e) w/c 14-Oct-13 Flashcards
Types of cytology
Fine needle aspirate, fine needle biopsy, imprints
Difference between FNA and FNB?
Fine needle aspirate requires negative pressure. Fine needle biopsy = NO NEG PRESSURE.
Only do FNA (NEG PRES) if previous method unrewarding
Smear preparation method
Remove needle from syringe, draw air into syringe, replace needle, expe aspirated fiod from needle lumen with air filled syringe. WANT THIN areas with good cell spread, minimise cell damage and minimise BLOOD content
What must be done before imprints are taken?
Use fresh cut surface, BLOT until dry before INPRINT.
What pot should be used for a) Clot presentation b) Bacteriology
a) EDTA
b) Bacto: Sterile pot
How to differentiate Inflammation from Neoplasm on a slide?
Inflammation: Sample dominated by inflamm cells (neutropgils, eosino, lymphocytes
Neoplasm: Sample dominated by tissue cells
Can have both = EXPERIENCE
If the slide contains a mixed population i.e. inflammatory cells and tissue cells; what are the two possibilities it could be?
Inflamm with secondary dysplasia
OR
Neoplasm with secondary inflammation
In an inflammatory sample, how can we tell if its septic?
Contains bacteria/ organisms.
Degenerate neutrohpils
Bacteria must be intraceullar within neutrophils to be significant. If extracellular may be contaminants.
DEGENERATIVE CHANGES IN NEUTROPHILS: NUCELAR CHANGE, SWELLS AND LOOSES LOBATION
The sample has increased number of macrophages. What would be the most likely cause?
Granulomatous inflammation (Mycobacterium sp). If Macrophages and Neutrophils = Progranulomatous inflamm - Fungal infection???
Is cytology or histology better for examining round cells?
Cytology. Can be indicitive of round cells tumour.
Lymphoma, Plasmacytoma, Histiocutoma, Mast cell tumour
What are the cellular and nuclear criteria of malignancy?
Need at least for malignancy otherwise could be dysplastic.
- Anisoctosis
- Macrocytosis
- Cell crowding
- Anisokarosis
- Multiniucleation
- Macrokaroysis
- Increased mitotic figures
Strongest nuclear criteria of malignancy?
Macrokaroysis
How do the serological markers vary between the INNATE and ADAPTIVE immune system?
INNATE: Acute phase proteins e.g. serum amyloid A,
ADAPTIVE: Antibodies and Cytokines
When would you look for ANTIGEN rather than ANTIBODY in an ELISA
Indirect= looking for ANTIBODY.
You would look for antigen if recent exposure (<5days) and antibody if longer.
Difference between virus neutralisation test and Immunofluorescence assay?
IFA tells you if the antibody is present (similar to ELISA but flourence marker instead of enzyme).
VN tells you if antibody is effective (measures whether any CYTOPATHIC effects)
Why is a +ve culture result for E-coli from a faecal sample of affected calves be of little use?
Non pathogenic E-coli are very common in faeces. ONLY determining the presence of F4/F5 toxins confirm presence of ETEC
How does pooling samples for Johnes disease reduce cost?
Pool 5 faecal samples, from 5 different cows.
If the pool sample is positive test those cows individually.
Aetiology of PPE in pigs
Porcine Proliferative Enteritis is caused by Lawsonia intracellularis; an intracellular gram negative rod.
It has a non-haemorragic form and haemorragic (less common).
Present with sudden onset diarrhoea and yellow fibronecrotic casts from ilium.
How is bilrubin exreted?
Needs to become water soluble. Conjugated with Glucaronic acid in liver (RATE LIMITING STEP)
Can then be exreted in urine
Explain enterohepatic recycling
The bilrubin conj with glucaronic acid is converted by bacteria in the lower UTI to urobilinogen.
Excessive drooling is known as…….
ptyalism (TIE-A-LISM)
Difficulty passing urine is known as
Dysuria
How do you differentiate a) pre-hepatic and hepatic
b) hepatic- post hepatic
a) pre-hep and hepatic. PCV <30 = PRE
b) heptatic and post hepatic. Ultrasound and X-ray
Increased liver enzymes are indicative of….
Mostly indicitive of reversible liver DAMAGE.
Liver has huge regenerative capacity
What is the most specific liver enzyme?
ALT is most specific.
What iatrogenic increase in liver enzyme is only found in the dog…
Cortisol-induced increase in AP
What is liver failure?
When the liver’s capacity to regenerate is overwhelmed
What are the indications for liver failure on the chemistry profile?
Low albumin, low cholesterol, low glucose, low BUN (Urea). If just low ALP = only damage
What are the clinical signs of hepatic encephalopathy and what CAUSES these clinical signs?
Digestion of proteins, NH3 and AA go directly into blood without passing through liver; exposure of CNS to shunted toxins therefore neurological signs.
Head pressing, seizures, ptyalism, bizarre behaviour
Two diseases causing hepatic encephalopathy in CATS and DOGS
Cats: Acute liver failure, Hepatic Lipodosis, Neoplasm
Dogs: Portosystemic shunt, liver failure (acute), liver failure (chronic)