Chapter 9 Toxicology Test Review Notes

factors affecting alcohol absorption:

- body weight - how much alcohol is consumed -over what time period - amount of food in the stomach - frequncy of drinking alcohol - body fat percentage - medications and popular energy drinks 20% absorption in stomach 80% in small intestines

Anthrax

- causes by bacteria Bacillus anthracis, which forms spores - most commonly spread to animals from infected animals, soils, animal products (hide and wool) - can enter the body through --- INHALATION- deadliest form - causing breathing problems that usually results in death - symptoms may not appear for a few months - fever, chills, cough, shortness of breath as lungs fill with fluid - INGESTION: becoming fatal in 25% to 60% cases - symptoms similiar to food poisoning (abdominal pain, vommitting) - absorbtion via the skin, leading to death in about 20% of untreated cases - causes skin blisters

Toxicity depends on:

- dosage (amount taken) - Durancy ( frequency and length of exposure) - nature of exposure - interaction with other substances (alcohol, prescription drugs, etc.)

Narcotics

- induce sleep and reduce pain - can be very habit forming - suppresses central nervous systems ability to relay pain ex: opium, heroin, codeine, morphine, methadone, oxycodone

sarin (nerve gas)

- interferes with nerve impulses - symptoms occur within seconds of inhaling - 1995, japanese terrorists releases it in Tokyo subway killing 12 and injuring 6,000

Injecting: Heroin

- produces nearly INSTANT euphoria followed by drowsiness - converted to morphine in the brain - high doses lead to depression of respiratory centers in the brain and quickly to respiratory arrest

Forensic toxicologists:

- study the medical and legal aspects of alcohol, drugs, poisons, and toxins in bodily fluids - work closely with a pathologist - determine whether alcohol or drugs are contributing factors in criminal cases - present expert testimony in court

Drugs:

-crimes associated with drug use and abuse include possession, sale and use, drug- related crimes )robbery burglary, homicide) - identify/ detect drugs in body or body fluid - test athletes for perf.- enhancing drugs - screen crime victims for "date-rape" or other specific drugs - controlled substances

5 classes:

1. Hallucinogens 2. Narcotics 3. Stimulants 4. Anabolic steroids 5. Depressants

Most people are exposed to drugs or other toxins by:

1. ingesting them (gastrointestinal system) 2. Inhaling them through lungs 3. Injecting them into bloodstream 4. absorbed through the skin

Forensic toxicology helps determine:

1. the cause and effect relationships btw. exposure to a drug or other substance and... 2. the toxic or lethal effects from that exposure

more than ----% of federal prison population and about ---% of pop. in state prisons consist of drug offenders

50 20 steady increase since the early 1990's

Ingesting:

90% at home with young children household products cleaning products cosmetics over- the counter medications - Targets specific organs or regions of the body

Hallucinogens:

The intensity and effect of response to drugs varies from person to person - often derived from plants - hallucinogens affect users perceptions, thinking, self- awareness, and emotions - overdose= increased heart rate, blood pressure, panic attacks, anxiety, or psychosis MARIJUANA mdma, DCP, LSD

stages of intoxication:

a blood alcohol concentration of 0.08 means 8g of alcohol per 10,000 mL of blood affects people differently

functional tolerance

a person displays fewer visible symptoms of intoxication without affecting blood alcohol concentration

depressants

act on CNS increase activity of the neurotransmitter GABA - drowsiness and slowed brain activity - these drugs, consequently relieve anxiety and produce sleep - side effects= similiar to intoxication due to alcohol - mixing depressants with alcohol and other drugs increase their effects and health risks, possibly leading to coma and death - Alcohol, barbituates, tranquilizers

Alcohol (toxin):

all alcohols are toxic in sufficient quantities as little as 30ml of methanol can kill ethanol, ethyl alchol, is a colorless liquid obtained from fermented grains or fruits - initial reaction to alcohol is euphora alcohol= depressant

emission spectroscopy

atomic absorption spectrometry- identifies the specific metal

people can be exposed to toxic substance accidently:

by harmful combinations or overdoses

people can be exposed to toxic substances deliberately:

by harming or killing others by commiting suicide

people can be exposed to toxic substances intentionally:

by treating illness or relieving pain

Inhaling:

carbon monoxide gas combines with hemoglobin in RBC and replace oxygen carrying capacity - dizziness, shortness of breath, loss of consciousness

accidental drug overdoses are more ----

common

Toxicological testing:

detect trace amounts of drugs in blood, urine and body tissues with --- thin layer chromatography --- gas chromatorgraphy --- immunoassay techniques --- confirmation is used using GC/MS

Blood gas screenings

detects level of CO in the blood stream

Alcohol in the body:

diffuses through stomach and small intestines - as concentration increases: -- ability to respond to stiumuli decreases -- temporary euphoria -- loose cordination and become confused -- memory dimishes - the liver metabolizes alcohol with an enzyme called alcohol dehydronase (ADH) -resulting product is acetaldehyde - more enzymes break this into CO2 AND H20 - the body can metabolize 15 to 30 ML of alcohol per hr - excess alcohol is distributed to body tissues

EMIT

enzyme multiplied immonoassay technique - rapidly detects several drugs and their metabolites

Toxicological testing: Reinsch test

heavy metal poisoning - certain metals dipped in hydrochloric acid produce a silver- coating on copper

acute poisoning

high dose in short time

stimulants:

increase feelings of energy and alertness by speeding up functions of the CNS while SUPPRESSING appetite - as drug wears off depression often results - affects of an overdose can include high blood pressure, agitation, confusion, or seizures - highly addictive EX: cocaine, crack cocaine, methamphetamine

Bioterrism agents: Ricin

is a poisonous protein in the castor bean - waste product from castor oil - is lethal in extremely small amounts (500 mg) - can enter body in various ways - inhaled as a mist or a powder - tightness in chest, coughing and fever, within a few hrs - ingested as food or drink - lesions in digestive tract: abdominable pain, nausea, vomitting - injected into the body - Inactivates ribosomes causing cell death= you die - can cause death within a few hrs, definately in 3-5 days after exposure

Bacterial Toxins: Tetanus

lockjaw, as it is sometimes called is produced by the clostridium tetani bacteria - its poisons can cause violent muscle spasms

chronic poisoning

low dose over long periods of time

poison prevention packaging act of 1970:

mandatory for companies to place child- proof caps and lids on medicines and house-hold products

immunoassay

measures the level of antibodies produced in response to antigens (poisons) entering blood stream

Horizontal gaze nystagmus (HGN) test

nystagmus is the involuntary jerking of human eyes, which increases with intoxication - divided attention tests - breath tests -- direct correlation btw. alcohol in breath and alcohol in blood stream ratio= 1:2100

pesticides and heavy metals:

pesticides are mostly used to protect plants or food crops - metal compunds are very poisonous - metal compounds can damage many organs in the body

less than 1/2 of 1% of all homicides result from

poisoning

organic toxins:

poisonous substances produced by living organisms (natural) - can be absorbed by other living organisms and interferes with that organisms metabolism

Bacterial toxins: Botulism

produced by the bacteria clostridium botulinum, botulism paralyzes muscles - it causes irreversible damage to nerve endings - very small amounts are extremely deadly - canned veggies, cured pork and ham, smoked/ raw fish, honey, corn syrup

Anabolic steroids:

promote cell and tissue growth increasing bone mass and body muscle - popular with weightlifters, body builders, or other athletes - produced in lab and have a similiar chemical structure to testosterone -used as treatment - Hypogonadism, delayed puberty, impotence, muscle wasting (HIV) Negative side effects: acne, increased body hair, baldness, high blood pressure, cholesterol levels, impaired fertility in males, blood clotting, depression, anger, destructive behavior, kidney and liver cancer, heart attack

Absorbing:

skin, eyes, and mucous membranes - sarin can also be absorbed - symptoms include: redness and irritations, blisters, and death YPERITE: mustard gas ( strips mucosal lining of the bronchial tubes causing difficulty breathing) - Attacks cornea in the eye leading to blindness - used as a chemical weapon in 1917 WWI

toxicology

study of poisons and identification of drugs and other substances a person may have used for medicinal, recreational, or criminal purposes

tolerance Metabolic

the body produces larger amounts of alcohol dehydrogenase

Botulism is:

the most poisonous biological substance known to humans "Botox" purified botulinum toxin

blood and urine tests:

toxicology labs use gas chromatography/ mass spectrometry (GC/MS) - gas chromatorgraphy seperates the sample into individual components