Term
| What features contribute to infectivity and virulence? |
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Definition
| Gain access to body, avoid multiple host defenses, accomodate to growth in the human milieu, parasitize human resources |
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Term
| What characteristics of influenza viruses contribute to the generation of new strains frequently? |
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Definition
| RNA genome (inherently unstable), high mutation rate, genetic shift |
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Term
| Antibodies to which protein of HIV keep the virus in control? |
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Definition
| Env protein (gp120) - binds CD4, CXCR4 (on T lymphocytes), and CCR-5 (on many phagocytic cells) |
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Term
| How does VZV cause shingles? |
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Definition
| Virions inhaled by a nonimmune person, initially causes a "silent" infection of nasopharynx; progresses to viremia, seeding of fixed macrophages and dissemination of VZV to skin (chickenpox) and viscera. VZV resides in a dorsal spinal ganglion, where it remains dormant for many years. LATs (inactivates p53) reactivate VZV (stress, UV light, shock, other stimuli) and causes it to spread from ganglia along the sensory nerves to peripheral nerves of sensory dermatomes, causing shingles (Srini) - attacks dermatomes |
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Term
| What do VZV and HSV have in common? |
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Definition
| Similar skin lesions, latent and lytic cycles |
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Term
| "Strep throat" is caused by which bacterium, and which of its virulence factors prevents complement binding? |
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Definition
| S. pyogenes, M protein prevents complement binding |
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Term
| What are the two significant virulence factors of N. gonorrhoeae and how do they work? |
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Definition
| Pili - protease that digests IgA; also, can attach to sperm head |
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Term
| How does shigella prevent the recruitment of PMN to sites of infection? |
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Definition
| Blocks IL-8 transcription |
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Term
| What does cholera toxin do? |
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Definition
| Binds GM1 receptor --> activates GTPase --> activates Adenylyl cyclase --> >[cAMP] (shuttles Na and H20 - dumping water out of the cell) |
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Term
| How do clostridium species cause tetanus and botulism? |
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Definition
| Tetanus toxin induces Ach release; botulinum inhibits it (farther up the line) |
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Term
| Plaque, lyme disease, and typhus have what important feature in common? |
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Definition
| All rickettsiae (small, gram-negative, coccobacillary bacteria), all obligate intracellular pathogens, cannot replicate outside a host, insect vector, target endothelial cells of capillaries, produce a necrotizing vasculitis |
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Term
| Unlike bacteria and viruses, significant fungal infections are generally restricted to which group of individuals? |
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Definition
| Immunosuppressed - corticosteroid administration, antineoplastic therapy, congenital/acquired T-cell deficiencies |
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Term
| Malaria is caused by what type of infectious agent? |
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Definition
| Plasmodium (protozoa) - P. falciparum and P. vivax infect humans the most, with P. falciparum being the deadliest |
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Term
| What parasite is present in most if not all surface waters in the US? |
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Definition
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Term
| Ascariasis and shistosomiasis are significant worm diseases because? |
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Definition
| Both are helminth; low amounts not noticable, both mostly in areas with poor sanitation, ascarias causes massive weight loss because of nutrient siphoning, schistosomiasis causes massive inflammation and fibrosis in liver and bladder |
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Term
| What are the four categories of developmental and genetic diseases? |
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Definition
| Errors of morphogenesis, chromosomal abnormalities, single-gene defects, polygenic inherited diseases |
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Term
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Definition
| Teratogens are chemical, physical, and biological agents that cause developmental anomalies. Includes cytotoxic drugs, alcohol, some antiepileptic drugs, heavy metals, and thalidomide |
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Term
| What are the periods of sensitivity to teratogens for specific organs? |
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Definition
| Preimplantation (most cause death), early postimplantation (death common) |
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Term
| What is the TORCH complex? |
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Definition
| Toxoplasma (parasitic protozoa), Others, Rubella, Cytomegalovirus, Herpes simplex virus |
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Term
| What is RDS and why/how does it occur? |
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Definition
| Linked to a surfactant deficiency (reduces surface tension in alveoli - allows them to come apart from teach other after birth); this causes the alveoli to collapse and tear, leaking plasma into air spaces; plasma constituents (e.g. fibrinogen and albumin) will also bind surfactant and impair its function. Alveoli become perfused with blood, leading to hypoxia and acidosis, further compromising surfactant production by type II pneumocytes. Hypoxia also produces pulmonary arterial vasoconstriction, increasing right-to-left shunting in the heart, causing pulmonary ischemia, and further exacerbating damage |
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Term
| Review chromosomal nomenclature |
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Definition
| DEL - deletion; p - short arm, q - long arm; DEL(5q) - deletion on long arm of chromosome 5 |
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Term
| What are the chromosomal structural abnormalities? |
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Definition
| [image]Chromosomal translocation (acentric), Robertsonian translocation (acrocentric), chromosomal inversion, ring chromosome, intrachromosomal deletion |
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Term
| What are the outcomes on non-disjunction in meiosis I versus meiosis II? Which accounts for almost all trisomy 21? |
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Definition
| Meiosis I - (n+1)(n+1)(n-1)(n-1) function; meiosis II - (n+1)(n-1)(n)(n). Meiosis I nondisjunction responsible for 95% trisomy 21. |
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Term
| What are the four mechanisms of mutations in single gene abnormalities? |
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Definition
| Point mutation, deletion, insertion, trinucleotide expansion (frame shift) |
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Term
| What is the Sherman paradox and how does this relate to fragile X syndrome? |
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Definition
| Sherman paradox states that, with fragile X syndrome (CGG repetition), better off being F(1) rather than F(1+n); CGG is self-replicating, with >200 copies --> severe mental retardation (1/1250 men, 1/2500 women) |
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Term
| How does polygenic inheritance impact phenotype? |
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Definition
| Gives "shades of gray" rather than a binary phenotype |
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Term
| Which student presentations specifically identified genetic components and what was the evidence? |
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Definition
| Diabeetus (familial pattern, genetic predisposition to T1DM), thrombus formation (antithrombin deficiency, mutation in factor 5 protein), colorectal cancer (duh), asthma (IgA failure), irritable bowel syndrome |
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Term
| Which student presentations discussed an infectious agent as a significant influencing factor and what was the agent? |
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Definition
| Bacterial pneumonia (s. pneumonia), viral hepatitis (hep virus), myocardial inflammation (various agents), rheumatic heart disease (S. pyogenes) |
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Term
| Which student presentations discussed inflammation and how did it contribute? |
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Definition
| Stroke via thrombotic ischemic event, tylenol toxicity (inhibition of cyclooxygenase pathway, liver necrosis), bacterial pneumonia (monocyte/neutrophil invasion), thrombi (duh), viral hepatitis (inflammatory response to virions), myocardial inflammation (carditis), diabeetus (MAP kinase, systemic inflammation), asthma (Ab-mediated asthma pathway) |
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Term
| Which student presentations specifically discussed a role of the CNS or PNS and how was it involved? |
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Definition
| FAS (CNS attack by ethanol), stroke (duh), asthma (idiosyncratic - neuron-mediated) |
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Term
| In diabeetus, what are the 3 components of pathogenesis leading to hyperglycemia and what are the chief mechanisms of each? |
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Definition
| Loss of beta cells (autoimmune cell destruction), insulin resistance (receptor down-regulation), decreased insulin production (beta cells overwork themselves and die) |
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Term
| In asthma, what are the two types and how are they the same and different? |
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Definition
| Allergic - Ab-mediated; idiosyncratic - neuron-mediated; same symptoms, same treatment, slightly different prevention |
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Term
| In congestive heart failure, what is the role/relationship of the kidney to the disease? |
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Definition
| Renal retention --> higher BP --> increased workload on the heart |
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Term
| In IBD, what are the similarities and differences between Crohn's and Ulcerative Colitis? |
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Definition
| Crohn's is more severe, commonly having all symptoms; whereas UC usually will only occasionally have transmural involvement, strictures, and granulomas |
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Term
| In colon cancer, what are the categories of genes that are mutated? |
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Definition
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Term
| In Lobar Pneumonia, what are the four stages of morphologic changes? |
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Definition
| Congestion (vascular engorgement), red hepatization (accumulating fluid), grey hepatization (RBCs disintegrate, fibrin exodate), resolution |
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Term
| In thrombotic conditions, what is factor V leiden and how does it contribute to thrombosis? |
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Definition
| Mutation in factor V (thrombin formation cofactor, leiden is immune to degradation) gene, accumulation of fibrin |
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Term
| In RHD, how does an infection with S. pyogenes in the throat lead to heart valve dysfunction? |
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Definition
| Molecular mimicry between M protein epitopes and heart valve endothelium. Cross-reactivity --> inflammatory response against heart valves, invasion and neovascularization |
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Term
| In hepatitis, what accounts for liver cell necrosis? |
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Definition
| Infection of cells --> release of cytokines --> bystander effect of necrosis |
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Term
| In tylenol toxicity, how is it metabolized and how does the toxic form effect cells? |
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Definition
| Metabolized to NAPQI (affects mitochondria, increases cytosol [Ca2+]), causing cell necrosis |
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Term
| In FAS, how is alcohol thought to act? |
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Definition
| Disrupts neuron development, metabolites accumulate in brain, mostly frontal cortex damage |
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Term
| In stroke, what are the two types and what most likely accounts for the difference in stroke sensitivity? |
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Definition
| Ischemic and hemorrhagic, difference thought to be due to the difference in BP requirement. |
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