Discontinuous Monitoring of Propofol Concentrations in Expired Alveolar Gas and in Arterial and Venous Plasma during Artificial Ventilation

2006 ◽  
Vol 104 (4) ◽  
pp. 786-790 ◽  
Author(s):  
Martin Grossherr ◽  
Andreas Hengstenberg ◽  
Torsten Meier ◽  
Leif Dibbelt ◽  
Klaus Gerlach ◽  
...  
Keyword(s):  
High Performance ◽  
Artificial Ventilation ◽  
Plasma Concentrations ◽  
Reversed Phase ◽  
Gas Chromatography Mass Spectrometry ◽  
Arterial Blood ◽  
Continuous Application ◽  
Species Specific ◽  
Venous Plasma

Background Analyzing propofol concentration in expired alveolar gas (cPA) may be considered as a convenient, noninvasive method to follow the propofol concentration in plasma (cPPL). In the current study, the authors established procedures to measure cPA and cPPL for the assessment of their relation in two animal models during anesthesia. Methods Expired alveolar gas and mixed venous and arterial blood were simultaneously sampled during continuous application of propofol for general anesthesia to three goats and three pigs. Propofol infusion rates were varied to modify plasma concentrations. cPA, sampled cumulatively over several respiratory cycles, was quantified by thermal desorption gas chromatography-mass spectrometry. cPPL was determined using reversed phase high-performance liquid chromatography with fluorescence detection. Results cPA ranged from 0 to 1.4 and from 0 to 22 parts per billion in goats and pigs, respectively, at cPPL of 0-8 microg/ml. The relation between cPA and cPPL was linear; however, the slopes of the regression lines varied between animals. Conclusion Propofol can be quantified in expired alveolar gas. The results stress the role of marked species-specific variability.

The role of the temperature in reversed-phase high-performance liquid chromatography using pyrocarbon-containing adsorbents

1978 ◽  
Vol 167 ◽  
pp. 41-65 ◽  
Author(s):  
Henri Colin ◽  
José Carlos Diez-Masa ◽  
Georges Guiochon ◽  
Teresa Czjkowska ◽  
Iréna Miedziak
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Reversed Phase

Evidence for LH-inhibiting activity in ovine peripheral and testicular blood

1990 ◽  
Vol 123 (3) ◽  
pp. 345-352 ◽  
Author(s):  
V. Papapdopoulos ◽  
P. Kamtchouing ◽  
N. Boujrad ◽  
C. Pisselet ◽  
C. Perreau ◽  
...  
Keyword(s):  
Cyclic Amp ◽  
Breeding Season ◽  
Specific Binding ◽  
Apparent Molecular Weight ◽  
Rete Testis ◽  
Arterial Blood ◽  
Inhibiting Factor ◽  
Arterial Plasma ◽  
Species Specific ◽  
Venous Plasma

Abstract. Intracellular cyclic AMP and testosterone productions by purified mature rat Leydig cells were stimulated by oLH (25 μg/l) 18- and 12-fold, respectively, after a 5-h incubation period. The replacement of the incubation medium by charcoal-treated testicular venous plasma (40%, v/v) from adult rams in the breeding season induced an inhibition of cyclic AMP and testosterone productions (82 and 66%, respectively, of oLH-stimulated values). Testicular arterial plasma is less effective than testicular venous plasma, even when it originates from non-breeding season rams; in that case, testicular venous and arterial plasma strongly inhibit testosterone productions (84 and 67%, respectively of oLH-stimulated values), which probably indicates that the inhibitory activity is higher in the non-breeding season. The addition of peripheral plasma leads to a testosterone production equal to 35 and 65% of the oLH-stimulated values, respectively, for ram blood collected in non-breeding and breeding seasons. The same concentration of ovine testicular lymph or rete testis fluid is without significant effect on cyclic AMP production; however, testosterone is slightly decreased by lymph but enhanced by rete testis fluid. Increasing amounts of venous or arterial testicular blood induce a dose-related decrease of the specific binding of labelled hCG in both rat and ram testicular membranes. This inhibiting factor is present in peripheral and testicular blood of either control or hypophysectomized or castrated rams, is a protein in nature, heat-sensitive, and has an apparent molecular weight higher than 10 000 daltons. These results suggest the existence of a control of LH-specific binding to its receptors and of Leydig cell cyclic AMP and testosterone outputs; these activities are not species-specific and are more concentrated in testicular venous than in arterial blood. The origin of this inhibiting factor remains to be determined, since it is not confined to the testis and not of pituitary origin.

EVIDENCE FOR BIIIARY EXCRETION OF PHENPROCOUMON AND ITS METABOLITES IN HUMANS; IDENTIFICATION BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY AND GAS CHROMATOGRAPHY-MASS SPECTROMETRY

1987 ◽  
Author(s):  
J X de Vries ◽  
R Raedsch ◽  
A Stiehl ◽  
U Voelker ◽  
I Walter-Sack ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Gradient Elution ◽  
Reversed Phase ◽  
Gas Chromatography Mass Spectrometry ◽  
Phase Gradient ◽  
Chromatography Mass Spectrometry

Recently it has been shown that in man the oral couma-rin anticoagulant phenprocoumon is eliminated up to 60-70 % in urine and 30-40 % in faeces; in urine phenprocoumon (PH) and its metabolites 7-hydroxy-(7-OH),6-hydroxy-(6-OH) and 4'-hydroxy-(4'-OH) phenprocoumon are present mainly as conjugates. No data so far were available on the biliary excretion of these compounds.We examined bile obtained from four in-patients during PH treatment; bile samples were aspirated in the duodenum at the papilla during routine diagnostic endoscopy and immediately deep frozen before analysis. Samples were extracted both untreated as well as after hydrolysis with 6-glucuronidase/aryl sulfatase and separated by reversed phase gradient elution high performance liquid chromatography (HPLC) with fluorescence detection; for confirmation, the same extracts were methylated and analysed by gas chromatography-mass spectrometry (CG-MS) (J.X.de Vries et al J Chromatogr., 338 (1985) 325). PH, 7-OH, 6-OH and 4'-OH were identified by comparison with synthetic authentic samples'''''''

scholarly journals Bioactive Sesquiterpene Obtained from Schinus areira L. (Anacardiaceae) Essential Oil

Proceedings ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 85
Author(s):  
Silvana Rodriguez ◽  
Rosa Ana Sueiro ◽  
Ana Paula Murray ◽  
José Manuel Leiro
Keyword(s):  
Antioxidant Activity ◽  
High Performance ◽  
Ex Vivo ◽  
Metabolic Activation ◽  
Mutagenic Effect ◽  
13C Nmr Spectroscopy ◽  
Reversed Phase ◽  
Gas Chromatography Mass Spectrometry ◽  
Trolox Equivalent

The essential oils (EOs) from the leaves of Schinus areira and one of its components, globulol, were studied for their antioxidant, antimutagenic and antipromutagenic activities. The chemical composition of the EOs obtained using hydrodistillation was determined using gas chromatography-mass spectrometry (GC-MS), and fractionated using reversed phase high performance liquid chromatography (RP-HPLC). The active compound (16.61%) isolated was identified by comparison of its 1H and 13C NMR spectroscopy with those reported in the literature. The antioxidant activity of the EOs and globulol were determined using two methods: crocin bleaching inhibition (Trolox Equivalent Value, TEV Krel = 1.16 ± 0.11 vs. 1.24 ± 0.22) and scavenging of the DPPH radical (IC50 = 38.75 ± 2.5 μg/mL vs. 5.60 ± 0.9 μg/mL). The antimutagenic and antipromutagenic activities were evaluated in vitro and ex vivo, using the Ames assay with five strains of Salmonella typhimurium with and without exogenous metabolic activation (rat liver fraction S9), against different mutagens. The result determined that globulol and EOs of S. areira at the applied doses do not exhibit any mutagenic effect and showed the highest antioxidant activity.

Hypoxemia raises muscle sympathetic activity but not norepinephrine in resting humans

1989 ◽  
Vol 66 (4) ◽  
pp. 1736-1743 ◽  
Author(s):  
L. B. Rowell ◽  
D. G. Johnson ◽  
P. B. Chase ◽  
K. A. Comess ◽  
D. R. Seals
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Nervous Activity ◽  
Plasma Concentrations ◽  
Random Order ◽  
Sympathetic Nervous Activity ◽  
Severe Hypoxemia ◽  
Arterial Blood ◽  
End Tidal ◽  
Venous Plasma

The experimental objective was to determine whether moderate to severe hypoxemia increases skeletal muscle sympathetic nervous activity (MSNA) in resting humans without increasing venous plasma concentrations of norepinephrine (NE) and epinephrine (E). In nine healthy subjects (20–34 yr), we measured MSNA (peroneal nerve), venous plasma levels of NE and E, arterial blood pressure, heart rate, and end-tidal O2 and CO2 before (control) and during breathing of 1) 12% O2 for 20 min, 2) 10% O2 for 20 min, and 3) 8% O2 for 10 min--in random order. MSNA increased above control in five, six, and all nine subjects during 12, 10, and 8% O2, respectively (P less than 0.01), but only after delays of 12 (12% O2) and 4 min (8 and 10% O2). MSNA (total activity) rose 83 +/- 20, 260 +/- 146, and 298 +/- 109% (SE) above control by the final minute of breathing 12, 10, and 8% O2, respectively. NE did not rise above control at any level of hypoxemia; E rose slightly (P less than 0.05) at one time only with both 10 and 8% O2. Individual changes in MSNA during hypoxemia were unrelated to elevations in heart rate or decrements in blood pressure and end-tidal CO2--neither of which always fell. We conclude that in contrast to some other sympathoexcitatory stimuli such as exercise or cold stress, moderate to severe hypoxemia increases leg MSNA without raising plasma NE in resting humans.

Osmotic regulation of hypothalamo-neurointermediate lobe corticotrophin-releasing factor-41 in the rat

1989 ◽  
Vol 120 (1) ◽  
pp. 119-124 ◽  
Author(s):  
D. S. Jessop ◽  
D. J. A. Eckland ◽  
K. Todd ◽  
S. L. Lightman
Keyword(s):  
High Performance ◽  
Supraoptic Nucleus ◽  
Tap Water ◽  
Plasma Concentrations ◽  
Reversed Phase ◽  
Osmotic Regulation ◽  
Intracerebroventricular Injection ◽  
Neurointermediate Lobe ◽  
Corticotrophin Releasing Factor ◽  
Osmotic Stimulus

ABSTRACT We have detected significant amounts of corticotrophin-releasing factor-41 (CRF-41) in the rat hypothalamo-neurointermediate lobe system using a radioimmunoassay and reversed-phase high-performance liquid chromatography. Total amounts of CRF-41 in extracts of median eminence (ME), supraoptic nucleus (SON), paraventricular nucleus (PVN) and neurointermediate lobe (NIL) from control animals were 1076 ± 132, 196 ± 44, 22 ± 7 and 147 ± 50 fmol respectively (means ± s.e.m., n = 6). In animals given 340 mmol NaCl/l instead of tap water to drink for 12 days, no significant changes occurred in the CRF-41 content of the ME, SON or PVN, but CRF-41 content increased more than twofold in the NIL (362 ± 58 fmol). Plasma concentrations of CRF-41 and ACTH in control animals were 23 ± 6 and 51 ± 8 pmol/l respectively. After saline treatment no significant change in plasma CRF-41 was detected (20 ± 8 pmol/l) but concentrations of circulating ACTH were decreased (15 ± 2 pmol/l). The CRF-41 content of both the ME and the NIL was significantly depleted after intracerebroventricular injection of colchicine (414 ± 81 and 34 ± 7 fmol respectively). These data suggest that NIL CRF-41 is of hypothalamic origin and can be regulated by an osmotic stimulus. Journal of Endocrinology (1989) 120, 119–124

scholarly journals Clinical Evaluation of a Dried Blood Spot Assay for Atazanavir

2010 ◽  
Vol 54 (10) ◽  
pp. 4124-4128 ◽  
Author(s):  
Trevor Van Schooneveld ◽  
Susan Swindells ◽  
Sarah R. Nelson ◽  
Brian L. Robbins ◽  
Ryan Moore ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
High Performance ◽  
Plasma Concentrations ◽  
Reversed Phase ◽  
Hiv Protease ◽  
Dried Blood Spot ◽  
Hiv Protease Inhibitors ◽  
Hiv Rna ◽  
Drug Concentrations ◽  
Blood Spot

ABSTRACT Current procedures for obtaining and measuring plasma concentrations of HIV protease inhibitors (PIs) are technically challenging. Dried blood spot (DBS) assays offer a way to overcome many of the obstacles. We sought to develop a DBS assay for quantitation of the PI atazanavir (ATV) and to compare this method with a previously validated plasma assay. We prospectively enrolled 48 patients with well-controlled HIV disease who had been on ATV for at least 7 days. ATV was quantified from plasma by use of high-performance liquid chromatography (HPLC). A reversed-phase ultrahigh-performance liquid chromatography (UPLC) assay was utilized for DBS samples. The concentrations of ATV quantified in a DBS matrix showed very strong agreement with those measured in plasma (r 2 = 0.988). The mean difference in ATV concentration between the two methods was −10.8% (95% confidence interval [95% CI], −7.65% to −13.95%), indicating that the DBS method has a slight negative bias. A majority (97.8%) of the differences in concentration between the two assays fell within ±2 standard deviations. ATV concentrations were lower in subjects who had detectable HIV RNA in plasma (mean, 543 ng/ml) than in those with HIV RNA of <50 copies/ml (mean, 1,582 ng/ml) (P = 0.03, Wilcoxon rank-sum test). In conclusion, our study demonstrated that ATV quantitation in a DBS matrix is feasible and accurate. DBS use offers a convenient alternative for measuring plasma concentrations of ATV and may have utility in monitoring of drug concentrations in clinical practice and in future studies.

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