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Biomedical subjects

C R Short

Publications and source records attributed to C R Short.

At least 73 records · Page 4Linked to original sources

Binding of 14-C-salicylic acid and 14-C-pentobarbital to plasma proteins of several species during the perinatal period.

The fraction binding of 14-C-salicylic acid and 14-C-pentobarbital was studied as a function of age in plasma of the pig, dog, goat and human. The pig exhibited an unusual degree of hypoalbuminemia and low fractional binding of salicylic acid at birth. Albumin levels and the percent binding of the salicylic acid were not significantly lower in newborn plasma than in adult plasma of the other species studied. The pig was also exceptional in that the high fractional binding of pentobarbital observed at low ligand concentrations in plasma of the newborn was not observed in the other species studied. Depletion of albumin in newborn pig plasma did not appreciably affect the binding of pentobarbital. Thus it is suggested that the plasma of the fetal and newborn pig may contain a nonalbuminoid protein, such as fetal globulin, which is capable of binding pentobarbital but does not have a high avidity for salicylic acid. It apparently does not exist at birth in the plasmas of the other species studied, as depletion of albumin markedly reduced the fractional binding of pentobarbital.

Age Factors↗

Subacute toxicity of several ring-substituted dialkylanilines in the rat.

Aniline, o-toluidine, 2,4-dimethylaniline, 2,6-dimethylaniline, 2,6-diethylaniline, 2,6-methylethylaniline, 2,6-diisopropylaniline, and methylene-bis-2,6-diisopropylaniline were administered to male Fischer 344 rats daily for 5, 10 or 20 days. Histopathologic evaluation of selected tissues revealed splenic congestion, increased hematopoiesis and hemosiderosis, and bone marrow hyperplasia in aniline- and o-toluidine-treated animals. These changes, characteristics consistent with enhanced erythrocytic destruction, were not observed in any of the dialkylaniline-treated animals. Hepatoxicity, characterized by biliary hyperplasia, periacinar vacuolar degeneration, hepatocytic cloudy swelling and periacinar necrosis, was observed in methylene-bis-2,6-diisopropyl-, aniline- and 2,4-dimethylaniline-treated animals. Multifocal discrete areas of necrosis were also observed in livers of animals treated with the latter compound. There were no histopathologic changes which could be attributed to any of the alkylanilines studied in kidney, esophagus, trachea, thyroid, parathyroid or urinary bladder.

Aniline Compounds↗

Matrix solid phase dispersion (MSPD) isolation and liquid chromatographic determination of furazolidone in pork muscle tissue.

A method for the isolation and liquid chromatographic (LC) determination of furazolidone in pork muscle tissue is presented. Blank or furazolidone-fortified pork muscle tissue samples (0.5 g) were blended with octadecylsilyl (C18, 18% load, endcapped, 2 g) derivatized silica. A column made from C18/pork matrix was first washed with hexane (8 mL), followed by elution of furazolidone with ethyl acetate. The ethyl acetate extract was then passed through an activated alumina column. The eluate contained furazolidone that was free from interfering compounds when analyzed by LC with UV detection (photodiode array, 365 nm). Detector response with increasing concentrations of furazolidone isolated from fortified samples was linear (r = 0.998 +/- 0.002) with an average percentage recovery of 89.5 +/- 8.1% for the concentration range (7.8-250 ng/g) examined and resulted in a minimum detectable limit of 390 pg on column, and a detector response of more than 5 times baseline noise. The inter-assay variability was 9.9 +/- 5.4% with an intra-assay variability of 1.5%.

Animals↗

Matrix solid-phase dispersion (MSPD) isolation and liquid chromatographic determination of oxytetracycline, tetracycline, and chlortetracycline in milk.

A multiresidue method for the isolation and liquid chromatographic determination of oxytetracycline (OTC), tetracycline (TC), and chlortetracycline (CTC) antibiotics in milk is presented. Blank and tetracycline (OTC, TC, and CTC) fortified milk samples (0.5 mL) were blended with octadecylsilyl (C18, 40 microns, 18% load, endcapped, 2 g) derivatized silica packing material containing 0.05 g each of oxalic acid and disodium ethylenediaminetetraacetic. A column made from the C18/milk matrix was first washed with hexane (8 mL), following which the tetracyclines were eluted with ethyl acetate-acetonitrile (1 + 3; v/v). The eluate contained tetracycline analytes that were free from interfering compounds when analyzed by liquid chromatography with UV detection (photodiode array, 365 nm). Correlation coefficients of standards curves for individual tetracycline isolated from fortified samples were linear (from 0.982 +/- 0.009 to 0.996 +/- 0.004) with average percentage recoveries from 63.5 to 93.3 for the concentration range (100, 200, 400, 800, 1600, and 3200 ng/mL) examined. The inter-assay variability ranged from 8.5 +/- 2.4% to 20.7 +/- 13.0% with an intra-assay variability of 1.0-9.3%.

Animals↗

Matrix solid phase dispersion isolation and liquid chromatographic determination of five benzimidazole anthelmintics in fortified beef liver.

A multiresidue method for isolation and liquid chromatographic determination of 5 benzimidazole anthelmintics (thiabendazole, oxfendazole, mebendazole, albendazole, and fenbendazole) in beef liver tissue is presented. Blank or benzimidazole-fortified liver samples (0.5 g) were blended with octadecylsilyl derivatized silica packing material (C18, 18% load, endcapped, 2 g). A column made from the C18/liver matrix was first washed with hexane (8 mL), following which the benzimidazoles were eluted with acetonitrile. The acetonitrile extract was then passed through an activated alumina column. The eluate contained benzimidazole analytes that were free from interfering compounds as determined by UV detection (photodiode array, 290 nm). Correlation coefficients of standard curves for individual benzimidazoles isolated from fortified samples, using internal standardization, were linear (0.996 +/- 0.002 to 0.999 +/- 0.001) with average relative percentage recoveries from 62.0 +/- 6.7 to 86.8 +/- 8.6% for the concentration range (100-3200 ng/g) examined. The interassay variability was 7.0 +/- 4.1 to 12.9 +/- 10.2% with an intra-assay variability from 2.2 to 4.0%.

Animals↗

Matrix solid phase dispersion isolation and liquid chromatographic determination of oxytetracycline in catfish (Ictalurus punctatus) muscle tissue.

A method for isolation and liquid chromatographic determination of oxytetracycline in catfish (Ictalurus punctatus) muscle tissue is presented. Blank control and oxytetracycline-fortified fish muscle tissue samples (0.5 g) were blended with octadecylsllyl (C18, 40 microns, 18% load, endcapped) derivatized silica packing material (2 g) containing 0.05 g each of oxalic acid and disodium ethylenediaminetetraacetate. A column made from the C18/fish tissue matrix was first washed with hexane (8 mL), following which the oxytetracycline was eluted with acetonitrile-methanol (1 + 1, v/v) containing 0.06% w/v each of butylated hydroxyanisole and butylated hydroxytoluene. The eluate contained oxytetracycline analyte that was free from interfering compounds when analyzed by liquid chromatography with UV detection (photodiode array set at 365 nm). Standard curves for oxytetracycline isolated from fortified samples were linear (0.998 +/- 0.002) with an average absolute percentage recovery of 80.9 +/- 6.6% for the concentration range (50, 100, 200, 400, 800, 1600, and 3200 ng/g) examined. The interassay variability was 11.3 +/- 5.2% with an intra-assay variability of 1.1%.

Animals↗