PTS Reading Week 2 Flashcards
Which TLRs are intracellular?
TLR 3,7,8 and 9
What is the mechanism of action of Beta Lactams antibiotics?
Inhibit the synthesis of the peptidoglycan layer of bacterial cell walls by binding irreversibly to Penicillin Binding Proteins
Name 4 categories of beta lactam antibiotics
- Penicillins
- Cephalosporins
- Carbapenems
- Monobactams
Name some penicillins
- Penicillin
- Amoxacillin
- Flucloxacillin
Name some cephalosporins
- Cefotaxime
- Ceftriaxone
- Cefuroxime
Name some carbapenems
- Meropenem
What sorts of bacteria are more susceptible to beta lactam antibiotics?
Gram positive
Staph & Strep
What is responsible for differences in the spectrum and activity of beta lactams?
Their relative affinities for different Penicillin Binding Proteins
What can beta lactams not be used in?
Intracellular pathogens
What is the mechanism of action of glyopeptides?
Block bacterial cell wall synthesis
Name 2 glyopeptide antibiotics
- Vancomycin
- Teicoplanin
What is the mechanism of action of quinolones?
Block DNA replication by inhibiting DNA gyrase
Name some quinolones
- Ciprofloxacin
- Levofloxacin
What is the mechanism of action of Metronidazole?
Causes a loss of helical DNA structure and strand breakage, and disrupts protein synthesis
What is the mechanism of action of Rifampicin?
Inhibits RNA polymerase
What is the mechanism of action of macrolides?
Bind to the 50S subunit of the ribosome and inhibit protein transcription
Name some macrolides
- Clarithromycin
- Azithromycin
- Erythromycin
What is the mechanism of action of aminoglycosides?
Bind to the 30S subunit of the ribosome and inhibit protein transcription
Name an aminoglycoside
- Gentamicin
What is the mechanism of action of lincosamides?
Bind to the 50S subunit of the ribosome and inhibit protein transcription
Name a lincosamide
- Clindamycin
What is the mechanism of action of tetracyclines?
Bind to the 30S subunit of the ribosome and inhibit protein transcription
Name a tetracycline
Doxycycline
What is the mechanism of action of streptogramins?
Bind to the 50S subunit of the ribosome and inhibit protein transcription
Name a streptogramin
- Virginiamycin
What is the mechanism of action of sulphonamides?
Bind to the DHPS enzyme and inhibit folate synthesis
Name a sulphonamide
Sulfasalazine
What is the mechanism of Trimethoprim?
Inhibits folate synthesis
What is the purpose of clavulanic acid in Co-Amoxiclav?
Makes it harder for the bacteria to break down the amoxicillin
What is a key finding in the blood or CSF during bacterial infection?
Neutrophils!!
What is type 1 hypersensitivity?
Mass cell degranulation (basophils and mast cells) mediated by IgE linkage
What is type 2 hypersensitivity?
IgM and IgG linkage to surface cell antigens or tissue components
What is type 3 hypersensitivity?
Antibody-antigen complexes deposit into tissues
What is type 4 hypersensitivity?
T cell mediated response
What is type 5 hypersensitivity?
Stimulatory autoantibodies
Give examples of a type 1 hypersensitivity reaction
- Anaphylaxis
- Atopy
Give examples of a type 2 hypersensitivity reaction
- Goodpasture syndrome
- Autoimmune haemolytic anaemia
Give examples of a type 3 hypersensitivity reaction
- Systemic Lupus Erythematosus
Give examples of a type 4 hypersensitivity reaction
- Tuberculosis
Give examples of a type 5 hypersensitivity reaction
- Grave’s Disease
What is the test for delayed type 4 hypersensitivity reactions
Patch test
Which antibody is first released in the humoral response?
IgM
What is the most efficient and powerful antigen presenting cell?
Dendritic cells
What is the most common opportunistic infection and presentation of AIDS?
Pneumocystis Pneumonia
(caused by the pneumocystis jirovecii fungus)
What bacteria is the most common cause of UTI?
Escherichia Coli
What bacteria is the most common cause of Pyelonephritis?
Escherichia Coli
What pathogen is most commonly isolated in cases of chronic diarrhoea associated with HIV
Cryptosporidium
What is the mechanism of action of rivaroxaban (and other DOACs)
Directly inhibits activated clotting factor X to prevent conversion of prothrombin to thrombin
What is the mechanism of bisphosphonates?
Inhibit osteoclastic activity to decrease bone resorption, which reduces bone turnover and improves bone mass
What sort of drug is Diclofenac?
NSAID
What medicines can cause constipation?
Opiates! eg, Codeine
What can decrease the effects of warfarin?
Leafy green vegetables
What can increase the effects of warfarin?
Alcohol
What anti-emetic is contraindicated in Parkinson’s?
Metoclopramide - because it is a dopamine blocker
What are the diagnostic criteria for DKA?
- Blood glucose > 11mmol/L
- Plasma ketones > 3mmol/L
- Blood pH < 7.3
- Bicarbonate < 15mmol/L
What is the most common subtype of thyroid cancer?
Papillary
What is the gold standard investigation for carcinoid syndrome?
Chromagranin-A + octreoscan
What are typical EKG findings in hyperkalaemia?
- Tall tented T waves
- Wide QRS
- Prolonged PR
- Absent P waves
What are some symptoms of polycystic ovarian syndrome?
- Oligomenorrhea
- Hirsutism
- Acne
- Ovarian cysts
What is the difference between Gigantism and Acromegaly?
Gigantism is the over secretion of GH PRIOR to the fusion of the epiphyses
What is the management for diabetic ketoacidosis?
IV Fluids immediately
Then insulin and potassium (as insulin can cause hypokalaemia_
What is the epithelium of the Vas Deferens?
Pseudostratified columnar epithelium with stereocilia
Where in the female reproductive tract does fertilisation usually occur?
Ampulla
What is cardiac tamponade?
The accumulation of fluid in the pericardial cavity that compresses the heart and reduce cardiac function
What are the four main features of Tetralogy of Fallot?
- Ventricular septal defect
- Pulmonary artery stenosis
- Right ventricular hypertrophy
- Overriding aorta
What is orthopnoea?
Difficulty breathing when lying down
What is a Mobitz type 1 second degree heart block?
Increasingly long PR intervals followed by a drop in a QRS complex
What is a Mobitz type 2 second degree heart block?
Constant length PR intervals but drops in QRS complexes (eg, 2 or 3 PRs for every QRS)
What are roth spots?
Retinal haemorrhage with pale centers
What are the signs of left sided heart failure on Xray?
- Alveolar oedema
- Kerley B lines
- Cardiomegaly
- Dilated upper lobe vessels
- Pleural effusion
What are the signs of right sided heart failure?
- Increased JVP
- Hepatomegaly
- Ascites
- Pitting oedema
What is primary prevention?
Methods taken to prevent the onset of disease
What is secondary prevention?
Methods to detect and address an existing disease prior to the appearance of symptoms
What is the most appropriate 1st line test in patients with symptoms for stable angina?
CT coronary angiography
What is taken for the prevention of angina attacks?
1st line treatment is beta blocker or a cardioselective CCB (eg, Verapamil)
- After that, combine beta blockers with a non-cardioselective CCB such as Nifedipine
What is the most appropriate initial treatment for STEMI?
- Dual antiplatelets (Aspirin + Clopidogrel & Ticagrelor)
- Anticoagulation (Heparin)
- Percutaneous Coronary Intervention
What is the 1st line treatment for hypertension in people aged 55+ or Afro Caribbeans?
Calcium Channel Blocker, eg. Amlodipine
What is the 1st line treatment for hypertension in people aged < 55 or ANY AGE with T2DM?
Ace-i
What is the treatment given in atrial fibrillation to prevent strokes?
Warfarin or DOAC
When is Warfarin more effective than a DOAC?
In a patient with metal heart valves
What is the treatment for pericarditis?
NSAIDs & Colchicine
What is the mechanism of action of colchicine
Tubulin disruption which reduces inflammatory pathways
What is the 1st line treatment for iron deficiency anaemia?
Ferrous sulphate
What is G6PD deficiency?
A deficiency in Glucose-6-phosphate-dehydrogenase which causes haemolytic anaemia
What drug is contra-indicated in G6PD deficiency?
Nitrofurantoin - as it can cause a drug induced oxidative crisis
What is a diagnostic test for DVT?
Doppler ultrasound
What are some causes of thrombocytopenia?
- HIV
- Myeloma
- Heparin
- Alcohol abuse
What leukaemia is most common in children?
Acute lymphoblastic leukaemia
What is the diagnostic test for sickle cell anaemia?
Hb electrophoresis
What is the treatment for chronic myeloid leukaemia?
Chemotherapy and a tyrosine kinase inhibitor, eg. Imatinib
What is the pathology of hereditary spherocytosis?
Defects in the red cell membrane, resulting in them having increased permeability to sodium
What is the infective stage of the malaria parasite?
Sporozites