1
Q
what is the most common cause of bacterial pneumonia?
A
strep pneumoniae
2
Q
which antibiotics inhibit cell wall synthesis?
A
Benzylpenicillin, Cefotaxime, Teicoplanin, Vancomycin
3
Q
which heart valve is most commonly affected in infective endocarditis?
A
tricuspid
4
Q
state 4 symptoms of severe infective gastroenteritis
A
bloody diarrhoea, fever, headache, reduced skin turgor
5
Q
state some complications of C. difficile infection
A
ascending cholangitis, diverticulitis, ischaemic colitis, peptic ulcer
6
Q
list the gram positive cocci
A
- staphylococci
- streptococci (including enterococci)
7
Q
list the gram negative diplococci
A
- Neisseria meningitidis
- Neisseria gonorrhoeae
- also Moraxella catarrhalis
8
Q
list the gram positive bacilli
A
mneumonic: ABCD L
- Actinomyces
- Bacillus anthracis (anthrax)
- Clostridium
- Diphtheria: Corynebacterium diphtheriae
- Listeria monocytogenes
9
Q
list some common gram negative bacilli
A
- Escherichia coli
- Haemophilus influenzae
- Pseudomonas aeruginosa
- Salmonella sp.
- Shigella sp.
- Campylobacter jejuni
10
Q
why is phenoxybenzamine prescribed to prepare for phaeochromocytoma surgery?
A
- during removal of the tumour it is possible for a large amount of catecholamine release to occur - causing refractory hypertension.
- therefore, pre-blocking the a-receptors with phenoxybenzamine you prevent this
11
Q
what medication is used to treat heroin addiction?
A
methadone
12
Q
what is co-amoxiclav a mix of?
A
amoxicillin and clavulanic acid
13
Q
what food decreases warfarin’s effect and how?
A
spinach
- warfarin is a vit K antagonist
- vit K is required for the synthesis of clotting factors 2,7,9,10 - antagonism decreases production of these
- blood becomes thinner and increases INR
- spinach is high in vit K so may decrease effect of warfarin
14
Q
what is the mechanism of action for penicillin antibiotics?
A
inhibits bacterial wall synthesis
15
Q
define pharmacodynamics
A
action of drug on body
16
Q
define pharmacokinetics
A
action of body on drug
17
Q
what makes mycoplasma resistant to β-lactam antibiotics?
A
they lack a cell wall
18
Q
What is the mechanism of dobutamine?
A
B1-agonist
19
Q
what is the basic mechanism of furosemide?
A
Na+/K+/2Cl- inhibitor
20
Q
which leukocyte in peripheral blood can become pulmonary macrophages in chronic irritation?
A
monocytes
21
Q
Which investigations is used to confirm a nickel allergy?
A
patch test
22
Q
which antibody is the initial response to a hep B infection?
A
IgM
23
Q
Antibody transfer from a mother to infant during breastfeeding is most likely an example of which type of immunity?
A
naturally acquired; passive
24
Q
What is secreted by virally infected cells as part of a signalling mechanism, and what is its action?
A
interferon-a - they bind target innate cells such as macrophages and NK cells and induce an antiviral state
25
Which cell in the normal lymph node is a specialised, highly efficient antigen-presenting cell (APC) found mostly in areas of T-cell concentration?
dendritic cell
26
What investigations will be most useful in estimating risk of developing an opportunistic infection in HIV?
CD4 count
27
What is the most common causative organism of traveller’s diarrhoea?
E.Coli
28
Which pathogen is most commonly isolated in cases of chronic diarrhoea associated with HIV?
campylobacter
29
what are toll-like receptors?
a type of intracellular pattern recognition receptor that proteins recognise and then bind to PAMPs
30
what are pathogen associated molecular patterns (PAMPs)?
an immune cell that recognises some general molecular features common to many types of pathogen
31
what is TLR1 associated in detecting?
malaria
32
what is TLR2 associated with detecting?
lipoteichoic acid on gram positive bacteria
33
what is TLR4 associated with detecting?
Lipopolysaccharide on the surface of gram negative bacteria
34
what is TLR5 associated with detecting?
flagellin
35
Which diuretic increases sodium and water excretion by competitively binding to aldosterone receptors in the distal tubules of the kidney?
spironolactone
36
What is the mechanism of action of alendronic acid (bisphosphonate)?
Inhibits osteoclastic activity to decrease bone resorption, which reduces bone turnover and improves bone mass
37
What is the mechanism of action of rivaroxaban (anticoag. medication used in patients with a.fib to reduce risk of stroke)?
Directly inhibits activated clotting factor X to prevent conversion of prothrombin to thrombin
38
name 4 drugs that inhibit the action of COX enzymes and therefore inhibit formation of prostanoids and prostaglandins?
aspirin, celecoxib (NSAID), paracetamol, ibuprofen
39
name 2 side effects of diclofenac (NSAID)?
heartburn, abdo pain
40
name 1 side effect of codeine
constipation
41
how does bendroflumethiazide work?
inhibits sodium reabsorption at the DCT by blocking the Na+/Cl- symporter
42
name one medication contraindicated in parkinson's disease and explain why
metoclopramide - D2 receptor antagonist that crosses the BBB and can cause extra-pyramidal side effects and parkinsonism
43
The culture showed gram positive cocci, found in clusters. A coagulase test was positive. Name the organism
staphylococcus aureus
44
what does staphylococcus look like on blood cultures / microscopy?
gram positive cocci found in clusters. coagulase positive
45
what substance gives green / yellow colonies in beta haemolysis?
biliverdin
46
What causes a positive coagulase test?
Organisms that produce an enzyme that converts soluble fibrinogen to insoluble fibrin
47
What colour do gram positive organisms stain and why?
- Purple
- they have a thick layer of peptidoglycan in their cell walls which retains the crystal violet
48
What organism does the optochin test identify?
streptococcus pneumoniae
49
What is the antibiotic used for treatment of streptococcal pneumonia?
flucloxacillin
50
gram positive, catalase negative microorganism family?
streptococcus
51
what does beta haemolysis look like?
clear/colourless zone around colonies
52
What is the recommended treatment for a confirmed group A streptococci infection?
- IV benzylpenicillin
- IV clindamycin
- Urgent surgical exploration with extensive debridement
- amputation
53
What do gram-positive bacteria secrete which causes pathogenicity?
exotoxin
54
Give 3 differences between the structure of the cell envelope of gram- positive and gram-negative bacteria.
- Gram positive have single cytoplasmic membrane
- Gram positive have large layer of peptidoglycan
- Gram positive do not have endotoxin/LPS
55
What is the name for a malignant tumour of smooth muscle?
leiomyosarcoma
56
what is the name for a malignant striated muscle neoplasm
rhabdomyosarcoma
57
what is the definition of a granuloma?
an aggregate of epithelioid histiocytes
58
name 4 constituents of an atherosclerotic plaque
connective tissue, foam cells, lymphocytes, smooth muscle cells
59
typical history of legionella pneumophila?
productive cough, rusty coloured sputum, achy joints, headaches, recent travel (spain!!), crackles in right lung base
60
immediate treatment for suspected septic meningitis?
IM benzylpenicillin
61
describe strep pyogenes
beta-haemolytic gram-positive streptococcus with Lancefield grouping A
62
first line treatment for UTI?
- usually nitrofurantoin
- if non-pregnant or male, trimethoprim pay be used if low risk of resistance
63
classical triad of encephalitis?
- fever, altered mental state, headache
- can present with flu like symptoms and be a DD for meningitis
64
what nutrient agar is used to grow mycobacterium tuberculosis?
Lowenstein-Jensen
65
describe pseudomonas
non-lactose fermenting aerobic bacilli with positive oxidase test
66
what is the most common cause of infective endocarditis in adults with poor dental hygeine? describe it
strep. viridans - optochin resistant alpha-haemolytic strep
67
Which test is used to distinguish between staphylococcus and streptococcus?
catalase
68
which organisms does the 1,3 beta D-glucan assay detect?
- aspergillus fumigatus
- candida albicans
- pneumocystis jirovecii
69
which cell wall feature enables a causative pathogen to resist phagocytic killing?
mycolic acid
70
what is the mechanism of action for flucloxacillin?
disrupts peptidoglycan
71
what is a papilloma?
benign tumour of non-glandular, non-secretory epithelium
72
what is the ligand for TLR-4?
lipopolysaccharide, part of the bacterial cell wall
73
what is an adenoma
benign tumour of glandular or secretory epithelium
74
what is a carcinoma?
malignant tumour of non-glandular, non-secretory epithelium
75
what is a sarcoma?
malignant tumour of connective tissue
76
which structure in the bacterial cell do macrolide antibiotics (e.g rifampicin) interfere with to exert their bactericidal effect?
ribosome (50s subunit)
77
what is margination?
slowing of blood velocity to allow neutrophils to line up along endothelium
78
what is adhesion?
"sticking" of neutrophils to endothelium via adhesion molecules
79
what is emigration?
Neutrophils move through the walls of small blood vessels
80
what is diapedesis?
Where red cells passively escape the circulation due to hydrostatic pressure
81
what is chemotaxis?
Where neutrophils follow a concentration gradient of certain compounds
82
what is MHC-1?
- an antigen found on all nucleated cells in the body
- function: display peptide fragments of proteins from within the cell to cytotoxic T cells to allow response to be triggered
83
describe mycobacteria
slow growing, predominantly immobile, rod shaped, intracellular, gram positive
84
what is the most common organism to cause menigitis?
strep pneumoniae - gram neg
85
when is a LP contraindicated in meningitis?
if septicaemia is suspected e.g. rash
86
what is a dormant malaria spore called?
hypnozoites
87
Describe the lifecycle of a malarial plasmodium within the human body, naming each stage of plasmodium development
- sporozoites in mosquito saliva enters blood
- matures into a hypnozoite in liver and released into blood as schizont
- then explodes releasing merezoites which enter RBCs and become trophozoites
- eventually they become gametocyes which are taken up by mosquito
88
what is the gold standard test for malaria?
microscopy of thick and thin blood smears stained with Giemsa stain
89
what is the treatment for a non-falciparum malaria infection?
chloroquine
90
what is the treatment for a falciparum malaria infection?
oral quinine sulfate
91
complications of untreated malaria?
seizures, impaired consiousness, renal impairment, anaemia, hypoglycaemia
92
name 2 genes of the HIV genome and their function
- Nef - increases infectivity
- Eny - encodes the envelope proteins
93
give 2 example of an opportunistic infection that can result from HIV infection
- cytomegalovirus
- pneumocystis jiroveci
94
What cells do HIV antigens bind to and enter?
CD4+ T-lymphocyte
95
Part of the HIV replication process involves the reverse transcriptase enzyme. Give an example of a drug that can inhibit the reverse transcriptase enzyme
zidovudine - nucleoside reverse transcriptase inhibitor
96
what is the treatment for syphilis?
first line: benzathine penicillin, second line/contraindicated: azithromycin
97
what is the mechanism of action of adrenaline?
agonist of beta adrenergic receptors
98
what is the general antibiotics for UTIs?
trimethoprim or nitrofurantoin
99
what are DMARDs and give an example
- methotrexate
- Disease Modifying Anti-Rheumatic Drugs
- inhibition of pyramidine synthesis
100
what hypersensitivity is Coeliac disease?
type 4
101
first line treatment for tonsilitis?
Phenoxymethylpenicillin QDS 10 days - only given if severe or persistent
102
Which bacterial structure do glycopeptide antibiotics target?
cell wall
103
what does rifampicin target?
RNA polymerase
104
what does ethambutol cause?
optic neuritis
105
which diuretic can cause hyperkalaemia
spironolactone
106
mechanism of action of b-lactam antibiotics?
inhibit transpeptidation reactions needed to cross-link peptidoglycans in the cell wall
107
what is the difference between active and latent TB?
- active -> containment of the disease by the immune system is inadequate so the disease shows symptoms and can be spread
- latent -> infection without disease due to persistence immune system containment
108
define systemic sclerosis
A multi-system autoimmune disease in which fibrous tissue accumulates in multiple organs
109
give 4 signs/symptoms of scleroderma
- Calcium deposits,
- Raynaud’s phenomenon,
- oesophageal dysfunction,
- pulmonary hypertension, severe hypertension,
- renal crisis (due to hypertension),
- pulmonary fibrosis,
- skin ulcers
110
describe the pathophysiology of scleroderma
- an abnormal response to an unidentified trigger.
- This results in the production of cytokines
- These cytokines stimulation of collagen deposition by fibroblasts.
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