Search results for "diuretic"

Effects of pH and the presence of micelles on the resolution of diuretics by reversed-phase liquid chromatography

2004

A comparative study on the performance of two RPLC modes on the separation of 18 diuretics with diverse acid-base behaviour (acetazolamide, althiazide, amiloride, bendroflumethiazide, benzthiazide, bumetanide, canrenoic acid, chlorothiazide, chlorthalidone, ethacrynic acid, furosemide, hydrochlorothiazide, piretanide, probenecid, spironolactone, triamterene, trichloromethiazide and xipamide) was carried out. A conventional octadecylsilane column and acidic acetonitrile-water mobile phases, in the absence and presence of micelles of the anionic surfactant sodium dodecyl sulphate (SDS), were used. The effects of pH and the modifiers acetonitrile and SDS on peak asymmetry, efficiency, selectiv…

Chromatographic monitoring of diuretics in urine samples using a sodium dodecyl sulphate—propanol micellar eluent

1994

Abstract The effect of a varying pH, in the range 3−7, on the retention of several diuretics eluted with a sodium dodecyl sulphate (SDS) micellar mobile phase and with UV detection was studied. Significant changes in the capacity factors ( K′ of the diuretics bumetanide, ethacrynic acid, furosemide, probenecid and xipamide were observed. The protonation constants of these compounds were calculated from the k′ data. A study was also performed to select the optimum composition of the mobile phase (pH, concentration of SDS and nature and concentration of alcohol) for the separation of the above diuretics and the diuretics amiloride, bendroflumethiazide, chlorthalidone, hydrochlorothiazide, spi…

Chromatographic determination of diuretics in urine samples using hybrid micellar mobile phases with fluorimetric detection

1998

Abstract A rapid and simple chromatographic procedure, that uses hybrid micellar mobile phases of sodium dodecyl sulphate (SDS), propanol and phosphate buffer at pH 3, and fluorimetric detection ( λ exc =270 nm, λ em =430 nm), is reported for the determination of mixtures of seven diuretics of diverse efficacy (amiloride, bendroflumethiazide, bumetanide, furosemide, hydroflumethiazide, piretanide and triamterene), in urine samples. The application of a sequential optimization procedure for the resolution of the mixtures of the diuretics was problematic. However, their separation was achieved through the use of an interpretive optimization procedure based on the accurate description of the r…

Agonist and antagonist-dependent internalization of the human vasopressin V2 receptor.

1998

Abstract In this report we demonstrate that in HEK293 cells stably expressing the human V2vasopressin receptor, ligand-induced internalization of the hormone receptor occurs via the clathrin-dependent pathway. Studies of receptor trafficking either by direct visualization of the V2receptor by confocal microscopy or binding experiments show a rapid internalization (half-time 6–7 min). Blocking of the clathrin-dependent pathway by hypertonic sucrose increased vasopressin-induced cellular cAMP production and decreased the desensitization of the V2receptor–adenylyl cyclase system. Thus, internalization appears to be a major regulatory mechanism terminating vasopressin action in HEK293 cells. Tw…

Multi-scale optimisation vs. genetic algorithms in the gradient separation of diuretics by reversed-phase liquid chromatography

2019

Abstract Multi-linear gradients are a convenient solution to get separation of complex samples by modulating carefully the gradient slope, in order to accomplish the local selectivity needs for each particular solute cluster. These gradients can be designed by trial-and-error according to the chromatographer experience, but this strategy becomes quickly inappropriate for complex separations. More evolved solutions imply the sequential construction of multi-segmented gradients. However, this strategy discards part of the search space in each step of the construction and, again, cannot deal properly with very complex samples. When the complexity is too large, the only valid alternative for fi…

Peak capacity estimation in isocratic elution.

2008

Peak capacity (i.e. maximal number of resolved peaks that fit in a chromatographic window) is a theoretical concept with growing interest, but based on a situation rarely met in practice. Real chromatograms tend to have uneven distributions, with overlapped peaks and large gaps. The number of resolved compounds should, therefore, be known from estimations. Several equations have been reported for this purpose based on three perspectives, namely, the intuitive approach (peak capacity as the size of the retention time window measured in peak width units), which assumes peaks with the same width, and the outlines of Giddings and Grushka, which consider changes in peak width with retention time…

Combined effect of solvent content, temperature and pH on the chromatographic behaviour of ionisable compounds.

2008

The organic solvent content and the pH in the mobile phase are the usual main factors in reversed-phase liquid chromatographic separations, owing to their strong effects on retention and/or selectivity. Temperature is often neglected. However, even in cases where the impact of this factor on selectivity is minor, the reduction in analysis time is still an interesting reason to consider it. In addition, ionisable compounds may exhibit selectivity changes, owing to the interaction of organic solvent and/or temperature with pH. The separation of ionisable compounds (nine diuretics: bendroflumethiazide, benzthiazide, bumetanide, chlorthalidone, furosemide, piretanide, probenecid, trichloromethi…

Trattamento cronico con diuretici ed omeostasi glico-metabolica in un campione di adulti privi di diabete noto

Lewosimendan - cenny gracz w leczeniu ciężkiej prawokomorowej niewydolności krążenia

2019

66-letni otyły mężczyzna, obciążony cukrzycą typu 2 i nadciśnieniem tętniczym, przewlekłą chorobą nerek w okresie 4, utrwalonym migotaniem przedsionków z bradykardią, przyjęty został na oddział kardiologii z powodu objawów ciężkiej prawokomorowej niewydolności krążenia. W leczeniu zastosowano standardową terapię, w tym złożone leczenie moczopędne. Z uwagi na jej nieskuteczność rozpoznano oporność na diuretyki i włączono do leczenia lewosimendan, uzyskując obfitą diurezę, znaczną redukcję wagi ciała i istotną poprawę wydolności krążenia, co pozwoliło na dalszą diagnostykę i adekwatne, przyczynowe leczenie zabiegowe. W artykule zarysowano ponadto aktualny stan wiedzy na temat miejsca lewosime…

Rationale and Design of the Efficacy of a Standardized Diuretic Protocol in Acute Heart Failure Study

2021

AIMS: Although acute heart failure (AHF) with volume overload is treated with loop diuretics, their dosing and type of administration are mainly based upon expert opinion. A recent position paper from the Heart Failure Association (HFA) proposed a step-wise pharmacologic diuretic strategy to increase the diuretic response and to achieve rapid decongestion. However, no study has evaluated this protocol prospectively. METHODS AND RESULTS: The Efficacy of a Standardized Diuretic Protocol in Acute Heart Failure (ENACT-HF) study is an international, multicentre, non-randomized, open-label, pragmatic study in AHF patients on chronic loop diuretic therapy, admitted to the hospital for intravenous …