Clinical Sciences Flashcards
Genetic predisposition of coeliac
95% patients have HLA DQ2 or 8
Tissue transglutaminase acts on alpha gliadin -> generates epitopes to CD4 T cells -> intestinal wall inflammation
If untreated CD4 t cells make IFN g in intestinal wall
Is clexane monitored in pregnancy
No
Cardiac defect seen in trisomy 21
ASD seen in Down’s
Huntington’s inheritance
AD
What does a specificity of 90% mean?
if 100 people without disease, 90 will test negative, 10 will test positive
Sensitivity vs specificity
Sensitivity = SPIN
(Specific test, POSITIVE rules IN the disease)
Specificity = SNOUT
(Sensitive test when Negative rules OUT the disease)
How do you calculate specificity
TN / TN+FP
ADH
Where is it made and released?
Nonapeptide
made in hypothalamus, Released from posterior pituitary
ADH
MOA?
Acts on CD, increases water permeability and water retention
ADH
What drugs increase and decrease release?
Carbamazepine, thiazides, SSRIs increase ADH release
Ethanol usually inhibits release
superior pancreaticoduodenal artery
Branches off?
Supplies?
S P-D A
branch of the gastroduodenal artery
supplies the head of the pancreas + upper duodenum
right hepatic artery supplies
supplies the right lobe of the liver and part of the caudate lobe
right gastric artery supplies
supply the pylorus and the lesser curvature of the stomach
right and left gastroepiploic arteries
supply the greater curvature of the stomach
hyperkalaemia due to reduced renal excretion caused by
acidosis rhabdomyolysis tumour lysis malignant hyperthermia, and burns. Drugs that cause hyperkalaemia include:
AKI
Type 4 RTA
Addison’s
Cellular causes of hyperkalaemia
acidosis
rhabdomyolysis
lumour lysis
malignant hyperthermia and burns
Drugs causing hyperkalaemia
K-sparing diuretics
ACEi
NSAIDs
CYCLOSPORIN
BB
Progressive massive fibrosis associated with which lung condition?
complicated silicosis
Cyanide MOA
inhibition of the enzyme cytochrome oxidase c
interferes with the basic process of cellular respiration, preventing the formation of ATP and causing rapid cell death
Sarin gas MOA
inhibition of the enzyme acetylcholinesterase
causing acetylcholine to build up
causing prolonged sustained contraction of the diaphragm
Cystic fibrosis gene mutation
CFTR gene on chromosome 7
Cystic fibrosis gold standard Ix
Chloride concentration >60mmol/L
with sodium concentration lower than that of chloride on two separate occasions
Extrinsic Allergic Alveolitis/ farmers lung
What is it?
Typical feature O/E?
Common precipitins? Ix?
hypersensitivity pneumonitis (caused by immune response to inhaled allergens)
Basal crackles
Check for Abs to precipitins S rectivirgula and T vulgaris
thyroid hormone receptor
is what kind of receptor?
nuclear receptor
When T3 binds TH receptor, can bind genes and initiate transcription
Bronchial asthma
affected by which alleles
HLA alleles
G6PD deficiency inheritance
Who of children will have it if dad affected mum is not carrier?
X linked
NO ONE AFFECTED
male will pass on the X chromosome to any daughters, who will not be affected, as they will have a ‘good’ X from the mothers, and the father will pass on the Y chromosome to his sons, who will not be affected
Hereditary haemorrhagic telangiactasia inheritance
AD
Congenital adrenal hyperplasia inheritance
AR
cellular telomerase activity affects
The number of cell divisions a cell is capable of undergoing
MEN 1
3 P’s
Pituitary adenoma
Parathyroid
Pancreas (Gastrinoma)
MEN 2A
PPM
-
Parathyroid
Medullary Thyroid
Phaeochromocytoma
MEN 2B
MMMP
Mucosal neuromas
Medullary thyroid
Marfanoid body
Phaeo
Lesions of the frontal lobe cause
Expressive aphasia (receptive aphasias are due to a temporal lobe lesion)
Primitive reflexes
Perseveration (repeatedly asking the same question or performing the same task)
Anosmia, and
Changes in personality.
Lesions of the parietal lobe include:
Apraxias
Neglect
Astereognosis (unable to recognise an object by feeling it), and
Visual field defects (typically homonymous inferior quadrantanopia).
Lesions of the temporal lobe cause:
Wernicke’s (receptive) aphasia
Visual field defects (typically homonymous superior quadrantanopia)
Auditory agnosia, and
Memory impairment.
Occipital lobe lesions include:
Cortical blindness (blindness due to damage to the visual cortex and may present as Anton syndrome where there is blindness but the patient is unaware or denies blindness) Homonymous hemianopia, and Visual agnosia (seeing but not perceiving objects - it is different to neglect since in agnosia the objects are seen and followed but cannot be named)
ITP Abs are to
Majority ITP actually autoimmune
Abs to glycoproteins IIb-IIIa or Ib-IX (IgG) in 80% ITP
Soating of platelets with IgG -> phagocytosis by splenic macrophages.
Neurofibromatosis type 1 inheritance
AD
Chromosome 17
Neurofibromatosis type 1 inheritance
Chromosome 22
Cholecystokinin (CCK) is made in I cells of duodenum, jejunum and enteric nerves.
promotes gallbladder contraction and intestinal motility
increases secretion of pancreatic enzymes including insulin, glucagons, pancreatic polypeptides
role in satiety, and
short half life, less than three minutes, cleared by the kidneys.
Stimulus for secretion:
mixtures of polypeptides and amino acids especially phenylalanine and tryptophan stimulate release but undigested protein does not
gastric acid entering duodenum
fatty acids, especially in micelles
secretion inhibited by somatostatin.
inherited in a autosomal codominant manner with certain combinations resulting in alpha-1 antitrypsin deficiency.
homozygous SS or ZZ are those who are most likely to manifest clinical disease
tremor in parkinson’s vs essential tremor
PD - resting tremor
essential - postural tremor (on movement)
Rx Sickle Cell Crisis
Give O2 IV Fluids Analgesia Exchange transfusion if low Hb (get HbS to <30%) ABx if infection
40M
muscle weakness UL and LL
Cannot let go of someone’s hand after shaking it
Myotonic dystrophy
(muscle wasting + unable to relax muscles(myotonia))
Can affect heart/resp/GI muscles
Features myotonic dystrophy
Cataracts Ptosis Frontal baldness Gynaecomastia Diabetes Reduced reflexes + myotonia (can't relax)
Contraindication for BCG (live) vaccine
immunosuppressed e.g. steroids
Porphyria precipitants
Non drugs
Drugs
Non-drugs - stress, menstruation infection, pregnancy, starvation
Drugs - phenytoin, barbiturates, sulphonamides
24M haematuria proteinuria sensorineural deafness
alport syndrome
Alport syndrome mutation
Collagen IV gene
high triglycerides associated with what deficiency
lipoprotein lipase deficiency
Which intracellular structure has own self-replicating DNA?
mitochondria
Henoch Schonlein Purpura pathophysiology
Mesangial IgA deposits
Commonest cause of urticaria
Idiopathic (50%)
Also immune and non-immune
Which IL involved in anaphylaxis?
IL 4
IL 13
CD4 T cells
IgE
CREST / (limited) systemic sclerosis
anti-centromere antibodies
diffuse cutaneous sclerosis
anti-scl70/ anti topoisomerase
Pregnant woman
HepB core Ab POSITIVE
HepB sAg POSITIVE
HepB e Ag NEGATIVE
Mx?
give baby Hep B vaccine and Hep B Ig
give IG only if mum has Abs or acute infection during pregnancy
73M
diplopia
left hemiparesis
facial weakness of forehead + cheeks (LMN)
pontine stroke
diplopia
hemiparesis
LMN lesion
Class II MHCs present on which cells
APCs:
B cells
dendritic cells
macrophages
allergen-specific IgE Ix
skin prick testing
Apoptosis induced by
caspase activation
causes high Mg
iatrogenic
CKD
50F on ABx 1/52 for pneumonia then has fever maculopapular rah arthralgia eosinophilia/ eosinophiuria proteinuria
acute interstitial nephritis
type IV hypersensitivity to drugs
RTI or gastroenteritis
then recurrent visible haematuria
IgA nephropathy / Berger’s disease
Ix IgA nephropathy
renal biopsy
Genetics Myotonic dystrophy (2)
AD inheritance genetic anticipation (trinucleotide repeats)
progressive weakness
sensory level loss e/g/ T10
meningioma
GLP-1 function
glucagon-like-peptide 1
promotes satiety (reduces rate gastric emptying)
promotes insulin release
suppresses glucagon release
exanatide MOA and indication
GLP-1 analogue
T2DM treatment
Intrinsic factor
Where is it made?
Synthesis is stimulated what?
Used for?
Parietal cells
Gastrin, food, histamine
B12 absorption in ileum
VItamin D resistant rickets inheritance
X-linked dominant
Secretin function
increases bicarb secretion
reduces gastric acid formation
increases bile flow
Achondroplasia inheritance
AD
Achondroplasia features
normal spine, short limbs, macrocephaly
Can be diagnosed radiologically at birst
GGT made by
muscle
prostate
liver
Risk of Hep B
from needlestick injury
from chronic Hep B w high infectivity
1/3
Function of
Type I pneumocytes
Type II pneumocytes
Type I - gas exchange
Type II - make lung surfactant (stop alveoli collapsing when they expand)
Friedrich’s ataxia inheritance
AR
Haemolytic anaemia
DAT reticulocytes bilirubin LDH haptoglobins blood film urinary uribilinogen
blood film - spherocytes/ fragmented RBC
Which hormones act on cells through cAMP pathway (as unable to pass membrane)
pituitary hormones
LH, FSH, PTH, TSH
(also adrenaline, glucagon)
Which hormones act on cells through cAMP pathway (as unable to pass membrane)
pituitary hormones
LH, FSH, PTH, TSH
(also adrenaline, glucagon)
Triceps reflex nerve
C7 radial nerve
What is the Fick principle
Measures renal blood flow
approx 25% of cardiac output
Addisons and Conn’s syndrome
Na and K levels
Addison’s
Na - low K - high
Conn’s
Na - high K - low
Turner’s syndrome (webbed neck)
Heart abnormality
Aortic coarctation
Causes of pes cavus
Friedrich’s ataxia
Charcot Marie tooth
Conditions where you get genetic anticipation (3)
Friedrich’s ataxia
Myotonic dystrophy
Huntington’s
Type 4 RTA MOA
Features:
- Na and K levels
- urine
hypoaldosteronism
low Na and high K
normal urine acidification
Rx type 4 RTA
for aldosterone deficiency
for aldosterone resistance
Aldosterone deficiency - fludrocortisone
Aldosterone resistance - K restriction, loop diuretics, sodium bicarb
Antihypertensives CI in pregnancy
Why?
ACEi and ARBs
Cause renal dysgenesis in foetus
Anti-HTN used in pregnancy
Labetolol
Hyperaldosteronism
Na and K
BP?
High Na
Low K
High BP
Causes Primary hyperaldosteronism
Conn’s (adrenal adenoma) (>50%)
Adrenal hyperplasia
Adrenal carcinoma (rare)
Cortisol (glucocorticoid) deficiency
(as inc. ACTH -> inc. Ald)
NB Addison’s is deficiency of gluco and mineralocorticoid
What is enterohepatic circulation?
Bile products reabsorbed in terminal ileum
then return to liver in portal circulation
Hypogonadotrophic hypogonadism
Cannot smell
Kallman’s syndrome
deficiency hypothalamic GRH
Focal Segmental Glomerulosclerosis
MOA
Cause
Features
Ix
Rx
Complications
MOA - podocyte injury in glomeruli
Cause - Idiopathic or 2 to HIV/obesity/meds
Features - proteinuria, low albumin, oedema
Ix - renal biopsy - scarring glomeruli
Rx = corticosteroids (if Sx/nephrotic proteinuria), otherwise give ACEi
Complications - ESRF +/- transplant (in 50%)
How to distinguish cardiac vs respiratory causes of SOB
cardiac cause would have orthopnoea
When to give the (live) MMR vaccine in pregnancy
Post partum
Live vaccines are contraindicated in pregnancy
45F reduced hearing R side
MRI - 3cm mass in left cerebellopontine angle
Dx?
Prognosis?
Acoustic neuroma
can be fully resected, good prognosis
68F
multiple falls in last 6m
broad based (ataxic) gait
she has a ‘jerky’ tremor
Dx?
Multiple systems atrophy
PSP, you don’t get cerebellar signs
On/off phenomena in Parkinson’s.
Which drug would you add?
Cabergoline
Two drugs that increase risk of VTE
OCP
Antipsychotics
Rare eye complication of Diclofenac
Optic neuritis
Chlamydia Rx
Azithromycin or Doxycycline
Bloods abnormality in Phenytoin
macrocytic anaemia
B12 deficiency
Sildenafil (phosphodiesterase 5 inhibitors) should be avoided which which drugs?
Why?
nitrates or nicorandil
Due to vasodilatation potentially causing hypotension and precipitating a myocardial event
TCA (amitriptyline) OD Rx
IV sodium bicarbonate
tremor in parkinson’s vs essential tremor
PD - resting tremor
essential - postural tremor (on movement)
loss knee jerk reflex
which nerve is affected?
femoral nerve
supplies quadriceps femoris
loss sensation lateral aspect thigh
which nerv affected?
lateral cutaneous nerve
loss hip adduction and loss sensation inner thigh
which nerve affected?
obturator nerve
condition with hyperphenylalaninaemia (amino acid)
phenylketonuria
inheritance phenylketonuria
AR
test for phenylketonuria
high urine phenylalanine metabolites
learning disabilities
microcephaly
decreased growth
high urine phenylalanine metabolites
phenylketonuria
SA node and AV node supplies by
right coronary artery
asymmetrical funnel plots means
publication bias
tuberculin skin test
which typer hypersensitivity reaction
Type IV
where is GGT made
muscle
prostate
liver
PTH resistance
pseudohypoparathyroidism
anosmia
hypothalamic gonadotrophic releasing hormone (GRH) deficiency
Kallmann syndrome
diagnostic test Kallmann syndrome
FISH (chromosomal test)
Ciprofloxacin MOA
interferes with DNA synthesis
nephritis
haematuria
progressive renal failure
deafness
M>F
Alport syndrome
Hypokalaemia
Metabolic acidosis
High urinary pH (above 6)
Type 1 or 2 RTA
Pathophysiology Type 1 RTA
DCT
cannot excrete H+ ions
Pathophysiology Type 2 RTA
GET OSTEOMALACIA due to ACIDOSIS
PCT
cannot reabsorb bicarbonate ions
Causes Type 1 RTA
Genetic. AR and AD SLE Sjogren’s Primary biliary cirrhosis Hyperthyroidism Sickle cell anaemia Marfan’s syndrome
Cause Type 2 RTA
Fanconi syndrome
Hyperkalaemia
High chloride
Metabolic acidosis
Low urinary pH
Type 4 RTA
Pathophysiology Type 4 RTA
low aldosterone
-> low Na, high K, high H+
Causes Type 4 RTA
adrenal insufficiency ACE inhibitors spironolactone systemic lupus erythematosus diabetes HIV
Rx Type 4 RTA
fludrocortisone
sodium bicarb
treat high K
Rx Type 1 and 2 RTA
sodium bicarbonate
SLE associated w/ complements:
C1qrs
C2
C4
