2001a-Paper 1 – Medical Sciences

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Pregunta 1 de 70

A 47-year-old woman with overt thyrotoxicosis is found to have aortic stenosis.
Which one of the following features, if present in this woman, is most likely to indicate the need for aortic valve replacement?

Selecciona una de las siguientes respuestas posibles:

A. A peak systolic left ventricular aortic pressure gradient of 60 mmHg.
B. The presence of New York Heart Association (NYHA) class III angina.
C. A resting heart rate greater than 120/minute.
D. An aortic valve orifice area of 0.9 cm2.
E. The presence of concomitant moderate aortic regurgitation

Explicación

Pregunta 2 de 70

The diagram below shows cumulative quantal dose-response curves for a hypothetical drug (drug X). The Y-axis represents the percentage of the population studied who: for curve (a) achieved the desired therapeutic effect at a given dose; and for curve (b) experienced the most important toxic effect at a given dose.
Based on this information, the best estimate of the therapeutic index of drug X is approximately:

Selecciona una de las siguientes respuestas posibles:

A. 0.
B. 0.3.
C. 0.7.
D. 1.
E. 3.

Explicación

Pregunta 3 de 70

The alveolar-arterial gradient for oxygen tension in arterial blood (PA-aO2) can be up to 15 mmHg in healthy young adults and as high as 30 mmHg in elderly people.
Which one of the following is considered to be the predominant physiological mechanism for a normal PA-aO2?

Selecciona una de las siguientes respuestas posibles:

A. Variation in distribution of ventilation.
B. Variation in diffusion for oxygen.
C. Right to left shunt.
D. Ventilation/perfusion (V/Q) inequality.
E. Variation in distribution of pulmonary blood flow.

Explicación

Pregunta 4 de 70

Significant intercurrent illness is commonly associated with disturbances of thyroid function (sick euthyroid syndrome).
Which one of the following is least likely to be present in a euthyroid patient with a severe illness?

Selecciona una de las siguientes respuestas posibles:

A. Raised free thyroxine (free T4).
B. Raised free triiodothyronine (free T3).
C. Low free T3.
D. Low thyroid-stimulating hormone (TSH).
E. Raised TSH.

Explicación

Pregunta 5 de 70

At 72 hours following a significant paracetamol overdose, which one of the following tests will allow the best prediction of death or need for liver transplantation?

Selecciona una de las siguientes respuestas posibles:

A. Serum alanine transaminase (ALT).
B. Serum bilirubin.
C. Prothrombin time-international normalised ratio (PT-INR).
D. Serum gamma glutamyltranspeptidase (GGT).
E. Blood ammonia.

Explicación

Pregunta 6 de 70

The most common cause of blindness in elderly Caucasians is:

Selecciona una de las siguientes respuestas posibles:

A. glaucoma.
B. cataract.
C. macular degeneration.
D. diabetes mellitus.
E. retinal ischaemia.

Explicación

Pregunta 7 de 70

Graft-versus-host disease is a major complication of allogeneic stem cell transplantation for haematological malignancy in adults.
Which one of the following has the least influence on the risk of developing graft-versus-host disease?

Selecciona una de las siguientes respuestas posibles:

A. Age of recipient.
B. Donor-recipient ABO blood group incompatibility.
C. In vitro T cell depletion of the graft.
D. Type of HLA-matched donor (sibling versus unrelated).
E. Donor-recipient HLA mismatch.

Explicación

Pregunta 8 de 70

Dendritic cells are distinguished by an exceptional ability to carry out which one of the following immune functions?

Selecciona una de las siguientes respuestas posibles:

A. Phagocytosis.
B. Cytokine secretion.
C. Chemokine secretion.
D. Immunoglobulin secretion.
E. Antigen presentation

Explicación

Pregunta 9 de 70

The most useful investigation for the diagnosis of multiple sclerosis is:

Selecciona una de las siguientes respuestas posibles:

A. cerebrospinal fluid protein concentration.
B. visual evoked responses.
C. magnetic resonance imaging (MRI) scan of the brain.
D. serum oligoclonal bands.
E. cerebrospinal fluid microscopy

Explicación

Pregunta 10 de 70

A mutation is located in the middle portion of a double-stranded DNA molecule 200 nucleotides long. At each end of the DNA molecule are sites at which short DNA primers for the polymerase chain reaction (PCR) bind to each strand.
In the figures shown below, five possible combinations of primer location and orientation relative to the mutation are shown. In each figure, the long pair of arrows represents the anti-parallel strands of the long DNA molecule and the short arrows represent each short single-stranded DNA primer binding to the closer of the two long strands. The mutation is located at position (II), the primers are located at positions (I) and (III), and the arrowhead on each DNA strand indicates the direction of DNA polymerisation (5’ to 3’).
Which one of the following combinations of primer location and orientation is required to amplify the mutation by PCR?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 11 de 70

A number of patients in a ward have been found to be colonised with vancomycin-resistant enterococci. What would be the best laboratory test to determine if transmission from one patient to another has occurred?

Selecciona una de las siguientes respuestas posibles:

A. Comparison of antibiotic susceptibility (antibiogram).
B. Polymerase chain reaction (PCR) for the van A and van B genes.
C. Enterococcal serology.
D. Pulse-field gel electrophoresis.
E. Speciation (e.g. faecalis vs. faecium).

Explicación

Pregunta 12 de 70

A 35-year-old woman with hypertrophic cardiomyopathy presents with chest pain and palpitations. Her heart rate is 155/minute and irregular, and her blood pressure is 130/80 mmHg.
What is the most appropriate initial therapy?

Selecciona una de las siguientes respuestas posibles:

A. Beta-adrenergic blocker.
B. Nitroglycerine.
C. Amiodarone.
D. Frusemide.
E. Digoxin.

Explicación

Pregunta 13 de 70

In a patient with cryptogenic fibrosing alveolitis (idiopathic pulmonary fibrosis), the finding on bronchoalveolar lavage of an elevated proportion of which one of the following cell types is associated with a better response to therapy?

Selecciona una de las siguientes respuestas posibles:

A. Eosinophils.
B. Lymphocytes.
C. Macrophages.
D. Mast cells.
E. Neutrophils.

Explicación

Pregunta 14 de 70

A bioavailability study has been performed to compare a proposed new generic capsule, in a strength of 50 mg, with a marketed tablet preparation in a strength of 100 mg. The active ingredient is a drug with linear kinetics. A cross-over design was used, with each subject receiving, in random order and with an adequate wash-out period, a single oral dose of one tablet on one occasion and one capsule on the other. The mean results for the area under the plasma concentration versus time curve (AUC) are 300 mg.h/L for the capsule, and 500 mg.h/L for the tablet.
The best estimate of the relative bioavailability of the capsule with respect to the tablet is:

Selecciona una de las siguientes respuestas posibles:

A. 0.3.
B. 0.6.
C. 1.2.
D. 1.7.
E. 3.3.

Explicación

Pregunta 15 de 70

A 25-year-old woman presents to the emergency department with renal colic and macroscopic haematuria. She reports having had several previous episodes treated at another hospital.
The least likely diagnosis is:

Selecciona una de las siguientes respuestas posibles:

A. IgA disease.
B. warfarin use.
C. narcotic abuse.
D. Goodpasture’s syndrome.
E. polycystic kidney disease.

Explicación

Pregunta 16 de 70

The COX-2 isoform of cyclo-oxygenase is most strongly expressed in which one of the following tissues?

Selecciona una de las siguientes respuestas posibles:

A. Platelets.
B. Established scar tissue.
C. Synovium from osteoarthritic joint.
D. Gastric mucosa.
E. Rheumatoid synovium.

Explicación

Pregunta 17 de 70

Which one of the following is the most potent inhibitor of aldosterone secretion in a healthy individual?

Selecciona una de las siguientes respuestas posibles:

A. Elevated plasma potassium.
B. Elevated plasma angiotensin II.
C. Elevated plasma atrial natriuretic peptide.
D. Elevated adrenocorticotrophic hormone.
E. Dietary sodium restriction.

Explicación

Pregunta 18 de 70

A 45-year-old man develops stage C cancer of the caecum. There is a strong family history of bowel cancer in the absence of polyps and there is no history of colitis.
The most likely underlying inherited genetic abnormality is in:

Selecciona una de las siguientes respuestas posibles:

A. the ras gene.
B. the DNA mismatch repair (MMR) gene.
C. the p-glycoprotein (MDR1) gene.
D. the adenomatous polyposis coli (APC) gene.
E. the deleted in colon cancer (DCC) gene.

Explicación

Pregunta 19 de 70

A 19-year-old woman presents with recent-onset of right leg swelling and pleuritic chest pain and is found to have iliofemoral thrombosis on Doppler ultrasound examination. Results of a ventilation-perfusion lung scan indicate a high probability for pulmonary emboli. She had been taking the oral contraceptive pill for the last three years but has now ceased. She is a non-smoker. There is no significant medical history and no known family history of venous thromboembolism.
Which one of the following investigations for an underlying hypercoagulable state is most likely to be affected by the presence of the extensive thrombosis?

Selecciona una de las siguientes respuestas posibles:

A. Antiphospholipid antibody screen.
B. Antithrombin level.
C. Factor V and prothrombin genotype assessment.
D. Activated partial thromboplastin time (APTT).
E. Full blood count including blood film.

Explicación

Pregunta 20 de 70

Which one of the following is associated with the highest risk of NSAID (non-steroidal anti-inflammatory drug)-induced gastric ulceration?

Selecciona una de las siguientes respuestas posibles:

A. Concomitant use of steroids.
B. Infection with Helicobacter pylori.
C. Higher therapeutic dose of NSAID.
D. Advanced age.
E. Concomitant use of anticoagulants.

Explicación

Pregunta 21 de 70

T lymphocytes expressing both CD4 and CD8 on the cell surface are most likely to be found in which one of the following anatomical locations in healthy individuals?

Selecciona una de las siguientes respuestas posibles:

A. Bone marrow.
B. Thymus.
C. Peripheral blood.
D. Lymph nodes.
E. Spleen.

Explicación

Pregunta 22 de 70

In treating constipation, which one of the following agents administered over an extended period of time is most likely to lose its effectiveness?

Selecciona una de las siguientes respuestas posibles:

A. Docusate sodium (Coloxyl).
B. Lactulose.
C. Senna.
D. Psyllium husk powder (Metamucil).
E. Epsom salts.

Explicación

Pregunta 23 de 70

An 18-year-old woman presents with a two-week history of cervical lymphadenopathy, fever, fatigue and myalgia. A Paul-Bunnell test (heterophile antibody) has been negative on two occasions, a week apart. Full blood examination reveals a lymphocytosis with many atypical lymphocytes.
The most likely diagnosis is acute:

Selecciona una de las siguientes respuestas posibles:

A. Epstein-Barr virus (EBV) infection.
B. streptococcal pharyngitis.
C. toxoplasmosis.
D. cytomegalovirus (CMV) infection.
E. human immunodeficiency virus (HIV) infection.

Explicación

Pregunta 24 de 70

The picture below shows a computed tomography (CT) scan of the heart.
Which one of the following is the most likely diagnosis?

Selecciona una de las siguientes respuestas posibles:

A. Metastatic tumour in the pericardium.
B. Left atrial myxoma.
C. Ruptured myocardial papilla.
D. Cor triatriatum.
E. St. Jude mitral valve prosthesis.

Explicación

Pregunta 25 de 70

Vertigo which occurs with neck extension is most likely due to:

Selecciona una de las siguientes respuestas posibles:

A. cervical spondylosis.
B. benign paroxysmal positional vertigo.
C. kinking of the vertebral artery.
D. endolymphatic hydrops.
E. Chiari 1 malformation.

Explicación

Pregunta 26 de 70

Allopurinol precipitates azathioprine toxicity by which one of the following mechanisms?

Selecciona una de las siguientes respuestas posibles:

A. Displacement of azathioprine from protein-binding sites.
B. Impairment of the renal excretion of azathioprine.
C. Promotion of gastrointestinal absorption of azathioprine.
D. Prolongation of the half-life of the biologically active azathioprine metabolite.
E. Inhibition of hydrolysis of azathioprine.

Explicación

Pregunta 27 de 70

Which one of the following mutations in a gene is most likely to disrupt the production of a protein?

Selecciona una de las siguientes respuestas posibles:

A. Splicing defect.
B. Missense change.
C. Nucleotide transversion.
D. Nonsense change.
E. A three base pair deletion.

Explicación

Pregunta 28 de 70

In a patient with a severe exacerbation of asthma, the use of a peak-flow meter may underestimate the severity of airflow limitation compared to the use of spirometry and measurement of the forced expiratory volume in 1 second (FEV1).
Which one of the following is mainly responsible for this reduction in the accuracy of the peak-flow meter?

Selecciona una de las siguientes respuestas posibles:

A. The hyperinflation of severe asthma.
B. The effort-independent component of the forced expiratory manoeuvre.
C. The effort-dependent component of the forced expiratory manoeuvre.
D. Narrowing of small airways.
E. Narrowing of large airways.

Explicación

Pregunta 29 de 70

The most important rationale for using adjuvant chemotherapy soon after surgery for cancer (rather than deferring chemotherapy until the cancer has recurred) is that after surgery:

Selecciona una de las siguientes respuestas posibles:

A. cancer volume is smaller.
B. there is no resistance to cytotoxic agents.
C. there are fewer cells in cell cycle.
D. drug penetration into the tissues is reduced.
E. cancer growth is slower.

Explicación

Pregunta 30 de 70

Which one of the following is the best predictor of outcome in a patient with colorectal cancer?

Selecciona una de las siguientes respuestas posibles:

A. Tumour stage.
B. Degree of microsatellite instability.
C. Ethnic background.
D. Strong family history.
E. Sporadic occurrence.

Explicación

Pregunta 31 de 70

A 32-year-old woman, who has recently migrated from India, is breastfeeding her third child and presents with lethargy and a history of recurrent chest infection. She has a vegetarian diet. Physical examination shows her to be anaemic with no site of blood loss clinically evident and no other abnormalities.
Investigations show:
Full blood count
haemoglobin 64 g/L [120-155]
mean corpuscular volume (MCV) 68 fL [80-95]
white cell count 7.4 x 109/L [3.5-9.5]
differential normal
platelet count 412 x 109/L [130-330]
Blood film is shown below.
With respect to the patient’s anaemia, which one of the following laboratory results has the most diagnostic value?

Selecciona una de las siguientes respuestas posibles:

A. A lower than normal serum iron level.
B. A lower than normal serum ferritin level.
C. A higher than normal serum transferrin level.
D. A negative urinary haemosiderin test.
E. A normal plasma haemoglobin A2 leve

Explicación

Pregunta 32 de 70

A 28-year-old woman presents with galactorrhoea. She has been treated for hypothyroidism for five years with thyroxine 0.1 mg/day. She is also receiving lithium carbonate for depression and her serum lithium levels are in the mid-therapeutic range. She takes diazepam 5 mg nocte for insomnia and metoclopramide 10 mg as required for nausea. Her serum prolactin concentration is 1800 mU/L [<600].
From this history, which one of the following factors is most likely to be responsible for her hyperprolactinaemia and galactorrhoea?

Selecciona una de las siguientes respuestas posibles:

A. Use of metoclopramide.
B. History of hypothyroidism.
C. Treatment with thyroxine.
D. Use of lithium.
E. Use of diazepam.

Explicación

Pregunta 33 de 70

In renal transplant biopsies, which one of the following features of acute rejection has the worst prognostic implication?

Selecciona una de las siguientes respuestas posibles:

A. Glomerular T cell infiltrate.
B. Dense interstitial mononuclear infiltrate.
C. Increased expression of HLA-DR on graft cells.
D. Vascular injury.
E. Tubulitis due to CD8+ T cells.

Explicación

Pregunta 34 de 70

Which one of the following biologically active components of the complement cascade is most directly responsible for the formation of transmembrane channels leading to cell lysis?

Selecciona una de las siguientes respuestas posibles:

A. C3a.
B. C3b.
C. C4a.
D. C5a.
E. C5-9.

Explicación

Pregunta 35 de 70

Which one of the following is the most common association of the abnormality shown in the X-ray above?

Selecciona una de las siguientes respuestas posibles:

A. Haemochromatosis.
B. Hypomagnesaemia.
C. Old age.
D. Hyperparathyroidism.
E. Osteoporosis.

Explicación

Pregunta 36 de 70

A young man presents with breathlessness and ankle swelling. He had a ventricular septal defect (VSD) repaired at the age of three years. He is centrally cyanosed and has a prominent right ventricular heave on palpation of the chest.
The most likely finding is:

Selecciona una de las siguientes respuestas posibles:

A. pulmonary hypertension.
B. blood oxygen saturation of 95%.
C. left ventricular hypertrophy.
D. left to right shunt.
E. normal haemoglobin.

Explicación

Pregunta 37 de 70

The principal aim of a phase 1 trial of a cytotoxic agent is to:

Selecciona una de las siguientes respuestas posibles:

A. maintain the patient’s hope that treatment is possible.
B. determine the best schedule of administration.
C. define tumour response rate.
D. measure progression-free survival.
E. establish the maximum tolerated dose (MTD).

Explicación

Pregunta 38 de 70

A 67-year-old woman with severe chronic obstructive pulmonary disease undergoes an all-night respiratory sleep study. The study reveals no evidence of obstructive sleep apnoea but there are three periods of repeated falls in oxyhaemoglobin saturation (SaO2).
Which one of the following is the most likely explanation for the falls in SaO2?

Selecciona una de las siguientes respuestas posibles:

A. SWS (slow wave sleep)-related upper airway narrowing.
B. REMS (rapid eye movement sleep)-related increase in nasal resistance.
C. REMS-related increase in ventilation-perfusion mismatching.
D. SWS-related reduction in cardiac output.
E. REMS-related reduction in respiratory drive.

Explicación

Pregunta 39 de 70

Which one of the following is the strongest independent risk factor for stroke?

Selecciona una de las siguientes respuestas posibles:

A. Hypertension.
B. Cigarette smoking.
C. Physical inactivity.
D. Age.
E. Hypercholesterolaemia.

Explicación

Pregunta 40 de 70

The diagram below shows cumulative quantal concentration-response curves for a hypothetical drug (drug X) which has linear kinetics. The Y-axis represents the percentage of the population studied who: for curve (a) achieved the desired therapeutic effect at a given plasma concentration; and for curve (b) experienced the most important toxic effect at a given plasma concentration.
If a patient with no evidence of toxicity who has not achieved the desired therapeutic response has a measured concentration of 40 mg/L, the best response would be to:

Selecciona una de las siguientes respuestas posibles:

A. check compliance with no change in dose.
B. increase the dose by 25%.
C. increase the dose by 50%.
D. increase the dose by 75%.
E. increase the dose by 100%.

Explicación

Pregunta 41 de 70

A patient undergoes a Schilling test because of vitamin B12 deficiency. The following results are obtained:
The most likely pathology is:

Selecciona una de las siguientes respuestas posibles:

A. small bowel bacterial overgrowth.
B. pernicious anaemia.
C. partial (Billroth II) gastrectomy.
D. terminal ileal Crohn’s disease.
E. short bowel syndrome.

Explicación

Pregunta 42 de 70

Which one of the following antibiotics is least active against pathogenic anaerobic bacteria (e.g. Bacteroides fragilis, Clostridium perfringens)?

Selecciona una de las siguientes respuestas posibles:

A. Ticarcillin plus clavulanate.
B. Metronidazole.
C. Clindamycin.
D. Ceftriaxone.
E. Chloramphenicol.

Explicación

Pregunta 43 de 70

A 22-year-old woman has been on a stable dose of anticonvulsant for three years. She has recently experienced difficulties in seeing at night. A formal ophthalmological assessment demonstrates visual field constriction.
For which one of the following anticonvulsants is it important to monitor visual fields?

Selecciona una de las siguientes respuestas posibles:

A. Carbamazepine.
B. Gabapentin.
C. Lamotrigine.
D. Valproate.
E. Vigabatrin.

Explicación

Pregunta 44 de 70

A 64-year-old woman undergoes a dual-energy X-ray absorptiometry scan. The report is shown below.
According to World Health Organisation (WHO) definitions, the patient's lumbar spine bone density is:

Selecciona una de las siguientes respuestas posibles:

A. high normal.
B. normal.
C. osteopenic.
D. osteoporotic.
E. severely osteoporotic.

Explicación

Pregunta 45 de 70

A 48-year-old previously well man is receiving a transfusion of four units of packed red cell concentrate via a peripheral intravenous line after presenting with melaena secondary to a bleeding duodenal ulcer. He has not been previously transfused. Admission biochemistry (including urea, electrolytes and creatinine) is normal and pre-transfusion blood counts are normal apart from anaemia (haemoglobin 64 g/L [135-170]). Less than five minutes after transfusion of the third unit of blood is commenced, he complains of feeling very unwell and abruptly develops fever, chills, rigors and profound hypotension.
In the absence of ABO, Rhesus or minor blood group donor-recipient incompatibility, the most likely diagnosis is:

Selecciona una de las siguientes respuestas posibles:

A. bacterial contamination of the transfused blood.
B. transfusion-associated graft-versus-host disease.
C. electrolyte disturbance.
D. citrate toxicity.
E. reaction to plasticiser in infusion bag.

Explicación

Pregunta 46 de 70

The following pharmacokinetic data (normalised to a 70 kg individual) are provided for five drugs.
Which one of the following drugs is most likely to have the slowest rate of clearance from plasma?

Selecciona una de las siguientes respuestas posibles:

A. Amiloride.
B. Amiodarone.
C. Dapsone.
D. Tolbutamide.
E. Trimethoprim.

Explicación

Pregunta 47 de 70

A non-consanguineous family with a rare genetic disease has been identified. The pedigree is shown below.
What is the most likely mode of inheritance?

Selecciona una de las siguientes respuestas posibles:

A. Mitochondrial.
B. X-linked.
C. Autosomal dominant.
D. Autosomal recessive.
E. Polygenic.

Explicación

Pregunta 48 de 70

Which one of the following findings during a stress exercise ECG test is most predictive of angiographically significant multivessel or left main coronary artery disease?

Selecciona una de las siguientes respuestas posibles:

A. Late-onset of ST-segment depression.
B. Return to normal of ST-segment changes early in recovery phase.
C. ST-segment elevation in lead aVR.
D. Multifocal premature ventricular contractions.
E. Failure to increase systolic blood pressure by at least 10 mmHg.

Explicación

Pregunta 49 de 70

At the onset of infection or inflammation, the level of which one of the following acute phase proteins rises most rapidly and by the highest percentage over background?

Selecciona una de las siguientes respuestas posibles:

A. Fibrinogen.
B. Haptoglobin.
C. Transferrin.
D. C-reactive protein.
E. Complement component 3 (C3).

Explicación

Pregunta 50 de 70

A 40-year-old woman presents with progressive breathlessness on exertion. She is a non-smoker. Physical examination and chest X-ray reveal no significant abnormality. Pulmonary function tests show the following results:
Which one of the following is the most likely explanation for this woman's pulmonary function test results?

Selecciona una de las siguientes respuestas posibles:

A. Pulmonary vascular disease.
B. Pulmonary fibrosis.
C. Small airway disease.
D. Inadequate effort during the tests.
E. Hyperventilation syndrome.

Explicación

Pregunta 51 de 70

For an 82-year-old nursing home resident who experiences recurrent falls, which one of the following is least likely to prevent hip fracture?

Selecciona una de las siguientes respuestas posibles:

A. Oestrogen replacement therapy.
B. Bisphosphonates.
C. Calcium supplements.
D. Balance and muscle strengthening exercises.
E. Hip protectors.

Explicación

Pregunta 52 de 70

The manometric feature most characteristic of achalasia is:

Selecciona una de las siguientes respuestas posibles:

A. lack of peristalsis in the oesophageal body.
B. high resting tone of the lower oesophageal sphincter.
C. failure of lower oesophageal sphincter relaxation with swallowing.
D. poor propagation of oesophageal contraction waves.
E. diffuse spasm in the oesophageal body.

Explicación

Pregunta 53 de 70

Cytokine regulation (especially involving interleukin 2) is least affected by which one of the following immunosuppressive drugs?

Selecciona una de las siguientes respuestas posibles:

A. Prednis(ol)one.
B. Mycophenolate.
C. Cyclosporin.
D. Tacrolimus (FK506).
E. Rapamycin.

Explicación

Pregunta 54 de 70

The mechanism of penicillin resistance in pneumococcal infections is most likely to be due to which one of the following?

Selecciona una de las siguientes respuestas posibles:

A. Plasmid-mediated beta lactamase production.
B. Chromosome-mediated beta lactamase production.
C. Plasmid-mediated penicillinase production.
D. Decreased affinity of penicillin-binding proteins.
E. Altered permeability to penicillin.

Explicación

Pregunta 55 de 70

The most important application of carcinoembryonic antigen (CEA) measurements in patients with colon cancer is:

Selecciona una de las siguientes respuestas posibles:

A. testing of relatives.
B. detection of resectable relapse.
C. determining prognosis of stage III disease.
D. identification of patients who require adjuvant chemotherapy.
E. monitoring during adjuvant treatment.

Explicación

Pregunta 56 de 70

In complex partial seizures of temporal lobe type, the most common finding at surgery for the epilepsy is:

Selecciona una de las siguientes respuestas posibles:

A. mesial temporal sclerosis.
B. neuronal migration disorder.
C. old infarction.
D. normal brain.
E. cavernous angioma.

Explicación

Pregunta 57 de 70

The diagram below shows the relationship between the plasma concentration of a drug and the effect of that drug over time in a single individual given one dose of the drug. The direction of change over time is shown by the arrows. The relationship is described by an anti-clockwise hysteresis loop. The numbers on the loop indicate the number of hours after the dose was given.
The best explanation of this phenomenon is that:

Selecciona una de las siguientes respuestas posibles:

A. the drug is binding irreversibly to its target receptor.
B. the drug is active itself but has no active metabolites.
C. there is a delay in the absorption of the drug from the gastrointestinal tract.
D. there is down-regulation of the drug’s target receptor over time.
E. there is a delay in the distribution of the drug from plasma to its site of action

Explicación

Pregunta 58 de 70

Genetically determined variation in which one of the following cell surface molecules is capable of conferring the greatest resistance to human immunodeficiency virus (HIV) infection?

Selecciona una de las siguientes respuestas posibles:

A. Mannose-binding lectin.
B. Chemokine receptor CCR5.
C. Chemokine receptor CXCR4.
D. Human leucocyte antigen (HLA) class I.
E. Human leucocyte antigen (HLA) class II.

Explicación

Pregunta 59 de 70

Deficiency of which one of the following enzymes is most likely to cause severe hyperuricaemia?

Selecciona una de las siguientes respuestas posibles:

A. Xanthine oxidase.
B. Adenosine deaminase.
C. Phosphoribosyl pyrophosphate (PRPP) synthetase.
D. Hypoxanthine-guanine phosphoribosyl transferase (HGPRTase).
E. Hexosaminidase

Explicación

Pregunta 60 de 70

Which one of the following physical findings would be least expected in association with the chest X-ray shown above?

Selecciona una de las siguientes respuestas posibles:

A. A soft pulmonary component of the second heart sound (P2).
B. Prominent "v" wave in the jugular venous pressure.
C. Right ventricular lift.
D. Ejection click.
E. Early diastolic murmur

Explicación

Pregunta 61 de 70

Which feature of glomerular pathology is least consistent with the diagnosis of Wegener's granulomatosis?

Selecciona una de las siguientes respuestas posibles:

A. Focal necrosis.
B. Crescents.
C. IgG deposition.
D. T cell infiltrate.
E. Macrophage infiltrate.

Explicación

Pregunta 62 de 70

A 62-year-old man on weekly oral methotrexate for psoriatic arthritis inadvertently receives a course of oral trimethoprim-sulfamethoxazole therapy for urinary infection. He becomes ill with mucositis, fever and bruising and is found to have moderately severe pancytopenia.
Folinic acid (in the form of calcium folinate) is administered intravenously as an antidote for presumed methotrexate toxicity.
The principal mode of action of folinic acid is:

Selecciona una de las siguientes respuestas posibles:

A. enhanced renal excretion of methotrexate.
B. reduced intracellular accumulation of methotrexate.
C. conversion of methotrexate to an inactive metabolite.
D. activation of the enzyme dihydrofolate reductase.
E. provision of reduced folates for nucleic acid synthesis

Explicación

Pregunta 63 de 70

A young woman presents with thirst and polyuria. Following overnight water deprivation, which one of the following is the best indicator that she has partial (and central) diabetes insipidus rather than psychogenic polydipsia?

Selecciona una de las siguientes respuestas posibles:

A. Severe thirst.
B. Failure to reach normal urinary concentrations.
C. Low serum osmolality.
D. Increased urine osmolality in response to injected vasopressin.
E. Increased blood urea.

Explicación

Pregunta 64 de 70

In the pedigree shown below, the man indicated by an arrow has been shown to have an autosomal recessive biochemical disorder with complete penetrance. The causative gene has not been identified. His parents are obligate carriers and do not exhibit any biochemical abnormalities. His sister also has normal biochemical studies. The carrier frequency in this population is 10%.
In the absence of consanguinity, what is the risk of the sister having a child with the biochemical abnormality?

Selecciona una de las siguientes respuestas posibles:

A. 1 in 40.
B. 1 in 60.
C. 1 in 80.
D. 1 in 100.
E. 1 in 120.

Explicación

Pregunta 65 de 70

In a patient with oropharyngeal dysphagia following a stroke, which one of the following would be the strongest indicator of increased risk of aspiration?

Selecciona una de las siguientes respuestas posibles:

A. Facial weakness with drooling.
B. Refusal to eat.
C. Moist vocal quality and weak cough.
D. Bilateral absent gag reflex.
E. Dysarthria.

Explicación

Pregunta 66 de 70

Which one of the following pharmacokinetic parameters is most important in the optimal prescribing of beta-lactam antibiotics?

Selecciona una de las siguientes respuestas posibles:

A. The peak concentration/mean inhibitory concentration (MIC) ratio.
B. Area under the plasma concentration versus time curve (AUC).
C. The AUC/MIC ratio.
D. Time above the MIC.
E. Both AUC/MIC ratio and peak concentration/MIC ratio.

Explicación

Pregunta 67 de 70

Drug X is given intravenously, using two different regimens, to the same patient on two different occasions. On both occasions, there is no measurable amount of the drug in plasma prior to its administration. On both occasions, the volume of distribution of X is 0.85 L/kg and the plasma half-life is six hours.
Regimen A: continuous intravenous infusion of 10 mg/kg/h, with no loading dose.
Regimen B: a loading dose of 50 mg/kg given rapidly intravenously, then a continuous intravenous infusion of 10 mg/kg/h.
Using Regimen A, the plasma concentration of X after 48 hours was 100 mg/L.
Using Regimen B, the plasma concentration of X after 48 hours would most closely approximate:

Selecciona una de las siguientes respuestas posibles:

A. 50 mg/L.
B. 75 mg/L.
C. 100 mg/L.
D. 125 mg/L.
E. 150 mg/L.

Explicación

Pregunta 68 de 70

A 25-year-old man dislocates his right shoulder while playing football. This is reduced in the emergency department and he is discharged after observation. After removal of his sling he has problems with abduction of the arm. Examination shows weakness of abduction at the shoulder and sensory loss on the lateral aspect of his upper arm.
The nerve involved is the:

Selecciona una de las siguientes respuestas posibles:

A. accessory nerve.
B. axillary nerve.
C. musculocutaneous nerve.
D. radial nerve.
E. suprascapular nerve.

Explicación

Pregunta 69 de 70

In a randomised controlled trial of an intervention to stop smoking in patients with chronic obstructive pulmonary disease (COPD), the use of an intention-to-treat analysis is most likely to cause which one of the following?

Selecciona una de las siguientes respuestas posibles:

A. Bias that overestimates the efficacy of the intervention.
B. Bias that underestimates the efficacy of the intervention.
C. Bias due to selection of subjects.
D. Bias due to measurement of the outcome.
E. Bias due to known and unknown confounders.

Explicación

Pregunta 70 de 70

Which one of the following histopathological features is least likely to be seen in cranial (temporal) arteritis?

Selecciona una de las siguientes respuestas posibles:

A. Thickening of the intima.
B. Fragmentation of the internal elastic lamina.
C. Panarteritis.
D. Presence of giant cells.
E. Aneurysmal dilatation.

Explicación

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	Creado por Jeku Jacob hace más de 10 años

2001 FRACP Written Examination Adult Medicine Paper 1 – Medical Sciences

2001a-Paper 1 – Medical Sciences

Pregunta 1 de 70

A 47-year-old woman with overt thyrotoxicosis is found to have aortic stenosis. Which one of the following features, if present in this woman, is most likely to indicate the need for aortic valve replacement?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 2 de 70

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 3 de 70

The alveolar-arterial gradient for oxygen tension in arterial blood (PA-aO2) can be up to 15 mmHg in healthy young adults and as high as 30 mmHg in elderly people. Which one of the following is considered to be the predominant physiological mechanism for a normal PA-aO2?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 4 de 70

Significant intercurrent illness is commonly associated with disturbances of thyroid function (sick euthyroid syndrome). Which one of the following is least likely to be present in a euthyroid patient with a severe illness?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 5 de 70

At 72 hours following a significant paracetamol overdose, which one of the following tests will allow the best prediction of death or need for liver transplantation?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 6 de 70

The most common cause of blindness in elderly Caucasians is:

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 7 de 70

Graft-versus-host disease is a major complication of allogeneic stem cell transplantation for haematological malignancy in adults. Which one of the following has the least influence on the risk of developing graft-versus-host disease?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 8 de 70

Dendritic cells are distinguished by an exceptional ability to carry out which one of the following immune functions?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 9 de 70

The most useful investigation for the diagnosis of multiple sclerosis is:

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 10 de 70

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 11 de 70

A number of patients in a ward have been found to be colonised with vancomycin-resistant enterococci. What would be the best laboratory test to determine if transmission from one patient to another has occurred?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 12 de 70

A 35-year-old woman with hypertrophic cardiomyopathy presents with chest pain and palpitations. Her heart rate is 155/minute and irregular, and her blood pressure is 130/80 mmHg. What is the most appropriate initial therapy?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 13 de 70

In a patient with cryptogenic fibrosing alveolitis (idiopathic pulmonary fibrosis), the finding on bronchoalveolar lavage of an elevated proportion of which one of the following cell types is associated with a better response to therapy?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 14 de 70

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 15 de 70

A 25-year-old woman presents to the emergency department with renal colic and macroscopic haematuria. She reports having had several previous episodes treated at another hospital. The least likely diagnosis is:

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 16 de 70

The COX-2 isoform of cyclo-oxygenase is most strongly expressed in which one of the following tissues?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 17 de 70

Which one of the following is the most potent inhibitor of aldosterone secretion in a healthy individual?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 18 de 70

A 45-year-old man develops stage C cancer of the caecum. There is a strong family history of bowel cancer in the absence of polyps and there is no history of colitis. The most likely underlying inherited genetic abnormality is in:

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 19 de 70

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 20 de 70

Which one of the following is associated with the highest risk of NSAID (non-steroidal anti-inflammatory drug)-induced gastric ulceration?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 21 de 70

T lymphocytes expressing both CD4 and CD8 on the cell surface are most likely to be found in which one of the following anatomical locations in healthy individuals?

A 47-year-old woman with overt thyrotoxicosis is found to have aortic stenosis.
Which one of the following features, if present in this woman, is most likely to indicate the need for aortic valve replacement?

The alveolar-arterial gradient for oxygen tension in arterial blood (PA-aO2) can be up to 15 mmHg in healthy young adults and as high as 30 mmHg in elderly people.
Which one of the following is considered to be the predominant physiological mechanism for a normal PA-aO2?

Significant intercurrent illness is commonly associated with disturbances of thyroid function (sick euthyroid syndrome).
Which one of the following is least likely to be present in a euthyroid patient with a severe illness?

Graft-versus-host disease is a major complication of allogeneic stem cell transplantation for haematological malignancy in adults.
Which one of the following has the least influence on the risk of developing graft-versus-host disease?

A 35-year-old woman with hypertrophic cardiomyopathy presents with chest pain and palpitations. Her heart rate is 155/minute and irregular, and her blood pressure is 130/80 mmHg.
What is the most appropriate initial therapy?

A 25-year-old woman presents to the emergency department with renal colic and macroscopic haematuria. She reports having had several previous episodes treated at another hospital.
The least likely diagnosis is:

A 45-year-old man develops stage C cancer of the caecum. There is a strong family history of bowel cancer in the absence of polyps and there is no history of colitis.
The most likely underlying inherited genetic abnormality is in:

The picture below shows a computed tomography (CT) scan of the heart.
Which one of the following is the most likely diagnosis?

A young man presents with breathlessness and ankle swelling. He had a ventricular septal defect (VSD) repaired at the age of three years. He is centrally cyanosed and has a prominent right ventricular heave on palpation of the chest.
The most likely finding is: