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Question 1
Correct
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Which is the best source of vitamin D per average serving for a woman with suspected Osteomalacia?
Your Answer: Cod liver oil
Explanation:Serum vitamin D levels are influenced by sun exposure and diet. Cod liver oil is an important dietary vitamin D source in high-latitude countries like Norway where there is no sun-induced vitamin D production during the winter. 14 Norwegian Health Authorities have recommended 5 ml of cod liver oil daily (400 IU of vitamin D) for more than 60 years to prevent diseases like rickets, formerly more prevalent in areas with little access to vitamin D-rich fatty fish.
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This question is part of the following fields:
- Clinical Sciences
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Question 2
Correct
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A 27-year-old lady presents with severe morning headaches associated with nausea. Head MRI reveals a large compressive tumour arising from the falx cerebri. The tumour is well delineated. What is the most probable diagnosis?
Your Answer: Meningioma
Explanation:Meningiomas are the most common benign tumours of the brain. Their name is derived from the fact that they arise from the dura mater which together with the pia matter and arachnoid mater form the meninges. The chances that a meningioma is benign are almost 98%. They are non-invasive and well delineated, causing sign and symptoms of brain compression.
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This question is part of the following fields:
- Clinical Sciences
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Question 3
Incorrect
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A 34-year-old man presents with haemoptysis and weight loss. History reveals he suffers from night sweats and upon auscultation you notice reduced breath sounds over the apex of his right lung and significant nail clubbing. You refer him to a pneumologist who administers the following antibiotics: rifampicin, ethambutol, pyrazinamide and isoniazid. What is the mechanism of action of the first drug?
Your Answer: Inhibit DNA synthesis
Correct Answer: Inhibit RNA synthesis
Explanation:Rifampicin specifically inhibits bacterial RNA polymerase, the enzyme responsible for DNA transcription, by forming a stable drug-enzyme complex with a binding constant of 10(-9) M at 37 C.
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This question is part of the following fields:
- Clinical Sciences
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Question 4
Incorrect
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Which one of the following immunological changes is seen in progressive HIV infection?
Your Answer: A rise in the CD4/CD8 ratio
Correct Answer: Increase in B2-microglobulin levels
Explanation:The immunological changes in HIV include depletion in CD4+ T cell, cytokine dysregulation and immune dysfunction. The dominant immunologic feature of HIV infection is progressive depletion of the helper T cell (CD4+ T cell), which reverses the normal CD4:CD8 ratio and subsequently lead to immunodeficiency. Other imuunological changes include:
increased B2-microglobulin
decreased IL-2 production
polyclonal B-cell activation
decreased NK cell function
reduced delayed hypersensitivity responses -
This question is part of the following fields:
- Clinical Sciences
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Question 5
Incorrect
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Where is secretin secreted from?
Your Answer: G cells in stomach
Correct Answer: S cells in upper small intestine
Explanation:Secretin is a peptide hormone produced in the S cells of the duodenum, which are located in the intestinal glands. In humans, the secretin peptide is encoded by the SCT gene.
Secretin helps regulate the pH of the duodenum by
1) inhibiting the secretion of gastric acid from the parietal cells of the stomach and
(2) stimulating the production of bicarbonate from the ductal cells of the pancreas.
G cells in the antrum of the stomach release gastrin
I cells in upper small intestine release CCK
D cells in the pancreas & stomach secrete somatostatin
K cells secrete gastric inhibitory peptide, an incretin, which also promotes triglyceride storage. -
This question is part of the following fields:
- Clinical Sciences
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Question 6
Correct
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A case-control study is developed to assess passive smoking as a risk factor for the development of asthma in children. The total number of patients recruited for this study is 200. 40 out of the 200 patients report at least one parent smoking in the house when they were younger. 200 more people without asthma are recruited and 20 out of them report that at least one parent smoked in the house when they were younger. What is the odds ratio of patients with asthma having been exposed to passive smoking during their childhood?
Your Answer: 2.25
Explanation:An odds ratio (OR) is a measure of association between an exposure and an outcome. The OR represents the odds that an outcome will occur given a particular exposure, compared to the odds of the outcome occurring in the absence of that exposure. Odds ratios are most commonly used in case-control studies, however they can also be used in cross-sectional and cohort study designs as well (with some modifications and/or assumptions). Where
a = Number of exposed cases
b = Number of exposed non-cases
c = Number of unexposed cases
d = Number of unexposed non-cases
OR=(a/c) / (b/d) = ad/bc
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This question is part of the following fields:
- Clinical Sciences
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Question 7
Incorrect
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A woman with severe renal failure undergoes a kidney transplant. However, after a few hours, she develops fever and anuria. The doctors are suspecting hyperacute organ rejection. Which are the cells primarily responsible for hyperacute organ rejection?
Your Answer: Macrophages
Correct Answer: B Cells
Explanation:Hyperacute rejection appears in the first minutes following transplantation and occurs only in vascularized grafts. This very fast rejection is characterized by vessel thrombosis leading to graft necrosis. Hyperacute rejection is caused by the presence of antidonor antibodies existing in the recipient before transplantation. These antibodies induce both complement activation and stimulation of endothelial cells to secrete Von Willebrand procoagulant factor, resulting in platelet adhesion and aggregation. The result of these series of reactions is the generation of intravascular thrombosis leading to lesion formation and ultimately to graft loss. Today, this type of rejection is avoided in most cases by checking for ABO compatibility and by excluding the presence of antidonor human leukocyte antigen (HLA) antibodies by cross-match techniques between donor graft cells and recipient sera. This type of rejection is also observed in models of xenotransplantation of vascularized organs between phylogenetically distant species when no immunosuppressive treatment is given to the recipients.
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This question is part of the following fields:
- Clinical Sciences
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Question 8
Incorrect
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A 42-year-old patient has been admitted with a very swollen and painful right knee. He was unable to walk on it so came into hospital. It is currently being treated as gout with non steroidal anti-inflammatory drugs. You notice he is of short stature, has shortened arms and legs and a flat nasal bridge. A mutation in which gene is responsible for this condition?
Your Answer: Epidermal growth factor receptor
Correct Answer: Fibroblast growth factor receptor
Explanation:Achondroplasia is a common cause of dwarfism. It is caused by a mutation in fibroblast growth factor receptor 3 (FGFR3). In normal development FGFR3 has a negative regulatory effect on bone growth. In achondroplasia, the mutated form of the receptor is constitutively active and this leads to severely shortened bones. The effect is genetically dominant, with one mutant copy of the FGFR3 gene being sufficient to cause achondroplasia, while two copies of the mutant gene are invariably fatal. A person with achondroplasia thus has a 50% chance of passing dwarfism to each of their offspring. People with achondroplasia can be born to parents that do not have the condition due to spontaneous mutation. It occurs as a sporadic mutation in approximately 80% of cases (associated with advanced paternal age) or it may be inherited as an autosomal dominant genetic disorder.
People with achondroplasia have short stature, with an average adult height of 131 centimeters (52 inches) for males and 123 centimeters (48 inches) for females. -
This question is part of the following fields:
- Clinical Sciences
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Question 9
Incorrect
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Which one of the following statements best describes a type II statistical error?
Your Answer: The alternative hypothesis is rejected when it is false
Correct Answer: The null hypothesis is accepted when it is false
Explanation:In statistical hypothesis testing there are 2 types of errors:
– type I: the null hypothesis is rejected when it is true – i.e. Showing a difference between two groups when it doesn’t exist, a false positive.
– type II: the null hypothesis is accepted when it is false – i.e. Failing to spot a difference when one really exists, a false negative. -
This question is part of the following fields:
- Clinical Sciences
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Question 10
Incorrect
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Which of the following is not a tumour suppressor gene?
Your Answer: NF-1
Correct Answer: myc
Explanation:Myc is a family of regulator genes and proto-oncogenes that code for transcription factors.
A tumor suppressor gene, or antioncogene, is a gene that protects a cell from one step on the path to cancer. When this gene mutates to cause a loss or reduction in its function, the cell can progress to cancer, usually in combination with other genetic changes. Tumor suppressor genes can be grouped into categories including caretaker genes, gatekeeper genes, and landscaper genes; the classification schemes are continually evolving.
Examples include:
Gene Associated cancers
p53 Common to many cancers, Li-Fraumeni syndrome
APC Colorectal cancer
BRCA1 Breast and ovarian cancer
BRCA2 Breast and ovarian cancer
NF1 Neurofibromatosis
Rb Retinoblastoma
WT1 Wilm’s tumour -
This question is part of the following fields:
- Clinical Sciences
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Question 11
Correct
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A 55-year-old woman with established metastatic breast cancer is admitted to the A&E with hypercalcemia. She has a clear medical history, doesn't smoke and works in an office based job. At the A&E she's given intravenous fluids and bisphosphonates. She's finally discharged after normalization of her calcium levels. However, before leaving the hospital she's sent to the endocrinology department for consultation regarding outpatient care and serum calcium monitoring. What is the most appropriate and useful advice for this patient?
Your Answer: Increase fluid intake
Explanation:NICE guidelines on hypercalcemia recommend that maintaining good hydration equals drinking 3-4 L of fluid/day, provided there are no contraindications. A low calcium diet is not necessary because intestinal absorption of calcium is reduced. The patient should avoid any other drugs or vitamins that could worsen the hypercalcemia. Mobilization is encouraged and any symptoms of hypercalcemia should be reported.
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This question is part of the following fields:
- Clinical Sciences
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Question 12
Correct
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How is the left ventricular ejection fraction calculated?
Your Answer: Stroke volume / end diastolic LV volume
Explanation:Left ventricular ejection fraction = (stroke volume / end diastolic LV volume ) * 100%
Stroke volume = end diastolic LV volume – end systolic LV volume
Pulse pressure = Systolic Pressure – Diastolic Pressure
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This question is part of the following fields:
- Clinical Sciences
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Question 13
Incorrect
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A 15-year-old girl is admitted to hospital following a ruptured ectopic pregnancy. She comes from a family of Jehovah's Witnesses. Her haemoglobin on admission is 6.7 g/dl. She consents to a blood transfusion but her mother refuses. What is the most appropriate course of action?
Your Answer: Transfer the patient to a hospital run by Jehovah's Witnesses
Correct Answer: Give the blood transfusion
Explanation:People aged 16 or over are entitled to consent to their own treatment. This can only be overruled in exceptional circumstances. Children under the age of 16 can consent to their own treatment if they’re believed to have enough intelligence, competence and understanding to fully appreciate what’s involved in their treatment. This is known as being Gillick competent.
Otherwise, someone with parental responsibility can consent for them.
This could be:
the child’s mother or father
the child’s legally appointed guardian
a person with a residence order concerning the child
a local authority designated to care for the child
a local authority or person with an emergency protection order for the child.
Giving the blood transfusion is therefore both clinically and ethically the right course of action.
Jehovah’s Witnesses frequently carry a signed and witnessed Advance Decision Document listing the blood products and autologous procedures that are, or are not, acceptable to them It is appropriate to have a frank, confidential discussion with the patient about the potential risks of their decision and the possible alternatives to transfusion, but the freely expressed wish of a competent adult must always be respected. -
This question is part of the following fields:
- Clinical Sciences
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Question 14
Incorrect
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A study is performed to assess a new proton pump inhibitor (PPI) in 120 elderly patients who are receiving aspirin. A control group of 240 elderly patients is given the standard PPI. The final evaluation after five years revealed that 24 individuals receiving the new PPI experienced an upper GI bleed. What is the absolute risk reduction if 60 individuals receiving the standard PPI experienced the same condition?
Your Answer:
Correct Answer: 5%
Explanation:Absolute risk reduction (ARR) – also called risk difference (RD) – is the most useful way of presenting research results to help your decision-making. Absolute risk reduction = (Control event rate) – (Experimental event rate) = 0.05 = 5% reduction
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This question is part of the following fields:
- Clinical Sciences
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Question 15
Incorrect
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A study's objective is to find the normal reference range for IgE levels in the adult population. What percentage of individuals will have IgE levels higher than 2 standard deviations from the mean, assuming that the IgE levels follow a normal distribution?
Your Answer:
Correct Answer: 2.30%
Explanation:Normal distribution describes the spread of many biological and clinical measurements. Usually, 68.3% lies within 1 standard deviation (SD) of the mean, 95.4% lies within 2 SD of the mean and 99.7% lies within 3 SD of the mean.
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This question is part of the following fields:
- Clinical Sciences
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Question 16
Incorrect
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Which of following does not promote the release of endothelin?
Your Answer:
Correct Answer: Prostacyclin
Explanation:Prostacyclin (PGI2) generated by the vascular wall is a potent vasodilator, and the most potent endogenous inhibitor of platelet aggregation so far discovered. Prostacyclin inhibits platelet aggregation by increasing cyclic AMP levels. Prostacyclin is a circulating hormone continually released by the lungs into the arterial circulation. Circulating platelets are, therefore, subjected constantly to prostacyclin stimulation and it is via this mechanism that platelet aggregability in vivo is controlled.
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This question is part of the following fields:
- Clinical Sciences
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Question 17
Incorrect
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A 36-year-old lady with back pain is found to have loss of sensation of the kneecaps. Choose the dermatome most likely compromised:
Your Answer:
Correct Answer: L4
Explanation:L4 dermatome distribution includes the kneecaps.
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This question is part of the following fields:
- Clinical Sciences
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Question 18
Incorrect
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Choose the hormone secreted only by the adrenal medulla:
Your Answer:
Correct Answer: Adrenaline
Explanation:The major endocrine functions of adrenal gland are to produce catecholamines and steroids. Catecholamine, synthesized by the adrenal medulla, is responsible for blood pressure and blood flow regulation whereas steroids produced by the cortex control energy and water homeostasis and immune responses. Glucocorticoids, a major group of adrenal steroids, have a stimulatory effect on catecholamine synthesis in the medulla.
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This question is part of the following fields:
- Clinical Sciences
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Question 19
Incorrect
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What do T-helper cells of the Th2 subset typically secrete?
Your Answer:
Correct Answer: IL-4, IL-5, IL-6, IL-10, IL-13
Explanation:Interleukin-4 (IL-4), IL-5 and IL-13, the signature cytokines that are produced during type 2 immune responses, are critical for protective immunity against infections of extracellular parasites and are responsible for asthma and many other allergic inflammatory diseases. Although many immune cell types within the myeloid lineage compartment including basophils, eosinophils and mast cells are capable of producing at least one of these cytokines, the production of these “type 2 immune response-related” cytokines by lymphoid lineages, CD4 T helper 2 (Th2) cells and type 2 innate lymphoid cells (ILC2s) in particular, are the central events during type 2 immune responses.
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This question is part of the following fields:
- Clinical Sciences
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Question 20
Incorrect
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From which cells is somatostatin secreted?
Your Answer:
Correct Answer: D cells in the pancreas
Explanation:The somatostatin-secreting D-cells comprise ,5% of the cells of the pancreatic islets. The D-cells have a complex morphology and may, via cellular process, interact with many more islet cells than suggested by their low number. D-cells are equipped with ATP-sensitive potassium channels (KATP channels).
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This question is part of the following fields:
- Clinical Sciences
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Question 21
Incorrect
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A study is carried out to assess the efficacy of a new anti-epileptic drug for children with absence seizures. The total number of the children selected for the study was 400, from which 150 children were assigned to take the new drug and 250 children were assigned in the control group. After a period of four months, only 15 children taking the new drug had a seizure compared to 100 children from the control group who had seizure. What is the correct value regarding the relative risk reduction?
Your Answer:
Correct Answer: 75%
Explanation:Relative risk reduction (RRR) tells you by how much the treatment reduced the risk of bad outcomes relative to the control group who did not have the treatment. In the previous example, the relative risk reduction of fever and rash in the group of the children on the intervention was 40 per cent (1 – 0.6 = 0.4 or 40 per cent). RRR = (EER -CER) / CER = (0.1 – 0.4) / 0.4 = -0.75 or 75% reduction.
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This question is part of the following fields:
- Clinical Sciences
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Question 22
Incorrect
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A 34-year-old male patient is admitted with hemisection of the spinal cord at the level T5, after being stabbed in the back. Which sign would you expect to see by assessing the patient's sensory function and muscle strength?
Your Answer:
Correct Answer: Contralateral loss of temperature, ipsilateral loss of fine touch and vibration, ipsilateral spastic paresis
Explanation:Depending on the level of SCI, patients experience paraplegia or tetraplegia. Paraplegia is defined as the impairment of sensory or motor function in lower extremities. Patients with incomplete paraplegia generally have a good prognosis in regaining locomotor ability (,76% of patients) within a year. Complete paraplegic patients, however, experience limited recovery of lower limb function if their NLI is above T9. The spinothalamic tract is the one responsible for sensory information such as pain or temperature. However, it decussates at the same level the nerve root enters the spinal cord, meaning that the sensory loss will be contralateral. However, the dorsal column carries sensory fibres for fine touch and vibration and it decussates at the medulla which means that the sensory loss will be ipsilateral. The corticospinal tract is responsible for motor functions and it decussates at the medulla, meaning that the motor function loss will be ipsilateral.
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This question is part of the following fields:
- Clinical Sciences
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Question 23
Incorrect
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A 58-year-old woman has multiple non-healing leg ulcers. She reports feeling unwell for several months. Examination findings include a normal blood pressure, pulse 90 bpm, pale conjunctivae and poor dentition associated with bleeding gums. What is the most likely underlying diagnosis?
Your Answer:
Correct Answer: Vitamin C deficiency
Explanation:Severe vitamin C deficiency results in scurvy, a disorder characterized by hemorrhagic manifestations and abnormal osteoid and dentin formation.
Vitamin C plays a role in collagen, carnitine, hormone, and amino acid formation. It is essential for bone and blood vessel health and wound healing and facilitates recovery from burns. Vitamin C is also an antioxidant, supports immune function, and facilitates the absorption of iron (see table Sources, Functions, and Effects of Vitamins).
Dietary sources of vitamin C include citrus fruits, tomatoes, potatoes, broccoli, strawberries, and sweet peppers. (See also Overview of Vitamins.) -
This question is part of the following fields:
- Clinical Sciences
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Question 24
Incorrect
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Which is the formula to calculate the number needed to treat?
Your Answer:
Correct Answer: 1 / (Absolute risk reduction)
Explanation:The number needed to treat (NNT) is valuable information in treatment decisions. NNT is the inverse of the absolute risk reduction (1/ARR) between two treatment options.
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This question is part of the following fields:
- Clinical Sciences
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Question 25
Incorrect
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A 19-year-old woman is admitted with diabetic ketoacidosis (DKA). It is her fourth episode in the past two months and she's known to be a type 1 diabetes mellitus patient. The doctors suspects she's non-compliant with her treatment to keep her weight down. She often self-discharges after 24 hours. What is the single most appropriate management?
Your Answer:
Correct Answer: Have a chat after the ward round about why she thinks her control is so bad
Explanation:In many Western countries and health plans in the United States, patients have a primary care physician who acts as a formal gatekeeper for medical specialist care and thereby determines together with the patient whether or not a patient requires medical specialist care. Ideally in such systems, patients are treated in primary care if possible, and referred to medical specialist care if necessary. For the gatekeeper system to be effective, it is vital that adequate decisions are made about when and who to refer. But it is also important that referred patients comply with the referral by consulting a medical specialist. In this case, the GP should discuss with the patient the reasons why she cannot follow the treatment plan. In other words, the GP should detect why the patient is being non-compliant.
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This question is part of the following fields:
- Clinical Sciences
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Question 26
Incorrect
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A 23-year-old man is referred to the pneumologist with a suspicion of bronchiectasis. History reveals he's been having recurrent pulmonary infections his whole life together with difficulties gaining weight. He's a non-smoker with a clear family history and he admits inhalers haven't helped him in the past. He is finally suspected of having cystic fibrosis. What is the normal function of the cystic fibrosis transmembrane regulator?
Your Answer:
Correct Answer: Chloride channel
Explanation:Chloride channels are involved in a diverse set of functions in normal physiology and acquired diseases. Additionally, there are genetic diseases caused by mutations in chloride channels (channelopathies) — the most common being cystic fibrosis, which has a prevalence of 1 in 2,000 Caucasians.
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This question is part of the following fields:
- Clinical Sciences
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Question 27
Incorrect
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Choose the karyotype associated with short stature:
Your Answer:
Correct Answer: 45,XO
Explanation:Turner syndrome (TS) is one of the most common genetic disorders; occurs with an incidence of I: 2,500 female live births. It results from complete or partial chromosome X monosomy. TS is associated with abnormalities of the X chromosome and characteristic clinical features of short stature, gonadal dysgenesis, sexual developmental deficiencies, cardiac and/or renal defects, webbed neck, low-set ears, skeletal deformities including cubitus valgus, a propensity to ear infections and hearing deficits.
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This question is part of the following fields:
- Clinical Sciences
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Question 28
Incorrect
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Which one of the following statements regarding mitochondrial inheritance is true?
Your Answer:
Correct Answer: Poor genotype:phenotype correlation
Explanation:The human cell has two type of DNA: Nuclear DNA and Mitochondrial DNA (MtDNA). A MtDNA copy is passed down entirely unchanged, through the maternal line. Males cannot pass their MtDNA to their offspring although they inherit a copy of it from their mother. There is poor genotype:phenotype correlation. Within a tissue or cell there can be different mitochondrial populations (this is known as heteroplasmy).
Examples of mitochondrial diseases include:
– Leber’s optic atrophy
– MELAS syndrome (mitochondrial encephalomyopathy lactic acidosis and stroke-like episodes)
– MERRF syndrome (myoclonus epilepsy with ragged-red fibres)
– Kearns-Sayre syndrome (more severe syndromic variant of chronic progressive external ophthalmoplegia, onset in patients < 20 years old) -
This question is part of the following fields:
- Clinical Sciences
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Question 29
Incorrect
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A new study was developed to assess the benefit of omega-3 fish oils in patients with established ischaemic heart disease. The power of the study is equal to:
Your Answer:
Correct Answer: 1 - probability of making a type II error
Explanation:The power of a test is defined as 1 − the probability of Type II error. The Type II error is concluding at no difference (the null is not rejected) when in fact there is a difference, and its probability is named β. Therefore, the power of a study reflects the probability of detecting a difference when this difference exists. It is also very important to medical research that studies are planned with an adequate power so that meaningful conclusions can be issued if no statistical difference has been shown between the treatments compared. More power means less risk for Type II errors and more chances to detect a difference when it exists.
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This question is part of the following fields:
- Clinical Sciences
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Question 30
Incorrect
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A 54-year-old man is found collapsed in the street and is brought to the A&E. The results from the blood tests reveal Calcium = 1.62mmol/l and Albumin = 33g/l. The man is known to have a history of alcoholic liver disease. Which of the following is the best management regarding his calcium levels?
Your Answer:
Correct Answer: 10ml of 10% calcium gluconate over 10 minutes
Explanation:Acute, symptomatic hypocalcaemia is treated with 10ml of 10% calcium gluconate over 10 minutes.
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This question is part of the following fields:
- Clinical Sciences
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Question 31
Incorrect
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A 45-year-old male patient presents with severe pharyngitis and dysphagia. He's found to be HIV positive and with oesophageal candidiasis. Which of the following regarding HIV virus is correct?
Your Answer:
Correct Answer: HIV is an RNA virus
Explanation:The human immunodeficiency virus (HIV) is grouped to the genus Lentivirus within the family of Retroviridae, subfamily Orthoretrovirinae. The HIV genome consists of two identical single-stranded RNA molecules that are enclosed within the core of the virus particle. The genome of the HIV provirus, also known as proviral DNA, is generated by the reverse transcription of the viral RNA genome into DNA, degradation of the RNA and integration of the double-stranded HIV DNA into the human genome.
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This question is part of the following fields:
- Clinical Sciences
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Question 32
Incorrect
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A 34-year-old woman is admitted to the oncologist clinic for further investigations. She has experienced fever, sometimes glandular and night sweats. Clinical examination reveals lymphadenopathy and a biopsy is performed. The biopsy reveals the presence of Reed-Sternberg cells, confirming what was suspected to be a Hodgkin's lymphoma. Which cell surface marker is associated with this condition?
Your Answer:
Correct Answer: CD15
Explanation:The CD15 antigen, also known as Lewis (hapten)X, serves as an immuno-phenotypic marker for Reed-Sternberg cells and its expression has diagnostic, but also prognostic significance in Hodgkin Lymphoma.
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This question is part of the following fields:
- Clinical Sciences
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Question 33
Incorrect
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A new blood test developed to screen individuals for cardiac failure was performed on 500 patients. The results were positive for 40 out of 50 patients with echocardiography-established heart failure. However, the test was also positive for 20 patients with no signs of heart failure. What is the positive predictive value of the test?
Your Answer:
Correct Answer: 0.66
Explanation:Positive predictive value = TP (true positives) / [TP + FP (false positives)] = 40 / (40 + 20) = 0.66
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This question is part of the following fields:
- Clinical Sciences
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Question 34
Incorrect
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You are a ST1 doctor working on a medical ward. You are struggling to cope with the workload and often leave the ward late. Who is the most appropriate action to take?
Your Answer:
Correct Answer: Speak to your consultant
Explanation:Speaking to your consultant is the most appropriate first action to take in this scenario. They are best placed to be able to take action to try and amend the situation. The consultant is also ultimately responsible for patient care and hterefore have a right to know if you are struggling, as this may affect patient care.
Arriving early and taking time off sick do not address the problem. -
This question is part of the following fields:
- Clinical Sciences
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Question 35
Incorrect
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Which one of the following occurs during reverse transcriptase polymerase chain reaction?
Your Answer:
Correct Answer: RNA is converted to DNA
Explanation:Reverse transcription polymerase chain reaction is a laboratory technique combining reverse transcription of RNA into DNA and amplification of specific DNA targets using polymerase chain reaction. It is primarily used to measure the amount of a specific RNA. The main advantage of PCR is its sensitivity: only one strand of sample DNA is needed to detect a particular DNA sequence. It now has many uses including prenatal diagnosis, detection of mutated oncogenes and diagnosis of infections.
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This question is part of the following fields:
- Clinical Sciences
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Question 36
Incorrect
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An 18-year-old male was diagnosed with meningococcal meningitis, confirmed on lumbar puncture. After 6 months he presents in the infectious clinic with a second episode of meningitis. His past history is clear and he takes no regular medication. Which of the following is most probably deficient?
Your Answer:
Correct Answer: C5
Explanation:Pneumococcal meningitis is the most common and severe form of bacterial meningitis. Fatality rates are substantial, and long-term sequelae develop in about half of survivors. Disease outcome has been related to the severity of the proinflammatory response in the subarachnoid space. The complement system, which mediates key inflammatory processes, has been implicated as a modulator of pneumococcal meningitis disease severity in animal studies. C5 fragment levels in cerebrospinal fluid (CSF) of patients with bacterial meningitis correlated with several clinical indicators of poor prognosis.
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This question is part of the following fields:
- Clinical Sciences
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Question 37
Incorrect
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A study is done on 1000 patients to assess the specificity of a new rapid finger-prick blood test developed to help diagnose deep vein thrombosis (DVT). The new test was positive on 200 patients with DVT and on 100 patients without DVT. It was also negative on 20 patients with DVT and 680 without DVT. What is the specificity of the new test?
Your Answer:
Correct Answer: 680/780
Explanation:Specificity (negative in health)
The ability of a test to correctly classify an individual as disease- free is called the test′s specificity. [Table 2]Specificity = d / b+d
= d (true negative) / b+d (true negative + false positive)
= Probability of being test negative when disease absent.
Example: One hundred persons with normal angles (diagnosed by ′gold standard′: gonioscopy) are examined by peripheral angle chamber depth examination. Eighty-five persons had normal peripheral angle chamber depth [Table 3]. The specificity of the peripheral angle chamber depth examination to PACG is therefore –
85 / 100 = 85%.
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This question is part of the following fields:
- Clinical Sciences
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Question 38
Incorrect
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A 68-year-old male patient presents with haematemesis. Gastroscopy and biopsy reveal a carcinoma. Who is the one to inform the patient of his diagnosis?
Your Answer:
Correct Answer: The consultant in-charge of his care
Explanation:One of the questions the therapist poses himself while informing a patient is: whom shall I inform about the diagnosis, treatment and prognosis? If we unconditionally accepted the view that information belongs to the patient from an ethical and legal standpoint, we would automatically exclude the partner and the family. Therefore, the therapist should raise another question: what is the benefit to the patient? To answer the question and the resulting dilemma, we have to leverage the long experience of family therapy and tailor it to the cases we are dealing with. It should be taken into consideration that patient and family are a dynamic system which was balanced before the onset of the disease, but is now disrupted, entering into crisis. Therefore, the denial mechanisms and personality characteristics we have previously elaborated on, and communication among members play a crucial role in determining the information strategy and the way family should be approached. In this particular case, the most appropriate person to inform the patient is the consultant, meaning the one currently responsible for the patient’s care. The patient most probably has already developed some form of close and trustful relationship with his consultant.
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This question is part of the following fields:
- Clinical Sciences
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Question 39
Incorrect
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Supplementation of which one of the following might help a patient diagnosed with homocystinuria?
Your Answer:
Correct Answer: Pyridoxine
Explanation:In general, the aim is to keep the homocysteine (Hcy) concentration as close to normal as possible. In patients who are fully-responsive to pyridoxine, standard doses can lead to tHcy levels below 50 μmol/L (and sometimes within the normal range). Some patients who are partially-responsive to pyridoxine may be able to achieve a tHcy level below 50 μmol/L if they are also on a low-Met diet; for others it is not a realistic goal.
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This question is part of the following fields:
- Clinical Sciences
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Question 40
Incorrect
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Choose the correct statement regarding leptin:
Your Answer:
Correct Answer: Is produced mainly by the hypothalamus
Explanation:Leptin, a 167–amino acid hormone, was discovered in 1994 and is secreted mainly by adipocytes. Plasma leptin levels are significantly correlated with body mass index (BMI) and the total amount of body fat.
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This question is part of the following fields:
- Clinical Sciences
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Question 41
Incorrect
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A study is developed to assess a new mandible advancement device designed to reduce snoring. A 10 point scale was used to assess the severity of snoring before and after applying of the device by the respective partner. The number of the people involved in the study was 50. What test would you apply in this particular study?
Your Answer:
Correct Answer: Wilcoxon signed-rank test
Explanation:Steps required in performing the Wilcoxon signed rank test:
1 State the null hypothesis and, in particular, the hypothesized value for comparison
2 Rank all observations in increasing order of magnitude, ignoring their sign. Ignore any observations that are equal to the hypothesized value. If two observations have the same magnitude, regardless of sign, then they are given an average ranking
3 Allocate a sign (+ or -) to each observation according to whether it is greater or less than the hypothesized value (as in the sign test)
4 Calculate:
R+ = sum of all positive ranks
R- = sum of all negative ranks
R = smaller of R+ and R-
5 Calculate an appropriate P value What makes this test the most appropriate for this study is that the data is non-parametric, paired and comes from the same population. -
This question is part of the following fields:
- Clinical Sciences
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Question 42
Incorrect
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Which one of the following best describes the main action of the polymerase chain reaction?
Your Answer:
Correct Answer: DNA amplification
Explanation:Polymerase chain reaction (PCR) is a method widely used in molecular biology to make several copies of a specific DNA segment. Using PCR, copies of DNA sequences are exponentially amplified to generate thousands to millions of more copies of that particular DNA segment.The main advantage of PCR is its sensitivity: only one strand of sample DNA is needed to detect a particular DNA sequence. It now has many uses including prenatal diagnosis, detection of mutated oncogenes and diagnosis of infections. PCR is also extensively used in forensics.
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This question is part of the following fields:
- Clinical Sciences
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Question 43
Incorrect
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Choose the correct formula to calculate the negative predictive value of a screening test:
Your Answer:
Correct Answer: TN / (TN + FN)
Explanation:NPV = TN / FN+TN
= TN (true negative) / FN+TN (false negative + true negative)
= Probability (patient not having disease when test is negative)
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This question is part of the following fields:
- Clinical Sciences
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Question 44
Incorrect
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A 24-year-old man was hit on the lateral aspect of his head by a high velocity cricket ball and lost consciousness immediately. Paramedics found him to have a Glasgow coma score of 15 but take him to the A&E for further investigation. His Glasgow coma score on examination in the A&E is 13 (M5, V4, E4) and he has anterograde and retrograde amnesia to recent events. The doctors arrange an urgent CT scan. Which clinical sign would be most concerning if present?
Your Answer:
Correct Answer: Bradycardia
Explanation:Intracranial pressure (ICP) is a complex brain modality that determines cerebral perfusion pressure (CPP), which is the difference between arterial blood pressure (ABP), and ICP. Raised ICP reduces CPP and blood delivery to the brain. This jeopardizes cerebral function and organismal survival in many species. A massive rise in ICP is also known to produce an increase in ABP, bradycardia and respiratory irregularities termed Cushing response. This mechanism is generally considered to be an agonal and terminal event occurring in extreme condition of brainstem ischaemia leading to a sympatho-adrenal response.
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This question is part of the following fields:
- Clinical Sciences
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Question 45
Incorrect
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Intracellular proteins tagged with mannose-6-phosphate are destined to which of the following organelles?
Your Answer:
Correct Answer: Lysosome
Explanation:Lysosomal hydrolases are synthesized in the rough endoplasmic reticulum and specifically transported through the Golgi apparatus to the trans-Golgi network, from which transport vesicles bud to deliver them to the endosomal/lysosomal compartment. The explanation of how the lysosomal enzymes are accurately recognized and selected over many other proteins in the trans-Golgi network relies on them being tagged with a unique marker: the mannose-6-phosphate (M6P) group, which is added exclusively to the N-linked oligosaccharides of lysosomal soluble hydrolases, as they pass through the cis-Golgi network. Generation of the M6P recognition marker depends on a reaction involving two different enzymes: UDP-N-acetylglucosamine 1-phosphotransferase and α-N-acetylglucosamine-1-phosphodiester α-N-acetylglucosaminidase.
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This question is part of the following fields:
- Clinical Sciences
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Question 46
Incorrect
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Which of the following phases determines the length of the cell cycle?
Your Answer:
Correct Answer: G1
Explanation:The duration of these cell cycle phases varies considerably in different kinds of cells. For a typical rapidly proliferating human cell with a total cycle time of 24 hours, the G1 phase might last about 11 hours, S phase about 8 hours, G2 about 4 hours, and M about 1 hour. The proliferation of most animal cells is similarly regulated in the G1 phase of the cell cycle. In particular, a decision point in late G1, called the restriction point in animal cells, is the point at which the cell becomes committed to the cell cycle and after which extracellular proliferation stimulants are no longer required.. Although the proliferation of most cells is regulated primarily in G1, some cell cycles are instead controlled principally in G2.
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This question is part of the following fields:
- Clinical Sciences
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Question 47
Incorrect
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A 75-year-old woman experiences weakness of her left hand. Clinical examination reveals wasting of the hypothenar eminence and weakness of finger abduction and thumb adduction. The lesion is most probably located at:
Your Answer:
Correct Answer: Ulnar nerve
Explanation:Patients with compressive neuropathy of the ulnar nerve typically describe numbness and tingling of the ulnar-sided digits of the hand, classically in the small finger and ulnar aspect of the ring finger. Among the general population, symptoms usually begin intermittently and are often worse at night, particularly if the elbow is flexed while sleeping. As the disease progresses, paraesthesia may occur more frequently and during the daytime.
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This question is part of the following fields:
- Clinical Sciences
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Question 48
Incorrect
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Choose the correct statement regarding relative risk:
Your Answer:
Correct Answer: It is the usual outcome measure of cohort studies
Explanation:Relative Risk = (Probability of event in exposed group) / (Probability of event in not exposed group). The relative risk is mistaken by some, with the odds ratio and absolute risk. Relative risk is the ratio of the probability of an event occurring with an exposure versus the probability of the event occurring without the exposure. Thus to calculate the relative risk, we must know the exposure status of all individuals (either exposed or not exposed). This implies that relative risk is only appropriate for cases where the exposure status and incidence of disease can be accurately determined such as prospective cohort studies.
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This question is part of the following fields:
- Clinical Sciences
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Question 49
Incorrect
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A cohort study is being designed to look at the relationship between smoking and prostate cancer. What is the usual outcome measure in a cohort study?
Your Answer:
Correct Answer: Relative risk
Explanation:A cohort study is a particular form of longitudinal study that samples a cohort (a group of people who share a defining characteristic, typically those who experienced a common event in a selected period, such as birth or graduation), performing a cross-section at intervals through time.
The relative risk (RR) or risk ratio is the ratio of the probability of an outcome in an exposed group to the probability of an outcome in an unexposed group. Relative risk is used in the statistical analysis of the data of experimental, cohort and cross-sectional studies, to estimate the strength of the association between treatments or risk factors, and outcomes. -
This question is part of the following fields:
- Clinical Sciences
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Question 50
Incorrect
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Each one of the following statements regarding atrial natriuretic peptide are true, except:
Your Answer:
Correct Answer: Secreted mainly by the left atrium
Explanation:Atrial natriuretic peptide (ANP) is a 28-amino acid peptide that is synthesized, stored, and released by atrial myocytes in response to atrial distension, angiotensin II stimulation, endothelin, and sympathetic stimulation (beta-adrenoceptor mediated). ANP is synthesized and secreted by cardiac muscle cells in the walls of the atria in the heart. The main physiological actions of natriuretic peptides is to reduce arterial pressure by decreasing blood volume and systemic vascular resistance. It causes a reduction in expanded extracellular fluid (ECF) volume by increasing renal sodium excretion.
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This question is part of the following fields:
- Clinical Sciences
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Question 51
Incorrect
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Choose the correct definition regarding the standard error of the mean:
Your Answer:
Correct Answer: Standard deviation / square root (number of patients)
Explanation:The SEM is an indicator of how close the sample mean is to the population mean. In reality, however, only one sample is extracted from the population. Therefore, the SEM is estimated using the standard deviation (SD) and a sample size (Estimated SEM). The SEM computed by a statistical program is an estimated value calculated via this process.
Estimated Standard Error of the Mean (SEM)=SDn√
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This question is part of the following fields:
- Clinical Sciences
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Question 52
Incorrect
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What is the site of action of antidiuretic hormone?
Your Answer:
Correct Answer: Collecting ducts
Explanation:Vasopressin, also called antidiuretic hormone (ADH), regulates the tonicity of body fluids. It is released from the posterior pituitary in response to hypertonicity and promotes water reabsorption in the collecting ducts of the kidneys by the insertion of aquaporin-2 channels.. An incidental consequence of this renal reabsorption of water is concentrated urine and reduced urine volume. In high concentrations may also raise blood pressure by inducing moderate vasoconstriction.
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This question is part of the following fields:
- Clinical Sciences
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Question 53
Incorrect
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Which of the following suggests a diagnosis of molluscum contagiosum rather than chickenpox?
Your Answer:
Correct Answer: Absence of erythema surrounding lesions
Explanation:Molluscum contagiosum (MC), is a viral infection of the skin that results in small, raised, pink lesions with a dimple in the center with little to no surrounding erythema. They may occasionally be itchy or sore. They may occur singularly or in groups. Any area of the skin may be affected, with abdomen, legs, arms, neck, genital area, and face being most common. Onset of the lesions is around 7 weeks after infection. It usually goes away within a year without scarring.
Chickenpox lesions in the early stages may be mistaken for molluscum. However, the presence of associated macules and later vesicles and pustules help to differentiate them. -
This question is part of the following fields:
- Clinical Sciences
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Question 54
Incorrect
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A 45-year-old woman with a history of hypothyroidism, presents with ptosis and muscle weakness. She's noticed that her muscle weakness becomes worse towards the end of the day. Clinical examination reveals fatigable ptosis and proximal limb weakness. Myasthenia gravis is suspected. Which receptor is implicated in the pathophysiology of this condition?
Your Answer:
Correct Answer: Nicotinic acetylcholine receptors
Explanation:Myasthenia gravis (MG) is an organ-specific autoimmune disease caused by an antibody-mediated assault on the muscle nicotinic acetylcholine receptor (AChR) at the neuromuscular junction. Binding of antibodies to the AChR leads to loss of functional AChRs and impairs the neuromuscular signal transmission, resulting in muscular weakness.
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This question is part of the following fields:
- Clinical Sciences
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Question 55
Incorrect
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A study is developed to compare two chemotherapy schemas for individuals with small cell lung cancer. Which of the following would you choose to compare survival time with in this particular study?
Your Answer:
Correct Answer: Hazard ratio
Explanation:The hazard ratio describes the relative risk of the complication based on comparison of event rates.
Hazard ratios have also been used to describe the outcome of therapeutic trials where the question is to what extent treatment can shorten the duration of the illness. However, the hazard ratio, a type of relative risk, does not always accurately portray the degree of abbreviation of the illness that occurred. In these circumstances, time-based parameters available from the time-to-event curve, such as the ratio of the median times of the placebo and drug groups, should be used to describe the magnitude of the benefit to the patient. The difference between hazard-based and time-based measures is analogous to the odds of winning a race and the margin of victory. The hazard ratio is the odds of a patient’s healing faster under treatment but does not convey any information about how much faster this event may occur.
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This question is part of the following fields:
- Clinical Sciences
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Question 56
Incorrect
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Empagliflozin was found to reduce the risk of cardiovascular deaths, non-fatal myocardial infarction and non-fatal stroke when added to standard treatment plans in patients with type 2 diabetes mellitus. This information was shared in 2015 by The New England Journal of Medicine and the results were expressed per 1000 patient years. In fact, empagliflozin had an event rate of 37.3/1000 patient years and placebo an event rate of 43.9/1000 patient years. How many patients who are at high cardiovascular risk need to be treated with empagliflozin to prevent a cardiovascular death, a non-fatal myocardial infarction or a non-fatal stroke?
Your Answer:
Correct Answer: 150
Explanation:The number needed to treat (NNT) is an absolute effect measure that has been used to assess beneficial and harmful effects of medical interventions. In this case the NNT can be calculated as follows: NNT = 1/ Absolute risk reduction (ARR). ARR=(Control event rate expressed per 1000 patient years) – (Experimental event rate expressed per 1000 patient years) = 43.9-37.3 = 6.6/1000 patient years
NNT=(Patient years)/ARR = 1000/ 6.6 = 151.5. The closest to 151.5 is 150, thus it is the correct answer.
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This question is part of the following fields:
- Clinical Sciences
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Question 57
Incorrect
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Choose the correct statement regarding interferon:
Your Answer:
Correct Answer: Interferon-alpha and interferon-beta bind to the same type of receptor
Explanation:Type I interferons (IFNs) form a network of homologous cytokines that bind to a shared, heterodimeric cell surface receptor and engage signalling pathways that activate innate and adaptive immune responses.
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This question is part of the following fields:
- Clinical Sciences
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Question 58
Incorrect
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A 13-year-old girl is brought by her mother to the A&E with breathlessness, fatigue and palpitations. Anamnesis does not reveal any syncope or chest pain in the past. on the other hand, these symptoms were present intermittently for a year. Clinical examination reveals a pan-systolic murmur associated with giant V waves in the jugular venous pulse. Chest auscultation and resting ECG are normal. 24 hour ECG tape shows a short burst of supraventricular tachycardia. What is the most probable diagnosis?
Your Answer:
Correct Answer: Ebstein's anomaly
Explanation:Ebstein’s anomaly is characterised by apical displacement and adherence of the septal and posterior leaflets of the tricuspid valve to the underlying myocardium, thereby displacing the functional tricuspid orifice apically and dividing the right ventricle into two portions. The main haemodynamic abnormality leading to symptoms is tricuspid valve incompetence. The clinical spectrum is broad; patients may be asymptomatic or experience right-sided heart failure, cyanosis, arrhythmias and sudden cardiac death (SCD). Many Ebstein’s anomaly patients have an interatrial communication (secundum atrial septal defect (ASD II) or patent foramen ovale). Other structural anomalies may also be present, including a bicuspid aortic valve (BAV), ventricular septal defect (VSD), and pulmonary stenosis. The morphology of the tricuspid valve in Ebstein anomaly, and consequently the clinical presentation, is highly variable. The tricuspid valve leaflets demonstrate variable degrees of failed delamination (separation of the valve tissue from the myocardium) with fibrous attachments to the right ventricular endocardium.
The displacement of annular attachments of septal and posterior (inferior) leaflets into the right ventricle toward the apex and right ventricular outflow tract is the hallmark finding of Ebstein anomaly. -
This question is part of the following fields:
- Clinical Sciences
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Question 59
Incorrect
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A 38-year-old female is referred to the dermatologist for a rash on both her elbows. The rash is red, is papulovesicular in nature, and looks like it has many small blisters. The dermatologist diagnoses her with dermatitis herpetiformis. Which HLA haplotype is this associated with?
Your Answer:
Correct Answer: HLA-DR3
Explanation:Dermatitis herpetiformis (DH), or Duhring’s disease, is a chronic blistering skin condition,characterised by blisters filled with a watery fluid. Despite its name, it is neither related to nor caused by herpes virus: the name means that it is a skin inflammation having an appearance similar to herpes.
Dermatitis herpetiformis is characterized by intensely itchy, chronic papulovesicular eruptions, usually distributed symmetrically on extensor surfaces (buttocks, back of neck, scalp, elbows, knees, back, hairline, groin, or face)
Dermatitis herpetiformis is an autoimmune condition associated with HLA-DR3.
HLA-A3 is associated with haemochromatosis. HLA-B5 is most commonly associated with Behcet’s disease. HLA-DR4 is associated with both type 1 diabetes mellitus and rheumatoid arthritis. HLA-B27 is most commonly associated with several diseases, most commonly ankylosing spondylitis. -
This question is part of the following fields:
- Clinical Sciences
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Question 60
Incorrect
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Through which foramen does the maxillary nerve pass through?
Your Answer:
Correct Answer: Foramen rotundum
Explanation:The foramen rotundum is one of the several circular apertures (the foramina) located in the base of the skull, in the anterior and medial part of the sphenoid bone. The maxillary branch (V2) of the trigeminal nerve (CN V) passes through and exits the skull via the pterygopalatine fossa and the foramen rotundum.
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This question is part of the following fields:
- Clinical Sciences
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