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Alberto Cepeda - One of the best experts on this subject based on the ideXlab platform.
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A sensitive and validated HPLC–MS/MS method for simultaneous determination of seven coccidiostats in bovine whole milk
Food Control, 2012Co-Authors: Carolina Nebot, Alejandra Iglesias, Patricia Regal, Jose M Miranda, Cristina A. Fente, Alberto CepedaAbstract:Abstract Sensitive and reliable methods for the identification and quantification of coccidiostats in milk are needed as the European Parliament had established maximum level for these substances in milk ( Commission Regulation 124/2009/EC ). This study presents a method for the simultaneous extraction, identification, and quantification of seven coccidiostats (robenidine, Decoquinate, monensin, salinomycin, lasalocid, maduramicin, and narasin) in bovine whole milk. The method was validated in-house in accordance with the European Commission Decision 2002/657/EC . Recoveries, decision limit, and limit of quantification values ranged from 69 to 109%, 9.9–18.4 μg kg −1 , and 0.4–1.0 μg kg −1 , respectively. The method was successfully applied to a total of 120 samples obtained from dairy farms located in the northwest of Spain, and Decoquinate was detected in one of them.
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Detection and quantitative analysis of 21 veterinary drugs in river water using high-pressure liquid chromatography coupled to tandem mass spectrometry
Environmental Science and Pollution Research, 2012Co-Authors: Alejandra Iglesias, Carolina Nebot, Jose M Miranda, Beatriz I. Vázquez, Alberto CepedaAbstract:Introduction The use of veterinary drugs in food production focuses on the control and improvement of animal health. The disadvantage of this practice is that pharmaceuticals and their metabolites are released into the environment, finding their way to natural water systems and becoming a potential risk to non-target organism. Methods This paper reports the development and validation of a quantitative method, based on high-performance liquid chromatography coupled to tandem mass spectrometry, for the simultaneous analysis of 21 veterinary drugs, antimicrobials, corticosteroids, coccidiostats and antifungal agents, in surface water. Results The precision of the method was established by calculating the mean recoveries, which were in the range of 94–101%. The developed method was employed to conduct the first monitoring study on the presence of veterinary drugs in the Galicia region, Northwest of Spain and was applied to 235 surface water samples. Eleven veterinary drugs were detected at concentrations from below the limit of quantification to 2,978.6 ng L^−1. Limits of detection and quantification were in the range of 6.2 (betamethasone, cortisone, Decoquinate, dexamethasone, maduramycin, monensin, narasin, salinomycin, sulfachloropyridazine, sulfamethoxypyridazine and trimethoprim) to 12.5 ng L^−1 (for the rest of the selected drugs) and 12.5 (betamethasone, cortisone, Decoquinate, dexamethasone, maduramycin, monensin, narasin, salinomycin, sulfachloropyridazine, sulfamethoxypyridazine and trimethoprim) to 25.0 ng L^−1 (for the remaining pharmaceuticals), respectively. Conclusion Sulfonamides were the group most frequently found, which are widely used in veterinary medicine.
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Sensitive Determination of Decoquinate in Milk by High-Performance Liquid Chromatographic Coupled to Laser-Induced Fluorescence Detection
Food Analytical Methods, 2010Co-Authors: Xesús Feás, Cristina A. Fente, Beatriz I. Vázquez, Antonio Iglesias, Jesús Cantalapiedra, Alberto CepedaAbstract:A new and sensitive method based on high performance liquid chromatography with laser-induced fluorescence detection has been developed for the determination of Decoquinate in milk. Laser source was obtained with a He–Cd laser using a continuous excitation wavelength at 325 nm. Decoquinate exhibits moderate fluorescence, but it is increased using Ca(NO_3)_2 in the mobile phase. The chromatographic separation was performed on a Luna C_18 5-mm reversed phase column, which solves the broadening of peaks and peak tailing compared with other columns tested. The mobile phase, delivered at 1 ml min^−1, consisted of methanol–calcium nitrate (0.025 M)–acetonitrile (83/13/4 v / v / v ). Decoquinate was successfully cleaned up from milk by solid-phase extraction using C_18 cartridges. The method was found to be linear between 0.16 and 16.33 ng ml^−1. The results of recovery studies were found to be satisfactory; an average recovery rate of 88.7% was obtained. The LOQ of Decoquinate in milk was 0.16 ng ml^−1. The intraday relative standard deviation (RSD) was 4%, and interday assay gave an RSD of 4.4%.
Byron L. Blagburn - One of the best experts on this subject based on the ideXlab platform.
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Activity of Decoquinate against Cryptosporidium parvum in cell cultures and neonatal mice
Veterinary parasitology, 2000Co-Authors: David S. Lindsay, Keith M. Woods, Steve J. Upton, Byron L. BlagburnAbstract:Abstract Cryptosporidium parvum is an apicomplexan parasite that is an important cause of diarrhea in neonatal calves and humans. No treatment is currently available for neonatal calves. We have recently learned from colleagues in the pharmaceutical industry that dairy practitioners are sometimes using Decoquinate for the treatment of neonatal bovine cryptosporidiosis. Therefore, the present study was undertaken to determine whether the clinical observations in calves can be substantiated by laboratory investigation. Oocysts of the KSU-1 isolate of C. parvum were used to infect human ileocecal epithelial cells in vitro to measure the efficacy of treatment using an ELISA based assay. No activity was observed at 10 or 50 μM Decoquinate, but at 100 μM an 8% inhibition of development was seen. Oocysts of the AUCp-1 isolate of C. parvum were then used to infect suckling mice. The numbers of oocysts observed in suckling mice treated with 2.5 or 5.0 mg/kg Decoquinate were not significantly different from untreated control suckling mice ( p >0.05). The results of our study suggest that Decoquinate should have little efficacy for treatment of neonatal bovine cryptosporidiosis if administered once per day and that any clinical improvement observed in treated calves may be due to factors unrelated to Decoquinate’s effect on C. parvum .
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Decoquinate induces tissue cyst formation by the RH strain of Toxoplasma gondii
Veterinary Parasitology, 1998Co-Authors: David S. Lindsay, M. Toivio-kinnucan, Byron L. BlagburnAbstract:Decoquinate is an anticoccidial agent that inhibits respiration in the parasites mitochondrion. We examined human foreskin fibroblast cell cultures infected with the normally tissue cyst-less RH strain of Toxoplasma gondii and treated with Decoquinate for evidence of tissue cyst induction and formation. Transmission electron microscopy observations demonstrated tissue cysts in Decoquinate-treated cultures on days 3, 4, 5, and 6 after inoculation. Tissue cysts contained a tissue cyst wall that enclosed stages that resembled tachyzoites and stages that were structurally bradyzoites. Similar treatment of human foreskin fibroblast cells infected with tachyzoites of the TS-4 temperature-sensitive mutant of the RH strain did not result in production of tissue cysts.
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Efficacy of Decoquinate against Neospora caninum tachyzoites in cell cultures.
Veterinary Parasitology, 1997Co-Authors: David S. Lindsay, Jamie M. Butler, Byron L. BlagburnAbstract:Abstract Neospora caninum is a major cause of abortion in dairy cattle in the United States and other countries. Abortions and neonatal mortality also occur in other ruminant species. Decoquinate is an anticoccidial that is approved for use in cattle and goats in the United States. We studied the efficacy of Decoquinate against tachyzoites of N. caninum in a 5-day of treatment, cell culture flask lesion-based assay. Decoquinate killed tachyzoites at concentrations of 0.1 and 0.01 μg ml−1. Decoquinate had little measurable effect on extracellular tachyzoites. Decoquinate acted quickly to kill intracellular stages at coccidiocidal concentrations; tachyzoites were killed within 5 min at 0.1 μg ml−1 Decoquinate.
E R Pfefferkorn - One of the best experts on this subject based on the ideXlab platform.
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Toxoplasma gondii: susceptibility and development of resistance to anticoccidial drugs in vitro.
Antimicrobial agents and chemotherapy, 1993Co-Authors: A. P. Ricketts, E R PfefferkornAbstract:Anticoccidial drugs were evaluated for activity and for the development of resistance in a model of Toxoplasma gondii growing in human fibroblast cultures. Of 13 anticoccidial drugs tested, 9 had selective antitoxoplasma activity (50% inhibitory concentration, in micrograms per milliliter): Decoquinate (0.005), arprinocid-N-oxide (0.015), robenidine (0.03), the aryl triazine CP-25,415 (0.2), toltrazuril (0.4), clopidol (1), dinitolmide (Zoalene; Dow) (10), and the carboxylic acid ionophores monensin (0.001) and salinomycin (0.04). Glycarbylamide, amprolium, nicarbazin, and the 6-(p-bromophenoxy)-7-chloro analog of halofuginone (Stenorol; Roussel-UCLAF) (CP-63,567) were toxic for the fibroblasts. Since Eimeria tenella has a similar drug susceptibility profile, anticoccidial durgs can be viewed as a potential source of new antitoxoplasma therapies. The development of resistance has limited the usefulness of most of these drugs as anticoccidial agents; in coccidia, resistance to all except the ionophores occurs readily in vivo. We explored the development of resistance in T. gondii by attempting to select mutants in vitro from parasites mutagenized with ethylnitrosourea. Mutants that had 20- to 50-fold-reduced susceptibility to Decoquinate, arprinocid-N-oxide, and CP-25,415 were obtained. Ionophore-resistant T. gondii mutants were also selected in vitro; however, there was only a twofold difference in susceptibility between these mutants and the wild type. For three drugs (clopidol, robenidine, and toltrazuril), we were unable to select resistant mutants. For experimental anticoccidial drugs, there is currently no in vitro method for assessing the risk of development of resistance in Eimeria species. Our results suggest that T. gondii may offer a useful surrogate for this assessment.
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MUTANTS OF TOXOPLASMA GONDII RESISTANT TO ATOVAQUONE (566C80) OR Decoquinate
The Journal of parasitology, 1993Co-Authors: E R Pfefferkorn, Susan E. Borotz, Robert F. NothnagelAbstract:Mutants of Toxoplasma gondii resistant to drugs that appear to affect the mitochondrial bc1 complex were isolated with the aid of mutagenesis with ethylnitrosourea. Mutant DeqR-1 was > 1,000-fold more resistant to Decoquinate than was the wild type but more sensitive to atovaquone (formerly called 566C80). Mutant AtoR-1 was 20-fold more resistant to atovaquone than was the wild type and was also partially cross-resistant to Decoquinate. Both drugs rapidly inhibited oxygen uptake by freshly prepared extracellular parasites, and the mutants were resistant to this inhibition. Neither the addition of uracil to the medium nor the use of a mutant of T. gondii with a defect in pyrimidine salvage had a substantial effect on the in vitro anti-parasitic activity of these drugs, suggesting that de novo pyrimidine synthesis was not the major biochemical target of either drug.
David S. Lindsay - One of the best experts on this subject based on the ideXlab platform.
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Efficacy of Decoquinate against Sarcocystis neurona in cell cultures.
Veterinary parasitology, 2013Co-Authors: David S. Lindsay, M Mudasser Nazir, Azhar Maqbool, Siobhan P Ellison, Jeannine S StroblAbstract:Decoquinate is a quinolone anticoccidial approved for use in the prevention of intestinal coccidiosis in farm animals. This compound has good activity against Toxoplasma gondii and Neospora caninum in cell cultures. The drug acts on the parasites' mitochondria. The activity of Decoquinate against developing merozoites of 2 isolates of Sarcocystis neurona was examined in cell culture. Merozoite production at 10 days was completely inhibited when Decoquinate was used at 20 or 240 nM. The IC50 of Decoquinate was 0.5 ± 0.09nM for the Sn6 isolate of S. neurona from a horse and 1.1 ± 0.6 nM for the SnOP15 isolate of S. neurona from an opossum. Levamisole was toxic at 5 μg/ml and no synergism was observed when Decoquinate was combined with levamisole and tested against the Sn3YFP isolate of S. neurona. Decoquinate was cidal for developing schizonts of S. neurona at 240 nM.
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Activity of Decoquinate against Cryptosporidium parvum in cell cultures and neonatal mice
Veterinary parasitology, 2000Co-Authors: David S. Lindsay, Keith M. Woods, Steve J. Upton, Byron L. BlagburnAbstract:Abstract Cryptosporidium parvum is an apicomplexan parasite that is an important cause of diarrhea in neonatal calves and humans. No treatment is currently available for neonatal calves. We have recently learned from colleagues in the pharmaceutical industry that dairy practitioners are sometimes using Decoquinate for the treatment of neonatal bovine cryptosporidiosis. Therefore, the present study was undertaken to determine whether the clinical observations in calves can be substantiated by laboratory investigation. Oocysts of the KSU-1 isolate of C. parvum were used to infect human ileocecal epithelial cells in vitro to measure the efficacy of treatment using an ELISA based assay. No activity was observed at 10 or 50 μM Decoquinate, but at 100 μM an 8% inhibition of development was seen. Oocysts of the AUCp-1 isolate of C. parvum were then used to infect suckling mice. The numbers of oocysts observed in suckling mice treated with 2.5 or 5.0 mg/kg Decoquinate were not significantly different from untreated control suckling mice ( p >0.05). The results of our study suggest that Decoquinate should have little efficacy for treatment of neonatal bovine cryptosporidiosis if administered once per day and that any clinical improvement observed in treated calves may be due to factors unrelated to Decoquinate’s effect on C. parvum .
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Decoquinate induces tissue cyst formation by the RH strain of Toxoplasma gondii
Veterinary Parasitology, 1998Co-Authors: David S. Lindsay, M. Toivio-kinnucan, Byron L. BlagburnAbstract:Decoquinate is an anticoccidial agent that inhibits respiration in the parasites mitochondrion. We examined human foreskin fibroblast cell cultures infected with the normally tissue cyst-less RH strain of Toxoplasma gondii and treated with Decoquinate for evidence of tissue cyst induction and formation. Transmission electron microscopy observations demonstrated tissue cysts in Decoquinate-treated cultures on days 3, 4, 5, and 6 after inoculation. Tissue cysts contained a tissue cyst wall that enclosed stages that resembled tachyzoites and stages that were structurally bradyzoites. Similar treatment of human foreskin fibroblast cells infected with tachyzoites of the TS-4 temperature-sensitive mutant of the RH strain did not result in production of tissue cysts.
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Efficacy of Decoquinate against Neospora caninum tachyzoites in cell cultures.
Veterinary Parasitology, 1997Co-Authors: David S. Lindsay, Jamie M. Butler, Byron L. BlagburnAbstract:Abstract Neospora caninum is a major cause of abortion in dairy cattle in the United States and other countries. Abortions and neonatal mortality also occur in other ruminant species. Decoquinate is an anticoccidial that is approved for use in cattle and goats in the United States. We studied the efficacy of Decoquinate against tachyzoites of N. caninum in a 5-day of treatment, cell culture flask lesion-based assay. Decoquinate killed tachyzoites at concentrations of 0.1 and 0.01 μg ml−1. Decoquinate had little measurable effect on extracellular tachyzoites. Decoquinate acted quickly to kill intracellular stages at coccidiocidal concentrations; tachyzoites were killed within 5 min at 0.1 μg ml−1 Decoquinate.
Alejandra Iglesias - One of the best experts on this subject based on the ideXlab platform.
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A sensitive and validated HPLC–MS/MS method for simultaneous determination of seven coccidiostats in bovine whole milk
Food Control, 2012Co-Authors: Carolina Nebot, Alejandra Iglesias, Patricia Regal, Jose M Miranda, Cristina A. Fente, Alberto CepedaAbstract:Abstract Sensitive and reliable methods for the identification and quantification of coccidiostats in milk are needed as the European Parliament had established maximum level for these substances in milk ( Commission Regulation 124/2009/EC ). This study presents a method for the simultaneous extraction, identification, and quantification of seven coccidiostats (robenidine, Decoquinate, monensin, salinomycin, lasalocid, maduramicin, and narasin) in bovine whole milk. The method was validated in-house in accordance with the European Commission Decision 2002/657/EC . Recoveries, decision limit, and limit of quantification values ranged from 69 to 109%, 9.9–18.4 μg kg −1 , and 0.4–1.0 μg kg −1 , respectively. The method was successfully applied to a total of 120 samples obtained from dairy farms located in the northwest of Spain, and Decoquinate was detected in one of them.
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Detection and quantitative analysis of 21 veterinary drugs in river water using high-pressure liquid chromatography coupled to tandem mass spectrometry
Environmental Science and Pollution Research, 2012Co-Authors: Alejandra Iglesias, Carolina Nebot, Jose M Miranda, Beatriz I. Vázquez, Alberto CepedaAbstract:Introduction The use of veterinary drugs in food production focuses on the control and improvement of animal health. The disadvantage of this practice is that pharmaceuticals and their metabolites are released into the environment, finding their way to natural water systems and becoming a potential risk to non-target organism. Methods This paper reports the development and validation of a quantitative method, based on high-performance liquid chromatography coupled to tandem mass spectrometry, for the simultaneous analysis of 21 veterinary drugs, antimicrobials, corticosteroids, coccidiostats and antifungal agents, in surface water. Results The precision of the method was established by calculating the mean recoveries, which were in the range of 94–101%. The developed method was employed to conduct the first monitoring study on the presence of veterinary drugs in the Galicia region, Northwest of Spain and was applied to 235 surface water samples. Eleven veterinary drugs were detected at concentrations from below the limit of quantification to 2,978.6 ng L^−1. Limits of detection and quantification were in the range of 6.2 (betamethasone, cortisone, Decoquinate, dexamethasone, maduramycin, monensin, narasin, salinomycin, sulfachloropyridazine, sulfamethoxypyridazine and trimethoprim) to 12.5 ng L^−1 (for the rest of the selected drugs) and 12.5 (betamethasone, cortisone, Decoquinate, dexamethasone, maduramycin, monensin, narasin, salinomycin, sulfachloropyridazine, sulfamethoxypyridazine and trimethoprim) to 25.0 ng L^−1 (for the remaining pharmaceuticals), respectively. Conclusion Sulfonamides were the group most frequently found, which are widely used in veterinary medicine.
