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Cortinarius orellanus
General Details, Taxonomy and Biology, Clinical Effects, First Aid
Phylum: Basidiomycota
Class: Basidiomycetes
Order: Agaricales
Family: Cortinariaceae
Genus: Cortinarius
Species: orellanus
Clinical Group: GROUP 1 - Cytotoxic mushroom poisoning
Common Names: Fool's webcap
Countries
zz NOT LISTED
 
Biology
Habitat
Grows in the mountains specially under oak, birch and pine trees
Description
PILEUS (cap) 3-8 cm diameter. Conical at first expanding to become bell shaped then convex to plane often with a central umbo. Rust brown to pink, orange or red fading to yellowish shades with age. Surface dry, with olive green soft silky hairs or hairy scales. Margin thin, often lobed and wavy, marginal zone occasionally decurved.

LAMELLAE (gills) attached to stipe, sometimes eroded near it. Moderately distant, broad (8-10 mm), thick, sometimes wrinkled. Yellowish orange at first turning darker closer to the colour of the pileus, but with pinkish iridescence.

STIPE (stem) 4-9 cm in height, 1-2 cm thick. Equal to tapering towards the base, sometimes thickened in the middle. Surface longitudinally striate, yellow or slightly paler than the cap, with thread like reddish fibers, darker at the base.

CORTINA yellowish and evanescent.

FLESH yellowish, slightly pinkish under the pileus cuticle and juicy.

SPORE PRINT rust brown.

MICROSCOPIC DETAILS
Spores 8.5-12 x 5.5-6.5 μm, ellipsoidal to amygdaliform, light yellowish brown, verrucose.
Hyphae of the epicutis 8 -17 μm wide, with short cells with walls that have an intense yellowish brown incrustation, hyphae of the subcutis 25-30 μm wide. Hyphal septa especially of the cortina and basal mycelium have clamp connections.
 
First Aid
Description: First aid for poisoning by plants or mushrooms where no agreed first aid method is currently available.
Details
In the absence of research or clinical data about first aid for poisoning caused by this species, no first aid method can currently be recommended. Seek Medical Advice without delay.
 
Clinical Effects & Treatment
Dangerousness
Poisonous
Clinical Classification
Group 1C - Delayed primary nephrotoxicity
Toxins
Contains orellanine.

Orellanine is a homogeneous substance which decomposes under the influence of light (UV light or day light) it will break down in to orellinine and a non-toxic product orelline. Oxygen has no detectable effect on the toxin.
Both orellanine and orelline were bipyridines occuring in two tautomeric configurations.
It is a colourless, polar, blue-fluorescing compound, somewhat unstable; it yields the non toxic orelline, slowly at 150 degrees and explosively at 267 degrees.

Orellanine
Molecular weight is 252.039
3,3',4,4'-tetrahydroxy-2,2'-bipyridyl-N,N'-dioxide
Molecular formula is C10H10O6N2

Orellinine
Molecular weight 236.04
3,3',4,4'-tetrahydroxy-2,2'-bipyridly-N-oxide
Molecular formula is C10H9O5N2

Orelline
Molecular weight 220.048
3,3',4,4'-tetrahydroxy-2,2'-bipyridyl
Molecular formula C10H8O4N2

Orellanine is a nephrotoxin. It has also been found that the toxin found in C. orellanus inhabits DNA depended RNA polymerase B from rat liver and DNA depended RNA polymerase from Ecoli.

About 0.93 pg/spore of orellanine has been found in C,, orellanus spores. The percentage of orellanine in dried C. orellanus cap and stem were 0.9% and 0.5%

An average size specimen contains about 15-20 mg of orellanine. orellanine occurrs as colourless to pale yellow crystals. it is slightly soluble in water giving an acid reaction. More soluble in ethanol and methanol and very soluble in pyridine.
Clinical Effects Overview
Poisoning by ingestion of nephrotoxic mushrooms (specifically Cortinarius spp.) results in delayed onset of renal damage, with a latent period of 36hrs to 17 days before onset of symptoms (shorter delay associated with more severe renal damage).

Following the symptom-free latent period, there may be a varied mixture of symptoms prior to onset of renal failure. These "prerenal" symptoms may last up to a week and can include gastrointestinal effects (nausea, vomiting, thirst, anorexia), neurologic effects (headache, chills, shivering, parastheseae, tinnitus, drowsiness, coma), non-specific (sweats, generalised rash, dyspnoea, lumbar pain).

Following the "prerenal" symptoms, there is onset of renal failure, usually commencing with a polyuric phase, then (in more significant cases), oliguric or anuric renal failure, with slow recovery over weeks in some cases, but with permanent renal failure in a minority of cases, requiring prolonged dialysis or renal transplant.
Primary Clinical Effect
Cytotoxicity specific for kidneys, with delayed onset acute renal failure.
Treatment Overview
In general, treatment of Orellanine poisoning is based on assessment of severity of renal damage and consequent provision of appropriate renal support, up to and including haemodialysis and renal transplant in the most severe cases.

The latent period makes it unlikely patients will present early enough for decontamination to be of benefit. No antidote is available.
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