Metabolic gas effect on phase III slopes of single-breath nitrogen tests

1982 ◽  
Vol 53 (3) ◽  
pp. 789-792 ◽  
Author(s):  
Y. Cormier ◽  
J. Belanger

This study was designed to estimate the relative contribution of gas exchange to the slope of phase III and the mean respiratory quotient (R) during this maneuver. With eight normal volunteers, we studied single-breath nitrogen tests and single-breath reversed tests (SB-N2, SB-R) without and with CO2 added to the test inspiration (SB-N2CO2, SB-RCO2). With an inspired CO2 of about 6% the slope of phase III in SB-N2 and SB-N2CO2 increased from 0.87 +/- 0.24 (mean +/- SD) to 1.03 +/- 0.21% N2.l-1 (P less than 0.01); however, in SB-R an SB-RCO2 the steepness of the slope of phase III decreased from 0.65 +/- 0.13% to 0.50 +/- 0.14% N2.l-1 (P less than 0.01). From these data we can calculate that gas exchange accounted for 13% of the slope of phase III in SB-N2 and SB-R. The mean R value during the slope of phase III for this effect was between 0.6 and 0.7. R was further decreased when CO2 was added, and its influence was increased to 26% of the slope of phase III.

1994 ◽  
Vol 76 (4) ◽  
pp. 1719-1729 ◽  
Author(s):  
H. J. Guy ◽  
G. K. Prisk ◽  
A. R. Elliott ◽  
R. A. Deutschman ◽  
J. B. West

Gravity is known to cause inhomogeneity of ventilation. Nongravitational factors are also recognized, but their relative contribution is not understood. We therefore studied ventilatory inhomogeneity during sustained microgravity during the 9-day flight of Spacelab SLS-1. All seven crew members performed single-breath nitrogen washouts. They inspired a vital capacity breath of 100% oxygen with a bolus of argon at the start of inspiration, and the inspiratory and expiratory flow rates were controlled at 0.5 l/s. Control measurements in normal gravity (1 G) were made pre- and postflight in the standing and supine position. Compared with the standing 1-G measurements, there was a marked decrease in ventilatory inhomogeneity during microgravity, as evidenced by the significant reductions in cardiogenic oscillations, slope of phase III, and height of phase IV for nitrogen and argon. However, argon phase IV volume was not reduced, and considerable ventilatory inhomogeneity remained. For example, the heights of the cardiogenic oscillations during microgravity for nitrogen and argon were 44 and 24%, respectively, of their values at 1 G, whereas the slopes of phase III for nitrogen and argon were 78 and 29%, respectively, of those at 1 G. The presence of a phase IV in microgravity is strong evidence that airway closure still occurs in the absence of gravity. The results were qualitatively similar to those found previously during short periods of 0 G in parabolic flight.


1981 ◽  
Vol 50 (3) ◽  
pp. 487-492 ◽  
Author(s):  
H. D. Van Liew ◽  
R. Arieli

Concentration of inert gas in the lung is lowered when CO2 entrance exceeds O2 exit and is raised when O2 exit predominates. In air-breathing subjects who expire to residual volume, this "metabolic gas effect" often causes a rising N2 concentration when in fact there should be a terminal fall because of low N2 in apical regions. In single-breath tests, we compared the dilution of resident N2 with dilution of an inspired gas, Ne, to find the "ideal" inert gas concentration (due only to mixing of resident gas with inspired gas). The displacement from the ideal concentration vs. volume pattern depends on the timing of the breath, because early CO2 entrance gives way later to O2 exit. Sometimes observed patterns are above or below but parallel to the ideal, and sometimes the observed slope of phase III is steeper than ideal for N2 and flatter than ideal for Ne. In addition to phase III distortions, the metabolic gas effect sometimes also distorts phase IV height and the intersection between phases III and IV. The distortions depend strongly on absolute concentration of the indicator gas in the lung, so they are very small when "closing volume" maneuvers are done in the conventional manner. However, distortions can be large and misleading when single-breath maneuvers are done in unconventional ways.


1993 ◽  
Vol 75 (2) ◽  
pp. 927-932 ◽  
Author(s):  
D. J. Cotton ◽  
M. B. Prabhu ◽  
J. T. Mink ◽  
B. L. Graham

In normal seated subjects we increased single-breath ventilation inhomogeneity by changing both the preinspiratory lung volume and breath-hold time and examined the ensuing effects on two different techniques of measuring the diffusing capacity of the lung for carbon monoxide (DLCO). We measured the mean single-breath DLCO using the three-equation method (DLCOSB-3EQ) and also measured DLCO over discrete intervals during exhalation by the "intrabreath" method (DLCOexhaled). We assessed the distribution of ventilation using the normalized phase III slope for helium (SN). DLCOSB-3EQ was unaffected by preinspiratory lung volume and breath-hold time. DLCOexhaled increased with increasing preinspiratory lung volume and decreased with increasing breath-hold time. These changes correlated with the simultaneously observed changes in ventilation inhomogeneity as measured by SN (P < 0.01). We conclude that measurements of DLCOexhaled do not accurately reflect the mean DLCO. Intrabreath methods of measuring DLCO are based on the slope of the exhaled CO concentration curve, which is affected by both ventilation and diffusion inhomogeneities. Although DLCOexhaled may theoretically provide information about the distribution of CO uptake, the concomitant effects of ventilation nonuniformity on DLCOexhaled may mimic or mask the effects of diffusion nonuniformity.


1966 ◽  
Vol 16 (01/02) ◽  
pp. 038-050 ◽  
Author(s):  
Ulla Hedner ◽  
Inga Marie Nilsson ◽  
B Robertson

SummaryThe plasminogen content was determined by a casein method in plasma and serum from 20 normal volunteers. The mean plasminogen content was found to be 10.1 ACU (the arbitrary caseinolytic unit defined in such a way that using a 3% casein solution and a digestion time of 20 min. at 37°C, 10 ACU gave an extinction of 0.300). No difference between serum and plasma regarding the plasminogen content was found.Plasminogen was determined in drained and drained plus washed clots prepared from 2 ml plasma. The highest values found in the drained clots were 0.9 ACU/clot and 0.2 ACU/clot in the drained plus washed clots.Plasminogen was also determined in drained and drained plus washed clots prepared from plasma with added purified plasminogen. The plasminogen was recovered in the washing fluid. According to these tests, then, purified added plasminogen is washed out of the clots.The plasminogen content of 20 thrombi obtained post mortem was also determined. The mean value was found to be 0.7 ACU/cm thrombus. Judging from our results, the “intrinsic clot lysis theory” is not the main mechanism of clot dissolution.


1987 ◽  
Vol 115 (2) ◽  
pp. 235-242 ◽  
Author(s):  
Y. Reznik ◽  
B. P. Winiger ◽  
M. L. Aubert ◽  
P. C. Sizonenko

Abstract. The disappearance rate of [D-Ser(t-bu)6,des-Gly10]GnRH ethylamide (Buserelin®, HOE 766) was studied in plasma and urine after intranasal (300 μg) or sc (10 μg/kg) administration. A radioimmunoassay for HOE 766 was developed using 125I[D-Trp6,Des-Gly10]GnRH ethylamide as tracer and an antiserum raised against HOE 766. Cross-reaction with native GnRH was only 1.7%. Sensitivity was 1 pg/tube. In 6 male adolescents, the mean plasma HOE 766 concentration (± sem) was 0.46 ± 0.08, 0.50 ± 0.10, 0.28 ± 0.04, 0.24 ± 0.04, 0.13 ± 0.03, and 0.08 ± 0.02 μg/l 30, 60, 90, 120 and 180 min after the intranasal administration, respectively. Concomitant urinary excretion of HOE 766-like material was 9.43 ± 1.96 μg/4 h. There was a good correlation between integrated plasma levels and urinary excretion (r = 0.92). In the same 6 volunteers, the plasma HOE 766 levels were 21.2 ± 3.0, 25.9 ± 0.8, 21.2 ± 0.9, 17.1 ± 0.7, 12.8 ± 1.1, 8.9 ± 0.4, and 5.9 ± 0.8 μg/l 20, 40, 60, 90, 120, 180 and 240 min after sc injection, respectively. The mean urinary excretion was 543 ± 61 μg/4 h. In two girls with precocious puberty treated during 12 to 15 months with intranasal administration of HOE 766, urinary excretion of HOE 766-like material was shown to correlate well with the degree of inhibition of plasma 17β-E2and of plasma LH and FSH responses to a GnRH challenge. Thus, monitoring of HOE 766 in urine appears to be helpful for evaluating of intranasal therapy with a GnRH analog in precocious puberty.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ho Hyun Ryu ◽  
Sei Hyun Ahn ◽  
Seon Ok Kim ◽  
Jeong Eun Kim ◽  
Ji sun Kim ◽  
...  

AbstractSurvival of breast cancer patients has improved, and treatment-related changes regarding metabolic profile deterioration after neoadjuvant systemic treatment (NST) become important issues in cancer survivors. We sought to compare metabolic profile changes and the neutrophil-to-lymphocyte ratio (NLR) between patients undergoing neoadjuvant chemotherapy (NCT) and neoadjuvant endocrine therapy (NET) 3 years after the treatment. In a prospective, randomized, phase III trial which compared 24 weeks of NCT with adriamycin and cyclophosphamide followed by docetaxel and NET with goserelin and tamoxifen (NEST), 123 patients in the Asan Medical Center were retrospectively reviewed to evaluate metabolic changes, such as body mass index (BMI), blood pressure (BP), total cholesterol (TC), fasting glucose, and the NLR. The mean age of patients was 42 years. The changes in BMI, serum glucose, and TC during NST and after 3 years were significantly different between NCT and NET. The proportion of overweight + obese group and the mean BMI were significantly increased during NCT (26.6% to 37.5%, 22.84 kg/m2 to 23.87 kg/m2, p < 0.05), and these attributes found to have normalized at the 3-year follow-up. In the NET group, BMI changes were not observed (p > 0.05, all). There were no differences in changes over time among in the Hypertension group during NCT and NET (p = 0.96). The mean value of serum TC and fasting glucose significantly increased (< 0.05, both) during NCT and decreased 3 years after NCT (p < 0.05); however, no significant changes were observed in the NET group. The NLR was increased from 1.83 to 3.18 after NCT (p < 0.05) and decreased from 1.98 to 1.43 (p < 0.05) after NET. Compared with minimal metabolic effect of NET, NCT worsens metabolic profiles, which were recovered over 3 years. The NLR was increased after NCT but decreased after NET.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 20.2-21
Author(s):  
G. Hatemi ◽  
A. Mahr ◽  
M. Takeno ◽  
D. Kim ◽  
M. Melikoglu ◽  
...  

Background:Oral ulcers (OU) associated with Behçet’s syndrome are often painful, may interfere with the ability to eat and can negatively affect quality of life.1,2Apremilast (APR), an oral phosphodiesterase 4 inhibitor, demonstrated efficacy in the treatment of OU associated with Behçet’s syndrome in a phase III, multicenter, randomized, double-blind, placebo (PBO)-controlled study (RELIEF; BCT-002).3Objectives:To describe the efficacy of APR treatment in improving OU pain associated with Behçet’s syndrome in RELIEF.Methods:Patients were randomized (1:1) to APR 30 mg twice daily (APR 30 BID) or PBO twice daily for a 12-week PBO-controlled phase, followed by a 52-week active treatment extension. Eligible patients were ≥18 years of age and had active Behçet’s syndrome with ≥3 OU at randomization or ≥2 OU at screening and randomization and without active major organ involvement. Clinical improvement in OU was evaluated by the area under the curve for the number of OU through Week 12 (AUCWk0-12; primary efficacy endpoint) and by assessments of OU number. Patient-reported OU pain was evaluated by the 100-mm visual analogue scale (VAS). The statistical tests were 2-sided (α=0.05). The proportions of patients achieving the minimal clinically important difference (MCID) and higher rates of improvement, defined as ≥10-mm,4≥30-mm (3-fold MCID), ≥50-mm (5-fold MCID) improvements in OU pain VAS scores, respectively, were analyzed through Week 12. An ANCOVA model was used to analyze the primary endpoint and assessments of OU number and OU pain (VAS). The proportion of patients achieving improvement in OU pain VAS scores at Week 12 were summarized descriptively.Results:A total of 207 patients were randomized and received ≥1 dose of study medication (APR: n=104; PBO: n=103). At baseline, the mean (SD) number of OU was 4.2 (3.7) in the APR 30 BID group and 3.9 (2.7) in the PBO group, and the mean (SD) OU pain VAS scores were 61.2 (27.6) and 60.8 (26.9), respectively. At Week 12, significantly greater improvements were observed with APR 30 BID vs. PBO in AUCWk0-12(least-squares [LS] mean [SE]: 129.5 [15.9] vs. 222.1 [15.9];P<0.0001), number of OU (LS mean [SE]: 1.1 [0.2] vs. 2.0 [0.3];P=0.0003) and OU pain VAS scores (LS mean [SE] change from baseline: −40.7 [3.3] vs. −15.9 [3.3];P<0.0001). The proportion of patients who achieved the MCID of ≥10-mm improvement in OU pain VAS scores at Week 12 was greater with APR 30 BID vs. PBO; this pattern was also observed for the higher 3- and 5-fold improvements in MCID (Figure 1). Greater proportions of APR 30 BID vs. PBO patients achieved ≥10-mm and ≥30-mm improvements in OU pain VAS scores over 12 weeks. Notably, greater achievement of ≥50-mm improvement in OU pain VAS scores was observed with APR 30 BID vs. PBO as early as Week 1 and maintained up to Week 12 (Figure 2).Conclusion:For patients with active Behçet’s syndrome, APR 30 BID provided significantly greater improvements vs. PBO in OU number and OU pain at Week 12, including the greater proportion of patients achieving MCID and 3- and 5-fold MCID of OU pain in the APR 30 BID group vs. the PBO group. These results indicate a clinically meaningful treatment effect of APR 30 BID on the OU associated with Behçet’s syndrome.References:[1]Kokturk A.Patholog Res Int. 2012;2012:690390.[2]Hatemi G, et al.Ann Rheum Dis. 2008;67:1656-1662.[3]Hatemi G, et al.N Engl J Med. 2019;381:1918-1928. 4. Dworkin RH, et al.J Pain. 2008;9:105-121.Disclosure of Interests:Gulen Hatemi Grant/research support from: BMS, Celgene Corporation, Silk Road Therapeutics – grant/research support, Consultant of: Bayer, Eli Lilly – consultant, Speakers bureau: AbbVie, Mustafa Nevzat, Novartis, UCB – speaker, Alfred Mahr Consultant of: Celgene, Speakers bureau: Roche, Chugai, Mitsuhiro Takeno Speakers bureau: Esai, Tanabe-Mitsubishi – speaker; Celgene Corporation – advisory board, Doyoung Kim: None declared, Melike Melikoglu: None declared, Sue Cheng Employee of: Amgen Inc. – employment; Celgene Corporation – employment at the time of study conduct, Shannon McCue Employee of: Amgen Inc. – employment; Celgene Corporation – employment at the time of study conduct, Sven Richter Employee of: Amgen Inc. – employment; Celgene Corporation – employment at the time of study conduct, Michele Brunori Employee of: Amgen Inc. – employment; Celgene Corporation – employment at the time of study conduct, Maria Paris Employee of: Amgen Inc. – employment; Celgene Corporation – employment at the time of study conduct, Mindy Chen Employee of: Amgen Inc. – employment; Celgene Corporation – employment at the time of the conduct, Yusuf Yazici Consultant of: BMS, Celgene Corporation, Genentech, Sanofi – consultant, Consultant of: BMS, Celgene Corporation, Genentech, Sanofi – consultant


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anne-Christine Bay-Jensen ◽  
Asger Bihlet ◽  
Inger Byrjalsen ◽  
Jeppe Ragnar Andersen ◽  
Bente Juhl Riis ◽  
...  

AbstractThe heterogeneous nature of osteoarthritis (OA) and the need to subtype patients is widely accepted in the field. The biomarker CRPM, a metabolite of C-reactive protein (CRP), is released to the circulation during inflammation. Blood CRPM levels have shown to be associated with disease activity and response to treatment in rheumatoid arthritis (RA). We investigated the level of blood CRPM in OA compared to RA using data from two phase III knee OA and two RA studies (N = 1591). Moreover, the association between CRPM levels and radiographic progression was investigated. The mean CRPM levels were significantly lower in OA (8.5 [95% CI 8.3–8.8] ng/mL, n = 781) compared to the RA patients (12.8 [9.5–16.0] ng/mL, n = 60); however, a significant subset of OA patients (31%) had CRPM levels (≥ 9 ng/mL) comparable to RA. Furthermore, OA patients (n = 152) with CRPM levels ≥ 9 ng/mL were more likely to develop contra-lateral knee OA assessed by X-ray over a two-year follow-up period with an odds ratio of 2.2 [1.0–4.7]. These data suggest that CRPM is a blood-based biochemical marker for early identification OA patients with an inflammatory phenotype.


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