Describe Cytology testing including pros/cons
what type of lesion is this
Round, mass-cell granules - Mast-cell tumour
what does a leucogram tell us
Leucogram: inflammation/infection/chronic/acute/ Viral
Which Biochem parameters shows liver function
AST, ALT, AP,
Which Biochem parameters shows kidney function
Urea
Creatinine
Why is urinalysis used
- Renal disease - RBCs, WBCs, Protein
Urine conc
pH,
Specific gravity - hydration
Cytology of urine: crystals, bacteria, bilirubin, WBCs, RBCs
what diagnosis can u give for
A) high glucose in blood only
B) Glycosuria and high blood glucose
A) hyperglycemia - Diabetes
B) Glycosuria - issues with renal filtration - Most likely kidney dx
When doing a necropsy, what samples must you take
Samples of all tissue for
-Histology
-Virology
-Bacteriology
-Toxicology
Give DDx for this
For Histopath, tissues are fixed in
10% buffered formalin
1:10 ratio
Define IHC
-purpose
-Steps
ImmunoHistoChem combines Immunology, Histology, and Chemistry to form a dx.
-can identify specific viral antigen tissue
What are the main cell types seen in biopsies
What is histopathology used for in disease dx
how do you use IHC to differentiate between tumor types
Describe the IHC assay step in IHC
if the target antigen is present, the primary antibody will bind to it and won’t wash away during the assay. Then a secondary antibody that is conjugated with an ezy will attach to the primary one. Once a substrate is added the presence of all the components in tact will cause a colour change signalling the presence of the antigen.
why is IHC used instead of Histo in identifying the presence of viral components in tissues
v difficult to see viral under H and E staining unless inclusion bodies are seen.
IHC can help target viral antigen in tissues.
Describe Pathology isolation for Bacteria, Toxins, and Viruses
LA
What is pathogen isolation?
-what does it involve?
-Tissue types
Pathogen isolation is the process of identifying the pathogen responsible for the dx using Histo/IHC. This involves:
Staining e.g Gram-stain, Inflammation type, necrosis
Usually requires further work-up to identify genus and species of pathogen.
Fresh samples are best. Take multiple samples of key tissues and store frozen. Key tissue sites: Liver, Stomach, Urine, lung, spleen, kidney, brain.
Liver - good for toxin testing because of metabolism.
Hair - good for genetic testing
What is usually used for molecular testing of fresh/frozen tissue and describe the methodology and cons. LA
PCR
- targets and amplifies small amounts of DNA from viruses, bacteria, fungi
Cons:
nucleic acid presence or not detected Not localised to a lesion or within a specific cell location
sample if homogenised
When are samples sent for toxicology testing?
-how much tissue is submitted and from where?
-Toxicology testing is used when:
- unexpected or unexplained illness or death
- Muktiple animals in a group affected
-could be environmental - toxic plant growth in pasture
-approx 50mL of ingesta, feces, fresh tissue
-Collect from liver, urine, stomach
What are serological tests and what are they used for?
2 types:
Direct (1only), Indirect (1 and 2 abs)
Serological tests use antigen-antibody interactions to detect antigen or antibody in body fluid such as cancer-cell specific components, infectious agents, toxins, cytokines.
These tests are easier, quicker,and cheaper compared to pathogen isolation methods.
Define Antigen, Antibodies, Epitopes
Antigens are made up of multiple epitopes. Antigens are toxins/xenobiotes (foreign substances) - that illicits an immune response. This causes the production of Antibodies by the body.
Antibodies bind to the antigen at antigen-binding sites. Are Y-shaped protein called Immunoglobulins.
Describe antibodies
-poly vs monoclonl
-primary vs secondary
Describe the antibody production vs exposure to antigen over time.
First exposure: latency period
primary Abs produced and primary response
Secondary abs will only be produced in the lab.
Second exposure: secondary abs produced and secondary response
