scholarly journals Use of parallel erlang density functions to analyze first-pass pulmonary uptake of multiple indicators in dogs

1996 ◽  
Vol 24 (6) ◽  
pp. 569-588 ◽  
Author(s):  
T. C. Krejcie ◽  
J. A. Jacquez ◽  
M. J. Avram ◽  
C. U. Niemann ◽  
C. A. Shanks ◽  
...  
Keyword(s):  
Density Functions ◽  
Multiple Indicators ◽  
Pulmonary Uptake ◽  
First Pass

Demonstration and Quantitation of Pharmacological Inhibition of Pulmonary Uptake of N-lsopropyl-123l-p-lodoamphetamine by Propranolol

1989 ◽  
Vol 28 (03) ◽  
pp. 100-104 ◽  
Author(s):  
S. F. Akber
Keyword(s):  
Binding Sites ◽  
Bolus Injection ◽  
Cell Function ◽  
Lung Pathology ◽  
Lung Uptake ◽  
Pharmacological Inhibition ◽  
Sensitive Index ◽  
Pulmonary Uptake ◽  
First Pass

The first-pass pulmonary extraction values of N-lsopropyl-123l-p-lodoamphetamine (123I-IMP) in pretreated dogs decreases from 90 to 62% as the amount of propranolol increases from 0 to 20 mg. The first-pass pulmonary extraction values of 123I-IMP in dogs with a simultaneous bolus injection of propranolol decreases from 90 to 62% as the amount of propranolol increases from 0 to 10 mg. The pulmonary extraction of 123I-IMP with a simultaneous bolus injection of ketamine and 123I-IMP decreases from 90 to 64% as the ketamine dose increases from 0 to 100 mg. These results suggest that the pulmonary uptake of 123I-IMP may be at least partially mediated by receptors. They also indicate that endothelial metabolic cell function may be a useful index of early lung pathology. Furthermore, studies of the degree of lung uptake may be a sensitive index of pathologic states in which alterations of amine binding sites have occurred.

The Pulmonary First-pass Uptake of Five Nondepolarizing Muscle Relaxants in the Pig 

1999 ◽  
Vol 90 (2) ◽  
pp. 477-483 ◽  
Author(s):  
Ton M. Beaufort ◽  
Johannes H. Proost ◽  
Martin C. Houwertjes ◽  
Jan Roggeveld ◽  
Mark J.K. H. Wierda
Keyword(s):  
Mean Transit Time ◽  
Onset Time ◽  
Muscle Relaxants ◽  
Arterial Blood ◽  
Tibialis Muscle ◽  
Pulmonary Uptake ◽  
Org 9487 ◽  
First Pass ◽  
The Right ◽  
Org 7617

Background It is not known whether the lungs influence the early pharmacokinetics of muscle relaxants and, if they do, whether differences in pulmonary uptake contribute to the differences in potency and/or onset time among muscle relaxants. Because the lungs are uniquely positioned, receive the entire cardiac output, have a large capillary surface area, and can temporarily store various basic drugs, the authors determined whether substantial pulmonary first-pass uptake of muscle relaxants occurs. Methods In 14 pigs, rocuronium, vecuronium, Org 9487, Org 7617, or d-tubocurarine were administered simultaneously with indocyanin green within 1 s into the right ventricle, and then arterial blood was sampled every 1.2 s (in the first min). The tibialis muscle response was registered mechanomyographically. Results The maximum block was 93% (68-100% [median and range]). Onset times ranged from 83 s (78-86 s) for rocuronium to 182 s (172-192 s) for d-tubocurarine. Fraction-versus-time outflow curves showed that the peak of muscle relaxants and indocyanin green occurred almost simultaneously. Pulmonary first-pass retention was negligible. The retention of muscle relaxants at 95% passage of indocyanin green was -9% (-31 to 18%). The difference in the mean transit time between muscle relaxant and indocyanin green was 1.0 (0.8 to 1.4), 0.2 (-0.8 to 0.3), 0.3 (0.2 to 0.4), 0.5 (0.2 to 1.3), and -2.2 s for rocuronium, vecuronium, Org 9487, Org 7617, and d-tubocurarine, respectively. Conclusions There is no substantial pulmonary first-pass uptake of rocuronium, vecuronium, Org 9487, Org 7617, or d-tubocurarine in pigs. Therefore, differences in pulmonary first-pass uptake do not contribute to the differences in potency and/or onset time among muscle relaxants.

First-pass Lung Uptake and Pulmonary Clearance of Propofol 

1999 ◽  
Vol 91 (6) ◽  
pp. 1780-1780 ◽  
Author(s):  
Jette A. Kuipers ◽  
Fred Boer ◽  
Wim Olieman ◽  
Anton G. L. Burm ◽  
James G. Bovill
Keyword(s):  
Pulmonary Tissue ◽  
Tissue Compartment ◽  
Arterial Blood ◽  
Concentration Time ◽  
Pulmonary Uptake ◽  
First Pass ◽  
Recirculatory Model ◽  
Pass Through ◽  
The Right ◽  
Kinetics Of

Background The principal site for elimination of propofol is the liver. The clearance of propofol exceeds hepatic blood flow; therefore, extrahepatic clearance is thought to contribute to its elimination. This study examined the pulmonary kinetics of propofol using part of an indocyanine green (ICG) recirculatory model. Methods Ten sheep, immobilized in a hammock, received injections of propofol (4 mg/kg) and ICG (25 mg) via two semipermanent catheters in the right internal jugular vein. Arterial blood samples were obtained from the carotid artery. The ICG injection was given for measurement of intravascular recirculatory parameters and determination of differences in propofol and ICG concentration-time profiles. No other medication was given during the experiment, and the sheep were not intubated. The arterial concentration-time curves of ICG were analyzed with a recirculatory model. The pulmonary uptake and elimination of propofol was analyzed with the central part of that model extended with a pulmonary tissue compartment allowing elimination from that compartment. Results During the experiment, cardiac output was 3.90+/-0.72 l/min (mean +/- SD). The blood volume in heart and lungs, measured with ICG, was 0.66+/-0.07 l. A pulmonary tissue compartment of 0.47+/-0.16 l was found for propofol. The pulmonary first-pass elimination of propofol was 1.14+/-0.23 l/min. Thirty percent of the dose was eliminated during the first pass through the lungs. Conclusions Recirculatory modeling of ICG allows modeling of the first-pass pulmonary kinetics of propofol concurrently. Propofol undergoes extensive uptake and first-pass elimination in the lungs.

Pulmonary Disposition of Propofol in Surgical Patients

2000 ◽  
Vol 93 (4) ◽  
pp. 986-991 ◽  
Author(s):  
Yan-Ling He ◽  
Hiroshi Ueyama ◽  
Chikara Tashiro ◽  
Takashi Mashimo ◽  
Ikuto Yoshiya
Keyword(s):  
Plasma Concentrations ◽  
Area Under The Curve ◽  
Back Diffusion ◽  
Blood Samples ◽  
Arterial Blood ◽  
Pulmonary Uptake ◽  
Human Lungs ◽  
Infusion Study ◽  
Significant Difference ◽  
First Pass

Background The lungs have been mentioned as a possible site contributing to the extrahepatic clearance of propofol. The objective of the present study was to clarify the pulmonary disposition of propofol directly in human lungs by investigating both the first-pass uptake and pulmonary extraction at pseudo-steady state. Methods Nine patients were enrolled in the first-pass uptake study. Propofol (5 mg) and indocyanine green (ICG; 15 mg) were simultaneously administered via a central venous catheter within 1 s, and sequential arterial blood samples were obtained from the radial artery at 1-s intervals up to 45 s. Eleven patients were included in the infusion study, and propofol was infused via the jugular vein at a rate of 50 microgram. kg-1. min-1. Blood samples were simultaneously collected from pulmonary and radial arteries up to 60 min. Results A pronounced difference in the dilution curves between propofol and ICG was observed, and 28.4 +/- 11.6% (mean +/- SD) of propofol was taken up during the single passage through the human lung. The mean pulmonary transit time of propofol (31.3 +/- 6.0 s) was significantly longer than that of ICG (22.4 +/- 2.7 s; P < 0.01), indicating that some of the propofol trapped by lungs returned to the circulation by back diffusion. In the constant infusion study, no significant differences were observed with the plasma concentrations of propofol between pulmonary and radial arteries except for that at 2 min. The area under the curve of pulmonary and radial arterial concentration curves to 60 min were 59.1 +/- 14.8 and 56.8 +/- 12.5 microg. ml-1. min-1, respectively. No significant difference was observed with the area under the curve, suggesting that metabolism was not involved in the pulmonary uptake in human lungs. Conclusions Most of the propofol that undergoes pulmonary uptake during the first pass was released back to the circulation by back diffusion. Metabolism was not involved in the pulmonary uptake in human lungs.

Embedding Procedure for Water Swollen Samples

1970 ◽  
Vol 28 ◽  
pp. 504-505
Author(s):  
Ann M. Thomas ◽  
Virginia Shemeley
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ion Exchange ◽  
Structural Changes ◽  
Cross Linking ◽  
Ion Exchange Resins ◽  
Transmission Electron ◽  
First Pass ◽  
Exchange Resins

Those samples which swell rapidly when exposed to water are, at best, difficult to section for transmission electron microscopy. Some materials literally burst out of the embedding block with the first pass by the knife, and even the most rapid cutting cycle produces sections of limited value. Many ion exchange resins swell in water; some undergo irreversible structural changes when dried. We developed our embedding procedure to handle this type of sample, but it should be applicable to many materials that present similar sectioning difficulties.The purpose of our embedding procedure is to build up a cross-linking network throughout the sample, while it is in a water swollen state. Our procedure was suggested to us by the work of Rosenberg, where he mentioned the formation of a tridimensional structure by the polymerization of the GMA biproduct, triglycol dimethacrylate.

Evidence for Early closure Attachment on First pass Reading Times in French

1997 ◽  
Vol 50 (2) ◽  
pp. 421-438 ◽  
Author(s):  
Daniel Zagar ◽  
Joel Pynte ◽  
Sylvie Rativeau
Keyword(s):  
First Pass ◽  
Early Closure

Therapie mit Opioiden bei Patienten mit Leberzirrhose

2020 ◽  
Vol 77 (1) ◽  
pp. 14-19
Author(s):  
Stephan Krähenbühl
Keyword(s):  
First Pass

Zusammenfassung. Für die Dosisangleichung bei Patienten mit Leberzirrhose gibt es keinen verlässlichen endogenen Parameter, der die metabolische Aktivität und das Ausmass der portacavalen Shunts repräsentiert. Die Angleichung muss deshalb unter Beachtung der pharmakokinetischen Eigenschaften der verabreichten Arzneistoffe erfolgen. Bei Arzneistoffen mit einem starken Abbau während der ersten Passage durch die Leber (first-pass Effekt) muss nach oraler Verabreichung mit einer Zunahme der Bioverfügbarkeit und verminderter Clearance gerechnet werden. Nach topischer, buccaler oder parenteraler Applikation spielt nur der Effekt auf die Clearance eine Rolle. Für Arzneistoffe mit einer hohen Bioverfügbarkeit (> 70 %) ist ebenfalls nur die hepatische Clearance entscheidend. In der Folge werden die in der Schweiz gebräuchlichen Opioide bezüglich pharmakokinetischer Eigenschaften und Konsequenzen bezüglich Dosisangleichung bei Patienten mit Leberzirrhose besprochen. Buprenorphin, Fentanyl, Hydromorphon, Morphin, Naloxon und Tapentadol sind Arzneistoffe mit einem hohen first-pass Effekt, währenddem Methadon, Oxycodon und Tramadol eine Bioverfügbarkeit von > 70 % aufweisen.

Review of Multiple indicators: An introduction.

1980 ◽  
Vol 25 (6) ◽  
pp. 505-505
Author(s):  
GEOFFREY KEPPEL
Keyword(s):  
Multiple Indicators

Maltreatment Variation and Trends in Six Developed Countries Using Multiple Indicators: Methods and Policy Implications

2012 ◽  
Author(s):  
Ruth Gilbert ◽  
John D. Fluke ◽  
Melissa O'Donnell ◽  
Arturo Gonzalez-Izquierdo ◽  
Marni Brownell ◽  
...  
Keyword(s):  
Developed Countries ◽  
Policy Implications ◽  
Multiple Indicators
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