Diagnostic guidelines for ruminant toxicoses.

Management of poisoning is best accomplished when an accurate diagnosis is made and enhanced by attention to five major diagnostic criteria: history, clinical signs, clinical laboratory evaluation, lesions, and chemical analysis. Used properly, all of these factors allow for a better understanding of clinical poisoning. Although not all of these are possible for individual incidents, a systematic approach to support these criteria will bring a more useful assessment of risk and an accurate diagnosis. This article covers key principles of diagnostic toxicology and provides specific suggestions for clinical, laboratory, postmortem, and chemical testing to best suggest and confirm a toxicologic diagnosis.

Fumonisin B-glucose reaction products are less toxic when fed to swine.

The effects of fumonisin B-glucose reaction products in swine diets was examined. Pigs were fed diets containing 528 micromol of total fumonisin B/kg (FB), 528 micromol of total FB-glucose adducts/kg (FB-G, 122 micromol of unreacted FB/kg), or 0 micromol of total FB/kg for 15 days to test the efficacy of the FB-G reaction products in detoxifying FB. Weight gain in FB pigs was lower than in FB-G or controls, which was correlated with feed intake reduction in FB pigs. Serum aspartate aminotransferase, gamma-glutamyltransferase, and total bilirubin in FB pigs were higher than in FB-G or control pigs. Serum sphinganine/shingosine ratios in FB pigs were higher than in FB-G or control pigs. Microscopic examination of tissues from FB pigs showed generalized liver necrosis and apoptosis with marked cellular pleomorphism and disorganized hepatic cords. The liver and kidneys in the FB-G group appeared to be normal. Tissues of controls were free of lesions. Results suggest that dietary FB-G products are less toxic to swine and may provide an detoxification approach in instances of widespread FB grain contamination (p < 0.05).

Glucose reaction with fumonisin B1 partially reduces its toxicity in swine.

Acute and subacute intraperitoneal doses of fumonisin B(1) (FB(1)) were administered to test the efficacy of the FB(1)-glucose reaction products in detoxifying FB(1) in swine. In the acute study at 11 mumol of FB(1)/kg of body weight, five of six pigs administered FB(1) and four of six pigs administered FB(1)-glucose died from acute pulmonary edema. Analysis of weight gain, serum aspartate aminotransferase and gamma-glutamyltransferase, total cholesterol, and pathological evaluation did not provide evidence of protection against FB(1) toxicity by the FB(1)-glucose reaction products. In the subacute study at 5.5 mumol of FB(1)/kg of body weight, one pig administered FB(1) died from liver damage. Analysis of serum aspartate aminotransferase, gamma-glutamyltransferase, and total bilirubin showed protection against FB(1) toxicity by the FB(1)-glucose reaction products. The levels of sphinganine and sphinganine/sphingosine ratios in serum and liver as well as pathologic findings provided definitive evidence of protection against the FB(1) toxic effects by this detoxification procedure (p < 0.05).

Overingestion of methionine tablets by a dog.

Methionine tablets are used as urinary acidifiers for pets and to decrease damage from dog urine to lawns. A 39-kg Labrador Retriever ingested approximately 350 tablets containing 150 mg methionine/tablet and was presented after repeated episodes of vomiting. The only abnormality was posterior ataxia suggestive of spinal cord injury. The animal was treated with i.v. fluids, steroids and gastrointestinal protectants. Approximately 4.5 h after entering the clinic the dog had a single seizure episode lasting 2-3 min which was treated with phenobarbital. Serum ammonia at that time was normal (0.19 mg/dL). The animal did not show further CNS abnormalities and awoke apparently normal. A musty odor to the breath was noticed through the course of the day, possibly due to volatile mercaptans produced from methionine metabolism. The animal made an uneventful recovery and was discharged the next day.

Characterization of fumonisin B(1)-glucose reaction kinetics and products.

The reaction of fumonisin B(1) with the reducing sugar D-glucose can block the primary amine group of fumonisin B(1) and may detoxify this mycotoxin. A method to separate hundred milligram quantities of fumonisin B(1)-glucose reaction products from the excess D-glucose with a reversed-phase C(18) cartridge was developed. Mass spectrometry revealed that there were four primary products in this chain reaction when fumonisin B(1) was heated with D-glucose at 65 degrees C for 48 h: N-methyl-fumonisin B(1), N-carboxymethyl-fumonisin B(1), N-(3-hydroxyacetonyl)-fumonisin B(1), and N-(2-hydroxy, 2-carboxyethyl)-fumonisin B(1). The N-(1-deoxy-D-fructos-1-yl) fumonisin B(1) (fumonisin B(1)-glucose Schiff's base) was detected by mass spectrometry when fumonisin B(1) was heated with D-glucose at 60 degrees C. The nonenzymatic browning reaction of fumonisin B(1) with excess D-glucose followed apparent first-order kinetics. The activation energy, E(a), was 105.7 kJ/mol. Fumonisin B(1) in contaminated corn could precipitate the nonenzymatic browning reaction with 0.1 M D-glucose at 60 and 80 degrees C.

Diagnostic analyses of biological agent-caused syndromes: laboratory and technical assistance.

The impact of a bioterrorism attack can be greatly reduced by collaboration among primary healthcare providers, laboratories, the veterinary community, public health officials, and emergency response personnel. Improved communication and coordination are essential to make this happen. As a first-line provider, the emergency physician must keep in mind the possibility of bioterrorism and alert the laboratory so that samples can be processed in the correct fashion. New and exciting developments in laboratory organization, communication, and diagnostic capabilities will ensure that all patients receive the best possible care.