>>: hello. okay. happy monday. i think we'regoing to get started we're lucky today to have dr. kent olson who isclinic professor of (inaudible) of health and medical sciences here at ucb. he'salso the medical director of the poison control system and editor of drugoverdose and he's going to be speaking with us today about toxicology and.kent olson: thank you. can you hear me well in the back. great. i can'tstart a lecture about poisoning without visiting one of the great historicalpoisoning of all times. many of you might know this case, a young princesswho ate part of an apple that was given to her by the wicked witch. shepresented comatose and unresponsive as in
a deep sleep. and airwaypositioning and mouth to mouth ventilation were performed and she recovered.to me that's the original application to an antidote was loves first kiss andwas probably actually good airway positioning and good supportive care. thisis a theme i'll come back to which is in the treatment of poisoning turns outthat attention to airway and supportive air makes a big difference in mostcases. there's cases where there is certain antidotes like love's first kiss,but that's relatively uncommon. what's there to review about poisonings? there'smany different kinds of poisons, synthetic poisonings and naturalpoisonings. it's a huge cause of
illness and death in history as well as inpresent time. there's a long historical tradition. i'll name a few of themto you. and one thing to keep in mind in poisoning, how much was the dose,what was the dose? this is what our poison control center staff does everyday. they are worried about not only what the child got into that the parentsare calling about but how much of it. was it a full or half of bottle orjust a sip? that's a huge issue in poisoning. just to review some of the interestingpoisonings from history, mithridates, king of pontus, was well knownto poison some of his subjects as well as practice poisoning as well as forpersecution. he was also thought to
have ingested a lot of poisons in small quantitiesover time to try to make himself immune to poisons. i don't know ifthat really happened or if it occurred but that was the legend.in the middle ages, there were periodic epidemics called st. anthony's fire.have you heard this term before? this was mini epidemics involving probablypoisonings by an ergot. it's a chemical that produced by certain molds andthe moldy rye was being ingested in the form of bread was causing ergotism.ergotism causes intense vaso constriction, that's spasm of the small bloodvessels of the tips and toes. it can lead to gangrene of the fingers andfingers will feel to become hot like they
are on fire. it causes them tobecome blackened and loss of blood.and supply. so people had this impressionthat some visitation had occurred to them and was causing this fingertipburning. in addition ergots are known to cause hallucinogens. so lysergicacids or diethylamide lsd is derived from ergots and it might be that thesepeople were not only intoxicated by ergots but lsd at the same time. we havean unfortunate history of chemical war fair in i the 20th century. we havethe nazi exterminations with zyklon-b. and more recent time a few years agodiethylene glycol was used as a substitute solvent in children's cough syrupeffected children worldwide particularly in
el salvador and haiti. causingkidney injury and long lasting problems with arsenic in the ground water inbangladesh and that part of india and the india subcontinent involving chronic exposure of arsenic resulting in toxicity.this was a horrible disaster that occurred when i was an intern in sanfrancisco there was a cult run by the reverend jim jones who was out of sanfrancisco and many of the cult members were actually from san francisco.family members we were treating at mt. zion hospital at the time new aboutthis problem down in guyana with about a thousand members of this cult that onthe orders of jim jones ingested cyanide laced
kool aid.just to look back, what are the types of poisons we come across, how do theyget into our body, what do they do, what are the dose issues? let's juststart by thinking about poisons. they can be in the form of a solid like apill. they can be a liquid. they can be in a gas form. of course liquidscan become gases by being warmed up or converted into a myst. and they canget into the body by different ways. they can be inhaled. they can get intothe skin or eyes. so think of tear gas, for example, as a type of poison.it's used for particular purpose which is to drive people in a certaindirection. a poison can be ingested either
intentionally or accidentally.and it can be injected that could be in the form of ar needle injection eitherfor recreational purposes or the accidental use of the wrong drug in ahospital. they could also be in the form of an injection by a venomouscreatures. so in the bay area, northern california we have a venomous animalknown as the rattlesnake. a very-well developed venom apparatus. itbasically has fangs that act like hypodermic needles. they come out on hingesand inject the venom through these very specialized teeth, these fangs deepinto the tissue. so that they have a very -- a very effective mechanism forgetting the poison into the body. compare
that to say probably the most venomous snake we know which is a sea snake,hardly ever causes human intoxication, not because we are not swimmingwith them. you can. but because they have very small mouth and it'svery difficult for them to bite the human body. so we don't end up gettinginjected because the opportunity is not there. and a lot of poisoning has todo with opportunity. so, another example would be how many of you have a car?so, from time to time you may have to put some coolant in the radiator.we also call it antifreeze because it keeps it from freezing if you are in thecold climates and antifreeze is
about 99 percent ethylene glycol. very toxicchemical. you drink a couple of tablespoons, it can cause kidney damage, kidneyfailure. perhaps even death. so very, very toxic compound, but we get iton our hands and inhale it. we don't think much of it because it's not absorbedthrough the skin. it's not taken in by inhalation because it's not veryvolatile. so you have to ingest it in order to become poisoned. so the routeof exposure becomes very important then. let's talk a little bit abouttypes of toxic effects. i'm going to start with local injury and thenwe'll come back to systemic effects later. so, local injury means the direct applicationof the toxicant to the
skin or eyes or ingestion so that it burnsthe mouth or throat or intestinal tract. and inhaling it can cause burns tothe inside linings of the lungs. there are a lot of chemicals that can do thisand for reason in chemistry or biology lab there are times you have to workin a hood because the chemical is volatile and you may inhale it if you don't.or in the another environment you may have to wear a special kind of facialprotection with supplied air so you don't breathe in the chemical. so here'sa quiz question. i don't know how many of you are going to get this, buti'll give you the answer in a moment. what toxic gas is released whenyou mix household bleach and an acid?
it's actually a very common problem. we cancall the poison center dozens of times per year by someone who is trying todo an extra good job on their toilet cleaning. starts with a toilet bowlcleaner which has an acid in it and then add some bleach to finish off thejob and a gas is produced. this same gas was used as a chemical warfare agentin wwi. and the gas is chlorine. so, the combination of hypo-chloridewhich is bleach plus hydro chloric acid gives you this chlorine gas.and chlorine gas is extremely toxic. it's very irritating to the eyes andthroat. it can cause burns to the lung or chemical pneumonia. it was usedin the battle of loose in
september of 1915. this is the air -- i meanwind currents drawing the gas across enemy lines. and it's widely used -- didyou have a question? euflpt: (inaudible).professor: yes a lot of toilet bowl cleaners have acid, either hydrochloricor sulfuric acid. so also if you mix bleach with ammonia, another householdcleaner, you can get a gas called chloramine which is also toxic in a similarway. so chlorine is used in very large quantitiesin the industry fl the u.s. both as a chemical precursor as well as a bleachingagent. make paper white, for example. obviously, commercial bleaching applications,household bleaching
agents, water purification. swimming poolpurification. 14 million-tons in 1998 and of course, it gets transported aroundin big tanker cars. so every once in a while there will be a train derailment.lots of gas released. and people that are injured or die as a resultof that exposure. so chlorine is what we call an irritant gas and it's a gasthat's very soluble in water. so it combines with water to make hydrochloricacid which produces hydrogen (inaudible) and burns the tissue. and we sayas a result of being very water soluble and being likely to attach moisturein the eyes, nose and throat that it's an agent with good warning propertiesbecause as soon as you start to
inhale it, your eyes start to burn, your throatstarts to hurt. you start to cough or have wheezing and you are likelyto be warned about the presence of the gas and to leave the area quickly to preventfurther exposure. on the other hand, imagine a gas that has less soluble,has poor warning properties because it doesn't get converted rapidly intoan acid. it can penetrate deeply into the lower airways as a resultbecause you don't know you are being exposed to it and the effects can be verydelayed because it takes some time for the acid to be produced from the combinationof the gas plus moisture. so these are agents with poor warning properties.an example of that, i give
you hear is phosgene. this was a gas usedin wwi. because of its slower onslaught effect, you might think why wouldan army want to use a gas with poor warning properties with a slow onslaughtof effects? obviously you are not going to drive the enemy back quicklylike you would with tear gas or chlorine, but what you are going to do ishave people inhaling the gas unknowingly. large numbers of people inhalingthe gas and then in ten or 12 hours presenting to the medical tent in hugenumbers with delayed onset of chemical pneumonia. so a larger number ofpeople would be effected for a larger period of time. and that was the ideaof using this gas with poorer
warning properties.and in fact this gas doesn't have that irritant effect on the eyes nose andthroat. instead it has this smell. some people call it like pneumonia hay. some call it green corn or musty hay. theseare some warning posters that were created in the wwi, wwii era to warnsoldiers to be on the lookout for that smell and to get away from it if theysmelled it. so we've talked about an agent effecting the skin, the lungs. wehave not talked about the gi tract but imagine an acid or a base that's ingestedis going to have effects on the esophagus, the stomach, perhaps burns evenpenetration through the gulls of
the stomach causing a terrible injury to thoseareas. if the poison gets into the bloodstream and can be carried into thebloodstream to some target organ. and we call this distribution. and perhapsmetabolism or detoxification. but we then think about the systemic effects,not just the effects on the eyes, the throat, the breathing, et cetera. butwhat are some systemic effects of poisonings? well they can include anythingfrom mild effects like dizziness, nausea. if you are working, let's say in anenclosed area with a solvent, you might begin to feel a little bit high aftera bit. and then perhaps a little headachy and nauseated. if you are exposedto it longer, you may end up
having some vomiting. with more in seriouspoisonings, inhalation or ingestion can go to the heart lung or brainsand causing coma, causing seizures, causing cardiac arrhythmias, andpotentially in death. then there are long-term systemic issues that we alsoworry about either from a single exposure with some delayed effect or morecommonly a chronic low-level exposure that results in some toxicity whichcould include chronic lung disease or cancer re-productive effects. here'sa chemical that used to be used widely as a cleaning agent or antiseptic.the smell of old doctor's offices was largely of that of carbolic acidwhich is phenol. this is 86%
phenol. and this has both local and systemiceffects. so if you get it on the skin, you can get a burn. if you swallowit, you can get burns to the throat and the intestinal tract. but you canalso get serious systemic e if he cans both seizures as well as liver injuryas a result of absorbing the poison systemically. when you absorb a poisonsystemically, how do you end up dying? there are many different ways thata poisoned patient can die. these are just some of the main consideration. respiratoryfailure is probably the biggest one. that's the comatose person whohas been poisoned by a drug or a chemical is unconscious and as a result ofthat, their brain is forgetting to
tell them to breathe. so their breathing slowsdown or even stops. and that would be a very common way somebody woulddie after poisoning, would simply stop breathing. this is probably the way thatsnow white would have died if she had not received love's first kiss fromthe handsome prince. there's another type of respiratory failurethe gas expose victim who ends up with a chemical burn in the lungs and getsa bacterial pneumonia and then dies from the pneumonia. with seizures they canbe self-limited and benign that is they stop and the patient wakes up and isfine. but if they are multiple and frequent or prolonged, they can make it verydifficult for the patient to
breathe normally and in addition, all themuscle activity from the seizures can actually lead to heat stroke, excessiveheat generation and complications that result from body heat. here's some otherways people can die. cardiovascular failure as a result of an abnormalheart rhythm. very common with drugs that we use, specifically to manageheart rate and heart rhythm. so for example, people who elderly peoplewho have arterio fibrillation are often given digoxin which is derived fromthe plant foxglove. if the person gets too much of it, their abnormal rhythmmay not be controlled, maybe made too slow and the person could end up havingpassed out or even dying from a
heartbeat that's way too slow.some of the drugs can depress the muscle activity of the heart so that eventhough it's moving at the normal rate, it's not able to squeeze as hard as itnormally does. and you can lose vascular tone, that's the blood vessels canbecome dilated and it's impossible to maintain a heart rate because the bloodcant squeeze hard and fast enough to keep the blood pumping and blood pressureup. then there are a variety of target organs that are effected by poisoning.probably the most common ones that we see are liver injury, kidney failure,and brain damage as -- usually the brain damage is a result of shock orstopping breathing for a period of time. kidney
failure can occur from avariety of things. there's a number of toxins, that are nephro toxicant andthey effect the kidney directly. or there could be things like heat, a heatstroke patient. liver injury, very common. this time of year with the recentrains and the warmish weather, any of you are mushroom fans here? pick youknow, pick mushrooms? wild mushrooms or just store bought? stick to thestore bought, my recommendation. um, i mean there are a lot of good wildmushrooms to eat in california and i know people that are very good mushroompickers. very careful. they love wild mushrooms, but there are some outthere that are deadly and primarily through
liver injury, they can causecomplete damage, complete necrosis of the liver in a short period of time.so now getting to this notion of dose and there was a famous physician in the1500s named paracelsus, an italian physician. and he's credited with thisstatement that "everything is poisonous. it's all about the dose. everythingis poisonous, only the dose makes the difference." so if you think about it, if you drink enough water, you can poisonyourself with water intoxication to the point of death. somebody did that fewyears ago in sacramento as part of a contest that was sponsored by a local radiostation. hold your pee for a
wii was the contest. if you could drink xamount and hold your pee for a period of time, they would give you a wiigame. and this person took it seriously, drank a whole lot of water. hersodium level because it was diluted by all the water actually went downso low that she went into coma, had seizures and ended up dying. so, evenwater, salt, alcohol, of course, small amounts are okay, larger amounts verydangerous. so it's all about the dose. this is an example just a picture ofa typical pill. and then some tiny granules. and there are drugs we useall the time a morphine related drugs. so we call them opioids. they can includemorphine, heroin is an
opioid. fentanyl. codeine you might have beengiven vicodeine if you had a painful injury. so those are all types ofopioids and they are different potencies the amount of drug it takes to effectthe drug varies a bit. so you might get the same effect from a pill if it'sthe same opioid or one tiny fragment if it's another opioid. this couldbe morphine and this could be fentanyl. and the difference in dose wouldgive you the same effect. so you can see how if you took this size of fen til,you would have a massive overdose.so it's all about the amount, yeah question? euflpt: (inaudible).professor: so the question is variable in
people's metabolism and theirvariability in individual response. that's a great segue for what i'm gettinginto because there's a variability. each person if we line up ten of us in a row and all took the same dose, we mighthave a slightly different effect. or thought of another way, if we wanted a particulareffect, like the dose that would put me to sleep, let's say, we haveten people lined up. each person, the amount it took to make that person goto sleep might vary just a little bit, low to high. so there is that variability.we try to reduce the variability by adjusting for size. so we saymilligrams per kilogram of body
weight, for example. that gives some standardizationbut even within that, there will be individual variations and metabolism,how quickly you get rid of the drug can make a big difference.so the first concept regarding dose that i'm going to introduce to you,something called the ld50, you may have heard of this before. it's the lethaldose within 50%. this means that if you found a population and you gave abunch of doses, you would find a particular dose that killed 50% of thatpopulation. that would be the lethal dose in the 50%. it's kind of themidpoint. some people would survive that dose, about half and the other halfwould die as a result of that dose. and here
are some ld50s to give you anidea of the broad range. the higher the amount, the less toxic the drugbecause it take as larger dose to kill. so very small amount. in fact thisis one of the most toxic substances known is botulinum toxin, that's the toxinthat causes botulism. food poisoning. extremely low milligram per kilogramlethal dose. ricin is down there. chloro sodium which is table salt isactually less toxic, sorry, more toxic than alcohol on a per weight basis.this is booze. you might wonder why i have a umbrella here. there was apicture here that somehow didn't show up but it's a picture of georgie markov.do any of you know that name? georgie markov?
he's a man who died in london about 20 years ago. he was standing on astreet corner waiting for a bus and someone walked next to him and jabbed himin the leg with the tip of an umbrella and said, oh i'm very sorry. it wasjust kind of an accident. didn't think much of it. but within severalhours he was extremely sick and within a couple of days he was dead. and allthey could find examining him was this little puncture wound on his thighand when they looked more carefully, they found a little tiny metalball that had been injected under the skin and they believed that he was poisonedby ricin because of the
symptoms they had. they never proved therewas ricin in the ball but was suggested. and this was thought to be carriedout by the bulgarian secret service branch. who was the kgb at that time.this was before the fall of the iron curtain. a very small toxin, a smallamount can result in death. there's georgie markov. so talking about individualvariability leads us to a discussion about or reminder of the old bell-shapedcurve. and i found this one, i thought was an interesting depictionof the bell-shaped curve, looking at the time it's needed to adopt a new technology.but you could apply it to anything, which includes for example, thedose it takes to cause a particular
symptom in a particular population. so, inany, let's say, new technology that's developed, there will be some people,a small per sten taj of the population that are innovators and will immediatelybe attracted to this new technology and will adopt it. the early adoptersthat followed them. then the early late majority and then the laggardswho people who really don't believe this new technology is going to workand until they are going to wait until 90% of the population is proven thatthis is valuable. so we get this bell- shaped curve where mostpeople fall someone in the middle and this 50% point separates the early adoptersfrom the late adopters. or if
we are talking about ld50, the first halfwould be the people who died at a low dose. and the second half, those who requireda much higher dose to die. now if you take this same concept and insteadof looking at it as a bell shaped curve, you look at it as an accumulativeeffect in the population. you look here and the percentage of individualswho respond to a particular dose from zero individuals all the way up to 100%,that's everyone is accounted for. so really it's a bell shaped curve thatused to look like this and instead we've stacked it up on itself to looklike that. and it becomes an s shaped curve and we call this dose-responsecurves. so a small dose, a very
small percentage of the population is goingto have any effect. and a larger dose you're going to have more and more peopleeffected and finally you'll end up everybody has been effected by the timeyou get to this dose. in this case, we are talking act the effective dose.so that might be for a new headache pill, that might be the dose that'srequired to get rid of the headache. and some people responded to a lowdose and some people took a large amount. but there's a point at which50% of that population responded that dose and we call that the ed50 or theeffective dose for 50 percent. there might be a toxic effect like the headachepill causes nausea and it
causes nausea at this dose in some people,but other people are able to tolerate it way up to this dose without gettingnauseated. so this is t d50 or toxic dose 50 for the particular symptomwe are interested in, nausea or a seizure or it could be shock. and finallyand we hope this one is way over here on the dose curve. there's a similareffect which is lethal dose. there's going to be some people who die atthis dose and others who won't die until they get up to this dose. we hopethese curves don't overlap, that is that the lethal dose is close to the effectivedose. obviously you would have some percentage of the population who mightdie while getting their effective
dose. we don't like that to happen. so welook at this, the distance between these or the distance between the effectiveand the toxic as being a kind of toxic therapeutic window. how much room dowe have to play with the dose before running into problems? now you mightwonder how did we find out the lethal dose in 50%? obviously you need 50%of some population and remember in scientific studies, the larger the number,the better for statistical purposes. so maybe we would like to have saya thousand individuals that all took varying doses until we figured out whatdose killed 50% of the population we are looking at. well, clearly you can'tdo that in humans. that would be
highly unethical. we do it in animals becausethere are substitute for humans. but we recognize animals and humansare not necessarily alike but that's what we end up doing. so rarely arewe actually looking at an ld50 that's been established in humans.now, thinking about ld50s, these are two compounds. they have the same ld50,the same dose that causes death in 50% but they obviously have a differentshape, don't they? this red one causes a certain percent of the population,what is it? 10% to die at the lowest dose that was tested. so it has a verydifferent shape compared to this one where you had almost nobody effected attwo or three times the dose of compound a.
so the shape varies. just knowingthe ld50 in other words doesn't tell us what the ld 10% might be. if we callthis the ld10 or the ld90. what is the dose that kills 90%? the ld50 issitting by itself. animal derived number usually smaller than a thousand as well. usually a hundred animals or eventen in some of the studies and we don't know the shape of the curve. we don'tknow the ld10 or ld90. so it gives us a ballpark of legality but it's notthe end all. and it is helpful to look at higher or lower doses. you couldeven say for toxic dose, the t d10, t d50, t d90, you understand what i meanthen, the 10% population
effected, at that dose, that's the t d10.so, we also look for besides ld50, which is lethality and of course if we areinterested in what dose is potentially going to kill someone, what weare also interested in well, what about doses that might end up causing nausea?or what about doses that might cause pancreatitis or the person to have aseizure? there are nonlethal effects so they are not going to be pickedup by the ld50. you might need to know something about what doses are safe,particularly low doses because we are interested particularly in public health,we are interested in what is the dose of something in our food or our waterthat we consider to be safe? so we
are wanting to find, what is the lowest dosethat might cause a problem. and there are two doses those terms that are veryhelpful here, the know all, the know observable adverse effect level. somepeople call this the no observable effect level or noaa and this is taking increaseddoses and seeing at what point you no longer see no effect. in otherwords, the highest dose that you can give in which the animal doesn't haveany observable toxic effect. that's a very helpful dose to know. boy, animalscan tolerate 10-grams of this stuff every day for weeks without any apparent effecton their reproduction, on their behavior et cetera. that's somethingthat regulators take into account
very importantly in trying to decide whatis a safe level. another dose term that's similar but coming kind of from theother direction which is we are seeing toxic effects. let's keep loweringthe dose until we no longer see the toxic effects anymore. so what's the lowestdose that will still cause a toxic effect? now these may reasonably befairly close together. let's say on this particular response, this is againpercent curve, so we have this s shaped curve and dose. i always say, wellno effect, no effect, no effect, no effect. and now we're starting to see someeffect. so this might be the no effect level. the highest dose you can seeno effect. then you go up here
and if you come down from this side and go,what is the lowest dose which you are seeing no effect, which comes from thisdirection. usually they are pretty close together. now there's alwaysbecause these are animal studies. there's a small number of animals, there'ssome statistical error that you are going to run into that is, you really don'tknow for really small doses, and you are looking for a small percentage changein the animal group, you know one out of the 20 is going to have a cancerappear, for example. so we are talking about small percentages. which meansthat actually the curve looks something more like this, the no observablelevel is not zero, because we
figure there's some at five to 10%, there'ssome unknowns. we really don't know what might be happening because we havenot tested enough animals for a long enough period of time at the right dosagegroupings. at very low doses. so you might have the shape that varies quitea bit and remember the shape makes quite a difference. because this suggestthat um, you can start to see effect rapidly at low doses or not or theremight even be no effect until you reach a threshold. so you are perfectly safebelow that if you could prove there was a threshold for effect. well i'vealready mentioned this, that animals and humans are not necessarily alike.and these are the kinds of
animals that are often used in laboratorytesting. and they do have differences. in fact, one of the most importantpoisoning that we deal with at the center is methanol. it's wood alcohol.it's used in camp stoves as fuel. it's produced as a by-product sometimesduring bootlegging, creating illicit whiskey. it's used in record or cdcleaning solutions. some windshield wiper solutions. it's very toxic.it's similar to ethylene glycol or antifreeze and a tablespoon of it couldbe deadly. and that's because in humans a methanol getsconverted by the body into fer maldahide. that's a preservative that's verycaustic and fer maldahide it
gets turns into formic acid, toxic acid verytoxic that causes blindness and brain damage. in every other animal species,every other animal species but humans, they are able to metabolize the fermaldahide and formic quickly and turn it into carbon dioxide. so the animalbecomes intoxicated in a way like a person might be intoxicated on alcohol.you know a lilt l wobbly on their feet, a little euphoric, get punchdrunk butthen they clear it and metabolize it safely. they don't get blind. they don'tgo into coma. the only animal besides humans that has ever been able tobe poisoned with methanol is a primate that's been made folic acid deficient.that's one of the essential
nutrients we eat every day. if you make monkeysfolic deficient they can become methanol poisoned. so if you did abunch of testing and 20 different animal species for a poison, could you reallyguarantee that it wasn't poisonous in humans if it was safe in allthe others. we don't know as you mentioned before one of the students commentsabout metabolism. metabolism in humans may not be the same as in other animals.we know a fair amount about this and we know how to correlate the toxicityof guinea pigs to humans or pigs to humans but we are always learningmore. so that's a big unknown we have to deal with.so dose is determined um, we talk about how
dose is important but what is thedose that one actually achieves and that's going to depend on the amounttaken, obviously as well as the duration. and as you already know because imentioned these comments -- these examples before, how is it delivered? wasit delivered in a way that the body could actually be intoxicated by. so thesnake injects the venom deep into the tissue by using his fangs, then thetoxic is going to be very effective. if the snake were to spit the venom ontoour skin, it probably wouldn't do anything. uh, combined with this durationconcept, is the concept refer to as acute versus chronic. acute being veryshort-term exposure, usually hours. and chronic
being more like days tomonths. so here's some examples. a 16 year-old boy ingest a hundred tylenoltablets. this causes liver damage. this is called an acute ingestion in avery short period of time. another example would be someone also usingtylenol but this woman developed liver failure after using excessive amountsof tylenol and vicodin which also contains tylenol. it's hidden in the brandname vicodin but it's a combination of hydro codeine plus tylenol and she wastaking it every day for several days. she was using too much every day. ifshe had taken it one day it wouldn't be poisonous. but after taking it over acouple of days it was accumulated too much
in her system and her ability todeal with that extra poison had been dissipated that she developed liverfailure. we call this chronic. here's a 64 year-old man who developedleukemia 20 years after working with benzene is in his laboratory. this ischronic and delayed. so the tempo can vary quite a bit with this particular type of poison and with the ways its beendelivered. you may see these different terms from time to time and i amsorry to deliver you so many terms. i don't know how much you have to memorizefor your exam, but i'll let your professor decide that but please be awareof what these terms mean. you
you've probably seen them before, ppm whichstands for parts per million, that's parts of poison per million parts ofair usually. could be per liquid. so parts of poison per million of parts perliquid. and ppb is parts per billion so that's obviously a lower concentration.milligrams per meters cubed. that's milligrams of poison of milligramsper meter cubed air. and these are types we are talking about usuallywith inhalation. but with ingestion it's usually milligrams we are talkingabout we're talking about milligrams per kilogram. that's milligramsof poison per kilograms of the body weight of the person ingesting poison.now you can look at toxicity
ratings based upon either ld50 or somethingcalled the lc50 which is simply a lethal concentration. so if you were thinkingof breathing air that contained a poison suspended in the air for a periodof time, there would be a concentration of poison in the air. and weusually look in the air concentrations for a period of time becauseyou have to take a certain number of breaths to inhale. so we have lc50, fourhours. something that's extremely toxic is going to have an ld50 ofless than a milligram per kilogram. or less than ten parts per million.very small. where something relatively harmless is now converted. here'smilligrams to kilogram to grams
per kilograms. we are talking greater than15-grams per kilogram. that's almost like shovels full of the poison ora hundred thousand parts per million which is essentially 10% in air. there aresome workplace limits that use these terminologies. so if a person is workingin a company that uses solvents or chemicals of particular types,then they are required by the occupation and safety and health administrationto abide by certain regulatory levels. that is a person should not be exposedto certain levels for more than x amount for all day or short periodsof time. so the permissible exposure limit is an eight hour average. sothat you could be exposed to that
as long as the levels didn't say exceed 20parts per million in the average of an eight hour day. might be a little up ordown like that. but it's a relatively safe concentration. the short-termexposure limit would mean you couldn't go above that parts per million,say a thousand parts per million of that particular chemical for more than 15minutes because it might lead to some symptoms or a person might get nauseatedand pass out. whatever. then there's a ceiling limit that should neverbe exceeded not even for one minute. these are all known as the pel, sdl, or cdlimits. then there's something called the ideal h. these are self-explanatoryand these are levels saying
okay for this chemical it's 2,000 parts permillion. is immediately dangerous to life or health. it would impair the person'sability to escape and save their own life if it was at that kind of alevel. that's obviously very dangerous. and exposures in that range workersneed special protective gear. so in this case, these firefighters are wearingmasks provided with a scuba tank on the back. so they are basically wearingscuba gear. they have a very tight fitting mask with their own air supply.so they are not inhaling any of the chemical on the outside. they've obviouslyfound themselves in a toxic zone. if you find yourself on acetone street,you probably are in the area
where the chemicals in the air are dangerous.but notice for this particular exposure their main concern is somethingthey might inhale. what if that chemical was toxic by application to the skin?do they look like they are protected? i see a patch of bare skin on thisguy's neck right here. so if they were walking into a cloud of cyanidegas, this would be a no no. sure they're protected from inhaling it but cyanidegas can penetrate the skin and cause toxicity. so it wouldn't be okay forthem to be exposed to that particular substance. so it's important forthem to know what they are being exposed to whether or not its of toxic tothe skin or by inhalation and what
level of gear to wear. they might have toend up putting on one of the giant moon suits that's totally impervious to thechemical in order to be protected. all right. one more dose reference number.and this also relates to chronic exposure. this is used by the epa, the environmentalprotection agency to give them some ideas about maximum daily exposuresin drinking water or food et cetera. so various government agencieswill look at this rfd reference dose. that i have taken the noaa and no observableevents and taken the highest level we can go to, no effects atthe time we observed the animals and they are dividing by it by various fudge factorslooking for interindividual
variability, that's one rat to the next, interspecies,one rat to one you know compared to a guinea pig, intraspecies, onerat to the next and other fudge factors and with each of them at least a tenfoldsafety factors. you start multiplying these safety factors, they usuallyend up with at least 100 fold safety factor meaning they take the knoll,whatever the lowest level they think safe and they are dividing it by a hundredor a thousand. so we figure that's pretty good to protect the populationfrom effects of the agent by having a safety factor that's a thousand foldor hundred fold below the lowest level, the highest level we have ever foundthat had no effect.
but remember, there's always that little bitof uncertainty because we really don't know what happens at those very, verylow levels. okay. so let's move a little bit more clinical now. looking fortime, good. a young man is found unconscious, barely breathing. his pupilsare very small and by history he had been doing drugs with his friends andpassed out. so, um, this is fairly straight forward. this is person using drugs,small pupils passed out, immediately the emergency physician or emtis going to think, okay that's heroin. heroin makes people really sleepyand their pupils really small he was doing drugs so probably something likethat. he was given the antidote
which is na lox zone, which is a direct antagonistto the opioids and woke him upright away and he was wide awake and hehad some screening done which was positive for opioids, namely the break downproducts of heroin. these are some examples of different forms of heroins.this is called black tar heroin which is most poplar in california associatedwith increased incidences of botulism when people inject it under theirskin. so this was pretty straight forward, the diagnosis was based on the historyof doing drugs with friends and the physical findings of small pupilsand sleepiness. so when we are trying to diagnose poisoning, that's wherewe start by asking what were you
exposed to? obvious question. what did youtake? what do you have in your workplace. if the patient is unresponsive,ask the boss, what was he working with, what was she doing at the time? thatwill help. then we look for characteristic findings and physical examlike are they wheezing or do they have small pupils is their blood pressurehigh or low? we look at some laboratory testing of the blood and urine.we do things called tox screens looking for the common elements that areoften abused like methamphetamine and cocaine and heroin bez sew die as peen. sometimesyou can get some useful information from x-rays and so putting thisall together we make an euharmonic
diagnosis and we can compare it with somediagnostic testing. all that tends to take longer. you all know when some celebritydies and the coroner says well we'll have the results of toxicologytesting in two months. wow how does it take them so long? there's a lot more thatgoes into forensic testing to look for every kind of poison somebody mighthave taken compared to a quick screen we do in an emergency department lookingfor a few common ones. euflpt: how are x-rays used?professor: i'll show you an example. this is a picture with someone withchronic arsenic poisoning. i think i mentioned earlier this problem wasdiscovered ten or 15 years ago, i think. two
wells have been dwelled betweeninto this sub soil in bangladesh and that area of the indian peninsula andfound to have been known to have large quantities of arsenic and people havebeen depending on these deep two wells for some time and have had someexposure over time. this is a characteristic where we call hyper-car toe sis.mean hyper-is increased and car toe sis related to production of skin, careton. so it's excess production of skin and there's a lot of hyper-build up ofthe skin tissue it gets thickened and flaky and this is characteristic findingwith chronic arsenic poisoning. so that's something you look at and go, oh iwonder if this person has arsenic poisoning.
here's an example we are lookingat someone and here's an x-ray showing evidence of lead poisoning with theselead lines on the gingival on the margins of the teeth. this is lead built upin the long bones so this is the fee mor, this is the knee joint and the lower leg. the ends of these bone is white becausethey have a lot of lead and lead is radio dense. here's looking at someoneyou can say, well this person looks like someone who chronically abuses methamphetamine.if you have had a current picture the use of picking at theskin and aging process, that might suggest methamphetamine use. when we see peoplethat are picking at their
skin a lot, this is a very common problemwith methamphetamine and koa tain users. they begin to believe there are tinybugs under their skin. we call it formication. and they pick at the skinuntil they end up with le lesions all over the skin and literally scar marksfrom picking at these imaginary bugs. may be some characteristic featuresof the person presenting in the emergency room that suggests you are dealingwith methamphetamine poisoning. so the big pupils, sweating and angry aggressiveapproach, belligerent, those are all things you might associate with methamphetaminepoisoning and make you think of the diagnoses.so what about treatment? once we have made
a diagnosis or a tentativediagnosis, the first thing is to always try to prevent the poisoning in thefirst place. i mentioned earlier about mushroom poisoning. this is the timeof year when we go about reminding people that mushrooms grow after the firstheavy rains when it warms up a little bit and if you take any weekend hikes upto point ray, you find them up there and (inaudible) very toxic mushrooms anddon't be tempted to each them. they taste and look very nice and even looklike some in the guide book. but they are really dangerous. so don't do itunless you are with somebody who really knows what they are doing. i alwayssay, there's old mushroom hunters and there's
bold mushroom hunters but youhave a hard time finding an old and bold mushroom hunter. if you are with somebody who says they know what they aredoing and they are going to try something they have not tried before. watchout. the other thing is try to detect the poisoning as soon as possible.so that you can begin treatment. if you wait a long time and the poison hashad a chance to do more damage it's going to be harder to treat. then we havevarious options. one of the things we like to try to do is to limit the amountof poison that gets absorbed into the body. so by washing it off the skin outof the eyes, washing it out of
the gastral tract that's where gastral boshor pumping the stomach comes. things that might bind it in the gastral tractlike charcoal. then supportive care, this is love's first kiss, good airwaymanagement. supporting the blood pressure, putting a patient in a icu. we hadpeople who survive. we had a very good example of that last week at sanfrancisco general, somebody who had overdosed on a barbituric was deeply comatose.we didn't provide any antidote. they were intubated on a breathingmachine for four days and woke up and were completely fine after that. sogood supportive care is all they needed. then there are few antidotes. so here'sa picture of am knee tas,
nice looking mushrooms. they do look verysimilar to an eatable am knee ta that looks, smells and taste just like it.so what about decontamination? this is a -- this is a um, set up just todemonstrate how decontamination might be done. this was just a practice. normallythe person would have had to take their clothes off since this was apractice round. they didn't. these guys are dressed up in full suits, sothey have protection of their skin. they have gloves, they have face maskswith filters on them. and this the idea here is there's been a hazardousmaterial spill, maybe a chlorine gas cloud for example. maybe 40 or 50 people werein the cloud and have it in
their skin and clothing and it's being washedoff. so this is external decontamination. what about internal decontamination?we used to really believe in this, that's forced vomiting asa way of getting the material out. certainly, for example, if i came across somebodywho was eating wild mushrooms on my walk on point rays, i wouldget them to start vomiting right away, whatever we could do to get them startvomiting, put the finger in the back of the throat, whatever, just get thatmaterial out as quickly as possible. we use a product for many years,called ipecac syrup which was derived from the ipecac plant and it inducesvomiting after 15 minutes of
taking it. we used it for many years as away of getting pills and mushrooms out of the gut.euflpt: (inaudible). professor: no it's changed now, so the ipecacsyrup, a few years ago there was a confluence of things that happened.one thing that happen was we began to look at the results of studies trying todetermine how effective it was. i mean we know it makes people vomit, but wecouldn't prove that it actually made them less likely to get poisoned or madethem get better faster. so when it came to the bottom line, is this betterfor the patient, we couldn't prove it. and there's some downsides to it. it makespeople vomit and they get
horribly uncomfortable, they may rupture partof their stomach while vomiting and start bleeding or the product will beabused by people who want to force themselves to vomit for another reason, theyhave an eating disorder or they have a parent who is giving them ipecac asa punishment method. so it seemed the benefits ipecac method was falling awayand the side effects or misuse of ipecac was increasing in concern and at somepoint the american academy of pediatrics recommended forget it. we'renot going to recommend it be in the home anymore and it's going to go behind thecounter, not over-the-counter and pretty much it's evaporated from use.euflpt: (inaudible).
professor: sure yes, so when would you givethe ipecac? typically would be most helpful if you give it right after thepoisoning. we at the poison center when we would get called by a motheror father of a child who just eaten several pills like five minutes before,we would say give them the ipecac because it was at home, the pediatriciansrecommended keeping it there and they would give it to them at home 20minutes later they are vomiting and all the pills came up. we thought great wehave succeeded. maybe it was beneficial but we couldn't prove it. so eventuallythe consensus amongst toxicologist if we can't prove it really worksand makes kids less likely to
get toxic, then why be taking the chance withit. gastral lavage kind of fell to the same axewhich is it seemed to be effective, we are taking this stuff out ofthe stomach with a tube. there's pills and poison in there why not get it outof there. it shouldn't be bad but we felt it was more effective than notdoing it at all. few people get gastric lavage but those who do would be somebodysuffering something toxic shortly before arrival. so i gave an exampleearlier, the carboxyl phenol that causes burns as well as causing seizuresand it's a liquid. if the person drank it and then walked into the emergencydepartment we would have a
tube down trying to suck out that stuff asquickly as possible because we know it burns as well as causes seizures but inmost cases people coming to the emergency an hour or two or maybe three hoursafter the ingested poison has been taken in and mostly all the poisonhas been absorbed. something else we have to turn to is something called activatedcharcoal. this is a very fine li powdered and steam treated product. itcomes as a powder although typically it's sold as a suspension. thisis a white bottle of instachar and it's an aqueous or water suspension. and theoriginal powder if you were to spread it out, if you could spread out thesurface area, this very finally
particulate granules with a lot of nooks andcrannies in it like an english muffin. and you spread it out and this tablespoonof charcoal would have the surface area equivalent of a football field.so it's a huge surface area in this finely powdered material that's thenplaced in this suspension and you drink it. well then it starts to bind to thepoison by weakened wall forces. it takes and absorbs many drugs and poisonsvery effectively. if you put them in a flask together pour them out and filterit, it actually has absorbed most of the poison it's very effective. this goesback to the romans they used burnt wood and various other things and takeit after a meal if they were
suspicious someone had poisoned them. so acharcoal like substance but the question is how effective is it? probablyis effective if you give it early and if you give enough of it so that it bindsall the poison you took. but it's hard to prove in large scale studiesthat it makes a difference in outcome. so we were uncertain about it. wedo use this, we use it much more than the gastric lavage or ipecac inducedvomiting because we do believe it works but it's got its potential downsidestoo. if you are forcing someone to drink a suspension charcoal, they may gagand get some down in their lungs which is not a good thing. so we use it cautiouslybut we still use this
every day in poison management. at one pointit was even thought this is a great thing to have at home. along withthe ipecac if johnny got into some pills we will have him drink this charcoalthe problem is johnny may not always want to drink the charcoal and spitit on everyone else. we have this charcoal externally and have no idea how muchhe swallowed. so that's basically fell by the waist side. i don'tthink anybody uses charcoal at home. what about antidotes, i'll say it again,best antidote is good supportive care which is attention to theairway, to breathing and to circulation. that's you open the airway, youbreathe for the person or help
them allow them to breathe on their own andget some fluids into them if their circulation is poor. there are a few antidotesso for example, acetaminophen which is the generic name for tylenol. wehave antidotes very effective for preventing liver damage as long as we giveit soon enough within eight hours or so. we are very interested in looking atfinding out if someone has taking acetaminophen overdose. because we can treatit very effectively. for carbon dioxide there's oxygen which helps to knockthe carbon dioxide off of our blood cells. cyanide there's actually an antidoterelated closely to vitamin b12. when you combine this product with cyanideyou end up with vitamin b12.
it's a precursor to vitamin b12. ver digitalisthat's the heart poison created from the fox dog plant. a lot of elderlypeople taking it. we have antibodies we have created to bind the digitalisand excrete it from the body. similar to that we use antibodies againstthe snake venom and spider venom and we call it antivenom. and we have naloxonefor heroin and the opioids we have chelating drugs the drugs that bind to heavymetals like arsenic, mercury, lead that can be used for these poisons. sothere's many antidotes but it's a limited number and most of the time it's thesupportive care. i'd like to spend the last few minutes talking aboutwhat we do at the poison control
center. the poison center is a statewide service.we have four answering centers. there's one in san francisco, there'sone in sacramento, one in fresno and one in san diego and we cover thewhole state to get. and we get collectively as a group about three hundredthousand calls per year. so about a thousand calls per day. mostly from parentsof small children who have gotten into something at home but also fromhospital emergency departments, from paramedics, from police, fire, askingabout hazardous materials or asking about how to manage a particular overdoseor something like that. so why a poison control center why don't you just lookit up which many people argue.
well here's some examples of common substancesfound about the house or in the hospital that are nontoxic. nail polish, oilof olay, barium sulfate which is the contrast agent used when you are gettingx-rays, hair conditioner. compare that to these very toxic substancesthat sound very similar. nail glue remover, these can contain somethingcalled na seat l nitride and children have died from cyanide poisoningafter eating just a small amount of nail glue remover. oil of winter green, thisis a toxic form of salicylate aspirin type poisoning. very dangerous, atablespoon of this could be fatal. barium chloride is a different salt but thisone happens to be very soluble
whereas this one is insoluble. so this passesthrough the gastral intestinal tract, no harm no foul but barium chloridewill cause extreme body muscle weakness to the point where the respiratorymuscles stop breathing. and hair straightener compared to hair conditioner,a very toxic products. so by knowing the difference between what's toxicand what's not, getting an idea of the dose involved, making a quick calculationfor example how many tylenol tablets how much does the child weigh, don'tworry that's not a toxic dose, no need to go to the hospital for antidotal treatment.we can manage most of the cases at home. seventy-five pe sent of caseswe manage over the telephone
without sending somebody to the er. and only8% are actually sent to the er and the other 17% involve calls from the hospitalor somewhere else. so let me give you some examples. it's 7:00 o'clockin morning a frantic mother calls and her 18 month old child might haveeaten a pill from a plastic zip lock bag, not a goods idea to keep pills ina zip lock bag. we say fine, well what did you put in it? no they belong tothe grandmother she's not here right now. great what are we going to do?fortunately there's an enprint code on the pill. so we can look that up.another case happening right on the hills, five minutes later, a father callssays he knew he doesn't believe
his child ate any but he found the containerof ver ramp mill on the floor. i was only out of the room for a minute. thisis a common statement, there's no way my child got one or more than one becausei turned my back for just a second. the kid looks fine and he's playingwith his blocks, no issue. yeah. and then this another case comes in a fewminutes after that. this is a real case. two men in the er in the morning ofjuly 4th they ate watermelon and got really sick, vomiting diarrhea and sweating.so in each of these cases poison center staff need to make a criticaltime sensitive decision to this do they treat at home, do they send them to theer, do they call the health
department, you know, watermelon poisonings,fourth of july. so let's go back and find the answers. in this case the poisoncenter identified the pills as aniprazol. this is a safe harmless drug usedfor acidity and the child can eat several of them and have no intoxication.okay. next one, well poison control warns the dad that even a singlepill of ver ran mill can kill the child, just a single one that's missing. thatmeans immediate transport to the merge si department, observation in theer for probably overnight. this one, the poison control staff heard the symptoms,vomiting, diarrhea and excessive sweating and said i wonder if thiscould be pesticide poisoning,
because it sounds like organophosphate, that'sgoing for the history and sort of physical findings and they said well, okay.um, let's consult with their medical director, we called the health departmentlet them know, they called around to other emergency departments in californiaand find more cases very similar. ate watermelon, got sick and justabout 7:00 o'clock or 8:00 o'clock in the morning on the fourth of july, whatdo you think we should do? this is a public health emergency. right? i mean thismeans there's more than one person involved. they are not related to eachother. these are ers in different parts of the california and thesewatermelons could be toxic and
people are going to be eating them on fourthof july. there was a statewide watermelon recall within six hours so kenkaiser who is the director of health services at the time was on the radio on televisionby 11:00 o'clock that morning, warning people do not eat your watermelons.return the watermelons and there was a huge recall.euflpt: do you feel the watermelon was (inaudible)? professor: if you fill it with vodka, notthis poison, no. it might make you less attentive to the poisoning. so in spiteof the recall, and this was the tip of the ice burg, right, we just did afew cases but there was potential for huge numbers of cases if we didn't dosomething. over 2,000 people were
sickened by this. a couple of miscarriages,possibly one death. um, so, this was a huge -- this was a success story 2,000cases that's because if we had not done the recall to the state health departmentit might have been 10,000 cases. don't know. in more recent years wehave kept our eyes out for new trends things on the market, more kind ofthe idea for looking for the tip of the iceberg, so some years ago you've probablyheard the drug ghb? one of our staff joe dire was working the phones andgot a call about a guy who was driving home across the bay bridge pulledover and had a seizure in his car and was found sort of having these jerky movements,very sleepy. was taken to
the er and woke up soon after that and saidhe had been using this new drug he had received from his pal at the gym. andit was supposed to be really good for work outs and he didn't quite understandhow to use it properly because you were supposed to take it and then go tosleep. and it was supposed to build your muscles while you slept. believeit or not, they were selling it as a body building drug because it increasesgrowth hormone levels while you sleep. well, um, but unfortunately the sideeffect when you take it you get really sleepy and you have seizure like activityand you are in a coma for a couple of hours and you don't want to be drivingwhen you do that. but
obviously it's something that causes comanaturally people are going to abuse it because it also gets you high. you feelgreat before you pass out or you can give something to someone and make thempass out and then you can assault them. so that's where this drug suddenly becamea huge drug of abuse and a drug used to facilitate sexual assault. joedire picked up on this early on and started writing about it started collectingcases and know fiking public health agencies about it and getting informationout based on initial calls. recent days you've heard about bath salts.here's one. this is not intended for your bath. they are $30 for a littlepact, a size of a gar bonn sow bean
material. it's clearly intended for somethingother than baths although they'll say not for human consumption on itas well. the intention of course is to snort it. these are amphetamine likedrugs that produce a high for a while they were legal technically becausethey were new chemicals that the drug enforcement agency had not yet deemedillegal. now they are deemed illegal and they don't count. but bath saltsand a variety of things including cannabinoids, they act like marijuanabut they are not. so they don't show up on a drug tox test but they'llget you high. these are things that we hear about at the poison center fromtime to time. interesting one
that i became aware of last year is medicalmarijuana dark chocolate. sold in nice you know, very spiffy looking containerswith a nutritional guide on the back even. grams of fault and carb hydratessold through marijuana dispensaries, my concern is that childrenwill get into these things and eat them. and children can get quite drowsy aftertaking marijuanas. and we have had a few cases of children getting intoxicatedwith household marijuana. this is a screen shot of poison center cases,you see things like bleach, nor koa which is like vicodin, flex koa whichis a muscle relaxer, baggies of drugs. so mo which is another relaxer, lithiumand restoril, here's one lsd
in girl scout cookies? this is bogus. there'sno lsd in girl scout cookies. but this is to show we have cases that goby we have thousand of cases each day. how do you keep track of the ones thatare potential tip of the ice berg the public health case? so we instituted aprogram within the poison center where if you got a case that's sort of strange,question mark, maybe the tip of the iceberg maybe that funny watermeloncase in order for your colleagues to see it because your colleagues see allthese cases come buy, you just highlight it in yellow. so all the cases thatseem strange are highlighted in yellow and the staff can pick up on it. oh,frank you had a call a few
minutes ago like this. i see it's highlightedin yellow. and there's another one and another one and now we see we're atthe beginning of this ice berg effect. again, this didn't really happen butit's the idea of what we are on the look out for at all times. we are basicallylooking for the zebra or the needle in the haystack. where do you findinformation about toxicology? it's a huge field and it's not highly organizedi would say but there's some good sources. this is a good place to start onthe web. this is tox ne t. if you type it on a google search, it will take youthere and you can tag it. it contain as number of data basis of varyingquality but they have a let of
information. you can find ld50s for variousanimal species. so you can compare this is shovel fulls versus micrograms toxicity. you can get some idea of the qualitative toxic effects what'sit likely to do, does it cause seizures, does it cause chemical pneumoniaand so far. there's books, i think you are familiar with casnet and doull. theseare more clinically oriented. these are the books we write for the poisoncontrol. i don't mind advertising it because i don't get any money from it.al the money from the sales of the book goes to the poison sent tore fund ourtraining program. paul blanch one of our colleagues has written a really neatbook, i recommend this one for
anybody in public health. it's a wonderfulhistory of everyday products that were used all the time and their relativetoxicity and their use and what was used more toxic or lez. it's an interestingbook. how everyday products make people sick. this is a big textbook, goldfrankstoxicologically. 250 text book. you might look it up online. thenyou can always call the poison control center. this is a nationwide number,222-1222. available 24/7. this is a copy of our book, the poison center it'swritten by the faculty and staff of the poison system statewide and nobodytakes any royalties from it at all. it all goes to the poison center. this ispaul blanch's book. and that's the
poison center number. so, thank you very muchfor your attention. i'll be happy to take any questions if you have them.thanks. (**applause**). euflpt: i'm wondering about (inaudible) i.professor: okay. msg. so, this is a very interesting topic. a lot ofstrong feelings on both sides of the issue. and a poison center got involvedkind of i would say we didn't want to get involved in a political argumentbecause at the time the poison center was funded by the city of san francisco.this was some years ago. so we depended on them for funding and the subproviders said can you come and testify about the toxicity of msg because weare setting a law to ban it in the city of
san francisco. so we set out tofind out about what is known as the chinese food syndrome. people describedthe syndrome of not feeling wet, buzzing sensation, burning feeling. um,dizziness, nausea, after eating chinese food. and they connected it to theuse of msg. on the other hand,msg is a naturally currying substance and it'sbeen refined to a powder that's added to foods but it's naturally curry andit's derived from there. it's for the mouth to give a fullness to the taste.it's related closely to glutamate. so msg is glutamate and glutamate is atransference in the brain. the only thing glutamate is polar and it doesn'tget into the brain if you swallow it. it's
very hard to see how it would getfrom the blood system to the brain because it doesn't cross the blood brain barrier very well. so my own feeling aboutit is it's probably not a true brain related symptom syndrome but clearlypeople feel something in certain people are more susceptible than others. somepeople are susceptible. it could have something to do with these mnemonicreceptors. i would say it's still controversial. some people are sensitiveand would like to know what's in it. but the other problem is that it canbe put back into food because it's a great flavor enhancer. it can be putback into food with different
names like hydrolyzed vegetable protein containsmsg even though it doesn't have the name. so if you are looking for thepackage for msg, and you don't see it, doesn't mean it's not necessarilyin it. any other questions? okay. thanks.
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