Cells, clinical biochem, anatomy and physiology Flashcards
(249 cards)
1
Q
Cushings with raised ACTH. No suppression on low-dose dex. >50% suppression with high dose. Where is ACTH being produced?
A
Pit (cushings disease)
2
Q
Cushing’s with raised ACTH. Suppression on low-dose dex. . Where is ACTH being produced?
A
Adrenal
3
Q
Cushing’s with raised ACTH. No suppression on low-dose dex. no suppression with a high dose. Where is ACTH being produced?
A
Ectopic tumour eg SS Lung / carcinoid
4
Q
Foot drop + sensory loss lateral lower leg nerve? Rx?
A
Common peroneal
Physio + splint while recovering
5
Q
Quads weakness/wasting. Loss of knee reflex. nerve? Where is paraesthesia?
A
femoral
Medial thigh. Anteriomedial calf (L2-4 dermatome)
6
Q
Hip adductors nerve root?
A
L3
7
Q
Knee extension nerve root?
A
L3/4
8
Q
Pt buying over the counter anti-indegestion tablets -> Epi gastic tenderness + raised Ca/K
A
Milk-alkali syndrome
9
Q
3 things which stimulate PTH release
A
HypoCa
HyperPO4
low vit D
10
Q
Golfers elbow (medial epicondylitis) affects which nerve? Weakness?
A
Ulnar
Adduction of thumb (grip strength) - adductor pollicis
[Test with the paper test -> when pull out have to flex thumb as adduction not there]
11
Q
Sensory loss snuff box
A
Radial
12
Q
Numbness on lateral thigh
A
Lateral cutaneous femoral nerve
13
Q
Which nerve supplies the interossei muscles of hand
A
Ulnar
14
Q
Wrist drop caused by
A
Radial
15
Q
Hypoglossal damage ->
A
Loss of intrinsic muscles on that side of tongue
[Will deviate towards the side of lesion as fibres ‘push’ tongue away]
16
Q
Lead poisoning on bloods
A
anaemia
basophilic stippling on blood film
17
Q
Why do thiazide diuretics cause hypokalaemia? H+ effect? Why are they effective antihypertensive?
A
Increase sodium loss in distal convoluted tubule
=>Increased sodium reabsorption from sodium pump in exchange for potassium
-> Hypokalaemic alkalosis
+ hyperCa and hypourineCa
Affect renal prostaglandins -> hypotension
18
Q
Phase 0 of action potential
A
Influx of sodium
19
Q
Kcal in dextrose / lipid emulsions - only thing to remember
A
1L of 50% dextrose = 2000 kcals
1L of 20% lipid = 2000 kcals
Eg if pt needs 2500kcals then will need 1.25L of above
20
Q
Which artery supplies L atrium
A
Circumflex (off LAD)
21
Q
L marginal artery supplies
A
Left ventricle
22
Q
CAH - if presents in late teens with hairy and amenorrhea is what enzyme? What does this lead to?
If presents with salt wasting in child?
A
Partial 21-hydroxylase deficiency
This leads to an increase in 17-hydroxyprogesterone - >virulisation
Total 21-hydroxylase deficiency
->Salt wasting and Addisonian crisis in child
23
Q
How does 17-hydroxylase deficiency present
A
Delayed puberty + mineral corticoid excess
24
Q
Largest arteries from circle of Willis
A
Middle cerebral
25
Where do vertebral arteries meet to form circle of willis
Brainstem
26
In who and why can heparin cause hyperK?
Diabetes or acidotic
->Heparin inhibits aldosterone secretion from the adrenal cortex -> reduced renal K excretion
ie you get hyperkalemia and no significant AKI
27
When do you get pseudohyperkalaemia ?
(3 reasons)
Haemolysed sample
High platelets / WCC
28
Urinary sodium in ATN?
Goes up
[>20mmol/l
29
Nitrates are often used in unstable angina. Which vessels are affected most?
Large veins
-> reduces preload
30
HypoK, HyperCl metabolic acidosis most likely
Chronic Laxative abuse
31
Barter syndrome electrolytes acid?
Hypokalaemia, HypoCa
HyperCa-uria
Metabolic alkalosis
Sensory neural hearing loss
32
Guiltellam syndrome electrolytes acid?
HypoK
HypoMg
HypoCa (normal urineCa)
Metabolic Alkalosis
Its all low G
33
Liddles syndrome electrolytes? acid?
Hypertensive*
HypoK
Metabolic alkalosis
34
Differentiate barter and gilelman
Barter has SN hearing loss and high Ca in urine
G- all electrolytes are low in blood
35
metabolic acidosis. What signals increased respiratory drive?
Carotid bodies in common carotid (chemoreceptors)
36
Which superficial veins drain into cavernous sinus? Sx?
Upper lip -> veins drain into cavernous sinus
Total ophthalmoplegia
-CN 3,4,6 travel through
horners syndrome (sympathetic plexus)
Facial paraesthesia
37
Where is BNP produced
Cardiac ventricles (stretching)
38
Apex of lung vs base when standing. Which has higher PCO2? V/Q? Compliance?
Apex at top so less blood
->Increased V/Q
->Increased O2 and decreased CO2
Base more compressed so can expand more as starts more squished as a baseline
->Increased compliance
39
Nerve root damage causing global wasting of hand muscles
T1
40
When would you use Demeclocycline
HypoNa not responding to fluid restriction
(or use hypertonic saline)
Also used for some infections Eg chlamid / rickettsia / mycoplasma
41
Gilbert's syndrome what do you get?
Isolated unconjugated bilirubin
This alongside an absence of bilirubin in urine
[as bilirubin needs to be conjugated before going into urine]
42
Calculate anion gap
Na - (Cl + HCO3)
43
Biceps / triceps reflex nerve root
Biceps - C5/6
Triceps - C7
44
During exercise why is CO increased
Increased SV and HR
45
Which cancer secretes PTH-related peptide?
Squamous most commonly
46
Odds =?
Odds = number of new cases in time period/number who did not become a case in the time period
47
What is person at time risk used for? other name?
• Not everyone is at risk for full length of time so use incidence rate
• incidence rate = Number of new cases in time period / total person time at risk during time period
48
What is prevelence ratio
Prevalence ratio = Prevalence in exposed / prevalence in unexposed
49
What is Relative risk? relative risk reduction?
Risk ratio (Relative risk) = Risk in exposed / risk in unexposed
Relative risk reduction = 1-RR
50
How do you calculate absolute risk reduction?
NNT?
Absolute risk reduction = Risk in unexposed – Risk in exposed
NNT = 1/ARR
51
What is odds ratio? why wold you calculate
Odds ratio = Odds of outcome in exposed / odds of outcome in unexposed
Used in case control as cant calculate risk
52
How are odds and risk seperate?
• Odds - comparison of who experienced exposure and who did not.
• Risk is comparison of people who had exposure vs everyone in the group
53
PPV? is it higher with good sens or spec?
Positive predicted value - the proportion of people with a positive test result who actually have the disease
• a / a+b
High specificity = high PPV
54
What are lead time and length time biases
Lead time- Diagnose earlier
Length time – More likely to identify slow diseases
55
Mortality in control 12.5%. Relative Risk in trial group of 0.8. What is NNT ?
Need to calculate ARR
A) Calculate mortality in trial group
= 12.5x0.8 = 10%
B) Calculate ARR
=12.5-10= 2.5%
nnt=1/arr
1/0.025 = 40
56
What does a larger sample size do? Reduces risk of what error?
Makes estimate more precise and reduces risk of Type 2 error
57
Type 1 error is?
Rejecting null hypothesis when it is true
Ie chance
-Usually fixed before the study p<0.05
58
Calculate NPV
What makes it higher?
Negative predictive value – the proportion of people with a negative test result who do not have the disease
• d/ c+d
High sensitivity = high NPV
59
What does the intention to treat mean in a study?
Total recruited for it
ie if 500 control and 500 new drug.
It is irrelevant how may people drop out during study the INTENTION is what you intended at the start
=500 control, 500 drug
60
Cancer in 15/50 on treatment
Cancer in 20/50 on placebo
What is RRR
(Relative risk) = Risk in exposed / risk in unexposed
RR = (15/50) / (20/50) = 3/4
Relative risk reduction = 1-RR
=25%
61
ARR calculation
Absolute risk reduction = Risk in unexposed – Risk in exposed
62
Why is bechets different from many other vasculitis ?
Affects veins too
Can get arterial and venous thrombotic events
63
HIV have deficiency of what cell type predominantly
cd4 T-cells
64
Compare skin in NF1 and tuberous sclerosis
NF1 - Cafe-au-lait, freckling in auxiliary/groin,
TS - HYPOpigmented macules (ash leaf), angiofibroma, shagreen patches (raised connective tissue lesion on lower back)
65
Which antibodies in autoimmune encephalitis
anti-LGI 1
[previously called anti-VGKC)
66
Presnece of M protein but no end organ damage
Eg NO lytic lesions / hyperCa / anaemia / ckd
MGUS
[premalignant condition with 1% risk of myeloma each year]
67
Blistering rash on sun exposed areas,
hyperpigmentation
often dark urine =? Usual trigger? cause? ix?Rx?
Porphyria cutanea tarda
Alcohol
Deficiency in UROD (uroporphyrinogen decarboxylase)
Plasma/urine porphyrins + iron overload
Plebotomy
68
Multiple presentations with neuropsychiatric distubances, hypertension and abdo pain?
Acute Intermittent Porphyria (AIP)
[Due to deficiency of hydroxymethylbilane synthase (HMBS)]
69
Types I-IV hypersensitivity reactions and cells
I - Allergic reactions - IgE/mast/basophils
ii - antibody dependent - IgG
-Eg drug induced haemolytic anaemia, transfusion reactions, goodpastures
III - Immune complex - immune complexes
-Eg Post strep GN, SLE
IV - cell mediated - T cells
contact dermatitis, BCG
70
IgE deficiency leads to inceased risk of?
viral and parasitic infections
71
IgD deficinecy leads to? Which ethnic group?
small increased risk of minor infections Et URTIs
Pt will be Spanish in question
72
Raised IgE (Or any thing) in are normal in what % of population
2.5%
In a normal distribution, 95% of values are within 2 standard deviations of the mean. So raised in 2.5% and low in 2.5%
73
Phaeo, cushings and what thyroid cancer in which syndrome? Due to mutations of what
Medullary
MEN2a
RET protooncogene
74
Hereditary spherocytosis defect in what
Spectrin and ankyrin
75
IgA deficiency ->
Deficiency of IgG2
-> Recurrent bacterial infections
76
which Ig deficinecy most common in recurrent mild bacterial infections
IgA
77
Ig A/D/E/G/M deficiency basics
A - increased risk of bacterial infections + allergic reaction to blood products (containing IgA)
D - no real increased risk of anything
E - Viral and parasitic eg parvovirus / maleria
G - Recurrent otitis media and sinopulm infection
M - Recurrent gram -ve eg Pseudomonas
78
Short stature, short 5th metacarpals, sub cut calcification, hypocalcaemia, intellectual impairment = ? due to?
PseudoHYPOparathyroidism
G protein linked to PTH receptor
79
Mild haemophillia should get what prior to procedures
Desmopressin
+ Factor VIII if significant bleeding
80
Haemophilia coag screen
normal PT (and VWF)
prolonged APTT
81
Anti-smith
Highly specific SLE
82
Mixed connective tissue disease (MTCD)
-raynauds, myositis, interstitial lung disease, pericarditis....
has what antibody?
Anti-RNP
Ribonucleoprotein
83
Neonatal lupus antibody ? presents with?
Anti-Ro
Bradycardia + heart block
baby ro ro
84
Most common infection post splenectomy
pneumococcus
85
Most common infection post splenectomy
pneumococcus
86
Why ANA positive in vauge symptoms of fatigue in middle age
ANA is age related and titre increases with age.
86
Muscular dystrophy which affects FACE eg ptosis / cataracts
Myotonic muscular dystrophy
87
Score system for pressure ulcers
waterlow score
88
Way to present meta analysis as plot
forrest plot - (looks like box and whiskers on its side )
shows OR with each blob being size of importance of each study
89
Carpal tunnel pain affects where
hand and sometimes up forearm and even shoulder
[all along median nerve)
90
What enzyme stimulates release of pancreatic enzymes?
CCK
91
Achondroplasia inheritance. What are the odds of a child from couple with this not having achondroplasia
Dominant
=25% risk not having it
92
Which Ig makes up 75% of total serum Igs
IgG
93
All nerves from lumbar plexus emerge lateral to the psoas bar?
Genitofemoral and obturator
94
Which Anti-body can cross placenta?
Brest millk?
G - looks like a curved placenta
A - Aeyyy look at those titties
95
abnormal ears, short philtrum, micrognathia, hypertelorism (distance between eyes). What syndrome? Blood finding? why tetany?
Di geroge
Low T-lymphocytes -> infections
-Absence of normal thymus
Congenital cardiac
HypoCa tetany due to failure of Parathyroid development
96
PPV in terms of what the letters mean!
Sometimes give you a table the wrong way round to fool ya
Those with a disease and a positive test / All with a Positive test
97
Around mean where do 95% of values lie?
How do you say you are 95% confident of where the mean lies?
2 SD's
95% confident the true mean is 2 standard errors from the mean you have calculated
98
Which layer of skin is a mantoux test injected into
intradermal
99
Mechanism of angiooedema in ACEi
bradykinin release
100
Alkaptonuria (black urine), arthritis. Blue ears, CV disease in later life =
Homogentisic oxidase deficiency
101
How does sunburn damage you
formation of pyrimidine dimers
102
First ECG change in hyperkalaemia
Tall T waves
103
Liver fibrosis - which cells do the stimulation? Which do the fibrosing
Kupffer cells - stimulate
Stellate cells (basically fibroblasts)- do the fibrosing
104
Latex allergy also which food allergies commonly?
Banana
Kiwi
Avacado
Chesnut
105
How does hyaline cartilage get its nutrients
Diffusion from synovial fluid
106
Painless jaundice:
3 things on bloods that would make you think alcohol related hepatitis rather than pancreatic CA
High MCV
High GGT
AST:ALT ratio >2
107
Tall, hypogonad and low fertility man. Boobies/wide hips? On bloods?
Klienfelter
XXY
Low testosterone
High FSH/LH
108
Major trauma -> high glucose after 4 hrs caused by?
Adrenaline
Later on will be cortisol
109
Eat fish
Anaphylaxis-like symptoms with normal tryptase and IgE?
Scromboid poisoning
110
What does reverse transcriptase do?
Transcribes DNA from RNA
111
What does helicase do?
Splits DNA strands
112
What does DNA polymerase do?
Adds nucleotides to single strands of DNA
113
What does RNA polymerase do?
Transcribe RNA from DNA
114
Protein aggregation -> lewy body production means what is involved
Proteasome
115
Posterior lens dislocation. Marfanoid habitus. DVTs. Learning difficulty
Homocystinuria
[also have a high arched palate and crowded teeth]
116
Homocystinuria has 3 forms. Classical type 1
type 2
type 3
Classical - Vit B6 (pyridoxine) deficiency (due to lack of cystathionine-beta-synthase CBS)
Type 2 - issue with methylation of B12
(Colabamin)
Type 3 - issue with methylation of B9 (folate)
117
When do you get activation of the non-classical complement pathway
Gram-negative sepsis
118
Blood gas in preg usually
Respiratory alkalosis
119
Lots of people drop out a study - what type of analysis should you do?
Sensitivity analysis
[Ie check if there was differences with the people who dropped out and those who did not]
120
Bleomycin works how
Single DNA strand sission
121
Multiple family members have a genetic condition (and some don't) but the gene isn't known. What test can be done to track the allele
Linkagae analysis
[compares DNA of aSx and those with it to track the allele]
122
What to compare outcomes of patients admitted in day vs at night. How to avoid selection bias
Case mix (risk) adjustment
i.e as patients admitted in day might be elective and less sick. So need to control for confounding factors
[If not randomisation is always best for avoiding selection bias. Its just not possible in this case and cant control when people are admitted]
123
Where and by what is intrinsic factor produced
Parietal cells in fundus of stomach
124
Name a diuretic that works on:
Proximal tubule
Ascending loop of henle
Early distal tubule
Collecing ducts (and late distal tubule)
Proximal tubule - Mannitol / acetazolamide
Ascending loop of Henle - Loop diruretics
Early distal tubule - Thiazide diuretics
Collecting ducts (and late distal tubule) - K plus sparing (amiloride / spironolactone)
125
What does nuclease do
Cleaves bonds between nucleic acid sub units
126
Pancreatic adenocarcinoma gene
KRAS (80%)
p53 (50%)
127
What are the most common type of inherited disorder
sex-linked (x chromasome)
128
Multiple fractures, bilat hearing loss, teeth discolouration =
Osteogenesis imperfecta
129
Antibodies in lambert Eaton myasthenic syndrome
Voltage-gated calcium channel antibodies
130
Which test to compare means between 2 groups with normal distribution?
T-test
[Paired if measuring a pre and post score in groups]
131
Blood gas of cirrhosis will show? Why?
Metabolic alkalosis
Relative Low intravascular volume due to low albumin
->Increase aldosterone
1 - Albumin is a weak acid and so low levels -> alkalosis
2 - Aldosterone Na absorption K excretion -> later in collecting duct K+ exchanged for H+
132
Inguinal vs femoral hernia position? Which strangulates? Which is more common?
Inguinal - above and medial to the pubic tubercle
10x more common
Femoral - inferior and lateral
Much higher risk of strangulation
133
Morphine -> comes out in a red rash what cells?
Histamine release from direct action on mast cells
[NOT IgE mediated and so can't do a skin prick]
134
Hereditary angioedema issue? Due to?
What would be low between attacks?
C1 esterase inhibitor
SERPING 1 gene
Low levels of c4 between attacks
Autosomal dominant inheritance
135
This condition lead to high levels of an Ig? and almost undetectable levels of ? risk of?
hyper-IgM syndrome
IgA, IgG and IgE levels are undetectable
->sino/pulm infections and opertunistic Eg PCP / crytosporidial
136
What is name of B6
pyridoxine
137
What is name of B9
Folate
138
Vit B2 name
Riboflavin
139
Vit b3 name
Niacin
140
Where is cell is circular DNA found
Mitochondria
141
Classic serum lipids in diabetes
Normal LDL
Low HDL
Raised triglycerides
[due to insulin resistance or isulinopenia]
142
Lateral STEMI which vessel
Inferior STEMI which vessel
Distal LAD
Right coronary
143
Posterior myocardial infarction looks like? which vessel
Posterior coronary
Depression in anterior leads
144
Posterior myocardial infarction looks like? which vessel
Posterior coronary
Depression in the anterior leads
145
What are analytical statistics sometimes called
inferential statistics
146
Severe combined immunodeficiency (SCID) Lack what? What does this do?
Adenosine deaminase
Usually Converts adenosine ->inosine
and deoxyadenosine -> deoxynosine
High levels of deoxyadenosine
->toxic to lymphocytes (especially immature ones in thymus)
-> symptoms of immunodeficiency due to lymphopenia
147
G6PD inheritance
X linked
148
Impaired glucose tolerance vs diabetes on OGTT
Impaired
Fasting <7
2hr 7.8-11
Diabetes
Fasting >7
2hr >11
149
Which cholesterol in familial hypertriglycerideaemia?
Where are these synthesised?
Risk of?
VLDL synthesised continuously in the liver
Retinal vein thrombosis / pancreatitis when level >11mmol/L
150
Which complement in the classical pathway ?
Which in alternative ?
Classical C1 [c2, c4]
Alternative C3
[alternative is continuously activated at low level]
151
Most common inherited disorder in northern Europe
A1AT
[CF is highest in UK / States]
152
Where is a-1antitriptase produced? Which gene?
Liver
SERPINA1
153
Ashkenazi jew
Bone pain / hepatosplenomegaly
Normochromic normocytic anaemia
Elevated transaminases?
What are the other types of this?
Due to?
Gaucher's disease Type 1
Type 2/3 have neurological sequale
elevated glucosylceramide in lysosomes [deficient glucocerebrosidase]
154
Ashkenazi jew
Bone pain / hepatosplenomegaly
Normochromic normocytic anaemia
Elevated transaminases?
What are the other types of this?
Due to?
What other key finding on blood
Gaucher's disease Type 1
Type 2/3 have neurological sequelae
elevated glucosylceramide in lysosomes [deficient glucocerebrosidase]
Raised ACID phhosphotase
155
Where does the spinal cord terminate
L1/2
156
What is found in the extradural space
Loose fat
[allows for ready diffusion of local anaesthetic in an extradural block]
157
Drug has rare adverse outcome Eg 1 in 1000. How many people would you need to recruit to have 95% chance of picking at least 1 up?
3000
[need 3x as many participants as the rate of effec to have 95% power at picking it up ]
158
What is surfactant made of
Phospholipoproteins
159
What is the power of a study
The probability of correctly rejecting the null hypothesis
[avoiding type 2 error]
160
UK Grade or evidence
A
B
C
D
A - Consistent RTC/Cohort validated in different populations
B- consistent retrospective cohort / case-control
C- case study or case series
D - expert opinion
161
Mean/median/mode in Gaussian distribution
All the same
[Gaussian = normal]
162
Mean/median/mode positive skew
mean>median>mode
163
How to calculate the coefficient of variation ?- what is this?
SD/mean
An appropriate measure for distributions
[The higher the coefficient of variation, the greater the level of dispersion around the mean.]
164
How to calculate NNT from exposure rates and outcomes
ARR =(Absolute risk in exposed)-(absolute risk in unexposed)
1/ARR
165
What is the standard error
How precise the sample mean is from the population mean
166
Type 1 vs type 2 error
Type 1 - incorrectly rejecting the null hypothesis - chance
Type 2 - incorrectly accepting the null hypothesis
167
Comparing new drug X to old drug Y in effect on BP. How to present?
Mean and confidence interval for the difference in reduction of BP between the two groups
168
Compare discontinuous categorical data test?
Chi-squared
169
Test to see if observed results differ from expected if only 2 outcomes Eg Sucess or failure
Binomial
170
Test when each individual in a group has been measured twice with normal distribution
Paired T-test
171
Differences between two different groups in a variable of interest
Unpaired (students) t-test
172
Eukaryote cell cycle?
M phase - mitosis
G1 phase - gap where cell grows + synthesises mRNA
S phase (synthesis) - DNA replication
G2 phase - cell grows and prepares for mitosis
[Interphase involves G1, S and G2]
173
What phase is 95% of cell cycle time? What happens here
Interphase
chromosomes are decondensed and distributed throughout the nucleus
174
which phase determines the variability of cell cycle length
G1 phase
175
Severe hypertriglyceridemia Eg causing pancreatitis + tendon issues + xanthomata Rx ?
Fibrates 1st line
Omega 3 carboxylic acid - used as adjunct / alternative
[Statins not advised]
176
Which mab lowers LDL cholesterol
Evolocumab
[man has evolved to love fatty food -> LDL]
177
Fabry disease gene? Inheritance?
What happens?
Sx?
Seen on slit lamp?
Key risks?
a-Galactosidase A
X linked
Unable to break down GL3 which build up in lysosomes
Neuropathic pain in hands or feet especially during exercise
Mey get rash on abdo / GI Sx
Verticillata on slit lamp - vision unaffected
Cardiomyopathy / arrhythmias, strokes, CKD
178
What is DNA splicing? Used for?
Exclusion of introns (and joining together exons) to make proteins
Modify bacteria / yeast to produce human peptides Eg insulin
179
Stages of mitosis
Prophase – The chromosomes shorten and thicken.
[Get Phat]
Metaphase – Chromosomes line up in the middle of the cell.
[Middle]
Anaphase – Chromatids break apart at the centromere and move to opposite poles.
[Apart]
Telophase – Two nuclei formed after nuclear envelopes reform around each group of chromosomes.
180
Pemphigus Vulgaris is a disorder of
Desmoglein-3
181
How would homocystinuria present in a question? Cause? Inheritance? Ix/blood findings? Common Rx?
Marfanoid / skeletal abnormalities
Learning difficulties
DVT
Hypotonia
Livedo reticularis
Cystathionine beta-synthase deficiency
Autosomal recessive
Elevated homocysteine in urine + blood
Increased methionine
Decreased cysteine
Methionine-restricted, cystine-supplemented diet
[think need to replace the cystine]
B6 - pyridoxine (converts homocysteine to cystine)
Low animal protein diet
[B9- folate replacement]
182
Skeletal abnormalities, hypoparathyroidism and recurrent infections ? Deficient in what ?
T cells
[di geroge syndrome]
183
Who gets anaphylaxis with blood products
IgA deficiency
184
C3 deficiency results in
Overwhelming infections from encapsulated bacteria from young age
[need abx prophylaxis]
185
IgM deficiency leads to?
Overwhelming encapsulated infections
186
You hypothesise your new drug will reduce MIs by 20%. If it only reduces by 10% so you accept the null hypothesis.
What is this an example of?
Type 2 error
Incorrectly accepting the null hypothesis [as it has missed a positive effect]
187
How is genetic testing done for Huntington
PCR
[now has triplet primed assays]
188
What is it called when DNA polymerase goes down a section of DNA and excises an incorrect base and replaces it with the correct one ?
Proofreading
189
What are Gaucher cells?
Lipid laden macrophages
[dur to macrophages being unable to digest glucocerebroside]
190
How do basophils, mast cells and eosinophils release their granules? Why is this important?
The lysosome (intracellular and containing enzymes) binds to the plasma membrane of the cell and then discharges the contents out.
This allows extracellular degradation of larger infecting organisms Eg Protozoa/worms which cannot be intracellularly digested by phagocytosis
[Ie this is why eosinophils are raised in worm infections]
191
Stages in phagocytosis
Chemotaxis
Ingestion within a phagosome
Intracellular enzymatic degradation
Exocytosis
192
What does IL-5 do
essential for maturation of eosinophils/basophils in the bone marrow and their release into the blood
[Think IL 5 and E which is 5th letter]
193
Formation of multiple telangiectasia/av malformation with hereditability in the question? Also known as? Inheritance? Usual presentation? What are the significant issues?
Hereditary haemorrhagic telangiectasia [Olser-weber-rendu - web of telangectasia]
Autosomal dominant
Usually present with nose bleed as a kid and should be a clue with telangiectasia.
Adults get serious GI (or cerebral) bleeds from AV malformations
193
Formation of multiple telangiectasia/av malformation with hereditability in the question? Also known as? Inheritance? Usual presentation? What are the significant issues?
Hereditary haemorrhagic telangiectasia [Olser-weber-rendu - web of telangectasia]
Autosomal dominant
Usually present with nose bleed as a kid and should be a clue with telangiectasia.
Adults get serious GI (or cerebral) bleeds from AV malformations
194
What are foam cells? Where are they found ?
Type of macrophage (derived from monocytes)
They take up LDL on the vessel wall but become saturated and lipid-laden and die in the vessel wall contributing to the formation of atherosclerosis.
195
what is the 95% confidence interval
95% sure the true mean lies within the confidence interval
196
Pit hormons all low. A single dose of GnRH makes a small difference but regular doses for a week raise all the hormones. Where is the issue?
Hypothalamus.
[By the end of the week the pit hormones all recovered indicatig the pituitary is capable of producing the hormones and so defect bmust be pre pit - ie the issue was from prolonged pit understimulations]
197
Total gastrectomy - what are you deficient in?
B12 - as loose parietal cells which produce intrinsic factor....
[Iron in partial gasterctomy + proximal jej]
198
Cox proportional hazards is ?
A survival analysis which works out amount of time which occurs before an event when comparing more than one covariate.
199
Test to compare differences between 2 or more means?
Anova
200
Test to compare categorical outcome between 2 groups
Chi-squared
201
Test to assess the correlation between 2 variables
Pearson coefficient
202
What type of chromosomal disorder carries the most severe phenotype
Unbalanced autosomal translocation
[Basically the bigger the effect on chromosomes the worse it is]
203
Difference between angioedema from ACEi and angiooedema from histamine sources
No urticarial rash [or itching] in pure bradykinin-mediated angioedema (ACEi) or in hereditary angioedema
204
If blood is not agglutinated by anti-A or B what type is it
OO
[ie cannot contain A or B antigens]
205
Why do sickle cell need vaccines
Hyposplenism
206
Sickle cell - How much HbS / HbA / HbF
70-90% HbS
10-30% HbF
No HbA - sickle cell is recessive
207
Endothelin I does?
Vasoconstriction - mostly in pulm circulation
208
Teriparatide is used for? How do you measure the response to it?
Osteoporosis
Using procollagen peptides
[-C-terminal (PICP)
-N-terminal (PCNP)
-Osteocalcin (OC)]
209
Left homonymous hemaniopia with central sparing = lesion where
R occiptal cortex
[cortex has sparing of foveaa]
210
Inheritance of BRCA
Dominant
211
Which electrolyte finding most indicates CKD
HypoCa
212
Fluid to replace that drained from NG
0.9% NaCl
213
What is NO synthesised from in the body
L-arginine
214
How do PDE-5 inhibitors cause vasodilation
Enhance NO mediated vasodilation
215
What is riboflavin? Used for?
Vit B2
Hydrogen-transfer chain in mitochondria
[formation of ATP]
216
Which vitamin modulates prostaglandin synthesis
Vit D
217
Which vitamin for the synthesis of glycogen from glucose phosphate
Vit B6 - Pyridoxine
218
Which vitamin for synthesis of amino acids
Folate - b9
219
Which vitamin for synthesis of collagen
Vit C
220
Severe pancreatitis and ++ nausea. What to do with respect for feeding?
NG feed
-Essesntial they keep getting the calories in
221
Where is the organ of corti found? Endo or ectolymph?
Scala media (inner ear)
Scala media filled with endolymph
222
Where are high frequenxy sounds detected? Low frequency
High - Scala vesibuli
Low-Scala tympani
[Vertigo is fear of high, and when you hit the low ground you go Tymph]
223
Where is the inner ear found
Petrous part of temporal bone
224
Where is endo lymph found?
Compare endo/ peri lymph
Bony labyrinth
[Semi-circular cannals
vestibule
cochlear]
Endolymph - High potassium
low in sodium and calcium
Perilymph high sodium
low in potassium and calcium
225
Test to compare haemochromatosis and secondary iron overload? What is the difference?
Liver biopsy
Haemochromatosis - iron found in parenchymal cells
Secondary overload - Iron in kuppfer cells
226
Which mutations in hereditary haemochromatosis
C282Y
H63D
227
How does tranexamic acid work
Antifibrinolytic - therefore will stablise clots that form
228
2 places VWF found?
-Weibel-palade bodies in endothelial cells
-platelet a-granules
229
Which chromosome for VWD? inheritance?
12
AD
230
Phase 0,1,2 cardiac action potential
0- Sodium inflow
1- Potassium outflow
2- Calcium inflow
[K+, Ca++]
231
Gingival hypertrophy caused by
Which class of cardiac drugs?
Which anti-epileptic ?
Which immunosuppressant?
Which aBX ?
Calcium channel blockers
phenytoin [also valproate/vigabatrin/phenobarbital]
Ciclosporin
Erythromycin
232
Pain on pronation = lateral or medial epicondylitis
Medial
233
Medial epicondylitis may affect which nerve if severe
Ulnar
234
UK grading of edicnce
Ia, Ib
IIa, IIb
III
IV
Ia: systematic review or meta-analysis of RCTs.
Ib: at least one RCT.
IIa: at least one well-designed controlled study without randomisation.
IIb: at least one well-designed quasi-experimental study, such as a cohort study.
III: well-designed non-experimental descriptive studies, such as comparative studies, correlation studies, case-control studies and case series.
IV: expert committee reports, opinions and/or clinical experience of respected authorities.
235
alpha/beta/gamma interferon which for hepatitis? MS? which MHC class?
Alpha - HepB/C
Beta- MS
-a/b Increase MHC class 1 expression
y-Increase MHC class 2
236
When does the body produce a/b interferon? Why?
Viral infections
-bind to uninfected cells and inhibit viral production RNA / DNA
-Induce MHC class 1 which causes cell lysis of viral infected cells
237
Which interferon activates macrophage and neutrophil intracellular killing
A-interferon
238
Which fruit causes itchy mouth in people with hayfever [birch-pollen syndrome]
Apple
239
What receptor does cholera bind to causing profuse watery diarrhoea
GM1 agonism
240
Where is CSF made? by which cell?
What absorbs it? What layer is it found?
Choroid plexus in the 4th ventricle
-Ependymal cells
Absorbed by arachnoid villi
Between pia and arachnoid
241
Which cells are the macrophages of the brain
Microglia
242
A/B/Theta/Delta waves EEG mean and Hz
Alpha waves are related to relaxation and attention. They are present when you are awake with your eyes closed.
8-13Hz
Beta waves are normal in people who are awake
>14Hz
Theta waves are related to sleep
4-7Hz [kids aged 4-7 not quite alspeep]
Delta waves - Sleep in adults
<4Hz
243
New test 99% sensitive, 90% specific
Prevalence is 1 %
What is the PPV?
Draw table for 1000
10 have disease 990 don't
a= 10 x 0.99(sensitivity) = 9.999= 10
d= 990 x 0.9(specificity) = 891
Can then fill in rest of table
PPV = 10/(10+99) = 92%
244
Sens 92%, spec 93%
Prevalence = 1.2%
What is PPV
12 have disease 988 don't
a= 12x0.92 = 11
d= 988x0.93 = 919
b = 988-919=69
PPV = 11/(11+69) = 14%
245
EPO not helping anaemia in dialysis, what should you check?
Ferritin - probs iron defficiency
246
Ring-shaped rash with peripheral crusting in pregnancy =
Pustular psorasis of pregancny
[prev called impetigo herpetiformis but its not actually an infection ]
247
Bullous rash in pregnancy? what would biopsy show?
Pemphigoid gestationis
Linear deposits of C3
