Histopathology

Question 1

What are biopsies

Answer 1

Small sections of tissues which are removed from the patient and placed in a formalin solution which preserves tissues by cross linking proteins

Question 2

Where are the biopsies placed

Answer 2

Embebed in the paraffin wax to allow very thin sections which are usually just about 2-3micrometers thick so they can be cut by a microtome

Then placed in a microscope

Question 3

What are the questions asked when looking at a biopsy 3

Answer 3

Is it normal
Is it inflamed
Is it cancerous and what type
Easier to make diagnosis

Question 4

What are the chemical stains used also 3 here

Answer 4

haemotoxylin and eosin to identify nuclei and cytoplasmic granules of the leukocytes within the tissues
Ziehl - Neelsen stain which will stain acid fast bacteria aiding the diagnosis of TB

Question 5

How long is needed for a biopsy

Answer 5

2-3 days

Question 6

What is always needed for samples to be done before analysis

Don’t over think, it is simple

Answer 6

Always label correctly and avoid confusion and misdiagnosis

Question 7

What is a resection specimen

Answer 7

It is taken from tissues removed as part of a surgical procedure and processed as a biopsy

Question 8

What is it used for and what questions are asked 2

Answer 8

Used to look for the stage of the disease

How far it has progressed and how has it spread

Question 9

What other thing can be done with this tissue without regarding the patient

Answer 9

Can be donated to bio banks and used to inform genomic studies of the disease process with the input of other medical professional such as immunologists and microbiologists

Question 10

How long for a resection specimen

Answer 10

5-7 days

Question 11

What is a frozen section

Answer 11

It is taken during the surgical procedure and examined by the pathologist in real time while patient operated on

Question 12

What is the procedure

Answer 12

The freshly cut section is frozen by a machine known as a cryostat and mounted on glass slides and stained. Then analysed as biopsies

Question 13

Why is it preferred during surgery

Answer 13

Very fast only 30 minutes

Question 14

What questions can it answer? 2

Answer 14

Is it cancerous

Is all cancer removed

Question 15

What is a problem with this technique

Answer 15

Not all processes are compatible with the initial preparation of the sample

Question 16

What is the process for cytopathology 4

Answer 16

Collect cells
Smear on microscope
Stain
Slide stain and examine

Question 17

How can cells be extracted

Answer 17

Fine needle to be used to get into a lesion and aspirate cells which can be analysed for a smear

Question 18

What can a cytopathologist comment on

Answer 18

Just the cells not the architecture of the tissues — only a histopathologists can do that

Question 19

How many tests for antibodies

Answer 19

86 different diagnostic tests

Question 20

What can the antibodies test for 4 disease but can be any really

Answer 20

DNA, systematic lupus erythematosus , Sjongens syndrome, rheumatoid arthiritisn

Question 21

What can antibodies form when attaching to other things and where do these others attach

Answer 21

Conjugations, they attach at the Fc regions

Question 22

What are the 4 things they can attach to

Answer 22

Enzymes, fluorescent probes, magnetic beads, drugs

Question 23

What can you say about enzymes conjugation?

Answer 23

Peroxidase and alkaline phosphotase which can change colour of one thing can show presence.

Question 24

Explain fluorescent probes

Answer 24

Rapid measurements of levels of molecules within sample because the colour is there

Can do multiplexing with several antibodies within the solution, several molecules in a sample

Question 25

Why is multiplexing important

Answer 25

Some samples are really hard to obtain so more information we can get from them the better

Question 26

How can we use magnetic beads

Answer 26

Purifying cell types by attaching to Fc region which allows cells to be purified

eg anti CD3+ can be used for depleting the bone marrow of T cells before we use them for bone marrow grafts

Question 27

Drugs on antibodies

Answer 27

Kadcyla - an anti HER2 antibody linked to cytotoxic chemical emstansine to allow treat breast cancer.

Her expressed in 30% of cancers

Approved for advanced metastatic cancers

Question 28

What are the two types of diagnostic tools and what are they

Answer 28

Direct - antibody to antigen

Indirect - antigen and antibody and secondary antibody

Question 29

What are some uses of the antibodies? 3

Answer 29

Blood group serology
Immunoassay - detect hormones and circulating antibodies/ antigens
Immunodiagnosis — infectious diseases, antibody levels, IgE hypersensitivity - allergic phenotype

High levels of antibodies can be suggested of a myeloma

Question 30

Describe ELISA test

Answer 30

Clinical samples on plastic plate
Probe with specific antibody raised against the molecule of interest.
Enzyme conjugation generates a coloured product
Reference to a standard curve the relative absorbance determine precise concentrations of molecule of the sample

It allows us to measure the amount

Question 31

Describe flow cytometry

Answer 31

It allows measurements of specific cells particularly lymphocytes

Fluorescent antibodies specific for leucocyte antigens but have different colour

Runs as single cells through a laser beam and excite the flourophores on these and the colour of light emitted coupled with forward or side scatter tells us identity - size and granularity

Can work out which white blood cells are included and see which inflammatory reaction is occurring

Question 32

Say the CD+ number for each of these 
Pan T cell marker 
t helper cells 
t cytotoxic cells 
B cells 
natural killer cells

Answer 32

3 
4
8
19
56