A Case Study: What Doses of Amanita phalloides and Amatoxins Are Lethal to Humans?

There are few data estimating the human lethal dose of amatoxins or of the toxin level present in ingested raw poisonous mushrooms. Here, we present a patient who intentionally ingested several wild collected mushrooms to assess whether they were poisonous. Nearly 1 day after ingestion, during which the patient had nausea and vomiting, he presented at the emergency department. His transaminase levels started to increase starting from hour 48 and peaking at hour 72 (alanine aminotransferase 2496 IU/L; aspartate aminotransferase 1777 IU/L). A toxin analysis was carried out on the mushrooms that the patient said he had ingested. With reversed-phase high-performance liquid chromatography analysis, an uptake of approximately 21.3 mg amatoxin from nearly 50 g mushroom was calculated; it consisted of 11.9 mg alpha amanitin, 8.4 mg beta amanitin, and 1 mg gamma amanitin. In the urine sample taken on day 4, 2.7 ng/mL alpha amanitin and 1.25 ng/mL beta amanitin were found, and there was no gamma amanitin. Our findings suggest that the patient ingested approximately 0.32 mg/kg amatoxin, and fortunately recovered after serious hepatotoxicity developed.

Co-ingestion of amatoxins and isoxazoles-containing mushrooms and successful treatment: A case report.

Mushroom poisonings occur when ingestion of wild mushrooms containing toxins takes place, placing the consumers at life-threatening risk. In the present case report, an unusual multiple poisoning with isoxazoles- and amatoxins-containing mushrooms in a context of altered mental state and poorly controlled hypertension is presented. A 68-year-old female was presented to São João hospital (Portugal) with complaints of extreme dizziness, hallucinations, vertigo and imbalance, 3 h after consuming a stew of wild mushrooms. The first observations revealed altered mental state and elevated blood pressure. The examination of cooked mushroom fragments allowed a preliminary identification of Amanita pantherina. Gas chromatography-mass spectrometry (GC-MS) showed the presence of muscimol in urine. Moreover, through high-performance liquid chromatography-ultraviolet detection (HPLC-UV) analysis of the gastric juice, the presence of α-amanitin was found, showing that amatoxins-containing mushrooms were also included in the stew. After 4 days of supportive treatment, activated charcoal, silybin and N-acetylcysteine, the patient recovered being discharged 10 days post-ingestion with no organ complications. The prompt and appropriate therapy protocol for life-threatening amatoxins toxicity probably saved the patient's life as oral absorption was decreased and also supportive care was immediately started.

Flow-through comb electroporation device for delivery of macromolecules.

We present a microfluidic electroporation device with a comb electrode layout fabricated in polydimethylsiloxane (PMDS) and glass. Characterization experiments with HeLa cells and fluorescent dextran show efficient delivery (∼95%) with low toxicity (cell viability ∼85%) as well as rapid pore closure after electroporation. The activity of delivered molecules is also verified by silencing RNA (siRNA) studies that demonstrate gene knockdown in GFP expressing cells. This simple, scalable approach to microfluidic, flow-through electroporation could facilitate the integration of electroporation modules within cell analysis devices that perform multiple operations.

Memory extinction requires gene expression in rat hippocampus.

Rats with cannulae in the dorsal CA1 region of the hippocampus were trained in one-trial step-down inhibitory avoidance, and submitted to four consecutive daily test sessions without the footshock. This produced extinction of the conditioned response in control animals. The bilateral infusion into the CA1 region of the dorsal hippocampus of two different inhibitors of gene transcription, DRB (80 microg/side) or alpha-amanitin (25 pg/side), or of the protein synthesis inhibitor, anisomycin (80 microg/side) blocked extinction of the CR. The treatments were effective when given 15 min before, but not 1 or 3h after the first test session. Retrieval itself was not affected by the drugs. The treatments did not affect general activity in an open field or anxiety levels measured in an elevated plus maze. The data indicate that gene transcription and protein synthesis are necessary at the time of the first test session in order to generate extinction. These requirements are to be expected from learning that involves new synaptic associations.

Increased intracranial pressure in a porcine model of fulminant hepatic failure using amatoxin and endotoxin.

BACKGROUND/AIMS: The purpose of this study was to develop a clinically relevant porcine model of fulminant hepatic failure (FHF) by means of administration of amatoxin and endotoxin. METHODS: Pigs were intraportally administered only saline in group 1 (n = 3), 1 microg/kg of lipopolysaccharide (LPS) in group 2 (n = 4), 0.1 mg/kg of alpha-amanitin in group 3 (n = 5), and amanitin plus LPS in group 4 (n = 9). RESULTS: All the pigs in groups 1 and 2 survived with minimal changes in liver function tests. In contrast to the 60% mortality in group 3, all the pigs in group 4 died within 96 h, with a significant increase in aspartate transaminase at 24 h (9,757 +/- 2,167 IU/I). In addition, they demonstrated severe metabolic disorders, such as serum lactate accumulation, hypoglycemia, coagulopathy, plasma amino acid imbalance, and hyperammonemia. The intracranial pressure significantly increased to 17.8 +/- 2.5 mmHg immediately before death. Reversal of FHF in these pigs following orthotopic liver transplantation confirmed that the toxicity is liver-specific and that the graft liver is unaffected. CONCLUSIONS: This porcine model of FHF induced by a combination of amanitin and LPS will be of much use in the development of new therapies for human FHF.

Hemoperfusion with alpha-amanitin: an in vitro study.

The authors carried out sixteen hemoperfusions with alpha-amanitin in vitro in a closed system using active charcoal, Amberlite XAD-2 and Amberlite XAD-4 in hemoperfusion capsules. As a perfusion solution 4 liters of 0.9% NaCl solution was used. The alpha-amanitin concentration in the solution was 8.3 +/- 0.36 mg/L. Individual hemoperfusion lasted 5 hours. Two hundred and forty minutes of Amberlite XAD-2 hemoperfusion led to the zero values of alpha-amanitin concentration in 0.9% NaCl solution. When using active charcoal the adsorption capacity of the hemoperfusion capsule was already exhausted at 120 min. The results gathered suggest that the most effective alpha-amanitin hemoperfusion in vitro was obtained with Amberlite XAD-2 and the least effective with active charcoal. The authors recommend the use of hemoperfusion with Amberlite XAD-2 for acute intoxication with Amanita phalloides in humans up to 24-36 hours after poisoning.

Targeting of antiviral drugs by coupling with protein carriers.

Side effects of antiviral drugs might be circumvented by their selective delivery into infected cells. This targeting can be obtained by conjugation of the drugs to macromolecules which are taken up specifically by the infected cells. The experiments reviewed, on this approach to antiviral chemotherapy, are mainly directed at improving the chemotherapeutic index of adenine arabinoside (ara-A) in the treatment of chronic hepatitis B by its coupling to galactosyl terminating glycoproteins.

A conjugate of alpha-amanitin and monoclonal immunoglobulin G to Thy 1.2 antigen is selectively toxic to T lymphoma cells.

A covalent conjugate of an alpha-amanitin azo derivative and a monoclonal immunoglobulin G to the Thy 1.2 antigen on murine T lymphocytes was synthesized. The conjugate was 375- to 750-fold more inhibitory to murine T lymphoma S49.1 cells than the unconjugated derivative. At 0.7 X 10(-7) to 1.5 X 10(-7) M and at 4 X 10(-7) M amanitin equivalents, the conjugate inhibited protein synthesis in S49.1 cells by 50 percent and 80 to 96 percent, respectively. At these concentrations, mutant Thy l-deficient S49 cells and other murine lymphoma lacking Thy l altogether or carrying Thy 1.1 antigens were unaffected. This result demonstrated the potential for targeting amanitin to specific cell types.