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Biomedical subjects

W B Buck

Publications and source records attributed to W B Buck.

At least 73 records · Page 4Linked to original sources

Experimental T-2 toxicosis in swine. I. Changes in cardiac output, aortic mean pressure, catecholamines, 6-keto-PGF1 alpha, thromboxane B2, and acid-base parameters.

T-2 toxin given as a single intravascular dose to swine produced a shock syndrome. Dosages of 0.6 or 4.8 mg/kg were administered to different groups of swine. Shock was characterized by reductions in cardiac output and blood pressure, and increased plasma concentrations of epinephrine, norepinephrine, thromboxane B2, 6-keto PGF1 alpha, and lactate. Total peripheral resistance was unchanged in the high-dose group but decreased in the low-dose group. Pulmonary vascular resistance increased in both groups. Decreases occurred in arterial pH and arterial oxygen partial pressure. No alterations occurred in plasma concentrations of histamine or serotonin.

6-Ketoprostaglandin F1 alpha↗

Experimental T-2 toxicosis in swine. II. Effect of intravascular T-2 toxin on serum enzymes and biochemistry, blood coagulation, and hematology.

T-2 toxin was given as a single intravascular dose at either 0.6 or 4.8 mg/kg to different groups of 50-kg female swine. Blood samples were taken at hourly intervals for determination of concentrations or activities of the following substances in serum or plasma: creatinine, blood urea nitrogen, inorganic phosphorus, total calcium, ultrafilterable calcium, magnesium, sodium, potassium, chloride, total protein, albumin, cholesterol, glucose, alkaline phosphatase, aspartate aminotransferase, and total bilirubin. Coagulation analyses included prothrombin time, partial thromboplastin time, activated coagulation time, and fibrin degradation products. Red blood cell, white blood cell, and platelet counts, hemoglobin concentrations, and hematocrits were determined from whole blood samples. An initial leukocytosis was followed by a leukopenia. The numbers of red cells, the hemoglobin concentration, and the hematocrit were increased. Nucleated red blood cells were seen in the blood smears. The serum concentration of bound calcium decreased, while phosphorus, magnesium, and potassium increased. Clinical screening tests detected no evidence of a coagulopathy in swine given T-2 toxin intravascularly.

Alkaline Phosphatase↗

Sex-related reduced weight gains in growing swine fed diets containing deoxynivalenol.

A 5-wk feeding trial was conducted with 30 castrated male and 28 female, 5-wk-old crossbred piglets. Three different deoxynivalenol (DON) and zearalenone (Z)-contaminated diets were fed: .7, 3.1 and 5.8 ppm DON and 0, .05, and .1 ppm Z, respectively. The animals were fed their respective diets for 4 wk followed by the .7:0-ppm diet during wk 5. Feed intake and weight gain varied in a manner reciprocal to the levels of DON-Z in the diets during the first 4 wk (P less than .05). The castrated males had an overall lower weight gain compared with the females receiving the same diet (P less than .05). Gross postmortem changes were not different in either sex and tended to be most prominent in the pigs fed the lower DON:Z-contaminated diets after the first week, although they were seen in pigs fed the higher DON:Z diets after 4 wk of feeding. Lesions included mild to moderated reddening of the fundic mucosa of the stomach, reddening of the mucosa of the small intestine, and mild to moderate enlargement and edema of the mesenteric lymph nodes. Similarly, the severity of histologic changes tended to vary inversely with the concentrations of DON:Z in the diets after the first week but varied with the concentrations of DON:Z after 4 wk. They consisted of vascular congestion with mild to moderate multifocal erosions and degeneration of the mucosa in the stomach and small intestine. Mild to moderate lymphoid degeneration and depletion were also observed in the Peyer's patches of the intestines, bronchial and mesenteric lymph nodes, spleen, tonsil and thymus.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗

Preliminary study of the pharmacokinetics and toxicopathy of deoxynivalenol (vomitoxin) in swine.

Study was made of the pharmacokinetics and toxicopathy of deoxynivalenol (DON, vomitoxin) given IV to swine. In the 24 hours after swine were given DON, clinical signs of vomiting, diarrhea, muscular weakness, tremors, and twilight coma were similar to those observed with other 12,13-epoxytrichothecenes. Hypoglycemia and pancreatic islet cell lesions were observed which indicated that DON-induced changes in intermediary metabolism may be an insidious aspect of DON intoxication. Histopathologic examination of all organ systems revealed pancreatic acinar and islet cell necrosis and mild lympholysis of the mesenteric lymph nodes. The renal excretion of DON was altered by IV infusion of saline solution. Pharmacokinetic findings may indicate that DON was both secreted and reabsorbed by the renal tubules. The half-life of DON ranged from 2.08 to 3.65 hours. Residues of DON were not found in skeletal muscle of swine at 24 hours after dosing.

Animal Feed↗

Induction of cleft palate in newborn pigs by maternal ingestion of poison hemlock (Conium maculatum).

Cleft palates were induced in newborn pigs of gilts fed Conium maculatum seed or plant during gestation days 30 through 45. Twelve of 23 newborn pigs born to 3 gilts given Utah-grown C maculatum seed and 9 of 12 newborn pigs born to a single gilt given the fresh Utah spring-growth C maculatum plant had cleft palates. The cleft palates ranged from a unilateral cleft, involving only 1 side of the palate, to a full bilateral cleft. Brachygnathia was also observed in some of these newborn pigs with cleft palate. Other malformations were not observed. Chemical analysis of seed and plant samples indicated that gamma-coniceine was the responsible teratogenic alkaloid. A daily dose of plant or seed that provided greater than or equal to 1.07 mg of gamma-coniceine/kg of body weight fed to gilts during the 30th through the 45th day of pregnancy resulted in teratogenic effects.

Alkaloids↗

Congenital skeletal malformations induced by maternal ingestion of Conium maculatum (poison hemlock) in newborn pigs.

Skeletal malformations were induced in newborn pigs from gilts fed Conium maculatum seed or plant during gestation days 43 through 53 and 51 through 61. The teratogenic effects in groups dosed during gestation days 43 through 53 were more severe than those in groups dosed during the later period, with many newborn pigs showing arthrogryposis and twisted and malaligned bones in the limbs and with 1 pig showing scoliosis and deformity of the thoracic cage. The pigs born to gilts given C maculatum during gestation days 51 through 61 had excessive flexure primarily in the carpal joints, without scoliosis or bone malalignment in the limbs. The teratogenicity of poison hemlock depends on the alkaloid concentration and content. Based on the data presented, we speculate that gamma-coniceine is the teratogenic alkaloid in the poison hemlock fed to the gilts.

Abnormalities, Drug-Induced↗

Survey of vomitoxin-contaminated feed grains in midwestern United States, and associated health problems in swine.

During the 1981 corn harvest season in Illinois and surrounding states, cold wet weather enhanced the growth of Fusarium graminearum, with resulting contamination by vomitoxin and, to a lesser extent, zearalenone. Of 342 feed samples analyzed, 274 contained vomitoxin at a concentration ranging from 0.1 to 41.6 ppm (mean, 3.1 ppm) and 40 samples contained zearalenone at a concentration ranging from 0.1 to 8 ppm (mean, 0.66 ppm). Animal health problems and reduced growth performance were observed mainly in swine fed vomitoxin-contaminated rations. The predominant clinical complaints, in decreasing frequency were: reproductive problems (50%), feed refusal (43%), reduced weight gain (25%), diarrhea (17%), death (14%), and emesis (11%).

Animal Feed↗

Effect of chlorpyrifos on Holstein steers and testosterone-treated Holstein bulls.

The effect of chlorpyrifos application was studied in a high-testosterone (testosterone-treated bulls) and a low-testosterone group (corn oil-treated steers). Frequent sampling of blood before and after 2 chlorpyrifos applications was used to monitor plasma testosterone concentrations and blood cholinesterase activities. Bulls had significantly higher testosterone concentrations (P less than 0.01) than did the steers, before and after the 1st and 2nd chlorpyrifos applications. Bulls had higher cholinesterase activities (P less than 0.01) than did steers before the 1st chlorpyrifos application. However, cholinesterase activity decreased more in bulls when compared with that in steers (P less than 0.01) after the 1st and 2nd chlorpyrifos application. Abnormal clinical signs were not observed in the steers, but 2 of 4 bulls had severe clinical signs of organophosphorus insecticide toxicosis after the 2nd application. Seemingly, chlorpyrifos is more toxic for testosterone-treated bulls than for corn oil-treated steers of similar age and weight.

Animals↗

Gas-liquid chromatographic determination of T-2 toxin in plasma.

A gas-liquid chromatographic method for the determination of T-2 toxin in plasma is described. The toxin is extracted with benzene, washed with aqueous sodium hydroxide, and chromatographed on a small Florisil column; the heptafluorobutyryl derivative is prepared by reaction with heptafluorobutyrylimidazole. The T-2 HFB derivative is chromatographed on OV-1 at 230 degrees C and measured with an electron capture detector. Iso-T-2, an isomer of T-2 toxin, is added to samples as an internal standard before extraction. Recoveries averaged 98.0 +/- 5.5% at levels ranging from 50 to 1000 ng/mL. The limit of detection is 25 ng/mL.

Chromatography, Gas↗

Fetal rat development as influenced by maternal lead exposure.

The teratogenic and neurologic effects of lead acetate on fetal rat development were investigated. Thirty-six female hooded rats were assigned to 4 treatment groups (0, 50, 75, and 100 mg/kg) and given daily oral doses of lead acetate. Animals were treated for 3 weeks prior to breeding and continuing throughout gestation. Rats were euthanized at day 20 of gestation. Blood sampling indicated that maternal blood lead concentrations in treated dams were maintained during gestation. Lead exposed groups had significant (at least p less than .01) maternal kidney and liver as well as fetal kidney lead content. Conceptus weight was significantly reduced in treatment groups. It was concluded that although significant amounts of lead crossed the placenta, as exemplified by fetal kidney values, no teratogenic response or reduction in fetal brain DNA content was produced in the rat.

Animals↗