Peripheral Airways Resistance, Static Recoil and the Forced Expiratory Volume

1972 ◽  
Vol 42 (4) ◽  
pp. 505-514 ◽  
Author(s):  
Ruth M. Cayton ◽  
P. Howard
Keyword(s):  
Forced Expiratory Volume ◽  
Second Phase ◽  
Forced Expiration ◽  
Elastic Recoil ◽  
Peripheral Airways ◽  
Mouth Pressure ◽  
History Of ◽  
Obstructive Airways Disease ◽  
Airways Resistance ◽  
Three Stages

1. The forced expiratory volume (FEV0·75) was measured at increasing mouth pressures in twenty-seven patients with obstructive airways disease. Attempts were made to divide the patients on clinical grounds into emphysematous, bronchitic or asthmatic categories; there was no evidence from the (FEV/mouth pressure) plots that their airways functioned differently during forced expiration. 2. Static elastic recoil was measured in twelve patients. There was no evidence that this factor alone caused the loss of FEV in any patient. 3. It is suggested that the use of the FEV as a test of respiratory function during the natural history of obstructive airways disease should be considered in three stages. There is an initial phase when peripheral airways disease develops with little or no alteration of the FEV. In the second phase the FEV decreases from normal values to below 1·0 litre, and at this stage is considered a sensitive indicator of peripheral airways resistance. In stage 3 the FEV is low and further changes can only be small. But airways resistance continues to increase and could be a more sensitive measurement of further airways disease.

Resistance and Collapse in Bronchial Airways

1970 ◽  
Vol 38 (6) ◽  
pp. 767-782 ◽  
Author(s):  
P. Howard ◽  
I. W. Webster
Keyword(s):  
Air Flow ◽  
Forced Expiratory Volume ◽  
The Body ◽  
Alveolar Pressure ◽  
Functional Changes ◽  
Chest Disease ◽  
Acute Exacerbations ◽  
Forced Expiratory Flow ◽  
Obstructive Airways Disease ◽  
Airways Resistance

1. The Forced Expiratory Volume (FEV) was measured in normal persons and patients with obstructive airways disease at mouth pressures from 0 mmHg to levels high enough to prevent air flow altogether by using a Starling resistor at the mouth. 2. Evidence was obtained in support of the idea that, during forced expiratory flow, airways might function with the properties of a Starling resistor. This is considered to divide the airway into upstream and downstream segments at the site of airway collapse. The technique was simple, capable of being performed on outpatients and provided a means of studying the collapsibility of airways, airways resistance and alveolar pressure. 3. The FEV in normal persons and patients with disease was determined by the properties of the upstream segment. Since this segment contains only a proportion of the total airways resistance it was not surprising to find imprecise correlations between the FEV and airways resistance measured by the body plethysmograph. 4. Preliminary observations of patients during acute exacerbations of chest disease suggest that functional changes can occur throughout the length of the airway (i.e. in both upstream and downstream segments). 5. In the longer term during the natural history of obstructive airways disease, airways resistance and the more ready collapse of airways may develop independently. 6. Impaired alveolar pressure may contribute towards the reduction in air flow during acute exacerbations of chest disease.

Mouth pressure curve on abrupt interruption of airflow during forced expiration

1989 ◽  
Vol 66 (1) ◽  
pp. 509-517 ◽  
Author(s):  
N. Ohya ◽  
J. Huang ◽  
T. Fukunaga ◽  
H. Toga
Keyword(s):  
Phase 1 ◽  
Pressure Curve ◽  
Second Phase ◽  
Forced Expiration ◽  
Phase 2 ◽  
Maximal Flow ◽  
Alveolar Pressure ◽  
Mouth Pressure ◽  
Pressure Phase ◽  
Abrupt Rise

An attempt was made to investigate how the mouth pressure curve represents the process of air flowing into the collapsed segment downstream to the choke point when the airflow is abruptly interrupted at the mouth during forced expiration. Immediately after the interruption of airflow, the mouth pressure suddenly increased (phase 1), followed by a slower rise in pressure (phase 2) within approximately 100 ms until the pressure reached the alveolar pressure. The pleural and alveolar pressures remained constant during this process. The first phase of the abrupt rise represented the pressure induced by the instantaneous interruption of the airflow itself. Analysis of the supramaximal flow (Vsupramax) observed after resumption of the airflow suggested that the choke point remained constant during the second phase of the mouth pressure after interruption of maximal flow (Vmax). From these results, examination of the second phase of the mouth pressure curve may provide useful information about the downstream segment of the airway.

Nikolay Sieber in the history of prerevolutionary Russian economic thought

2018 ◽  
pp. 95-110
Author(s):  
L. D. Shirokorad
Keyword(s):  
Economic Theory ◽  
Political Economy ◽  
Organic Synthesis ◽  
Marginal Utility ◽  
Economic Thought ◽  
History Of ◽  
Three Stages

This article shows how representatives of various theoretical currents in economics at different times in history interpreted the efforts of Nikolay Sieber in defending and developing Marxian economic theory and assessed his legacy and role in forming the Marxist school in Russian political economy. The article defines three stages in this process: publication of Sieber’s work dedicated to the analysis of the first volume of Marx’s Das Kapital and criticism of it by Russian opponents of Marxian economic theory; assessment of Sieber’s work by the narodniks, “Legal Marxists”, Georgiy Plekhanov, and Vladimir Lenin; the decline in interest in Sieber in light of the growing tendency towards an “organic synthesis” of the theory of marginal utility and the Marxist social viewpoint.

Frontiers of Visibility

Transfers ◽  
2013 ◽  
Vol 3 (2) ◽  
pp. 24-46 ◽  
Author(s):  
Franziska Torma
Keyword(s):  
Twentieth Century ◽  
Current Understanding ◽  
Machine Age ◽  
History Of ◽  
Three Stages ◽  
The 1950S ◽  
The 1960S ◽  
Popular Images ◽  
Cinematic Technology

This article deals with the history of underwater film and the role that increased mobility plays in the exploration of nature. Drawing on research on the exploration of the ocean, it analyzes the production of popular images of the sea. The entry of humans into the depths of the oceans in the twentieth century did not revitalize myths of mermaids but rather retold oceanic myths in a modern fashion. Three stages stand out in this evolution of diving mobility. In the 1920s and 1930s, scenes of divers walking under water were the dominant motif. From the 1940s to the 1960s, use of autonomous diving equipment led to a modern incarnation of the “mermen“ myth. From the 1950s to the 1970s, cinematic technology was able to create visions of entire oceanic ecosystems. Underwater films contributed to the period of machine-age exploration in a very particular way: they made virtual voyages of the ocean possible and thus helped to shape the current understanding of the oceans as part of Planet Earth.

scholarly journals Validation of Clinical Characteristics and Effectiveness of Pulmonary Rehabilitation in a COPD Population with Discrepancy between Exercise Tolerance and FEV1

Healthcare ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 53
Author(s):  
Jun Horie ◽  
Koichiro Takahashi ◽  
Shuuichi Shiranita ◽  
Kunihiko Anami ◽  
Shinichiro Hayashi
Keyword(s):  
Gait Speed ◽  
Pulmonary Rehabilitation ◽  
Exercise Tolerance ◽  
Respiratory Illness ◽  
Forced Expiratory Volume ◽  
Walking Distance ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
St George's Respiratory Questionnaire ◽  
History Of

This study’s objective was to examine the characteristics of patients with chronic obstructive pulmonary disease (COPD) presenting with various exercise tolerance levels. A total of 235 patients with stable COPD were classified into 4 groups: (1) LoFlo + HiEx—patients with a six-minute walking distance (6MWD) ≥350 m and percentage of predicted forced expiratory volume in 1 s (%FEV1.0) <50%; (2) HiFlo + HiEx—patients with a 6MWD ≥350 m and a %FEV1.0 ≥50%; (3) LoFlo + LoEx—patients with a 6MWD < 350 m and %FEV1.0 < 50%; and (4) HiFlo + LoEx—patients with a 6MWD <350 m and %FEV1.0 ≥ 50%. Aspects of physical ability in the HiFlo + LoEx group were significantly lower than those in the HiFlo + HiEx group. The HiFlo + LoEx group was characterized by a history of hospitalization for respiratory illness within the past year, treatment with at-home oxygen therapy, and lacking daily exercise habits. Following three months of pulmonary rehabilitation, the LoFlo + HiEx group significantly improved in the modified Medical Research Council dyspnea score, maximum gait speed, and 6MWD, while the HiFlo + LoEx group significantly improved in the percentage of maximal expiratory pressure, maximum gait speed, 6MWD, incremental shuttle walking distance, and St. George’s Respiratory Questionnaire score. The HiFlo + LoEx group had the greatest effect of three-month pulmonary rehabilitation compared to other groups.

scholarly journals Preoperative predictors of dysphagia after transoral surgery

2021 ◽  
Author(s):  
Kazunori Fujiwara ◽  
Kenkichiro Taira ◽  
Ryohei Donishi ◽  
Satoshi Koyama ◽  
Tsuyoshi Morisaki ◽  
...  
Keyword(s):  
Head And Neck ◽  
Forced Expiratory Volume ◽  
Transoral Surgery ◽  
Postoperative Dysphagia ◽  
Swallowing Function ◽  
History Of ◽  
Group A ◽  
Low Bmi ◽  
Head And Neck Radiotherapy

Abstract Background Transoral surgery (TOS) has been used to remove pharyngeal and laryngeal cancers with the objective of improving functional without worsening survival. However, there is a risk of postoperative dysphagia, which can severely impair quality of life. The aim of this study was to evaluate the preoperative predictive factors for postoperative dysphagia in patients undergoing TOS. Methods One hundred and twenty patients who underwent TOS were evaluated in this study. The degree of dysphagia was evaluated using the Functional Outcome Swallowing Scale (FOSS) both preoperatively and 3 months postoperatively. Those whose FOSS stage was maintained postoperatively were classified into the FOSS-M group, while those with increased FOSS stage postopratively were classified into the FOSS-I group. The following parameters were assessed before surgery: age, weight, height, body mass index (BMI), forced expiratory volume in 1 s, and history of head and neck radiotherapy. Videofluoroscopy (VF) was performed preoperatively to evaluate swallowing function using the Penetration-Aspiration Scale (PAS). Results The BMI of the FOSS-M group was significantly higher than that of the FOSS-I group. A history of radiotherapy was significantly more common in the FOSS-I group than in the FOSS-M group. Finally, preoperative PAS in the FOSS-M group was lower than that in the FOSS-I group. Conclusion This study suggested that patients with preoperative aspiration detected using VF might develop postoperative dysphagia severely. In addition, preoperative low BMI and a history of previous radiotherapy for head and neck cancer were associated with postoperative dysphagia. Objective examinations such as VF should be performed preoperatively.

Effects on insulin secretion and insulin action of a 48-h reduction of plasma free fatty acids with acipimox in nondiabetic subjects genetically predisposed to type 2 diabetes

2007 ◽  
Vol 292 (6) ◽  
pp. E1775-E1781 ◽  
Author(s):  
Kenneth Cusi ◽  
Sangeeta Kashyap ◽  
Amalia Gastaldelli ◽  
Mandeep Bajaj ◽  
Eugenio Cersosimo
Keyword(s):  
Type 2 Diabetes ◽  
Insulin Secretion ◽  
Family History ◽  
Second Phase ◽  
Β Cell ◽  
C Peptide ◽  
Hyperglycemic Clamp ◽  
History Of ◽  
Plasma Ffa

Elevated plasma FFA cause β-cell lipotoxicity and impair insulin secretion in nondiabetic subjects predisposed to type 2 diabetes mellitus [T2DM; i.e., with a strong family history of T2DM (FH+)] but not in nondiabetic subjects without a family history of T2DM. To determine whether lowering plasma FFA with acipimox, an antilipolytic nicotinic acid derivative, may enhance insulin secretion, nine FH+ volunteers were admitted twice and received in random order either acipimox or placebo (double-blind) for 48 h. Plasma glucose/insulin/C-peptide concentrations were measured from 0800 to 2400. On day 3, insulin secretion rates (ISRs) were assessed during a +125 mg/dl hyperglycemic clamp. Acipimox reduced 48-h plasma FFA by 36% ( P < 0.001) and increased the plasma C-peptide relative to the plasma glucose concentration or ΔC-peptide/Δglucose AUC (+177%, P = 0.02), an index of improved β-cell function. Acipimox improved insulin sensitivity (M/I) 26.1 ± 5% ( P < 0.04). First- (+19 ± 6%, P = 0.1) and second-phase (+31 ± 6%, P = 0.05) ISRs during the hyperglycemic clamp also improved. This was particularly evident when examined relative to the prevailing insulin resistance [1/(M/I)], as both first- and second-phase ISR markedly increased by 29 ± 7 ( P < 0.05) and 41 ± 8% ( P = 0.02). There was an inverse correlation between fasting FFA and first-phase ISR ( r2 = 0.31, P < 0.02) and acute (2–4 min) glucose-induced insulin release after acipimox ( r2 =0.52, P < 0.04). In this proof-of-concept study in FH+ individuals predisposed to T2DM, a 48-h reduction of plasma FFA improves day-long meal and glucose-stimulated insulin secretion. These results provide additional evidence for the important role that plasma FFA play regarding insulin secretion in FH+ subjects predisposed to T2DM.

The Problematic Text of Athenagoras of Athens’s Leg. 12.3: A Proposed Emendation

2016 ◽  
Vol 70 (3) ◽  
pp. 319-334
Author(s):  
Devin L. White
Keyword(s):  
Religious Epistemology ◽  
History Of Interpretation ◽  
History Of ◽  
Three Stages ◽  
The Creation ◽  
Argument Proceeds ◽  
Text Context

This study argues that Athenagoras of Athens’s Leg. 12.3 contains a lacuna. A vital clause should be emended to read ὑπὸ µόνου δὲ παραπεµπόµενοι τοῦ τὸν ὄντως θεὸν καὶ τὸν παρ’αὐτοῦ λόγον [πνεύµατος] εἰδέναι. The argument proceeds in three stages. First, an overview of the text, context, and history of interpretation of Leg. 12.3 will demonstrate that the text contains a lacuna. Second, a brief survey of Athenagoras’s religious epistemology will argue that πνεύµατος was the most likely original word. Finally, an analysis of the Spirit’s role in Leg. 7.2-3 will demonstrate that the reconstructed text of Leg. 12.3 is consistent with Athenagoras’s pneumatology, which relied upon traditional Jewish exegesis of the creation narratives.

Deep breaths, methacholine, and airway narrowing in healthy and mild asthmatic subjects

2002 ◽  
Vol 93 (4) ◽  
pp. 1384-1390 ◽  
Author(s):  
Emanuele Crimi ◽  
Riccardo Pellegrino ◽  
Manlio Milanese ◽  
Vito Brusasco
Keyword(s):  
Forced Vital Capacity ◽  
Healthy Subjects ◽  
Vital Capacity ◽  
Forced Expiratory Volume ◽  
Forced Expiration ◽  
Airway Narrowing ◽  
Significant Difference ◽  
Mild Asthmatic ◽  
Residual Capacity ◽  
Airway Conductance

Deep breaths taken before inhalation of methacholine attenuate the decrease in forced expiratory volume in 1 s and forced vital capacity in healthy but not in asthmatic subjects. We investigated whether this difference also exists by using measurements not preceded by full inflation, i.e., airway conductance, functional residual capacity, as well as flow and residual volume from partial forced expiration. We found that five deep breaths preceding a single dose of methacholine 1) transiently attenuated the decrements in forced expiratory volume in 1 s and forced vital capacity in healthy ( n = 8) but not in mild asthmatic ( n = 10) subjects and 2) increased the areas under the curve of changes in parameters not preceded by a full inflation over 40 min, during which further deep breaths were prohibited, without significant difference between healthy ( n = 6) and mild asthmatic ( n = 16) subjects. In conclusion, a series of deep breaths preceding methacholine inhalation significantly enhances bronchoconstrictor response similarly in mild asthmatic and healthy subjects but facilitates bronchodilatation on further full inflation in the latter.

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