Dependence of pulmonary prostaglandin metabolism on carrier-mediated transport processes

1977 ◽  
Vol 232 (4) ◽  
pp. E382-E387 ◽  
Author(s):  
L. Z. Bito ◽  
R. A. Baroody ◽  
Mary E. Reitz
Keyword(s):  
Transit Time ◽  
Transport Process ◽  
Transport Processes ◽  
Systemic Effects ◽  
Effective Inhibitor ◽  
Rat Lung ◽  
Carrier Mediated Transport ◽  
The Difference ◽  
Pulmonary Transit Time ◽  
Bromcresol Green

Inhibitors of prostaglandin (PG) transport (probenecid, indomethacin, or bromcresol green) were found to eliminate the difference between the pulmonary transit time of 3H and 14C when [3H]PGF2alpha and E114C]sucrose were injected as a single intra-arterial bolus into the isolated perfused rat lung. Similar results were obtained with PGE1. The transit time of [3H]PGA1 was not significantly different from that of [14C]sucrose even in the absence of an inhibitor. These inhibitors increased the amount of [3H]PGF2alpha or [3H]PGE1 and decreased the amount of [3H]PG metabolites found in the venous effluent: these agents also inhibited the pulmonary metabolism of continously infused, nonradioactive PGF2alpha. One of the three inhibitors, bromcresol green, was shown not to be an effective inhibitor of PG metabolism in cell-free preparations of rat lung homogenates. These results indicated that under normal conditions, PG's are rapidly transported into intracellular compartment(s) where they are metabolized. Inhibition of this transport process prevents rapid access of PG's to the cytoplasmic enzymes and therefore inhibits pulmonary PG metabolism. This implies that inhibitors of PG transport, including anti-inflammatory organic acids, and some PG antagonists, metabolites, and analogues, can be expected to inhibit the pulmonary metabolism of PG's and thus could potentiate the systemic effects endogenous or exogenous PG's.

Correlation of Data Obtained by Radiocardiography and Right-Heart Catheterization in Cardiac Patients

1968 ◽  
Vol 07 (02) ◽  
pp. 125-129
Author(s):  
J. Měštan ◽  
V. Aschenbrenner ◽  
A. Michaljanič
Keyword(s):  
Capillary Pressure ◽  
Transit Time ◽  
Right Heart Catheterization ◽  
Heart Catheterization ◽  
Right Heart ◽  
Pulmonary Capillary ◽  
Filling Time ◽  
Pulmonary Capillary Pressure ◽  
The Mean ◽  
Pulmonary Transit Time

SummaryIn patients with acquired and congenital valvular heart disease correlations of the parameters of the radiocardiographic curve (filling time of the right heart, minimal pulmonary transit time, peak-to-peak pulmonary transit time, and the so-called filling time of the left heart) with the mean pulmonary artery pressure and the mean pulmonary “capillary” pressure were studied. Further, a regression equation was determined by means of which the mean pulmonary “capillary” pressure can be predicted.

P4129cMR-Pulmonary transit time and pulmonary blood volume have an additional prognostic value over cMR-right ventricular ejection fraction in predicting mortality in HF-rEF patients

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
L Houard ◽  
H Langet ◽  
S Militaru ◽  
M F Rousseau ◽  
A C Pouleur ◽  
...  
Keyword(s):  
Blood Volume ◽  
Transit Time ◽  
Primary Endpoint ◽  
Prognostic Value ◽  
Beta Blockers ◽  
Class Iii ◽  
Baseline Model ◽  
Pulmonary Blood Volume ◽  
Pulmonary Transit Time ◽  
Overall Mortality

Abstract Background Assessment of congestion and cardiac function has been shown to have both therapeutic and prognostic implication for the management of patient with CHF. Pulmonary transit time (PTT) assessed by cMR is a novel parameter, which reflects not only hemodynamic congestion but also LV and RV function. Purpose We sought to explore the prognostic value of the pulmonary transit time assessed in seconds (PTT) and in beats (PTB) and the pulmonary blood volume indexed (PBVi) above conventional well-known risk factors including cMR-RVEF and estimated pulmonary artery pressure (eSPAP) in predicting outcomes. PBVi is defined by the product of PTB and the stroke volume indexed to body surface area. Methods 401 patients in sinus rhythm with a LVEF <35% (age 61±13 years; 25% female) underwent a cMR and an echocardiography. Patients were followed for a primary endpoint of overall mortality. Results Average cMR-LVEF was 23±7%, cMR-RVEF was 43±15%, average estimated systolic pulmonary pressure (eSPAP) was 33±12mmH, average PTT was 11±6s, PTB 8.9±5.6 bpm and average PBVi 305.5±254.9ml/m2. After a median follow-up of 6 years, 182 reached the primary endpoint. In univariate cox regression, age, ischemic cardiomyopathy, hypertension, diabetes, NYHA class III-IV, eSPAP >40mmHg, E/A ratio, e/e'ratio, cMR-RVEF, LV scar, PTT, PTB, PBVi, GFR, beta blockers and diuretics were associated with overall mortality. For the multivariate analysis, a baseline model was created where age, ischemic etiology, NYHA functional class III-IV, eSPAP >40 mmHg, beta-blockers and cMR-RVEF were found to be significantly and independently associated with the primary endpoint. PTT (X2 to improve = 5.3, HR: 1.03; 95% CI: [1.01; 1.06]; P=0.015), PTB (X2 to improve = 11.8, HR: 1.06; 95% CI: [1.03; 1.09]; P<0.001) and PBVi (X2 to improve = 7.7, HR: 1.08; 95% CI: [1.03; 1.14]; P=0.002) showed a significantly additional prognostic value over the baseline model (p<0.001). Conclusion Pulmonary transit time and pulmonary blood volume provide higher prognostic information over well-known risk factors including cMR-RVEF and eSPAP with high power to stratify prognosis in HF-rEF and might be promising tools to identify patients at higher risk among HF patients. Acknowledgement/Funding Fond National de recherche scientifique (FNRS)

Use of contrast echocardiography for quantitative and qualitative evaluation of myocardial perfusion and pulmonary transit time in healthy dogs

2012 ◽  
Vol 73 (2) ◽  
pp. 194-201 ◽  
Author(s):  
Serena Crosara ◽  
Ingrid Ljungvall ◽  
Marco L. Margiocco ◽  
Jens Häggström ◽  
Alberto Tarducci ◽  
...  
Keyword(s):  
Myocardial Perfusion ◽  
Transit Time ◽  
Contrast Echocardiography ◽  
Qualitative Evaluation ◽  
Healthy Dogs ◽  
Pulmonary Transit Time

scholarly journals The effect of resistant starch on colon function in humans

1990 ◽  
Vol 64 (2) ◽  
pp. 589-595 ◽  
Author(s):  
J. Tomlin ◽  
N. W. Read
Keyword(s):  
Transit Time ◽  
Resistant Starch ◽  
Bacterial Flora ◽  
Random Order ◽  
Observable Effect ◽  
Total Carbohydrate ◽  
Diet Supplements ◽  
Significant Difference ◽  
Dietary Period ◽  
The Difference

Starch that is resistant to human amylases forms during the cooking and subsequent cooling of some foods, and may therefore be a substrate for the bacterial flora of the colon. It is thus possible that resistant starch (RS) will affect colon function in a similar manner to non-starch polysaccharides. To test this theory, a group of eight volunteers took two diet supplements for 1 week each in a random order with a 1 week separation. One supplement comprised mainly 350 g Cornflakes/d and the other 380 g Rice Krispies/d, providing 10.33 and 0.86 g RS/.d respectively. The amounts of amylase-digestible starch, non-starch polysaccharides, total carbohydrate, energy, protein and fat were balanced between the two periods by giving small amounts of Casilan, wheat bran, butter and boiled sweets. The volunteers made faecal collections during day 3 to day 7 of each period. Whole-gut transit time was calculated using the continuous method. Stool consistency and ease of defaecation were assessed by the volunteers. All episodes of flatulence noticed were recorded in a diary, along with food intake. Serial breath hydrogen measurements were made at 15 min intervals for 8 h on day 1 of each supplement. Questionnaires regarding colon function were completed at the end of each dietary period. There were no significant differences in the stool mass, frequency or consistency, ease of defaecations, transit time or flatulence experienced during the two supplements (P > 0.05). Significantly more H2 (area under curve) was produced while eating Cornflakes than Rice Krispies (P < 0.05). The difference of 9.47 g RS/d between the two diets was over three times the calculated normal daily RS intake of 2.76 g/d. As the only significant difference observed was in the breath H2 excretion on day 1, we suggest that either RS is rapidly and completely fermented to end-products including H2 gas, which is subsequently excreted via the lungs and has little influence on colon function, or that bacterial adaptation removed any observable effect on faecal mass and transit time by day 3.

Validation of cerebral arteriovenous malformation hemodynamics assessed by DSA using quantitative magnetic resonance angiography: preliminary study

2017 ◽  
Vol 10 (2) ◽  
pp. 156-161 ◽  
Author(s):  
Sophia F Shakur ◽  
Denise Brunozzi ◽  
Ahmed E Hussein ◽  
Andreas Linninger ◽  
Chih-Yang Hsu ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Angiography ◽  
Transit Time ◽  
Internal Carotid ◽  
Flow Measurements ◽  
Quantitative Magnetic Resonance ◽  
Transit Times ◽  
Before And After ◽  
Preliminary Study ◽  
The Difference

BackgroundThe hemodynamic evaluation of cerebral arteriovenous malformations (AVMs) using DSA has not been validated against true flow measurements.ObjectiveTo validate AVM hemodynamics assessed by DSA using quantitative magnetic resonance angiography (QMRA).Materials and methodsPatients seen at our institution between 2007 and 2016 with a supratentorial AVM and DSA and QMRA obtained before any treatment were retrospectively reviewed. DSA assessment of AVM flow comprised AVM arterial-to-venous time (A-Vt) and iFlow transit time. A-Vt was defined as the difference between peak contrast intensity in the cavernous internal carotid artery and peak contrast intensity in the draining vein. iFlow transit times were determined using syngo iFlow software. A-Vt and iFlow transit times were correlated with total AVM flow measured using QMRA and AVM angioarchitectural and clinical features.Results33 patients (mean age 33 years) were included. Nine patients presented with hemorrhage. Mean AVM volume was 9.8 mL (range 0.3–57.7 mL). Both A-Vt (r=−0.47, p=0.01) and iFlow (r=−0.44, p=0.01) correlated significantly with total AVM flow. iFlow transit time was significantly shorter in patients who presented with seizure but A-Vt and iFlow did not vary with other AVM angioarchitectural features such as venous stenosis or hemorrhagic presentation.ConclusionsA-Vt and iFlow transit times on DSA correlate with cerebral AVM flow measured using QMRA. Thus, these parameters may be used to indirectly estimate AVM flow before and after embolization during angiography in real time.

Pulmonary transit time derived from pulmonary angiography for the diagnosis of hepatopulmonary syndrome

2018 ◽  
Vol 38 (11) ◽  
pp. 1974-1981 ◽  
Author(s):  
He Zhao ◽  
Jiaywei Tsauo ◽  
Xiaowu Zhang ◽  
Huaiyuan Ma ◽  
Ningna Weng ◽  
...  
Keyword(s):  
Transit Time ◽  
Hepatopulmonary Syndrome ◽  
Pulmonary Angiography ◽  
Pulmonary Transit Time

scholarly journals Comparison of the prognostic value of stress and rest pulmonary transit time estimation using myocardial perfusion CMR

2021 ◽  
Vol 22 (Supplement_2) ◽  
Author(s):  
A Seraphim ◽  
K Knott ◽  
K Menacho ◽  
J Augusto ◽  
R Davies ◽  
...  
Keyword(s):  
Myocardial Perfusion ◽  
Transit Time ◽  
Cardiovascular Events ◽  
Prognostic Value ◽  
Time Estimation ◽  
Left Ventricular ◽  
Major Adverse Cardiovascular Events ◽  
Pulmonary Transit Time ◽  
Perfusion Cmr ◽  
Center Study

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): British Heart Foundation Clinical Research Training Fellowship Background Pulmonary transit time (PTT) is a quantitative biomarker of cardiopulmonary status. Rest PTT was previously shown to predict outcomes in specific disease models, but clinical adoption is hindered but challenges in data acquisition. Whether evaluation of PTT during stress encodes incremental prognostic information has not been previously investigated as scale. Objectives To compare the prognostic value of stress and rest PTT derived from a fully automated, in-line method of estimation using perfusion CMR, in a large patient cohort. Methods A retrospective two-center study of patients referred clinically for adenosine stress myocardial perfusion assessment using CMR. Analysis of right and left ventricular cavity arterial input function curves from first pass perfusion was performed automatically, allowing the in-line estimation of both rest and stress PTT. Association with major adverse cardiovascular events (MACE) was evaluated. MACE was defined as a composite outcome of myocardial infarction, stroke, heart failure admission and ventricular tachycardia or appropriate ICD treatment (including ICD shock and/or anti-tachycardia pacing). Results 985 patients (67% male, median age 62 years (IQR 52,71)) were included, with median left ventricular ejection fraction (LVEF) of 62% (IQR 54-69). Median stress PTT was shorter than rest PTT 6.2 (IQR 5.1, 7.7) seconds versus 7.7 (IQR, 6.4, 9.2) seconds. Stress and rest PTT were highly correlated (r = 0.69; p &lt; 0.001). Stress PTT also correlated with LVEF (r=-0.37), stress MBF (r=-0.31), LVEDVi (r = 0.24), LA area index (r = 0.32) (p &lt; 0.001 for all). Over a median follow-up period of 28.6 (IQR, 22.6 35,7) months, MACE occurred in 61 (6.2%) patients. After adjusting for prognostic factors, both rest and stress PTT, independently predicted MACE, but not all-cause mortality. For every 1xSD (2.39s) increase in rest PTT the adjusted hazard ratio (HR) for MACE was 1.43 (95% CI 1.10-1.85, p = 0.007). The hazard ratio for one standard deviation (2.64s) increase in stress PTT was 1.34 (95% CI 1.048-1.723; p = 0.020) after adjusting for age, LVEF, hypertension, diabetes, sex and presence of LGE Conclusions In this 2-center study of 985 patients, we deploy a fully automated method of PTT estimation using perfusion mapping with CMR and show that both stress and rest PTT are independently associated with adverse cardiovascular outcomes. In this patient cohort, there is no clear incremental prognostic value of stress PTT, over its evaluation during rest. Figure 1. Stress and Rest Pulmonary Transit Time estimation using myocardial perfusion CMR Figure 2. Event-free survival curves for major adverse cardiovascular events (Heart failure hospitalization, myocardial infarction, stroke and ventricular tachycardia/ICD treatment) according to mean rest PTT (8.05seconds) and mean stress PTT (6.7seconds). Log-rank for both p &lt; 0.05

scholarly journals Unprecedented strength of Hadley circulation in 2015–2016 impacts on CO<sub>2</sub> interhemispheric difference

2018 ◽  
Author(s):  
Jorgen S. Frederiksen ◽  
Roger J. Francey
Keyword(s):  
Global Warming ◽  
Hadley Circulation ◽  
Co2 Concentration ◽  
Transport Processes ◽  
Boreal Summer ◽  
Boreal Winter ◽  
Advective Transport ◽  
Interhemispheric Difference ◽  
Eddy Transport ◽  
The Difference

Abstract. The extreme El Niño of 2015 and 2016 coincided with record global warming and unprecedented strength of the Hadley circulation with significant impact on mean interhemispheric (IH) transport of CO2 and on the difference in CO2 concentration between Mauna Loa and Cape Grim (Cmlo-cgo). The relative roles of eddy transport and mean advective transport on IH CO2 annual differences from 1992 through to 2016 is explored. Eddy transport processes occur mainly in boreal winter-spring when Cmlo-cgo is large; an important component is due to Rossby wave generation by the Himalayas and propagation through the equatorial Pacific westerly duct generating and transmitting turbulent kinetic energy. Mean transport occurs mainly in boreal summer-autumn and varies with the strength of the Hadley circulation. The timing of annual changes in Cmlo-cgo is found to coincide well with dynamical indices that we introduce to characterize the transports. During the unrivalled 2009–2010 step in Cmlo-cgo indices of eddy and mean transport reinforce. In contrast for the 2015 to 2016 change in Cmlo-cgo the mean transport counteracts the eddy transport and the record strength of the Hadley circulation determines the annual IH CO2 difference. The interaction of increasing global warming and extreme El Niños may have important implications for altering the balance between eddy and mean IH CO2 transfer.

scholarly journals Quasi-biennial and quasi-triennial oscillations in the growth rates of atmospheric chlorofluorocarbons 11 and 12

MAUSAM ◽  
2022 ◽  
Vol 53 (3) ◽  
pp. 349-358
Author(s):  
R. P. KANE
Keyword(s):  
Southern Hemisphere ◽  
Growth Rates ◽  
Southern Oscillation ◽  
Spectral Characteristics ◽  
Linear Increase ◽  
Transport Processes ◽  
Emission Rates ◽  
Low Latitude ◽  
The Difference ◽  
Prominent Peak

The 12-monthly running means of CFC-11 and CFC-12 were examined for 1977-1992. As observed by earlier workers, during 1977-1988, there was a rapid, almost linear increase of these compounds, ~70% in the northern and ~77% in the southern hemisphere. From 1988 up to 1992, growth rates were slower, more so for CFC-11 in the northern hemisphere. Superposed on this pattern were QBO, QTO (Quasi-Biennial and Quasi-Triennial Oscillations). A spectral analysis of the various series indicated the following. The 50 hPa low latitude zonal wind had one prominent QBO peak at 2.58 years and much smaller peaks at 2.00 (QBO) and 5.1 years. The Southern oscillation index represented by (T-D), Tahiti minus Darwin atmospheric pressure, had a prominent peak at 4.1 years and a smaller peak at 2.31 years. CFC-11 had only one significant peak at 3.7 years in the southern hemisphere, roughly similar to the 4.1 year (T-D) peak. CFC-12 had prominent QBO (2.16-2.33 years) in both the hemispheres and a QTO (3.6 years) in the southern hemisphere. For individual locations, CFC-11 showed barely significant QBO in the range (1.95-3.07 years), while CFC 12 showed strong QBO in the range (1.86-2.38 years). The difference in the spectral characteristics of CFC-11 and CFC 12 time series is attributed to differences in their lifetimes (44 and 180 years), source emission rates and transport processes.

scholarly journals Evaluation of Transport Processes Quality with Servqual and TUL Methods

2018 ◽  
Vol 9 (2) ◽  
pp. 61-72
Author(s):  
Aleksander Sładkowski ◽  
Maria Cieśla ◽  
Bartosz Krupa
Keyword(s):  
Service Provider ◽  
Transport Process ◽  
Transport Processes ◽  
Quality Of Services ◽  
Quality Level ◽  
Comparison Of Methods ◽  
Logistics Service ◽  
Scientific Goal ◽  
Logistics Service Provider

Abstract The theoretical part of this article presents knowledge of selected methods used to study the quality level of basic processes. Authors paid particular attention to the Servqual method, which shows the differences that exist between the perceived and delivered quality of services provided by enterprises and the TUL method. The research part will show the Servqual and TUL analysis based on the processes of the existing transport company. The article is based on well-known methodology of Servqual and TUL analysis, which was adjusted to observation of transport processes of logistics service provider. The main scientific goal of the paper was to examine the effectiveness of the methodology used on the example of a transport company and comparison of methods utility. The improvement of the transport process will increase the level of customer satisfaction, and this is the first step to increase the number of transport orders received.

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