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Commercial Reagents (commercial + reagent)
Selected AbstractsPharmacokinetics and residues in milk of oxytetra-cyclines administered parenterally to dairy goatsAUSTRALIAN VETERINARY JOURNAL, Issue 7 2001R. RULE Objective To determine for two commercial preparations of oxytetracycline (OTC) the pharmacokinetic behaviour, the presence of detectable milk residues and the penetration in milk of OTC administered by intravenous (IV) (conventional formulation [CF]) and intramuscular (IM) routes (CF and long-acting [LA] formulations) in goats producing milk. The effects of these formulations on plasma activity values of creatine kinase (CK) and lactate dehydrogenase (LDH) were also determined as indicators of tissue damage. Procedure Five healthy lactating goats producing 1.5 ± 0.5 L/d milk and weighing 56.0 ± 4.8 kg were used. Single doses of OTC chlorhydrate (CF) were administered (20 mg OTC/kg) by IV (Trial 1 IV) and IM (Trial 1 IM) routes and OTC dehydrate (LA) by the IM route. The same goats were first given IV CF, then IM CF followed by IM LA with 3 weeks between each treatment. Blood and milk samples were taken. The quantification of OTC was performed by HPLC and the plasma activities of CK and LDH enzymes were determined by spectrophotometry. The presence of OTC residues in milk was determined by a commercial reagent. The plasma pharmacokinetic parameters were calculated using a two-compartment model. Results Estimates of kinetic variables following IV administration were: Vss= 400.0 ± 120.0 mL/kg and CL= 110.0 ± 14.0 (mL/h)/kg. The tfi for IV= 3.0 ± 0.3 h; IM, CF = 10.5 ± 2.1 h and IM, LA = 15.1 ± 3.1 h. The concentration of OTC in milk at 48 h was: IV= 0.6 ± 0.4; IM CF= 1.1 ± 0.2 and at 72 h (IM LA)= 0.6 ± 0.1 ,g/mL and the penetration in milk of OTC was: IV= 70.0 ± 18.0; IM CF= 79.0 ± 14.0 and IM LA= 66.0 ± 6.0 %. The areas under the curve of CK and LDH activities in plasma were calculated by the trapezoidal method. Values of CK and LDH IM, LA were greater (P < 0.05) than those observed for IM, CF at 2 and 3 days after administration of the antibiotic. Finally, the bioavailability of OTC CF = 92.0± 22.0 and LA= 78.0 ± 23.0 % was suitable for its usage by the IM route in lactating goats. Conclusion Plasma concentration-time values of OTC administered parenterally in production dairy goats showed similar bioavailability for the two pharmaceutical preaprations. The presence of detectable residues in milk indicates that milk should not be used for human consumption for 2 and 3 days after administration of conventional and long-acting formulations, respectively. The increments in CK and LDH activities after the IM administration of LA are consistent with the presence of tissue damage provoked by the pharmaceutical preparations at the injection site. [source] Influence of factor VIII:C and factor IX activity in plasmas of haemophilic dogs on the activated partial thromboplastin time measured with two commercial reagentsHAEMOPHILIA, Issue 3 2000R. Mischke The present study is based on 145 plasma samples with a reduced activity of factor VIII:C (range: 0.009,0.62 IU mL,1) and 28 samples with a reduced factor IX activity (range: 0.035,0.55 IU mL,1). The samples were collected from dogs with haemophilia A (n=22) or haemophilia B (n=3), some of these during substitution therapy. For all samples the activated partial thromboplastin time (APTT) was measured with two commercial reagents containing kaolin as a contact activator. In each case, the deficiency of factor VIII:C or IX was reflected in abnormal results of the APTT. This was true for both reagents. A significant correlation (P < 0.001) was found between factor VIII:C activity and APTT (reagent 1, Pathromtin®; Spearman's rank correlation coefficient, rS=,0.731, reagent 2, PTT-Reagenz; rS=,0.875) as well as between factor IX activity and APTT (reagent 1, rS=,0.819; reagent 2, rS=,0.955]. In each case, the relationship between coagulation factor activity and APTT could be proven most precisely by geometric regression. The results of this study illustrate the applicability of commercial APTT test kits as a sensitive screening test of factor VIII:C and IX deficiencies in canine plasma. [source] Properties and Catalytic Activities of New Easily-Made Amphiphilic Phosphanes for Aqueous Organometallic CatalysisADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 7 2010Michel Ferreira Abstract Mono- and disulfonated amphiphilic versions of triphenylphosphane (PPh3) and cyclohexyl(phenyl)phosphane were easily synthesized from commercial reagents and sulfuric acid. The behaviour of these phosphanes in solution was investigated by surface tension, isothermal titration calorimetry, nuclear magnetic resonance and cryo-transmission electron microscopy. Two different supramolecular assemblies were evidenced according to the degree of sulfonation. The monosulfonated phosphanes formed well organized micelle-like aggregates while the disulfonated phosphanes formed heterogeneous and disorganized vesicle-like assemblies. The efficiency of these amphiphilic phosphanes was evaluated in the aqueous biphasic, palladium-catalyzed cleavage of allyl alkyl carbonates. [source] Interlaboratory Comparison of Cytomegalovirus Viral Load AssaysAMERICAN JOURNAL OF TRANSPLANTATION, Issue 2 2009X. L. Pang To assess interlaboratory variability in qualitative and quantitative cytomegalovirus (CMV) viral load (VL) testing, we distributed a panel of samples to 33 laboratories in the USA, Canada and Europe who performed testing using commercial reagents (n = 17) or laboratory-developed assays (n = 18). The panel included two negatives, seven samples constructed from purified CMV nucleocapsids in plasma (2.0,6.0 log10 copies/mL) and three clinical plasma samples. Interlaboratory variation was observed in both actual (range, 2.0,4.0 log10 copies/mL) and self-reported lower limits of detection (range, 1.0,4.0 log10 copies/mL). Variation observed in reported results for individual samples ranged from 2.0 log10 (minimum) to 4.3 log10 (maximum). Variation was greatest at low VLs. Assuming ± 0.5 log10 relative to the expected result represents an acceptable result, 57.6% of results fell within this range. Use of commercially available reagents and procedures was associated with less variability compared with laboratory-developed assays. Interlaboratory variability on replicate samples was significantly greater than intralaboratory variability (p < 0.0001). The significant interlaboratory variability in CMV VL observed may be impacting patient care and limiting interinstitutional comparisons. The creation of an international reference standard for CMV VL assay calibration would be an important step in quality improvement of this laboratory tool. [source] Relating Chemical and Biological Diversity Space: A Tunable System for Efficient Gene TransfectionCHEMBIOCHEM, Issue 12 2008Liisa D. Van Vliet Dr. Abstract Polyethyleneimine (PEI), a well-established nonviral transfection reagent, was combinatorially modified with varying proportions of methyl, benzyl, and n -dodecyl groups to create a library of 435 derivatized polymers. Screening of this library for transfection, DNA binding, and toxicity allows systematic correlation of the biological properties of our polymers to their derivatizations. Combinations of derivatizations bring about a 100-fold variation in transfection efficiency between library members. The best PEI derivatives exhibit increases in transfection efficiency of more than 80-fold over unmodified PEI (up to 28±7,% of cells transfected) and rival commercial reagents such as Lipofectamine 2000 (21±10,%) and JetPEI (32±5.0,%). In addition, we can identify compounds that are specifically tuned for efficient transfection in CHO-K1 over Ishikawa cells and vice versa, demonstrating that the approach can lead to cell-type selectivity of at least one order of magnitude. This work demonstrates that multivalent derivatization of a polymeric framework can create functional diversity substantially greater than the structural diversity of the derivatization building blocks and suggests an approach to a better understanding of the molecular underpinnings of transfection as well as their exploitation. [source] | |||||||||||||