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Question 1
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: Ipsilateral loss of temperature, contralateral loss of fine touch and vibration, ipsilateral spastic paresis
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 2
Incorrect
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A study is carried out to assess the efficacy of a rapid urine screening test developed to detect Chlamydia. The total number of people involved in the study were 200. The study compared the new test to the already existing NAAT techniques. The new test was positive in 20 patients that were Chlamydia positive and in 3 patients that were Chlamydia negative. For 5 patients that were Chlamydia positive and 172 patients that were Chlamydia negative the test turned out to be negative. Choose the correct value regarding the negative predictive value of the new test:
Your Answer: 20/23
Correct Answer: 172/177
Explanation:The definition of negative predictive value is the probability that the individuals with truly negative screening test don’t have Chlamydia. The equation is the following: Negative predictive value = Truly negative/(truly negative + false negative) = 172 / (172 + 5) = 172 / 177
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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 68-year-old male patient presents with central chest pain and associated flushing. He claims the pain is crushing in character. ECG reveals T wave inversion in II, III and AVF. Blood exams are as follows: Troponin T = 0.9 ng/ml. Which substance does troponin bind to?
Your Answer: Myosin
Correct Answer: Tropomyosin
Explanation:Troponin T is a 37 ku protein that binds to tropomyosin, thereby attaching the troponin complex to the thin filament.
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This question is part of the following fields:
- Clinical Sciences
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Question 4
Correct
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A 23-year-old woman presents to the A&E with a 24-hour-history of gradual-onset fever, light sensitivity and headache. Clinical examination reveals neck stiffness and an area of rash which does not disappear upon pressure on her right shin. Anamnesis reveals a history of 3 episodes of meningococcal meningitis in the past and she was started on ceftriaxone for another suspected meningitis. However, you suspect that the patients might be immunodeficient. Which immunodeficiency does she most probably have?
Your Answer: C5-9 deficiency
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. The common terminal pathway consists of complement components C5–C9, and activation forms the anaphylatoxin C5a, a strong proinflammatory mediator, and the membrane attack complex (MAC), which creates pores in the bacterial cell wall (12). Deficiencies in these late complement components have been recognized as a cause of recurrent and familial meningococcal infections.
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This question is part of the following fields:
- Clinical Sciences
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Question 5
Correct
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A cohort study is developed to assess the correlation between blood pressure and working long hours. After 10 years of follow-up and for the 1050 individuals working less than 40 hours per week, 1000 patients had normal blood pressure and 50 patients were diagnosed with hypertension. For the 660 patients working more than 40 hours per week, 600 patients had normal blood pressure and 60 patients were diagnosed with hypertension. If you work more than 40 hours per week, what is the odds ratio of developing hypertension compared to the individuals working less than 40 hours per week?
Your Answer: 2
Explanation:An odds ratio (OR) is a measure of the 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 6
Correct
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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: 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 7
Incorrect
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The average weight of 64 patients with type 2 diabetes mellitus was 81 kg, with a standard deviation of 12 kg. What is the standard error of the mean?
Your Answer: 9-Dec
Correct Answer: 1.5
Explanation:The SEM is dependent on the variation in the population and the number of the extracted samples. A large variation in the population causes a large difference in the sample means, ultimately resulting in a larger SEM. However, as more samples are extracted from the population, the sample means move closer to the population mean, which results in a smaller SEM. In short, the SEM is an indicator of how close the sample mean is to the population mean. Standard error of the mean = standard deviation / square root (number of patients)
The standard error of the mean is calculated by the standard deviation / square root (number of patients)= 12 / square root (64) = 12 / 8 = 1.5
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This question is part of the following fields:
- Clinical Sciences
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Question 8
Correct
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A study is developed to compare the calcemia of men and women with Crohn's disease. The objective of the study is to detect any differences between the average calcium levels in men compared to women. Previous studies have shown a normal distribution regarding calcium levels. Which of the the following tests would you most likely apply?
Your Answer: Student's unpaired t-test
Explanation:A t test is a type of statistical test that is used to compare the means of two groups. It is one of the most widely used statistical hypothesis tests in pain studies. There are two types of statistical inferences: parametric and nonparametric methods. Parametric methods refer to a statistical technique in which one defines the probability distribution of probability variables and makes inferences about the parameters of the distribution. In cases in which the probability distribution cannot be defined, nonparametric methods are employed. T tests are a type of parametric method; they can be used when the samples satisfy the conditions of normality, equal variance, and independence. In this case the data is parametric, comparing two independent samples from the same population.
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This question is part of the following fields:
- Clinical Sciences
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Question 9
Incorrect
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Choose the correct definition regarding the standard error of the mean:
Your Answer: Number of patients / square root (standard deviation)
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 10
Correct
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Which is the formula to calculate the number needed to treat?
Your 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 11
Incorrect
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A 65-year-old woman with type 2 diabetes mellitus is feeling more fatigued than usual. She has not attended the previous three annual check-ups and her blood glucose control has been poor. She has not been compliant with his medications. Blood pressure is 170/90 mmHg. Urinalysis shows microalbuminuria. A blood test reveals her glomerular filtration rate (GFR) is 26mL/min. If a renal biopsy was to be performed in this patient, what would be the expected findings?
Your Answer:
Correct Answer: Nodular glomerulosclerosis and hyaline arteriosclerosis
Explanation:This patient has a poorly controlled T2DM with an underlying diabetic nephropathy. The histological findings are Kimmelstiel-Wilson lesions (nodular glomerulosclerosis) and hyaline arteriosclerosis. This is due to nonenzymatic glycosylation.
Diabetic nephropathy is the chronic loss of kidney function occurring in those with diabetes mellitus. Protein loss in the urine due to damage to the glomeruli may become massive, and cause a low serum albumin with resulting generalized body swelling (edema) and result in the nephrotic syndrome. Likewise, the estimated glomerular filtration rate (eGFR) may progressively fall from a normal of over 90 ml/min/1.73m2 to less than 15, at which point the patient is said to have end-stage kidney disease (ESKD). It usually is slowly progressive over years.
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This question is part of the following fields:
- Clinical Sciences
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Question 12
Incorrect
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A study was developed to assess a new oral antithrombotic drug on the chance of stroke in high-risk patients, compared to warfarin. The total number of patients receiving the new drug were 200 compared to 600 who were receiving warfarin. From the ones receiving the new drug, 10 patients had a stroke within 3 years, compared to 12 patients who were receiving warfarin and had a stroke. What is the relative risk of having a stroke within 3 years for patients receiving the new drug?
Your Answer:
Correct Answer: 2.5
Explanation:Relative Risk = (Probability of event in exposed group) / (Probability of event in not exposed group)
Experimental event rate, EER = 10 / 200 = 0.05Control event rate, CER = 12 / 600 = 0.02
Therefore the relative risk = EER / CER = 0.05 / 0.02 = 2.5
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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 13-year-old girl presents with a swollen left knee following a fall. Her parents state she suffers from haemophilia and has been treated for a right-sided haemarthrosis previously. What other condition is she most likely to have?
Your Answer:
Correct Answer: Turner's syndrome
Explanation:Haemophilia is a X-linked recessive disorder. In X-linked recessive inheritance only males are affected. An exception to this seen in examinations are patients with Turner’s syndrome, who are affected due to only having one X chromosome. X-linked recessive disorders are transmitted by heterozygote females (carriers) and male-to-male transmission is not seen. Affected males can only have unaffected sons and carrier daughters.
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This question is part of the following fields:
- Clinical Sciences
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Question 14
Incorrect
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Double-stranded DNA is found in which of the following cell organelles?
Your Answer:
Correct Answer: Mitochondria
Explanation:Mitochondrial DNA (mtDNA) is a double-stranded molecule of 16.6 kb (Figure 1, lower panel). The two strands of mtDNA differ in their base composition, with one being rich in guanines, making it possible to separate a heavy (H) and a light (L) strand by density centrifugation in alkaline CsCl2 gradients.
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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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How is the left ventricular ejection fraction calculated?
Your Answer:
Correct 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 16
Incorrect
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Which one of the following congenital infections is most characteristically associated with chorioretinitis?
Your Answer:
Correct Answer: Toxoplasma gondii
Explanation:The common congenital infections encountered are rubella, toxoplasmosis and cytomegalovirus. Cytomegalovirus is the most common congenital infection in the UK. Maternal infection is usually asymptomatic.
Congenital toxoplasmosis is associated with fetal death and abortion, and in infants, it is associated with neurologic deficits, neurocognitive deficits, and chorioretinitis. -
This question is part of the following fields:
- Clinical Sciences
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Question 17
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 18
Incorrect
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A 69-year-old woman is admitted with confusion. She's known to have a history of multiple myeloma. Blood exam reveals the following: Na+ = 147 mmol/l, K+ = 4.7 mmol/l, Urea = 14.2 mmol/l, Creatinine = 102 μmol/l, Adjusted calcium = 3.9 mmol/l. What is the single most appropriate management?
Your Answer:
Correct Answer: IV 0.9% saline
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 19
Incorrect
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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:
Correct 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 20
Incorrect
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A 61-year-old female presents to the A&E with malaise and muscle twitching. Her blood pressure is 114/78 mmHg and her pulse is 84/min. Blood exam reveals Calcium = 1.94 mmol/l and Albumin = 38 g/l. Which of the following tests is most useful in establishing her diagnosis?
Your Answer:
Correct Answer: Parathyroid hormone
Explanation:Hypocalcaemia occurs in patients with impaired function of the parathyroid glands. This is most common after thyroid or parathyroid surgery, but it can be idiopathic—mostly in young adults and less often as part of a genetic syndrome, such as autoimmune polyglandular syndrome type 1. Usually, the first and most useful test to perform in such cases is the measurement of the parathyroid hormone.
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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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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 22
Incorrect
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Which of the following is not a tumour suppressor gene?
Your Answer:
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 23
Incorrect
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A 54-year-old female patient presents with a one week history of bloody diarrhoea, fever and abdominal pain. She has a history of rheumatoid arthritis which she controls with methotrexate. Her stool sample shows Campylobacter jejuni. What is the single most appropriate management?
Your Answer:
Correct Answer: Fluids + clarithromycin
Explanation:This woman is receiving methotrexate, an immunosuppressant, to control her rheumatoid arthritis. In such immunocompromised patients, BNF suggests clarithromycin as first-line management.
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This question is part of the following fields:
- Clinical Sciences
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Question 24
Incorrect
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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:
Correct 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 25
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 26
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 27
Incorrect
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A 22-year-old man presents with red and flaky patches at the corners of his mouth. Upon examination, angular cheilitis is diagnosed. Anamnesis reveals a history of excessive drinking and malnutrition. What is the most probable deficiency responsible for his condition?
Your Answer:
Correct Answer: Vitamin B2 deficiency
Explanation:Riboflavin, vitamin B2, is a water-soluble and heat-stable vitamin that the body uses to metabolize fats, protein, and carbohydrates into glucose for energy. Riboflavin deficiency can cause fatigue, swollen throat, blurred vision, and depression. It can affect the skin by causing skin cracks, itching, and dermatitis around the mouth. Hyperaemia and oedema around throat, liver degeneration, and hair loss can also occur along with reproductive issues. Usually, people with riboflavin deficiency also have deficiencies of other nutrients. In most cases, riboflavin deficiency can be reversed unless it has caused anatomical changes such as cataracts.
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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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A 60-year-old male presents with dyspnoea and an urgent chest X-ray is scheduled. Sputum cultures reveal pneumonia and he receives treatment with erythromycin. What is the mechanism of action of this drug?
Your Answer:
Correct Answer: Inhibit 50S subunit of ribosomes
Explanation:Erythromycin is a bacteriostatic antibiotic. This means it stops the further growth of bacteria rather than directly destroying it. This is achieved by inhibiting protein synthesis. Erythromycin binds to the 23S ribosomal RNA molecule in the 50S subunit of the bacterial ribosome. This causes a blockage in the exiting of the peptide chain that is growing. Given that humans have 40S and 60S subunits, and do not have 50S subunits, erythromycin does not affect protein synthesis in human tissues.
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This question is part of the following fields:
- Clinical Sciences
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Question 29
Incorrect
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Choose the correct statement regarding standard polymerase chain reaction:
Your Answer:
Correct Answer: A thermostable DNA polymerase is required
Explanation:In the PCR, DNA amplification is performed by thermostable enzymes; invariably either family A DNA polymerases from thermophilic and hyperthermophilic Bacteria or family B DNA polymerases from hyperthermophilic Archaea. Family Y DNA polymerase from the hyperthermophilic archaeon Sulfolobus solfataricus, Sso-polY, is also an enzyme marketed for PCR, but with specialist applications. Each thermostable DNA polymerases has different characteristics and to achieve optimal results, the choice of a PCR enzyme depends on the application itself.
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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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What percentage of values lie within 3 standard deviations of the mean in a normal distribution?
Your Answer:
Correct Answer: 99.70%
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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SESSION STATS - PERFORMANCE PER SPECIALTY
