Clinical Chemistry – Flashcards

Gluc_serum> 180mg/dL=> +Gluc_urine

- dipstick--> gluc oxidase & peroxidase--> sensitive  

gluc--> gluconate + hydrogen peroxide

- Copper sulfate method

- Copper sulfate method --> low senstivity

1.Unique solubility property of light chain proteins

Precipitate-40⁰C & Re-dissolve - 100^oC

when cooled--> Precipitate-60⁰C & Re-dissolve-40^oC

2.Urine protein electrophoresis

- Myoglobinuria--> Hx: severe muscle tenderness, elevated [CK/aldolase]_serum, [haptoglobin]_nml

- Hemoglobinuria <-- hematuria / Hemolysis_{intravascular}

!!!Mgb = soluble in NH₄SO₄

Conjugated Hyperbilirubinemia

Hepatitis

UTI --> most organisms = nitrite + (E.coli)

!!! - = enterococci, N. gonorrhea, M tb

UTI--> screen -->reflection of urinary neutrophils #

!!!false + <-- trichomonads & eosinophils

Isosthenuria

tubular damage-- renal medullary dysfunction

Sickle Cell disease

Ascorbate --> inhibits

Dipstick tests: Gluc, Hgb, Bilirubin, nitrite, leukocyte esterase

Crohn's, s/p small bowel resection/bypass, ingestion of excessive amounts of oxalate(rhubarbs, spinach, nuts)

1⁰ hyperoxaluria --> stones in childhood

--> little effect on Calcium oxalate crystallization

--> elevated pH--> Calcium Phosphate stones, struvite

--> acidotic pH--> urate stones

Mutation in the voltage gated chloride channel5 gene=>

hypercalciuria--> stone

Struvite

--> urea-splitting organisms=> alkalotic pH

Urate stones-Hyperuricosuria-Rx: 1.allopurinol=xanthine oxidase inhibitor--> reduces endogenous urate

2.Urine alkalization

deficiency - Adenine phosphoribosyl transferase

-->purine metabolism

Rx: Allopurinol

Calcium oxalate Dihydrate(envelopes)/monohydrate (dumpells,spindle/oval)

"recieved the -envelope late-> dump it"

Uric acid

DDx:Sulfonamide crystals-->soluble in acetone

"URing w shapes/diamonds/colors"

Struvite-Triple Phosphate (Mg, ammonium phosphate)

--> alkaline pH, staghorn calculi

"Coffin of Proteus-->staghorn-->struvite "

Cysteine --> cystinuria

"Cola --> hexagonal glass bottle"

Bilirubin

"Bins and needles"

Sulfadiazine

<-- trimethoprim-sulfadiazine administration

Cholesterol

"cholesterol results-->broke the glass"

Tyrosine

<--severe liver disease

Ammonium biurate

"thorn=ankathi"

Leucine

"Leukos cross"

often--> severe liver disease

rare: Tyrosinosis, "Maple syrup disease"

Hyaline casts = nonspecific

<--Dehydration, vigorous exercise, renal disease

white cell cast and budding yeast

<--Tubulointerstitial nephritis

Granular cast (acellular)~>nonspecific

<--renal disease

Fatty cast<-- Nephrotic syndrome

lipid droplets-->polarized light--> maltese cross

Red  cell cast

<-- glomerulonephritis

waxy cast

<-- renal diseaserenal disease

RPGN

"Phagocytosis"

AIN

"Nephritis-numerous neutros"

Xanthochromia

Pink<-- free Hgb--> subarachnoid hemorrhage

Yellow<--Bilirubin (12hrs,peak72hrs, t_1/2=2wks)

Artifactual: hyperbili,CSF_protein>150mg/dL, carotinoids, melanin,rifambin, >1hr processing delay

[Gluc ] = [Gluc]_CSF-->nonspecific

Protein electrophoresis--> twin transferrin peak ,pre-albumin band

[asialated transferrin]

MS

IgG index =IgG_CSF:IgG_serum/ control

--> exclude the effect of increase permeability

MS

2 or >2 band = +

IEF (+IgG Ab) -->4 or > 4

CSF- FTA-ABS

CSF-VDRL

--> counter to serum

Bacterial meningitis

~ predom lymphos --> if partially treated

early viral meningitis--> HSV (Gluc=decreased)

lymphs--> late viral meningitis vs. fungal/mycobacterial( also Gluc-->decreased) 

Most common -->CHF (larger on the right)

Cirrhosis, nephrotic syndrome--> decreased Osmotic pressure

most common = RA

collagen vascular diseases

Malignancy

Esophageal perforation--> pH<6.0

Pancreatitis--> left-sided

Chylous-chylothorax

<--thoracic duct obstruction

Pseudochylous effusion

<-- gradual accumulation of lipids<--cellular break down <--Tb, RA, myxedema

Portal hypertension

<1.1 <-- other causes

gross blood >15mL / RBCs > 100,000/mL

WBCs>500/mL, Gram stain: bacteria

Chest tube/ Foley catheter : peritoneal fluid 

1. septic artritis

2. RA / Lupus

Calcium pyrophosphate

<--pseudogout