Simultaneous analysis of the enantiomers of verapamil and norverapamil in rat plasma by liquid chromatography tandem mass spectrometry

An enantioselective micromethod for the simultaneous analysis of verapamil (VER) and norverapamil (NOR) in plasma was developed, validated and applied to the study of the kinetic disposition of VER and NOR after the administration of a single oral dose of racemic-VER to rats. VER, NOR and the internal standard (paroxetine) were extracted from only 100-mu L plasma samples using n-hexane and the enantiomers were resolved on a Chiralpak AD column using n-hexane:isopropanol: ethanol: diethyl ami ne (88:6:6:0.1) as the mobile phase. The analyses were performed in the selected reaction monitoring mode. Transitions 456 > 166 for VER enantiomers, 441 > 166 for NOR enantiomers and 330 > 193 for the internal standard were monitored and the method had a total chromatographic run time of 12 min. The method allows the determination of VER and NOR enantiomers at plasma levels as low as 1.0 ng/mL. Racemic VER hydrochloride (10 mg/kg) was given to male Wistar rats by gavage and blood samples were collected from 0 to 6.0 h(n = 6 at each time point). The concentration of (-)-(S)-VER was three folds higher than (+)-(R)-VER, with an AUC ratio (-)/(+) of 2.66. Oral clearance values were 12.17 and 28.77 L/h/kg for (-)-(S)-VER and (+)-(R)-VER, respectively. The pharmacokinetic parameters of NOR were not shown to be enantioselective. (c) 2007 Elsevier B.V. All rights reserved.

Reversed phase HPLC determination of zidovudine in rat plasma and its pharmacokinetics after a single intranasal dose administration

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Investigation of Plasma Immersion Ion Implantation Process in Magnetic Mirror Geometry

Plasma immersion ion implantation (PIII) with low external magnetic field has been investigated both numerically and experimentally. The static magnetic field considered is essentially nonuniform and is generated by two magnetic coils installed outside the vacuum chamber. Experiments have been conducted to investigate the effect of two of the most important PIII parameters: target voltage and gas pressure. In that context, it was found that the current density increased when the external parameters were varied. Later, the PIII process was analyzed numerically using the 2.5-D computer code KARAT. The numerical results show that the system of crossed E x B fields enhances the PIII process. The simulation showed an increase of the plasma density around the target under the operating and design conditions considered. Consequently, an increase of the ion current density on the target was observed. All these results are explained through the mechanism of gas ionization by collisions with electrons drifting in crossed E x B fields.

Semen parameters, fertility and testosterone levels in male rats exposed prenatally to betamethasone

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Plasma concentrations and placental immunostaining of interleukin-10 and tumor necrosis factor-alpha as predictors of alterations in the embryo-fetal organism and the placental development of diabetic rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Experimental pancreas transplantation: the consequences of the portocaval shunt on the blood glucose, plasma insulin, and glucagon

A proposição foi realizada, no período pós-operatório imediato, em 40 ratos Wistar, distribuídos por sorteio em doi grupos: grupo NC, vinte ratos correspondentes ao grupo controle, não diabético, submetidos a operação simulada e o grupo PT, 20 ratos correspondentes ao grupo diabético que recebeu transplante de pâncreas heterotópico de ratos Wistar normais. Durante sete dias, antes do transplante, e 1, 3, 6, 12, 24, 48, 72, 96 horas após, determinava-se a glicose sanguínea, a insulina plasnática e o glucagon. Estes parâmetros eram obtidos também do grupo NC. Diabetes mellitus experimental era induzida pela administração intravenosa de aloxana. O grupo PT era imunosuprimido com ciclosporina A. O grupo NC apresentou níveis normais de glicose sanguínea, de insulina plásmica e de glucagon, durante todo o experimento. Foi encontrada nítida hiperinsulinemia no sangue venoso periférico do grupo PT. A insulina plasmática era significantemente maior no grupo PT comparada ao grupo NC começando 72 horas após o transplante. O glucagon plasmático, elevado no período pré-transplante, não se alterou após o transplante. Apesar de hiperinsulinemia e hiperglucagonemia, os níveis de glicose sanguínea eram elevados 6 horas após o transplante e mantiveram-se normais após este período. Considerando-se os níveis de glicose sanguínea 12 horas pós-transplante, não houve diferença estatisticamente significante entre os grupos PT e NC, até o sacrifício.

Prognostic value of canine frozen-thawed semen parameters on in vitro sperm-oocyte interactions

Combining the data from conventional semen analysis with oocyte penetration assays should improve the assessment of the fertilizing ability of a semen sample. Thus, the objective of the present study was to evaluate the prognostic value of various semen parameters on the in vitro interactions between frozen-thawed canine sperm and homologous oocytes. Ten ejaculates from five stud dogs (two ejaculates/dog) were collected by digital manipulation. Semen samples were evaluated, extended in Tris-egg yolk-glycerol, frozen and stored in liquid nitrogen, and thawed several weeks later. Samples were evaluated for motility and sperm populations by computer-aided semen analysis (CASA), plasma membrane integrity (carboxy-fluorescein diacetate and propidium iodide), and sperm morphology (Bengal Rose). Thawed spermatozoa were also incubated with homologous oocytes for 18 h in an atmosphere of 5% CO2 and 95% air at 38 degrees C and sperm-oocyte interactions were evaluated. Simple linear regression models were calculated, with sperm parameters as independent variables and sperm-oocyte interactions as the dependent variable. There were significant associations between: percentage of oocytes bound to spermatozoa and beat cross frequency (BCF; R-2 = 63%); percentage of oocytes that interacted with spermatozoa and BCF (R-2 = 73%); and number of penetrated spermatozoa and velocity average pathway (VAP; R-2 = 64%) and velocity straight line (VSL; R-2 = 64%). Although plasma membrane integrity and sperm morphology had little prognostic value for in vitro interactions between canine frozen-thawed sperm and homologous oocytes, some motility patterns (evaluated by CASA) were predictive of in vitro sperm-oocyte interactions. (c) 2005 Elsevier B.V. All rights reserved.

Heparin-binding proteins of canine seminal plasma

Heparin-binding proteins (HBP) from seminal plasma have been expected to participate in modulation of the acrosomal reaction, and have been correlated with fertility in some species. However, they have not been described in the dog. The aim of this study was to document the HBPs of canine seminal plasma. Six pooled samples of seminal plasma from three crossbred dogs were used. The HBPs were isolated by heparin affinity chromatography and the fractions recovered were pooled. One-dimensional sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) was carried out on 12 and 18% vertical minigels. The stained gels were scanned and the molecular weight (kDa) values for each band within a lane were calculated by image analysis software. The electrophoresis analysis of the pooled eluded fractions identified 19 bands, with molecular weights varying from 61.5 to 5.2 kDa. Previous studies, using one-dimensional SDS-PAGE, identified two bands (67 and 58.6 kDa), which were positively correlated with some semen parameters (sperm motility, sperm vigor, percentage of morphologically normal sperm and plasma membrane integrity). The 61.5 kDa band detected in the present study apparently corresponded to the 58.6 kDa band identified previously. Canine seminal plasma contained HBP; since HBP modulate the acrosome reaction in other species, they may have the same function in the dog. Further studies are necessary to better characterize this protein and determine if it is associated with fertility in the dog. (c) 2006 Elsevier B.V. All rights reserved.

Argon-based atmospheric pressure plasma enhances early bone response to rough titanium surfaces

This study investigated the effect of an Argon-based atmospheric pressure plasma (APP) surface treatment operated chairside at atmospheric pressure conditions applied immediately prior to dental implant placement in a canine model. Surfaces investigated comprised: rough titanium surface (Ti) and rough titanium surface + Argon-based APP (Ti-Plasma). Surface energy was characterized by the Owens-Wendt-Rabel-Kaelble method and chemistry by X-ray photoelectron spectroscopy (XPS). Six adult beagles dogs received two plateau-root form implants (n = 1 each surface) in each radii, providing implants that remained 1 and 3 weeks in vivo. Histometric parameters assessed were bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO). Statistical analysis was performed by Kruskall-Wallis (95% level of significance) and Dunn's post-hoc test. The XPS analysis showed peaks of Ti, C, and O for the Ti and Ti- Plasma surfaces. Both surfaces presented carbon primarily as hydrocarbon (C?C, C?H) with lower levels of oxidized carbon forms. The Ti-Plasma presented large increase in the Ti (+11%) and O (+16%) elements for the Ti- Plasma group along with a decrease of 23% in surface-adsorbed C content. At 1 week no difference was found in histometric parameters between groups. At 3 weeks significantly higher BIC (>300%) and mean BAFO (>30%) were observed for Ti-Plasma treated surfaces. From a morphologic standpoint, improved interaction between connective tissue was observed at 1 week, likely leading to more uniform and higher bone formation at 3 weeks for the Ti-Plasma treated implants was observed. (C) 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 2012.

Influence of eNOS gene polymorphism on cardiometabolic parameters in response to physical training in postmenopausal women

The health-promoting effects of exercise training (ET) are related to nitric oxide (NO) production and/or its bioavailability. The objective of this study was to determine whether single nucleotide polymorphism of the endothelial NO synthase (eNOS) gene at positions -786T>C, G894T (Glu298Asp) and at the variable number of tandem repeat (VNTR) Intron 4b/a would interfere with the cardiometabolic responses of postmenopausal women submitted to physical training. Forty-nine postmenopausal women were trained in sessions of 30-40 min, 3 days a week for 8 weeks. Genotypes, oxidative stress status and cardiometabolic parameters were then evaluated in a double-blind design. Both systolic and diastolic blood pressure values were significantly reduced after ET, which was genotype-independent. However, women without eNOS gene polymorphism at position -786T>C (TT genotype) and Intron 4b/a (bb genotype) presented a better reduction of total cholesterol levels (-786T>C: before = 213 ± 12.1, after = 159.8 ± 14.4, Δ = -24.9% and Intron 4b/a: before = 211.8 ± 7.4, after = 180.12 ± 6.4 mg/dL, Δ = -15%), and LDL cholesterol (-786T>C: before = 146.1 ± 13.3, after = 82.8 ± 9.2, Δ = -43.3% and Intron 4b/a: before = 143.2 ± 8, after = 102.7 ± 5.8 mg/dL, Δ = -28.3%) in response to ET compared to those who carried the mutant allele. Superoxide dismutase activity was significantly increased in trained women whereas no changes were observed in malondialdehyde levels. Women without eNOS gene polymorphism at position -786T>C and Intron 4b/a showed a greater reduction of plasma cholesterol levels in response to ET. Furthermore, no genotype influence was observed on arterial blood pressure or oxidative stress status in this population.

RESPONSES of HEMATOLOGICAL PARAMETERS and AEROBIC PERFORMANCE of ELITE MEN and WOMEN SWIMMERS DURING A 14-WEEK TRAINING PROGRAM

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evaluation of the haematological parameters in Piaractus mesopotamicus Holmberg (Osteichthyes, Characidae) with Argulus sp. (Crustacea, Branchiura) infestation and treatment with organophosphate

Haematological parameters as erythrocytes, leukocytes and plasma glucose in Piaractus mesopotamicus Holmberg, 1887 were analyzed. Fish were parasitized with Argulus sp. (Crustacea, Branchiura) and treated with 0.4 mg of thriclorphon 500/L water. The effects of parasitism and the action of the treatment were evaluated. Parasitized fish showed greater number of monocytes (P>0.05) and special granulocitic cells (P<0.01) in the peripheric blood than the unparasitized (control) fish. Parasitized fish showed lower number of thrombocytes (P>0.05). Organophosphate treatment presented significantly reduction (P>0.05) in red blood cells (RBC) and hemoglobin.

The acid-base impact of free water removal from, and addition to, plasma

Water, compared with plasma at a pH of 7.4, is a weak acid. The addition of free water to a patient should have an acidifying effect (dilutional acidosis) and the removal of it, an alkalinizing effect (concentrational alkalosis). The specific effects of free water loss or gain in a relatively complex fluid such as plasma has, to the authors' knowledge, not been reported. This information would be useful in the interpretation of the effect of changes in free water in patients. Plasma samples from goats were either evaporated in a tonometer to 80% of baseline volume or hydrated by the addition of distilled water to 120% of baseline volume. The pH and partial pressure of carbon dioxide, sodium, potassium, ionized calcium, chloride, lactate, phosphorous, albumin, and total protein concentrations were measured. Actual base excess (ABE), standard bicarbonate, anion gap, strong ion difference, strong ion gap, unmeasured anions, and the effects of sodium, chloride, phosphate, and albumin changes on ABE were calculated. Most parameters changed 20% in proportion to the magnitude of dehydration or hydration. Bicarbonate concentration, however, increased only 11% in the evaporation trial and decreased only -2% in the dehydration trial. The evaporation trial was associated with a mild, but significant, metabolic alkalotic effect (ABE increased 3.2 mM/L), whereas the hydration trial was associated with a slight, insignificant metabolic acidotic effect (ABE decreased only 0.6 mM/L). The calculated free water ABE effect (change in sodium concentration) was offset by opposite changes in calculated chloride, lactate, phosphate, and albumin ABE effects.

On-line determination of Sb(III) and total Sb using baker's yeast immobilized on polyurethane foam and hydride generation inductively coupled plasma optical emission spectrometry

The yeast Saccharomyces cerevisiae was immobilized in cubes of polyurethane foam and the ability of this immobilized material to separate Sb(III) and Sb(V) was investigated. A method based on sequential determination of total Sb (after on-line reduction of Sb(V) to Sb(III) with thiourea) and Sb(Ill) (after on-line solid-liquid phase extraction) by hydride generation inductively coupled plasma optical emission spectrometry is proposed. A flow system assembled with solenoid valves was used to manage all stages of the process. The effects of pH, sample loading and elution flow rates on solid-liquid phase extraction of Sb(III) were evaluated. Also, the parameters related to online pre-reduction (reaction coil and flow rates) were optimized. Detection limits of 0.8 and 0.15 mu g L-1 were obtained for total Sb and Sb (III), respectively. The proposed method was applied to the analysis of river water and effluent samples. The results obtained for the determination of total Sb were in agreement with expected values, including the river water Standard Reference Material 1640 certified by the National Institute of Standards and Technology (NIST). Recoveries of Sb(III) and Sb(V) in spiked samples were between 81 19 and I I I 15% when 120 s of sample loading were used. (c) 2006 Elsevier B.V. All rights reserved.

Determination of Cd(II) and Cd-metallothioneins in biological extracts using baker's yeast and inductively coupled plasma optical emission spectrometry

The use of Saccharomyces cerevisiae as a sorbent material to separate Cd(II) and Cd-metallothionein complex (Cd-MT) has been explored. Solid-liquid phase extractions were carried out in batch mode and the main parameters of the process (pH, temperature, time of incubation, amount of biomass and analyte) were evaluated. Under optimized conditions, the yeast quantitatively retain (94 +/- 5%) the Cd(II) while 97 +/- 2% of the Cd-MT remain in the supernatant. on base of the findings of this study, a simple method is proposed to determine Cd(II) and Cd-MT in cytosols extracted from mouse kidney and crab hepatopancreas. Inductively coupled plasma optical emission spectrometry was used to quantify the analytes in solid and liquid phase. Determination of Cd in the solid phase was carried out by introducing a slurry of the yeast (0.0625 g/10 mL) directly to the inductively coupled plasma optical emission spectrometer. Mixed standards solutions, which also have been submitted to the extraction procedure, were used to quantify the analytes in the samples. Thus, matrix effects due to nebulization of the slurry were overcame. Limits of detection (3 sigma) for Cd(II) and Cd-MT were 1.5 and 1.2 mu g L-1, respectively. Relative standard deviations of signals were 4.2% for measurements in the slurry of solid phase and 2.1% for measurements in the liquid phase. Recoveries of the analytes in cytosol samples were between 76 and 114%. The concentrations of Cd(II) (2.4 +/- 0.5 mu g L-1) and Cd-MT (3.0 +/- 0.5 mu g L-1) found by using the proposed approach were close to those found by tangential-flow ultrafiltration technique (2.6 +/- 0.7 mu g L-1 for Cd(II) and 3.7 +/- 1.7 mu g L-1 for Cd-MT).