Academic literature on the topic '13CO2 breath test'
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Journal articles on the topic "13CO2 breath test"
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SUEHIRO, Makiko, Akira KURODA, Masahiro MAEDA, Kou HINAGA, and Hiroyuki WATANABE. "Automated 13CO2 analyzing system for the 13C breath test." RADIOISOTOPES 36, no. 1 (1987): 7–13. http://dx.doi.org/10.3769/radioisotopes.36.7.
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Fourie, J., L. K. Mattison, T. E. Wood, J. A. Posey, A. Modak, and R. B. Diasio. "The 2-13C-5-fluorouracil breath test (FUBT) as a novel, rapid method for assessment of dihydropyrimidine dehydrogenase (DPD) activity in cancer patients: Initial characterization and comparison to the 2-13C-uracil breath test (UraBT)." Journal of Clinical Oncology 25, no. 18_suppl (June 20, 2007): 2551. http://dx.doi.org/10.1200/jco.2007.25.18_suppl.2551.
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2551 Background: The UraBT is currently in development as a phenotypic test to screen for DPD deficiency. Following an oral dose of 2-13C-uracil, the UraBT shows a significant relationship between breath 13CO2 metabolite formation and plasma 2-13C-uracil and 2-13C-dihydrouracil pharmacokinetics. We herein describe a novel, potentially more clinically relevant test in which a small oral dose of 2-13C-5-fluorouracil (5-FU) is administered, followed by assessment of breath 13CO2 metabolite formation as previously described for the UraBT. We hypothesize that the FUBT can rapidly assess interindividual variability in 5-FU catabolism and predisposition to 5-FU toxicity. Methods: Over two sessions separated by a seven day washout, a single dose (6mg/kg, p.o.) of 2-13C-uracil or 2-13C-5-FU was administered to patients with stage III-IV colorectal cancer (n = 4). Subsequent to drug administration, in each session, 13CO2 catabolite formation was quantified in the breath over eight hours. In a separate investigation over two sessions separated by a seven day washout, a single dose (3mg/kg, p.o.) of 2-13C-uracil or 213C-5-FU was administered to colorectal cancer patients with previously documented severe (n=2) or moderate (n=2) 5-FU dose-related hematological/gastrointestinal toxicity. Following drug administration 13CO2 catabolite formation was quantified over eight hours. 13CO2 concentration was expressed as Delta Over Baseline (DOB) in all sessions. Results: Compared to the UraBT, the FUBT showed an increased Cmax (50.7 ± 6.6 DOB/mg vs. 36.8 ± 7.8 DOB/mg; mean ± SD) and decreased Tmax (25 ± 4 min vs. 45 ± 6 min) for 13CO2 formation (p<0.05). The FUBT was able to distinguish patients with previously reported severe and moderate 5- FU toxicity, with 13CO2 Cmax values of 35.5 ± 9.5 DOB/mg (mean ± SD) and 59.8 ± 7.3 DOB/mg, respectively. Importantly, FUBT Cmax values positively correlated with DPD activity (rs=1.00, p<0.01). Conclusions: These data lend support to further development of the FUBT as a rapid and informative test to assess DPD activity and to predict susceptibility to severe dose-related 5-FU toxicity. [CA116964] No significant financial relationships to disclose.
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Murphy, M. S., E. J. Eastham, R. Nelson, and A. Aynsley-Green. "Non-invasive assessment of intraluminal lipolysis using a 13CO2 breath test." Archives of Disease in Childhood 65, no. 6 (June 1, 1990): 574–78. http://dx.doi.org/10.1136/adc.65.6.574.
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Roecker, K., E. Landaw, H. Striegel, F. Mayer, and H. H. Dickhuth. "First-pass effect of an intravenous bolus of [13C]bicarbonate displayed breath-by-breath." Journal of Applied Physiology 90, no. 6 (June 1, 2001): 2181–87. http://dx.doi.org/10.1152/jappl.2001.90.6.2181.
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The dilution of an intravenous bolus dose of [13C]bicarbonate is used as an estimate for the metabolic rate under certain conditions. It is a consistent finding in all studies that the total amount of intravenous [13C]bicarbonate cannot be recovered as breath 13CO2. In this study, we used a breath-by-breath analysis of 13CO2 to depict the washout of 13CO2 at a high temporal resolution to analyze the extent to which a probable first-pass effect is responsible for the reduced recovery. Eight healthy men were tested at seated rest and with bicycle exercise at a constant load relative to 40 and 75% maximal O2 consumption (V˙o 2 max). [13C]bicarbonate (0.0125 g/kg body wt) was administered as an intravenous bolus in each test. Respiratory mass spectrometry was used to derive the course of the end-tidal13CO2-to-12CO2 ratio from the breath-by-breath data. Approximately 2 min after13C administration, the washout curve could be fitted well by a two-exponential curve describing a two-compartment mammillary model. Immediately after administration of the bolus dose, an excess peak in the end-tidal13CO2-to-12CO2 ratio appeared. This peak could not be included in the two-exponential fitting. The area under the first peak resulted in 3.8 ± 1.3% of the total [13C]bicarbonate dose at rest, 11.5 ± 2.9% at moderate exercise (40%V˙o 2 max), and 16.9 ± 4.0% at intensive exercise (75% V˙o 2 max). The first-pass effect had an increasing impact of up to about two-thirds of the lacking bicarbonate with higher exercise intensity. The “loss” of tracer via this first-pass effect must be considered when the results of studies with parenteral administration of [13C]bicarbonate are considered, especially when it is given as a bolus dose and during exercise.
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Ventrucci, M., A. Cipolla, G. M. Ubalducci, A. Roda, and E. Roda. "13C labelled cholesteryl octanoate breath test for assessing pancreatic exocrine insufficiency." Gut 42, no. 1 (January 1, 1998): 81–87. http://dx.doi.org/10.1136/gut.42.1.81.
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Background—A non-invasive test for assessment of fat digestion has been developed based on the intraluminal hydrolysis of cholesteryl-[1-13C]octanoate by pancreatic esterase.Aims—To determine the diagnostic performance of this breath test in the assessment of exocrine pancreatic function.Methods—The test was performed in 20 healthy controls, 22 patients with chronic pancreatic disease (CPD), four with biliopancreatic diversion (BPD), and 32 with non-pancreatic digestive diseases (NPD); results were compared with those of other tubeless tests (faecal chymotrypsin and fluorescein dilaurate test).Results—Hourly recoveries of13CO2 were significantly lower in CPD when compared with healthy controls or NPD. In patients with CPD with mild to moderate insufficiency, the curve of 13CO2recovery was similar to that of healthy controls, while in those with severe insufficiency it was flat. In three patients with CPD with severe steatorrhoea, a repeat test after pancreatic enzyme supplementation showed a significant rise in13CO2 recovery. The four BPD patients had low and delayed 13CO2 recovery. Only eight of the 32 patients with NPD had abnormal breath test results. There was a significant correlation between the results of the breath test and those of faecal chymotrypsin, the fluorescein dilaurate test, and faecal fat measurements. For the diagnosis of pancreatic disease using the three hour cumulative 13CO2 recovery test, the sensitivity was 68.2% and specificity 75.0%; values were similar to those of the other two tubeless pancreatic function tests. In seven healthy controls, nine patients with CPD, and nine with NPD a second breath test was performed using Na-[1-13C]octanoate and a pancreatic function index was calculated as the ratio of13C recovery obtained in the two tests: at three hours this index was abnormal in eight patients with CPD and in three with NPD.Conclusion—The cholesteryl-[1-13C]octanoate breath test can be useful for the diagnosis of fat malabsorption and exocrine pancreatic insufficiency.
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Ishii, Yukimoto, Satoshi Asai, Tadashi Kohno, Shigeru Suzuki, Munehiro Ishii, Isaburou Hosoi, Masashi Fujii, Shigetomi Iwai, and Koichi Ishikawa. "13CO2 Peak Value of l-[1-13C]phenylalanine Breath Test Reflects Hepatopathy." Journal of Surgical Research 86, no. 1 (September 1999): 130–35. http://dx.doi.org/10.1006/jsre.1999.5705.
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Cimmino, M., F. Mion, F. Goglia, Y. Minaire, and A. Géloën. "Demonstration of in vivo metabolic effects of 3,5-di-iodothyronine." Journal of Endocrinology 149, no. 2 (May 1996): 319–25. http://dx.doi.org/10.1677/joe.0.1490319.
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Abstract The objective of the present study was to test in vivo the metabolic effects of 3,5-di-iodothyronine (3,5-T2) in unanesthetized and unrestrained male Sprague–Dawley rats. Amino acid and lipid metabolisms were investigated by breath tests using as tracers the 13C-carboxyl-labeled molecules of leucine, α-ketoisocaproic acid (KIC) and octanoic acid, in four different groups of rats: hypothyroid animals (receiving propylthiouracil (PTU) and iopanoic acid), hypothyroid animals treated with either a daily i.p. injection of 3,5-T2 (25 μg/100 g body weight), or triiodothyronine (T3) (1 μg/100 g body weight), and control euthyroid animals receiving equivalent volumes of the vehicle solutions. Energy expenditure was measured by continuous monitoring of O2 consumption and CO2 production in these different groups. Daily energy expenditure was decreased by 30% in PTU-treated rats. The chronic treatments with 3,5-T2 and T3 restored daily energy expenditure to the control level. 13CO2 recovered in breath following the i.v. injection of octanoic acid-[1-13C] was decreased in hypothyroid animals compared with control animals (P<0·05) and restored to control values by T3 and 3,5-T2 treatments. The 13CO2 recovered in breath after i.v. injection of leucine-[1-13C]was increased in PTU-treated compared with control animals (P<0·05). Chronic treatment with either 3,5-T2 or T3 restored 13CO2 to control values. Excretion of 13CO2 recovered in breath following the i.v. injection of KIC-[1-13C] was increased in PTU-treated compared with control animals. Chronic treatments with either 3,5-T2 or T3 did not restore KIC decarboxylation. These results suggest that 3,5-T2 exerts metabolic effects on energy expendi ture, on both lipid β-oxidation and leucine metabolism in hypothyroid rats. We conclude that 3,5-T2 is a metabolically active iodothyronine. Journal of Endocrinology (1996) 149, 319–325
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Turki, Abrar, Sylvia Stockler, Sandra Sirrs, Ramona Salvarinova, and Rajavel Elango. "Development of Minimally Invasive 13C-Glucose Breath Test to Examine Different Dietary Therapies in Patients with Glycogen Storage Disorders." Current Developments in Nutrition 4, Supplement_2 (May 29, 2020): 1149. http://dx.doi.org/10.1093/cdn/nzaa055_034.
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Abstract Objectives The objectives of the current study were: 1) to establish the use of ,13C-Glucose Breath Test (,13C-GBT) and its oxidation to ,13CO2 as a minimally invasive technique to examine in vivo glucose oxidation in healthy adults, and 2) to measure the utilization of uncooked cornstarch (UCCS) and Glycosade® in patients with glycogen storage disease type Ia (GSD-Ia) and healthy controls using ,13C-GBT, based on the natural enrichment of ,13C in UCCS and Glycosade®. Methods Experiment 1- Ten healthy adults (22 – 33y) underwent ,13C-GBT protocols twice as a proof-of-principle, once without oral isotope dose (only D-glucose 75 g/d) and once with isotope (D-glucose 75 g/d + U-,13C-glucose 75 mg/d). Breath samples were collected at baseline and every 20 min for 240 min to measure ,13CO2. Experiment 2- Two patients (12 and 28y) with GSD-Ia and five healthy controls (10 – 32y) underwent ,13C-GBT protocols twice. Subjects received UCCS or Glycosade® orally (based on their current prescribed dose 42 – 100 g) after a 4 hour fast according to GSD-Ia fasting tolerance. Breath samples were collected at baseline and every 30 min for 240 min. ,13CO2 oxidation of glucose from UCCS and Glycosade® were measured using an isotope ratio mass spectrometer and compared using a paired t-test. Blood glucose was measured using a glucometer hourly to test hypoglycemia (≤3.4 mmol/L). Results Results 1- The mean rate of ,13CO2 in all healthy adults from D-glucose without U-,13C-glucose 0.435 ± 0.162 was significantly lower than the mean rate of ,13CO2 in the same group with U-,13C-glucose 3.518 ± 0.988. The peak occurred at 200 minutes in all healthy adults without and with U-,13C-glucose. Results 2- Glucose oxidation from Glycosade® was lower than glucose oxidation from UCCS in the 12y GSD-Ia. Glucose oxidation from UCCS and Glycosade® remained the same in the 28y GSD-Ia. However, oxidation of glucose by the 28y GSD-Ia for both starches displayed a higher rate, compared to age matched controls. Conclusions Our results show that the minimally invasive,13C-GBT test over 4 hours can be useful to examine glucose metabolism from various exogenous carbohydrate sources in GSD. Future studies are needed to use ,13C-GBT in response to different doses to determine optimal glucose management in GSD patients. Funding Sources Saudi Arabian Cultural Bureau, Ottawa and BC Children's Hospital Research Institute.
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Zanconato, S., D. M. Cooper, T. J. Barstow, and E. Landaw. "13CO2 washout dynamics during intermittent exercise in children and adults." Journal of Applied Physiology 73, no. 6 (December 1, 1992): 2476–82. http://dx.doi.org/10.1152/jappl.1992.73.6.2476.
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To test the hypothesis that children store less CO2 than adults during exercise, we measured breath 13CO2 washout dynamics after oral bolus of [13C]bicarbonate in nine children [8 +/- 1 (SD) yr, 4 boys] and nine (28 +/- 6 yr, 5 males) adults. Gas exchange [O2 uptake and CO2 production (Vco2)] was measured breath by breath during rest and during light (80% of the anaerobic threshold) intermittent exercise. Breath samples were obtained for subsequent analysis of 13CO2 by isotope ratio mass spectrometry. The tracer estimate of Vco2 was highly correlated to Vco2 measured by gas exchange (r = 0.97, P < 0.0001). The mean residence time was shorter in children (50 +/- 5 min) compared with adults (69 +/- 7 min, P < 0.0001) at rest and during exercise (children, 35 +/- 7 min; adults, 50 +/- 11 min, P < 0.001). The estimate of stored CO2 (using mean Vco2 measured by gas exchange and mean residence time derived from tracer washout) was not statistically different at rest between children (254 +/- 36 ml/kg) and adults (232 +/- 37 ml/kg). During exercise, CO2 stores in the adults (304 +/- 46 ml/kg) were significantly increased over rest (P < 0.001), but there was no increase in children (mean exercise value, 254 +/- 38 ml/kg). These data support the hypothesis that CO2 distribution in response to exercise changes during the growth period.
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Tugtekin, I., U. Wachter, E. Barth, H. Weidenbach, D. A. Wagner, G. Adler, M. Georgieff, P. Radermacher, and J. A. Vogt. "Phenylalanine kinetics in healthy volunteers and liver cirrhotics: implications for the phenylalanine breath test." American Journal of Physiology-Endocrinology and Metabolism 283, no. 6 (December 1, 2002): E1223—E1231. http://dx.doi.org/10.1152/ajpendo.0311.2001.
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Expired 13CO2recovery from an oral l-[1-13C]phenylalanine ([13C]Phe) dose has been used to quantify liver function. This parameter, however, does not depend solely on liver function but also on total CO2 production, Phe turnover, and initial tracer distribution. Therefore, we evaluated the impact of these factors on breath test values. Nine ethyl-toxic cirrhotic patients and nine control subjects received intravenously 2 mg/kg of [13C]Phe, and breath and blood samples were collected over 4 h. CO2 production was measured by indirect calorimetry. The exhaled 13CO2 enrichments were analyzed by isotope ratio mass spectrometry and the [13C]Phe and l-[1-13C]tyrosine enrichments by gas chromatography-mass spectrometry. The cumulative13CO2 recovery was significantly lower in cirrhotic patients (7 vs. 12%; P < 0.01), in part due to lower total CO2 production rates. Phe turnover in cirrhotic patients was significantly lower (33 vs. 44 μmol · kg−1 · h−1; P < 0.05). When these extrahepatic factors were considered in the calculation of the Phe oxidation rate, the intergroup differences were even more pronounced (3 vs. 7 μmol · kg−1 · h−1) than those for 13CO2 recovery data. Also, the Phe-to-Tyr conversion rate, another indicator of Phe oxidation, was significantly reduced (0.7 vs. 3.0 μmol · kg−1 · h−1).
Dissertations / Theses on the topic "13CO2 breath test"
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Matthews, Todd James. "Clinical analysis of liver function: development of a novel method for the detection of portosystemic shunts." Thesis, 2014. http://hdl.handle.net/2440/85509.
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A portosystemic shunt (PSS) is defined as a congenital or acquired abnormal blood vessel that redirects blood around the liver without being filtered through hepatic parenchyma. PSS are thought to contribute to the distribution of isolated secondary metastases beyond the liver in 1.7 - 7.2% of all colorectal cancer patients without cirrhosis of the liver. No standardised clinical test for PSS yet exists and subsequently, the majority of PSS cases are detected incidentally through radiological means. To better identify PSS, a simple standardised clinical test for its detection is needed. The aim of this thesis was to develop a cost effective, non-invasive technique that can detect and measure PSS in a healthy liver model. Methods An artificial 8mm diameter PSS was created between the portal vein and the inferior vena in a pig model with a catheter inserted in the confluence of the hepatic veins for sample collection. A spectrum of compounds including indocyanine green (ICG), ¹³C-methacetin, sorbitol and lignocaine, were injected into the portal system. To analyse the pharmacokinetic nature of the shunt and liver, Evans blue dye and ¹⁴C-sucrose were also administered. ICG was measured via a LiMON® spectrometer attached to the pig’s snout, while levels of the other indicators were measured by serial blood and breath sample collection over a 40 minute period. The process was repeated with the PSS clamped as the control. Results Of the administered compounds, only ICG had the potential to clearly identify and quantify the shunt due to the rapid serial sampling via the LiMON®. Further simulations using ICG demonstrated that the shunted fraction can be calculated using the transit times, including mean residence time, lag time and pharmacokinetic modelling. Conclusion Although this study has not yet provided a concise method for PSS detection available for immediate clinical use, it does provide a large foundation for further exploration into a quantitative technique. A future PSS test would allow an added risk assessment for secondary cancer, and consequently individual cancer therapy may be better targeted for individual patient care.Thesis (Ph.D.) -- University of Adelaide, School of Medicine, 2014
Books on the topic "13CO2 breath test"
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Merle, Olivier. A 13CO2 breath test for cytochrome P450 CYP3A based on tamoxifen N-demethylation. Leicester: De Montfort University, 1999.
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