Environmental Pathology Flashcards
(92 cards)
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