clin sciences Flashcards
Hazard ratio can be used for what?
Analysing survival over time
What is the key factor responsible for neutrophil increase in infection?
IL8
Mitochondrial inheritance characteristics?
Affected mothers - all children will inherit disease
Affected fathers - no children will inherit disease
Investigation used to detect mutated oncogenes?
PCR
Molecular techniques?
Southern - DNA
Northern - RNA
Western - protein
snow drop
Expressivity?
Describes the extent to which a genotype shows its phenotypic expression in an individual
Penetrance
Describes ‘how likely’ it is that a condition will develop
Allelic heterogeneity
Different mutations within the same gene causing similar clinical conditions
Germline mosaicism
Mutation is present in a subset of germ cells, potentially leading to offspring with genetic conditions despite unaffected parents
Variable inheritance
Differences in the pattern of inheritance, such as autosomal dominant versus recessive
First line for prolactinomas?
Cabergoline - dopamine agonists
Vitamin D function?
Increases plasma phosphate
What would exclude dx of GCA?
Normal plasma viscosity
Parametric tests and their definitions?
Student’s t-test: paired/unpaired
Pearson’s product-moment coefficient: correlation
Non parametric tests?
Mann Whitney U test: compares ordinal, interval or ratio scales of unpaired data
Wilcoxon: compares 2 sets of obs i.e. before and after on same population after intervention
Chi squared test: compares proportions/percentages i.e. compares % of pts who improved following 2 diff interventions
Spearman, Kendall rank: correlation
Definition of paired and unpaired?
Paired: one population
Unpaired: comparing response to diff interventions in 2 groups
c-MYC oncogene?
Burkitt’s lymphoma
n-MYC oncogene?
Neuroblastoma
BCL-2 oncogene?
Follicular lymphoma
RET oncogene?
MEN II, III
RAS oncogene?
Pancreatic cancer
Levels of evidence?
1a - meta analysis of RCTs - GRADE A
1b - 1 RCT - GRADE A
2a - 1 non randomised CT - GRADE B
2b - 1 experimental trial - GRADE B
3 - case controlled, correlation studies - GRADE B
4 - panel of experts - GRADE C
How does NO improve oxygenation?
Pulm vasodilation and inceased cyclic GMP
Which structure is involved in the degradation of polypeptides?
Proteasome
Poor genotype: phenotype correlation in which type of inheritance?
Mitochondrial
LBBB occurs due to?
Damaged LBBB and associated Purkinje fibres
Developmental delay and cherry red spot on the macula, without hepatomegaly or splenomegaly?
Tay Sachs
Which drug can cause sleep disturbance?
Beta blockers
Most common cause of death in patients with HOCM?
Vent arrythmias
Peroxisomes function?
Catabolism of long chain fatty acids
Guttate psoriasis appearance and rx?
Teardrop lesions - UVB phototherapy
Most common cardiac abnormality in Turner’s?
Bicuspid aortic valve
Anticipation is seen in which conditions?
Myotonic dystrophy, fragile X, Huntington’s
Which test is most likely to remain positive in a patient with syphilis despite treatment?
TPHA
Mechanism of vitamin K?
Cofactor in the carboxylation of clotting factors 2 7 9 10
What does adrenal medulla secrete?
Adrenaline
Which deficiency predisposes to Neisseria meningitis infections?
C5-9
Which cytokine is involved in the activation of macrophages?
Interferon gamma
Following a diagnosis of tetanus, what is the most appropriate antibiotic therapy to give with human tetanus immunoglobulin?
IV metro
How to show publication bias in meta analysis?
Funnel plot
IL8 function?
Neutrophil chemotaxis
Where does RNA splicing take place?
Nucleus
Homocystinuria is caused by a deficiency of?
Cystathionine beta synthase
This condition typically presents with proteinuria and is associated with early onset strokes or myocardial infarctions with a typical rash known as angiokeratomas?
Fabry disease
A CT head is organized, which demonstrates scattered cerebral calcification bilaterally and hydrocephalus?
Congenital toxoplasmosis
HLA B27 present in?
Reactive arthritis
The HLA-DRB1 gene is the major genetic susceptibility locus for?
Rheumatoid arthritis
The adrenergic receptor is an example of a?
G protein coupled receptor
Increased lung compliance?
Age and emphysema
Decreased lung compliance?
Pulmonary fibrosis, pulmonary oedema, pneumonectomy, kyphosis
N1 → N2 → N3 → REM
Theta (jerks) -> Sleep spindles/K complexes (deeper sleep) -> Delta (night terrors, nocturnal enuresis) -> Beta (dreaming, erections)
Which pneumocyte secretes surfactant?
Type 2
HIV, neuro symptoms, single brain lesions with homogenous enhancement?
Lymphoma
Linear, well-demarcated skin lesions that appear suddenly, with ‘la belle indifference’?
Dermatitis artefacta
Specificity?
Proportion of patients without the condition who have a negative test result
How to calculate positive predictive value?
Calculating specificity?
Beriberi - dry and wet?
Dry - causes peripheral neuropathy
Wet - causes HF
Which one of the following immunological changes is seen in progressive HIV infection?
Increase in B2-microglobulin levels
Treating immunocompromised patients with cryptosporidiosis?
Nitazoxanide
Fabry disease inheritance?
X linked recessive
Which surface marker on Reed Sternberg cells?
CD15
Tall, long fingered, downward lens dislocation, learning difficulties, DVT?
Homocystinuria
ANP role?
Vasodilator
Usual outcome in case control study?
Odds ratio
Scabies reaction?
Type 4 hypersensitivity
Achondroplasia inheritance and mutation in which gene? Typical features?
Auto dominant, FGFR-3
Features - trident hands, short limbs and fingers, flattened nasal bridge
Alkaptonuria (ochronosis) inheritance and mutation in which gene? Typical features?
Auto recessive, HGD
Features - pigmented sclera, black urine upon prolonged exposure, renal stones
Where is ANP secreted from?
Right atrium
Autosomal dominant conditions tend to be structural or metabolic?
Structural
Which type of bias is a problem in case control studies?
Recall bias
Which type of bias is important in meta analyses?
Publication bias
Issue only in non blinded trials?
Expectation bias
Pleomorphic tumour cells border necrotic areas?
GBM
Spindle cells in concentric whorls and calcified psammoma bodies?
Meningioma
Derived from remnants of Rathke pouch?
Craniopharyngioma
PTH hormone function?
Increases plasma calcium, decreases plasma PO4
Cardiac action potentials? Explain phases and mechanism?
Phase 0 - rapid depol - rapid sodium influx
Phase 1 - early repol - efflux of potassium
Phase 2 - plateau - slow influx of ca
Phase 3 - final repol - efflux of potassium
Phase 4 - resting potential restored by sodium potassium pump
Describe cell cycle?
G0 - resting phase
G1 - determines length of cell cycle
S - synthesis of DNA RNA histone, centrosome duplication
G2 - cell size increase
M - mitosis, shortest phase of cycle
Karyotype in Noonan’s vs Turner’s?
Noonan’s - normal karyotype
Turner’s - abnormal karyotype
Wide vermillion border, small spaced teeth and a flat nasal bridge, disinhibited friendly behaviour?
William’s syndrome
Which karyotypes is associated with short stature?
45XO
Shortened neck, protruding tongue and Brushfield’s spots?
Downs
Primary amenorrhoea, short in stature with low-set ears and a webbed neck? Associations?
Turner’s, coarctation of aorta + aortic dilation
Fever, grey discolouration, urgent bone marrow biopsy? Rx?
Visceral leishmaniasis, rx - sodium stibogluconate
Normotension, hypokalaemia + hypocalciuria?
Gitelman’s
Vit D mechanism?
Increases calcium absorption through small intestine
What happens during reverse transcriptase reaction?
RNA -> DNA
Which virus is strongly associated with oropharyngeal ca?
HPV 16
Calculating positive predictive value?
Sensitivity/(1-Specificity)
NNT calculation? Ideal value?
1/(absolute risk reduction)
NNT is a time-specific epidemiological measure of the number of patients who need to be treated in order to prevent one adverse outcome. A perfect NNT would be 1, where everyone improves with treatment, thus the higher the NNT, the less effective the treatment.
Cushing’s reflex?
Brady, hypertension, wide pulse pressure
Function of microtubules?
Microtubules help guide movement during intracellular transport and also help bind internal organelles
Man has haemophilia - chance of his daughter’s son having condition - daughter’s partner no PMH? Inheritance of haemophilia?
50% - x linked recessive
Interferon gamma produced by which cells?
Natural killer and T cells
Flu-like symptoms, dry cough, dyspnoea, relative bradycardia (65 bpm despite his fever), and hyponatraemia suggest pneumonia due to?
Legionella
The nicotinic acetylcholine receptor is an example of a?
Ligand-gated ion channel receptor
Patients who are immunosuppressed secondary to long-term steroids or methotrexate should receive x if they are exposed to chickenpox and have no antibodies to varicella?
VZ immunoglobulin
A 15-year-old boy is reviewed. He has been referred by his GP with ptosis, diplopia and night blindness. On examination he is noted to have a degree of ophthalmoplegia, bilateral partial ptosis and evidence of retinitis pigmentosa during fundoscopy. His mother developed a similar problem when she was 18-years-old. What is the most likely diagnosis?
Kearns-Sayre
Eczema herpeticum appearance?
Monomorphic, blistered, punched out lesions
Probability of detecting a statistically significant difference?
Power
Calculating NNT?
Steps for calculating NNT
Calculate the absolute risk (AR) for the control and treatment groups
Calculate the absolute risk reduction (ARR) by subtracting the AR of the treatment group from the AR of the control group
Calculate the NNT by taking the reciprocal of the ARR - (1/ARR)
