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Question 1
Correct
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Which of the following with regard to DNA mutations does not fit:
Your Answer: All gene mutations cause clinical disease entities
Explanation:All gene mutations do not cause a clinical manifestation of the disease, some gene mutations are silent mutations. They are present but do not cause any disease.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 2
Correct
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An obstruction in a pulmonary artery causes impaired perfusion to an area in the lung. The gas values in the unperfused alveoli at sea level will be:
Your Answer: PO2 = 149 C02 =0
Explanation:Partial pressure of oxygen at sea level is approximately 160 mmHg. Partial pressure of oxygen in alveoli is around 150 mmHg and in an arteriole is around 80-100 mmHg. Partial pressure of carbon dioxide is around 35 mmHg in alveolar air and around 40 mmHg in the arteriole.
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This question is part of the following fields:
- Medicine
- Respiratory
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Question 3
Incorrect
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Which of the following statements regarding psoriasis is incorrect?
Your Answer: Often occurs on extensor surfaces
Correct Answer: Mediated by type 2 helper T cells
Explanation:Psoriasis is a long-lasting autoimmune disease which is characterized by patches of abnormal skin. These skin patches are typically red, itchy, and scaly commonly on the extensor surfaces. Psoriasis is associated with an increased risk of psoriatic arthritis, lymphomas, cardiovascular disease, Crohn’s disease, and depression. Psoriatic arthritis affects up to 30% of individuals with psoriasis. Psoriasis is mediated by type 1 helper T cells which are involved in the cell mediated response, rather than type 2 helper T cells
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This question is part of the following fields:
- Dermatology
- Medicine
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Question 4
Correct
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A 28-year-old female admitted for a course of chemotherapy, has been taking high dose steroids for a few days. The nurses report that she is very agitated and talks about trying to open the window of her room and jump out from the fourth floor.You review her notes and see that she admits to drinking a few glasses of wine per week and has smoked cannabis on a few occasions.On examination her BP is 145/88 mmHg, her pulse is 80 bpm.Blood investigations reveal:Haemoglobin: 12.1 g/dL (11.5-16.5)WBC count: 16.2 x 103/dL (4-11)Platelets: 200 x 109/L (150-400)C-reactive protein: 9 nmol/l (<10)Sodium: 140 mmol/l (135-146)Potassium: 3.9 mmol/l (3.5-5)Creatinine: 92 μmol/l (79-118)Which of the following is the most likely diagnosis?
Your Answer: Corticosteroid-related psychosis
Explanation:Agitation, hypomania and suicidal intent within a few days after initiating corticosteroid therapy is highly suggestive of a diagnosis of corticosteroid-induced psychosis.In some patients corticosteroid related psychosis has been diagnosed up to 12 weeks or more after commencing therapy.Euphoria and hypomania are considered to be the most common psychiatric symptoms reported during short courses of steroids.During long-term treatment, depressive symptoms were the most common. Higher steroid doses appear to carry an increased risk for such adverse effects; however, there is no significant relationship between dose and time to onset, duration, and severity of symptoms. Management: Reduction or cessation of corticosteroids is the mainstay of treatment for steroid psychosis. For those patients who cannot tolerate this reduction/cessation of steroids, mood stabilizers may be of some benefit.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 5
Correct
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A 30-year-old male with a history of premature cardiovascular disease in the family has come for review of his lab investigations. His fasting cholesterol is 8.4 mmol/l with high-density lipoprotein (HDL) of 1.6 mmol/l. You elect to commence him on atorvastatin 20 mg PO daily.Which of the following best describes the mechanism of action of the statins?
Your Answer: They inhibit HMG CoA reductase
Explanation:Statins are a selective, competitive inhibitor of hydroxymethylglutaryl-CoA (HMG-CoA) reductase, which is the enzyme responsible for the conversion of HMG-CoA to mevalonate in the cholesterol synthesis pathway.Statins are usually well tolerated with myopathy, rhabdomyolysis, hepatotoxicity, and diabetes mellitus being the most common adverse reactions. This is the rate-limiting step in cholesterol synthesis, that leads to increased hepatic low-density lipoprotein (LDL) receptors and reduced hepatic VLDL synthesis coupled with increased very-low-density lipoprotein (VLDL) clearance.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 6
Correct
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What is the function of the pro-apoptotic Bcl-2 family of proteins, Bax and Bak?
Your Answer: Form permissive pores in the mitochondrial membrane
Explanation:The pro-apoptotic proteins in the BCL-2 family, including Bax and Bak, normally act on the mitochondrial membrane to promote permeabilization and release of cytochrome C and ROS, that are important signals in the apoptosis cascade. Growing evidence suggests that activated BAX and/or Bak form an oligomeric pore, MAC in the mitochondrial outer membrane. This results in the release of cytochrome c and other pro-apoptotic factors from the mitochondria, often referred to as mitochondrial outer membrane permeabilization, leading to activation of caspases.
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This question is part of the following fields:
- Cell Biology
- Medicine
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Question 7
Incorrect
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Which of the following features is least commonly seen in Gitelman’s syndrome?
Your Answer: Metabolic alkalosis
Correct Answer: Hypertension
Explanation:Gitelman syndrome is an autosomal recessive kidney disorder characterized by hypokalaemia metabolic alkalosis with hypocalciuria, and hypomagnesemia. In contrast to patients with Gordon’s syndrome, those suffering from Gitelman’s syndrome are generally normotensive or hypotensive.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 8
Correct
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Which of the following cells are attracted to the surface of endothelium by selectins?
Your Answer: Neutrophils
Explanation:Selectins are expressed on the surface of the endothelium. P selectins are released from weibel-palade bodies and E selectins are induced by cytokines (TNF and IL-1). They bind to receptors on the neutrophils called saiyl lewis X.
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This question is part of the following fields:
- Immunology
- Medicine
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Question 9
Correct
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A son has brought his 72-year-old mother to clinic. He is concerned about her short-term memory problems for the past 10 months. He has to remind her to take her medications and she has had two incidents of falling over in the last 10 months. Which of the following assists in the diagnosis of above condition?
Your Answer: Progressive loss of function
Explanation:The clinical presentation is dementia. To differentiate Alzheimer disease and vascular dementia, the progressive loss of function is important. Progressive loss of function is usually associated with vascular dementia and rest of the responses are associated with Alzheimer disease.
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This question is part of the following fields:
- Geriatrics
- Medicine
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Question 10
Correct
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Southern Blotting and DNA probes:
Your Answer: DNA fragments are separated by gel electrophoresis and transferred onto membrane sheets in southern blotting
Explanation:A Southern blot is a method used in molecular biology for detection of a specific DNA sequence in DNA samples. Southern blotting combines transfer of electrophoresis-separated DNA fragments to a filter membrane and subsequent fragment detection by probe hybridization. The other forms of blotting involve the use of RNA and proteins.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 11
Incorrect
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A patient has been diagnosed with multi-drug resistant tuberculosis and is currently bring treated with rifampicin, isoniazid, and pyrazinamide. He is commenced on streptomycin.Which among the following is the most likely neurological side-effect of streptomycin?
Your Answer: Cochlear damage
Correct Answer: Vestibular damage
Explanation:Vestibular damage is a neurological side effect of streptomycin.Streptomycin is an aminoglycoside bactericidal antibiotic. It is used in the treatment of tularaemia and resistant mycobacterial infections.The most common neurological side-effect is vestibular damage leading to vertigo and vomiting. Cochlear damage is less frequent and results in deafness. Other side-effects include rashes, angioneurotic oedema, and nephrotoxicity.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 12
Incorrect
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Which one of the following skin disorders is least commonly associated with hypothyroidism?
Your Answer: Eczema
Correct Answer: Pretibial myxoedema
Explanation:Pretibial myxoedema is an infiltrative dermopathy, resulting as a rare complication of Graves’ disease (hyperthyroidism) and very occasionally occurs in non-thyrotoxic Graves’ disease and Hashimoto’s thyroiditis.
Hypothyroidism typically presents with symptoms such as dry skin, brittle hair, and thinning of the outer third of the eyebrows. While skin conditions like dryness and hair changes are common in hypothyroidism due to reduced metabolic activity, acne is also not typically associated with it.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 13
Correct
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Question 14
Correct
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The following play a role in regulation of intestinal iron absorption except:
Your Answer: Urinary iron excretion rate
Explanation:The human body’s rate of iron absorption appears to respond to a variety of interdependent factors, including total iron stores, dietary intake, the extent to which the bone marrow is producing new red blood cells, the concentration of haemoglobin in the blood, and the oxygen content of the blood. Classic examples of genetic iron overload includes hereditary hemochromatosis (HH) and the more severe disease juvenile hemochromatosis (JH).
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This question is part of the following fields:
- Haematology
- Medicine
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Question 15
Incorrect
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Select the correct statement regarding the macro anatomy of the thyroid gland.
Your Answer: It arises embryologically from the 3rd and 4th brachial pouches.
Correct Answer: It surrounds the trachea at the front of the neck.
Explanation:The thyroid is located around the trachea, in the anterior portion of the neck. It is formed by two lobes which are connected by an isthmus. The presence of a pyramidal lobe, or third lobe, is considered to be a normal anatomical variant. It originates from the primitive pharynx and the neural crest and has a rich vascular supply.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 16
Incorrect
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The coronary arteries fill during?
Your Answer: Isometric ventricular contraction
Correct Answer: Diastole
Explanation:During systole the coronary arteries collapse as a result of the pressure due to contraction that is exerted on them. During diastole the heart muscle relaxes and the pressure on the coronary vessels is relieved allowing blood to flow through them to the subendocardium.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 17
Incorrect
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In terms of relative steroid potency, how much prednisone is equivalent to 100mg hydrocortisone?
Your Answer: 10mg
Correct Answer: 25mg
Explanation:Different corticosteroids have varying degrees of potency. 1 mg of prednisone is equivalent to 4 mg of hydrocortisone. Therefore, 25 mg of prednisone are equivalent to 100 mg of hydrocortisone.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 18
Incorrect
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Which are the main hormones secreted by the posterior pituitary gland.
Your Answer: Oxytocin and prolactin
Correct Answer: Oxytocin and vasopressin
Explanation:The posterior pituitary gland secretes oxytocin and vasopressin (antidiuretic hormone). These hormones are stored in Herring bodies before being secreted into the bloodstream.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 19
Incorrect
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Vasodilatation of coronary arteries is caused by:
Your Answer: Carbon-monoxide
Correct Answer: Hypoxia
Explanation:The heart is highly metabolically active and boasts the highest oxygen consumption by mass of any organ. This demand for oxygen is met by the coronary circulation, which is responsible for delivering blood to the myocardium and represents approximately 5% of cardiac output. Vasodilation may be due to the local effect of hypoxia on coronary vessels, or local metabolic vasodilation, or the activation of β-adrenoceptors or some combination of these mechanisms.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 20
Incorrect
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Drug-induced lupus erythematosus most often occurs after taking which of the following drugs?
Your Answer: Methotrexate
Correct Answer: Procainamide
Explanation:Many drugs are responsible for causing drug induced lupus. However, it is most commonly associated with hydralazine, procainamide and quinidine.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 21
Incorrect
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Which one of the following is a cause of a soft second heart sound?
Your Answer: Mitral stenosis
Correct Answer: Aortic stenosis
Explanation:Second heart sound (S2) forms the dub of lub-dub and is composed of components A2 and P2. •   loud: hypertension•   soft: AS•   fixed split: physiological split (normally occurs during inhalation), right bundle branch block, pulmonary stenosis, and atrial septal defect.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 22
Correct
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Vitamin K deficiency can be found in which of the following condition?
Your Answer: Cholestatic jaundice
Explanation:Vitamin K1-deficiency may occur by disturbed intestinal uptake (such as would occur in a bile duct obstruction), by therapeutic or accidental intake of a vitamin K1-antagonist such as warfarin, or, very rarely, by nutritional vitamin K1 deficiency.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 23
Incorrect
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During exercise, a man consumes 2L O2/min, his arterial 02 content is 190 ml/l and the 02 content of his mixed venous blood is 130ml/l. His cardiac output is approximately:
Your Answer: 3,3 l/min
Correct Answer: 33l/min
Explanation:In Fick’s original method, the following variables are measured:VO2, oxygen consumption in ml of pure gaseous oxygen per minute. This may be measured using a spirometer within a closed rebreathing circuit incorporating a CO2 absorberCa, the oxygen concentration of blood taken from the pulmonary vein (representing oxygenated blood)Cv, the oxygen concentration of blood from an intravenous cannula (representing deoxygenated blood)From these values, we know that:VO2 = (CO x Ca) – (CO x Cv)where CO = Cardiac Output, Ca = Oxygen concentration of arterial blood and Cv = Oxygen concentration of mixed venous blood.This allows us to sayCO = VO2/{Ca – Cv}and hence calculate cardiac output.Therefore CO = 2/(0.190-0.130) = 33l/minNote that (Ca – Cv) is also known as the arteriovenous oxygen difference.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 24
Incorrect
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The process by which DNA fragments are separated by gel and transferred onto a membrane sheet is called:
Your Answer: Central blotting
Correct Answer: Southern blotting
Explanation:A Southern blot is a method used in molecular biology for detection of a specific DNA sequence in DNA samples. Southern blotting combines transfer of electrophoresis-separated DNA fragments to a filter membrane and subsequent fragment detection by probe hybridization. The other forms of blotting involve the use of RNA and proteins.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 25
Incorrect
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Which of the following treatments would you advise for a young, 21 year old student who has ankylosing spondylitis and complains of worsening back pain and morning stiffness?
Your Answer: Oral prednisolone
Correct Answer: Oral NSAIDs
Explanation:NSAIDs are considered as the first line of treatment for managing pain and stiffness associated with ankylosing spondylitis. Other useful medications include TNF-alpha inhibitors. Other drugs like paracetamol, colchicine, and steroids are not routinely used. Bilateral total hip replacement might be indicated in advanced disease contrary to complicated spinal surgery.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 26
Incorrect
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During anaerobic glycolysis, the net production of ATP is:
Your Answer: 6
Correct Answer: 2
Explanation:Anaerobic glycolysis is the transformation of glucose to lactate when limited amounts of oxygen (O2) are available. Anaerobic glycolysis is only an effective means of energy production during short, intense exercise, providing energy for a period ranging from 10 seconds to 2 minutes. It produces 2 ATP molecules per glucose molecule.
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This question is part of the following fields:
- Medicine
- Metabolism
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Question 27
Incorrect
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Activation of baroreceptor reflex involves:
Your Answer: None of the above
Correct Answer: Short term regulation of systemic blood pressure
Explanation:Baroreceptors are found in the heart and the blood vessels. They are the carotid sinus and the aortic arch receptors and respond to the minute to minute change in the blood pressure i.e. a change in the pulsatile pressure and not to a change in the mean arterial pressure. If the pulse pressure decreases, the rate of firing of the receptors decreases, stimulating an increase in the heart rate and blood pressure. Mechanisms that regulate the long term blood pressure control include the renin-angiotensin-aldosterone mechanism.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 28
Incorrect
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Osteopetrosis occurs as a result of a defect in:
Your Answer: Calcium resorption in proximal tubule
Correct Answer: Osteoclast function
Explanation:It is a metabolic bone disease caused by defective osteoclastic resorption of immature bone. Osteopetrosis is also known as marble bone disease. Osteoclasts are unable to adequately acidify bone matrix. Impaired bone resorption leads to overly dense bone that is more likely to fracture. It is usually treated with bone marrow transplant and high dose calcitriol.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 29
Incorrect
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Which of the following cancers is responsible in producing osteoblastic bone metastases instead of osteolytic?
Your Answer: Granulosa cell tumour of the ovary
Correct Answer: Prostate adenocarcinoma
Explanation:Osteoblastic (or sclerotic) bone metastases, characterized by deposition of new bone, present in prostate cancer, carcinoid, small cell lung cancer, Hodgkin lymphoma or medulloblastoma.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 30
Incorrect
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An 87-year-old woman had to double up her dosage of morphine 60mg into 120mg twice a day, in addition to another 10mg oral Morphine 6 times a day. What is the best method of management?
Your Answer: 90mg MR morphine plus 30mg every 4 hours
Correct Answer: Subcutaneous morphine infusion
Explanation:Stable dose of Morphine is essential for chronic cases of pain that are non-malignant in origin. Using the SC route avoids having to intravenously cannulate a patient and allows for a continuous infusion of drugs over a calculated period of time providing constant dosing A significant advantage is that plasma levels of a drug are much more stable, and appropriate symptom control can be achieved without the toxic effects of the peaks and troughs resulting from episodic drug administration.
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This question is part of the following fields:
- Geriatrics
- Medicine
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SESSION STATS - PERFORMANCE PER SPECIALTY
