Veterinary and human toxicology最新文献

Ageratum houstonianum (Ageratum, flossflower, blue billygoat weed) is an annual plant that tends to become a pest in gardens and pastures. Clinical signs for A. houstonianum toxicosis in cattle are characterized by either an acute hemorrhagic course or sub-acute photodynamic dermatitis. The toxicosis has often been associated with Holstein-Friesian or crossbreed Holstein cattle less resistant to tropical climate conditions. During a recent especially dry spring about 40 adult Zebu cattle were found dead, while another 40/800 animals were sacrificed. The animals had been relocated to the problem area about 4 mo before, where due to the prolonged drought, A. houstonianum was almost exclusively the only pasture available. The intoxicated cattle did not show the characteristic toxic dermatitis reported for A. houstonianum acute toxicosis; but post-mortem examination revealed bloody serous fluid in coccyx-femoral joints and hemorrhages in the large muscle tissues, while liver, kidney and heart also had hemorrhages. To confirm the toxic plant as cause of the toxicosis, phytochemical Qualitative screening and a novel thin-layer chromatographic characterization of plant extracts were done. The chromatographic profiles of coumarin compounds, alkaloids and triterpens in ruminal and intestinal contents were similar to those obtained from A. houstonianum plants from the same area, confirming ingestion of A. houstonianum as cause of the toxicosis. The coincidence of adverse nutritional conditions together with the cattle's ignorance of the grazing area predisposed the plant toxicosis.

There are few studies that use measurable outcomes to gauge the effect of a public educator on the mission of the poison center. Human exposures, penetrance and total call volume from 2 regional poison centers for 7y (1996-2002) were evaluated. In poison center 1 a dedicated educator was employed for the final 4y of data (1999-2002). Poison center 2 data acted as a control with no dedicated educator for the 7-y period. The 2 centers were comparable in a number of ways: similar demographic rural and urban populations; similar geographic and economic region; and served the entire state. Human exposures in poison center 1 increased 4.3 % after employment of a dedicated educator, while exposure continued to decline at center 2 (1.7%). A steep decline in penetrance in poison center 1 was reversed after employment of a dedicated educator. Human exposures and penetrance for poison center 2 continued to decline during the study years. Total calls to center 1 increased 13.8% while total calls to center 2 remained flat (0.2%). This is the first study to use measurable outcomes to evaluate the impact of a public educator on the mission of a poison center. The addition of a public educator was associated with a positive impact on human exposures and penetrance reported to a regional poison center.

About 90 scorpion species occur in the US, and scorpion stings accounted for over 15,600 calls to poison centers in the US in 2002. However, epidemiologic information on scorpion envenomations in the US, and Texas in particular, is limited. This study investigated the relationship between epidemiological factors and the scorpion stings reported to the Texas poison centers. Cases consisted of all human exposure calls of scorpion stings to Texas poison centers during 1998-2003; there were 11,545 total cases. The reported scorpion envenomation penetrance increased during 1998-2002. Among cases with a known patient age, 10.9% were < 6 y of age, 21.7% were age 6-19 y and 67.3% were > 19 y of age. Females accounted for 55.8% of the cases and males for 44.2% of the cases. Scorpion stings were most frequently reported in May and June with envenomation penetrance lowest in northeast Texas and highest in west Texas. The exposure site was the patient's own residence for 93.9% of the cases. The management site was not a health care facility for 95.8% of cases, and there were minor effects in 88.4% of cases with a known clinical outcome.

This report describes 5-fluorouracil (5-FU) toxicity in a dog that resulted in severe bone marrow suppression. The dog initially was presented with neurologic and gastrointestinal signs and developed pancytopenia characterized by severe neutropenia and thrombocytopenia. Examination of bone marrow aspirate showed aplasia. The dog also had marked echinocytosis, which has been previously associated with in vitro 5-FU exposure. The patient was given aggressive supportive care and recovered within 25 d of exposure. To the authors' knowledge, this is the first report of a case of 5-FU toxicity in a dog to include results of bone marrow examination, as well as the first to describe echinocytosis related to 5-FU toxicity.

The contents of the safety section of dossiers supporting marketing authorisation applications for veterinary medicinal products have improved markedly over the last 15-20y. This is particularly true for products intended for use in food producing animals and well exemplified in the European Union. The concept of the acceptable daily intake has been refined and in addition to toxicological safety, pharmacological and microbiological considerations are also now taken into account. All of these factors are built into the approach for the elaboration of maximum residue limits for residues of veterinary drugs in food of animal origin, and the subsequent determination of their withdrawal periods in each species. These developments have been matched by improvements in residues surveillance. More emphasis is now given to the safety of those using veterinary medicinal products, and to possible environmental effects. Consumers, users and the environment are therefore better protected from any potential harmful effects. Both industry and regulatory authorities have invested significant efforts into communicating these developments to the public. However, it is still worthwhile questioning whether more can be done to bring these achievements to a wider public audience, and thus to increase confidence in the safety of veterinary medicines by both consumers and user alike.

This study evaluated the characteristics of orally poisoned patients admitted to our emergency department (ED) between January 1, 1998 and February 28, 2002. This study included 1098 patients. Poisoning cases annualy accounted for 0.5-1.3% of total patient admission during this period. The average age of the patients was 26y old. Poisoning was particulary common in students and housewives. Poisoning cases presented to the ED most commonly between 6 pm and 12 am (38%). More than half of study patients (52%) were admitted to the ED within 2 h of exposure. The incidence of concomitant alcohol intake with another intoxicant was 11%. The ingested drugs were 32% various antidepressants, 23% paracetamol, 20% analgesics (excluding paracetamol and salicylates), 10% antibiotics, 9% benzodiazepines, 7% salicylates and 7% cardiovascular drugs. Most patients received at least 1 of the following treatments: gastric lavage, oral activated charcoal, iv hydration, or diuresis. Thirty-two percent of patients were hospitalized beyond 24 h and 68% of were discharged within 24 h. The mortality rate of the overall cohort was < 1%. Psychiatric consultation was obtained for 55% of patients.

Carbon monoxide (CO) exposure and toxicity is a potentially lethal disorder with immediate and delayed side effects. A 24-y-old driver was admitted to the University-based emergency department with altered mental status. He was found unconscious in the driver's seat of his vehicle in an indoor garage the morning before. An estimated 7 h later, he was comatose and taken to a nearby village clinic. Oxygen was administered immediately. Later, he was transferred to the university hospital. At the 12th h after exposure, the Glasgow Coma Scale score was 12/15 (E3, M5, V4). Co-oximetry disclosed a carboxyhemoglobin concentration of 10.5%. Normobaric oxygen was administered. He recovered completely the 3rd d after exposure; however, on the 7th d disorientation and agitation was noted, and the interval form of CO poisoning and leukoencephelopaty were suspected, for which he was readmitted the 10th d after exposure. Analysis of cerebrospinal fluid and blood revealed no abnormalities. Magnetic resonance imaging on the 11th d after exposure demonstrated an ischemic area in the posterior temporoparietal area. The patient continued improvement to discharge at 7th d of the second admission. Close follow-up should be scheduled for CO-poisoned patients to rule out the post-interval syndrome for at least 1 mo. This should also include those with apparent clinical and laboratory recovery.

Most fatalities from fires are not due to burns, but are a result of inhalation of toxic gases produced during combustion. Fire produces a complex toxic environment, involving flame, heat, oxygen depletion, smoke and toxic gases. As a wide variety of synthetic materials is used in buildings (insulation, furniture, carpeting, electric wiring covering, decorative items), the potential for poisoning from inhalation of products of combustion is continuously increasing. In the present review, the problems that are present in a fire event, the toxicology of the toxic substances and the specific chemical hazards to firefighters are described. Regulatory toxicology aspects are presented concerning the use of non-flammable building and furnishing materials to prevent fires and decrease of poisonings and deaths resulting from fires.