Physicochemical stability of norepinephrine bitartrate in polypropylene syringes at high concentrations for intensive care units.

OBJECTIVES: Norepinephrine is usually used in emergency situations such as in intensive care units (ICUs) for the restoration of blood pressure. The objective was to study the stability of highly-concentrated solutions of norepinephrine at 0.50mg/mL and 1.16mg/mL, diluted in glucose 5% (G5%) in polypropylene syringes, protected or not from light, up to 48h. MATERIALS AND METHODS: Chemical stability was analysed by high-performance liquid chromatography coupled to photodiode array detection at each time of the analysis. The method was validated according to the International Conference on Harmonisation Q2(R1). Physical stability was evaluated by visual and subvisual inspection. Three syringes for each condition were prepared. At each time of the analysis, three samples were analysed for each syringe. pH values were evaluated at each moment of the analysis. RESULTS: Solutions of norepinephrine at 0.50 and 1.16mg/mL, diluted in G5%, with or without protection from light, retained more than 95.0% of the initial concentration after a 48-hour storage at 20-25°C. No visual and subvisual modification occured during the stability study. No degradation product appearing during the stressed degradation was observed during the study but an additional peak with a relative retention at 0.66 was observed and constant. This peak was identified as 5-hydroxymethylfurfural, a degradation product of glucose. CONCLUSION: Norepinephrine diluted in G5% at 0.50mg/mL and 1.16mg/mL was physically and chemically stable over a period of 48hours at room temperature. These stability data of highly concentrated solutions provide additional knowledge to assist intensive care services in daily practice.

Segmental Hair Analysis-Interpretation of the Time of Drug Intake in Two Patients Undergoing Drug Treatment.

The present study involved segmental testing of hair in two clinical cases with known dosage histories. Hair analysis confirmed the first patient's exposure to the prescribed sertraline and citalopram for several months. Citalopram was generally distributed along the hair shaft in accordance with the drug ingestion period. By contrast, "false" positive results were observed for sertraline in distal hair segments, corresponding to a period of no sertraline exposure, which may indicate incorporation from sweat or sebum, which transport the drugs along the hair surface. The second patient received various drugs during her treatment for brain cancer. Metoclopramide, morphine, oxazepam, paracetamol, sumatriptan, tramadol, and zopiclone, which had been part of the therapy, were all detected in the proximal hair segment. The results of these two cases indicated that results-especially concerning the time of drug intake-must be interpreted with caution and allow for the possibility of incorporation from sweat or sebum.

Two-dimensional correlation infrared spectroscopy applied to the identification of ephedrine and pseudoephedrine in illegally adulterated slimming herbal products.

Two-dimensional correlation spectroscopy (2DCOS) was employed for the identification of ephedrine (Ep) and pseudoephedrine (Ps) present in illegally adulterated slimming herbal products (SHPs). Second derivative (SD) spectral pretreatment was used prior to 2DCOS analysis to highlight specific features not readily observable by Fourier transform infrared spectroscopy (FTIR), SD-FTIR, or original 2DCOS, leading to enhanced resolution and a reduced lower limit of detection (<1% in this study). After examining the power spectra of suspicious SHPs, bands containing characteristic peaks for Ep (701, 747, 1042, 1363, 1375, 1451, 1478 cm-1 etc) and/or Ps (703, 767, 1037, 1375, 1428, 1455, 1590 cm- 1, etc.) were selected to construct synchronous and asynchronous maps for further analysis, while the latter was applied to discriminate positive SHPs adulterated simultaneously with Ep and Ps. The proposed method is simple and economical and has the potential to identify other chemicals in illegally adulterated herbal products. Copyright © 2016 John Wiley & Sons, Ltd.

8-Isoprostane: a lipid peroxidation product in gingival crevicular fluid in healthy, gingivitis and chronic periodontitis subjects.

OBJECTIVE: The idea that reactive oxygen species (ROS) are associated with the pathogenesis of inflammatory periodontal diseases and have a role (direct or indirect) in tissue damage has become a major area of research over the last decade. The purpose of this study is to determine, presence of 8-isoprostane in gingival crevicular fluid (GCF) in healthy, gingivitis and chronic periodontitis (CP) subjects and to find an association, if any between GCF 8-isoprostane levels and clinical periodontal parameters. MATERIALS AND METHODS: 78 subjects (40 males and 38 females) were selected based on their clinical parameters into three groups: Group 1 (26 healthy), Group 2 (26 gingivitis subjects) and Group 3 (26 CP subjects). GCF 8-isoprostane levels were estimated by ELISA. RESULTS: The 8-isoprostane concentration in GCF was highest in subjects with chronic periodontitis as compared to gingivitis and healthy subjects and a significant association was observed between GCF 8-isoprostane levels and all periodontal parameters. CONCLUSIONS: There was increase in 8-isoprostane levels in GCF as the disease process progressed from health to gingivitis and chronic periodontitis, suggesting a role for increased oxidative stress in CP.

Analytical aspects of marinobufagenin.

Marinobufagenin (MBG), a steroid compound belonging to the bufadienolide cardiac inotropes, is a molecule enjoying a growing interest in the early diagnostic of volume expansion-mediated hypertensive states. This endogenous mammalian cardiotonic and natriuretic bufadienolide (characterized by vasoconstrictive activities) inhibits the α1 isoform of Na(+), K(+)-ATPase, implicating it in series of pathophysiological circumstances such as volume-expansion, essential hypertension and preeclampsia. Indeed, the enhanced production of MBG in preeclamptic patients has been confirmed in several studies, leading us to consider MBG as a biomarker for preeclampsia. The main source for MBG is located in the parotid and skin gland secretions of the toad Bufo marinus in which MBG is the major steroid cardiotonic component. This review emphasizes the key role of analytical development for dosage methods of MBG in biofluids, in the emergence of future perspectives in the diagnostic and therapeutic fields of preeclampsia (e.g. to investigate the biosynthetic origin of MBG and to better understand its implications).

Determination of 8-epi PGF(2alpha) concentrations as a biomarker of oxidative stress using triple-stage liquid chromatography/tandem mass spectrometry.

F2-isoprostanes are a family of prostaglandin F2-like compounds that are formed by free-radical-catalyzed peroxidation of arachidonic acid. Several F2-isoprostanes, but in particular 8-epi PGF(2alpha), are widely used as oxidative stress biomarkers. An analytical method based on liquid chromatography with negative electrospray ionization (ESI) coupled to tandem mass spectrometric detection (LC/MS/MS) was developed for the determination of 8-epi PGF(2alpha) concentrations in human plasma, whole blood, erythrocytes and urine. 8-epi PGF(2alpha)-d4, a stable isotope derivative of 8-epi PGF(2alpha), was used as an internal standard (IS). A 50 microL sample was focused on-column and separated on two 3 microm particle size SUPELCOSIL ABZ+Plus HPLC columns (15 cm x 4.6 mm and 7.5 cm x 4.6 mm) connected in series. An Applied Biosystems 4000 Q TRAP LC/MS/MS system with ESI was operated in multiple reaction monitoring (MRM) mode with the precursor-to-product ion transitions m/z 353.4 --> 193.1 (8-epi PGF(2alpha)), 357.4 --> 197.1 (8-epi PGF(2alpha)-d4), used for quantification. The assay was fully validated and found to have adequate accuracy, precision, linearity, sensitivity and selectivity. The mass limit of detection (mLOD) was 1 pg of analyte eluting from the column. The assay has been successfully applied to the analysis of human plasma, whole blood, erythrocytes and urine samples.

Investigation of vasoactive ion content of herbs used in hemorrhoid treatment in Turkey.

OBJECTIVES: The aim of the present study is to determine anion and cation contents of the herbals used in Turkish folk remedy to explore the rationale of their use in hemorrhoid treatment in the context of the vasoactivity of these elements. DESIGN: Herbs used in the treatment of hemorrhoid were determined by the way of literature search. These herbs were obtained from certified herb sellers. Ground herb samples were placed in individual tubes containing methanol and incubated for 48 hours at 30 degrees C. At the end of the incubation, supernatants were analyzed for their ion concentrations by using ion chromatography. RESULTS: The difference between ion levels between systemic and locally used herbs, was not statistically significant (p>0.05). Anion concentrations (except nitrate) of locally used herbs were slightly higher than systemically used herbs (p>0.05). Cation levels (except magnesium) of systemically used herbs were slightly higher than locally used herbs (p>0.05). It was shown that the concentration of vasoconstrictor effective ions was higher than the concentration of vasodilator effective ions (p<0.001). While vasoconstrictor ion concentration of systemically used herbs was 88.06 +/- 147.42 mg, vasodilator ion concentration of locally used herbs was 90.15 +/- 136.94 mg. The difference between vasodilator concentrations of groups was more evident; 5.39 +/- 9.80 mg and 14.32 +/- 66.48 mg for locally and systemically used herbs respectively. CONCLUSIONS: This study showed that herbal remedies used for the treatment of hemorrhoid in Turkey contain vasoactive and especially vasoconstrictor ions. Vasoconstrictor agents could amplify each others' effects as it has been previously shown, therefore, it is probable that the vasoconstrictor ion contents could contribute to the curative effects of herbals in the treatment of hemorrhoids.

Fatty acid composition of human spermatozoa and seminal plasma levels of oxidative stress biomarkers in subfertile males.

INTRODUCTION: The lipid composition of the sperm membrane has a significant effect on the functional characteristics of spermatozoa. PATIENTS AND METHODS: In the present study, fatty acid composition of spermatozoa and seminal plasma levels of free 15-F(2t)-Isoprostane and catalase were assayed in men with normozoospermia, asthenozoospermia, asthenoteratozoospermia, and oligoasthenoteratozoospermia. RESULTS: In spermatozoa from asthenozoospermic men only oleic acid levels showed a significant difference from normozoospermic men. In spermatozoa from asthenoteratozoospermic and oligoasthenoteratozoospermic samples all of the tested fatty acids were significantly higher than those from normozoospermic samples. Seminal plasma levels of catalase were significantly lower in all patients while levels of free 15-F(2t)-Isoprostane were significantly higher in all patients compared with normozoospermic men. DISCUSSION: Spermatozoa from pathological samples may have higher levels of polyunsaturated fatty acids, especially docosahexaenoic acid (DHA), than spermatozoa from normozoospermic men. Therefore, damage induced by lipid peroxidation would be higher in spermatozoa from pathological samples than those from normozoospermic men.

Biochemical and pharmacological characterization of toxins obtained from the fire coral Millepora complanata.

Millepora complanata is a normal resident of coral reefs in the Mexican Caribbean. In this study, we describe for the first time the vasoconstrictor, phospholipase A2 (PLA2), and hemolytic activities elicited by a crude extract obtained from M. complanata. This extract caused a concentration-dependent contraction of isolated rat aortic rings (EC50=22.4+/-1.1 microg protein/mL). This effect was endothelium independent and significantly reduced in the absence of extracellular Ca2+ and when the intracellular Ca2+ stores were depleted. In addition, the crude extract obtained from M. complanata showed PLA2 activity (7.231+/-0.092 mmol min(-1) mg(-1)) and hemolysis of rat erythrocytes (HU50=1.64+/-1.04 mug protein/mL). The hemolysis increased in the presence of Ca2+ and decreased in the presence of cholesterol. Furthermore, this hemolysis was significantly reduced after incubation with an inhibitor of PLA2 enzymes. The hemolytic and vasoconstrictor effects were abolished after incubating the extract under denaturing conditions. Reverse phase chromatography of the M. complanata extract afforded 19 fractions (F1 to F19). F4 induced hemolysis and contained mainly a protein of 30 kDa, probably a PLA2 enzyme, while F8 and F11, containing mainly proteins of 15 and 20 kDa respectively, produced vasoconstrictor effects mediated by different mechanisms of action.

A rapid and simple procedure for the determination of synephrine in dietary supplements by gas chromatography-mass spectrometry.

A simple and rapid procedure based on gas chromatography-mass spectrometry (GC-MS) is described for determination of synephrine, active principle of Citrus aurantium plant, in solid and liquid dietary supplements. After the addition of 3,4-methylenedioxypropylamphetamine as internal standard (I.S.), a liquid-liquid extraction procedure in alkaline conditions with chloroform/isopropanol (9:1, v/v) was applied to the samples prior to analysis. Chromatography was performed on a fused capillary column and synephrine and I.S., derivatized with pentafluoropropionic anhydride, were determined in the selected-ion-monitoring (SIM) mode. The method was validated in the range 0.1-50 microg/mg or microg/mL synephrine. Mean recovery ranged between 89.3% and 90.5% in both solid and liquid dietary supplements. The quantification limit was 0.1 microg/mg or microg/ml. The method was applied to analysis of various dietary supplements promoted for aiding weight control containing, among other constituents such as ephedrine alkaloids and methylxanthines, Citrus aurantium. Amount of synephrine present in such products ranged from 3.1 microg/mg solid product to 480.2 microg/mL liquid product.

Development and validation of HPLC methods for the analysis of phenethylamine and indoloquinazoline alkaloids in Evodia species.

The aim of this study was to evaluate the chromatographic performance of a PEG stationary phase, in comparison with those of C18 columns, for the HPLC analysis of phenethylamine ((+/-)-synephrine) and indoloquinazoline (rutaecarpine and evodiamine) alkaloids in methanolic extracts of fruits of Evodia rutaecarpa (Juss.) Benth. and E. rutaecarpa (Juss.) Benth. var. officinalis (Dode) Huang (i.e., E. officinalis Dode) (Rutaceae family). The method was validated and showed good linearity, precision, accuracy, sensitivity, and specificity. The highest content of both phenethylamine and indoloquinazoline alkaloids was found in methanolic fruit extracts of E. rutaecarpa, and it was closely related to the degree of maturity. E. officinalis fruits displayed low amounts of both types of alkaloids. Furthermore, an enantioselective HPLC method for the enantioseparation of (+/-)-synephrine from Evodia fruits was applied, by using a protein-based chiral stationary phase with cellobiohydrolase (CBH) as the chiral selector (Chiral-CBH). Isolation of synephrine from Evodia aqueous fruit extracts was carried out by strong cation-exchange SPE. The results of the application of the method to the analysis of Evodia samples showed that (-)-synephrine was the main component while (+)-synephrine was present in low concentration.

Changes in metabolism and blood flow following catecholamine stimulation in the synovial membrane measured with microdialysis.

Adrenergic reactions could mediate metabolic and circulatory changes in the synovial membrane following knee surgery. The interstitial fluid of the synovial membrane and subcutaneous adipose tissue (reference) was monitored in vivo with microdialysis following knee arthroscopy with adrenaline added to the dialysis solvent, adrenaline together with a local anestetic added intra-articularly and without. Local metabolism and blood flow were measured. There was a similar increase, about two fold, in dialysate lactate in all three experimental conditions in the synovial membrane but no change in adipose tissue. Glucose and blood flow decreased by approximately 50% and 10% in both tissues following addition of adrenaline to the dialysate but no changes in the glucose concentrations or blood flow were observed in the other two experimental situations. As regards glycerol the addition of adrenaline caused an approximate 20% increase of the concentration in adipose tissue but an approximate 20% decrease in the synovial membrane. The intra-articular injection caused an approximate 50% increase of the glycerol level in the synovial membrane but no change in adipose glycerol. Thus, the hypermetabolic state in the synovial membrane following standard arthroscopy and the tissue damage (increased glycerol level) in the synovial membrane following postoperative pain relief by intra-articularly injected local anesthetics together with adrenaline doesn't enhance the hypermetabolic state seen postoperatively without adrenaline. However, catecholamines have pronounced in vivo effects on metabolism and blood flow in the synovial membrane.

Arginine vasopressin and adrenocorticotropin secretion in response to psychosocial stress is attenuated by ethanol in sons of alcohol-dependent fathers.

Familial risk and environmental stress promote the development of alcohol dependence. We investigated whether a positive family history of alcoholism affects the neuroendocrine response to a standardized laboratory stress test in healthy subjects without alcohol use disorders. Twenty-four high-risk subjects with a paternal history of alcoholism (PHA) and 16 family history negative (FHN) controls were evaluated. Psychosocial stress was induced by having subjects deliver a 5-min speech and mental arithmetics in front of an audience on separate days, after drinking either placebo or ethanol (0.6 g/kg) in a randomized sequence. Adrenocorticotropin (ACTH) was measured in 10 plasma samples covering up to 75 min after the stress test. Plasma arginine vasopressin (AVP) was determined before the stressor, at the time of maximum ACTH secretion, and at 75 min after stress onset. The stress test induced a phasic increase in ACTH secretion. At the time of maximum ACTH, AVP was significantly increased in relation to baseline. Compared to placebo, alcohol administration significantly attenuated maximum ACTH concentration in PHA but not FHN subjects, and decreased AVP measured in the same samples in PHA but not FHN subjects. We conclude that activation of the hypothalamic-pituitary-adrenal system by psychosocial stress is accompanied by an increase in peripheral plasma AVP levels. Secretion of both ACTH and AVP suggest that alcohol attenuates the stress response selectively in PHA but not FHN subjects. This might imply some short-term positive alcohol effect in sons of alcoholics, but also constitute a mechanism by which their risk to develop alcohol use disorders is increased.

Quantification of 20-hydroxyeicosatetraenoic acid by colorimetric competitive enzyme linked immunosorbent assay.

Analysis of 20-hydroxyeicosatetraenoic acid (20-HETE), a potent vasoconstrictor produced by the cytochrome P450 pathway, presently requires high-performance liquid chromatography (HPLC) and gas chromatography/ mass spectrometry (GC/MS). To simplify 20-HETE analysis, competitive ELISAs were developed using polyclonal anti-20-HETE coated ELISA plates to which free 20-HETE and 20-HETE conjugated to horseradish peroxidase (HRP) or alkaline phosphatase (AP) were added. Assays were developed with and without a pro prietary enhancer solution which allows for the extraction-free measurement of 20-HETE in urine samples. The bound 20-HETE-HRP or 20-HETE-AP was detected using 3,3 ,5,5, -tetramethylbenzidine and p-nitrophenyl phosphate, respectively. Sensitivities expressed as 80% B/B0, were 0.1 ng/ml for the HRP assay, and 0 5 ng/ml for the AP assay, with r2 = 0 99 for both formats. Of the 17 lipids tested for cross-reactivity, arachidonic acid showed the highest (0.32%) followed by racemic 5-HETE (0.07%) and 8,9-dihydroxyeicosatrienoic acid (DHET) (0.04%). Preliminary validation experiments examining serum and urine concentrations of 20-HETE yield values that fall within the ranges established by GC/MS in the literature. These ELISAs provide simple and inexpensive methods for the analysis of 20-HETE in biological samples.

Prevalence of illicit drug use in plasmapheresis donors.

BACKGROUND AND OBJECTIVES: No data are presently available concerning the frequency of illicit drug use in plasmapheresis donors. We therefore examined source plasma units produced in the United States (US) and in Germany for evidence of illicit drug use among donors. MATERIALS AND METHODS: Seventy-five US plasma units from 10 different US states and 75 German plasma units that had been analysed principally for their protein composition were screened for drugs. Determinations were made, using automated immunoassays, of the presence of cannabis, cocaine, amphetamine, methamphetamine, methylenedioxymethamphetamine (MDMA), methylenedioxyethylamphetamine (MDE) and opiates. Positive results were confirmed by gas chromatography-mass spectrometry. RESULTS: Eleven US plasma units were found to be positive for cocaine (14.6%), whereas all German samples were cocaine negative (P = 0.0007). Fifteen US plasma units (20%) and one German unit (1.3%) were confirmed as positive for cannabis (P = 0.0003). Three out of 75 US plasma units were positive for both cannabis and cocaine. In none of the 150 samples were amphetamine, methamphetamine, MDMA, MDE or opiates detected. CONCLUSIONS: Our results strongly suggest differences in cocaine and cannabis consumption between US and German plasmapheresis donors. If these results are confirmed by larger-scale studies, random drug screening (including cocaine) of donors should be implemented in order to reduce the number of drug-containing plasma units, especially in the USA.

A diffusible substance(s) mediates endothelium-dependent contractions in the aorta of SHR.

A modified bioassay system was designed to demonstrate the diffusible nature of endothelium-derived contracting factor(s) released by acetylcholine in the aorta of spontaneously hypertensive rat. In "sandwich"-like layered preparation, isometric tension was recorded from a bioassay strip (without endothelium) in the presence of N(G)-nitro-L-arginine and tetrahydrobiopterin to selectively potentiate endothelium-dependent contractions. A donor strip (with or without endothelium) was stitched on the bioassay tissue so that it did not directly contribute to the recorded contractions. Acetylcholine induced contractions that occurred only when the donor strip was with endothelium. Superoxide dismutase did not affect but catalase and the combination of superoxide dismutase plus catalase significantly decreased the endothelium-dependent contraction. The contractions in the layered preparations were abolished when the donor strip with endothelium was treated previously with valeryl salicylate, an irreversible cyclooxygenase-1 inhibitor, but remained unaffected when the bioassay strip was treated with the compound. Previous treatment of the bioassay strip alone with S 18886 abolished the contractile response, whereas treatment of the donor strip with endothelium by the selective TP receptor antagonist only produced a moderate inhibition. These results indicate that in the aorta of spontaneously hypertensive rats, endothelium-dependent contractions to acetylcholine involve a diffusible substance(s) released by the endothelium. The production of this contracting factor(s) requires the activation of endothelial cyclooxygenase-1, and its action the activation of TP receptors on the vascular smooth muscle cells.

Poly(ethyleneglycol) column for the determination of acetaminophen, phenylephrine and chlorpheniramine in pharmaceutical formulations.

New polar reversed-phase stationary phases in HPLC provide specific selectivities which can help to solve traditional chromatographic problems related to the development of chromatographic methods with widely different retention times for the sample components. One such case is the analysis of pharmaceutical formulations against the common cold. Acetaminophen, phenylephrine and chlorpheniramine, compounds with different polarities, are frequently associated in these drugs. An isocratic and rapid HPLC method for the simultaneous determination of the three compounds, acetaminophen, phenylephrine and chlorpheniramine, in capsules as pharmaceutical formulations, including the separation of impurities (4-aminophenol and 4-chloracetanilide) and excipients, has been developed and validated. The final chromatographic conditions employed a Supelco Discovery HS PEG column poly(ethyleneglycol) 15x0.46 cm, 5 microm. The mobile phase was 20 mM phosphate buffer, pH 7.0-acetonitrile (90:10, v/v) at a flow-rate of 1 ml/min. UV detection was performed at 215 nm for all the compounds except acetaminophen, which was measured at 310 nm. Validation parameters permit us to consider this method suitable.

Papel de la agiotensina II en el desarrollo aterosclerótico: efecto de su bloqueo / Role of angiotensin II in the development of atherosclerosis: effect of blockade

La angiotensina II, el principal efector del sistema renina-angiotensina, ejerce un papel importante en la génesis y en las complicaciones de la aterosclerosis. La angiotensina II estimula la producción de especies reactivas de oxígeno en el vaso que desempeñan un papel clave en la disfunción endotelial y en la oxidación de las lipoproteínas de baja densidad (LDL). Asimismo, este péptido participa en la inducción de la respuesta inflamatoria en la pared vascular mediante la producción de moléculas de adhesión y citoquinas quimiotácticas y proinflamatorias. La angiotensina II, además, estimula la proliferación y migración de células de músculo liso y modula el cambio fenotípico de las mismas dando lugar a un aumento de la síntesis de la matriz extracelular. Finalmente, la angiotensina II también participa en las complicaciones de la aterosclerosis al favorecer la ruptura de la placa y trombogenicidad de la misma. En consecuencia, el sistema renina-angiotensina desempeña un papel clave en la patofisiología de la aterosclerosis, por lo que su bloqueo ejercerá un efecto beneficioso sobre el desarrollo aterosclerótico previniendo las alteraciones trombóticas asociadas a él (AU)

Increased exhaled cysteinyl-leukotrienes and 8-isoprostane in aspirin-induced asthma.

The pathogenesis of aspirin-induced asthma (AIA) has not yet been clearly elucidated, although eicosanoid metabolites appear to play an important role. We hypothesized that levels of eicosanoids in exhaled air condensate are abnormal in patients with AIA and that they change in patients receiving steroid therapy. We measured cysteinyl-leukotrienes (cys-LTs), prostaglandin E(2) (PGE(2)), and leukotriene B(4) (LTB(4)), and also 8-isoprostane as a marker of oxidative stress, by enzyme immunoassay in exhaled breath condensate from patients with AIA (17 steroid naive; mean age, 41 +/- 23 years; FEV(1), 63%pred), 26 patients with aspirin-tolerant asthma (ATA) (11 steroid naive; mean age, 47 +/- 18 years; FEV(1), 69%pred), and 16 healthy subjects (mean age, 45 +/- 17 years; FEV(1), 93%pred). Cys-LTs were significantly higher in steroid-naive patients with AIA compared with steroid-naive patients with ATA and healthy subjects (152.3 +/- 30.4 and 36.6 +/- 7.1 versus 19.4 +/- 2.8 pg/ml; p < 0.05 and p < 0.05, respectively). Steroid-naive patients with AIA also had higher levels of 8-isoprostane than normal subjects (131.8 +/- 31.0 versus 21.9 +/- 4.5 pg/ml; p < 0.05). There were significantly lower levels of both cys-LTs and 8-isoprostanes in steroid-treated patients with AIA. There was no difference in either the PGE(2) or LTB(4) level between the patient groups. This is the first study to show that cys-LTs and 8-isoprostanes are elevated in expired breath condensate of steroid-naive patients with AIA, and that cys-LTs are decreased in steroid-treated patients. Exhaled PGE(2) levels are not reduced, so that it is unlikely that a deficiency of PGE(2) is an important mechanism, whereas exhaled LTB(4) levels are unchanged, indicating an abnormality beyond 5-lipoxygenase.

[Validation of the HPLC method in the determination of dioxopromethazine and phenylephrine in eye drops]. / Validácia HPLC metódy pre stanovenie dioxoprometazínu a fenylefrínu v ocnej instilácii.

The present paper introduces a rapid HPLC method for the determination of dioxopromethazine and phenylephrine in eye drops. The method uses a modified C18 stationary phase optimized for the separation of basic compounds and a methanol/1.5 mM phosphoric acid (60/40 v/v, pH 3.02) mobile phase. The flow rate is set to 2 ml/min, sample volume 20 microliters, and compounds are detected at 275 nm. Prior to analysis, the eye drops are diluted with water in a ratio of 1:50. The elaborated HPLC method and the chromatographic system were validated according to the procedure for the validation of chromatographic systems and methods.