Micro Spring 2013 Block I – Flashcards

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question
What pathogen is responsible for the majority of UTIs?
answer
E. coli
question
What can increase the risk of ascending infection of UTIs?
answer
Use of a diaphragm and use of spermicides which increase vaginal colonization and adherence of E. coli and colonization of vagina with uropathogens
question
What is cystitis?
answer
Infection of the bladder wall
question
What are the symptoms of Cystitis?
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Frequency, urgency to urinate, dysuria, suprapubic tenderness, malodorous urine, bacteria and WBCs are common in urine
question
What is pyelonephritis?
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An infection of the kidney and renal pelvis, most commonly following a bladder infection
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What is present in the urine in cases of pyelonephritis?
answer
WBCs, cellular casts, bacteria, and protein
question
What is glomerulonephritis?
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Inflammation of the glomeruli in the nephrons
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How is glomerulonephritis detected?
answer
Glomerular capillary network becomes leaky allowing plasma protein and blood cells to be excreted in the urine
question
Acute prostatitis is often an extension of what?
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Bladder or urethra infection and often follows urethral instrumentation such as catheterization
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What are pathogenicity islands?
answer
Genes for these virulence factors are linked together as multigene segments. Encodes for virulence protiens which are components of finbriae, pili, and outermembrane proteins
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What determines anatomical location of infection?
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Adhesive properties of virulence factors
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Pathogenicity islands are absent in what?
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Normal, fecal coliforms
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Pathogenicity islands are similar to plasmids in that they're what?
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Mobile
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Describe the appearance of E. coli
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Gram-negative rods
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What is the pathogenicity of E. coli?
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Adhere to mucosa via pili, causes tissue damage, endotoxin (LPS) causes inflammation
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How is E. coli treated?
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Penicillin or ciprofloxacin
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What is the function of the P-pilli for E. coli?
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allows bacteria to bind to P blood group antigens on urinary tract cells, especially kidneys
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What is the function of Type I pilli for E. coli?
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allows bacteria to bind to bladder, epithelium, and glycoproteins in various cells
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What is the function of the K1 antigen for E. coli?
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Impedes phagocytosis
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Describe the appearance of Proteus vulgaris and mirabilis
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Gram-negative rods
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What are the characteristics of Prtoeus vulgaris and mirabilis?
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Opportunistic, transmitted via catheters, uerase positive and HIGHLY MOTILE, can swarm across agar
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What is the second most common cause of UTIs behind E. coli?
answer
Proteus
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What is critical to the virulence of Proteus?
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Swarming ability
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How does Proteus precipitate the formation of calculi?
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Urease activity raises pH
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What anti-swarming agent can be used to inhibit the expression of virulence factors in Proteus?
answer
Para-nitrophenyl glycerol (PNPG)
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What is used to treat Proteus causing UTIs?
answer
Broad spectrum penicillins and cephalosporins
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Proteus shows resistance to what drugs?
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Nitrofurantoin and tetracycline
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Describe the appearance of Stpahylococcus saprophyticus
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Gram positive cocci
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What are the characteristics of Staphylococcus saprophyticus?
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Nitrate and coagulase NEGATIVE
Catalase POSITIVE
Novobiocin RESISTANT
Nonhemolytic --> gamma-hemolysis
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Enterococcus faecalis can cause what types of maladies?
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Endocarditis, cystitis, wound infections
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Enterococcus faecalis is grown on what media?
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Blood agar (gamma hemolysis) and Bile-esculin agar (causes black discoloration)
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How is Enterococcus faecalis trated?
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Amoxicillin, Ampicillin, Vancomycin
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Describe the appearance of Klebsiella
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Gram negative rods, non-motile, forms large MUCOID colonies
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What protects Klebsiella from phagocytosis?
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K antigen
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What is used to treat Klebsiella infections?
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Cephalosporins
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What can increase the risk of Candida infections?
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Broad-spectrum antibiotics, pregnancy, diabetes, AIDS, surgery, indwelling catheters
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What most often causes a Candida infection
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Use of antibiotics that kill normal flora allow for infection
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What is used to treat Candida infections?
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Topical nystatin or clotrimazole
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What is necessary for Candida virulence?
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Germ tube formation which is induced by D-glucose and a pH of 7-8
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What is th emost common site of nosocomial infections?
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Catheter associated UTIs
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The isolation of what pathogens would imply acquisition from an exogenous source due to their absence in normal GI flora?
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Serratia marcescens and Pseudomonas cepacia
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The majority of catheter associated UTIs are due to what?
answer
Endogenous bowel flora
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What might lead to precipitation of phosphatic salts, stone formation and eventual blockage due to growth on catheters?
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Microorganisms such as Proteus mirabilis
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A UTI caused by Schistosoma haematobium can lead to what?
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Renal failure due to obstructive uropathy, pyelonephritis, bladder carcinoma, may vacilitate the spread of STDs due to causative lesions
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How do you diagnose Schistosoma haematobium?
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Identify and speciate eggs in the urine over a 24hr urine collection. Watch for hasting at room temp if necessary
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How do you treat Schistosoma haematobium?
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Antihelmintics --> Praziquantel
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Dark brown to red urine suggests the possible presence of what?
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Porphyrins
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Black-brown urine suggests the presence of what?
answer
Melanins
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What is used to detect nitrites in urine?
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Griess' Reaction
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What do nitrites in urine indicate?
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Bacteriuria, though not all bacteria convert nitrate to nitrite, mostly gram-negatives
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The presence of leukocytes in urine indicates what?
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Leykocyte esterase activity in WBCs
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Blood in the urine indicates what?
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Pseudoperoxidase activity of hemoglobin
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How does yeast present in urine?
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Does not come up in lab testing, requires microscopic evaluation
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Hyaline casts in urine indicate what?
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Capillary membrane damage with proteinuria
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Most UTIs are treated with what?
answer
Amoxicillin (TMP-SX) and levaquin (fluoroquinolone)
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How are UTI's caused by chlamydia and mycoplasma treated?
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Tetracycline or doxycycline
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Nonsecreters are at higher risk for UTIs. How is secretion genetically determined?
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Presence of secretor gene (Se) is inherited independent of ABO and H genes responsible for A, B, and H antigens that are secreted. However, the H-gene is a necessary precursor for ABO, so all seretors will have the H gene
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Type I hypersensitivity reactions are mediated by what?
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IgE --> allergy, anaphylaxix, asthma, an immune response releases vasoactive and spasmogenic substances that act on vessels and smooth muscles
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Type II hypersensitivity reactions are mediated by what?
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Antibodies, promotes cell phagocytosis or lysis and cellular injury by inducing inflammation
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What are the classic examples of Type II hypersensitivity?
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Autoimmune hemolytic anemia and Goodpasture's syndrome
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How is Goodpasture's diagnosed?
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Antibody targeting non-collagenous domain of type IV collagen
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Type II hypersensitivity reactions always present in what way?
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Always localized, antigen is always fixed or bound to either cell, tissue, or ECM
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Type III hypersensitivity reactions are mediated by what?
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Immune response, antigen is NOT fixed, binds antibodies and induces inflammation, recruites leukocytes, is almost NEVER localized
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What is the only type III hypersensitivity reaction that is localized?
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Arthus reaction (Tetanus reaction)
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Type IV hypersensitivity reaction is mediated by what?
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Cell-mediated immune disorder via sensitized T-lymphocutes, Th1 lymphocytes/CD4, etc. Ex. contact dermatitis, MULTIPLE SCLEROSIS, type I diabetes, transplant rejection, tuberculosis
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What are the 3 criteria of autoimmune dissorders?
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Presence of autoimmune reaction
Evidence that it is not secondary to tissue damage
The absence of another well defined cause of the disease
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What is the dominant genetic factor that affects susceptibility to autoimmune disease/
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HLA
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Reactive arthritis is associated with what gene?
answer
HLA-B27
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What is central tolerance?
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Development of tolerance to self-antigens when encountered in PRIMARY sites of maturation such as lymphoid organs
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What is the function of AIRE (autoimmune regulator gene) in central tolerance?
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Encodes a transcription factor that normally induces hundreds of genes in the cells of peripheral tissues as well as the thymus which are recognized by T lymphocytes that then undergo NEGATIVE SELECTION, leaving only T-cells that do not recognize the self proteins
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A defective AIRE gene gives rise to what?
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Inherited autoimmune polyglandular disease (APD)
or
autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED)
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What is peripheral tolerance?
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Development of tolerance when mature lymphocytes encounte rself-antigens in peripheral tissues
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What is anergy?
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Prolonged or irreversible functional inactivation of lymphocytes that encounter antigens in the periphery under specific conditions. A component of peripheral tolerance
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What is required for anergy?
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In absence of a second signal (CD28/B7)
OR
Inhibitory signal mediated via CTLA4/B7 interaction
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Where do regulatory T cells develop?
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In the thymus or in the periphery via recognition of self-antigens
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What mediates the development of regulatory T cells?
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IL-10 or TGF-beta secretion
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What gene is required for the development of regulatory T cells?
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Foxp3 gene
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A mutation in the Foxp3 gene causes what
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IPEX = immune dysregulation, polyendocrinopathy, enteropathy, X-linked
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How do regulatory T cells suppress autoreactive T cells?
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They recognize autoantigens presented in the context of MHC-II molecules
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What facilitates clonal deletion in peripheral tolerance?
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Fas/GasL interaction expressed by activated T cells that recognize self antigens, leads to apoptosis
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Mutation of the Fas gene results in what?
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ALPS = autoimmune lymphoproliferative syndrome
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What are the characteristics of ALPs?
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Lacks Fas molecules, cannot control size of lymphocyte population or remove autoimmune cells, secondary lymphoid organs cell and autoimmune reactions occur
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What are immune privileged sites?
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Tissues wher eantigens are hidden from the immune system due to lack of communication with blood and lymph.
e.g. testes, eye, brain
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How does sympathetic opthalmia occur?
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Trauma to one eye results in release of intraocular protein antigens which are carried to lymph nodes and activate T cells. Effector T cells return and attack antigen in both eyes
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When immature B lymphocytes interact strongly wit self-antigens in the bone marrow, B cells are deleted via what process?
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Clonal deletion induces apoptosis
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What is clonal anergy?
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Autoreactive B cells in lymph nodes fail to receive T cell help or enter primary lymphoid follicles, are trapped in T cell zone and undergo apoptosis. When the migrate to periphery, they remain anergic, encounter T cell specific their autoantigens, and activates Fas/FasL to induce apoptosis
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As a rule, autoimmune diseases are never caused by what immunoglobulin complex?
answer
IgE
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The formation and deposition of soluble immune complexes in autoimmune disease corresponds to what type of hypersensitivity?
answer
Type III
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What causes complement activation leading to autoimmune hemolytic anemia?
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IgG and IgM abs binding to components of erythrocyte surfaces
question
What are the 3 different means of RBC destruction in autoimmune hemolytic anemia following IgG/IgM binding induced complement activation?
answer
FcR+ cells in the spleen inducing phagocytosis
Complement activation and CR1+ cells in the spleen inducing phagocytosis
Complement activation and intravascylar hemolysis
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An uncommon autoimmune disease characterized by the presence of circulating autoantibodies targeting non-collagenous domains of the alpha-3 chain of type IV collagen is known as what?
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Goodpasture Syndrome
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The autoantibody targeting the alpha-3 chain of type IV collagen seen in Goodpasture Syndrome intiates inflammatory destruction of what?
answer
Basement membranes in renal glomeruli and lung alveoli
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How do you diagnose Goodpasture's syndrome?
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Linear IgG deposition on glomerular basement membranes and alveolar membranes detected by immmunofluorescence and the presence of anti-basememt membrane antibodies in the serum
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Both Goodpasture's and SLE autoantibodies show up on immunoflourescence. How are they distinguished?
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GPS is smooth, linear while SLE is lumpy/bumpy
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How is Goodpasture's treated?
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Primarily via **plasmapheresis.
Also can prescribe *prednisone for immunosuppression of new Ab formation
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An autoimmune blistering disease that results from a loss of normal intracellular attachment integrity is known as what?
answer
Pemphigus
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What is the most common typ eof pemphigus?
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Pemphigus vulgaris
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How does pemphigus present?
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Initialy as oral ulcers that progresses to skin involvement. Primary superficial vesicles and bullae that rupture easily and leave shallow erosions covered with crust
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What is the main complication of pemphigus?
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Secondary bacterial infection and EXTREME loss of fluid**
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Which strain of pemphigus is wart-like and presents on the axilla, groin, and flexure surfaces?
answer
Pemphigus vegetans
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Which strain of pemphigus is benign and shows up on the scalp, face, chest, and back with a lack of bullae due to fragility?
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Pemphigus foliaceus
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Which strain of pemphigus is less severe and involves the malar area in lupus-like fashion?
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Pemphigus erythematous
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Pemphigus involves acantholysis which is the loss of attachment of what?
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Attachment between keratinocytes due to deposition of Abs against desmosomes**
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Pemphigus foliaceus deposits Abs that react with what?
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Desmoglein-1 present in the superficial layers of the epidermis
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Pemphigus vulgaris, the most common cause of pemphigus, deposits Abs that react with what?
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Desmoglein-3** present in deeper layers of the epidermis
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Rheumatic fever is a complication of what?
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Infection by Streptococcal pharyngitis or Streptococcal pyogenes
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What is the Jone's criteria of diagnosis?
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2 major or 1 major + 2 minor criteria to confirm rheumatic fever
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What are the major Jone's criteria?
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Carditis, arthritis, chorea, subcutaneous nodules, arythema marginatum
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What are the minor Jone's criteria?
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Fever, joint pain, evidence of electrical changes in the heart
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How do you treat Rheymatic fever?
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10 day course of penicillin
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Rheumatic fever most commonly damages which valves?
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Mitral (most common), aortic (2nd most common)
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A hyperthyroid state due to an autoimmune abs acting as agonists on TSH receptors is known as what?
answer
Grave's disease
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Grave's disease is biased towards which thyroid response?
answer
TH2
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Graves disease commonly has what secondary manifestation?
answer
Hypertension
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Grave's disease is associated with what disease?
answer
HLA-B6 and HLA-DR3
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Most patients with Grave's disease have what antibody in their plasma?
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TSH:receptor ab
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What are the symptoms of Grave's disease?
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Heat intolerance, nervouseness, irritability, weight loss, BULGING EYES, pretibial myxedema, tremor, enlarged thyroid
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What causes exophthalmous bulging eyes in Grave's disease?
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Increased volume of retro-orbital connective tissue and extraocular muscle due to proteoglycan and HA accumulation
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Graves disease shows what labs?
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Inc T3 and T4, dec TSH, increased TSH-r Ab and ANA levels w/o evidence of SLE
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How do you treat Grave's disease?
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Propranolol (symptomatic), Methimazole and Propylthiouracil (thyourea drugs) or thyroidectomy/ablation
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What disease is characterized as an autoimmune reaction against thyroid cells causing thyroid destruction and a hypothyroid condition?
answer
Hashimoto's Thyroiditis
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Hashimoto's Thyroiditis is notable in among thyroid disorders in that it is what?
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Most common thyroid disorder in the US
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How does Hashimoto's Thyroioditis usually occur?
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Infection or non-specific inflammation causes IGN-gamma to induce HLA II, a normally absent molecule, to be expressed on thyroid cells. Specific T cells induce an autoimmune response
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What are the symptoms of Hashimoto's Thyroiditis?
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Enlarged thyroid, depression, fatigue, dry mouth, dry eyes, thyroid antibodies
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What thyroid antibodies can be seen in Hashimoto's thyroiditis?
answer
Antithyroid peroxidase** (90%)
Antithyroidglobulin** (40%)
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How is Hashimoto's thyroiditis treated?
answer
Synthetic thyroid
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Myasthenia Gravis is characterized by what?
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Blockade of AcH receptor by autoantibodies resulting in progressive muscle weakness
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What are the symptoms of myasthenia gravis?
answer
Dropy eyelids and double vision progressing to muscle weakness in the face to the trunk and extremities with possible breathing difficulty
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How is myasthenia gravis diagnosed?
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AcH ab detection and edrophonium test
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Type III hypersensitivity (immune-complex) is most often associated with what diseases?
answer
SLE and Hepatitis
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What is characteristic of SLE?
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Autoimmune response directed at autoantigens present in almost every cell in the body, has characteristic IgG abs which initiate inflammation, tissue destruction, and the release of soluble immune complexes
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How does SLE present?
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Butterfly shaped skin rash on face resembling a "wolf's head" due to deposition of immune complexes, may be provoked by sunlight
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What are the 2 most common symptoms of SLE?
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Glomerulonephritis and arthritis
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How does SLE cause glomerulonephritis?
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Hypercellularity due to proliferation of mesengial cells and endothelial cells in response to antigen-ab complex deposition
question
How is SLE diagnosed?
answer
40-60% have anti-DNA ab, 95% ANA-ab but this is NONSPECIFIC, 20-30% have anti-Sm (smith antigen), typically have HIGH IgG and LOW C3/C4
question
What drugs can induce SLE-like responses?
answer
Hydrallazin, Procainamide, D-peniccillamine, Isoniazid
question
How does intermolecular epitope spreading of SLE occur?
answer
Q-specific T-cell recognizes same epitope present by MHC-II on all 3 types of B cells (P, Q, R).
The reverse with B cells and P, Q, R T-cells canalso occur, helps recognize same epitope on different antigens
question
How is SLE treated?
answer
High dose of Prednisone
question
How is Chronic Discoid SLE different from classic SLE?
answer
Mimics skin manifestations by systemic manifestations are rare, anti-DNA ab is rarely present
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Skin biopsy shows deposition of what in pt with chronic discoid SLE?
answer
IgG and C3 at dermoepidermal junction (same as classic SLE)
question
How is subacute cutaneous lupus erythematosus differentiated from discoid lupus erythematosus?
answer
Rashes are widespread, superficial, nonscarring, has mild systemic symptoms consistent with SLE, strong association with Abs to SS-A antigen with HLA-DR3 genotype
question
Drug induced lupus has an extremely high frequency of what antibody?
answer
Anti-histone antibody
question
Drug induced lupus is associated with what gene?
answer
HLA-DR4 allele
question
What bacteria can cause acute glomerulonephritis?
answer
A complication of S. pyogenes infection
question
Which types of S. pyogenes is nephrogenic?
answer
GAS type 12, 3, and 1*****
Identification done based on M protein typing
question
What characterizes Polyarteritis Nodosa (PAN)?
answer
Necrotizing inflammation of the walls of small/medium sized arteries (NO VEINS)
question
Polyarteritis Nodosa is most likely associated with what diseases?
answer
HepB and CMV
question
How is Polyarteritis Nodosa distinguished from Wegener's?
answer
Wegener's involves the lungs, PAN does not
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What are the important type IV hypersensitivity/autoimmunity (T-cell mediated) diseases?
answer
Type I diabetes, rheumatoid arthrytis, myltiple sclerosis, celiac disease
question
What is the cause of Type I diabetes?
answer
Insulin an dglutamic acid decarboxylase (GAD) act as an antigen for T cell responses (type IV hypersensitivity)
question
What viral pathogen may possibly increase the risk of type I diabetes?
answer
Rubella
question
How is type I diabetes treated?
answer
Daily insulin injection
question
What is the cause of multiple sclerosis?
answer
Autoimmune response against the myelin sheath of nerve cells causes demyelination of neuronal tissues in the white matter of the CNS (type IV hypersensitivity), causes sclerotic plaques
question
What are the causative antigens for multiple sclerosis?
answer
All found in the myelin sheath:
Myelin basic protein
Proteolipid protein
Myelin oligodendrocyte glycoprotein
question
Multiple sclerosis is associated with what gene?
answer
HLADR2
question
How is multiple sclerosis treated?
answer
Initially with immunosuppressive drugs (corticosteroids) and injections of IFN-beta to prevent disease progression.
Later more aggressive immunosuppressives such as cyclophosphamides are added alongside corticosteroids
question
What is the cause of rheumatoid arthritis?
answer
A chronic systemic inflammatory disorder of unknown cause that principally attacks joints via inflammatory synovitis, causing permanent damage and ankylosis (bone fusion). A type IV hypersensitivity reaction
question
What is rheumatoid factor?
answer
Antiimmunoglobulin antibodies that are produced against the Fc portion of human IgG. Not diagnostic, though prevalent in rheumatoid arthritis
question
What is the classical presentation of patietns with rheymatoid arthritis?
answer
Affects proximal inter-phalangeal joints with polyarthritic fusiform swelling, is SYMMETRICAL, affects all hand and feet joints in chronic advanced stage
question
What is the pathological hallmark of Rheumatoid arthritis?
answer
Pannus formation: a mass of synovial stroma consisting of inflammatory cells growing over articular cartilage that causes bone and joint destruction
question
What are the major agents involved in pannus formation seen in rheumatoid arthritis?
answer
Cytokines IL-1 and TNF-alpha produced by macrophages and activated T cells induce inflammation
question
What activates osteoclasts and promotes bone destruction in rheumatoid arthritis?
answer
Activated T cells and synovial fibroblasts producing RANKL, contributes to pannus formation
question
What are rheumatoid nodules?
answer
Formations on the extensor surface of bone that are loosely affixed to underlying boney surface
question
How is rheumatoid arthritis diagnosed?
answer
4 out of 7 criteria:
Morning stiffness
Arthritis in 3+ joint areas
Arhtritis in typical hand joints
Symmetric arthritis
Rheumatoid nodules
Serum rh factor
Typical radiographic changes
question
How is rheumatoid arthritis treated?
answer
Anti-inflammatory drugs, immunosuppression, antibodies against TNF-alpha, and physiotherapy
question
What causes celiac disease?
answer
Specific lesions of small intestines due to abnormal immune responses to gluten protein present in wheat (type IV hypersensitivity)
question
What genes are associated with celiac disease?
answer
HLA-DQ2 and HLA-DQ8
question
T cells in celiac disease have receptors directed against what?
answer
Tissue transglutaminase complexes and proline-rich 33 amino-acid fragments, causes inflammation
question
All patients with celiac disease have autoantibodies specific for what?
answer
Tissue transglutaminase
Many also have anti-gliadin antibodies
question
What are the symptoms of celiac disease?
answer
Diarrhea, flatulence, weight loss, fatigue, malnutrition, some skin manifestations are possible, adults become anemic and depressive, prone to intestinal cancer, children fail to thrive
question
How is celiac disease treated?
answer
Gluten free diet
question
What is the classic characteristic of Sjogrens syndrome
answer
Dry eyes and dry mouth
question
What causes Sjogrens Syndrome?
answer
Lymphocitic infiltration of T cells and fibrosis of the lacrimal and salivary glands (type IV hypersensitivity reaction)
question
What autoantibodies are present in Sjogrens?
answer
Rh factor, ANAs, SS-A, and SS-B (not diagnostic, all are also present in SLE)
question
What are the symptoms of Sjogrens?
answer
Blurred vision, burning, itching, and accumulation of ocular secretions, cerostomia causes difficulty swallowing, reduced taste, enlarged parotid gland, dry mucosa, peripheral neuropathy
question
How is Sjogrens treated?
answer
Symptomatic care, supportive care, artificial tears, sipping water, cholinesterase inhibitors and Ach derivatives may improve xerostomia
question
White lesions unlike oral candiasis that cannot be removed by rubbing are what?
answer
Leukoplakia
question
Leukoplakia with an erythematous component is known as what?
answer
Erththroplakia
question
Lacy leukoplakia that may be erosive which requires a biopsy for diagnosis is known as what?
answer
Oral lichen planus
question
Leukoplakia that eventually invades into the tongue mass is known as what?
answer
Oral cancer
question
What causes leukoplakias?
answer
Chronic irritations from tobacco, dentures, excessive alcohol
question
The majority of erythroplasias are either what?
answer
Dysplasia or carcinoma
question
How is oral lichen planus treated?
answer
Corticosteroids, Cyclosporines, Retinoids
question
What are some predisposing conditions for oral candidiasis?
answer
Oral dentures, chronic debilitating disease, diabetes melitus, chronic anemia, chemotherapy, immunosuppression
question
How is Candida albicans diagnosed?
answer
Spore, non-septate hyphae, pseudo phyphae, and germ tube identification
question
How is Candida albicans treated?
answer
Locally via nystatin mouth rinse and systemically with fluconazole or itraconazole if fluconazole resistant
question
What is glossitis?
answer
Inflammation of the tongue with loss of filiform papillae leading to a red, smooth surfaced tongue
question
Glossitis is usually secondary to what?
answer
Nutritional deficiency, drug reaction to ACE inhibitors, dehydration, irritants, autoimmune reactions such as Sjogrens or psoriasis
question
Acute Necrotizing Ulcerative Gingivitis (ANUG or Trench Mouth) is found among whom?
answer
Young individuals under stressful conditions caused by mixed bacterial infections
question
What are the characteristics of ANUG/Trench mouth?
answer
Painful gingival inflammation and necrosis, bleeding, halitosis, fever, cervical lymphadenopathy
question
Synergistic infections between what types of pathogens is typical of ANUG/Trench mouth?
answer
Spirochetes and anaerobic bacteria such as Fusobacterium
question
What causes ANUG/trench mouth?
answer
Stress, malnutrition, or immunodeficiency. Not contagious
question
Fusobacterium pathogenesis is mediated by what?
answer
LPS
question
How is ANUG/trench mouth treated?
answer
Clinamycin and 3rd gen Cephalosporin
question
Aphthous ulcers/cancer sores/ulcerative stomatitis is caused by what?
answer
Uncertain, though association with HHV6 is suggested
question
Where are cancer sores found?
answer
Non-karatinized mucosa, buccal and labial mucosa, NOT on gingiva or palate
question
What do cancer sores look like?
answer
Painful ulcers with irregular margin and yellow-grey fibrinoid center surrounded by red halo**
question
Cancer sores occur in relation to what?
answer
Stress
question
How are Aphthous ulcers/cancer sores/ulcerative stomatitis treated?
answer
Nonspecific, topical corticosteroids, oral prednisolone, thalidomide if recurrent in HIV patients**
question
What is noma, aka cancrum oris?
answer
Severe gangrenous stomatitis progressing beyond the mucus membrane to involve soft tissue, skin, and ocasionaly bone
question
What types of patients exhibit noma (cancrum oris)
answer
Severely debilitates patietns and people with poor oral hygiene, immunocompromised, malnourished, sometimes precipitated by measles
question
What are the etiologic agents of noma/cancrum oris?
answer
Fusobacterium, Bacteroides, and P. aeruginosa
question
What are the 3 clinical forms of oral herpes simplex?
answer
Recurrent small blisters on the lips (aka herpes labialis, most common type)
Generalized oral infections (aka herpetic stomatitis)
Small ulcers found on the palatal mucosa
question
What causes hand foot mouth disease in children under age 6?
answer
Coxsackie virus type A16
question
How do you treat herpetic stomatitis?
answer
Acyclovir
question
What causes pharyngitis?
answer
An infection of the pharyngeal mucosa, most often viral (though bacterial is possible as well)
question
Which viruses are most likely to case pharyngitis?
answer
Rhinovirus, coronavirus, adenovirus, influenza, and EBV
question
What findings suggest a viral cause of pharyngitis?
answer
Mild pharyngeal symptoms with rhinorrhea, exudative pharyngitis, vesicular lesions and ulcers, conjunctival congestion, generalized rashes
question
What symptoms indicate a streptococcal infection behind pharyngitis?
answer
Fever, tender anterior cervical adenopathy, LACK OF COUGH, phayngeotonsillar exudate (3 or more to be likely)
question
Sreptococcus pharyngitis has what morphology?
answer
Gram positive oval cells growing in CHAINS, non-motile, lactic acid fermetator
question
Streptococcus pharyngitis grows best on what medium?
answer
Enriched blood agar
question
The virulence of Streptococcus pyogenes is mediated by what?
answer
Cell wall components, primarily M12 protein
question
What test can you use to quickly verify a strep infection?
answer
Rapid strep test or GAS rapid antigen detection test (RADT)
These are solid phase ELISA tests
question
How is Streptococcus pharyngitis treated?
answer
Penicillin is first line, amoxicillin plus clavulanate to avoid failure with penicillin, erythromycin and second gen cephalosporin if penicillin sensitive
question
What causes diptheria?
answer
Corynebacterium diphtheriae
question
What is the morphology of C. diphtheria?
answer
Gram positive rod, non motile, exhibits CHINESE LETTER PATTERN, catalase positive
question
What is the most characteristic feature of diphtheria?
answer
Greyish-white membrane on the tonsiles that adheres to the underlying tonsils and is not easily removed, is made up of clotted blood and epithelial cells of host mucus membrane
question
The exotoxins of C. diphtheria are also found in what other pathogen?
answer
Pseudomonas
question
How is diphtheria diagnosed?
answer
Clinical diagnosis
Definitive diagnosis via culturing on Tinsdale and Tellurite agar
question
How is Diphtheria treated?
answer
Diphtheria toxin anti-serum alongside penicillin or erythromycin. High mortality even with treatment
question
Describe the pathogenesis of Rhinoviruses
answer
Infects respiratory epithelium, causing them to lose their ciliary motion and slough off, injury causes inflammation, inducing acute symptoms. Inflammation eventually contains the infection
question
How is rihnovirus treated?
answer
Pleconaril is in trials, usually self limiting
question
Describe the morphology of adenovirus
answer
Non enveloped double stranded DNA virus that can remain infectious in environments for long periods but is easily inactivated by heat, chlorine, and disinfectants
question
What are the symptoms of adenoviral pharyngitis?
answer
Fever, runny nose, grey-white pus on pharynx and tonsils, enlarged cervical lymph nodes, conjunctivitis, and diarrhea
question
What symptom is present in adenoviral pharyngitis that is absent in the common cold?
answer
Enlarged cervical lymph nodes
question
How is adenovirus diagnosed?
answer
Lung biopsy and serologic testing
question
How is adenovirus treated?
answer
Self limiting
question
Describe the morphology of coronavirus
answer
Enveloped RNA virus with petal or club shaped spikes projecting from its surface giving it the appearance of a crown of thorns
question
What are the 3 types of human coronavirus?
answer
Etiologic agent for the common cold
Enteric infections in the intestines
Agent of severe acute respiratory distress syndrome (SARS)
question
What is essential for the diagnosis of pharyngitis?
answer
Pharyngeal pain and pain on swallowing (odynophagia)
question
When should a lateral neck X-ray be performed when suspecting pharyngitis?
answer
If pt has stridor or respiratory compromise to rule out laryngeal obstructions
question
What are the characteristics of Kawasaki's disease?
answer
Mucocutaneous lymph node syndrome most commonly affecting asian children younger than 5
question
What are the disease characteristics of Kawasaki's disease
answer
Fever and four of the following for at least 5 days: Mucous membrane changes (injected pharynx, erythema, or strawberry tongue) Peripheral extremity changes (edema, desquamination, erythema, induration) A polymorphous rash Cervical lymphadenopathy Bilateral nonexudative conjunctivitis
question
When do you intervene with warfarin in cases of kawasaki's disease?
answer
If an aneurysm larger than 8mm in diameter occurs
question
What are the possible complications of bacterial pharyngitis?
answer
Peritonsillar or retropharyngeal abscesses, jugular vein thrombosis, rheymatic heart disease, post-streptococcal GN, acute airway obstruction, myocarditis, neuritis
question
What are some possible viral pharyngitis?
answer
Secondary bacterial infection
question
A peritonsillar or retrotonsillar abscess indicates what type of infection? Characteristics?
answer
Bacterial, usually as a complication of tonsillitis
Tonsils should be ASYMMETRICAL, common ABOVE 5yo
There is a danger of rupture and aspiration pneumonia
question
A retropharyngial or lateral pharyngeal abscess arises due to what?
answer
A complication of bacterial pharyngitis or accidental perforation of the pharyngeal wall by a foreign body, characterized by pain, inability to swallow, phonation change, and extended neck w/widened space
Can rupture --> aspiration pneumonia, also osteomyelitis or acute mediastinitis
Seen UNDER 5yo
question
What kind of x-ray finding do you see in a retropharyngeal/lateral pharyngeal abscess?
answer
Widening of space between cervical spine and posterior pharyngeal wall
question
What is first line in treatment of pharyngitis in children?
answer
Oral penicillin or amoxicillin in
question
What 2nd and 3rd line in treatment of pharyngitis in children?
answer
Erythromycin, if penicillin allergic giv clarithromycin, azithromycin, or an oral cephalosporin
question
What are the symptoms of rhinnitis?
answer
**Headache**
Nasal congestion, post-nasal drainage (clear), Watery rhinorrhea, Sneezing
Scratchy throat, pharyngotonsilar irritation (from drainage), General malaise
question
Why do sinus infections occur?
answer
When blockage occurs due to upper respiratory infection or viral rhinitis, the bacteria cannot be removed and are able to grow in numbers and cause an infection
question
The change from rhinitis to sinusitis is marked by what?
answer
Change from clear and watery to mucoid (yelow/green) rhinorrhea, marks the growth of the first aerobic bacteria
question
How often are cases of bacterial sinusitis polymicrobial?
answer
1/3
question
What fungal pathogens are possible (rare) causes of sinusitis?
answer
Candida spp.
Aspergillus spp.
Mucor spp.
Rhizopus spp.
Absidia spp
question
What are the symptoms of acute sinusitis?
answer
Usually of bacterial origin (aerobes anaerobes)
More dental pain
Children rarely complain of headache or facial pain
Nasal discharge, congestion, facial pressure, postnasal drip, fever, cough, fatigue, ear pressure
question
How is sinusitis linked to smoking?
answer
H. influenza growth is stimulated by nicotine, thereby exacerbating infection in smokers
question
What are risk factors for sinusitis?
answer
Allergic rhinitis, Nasal trauma (including deviated septum), Immune compromised/diabetic, Smoking, Swimming/barotrauma, Nasal polyps, Cocaine abuse
question
How might Pseudomonas aeruginosa give someone sinusitis in a hospital setting?
answer
Common as a nosocomial infection from nasal tubes or catheters
question
What pathogen most commonly infects nasal passage hair follicles during a sinus infection?
answer
Staphylococcus aureus
question
What is the potential complication of fungal sinusitis?
answer
If invasive, will spread into CNS and eyes
question
Which strains of fungi that cause sinusitis are invasive?
answer
? Rhizopus spp., Mucor spp., Absidia spp.
question
What is the most common complication of bacterial sinusitis?
answer
Preorbital swelling
question
What are some less common complications of bacterial sinusitis?
answer
Orbital cellulitis
Subperiosteal abscess
Orbital abscess
Frontal and maxillary osteomyelitis
Subdural abscess
Cavernous sinus thrombosis
Meningitis
Brain abscess
question
How is sinusitis diagnosed?
answer
Clinical diagnosis. Cultures and x-rays are useless. MRI and CTscans may be useful in chronic or rare cases.
Only clear useful diagnostic is transilumination
question
How do viral and bacterial cases of sinusitis differ?
answer
Fungal infections may affect only one sinus.
Poor response to nasal decongestants (bacterial).
question
What are the two sites of ear infection?
answer
Otitis externa and Otitis media
question
How are ear infections contracted?
answer
Individual is exposed to environment that inhibits or removes cerumen and may also contain pathogens
question
What causes ear infections?
answer
98% of cases are bacterial
Pseudomonas aeruginosa (20-60%)
Staphylococcus aureus (10-70%)
Often polymicrobial
question
What is the hallmark sign of acute otitis externa ("swimmer's ear")?
answer
Tenderness of the tragus (when pushed), pinna (when pulled up and back), or both
question
What are the symptoms of otitis externa ("swimmer's ear")?
answer
Otalgia (70%), Itching (60%), fullness (22%), hearing loss (32%)
question
What was furunculosis?
answer
Infected hair follicle in outer third of ear canal, most commonly due to Staph aureus
question
What is otomycosis?
answer
Fungal infection of the ear canal, aka "tropical ear"
Common in humid or tropical environments
Causes: Aspergillus (60-90%), Candida spp. (10-40%)
question
What are the symptoms of otomycosis?
answer
Pruritis and thickened otorrhea (black, green, white)
question
How do you distinguish otitis externa from otitis media?
answer
Pneumatic otoscopy should show good tympanic membrane motion in AOE and absent or limited mobility in AOM
Yellow/green = acute otitis media
question
What is malignant Otitis Externa?
answer
A complication of acute otitis externa seen in elderly, diabetics, or immune compromised
Spreads to posterior cranial bone (osteomyelitis), soft tissue, middle ear, inner ear, and potentially the brai
question
What is the most common cause of malignant Otitis Externa?
answer
90% Pseudomonas aeruginosa
question
How is malignant otitis externa diagnosed?
answer
Raised ESR, and abnormal CT/MRI (bone erosion) are diagnostic.
Facial nerve paralysis may be an early symptom
question
How does an acute otitis media infection progress?
answer
Infection may spread from pharynx to middle ear (URT infection)
Abrupt onset otalgia, irritability, otorrhea, or fever
Infection is treated or pressure from bacterial growth bursts tympanic membrane
question
Acute otitis media must be differentiated from what?
answer
Otitis media with a clear effusion, a non-infectious condition of the middle ear
question
When is the peak first incidence of acute otitis media?
answer
6-9 months
question
What are some risk factors for acute otitis media?
answer
Bottle fed, Smoking parents, Attending daycare, Male
question
How is acute otitis media diagnosed?
answer
Rapid onset (48 hours*)
Presence of middle ear effusion
Signs and symptoms of middle ear inflammation
question
What is Chronic Suppurative Otitis Media?
answer
Chronic inflammation of the middle ear and mastoid mucosa in which the tympanic membrane is NOT intact and discharge (otorrhea) is present
question
What causes Chronic Suppurative Otitis Media?
answer
Untreated acute ototis media
question
What causes Cholesteatoma?
answer
Prolonged eustachian tube dysfunction, leading to negative pressure that draws the upper flaccid portion of the TM inward.
This creates a squamous epithlemium lined sac. When the opening becomes blocked/clogged this can lead to chronic infection
question
Cholesteatoma usually leads to what complication?
answer
Bone erosion
question
How is Cholesteatoma diagnosed?
answer
Physical examination reveals an epitympanic retraction pocket or perforation that exudes keratin debris
question
What is a complication of cholesteatoma?
answer
Osteomyelitis/ Mastoiditis
Meningitis
Brain Abscess
Dural Sinus Thrombosis (DST)
Otitic Hydrocephalus
Otitis Externa (most common)
question
What is Labyrinthitis?
answer
Acute onset of continuous, usually severe vertigo lasting several days to weeks, along with hearing loss and tinnitus
Cause is unknown but frequently follows upper respiratory tract infections
question
What are some ear problems associated with multiple sclerosis?
answer
Episodic vertigo and chronic imbalance. Hearing loss is usually unilateral with rapid onset that may abate spontaneously
question
What causes "honeymoon cystitis"?
answer
Staphylococcus saprophyticus
question
Which HLA genes are associated with Addison’s disease, Graves’ disease and myasthenia gravis?
answer
HLA-DR3
question
A patient presents with complaint of coughing up of blood and blood in urine. Which of the following is the most likely mechanism of this autoimmune disease pathology?
answer
Antibody deposition on both glomerular and alveolar basement membrane
question
You order a CBC on a patient suspected to have urinary schistosomiasis. What should you be checking for?
answer
eosinophilia
question
The main reason Escherichia coli is the most common cause of UTIs is that it is what?
answer
an enteric bacterium
question
What are the effects of urease activity by proteus mirabilis?
answer
Hydrolyzes urea, produces ammonia and carbon dioxide, raises pH precipitating the formation of calculi stones
question
Enterococcus faecalis is strongly associated with what bacterial infection?
answer
Endocarditis
question
Enterococcus faecalis is grown on what?
answer
Blood agar
Bile-esculin agar (black discoloration)
question
Enterococcus faecalis acquires 25% of its genome through what means?
answer
Lateral gene transfer between Staphylococcus and Streptococcus
Pathogenicity island located on genome produce toxin that forms holes in cell wall and allow for adherence
question
Enterococcus faecalis has high antibiotic resistance due to what?
answer
Ability to acquire mobile gene elements
question
How is Enterococcus faecalis treated?
answer
Amoxicillin
Ampicillin
Vancomycin
question
UTI caused by Salmonella sp. is suspicion for what?
answer
Urinary schistosomiasis
question
What are the statistics associated with recurrent UTIs?
answer
20% of women who contract a UTI will suffer another
Of these women, 30% will suffer additional UTIs
question
What causes Sub-acute bacterial endocarditis?
answer
Infection of the damaged valves by normal flora of mouth (Streptococcus viridans) and skin (Staphylococcus epidermidis)
question
Graves Disease is associated with what genes?
answer
HLA-B8 and HLA-DR3
question
Thickening of basement membrane in SLE is due to what?
answer
Immune-complex deposition on the basement membrane
The clinical correlate is proteinurea and microscopic hematuria
question
The most common causes of death from SLE are what?
answer
Renal failure and intercurrent infections
question
Does P-ANCA or C-ANCA present in polyarteritis nodosa?
answer
P-ANCA
question
In 90% of MS patients, the sclerotic plaque contain plasma cells that secrete what?
answer
Oligoclonal IgG into the CSF
question
Rheumatoid arthritis is most often associated with what gene?
answer
HLA-DRB1
question
Patients with Sjogren syndrome have an approximately 40-fold increased risk of developing what?
answer
Lymphoid malignancies
question
Some patients with limited scleroderma develop a combination of symptoms referred to as CREST which stands for what?
answer
Calcinosis, Raynaud phenomenon, Esophageal dysmotility, Sclerodactyly, & Telangiectasia
question
Reiters syndrome (reactive arthritis) is a clinical tetrad of what symptoms?
answer
Urethritis
Conjunctivitis (or less commonly uveitis)
Mucocutaneou lesions
Septic arthritis
question
Reiters syndrome usually develops following what kind of infection?
answer
Dysenteric infection (with Salmonella, Shigella, Yersinia, or Campylobacter) or a sexually transmitted infection (with Chlamydia trachomatis, or perhaps Ureaplasma urealyticum)
question
What is the clinical presentation of Reiters (reactive arthritis)?
answer
The arthritis is asymmetric and involves the major weight bearing joints
fever, weight loss
The mucocutaneous lesion include balanitis, stomatitis, keratoderma blennorhagicum
Most of the symptoms but arthritis subsides within weeks
question
How is Reiter's treated?
answer
Non-steroidal anti-inflammatory drugs are the main drugs used

Tetracycline in reactive arthritis with C. trachomatis reduce the duration of symptoms

Sulfasalazine and anti-TNF agents are tried in patients refractory to NSAID and tetracycline
question
What are the most common forms of amyloid protein?
answer
AL (amyloid light chain): is derived from plasma cells and contains immunoglobulin light chain
AA (amyloid-associated): is a unique non-immunoglobulin protein synstesized by the liver
Ab amyloid: found in the cerebral lesion of Alzheimer disease
question
How do you differentiate Group A from Group B Strep?
answer
Group A strep is bacitracin sensitive
question
What is the pathological hallmark of Kawasaki’s Disease?
answer
IgA plasma cell infiltration in the visceral organs, lungs, and coronary arteries
question
What can be given for influenza post-exposure prophylaxis
answer
Amantidine
question
What causes Acute Laryngitis?
answer
Infection of the larynx that results in an inflammatory reaction
Most often viral but can also be bacterial
question
Lateral X-rays help exclude what when diagnosing acute laryngitis?
answer
Acute bacterial epiglottitis
Bacterial tracheitis
question
What should be performed when hoarseness persists longer than 2 weeks with acute laryngitis?
answer
Direct laryngoscopy
question
What causes Croup (Acute Laryngotracheitis)?
answer
Subglottic inflammation and edema caused by a viral or bacterial infection of the larynx, trachea, and bronchi
question
What is the most common cause of upper respiratory tract obstructionin children between the ages of 6 months to 6 years
answer
Croup (Acute Laryngotracheitis)
question
What is the most common cause of croup in children?
answer
Parainfluenza virus type I and II
Influenza A or B
RSV
question
What is the most common cause of croup in adults?
answer
HSV
Influenza A or B
question
What are the signs and symptoms of croup?
answer
Hoarsness of voice
Brassy cough
Stridor, Fever, Rhinorrhea
Ronchi, crepitations or wheezing
Diminished breath sound
question
Imaging shows what in patients with croup?
answer
Narrowing of the air column
question
How is Croup treated?
answer
Cool air humidification
Racemic epinephrine
Dexamethasone
Intubation may be required if medical management fails
Antibacterial if bacterial
question
What is Acute Epiglottitis?
answer
Respiratory emergency
acute inflammation and edema of the epiglottis and can cause upper airway obstruction
More common among children between 2-6 years of age
Bacterial only
question
What causes acute epiglottitis?
answer
H. Influenzae type b
S. Aureus
S. Pneumoniae
S. pyogenes
question
What are the symptoms of acute epiglottitis?
answer
Short, rapidly progressing febrile illness
Sore throat (esp. in adults)
Dysphagia
Shortness of breath
Anxious looking and appears toxic
Forward leaning with neck extended posture
Drooling and muffled voice
May have a stridor
question
What can aid in rapid diagnosis of acute epiglottitis?
answer
Serum latex agglutination test for Hi type b
question
What imaging sign do you see in acute epiglottitis?
answer
Thumb sign
question
Hemophilus influenzae grows best on what?
answer
Chocolate agar media
Requires hematin (X factor) and NAD (nicotine adenamide diphosphate, V factor) for growth
question
Describe the pathogenesis of Hemophilus influenzae
answer
Pili and other adhesins bind to epithelial cells
Grows between the respiratory epithelial cells
The capsule inhibits opsonization and phagocytosis
Endotoxin is locally toxic, but does not cause endotoxemia
No exotoxins
question
Coccobacillus growing on chocholate agar but not on blood agar strongly suggest what?
answer
Hemophilus
question
What kind of prophylaxis is available for Acute epiglottitis and pneumonia?
answer
Rifampin
Infants are protected by maternal antibody up to 6 months of age
Antibody response to Hib PRP is poor in children less than 18 months of age
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