Lack of interaction of hyperpnoea with methacholine and histamine in asthma

1998 ◽  
Vol 95 (5) ◽  
pp. 611-619 ◽  
Author(s):  
Suree SOMPRADEEKUL ◽  
Rana HEJAL ◽  
Melissa McLANE ◽  
K. A. LENNER ◽  
J. A. NELSON ◽  
...  
Keyword(s):  
Blood Flow ◽  
Forced Expiratory Volume ◽  
Additive Effects ◽  
Positive Interaction ◽  
Bronchial Responsiveness ◽  
Individual Effects ◽  
The Individual ◽  
Airway Calibre ◽  
Effector Mechanisms

1.The thermal precipitants of asthma (exercise and hyperventilation) appear to have a unique pathogenesis that does not alter bronchial responsiveness. In the present work, we tested whether hyperpnoea interacts with other constrictor stimuli. 2.To provide data on this issue, we exposed 17 subjects with asthma to isocapnic hyperventilation of frigid air (HV), methacholine (METH) and histamine (HIS) alone and in combination. 3.With HV (mean ventilation = 55.6±7.7 litres/min), METH (2.20±0.7 ;mmol/l) and HIS (10.35±5.04 ;mmol/l) alone, the decrements in forced expiratory volume in 1 ;s (FEV1) from baseline were 27.4±3.4, 27.4±3.8 and 32.4±3% respectively (n = 9). Giving the agonists simultaneously did not produce additive effects (ΔFEV1 HV+METH = 32.8±3.6%; HV+HIS = 28.7±5.1%). None of the individual or combined responses was significantly different from each other. Changing the sequence of the experiments and giving METH at the height of the HV-induced bronchial narrowing, instead of during hyperpnoea, did not alter the findings (n = 8). The maximum fall in FEV1 after both bronchoconstrictors in this experiment (ΔFEV1 = 32.3±4.3%) was not significantly different from either alone (HV = 22.8±1.0%; METH = 27.3±1.9%). When METH and HIS were administered together, however (n = 5), a positive interaction ensued (METH = 1.53±0.56 ;mmol/l, ΔFEV1 = 15.6±4.6%; HIS = 4.77±2.07 ;mmol/l, ΔFEV1 = 18.8±3.1%; METH+HIS ΔFEV1 = 33.4±5.2%; P< 0.001 compared with the individual effects). 4.These results indicate that HV does not interact with stimuli that directly or indirectly modulate airway calibre. It is unclear if this effect represents protection conferred from increased bronchial blood flow or derives from differences in effector mechanisms between the thermal and pharmacological agonists.

Absence of a late-phase response or increase in histamine responsiveness after bronchial provocation with adenosine 5′-monophosphate in atopic and non-atopic asthma

1988 ◽  
Vol 75 (4) ◽  
pp. 429-436 ◽  
Author(s):  
G. D. Phillips ◽  
S. T. Holgate
Keyword(s):  
Mast Cell ◽  
Late Phase ◽  
Forced Expiratory Volume ◽  
Atopic Asthma ◽  
Phase Reaction ◽  
Bronchial Responsiveness ◽  
Late Phase Reaction ◽  
Inflammatory Changes ◽  
Bronchial Provocation ◽  
Airway Calibre

1. Adenosine 5′-monophosphate (AMP) causes bronchoconstriction in atopic and non-atopic asthma by a mechanism believed to involve histamine release from airway mast cells. To determine whether preformed mast cell mediators, principally histamine, can initiate a late-phase bronchoconstriction we have investigated the effect on the airways over a 24 h period of a single bronchial challenge with AMP. 2. Six atopic asthmatic subjects (all late responders to inhaled allergen) and six non-atopic asthmatic subjects were studied on two occasions for a 24 h period after inhalation of the provocation concentration of AMP required to produce a 20% fall in forced expiratory volume in 1 s (FEV1) from baseline (PC20) and 0.9% (w/v) sodium chloride placebo, respectively. The atopic asthmatic subjects were studied on a further occasion after challenge with the PC20 allergen. 3. Inhalation of the PC20 AMP resulted in an immediate fall in FEV1 to a mean maximum 25.5% below baseline without resulting in any late decrease in airway calibre. No significant increase in non-specific bronchial responsiveness as determined by measuring the PC20 histamine before, and at 3, 9 and 24 h after, AMP challenge, occurred. Inhalation of the PC20 allergen caused a reproducible late-phase bronchoconstriction and increase in non-specific bronchial responsiveness in all the atopic asthmatic subjects studied. 4. These results suggest that preformed mast cell mediators, principally histamine, play no role in the initiation of the late-phase reaction in allergen-provoked asthma, although they may contribute to the inflammatory changes involved.

Fit Vs Faint: Assessing Work Causation in “Idiopathic Fall” Cases

2014 ◽  
Vol 19 (5) ◽  
pp. 3-12
Author(s):  
Lorne Direnfeld ◽  
David B. Torrey ◽  
Jim Black ◽  
LuAnn Haley ◽  
Christopher R. Brigham
Keyword(s):  
Blood Flow ◽  
Electrical Activity ◽  
Loss Of Consciousness ◽  
Brain Electrical Activity ◽  
Medical Terminology ◽  
Scientific Analysis ◽  
Medical Causation ◽  
The Individual ◽  
The Brain ◽  
Current Science

Abstract When an individual falls due to a nonwork-related episode of dizziness, hits their head and sustains injury, do workers’ compensation laws consider such injuries to be compensable? Bearing in mind that each state makes its own laws, the answer depends on what caused the loss of consciousness, and the second asks specifically what happened in the fall that caused the injury? The first question speaks to medical causation, which applies scientific analysis to determine the cause of the problem. The second question addresses legal causation: Under what factual circumstances are injuries of this type potentially covered under the law? Much nuance attends this analysis. The authors discuss idiopathic falls, which in this context means “unique to the individual” as opposed to “of unknown cause,” which is the familiar medical terminology. The article presents three detailed case studies that describe falls that had their genesis in episodes of loss of consciousness, followed by analyses by lawyer or judge authors who address the issue of compensability, including three scenarios from Arizona, California, and Pennsylvania. A medical (scientific) analysis must be thorough and must determine the facts regarding the fall and what occurred: Was the fall due to a fit (eg, a seizure with loss of consciousness attributable to anormal brain electrical activity) or a faint (eg, loss of consciousness attributable to a decrease in blood flow to the brain? The evaluator should be able to fully explain the basis for the conclusions, including references to current science.

ALTERNATIVE ROUTES TO INNOVATION — THE EFFECTS OF CULTURAL AND STRUCTURAL FIT

2019 ◽  
Vol 24 (01) ◽  
pp. 2050006
Author(s):  
DAG INGVAR JACOBSEN ◽  
TORE HILLESTAD ◽  
BIRGITTE YTTRI ◽  
JARLE HILDRUM
Keyword(s):  
Response Rate ◽  
Organic Structure ◽  
Configurational Approach ◽  
Culture Strength ◽  
Individual Effects ◽  
Collective Phenomenon ◽  
The Individual ◽  
Alternative Routes ◽  
Innovative Culture ◽  
The Empirical Analysis

A configurational approach to organizations assumes that structural and cultural characteristics must be in “fit” to produce the wanted outcome. With a focus on innovation, this study examines empirically to what extent innovative activities with a large, global telecom company are produced by an innovative culture, an innovative structure, as well as the fit between the two. Based on an extensive survey (N = 21064, response rate = 65) of employees in seven countries in Europe and Asia, data was aggregated to unit level as culture by nature is a collective phenomenon. The empirical analysis detected both the individual effects of culture strength and homogeneity, structure, as well as the fit between the two. The results indicate that an innovative culture and an organic structure indeed fosters innovation, but that, somewhat surprisingly, there are not effects of the fit between the two. Both practical and theoretical implications are discussed.

Factors influencing the individual effects of blood transfusions on oxygen delivery and oxygen consumption*

2001 ◽  
Vol 29 (Supplement) ◽  
pp. S173-S179 ◽  
Author(s):  
Mattias Casutt ◽  
Burkhardt Seifert ◽  
Thomas Pasch ◽  
Edith R. Schmid ◽  
Marko I. Turina ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Delivery ◽  
Blood Transfusions ◽  
Factors Influencing ◽  
Individual Effects ◽  
The Individual

scholarly journals Influence of process variables on release properties of paracetamol tablets

2007 ◽  
Vol 57 (1) ◽  
pp. 73-86 ◽  
Author(s):  
Gbenga Alebiowu ◽  
Oludele Itiola
Keyword(s):  
Interaction Effects ◽  
Process Variables ◽  
Factorial Experimental Design ◽  
Disintegration Time ◽  
Individual Effects ◽  
Pregelatinized Starch ◽  
Tablet Formulations ◽  
Binder Concentration ◽  
The Individual ◽  
Paracetamol Tablet

Influence of process variables on release properties of paracetamol tablets A 23 factorial experimental design has been used to quantitatively study individual and interaction effects of the nature of binder (N), binder concentration (c) and relative density of tablet (d) on the disintegration time (DT) and dissolution times, t1, t50 and t90, of paracetamol tablet formulations. The factorial design was also used to study the quantitative effects of pregelatinization of starch binders on these parameters, i.e., N, c and d. In general, the most common ranking of the individual effects on DT, t1, t50 and t90 for native/native, pregelatinized/pregelatinized and native/pregelatinized starch binder formulations was c > d > N. For interaction effects, the most common ranking was N-c > c-d > N-d for all formulations. The results generally showed that c can considerably affect DT, t1, t50 and t90 of the tablets.

scholarly journals Renal endothelial function and blood flow predict the individual susceptibility to adriamycin-induced renal damage

2008 ◽  
Vol 24 (2) ◽  
pp. 413-420 ◽  
Author(s):  
P. Ochodnicky ◽  
R. H. Henning ◽  
H. Buikema ◽  
A. C. A. Kluppel ◽  
M. van Wattum ◽  
...  
Keyword(s):  
Blood Flow ◽  
Endothelial Function ◽  
Renal Damage ◽  
Individual Susceptibility ◽  
The Individual

scholarly journals The tolerogenic interplay(s) among HLA-G, myeloid APCs, and regulatory cells

Blood ◽  
2011 ◽  
Vol 118 (25) ◽  
pp. 6499-6505 ◽  
Author(s):  
Edgardo D. Carosella ◽  
Silvia Gregori ◽  
Joel LeMaoult
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Immune Responses ◽  
Recent Work ◽  
Large Body ◽  
Regulatory Cells ◽  
Individual Effects ◽  
The Individual ◽  
Key Aspects ◽  
Antigen Presenting

Abstract Myeloid antigen-presenting cells (APCs), regulatory cells, and the HLA-G molecule are involved in modulating immune responses and promoting tolerance. APCs are known to induce regulatory cells and to express HLA-G as well as 2 of its receptors; regulatory T cells can express and act through HLA-G; and HLA-G has been directly involved in the generation of regulatory cells. Thus, interplay(s) among HLA-G, APCs, and regulatory cells can be easily envisaged. However, despite a large body of evidence on the tolerogenic properties of HLA-G, APCs, and regulatory cells, little is known on how these tolerogenic players cooperate. In this review, we first focus on key aspects of the individual relationships between HLA-G, myeloid APCs, and regulatory cells. In its second part, we highlight recent work that gathers individual effects and demonstrates how intertwined the HLA-G/myeloid APCs/regulatory cell relationship is.

Is natural openness or trade policy good for the environment?

2011 ◽  
Vol 16 (6) ◽  
pp. 657-684 ◽  
Author(s):  
Steven Yamarik ◽  
Sucharita Ghosh
Keyword(s):  
Air Pollution ◽  
Trade Policy ◽  
Factor Endowment ◽  
Trade And Environment ◽  
Population Geography ◽  
Limited Impact ◽  
Individual Effects ◽  
Good For ◽  
The Individual ◽  
Trade Share

AbstractIn this paper, we estimate the individual effects of natural openness and trade policy on air pollution. Natural openness is the component of the trade share (imports and exports as a percentage of GDP) attributable to population, geography and factor endowment differences. We find that natural openness reduces air pollution, while trade policy has a limited impact. The implication is that ‘natural’ geographic and endowment differences play a more important role than deliberate trade policy decisions in explaining the trade and environment link.

scholarly journals Adrenergic airway vascular smooth muscle responsiveness in healthy and asthmatic subjects

2001 ◽  
Vol 90 (2) ◽  
pp. 665-669 ◽  
Author(s):  
Jorge Brieva ◽  
Adam Wanner
Keyword(s):  
Blood Flow ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Dead Space ◽  
Healthy Subjects ◽  
Contractile Response ◽  
Mucosal Blood Flow ◽  
Forced Expiratory Volume ◽  
Baseline Values ◽  
The Mean

The purpose of the present study was to determine the responsiveness of airway vascular smooth muscle (AVSM) as assessed by airway mucosal blood flow (Q˙aw) to inhaled methoxamine (α1-agonist; 0.6–2.3 mg) and albuterol (β2-agonist; 0.2–1.2 mg) in healthy [ n = 11; forced expiratory volume in 1 s, 92 ± 4 (SE) % of predicted] and asthmatic ( n = 11, mean forced expiratory volume in 1 s, 81 ± 5%) adults. Mean baseline values for Q˙aw were 43.8 ± 0.7 and 54.3 ± 0.8 μl · min−1· ml−1of anatomic dead space in healthy and asthmatic subjects, respectively ( P < 0.05). After methoxamine inhalation, the maximal mean change in Q˙aw was −13.5 ± 1.0 μl · min−1· ml−1in asthmatic and −7.1 ± 2.1 μl · min−1· ml−1in healthy subjects ( P < 0.05). After albuterol, the mean maximal change in Q˙aw was 3.0 ± 0.8 μl · min−1· ml−1in asthmatic and 14.0 ± 1.1 μl · min−1· ml−1in healthy subjects ( P < 0.05). These results demonstrate that the contractile response of AVSM to α1-adrenoceptor activation is enhanced and the dilator response of AVSM to β2-adrenoceptor activation is blunted in asthmatic subjects.

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