PoS Flashcards
(153 cards)
1
Q
What are the types of shock?
A
Septic/distributive/vasodilatory
Hypovolemic
Obstructive
Cardiogenic
2
Q
What are some causes of hypovolemic shock?
A
GI losses
Hemorrhage
3rd space losses
polyuria at very high volumes
3
Q
What are some causes of obstructive shock?
A
GDV
Pericardial effusion
Pneumothorax
4
Q
What causes cardiogenic shock?
A
Primary heart disease- generally a patient with this type of shock will also be in heart failure
5
Q
What are some causes of vasodilatory/septic/distributive shock?
A
SIRS (Systemic inflammatory response syndrome) Sepsis Pancreatitis Anaphylaxis Anesthesia
6
Q
What are the 6 perfusion parameters?
A
HR pulse quality Mucous membrane color CRT Temp Mentation
7
Q
Which shock type should NOT receive an IV fluid bolus?
A
Cardiogenic
8
Q
What are the signs of fluid overload?
A
congestive heart failure, peripheral edema, swelling of the conjunctiva, gelatinous feeling skin
9
Q
True or False: Shock patients will always have pale mucous membranes
A
False- hyperemic in vasodilatory
10
Q
Difference between shock and dehydration
A
Shock - fluid loss from intravascular space
Dehydration - generalized fluid loss - intracellular/interstitial loss
Treated in different ways - dehydration is longer administration of fluids, shock is a rapid bolus
11
Q
What is a stem cell?
A
Unspecialized cell with ability to self-renew and capability of differentiating into multiple cell types
12
Q
What are the 2 main categories of stem cells? And what is the main difference between them?
A
Embryonic and adult (somatic)
Main difference is their potentials- embryonic are totipotent (can make all cell types in the body) whereas adult stem cells are multipotent (can make many cell types but not every cell type in the body)
13
Q
Which part of the embryo are embryonic stem cells derived from?
A
Inner cell mass of the blastocyst
Only a very small number of cells here- need to amplify them!
14
Q
True or false: embryonic stem cells have infinite capacity to divide but adult stem cells do not
A
TRUE!!!
If you culture adult stem cells can only get a limited number
15
Q
True or false: embryonic stem cells are more likely to form teratomas
A
True
16
Q
What are some licensed uses of stem cells in vet med?
A
Horse tendon/ligament injuries- taken from bone marrow of horse
Horse or dog bone/joint/tendon injuries- derived from adipose tissue of animal
*in both cases these cells may not be actually forming new tissue but producing factors that promote tissue healing
17
Q
What kind of corticosteroid activity does prednisolone have and how does it compare to dexamethasone?
A
Pred- mostly glucocorticoid, some mineralocorticoid
Dex- only glucocorticoid
18
Q
How does chlorambucil work?
A
Alkylating agent- alkylates DNA, prevents protein synthesis and kills dividing cells
*First choice as 2nd immunosuppressive in cats
Other alkylating agents used for chemo: cyclophosphamide, lomustine, melphalan
19
Q
How do methotrexate and azathioprine work?
A
Compete with building blocks of DNA so get non-functional nucleic acid strands (anti-metabolites)
NEVER use azathioprine in cats- very narrow therapeutic index and overdose causes fatal myelosuppression
Other anti-metabolites used in chemo: cytarabine, 5-fluorouracil, hydroxycarbamide
20
Q
What group of drugs are Vincristine and Vinblastine and what are they used for?
A
Vinca Alkaloids- at low dose can increase platelet release from megakaryocytes, used for immune-mediated thrombocytopenia
Also used in higher dose as chemo- interfere with mitotic spindle apparatus
21
Q
What are the Calcineurin inhibitors?
A
Ciclosporin and Tacrolimus
Block IL-2 production so inhibits T helper 1 response and also indirectly suppresses T cells, NK cells, neutrophils, eosinophils & mast cells
*Tacrolimus use from cascade and topical only
22
Q
True or false: if a cat is on glucocorticoids and develops PU/PD it’s not a cause for concern
A
FALSE- this shouldn’t happen with cats, if it does happen they have developed diabetes mellitus
23
Q
True or false: PU/PD in a dog being treated with glucocorticoids is primary PU and secondary PD
A
False- primary PD from behavioral changes
24
Q
Explain the difference between COX1 and COX2
A
COX 1 = produces PGs that are IMPORTANT in the physiological modulation of function - gut mucosal barrier and intra-renal perfusion
COX 2 = activated and released by tissue damage, bacterial lipopolysaccharide, cytokines, growth factors, inflammation
25
When using NSAIDs what are the withdrawal periods for meat and milk?
Meat - 28 days
| Milk - 7 days
26
What are the different NSAID classifications?
Non-selective - no clinical differences in COX 1/2 inhibition = Aspirin, Phenylbutazone, Ketoprofen
Preferential - at least 2x greater inhibition of COX2, usually ~10-40x = Meloxicam, Carprofen, Mavacoxib
Selective - TRUE specific COX 2 inhibitor - more than 100 fold specific for COX 2 - Firocoxib (previcox), Robenocoxib (Onsior)
27
What are some adverse effects of NSAIDs on large animals and horses ?
LA Abomasal ulceration, Renal toxicity, Hepatic disease
| Horses - GI ulcers, renal toxicity, phlebitis (inflammation of a vein)
28
Why do high doses of NSAIDs cause GI ulceration?
PGs protect the gastric mucosa by decreasing gastric acid secretion and maintain mucosal blood flow, also enhances mucus production
** COX 1 and COX 2 need to be inhibited to generate mucosal injury**
29
Why do you NEVER use NSAIDs with a suspected case of dehydration/shock?
With dehydration and shock, the patient will already have decreased blood flow to the gut so giving NSAIDs will cause a significant increase in the risk of GI ulceration
Also, dehydrated and shock patients have a decreased renal perfusion - COX 1 and 2 help to maintain that GFR via vasodilatory actions so giving NSAIDs will continue to decrease renal perfusion
30
What are some preferred NSAIDs to use in dogs vs. cats. vs. horses?
Dogs - carprofen, firocoxib, paracetamol
Horses - Carprofen, firocoxib
Cats - Carprofen, aspirin, meloxicam, firocoxib (not licensed)
31
What is the main route of elimination for NSAIDs?
Hepatic
32
What are the best forms of treatment when you have a suspected case of chocolate toxicity?
TREAT THE PATIENT NOT THE TOXIN
1. Emesis - make the patient vomit if the ingestion is known to have been less than 4 hours ago (Dog - apomorphine, cat - xylazine, medetomidine/dexmedetomidine - can cause sedation)
* Do not use emesis if showing neurological signs*
* Can cause aspiration pneumonia *
2. Gastric/colonic lavage - use if the ingestion has been over 4 hours ago AND use if large amounts ingested
- Under GA - pass stomach tube and lavage stomach with tepid water, empty contents below patient, REPEAT
* Can cause aspiration pneumonia and hypothermia if using cold water*
3. Activated charcoal - stop it from being absorbed
33
What is the antidote for anticoagulant rodenticide?
VITAMIN K biiiitch!
34
What is the antidote for ethylene glycol?
Ethanol - GET THE VODKA!
35
What are some toxins that cause seizures?
METALDEHYDE (snail/slug pellets) - cause neuroexcitation and decreased GABA activity
MYCOTOXINS - from mold - cross BBB into cerebellum because they are lipid soluble - BIND TO ACTIVATED CHARCOAL
METHYLANTHINES/Theobromide - chocolate/coffee - antagonize adenosine receptors --> CNS stimulation - BIND TO ACTIVATED CHARCOAL
Permethrin - in flea/tick medication - toxic to cats - lead to hyperexcitability and tremors
36
What toxins will cause anemia?
RODENTICIDE --> Vitamin K antagonism which is required for the production of coagulation factors in the liver
- Treat with plasma transfusion and give Vitamin K for up to 6 weeks
PARACETAMOL - toxic to cats and dogs in high doses - causes oxidative damage to RBCs
- Treat with activated charcoal, N-acetylcystine
37
What are the toxins that can lead to renal failure?
Ethylene glycol - causes azotemia, isosthenuria and calcium oxalate crystal formation
* Will see oliguria/anuria* - TREAT WITH VODKA
NSAIDs - high doses can lead to renal failure - treat with emesis, activated charcoal, diuresis if needed, IVFT
Aminoglycosides (ABX)
Lillies - cats - lead to azotemia, isosthenuria - treat with emesis, activated charcoal, IVFT
Grapes/raisins - dogs
38
Which toxins can lead to hepatic toxicity?
Xylitol - increases insulin levels --> hypoglycemia and can cause hepatic necrosis at high doses
*treat with glucose bolus, liver protectants (NAC), fluids*
Mushrooms
Paracetamol
39
Describe the difference between endotoxins and exotoxins.
Endotoxins - part of the bacterial outer membrane - seen in GRAM NEGATIVE BACTERIA - lipid A part of the LPS - this is what is recognized by the PRR in host cells to indicate a bacterial infection is present
(when macrophages attack --> cytokine release to hypothalamus --> fever)
Exotoxins - bacterial proteins released during BACTERIAL GROWTH - can by cytolytic, enzymes, enterotoxins, neurotoxins, superantigens type 3 secretion systems
Superantigens - S. aureus --> TSS
Type 3 secretions- SALMONELLA - have a needle like structure that probes eukaryotic cells and secretes proteins in them to help bacteria infect
40
What are some examples of mycotoxins?
Toadstool poisoning - mushroom with yellow top/white stem - will cause sickness but not usually fatal
Ergotism - form in grass and cereal - ingestion leads to gangrene, lameness, convulsions (causes arteriole constriction-> hypoxia)
Aflatoxins - molded feed - leads to liver damage, tumors, TERATOGENIC
41
Why do we see drug toxicity in veterinary patients?
We use drugs off label
Not all animals are clones - some drugs affect some animals differently
Mistakes made in calculating doses/storage/handling
Animals usually have multiple diseases so multiple drugs are needed
Owner compliance
42
What is the difference between Type A and Type B drug reactions?
Type A - expected/predictable from drug MOA
| Type B - not related to the MOA - occur if used for prolonged periods, but can be unpredictable
43
Why might drugs be more readily absorbed from the gut in a neonate?
They have decreased gut motility, underdeveloped gut flora, and mucosal enzymes but they have increased total body water, decreased GFR and immature liver enzymes
So larger volume of distribution but delayed elimination
44
True or false - you can treat collies with Ivermectin.
FALSE YOU ABSOLUTE IDIOT!
Collies have deletion mutations on their MDR-1 gene which codes for P-glycoprotein. P-glycoprotein is what acts as an efflux pump to excrete ivermectins out of the brain
45
How do cancer cells sustain proliferative signaling?
Make their own growth factors and evade growth suppressors (P53 inhibits proliferation- loss of function of these genes -->proliferation )
Alter their receptors - overexpression of receptors to respond to low levels of ligand or have receptor always switched on
46
Which gene mutations are seen in 50% of canine mast cell tumors?
KIT gene mutations - seem to be associated with more aggressive disease
47
How do cancer cells enable replicative immortality?
TELOMERASE enzyme up-regulated to add new telomeres at end of the chromosomes
48
How do cancer cells form their own blood supply?
Release angiogenic factors - VEGF - to stimulate new blood vessel growth
49
What are some factors involved in tumor grading?
Mitotic index
Degree of Cellular differentiation
Amount of necrosis
Invasion of surrounding tissues
50
What is the system for staging tumors (not lymphomas)?
TNM system - good for solid tumors
T = primary tumor - assess size, mobility, ulceration, relationship to surrounding structures
N - Node - assess regional nodes for size, mobility, texture, consistency - may need FNA/Imaging
M= metastasis - will need imaging for this
51
What are baseline tests to assess the cancer patient and why?
CBC - health screen to provide baseline before chemo
Biochem - assess organ damage/function
UA - health status/renal function
Coagulation profiles - ensure no coagulopathies
52
What is the cell morphology for a MCT?
ROUND CELLS
Very common cutaneous tumor in dogs
Granules seen in cytoplasm
TMT = surgery with 2 cm margins
53
What vaccines are most often associated with Feline Injection site sarcomas?
Rabies and FeLV
TMT = surgical excision with 5 cm margins
Can use adjuvant radiation because it has high recurrence rates
54
What are some differentials for oral tumors?
Melanoma - pigmented mass with high metastatic rate usually to lungs (or may be amelanotic)
Fibrosarcoma - high rate of recurrence
SCC - important to stage, low metastatic rate
55
What is the most active and invasive part of a tumor?
The periphery! That is why margins are so important
56
What is the mainstay therapy for immune-mediated disease and how do they work?
CORTICOSTEROIDS- Various adjuvant therapies can also help - start with Prednisolone - clinical response should be within 7 days - if not give a 2nd agent
Decreased macrophage phagocytic action and antigen-presenting activity and suppression of T cell function
57
How is borreliosis transmitted? What are some clinical signs? How is it treated?
Ixodes ricinus - tick feeding
Signs = fever, inappetence, pain in small joints, glomerular nephritis, thrombocytopenia, lymphadenomegaly
Tmt= doxycycline
58
How do hemoplasma bacteria affect RBCs?
They sit on the surface of the RBC --> immune-mediated hemolytic anemia
Macrophages see them on the surface and try to remove them --> anemia
* Can sometimes see on blood smear*
PCR = gold standard diagnostic test
59
Which small mammal would you consider fasting before anesthesia?
FERRET - usually up to 4 hours prior to procedure
60
Where would you want to place a catheter in a rabbit and why?
Marginal ear vein - do not use the middle vessel within the ear because it is an artery
61
What is the best anesthetic induction option for small mammals?
IM/SQ injection with alpha 2 agonist, ketamine, and opioid OR
Gas induction using sevoflurane (less irritant than isoflurane) after pre-med with midazolam/opioid or hypnorm
**If sick rabbit, pre-med and then IV induction with alfaxalone (or propofol)
62
Who makes a disease notifiable?
OIE - World Organization for Animal Health - set general lists and then the National animal health offices (DEFRA, APHA in the UK) determine which are relevant for their individual countries
63
What is the role of the APHA?
Have to tell them if suspected ND
Give advice on the phone, visit farm, request samples
Impose restriction orders
Provide reference laboratories for testing of samples
64
What is a differential for a dog with acute collapse and hemoabdomen?
Ruptured splenic mass - 70% of dogs presenting with acute non-traumatic hemoabdomen had splenic hemangiosarcoma
Ruptured liver mass
Perforated GI mass
65
What is the traditional shock fluid rate for a bolus?
20-40 ml/kg given over 15-20 minutes
66
What is the treatment advised for cardiogenic shock?
O2
Diuretic - if hear crackles in lungs
Anti-arrhythmic if needed
Pimobendan to aid in heart contractility
67
When performing CPR, what is the difference between thoracic pump vs cardiac pump?
Thoracic pump - over the widest part of the chest, NOT OVER THE HEART - use in dogs >7kg
Cardiac pump - directly over the heart - use in dogs <7kg or if they are wedge shape like GREYHOUNDS
68
What is the best method of CPR for cats?
One hand around chest, directly over the heart (just behind elbow in ventral portion of chest)
69
What is the best method of CPR for barrel-chested dogs (bulldogs)?
Sternal compressions (lay on their back)
70
When performing CPR, how many breathes per minute is ideal? How many compressions per minute?
10-12 breathes/minute
100 compressions/minute - sing to staying alive
DO SIMULTANEOUSLY
71
When would defibrillation be indicated?
In a patient with ventricular fibrillation
72
What are the 5 agents of concern regarding food-borne infections?
```
Campylobacter
E. Coli
Salmonella
Norovirus
Listeria
```
73
A cat comes in after the owner has accidentally applied a permethrin flea product, what do you do?
Clip contaminated area
| Wash with vegetable oil and dish washing liquid
74
Why do geriatric patients have increased risk of ADRs?
smaller body size, poor nutritional status, usually multiple disease processes and they have age-related changes in organ function
75
What toxins do NOT bind activated charcoal?
| In what other cases would you not administer it even if it binds?
```
Xylitol
Ethylene glycol
Alcohol
Alkali
petroleum
heavy metals
```
You also wouldn't give it to patients with CNS signs (seizures, no reflexes, recumbent..)
76
What toxins can you treat with an intralipid?
```
*Soy bean fat that aims to bind lipid-soluble drugs and aid secretion (sry needed a reminder)*
Local anesthetic
Ivermectin
Permethrin
Naproxen
Baclofen
Marijuana
Mycotoxins
Tricyclic Antidepressants
Beta blockers
Ca channel blockers
```
77
What's the therapeutic index of a drug? Do we want it to be high or low?
High TI -> toxic dose a lot higher than therapeutic -> safer
| It's the toxic dose in 50% of animals / effective dose in 50% of animals
78
T or F: AMR is considered an adverse drug reaction
T. YOU NEED TO REPORT IT
| AMR = antimicrobial resistance
79
What drugs should you avoid in neonates?
Tetracyclines (teeth discoloration)
fluoroquinolones (damage to articular cartilage)
Any drug with narrow therapeutic index
80
What drugs should you avoid in horses?
Monesin (growth stimulant in sheep)
Ionophores
Sulphonamides given IV (cause arrhythmias)
81
What drugs should you avoid in collies?
ivermectin
loperamide
vincristine
cyclosporin A
82
How do enterotoxins work?
They are ADP ribosylation toxins
They add one more ADP to the Cl channels in the enterocytes-> persistent Cl- excretion -> Na and water follow -> secretory diarrhea
83
Name a few drugs that can NEVER be given to food producing animals
```
phenylbutazone
chloramphenicol
lidocaine
metronidazole
benzyl-penicillin
metoclopramide
gentamicin
```
84
What is Gabiprant?
Inhibits binding of PGE2 to EP4 receptor, so basically has NSAID effect without causing COX inhibition
very popular for OA treatment
85
Is the administration of NSAIDs perioperatively recommended?
| If so, what are some special considerations?
Yes, it is recommended to help with analgesia and recovery.
However if you give NSAIDs you have to be mindful of factors that may cause reduced perfusion during surgery.
You should avoid using ACP as premed and alpha2 as induction agents
Also, NEVER give after SPINAL SURGERY
86
T or F: NSAIDs potentiate the effect of diuretics.
F. NSAIDs actually inhibit diuretics (prostaglandins activate diuretics in the nephron)
87
Is it recommended to give NSAIDs to geriatric cats with OA and CKD?
If there is no other better option to control OA pain it is recommended.
NSAIDs are not usually administered if kidney function is compromised but recent studies showed that CKD cats on NSAIDs lived better and longer
88
What is passive vs. active vaccination?
```
Passive = administration of antibodies - short term to provide immediate protection
Active = administration of antigen for more long term protection - MLV, recombinant, killed, subunit
```
89
Why would a puppy/kitten need multiple doses of a vaccination?
When they are 6-12 weeks old, they may have interference with MDA
90
What are the core canine vaccines?
Distemper
Rabies
Parvovirus
Adenovirus
91
What are the core feline vaccines?
Calicivirus
Herpes virus
Panleukopenia
92
How long would you wait to do a serology test after giving vaccines?
3-4 weeks after vaccine to see if they have protective immunity or if a booster is needed
*This is usually not done in practice*
93
When looking at an ECG - what conditions would show pre-arrest rhythms?
ventricular tachycardia
Ventricular flutter (shit ton of up and down)
3rd degree AV block (more P waves than QRS)
94
Define cardiopulmonary arrest.
Sudden loss of heart function --> loss of blood flow --> loss of consciousness
95
What diseases are transmitted via ticks?
```
Babesia (some spp zoonotic)
Lyme (zoonotic)
Anaplasma (some spp zoonotic)
Bartonella
haemoplasma
Louping Ill (zoonotic)
```
96
What are two likely causes of anesthesia-related arrests?
Anesthetic overdose or hypoventilation/hypoxia
| *Usually reversible with good care*
97
What is the drug therapy of choice for ventricular tachycardia?
LIDOCAINE
98
What are the criteria for terminating resuscitation?
Return of spontaneous circulation (ROSC) should have occurred within 8-10 minutes
(>12 minutes - survival is 2-5%)
Consider comorbidity/prearrest state of health
99
What is the drug used for euthanasia?
Pentobarbital (euthatal) --> depression of the CNS --> stopping of breathing and cardiac arrest
100
True or false: perfusion is more important than the number of circulating RBCs.
TRUE!
101
Doberman needs pain management for OA. Would you administer NSAIDs?
Yes, but only after checking for vWF disease
102
What NSAIDs are licensed in sheep, goats and apalcas?
None!!!
You administer under the cascade, just keep in mind that:
1) SHEEP: initial dose is higher than cattle dose, maintenance dose is the same
2) no steroids for them camelids
103
When would you choose to prescribe Flunixin?
- very potent analgesic -> so for painful conditions and after surgeries
- also binds endotoxins -> use in toxic systemic conditions (mastitis,metritis..)
- BUT administration in cattle and horses ONLY IV!! Not practical for the farmer
104
When would you choose to prescribe Meloxicam?
- Prolonged half life in cattle -> dont have to inject as often
- lameness
- systemic inflammation
- surgery
- visceral and ophthalmic pain
105
What are the NSAIDs that have no milk withdrawal period?
Ketoprofen (also cheaper but shorter half life) and carprofen
106
Why would you give Firocoxib to a horse?
- only COX2 specific
- reaches high concentrations in the eye
- licensed for OA and lameness management (other drugs are licensed for this too tho)
107
What corticosteroid would you prescribe to a horse?
Prednisolone.
| Dexamethasone has higher risk of laminitis
108
What diseases are transmitted via ticks?
Babesia (some spp zoonotic)
Lyme (zoonotic)
Anaplasma
Louping Ill (zoonotic)
109
What are the rules for travelling under the PETS scheme?
```
Pet passport
Microchip
Rabies vaccine (+ antibody titre if travelling from an unlisted country)
Tapeworm treatment before entering UK
(echinococcus)
Must travel via "approved route"
```
110
Explain how the Thyroglobulin auto antibody test works (immune med hypothyroidism)
- well with thyroglobulin antigen
- add patient serum (which should contain the antibody)
- Add reagent that has antibody-labelled enzyme that attaches to patient's antibody
- If there are TAutoAb the enzyme will cause a color change
111
How does Coomb's test work?
Add patient serum to a well with RBC
Results:
- patients with IgG mediated IMHA will show agglutination in the anti-IgG well -> extravascular hemolysis
- patients with IgM mediated IMHA will show agglutination in the IgM and in the anti-C3 well (IgM causes hemolysis via complement activation) -> intravascular hemolysis
112
How does Anti Nuclear Antibody test work? What does it test for?
It's a test for SLE.
- the well contains the patient's own cells
- the serum is added, if it contains antibodies those will attach to the cells in the well
- antibodies to ANA are labelled with a fluorescent enzyme and then added
- binding = fluorescence
113
How does an IgE (allergen) test work?
- the well contains the allergen (a specific flea antigen or some shit, idk I'm tired)
- the patient serum is added
- mast cells expressing Fc epsilon receptors are also added and they are labelled with an enzyme that catalises a color change
- if you see a color change-> IgE was present in the serum
114
What are some ways that infections can cause the immune system to become overreactive?
- break vascular/tissue barriers-> exposure to self antigens (sperm, lens..)
- abnormal immunoregulation
- exposure to superantigens that trigger exaggerated immune response
- exposure of cryptic epitopes usually present inside cells
- molecular mimicry between pathogen and cells
115
What is a common side effect of long term chlorambucil administration?
Pancytopenia
116
What is a common side effect of long term azathioprene administration?
Hepatic toxicity, where ALT>>ALP (if glucocorticoids are causing hepatotoxicity you will see the opposite)
117
What's the immunosuppressive drug of choice for IM thrombocytopenia?
Vincristine
| Immunosuppressive + stimulates platelet release. also doesnt cause myelosuppression as frequently
118
Most common side effect of cyclosporin in dogs
```
gingival hyperplasia
(hepatotoxicity has been documented but uncommon)
```
119
Explain a DIVA Vaccine.
Differentiating infected from vaccinated animals - These vaccines, also termed as marker vaccines, induce an immune response which is different from that induced by natural infection to be able to distinguish between the 2
*DIVA vaccines for IBR, Avian influenza, FMD*
120
True or false: giving Johne's vaccine can give false positive on bTB test and vice versa.
TRUE - they are genetically closely related
121
What is the purpose of doing serial testing?
After doing parallel testing and finding the positives, the serial testing will retest the positives to CONFIRM they are truly positive. Helps us to rid of false positives leading to increased specificity
122
What is the Knudson 2-hit hypothesis?
| Hint: has to do with cancer development
You need mutations on BOTH copies (alleles) of a gene to promote malignancy
Explains why some people have a genetic predisposition to developing cancers
123
Why are NSAIDs part of appropriate treatment for cancer?
| For what cancers specifically?
chronic inflammation is one of the main features that helps cancers survive and grow
Lung, melanoma, pancreas, colon, transitional cell carcinoma
124
What are Tyrosine kinase inhibitors?
| What are they used for?
TKI are inhibitors of cellular membrane receptors (TK) which gets constitutively turned on in some cancers (especially MCT). Also, TKR are also found in endothelial cells and are important in angiogenesis.
TKI -> inhibit both sustained growth signaling and angiogenesis
125
What primary mechanisms are used by cancer cells to metastasize?
1) Ability to invade new tissue -> metalloproteinases secretion
2) Ability to detach and enter circulation -> E-cadherin mutation
126
How do cancer cells change their metabolism? What kind of treatment targets this change?
They shift from mitochondrial oxidation (needs O2) to glycolysis
Tx: GLUT1 inhibitors
GLUT1 are transporters that facilitate glucose entry in cells
127
What is the primary aim of cancer treatment in vetmed?
Improving quality of life
(slowing down progress, palliation, temporary remission as long as the patient doesn't suffer side effects)
NOT cure. Aggressive tx is not acceptable, even if it can be curative
128
What are some supportive treatment you have to consider in cancer patients (besides chemo)?
- Analgesia (opioids, NSAIDs, gabapentin)
- Nutrition (mirtazapine to stimulate appetite)
- Antibiotics (some cancers/chemo cause neutropenia)
- Gastro-protectants (sulfacrate, omeprazole..)
- Antiemetics
129
Dog has a mass, GREAT.
| What can you do to investigate?
1) FNA -> look at cell type and morphology (distinguish inflammation vs neoplasia in most cases)
2) Biopsy -> sent to a pathologist who will do TUMOR GRADING for you
3) Flow cytometry -> can be run on the FNA sample, tells you what cells are in it. Useful to differentiate T from B cell lymphoma
4) PARR (clonality assay)-> looks at cellular receptors and tells you if you have inflammation (polyclonal) or neoplasia (monoclonal population)
5) TUMOR STAGING -> main goal of staging is to know the extent of disease
6) other lab tests on blood and urine to assess the patient systemically before chemo/for supportive tx
130
Common paraneoplastic effects
1) Hypercalcemia (PUPD, bradycardia, vomiting...)
2) Hyperglobulinaemia (seizures, renal failure, dyspnoea...)
3) Hypoglycemia (collapse, seizures..)
4) Gastric ulcerations (melaena, vomit...)
5) Hormone secretion (SCT, phaeochromocytoma)
6) myastenia gravis (regurgitation, weakness)
131
Would you advice to spay at the time of a BENIGN mammary mass removal?
Yes. It's been shown that spaying reduces the risk of developing new masses by 50%
132
What mammary cancer carries the worst prognosis?
Mammary inflammatory carcinoma
133
How do carcinomas normally spread?
Through lymphatics
134
How do sarcomas normally spread?
Vascularly
135
What is the tumor that tends to be very invasive but has low metastatic rate?
fibrosarcoma!!
136
What tumors metastasize very early and rapidly?
- tonsillar carcinomas
- mammary tumors in cats
- pancreatic carcinomas
- osteosarcomas
- oral and digital melanomas
- anal sac carcinomas
137
What markers differentiate T from B cells in immunohistochemistry?
T cell-> CD3
| B cell-> CD79a or CD20
138
Tumor grading vs staging
GRADING - done by the pathologist. Basically they look at how poorly differentiated the tumor is, that can tell you how bad the tumor is
STAGING - done by the clinician, asses the spread of tumor
A high grade tumor can be at an early stage (if caught early)
139
What is the main concern in patients with intestinal lymphoma that are on chemo?
Bacterial translocation
| They should be on prophylactic antibiotics if neutropenic
140
What is the best protocol for renal lymphoma?
COAP
which has cytarabine instead of doxorubicin. cytarabine has higher CNS penetration (renal lymphoma commonly spread to CNS)
141
What are some side effects of vincristine? How do you manage them?
- extravasation during injection-> flush before and after administration
- ileus/ constipation -> give metoclopramide or ranitidine
142
In lymphomas, if remission is achieved with a protocol such as CHOP, what is the next appropriate protocol for maintenance?
CATS: Prednisolone + chlorambucil
DOGS: Prednisolone + chlorambucil + methotrexate
143
Aims of oncolological surgery
1) Curative (through local, wide or radical excision depending on tumor type)
2) Biopsy (excisional vs incisional)
3) Palliation (reducing the size -> reduce the discomfort and paraneoplastic syndrome)
4) Cytoreduction (reduce size to make it more susceptible to chemo or to perform radiotherapy)
5) Tumor prevention (spay)
144
Information needed to plan the surgery
- local extent of the mass (what structures does it compromise? How big)
- tumor grade and type
- distant metastasis (staging)
- nutritional status of the patient (may need to put in a feeding tube)
145
T or F: it's better to excise a tumor in stages
NOOOO
The first surgery has the highest chance of success. Previous surgeries may disrupt margins, spread cancer cells to adjacent tissues and disrupt structures for closure
146
What are the indications for local/ wide/ radical excisions?
- local: narrow margins. only for tumors like lipomas that are definitely benign and non invasive
- wide excision (so 2-3 cm margins and 1-2 deep fascial planes taken out) indicated for benign tumors that have invaded into adjacent tissue (sarcomas at early stage) or for malignant tumors with very limited local invasion (SCC at early stage)
- radical excision when you take out a whole muscle group or limb. indicated for tumors with widespread invasion, involving joints or if they have high rate or recurrence
147
Treatment of choice for nasal carcinomas
radiotherapy
148
For what cancer do we have a vaccine (tyrosinase DNA vaccine) used as treatment?
malignant melanoma
| Chemo not effective for this type of tumor
149
What is the 1,2,3 rule for feline injection sarcomas?
The tumor is probably a FIS if it appeared 1 mo after injection, is more than 2 cm in margins and if it persisted for more than 3 mo
150
T or F: always try to take an excisional biopsy of FIS to find out the tumor grade
FALSE DONT DO THAT!!!!
| Take an incisional biopsy and REFER for surgery. Removing them after a failed first excision attempt is really difficult
151
T or F: radiotherapy is the treatment of choice for oral fibrosarcomas
FALSE!!
| these tumors are radioresistant, surgery is best ( mandibulectomy) + chemo
152
What is the treatment of choice for SCC?
- mandibulectomy + RT
- follow up with chemo (carboplatin +TKI + NSAID) if there is systemic spread
In cats these tumors are much more aggressive so you may prefer metronomic therapy to chemo
153
Why should you send a mass you excised for histopath?
The pathologist will tell you if you have "clean margins" or if you need to follow up with RT/chemo
They will also tell yuo if there is evidence of hematogenous/lymphatic spread
