Environmental and Nutritional Diseases Flashcards
What is “personal environment?”
The stuff that we choose to expose ourselves to like smoking, alcohol, etc.
What is a xenobiotic?
An exogenous chemical in the environment that is absorbed by the body somehow (inhalation, ingestion, through skin, etc.).
Are most solvents and drugs lipophilic?
Yeah
Most chemicals are altered through a ____-step process.
two step process.
Describe the two phases of xenobiotic metabolism.
Phase 1: Hydrolysis, oxidation, or reduction produces a primary metabolite.
Phase 2: Conversion of the primary metabolite into H2O soluble compounds by gucuronidation, sulfation, methylation, or glutathione conjugation. Once compounds are H2O soluble, they can be excreted.
What is the most important enzyme system involved in drug metabolism?
CYP450
In which two ways can metabolism of drugs harm cells?
- Metabolism from an inactive compound into an active, harmful compound.
- ROS generated in the metabolic process.
What effect does grapefruit juice have on CYP3A4 in the intestine?
It inactivates it, increasing bioavailability.
The most common air pollutants are _______, which in combination with oxides and particulate matter forms smog, sulfur dioxide, acid aerosols, and particles of less than ___ μm in diameter.
ozone
less than 10 micrometers in diameter.
Describe the three toxic effects of ozone inhalation.
- Decreased lung function.
- Increased airway reactivity –> lung inflammation.
- Free radical production.
Describe the three toxic effects of nitrogen oxide inhalation.
- Decreased lung function.
- Increased airway reactivity.
- Increased respiratory infections.
Describe the three toxic effects of sulfur dioxide inhalation.
- Decreased lung function
- Increased respiratory symptoms.
- Increased mortality.
Describe the four toxic effects of acid aerosol inhalation.
- Decreased lung function.
- Altered mucociliary clearance.
- Increased respiratory infections.
- Increased hospitalization.
Describe the three toxic effects of particulate inhalation.
- Decreased lung function.
- Increased respiratory infections.
- Increased asthmatic attacks.
What is smog comprised of?
Ozone, oxides, and particulate matter.
Hemoglobin has a _____-fold greater affinity for CO than for O2.
200 fold
What are two clinical features of CO poisoning?
- Cherry red color of skin and mucous membranes.
2. CNS depression.
What is the treatment for CO poisoning?
Breathe pure O2, hyperbaric O2 therapy.
Lead exposure occurs through contaminated _____ and _____.
air and food
How much lead is contained in a lead paint chip 1 square cm?
170 micrograms
What is the major cause of lead poisoning amongst children?
Ingestion of lead-containing paint chips.
Ingestion of ______mg of lead per day may occur in a heavily contaminated environment.
200
What is the maximum allowable level of lead in blood for children? Can there be clinical effects below this threshold?
10 micrograms/dL. There still can be effects below this, including decreased IQ, impaired hearing, growth, nerve function.
What clinical effect does lead poisoning in adults typically have?
Peripheral neuropathy.
What clinical effect does lead poisoning in children typically have?
Centeral nervous system effects like low IQ and behavioral problems.
Compare the reversibility of lead poisoning in adults vs. in children.
CNS problems due to lead poisoning in children are typically IRREVERSIBLE, while peripheral neuropathy in adults with lead poisoning is typically reversible.
Which four systems in the body are affected by lead poisoning?
- Skeletal
- Hematopoietic
- Nervous system
- Kidneys
What physiologic effects are commonly seen in people with 11-20 milligrams/dL lead poisoning?
- Decreased Ca2+ homeostasis and as a result messed of up Vitamin D metabolism.
- Erythrocyte protoporphyrin (when RBCs incorporate zinc instead of iron into heme molecules).
- Increased nerve conduction velocity.
How does lead poisoning screw up the skeletal system (2)?
- LEAD LINES along the epiphyses in children due to abnormal bone remodeling.
- Delayed cartilage mineralization.
How does lead poisoning screw up the hematopoietic system?
- Iron incorporation into heme is impaired.
- Microcytic, hypochromic anemia.
- Basophilic stippling of RBCs.
- Hemolytic anemia due to increased fragility of cell membranes.
What does lead poisoning do to kidneys?
Damages proximal tubules
What are the treatments for lead poisoning?
Remove patient from the source. In severe cases, chelation therapy (administration of agents that will bind lead for excretion)
What is the effect of smoking on life expectancy?
Loss of 7 to 8 years
What are the most common diseases associated with smoking (3)?
- Emphysema
- Chronic bronchitis
- Lung cancer
Name 8 diseases that are “strongly linked” to cigarette smoking.
- Atherosclerosis
- MI
- Peripheral vascular disease
- Cerebrovascular disease
- Oral cancers
- Esophogeal cancers
- Pancreatic cancer
- Cancer of the bladder
What does maternal smoking increase risk for (3)?
- SAB
- Premature birth
- Intrauterine growth retardation
Smoke and smokeless tobacco interact with alcohol in the development of _______ cancer.
laryngeal
Can second-hand smoke inhalation produce health effects similar to that of active smoking?
Yeah
Name the effects of chronic alcohol abuse on the liver (4).
- Fatty liver
- Alcoholic hepatitis
- Portal hypertension
- Increase risk for hepatocellular carcinoma
Gastritis, gastric ulcers, peripheral neuropathies, cardiomyopathy, acute and chronic pancreatitis are all possible effects of chronic _______ abuse.
alcohol
Chronic alcohol abuse increases risk for which four cancers? Is risk further increased by concomitant smoking?
- Oral cancer
- Cancer of the pharynx
- Cancer of the larynx
- Esophogeal cancer
Yeah smoking is bad
What is post-menopausal hormone replacement therapy prescribed for?
To lower risk of osteoporosis and to decrease post-menopausal symptoms like hot flashes, diaphoresis, etc.
For which diseases does estrogen replacement therapy increase risk for?
Endometrial carcinoma and thromboembolism.
For which diseases does estrogen + progestin replacement therapy increase risk for?
Breast cancer and thromboembolism.
Is there evidence that post-menopausal hormone replacement therapy is protective against MI?
Nope
What are the three major complications from oral contraceptive use?
- Thromboembolism
- Cardiovascular diseases
- Hepatic adenoma
What are the two metabolic routes of acetaminophen?
- Phase II enzymes (95%)
- CYP2E1 (5%), which generates NAPQ. NAPQ can be conjugated with glutathione for excretion. If conjugation is overwhelmed, NAPQ is hepatotoxic.
Depletion of _______ ________ in the setting of acetaminophen toxicity results in free radical damage, covalent hepatic protein binding and cell death, including _________ necrosis of hepatic lobules.
Depletion of reduced glutatione (GSH) –> centrilobular necrosis of hepatic lobules
What is the treatment for acetaminophen poisoning and how does it work?
N-acetylcysteine restores reduced glutathione (GSH)
What four things determine the clinical significance of burns?
- Depth
- % of body surface
- Internal injury (inhalation of hot air and smoke).
- Promptness of medical intervention.
What is the leading cause of death from burns?
Organ system failure from burn sepsis
How are burns classified? Explain.
First degree: Epidermis necrosis only. Dermis, subcutaneous tissues are spared.
Second degree: Necrosis extends to the upper dermis but skin appendages like glands and hair follicles are spared.
Third degree: Necrosis extends into the deep dermis; subcutis may be involved, skin appendages destroyed.
What are the clinical effects of hyperthermia?
- Heat cramps - loss of electrolytes via sweating. Muscle cramps.
- Heat exhaustion - sudden onset and collapse. Cardiovascular system cannot compensate for the fluid loss. Equilibrium is usually spontaneously re-established. Can progress to heat stroke.
- Heat stroke - associated with high ambient temp and humidity. Failure of thermoregulatory mechanisms, sweating ceases and core temp rises. Peripheral vasodilation with pooling of blood, decreased circulating blood volume. Changes in metal status, arrhythmias, intravascular coagulation. 50% mortality rate with rectal temp of 106F/41C
What population is at the highest risk for heat stroke?
Elderly, people with CV disease, healthy people undergoing physical stress
By which two methods can ionizing radiation damage cells? Which one is most damaging?
Indirect, direct. Indirect is most damaging (free radical generation)
What are the six factors that influence the effects of ionizing radiation?
- Physical properties of the radiation.
- Sensitivity of the proliferating tissues (high turnover = high vulnerability).
- Vascular damage - late manifestation.
- Rate of delivery of the radiation.
- Hypoxic tissues are more resistant.
- Field size (large dose/small field is more potent than small dose/large field).
Which tissues are sensitive to ionizing radiation (3)? Can radiation cause neoplastic transformation?
Germ cells, bone marrow cells, GI cells are sensitive. It can lead to neoplastic transformation.
What results from small dose acute radiation syndrome?
Hemopoietic: 2 week latency, death in 3 weeks. Kills bone marrow with resultant leukopenia, thrombocytopenia, petechiae, infection, purpura.
What results from medium dose acute radiation syndrome?
Intestinal: 3 day latency, death in 2 weeks. GI epithelium necrosis and ulceration, infection, diarrhea, and septicemia.
What results from large dose acute radiation syndrome?
Cerebral: 1 hour latency, death in 1 day. Cerebral edema, neuronal necrosis, vasculitis, coma.
True or false: The following examples of non-neoplastic complications of radiation:
Myocardial fibrosis, constrictive pericarditis, esophogeal strictures, pulmonary fibrosis, transverse myelitis, nephritis, stricture of the small intestine, sterility, congenital malformations, radiodermatitis.
True.
Late manifestation of radiation injury to parenchymal cells often includes _________.
fibrosis
Name the two protein compartments of the body that are regulated separately.
- Somatic compartment: Proteins in the skeletal muscles.
2. Visceral compartment: Proteins in the viscera, primarily in the liver.
What is the difference between primary and secondary malnutrition?
Primary is due to inadequate intake of food, and secondary is due to a deficiency in absorption or utilization in the body, or increased needs.
Marasmus is a deficiency of ______.
calories
What are the clinical manifestations of marasmus?
Growth retardation, reduction in somatic protein (muscle loss), visceral protein is not affected much. Serum albumin is normal, subcutaneous fat is mobilized. Weak, thin extremities, head is disproportionately large. Anemia vitamin deficiencies, immune deficiency, concurrent infection.
Kwashiorkor is a deficiency of _______.
protein
What are the clinical manifestations of kwashiorkor?
Muscle mass and subcutaneous fat are spared. Visceral protein is affected, resulting in hypoalbuminemia and EDEMA. Skin has zones of hyper and hypopigmentation, changes to hair color, hair falls out or has fine texture. Fatty liver, apathy, listlessness, loss of appetite. Can cause vitamin D deficiency, immune deficiency, secondary infections.
Anorexia nervosa is self-induced _______ with marked weight loss.
starvation
What are seven complications of anorexia nervosa?
- Body fat loss
- Muscle atrophy
- Amenorrhea
- Dehydration and electrolyte imbalance
- Changes in skin and hair
- Decreased bone density
- Increased susceptibility to cardiac arrhythmia and sudden death.
What are the five complications of bulemia nervosa?
- Elecrolyte imbalance
- Predisposition to arrhythmias
- Pulmonary aspiration of gastric contents
- Esophogeal and gastric cardiac rupture
- Acid effects on teeth
What is orthorexia nervosa?
An obsession with righteous eating. Starts as an attempt to eat healthier and turns into obsession. A feeling of superiority over others ensues.
What is the normal functions of Vitamin A in the body (6)?
Vision, growth/differentiation, metabolism, resistance to infection, photo-protection and antioxidation.
What are the manifestations of vitamin A deficiency?
- Night blindness
- Xeropthalmia (dry eyes)
- Bitot’s spots (keratin plaques)
- Keratomalacia (cornea erosion)
Retinol, retinoic acid, retinoids are sources of vitamin ___.
A
On what molecule is vitamin A shuttled around in the body?
RBP
What cellular changes may occur with vitamin A deficiency?
Squamous metaplasia, especially in glandular epithelium, and hyperkeratinization immune deficiency.
Hyperkeratinization immune deficiency results from a ________ ____ deficiency.
vitamin A
Vitamin D is converted to its active form in the ______, then finally in the _______.
liver makes 1-OH cholecalciferol, then kidney makes 1, 25-OH cholecalciferol (active form)
Vitamin D promotes _______ absorption in the GI tract and also has an effect on ______ activity.
calcium absorption, osteoclast activity.
The basic derangement in both ______ and ______ is an excess of unmineralized matrix in bones.
rickets and osteomalacia
_______ ___ normally helps with prolyl and lysyl hydroxylation and amidation for things like collagen.
Vitamin C
What are the clinical manifestations of vitamin C deficiency?
Impaired COLLAGEN formation from procollagen –> bleeding, poor vascular support, inadequate osteoid matrix formation, impaired wound healing.
Scurvy is primarily caused by a ________ ___ deficiency.
vitamin C
What is one major risk of synthetic retinoid products used to treat skin conditions like psoriasis, acne, etc.?
Increases risk of fetal malformation.
