Environmental and Nutritional Disorders Flashcards
(51 cards)
1
Q
Toxicology Definitions
A
-
Threshold dose
- Expressed as a range
- Where effect first occurs
-
Threshold limit values / Permissible exposure level
- Max exposure before harmful effect occurs
-
Ceiling effect
- Plateau: if increases in dose, does not change level of response
2
Q
Metabolic Metabolites
A
-
Metabolism of parent compounds
- To more toxic metabolites (e.g. mercury)
- To less toxic substances
- To conjugation products
-
Exposures due to metabolites of lipophilic toxicants include:
- ↑ Bladder CA in dye workers
- ↑ Hepatic angiosarcoma in persons working w/ vinyl chloride
- Remember the concept of bioaccumulation
- Minamoto mercury poisoning
- Fish poisoned w/ mercury, then human eats fish
3
Q
Smoking
A
-
Know adverse effects include:
- Cancers
- Heart disease
- Chronic respiratory disease
- Atherosclerosis
- Cerebrovascular disease
- Low birthweight in fetus
4
Q
Acute Alcohol Intoxication
A
-
BAC between 0.01 and 0.1 percent:
- Feelings of wellbeing and confidence
- Disinhibition
- Urge to speak
- Feelings of tranquility and relaxation
-
Mild deficits in coordination
- Unsteady gait
- Difficulties standing upright
- Slightly decreased attention, memory, and judgement
- Reddening of the skin or flushing of the face
- Slightly ↑ HR
-
BAC between 0.15 and 0.3 percent:
- Mood variability
- Pronounced disinhibition
- Slurred speech
-
Greater deficits in coordination and psychomotor skills
- ↑ Unsteadiness of gait
- Clumsiness
- Increasingly impaired attention, memory, and judgement
- Reduction in responsiveness, alertness, and reaction time
- Confusion
- Uncontrolled eye movements
- Sleepiness
- Dizziness
- Nausea and vomiting
- Impaired vision and sound localization
- Memory gap
-
BAC greater than 0.3 percent:
- Delusions and hallucinations
- Severe difficulty speaking
- Severe dizziness
- Severe deficits in coordination and psychomotor skills
- Potential hypothermia
-
Potential coma
- Usually BAC > 0.4 percent
- LOC
- Lack of defensive reflexes
- Respiratory failure
- Usually BAC > 0.4 percent
5
Q
Chronic Alcoholism
A
- Liver: steatosis, alcoholic hepatitis, cirrhosis
- GI: acute gastritis, acute and chronic pancreatitis
- CNS: atrophy of mamillary bodies
- Reproductive: testicular atrophy
- Heart: cardiomyopathy
6
Q
Fetal Alcohol Syndrome
A
7
Q
Alcohol and Cancer
A
↑ risk of oral cavity, pharyngeal, esophageal, liver cancers
8
Q
Effects of Other Alcohols
A
Methanol toxicity: blindness
Ethylene glycol toxicity: obstruction of renal tubules by calcium oxalate crystals
9
Q
Commonly Abused Drugs
A
- CNS depressants
- CNS stimulants
- Narcotics
- Hallucinogens
- Combinations of drugs: e.g. alcohol and barbiturates
10
Q
HRT and Oral Contraceptives
A
-
Exogenous estrogen: possible effects of unopposed estrogen
- Endometrial carcinoma
- Thromboembolism: natural less risk than synthetic
- Cardiovascular disease
-
Oral contraceptives
- Breast carcinoma: probably slight ↑ in women over age 45
- Endometrial cancer: protective effect
- Cervical cancer: ↑ risk related to duration of use and lifestyle
- Ovarian cancer: protective effect
- Thromboembolism: higher risk w/ older women who smoke
- Hepatic adenoma
11
Q
Acetominophen
A
- Toxic doses may cause hepatic necrosis
- Concurrent renal and myocardial damage may occur
- Toxicity: Nausea, vomiting, diarrhea and shock, jaundice days later
12
Q
Aspirin
A
-
Acute overdose
- Respiratory alkalosis followed by metabolic acidosis
-
Chronic aspirin toxicity (Salicylism)
-
CNS changes
- HA, dizziness, tinnitus, AMS, drowsiness, N/V/D
- Acute erosive gastritis
- Bleeding tendency: petechial hemorrhages
-
Analgesic nephropathy
- Renal papillary necrosis
- May be caused by combo of aspirin and phenacetin or its metabolite; also acetaminophen
-
CNS changes
13
Q
Outdoor Air Pollution
A
- Acute toxicity: proximal effects
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Subacute/chronic: distal effects
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Subclinical chronic inflammation and fibrosis
- Ongoing toxic effects and hypersensitivity
- Degenerative changes
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Subclinical chronic inflammation and fibrosis
14
Q
Common Indoor Pollutants
A
- Carbon monoxide
-
Radon
- Emanates from earth into basements of homes
- Inhaled into lungs where decay products emit alpha radiation
- Asbestos: lung CA, mesothelioma
- Fiberglass: skin and lung irritation
- Bioaerosols: dust mites, fungi, molds
15
Q
Industrial Exposures
A
Volatile organic compounds:
-
Aliphatic hydrocarbons: dry cleaning
- CCl4 and chloroform: acute CNS depression, liver and kidney toxicity
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Aromatic hydrocarbons
- Benzene inhalation: bone marrow toxicity, aplastic anemia, acute leukemia
- Petroleum products: CNS depression
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Aromatic halogenated hydrocarbons
- Soot: scrotal cancer in chimney sweeps
- Plastics, rubber, polymers
16
Q
Lead
A
“PLUMBISM”
Peripheral demyelinating neuropathy
Lead lines in bones/gums
Urinary excretion: damage proximal tubules, interstitial fibrosis
Mental deterioration
Brain damage in children
Intestinal Manifestations: colic, anorexia
Serum: ↑ zinc protoporphyrin
Microcytic, hypochromic, mild hemolytic anemia
“BITES”
Bone accumulation
Inhibition of heme synthesis
Toxic blood level is greater than 10 micrograms/L
Erythrocyte basophilic stippling
Surgical abdomen: lead colic
17
Q
Cobalt/Tungsten Carbide
A
Metal workers: asthma, interstitial fibrosis
18
Q
Cadmium
A
Acute toxicity: swelling of pneumocytes
Chronic toxicity: kidney
19
Q
Nickel
A
Topical exposure: contact dermatitis
Inhalation: carcinogenic
20
Q
Mercury
A
Renal toxicity, dementia
21
Q
Chromium
A
Carcinogen in industry
22
Q
Arsenic
A
Skin, lung, liver cancers
23
Q
Occupational Exposure
Respiratory Effects
A
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Nasal cancer
- Isopropyl alcohol, wood dust
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Lung cancer
- Radon, asbestos, nickel, arsenic, chromium, mustard gas
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COPD
- Grain dust, coal dust, cadmium
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Hypersensitivity
- Beryllium
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Irritation
- Ammonia, sulfur oxides, formaldehyde
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Fibrosis
- Silica, asbestos, cobalt
24
Q
Agricultural Hazards
A
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Insecticides
- Many linked to neuro- and hepatotoxicity
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Herbicides
- Arsenic compounds: hyperpigmentation, gangrene, anemia, sensory neuropathy, cancer
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Fungicides
- ? Reproductive toxicity
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Rodenticides
- Warfarin: hemorrhage
25
Natural Toxins
* _Mycotoxins_
* **Ergot alkaloids**: gangrene, convulsions, abortion
* **Aflatoxins**: liver cancer
* _Animal toxins_
* **Venoms**
* **Cinguatoxin**: parasthesias, vomiting, diarrhea
* **Tetrodotoxin** (puffer fish): neurotoxin, shock
26
Radiation
* _Factors influencing damage to tissue/cells:_
* **Total dose**
* **Rate at which dose is delivered**
* **Rate of cell turnover**
* **Capacity for cellular repair**
* **Oxygen effects**: free radicals
* **Radiation-induced vascular changes**
* Injury → fibrosis and loss of the lumen
* _History:_
* Areas w/ nuclear disaster, after therapeutic radiation: **Papillary thyroid cancer**
* Early radiologists: **↑ aplastic anemia, brain tumors**
* Fetal exposure: **Mental retardation, leukemia, malformations**
27
Ionizing Radiation Damage
* _Acute effects after exposure_
* **Edema, mucosal erosion, atrophy of many tissues**
* _Delayed effects after exposure_
* **Fibrosis** in lung, heart, GI tract, bladder, ovary, breast
* **Malignancies** of bone marrow, liver, bladder, thyroid, breast, lymph nodes, brain
Know which organ systems are affected as whole-body dosage of ↑ radiation
28
Radiation Effects
29
Mechanical Trauma
* **Injuries are the most common cause of death in US up to age 34**
* Violence is an important factor
* **Abrasion** (scrape)
* **Contusion**: blunt force; damages small blood vessels, bruise
* **Laceration**: irregular skin tear, overstretching w/ bridging strands of fibrous tissue or blood vessels
* **Incised wound**: cut
* **Puncture wound**
* **Gunshot wound**: distance, direction
30
Thermal Burns
* _Classification_
* **Partial thickness**
* **First degree**: epidermis only
* **Second degree**: epidermis and superficial dermis
* **Full thickness**
* **Third degree**: Into deep dermis, will need skin graft
* **Fourth degree**: Into subcutaneous tissue
* _Factors for clinical significance_
* **Depth of burn**
* **Percentage of body surface involved** (rule of 9s)
* Possible presence of **internal injuries**
* **Inhalation** of hot/toxic fumes
* **Promptness and efficacy of therapy** is very important
* **Electrolyte management** is key
* **Infection prevention/control** is a critical component of therapy
31
Barotrauma
* High altitude sickness
* Blast injury
* Air/gas embolism
* Decompression (caisson disease): bends, chokes and staggers from too rapid ascent
32
Pneumoconiosis
* Simple coal workers pneumoconiosis (CWP)
* Complicated CWP: progressive massive fibrosis
* Silicosis
* Asbestosis
33
Primary Nutritional Deficiency
Caused by **inadequate diet**
Can be due to poverty, anorexia nervosa, lack of ionized salt, chronic alcoholism (inadequate diet aspect, remember thiamine)
34
Secondary Nutritional Deficiency
**Malnutrition despite adequate nutrient supply**
* Failure of digestion or absorption: e.g. fat soluble
* Failure of utilization: e.g. liver disease so can’t store Vitamin A
* ↑ Requirements: pregnancy, acute, or chronic illness
* ↑ Excretion: sweating
* Drugs: can block uptake or use of nutrients
35
Malnourishment
Weight is below 80% of normal
36
Marasmus
**Wasting due to too few calories**
Weight below 60% of normal
* Growth retardation
* ↓ muscle mass due to catabolism: loss of somatic protein compartment
* Deplete subcutaneous fat: emaciated
* Serum albumin only slightly reduced
* See anemia, immune deficiency, vitamin def.
* No edema or hepatomegaly
37
Kwashiorkor
* **Loss of visceral protein compartment**
* More severe than marasmus
* **Weight is 60-80% of normal**
* Masked by fluid retention
* **Relative sparing of subcutaneous fat and muscle mass**
* **Skin lesions**
* **Flaky paint sign**: affects squamous epithelium resulting in alternating zones of hyperpigmentation, desquamation and hypopigmentation
* Hair changes: **flag sign**
* Also, apathy, listlessness, loss of appetite, enlarged fatty liver, immunosuppression
38
Secondary Protein–Energy Malnutrition
Complication in patients w/ **advanced cancer, AIDS** (also called cachexia or wasting syndrome)
39
Anorexia Nervosa
**Severe protein energy malnutrition** w/ additional **endocrine system manifestations**
Includes amenorrhea, skin changes, ↓ body hair, ↓ bone density, ↑ susceptibility to cardiac arrhythmia
40
Fat Soluble Vitamins
Vitamins A, D, E, K
Patients w/ **biliary tract and pancreatic dysfunction** and **intestinal malabsorption syndromes** (e.g. cystic fibrosis) are predisposed to _deficiency of fat-soluble vitamins_
41
Vitamin A
* _Vitamin A Deficiency_
* **Eye changes**
* **Defects in cell differentiation**
* Epithelial metaplasia
* _Vitamin A Toxicity_
* **Acute**
* HA, vomiting, stupor, papilledema (pseudotumor cerebri)
* **Chronic toxicity**
* Weight loss, nausea, vomiting, dry lips, joint pain
42
Vitamin D
* _Deficiency_ causes **derangement of plasma levels of phosphorous and calcium**, w/ resultant **mineralization**
* See excess of mineralized matrix (osteoid material and cartilage)
* Children: **rickets**
* Altered **endochondral bone growth**
* **Prominent head deformity** in infant, **lumbar lordosis,** **bowed legs** in children w/ **rachitic rosary and pigeon breast deformity**
* Adults: **osteomalacia**
43
Vitamin E
* Important **antioxidant**
* _Deficiency_
* **Spinocerebellar degeneration** due to degeneration of axons in _posterior columns of spinal cord_
* ↓ DTRs, ataxia, dysarthria, loss of position and vibration sense, loss of pain sense, myopathy
* **Hemolytic anemia**: RBCs more susceptible to oxidative stress
44
Vitamin K
* _Deficiency is rare_ due to **endogenous production by gut flora**
* Seen in **newborns** (no gut flora, fat malabsorption, diffuse liver disease, suppression of nl intestinal flora due to use of abx)
* **Blood clotting abnormality** due to deficiency of clotting factors II, VII, IX, X and proteins C and S
* _Infants_: **hemorrhagic disease of the newborn**
* Intracranial bleed
* _Adults_: **ecchymosis, gingival bleed, hematoma, hematuria, melena**
45
Vitamin B1
| (Thiamine)
Deficiency seen in areas w/ **polished rice diet** and in **chronic alcoholism**
* **Dry Beriberi**: demyelinating peripheral polyneuropathy
* **Wet Beriberi**: w/ pulmonary edema, =/- mural thrombi secondary to hypokinetic walls
* **Wernicke Korsakoff syndrome**: nystagmus, ataxia, mental confusion, disorientation, confabulation, see atrophy of mamillary bodies
46
Vitamin B2
| (Riboflavin)
Deficiency: cheilosis, glossitis, dermatitis, corneal vascularization
47
Vitamin B3
| (Niacin)
Deficiency: **Pellagra**
Dermatitis, diarrhea, dementia
48
Vitamin B6
| (Pyridoxine)
Deficiency: Seborrheic dermatitis, cheilosis, peripheral neuropathy, glossitis
49
Vitamin C
Deficiency (**scurvy**)
* **Hemorrhages**: skin, gingival mucosa, subperiosteal hematomas, intracranial hemorrhages (due to loss of collagen in vessel walls)
* **Perifollicular, hyperkeratotic papular rash** which may be ringed by hemorrhages
* **Abnormal wound healing and localization of focal infections**
* _In growing child_: **bone abnormalities**
* Can fracture due to inadequate osteoid at epiphyseal plate
50
Folate
Deficiency: **Megaloblastic anemia, neural tube defects in fetus**
51
Vitamin B12
| (Cobalamin)
Deficiency: **Megaloblastic anemia** and **degeneration of posterolateral spinal cord tracts**
