-
Question 1
Correct
-
Regarding the foetal oxygen-haemoglobin dissociation curve, which of the following statements is CORRECT:
Your Answer: The HbF dissociation curve lies to the left of that for HbA.
Explanation:Foetal haemoglobin (HbF) has a higher affinity for oxygen than adult haemoglobin (HbA) because it’s gamma chains bind 2,3-DPG less avidly than beta chains of HbA. The HbF dissociation curve lies to the left of that for HbA. In the placenta PCO2moves from the foetal to the maternal circulation, shifting the maternal curve further right and the foetal curve further left (the double Bohr effect). The higher affinity of HbF relative to HbA helps transfer oxygen from mother to foetus. Therefore even through blood returning from the placenta to the foetus in the umbilical vein has a PO2of only about 4 kPa, its saturation is 70%. Oxygen transport in the foetus is also helped by a high Hb of about 170 – 180 g/L.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 2
Incorrect
-
Haemophilia B results from a deficiency in:
Your Answer: Von Willebrand factor
Correct Answer: Factor IX
Explanation:Haemophilia B is a bleeding disorder caused by a deficiency of clotting factor IX. It is the second commonest form of haemophilia, and is rarer than haemophilia A. Haemophilia B tends to be similar to haemophilia A but less severe. The two disorders can only be distinguished by specific coagulation factor assays.The incidence is one-fifth of that of haemophilia A. Laboratory findings demonstrate prolonged APTT, normal PT and low factor IX.Haemophilia B inherited in an X-linked recessive fashion, affecting males born to carrier mothers.There is also a variation called Leyden, in which factor IX levels are below 1% until puberty, when they rise, potentially reaching as high as 40-60% of normal. This is thought to be due to the effects of testosterone at puberty.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 3
Correct
-
Regarding the accessory nerve, which of the following statements is INCORRECT:
Your Answer: Accessory nerve palsy results in the inability to nod the head.
Explanation:Accessory nerve palsy results in inability to shrug the shoulders and to rotate the head to look at the opposite side to the lesion.
-
This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
-
-
Question 4
Correct
-
A 40-year-old male presents to your clinic complaining of a cough with bloody sputum for the past three months. He has also had fever, night sweats, and has noticed some weight loss over the past three months.Which ONE of the following statements regarding this disease is correct?
Your Answer: It can be diagnosed using the Ziehl-Neelson stain
Explanation:Tuberculosis is an infection caused by the microorganism Mycobacterium tuberculosis. TB can affect any organ system in the body, but it most commonly affects the lungs, followed by the lymph nodes. Option Tuberculosis is spread by the faecal-oral route: It is spread by inhalation of droplet nuclei. There are different methods to diagnose a tuberculosis infection. 1) Direct Microscopy: The organisms are visualised using Ziehl-Neelsen or Auramine staining. This is the quickest method to establish a diagnosis and start treatment.2) Culture: M. tuberculosis can be grown on Lowenstein-Jensen or Ogawa mediums, but it can take up to 8 weeks; therefore, ZN staining is also performed to start treatment immediately. Option There are several types of vaccine currently available: The BCG vaccine is the only vaccine approved to prevent TB and is administered at birth. Option Miliary tuberculosis refers to tuberculosis that affects the spine: Miliary tuberculosis refers to a tuberculosis infection disseminated throughout the body’s organ systems via the blood or lymphatics. Pott’s disease is extrapulmonary TB that affects the spine. It usually affects the lower thoracic and upper lumbar regions.Option A Ghon focus typically appears at the apex of a lung: The Ghon focus is a primary sign of TB that forms in the lung of previously unaffected patients. It typically occurs in the mid or lower zones of the lung.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 5
Correct
-
A 59-year-old man presents with increased sweating, weight loss, and palpitations. A series of blood tests done found a very low TSH level and a diagnosis of hyperthyroidism is made.What is the commonest cause of hyperthyroidism?
Your Answer: Graves’ disease
Explanation:Hyperthyroidism results from an excess of circulating thyroid hormones. It is commoner in women, and incidence increases with age.Hyperthyroidism can be subclassified into:Primary hyperthyroidism – the thyroid gland itself is affectedSecondary hyperthyroidism – the thyroid gland is stimulated by excessive circulating thyroid-stimulating hormone (TSH).Graves’ disease is the most common cause of hyperthyroidism (estimates are that it causes between 50 and 80% of all cases).Although toxic multinodular goitre, thyroiditis,TSH-secreting pituitary adenoma and drug-induced hyperthyroidism also causes hyperthyroidism, the commonest cause is Graves’ disease.
-
This question is part of the following fields:
- Endocrine Physiology
- Physiology
-
-
Question 6
Correct
-
A 45-year old man presented to the emergency room with complains of chest pain and breathlessness. Upon history taking and examination, it was discovered that he had a right-sided spontaneous pneumothorax and had a failed attempt at pleural aspiration. The pneumothorax is still considerable in size, but he remains breathless. A Seldinger chest drain was inserted but it started to drain frank blood shortly after. Which of the following complications is most likely to have occurred?
Your Answer: Intercostal artery laceration
Explanation:Injury to the intercostal artery (ICA) is an infrequent but potentially life-threatening complication of all pleural interventions. Traditional anatomy teaching describes the ICA as lying in the intercostal groove, protected by the flange of the rib. This is the rationale behind the recommendation to insert needles just above the superior border of the rib. Current recommendations for chest drain insertion suggest that drains should be inserted in the ‘safe triangle’ in order to avoid the heart and the mediastinum and be above the level of the diaphragm. The safe triangle is formed anteriorly by the lateral border of the pectoralis major, laterally by the lateral border of the latissimus dorsi, inferiorly by the line of the fifth intercostal space and superiorly by the base of the axilla. Imaging guidance also aids in the safety of the procedure.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 7
Incorrect
-
All of the following statement are correct regarding endothelium derived nitric oxide except:
Your Answer: Nitric oxide inhibits platelet activation and thrombosis.
Correct Answer: Nitric oxide production is inhibited by local mediators such as bradykinin, histamine and serotonin.
Explanation:Factors that elevate intracellular Ca2+ increase nitric oxide (NO) production by the endothelium included local mediators such as histamine and serotonin, bradykinin, and some neurotransmitters like substance P. NO production is also stimulated by increased flow (shear stress) and additionally activates prostacyclin synthesis. As a result of basal production of NO, there is continuous modulation of vascular resistance and as a result, there is increased production of nitric oxide acts which causes vasodilation. Platelet activation and thrombosis are inhibited by nitric oxide.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 8
Correct
-
You intend to suture a hand wound with plain 1 percent lidocaine.In 1 mL of plain 1 percent lidocaine solution, how much lidocaine hydrochloride is there?
Your Answer: 10 mg lidocaine hydrochloride
Explanation:10 mg of lidocaine hydrochloride is contained in each 1 mL of plain 1 percent lidocaine solution.
-
This question is part of the following fields:
- Anaesthesia
- Pharmacology
-
-
Question 9
Correct
-
One of the following pathogens is a conditional pathogen:
Your Answer: Neisseria meningitidis
Explanation:Obligate pathogens include Mycobacterium TB, HIV, Treponema pallidum, and Neisseria gonorrhoeae. Neisseria meningitidis, on the other hand, is a conditional pathogen.
-
This question is part of the following fields:
- Microbiology
- Principles
-
-
Question 10
Correct
-
Which of the following is NOT typically present in the nasopharyngeal flora:
Your Answer: Bacteroides spp.
Explanation:Bacteroides spp. are typically found in the normal flora of the lower gastrointestinal tract. Species commonly found in the flora of the nasopharynx include: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae, Corynebacterium spp., Moraxella spp. and Candida spp.
-
This question is part of the following fields:
- Microbiology
- Principles
-
-
Question 11
Correct
-
Adrenocorticotropic hormone release from the anterior pituitary is stimulated by which of the following:
Your Answer: Corticotropin-releasing hormone
Explanation:ACTH secretion is stimulated by corticotropin-releasing hormone (CRH) from the hypothalamus.
-
This question is part of the following fields:
- Endocrine
- Physiology
-
-
Question 12
Incorrect
-
Which nerve supplies the muscle flexor hallucis longus?
Your Answer: Deep peroneal nerve
Correct Answer: Tibial nerve
Explanation:Flexor hallucis longus is innervated by the tibial nerve, composed of spinal roots L4, L5, S1, S2, and S3.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 13
Correct
-
Bordetella pertussis causes which of the following infectious diseases:
Your Answer: Whooping cough
Explanation:Bordetella pertussis causes whooping cough. Acute bronchiolitis is typically caused by respiratory syncytial virus. Parainfluenza virus is the most common cause of croup. Acute epiglottitis is usually caused by an infection with Haemophilus influenzae type b (Hib) bacteria. The common cold may be caused by a number of viruses including rhinovirus and coronavirus.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 14
Correct
-
You review a 46-year-old woman who has recently been prescribed antibiotics for a urinary tract infection. She suffers from COPD and is currently prescribed salbutamol and Seretide inhalers, and Phyllocontin continus. Since starting the antibiotics, she has been experiencing nausea, vomiting and abdominal pain.Which of the following antibiotics is she MOST LIKELY to have been prescribed for her UTI? Select ONE answer only .
Your Answer: Ciprofloxacin
Explanation:Phyllocontin continus contains aminophylline (a mixture of theophylline and ethylenediamine), a bronchodilator used in the management of COPD and asthma.This patient is exhibiting symptoms of theophylline toxicity, which may have been triggered by the prescription of the antibiotic. Quinolone antibiotics, such as ciprofloxacin and levofloxacin, and macrolide antibiotics, such as erythromycin, increase the plasma concentration of theophyllines and can lead to toxicity.The drugs that commonly affect the half-life and the plasma concentration of theophylline are summarised in the table below:Drugs increasing plasma concentration of theophyllineDrugs decreasing plasma concentration of theophyllineCalcium channel blockers, e.g. VerapamilCimetidineFluconazoleMacrolides, e.g. erythromycinQuinolones, e.g. ciprofloxacinMethotrexateBarbituratesCarbamazepinePhenobarbitolPhenytoin (and fosphenytoin)RifampicinSt. John’s wort
-
This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
-
-
Question 15
Incorrect
-
The tetanus vaccination contains inactivated tetanus toxoid, which induces the body to produce protective antibodies. How do these antibodies protect the body from tetanus?
Your Answer: Opsonise cells of C. tetani
Correct Answer: Neutralise the protein exotoxin of C. tetani
Explanation:C. Tetanospasmin, an exotoxin produced by tetani, is responsible for the neurotoxic consequences of tetanus. The tetanus vaccination contains inactivated tetanus toxoid, which induces the body to produce protective antibodies that neutralize the tetanus toxin. It induces active immunization against Clostridium tetani exotoxin via toxoid-induced Ab generation.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 16
Correct
-
Which of the following statements concerning hepatitis D is TRUE:
Your Answer: It can only be transmitted with, or to somebody who is infected with, Hepatitis B.
Explanation:Hepatitis D virus (HDV) is an RNA virus that was discovered in 1977 and is structurally unrelated to the hepatitis A (HAV), hepatitis B (HBV), and hepatitis C (HCV) viruses. HDV causes a unique infection that requires the assistance of HBV viral particles to replicate and infect hepatocytes. Its clinical course is varied and ranges from acute, self-limited infection to acute, fulminant liver failure. Chronic liver infection can lead to end-stage liver disease and associated complications (including accelerated fibrosis, liver decompensation, and hepatocellular carcinoma).
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 17
Incorrect
-
A 22-year-old woman is brought in by ambulance from her GP surgery with suspected meningitis. She has been given a dose of benzylpenicillin already.What is the mechanism of action of benzylpenicillin? Select ONE answer only.
Your Answer: Inhibition of protein synthesis
Correct Answer: Inhibition of cell wall synthesis
Explanation:Penicillins and the other ß-lactam antibiotics are bactericidal. They produce their antimicrobial action by preventing cross-linkage between the linear peptidoglycan polymer chains that make up the bacterial cell wall. They, therefore, inhibit cell wall synthesis.An overview of the different mechanisms of action of the various types of antimicrobial agents is shown below:Mechanism of actionExamplesInhibition of cell wall synthesisPenicillinsCephalosporinsVancomycinDisruption of cell membrane functionPolymyxinsNystatinAmphotericin BInhibition of protein synthesisMacrolidesAminoglycosidesTetracyclinesChloramphenicolInhibition of nucleic acid synthesisQuinolonesTrimethoprim5-nitroimidazolesRifampicinAnti-metabolic activitySulfonamidesIsoniazid
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 18
Incorrect
-
Regarding Clostridium perfringens, which of the following statements is CORRECT:
Your Answer: It is a facultative anaerobe.
Correct Answer: It can cause exotoxin-mediated food poisoning.
Explanation:Clostridium perfringens is an obligate anaerobe and has exotoxin mediated effects. It is the most common cause of gas gangrene. C. perfringens is also implicated in food poisoning, cellulitis, enteritis necrotican (life-threatening infection involving ischaemic necrosis of the jejunum), and rarely, CNS infections such as meningitis and encephalitis.
-
This question is part of the following fields:
- Microbiology
- Pathogens
-
-
Question 19
Incorrect
-
Regarding ciprofloxacin, which of the following statements is INCORRECT:
Your Answer: Ciprofloxacin is eliminated mainly by the kidneys.
Correct Answer: Ciprofloxacin decreases plasma concentrations of theophylline.
Explanation:Ciprofloxacin increases plasma concentrations of theophylline. There is an increased risk of convulsions when quinolones are given with NSAIDs or theophylline. There is an increased risk of tendon damage when quinolones are given with corticosteroids. Quinolones are known to increase the QT-interval and should not be taken with concomitantly with other drugs that are known to cause QT-interval prolongation. There is an increased risk of myopathy when erythromycin or clarithromycin are taken with simvastatin or atorvastatin.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 20
Correct
-
Which of the following anatomical structures is most likely the cause of oedema and erythema of the arm in a patient who underwent modified radical mastectomy and radiotherapy?
Your Answer: Axillary lymph nodes
Explanation:Arm oedema is one of the sequelae after breast cancer surgery and radiation therapy. Arm oedema in the breast cancer patient is caused by interruption of the axillary lymphatic system by surgery or radiation therapy, which results in the accumulation of fluid in subcutaneous tissue in the arm, with decreased distensibility of tissue around the joints and increased weight of the extremity. Chronic inflammatory changes result in both subcutaneous and lymph vessel fibrosis.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 21
Incorrect
-
Calcium-channel blockers can be divided into two categories: dihydropyridines and non-dihydropyridines. The basic chemical structure of these two classes differs, as does their relative selectivity for cardiac versus vascular L-type calcium channels. The phenylalkylamine class and the benzothiazepine class are two subgroups of non-dihydropyridines.A phenylalkylamine calcium-channel blocker is, for example, which of the following?
Your Answer: Diltiazem
Correct Answer: Verapamil
Explanation:Calcium-channel blockers, also known as calcium antagonists, stop calcium from entering cells through the L-type calcium channel. This causes vascular smooth muscle in vessel walls to relax, resulting in a decrease in peripheral vascular resistance. They can be used for a variety of things, including:HypertensionAnginaAtrial fibrillationMigraineCalcium-channel blockers can be divided into two categories: dihydropyridines and non-dihydropyridines. The basic chemical structure of these two classes differs, as does their relative selectivity for cardiac versus vascular L-type calcium channels.Dihydropyridines have a high vascular selectivity and lower systemic vascular resistance and blood pressure. As a result, they’re frequently used to treat hypertension. Modified release formulations are also used to treat angina, but their powerful systemic vasodilator and pressure-lowering effects can cause reflex cardiac stimulation, resulting in increased inotropy and tachycardia, which can counteract the beneficial effects of reduced afterload on myocardial oxygen demand.The suffix -dpine distinguishes dihydropyridines from other pyridines. Examples of dihydropyridines that are commonly prescribed include:AmlodipineFelodipineNifedipineNimodipineThe phenylalkylamine class and the benzothiazepine class are two subgroups of non-dihydropyridines.Phenylalkylamines are less effective as systemic vasodilators because they are relatively selective for the myocardium. This group of drugs lowers myocardial oxygen demand and reverses coronary vasospasm, making them useful in the treatment of angina. They are also occasionally used to treat arrhythmias. A phenylalkylamine calcium-channel blocker like verapamil is an example.In terms of selectivity for vascular calcium channels, benzothiazepines fall somewhere between dihydropyridines and phenylalkylamines. They can lower arterial pressure without producing the same level of reflex cardiac stimulation as dihydropyridines because they have both cardiac depressant and vasodilator effects. Diltiazem is the only benzothiazepine currently in clinical use.
-
This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
-
-
Question 22
Incorrect
-
Tiredness, night sweats, and easy bruising are symptoms of a 58-year-old woman. Splenomegaly is observed during the examination.Which of the following diagnoses is the SINGLE MOST LIKELY?
Your Answer: Acute myeloid leukaemia (AML)
Correct Answer: Chronic myeloid leukaemia (CML)
Explanation:CML is a myeloproliferative disorder characterised by an abnormal pluripotent haemopoietic stem cell. A cytogenetic abnormality known as the Philadelphia chromosome, which results from a reciprocal translocation between the long arms of chromosomes 9 and 22, causes more than 80% of cases of CML.CML is a disease that develops slowly over several years. This is known as the ‘chronic stage.’ This stage is usually asymptomatic, and 90 percent of patients are diagnosed at this point, with the disease being discovered frequently as a result of a routine blood test. During this stage, the bone marrow contains less than 10% immature white cells (blasts).When CML cells expand, symptoms typically begin to appear. The ‘accelerated stage’ is what it’s called. Approximately 10% of people are diagnosed at this point. During this stage, between 10% and 30% of blood cells in the bone marrow are blasts. During this stage, common clinical features include:Fatigue and exhaustionNight sweats and feverDistension of the abdomenPain in the left upper quadrant (splenic infarction)Splenomegaly (commonest examination finding)HepatomegalyBruising is simple.Gout is a type of arthritis that affects (rapid cell turnover)Hyperviscosity is a condition in which the viscosity of (CVA, priapism)A small percentage of patients experience a ‘blast crisis’ (blast stage). More than 30% of the blood cells in the bone marrow are immature blast cells at this stage. Patients with severe constitutional symptoms (fever, weight loss, bone pain), infections, and bleeding diathesis typically present at this stage.In CML, laboratory findings include:White cell count is abnormally high (often greater than 100 x 109/l).Increased number of immature leukocytes causes a left shift.Anaemia that is mild to moderately normochromic and normocytic.Platelets can be low, normal, or elevated, and the Philadelphia chromosome can be found in > 80% of patients. Serum uric acid and ALP levels are frequently elevated. Tyrosine kinase inhibitors (TKIs), such as imatinib and dasatinib, are the current mainstay of CML treatment. Allogenic bone marrow transplantation is now only used in cases where TKIs have failed to work.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 23
Incorrect
-
You review an 18-months-old child who seems to be having a reaction following an immunisation she took earlier in the day.Which statement concerning immunity and vaccination is true?
Your Answer: Passively acquired immunity usually leads to long-lasting resistance to infection
Correct Answer: The strongest immunological response is seen with natural immunity
Explanation:Vaccination induces ACTIVE adaptive immunity. Actively acquired immunity involves the development of an immune response either due to vaccination or natural exposure to a pathogen and leads to long-lasting resistance to infection.Immediate protection is achieved with injection of immunoglobulin. The protection is transient lasting only a few weeks and is useful as post-exposure prophylaxis. Passively acquired immunity usually leads to short-lasting resistance to infection because it does not involve a host immune response. With inactivated bacteria, a series of primary vaccinations is usually required to induce an adequate immune response. In most cases, boosters are required to sustain adequate immunity.
-
This question is part of the following fields:
- General Pathology
- Pathology
-
-
Question 24
Incorrect
-
Which of the following is most likely to cause a bitemporal hemianopia:
Your Answer: Stroke
Correct Answer: Pituitary adenoma
Explanation:A bitemporal hemianopia is most likely due to compression at the optic chiasm. This may be caused by pituitary tumour, craniopharyngioma, meningioma, optic glioma or aneurysm of the internal carotid artery. A posterior cerebral stroke will most likely result in a contralateral homonymous hemianopia with macular sparing.
-
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 25
Incorrect
-
A 6-year-old child with a few itchy honey crusted sores on her left cheek is brought in by her mother. Following a thorough examination of the child, you diagnose impetigo and recommend a course of topical fusidic acid.Fusidic acid's mode of action is which of the following?
Your Answer: Forming pores that disrupt the cell membrane
Correct Answer: Inhibition of protein synthesis
Explanation:By binding EF-G-GDP, fusidic acid prevents both peptide translocation and ribosome disassembly, which slows protein synthesis. Because it has a novel structure and mechanism of action, it is unlikely to cause cross-resistance with existing antibiotics.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 26
Correct
-
Which of the following statements about sickle cell disease is TRUE:
Your Answer: Hand-foot syndrome is frequently a first presentation of the disease.
Explanation:Hand-foot syndrome in children is typically the first symptom of the disease, produced by infarction of the metaphysis of small bones. The disease is inherited as an autosomal recessive trait. By adulthood, the spleen has usually infarcted. Infection with the B19 parvovirus is usually followed by an aplastic crisis. Thrombocytopenia is caused by splenic sequestration.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 27
Correct
-
You review a patient with urinary sepsis and decide to start her on gentamicin.Which statement about gentamicin is true?
Your Answer: Ototoxicity is a dose-related effect
Explanation:Gentamicin, an aminoglycoside antibiotic, acts by binding to the 30S subunit of the bacterial ribosome inhibiting the binding of aminoacyl-tRNA, and thus prevents initiation of protein synthesis.Gentamicin is given by injection because it is NOT absorbed orally. It is excreted in the kidneys by glomerular filtrationGentamicin is not to be used for the treatment of Neisseria meningitidis, Neisseria gonorrhoea, or Legionella pneumophila.There is a risk of patient going into shock from lipid A endotoxin release.Two of its most notable side effects are hearing loss reversible nephrotoxicity and which are both dose-related and levels should be monitored in patients.
-
This question is part of the following fields:
- Infections
- Pharmacology
-
-
Question 28
Correct
-
A 78-year-old male presents to the Orthopaedic clinic with lower back pain for the past month. His past medical history reveals a history of cancer. After examination, you diagnose Metastatic Spinal Cord Compression (MSCC). Which one of the following cancers is this patient most likely to have had?
Your Answer: Prostate cancer
Explanation:Compression of the thecal sac causes metastatic Spinal Cord Compression (MSCC) due to a Metastatic tumour and its components. It can cause symptoms of limb weakness, sensory disturbances and back pain depending on the extent and level of Compression. The most common source of a tumour causing MSCC is a prostate carcinoma that metastasized to the spinal cord via the vertebral venous plexus.
-
This question is part of the following fields:
- General Pathology
- Pathology
-
-
Question 29
Incorrect
-
All of the following statements is considered true regarding Streptococcus pneumoniae, except:
Your Answer: Agammaglobulinaemia is a risk factor for severe infection
Correct Answer: It is the commonest cause of erysipelas
Explanation:Erysipelas is a rare infection of the skin and subcutaneous tissues observed frequently in elderly patients. It is characterized by an acute spreading skin lesion that is intensely erythematous with a plainly demarcated but irregular edge. It is most commonly caused by Streptococcus pyogenes or Group A Streptococcus (GAS).GAS are susceptible to penicillin, which remains the drug of choice for treatment. For patients allergic to penicillin, erythromycin can be used.S. pyogenes colonizes the throat and skin on humans, making these sites the primary sources of transmission. Infections resulting from S. pyogenes include pharyngitis, scarlet fever, skin or pyodermal infections, and other septic infections. In addition, the sequelae rheumatic fever and acute glomerulonephritis can occur as a result of infection with S. pyogenes.Agammaglobulinemia is mostly associated with S. pneumoniae.The M protein is attached to the peptidoglycan of the cell wall and extends tothe cell surface. The M protein is essential for virulence. The polysaccharide capsule is characteristic of S. pneumoniae.
-
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
-
-
Question 30
Correct
-
A 59-year-old otherwise well woman presents with a history of polydipsia and polyuria. There is a past history of kidney stones, and blood tests done reveal the following: Na: 147 mmol/L (135-147 mmol/L) K: 4.0 mmol/L (3.5-5.5 mmol/L) Urea: 7.3 mmol/L (2.0-6.6 mmol/L) Creatinine: 126 mmol/L (75-125 mmol/L) Fasting blood glucose: 5.0 mmol/L (3.4-5.5 mmol/L) Corrected calcium: 3.21 mmol/L (2.05-2.60 mmol/L) Phosphate: 0.70 mmol/L (0.8-1.4 mmol/L) Parathyroid hormone: 189 ng/L (10-60 ng/L)The most likely diagnosis is?
Your Answer: Primary hyperparathyroidism
Explanation:Primary hyperparathyroidism the commonest cause of hypercalcaemia. It is commonest in women aged 50 to 60.The commonest cause of primary hyperparathyroidism is a solitary adenoma of the parathyroid gland (approximately 85% of cases). Primary hyperparathyroidism may present with features of hypercalcaemia such as polyuria, polydipsia, renal stones, bone and joint pain, constipation, and psychiatric disorders.In primary Hyperparathyroidism:PTH is elevatedCalcium is elevatedPhosphate is loweredIn secondary Hyperparathyroidism:PTH is elevatedCalcium is low or low-normalPhosphate is raised in CRFIn tertiary Hyperparathyroidism:PTH is elevatedCalcium is elevatedPhosphate is lowered in CRF
-
This question is part of the following fields:
- Endocrine Physiology
- Physiology
-
SESSION STATS - PERFORMANCE PER SPECIALTY
