Proteins, lipids, carbs Ch 6 D&P Flashcards
Compare serum to plasma proteins.
Plasma has everything, Serum is missing fibrinogen, factor V and factor VIII. (think serum separator)
What accounts for the majority of colloid osmotic pressure of plasma and why?
Albumin. Due to abundance and small size.
What influence does albumin have on coagulation? So what may happen with low albumin?
It dampens platelet aggregation and augments AT III and so low albumin > prothrombotic implications.
What are the types of globulins and where do they come from?
- Alpha and Beta (lipoproteins, acute phase proteins and some globulins like IgM and IgA) ( Made in the Liver.)
- Gamma (B lymphocytes and plasma cells)
What are the different ways to measure TOTAL protein and how sensitive are they in the different types of fluids (3)?
- Biuret method (colorimetric, spectrophotometric) > accuracy for plasma or serum, accurate from 1-10g/dl.
- Precipitation and Dye binding assays > for small amounts, accurate from 10-200mg/dl, for CSF or urine proteins.
- REfractometry for plasma, serum and body cavities (read in g/dL); high conc of glucose, urea, sodium, chloride, lipemia, hemolysis, any turbidity may falsely elevate readings. Icterus doesn’t affect the reading as long as the sample is clear.
How is albumin measured individually most often? What is an alternative way to measure it?
Bromcresol green dye binding method (this is different from total protein measurement).
False high test results occur when levels are very low cause it can bind to other proteins.
Serum protein electrophoresis is an alternative way to quantitate albumin.
How is globulin concentration determined?
Usually calculated by subtracting albumin from total protein in a serum sample.
What Serum IgG concentrations tell you there is failure of passive transfer in a foal or calf?
Below 200mg/dL at 24-48 hrs.
200-400 mg/dL = partial failure
> 800mg/dL = good to go
What are the IgG screening tests for failure of passive transfer? (4)
Zinc sulfate turbidity Latex agglutination Glutaraldehyde coagulation ELISA (remember "LEGZ")
When would you have a decrease or increase in A:G ratio?
Decrease > Renal proteinuria and/or Ig production following following Ag stimulation.
Increase > lack of IgG production in adults or lack of colostrum in foals or calves.
NOTE: THE BODY DOESN’T OVERPRODUCE ALBUMIN.
How is fibrinogen concentration determined?
- Indirectly by refractometry using two centrifuged hct tubes and measuring fibrinogen and then heating the other and measuring it (fibrinogen is precipitated by heat denaturation) and subtracting them and you get fibrinogen in mg/dL.
The method is crude and can be used for hyperfibrinogenemia but not really for hypofibrinogenemia. - its more accurate to determine thrombin clotting time, or use direct automated measurement.
What does hyperalbuminemia tell you?
Dehydration, an absolute increase in albumin doesn’t really happen. (Globulins would also be increased so A:G would be normal unless something else is going on).
What does hyperfibrinogenemia tell you?
Inflammatory or neoplastic dz, its an acute phase protein, and also in dehydration. Early inflammation in large animals. Not on serum biochemical profiles cause its only in plasma.
Hyperglobulinemia may occur under what conditions?
Infection or inflammation
Near term pregnancy
Birds prior to egg laying
Acute phase response cause mild increase (alpha globulins mostly, some beta)
Besides inflammation, or tissue injury, what else results in production of acute phase proteins?
Estradiol
Physical stress
Steroid administration
(extra-hepatic production may also occur)
What stimulates production of acute phase proteins?
IL-1, IL-6, TNF, from macrophages at site of injury and maybe other cells too.
In terms of identifying an inflammatory response, which values are most useful?
- Acute phase proteins (more sensitive than WBC count, can be used in early detection and monitoring response to treatment).
- WBC count
Which tumors often have an elevation of acute phase proteins?
Lymphomas or tumors with significant inflammation.
What are examples of early responding acute phase proteins (within 24 hours) and later responding ones (w/in 48 hours and later)?
Rapid > Amyloid A, C reactive protein
Later > Haptoglobin, fibrinogen, LPS binding protein
(note amyloid a is better than fibrinogen cause it occurs faster and is higher)
Which acute phase protein has the greatest cross-species utility?
Which is best for dogs?
Dogs and cats?
Ruminants and horses?
Cross spp > Serum amyloid A
Dogs > C reactive protein
Dogs and cats > alpha 1 acid glycoprotein
Ruminants and horses > Haptoglobin
If you don’t have blood what may be used to test for acute phase protein?
Saliva
Which coagulation proteins are considered acute phase proteins?
Factors V, VIII and fibrinogen.
Which acute phase protein may be good for monitoring pancreatitis in dogs versus cats?
C reactive protein in dogs.
Serum amyloid A in cats.
What is haptoglobin?
Acute phase protein considered more sensitive than fibrinogen. It binds free hemoglobin and decreases in intravascular hemolysis..
Increases occur in Cushings or steroid admin.