Toxo- Mycotoxins 3

wilsbach's version from 2016-03-03 17:58

Z ctd

Question Answer
CSs of Z tox?all the typical signs of hyper E-- Vulvular swelling, Increased nipple size, Uterine and rectal prolapse, Cystic ovaries, Perinatal death
sensitivy to Z not only depends on what species or how it's metabolized-- 2 factrs which affect the outcomes of exposure?age dependant sensitivty as well as duration of exposure sensitivity
explain the "dual activity" of Zdepends on WHEN THEY ARE EXPOSED to this mycotoxin. If exposed intra-uterine, might result in hyperestrogenism in neonate. They have age dependant sensitivty as well as duration of exposure sensitivity....along with hyperE in neonate, can lead to cystic ovaries and other similar problems later in life.
Z is a Substrate for enzymes regulating the synthesis and inactivation of endogenous hormones (what enzyme is this?)hydroxysteroid dehydrogenase: HSD
Z is a ___ at estrogen receptors regulating transcriptionagonist (leads to all kinda problems)
so often see Z and DON CO-EXPOSURE!! so briefly go through Z's effects and what the effects depend on. Then go through DON's effects and resultsZ-->Effects via E-2 receptors--> Effects depend on age and Effects are hormone-dependent. 0---DON--> Effects via cytokines--> APR-like syndrome: IgA, eosinophilia--> Effects modulated by immune status
ZEA toxicity in dogs and cats--> prevalent in pet food. what is the hormone that breaks Z into the A-zol? B-zol?A-zol happens when Z broken down by 3aHSD (3 alpha hydrodysteroid dehydrogenase), and B-zol happens when it is broken down by 3-beta-hydroxysteroid dehydrogenase.
explain what he means by Z having Regulation of hormone activity at the pre-receptor level, and what is the result?bc it binds to receptor and then has affects on the DNA. RESULT: endocrine disruption
what are the DDX for Z in dogs/cats?age-related hormonal instability - pyometra

Aflatoxins, Citrinin, Tremorgenic mycotoxicosis

Question Answer
what are the 4 kinds of aflatoxins?B 1 , B 2 , G 1 , G 2 (uh M1 wasnt on slide)
which organ is most affected by aflas?HEPATOCYTE TOX (epoxide formation)
which fungi produce aflatoxins?Aspergillus flavus and parasiticus
which foods are contaminated with aflatoxins?(remember its aspergillus) Peanuts - soy - oily seeds
CSs of aflatoxicosis?gallbladder oedema - jaundice - liver degeneration - decreased feed intake
Aflatoxin B1 intoxication in dogs: which products most likely to get this toxin to the dog? what are lethal conc for a dog? CSs?Corn and corn extrusion products, coconut oil and cocoa oil. Lethal concentrations: 150-330ppb... CSs: weight loss, anorexia, icterus, delayed clotting time
DDX for aflatoxin tox in dogs? acetaminophen or rodenticide toxicity
what does Citrinin cause? in who?renal toxicosis in dogs.
ddx for citrinin in dogs?ethylene glycol intoxication.
CSs of dogs with citrinin? (mostly experimental data)specific renal intoxication: SIG INC IN: hematocrit - proteinuria - glycosuria - proximal tubule lesions..... als Granular cast in urine sediment - proteinuria - glycosuria
Tremorgenic mycotoxicosis in dogs: which two fungi cause this prob?Penicillium crustosum - P. roqueforti
Penicillium crustosum - P. roqueforti found in what foodsMoldy rice - cheese - walnuts
what is the tremorgenic toxin which is produced by Penicillium crustosum - P. roqueforti?penitrem A
what are the CSs of penitrem A tox? (which foods/agents again?)Penicillium crustosum - P. roqueforti on Moldy rice - cheese - walnuts---- CSs: lethargy - panting - trembling - ataxia - seizures
ddx for penitrem A/penicillium tremor tox? monensin intoxication

Moldy silage and prevention stuff, carryover.

Question Answer
Mouldy silage syndrome: the forgotten mycotoxins. These are mycotoxins produced in silage. Underestimated risk for what? An underestimated risk for human and animal health ((bc animals eat them--> mycotoxins now in meat and milk)
why are there not straightforward CSs in silage mycotoxins?mycotoxins ARe in the silage, but the conc is not high enough to over CSs but leads to dec in production.
Hazard identification: silage- 2 bacterial contamination peeps?Listeria monocytogenes, Clostridium butyricum
*Hazard identification: silage- 3 yeast/mold contaminaints? What to they do in general?Rhodotorula spp., Penicillium roqueforti, Monascus ruber... In general, lead to a variety of diff type sof exposure
what are 3 ways cattle are exposed to silage mold/yeast contaminants?(1) Inhalation of fungal spores (nose in feed) (2) Exposure of rumen to mycotoxins with antimicrobial activity (so exposure high enough, gonna shift normal flora in rumen-- then rumen less effective-- dec in production) (3) Exposure to mycotoxins that pass the rumen (direct effect on GI like DON/T2)
what problems can result from exposure to silage mycotoxins?Activation of the immune system. Impairment of rumen barrier function (dont produce well, dont take in enough feed)
what are explain the CHEMOPROTECTION and CHEMOPREVENTION methods for probs with silage mycosis(1) Chemoprotection: compounds that protect the individual by inhibiting absorption from the GI-tract, or by inducing excretion pathways (mycotoxin binderS)---> Reduction of the internal dose: kinetic studies in target animals [so stuff in feed that either neutralizes it or affects its MOA] [basically reduce internal dose!] (2) Chemoprevention: Compounds that successfully prevent/mitigate adverse effects of mycotoxins (antimycotoxicosis agetns) -->Interference with mechanisms of toxicity: measurement of biological effects
what are some chemoprotectans you can try to use to help with silage mycotoxins? probiotics and bacterial enzymes(De-epoxidation of the Trichothecenes---- if you can make this group go away, then the metabolite is much less active than parent compound ) (similar with esterases with Z.) Sequestering and degrading mycotoxins will be structure specific
Chemoprevention: targeting efflux transporters: explain this, what are 4 toxins theyre effecive against?make it easier to elim mycotoxin. Effective against OTA (organic anion transporter substrate), DON, NIV (nevalinol- part of DON, FB1) (ABC transporters or other transporters)
what are some examples of Toxin binders for mycotoxins?Bentonite, Montmorillonite, Sepiolite, Zeolite, Mineral clays (HSCAS - hydrated Na-Ca silicate) (ppl arent actually sure how well these work but are a common feed addetive)
what are Yeast cell wall products? what do they do?have an effect on some of the MOAs of the mycotoxins. chemoprevention and protection. Because mycotoxins can lead to depletion of antioxidant reserve, so if you replenish them, are able to counteract some of the liper peroxidation reactions. Replenishment: TROLOX assay-- have inc doses of glutathione peroxidases, can revert oxidative stresses.
Carryover: what are the human implications for AFB1? (where is it) AFM1 in milk, exposure of children (B1s in meat not really high enough to cause risk he said)
carryover: what are the human implications for OTA? (where is it)OTA can be in plasma - kidneys - liver - muscle. (so if you like to eat livers and kidneys, need to be more careful)
carryover: CPA (cyclopiazonic acid) have what implications for humans? (where is it)(toxin found together with melamine) muscle tissues broilers
where might Z. be that humans might consume it?might be in fat.
what is the main way humans are exposed to mycotoxins?HUMANS ARE MAINLY AFFECTED FROM EATING CONTAMINATED GRAIN, NOT EATING Animal PRODUCTS!
how common of a prob is mycotoxins?Mycotoxins appear to be the most common contaminants of feed materials
at what stage is it basically unavoidable (we cant treat) to get rid of mycotoxins?Fungal invasion of crops and mycotoxin formation at the pre-harvest stage is apparently unavoidable
what are managerial efforts focused on with mycotxin contamination?Managerial efforts are directed towards keeping the mycotoxin load in feed materials as low as reasonably achievable
good agricultural practice also tries to focus on what part of mycotoxin mgmt?Reduction of fungal invasion of crops at the post-harvest level is an objective of good agricultural practice
what is species sensitivity variation like?All animal species are sensitive, but animal sensitivity varies
what is the main way we tx mycotoxins?There is no specific antidote to any common mycotoxin and intervention focuses on prevention of absorption and symptomatic therapy
Inhalation of fungal spores is a prominent health risk for who? humans (farmer’s lung) and animals (RAO in horses)
what is the major determinant of tox of a mycotoxin?The oral bioavailability of mycotoxins is a major determinant of toxicity (internal dose)
what are two things which control oral bioavailability of myxotoxins?Oral bioavailability is controlled by the GI barrier (including effux transporters) and pre-systemic elimination (biotransformation)
mycotoxin barriers can act as ___ or ___ agentsMycotoxin binders may act as chemoprotective of chemopreventive agents
mycotox contamination in dog and cat food is most likely in what kinda foods?foods higher in grains/by-products