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Detectable Concentrations (detectable + concentration)
Selected AbstractsProspective Clinical Evaluation of Serum Cardiac Troponin T in Dogs Admitted to a Veterinary Teaching HospitalJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 5 2002Teresa C. DeFrancesco The purpose of this study was to measure serum cardiac troponin T (cTnT) with a commercially available human enzyme-linked immunoassay (ELISA) test in various groups of dogs, including those undergoing doxorubicin chemotherapy. Serum samples were obtained from 6 groups of dogs: (1) normal adult dogs (n = 15); (2) dogs with asymptomatic dilated cardiomyopathy (n = 5); (3) dogs with congestive heart failure (n = 10); (4) dogs with untreated neoplasia (n = 20); (5) dogs with skeletal muscle trauma (n = 10); and (6) dogs with neoplasia receiving doxorubicin chemotherapy (n = 4). One serum sample was obtained from each of the normal dogs, those with asymptomatic cardiomyopathy, those with congestive heart failure, and those with untreated neoplasia. Serum samples were obtained serially from the dogs that were undergoing doxorubicin chemotherapy; samples were collected before doxorubicin (30 mg/m2) administration and then 1,5,7, and 14 days after administration throughout 6 cycles for a cumulative total dose of 180 mg/m2. All normal dogs, dogs with untreated neoplasia, and dogs with asymptomatic dilated cardiomyopathy had cTnT concentrations below the lower limits of detection for the assay used (<0.05 ng/mL). Detectable concentrations of cTnT were found in 3 dogs with congestive heart failure and in 2 dogs with skeletal muscle trauma. Detectable concentrations also were found in both dogs that had received 180 mg/m2 of doxorubicin. We conclude that dogs with congestive heart failure and those with skeletal muscle trauma and dogs with neoplasia receiving high-dose doxorubicin chemotherapy may have increased serum cTnT concentration, which may be suggestive of myocardial damage. [source] The level of polyaromatic hydrocarbons in kajal and surma of major Indian brandsINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 3 2009D. K. Patel Synopsis Kajal and surma are eye cosmetics extensively used in Indian subcontinent. Kajal is prepared by burning of vegetable oil and butter oil while surma by grinding of the stones. High performance liquid chromatography and gas chromatography,mass spectrometry instruments were used for quantification and confirmation of 16 polyaromatic hydrocarbons (PAHs). Significant concentration of PAH was found in all the samples examined. The median concentration of PAH ranged from 0.14 (lowest, anthracene) to 31.18 ,g g,1 [dibenz(a,h)anthracene] in kajal sample and from not detectable concentration (naphthalene) to 197.47 ,g g,1 of benzo(a)pyrene in surma sample. Fifteen PAHs were detected in all the samples. Therefore the use of kajal and surma in eye should be strictly restricted. Résumé Le Kajal et le Surma sont des composés très utilisés sur le sous-continent indien pour le maquillage des yeux. Ils sont préparés par calcination d'huile végétale et d'huile de beurre, puis par broyage des résidus. La chromatographie liquide haute pression et la chromatographie en phase gazeuse couplée à la spectrométrie de masse ont été employées pour quantifier et valider seize hydrocarbures polyaromatiques (PAHs). Des concentrations significatives en PAHs ont été trouvées dans les échantillons examinés. La concentration médiane en PAH classées de la faible à la plus élevée est de 0,14 ,g g,1 (anthracène) à 31,18 ,g g,1 (dibenz (a,h) anthracène) dans l'échantillon de Kajal et d'une présence ND (naphtalène) à 197,47 ,g g,1 (benzo (a) pyrène) dans l'échantillon de Surma. Quinze PAHs ont été détectés dans tous les échantillons. En conséquence, l'utilisation de Kajal et de Surma pour la cosmétique des yeux doit être limitée de façon stricte. [source] Mechanistic study of membrane concentration and recovery of Listeria monocytogenesBIOTECHNOLOGY & BIOENGINEERING, Issue 3 2005Wan-Tzu Chen Abstract Detection of the foodborne pathogen Listeria monocytogenes requires that food samples be processed to remove proteins and lipids, concentrate microorganisms to a detectable concentration, and recover the concentrated cells in a small volume compatible with micron-scale biochips. Mechanistic considerations addressed in this research include the roles of membrane structure, pore size, and detergents in maximizing recovery of cells from a complex biological fluid. The fluid in this case was a food sample (hotdog extract) inoculated with L. monocytogenes. This study showed how membrane filtration using a syringe filter is able to concentrate L. monocytogenes by 95× with up to 95% recovery of living microorganisms by concentrating 50 mL of food sample into a volume of 500 ,L. Tween 20 was added to the sample to prevent irreversible adsorption of the microorganism to the membrane and thereby help to ensure high recovery. Comparison of polycarbonate, mixed cellulose, nylon, and PVDF membranes with 0.2 to 0.45 ,m pores showed the 0.2 ,m polycarbonate membrane with straight through, mono-radial pores gives the highest recovery of living microorganisms. The mixed cellulose, nylon, and PVDF membranes have a fibrous structure whose characteristic openings are much larger than their effective pore size cut-offs of 0.22 or 0.45 ,m. We define conditions for rapid membrane-based cell concentration and recovery that has the potential to supplant enrichment steps that require a day or more. This approach has the added benefit of facilitating examination of a large amount of fluid volume by reducing its volume to a range that is compatible with the microliter scales of biochip or other biosensor detection systems. © 2004 Wiley Periodicals, Inc. [source] Rapid assessment of ,-asarone content of Acorus calamus by micellar electrokinetic capillary chromatographyELECTROPHORESIS, Issue 4-5 2005Kim M. Hanson Abstract This report outlines a rapid, reproducible method for the determination of ,-asarone, a known carcinogen, using micellar electrokinetic capillary chromatography (MEKC)-UV-vis absorbance and a simple alcohol extraction. The MEKC method is based on a running buffer comprised of 100,mM sodium dodecyl sulfate (SDS), pH,10. The method is reproducible and provides baseline separation of ,-asarone and ,-asarone. This protocol was used to determine the ,-asarone content of Acorus calamus rhizome of a diploid variety harvested from the wetlands of the United States and the triploid variety from India obtained commercially. The results indicate raw product that originated from India contained 4.4%,w/w ,-asarone, while that from the United States contained 0.2%,w/w ,-asarone. Neither sample contained detectable concentrations of ,-asarone. This is the first report of the use of MEKC to determine asarone in a natural source. [source] Presence and distribution of wastewater-derived pharmaceuticals in soil irrigated with reclaimed waterENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2006Chad A. Kinney Abstract Three sites in the Front Range of Colorado, USA, were monitored from May through September 2003 to assess the presence and distribution of pharmaceuticals in soil irrigated with reclaimed water derived from urban wastewater. Soil cores were collected monthly, and 19 pharmaceuticals, all of which were detected during the present study, were measured in 5-cm increments of the 30-cm cores. Samples of reclaimed water were analyzed three times during the study to assess the input of pharmaceuticals. Samples collected before the onset of irrigation in 2003 contained numerous pharmaceuticals, likely resulting from the previous year's irrigation. Several of the selected pharmaceuticals increased in total soil concentration at one or more of the sites. The four most commonly detected pharmaceuticals were erythromycin, carbamazepine, fluoxetine, and diphenhydramine. Typical concentrations of the individual pharmaceuticals observed were low (0.02,15 ,g/kg dry soil). The existence of subsurface maximum concentrations and detectable concentrations at the lowest sampled soil depth might indicate interactions of soil components with pharmaceuticals during leaching through the vadose zone. Nevertheless, the present study demonstrates that reclaimed-water irrigation results in soil pharmaceutical concentrations that vary through the irrigation season and that some compounds persist for months after irrigation. [source] Persistence effects in flavour release from liquids in the mouthINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 3 2003Kevin M. Wright Summary The flavour of drinks, creams and liquid-like food consumed without chewing is an important quality factor for consumers and manufacturers alike, so reliable predictive models of flavour release from liquids in the mouth are highly desirable. In this paper we show how the breath-by-breath concentration of aroma in the headspace after swallowing an aliquot of liquid can be modelled using basic principles of interfacial mass transfer. This mechanistic model is used to fit the experimental data for dilute aqueous solutions of five aroma compounds consumed by trained panellists. It is shown that many aroma compounds give detectable concentrations in the exhaled breath several minutes after swallowing and after ten or more exhalations. The influence of liquid composition on this aroma persistence effect is discussed. [source] IDENTIFICATION AND ASSESSMENT OF DOMOIC ACID PRODUCTION IN OCEANIC PSEUDO-NITZSCHIA (BACILLARIOPHYCEAE) FROM IRON-LIMITED WATERS IN THE NORTHEAST SUBARCTIC PACIFIC,JOURNAL OF PHYCOLOGY, Issue 3 2008Adrian Marchetti We identified and investigated the potential toxicity of oceanic Pseudo-nitzschia species from Ocean Station Papa (OSP), located in a high-nitrate, low-chlorophyll (HNLC) region of the northeast (NE) subarctic Pacific Ocean. Despite their relatively low abundances in the indigenous phytoplankton assemblage, Pseudo-nitzschia species richness is high. The morphometric characteristics of five oceanic Pseudo-nitzschia isolates from at least four species are described using SEM and TEM. The species identified are Pseudo-nitzschia dolorosa Lundholm et Moestrup, P. granii Hasle, P. heimii Manguin, and P. cf. turgidula (Hust.) Hasle. Additional support for the taxonomic classifications based on frustule morphology is provided through the sequencing of the internal transcribed spacer 1 (ITS1) rDNA. Pseudo-nitzschia species identification was also assessed by the construction of ITS1 clone libraries and using automated ribosomal intergenic spacer analysis (ARISA) for environmental samples collected during the Subarctic Ecosystem Response to Iron Enrichment Study (SERIES), conducted in close proximity to OSP in July of 2002. Based on ITS1 sequences, the presence of P. granii, P. heimii, P. cf. turgidula, and at least five other putative, unidentified Pseudo-nitzschia ITS1 variants was confirmed within iron-enriched phytoplankton assemblages at OSP. None of the oceanic isolates produced detectable levels of particulate domoic acid (DA) when in prolonged stationary phase due to silicic acid starvation. The lack of detectable concentrations of DA suggests that either these strains produce very little or no toxin, or that the physiological conditions required to promote particulate DA production were not met and thus differ from their coastal, toxigenic congeners. [source] Biomarkers of inflammation in cattle determining the effectiveness of anti-inflammatory drugsJOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 1 2010M. J. MYERS Myers, M. J., Scott, M. L., Deaver, C. M., Farrell, D. E., Yancy, H. F. Biomarkers of inflammation in cattle determining the effectiveness of anti-inflammatory drugs. J. vet. Pharmacol. Therap.33, 1,8. The impact of nonsteroidal anti-inflammatory drugs (NSAID) on prostaglandin E2 (PGE2) production and cyclooxygenase 2 (COX-2) mRNA expression in bovine whole blood (WB) cultures stimulated by lipopolysaccharide (LPS) was determined, using the blood from six Holstein dairy cattle in various stages of lactation. Peak production of PGE2 occurred 24 h after LPS stimulation but did not result in detectable concentrations of thromboxane B2 (TXB2). The NSAID indomethacin, aspirin, flunixin meglumine, and 4-[5-phenyl-3-(trifluoromethyl)-1H-pyrazol-1-yl] benzene sulfonamide (PTPBS; celecoxib analogue), along with dexamethasone, were all equally effective in reducing the concentration of PGE2 in the bovine WB culture supernatants. Bradykinin exhibited peak supernatant concentrations 1 h after LPS stimulation. Dexamethasone and the NSAID used in this study were equally effective at inhibiting bradykinin production. Peak induction of COX-2 mRNA occurred 3 h post-LPS stimulation. However, neither dexamethasone nor any of the NSAID used in this study altered COX-2 mRNA concentrations. In contrast, aspirin, flunixin meglumine, and PTPBS reduced tumor necrosis factor-alpha (TNF,) mRNA concentration. These results demonstrate that bovine blood cells respond to NSAID therapy like other mammalian cells with respect to inhibition of PGE2 production and suppression of TNF mRNA induction, but do not inhibit induction of COX-2 mRNA. [source] N -Malonyl-1,2-dihydroisoquinoline as a Novel Carrier for Specific Delivery of Drugs to the BrainARCHIV DER PHARMAZIE, Issue 1 2010Mohamed Abdel-Aziz Abstract N -Malonyl-1,2-dihydroisoquinoline derivatives were synthesized and investigated as a novel carrier system for site-specific and sustained delivery of drugs to the brain. Such carriers are expected to be stable against air oxidation due to the presence of the carbonyl group close to nitrogen of the dihydroisoquinoline. Reduction of the prepared isoquinolinium quaternary derivatives with sodium dithionite afforded a novel group of N -malonyl-1,2-dihydroisoquinoline chemical delivery systems (CDS). The synthesized N -malonyl-1,2-dihydroisoquinoline chemical delivery systems were subjected to various chemical and biological investigations to evaluate their ability to cross the blood-brain barrier (BBB), and to be oxidized biologically into their corresponding quaternary derivatives. The in-vitro oxidation studies showed that the designed N -malonyl-1,2-dihydroisoquinoline chemical delivery system could be oxidized into its corresponding quaternary derivatives at an adequate rate. The in-vivo distribution studies showed that these N -malonyl-1,2-dihydroisoquinoline chemical delivery systems were able to cross the blood-brain barrier at detectable concentrations. [source] | ||||||||||||||||