Lecture 2/23

• at 15 seconds, read Clinitest
• Clinitest

  • reaction generates heat and CO2
  • heat comes from the reaction of sodium hydroxide and water
  • CO2 comes from reaction of citric acid and sodium bicarbonate forms a blanket over the liquid in the tube (oxygen cannot get into reaction)
  • at 15 seconds, tube is shaken, and color is observed
• squamous epithelia

  • “fried egg” appearance; can appear folded over or crumpled as a result of centrifugation
• • generally no pathological reason for squamous epithelia unless present in huge numbers
  • Sloughed off, sometimes in sheets
• • Transitional epithelia
  • Can take on several shapes 
  • Most common: pear shaped aka caudate
  • Oval or round
• transitional epithelial cells

  
• renal tubular cells

  
• • Casts
  • definition/composition - cylindrical protein bodies comprised of Tamm-Horsfall protein
• it is very common to have positive protein dipstick from casts
• casts are associated with an acidic pH
• • Hyaline cast - can be normal in low numbers; will not be present in alkaline urines; cylindrical and clear or translucent
  • Formed in distal tubule and collecting duct 
  • Considered normal with strenuous exercise or dehydration (2)
• • Granular casts - old degenerated cellular casts
  • Differentiated into fine and coarse granular casts
  • If the urine is fresh, granular casts mean the casts have been in urinary tract for sometime, as it takes times for cells to degrade
• • The finer the granularity of the cast, the more likely a pathology is occurring
• • Waxy cast - tend to be shorter, broader (bigger around), more defined 
  • Hyaline cast that is so old that water has left cast
  • Cast becomes denser
• waxy casts

  • Presence of several waxy casts means the kidneys are failing (casts are not moving through tubule) or patient is severely dehydrated
  • Splintered, fragmented ends, or splinter in middle
  • Degenerating hyaline cast
• casts are the only thing that is quantified under low power for urinalysis
• casts are best viewed under subdued light as they are translucent, you can close the diaphragm to increase contrast
• • Flow of nephron determines if mucous is excreted (urine flowing normally) vs casts secreted (urine flowing slowly and takes shape of protein)
• • if there is a normal amount of filtrate, but patient is secreting a large amount of proteins and casts result - casts with tail will result OR casts with mucous surrounding it
  • Cylindrical body with 1 definite rounded edge and other side with tapered off side 
• • Uric acid - seen as diamonds, hexagons, wedges, rosettes, football shapes, barrels
  • Most common - football shape or diamond shaped (squares or rectangles)
  • Have yellowish tint - the thicker they are, the more yellow they will appear
  • Very thick - brownish tint
• uric acid crystals

  • Typically seen in patients with gout
  • Will dissolve in alkaline urine
• high salt diets will result in calcium oxalate crystals as excess salt is excreted in urine as calcium; calcium combines with oxalate upon excretion
• calium oxalate is the most common kidney stone
• forms of calcium oxalate crystals include dihydrate form and monohydrate form
• dihydrate form of calcium oxalate

  
• monohydrate form of calcium oxalate

  
• • Amorphous urates - appear as brick dust or pink sand
  • Color is due to deposition of uroerythrin
  • Frequently seen in normal urine
• amorphous urates

  • Sediment that appears when clear urine is cooled (either RT or refrigerated)
  • Upon voiding, urine is clear
  • Microscopically, appear as grains of sands
• congenital tyrosinosis is a disorder of amino acid metabolism
• leucine