Exam 4 Objectives Flashcards
Define environmental disease
Disorders caused by exposures to chemicals or physical agents like radiation in the ambient, workplace, or personal environments
Define toxicology
The science of positions Distribution Effects Mechanisms Physical agents Medications can be positions if too much is taken
Define dosage
The amount of exposure to a substance.
Discuss the possible results of exposure to environmental toxins
Skin, lung, or GI absorption -> blood stream transport to tissues -> stored or excreted
Want excreted; stored can be a problem
Cell toxicity, repair, excretion
Discuss the sources and clinical symptoms to lead
Comes from contaminated air, food, and soil contamination; flaking paint
Everyone who is exposed is at risk; especially children
Children absorb more from food, have a more permeable blood brain barrier, taken up into developing bones and teeth because its in competition with calcium.
It interferes with enzymes involved in heme synthesis; causes anemia
Inhibits NA and K dependent ATPases = fragile RBCs
Inhibits bone healing
Discuss the sources and clinical symptoms to mercury
Sources of exposure: fish and dental amalgams (fillings)
Symptoms: tremor, gingivitis, bizarre behavior (“mad as a hatter”), birth defects from in utero exposure
Concerned with methyl mercury not ethyl mercury. Methyl mercury stays in the body. Ethyl mercury can be excreted.
Discuss the sources and clinical symptoms to arsenic
Naturally occurring in soil and water (mining), wood preservatives, herbicides
Large amounts cause GI, cardio, and CNS disturbances due to interference with oxidative phosphorylation - messes up the electron transport chain
Chronic exposure increases risk of basal and squamous cell carcinomas
Define pneumoconiosis and list the etiologic agents which most commonly cause these disorders
Fibrotic changes in the lungs that is not neoplastic or metaplastic due to chronic inflammation
Mineral dust: coal, asbestos, beryllium, smoking tobacco
List the types of cancer linked to cigarette smoking
90% of lung cancers are linked to smoking
Cancer of the mouth, esophagus, larynx, lung, pancreas, and bladder
Other problems: chronic bronchitis, emphysema, MI, peptic ulcer, atherosrerlosis
Explain how emphysema and smoking are linked
1
Describe the mechanisms of ethanol toxicity
Increases in NADH/NAD+ ratio
Leads to fat accumulation in the liver which causes lactic acidosis in smaller amounts
Acetaldehyde increases causes tachycardia and hyperventilation
Metabolism of ethanol releases ROS which causes lipid per oxidation in the liver
Release of endotoxin by GNB in intestine
Define adverse drug reaction
Untoward effects of therapeutic drugs given in proper settings
Explain the effects of cocaine on neurotransmission
Cardiovascular: vasoconstriction, tachycardia, fetal arrhythmias
CNS: seizures
Pregnancy: fetal hypoxia, spontaneous abortion
Contrast primary and secondary malnutrition
Primary: components are missing form the diet, not eating something that you should be
Secondary: malabsorption, impaired utilization of storage or too much is lost. Too high a dietary need
Bowel diseases that won’t let you absorb things correctly.
Compare and contrast Marasmus and Kwashiorkor
Both are protein-energy malnutrition
Marasmus; somatic protein depletion; loss of muscle mass. Visceral protein is protected. Albumin is normal. Emaciation, anemia, vitamin deficiencies, immune deficiency (T -cell deficient)
Kwashiorkor: lack of protein > total caloric reaction. Loss of protein is in the visceral protein. Hypoalbuminemia leads to edema, which masks weight loss. Not enough albumin to maintain fluid balance. Lesions, hair changes, fatty liver, vitamin deficiency, immune defects.
Discuss the function, metabolism and clinical symptoms of deficiency of vitamin A
Functions:
Normal vision at low light (human vision) - night blindness
Differentiation of cells into mucus secretors - end up with metaplasia
Immunity (resistance to infection, diarrhea)
Light protective
Antioxidants
Metabolism:
Ingested in food -> absorbed in small intestine -> transported and stored in the liver -> transported to tissue RBP -> oxidized to retinoid acid in peripheral tissues
Deficiency: Night blindness Xerophthalmia Squamous metaplasia of URT Immune deficiency
Toxicity
Acute: hedge, vomiting, dizziness, blurred vision, stupor
Chronic: weight loss, anorexia, nausea, bone pain, joint pain, risk of fracture
Discuss the function, metabolism and clinical symptoms of deficiency of vitamin D
Function: maintaining normal plasma levels of Ca and P - important for bone maintenance Stimulates intestinal absorption of Ca Stimulates Ca resorption in the kidney Works with PTH to regulate blood Ca Promotes mineralization of bone
Metabolism:
Absorption or production -> alpha1 globulin binding and transport to liver -> conversation to 25-OH-D in liver -> conversion to 1,25-(OH)-D in kidney -> functions
Deficiency: Rickets (in children) Osteomalacia (in adults) Weakens nones More cartilage at the epiphysis - in children Masses of cartilage in marrow cavity Disrupted cartilage placement Too many capillaries and fibroblasts trying to heal weak and injured zones Deformation fo skeleton
Discuss the function, metabolism and clinical symptoms of deficiency of vitamin C
Functions: biosynthesis
Activation of enzymes that hydroxylated pro collagen, making for strong collagen
Antioxidant
Metabolism: Absorption
Deficiency:
Scurry - poor vessel support; bleeding from gums, skin, and joints
Impaired healing and adequate bone matrix formation
Define obesity
Increased body weight due to adipose tissue accumulation that is of sufficient magnitude to produce adverse health effects
List factors that may affect weight
Genetics Environment Psychologic Microbiome Biochemistry Location of fat stores
Discuss the function of leptin
Linked to fat stored being enough
Induces signals to reduce food intake and increase energy expenditure
Mutations can cause massive obesity
List clinical conditions that are linked to obesity
Insulin resistance High triglycerides and low HDL Certain cancers: esophagus, endometrium, gallbladder, kidney NASH (non-alcoholic steatohepatitis) Gallbladder stone increase Respiratory problems Osteoarthritis Inflammation (chronic)
List two essential roles of the microbiota in healthy individuals
Crowding out pathogens
Extracting energy and nutrients from food
Discuss ways that human micro biome research may eventually influence clinical practice
Clinical monitoring and maybe management of your microbiome
Briefly state the routes of entry microbes use to initiate infection
Opportunists take advantage of suppressed immune system Breaks in the skin Inhalation Ingestion Sexual transmission
List three ways microbes cause damage
Release enzymes that destroy tissue and allow spread of proteases in cancer cells
Release visions
Transport within nerves
Inflammation
Describe three characteristics of bacterial virulence
Virulence - how infectious it is; what amount will make you sick
Adherence to host cells
Invasion of host cells
Delivery of toxins
Explain how quorum sensing and biofilm formation can make bacteria more virulent
How bacteria communicate with each other. Bacterial communication regulates biofilm formation, swarming, toxin production
Biofilms are especially resistant to the immune system and antibiotic treatment: EPS
Give two examples of bacterial adherence which contributes to virulence
Wide groups of proteins called adherions.
Pili: E.coli N. gonorrheae
Protein F: strep. pyogenes
Describe how bacteria invade a cell
Take a ride on the immune system
Use complement/opsonization
Type III secretion system
Manipulates the cytoskeleton
Describe and give examples of five types of bacterial toxins
Bacterial endotoxins: LPS
Found on the outer-membrane of gram negative bacterial. Too much LPS sets of a cytokine storm - inflammation
Exotoxins: enzymes/proteases. Toxins that alter a signal or regulation of a pathway. Super antigens. Neurotoxins. Enterotoxins
Describe three situations when the host response to bacterial or viral infection causes damage
Granulomatous inflammation: TB
Liver damage in HBV, HCV
Post-streptococcal glomerulonephritis - immune complexes; causes kidney issues
Describe how microbes avoid detection by the host immune system
Antigen variation Manipulating the immune response (down regulating MHC and up regulating homologues) MHC-1 deletion causes escape from CD8+ Lack of MHC-1 causes NK cells to kill Resistance to innate defenses Resistance to AMPs Resistance to phagocytosis Viral fighting of interferons, blocking apoptosis
State two major groupings of viruses based on nucleic acid content.
RNA and DNA
Explain how a virus enters a cell
- Virus attaches tot he cell membrane through protein invaded in tropism
- Virus enters the cell
- Virus moves to the site of replication within the host cell. Virus genome is released
- Viral replication
- Viral assembly and maturation
- Viral release from the host cells (virions)
State the effects of a viral infection on a cell or tissue
Direct effects of virus on host cell:
Damage or kill
Persist without injuring (persistent infection)
Transform the cell (cancer)
Host tissue reactions to above changes
Lots of necrosis and inflammation
Responses of the immune system - acute phase response from the liver (systemic effect)
State one main outcome from an acute productive viral infection and the effects on the cell and host
Active replication is happening
New viruses are being released by lysis or apoptosis
Acute illness/fever/cell death
Clear or die
State the 4 situations that can results from the failure to eliminate a virus and what the effect is on the host
- Latency
- Chronic infection
- Persistent and slow infection
- Oncogenic outcomes
State the 3 types of interferons and their sources
INF-alpha (leukocytes) Type I
IFN-beta (fibroblasts) Type I
IFN-gamma (T lymphocytes) Type II
State the facts of interferons on a virus/virally infected cell
Interferons are specific.
Appear after infection
Inhibit viral replication
Triggers kinase activity which leads to transcription of genes that block viral infections
Does not inhibit viral attachment or entrance to the cell
Block mRNA translation by increases adenine trinucleotide which activates ribonuclease to cleave mRNA
Inactivates a protein initiation factor, inhibiting protein synthesis
Define and recognize tropism
Binding or viral surface proteins to specific host cells proteins
HIV and CD4+ cells
In HIV there is a lack of CD4+ cells due to the infection killing them
