Evaluation of Brodifacoum-induced Toxicity by Metabonomics Approach Based on HPLC-TOF-MS / 法医学杂志

OBJECTIVES@#To analyse the metabolic changes in urine of rats with brodifacoum intoxication, and to reveal the molecular mechanism of brodifacoum-induced toxicity on rats.@*METHODS@#By establishing a brodifacoum poisoning rats model, the urine metabolic profiling data of rats were acquired using high performance liquid chromatography-time of flight mass spectrometry （HPLC-TOF-MS）. The orthogonal partial least squares analysis-discrimination analysis （OPLS-DA） was applied for the multivariate statistics and the discovery of differential metabolites closely related to toxicity of brodifacoum.@*RESULTS@#OPLS-DA score plot showed that the urinary metabolic at different time points before and after drug administration had good similarity within time period and presented clustering phenomenon. Comparing the urine samples of rats before drug administration with which after drug administration, twenty-two metabolites related to brodifacoum-induced toxicity were selected.@*CONCLUSIONS@#The toxic effect of brodifacoum worked by disturbing the metabolic pathways in rats such as tricarboxylic cycle, glycolysis, sphingolipid metabolism and tryptophan metabolism, and the toxicity of brodifacoum is characterized of accumulation effect. The metabonomic method based on urine HPLC-TOF-MS can provide a novel insight into the study on molecular mechanism of brodifacoum-induced toxicity.

Can we more efficiently save patients with vitamin K-dependent coagulopathy caused by superwarfarin intoxication?

No abstract available.

Evaluation of risk factors in patients with vitamin K-dependent coagulopathy presumed to be caused by exposure to brodifacoum

BACKGROUND/AIMS: Recently, many cases of vitamin K-dependent coagulopathy of unknown origin have been reported. Such patients lack any relevant family history and have no systemic disease, raising suspicion of superwarfarin intoxication. We evaluated individual risk factors causing coagulopathy and hemorrhagic symptoms in patients with suspected superwarfarin intoxication. In addition, we determined how to effectively treat vitamin K-dependent coagulopathy caused by suspected superwarfarin intoxication. METHODS: Seven patients with suspected superwarfarin intoxication who lacked any definitive history of rodenticide ingestion were included. Thirty-one patients initially diagnosed with rodenticide poisoning were also included. We performed a retrospective chart review of all subjects and examined clinical data including patient demographics and medical histories. RESULTS: Patients initially diagnosed with rodenticide poisoning were divided into two groups, one of which had a laboratory abnormality (prothrombin time [PT] > 13 seconds) and another group with PTs in the normal range. There was no significant difference between the two groups in any of age, gender, the extent of chronic alcohol consumption, the causative rodenticide, psychiatric problems, ingestion of drugs interacting with warfarin, the extent of intoxication, or the type of ingestion attempt. The albumin level of the former group was significantly lower than that of the latter group (p = 0.014). Furthermore, a significant difference between the two groups was evident in terms of simultaneous ingestion of rodenticide and alcohol (p = 0.023). CONCLUSIONS: Most patients with superwarfarin poisoning did not exhibit any complication. When such complications were evident, they were associated with serum albumin level and coingestion of rodenticide and alcohol.

A rare case of dilated invaginated odontome with talon cusp in a permanent maxillary central incisor diagnosed by cone beam computed tomography

It has been a challenge to establish the accurate diagnosis of developmental tooth anomalies based on periapical radiographs. Recently, three-dimensional imaging by cone beam computed tomography has provided useful information to investigate the complex anatomy of and establish the proper management for tooth anomalies. The most severe variant of dens invaginatus, known as dilated odontome, is a rare occurrence, and the cone beam computed tomographic findings of this anomaly have never been reported for an erupted permanent maxillary central incisor. The occurrence of talon cusp occurring along with dens invaginatus is also unusual. The aim of this report was to show the importance of cone beam computed tomography in contributing to the accurate diagnosis and evaluation of the complex anatomy of this rare anomaly.

Method for determining brodifacoum in workplace air by high-performance liquid chromatography / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To establish a method for determining brodifacoum in workplace air by high-performance liquid chromatography (HPLC).</p><p><b>METHODS</b>Brodifacoum in workplace air was collected with a polytetrafluoroethylene filter and desorbed by mixed solution of methanol and dichloromethane (20:80, V:V), and was then separated using an ODS column and determined by an ultraviolet detector; retention time was used for identification, and peak area was used for quantification.</p><p><b>RESULTS</b>The concentration of brodifacoum showed a linear relationship with peak area within 0.2∼10.0 µg/ml; the elution efficiency was 91.6%∼95.1%; the detection limit was 0.08 µg/ml (injection volume: 20 µl eluate); the minimum detectable concentration was 0.000 67 mg/m(3) (calculated by 240 L air sample).</p><p><b>CONCLUSION</b>This HPLC method is convenient and simple for air collection and sample preparation and meets the methodological requirements. Therefore, this method can be used for the determination of brodifacoum in workplace air.</p>

Determination of brodifacoum in rat plasma by HPLC / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>A determination method of brodifacoum in rat plasma with bromadiolone as an internal standard was developed.</p><p><b>METHODS</b>A volume of 10 microl internal standard (bromadiolone) was added into rat plasma, and then extracted by 0.5 ml of acetonitrile by shaking for 2 min. The residue was dissolved with 200 microl of mobile phase after centrifugation for 10 min, and evaporation to dryness by Nitrogen blowing. A C18 column and PDA detector were used for separating and detecting. The wavelength was 254 nm, the flow rate was 1.0 ml/min, and the injection volume was 20 microl.</p><p><b>RESULTS</b>The liner range was 1.0-20 microg/ml, and the correlation coefficient was 0.9992. The detection limit was 0.3 microg/ml in plasma (S/N=3). The intra-assay and inter-assay coefficients of variation were 1.89%-2.45% and 2.51%-3.61% respectively. The recoveries in plasma at levels of low, middle and high concentrations were (80.8 +/- 3.1)%, (81.8 +/- 2.7)% and (87.9 +/- 3.6)% (n=6), respectively. The accuracies were 84.1%-91.5% and 86.7%-93.2%, respectively.</p><p><b>CONCLUSION</b>This method is simple, fast and accurate for the determination of brodifacoum in rat plasma.</p>

A Case of Prolonged Coagulopathy in a Patient Intoxicated with Superwarfarin Rodenticide

Superwarfarin, such as brodifacoum, is a highly lethal vitamin K antagonist used as a rodenticide. Brodifacoum has a particularly long half-life in the body, which ranges to several months, and therefore requires prolonged treatment with antidotal vitamin K. We experienced a case whereby an 18-year-old male was presented to the hospital with a severe bleeding disorder. It was discovered that he had ingested brodifacoum rodenticide with intent to commit suicide. Despite continual treatment with vitamin K, the bleeding disorder persisted for several months before he recovered. We report this case with literature review.

Korean Patients with Superwarfarin Intoxication and Their Outcome

This observational study aimed at evaluating recent superwarfarin intoxication of Korean patients. Ten patients were diagnosed as or highly suspicious for superwarfarin intoxication. Case report forms described by attending hematologists of the patients were collected and analyzed. Bleeding symptoms were varied among the patients. Patients uniformly showed prolonged prothrombin time (PT) and activated thromboplastin time (aPTT) with decreased activity of vitamin K dependent coagulation factors. Positive serum brodifacoum test results in 4 of 5 requested patients contributed to confirmatory diagnosis. Psychiatric interview revealed an attempted ingestion in one patient. High dose vitamin K1 therapy promptly corrected prolonged PT and aPTT, but hasty discontinuation caused repeated bleeding diathesis in 6 patients. Route of intoxication was unknown or not definite among 8 of 10 patients. Three patients had a possibility of environmental exposure considering their occupations: there might be intoxication by transdermal absorption or inhalation. Therefore, high dose and prolonged use of vitamin K1 therapy is necessary for effective detoxification. Further detailed investigation on environmental exposure and efforts to improve availability of the blood level test in clinic are requested.

Efficacy of two rodenticides against leishmania reservoir host rat [psammomys obesus] in the rural area of Al-ahsa oasis, Saudi Arabia

Zoonotic cutaneous leishmaniasis [ZCL] is a serious and increasing public health problem in many parts of Saudi Arabia. Rodent control operations are effective in destroying rodents and reducing the incidence of disease. This study tested the efficacy of zinc phosphide and fenacoum against the reservoir host Psammomys obesus rat. The results showed that both the rodenticides were significantly [P<0.01] effective in reducing the number of active holes during one year of application

Susceptibility of bromadiolone anticoagulant rodenticide in two rodent species and its haematologic effect

Susceptibility levels of the Norway rat, Rattus norvegicus and the roof rat, Rattus rattus to bromadiolone anticoagulant rodenticide by bioassay and biochemical methods were studied. Animals were trapped from Giza and Qualyobia Governorates in which the anticoagulant rodenticides were used to control rodents for long periods. Complete mortality was obtained for both species and sexes within standard no-choice feeding test period [4 days] indicating bromadiolone susceptibility. Treatment of rats with LD50 showed high prothrombin times which also indicate the susceptibility of the tested animals. In treated rats, bromadiolone caused significant decrease in the total erythrocytic counts and increase in the total leucocytic counts. In survivors, RBCs, WBCs approximately reached the control levels at day 43 post treatment. Also, treatment decreased neutrophils, eosinophils, basophils and monocytes but increased the lymphocytes in dead and survived animals more than in controls

A Case of Superwarfarin Intoxication without a Definitive History of Brodifacoum Exposure / 대한혈액학회지

Superwarfarin intoxications that induce profound and prolonged coagulopathy are being increasingly reported, to such an extent that it is becoming a comparatively common intoxication. However, there have been few reported cases of superwarfarin intoxication with an inadvertent cause or an unknown origin. A 58-year-old man with recurrent painless hematuria was found to have an acquired deficiency of vitamin K dependent clotting factors, and a large amount of vitamin K was required to correct the coagulopathy. He had no history of warfarin use or any exposure to rodenticides, but brodifacoum was detected in his serum. It is important for physicians to be aware that significant coagulopathy can occur secondary to superwarfarin intoxication, without any known exposure to substances that might induce this.

Effect of bromadiolone on haematology, liver and kidney in Mus musculus.

Bromadiolone, a second generation anticoagulant rodenticide was tested on Mus musculus to evaluate its effects on blood, liver and kidney at varied time intervals of 6, 12, 24 and 48 hrs. Groups of six animals each were selected for experiment. Animals were administered with bromadiolone in the form of bait at 6, 12, 24 and 48 hrs time intervals. Control animals were maintained for each time interval. After each time interval the experiment and the control animals were sacrificed and the effect of bromadiolone on blood, liver and kidney were studied.

Evaluation of secondary poisoning of difethialone, a new second-generation anticoagulant rodenticide to barn owl, Tyto alba Hartert under captivity.

Secondary toxcity of difethialone to Barn owl (Tyto alba) has been investigated. Difethialone was fed to owls for successive periods of 1 (phase 1), 3 (phase 2) and 6 (phase 3) days via-rodenticide dosed rats. The owls survived after the treament of rodenticide on phase 1 and phase 2 experiments but they died during phase 3 experiment. The results suggest that the difethialone could cause more secondary toxicity to owls.

Effect of supplementary feeding of vitamin K1 on difethialone treated Indian gerbil, Tatera indica Hardwicke in laboratory.

Two dosages (1 and 2 mg/kg) of vitamin K1 supplementation for 5 and 15 days were given to Indian gerbil T. indica fed on difethialone bait (0.0025%) for one day. The results indicated that the lower dosage could not reverse the anticoagulation process, however the period of mortality was considerably increased from 3-9 days (in control) to 5-14 days (5 days supplementation regime). Subsequently when the vitamin K1 dosage was doubled and given for 15 days, there was 100% reversal of anticoagulation process and all the test gerbils became normal within a month of poisoning with difethialone bait.

Transplantation of human umbilical cord stem cells improves neurological function recovery after spinal cord injury in rats / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study whether intraspinally transplanted human cord blood CD34+ cells can survive, differentiate, and improve neurological functional recovery after spinal cord injury in rats.</p><p><b>METHODS</b>Rats were randomly divided into two groups. One group of rats was subjected to spinal cord left-hemisection and transplanted with human cord blood CD34+ cells labeled by bromodeoxyuridine (BrdU); The other group was carried by left-hemisection with injection of PBS (control group). The neurological function was determined before and 24 h, 1, 2, 3 and 4 weeks after spinal cord injury and cell transplantation using the modified Tarlov score. The distribution and differentiation of transplanted human cord blood cells in vivo in rat spinal cord were evaluated by histological and immnuhistochemical analysis.</p><p><b>RESULTS</b>Functional recovery determined by modified Tarlov score was significantly improved in the group receiving human cord blood CD34+ cells compared with the control group (P < 0.05). Moreover, human cord blood CD34+ cells were found to survive in rat spinal cord microenvironment, with the expression of the neural nuclear specific protein (NeuN) in 2% BrdU-reactive human cells and of the astrocytic specific protein glial fibrillary acidic protein (GFAP) in 7% BrdU-reactive human cells.</p><p><b>CONCLUSIONS</b>Intraspinally administered human cord blood CD34+ cells can survive, differentiate, and improve functional recovery after spinal cord injury in rats. Transplantation of human cord blood cells may provide a novel strategy for the treatment of neural injury.</p>

Field evaluation of difethialone, a new second generation anticoagulant rodenticide in the rice fields.

A new second generation anticoagulant rodenticide, difethialone (0.0025%), was evaluated in the rice fields at three different cropping stages, viz. Milky, Panicle formation and Panicle maturation, during Kuruvai and Thaladi seasons. The difethailone (0.0025%) yielded satisfactory control success suggesting a great potential as a rodenticide especially in the early stages of rice.

Evaluation of two rodenticides in the paddy fields during Samba and Thaladi seasons.

The single dose anticoagulant rodenticide, bromadiolone (0.005%) and the acute rodenticide, zinc phosphide (2%) were evaluated in the paddy fields during Samba and Thaladi seasons for two crop stages, viz. 20 and 40 days after transplantation. Three baiting methods namely, burrow, station and burrow+station were adopted for both rodenticides. Both the rodenticides were exposed for one and two days in the partitioned plots. In the plots with 20 days after transplantation, the two day exposure of both rodenticides in burrow+station baitings during both seasons cleared cent percent rodent population. The cost-benefit ratio of the employed rodenticides favoured zinc phosphide than bromadiolone. Thus, zinc phosphide is deemed to be an economic rodenticide than bromadiolone and it can be suggested for the control of rodent population with two day exposure by burrow+station baiting methods preferably 20 days after transplanted paddy fields in both seasons.