Chemistry Rotation

  1. Ion exchange chromatography
    based on ph/ionic strength
  2. Partition chromatography
    relative solubility
  3. Adsorption chromatography
    H boning and hydrophobic reaction
  4. Size exclusion chromatography
    based on molecule size
  5. Affinity chromatography
    binary separation
  6. Gas Chromatography
    Relative retention time
  7. First order kinetics
    Reaction rate dependent upon substrate concentration
  8. Zero Order kinetics
    reaction rate independent of substrate concentration
  9. Beer's Law
    • A= abc
    • absorbance= constant*light path*concentration
  10. Spectrophotometry
    measures light intensity
  11. Atomic absorption
    measures radiant energy, element specific
  12. Flouresence
    • Emission>excition
    • Absorbance followed by emission, detect at 90 degrees
  13. Turbidity
    measures amount of light scattered by looking at on axis light
  14. Nephlemotry
    Measures increase in off axis scattered light
  15. Refractometry
    Looks at the bend in light
  16. Potentiometry
    Measures potential difference (charge) btwn electrodes
  17. Severinghause Electrode
    Measure pCO2 w/gas permeable membrane, look at pH change
  18. Clark Electrode
    Measure pO2, amperometry look at change in current
  19. Coulometry
    Chloridometer, Ag electrode intereacts w/ Cl and precipitates, concentration of Cl is proportional to charge
  20. Osmometry
    look at number of particles
  21. Calculated Osmolality
    2Na + Gluc/18 +BUN/2.8
  22. Hook effect
    Too much Ag leads to underdetermination, all binding sites get used so excess Ab will wash away
  23. Chemiluminesence
    Light emitted with reaction, not measured with spectrophotometer
  24. Accuracy
    Consistently give an answer close to the true value of the analyte for a given specimen
  25. Precision
    Consistently give the same answer for a given specimen
  26. F test
    compares variance
  27. Hemolysis interferences
    • KLAMP
    • Potassium, LD, AST, Mg, PO4.
  28. Turbidity Interferences
    AKA lipemia, causes increased light scatter
  29. Bilirubin Interferences
    AKA Icterus, spectral interference
  30. Sensistivity
    • TP/TP+FN
    • Lowered by False Negatives
  31. Specificity
    • TN/FP+TN
    • Lowered by False Positives
  32. ROC plot
    Specificity vs. sensitivity, looking for maximum efficiency
  33. Delta Check
    used to reevaluate results after a large change
  34. AVP
    AKA ADH, reabsorption of water by the kidney to maintain osmolality
  35. Diabetes Insipidous
    • getting rid of too much water
    • central= insufficient AVP
    • nephrogenic= poor response to AVP
  36. Water deficit vs. excess
    • Deficit= increase osmolality, prompt AVP secretion
    • Excess= decreased osmolality, decrease thirst
  37. Osmolal Gap
    • measured-calculated (<13)
    • Alcohols etc. interfere, measured via freezing point
  38. Sodium (Na)
    • ~140 mmol
    • 90% of serm cations, responsible for serum osmolality
    • Absorbtion directly linked to water levels
  39. Potassium (K)
    • ~4 mmol
    • regulation by kidneys
    • follows glucose
    • important for muscle strength
  40. Chloride (Cl)
    • ~100mmol
    • passively maintains osmolality/neutrality by following Na
  41. Bicarbonate (HCO3)
    • ~23mmol
    • 90% of body's CO2
    • Most important buffer in blood
  42. Calcium (Ca)
    • ~9mmol
    • 99% in bone
    • 45% free, 45% bound, 10% complexed
    • require anaerobic handling or pH will increase
  43. Magnesium (Mg)
    • ~1mmol
    • essential cofactor for ~300 enzymes
    • regulated by the kidney
  44. Phosphate (H2PO4 0r HPO4)
    • ~3mmol
    • regulated by the kidney , age/sex related
    • react with ammonium molybdate to get complex @340
    • serum or hepranized plasma to avoid interference
  45. Lactate
    • result of anaerobic glycolysis
    • marker for sepsis
  46. Normal Blood Gas Levels
    • pH: 7.35-7.45
    • pO2: 90
    • HCO3: 45
    • pCO2: 23
  47. Anion Gap
    • Na(+K)- (Cl+HCO3)
    • Potassium often negligible
  48. Metabolic Acidosis
    • decreased pH due to loos of HCO3
    • Causes: MUDPILES
    • Methanol, Urea, Diabetes, Propylene glycol, Isoniazid, Lactate, ethylene glycol, Salicylates
    • Also diarrhea or Renal tubular disease, excess loss of HCO3
  49. Respiratory Acidosis
    • decreased pH due to increased CO2
    • slowed breathing or impaired gas exchange
    • Drug OD or asthma
  50. Metabolic Alkalosis
    • increased pH due to increased HCO3
    • loss or acid or excess bicarb
    • caused by things like vomitting
  51. Respiration alkalosis
    • increased pH due to increased CO2
    • loss of acid via respiration, like hyperventilation, altitude change, etc.
  52. Increased HgB O@ affinity
    increased pH, decreased pCO2, VitD and temp
  53. Decreased HgB O2 affinity
    decreased pH, increased pCO2, vit D and temp
  54. Blood gas anticoagulant
  55. Kidney function
    • excretes nitrogenous waste
    • maintains homeostasis by reclaiming compounds as needed
    • endorcrine functino- renin, erthrypoetin, Vit D
  56. GFR
    • Glomelular filtration rate
    • marker for renal function
  57. 3 main nitrogenous waste products
    • Urea- protein metabolism
    • Creatinine- muscle product
    • Uric Acid- purine metabolism
  58. Erythropoetin
    acts on BM to stimulate RBC production
  59. Urea
    • ~13 mmol as BUN
    • freely filtered, inverse to urine flow
    • Measured by urease kinetic rxn
  60. Creatinine
    • completely filtered by glomerluli, best indicator of glomelular function
    • measure by Jaffe rxn
    • dependent upon muscle mass
  61. Creatinine Clearance
    • UxV/PxT
    • urine creatxUrine vol./plasma creat (1440min)
  62. BUN creat ration
  63. Uric acid
    • product of purine metabolism
    • can cause renal disease, gout, etc
    • forms crystals
  64. What are aminotransferases?
    enzymes found in hepatocytes for AA metabolism.
  65. What is the biuret rxn for?
    Total Protein
  66. What tests are the true markers of hepatic function?
    Albumin and T/D biirubin
  67. What is ALP
    alkaline phosphatase, associated with biliary obstruction and inflammation
  68. What is GGT?
    marker of hepatobiliary disease, especially elevated in alcoholics
  69. Ammonia
    Scavenged from protein metabolism, easily contaminated
  70. What are the laboratory findings associated with hepatitis?
    Elevated ALT and AST
  71. Hepatitis A
    • RNA virus, vaccine available
    • fecal/oral transmission, never chronic
  72. Hepatitis B
    • DNA virus, vaccine available
    • sexually transmitted, chronic <5yo
    • tested for surface and envelope Ag
  73. Hepatitis C
    • RNA virus, no vaccine
    • sexually transmitted, chronic 75%
  74. Hepatitis D
    • defect RNA virus
    • requires coinfection of HBV
  75. Heptatits E
    • RNA virus
    • fecal/oral transmission, mostly 3rd world
  76. What are the main functions of the pancreas?
    • Endocrine- insulin and glucagon -> bloodstream
    • exocrine- digestive enzymes like amylase an dlipase to the ductal system
  77. Amylase
    • starch digestion, found in pancrease and salivary glands
    • obligate Ca cofactor
  78. Lipase
    • triglyceride digestion
    • most specific to the pancreas (9000x other organs)
  79. What is fecal fat testing for?
    measuring pancreas exocrine function, look for improperly processed lipids
  80. Instrinsic Factor
    producted by parietal cells in the stomach, required for b12 absorption
  81. What does a xylose absorption test look at?
    evaluates malabsorption
  82. Triglycerides
    primary storage form of energy
  83. Cholesterol
    • structural element of cell membranes
    • precursor of steroid hormones
  84. lipoproteins
    allow for lipid transport
  85. Cylomicron
    • transport of exogenous trig and some chol
    • apo B-48
    • will float
  86. VLDL
    trig rich, apo-100
  87. LDL
    chol rich, the "bad"
  88. HDL
    • the "good", gets rid of deposited chol
    • APO A-1
  89. Calculations of LDL
    • LDL= total chol- trig/5
    • invalid if trig>400 (no fast required)
  90. What is the desired total chol
    • <200, LDL <100
    • risk modification if HDL>60
  91. CRP
    • response to inflammation
    • prognostic value for coronary artery disease
  92. Myoglobin
    most rapidly rising marker of myocardial injury
  93. CK-MB
    • measures muscle damage, small amounts in skeletal muscle
    • being replaced by troponin
  94. Troponin
    • slow to peak cardiac marker, lasts longer before returning to normal
    • (+) always indicates myocardial injury
  95. What is the universal definition of an MI
    rise and/or fall of cardiac biomarkers with at least one value >99th percentile
  96. BNP
    marker of CHF, not a stand alone diagnosis
  97. Insulin
    • produced by pancreatic B cells, facilitates uptake of glucose and conversion to glycogen
    • only hormone to lower Gluc
  98. What is C-peptide
    produced alongside endogenous insulin.  Can serve as a marker to see if insulin issues are an overproduction (elevated C peptide) or overdose (normal C peptide)
  99. What is the reference method for glucose measurement?
    G6PDH hexokinase
  100. Type 1 DM
    • insulin deficiency due to autoimmunity to beta cells
    • Requires replacement
  101. Type 2 DM
    • body becomes resistant to insulin, metabolic syndrome causing B cell dysfunction
    • makes up ~90% of cases
  102. Diagnostic results for DM
    • Hgb A1C >6.5%
    • fasting glucose >126
    • 2 hr glucose >200
  103. Diagnostic values for GDM
    1 hr nonfasting GTT if >140 then perform 3hr GTT
  104. Urinary microalbumin
    measures excretion of albumin in urine, indicates leaking proteins.  Can be early sign of diabetes
  105. Iron Storage
  106. Normal amount of free iron
    0, free iron is toxic
  107. Iron transport
  108. Stages of Iron depletion
    • depletion: decreased ferritin, normal serum and TIBC
    • iron deficient erythropoiesis: decreased ferritin serum and Trf sat.  Increased TIBC
    • Iron deficient anemia: additionally decreased Hbg, MCV, MCH, MCHC.  (microcytic, hypochromic)
  109. Anemia of chronic Disease
    • normal amounts of iron, not used well
    • hepcidin prevenets iron release
    • Differentiate from IDA with normal ferritin and TIBC
  110. poyphyria
    metabolic disorder from partial enzyme deficiency
  111. Wilson's disease
    increased copper deposition throughout the body
  112. What can you look for to check for low B12 levels?
    methylmalonic acid
  113. What are the most common medias for electrophoresis?
    Agarose gel or polyacrylamide for IEF
  114. T/F albumin is the only protein specifically quantitated w/ electrophoresis
    True. All other fractions measure more than one types of protein
  115. Prealbumin
    Nutritional marker, esp. for nitrogen
  116. Alpha 1 proteins
    AAT, acid glycoprotein, fetoprotein (AFP, hepatic tumor marker)
  117. Alpha 2 proteins
    macroglobulin, ceruloplasm (copper transport, wilsons disease), haptoglobin (intravascular hemolysis)
  118. Beta proteins
    Transferrin (iron transport), complement (immune response)
  119. What to look for in electrophoresis for nephrotic syndrome
    decreased alb and gamma, increased alpha 2
  120. What to look for in electrophoresis of hypogloammaglobunemia
    decreased gamma region
  121. What to look for in electrophoresis of Hepatic cirrhosis
    decreased alb, increased gamma, bridged Beta/gamma (increased IgA)
  122. What to look for in electrophoresis of monoclonal gammopathy
    decreased alb
  123. What are tumor markers most often used for?
    predicting and monitoring treatment
  124. Liver cancer marker
  125. Colon cancer marker
  126. Breast cancer marker
    CA 15-3, CA 27-29
  127. Ovarian cancer marker
    CA 125
  128. Pancreatic tumor marker
    CA 19-9
  129. Describe the endocrine axis
    • Hypothalamus--> pituitary --> endocrine gland --> hormone
    • Works on a negative feedback loop most of the time
  130. Anterior Pituitary
    secretes direct effector hormones (GH, Prl) and trophic hormones (ACTH, FSH, LH, TSH)
  131. Posterior pituitary
    Secretes AVP and oxytocin
  132. GH
    • Growth Hormone
    • stimulated by GHRH, pulsatile secretion makes it hard to measure
    • Anabolic: protein synthesis, growth
    • catabolic: tissue breakdown
  133. GH feedback loop
    • Negative feedback from glucose
    • GHRH-->GH-->IGF
  134. IGF
    • Insulin-like Growth Factor
    • Good marker for GH
    • very age dependent
  135. Acromegaly
    excess GH after growth is complete
  136. GH testing
    test for hypersecretion with an oral GTT, negative feedback should lead to reduced levels of GH
  137. Prl
    • Prolactin
    • Synthesized in hypothalamus, stored in posterior pituitary, no releasing hormone
    • Under constant inhibition by dopamine
    • No target tissue, often influences lactation
    • Suppresses GnRH to maintain pregnancy
  138. C Cells
    primary function to secrete calcitonin, which has a mysterious role
  139. Primary secreted Thyroid Hormone
  140. Primary Active thyroid hormone
  141. Graves disesase
    • Hyperthyroidism, autoimmune against TSH receptors
    • overproduction of T4 and T3
  142. Hashimoto's Thyroiditis
    • hypothyroidism
    • antibodies against TPO or Tg
    • Look for a-TPO antibodies in diagnosis
  143. Thyroid Testing
    • TSH is primary test, 2x change in T4= 100x change in TSH
    • Will measure T4 over T3, much higher levels of T4 than T3
  144. Tg
    • Thyroglobulin, tumor marker for thyroid tissue
    • no Tg= no functioning thyroid tissue
  145. T/F Cortisol has constant levels within the body all day
    False, cortisol is on a diurnal variation with highest levels in the morning
  146. Addisonian Crisis
    • primary hypoadrenalism, decreased levels of glucocorticoids
    • No negative feedback to ACTH
  147. Cushings syndrome
    • Hyperadrenalism
    • excess cortisol, high levels of glucose
    • Cushings disease= ACTH producing tumor
  148. Cosyntropin Test
    • Draw baseline cortisol levels, then inject cosyntropin (ACTH mimic)
    • Check for expected increase in cortisol
  149. Catecholamine
    secreted by adrenal medulla, stress homeostasis
  150. Catecholamine testing
    plasma levels aren't recommended, look for plasma metanephrines
  151. GnRH
    Secerted in pulsatile fashion from hypothalamus, promotes FHS/LH
  152. FSH
    • Follicular maturation and estrogen
    • spermatogenesis
  153. LH
    • follicular rupture and progesterone
    • libido hormone (testosterone)
  154. Hormone patterns of Menopause
    decreased estrogen, increased FHS/LH
  155. PTH
    • Parathyroid Hormone
    • stimulates osteoclasts to break down bone to release Ca and Phos
Card Set
Chemistry Rotation
chemistry cls