-
Question 1
Correct
-
A patient with history of weight loss and diarrhoea was found out to have Giardia lamblia in her stool since returning from a holiday to Nepal.
Which of the following statements is considered true regarding the life cycle of Giardia lamblia?Your Answer: Trophozoites attach to the intestinal wall via a specialised sucking disc
Explanation:Cysts are resistant forms and are responsible for transmission of giardiasis. Both cysts and trophozoites can be found in the faeces (diagnostic stages). The cysts are hardy and can survive several months in cold water. Infection occurs by the ingestion of cysts in contaminated water, food, or by the faecal-oral route (hands or fomites).
In the small intestine, excystation releases trophozoites (each cyst produces two trophozoites).
Trophozoites multiply by longitudinal binary fission, remaining in the lumen of the proximal small bowel where they can be free or attached to the mucosa by a ventral sucking disk.
Encystation occurs as the parasites transit toward the colon. The cyst is the stage found most commonly in non diarrheal faeces.
Because the cysts are infectious when passed in the stool or shortly afterward, person-to-person transmission is possible. While animals are infected with Giardia, their importance as a reservoir is unclear. -
This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
-
-
Question 2
Correct
-
Which of the following study designs is considered the most appropriate to safely determine whether an association exists between a well-established, commonly used, anti-hypertensive medication and causing type II diabetes mellitus?
Your Answer: A meta-analysis
Explanation:Evidence-based medicine may be defined as the systematic, quantitative, preferentially experimental approach to obtaining and using medical information. Therefore, meta-analysis, a statistical procedure that integrates the results of several independent studies, plays a central role in evidence-based medicine.
Meta-analysis is a quantitative, formal, epidemiological study design used to systematically assess previous research studies to derive conclusions about that body of research. Outcomes from a meta-analysis may include a more precise estimate of the effect of treatment or risk factor for disease, or other outcomes, than any individual study contributing to the pooled analysis.
-
This question is part of the following fields:
- Evidence Based Medicine
-
-
Question 3
Correct
-
The most common site of ectopic pregnancy is?
Your Answer: Ampulla of Fallopian tube
Explanation:Nearly 95% of ectopic pregnancies are implanted in the various segments of the fallopian tube and give rise to fimbrial, ampullary, isthmic, or interstitial tubal pregnancies. The ampulla is the most frequent site, followed by the isthmus. The remaining 5% of non tubal ectopic pregnancies implant in the ovary, peritoneal cavity, cervix, or prior caesarean scar.
-
This question is part of the following fields:
- Abdomen And Pelvis
- Anatomy
-
-
Question 4
Incorrect
-
Haemophilia B results from a deficiency in:
Your Answer: Von Willebrand factor
Correct Answer: Factor IX
Explanation:Haemophilia B is a bleeding disorder caused by a deficiency of clotting factor IX. It is the second commonest form of haemophilia, and is rarer than haemophilia A. Haemophilia B tends to be similar to haemophilia A but less severe. The two disorders can only be distinguished by specific coagulation factor assays.
The incidence is one-fifth of that of haemophilia A. Laboratory findings demonstrate prolonged APTT, normal PT and low factor IX.
Haemophilia B inherited in an X-linked recessive fashion, affecting males born to carrier mothers.
There is also a variation called Leyden, in which factor IX levels are below 1% until puberty, when they rise, potentially reaching as high as 40-60% of normal. This is thought to be due to the effects of testosterone at puberty. -
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 5
Incorrect
-
A 30-year-old patient has a mild exacerbation of his asthma. His steroid inhaler ran out a couple of weeks ago, and he has not replaced it.
Which of these statements describes the mechanism of action of corticosteroids in asthma?
Your Answer: Stabilisation of mast cell membranes
Correct Answer: Reduction of bronchial inflammation
Explanation:Inhaled corticosteroids suppresses airway inflammation seen in asthma by downregulating pro-inflammatory proteins.
They also appear to reverse components of asthma-induced structural changes (airway remodelling), including increased vascularity of the bronchial wall.
Corticosteroids reduces the number of inflammatory cells (eosinophils, T lymphocytes, mast cells, and dendritic cells) in the airways. -
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
-
-
Question 6
Incorrect
-
Disease specific immunoglobulin is available for all of the following infectious diseases EXCEPT for:
Your Answer: Varicella-zoster
Correct Answer: Hepatitis A
Explanation:Disease specific immunoglobulins are available for:
hepatitis B
rabies
tetanus
varicella-zoster
Normal immunoglobulin can be used to confer protection against hepatitis A. -
This question is part of the following fields:
- Immunoglobulins And Vaccines
- Pharmacology
-
-
Question 7
Incorrect
-
Urine flow rate = 2 ml/min
Urine concentration of creatinine = 18 mg/ml
Plasma concentration of creatinine = 0.25 mg/ml
What is the estimated glomerular filtration rate (eGFR)?
Your Answer: 2.5 ml/min
Correct Answer: 144 ml/min
Explanation:GFR can be estimated by:
GFR = UCr x V / PCr
Where:
UCr = urine concentration of creatinine
PCr = plasma concentration of creatinine
V = rate of urine flowIn this case GFR = (18 x 2) / 0.25 = 144 ml/min
Note: Creatinine is used to estimate GFR because it is an organic base naturally produced by muscle breakdown, it is freely filtered at the glomerulus, it is not reabsorbed from the nephron, it is not produced by the kidney, it is not toxic, and it doesn’t alter GFR.
-
This question is part of the following fields:
- Physiology
- Renal Physiology
-
-
Question 8
Incorrect
-
Regarding the varicella zoster virus, which of the following statements is CORRECT:
Your Answer: The varicella zoster vaccine is part of routine childhood immunisation.
Correct Answer: Contracting chickenpox infection while pregnant is associated with a higher risk of developing varicella pneumonitis.
Explanation:Chickenpox infection in neonates, adults/adolescents and pregnant women is associated with more severe disease. Varicella zoster pneumonitis typically occurs in pregnant women or immunocompromised individuals and is associated with a high mortality. A live attenuated-virus vaccine is available and recommended for non-immune healthcare workers but is not part of the routine childhood immunisation schedule. Antiviral treatment is not typically recommended in childhood chickenpox but is indicated for shingles.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 9
Incorrect
-
An elderly female has a bacterial infection and you are asked to prescribe an antibiotic to her. This antibiotic is a nucleic acid synthesis inhibitor.
Which of the following antimicrobial drugs will be prescribed to this patient?Your Answer: Vancomycin
Correct Answer: Metronidazole
Explanation:Metronidazole and the other 5-nitroimidazole agents inhibit nucleic acid synthesis by forming toxic free radical metabolites in the bacterial cell that damage DNA.
Vancomycin inhibits cell wall peptidoglycan formation by binding the D-Ala-D-Ala portion of cell wall precursors.
Erythromycin inhibits protein synthesis and blocks translocation by binding to the 23S rRNA of the 50S ribosomal subunit.
Chloramphenicol blocks peptidyl transferase at 50S ribosomal subunit.
Gentamicin, an aminoglycoside antibiotic, acts by binding to the 30S subunit of the bacterial ribosome inhibiting the binding of aminoacyl-tRNA and thus preventing initiation of protein synthesis.
An overview of the different mechanisms of action of the various types of antimicrobial agents is shown below:
1. Inhibition of cell wall synthesis
– Penicillins
– Cephalosporins
– Vancomycin
2. Disruption of cell membrane function
– Polymyxins
– Nystatin
– Amphotericin B
3. Inhibition of protein synthesis
– Macrolides
– Aminoglycosides
– Tetracyclines
– Chloramphenicol
4. Inhibition of nucleic acid synthesis
– Quinolones
– Trimethoprim
– 5-nitroimidazoles
– Rifampicin
5. Anti-metabolic activity
– Sulphonamides
– Isoniazid -
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 10
Incorrect
-
A 67-year-old man complains of chest pain and goes to the emergency room. He takes several medications, including amiodarone.
Which of the following is amiodarone mechanism of action?Your Answer:
Correct Answer: Blocks Na + and K + channels and beta-adrenoreceptors in the heart
Explanation:Amiodarone is an anti-arrhythmic medication that can be used to treat both ventricular and atrial arrhythmias. It’s a class III anti-arrhythmic that works by blocking a variety of channels, including Na+ and K+ channels, as well as beta-adrenoreceptors. As a result, it slows conduction through the SA and AV nodes and prolongs phase 3 of the cardiac action potential (slowing repolarisation).
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
SESSION STATS - PERFORMANCE PER SPECIALTY
