scholarly journals Airway responsiveness to hypertonic saline: dose-response slope or PD15?

2005 ◽  
Vol 25 (1) ◽  
pp. 153-158 ◽  
Author(s):  
G. de Meer
Keyword(s):  
Hypertonic Saline ◽  
Dose Response ◽  
Airway Responsiveness ◽  
Response Slope

scholarly journals Airway responsiveness to methacholine and incidence of COPD: an international prospective cohort study

Thorax ◽  
2018 ◽  
Vol 73 (9) ◽  
pp. 825-832 ◽  
Author(s):  
Alessandro Marcon ◽  
Francesca Locatelli ◽  
Dirk Keidel ◽  
Anna B Beckmeyer-Borowko ◽  
Isa Cerveri ◽  
...  
Keyword(s):  
Cohort Study ◽  
Incidence Rate ◽  
Dose Response ◽  
Respiratory Health ◽  
Heart Diseases ◽  
Airflow Obstruction ◽  
Occupational Exposures ◽  
Airway Responsiveness ◽  
History Of ◽  
Rate Ratios

BackgroundIt has been debated, but not yet established, whether increased airway responsiveness can predict COPD. Recognising this link may help in identifying subjects at risk.ObjectiveWe studied prospectively whether airway responsiveness is associated with the risk of developing COPD.MethodsWe pooled data from two multicentre cohort studies that collected data from three time points using similar methods (European Community Respiratory Health Survey and Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults). We classified subjects (median age 37 years, 1st–3rd quartiles: 29–44) by their level of airway responsiveness using quintiles of methacholine dose–response slope at the first examination (1991–1994). Then, we excluded subjects with airflow obstruction at the second examination (1999–2003) and analysed incidence of COPD (postbronchodilator FEV1/FVC below the lower limit of normal) at the third examination (2010–2014) as a function of responsiveness, adjusting for sex, age, education, body mass index, history of asthma, smoking, occupational exposures and indicators of airway calibre.ResultsWe observed 108 new cases of COPD among 4205 subjects during a median time of 9 years. Compared with the least responsive group (incidence rate 0.6 per 1000/year), adjusted incidence rate ratios for COPD ranged from 1.79 (95% CI 0.52 to 6.13) to 8.91 (95% CI 3.67 to 21.66) for increasing airway responsiveness. Similar dose–response associations were observed between smokers and non-smokers, and stronger associations were found among subjects without a history of asthma or asthma-like symptoms.ConclusionsOur study suggests that increased airway responsiveness is an independent risk factor for COPD. Further research should clarify whether early treatment in patients with high responsiveness can slow down disease progression.

Comparison of bronchial responsiveness assessing dose-response slope between cough-variant asthma and classic asthma in young children

2013 ◽  
Vol 1 (4) ◽  
pp. 309 ◽  
Author(s):  
Jung Won Yoon ◽  
Hye Young Hur ◽  
Hye Mi Jee ◽  
Ji Hyeon Baek ◽  
Hyeong Yoon Kim ◽  
...  
Keyword(s):  
Young Children ◽  
Dose Response ◽  
Bronchial Responsiveness ◽  
Cough Variant Asthma ◽  
Response Slope

scholarly journals Comparison of regional lung perfusion response on longitudinal MAA SPECT/CT in lung cancer patients treated with and without functional tissue-avoidance radiation therapy

2019 ◽  
Vol 92 (1103) ◽  
pp. 20190174 ◽  
Author(s):  
Hannah Mary T Thomas ◽  
Jing Zeng ◽  
Howard J Lee, Jr ◽  
Balu Krishna Sasidharan ◽  
Paul E Kinahan ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Radiation Therapy ◽  
Cancer Patients ◽  
Dose Response ◽  
Lung Perfusion ◽  
Ct Scans ◽  
Lung Dose ◽  
Lung Cancer Patients ◽  
Response Slope ◽  
Regional Lung

Objective: The effect of functional lung avoidance planning on radiation dose-dependent changes in regional lung perfusion is unknown. We characterized dose-perfusion response on longitudinal perfusion single photon emission computed tomography (SPECT)/CT in two cohorts of lung cancer patients treated with and without functional lung avoidance techniques. Methods: The study included 28 primary lung cancer patients: 20 from interventional (NCT02773238) (FLARE-RT) and eight from observational (NCT01982123) (LUNG-RT) clinical trials. FLARE-RT treatment plans included perfused lung dose constraints while LUNG-RT plans adhered to clinical standards. Pre- and 3 month post-treatment macro-aggregated albumin (MAA) SPECT/CT scans were rigidly co-registered to planning four-dimensional CT scans. Tumour-subtracted lung dose was converted to EQD2 and sorted into 5 Gy bins. Mean dose and percent change between pre/post-RT MAA-SPECT uptake (%ΔPERF), normalized to total tumour-subtracted lung uptake, were calculated in each binned dose region. Perfusion frequency histograms of pre/post-RT MAA-SPECT were analyzed. Dose–response data were parameterized by sigmoid logistic functions to estimate maximum perfusion increase (%ΔPERFmaxincrease), maximum perfusion decrease (%ΔPERFmaxdecrease), dose midpoint (Dmid), and dose-response slope (k). Results: Differences in MAA perfusion frequency distribution shape between time points were observed in 11/20 (55%) FLARE-RT and 2/8 (25%) LUNG-RT patients (p < 0.05). FLARE-RT dose response was characterized by >10% perfusion increase in the 0–5 Gy dose bin for 8/20 patients (%ΔPERFmaxincrease = 10–40%), which was not observed in any LUNG-RT patients (p = 0.03). The dose midpoint Dmid at which relative perfusion declined by 50% trended higher in FLARE-RT compared to LUNG-RT cohorts (35 GyEQD2 vs 21 GyEQD2, p = 0.09), while the dose-response slope k was similar between FLARE-RT and LUNG-RT cohorts (3.1–3.2, p = 0.86). Conclusion: Functional lung avoidance planning may promote increased post-treatment perfusion in low dose regions for select patients, though inter-patient variability remains high in unbalanced cohorts. These preliminary findings form testable hypotheses that warrant subsequent validation in larger cohorts within randomized or case-matched control investigations. Advances in knowledge: This novel preliminary study reports differences in dose-response relationships between patients receiving functional lung avoidance radiation therapy (FLARE-RT) and those receiving conventionally planned radiation therapy (LUNG-RT). Following further validation and testing of these effects in larger patient populations, individualized estimation of regional lung perfusion dose-response may help refine future risk-adaptive strategies to minimize lung function deficits and toxicity incidence.

Human and rat airway smooth muscle responsiveness after ozone exposure in vitro

1996 ◽  
Vol 271 (4) ◽  
pp. L631-L636 ◽  
Author(s):  
E. Roux ◽  
C. Guibert ◽  
H. Crevel ◽  
J. P. Savineau ◽  
R. Marthan
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Dose Response ◽  
Ex Vivo ◽  
Airway Responsiveness ◽  
Ozone Exposure ◽  
Maximal Response ◽  
The Right ◽  
Rat Trachea

We previously reported that NO2 and acrolein administered ex vivo to the lung altered the subsequent responsiveness of airway smooth muscle. The aim of this study was to determine the dose-response relationship for O3 in both human isolated bronchi and rat tracheae and to investigate the mechanisms underlying O3-induced airway responsiveness. Exposure to 1 ppm O3 for 15 min significantly increased the maximal response to carbachol of rat tracheal rings to 149.6 +/- 5.4% of the reference response to acetylcholine (ACh) compared with that of unexposed rings (131.3 +/- 2.4%, n = 6, P < 0.05). The change in maximal airway responsiveness to carbachol, when plotted against the product of exposure concentration and exposure time to O3, a surrogate for the dose, formed a bell-shaped curve. The peak of this dose-response curve was shifted to the right for human bronchi (50 ppm x min, n = 5) compared with that of rat tracheae (15 ppm x min, n = 6). In the rat trachea, responses to KCl were not altered by O3, whereas those to 5-hydroxytryptamine hydrochloride (5-HT) were significantly increased. Finally, in the absence of external Ca2+, O3 exposure still potentiated the maximal response to carbachol from 73.6 +/- 13.9 to 137.0 +/- 6.0% and that to 5-HT from 21.5 +/- 5.5 to 38.7 +/- 2.2% of the reference ACh response. These results indicate that O3 alters the subsequent in vitro airway responsiveness depending on 1) the dose, 2) the nature of the agonist, and 3) the species investigated. Because in vitro exposure to O3 increases responses to agonists that release intracellular Ca2+ and since this effect is maintained in Ca(2+)-free solution, the mechanism of O3-induced increase in airway smooth muscle responsiveness is likely to involve an enhancement in intracellular Ca2+ release.

Evidence for existence of cortical androgen-stimulating hormone.

1979 ◽  
Vol 236 (6) ◽  
pp. E616 ◽  
Author(s):  
L N Parker ◽  
W D Odell
Keyword(s):  
Luteinizing Hormone ◽  
Dose Response ◽  
Thyroid Stimulating Hormone ◽  
Pituitary Hormone ◽  
Response Curves ◽  
Adrenal Androgen ◽  
Luteinizing Hormone Releasing Hormone ◽  
Response Slope ◽  
Wide Range ◽  
Stimulating Hormone

An animal model using dexamethosone-suppressed, castrated dogs was developed to test the hypothesis that a pituitary hormone other than ACTH modulates adrenal androgen (AA) secretion. Plasma samples were obtained every 15 min during infusions of saline, synthetic alpha 1-24 corticotropin, porcine 1-39 corticotropin (ACTH), or bovine pituitary gland extract (PE) in a wide range of doses. Androstenedione (A), dehydroepiandrosterone (DHA), and cortisol (F) were quantified by radioimmunoassay. When the ratio of AA levels was related to those of F, in order to correct for ACTH content in the PE, the slopes of the dose-response curves for corticotropin and PE were different at the 0.01 level. For A the dose-response slope for the PE was 0.18 +/- 0.5 SE, whereas that of ACTH was 0.02 +/- 0.01. For the DHA response the slopes were 0.17 +/- 0.04 for the PE and 0.04 +/- 0.03 for ACTH. Related studies showed no increase in AA levels in response to luteinizing hormone-releasing hormone, bovine growth hormone (GH), bovine prolactin, ovine thyroid-stimulating hormone (TSH), or synthetic aqueous arginine vasopressin (AVP). We conclude that a pituitary factor other than ACTH, prolactin, GH, luteinizing hormone, follicle-stimulating hormone, TSH, or AVP may be responsible for the observed increase in AA concentrations.

scholarly journals Dose-response slope of forced oscillation and forced expiratory parameters in bronchial challenge testing

1999 ◽  
Vol 13 (2) ◽  
pp. 295-300 ◽  
Author(s):  
A.b. Bohadana ◽  
R. Peslin ◽  
S-E. Megherbi ◽  
D. Teculescu ◽  
E.a. Sauleau ◽  
...  
Keyword(s):  
Dose Response ◽  
Forced Oscillation ◽  
Bronchial Challenge ◽  
Challenge Testing ◽  
Response Slope

Relation of Dose-response Slope to Respiratory Symptoms in a Population of Australian Schoolchildren

1991 ◽  
Vol 144 (3_pt_1) ◽  
pp. 663-667 ◽  
Author(s):  
Jennifer K. Peat ◽  
Cheryl M. Salome ◽  
Geoffrey Berry ◽  
Ann J. Woolcock
Keyword(s):  
Dose Response ◽  
Respiratory Symptoms ◽  
Response Slope

In vivo and in vitro comparisons of biological activities of bovine, ovine and rat CRF (corticotrophin-releasing factor)

1984 ◽  
Vol 106 (2) ◽  
pp. 158-167 ◽  
Author(s):  
Naoki Yasuda ◽  
Yuko Yasuda ◽  
Toru Aizawa ◽  
Sakae Maruta ◽  
Monte A. Greer
Keyword(s):  
Dose Response ◽  
Biological Activities ◽  
Bolus Administration ◽  
Corticotrophin Releasing Factor ◽  
Corticosterone Secretion ◽  
Response Slope ◽  
Significant Stimulation ◽  
Hypophysectomized Rats

Abstract. The biological activity of partially purified bovine hypothalamic CRF (corticotrophin-relasing factor) was compared to those of synthetic CRFs (ovine, rat) sauvagine and vasopressin in vivo and in vitro. ACTHprimed hypophysectomized rats with heterotopically transplanted pituitaries and medial basal hypothalamic ablation (H-T + MBHA), and intact rats pre-treated with chlorpromazine, morphine and Nembutal (C-M-N) were used for in vivo CRF assays. Perifused rat adenohypophyseal fragments were employed for in vitro studies. CRF-A (void volume fractions, 'big' CRF) and CRF-B (Kav = 0.583) purified from bovine hypophyseal stalk, synthetic ovine and rat CRF, and sauvagine all induced significant stimulation of ACTH and/or corticosterone secretion in these systems. Synthetic ovine and rat CRF and sauvagine showed comparable CRF potency. The CRF dose-response slopes for bovine CRF were somewhat steeper than those for ovine CRF or sauvagine in the in vitro system. Vasopressin had the least steep dose-response slope. Intravenous bolus administration of ovine CRF caused a more prolonged (>20 min) elevation of plasma ACTH compared to a relatively short duration after bovine CRF-A. These data suggest that bovine hypothalamus contains substance(s) which exhibits different CRF characteristics from those of ovine CRF.

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