clinical sciences Flashcards
(186 cards)
1
Q
ATN histopath features
A
loss of nuclei and detachment of tubular cells from BM
dilatation of tubules
necrotic cells obstructing tubule lumen
2
Q
stages of differentiation of erythrocyte (cell types)
A
haematocytoblast
proerythroblast
basophilic erythroblast
polychromatophilic erythroblast
normoblast (nucleus ejected)
reticulocyte (enters circulation)
erythrocyte
3
Q
renal cortical vs medullary blood flow
A
renal cortical blood flow > medullary blood flow
therefore tubular cells more prone to ischaemia
4
Q
what does GFR represent?
A
rate of plasma leaving capillaries and entering Bowman’s capsule
= (urine concentration x urine volume)/plasma concentration
5
Q
loop of henle
A
thin ascending limb impermeable to water, permeable to Na+ and Cl-
thick ascending limb fluid is hypo osmotic, reabsorbs Na and Cl
6
Q
what increases risk of calcium oxalate stones?
A
hypercalciuria, hyperoxoluria
hypocitraturia (citrate binds to calcium and makes it more soluble)
hyperuricosuria (may cause uric acid stones which calcium oxalate binds to)
7
Q
what increases risk of cystine stones?
A
inherited recessive disorder of transmembrane cystine transport
decreases intestinal and renal absorption
8
Q
what increases risk of uric acid stones?
A
low urinary pH
extensive tissue breakdown e.g. malignancy
9
Q
what increases risk of calcium phosphate stones?
A
RTA type 1 and 3, high urinary pH
10
Q
what increases risk of struvite stones?
A
urease producing bacteria
alkaline urine
11
Q
where is renin secreted and what does it do?
A
juxtaglomerular cells
hydrolyses angiotensinogen to angiotensin I
12
Q
factors stimulating renin secretion
A
hypotension, reduced renal perfusion
hyponatraemia
sympathetic stimulation
catecholaemines
erect posture
13
Q
what drugs reduce renin secretion?
A
beta blockers
NSAIDs
14
Q
adrenal cortex GFR ACD
A
zona Glomerulosa (outside)- mineralocorticoids, Aldosterone
zona Fasciculata (middle)- glucocorticoids, Cortisol
zona Reticularis (inside)- androgens, Dehydroepiandrosterone DHEA
15
Q
what does angiotensin II do?
A
vasoconstriction of vascular SM (raised BP)
vasoconstriction of efferent arteriole (increased filtration)
stimulates thirst
stimulates aldosterone and ADH
increases PCT Na and H
16
Q
what does ACE do?
A
in lungs
concerts angiotensin I to angiotensin II
17
Q
what does aldosterone do?
A
released by zona glomerulosa in response to raised angiotensin II, potassium, ACTH
causes retention of Na+ in exchange for K/H in DCT
18
Q
waxy casts in urine
A
advanced CKD
19
Q
fatty casts in urine
A
nephrotic syndrome
20
Q
phenylketonuria
A
autosomal recessive disorder of phenylalanine metabolism
chromo 12
learning difficulties, seizures
fair hair and blue eyes, eczema
musty urine and sweat
dx: heel prick test, hyperphenylalaninaemia, phenylpyruvic acid in urine
21
Q
homocystinuria
A
autosomal recessive deficiency of cystathionine beta synthase
fine, fair hair
marfinoid, osteoporosis, kyphosis
learning difficulties, seizures
dislocation of lense, myopia
CTE
treat with vit B6
22
Q
t helper cells
A
th1- cell mediated response and type IV delayed hypersensitivity
secrete IFNgamma, IL2, IL3
th2- antibody immunity, stimulate IgE
secrete IL4, 5, 6, 10, 13
23
Q
adaptive immune response cells
A
t helper (CD3, CD4, TCR, CD28, IL2, organ rejection)
cytotoxic T cells (CD3, CD8, TCR, organ rejection)
B cells (humoral, antigen presenting, hyperacute organ rejection)
plasma cells (differentiated B cells, produces large amount of antibodies)
24
Q
innate immune response cells
A
neutrophils
basophils
mast cells
eosinophils
monocytes
macrophages
natural killer cells
dendritic cells
25
basophil features
releases histamine
granules contain histamine and heparin
expresses IgE receptors
bilobed nucleus
26
mast cell features
similar to basophils
granules contain histamine and heparin
IgE receptors
27
eosinophil features
defends against protozoan and helminthic infections
bilobed nucleus
28
monocyte features
kidney shaped nucleus
differentiates into macrophage
29
macrophage features
phagocytosis
antigen presenting
IL1 source
30
dendritic cell features
antigen presenting
31
IgG
monomer
enhances phagocytosis
fixes complement, passes to fetal circulation
most abundant isotype in serum
32
igA
monomer/dimer
most predominant Ig in breast milk
also in digestive, resp, urogenital
provides localised protection on mucous membranes
transported across interior of cell via transcytosis
33
IgM
pentamer
first Ig to be secreted in response to infection
fixes complement but doesn't pass to fetal circulation
anti A, B blood antibodies
34
IgD
activation of B cells
monomer
35
IgE
monomer
type 1 hypersensitivity
binds to Fc receptors on mast and basophils
immunity to parasites e.g. helminths
least abundant isotype in serum
36
features of DIC
prolonged clotting time
thrombocytopaenia
decreased fibrinogen
increased fibrinogen degradation products
37
causes of DIC
infection
malignancy
liver disease
obstetric complications
trauma incl dissecting AAA, burns, shock
38
adult vs child brain tumours
adult: supratentorial
child: infratentorial
39
glioblastoma features
solid with central necrosis, contrast enhancing rim
vasogenic oedema due to BBB disruption
40
meningioma
2nd most common primary brain tumour in adults
benign
arachnoid cap cells next to dura
compressional symptoms
spindle cells in concentric whorls, calcified psammoma bodies
41
vestibular schwannoma
from CNVIII
cerebellopontine angle
hearing loss, facial nerve palsy, tinnitus
assoc with NF2
Verocay bodies
42
pilocytic astrocytoma
most common primary brain tumour in children
Rosenthal fibres- corkscrew eosinophilic bundle
43
medulloblastoma
aggressive child brain tumour
infratentorial
spreads through CSF
small blue cells, rosette pattern
44
ependymoma
brain tumour
commonly in 4th ventricle
may cause hydrocephalus
perivascular pseudorosettes
45
oligodendroma
benign, slow growing brain tumour
frontal lobes
calcification with fried egg appearance
46
haemangioblastoma
cerebellum
assoc with VHL
foam cells and high vascularity
47
pituitary adenoma
benign
secretory or non secretory
micro < 1cm vs macro > 1cm
48
craniopharyngioma
most common paediatric supratentorial tumour
sellar region
remnants of Rathke's pouch
hormonal disturbance, hydrocephalus, bitemporal hemianopia
49
cerebral perfusion pressure calculation
mean arterial pressure - intracranial pressure
50
brain tumours arising in what areas may reach considerable size before becoming symptomatic?
right temporal and frontal lobes
51
cranial nerve foramen
I: cribriform
II: optic canal
III: superior orbital fissure
IV: superior orbital fissure
V: SOF, foramen rotundum, foramen ovale
VI: SOF
VII: internal auditory meatus
VII: IAM
VIII: jugular foramen
IX: JF
X: JF
XI: JF
XII: hypoglossal canal
52
cranial nerves sensory vs motor vs both
I: Some
II: Say
III: Marry
IV: Money
V: But
VI: My
VII: Brother
VIII: Says
IX: Big
X: Brains
XI: Matter
XII: Most
53
cranial nerve reflexes
corneal- ophthalmic nerve afferent, facial nerve efferent
jaw jerk: trigeminal mandibular A, trigeminal mandibular E
gag: glossopharyngeal A, vagal E
carotid sinus: glossopharyngeal A, vagal E
pupillary light: optic A, oculomotor E
lacrimation: ophthalmic A, facial E
54
spinal cord grey matter
divided into Rexeds laminae
afferent fibres entering through dorsal roots usually terminate near point of entry but may travel in Lissauers tract to establish synaptic connections over several levels
dorsal horn tip: afferents, nociceptive stimuli
ventral horn: neurones innervating skeletal muscle
55
brown sequard
hemisection of cord
ipsi loss of proprioception and UMN signs
contra loss of pain and temp
56
spinal cord lesions below L1
tend to present with LMN signs
57
regulation of GH
increases secretion: GHRH, fasting, exercise, sleep
decreases secretion: glucose, somatostatin
58
causes of metabolic alkalosis
diuretics, vomiting
liquorice, carbenoxolone
hypokalaemia
primary hyperaldosteronism
cushings, bartter's
activation of RAAS- aldosterone > Na reabsorption in exchange for H+
ECF depletion > Na, Cl loss activates RAAS
hypokalaemia: K shift from cells > H+ into cells to maintain neutrality
59
tertiary hyperparathyroidism
normal or high Ca
high PTH, ALP
normal/low PO4, vit D
result of ongoing PTH hyperplasia after correction of underlying renal disorder
60
prolactin regulation
constant inhibition by dopamine
increases secretion: thyrotropin releasing hormone, pregnancy, oestrogen, breastfeeding, sleep, stress, metoclopramide, antipsychotics
61
achondroplasia genetics
autosomal dominant
mutation in FGR3 gene
62
leukotrienes action
LB4- neutrophil chemotaxis
LA4, LC4, LD4, LE4- bronchoconstriction
63
action of vitamin D
increases plasma calcium and PO4
64
calcitonin action
secreted by C cells of thyroid
inhibits osteoclast
inhibits renal tubular absorption of calcium
65
types of osteogenesis imperfecta
1: insufficient quantity collagen
2: poor quantity and quality
3: poorly formed collagen
4: poor quality collagen
66
what drugs affect folate?
interfere with metabolism: trimethoprim, MTX, pyrimethamine
reduce absorption: phenytoin
67
iron absorption
Fe2+ ferrous more than fe3+ ferric
increased by vit C and gastric acid
decreased by PPI, tetracycline, gastric achlorhydria, tannins
68
leptin
produced by adipose tissues
acts on satiety centres in hypothalamus to reduce apetite
stimulates release of MSH and CRH
low levels stimulates release of neuropeptide Y
69
ghrelin
stimulates hunger
produced by P/D1 cells in fundus of stomach and epsilon cells of pancreas
70
vit B2
riboflavin
cofactor of FAD and FMN
deficiency results in angular chelitis
71
vitamin B3
niacin
water soluble
precursor to NAD+ and NADP+
deficiency results in pellagra
72
Hartnup's disease
hereditary
reduces absorption of tryptophan
vit B3 deficiency
73
carcinoid syndrome vitamin deficiency
increased tryptophan metabolism to serotonin
vit B3 deficiency
74
vit B6
pyridoxine
water soluble
converted to PLP
deficiency > peripheral neuropathy, sideroblastic anaemia
75
vitamin C functions
(ascorbic acid)
antioxidant
collagen synthesis
iron absorption
norepinephrine synthesis
76
vit C deficiency
defective synthesis of collagen > capillary fragility, poor wound healing
gingivitis, loose teeth
bleeding gums, haematuria, epistaxis
general malaise
follicular hyperkeratosis and perifollicular haemorrhage
ecchymosis
sjogren's
arthralgia
oedema
77
vit D action
converted to prohormone calcifediol in liver
calcifediol converted to calcitriol in kidneys
78
sources of vit D
D2: plants
D3: dairy, sunlight on skin
79
vit D resistant rickets
X linked dominant
presents in infancy with failure to thrive
impaired PO4 reabsorption in renal tubules
normal calcium, low PO4, high ALP
XR: cupped metaphyses with widening of epiphyses
dx: increased urinary PO4
mx: high dose vit D, PO PO4
80
vit K function
fat soluble
cofactor in carboxylation of clotting factors II, VII, IX, X
reverses warfarinisation (takes 4h)
levels may fall in conditions affecting fat absorption
deficiency may occur after prolonged broad spectrum abx
81
atherosclerosis changes
subendothelial space infiltrated by LDL
monocytes migrate from blood and differentiate into macrophages
> phagocytose oxidised LDL
> turn into foam cells
smooth muscle proliferation and migration from tunica media into intima
> fibrous capsule covering fatty plaque
82
ANP actions
secreted mostly by right atrium (also right ventricle and left atrium)
secreted in response to increased blood volume
acts via cGMP
degraded by endopeptidases
> natiuresis
> lowers BP
> antagonises angiotensin II and aldosterone
83
phases of cardiac action potential
0- rapid depolarisation, rapid Na influx
1- early repolarisation, K efflux
2- plateau, slow Ca influx
3- final repolarisation, K efflux
4- restoration, Na/KATPase restores resting potential. slow Na entry until threshold potential reached which triggers new action potential
84
cardiac conduction velocity
ventricular: 2-4m/sec (fastest)
atrial: 1m/sec
AV node: 0.05m/sec
85
LV ejection fraction equation
stroke volume/end diastolic LV volume*100%
86
stroke volume equation
end diastolic LV volume - end systolic LV volume
87
what increases pulse pressure?
pulse pressure = systolic - diastolic
reduced aortic compliance
increased stroke volume
88
systemic vascular resistance equation
mean arterial pressure/ cardiac output
89
actions of endothelin
acts via G protein linked to phospholipase C
vasoconstriction
bronchoconstriction
90
what affects release of endothelin?
promotes:
angiotensin II
ADH
hypoxia
mechanical shearing forces
inhibits:
nitric oxide
prostacyclin
91
endothelin is raised in what conditions?
primary pulmonary HTN
MI
HF
AKI
asthma
92
when is pulmonary surfactant detectable from?
28 weeks
92
respiratory chloride shift
CO2 diffuses into RBC
CO2+H2O > carbonic anhydrase > HCO3 + H
H + Hb
HCO3 diffuses out of cell and Cl- replaces it
93
haldane effect
increased po2 > co2 binds less well to hb
94
Hering Bruer reflex
lung distension results in slowing of resp rate
95
what factors affect lung compliance?
increase: age, emphysema
reduce: pulmonary oedema, pulmonary fibrosis, pneumonectomy, kyphosis
96
function of leukotrienes
mediate inflammation and allergic reactions
bronchoconstriction
mucus production
increase vascular permeability
attract leukocytes
leukotriene D4: slow reacting substance of anaphylaxis
97
leukotriene production
secreted by leukocytes
formed from arachidonic acid by lipoxygenase
98
what drugs are safe for breastfeeding?
penicillins, cephalosporins, trimethoprim
glucocorticoids, levothyroxine
valproate, carbamazepine
salbutamol, theophyllines
TCAs, antipsychotics (not clozapine)
beta blockers, hydralazine
warfarin, heparin
digoxin
99
what drugs are unsafe when breastfeeding?
cipro, tetracyclines, chloramphenicol, sulfonamides
lithium, benzos
aspirin
carbimazole
MTX
sulfonylureas
cytotoxics
amiodarone
100
phases of cell cycle
G0- resting
G1- gap1, cells increase in size under p53 influence (cyclinD/CDK4, cyclinD/CDK6, cyclinE/CDK2 regulates transition to M)
S- synthesis of DNA, RNA, histone, centrosome duplication (CyclinA/CKD2)
G2- gap2, cells continue to increase in size (cyclin B/CDK1 regulates transition to M)
M- mitosis, shortest phase
101
phases of mitosis
prometaphase: nuclear membrane breaks down, microtubules attach to chromosomes
metaphase: chromosomes align at middle of cell
anaphase: paired chromosomes separate at kinetochores and move to opposite sides of cell
telophase: chromatids arrive at opposite poles of cell
cytokinesis: actin-myosin complex in centre of cell contacts resulting in pinching into two daughter cells
102
rough vs smooth endoplasmic reticulum
rough: translation and protein folding, manufacture of lysosomal enzymes, site of N linked glycosylation. e.g pancreatic, goblet, plasma cells
smooth: steroid and lipid synthesis. e.g. hepatocytes, adrenal cortex, testes, ovaries
103
nucleolus function
ribosome production
104
ribosome function
translation of RNA into proteins
105
peroxisome function
catabolises v long chain FAs and AAs
results in hydrogen peroxide formation
106
proteasome function
degrades protein molecules tagged with ubiquitin
107
C1 inhibitor deficiency
hereditary angioedema
uncontrolled release of bradykinin
108
C1q, C1rs, C2, C4 deficiency (classical pathway components)
predisposes to immune complex disease
SLE, HSP
109
C3 deficiency
recurrent bacterial infections
110
C5 deficiency
Leiner disease
recurrent diarrhoea, wasting, seb dermatitis
111
C5-9 deficiency
encodes membrane attack complex
neisseria meningitidis prone
112
how to calculate standard error of the mean
SD/ square root of n
113
interleukin source and function
IL1- macrophages, acute inflammation and fever
IL2- Th1 cells, growth and differentiation of T response
IL3- activated T helper cells, stimulates myeloid progenitors
IL4- Th2 cells, stimulates B cells
IL5- Th2 cells, stimulates eosinophils
IL6- macrophages and Th2 cells, B cells, fever
IL8- macrophages, neutrophil chemotaxis
IL10- Th2 cells, inhibits Th1 cytokines, anti inflam
IL12- dendritic cells and macrophages and B cells, activates NK and stimulates T cell differentiation into Th1
114
ordinal data
set categories which can be ordered
115
nominal data
categories have no order or hierarchy
116
dermatome landmarks
C2- posterior skull
C3- turtle neck
C4- crew neck
C4- upper limb
C6- thumb and index
C7- middle finger and palm
C8- ring and little finger
T4- nips
T5- inframammary fold
T6- xiphoid
T10- umbilicus
L1- inguinal lig
L4- knees (all 4s)
L5- big toe, dorsal foot
S1- lateral foot, small toe
S2, S3- genitalia
117
DiGeorge syndrome
T cell deficiency and dysfunction
microdeletion of chromo22
auto dom
viral and fungal infections
parathyroid hypoplasia, hypocalcaemia
thymus hypoplasia
C- cardiac abnormalities
A- abnormal face
T- thymic aplasia
C- cleft palate
H- hypocalcaemia, hypoparathyroid
22- chromo 22 microdeletion
118
Downs syndrome cardiac complications
AV septal canal defects
VSD
ASD secundum
tetralogy
PDA
119
layers of epidermis
stratum corneum: flat, dead, scaly keratin filled cells
stratum lucidum: clear layer present only in thick skin
stratum granulosum: cells form links with neighbours
stratum spinosum: squamous cells begin keratin synthesis, thickest layer
stratum germinativum: basement membrane, columnar cells, contains melanocytes and gives rise to keratinocytes
120
fabry disease
x recessive
def alpha galactosidase A
burning pain/paraesthesia
angiokeratomas
lens opacities
proteinuria
early CVD
121
HIV immunological changes
reduced CD4, IL2, NK, delayed hypersensitivity
increased B2 microglobulin
polyclonal B activation
122
HLA associations
encoded on chromo6
HLAA3- haemochromatosis
HLAB51- behcets
HLAB27- ank spond, reactive arthritis, acute anterior uveitis
HLADQ2/DQ8- coeliac
HLADR2- narcolepsy, goodpastures
HLADR3- derm hep, sjogrens, PBC
HLADR4- T1DM, RA
123
homocystinuria treatment
b6 pyridoxine supplements
124
types of hypersensitivity reactions
1- anaphylactic, atopy. IgE to mast cells
2- cell bound. IgM or IgG. autoimmune haemolytic anaemia, ITP, goodpastures, pernicious anaemia, acute haemolytic transfusion reactions, pemphigus/pemphigoid
3: immune complex. free antigen and ab IgG, IgA. SLE, post strep, extrinsic allergic alveolitis
4: delayed. T cell. TB, graft v host, allergic dermatitis, scabies, extrinsic allergic alveolitis, MS, GBS
5: antibodies recognising and binding surface abs. graves, MG.
125
IL1 inhibitors
anakinra- used in RA
canakinumab- used in JIA, stills disease
126
glycogen storage diseases
type1/von gierkes- G6P deficiency, hepatic accumualtion
type 2/pompes- lysosomal alpha 1,4 glucosidase deficiency. cardiac, hepatic, muscle accumulation
type 3/cori- alpha glucosidase deficiency. hepatic, cardiac accumulation
type 4/mcardles- glycogen phosphorylase def, skeletal accumulation
127
lysosomal storage diseases
gauchers- beta glucocerebrosidase def
tay sachs- hexpsaminidase A def
niemann pick- sphingomyelinase def
fabry- alpha galactosidase def
krabbes- galactocerebrosidase def
metachromatic leukodystrophy- arylsulfatase A def
128
mucopolysaccharidoses
hurler syndrome- alpha iduronidase defect
hunter syndrome- iduronate sulfatase def
129
ligand gated ion channel receptors
mediate fast responses
nicotinic ACh, GABAA, GABAC, glutamate
130
tyrosine kinase receptors
tyrosine kinase: insulin, IGF, EGF
non receptor tyrosine kinase: PIGGlET PRolactin, Immunomodulators, GH, GCSF, EPO, thrombopoietin
131
guanylate cyclase receptors
instrinsic enzyme activity
ANP. BNP
132
G protein coupled receptors
slow transmission
affect metabolic processes
7 helix membrane spanning domains
alpha, beta, gamma subunits
alpha linked to GDP which is phosphorylated to GTP
133
G proteins
Gs stimulates adenylate cyclase, increases cAMP and activates protein kinase A
Gi inhibits adenylate cyclase, decreases cAMP and inhibits protein kinase A
Gq activates phospholipase C and splits PIP2 to IP3 and DAG and activates protein kinase C
134
mechanism of metabolic alkalosis
RAAS activation
aldosterone causes Na reabsorption in exchange for H in DCT
ECF depletion causes NaCl loss, activates RAAS
hypokalaemia: K shifts from cells to ECF so H shifts into cells to maintain neutrality
135
microtubules are in all cells except...
RBC
136
structure of microtubules
cyclindrical
alternating alpha and beta tubulin subunits
positive and negative end
137
microtubules molecular transport
dynein and kinesin attatchment proteins move up and down
dynein moves postitive to negative towards centre of cell
kinesin moves negative to positive away from centre
facilitates movement of organelles
138
lebers optic atrophy
mitochondrial disease
develops 30y
central scotoma, loss of colour vision
rapid onset visual impairment
139
MELAS syndrome
mitochondrial disease
mitochondrial encephalomyopathy lactic acidosis and stroke like syndromes
140
MERRF syndrome
mitochondrial disease
myoclonus epilepsy with ragged red fibres
141
kearns sayre syndrome
mitochondrial disease
onset < 20y
external ophthalmoplegia, retinitis pigmentosa
ptosis
142
noonan
chromo 12
autosomal dom
similar features to turners
also pulm stenosis, ptosis, triangle face, low set ears, factor XI def
143
how to calculate 95% confidence interval?
range of mean - (1.96*SD) to the mean + (1.96*SD)
144
calculating numbers needed to treat
1/(absolute risk reduction) and round to nearest whole number
145
experimental event rate
(number who had particular outcome with the intervention)/ (total number who had intervention)
146
control event rate
(number who had particular outcome with control)/(total number who had control)
147
absolute risk reduction
find absolute different between control event rate and experimental event rate
if undesirable outcome: ARR= CER-EER
if desirable outcome: ARR= EER-CER
148
leptin acts on what?
stimulates MSH and CRH
low levels release neuropeptide Y
149
ghrelin
produced by P/D1 cells in fundus and epsilon cells in pancreas
stimulates hunger
150
odds vs probability
odds: ratio of people who incur outcome to the people who do not
e.g. rolling a 6 is 1/5
151
how can proto-oncogenes become oncogenes?
point mutation
chromosomal translocation
increased protein expression
152
c-MYC
transcription factor
Burkitt's lymphoma
153
nMYC
transcription factor
neuroblastoma
154
BCL-2
apoptosis regulator protein
follicular lymphoma
155
RET
tyrosine kinase receptor
MEN II, III
156
RAS
G protein
many cancers, esp pancreatic
157
erbB2
aka HER2/neu
tyrosine kinase receptor
breast and ovarian cancer
158
p53
tumour suppressor gene
offers protection by causing apoptosis of damaged cells
loss of function results in increased risk of cancer
159
Li-Fraumeni syndrome
rare
autosomal dom
early onset of cancers
p53 mutation
160
type 1 vs type 2 pneumocytes
1: thin squamous, 97%
2: cuboidal, secrete surfactant. can differentiate into type 1 during lung damage
161
club cell pneumocytes
non ciliated come shaped cells
inside bronchioles
protect against inhaled toxins
secrete glucosaminoglycans and lysozymes
162
what is required for PCR?
only 1 strand of sample DNA
2 DNA oligonucleotide primers
thermostable DNA polymerase Taq
163
how does PCR work?
boil and denature DNA
cool
complimentary strands pair up
excess primers pair with DNA
repeat the cycle and DNA doubles each time
164
reverse transcriptase PCR
amplifies RNA
RNA converted to DNA by reverse transcriptase
mRNA can be analysed
165
prader willi
prader willi if gene deleted from father
angelman if gene deleted from mother
chromo 15
infant hypotonia
short stature
hypogonadism
LDs, childhood obesity, behavioural problems
166
post test probability
post test odds/ (1+ post test odds)
167
relative risk
ratio of risk in experimental group to risk in control group
168
calculating sensitibty, specificity
sensitivity: TP/(TP+FN) proportion of patients with condition with positive result
specificity: TN (TN+FP) proportion of patients without condition with negative result
169
positive and negative predictive values
postitive predictive: TP/ (TP+FP)
negative predictive: TN/ (TN+FN)
170
likelihood ratio for a positive/negative result
positive: sensitivity (1-specificity) how much the odds increase when test is positive
negative: (1-sensitivity)/specificity how much odds decrease when test is negative
171
Wilson and Junger criteria for screening
- important public health problem
- acceptable treatment
- available facilities for dx and tx
- recognised latent or early symptomatic stage
- natural history adequately undertant
- suitable test/examination
- test/exam acceptable to population
- agreed policy on who to treat
- cost of case finding economically balanced
- case finding continuous process and not once for all
172
p value
probability of obtaining a result by chance at least as extreme as the one actually observed, assuming the null hypothesis is true
173
types of error when testing null hypothesis
1: null hypothesis is rejected when it is true. probability is alpha.
2: null hypothesis is accepted when it is false. probability is beta.
174
power of a study
probability of correctly rejecting the null hypothesis when it is false
power= 1-probability of type 2 error
175
non parametric tests
mann whitney U- compares ordinal, interval or ratio scales of unpaired data
wilcoxon signed rank- compares 2 sets of observations on a single sample. e.g. before and after
chi squared- compare proportions/percentages
spearman, kendall rank- correlation
176
sleep stages and EEG waves
N1- theta waves, light sleep
N2- sleep spindles adn K complexes, 50% of total sleep
N3- delta waves, deep sleep, night terrors, nocturnal enuresis, sleep walking
REM- beta waves, dreaming, loss of muscle tone
177
levels of evidence
1a- meta analysis of RCTs
1b- 1 or more RCTs
2a- 1 or more well designed but not randomised, controlled trial
2b- 1 or more well designed experimental trial
3- case, correlation and comparative
4- panel of experts
178
grading of recommendation
A- based on evidence from at least one RCT
B- based on evidence from non randomised controlled trials
C- based on evidence from a panel of experts
179
examples of trinucleotide repeat disorders
fragile x
huntingtons
myotonic dystrophy
friedreichs ataxia
spinocerebellar ataxia
spinobulbar muscular atrophy
dentatorubral pallidoluysian atrophy
180
turners
45X0
bicuspid aortic valve, coarctation of aorta
cystic hygroma
high arched palate
short 4th metacarpal
pigmented naevi
elevated gonadotrophins
hypothyroid
horseshoe kidney
181
variance
spread of scores away from mean
variance= square of standard deviation
182
how do diagnose williams syndrome?
FISH studies
chromo 7 microdeletion
183
x linked dominant conditions
alports
rett syndrome
vit D resistant rickets
184
x linked recessive conditions
only males are affected, except in cases of Turner syndrome because they only have one X
androgen insensitivity
becker muscular dystrophy
colour blindness
duchenne MD
fabry
G6PD
haemophilia a, b
huntes
lesch nyhan
nephrogenic DI
oscular albinism
retinitis pigmentosa
wiskott aldrich
185
