Pastest 2 Flashcards
1
Q
What are exons?
A
Coding sequences of DNA which code for peptides produced from mRNA
2
Q
What is the function of introns?
A
Code for switches that control gene expression in splicing
3
Q
From where does hyaline cartilage receive its nutrients?
A
Diffuses from synovial fluid - it is avascular
4
Q
What type of collagen does hyaline cartilage contain?
A
Type 2
5
Q
What do chondrocytes secrete?
A
Proteoglycans and collagen
6
Q
What is the cause of familial hypercholesterolaemia?
A
LDL receptor dysfunction
Familial apolipoprotein B-100 or PCSK-9 mutation
7
Q
In which patients should you suspect familial hypercholesterolaemia?
A
Serum cholesterol >7.5mmol
Family/personal history of CHD before 60 years
Tendon xanthomas
8
Q
Pyruvate kinase is the rate limiting enzyme in which processes?
A
Glycolysis
Gluconeogenesis
9
Q
How do thiazides cause hypokalaemia?
A
Increase delivery of sodium to the DCT where sodium is reabsorbed and potassium excreted
10
Q
How does aciclovir work?
A
Converted into tri-phosphate form by host cell kinases
This allows it to incorporate into viral DNA resulting in chain termination
Viral DNA polymerase is then unable to function
11
Q
What is the treatment of an acute attack of acute intermittent porphyria?
A
IV haemin/300g dextrose IV
12
Q
What is the prophylaxis for acute intermittent porphyria attacks?
A
IV haem arginate once or twice weekly
- risk of iron overload
GnRH analogue
Liver transplant
13
Q
What is the equivalent prednisolone dose to match with glucocorticoid production in humans?
A
0.1mg per kg bodyweight
E.g 60kg –> 6mg
14
Q
What enzyme is high in the serum in Gaucher’s disease?
A
Acid phosphatase
15
Q
Which cytokines stimulate the HPA axis by inducing secretion of CRH from the hypothalamus?
And what is the function of this?
A
TNF-alpha
IL-1
Cortisol released which reduces the stress response and prevents a lethal over-activation of the immune response
16
Q
How do you reverse alteplase?
A
FFP and tranexamic acid
17
Q
What is the mechanism of action of alteplase?
A
Converts plasminogen to plasmin, which degrades fibrin
18
Q
What type of b-adrenoreceptors line the airways?
A
B2
19
Q
How do beta-2 agonists influence bronchodilation?
A
Relaxation of bronchial smooth muscle by affecting b-2 receptors
Inhibition of mast cell mediator release
Enhanced mucociliary clearance
20
Q
Why does tachycardia and increased cardiac output occur with b-2 agonists?
A
Stimulation of cardiac b-adrenoreceptors
Reflex response to peripheral vasodilation
21
Q
What is the most common mutation causing hereditary spherocytosis?
A
Spectrin and ankyrin
22
Q
What is the criteria for liver transplant following paracetamol toxicity?
A
pH <7.3
OR
INR>6.5 AND Creatinine>300 AND grade 3/4 encephalopathy
23
Q
What are 6 causes of large kidneys?
A
Amyloidosis PKD Stage 1 diabetic nephropathy Hydronephrosis Acromegaly Renal vein thrombosis
24
Q
What is the treatment of radiation pneumonitis?
A
Prednisolone >60mg/day
25
What is the cause of carpal tunnel syndrome in patients undergoing long term haemodialysis?
B2 microglobulin deposition
26
What is the diastolic plop of left atrial myxomas?
The tumour is attached to the wall in a way so that it is mobile
It plops in and out of the mitral orifice, leading to a murmur that changes with position
27
What is posterior column syndrome?
Tabes dorsalis - neurosyphilis
| Loss of function of dorsal columns
28
What metabolic abnormality is seen in aspirin overdose?
Initially respiratory alkalosis --> stimulates central respiratory centres causing rapid deep breathing
Then toxicity --> metabolic acidosis
29
What type of bone is affected by osteoporosis and why?
Trabecular
Trabecular = outer surface and middle of bones.
Osteoclasts and osteoblasts inhabit surface of bones therefore trabecular bone is more subject to cell turnover
30
How is giardiasis diagnosed?
Stool antigen test
31
How do you prevent transfusion-related graft vs host disease in at risk patients such as Hodgkin's lymphoma?
Irradiated blood products
32
What is the cause of diarrhoea with metformin?
Bile acid malabsorption
33
Which type of leukaemia is associated with DIC?
APML
34
Where is the azygos lobe seen on CXRs?
Right upper zone behind medial end of clavicle
Reverse comma sign
0.5% CXRs
35
Name 5 muscarinic effects
```
Miosis
Hypersalivation
Sweating
Diarrhoea
Bradycardia
Excessive bronchial secretions
```
36
How do nerve agents and organophosphate poisoning work?
Inhibit AChE so ACh accumulates at nicotinic and muscarinic receptors
37
Name 2 nicotinic effects
Muscle fasciculation
| Tremor
38
Which tumours secrete ACTH and what are the features?
Small cell lung cancer
Bronchial carcinoid
Weight loss, muscle weakness
39
What is Bruce protocol exercise testing?
6 minutes of exercise testing
| If can't complete this, have a higher risk of cardiovascular adverse events --> cardiac angiography
40
What are the different hypolipiproteinaemias associated with?
```
Type 1: eruptive xanthomas
Type 2: tendon xanthomas
Type 3: tubo-eruptive xanthomas
Type 4: eruptive xanthomas
Type 5: similar to type 1 + high VLDL and chylomicrons
```
41
How does aprepitant treat chemotherapy induced nausea and vomiting?
Acts via neurokinin receptor, inhibits substance P
42
What medication can reduce alcohol craving and how?
Acamprosate
Increases GABA actvitity
43
What is the treatment of toxic alcohol poisoning e.g. ethylene glycol?
IV fomepizole - competitive inhibitor of alcohol dehydrogenase
44
What is a disadvantage of crystalloid solutions?
Need a relatively large volume to restore intravascular volume
45
What is a side effect of theophylline?
Agitation and insomnia
46
What is Brodie's abscess?
Chronic osteomyelitis of the knee
47
What is J point depression a physiological response to?
Increase in HR
48
How is pseudo-Cushing's differentiated from simple obesity?
Slight rise in urinary free cortisol (from long term alcohol XS)
49
What is HbcAb indicative of?
Prev hepatitis B infection
50
What markers are seen in bronchial carcinoid?
Chromogranin A
| Neuron specific enolase
51
What is syringobulbia?
Syringomelia but the lower brainstem is also affected (Xiin nuclei)
52
How does herceptin cause cardiomyopathy?
Inhibition of erb-b2 receptor
53
With chest drains what does swinging of the drain mean?
The drain is still in contact with the pleural space
54
What are the symptoms of cryptogenic pulmonary eosinophilia?
```
Malaise
Weight loss
Fever
Raised ESR and eosinophils
Asthma in 50%
```
55
What occurs if EPO therapy is started in CKD patients who also have iron deficiency anaemia?
Causes severe depletion of iron
56
At what stage of CKD is EPO deficiency expected?
CKD 3
57
What level of urine sodium suggests renal tubular acidosis (intrinsic renal cause)?
Over 40
58
Why do basal alveoli demonstrate greater compliance than apical alveoli?
Basal alveoli are compressed by the weight of the lungs
Compliance is volume change per unit pressure change
Therefore ventilation reduced at the bases
59
What is the cause of Crigler-Najjar syndrome?
Absence (T1 - autosomal recessive) or decrease (type 2 - autosomal recessive with pseudo-dominance) in glucuronyl transferase leading to severe unconjugated hyperbilirubinaemia
60
What is the blood supply of the liver?
Portal vein - 75%
| Hepatic artery - 25%
61
Why does anaemia occur in lead poisoning?
Inhibition of ferrochelatase, decreased red cell lifespan, and reduced stability of red cell membrane
62
How can you differentiate proximal LAD occlusion from distal LAD occlusion?
Proximal - STE in septal leads e.g. V1 and V2 - occlusion occurs before the septal branches
63
What are the symptoms of alkaptonuria?
Urine turns dark on standing
Arthritis
Black/blue pigment layer in cartilage
64
What is there a deficiency of in McArdle's disease?
Muscle phosphorylase
65
Why does hypokalaemia exacerbate digoxin toxicity?
Enhances binding of digoxin to Na/K pump
66
Which type of renal disease has no immune deposits on renal biopsy?
Granulomatosis with polyangiitis
67
What are IgA deficiency patients at risk of?
Developing coeliac disease
| GI and sinus infections
68
What is isotype suppression in multiple myeloma?
Normal IgG and IgA levels
69
What is DNA splicing?
Introduction of additional exons
70
Which complement deficiency is associated with early development of lupus?
C4
71
Which vessels do nitrates have the largest effect on?
Large veins
72
What is seen on ECG in posterior MI and what vessel does this correspond to?
ST depression leads V1-V3, large R wave
Proximal right coronary artery, left circumflex
73
What is a similar syndrome to Wolf-Parkinson White syndrome?
Lown-Ganong-Levine
| Short PR interval only
74
Which calcium channel blocker is contra-indicated in malignant hypertension?
Nifedipine
75
What are the indications for permanent pacing?
```
Complete heart block
Mobitz type 2 heart block
Drug resistant tachyarrhythmias
Persistent AV conduction blocks post MI
Sick sinus syndrome
```
76
What part of the ECG corresponds with the first heart sound?
R wave
77
What is the cause of paroxysmal nocturnal dyspnoea?
Increased atrial pressure
78
What is systolic click-murmur syndrome
MV prolapse
Recurrent non-coronary chest pains
On standing/during Valsalva - ventricular volume gets smaller; midsystolic click and late systolic murmur move earlier in systole
79
What can bundle branch blocks lead to?
Ventricular dyssynchrony --> heart failure
80
Where are leads placed in cardiac resynchronization therapy?
Right atrium
Right ventricle
Left ventricle
81
What is seen on blood film in myelofibrosis?
Nucleated red blood cells
| Tear drop cells
82
What are the main causes of aplastic anaemia (acquired and congenital)?
Congenital: Fanconi anaemia
Acquired: Cancer Tx, parvovirus B19, PNH, pregnancy, drugs (indomethacin, carbamazepine, phenytoin, chloramphenicol, propylthiouracil), SLE
83
What is the criteria for severe and very severe aplastic anaemia, versus non severe aplastic anaemia?
Non severe: marrow cellularity <25%
Severe: 2 or more of: absolute neutrophil count (ANC) <0.5, platelets <20, reticulocytes <20 (peripheral)
Very severe: the above, and ANC<0.2
84
What is the treatment of aplastic anaemia?
Non severe: Monitoring, blood transfusion + immunosuppressants e.g. anti-thymocyte globulin, lymphocyte globulin, ciclosporin
Severe: BM Tx if under 50 or immunosuppressants as above, eltrombopag (oral thrombopoietin receptor agonist)
85
What suggests hyperviscosity on fundoscopy?
Papilloedema with distended retinal vasculature
86
Which antigen is involved in the entry of plasmodium vivax into cells?
Duffy
87
What antibodies are found in HIT?
Anti PF4 heparin antibodies
88
What pathways of the coagulation cascade are represented by PT, APTT, and TT?
PT: extrinsic and final common
APTT: intrinsic and final common
TT: final common
89
Which coagulation factors are part of the intrinsic pathway of the coagulation cascade?
VIII, IX, XI, XII
90
What is clinically important bleeding in ITP?
Oral mucosal blood blisters
Intracerebral haemorrhage
Severe nosebleeds that do not stop with local measures
Severe menorrhagia that requires hormonal intervention
91
What are the features of post-partum thyroiditis?
Triphasic pattern of thyrotoxicosis 1-6 months post partum, hypothyroidism, return to euthyroidism at 9-12 months post partum.
92
What are the associations of polyglandular syndrome type 1?
```
Hypoparathyroidism
Mucocutaneous candidiasis
Adrenal insufficiency
Primary gonadal failure
Primary hypothyroidism
Autosomal recessive
```
93
What are the associations of polyglandular syndrome type 2?
Adrenal insufficiency (100%)
Hypothyroidism
T1DM
Gonadal failure
94
How is carcinoid syndrome diagnosed?
Urinary 5-HIAA collection
95
How does glucagon resolve bradycardia in beta-blocker overdose?
Promotes formation of cyclic AMP
96
How does cryptosporidium diarrhoea present in HIV patients?
Diarrhoea
| No abdo pain or fever
97
What is the 2nd most common malignancy in patients with FAP?
Duodenal adenoma with malignant transformation
98
What antibodies are found in autoimmune hepatitis?
Type 1: ANA, anti-smooth muscle
| Type 2: Anti-liver, kidney microsomal antibodies
99
Which type of neuro-endocrine tumour is usually benign?
Insulinoma
100
What are the features of carcinoid tumours?
Excessive 5-HT (serotonin) causing:
- Flushing
- Diarrhoea and abdo pain
- Wheezing
- Oedema
101
What type of drug is terlipressin?
Prodrug of lysine vasopressin
102
What is the significance of e antigen/antibody in hepatitis B?
Marker of infectivity:
- E antigen +ve: high infectivity
- E antibody +ve: low infectivity
E antigen always negative in people with pre-core mutations (false negative)
103
What are the features of pseudohypoparathyroidism?
Hypocalcaemia --> seizures
Basal ganglia calcification
Round face, short stature, and shortening of 4th and 5th metacarpals
104
What hormone levels are seen in PCOS?
```
High LH
Normal FSH
Normal oestrogen
High testosterone
Low sex hormone binding globulin (due to insulin resistance)
```
105
When does secondary syphilis occur?
4-12 weeks after primary infection
106
What are the features of secondary syphilis?
Pale pink symmetrical maculopapular rash on palms/soles/trunk
Condyloma lata - confluent plaques in flexures
Generalised lymphadenopathy
Muscle and joint pains
107
What are the features of Darier's disease?
Warty plaques in seborrhoeic areas
Palmar pits
Nail dystrophy
Autosomal dominant
108
What is seen on biopsy in granuloma inguinale?
Donovan bodies
109
What is seen on MRI in subacute degeneration of the cord?
Increased T2 weighted signal in the posterior columns
110
When is carotid endarterectomy indicated?
Stenosis >50%
111
What is the commonest cause of 6th nerve palsy?
Microvascular nerve palsy
112
What is the difference between medical and surgical 3rd nerve palsy?
```
Medical = pupil sparing - caused by diabetes/ischaemia
Surgical = pupil involvement - compression of the nerve e.g. posterior communicating artery aneurysm
```
113
How is tuberculous meningitis diagnosed?
CSF PCR
114
What are the features of spinal bulbar muscular atrophy aka Kennedy syndrome
Perioral fasciculations
Androgen insensitivity
Proximal weakness and cramps
