Environmental Pathology Flashcards
What is the mechanism of lead induced anemia?
-lead is found in air, soil, water, food, house dust, batteries, old paints, and gasoline
-85% of lead is taken up by bone and developing teeth
-lead competes with Calcium and interferes with remodeling
LEAD ALSO BLOCKS OR HINDERS THE INCORPORATION OF IRON INTO HEMOGLOBIN = anemia
What factors affect the clinical significance of thermal burns?
% body surface area (THE RULE OF 9's) *Head and Neck = 9% *Trunk Front = 18% *Trunk Back = 18% *Arms = 9% each *Hands= 1% each *Legs = 18% each *Perineum = 1 % [IF MORE THAN 50% BSA IS INVOLVED= grave prognosis] [IF MORE THAN 20% BSA IS INVOLVED= shock, infections, and hypermetabolic state]
What are the major cellular effects of radiation injury?
- Direct Damage to DNA
2. Indirect Damage: free radical production damages membranes, nucleic acids, and enzymes
What is the difference between marasmus and kwashiorkor?
Marasmus:
- deficient CALORIE intake
- break down proteins/amino acids for energy
- depletion of skeletal muscle and subcutaneous fat
- EMACIATED appearance of extremeties
- head looks too large for the body
- normal albumin
- T cell defects (Thrush is common infection)
- drop in body temp
Kwashiorkor:
- PROTEIN deficiency is greater than reduction in calories
- depletion of visceral protein compartments
- low albumin and generalized EDEMA
- skin/hair color changes
both: vitamin deficiencies, immune defects, growth retardation
What are the clinical signs of Vitamin A deficiency?
- impaired night vision (earliest sign)
- impaired immunity
- squamous metaplasia of respiratory and urinary tracts (infections and stones)
- dry eyes leading to corneal damage (later sign)
What are the clinical signs of Vitamin C deficiency?
- Scurvy:
- elderly, alcoholics, those with erratic eating habits, hemodialysis patients, infants fed non-fortified formula
- impaired collagen synthesis
- hemorrhages are common in skin and gingiva
- bleeding behind eyes, joints, and brain
- skeletal changes (cartilaginous overgrowth, bowing of long bones)
- depression of the sternum
- poor wound healing
- anemia is common
What are the clinical signs of Vitamin C toxicity? What is an excessive amount of Vitamin C?
> 2 grams per day
- fun fact: there are 51 mg in an orange*
- large doses causes enhanced iron absorption which could create iron overload
- high vitamin C will acidify urine and increase the risk for stones
- sudden change from high to low vitamin C could results in “rebound scurvy” which causes precipitation due to enhanced clearance mechanisms
What are the clinical signs of Vitamin A toxicity? What is an excessive amount of Vitamin A? Where do you get Vitamin A?
> 25,000 IU per day
= yellow/green leafy vegetables, liver, fish, EGGS, milk and butter
-usually toxicity is from supplement use
-acute toxicity: nausea, vomiting, irritability, headache, blurred vision
-chronic toxicity: anorexia, hair loss, dry skin, pruritis, dry mucous membranes, fissured lips, fatigue, weight loss, bone and joint pain
What are the four regulatory agencies for environmental hazards?
- EPA
- FDA
- OSHA
- Consumer Product Safety Commission
Injuries from _______ agents occur by inhalation, ingestion, injection, or absorption.
chemical
Children account for ____% of chemical injuries.
60
What are the factors that affect chemical injuries?
"CLADME" Concentration Liberation Absorption Distribution Metabolism Excretion
True or False: US work-related injuries occur twice as often as home injuries and has an annual cost of $500,000.
False
work injuries do occur twice as often
cost to the US is $25 BILLION annually!!!!!
True or False: Of the estimated 2 million hazardous exposures each year in the U.S., 90% are unintentional.
True
Oral intake accounts for ____% of exposures.
73
Children less than 6 years old account for ____% of exposures.
61
What are the most frequent agents of chemical exposure?
household items (cleaning agents, cosmetics, analgesics, plants, etc)
Anaphylaxis can occur with any medication but is most often associated with ______.
antibiotics (penicillin is the classic)
What are three common Adverse Drug Reactions (ADRs)?
- Aspirin
- Acetaminophen
- Exogenous estrogen/Oral contraceptives
- minor ADR = rash, GI upset
- major ADR = anaphylaxis, clots, anemia, arrythmias
True or False: ADRs are common.
True, adverse drug reactions account for 2%
Until 2002, exogenous estrogens were widely used for what reason? What does the recent data indicate?
Hormone Replacement Therapy for menopausal symptoms and osteoporosis prevention
-long term use is associated with elevated risk of breast cancer, strokes, and clots
What can been seen on x-rays and the gingival sulcus area in a patient exposed to high levels of lead?
“Lead Lines”
Wristdrop and Footdrop are associated with neural and sensory deficits from excess _____.
lead exposure
What is the threshold blood level of concern for lead?
greater than 45 micrograms/dL
True or False: Lead toxicity could take years to develop.
True
What kind of therapy is indicated when lead levels reach more than 45 micrograms?
Chelation therapy to bind the lead….however, there is no full recovery (kidney damage, GI tract damage)
What are the general classes of “drugs of abuse”?
- sedative-hypnotics (alcohol, benzo)
- CNS stimulants (cocaine)
- opioids (heroin, morphine, codeine)
- Cannabinoids (marijuana)
- Hallucinogens (LSD, ketamine)
- Inhalants (glue, paint thinner, gasoline)
- Nonprescription Drugs (atropine, antihistamines)
What are club drugs?
a collective term for substances that have become popular in dance clubs, bars, and raves. There are a variety of drugs including ecstasy, Meth, LSD, and Rohypnol (roofies)
What is a side effect of MDMA (ecstasy)?
bruxism
*many deal with the potential for fracturing teeth in a rave by using a pacifer (reportedly storing another hit)
Abrasion, contusion, and laceration are examples of _____ injuries.
mechanical
What is a laceration?
a tear in tissue, usually with irregular edges
What is a contusion?
a wound caused by a blunt object, doesn’t break the skin but could damage blood vessels (bruise)
____ is a wound caused by scraping or rubbing that leads to removal of superficial layers of skin.
abrasion
ADR’s are highly related to ______ which is seen most clearly with _______ drugs.
potency
anti-cancer drugs
In what temperature range does the body operate?
31 to 41 degrees celsius
90 to 105 degrees F
_____ cause more than 5000 deaths per year in the US.
Hyperthermia (burns)