Pastest Flashcards
How long after eating food contaminated with s.aureus until symptoms of food poisoning start?
1-6 hours
What are the side effects of sulfasalazine?
Myelosuppression
Stomatitis
Parotitis
Periorbital oedema
What are the general causes of prolonged APTT?
Factor VIII deficiency
Factor VIII inhibitor
Anti-phospholipid syndrome
How can factor VIII deficiency be differentiated from factor VIII inhibitor?
50:50 mixing study
Which drugs inhibit VIII (by producing autoantibodies)?
Phenytoin
Penicillin
Sulfa drugs
What are acquired causes of factor VIII deficiency?
Pregnancy Diabetes Psoriasis MS SLE
How do bile acids cause diarrhoea post ileocaecal resection?
Decrease transit time
Increase motility
Deconjugated by bacteria to produce end products that stimulate water and electrolyte secretion
Name 5 causes of a transudative ascites?
Budd-Chiari syndrome Hepatic cirrhosis Right sided heart failure Nephrotic syndrome Acute nephritis
Name 3 causes of exudative ascites.
Infection
Inflammation
Malignancy
Why is flexible sigmoidoscopy indicated in diagnosing severe flare of ulcerative colitis?
To exclude CMV colitis, which is associated with a poor response to treatment and high relapse rate
What are the features of intrahepatic cholestasis of pregnancy?
Pruritus
Jaundice
Raised ALT, bilirubin, bile acids
What is the treatment of intrahepatic cholestasis of pregnancy?
Ursodeoxycholic acid
What are the features of acute fatty liver of pregnancy?
Liver failure - inc coagulopathy and encephalopathy
High foetal and maternal mortalities
How do villous adenoma present?
Hypokalaemic hypochloraemic metabolic alkalosis
Copious diarrhoea
What is the cause of hydatid disease and where is it found?
Propagating cysts formed by echinococcus granulosis
Found in sheep farming areas
What is the most sensitive test for acute/ongoing Hep B infection?
HBV DNA
What is a consequence of giardia infection?
Lactose intolerance
What is the cause of jaundice in pernicious anaemia?
High bilirubin secondary to increased turnover of immature RBCs
What is seen on biopsy of sarcoid granulomas?
Asteroid bodies
What is neuralgic amytrophy AKA brachial plexitis?
Autoimmune, post vaccine/infection/surgery/childbirth
Severe pain followed by weakness, winging of the scapula
What is teraparatide?
A PTH analogue which increases osteoblastic activity
What is the cause of prolonged PR interval in hyperkalaemia?
Progressive paralysis of the atria
What does the right coronary artery continue as, after supplying the right atrium and right ventricle?
Posterior descending artery
Supplies posterior LV wall and posterior IV septum
What are the consequences of selective IgA deficiency?
Patients more likely to have a IgG2 deficiency which leads to recurrent bacterial infection
Increased risk of pernicious anaemia, allergy, and coeliac disease
Increased risk of anaphylactic response to blood products
What is the best way to determine the 3D structure of a protein?
X-Ray crystallography
What is the role of dual polarisation interferometry?
Provides information about how the conformation of a protein changes over time
What techniques identify DNA and RNA sequences?
RNA sequences - Northern blotting
DNA sequences - Southern blotting
What is the cause of acute intermittent porphyria?
Absence of porphobilinogen (PBG) deaminase
What are the molecular features of shock?
Cellular swelling
Depletion of ATP and cyclic AMP
Increase in sodium/potassium ATPase activity
Precipitation of calcium in the mitochondria
Reduced insulin mediated uptake of glucose to muscles
What is the mode of inheritance of the majority of complement deficiencies?
Autosomal recessive
What complement deficiency is associated with development of SLE?
C1 and C4
What is the direct precursor of cortisol?
11-deoxycortisol
Which HLA code is associated with psoriasis?
HLA-cw6
Overdose with which drugs is associated with a respiratory alkalosis?
Salicylates
Theophylline
Both respiratory stimulants
What is the biggest cause of death in Turner’s syndrome?
Rupture of thoracic AAA
How does the influenza virus avoid recognition?
Continuous changes in its surface proteins
Which part of the immune system is first to respond to infection?
Innate (including NK cells) before adaptive (including T cells)
What is the genetic cause of sickle cell anaemia?
Autosomal recessive
Replacement of valine with glutamic acid on position 6
What is the cause of hypercalcaemia in sarcoidosis?
Elevated Vitamin D, produced by alveolar macrophages
Causes increased efficiency of calcium absorption in small intestine
What occurs in the extrinsic apoptosis pathway?
Death domains attract intracellular adaptor proteins e.g. CD95/FADD, which attracts procaspase 8.
Procaspase 8 is modified to caspase 8, which activates caspase 3, an executioner caspase.
Then, the cell undergoes apoptotic changes such as chromatin condensation and cell fragmentation
Where are the intrinsic and extrinsic apoptosis pathways initiated?
Intrinsic - mitochondria
Extrinsic - death receptors on the cell surface
What is the mechanism of desmopressin in haemophilia?
Release of stored VWF and factor VIII
Why is bleeding time normal in haemophilia?
Normal adhesion of platelets to the endothelium
Which type of von Willebrand disease is the most severe?
Type 3
What is the management of auto-immune neutropenia?
G-CSF
Which drug can reverse alteplase and how?
Tranexamic acid
Inhibitor of the activation of plasminogen to plasmin, and inhibits plasmin at high concentrations
What is aplastic anaemia?
Pancytopenia with hypocellular bone marrow in the absence of abnormal infiltrate or marrow fibrosis
What is the most common congenital cause of aplastic anaemia?
Fanconi anaemia
How does ATRA work in treatment of acute promyelocytic leukaemia?
Promotes the differentiation of APML cells into mature granulocytes which then apoptose
What is the cause of band keratopathy?
Degenerative phase of chronic eye disease
Hypercalcaemia
From calcium deposition in Bowman’s layer of the cornea
What do Roth’s spots look like?
White centred haemorrhages - perivascular collections of lymphocytes
What is the drug class and mechanism of action of dorzolamide?
Carbonic anhydrase inhibitor
Reduced aqueous humour production
What is the earliest lesion to appear in diabetic retinopathy?
Microaneurysm
What are the features of pseudoxanthoma elasticum?
Loose skin folds and puckering
Angioid streaks from breaks in Bruch’s membrane
Which muscle is affected in Wernicke’s encephalopathy?
Lateral rectus
Why do patients with Ehlers-Danlos syndrome have increased risk of retinal detachment?
Short sighted - myopia
What type of uveitis is seen in sarcoidosis?
Bilateral
Granulomatous
How do you differentiate between insulin abuse and insulinoma?
Insulinoma - elevated both insulin and c-peptide
Insulin abuse - C-peptide normal
What osmolalities are seen in psychogenic polydipsia?
Urine - low
Plasma - low
What is the treatment of thyroid lymphoma?
R-CHOP and external beam radiotherapy
Why is alpha blockade indicated before beta blockade in treatment of phaechromocytoma?
Potential for hypertensive crisis because of unopposed stimulation of alpha-adrenergic receptors
Which drugs exacerbate or unmask the symptoms of phaeochromocytoma?
TCAs
Cocaine
Inhibit catecholamine reuptake
What should be done in the 7-14 days pre phaeochromocytoma removal?
Alpha blockade before beta blockade
High sodium and fluid intake diet to reverse catecholamine induced blood volume contraction and prevent severe hypotension after removal
What are the biochemical abnormalities seen in anorexia nervosa?
Low WCC
Low K, Ca, Mg
Low FSH, LH, oestradiol
Low GnRH
High fasting GH
High cortisol
What is the cause of pre-tibial myxoedema?
Accumulation of glycosaminoglycans
What do SGLT-2 inhibitors reduce the risk of?
Heart failure
Ischaemic heart disease
How can branch retinal vein thrombosis be differentiated from central retinal vein thrombosis on fundoscopy?
Segmental flame haemorrhages
More commonly seen in systemic conditions
Which hormone drives the development of secondary sexual characteristics in males?
Dihydrotestosterone as it has a higher level of affinity for the androgen receptor
What are the 2 types of amiodarone-induced thyrotoxicosis?
- Increased uptake, positive antibodies: propylthiouracil
2. Absent uptake, negative antibodies (destructive thyroiditis): prednisolone
What is the treatment of gastroparesis secondary to diabetes?
Domperidone (not metoclopramide)
What is the gold standard diagnosis of insulinoma?
72 hour fast
What is the treatment of narcolepsy?
Modafinil
What is seen on CXR in simple pneumoconiosis?
Nodular interstitial shadowing
How is DLCO measured?
Measurement of end-expiratory CO after inspiring a small amount and breath holding
Adjusted for haematocrit and alveolar volume
What are the surgical treatment options in pulmonary hypertension?
Pulmonary endarterectomy
Balloon pulmonary angioplasty in CTEPH
Atrial septostomy
Heart-lung transplant
To reduce the risk of pulmonary hypertension and right heart failure in COPD, for how many hours each day should patients have supplemental oxygen?
15 hours via a concentrator
What is the treatment of multidrug resistant TB?
Rifampicin, ethambutol, pyrazinamide, isoniazid, streptomycin
What is Cushing’s syndrome related to small cell lung cancer characterised by?
Hypertension Hyperglycaemia Hypokalaemia Alkalosis Muscle weakness
Which lung tumour is most common in non-smokers?
Adenocarcinoma
What are the stages of eosinophilic granulomatosis with polyangiitis?
- Asthma prodrome
- Tissue and peripheral eosinophilia
- Systemic vasculitis
What are the features of mycoplasma pneumonia?
Cold agglutins
Wheeze
Muscle tenderness/myringitis/pharyngitis
Disproportionate CXR features
What kind of cell does SCLC arise from?
Neuroendocrine`
What happens to the gas transfer in extrathoracic restriction?
Decreased gas transfer factor
Elevated gas transfer co-efficient
In which condition does LTOT improve mortality?
Cor pulmonale secondary to chronic airflow obstruction
In which cases of drug induced liver injury is it recommended to stop a drug?
If ALT>5x normal
What are the functional criteria for pneumonectomy?
- FEV1> 2 litres
- FEV1 >50% observed FVC
- Normal PaCO2 at rest
Why does orthodeoxia occur in hepatopulmonary syndrome?
Hepatic disease can result in R–>L shunt secondary to lower lobe intrapulmonary vasodilation
Therefore increased blood flow through lower lobes when patients moved from supine to erect position
Therefore poorly oxygenated blood from lower lobes enters left side of the heart.
What are the features of subacute combined degeneration of the cord?
Bilateral weakness Reduced vibration and proprioception Absent ankle reflexes Hyper-reflexia at the knees Plantars initially flexor --> then extensor
What type of neuropathy is associated with amyloidosis?
Autonomic
Why is vibration and proprioception spared in anterior spinal artery thrombosis?
The dorsal columns sits in the upper 1/3 of spinal cord therefore has a different blood supply (posterior spinal artery)
At what level does the spinal cord end?
L1
Which nerve root supplies the intrinsic muscles of the hand?
T1
What are the features of corticobasal degeneration?
Asymmetrical limb rigidity and apraxia
Alien limb phenomena
Dysphasia
What are the 5 classic lacunar syndromes?
- Pure motor hemiparesis
- Pure sensory stroke
- Sensorimotor stroke
- Ataxic hemiparesis
- Clumsy-hand dysarthria
What does pyoderma gangrenosum look like?
Multifocal
Painful and necrotic, deep
Violaceous border
How is pseudoxanthoma diagnosed?
Skin biopsy - the elastic fibres of the dermis are short and fragmented
Basophilic fibres
H&E stain, granulomas
Van Kossa stain - calcium deposits
What is the mainstay of treatment in PCT?
Venesection
What is seen on the full blood count in toxic epidermal necrolysis?
Eosinophilia
What is Marjolin’s ulcer?
SCC arising in scar/wound, or area of inflammation
Which infection can trigger guttate psoriasis?
Streptococcal
What part of the heart does the left circumflex artery supply?
Lateral and posterior LV walls
Why does aortic regurgitation occur in ankylosing spondylitis?
Aortitis –> aortic root dilatation –> failure of leaflet coaptation
What are the types of carotid sinus hypersensitivity?
Cardioinhibitory: cardiac asystole >3s
Vasodepressor: drop in systemic BP>50mmHgMixed type
What occurs in carotid sinus hypersensitivity and what is the management?
AV nodal block
Ventricular pacing +/- atrial pacing
What is a side effect of co-trimoxazole?
Allergic myocarditis
What is the cause of variable intensity of the first heart sound in VT?
AV dissociation causing variable filling of the ventricles from the atria
What is the pathophysiology of HfPef?
Ventricular stiffness causing poor cardiac filling and elevated diastolic pressures
What is the mechanism of action of ivabradine?
Inhibits funny current in the sinus node to slow sinus rhythm
What is rescue primary PCI?
If thrombolysis fails to reduce ST elevation by 50%
What are 5 differentials of acute pulmonary oedema?
Severe LV dysfunction Paroxysmal arrhythmias 3 vessel of left mainstem coronary artery disease Renal artery stenosis Phaeochromocytoma
What does LBBB mean?
The left ventricle depolarises via the right ventricle, rather than the conventional pathway
What are the signs of LBBB on auscultation?
Soft S1
Reversed split S2 - (split in expiration and single in inspiration) due to delayed closure of the aortic valve due to delayed depolarisation
What is seen on ECG in constrictive pericarditis?
Small complexes
Why is S2 normally split in inspiration?
During inspiration there is increased venous return to the right heart, which delays the closure of the pulmonary valve, relative to the aortic valve
In HOCM, what is most correlated with risk of sudden death?
Degree of septal hypertrophy
In malignant hypertension, what is the target BP reduction and why?
25% reduction in MAP in first hour
Greater reductions risk organ hypoperfusion due to tissue dysregulation
What is pulsus alternans associated with?
Left ventricular failure
What is the most common type of ASD?
Ostium secundum
What is the normal oxygen saturation of the pulmonary artery, right atrium, and right ventricle?
75%
What is the mechanism of action of quinolones?
Inhibit bacterial DNA gyrase
Why does digoxin need a loading dose?
High volume of distribution
What are the functions of endothelin A and B receptors in the pulmonary vasculature?
A: mediate vasoconstriction and smooth muscle proliferation
B: mediate production of nitric oxide and prostacyclin
What are the signs of digoxin toxicity?
Xanthopsia (yellow halos)
Complete heart block
Nausea and vomiting
Hypotension
chances increased with hypokalaemia
