Pastest 3 Flashcards
(107 cards)
1
Q
Which envelope proteins on the surface of HIV virus enable it to get into cells?
A
GP120 binds to primary receptor (CD4 molecule)
GP41 mediates movement through the cell membrane
2
Q
How long does it take for HIV to become AIDs?
A
5-10 years
3
Q
How does mefloquine toxicity present?
A
Acute psychosis
4
Q
What does bartonella henselae cause?
A
Cat scratch disease
5
Q
Which serological marker most strongly confirms recent acute hepatitis B infection?
A
Anti-HBC IgM
HbsAg often disappears by the time patients are jaundiced, and is present in acute and chronic
6
Q
What is Jo1 syndrome?
A
Polymyositis + interstitial lung disease
7
Q
When is methotrexate used in SLE?
A
If arthritis is present
8
Q
What are the causes of death in PAN?
A
Renal failure
Bowel obstruction or perforation
Cardiovascular causes
(does not affect the pulmonary arteries)
9
Q
What are the features of thoracic outlet syndrome?
A
Disappearance of arm pulse when raised above head
Pain, numbness and tingling
10
Q
What are the characteristics of scleroderma renal crisis?
A
Malignant hypertension
Rapid renal impairment
Onion skin intrarenal vasculature
More common in diffuse systemic sclerosis
11
Q
How is bronchiolitis obliterans diagnosed?
A
Irreversible obstructive picture
CT: bronchial wall thickening and air trapping
12
Q
What is the cause of hypoxia in primary pulmonary hypertension?
A
Intra-pulmonary shunting
Reduced diffusion capacity secondary to arterial fibromuscular dysplasia
13
Q
How does sleep apnoea lead to cor pulmonale?
A
Chronic nocturnal hypoxia –> pulmonary artery vasoconstriction –> secondary pulmonary hypertension
14
Q
What are the causes of primary pulmonary hypertension?
A
Plexogenic pulmonary arteriopathy
Chromosome 2
15
Q
What type of arthritis can worsen in the post-operative period?
A
Crico-arytenoid arthritis
Causes stridor
16
Q
What are the causes of type 2 membranoproliferative glomerulonephritis?
A
Partial lipodystrophy
Factor H deficiency
Measles
17
Q
What can acute kidney rejection be confused for?
A
Post-transplant lymphoproliferative disorder
Polyomavirus BK virus
18
Q
What are the two types of acute kidney transplant rejection?
A
Cell mediated
Antibody mediated
19
Q
What are the criteria for diagnosis of antibody mediated acute kidney transplant rejection?
A
Graft dysfunction
Histological evidence of tissue injury
Positive staining for C4d
Presence of donor specific antibody
20
Q
What medications are given during kidney transplant surgery?
A
1g methylprednisolone
Anti-CD25 monoclonal antibody e.g. basiliximab
21
Q
Which antibodies are involved in acute kidney transplant rejection?
A
IgG
22
Q
What is the WAGR triad?
A
Wilms’ tumour
Aniridia
Genitourinary problems
LD
23
Q
What are the causes of normal anion gap metabolic acidosis?
A
CAT MUDPILES
Cyanide poisoning Aminoglycosides Toluene Methanol Uraemia DKA Paracetamol Isoniazid Lactic acid Ethanol Salicylates
24
Q
Which type of nephropathy is caused by underlying malignancy in 10%?
A
Membranous
25
What are Bartter and Gitelman syndromes?
Bartter - kidneys cannot reabsorb chloride in the thick ascending limb of the Loop of Henle
Gitelman - kidneys cannot reabsorb chloride in the distal convoluted tubule
26
When are Bartter and Gitelman syndromes diagnosed?
Bartter - childhood
| Gitelman - later
27
What is disequilibrium syndrome?
Cerebral oedema caused by rapid shifts of uraemic toxins, associated with too-rapid haemodialysis
28
What type of antibody deficiency is associated with infection with polysaccharide coated organisms?
IgG2
29
What investigation confirms hyperaldosteronism?
Saline suppression test
But often hypertension, hypokalaemia, and raised aldosterone are adequate for diagnosis.
30
When is oral aciclovir given in chickenpox?
Adults presenting within 72h onset
| Pregnancy/immunocompromised
31
What are the features of Sweet's syndrome?
Associated with myelodysplastic disorders
Plum coloured lesions, mucosal involvement
Neutrophilia and fever
32
How does lorazepam enhance the effects of anti-emetics?
GABA-A modulator
| Increases the opening frequency of GABA activated chloride channels
33
What are the characteristics of disseminated mycobacterium avium complex?
Occurs in pts with CD4 <50
Fever + night sweats
Diarrhoea and weight loss
Hepatomegaly and lymphadenopathy
34
How effective is the BCG vaccine at preventing severe TB?
70-80%
35
What is the treatment of syphilis?
IM Procaine penicillin/benzathine penicillin
| Pen allergic - azithromycin
36
When should you suspect alpha thalassaemia?
Microcytic anaemia
| Normal/raised ferritin
37
How is methanol metabolised?
By alcohol dehydrogenase to formaldehyde
38
What are indications of haemodialysis in methanol poisoning?
```
Methanol concentration >50mg/dL
Visual disturbance/CNS toxicity
Severe metabolic acidosis
Severe electrolyte imbalance
Renal failure
Deterioration despite initial treatment with fomepizole/ethanol
```
39
How does heparin cause hyperkalaemia?
Inhibits aldosterone secretion
leads to impaired renal potassium secretion
Particularly in patients who are diabetic or acidotic
40
What receptor increases response to chemotherapy if expressed on cancer cells?
P-glycoprotein
41
How does HCOM compare to aortic stenosis?
Similar symptoms and signs
Jerky pulse in HCOM
Valsalva increases intensity of murmur in HCOM and decreases murmur in aortic stenosis
42
Which cytotoxic agent is used in colorectal carcinoma?
5-fluoruracil
43
What is seen on fundoscopy in CMV retinitis?
Necrotising retinitis with haemorrhages
| Brush fires
44
What is the treatment of hyphaema?
Acetazolamide to lower IOP (blood clots and blocks trabecular network)
Anterior chamber paracentesis 2nd line
45
What does asymmetrical diabetic retinopathy suggest?
Ocular ischaemic syndrome (on the side affected worse)
46
Why are nerve conduction studies normal in MS?
Peripheral nerves are unaffected
47
What are the ocular features of rosacea?
Blepharitis
| Keratitis
48
Why are IV nitrates used in acute pulmonary oedema?
Activation of RAAS and high catecholamine levels lead to peripheral vasoconstriction which increases myocardial oxygen demand
49
What pressures are seen in right ventricular infarct?
High right atrial pressure
| Low left atrial pressure
50
What is reversed splitting of the 2nd heart sound?
The pulmonary valve closes before the aortic valve
| LBBB, HCOM, AS
51
What is a fixed splitting of the 2nd heart sound represent?
ASD or VSD
52
What is the choice of rhythm control in AF?
Structurally normal heart - flecainide
LVSD - amiodarone
IHD - sotalol
53
Which drugs can cause primary pulmonary hypertension?
Appetite suppressants - fenfluramine
| Methamphetamine
54
Why is the posteromedial papillary muscle more likely to rupture than the anterolateral papillary muscle?
Supplied by right coronary artery only
| Anterolateral is supplied by LAD and left circumflex
55
Where is the focus of radiofrequency ablation in AF?
Where the pulmonary veins join with the atrium
56
What is pro-insulin cleaved to?
Insulin and C peptide
57
What anaesthetic agents are patients most likely to be allergic to?
Neuromuscular blocking agents e.g. vecuronium
58
What is the cause of hyperglycaemia in trauma?
Noradrenaline and glucagon --> glycogenolysis
| Cortisol acts more slowly --> gluconeogenesis
59
What is the cause of hoarse voice in recurrent laryngeal nerve injury?
Paralysis of the posterior cricoarythenoid muscle, which opens the vocal cords
60
What is the cause of Kartagener's syndrome?
Absence of dynein - which converts chemical energy from ATP into ciliary movement
61
Why is renal disease not seen in Waldenstrom's macroglobulinaemia?
Absence of light chains
62
In which population is Gaucher disease most prevalent in?
Ashkenazi Jews
63
Which complement changes are associated with acquired lipodystrophy?
Low C3
| High C3b nephritic factor
64
Which cells produce CSF?
Ependymal cells
65
What are the two most common types of autoimmune encephalitis?
1) NMDA receptor abs --> presents with psychiatric sx
| 2) LGI1 receptor abs --> faciobrachio dystonic seizures
66
What are the features of progressive supranuclear palsy?
```
Symmetrical rigidity, proximal worse than distal
Dysphagia
Loss of verbal fluency
Minimal autonomic dysfunction
Vertical gaze palsy
Early falls
Poor response to levodopa
```
67
What is T wave discordance with LBBB?
The T wave deflection must be opposite the terminal deflection of the QRS complex
Concordant deflections suggest IHD/MI
68
Why are people with liver disease susceptible to hypoglycaemia?
Liver's inability to produce glycogen
69
How are myeloproliferative disorders classified?
According to the proliferating type of cell
RBC: polycythaemia vera
WBC: CML
Platelets: essential thrombocytosis
Fibroblasts: myelofibrosis
70
What is melanosis coli pathognomic of?
Senna abuse
71
What are the signs of cardiac amyloid?
Dilated atria (restrictive filling pattern)
Thickened LV walls
Granular sparkling appearance of LV
Heart block
72
What is seen on MRI in variant and sporadic CJD?
Variant: increased signal in the pulvinar of the thalamus
Sporadic: increased signal in the caudate nucleus with cortical ribbon hyperdensity
73
What are the differences in presentations of variant and sporadic CJD?
Variant: 26 years, neuropsychiatric, painful sensory disturbance
Sporadic: 40-60 years, myoclonus, dementia, ataxia
74
What are the characteristics of inclusion body myositis?
Muscle weakness - esp quadriceps and finger flexors
CK can be normal
Aged over 50
75
What is the CSF biomarker for sporadic CJD?
14-3-3 protein
76
What is the cause of cavernous sinus thrombosis?
Suppurative process in the orbit, nasal sinuses, or upper half of face --> s.aureus
77
What are the features of cavernous sinus thrombosis?
Obstruction of ophthalmic vein: chemosis, oedema, cyanosis of upper face
Damage to 3rd, 4th, 6th CN: ophthalmoplegia
Damage to V1th CN: eye pain and hyperaesthesia of the forehead
78
What is myocardial bridging?
Coronary artery (commonly proximal portion of LAD) takes an intramuscular course - predisposes to IHD as compressed during systole
79
What are single nucleotide polymorphisms?
Point mutations (substitution of a single nucleotide) that result in changes in alleles
80
How does oestrogen form?
Cholesterol --> testosterone --> oestradiol (catalysed by aromatase)
81
Why can obese/alcoholic patients become feminised?
Alcohol and obesity increase aromatase activity
82
What is seen on bone biopsy in Paget's disease?
Multinucleated osteoclasts
83
What does the RET protooncogene code for?
A receptor tyrosine kinase
84
How is an extra-adrenal phaeochromocytoma diagnosed?
Noradrenaline is particularly raised
| MIBG scan - specific uptake in sites of sympathetic activity
85
What is the cause of nephrotic syndrome in SLE?
Class V nephritis - membranous nephropathy
86
Untreated UTI in diabetic patients can result in?
Renal papillary necrosis
87
Why can RV infarction cause hypovolaemic shock?
Blood pools in RV
| Consequential decreased preload in LV
88
Why does proximal R coronary artery occlusion have a higher rate of complete heart block than distal?
Includes AV nodal artery and right superior descending artery
89
What type of axis deviation is seen in ASDs?
LAD: ostium primum
RAD: ostium secundum
90
What is the mode of action of adenosine?
G-protein coupled receptor agonist of the adenosine A1 receptor in AV node
91
What are the differences between cauda equina syndrome and conus medullaris syndrome?
C.E: gradual and unilateral, unilateral weakness, ankle and knee jerks affected, urinary retention
C.M: sudden and bilateral, symmetrical weakness distal>proximal, knee jerks preserved, urinary and faecal incontinence, fasciculations
92
Where does pre-mRNA splicing occur?
Nucleus
93
Why does quinine lead to hypoglycaemia?
Stimulates insulin release
94
What type of laxative is recommended to prevent/treat opioid induced constipation?
Stimulant e.g. senna
95
Why might a patient with allergies and coeliac disease have negative anti-endomyseal antibody?
IgA deficiency - they may have used IgA assay instead of IgG
96
Which cytokine drives the production of CRP?
IL-6
97
Which interleukin is seen in transplant rejection?
IL-2, as it causes T cell proliferation
| Therefore use of calcineurin inhibitors such as tacrolimus and ciclosporin
98
Which antibody confirms recent infection?
IgM
| As it is the first to be secreted in response to infection
99
What type of T helper cell drives autoimmune disease?
Th-17 - secretes IL-17
100
Which part of the antibody forms the antigen binding site?
The variable domains of each light and heavy chain of the antibody
101
How do you calculate ejection fraction?
(EDV - ESV) / EDV
102
Which antibody is negative in discoid lupus?
ANA
103
What is the treatment of cataracts?
Extracapsular lens extraction with a posterior chamber lens implant
104
What are the features of sarcoid granulomas?
Non caseating
Centre contains macrophages and Langerhans giant cells (which contain >10 nuclei)
Schumann body containing calcium phosphate crystals
Surrounded by ring of CD4 helper and then CD 8 suppressor cells
105
What is a crossover study?
The patient will receive all the drugs in the study
106
How does lambert Eaton syndrome differ from myasthenia graves?
- loss of reflexes
- autonomic symptoms
- ptosis, no oculoparesis
107
How does Terlipressin treat hepatorenal syndrome?
Decreased renin activity
