Flashcards in Environmental Pathology Deck (82):
Most xenobiotics are
Lipophilic toxicants are metabolized to hydrophilic metabolites in two steps;
Phase 1: adding a polar group
Phase 2: conjugation products
There are __ in the level of activity of the xenobiotic metabolizing enzymes.
Phase I reactions generate
Oxygen free radicals as byproducts.
All of the reactions occur in the SER.
Most important phase I reactions
Cytochrome P-450- dependent monooxygenase system
Flavin containing monooxygenase system
Peroxidase dependent cooxidation
Examples of phase II reactions
Systemic diseases caused by tobacco use
Ischemic heard disease
Tobacco use can lead to risk factors for
Myocardial infarction in women who take oral contraceptives
Maternal smoking can cause
Passive smoking causes increased risk for
Respiratory/ear infections in children
Asthma in children
Ingestion of methanol/ethylene glycol (anti-freeze) can cause:
Initial: dizziness, blindness, respiratory depression
Days after: acute renal failure.
It is treated with ethanol
Alcohol abuse: acute and chronic abuse causes
Acute: drowsiness, euphoria
Chronic: cirrhosis, vitamin deficiency, ulcers, cardiomyopathy
Fatty change, actue hepatitis and cirrhosis in the liver is caused by
Nervous system disorders are caused by
Thiamine deficiency/nutritional deficiency
Cardiovascular system lesions cause cardiomyopathy and hypertension. They are caused by
Toxicity and vasopressor
GI tract, skeletal, reproductive and fetal alcohol syndrome are all caused by
Depressors (ethanol and barbituates) induce
Sedation and decrease anxiety, but tolerance develops rapidly.
Stimulants such as amphetamines and cocain cause
Cardiac arrhythmias, ischemia and respiratory arrest. In a fetus, it can cause placental abruption.
Opioid narcotics (heroin, codeine) can cause
Convulsions, cardiorespiratory arrest (overdose)
Cannabinoids and hallucinogens cause
Acetaminophen can cause toxicity due to overdose. The adverse effect is
Liver necrosis and failure
NSAIDs can have a side effect of
A deficiency of tiopurine S-methyltransferase and azathiprine can cause
Bone marrow failure
Cytocrome P-450 CYP2C9 and anicoagulants can cause
Cytochrome P-450 and CYP2D6 and some antipsychotic drugs can cause
Sedation and prakinsonism
N-actyltransferase and hydralazine can cause
Chloramphenicol can cause
Benefits and side effects of oral contraceptive pills
Benefit: decrease risk of endometrial and ovarian cancers.
Adverse effects: deep vein thrombosis, MI, stroke, benign hepatic ademonas
Hormone replacement therapy benefits and adverse effects
Benefits: improve menopause symptoms and prevent osteoperotic fractures.
Effects: increased risk of breast cancer, venous thrombosis, and cholecystitis
Long term effect of Acetaminophen and NSAIDs
Radon and asbestos cause
Allergic rhinitis, asthma
Volatile organic compounds can cause
Headache, dizziness and liver or kidney toxicity
Cadmium can cause
Nickel can cause
Lead is most commonly inhaled. Some adverse effects are
Basophilic stippling of erythrocytes (KIDS)
Damage to proximal tubules
Gout, renal failure
A single dose of external radiation administered to the whole body is ___ than regional doses with shielding.
Cells in the ___ phases of the cell cycle are most sensiitive to ionizing radiation
G2 and mitotic phase
Cell injury induced by x rays and gamma rays is enhanced by
Sublinical radiation: dose, symptoms, prognosis
Symptoms: mild nausea, vomiting, lymphocytes <1500
Prognosis: 100% survival
Hematopoietic radiation: dose, symptoms, prognosis
Dose: 200 - 600
Symptoms: intermittent nausea and vomiting, petechiae, hemorrhage, neutrophil/platelet depression, lymphocytes <1000
Prognosis: infections, possible bone marrow transplant
Gastrointestinal radiation: dose, symptoms, prognosis
Dose: 600 - 100 rem
Symptoms: nausea, vomiting, diarrhea, hemorrhage, infection, severe neutrophil and platelet depression, lymphocytes <500
Prognosis: shock and death in 10 - 14 days
Central nervous system radiation: dose, symptoms, prognosis
Dose: >1000 rem
Symptoms: nausea, vomiting, confusion, somnolence, convulsions, coma, lymphocytes absent
Death: 14 - 36 hours
The most susceptible period of radiation injury to a fetus is
From implantation to 9 weeks gestation.
From 9 weeks gestation to birth, there are underdeveloped reproductive organs, mental retardation and childhood leukemia.
Postnatal: retarded bone growth and maturation, perturbed CNS
Delayed radiation injury causes fibrosis. Some areas affected are
Blood vessels: fibrosis of blood vessels
Skin: radiation dermatitis and skin cancer
Heart: fibrosis of pericardium
Lungs: intra-alveolar and intersitial fibrosis
Kidneys/bladder: moderately susceptible
The spermatogonia are ____ to irradiation.
Are extremely sensitive to irradiation.
The eyes and CNS are also sensitive to ionizing radiation.
UV causes degenerative cahnges in
Elastin and collagen
Burns, depth of the burn in 1-3 degrees
2: epidermis and superficial dermis
3 & 4: epidermis and dermis, dermal appendanges.
50% of burnt skin is fatal. 20% causes
Heat cramps result from loss of
Electrolytes through sweating
The most common head syndrome
It is sudden and is caused by a failure of the CV system to compensate for hypovolemia.
Heat stroke results from
High temperatures and humidity.
Thermoregulatory mechanisms fail, sweating ceases and core body temperature rises.
Malnutrition caused by severe reduction in caloric intake.
Albumin levels are normal, extremities are emaciated and there is an immune deficiency.
Kwashiorkor protein deprivation is relatively greater than the reduction in total calories. Its signs are
Albumin levels low
Poorer prognosis than marasmus
Enlarged, fatty liver
Defects in immunity
Functions and deficiency of vitamin A
Functions: component of visual pigment, maintenance of specialized epithelia, maintenance of resistance to infection.
Deficiency: night blindness, squamous metaplasia, vulnerability to infection.
Function and deficiency of vitamin D
Function: facilitates internal absorption of calcium and phosphorus and mineralization of bone
Deficiency: rickets (children), osteomalacia (adults)
Vitamine E: function and deficiency
Function: major antioxidant; scavenges free radicals
Deficiency: spinocerebellar degeneration
Vitamin K: function and definciency
Cofactor in procoagulants.
Deficiency: bleeding diathesis
Vitamin B1: functions, deficiency
Function: coenzyme in decarboxylation reactions
Deficiency: wernicke, korsakoff
Vitamin B2 (riboflavin): function and deficiency
Function: converted to flavin coenzymes, cofactors for intermediary metabolism
Deficiency: glossitis, dermatitis, corneal vascularization
Vitamin B6 (pyridoxine): function and deficiency
Function: serves as coenzymes
Deficiency: glossitis, dermatitis, peripheral neuropathy
Vitamin B12: function and deficiency
Function: folate metabolism and DNA synthesis, myelinization of spinal cord
Deficiency: anemia, degeneration of posterolateral spinal cord tracts.
Niacin: function and deficiency
Function: incorporated into NAD
Deficiency: dementia, dermatitis, diarrhea
Vitamin C: function and deficciency
Function: redox reactions
Folate: function and deficiency
Function: essential for transfer and use of 1-carbon units of DNA synthesis
Disease: megaloblastic anemia, neural tube defects
Pantothenic acid: function
Incorportated in coenzyme A; no syndromes due to deficiencies
Cofactor in carboxylation reactions; no clearly defined deficiency
The most important form of vitamin A is
Retinol; it is stored in the liver.
Toxicity causes headache, vomiting, papilledema
The most active form of vitamin D is
It stimulates intestial absorption of calcium and phosphorus and collaborates with PTH in the mobilization of calcium from the bone.
Frontal bossing, square appearance to the head
Pigeon breast deformity
Lymbar lordosis/bowing of the legs.
Affects the vertebral bodies and femoral necks
Deficiencies of vitamin K cause
Small liver in neonates
Diffuse liver disease
Cause of thiamine deficiences are
Chronic alcoholism, pernicious vomiting
It presents as: polyneuropathy, cardiovascular syndrome, wernicke and korsakoff syndromes
Deficiency of vitamin B 6 can occur with the use of
Isoniazid, estrogens and penicillamine
Presentations of vitamin C deficiency
Gingival sweeling, hemorrhages, periodontal infection
Vitamin B 12 occurs in
Atrophic gastritis, vegetarianism and bacterial overgrowth.
Presentations of deficiency include megaloblastic anemia and myelin degeneration.
Iron deficiency presents as
Hypochromic microcytic anemia
Iodine deficiency presents as
Goiter and hypothyroidism
Manganese deficiency presents as
Fluoride deficiency presents as
Associated disease risk is associated with BMIs of
Overweight 25 - 29.9