Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Lab Diagnostics > Lab 6 - Changes of metabolic parameters > Flashcards

Lab 6 - Changes of metabolic parameters Flashcards

1
Q

What is the Total protein concentration in blood (TP) and ways of measure

A

In plasma: dependent on the intake, synthesis, transformation, catabolism, and hydration (hyper decr TP etc)

Measurements: chromatography(mean spectrophotometry?), electrophoresis and refractometry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the best method to determine total protein in blood concerning the concentration sensitivity

A

Biuret method (spectophotometry) is most sensitive

refractory is second -

  • can measure 25-95g/L, less precise than biuret.
  • May give biased result in haemolysis or lipaemia.
  • Is temperature sensitive
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How to measure TP conc in other fluids than blood, why is it different?

A

Total protein in urine, CSF, body cavity fluids or tissue homogenates have too low conc. To be determined using biuret test or refractory method.

Lowry method - folin-phenol reagent
OR
Ultrasensitive TP method - proteins directly bound to stain molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

why and how do we do biuret test (spectophotometry

A

Why: to measure total protein conc of SERUM
How: peptide bonds and copper ions react in alkaline environment and creates purple complex which can be measured using chromatography. Then we use a calibration curve or formula using a a standard solution to calculate the concentration

More color more protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How and when do we use Ultrasensitive total protein analysis

A

Na-molibdate, and pirogallol-red reagent forms a complex molecule by binding proteins. More color more proteins

Sensitivity is 0.2 g/L - 4g/L, so we use it for body fluids sith low protein concentration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the mechanism of Refractometry in TP

A

Light is refracted when reaching the border of media (from glass to plasma/serum) with different specific gravity, which is dependant on TP and temperature which is why the test must be performed in room temperature.

The TP has the highest conc in the plasma/serum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the method of Refractometry use in TP

A
  1. calibration using distilled water
  2. 1 drop of plasma/serumon the glass
  3. Close the cover so no light gets in
  4. Read result, the horizontal line on scale of serum/plasma TP indicated the TP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the different protein fractions, size and quick calculation

A

Major fractions are albumin, globulin and fibrinogen which is the smallest - so globulins is normally measured by TP-albumins. Also nv when we check twonoarameters we also check if there is dysproteinaemia (normal TP, abnormal fractions)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the different methods to determine albumin conc of serum, and which is better and why

A

Spectophotometry: common method

Serum electrophoresis:

  • more exprensive but more reliable
  • used in protein fraction analysis, gives albumin % so TP must be known
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How do you perform spectophotometry when measuring albumin

A

bromocresol green is used as a reagent, binds to albumin on pH: 4.2 and forms a blue-green complex, more folor more albumin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Reasons for a decreased albumin concentration

A
  1. decr intake of proteins
  2. decr absorption
  3. decr synthesis (in liver): liver failure, due to acute inflammatiin, its a -APP
  4. incr use during excersize, pregnancy, production(milk, egg), chronic diseases
  5. Incr loss: (same as in globulins)
    - diarrhea protein loosing enteropathy
    - incr filtr/decr absorpt due to renal failure - protein loosing nephropathy
    - burn: ec fluid loss, shock decr albumin
    - blood loss
    - body cavities - cannot be utilised (peritonitis)
  6. Other: hyperhydration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Reasons for a increased albumin concentration

A

Dehydration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the different methods to determine globulin conc of serum

A
  1. Difference btw TP and albumin conc

2. Serum electrophoresis if protein fractions are to be evaluated. Give % so conc must be known (method 1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Changes of the Alb/Glob ratio due to what, how do we measure?

A

60A/40G
🔺 usually due to incr in globulins(mono/polyclonal)
🔺 or due to decr in albumins (see list)
🔺 selective vs. Non-selective protein loss
🔺 Measured using ESR or glutaric aldehyde test as the most frequent reason for changed ratio is the incr of igs(inflammation or neoplasia)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

most commonly used protein electrophoresis forms

A

SDS-PAGE
- SDS-polyacrylamide gel electrophoresis
IEF
- isoelectric focusing

Gives protein% so TP must be known from biuret or refractometry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Explain the mechanism of Serum protein electrophoresis (SPEP) - not as frequently used!

A

Proteins havr amphoteric character:
- acidic aa`s go to pos pole, alkaline to neg pole in el. Current.

  • Serum is put on agarose treated paper which limit diffusion, and put in an electrical current.
  • The serum proteins are sep into 5 categories according to size, viscosity of medium=agarose(makes it slower) and electrical charge(makes it faster)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Explain the mechanism of sodium docecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)

A
  1. denaturation by heating
  2. coating of the polypeptides with negatively charged SDS molecules
  3. applied to one end of a slab of polyacrylamide
  4. Electrodes are then attached, cathode (-) at the end where the denatured protein
  5. Application of voltage - migration
  6. After a predetermined period of time, the electrodes are removed and the gel slab is stained with dye to show the locations of proteins in the gel.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Densitometer - use

A

To interpret results from stained separated protein fractions in concentrations. From serum electrophoresis. Diagnose mono/polyclonal gammopathy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Increase in ig’s important terms

A

Polyclonal gammopathy: globulin incr due to some form (inflamm, disease) immune system response, several ig types will increase.

monoclonal gammopathy: globulin incr due to immune medated or neoplastic disease, one ig type will increase. sharp spike like the albumin spike.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

monoclonal gammopathy caused by neoplastic disease examples

A
  1. most common = Multiple myeloma (IgG, IgA) antigenic activation of B cells, then travel to BM - BM disease
  2. Lymphoma (IgM, IgG) eg. Neoplasm of B cells - IgM
  3. Chronic lymphocytic leukemia IgG
  4. Extramedullary plasmalymphomas. Solid tumors or plasma cells in skin of dogs.
21
Q

monoclonal gammopathy caused by non-neoplastic disease examples

A

Rare! Monoclonal gammopathies (usually IgG) have been reported with occult heartworm disease, FIPV (rarely), Ehrlichia canis - in polycloonal too!)

lymphoplasmacytic enteritis, lymphoplasmacytic dermatitis and amyloidosis must be ruled out before considering multiple myeloma(neoplasia)

22
Q

The 3 that are found in mono and polyclonal gammopathy

A

Cause enormeous reaction. In nature its polyclonal, but so huge reaction it will be monoclonal at the end

23
Q

Reasons for Hypoglobulinaemia

A
  • decreased intake of globulins: in neonates before drinking colostrum, absorption disorders of neonates
  • decreased synthesis of globulins: acquired of inherited immunodeficiency, liver function impairment
  • increased loss: (same as albumin) PLE, PLN, via skin (burns, inflammation), bleeding
24
Q

Describe the 3 methods of fibrinogen concentration measurement

A
  1. difference of plasma and serum TP-concentration gives fibrinogen concentration.
  2. Refractometry is used: One part of plasma is measured for TP, the other part is heated to 50-60 which destroy the fibrinogen, then the TP is measured. The difference btw the two is the conc of fibrinogen.
  3. Thrombin time is used: chckes time for thrombin to convert fibrinogen into the insoluble fibrin clot. The clot (time) formation can be determined by using standards of different fibrinogen concentrations. Faster coagulation, more fibrinogen(and XIII) in plasma
25
Q

Causes of fibrinogen concentration changes

A

Increase
• acute inflammation +APP (especially ruminants), dehydration
Decrease
• liver function impairment, advanced protein deficiency, DIC, sequestration after
bleeding to body cavity, chronic bleeding, blood loss, inherited afibrionogenaemia (St. Bernard dog)

26
Q

How do we measure the glucose conc of the blood

A

Physiological conditions: whole blood is used. glucometer using electric conductance, which is dependant on the amount of RBC aswell as the glucose concentration!

Polycythaemia/anemia: enzymatic method for reliable measure!

27
Q

Glucose catabolism during sampling - preparations to be done

A

Plasma glucose is quickly catabolysed by the enzymes of rbc, so we must determine blood glucose concentration quickly after sampling, or we have to ensure to avoid in vitro catabolism:
• Store the sample cooled
• Separate plasma from blood quickly as it can be kept longer thant serum
• Coagulate RBC
• BEST! Take blood samples in tubes containing NaF which inhibits enolase(inhibits glycolysis!)

28
Q

Enzymatic method aka GOD/POD reaction

A

🔺Glucose is oxydised, and the oxygen produced oxydises a stain giving a color,
🔺stronger color - higher glucose concentration.
🔺Spectophotometry or refractory method is used to measure.
🔺 NaF tube plasma is used bc plasma to decr glucose catabolism, NaF inhibit glcycolysis!

29
Q

Reasons for Short lasting Increased glucose concentration

A

Own mistakes:
o laboratory errors (haemolysis, lipaemia, icterus)
o after/during administration of glucose containing fluid therapy

o chronic stress (cats!)( cushings - insulin resistance and incr GC)
o food intake (dogs and humans!)
o xylazin effect (reduce sensitivity to insulin and glucose uptake)
o cranial trauma or inflammation (Rabies, Aujeszky disease)

30
Q

Reasons for Constant Increased glucose concentration

A 
o diabetes mellitus - insulin deficiency or resistance
o hyperadrenocorticism and glucocorticosteroid therapy! Incr glucose need
o Progesterone effect (iatrogen or endogenous – insulin resistance! Dureing oestrus) 
o enterotoxaemia (sheep) Hyperfermentation, incr glucose prod in caecum? Bacterium
31
Q

Decreased glucose concentration:

A

• laboratory error
• decreased energy status(starv, pregnancy third trimester)
• insulin overdose
• insulinoma, pancreatic tumor
• anabolic steroid effect incr insulin sensitvity
• liver failure, terminal stage, no storage or breakdown of glycogen
• acute liver failure (fast depletion of liver glycogen after a very short hyperglycaemic
phase)
• hypoadrenocorticism GCs are responsible for production and storage(addisons disease)
• septicaemia incr use, impaired GNG
• hyperthyroidism, insulin lingers
• paraneoplastic syndrome, tumor increase insulin-like growth factor
• addisons disease (decr GC)

32
Q

Intravenous glucose tolerance test: why, when, how

A
  • Why: when we suspect the onset of latent diabetes mellitus or insulinoma
  • When: when the animal starved for 24 hours, not if glucose conc is above 20mmol/L!
  • How:
    1. Blood sampling
    2. 40% glucose iv infusion for 1/2 min
    3. Blood sampling after 5 min, 15min, then every 15 min. Should be normalised after 30-60mins
33
Q

Oral glucose tolerance test (glucose absorption test) why, when, how

A
  • Why: when we suspect chronic bowel disease, exocrine pancreatic insufficiency, or it can be used instead of iv glucose tolerance test.
  • when: when the animal starved for 24 hours
  • how:
    1. Blood sampling
    2. 12,50% glucose solution is given orally
    3. Blood sampling at 15, 30, 60, 90, 120 min.
    4. Blood glucose should be increased twice as normal value at 30 min. and should be normalised at 120 min
34
Q

How to check if glucose change is long term or not

A

• represents 2-3weeks prior to sampling. Glucose can be bound To various proteins forming complexes:
1️⃣ macroamylase (a-amylase)
2️⃣ fructoamine (several proteins)
Short term these arent affected by hyperglycemia, but long term they are, which makes them suitable for this measurement (bc too big for renal escretion!)

• glocose conc representation 2-3 months prior to sampling.
1️⃣ Glycated hgb

35
Q

What are ketons

A

due to energy deficiency in liver cells, caused by decreased intake of carbohydrates or decreased insulin production (diabetes ketoacidosis)

36
Q

How are ketone bodies detected

A

Ross-reagent contaminated by keton bodies (acetone, acetoacetic-acid) changes its colour from white (grey) to purple. The depth of the colour depends on the ketone concentration.

37
Q

Sample of ketone body detection and method

A

plasma5 : urine10 : milk1

Drip some drops of prefferably urine sample onto the Ross-reagent, wait one minute and see the results.

38
Q

Cause of Urea concentration change of milk and plasma

A

to see energy status of dairy cows: If rumen has energy deficiency due to decreased carbohydrate intake, NH3-level increases in the rumen, this results in increased urea production by the liver, so urea concentration increases in milk and in plasma.

39
Q

Lipemia - how do we measure it and describe the two sorts of results

A

differentiate chylomicrons(from intestines!) from other lipids in blood plasma - freeze the plasma -18 oC wait 12-24 hours then warm it slowly again and centrifuge. The protein part of the chylomicrons coagulates.

A) layer under the fat (which is located on the top of the plasma) is clear after the centrifugation, lipaemia is caused by the food intake, in this case the plasma is ready for the measurement.
B) If the plasma is not clear after the centrifugation it means that there is an increased lipid mobilisation from the fat stores.

40
Q

Causes of hyperlipidaemia

A
  • hyperlipidaemia of ponies (restricted calorie intake or excessive exercise)
  • increased fat content in diet
  • diabetes mellitus (decreased free fatty acid /FFA/ influx into the cells)
  • hypothyroidism - hormones imp role in metabolism of lipids
  • hyperadrenocorticism or glucocorticosteroid therapy
  • nephrotic syndrome
  • sepitcaemia (energy deficiency, in blood moe available)
  • pancreatitis (lipase activation, incr in blood)
  • idiopathic(means for no reason)– familiar hyperlipidaemia in miniature schnauzers, beagles
41
Q

Causes of decreased lipid content:

A
  • starvation (long term)
  • liver failure (e.g. PSS synth in liver! Its bypassed, also proteins from liver needed to transport lipids!
  • malabsorptio, maldigestio (e.g EPI exocrine pancreqtic insufficiancy)
  • chronic bowel disease
42
Q

Why do we do a Lipid absorption test, describe the mechanism, normal value, dog

A

To determine whether there is existing malabsorption, maldigestion (especially in exocrine pancreatic insufficiency) or when there is chronic bowel disease

When there is fast lipid intake in normal conditions, plasma triglycerol (TG) concentration rises to twice as normal value (normal for dogs: 1 mmol/l).

43
Q

When and how ho we perform a Lipid absorption test

A

when the animal starved for 24 hours:

  1. Blood sampling
  2. corn oil given orally
  3. Blood sampling at 1st, 2nd, 3rd, 4th, 5th hours
  4. Blood should be lipaemic, and TG concentration must show minimal 2 fold rise from the normal value, If no such change, we repeat the test by giving predigested corn oil. mix corn oil by pancreatic enzyme extract to corn oil and incubate it on 37 oC give the same dose and check lipaemia every hours.

If incr. TG conc and lipaemia then it could be exocrine pancreatic insufficiency (EPI), no change - intestinal absorption defect

44
Q

Why do we measure Total cholesterol and cholesterol-ester, normal value

A

for the detection of increased fat mobilisation - in this case the total cholesterol value increases,

or decr. Conc: Decreased esterification of cholesterol as a result of impaired liver-function causes decreased total cholesterol concentration.
normal value, cholesterol conc.: 2-6 mmol/l
(Cholesterol ester is 40% of tcholesterol)

45
Q

Causes of hypocholesterolaemia:

A
  • malnutrition
  • liver failure (decreased synthesis)
  • neoplastic disease in liver
  • hyperthyroidism (insulin)
  • decreased apolipoprotein synthesis in liver, for tp of lipids except for FFA
46
Q

Causes of hypercholesterolaemia:

A
  • increased dietary fat content
  • hypothyroidism, insulin
  • hyperadrenocorticism, GC
  • diabetes mellitus, incr vldl cholesterol
  • nephrotic syndrome (concurrent low TP)
  • cholestatic diseases (increased leakage from liver due to bile duct obstruction)
  • idiopathic - primary dyslipidosis= abnormal metabolism
47
Q

FFA or NEFA (non-esterised-fatty-acid) concentration measurement, why and how is it mobilised

A

detect increased or decreased lipid mobilisation.

tissue lipase is the major enzyme breaking down lipids from triglycerols in tissues to ffa and glycerol due to energy deficiency

48
Q

What happens during a severe energy deficiency/starvation in ruminants (PQ)

A

total lipid (TL) concentration decreases because liver can not produce enough apolipoproteins for transporting lipids, however FFA concentration is increased, because it is transported by albumin.

(cause increased blood FFA concentration as a result of the energy need. FFA can compensate energy deficiency until liver is able to produce enough OAA (oxal-acetic-acid) for the beta oxidation.)

Lab Diagnostics (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions