Exam Tidibits

Question 1

What are the absolute and relative contraindications for thrombolysis in an acute ischaemic stroke?

Answer 1

Absolute Contraindications
· Intracranial haemorrhage on CT
· Clinical presentation suggests subarachnoid haemorrhage
· Neurosurgery, head trauma or stroke in the past 3 months
· Uncontrolled hypertension (>185/110)
· History of intracranial haemorrhage
· Known intracranial ateriovenous malformation, neoplasm or aneurysm
· Active internal bleeding
· Suspected/confirmed endocarditis
· Known bleeding diathesis
○ Platelet count <100,000
○ Received heparin within 48 hours and elevated aPTT
○ Current use of oral anticoagulation and INR > 1.7
○ Current use of direct thrombin inhibitors or direct factor Xa inhibitors
· Abnormal blood glucose (<50mg/dL, 2.8mmol/L)

Relative Contraindications
· Minor or rapidly improving stroke symptoms
· Major surgery of serious non-head trauma in the previous 14 days
· History of GIT or urinary tract haemrrhage within 21 days
· Seizure at stroke onset
· Recent arterial puncture at non-compressible site within 7 days
· Recent lumbar puncture
· Post myocardial infarction pericarditis
· Pregnancy

Question 2

Why is dexamethasone used in meningitis?

Answer 2

To cover pneumococcus meningitis which is gram positive diplococci, to prevent hearing loss associated with pneumococcal meningitis
This is also why vancomycin is given as ceftriaxone can not cover pneumococcus.

Question 3

Elevations in which of the following measures would most accurately predict increased disease activity in a patient with RA?
A. Anti-CCP titre
B. Elevated ESR 
C. Immunoglobulin levels 
D. RF titre 
E. Tumour necrosis factor leve

Answer 3

B- elevated ESR

Anti-CCP:

• Marker of severe erosive disease
• Not helpful to assess current RA activity

RF:

• Marker of extra-articular involvement
• Not helpful to assess current RA activity

Question 4

A number of biological therapeutics have been genetically altered to couple the biologically active moiety to the Fc segment of IgG. This is done to
A. Target the biologic to B cells
B. Maximise interaction of the biologic with cells expressing the Fc gamma receptors
C. Target biologic to macrophages
D. Increase interaction with target cell
E. Increase half life of therapeutic

Answer 4

E. Increase half life of therapeutic

Question 5

What can cause elevated CEA levels?
A. Gastric cancer
B. Colocrectal cancer 
C. Breast cancer 
D. Lung cancer
E. All of the above

Answer 5

All of the above

Question 6

What is hepcidin?

Answer 6

Hepcidin is a key regulator of iron homeostasis and plays a role in the pathogenesis of ANAEMIA OF CHRONIC DISEASE. Its levels are increased in patients with chronic kidney disease (CKD) due to diminished renal clearance and an inflammatory state.

Question 7

What is the most common mutation in papillary thyroid cancer?

Answer 7

BRAF V600E

Question 8

What is a truncating mutation/protein truncation?

Answer 8

A genetic variant which results in a shorter version of the protein being produced.

Question 9

Which anti-histamine should not be used in anaphylaxis?

Answer 9

Promethazine can worse hypotension and cause muscle necrosis

Question 10

In patients infected with HIV, risk for which of the following cancers does not decline following initiation of antiretroviral therapy and restoration of CD4 count > 500?
A. Lung cancer 
B. Anal cancer
C. NHL
D. Hodgkins lymphoma 
E. Risk for all above declines

Answer 10

E. Risk for all above declines

Question 11

All of the following nutrients are absorbed by the small intestine except for:
A. Iron 
B. Carbohydrates
C. Short chain fatty acids 
D. Amino acids 
E. Vitamin B12

Answer 11

Short chain fatty acids

Question 12

Which among the following does not affect serum potassium levels? 
A. ADH
B. Aldosterone
C. Thyroxine
D. Adrenaline
E. Insulin

Answer 12

ADH

REMEMBER: in thyroid storm
- Lugol solution or potassium iodide solution is given to inhibit thyroid hormone release/inhibit release of pre-formed thyroxine (through the Wolff-Chaikoff Effect)

Question 13

MOA of levosimendan

Answer 13

Positive inotropic drug with vasodilatory effects
Levosimendan is a calcium sensitizer — it increases the sensitivity of the heart to calcium, thus increasing cardiac contractility without a rise in intracellular calcium. Levosimendan exerts its positive inotropic effect by increasing calcium sensitivity of myocytes by binding to cardiac troponin C in a calcium-dependent manner. It also has a vasodilatory effect, by opening adenosine triphosphate (ATP)-sensitive potassium channels in vascular smooth muscle to cause smooth muscle relaxation. The combined inotropic and vasodilatory actions result in an increased force of contraction, decreased preload and decreased afterload. Moreover, by opening also the mitochondrial (ATP)-sensitive potassium channels in cardiomyocytes, the drug exerts a cardioprotective effect

Question 14

Graves disease is driven by autoantibodies to the TSH receptor, but autoantibodies to thyroid peroxidase or thyroglobulin are often also found. This observation most likely represents which phenomenon in autoimmunty?
A. Molecular mimicry
B. Release of sequestered antigens from immunologically privileged sites
C. Epitope/antigen spreading
D. Altered self
E. Immune complex deposition

Answer 14

C. Epitope/antigen spreading

Molecular Mimicry
- Molecular mimicry is one of the leading mechanisms by which infectious or chemical agents may induce autoimmunity. It occurs when similarities between foreign and self-peptides favor an activation of autoreactive T or B cells by a foreign-derived antigen in a susceptible individual. EG; Guillain barre syndrome elicited by a previous infection.

Epitope/antigen spreading: Epitope spreading refers to the recruitment of autoreactive lymphocytes against normally tolerated host antigens, which contributes to disease chronicity and course, eg: Bullous Pemphigoid

).

Question 15

In 2015, novel resistance mechanism called mcr-1 was described in E coli isolates from China. mcr-1 confers resistance to clistin and polymyxin B and has subsequently been found in many isolates in Europe, Asia and America. Which genetic element within bacteria is mcr-a found in?
A. Transposons
B. Plasmids 
C. Bacterial chromosome
D. Intron
E. Insertion sequences

Answer 15

B. Plasmids

Question 16

What is the mechanism action of mesna?

Answer 16

Mesna helps protect your bladder to prevent irritation and bleeding. Mesna is always given with ifosfamide.

Question 17

Which of the following statements are most correct regarding X linked dominant inheritance?
A. Affected males are linked by unaffected females in the family
B. There is no female to female transmission
C. Affected males and females show the same phenotype
D. Female carriers show a phenotype
E. Affected females are linked by unaffected males in the family

Answer 17

D- female carriers show a phenotype

• Families with an X-linked recessive disorder often have affected males, but rarely affected females, in each generation.
• For X-linked dominant diseases, however, a mutation in one copy of an X-linked gene will result in disease for both males and females.

Question 18

Which of the following terms is used to describe when multiple, often seemingly unrelated, physical effects are caused by a mutation in a single gene?
A. Haplotype
B. Allelic heterogeneity
C. Locus heterogeneity 
D. Pleiotropy
E. Heteroplasmy

Answer 18

D. Pleiotropy

• Haploptye: A haplotype is a group of genes within an organism that was inherited together from a single parent, eg: HLA
• Allelic heterogeneity: occurs when different variants at a single gene locus cause the same or similar phenotypic expressions of a disease or condition.
• Locus heterogeneity: occurs when variants at different gene loci cause the same or similar phenotypic expressions of a disease or condition.
• Pleiotropy: occurs when one gene influences two or more seemingly unrelated phenotypic traits, eg: A common example of pleiotropy is the human disease phenylketonuria (PKU). This disease causes mental retardation and reduced hair and skin pigmentation, and can be caused by any of a large number of mutations in the single gene on chromosome 12 that codes for the enzyme phenylalanine hydroxylase, which converts the amino acid phenylalanine to tyrosine. Depending on the mutation involved, this conversion is reduced or ceases entirely. Unconverted phenylalanine builds up in the bloodstream and can lead to levels that are toxic to the developing nervous system of newborn and infant children.
• Heteroplasmy: Heteroplasmy is the presence of more than one type of organellar genome within a cell or individual. It is an important factor in considering the severity of mitochondrial diseases

Question 19

What are features of mitochondrial disease?

Answer 19

Common clinical features of mitochondrial disorders include ptosis, external ophthalmoplegia, proximal myopathy and exercise intolerance, cardiomyopathy, sensorineural deafness, optic atrophy, pigmentary retinopathy, and diabetes mellitus. Diabetes mellitus and deafness is also a well-recognized clinical phenotype

Although it is not specific, an unexplained elevation of lactate in any tissue (blood, cerebrospinal fluid, brain, or urine) should raise suspicions for a mitochondrial disorder and warrants evaluation, whereas a normal lactate level in any or all tissues does not eliminate the possibility of a mitochondrial disorder.

Question 20

The advancements in surgical technique and immunosuppressive regimens have greatly improved the long term outcomes of patients receiving a liver transplant? In which of the following indications for transplant (assuming end stage cirrhosis) is recurrent disease most likely to be the cause of an adverse impact on long term outcomes?
A. Chronic hep C, untreated pre-transplant
B. Chronic hep B
C. Non-alcoholic steatohepatitis
D. Primary sclerosing cholangitis
E. Alcoholic cirrhosis

Answer 20

D. Primary sclerosing cholangitis

Question 21

If there is a head of pancreas tumour - think Ig4 disease which is treated with steroids

Answer 21

If there is a head of pancreas tumour - think Ig4 disease which is treated with steroids

If there is a head of pancreas tumour
Contraindications to surgery; if too close to artery, mets
To acquire tissue - EUS + biopsy

Question 22

Which organism can cause haemoptysis and pneumonia?

Answer 22

Legionella - found mainly in water but also soil

Question 23

Treatment of High-severity CAP in adults: tropical regions

Answer 23

• The Gram-negative bacteria Burkholderia pseudomallei and Acinetobacter baumannii can cause community-acquired pneumonia (CAP);
• Treatment: meropenem + azithromycin

Question 24

Anaphylaxis

Answer 24

IM 0.5mg of 1:1000 adrenaline

If this doesn’t work

• IV adrenaline infusion
  (a) If upper airway obstruction: nebulised adrenaline or intubation

(b) If persistent hypotension/shock:
Normal saline
Cardiogenic shock: glucagon bolus
ICU can consider metaraminol

(c) If persistent wheeze: bronchodilators, oral pred/IV hydrocortisone
- Do not give promethazine as it can worsen hypotension and cause muscle necrosis