Multiple Choice Questions MCQ

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Multiple Choice Questions (MCQ)

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Question 156# Print Question

Which one of the following best describes rheumatoid factor?

A. IgG against the Fc portion of IgM

Correct Answer D: Rheumatoid factor is an IgM antibody against IgG.

Rheumatoid factor:
Rheumatoid factor (RF) is a circulating antibody (usually IgM) which reacts with the Fc portion of the patients own IgG.

RF can be detected by either:

Rose-Waaler test: sheep red cell agglutination
Latex agglutination test (less specific)

RF is positive in 70-80% of patients with rheumatoid arthritis, high titre levels are associated with severe progressive disease (but NOT a marker of disease activity).

Other conditions associated with a positive RF include:

Sjogren's syndrome (around 100%)
Felty's syndrome (around 100%)
Infective endocarditis (= 50%)
SLE (= 20-30%)
Systemic sclerosis (= 30%)
General population (= 5%)
Rarely: TB, HBV, EBV, leprosy

Question 157# Print Question

Which one of the following stimulates the release of gastrin from G-cells?

Correct Answer E:

Gastrointestinal hormones:

Below is a brief summary of the major hormones involved in food digestion:

Question 158# Print Question

A 67-year-old woman who is taking long-term prednisolone for polymyalgia rheumatica presents with progressive pain in her right hip joint. A diagnosis of avascular necrosis is suspected.

Which investigation is most likely to be diagnostic?

A. Radionuclide bone scan

Correct Answer B: In early avascular necrosis a radionuclide bone scan is less sensitive than MRI and the findings may be nonspecific. MRI is therefore the investigation of choice.

Avascular necrosis:
Avascular necrosis (AVN) may be defined as death of bone tissue secondary to loss of the blood supply. This leads to bone destruction and loss of joint function. It most commonly affects the epiphysis of long bones such as the femur.

Causes:

Long-term steroid use
Chemotherapy
Alcohol excess
Trauma

Features:

Initially asymptomatic
Pain in the affected joint

Investigation:

Plain x-ray findings may be normal initially
MRI is the investigation of choice. It is more sensitive than radionuclide bone scanning

Question 159# Print Question

What is the underlying problem in methaemoglobinaemia?

A. The oxidation of Fe²⁺ in haemoglobin to Fe³⁺

Correct Answer A: Methaemoglobinaemia = oxidation of Fe²⁺ in haemoglobin to Fe³⁺

Methaemoglobinaemia:
Methaemoglobinaemia describes haemoglobin which has been oxidised from Fe²⁺ to Fe³⁺. This is normally regulated by NADH methaemoglobin reductase, which transfers electrons from NADH to methaemoglobin resulting in the reduction of methaemoglobin to haemoglobin. There is tissue hypoxia as Fe³⁺ cannot bind oxygen, and hence the oxidation dissociation curve is moved to the left.

Congenital causes:

Haemoglobin chain variants: HbM, HbH
NADH methaemoglobin reductase deficiency

Acquired causes:

Drugs: sulphonamides, nitrates, dapsone, sodium nitroprusside, primaquine
Chemicals: aniline dyes

Features:

'Chocolate' cyanosis
Dyspnoea, anxiety, headache
Severe: acidosis, arrhythmias, seizures, coma
Normal pO₂ but decreased oxygen saturation

Management:

NADH - methaemoglobinaemia reductase deficiency: ascorbic acid
IV methylene blue if acquired

Question 160# Print Question

A 65-year-old Asian female presents with generalized bone pain and muscle weakness. Investigations show:

Calcium 2.07 mmol/l
Phosphate 0.66 mmol/l
ALP 256 U/l

What is the most likely diagnosis?

A. Bone tuberculosis

Correct Answer D:

Osteomalacia:

Low: calcium, phosphate
Raised: alkaline phosphatase

The low calcium and phosphate combined with the raised alkaline phosphatase point towards osteomalacia.

Osteomalacia:
Basics:

Normal bony tissue but decreased mineral content
Rickets if when growing
Osteomalacia if after epiphysis fusion

Types:

Vitamin D deficiency e.g. malabsorption, lack of sunlight, diet
Renal failure
Drug induced e.g. anticonvulsants
Vitamin D resistant; inherited
Liver disease, e.g. cirrhosis

Features:

Rickets: knock-knee, bow leg, features of hypocalcaemia
Osteomalacia: bone pain, fractures, muscle tenderness, proximal myopathy

Investigation:

Low calcium, phosphate, 25(OH) vitamin D
Raised alkaline phosphatase
X-ray: children - cupped, ragged metaphyseal surfaces; adults - translucent bands (Looser's zones or pseudofractures)

Treatment:

Calcium with vitamin D tablets

Question 156# Which one of the following best describes rheumatoid factor?
A. IgG against the Fc portion of IgM
B. IgM against the Fc portion of IgA
C. IgM against the Fc portion of IgM
D. IgM against the Fc portion of IgG
E. IgG against the Fc portion of IgA
Correct Answer D: Rheumatoid factor is an IgM antibody against IgG. Rheumatoid factor: Rheumatoid factor (RF) is a circulating antibody (usually IgM) which reacts with the Fc portion of the patients own IgG. RF can be detected by either: Rose-Waaler test: sheep red cell agglutination Latex agglutination test (less specific) RF is positive in 70-80% of patients with rheumatoid arthritis, high titre levels are associated with severe progressive disease (but NOT a marker of disease activity). Other conditions associated with a positive RF include: Sjogren's syndrome (around 100%) Felty's syndrome (around 100%) Infective endocarditis (= 50%) SLE (= 20-30%) Systemic sclerosis (= 30%) General population (= 5%) Rarely: TB, HBV, EBV, leprosy

Question 157# Which one of the following stimulates the release of gastrin from G-cells?
A. Histamine
B. Somatostatin
C. Gastric acid
D. Cholecystokinin
E. Luminal peptides
Correct Answer E: Gastrointestinal hormones: Below is a brief summary of the major hormones involved in food digestion:

Question 158# A 67-year-old woman who is taking long-term prednisolone for polymyalgia rheumatica presents with progressive pain in her right hip joint. A diagnosis of avascular necrosis is suspected. Which investigation is most likely to be diagnostic?
A. Radionuclide bone scan
B. MRI
C. Plain x-ray
D. CT
E. DEXA scan
Correct Answer B: In early avascular necrosis a radionuclide bone scan is less sensitive than MRI and the findings may be nonspecific. MRI is therefore the investigation of choice. Avascular necrosis: Avascular necrosis (AVN) may be defined as death of bone tissue secondary to loss of the blood supply. This leads to bone destruction and loss of joint function. It most commonly affects the epiphysis of long bones such as the femur. Causes: Long-term steroid use Chemotherapy Alcohol excess Trauma Features: Initially asymptomatic Pain in the affected joint Investigation: Plain x-ray findings may be normal initially MRI is the investigation of choice. It is more sensitive than radionuclide bone scanning

Question 159# What is the underlying problem in methaemoglobinaemia?
A. The oxidation of Fe²⁺ in haemoglobin to Fe³⁺
B. The reduction of Fe²⁺ in haemoglobin to Fe⁺
C. The oxidation of Fe³⁺ in haemoglobin to Fe²⁺
D. The reduction of Fe²⁺ in haemoglobin to Fe³⁺
E. The reduction of Fe³⁺ in haemoglobin to Fe²⁺
Correct Answer A: Methaemoglobinaemia = oxidation of Fe²⁺ in haemoglobin to Fe³⁺ Methaemoglobinaemia: Methaemoglobinaemia describes haemoglobin which has been oxidised from Fe²⁺ to Fe³⁺. This is normally regulated by NADH methaemoglobin reductase, which transfers electrons from NADH to methaemoglobin resulting in the reduction of methaemoglobin to haemoglobin. There is tissue hypoxia as Fe³⁺ cannot bind oxygen, and hence the oxidation dissociation curve is moved to the left. Congenital causes: Haemoglobin chain variants: HbM, HbH NADH methaemoglobin reductase deficiency Acquired causes: Drugs: sulphonamides, nitrates, dapsone, sodium nitroprusside, primaquine Chemicals: aniline dyes Features: 'Chocolate' cyanosis Dyspnoea, anxiety, headache Severe: acidosis, arrhythmias, seizures, coma Normal pO₂ but decreased oxygen saturation Management: NADH - methaemoglobinaemia reductase deficiency: ascorbic acid IV methylene blue if acquired

Question 160# A 65-year-old Asian female presents with generalized bone pain and muscle weakness. Investigations show: Calcium 2.07 mmol/l Phosphate 0.66 mmol/l ALP 256 U/l What is the most likely diagnosis?
A. Bone tuberculosis
B. Hypoparathyroidism
C. Myeloma
D. Osteomalacia
E. Paget's disease
Correct Answer D: Osteomalacia: Low: calcium, phosphate Raised: alkaline phosphatase The low calcium and phosphate combined with the raised alkaline phosphatase point towards osteomalacia. Osteomalacia: Basics: Normal bony tissue but decreased mineral content Rickets if when growing Osteomalacia if after epiphysis fusion Types: Vitamin D deficiency e.g. malabsorption, lack of sunlight, diet Renal failure Drug induced e.g. anticonvulsants Vitamin D resistant; inherited Liver disease, e.g. cirrhosis Features: Rickets: knock-knee, bow leg, features of hypocalcaemia Osteomalacia: bone pain, fractures, muscle tenderness, proximal myopathy Investigation: Low calcium, phosphate, 25(OH) vitamin D Raised alkaline phosphatase X-ray: children - cupped, ragged metaphyseal surfaces; adults - translucent bands (Looser's zones or pseudofractures) Treatment: Calcium with vitamin D tablets

Your-Doctor Multiple Choice Questions (MCQ)

Your-Doctor
Multiple Choice Questions (MCQ)