Chlorpromazine quantification in human plasma by UPLC-electrospray ionization tandem mass spectrometry. Application to a comparative pharmacokinetic study

In the present study a method to quantify chlorpromazine in human plasma using cyclobenzaprine as the internal standard (IS) is described. The analyte and the IS were extracted from human plasma by a liquid-liquid extraction with diethyl ether/dichloromethane (70/30, v/v) and analyzed by an ultra performance liquid chromatography (UPLC) coupled to an electrospray tandem triple quadrupole mass spectrometer in positive mode (UPLC-ES(+)-MS/MS). Chromatography was performed isocratically on an Aquity UPLC BEH C18 1.7 μm (50 mm × 2.1 mm i.d.) operating at 40°C. The mobile phase was a mixture of 65% water+1% formic acid and 35% of acetonitrile at a flow-rate of 0.5 mL/min. The lowest concentration quantified was 0.5 ng/mL and a linear calibration curve over the range 0.5-200 ng/mL was obtained, showing intra-assay precisions from 2.4 to 5.8%, and inter-assay precisions from 3.6 to 9.9%. The intra-assay accuracies ranged from 96.9 to 102.5%, while the inter-assay accuracies ranged from 94.1 to 100.3%. This analytical method was applied in a relative bioavailability study in order to compare a test chlorpromazine 100 mg simple dose formulation versus a reference in 57 volunteers of both sexes. The study was conducted in an open randomized two-period crossover design and with a fourteen days washout period. Plasma samples were obtained over a 144-h interval. Since the 90% CI for both C(max), AUC(last) and AUC(0-inf) were within the 80-125% interval proposed by the Food and Drug Administration and ANVISA, it was concluded that chlorpromazine 100 mg/dose was bioequivalent to the reference formulation, according to both the rate and extent of absorption.     

Progressive hypervolemia despite hypoproteinemia and massive edema formation in rats with nephrotoxic serum nephritis.

Blood volume and whole kidney and single nephron function were evaluated 2 and 10 days after nephrotoxic serum nephritis (NSN) induction in Wistar rats. Progressive proteinuria, hypervolemia and edema were observed in NSN rats. Sodium retention was associated with a progressive depression of single nephron glomerular filtration rate and elevated fractional tubular reabsorption rates. Since hypervolemia rather than hypovolemia was observed in this study, edema formation must have been a consequence of intrarenal rather than extrarenal phenomena.     

Filling the gap - COI barcode resolution in eastern Palearctic birds

Background

Many fish species experience long periods of fasting in nature often associated with seasonal reductions in water temperature and prey availability or spawning migrations. During periods of nutrient restriction, changes in metabolism occur to provide cellular energy via catabolic processes. Muscle is particularly affected by prolonged fasting as myofibrillar proteins act as a major energy source. To investigate the mechanisms of metabolic reorganisation with fasting and refeeding in a saltwater stage of Atlantic salmon (Salmo salar L.) we analysed the expression of genes involved in myogenesis, growth signalling, lipid biosynthesis and myofibrillar protein degradation and synthesis pathways using qPCR.

Results

Hierarchical clustering of gene expression data revealed three clusters. The first cluster comprised genes involved in lipid metabolism and triacylglycerol synthesis (ALDOB, DGAT1 and LPL) which had peak expression 3-14d after refeeding. The second cluster comprised ADIPOQ, MLC2, IGF-I and TALDO1, with peak expression 14-32d after refeeding. Cluster III contained genes strongly down regulated as an initial response to feeding and included the ubiquitin ligases MuRF1 and MAFbx, myogenic regulatory factors and some metabolic genes.

Conclusion

Early responses to refeeding in fasted salmon included the synthesis of triacylglycerols and activation of the adipogenic differentiation program. Inhibition of MuRF1 and MAFbx respectively may result in decreased degradation and concomitant increased production of myofibrillar proteins. Both of these processes preceded any increase in expression of myogenic regulatory factors and IGF-I. These responses could be a necessary strategy for an animal adapted to long periods of food deprivation whereby energy reserves are replenished prior to the resumption of myogenesis.     

Mid-Holocene vegetation dynamics with an early expansion of <Emphasis Type="Italic">Mauritia flexuosa</Emphasis> palm trees inferred from the Serra do Tepequém in the savannas of Roraima State in Amazonia,northwestern Brazil

Transition zones between forest and savanna in northern South America are important areas for improving our understanding of ecosystem dynamics and climate change. The uniquely available mid-Holocene sediment deposits from the Serra do Tepequém plateau in Roraima State, northwestern Brazil, were used to analyze past forest-savanna dynamics through pollen, spores, microcharcoal and loss on ignition (LOI). In this newly studied landscape, two distinct periods of vegetation, fire and climate dynamics have been recorded. The first phase from ca. 7,570 to 6,190 cal bp, with the dominance of savanna vegetation in particular with Poaceae and Cyperaceae and some small forest patches with Moraceae/Urticaceae, Alchornea and Schefflera, indicates a relatively dry period. Based on the microcharcoal concentration and influx data, frequent regional fires occurred at that time. The second phase from ca. 6,190 to 4,900 cal bp shows a change in the vegetation composition with an increase of Ilex, Schefflera and Fabaceae. In this period forest expanded, while savanna became reduced, reflecting an increase of wetter conditions. The fire frequency was markedly lower. The first occurrence of Mauritia flexuosa palm was at ca. 7,300 cal bp and an early expansion occurred at around 6,600 cal bp. This early expansion of M. flexuosa showed a development that was in opposition to the increase of fire and savanna expansion found in other regions in northern South America. The increase of wetter conditions in Serra do Tepequém in the mid-Holocene confirms other results found in savannas of Colombia and Venezuela between 7,000 and 6,600 cal bp.     

Correlation of male genital filaments and female spermathecal ducts in New World sand flies of the Lutzomyia intermedia species complex (Diptera: Psychodidae,Phlebotominae)

The lengths of the male genital filaments and female spermathecal ducts were measured in phlebotomine sand flies of the Lutzomyia intermedia species complex and the ratios between these characters calculated. Ratios for L. intermedia s. s. from Northeast vs Southeast Brazil (Espírito Santo and Minas Gerais), Espírito Santo/Minas Gerais vs Rio de Janeiro/S?o Paulo and L. intermedia vs L. neivai were significantly different at P < 0.1, 0.05 and 0.01 respectively when compared using ANOVA. The spermathecal ducts and genital filaments of L. intermedia were significantly longer than those of L. neivai (P < 0.01) and could be used to differentiate these species. The taxonomic and biological significance of these differences is discussed.     

In vivo effects of the controlled NO donor/scavenger ruthenium cyclam complexes on blood pressure

Ruthenium(II/III) complexes able to bind and release NO* were tested in vivo, in conscious Wistar rats instrumented for continuous blood pressure (BP) measurement and administration of in bolus injections (5 to 100 nmol/Kg i.v.) of trans-[Ru(II)Cl(NO+)(cyclam)](PF6)2 (cyclam-NO) or sodium nitroprusside (SNP). For normotensive rats, cyclam-NO produced a sustained 10% BP reduction of basal MAP during 7 +/- 0.4 to 11 +/- 0.3 min. In acute hypertensive rats, cyclam-NO produced BP reduction 3-fold larger than in normotensive rats and similar to that of SNP (maximal effect: 41 +/- 1.3 vs. 45 +/- 2.2 mmHg, respectively). However, the duration of the effect of cyclam-NO was 13 to 21-fold longer than that of SNP. The hypotensive effect of cyclam-NO was fully blocked in presence of continuous infusion of a NO* scavenger, carboxy-PTIO (6 mmol/Kg/min), or of the inhibitor of cGMP activation, methylene blue (83 nmol/Kg/min), or of the cyclam-NO precursor, trans-[RuCl(tfins)(cyclam)](tfms) (cyclam-tfms) (500 mmol/Kg/min). The long lasting BP reduction of cyclam-NO can be interpreted in terms of a slower rate of NO* release (k-NO = 2.2 x 10(-3) S(-1) at 35 degrees C) following chemical reduction (E(0') = 0.10 V vs NHE). In summary, cyclam-NO showed an hypotensive effect around 20 times longer than SNP in either normotensive or hypertensive rats, which was completely inhibited by methylene blue or carboxy-PTIO. Continuous infusion of cyclam-tfms completely blocked the hypotensive effect of cyclam-NO by scavenging the NO* released by the reduced cyclam-NO.     

A taxonomic review of Aramides cajaneus (Aves,Gruiformes, Rallidae) with notes on morphological variation in other species of the genus

The taxonomy of the polytypic and wide-ranging Gray-necked Wood-rail, Aramides cajaneus is reviewed, based on external morphology and voice. Throughout its distribution, there is extensive plumage variation, much of it taxonomically uninformative. However, through three informative plumage characters, as well as morphometric and vocal variation, three phylogenetic species were identified within what is today known as Aramides cajaneus, all of which already had available names: Aramides albiventris Lawrence, 1868, from southern Mexico to northeastern Costa Rica, Aramides cajaneus (Statius Müller, 1776) (sensu stricto), from southwestern Costa Rica to Argentina, and Aramides avicenniae Stotz, 1992, from a small section of the coast of southeastern Brazil. Aramides albiventris presents extensive plumage variation, but with no geographic structure. The song of Aramides cajaneus and Aramides avicenniae is strikingly and completely different from the song of Aramides albiventris. A previously unnoticed parapatric pattern of distribution of Aramides cajaneus and its congener Aramides saracura in southeastern Brazil is described, and we clarify that the name Aramides plumbeicollis, included in the synonymy of Aramides albiventris, was first made available in 1892, rather than in 1888 as is widely referred. In addition, plumage variation in Aramides ypecaha, Aramides wolfi, and Aramides mangle is discussed.