. We demonstrated, using microultrasound measurements of blood velocity and microcomputed tomography imaging of the uteroplacental vasculature, that chronic maternal exposure to CO doubled uterine artery blood flow and augmented uteroplacental vascular diameters and branching. This finding may be of benefit to women with PE, as they exhibit uteroplacental vascular compromise. The ratio of VEGF protein to its FLT1 receptor was increased in the placenta, suggesting a shift to a more angiogenic state; however, maternal circulating levels of VEGF, sFLT1, and their ratio were not significantly changed. Doppler blood velocities in the maternal uterine artery and fetal umbilical artery and vein were unaltered. This study provides in vivo evidence that chronic inhalation of 250 ppm CO throughout gestation augments uterine blood flow and uteroplacental vascular growth, changes that may protect against the subsequent development of preeclampsia.

Comparison of Amsorb®, Sodalime, and Baralyme®Degradation of Volatile Anesthetics and Formation of Carbon Monoxide and Compound A in Swine In Vivo 

2002 ◽  
Vol 96 (1) ◽  
pp. 173-182 ◽  
Author(s):  
Evan D. Kharasch ◽  
Karen M. Powers ◽  
Alan A. Artru
Keyword(s):  
Carbon Monoxide ◽  
Volatile Anesthetic ◽  
Soda Lime ◽  
In Vivo Model ◽  
Inhalation Induction ◽  
Strong Base ◽  
Compound A ◽  
End Tidal

Background Consequences of volatile anesthetic degradation by carbon dioxide absorbents that contain strong base include formation of compound A from sevoflurane, formation of carbon monoxide (CO) and CO toxicity from desflurane, enflurane and isoflurane, delayed inhalation induction, and increased anesthetic costs. Amsorb (Armstrong Ltd., Coleraine, Northern Ireland) is a new absorbent that does not contain strong base and does not form CO or compound A in vitro. This investigation compared Amsorb, Baralyme (Chemetron Medical Division, Allied Healthcare Products, St. Louis, MO), and sodalime effects on CO (from desflurane and isoflurane) and compound A formation, carboxyhemoglobin (COHb) concentrations, and anesthetic degradation in a clinically relevant porcine in vivo model. Methods Pigs were anesthetized with desflurane, isoflurane, or sevoflurane, using fresh or partially dehydrated Amsorb, Baralyme, and new and old formulations of sodalime. Anesthetic concentrations in the fresh (preabsorber), inspired (postabsorber), and end-tidal gas were measured, as were inspired CO and compound A concentrations and blood oxyhemoglobin and COHb concentrations. Results For desflurane and isoflurane, the order of inspired CO and COHb formation was dehydrated Baralyme &gt; soda-lime &gt; Amsorb. For desflurane and Baralyme, peak CO was 9,700 +/- 5,100 parts per million (ppm), and the increase in COHb was 37 +/- 14%. CO and COHb increases were undetectable with Amsorb. Oxyhemoglobin desaturation occurred with desflurane and Baralyme but not Amsorb or sodalime. The gap between inspired and end-tidal desflurane and isoflurane did not differ between the various dehydrated absorbents. Neither fresh nor dehydrated Amsorb caused compound A formation from sevoflurane. In contrast, Baralyme and sodalime caused 20-40 ppm compound A. The gap between inspired and end-tidal sevoflurane did not differ between fresh absorbents, but was Amsorb &lt; sodalime &lt; Baralyme with dehydrated absorbents. Conclusion Amsorb caused minimal if any CO formation, minimal compound A formation regardless of absorbent hydration, and the least amount of sevoflurane degradation. An absorbent like Amsorb, which does not contain strong base or cause anesthetic degradation and formation of toxic products, may have benefit with respect to patient safety, inhalation induction, and anesthetic consumption (cost).

Bioactivity Responses of Different Uhmwpe Particles from In-Vivo and In-Vitro Tests

2000 ◽  
Vol 662 ◽  
Author(s):  
YoungSoo Park ◽  
ShangYou Yang ◽  
Paul H. Wooley ◽  
Katharine Merritt ◽  
Stephen Hsu ◽  
...  
Keyword(s):  
The Other ◽  
In Vitro Tests ◽  
Textured Surfaces ◽  
Aspect Ratios ◽  
In Vivo Tests ◽  
The Mean ◽  
Particle Size And Shape ◽  
Ultra High Molecular Weight

AbstractThis paper describes the results of bioactivity responses to different ultra high molecular weight polyethylene (UHMWPE) particles. Particles were produced by a wear tester using two different textures of steel counters, one with cross-hatched and the other with uni-hatched grooves. These two textured surfaces produced two distinct populations of wear particles. One is larger and more elongated (fibril shapes) than the other. The mean sizes and aspect ratios of the particles are in the ranges of 5 μm to 25 μm and about 1.5 to 3, respectively. These two distinct UHMWPE particles were examined through in-vitro and in-vivo tests. Macrophages RAW 264.7 and the murine air-pouch model of inflammation were employed to characterize the effect of the particle size and shape. Preliminary in-vivo tests results showed that more elongated and larger particles enhanced bio-reactions.

Effects of NO-Donors on Thrombus Formation and Microcirculation in Cerebral Vessels of the Rat

1996 ◽  
Vol 76 (01) ◽  
pp. 111-117 ◽  
Author(s):  
Yasuto Sasaki ◽  
Junji Seki ◽  
John C Giddings ◽  
Junichiro Yamamoto
Keyword(s):  
Blood Flow ◽  
Thrombus Formation ◽  
Dependent Manner ◽  
Red Cell ◽  
Cell Velocity ◽  
Red Cell Velocity ◽  
The Mean ◽  
Wall Shear ◽  
Dose Dependent

SummarySodium nitroprusside (SNP) and 3-morpholinosydnonimine (SIN-1), are known to liberate nitric oxide (NO). In this study the effects of SNP and SIN-1 on thrombus formation in rat cerebral arterioles and venules in vivo were assessed using a helium-neon (He-Ne) laser. SNP infused at doses from 10 Μg/kg/h significantly inhibited thrombus formation in a dose dependent manner. This inhibition of thrombus formation was suppressed by methylene blue. SIN-1 at a dose of 100 Μg/kg/h also demonstrated a significant antithrombotic effect. Moreover, treatment with SNP increased vessel diameter in a dose dependent manner and enhanced the mean red cell velocity measured with a fiber-optic laser-Doppler anemometer microscope (FLDAM). Blood flow, calculated from the mean red cell velocity and vessel diameters was increased significantly during infusion. In contrast, mean wall shear rates in the arterioles and venules were not changed by SNP infusion. The results indicated that SNP and SIN-1 possessed potent antithrombotic activities, whilst SNP increased cerebral blood flow without changing wall shear rate. The findings suggest that the NO released by SNP and SIN-1 may be beneficial for the treatment and protection of cerebral infarction

Influence of Platelet Membrane Sialic Acid and Platelet-Associated IgG on Ageing and Sequestration of Blood Platelets in Baboons

1993 ◽  
Vol 70 (04) ◽  
pp. 676-680 ◽  
Author(s):  
H F Kotzé ◽  
V van Wyk ◽  
P N Badenhorst ◽  
A du P Heyns ◽  
J P Roodt ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Life Span ◽  
Blood Platelets ◽  
Senescent Cell ◽  
Platelet Membrane ◽  
Antigen Complex ◽  
The Mean ◽  
Aggregation Of Platelets

SummaryPlatelets were isolated from blood of baboons and treated with neuraminidase to remove platelet membrane sialic acid, a process which artificially ages the platelets. The platelets were then labelled with 111In and their mean life span, in vivo distribution and sites of Sequestration were measured. The effect of removal of sialic acid on the attachment of immunoglobulin to platelets were investigated and related to the Sequestration of the platelets by the spleen, liver, and bone marrow. Removal of sialic acid by neuraminidase did not affect the aggregation of platelets by agonists in vitro, nor their sites of Sequestration. The removal of 0.51 (median, range 0.01 to 2.10) nmol sialic acid/108 platelets shortened their life span by 75 h (median, range 0 to 132) h (n = 19, p <0.001), and there was an exponential correlation between the shortening of the mean platelet life span and the amount of sialic acid removed. The increase in platelet-associated IgG was 0.112 (median, range 0.007 to 0.309) fg/platelet (n = 25, p <0.001) after 0.79 (median, range 0.00 to 6.70) nmol sialic acid/108 platelets was removed (p <0.001). There was an exponential correlation between the shortening of mean platelet life span after the removal of sialic acid and the increase in platelet-associated IgG. The results suggest that platelet membrane sialic acid influences ageing of circulating platelets, and that the loss of sialic acid may have exposed a senescent cell antigen that binds IgG on the platelet membrane. The antibody-antigen complex may then provide a signal to the macrophages that the platelet is old, and can be phagocytosed and destroyed.

Antitumor Effect of Zwitterions of Imidazolium Derived from L-methionine in BALB/c Mice with Lymphoma L5178Y

2020 ◽  
Vol 17 (1) ◽  
pp. 33-39
Author(s):  
Karen C. Vargas-Castro ◽  
Ana M. Puebla Pérez ◽  
Irma I. Rangel-Salas ◽  
Jorge I. Delgado-Saucedo ◽  
José B. Pelayo-Vázquez ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Antitumor Activity ◽  
Antitumor Agent ◽  
Inhibitory Effect ◽  
Stabilizing Agent ◽  
Biological Compatibility ◽  
In Vivo Tests ◽  
Antitumoral Agent ◽  
Group 1

Background: In the therapy of cancer, several treatments have been designed using nanomaterials, among which gold nanoparticles (AuNPs) have been featured as a promising antitumoral agent. Our research group has developed the synthesis of gold nanoparticles L-AuNPs and D-AuNPs stabilized with zwitterions of imidazolium (L-1 and D-1) derived from L-methionine and D-methionine. Because the stabilizer agent is chiral, we observed through circular dichroism that AuNPs also present chirality; such chirality as well as the fact that the stabilizing agent contains fragments of methionine and imidazolium that are commonly involved in biological processes, opens up the possibility that this system may have biological compatibility. Additionally, the presence of methionine in the stabilizing agent opens the application of this system as a possible antitumor agent because methionine is involved in methylation processes of molecules such as DNA. Objective: The aim of this research is the evaluation of the antitumor activity of gold nanoparticles stabilized with zwitterions of imidazolium (L-AuNPs) derived from L-methionine in the model of BALB/c mice with lymphoma L5178Y. Methods: Taking as a parameter cell density, the evaluation of the inhibitory effect of L-AuNPs was carried out with a series of in vivo tests in BALB/c type mice; three groups of five mice each were formed (Groups 1, 2 and 3); all mice were i.p. inoculated with the lymphoblast murine L5178Y. Group 1 consisted of mice without treatment. In the Groups 2 and 3 the mice were treated with L-AuNPs at 0.3 mg/Kg on days 1, 7 and 14 by orally and intraperitonally respectively. Results: These results show low antitumor activity of these gold nanoparticles (L-NPsAu) but interestingly, the imidazolium stabilizing agent of gold nanoparticle (L-1) displayed promising antitumor activity. On the other hand, the enantiomer of L-1, (D-1) as well as asymmetric imidazole derivate from L-methionine (L-2), do not exhibit the same activity as L-1. Conclusion: The imidazolium stabilizing agent (L-1) displayed promising antitumor activity. Modifications in the structure of L-1 showed that, the stereochemistry (like D-1) and the presence of methionine fragments (like L-2) are determinants in the antitumor activity of this compound.

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