Clinical Sciences Flashcards
Risk factors of statin myopathy
Female
Old
Low BMI
Multisystem disease
An old think woman with lots wrong
Statin mechanism of action
Inhibits HMG-CoA reductase.
This is the rate limiting enzyme in cholesterol synthesis
Lipophilic statins - simvastatin and atorvastatin- more myopathy
Hydrophilic- rosuvastatin, pravastatin, fluvavastin - less myopathy
Erythromycin/clarithromycin - increase CK
Stop statin if after 3/12 trbsaminases rise by 3x
Innate immune response
Neutrophil - primary phagocytise in acute inflammation. Contains myeloperoxidase + lysozyme. Multilobed nuclei
Basophils - histamine I’m allergic response m. Expresses IgE - bilobed nuckeus
Mast cells - similar to basophils function Present in tissues.
Eosinophils- defence vs protozoan and helminthic infect - bilobed nuclei
Macrophage - phagocytosis of vellular debris + pathogen. APC. Nah source of IL-1 (fat laden = FOAM. CELL)
Dendritic cell - APC
Helminths
Seen in poorer countries with ooor sanitation and communities. Eggs in soil from poo in soil.
Get in body from eating eggs - veg or meat infected with eggs
Grow inside —> anaemia, WL, malnutrition.
Can lead to Bowel obstruction —> surgery
To bendazoles mainly
Adaptive immune response cells
Helper T - cell mediated respond CD4 - recog MHC class 2 - acute + chronic organ rejection
Cytotoxic T cells - MHC class 1 recognition - Expresses CD8. Acute in chronic rejection
B cells - hyperacute rejection - humoral immune response
Plasma cells - differentiate from B cells. Specific
Endothelin
Bunds to target tissues —> ETA & ETb to coulek to Gq protein —> formation of IP3 —> calcium release from SR
Causes: vasoconstriction and Positivr inotropic. Causes aldosterone secretion, decreases renal
BF & eGfFR and release ANP
Stimulated by- ADH, AT2, thrombin, Hypoxia, shearing force
Inhibited by: prostacyclin and ANP(neg feedback)
Hungry bone syndrome
Rare
Follows parathyroidectomy for hyperPTH and a rapid decrease in PTH
Normal
To get trainsient hypoPTH for few weeks —> hypocalcaemia, but I’m hungry bone you get a rapid absorption of Ca into bones which prolongs hypocalcaemia.
Suppressed PTH and low Ca, PO4- and Mg
T helper cells
TH1 (think gamma (1)-2-3)
- cell mediated response in Type 4 hypersensitivity
- Secretes: IFN-gamma, Il 2 and Il3
Th2:
- humoral immunity
- eg stimulating IgE in asthma
- IL4,5,6,10,13
TH-17
- driven by IL17
- unknown
HLA classes
HLA-A3 - haemochromatosis
HLA-B51: Bechets
HLA-B27 - Ank spond, Reiter’s, acute ant uveitis
HLA-DQ2/8 - Coeliac disease
HLA- DR2 - narcolepsy + goodpasteures
HLA - DR3 - dermatitis heroetiformis, sjrogrens, PBC
HLA-DR4 - DB type 1/RA
Standard deviations and percentage values
1 SD - 68.3%
2 SD - 95.4%
3 SD -99.7%
68.3–> 95.4 —> 99.7
Clopidogrek mexhsnism of action
Inhibits ADP binding to platelet, therefore inhibits activation of platelets
Pulmonary surfactant
Released by type 2 pneumocystis.
Main component is dipalmitoyl phosphatidylcholine (DPPC)
1st detected at 28 weeks
Mechanism: as alveoli decrease in size it increases in conc, therefore making sure no collapse - by lowering elastic recoil
Reduces manic forces needed to expand lungs
Pellagra
Vitamin B3 deficiency - niacin
Get in alcoholism
3Ds
Dementia
Diarrhoea
Dermatitis
Likelihood ratios
LR+ = sensitivity/(1- specificity)
LR- = (1- sens)/spec
Common Tumour supressor genes.
APC - colorectal Ca
p53 - multipla Ca. Li Fraumeni
BRCA1 - Breast + Ovarian Ca
BRCA2 - Breast Ca
RB - Retinoblastoma
NF1 - Neurofibromatosis
Cell Cycle:
G0 - resting phase
G1 - Gap 1 - Cell increase in size - determines length of cell cycle (p53)
S - Synthesis phase - RNA + DNA + Histones form
G2 - Gap 2 - cell increase in Size
M - Mitosis = shortest phase
IFN
IFN - alpha:
- think a for A - best antiviral acttion
- Vs Hep B + C, Karposi sarcome, metestatic RCC
IFN - B:
- antiviral
- shown to decrease freq of exac. in R-R M.S.
IFN - G:
- Immunomodulation
- Chronic granulamtous dx & Osteopetrosis
IFN a + B = bind to type 1 receptor
IFN–gamma - binds type 2
Haldane vs Bohr Effect
Haldane:
O2 causes Hb to have a decreased affinity for CO2
Bohr:
CO2 + pH (acid) causes Hb to have a decreased affinity for O2
Organelles and their fn:
1) Endoplasmic reticulum
2) Golgi apparatus
3) Mitochondrion
4) Nucleus
5) Nucelous
6) Ribosome
7) Lysosome
8) Peroxisome
9) Proteasome
1) Rough ER - Translation and folding of proteins. Manafacturesn lysosomal enzymes
N-linked glycosylation
1) Smooth ER - steroid + lipid syntesis
2) Packaging of above for those that are destined to be secreted by cell. O-linked glycosylation
3) Aerobic resp. Contains mitochondrial circular DNA
4) DNA –>RNA
5) Produces ribosome
6) RNA –> protewin
7) B.D>. of proteins + polysaccharides
8) B.D. of long chain fatty acids –> forms hydrogen peroxide
9) B.D> of proteins
Common CDs
CD1 - MHC molecule that presents lipid molecules
CD2 - Found on thymocytes, T cells, and some natural killer cells
CD3 - The signalling component of the T cell receptor (TCR) complex
CD4 - Found on helper T cells.
Co-receptor for MHC class II
Used by HIV to enter T cells
CD5 Found in the majority of mantle cell lymphomas
CD8 Found on cytotoxic T cells.
Co-receptor for MHC class I
Found on a subset of myeloid dendritic cells
CD14 Cell surface marker for macrophages
CD15 Expressed on Reed-Sternberg cells (along with CD30)
CD16 Bind to the Fc portion of IgG antibodies
CD21 Receptor for Epstein-Barr virus
CD28 Interacts with B7 on antigen presenting cell as costimulation signal
CD45 Protein tyrosine phosphatase present on all leucocytes
CD56 Unique marker for natural killer cells
CD95 Acts as the FAS receptor, involved in apoptosis
Compliment deficiencies
- C1 inhibitor – hereditary angioedema (remember 1 = A 1st letter alphabet)
- C1q, C1rs, C2, C4 –> immune complex dx – HSP/SLE
- C3 – Bacterial infections – 3 looks like a B
- C5 – leinier disease – recurrent diarrhoea, wasting and seberrhoeic dermatitis.
- C5-9 – MAC complex disorder – Neisseria meningitides
Chicken pox
Highly infectious:
- Spread via reps route.
- Infectivity – 4days before rash, until 5 days after
- Incubation = 10-21 days
Mx symptoms– lotion + trim nails
Immunocompromised, newborns with periparrtum exposure –> VZIG
If chicken pox develop –> IV Aciclovir
Complications:
Pneumonia –> Giv IV Acicllovir – fine crackles bilaterally. Multiple itny opacities
Encephalitis
Arthritis
nephritis
pancreatits
GI Hormones
Gastrin
- secreted by G cells of antrum
- stimulus: vagus nerve activity vi distension. Luminal peptides + AA. Low Ph
- secretes acid + digestive enzymes, increase motility
Somatostatin:
- D cells of stomach + SI
- stimulated by digestive prod - fat, bile salts + glucose
- essentially opp of above: decrease acid + motility + digestive enzymes
CCK:
- I cells of SI
- stim: partially digested protein + TG
- increases secretion of pancreas, contract GB relax sphincter of oddi. Decrease gastric emptying. Induces satiety
Secretin:
- S cells of SI
- acidic chyme + FA
- increase BICARBONATE secretion + decrease acid
VIP:
- secreted by cells SI
- Naural
- secretion if pancreas’s + intestine
Sigmificance tests and statistical
Errors:
Null
Hypothesis - two to see equally effective
Alternative hypotheses- is the opp null hypothesis
Type 1 statistical error: null hypothesis rejected when it’s true.
Type 2 statistical error: null hypothesis accepted when it’s fals
Respiratory physiology: control
Control of resp:
Central reg centres
- medullary resp centre
- apneustic centre- lowerpons
- pneumotaxic Centre- upped pons
Central + peripheral chemoreceptors
- central: raised (H+) ECF
- perioheral; carotid + aortic bodies - respond to raised pCO2/(H+, lesser extent low pO2
Pulm receptors
- stretch receptors. Distension —> slower RR (hering-bruer reflex)
- irritant receptor —> bronchoconstriction
- juxtacapillary - stretching of micro add
Clinical trial: phases
Phase 1
- determines pharmokinetics, pharmodynamocd and side effects
- healthy volunteers
Phase2:
- 2a - optimal dosing
- 2b - assessed efficacy
- small number of dx patients
Phase 3:
- assess effectiveness.
- RCT
Phase 4:
- post marketing surveillance
- Lt effectiveness and side-effects
Immunoglobulins
IgG - most common - phagocytosis. Complement. Passes to foetal circulation
IgA - breast milk. Secreted by resp/digestive/urogenitak. Localised protection to mucous membrane
IgM - 1st secreted in response to infection. Complement. Doesn’t pass into foetal circ. BLOOD GROUPS.
IgD - activation of B cells
IgE - LEAST COMMON - type 1 hypersensitivity.
Hypersensitivity reactions
A B.C D E
Type 1 = A -
- Allergic, Anaphylactic,Atopy.
- IgE
- Caused by cross linking of multiple IgE on mast cell/Basophils. —> mast cell granules —> histamine release. (Can be presensitised - happens V quick)
Type 2 - B
- anti-B-ody, = IgG and IgM
- antibody dependedant cytotoxicity. Same as humours immunity but targeted at own body cells.
- examples include goodpasteures , haemolytic dx of newborns
- GRAVES DISEASE
Type 3 - C
- immune-C-omplex
- increase Ag Ab ratio in body.
- clumping —> inflammation by aCompement + attracting neutrophils.
- SLE, rheumatoid, golmerulonephritis
- hypoclompementaemia
Type 4 - D
- D-elayed hypersensitivy
- Th 1 attract and activate macrophages
- cell mediated and antibody independent
- GvH dx And BCG
- contact dermatitis/ PPD - TB skin test/ MS
Type 5 - E
- Ab that recognise cell surface or E-xternal receptors
- graVEs or MG
Staph epididermis
Most common organism for central line infection
Standard error of the mean
Standard deviation/square root of number of patients
Acute phase proteins
CRP Ferritin Complement Alpha - 1 antitrypsin Procalcitonin Serum amyloid A & P Caeruloplasmkn Haptoglobin
Alkaptonuria
Lack of enzyme homogentisic dioxygenase.
Get build up of homogentisic acid in urine
Blue sclera and black urine
Intervertebral disc calc —> back pain
Renal stones
Tx:
- high dose vitamin C
- diet: restrict phenylalanine and tyrosine
HIV immunology
Progressive HIV you se:
- reduced CD4
- reduced IL2
- increase B2-microglobulin
- polyclonal activation of B cells
- decrease Nkcells
- reduced delayed hypersensitivity rxn
Proto-oncogenes
Gain of function via:
- mutation
- translocation
- increased protein expressions
ABL - CML
c-MYC - burkitts lymphoma
n-MYC - neuroblastoma
BCL-2 - follicular lymphoma
RET - MEN 1 & 2
RAS - many cancers
Erb- B2 (HER2) - Brest and ovarian ca
Innate
Immune response
PRRs on phagocytic cells recognise PAMPs —> complement/chemokines/ cytokines —> phagocytosis —> release pathogenic peptides —> APCs
Complement pathway triggers
Classic - Anyibody activated
Alternative and leptin - polysaccharide component of cell wall.
Hereditary A-ngioedema
Think C-1 and letter -A-
Increase in classic pathway and kallikerin
Kallikerin —> bradykinin driven angioedena
Distinguish from anaphylaxis as
- NO URTICARIA
- NO HYPOTENSION
Cytokines
IL-1 - proinflamm of innate - seen in autoinflamm dx - periodic fever syndrome
Il-2 - T cell driven response - inhibition useful
In Transplant rejection - calcineurin inhib, ciclosporin, tacrolimus - s.e. HIV LIKE
Il-6 - proinflamm - ACUTE PHASE RESPONSE CRP - inhibition used in RA - therefore falsely reassuring low CRP
Il-10 - decreases cytokines and inhib HLA —> ANTINFLAMM
Il-17 —> TH17
TNF
- pro inflamm —> Tcell recruitment.
- prod by Mac
- s.e of TNF-I —> granuloma reactivation
IFN:
- proinflamm
- seen in VIRAL infection
- used to tx chronic viral Infection
- SE —> FLU LIKE SX
Adaptive immunity —> cellular and humoral response
Humoral:
- circulating B cells recognise circulating antibodies
- Initial IgM response —> memory cells which produce IgG
- re-exposure —> rapid specific IgG response
Cellular:
- some pathogens hide in cells
- therefore cells present intracellular material using HLA system (APCs)
- interact with Tcells
- this system recognised self vs non-self
Cryoglobulin
Ig that precipitate out at low temp
3 types:
Type1 - monoclonal IgM - Walldenstroms macroglobuniaemia —> hypervsicosity
Type 2 - mixed - chronic infection - Hep C
Type 3 - polyclonal - mixed CT dx
Cold agglutin
Different from
Cryoglobulin
A form of haemolytic anaemia
Seen in lymphoproliferative dx and mycoplasma pneumonia
Rituximab
Causes complement mediated lysis of CD20 express cells - B CELLS
Transplantation
Hyperacute:
- humoral
- Min’s —> hrs
- pre-existing ab bs donor HLA1
Acute:
- <6/12
- mismatched HLA / CMV
- reversible with IS
Chronic:
- > 6/12
- ab & cell mediated —> fibrosis
Neutrophil deficiency
Recurrent bacterial or fungal
Skin infection
Causes:
- primary - chronic granulmatous dx
- secondary -DB
B cell deficiency
Get spinopulmonary infection/bronchiectasis
Primary:
- common variable immunodeficiency
- IgA deficiency
- bruttons agammaglobulinaemia
- Wishkott Aldrich - eczema + Thrombocytopaenia
Secondary:
- CLL
- Rituximab
- Gold
- Phenytoin
T cell deficiency
results in HIV like syndromes —> PCP CMV SALMONELLA MYCOBACTER
Causes
Primary:
- di George
- SCID
- Ataxia telangectasia
SEcondary:
- HIV
- Ciclosporin / calcineurin inhib /
Tacrolimus
IL-1
Secreted by macrophages/monocytes
Causes T and B cell prolif
Layers of the epidermis
Come Lets Get Some Beers
Corneum Lucidum Granukosum Spinosum - swuamous cells Germinatavum - deepest - columnar cells. Produce keratinocytes and has melanocytes
Molecular biology techniquss
SNoW DRoP
S-outhern - detects D-NA
- N-othern - detexts - R-NA
- W- est - detects - P-rotein
Carcinomas and their cancers
Aflatoxin - liver - hepatocellular carcinoma
Aniline dyes - bladder - transitional cell carcinoma
Asbestos - mesothelioma and bronchial carcinona
Nitrosamines - oesophageal and gastric ca
Vinyl chloride - hepatic angiocarcinoma
Positive vs NFlegative skewed data
Positively skewed data = Nailed down and pullled to the right –> so the right had is longed out and lower
NEgatively = opposite
in normal distribution median and mean = the same.
In skewed data - Median still the same as this its the apex, but the mean is pulled into the tail.
- Neg skew - MEan Med
Muscle relaxants
Suxamethonium:
- Depolarising musc relaxant
- Inhibits Ach at NMJ
- Fastest onset and shortest duration of all musc relax - RSI
- PRod gen contraction –> Relaxation
- s.e.: HyperK+ / MAlignant hyperthermia and AcH lack.
Atracurium:
- Non-depolarising
- Duration 30-45 mins
- Histamine release –> Flushing, tachy, hypotensive
- Not BD by kidneys/liver (hydrolysis)
- Reversed by NEostigmine
VEcuronium:
- Non depolarision
- duration = 30-40 mins
- B.D> by kidney/liver –> therefore dysfn –> acccumulatuin
- Reversed by neostigmine
Pancuronium:
- Non-depolarising
- long duration 2 hours
- effects partially revered by nestigmine
pre and post test odds
pre-test probability = prevelance
Post-test probability = post test odds/ 1+post test odds
Pre test odds = pretest probability / 1 - pretest prob
Post test odds = pre-test odds x likelihood ratio
Most common gene disorder in down syndrome ?
NON-DYSJUNCTION
Significance tests
Parametric data (measureable and normally distrivuted)
- Students - paired or unpaired
- Pearsons - CORRELATION
non=paramterict - Chi-squared - PROPORTIONS AND PERCENTAGES or Fisheres exact (small sample size) ]- Mann -whitney - unpaired - Spearman-kendal rank - CORRELATION - Wilcoxon signed
PAired = data from single group unpaired = data from 2 diff groups
Adrenoreceptors
alpa-1
- activates phopholipase C –> IP3 –> DAG
- VC
- Relax Gastic SM
- salivary secretion
alpha - 2 :
- Inhibits pre-synaptic NT
- Inhibits adenyl cyclase
- Inhibit insulin secretion
- Platelet aggregation
Beta 1 =
- Stim Adenyl cyclase
- Heart –> +chronotrope +ionotrope
Beta 2
- Stim AC
- Bronchodilation
- vasodilation
- Relax gastric SM
Beta 3
- Stim AC
- Lipolysis
What is gthe power of a study
1 - probablity of a type 2 error
Types of error
Type 1: - null hypothesis is rejected when its true
(Type 1, what people doing study want)
Type 2 - accepting null hypothesis when it is false.
Post-test odds =
Pre test odds x +ve likelihood ration
positive likelihood ratio = sensitivity/(1 - spec)
Which cytokines involved in acute phase response
Tbf - alpha (a in acute phase)
Il-1 (1 for first phase)
Ik-6 (6 looks like upside down p)
How does variance relate to standard deviation
Standard deviation is the square root of the variance
Remember 95% of normally distributed data will. Like between 2 SD bellow and above the mean
Shock
Grade 1:
- losss of 15% of blood vol - 750 ml
- Not low BP
- MAY nbe tach
GRade 2:
- 15-30%
- BP normal
- Tachy
~GRade 3:
- 30-40
- Decreased UO
GRade 4:
- > 40%
- Anuria
What is degranulation - in respect to eosinophils?
degranulation is where mast cells/eosinophils/basophils, release their lysosomes.
intracellular lysosomes fuse with plasma membrane and release their contents –> extracelllular
This maks them useful vs larger organisms such as helminths and protozoa
Process of phagocytosis
chemotaxis –> ingestion –> intracellular enzymatic degradation –> exocytosis
What is the product of a codon?
Codon is 3 adjacent nucletodies –> code for Amino acid
Linear vs logistic regression
measures teh strength of a relationship between two variables.
y= a +b.X
X = input Y = ouput
if Y = continuus - linear (i.e. dose)
If Y = 2 x categories = logistic.
Fisher exact test and chi2 test
Both sinificance tests
Essentially the same, but Fishers is Exact P-value and Chi2 is approximate P value
therefore fishers is better if SMALL SAMPLES
Chi2 is ok in BIG SAMPLES
Number needed to treat
1/absolute risk reduction
DNA - investigations - FISH:
FISH:
- Microdeletion conditions - DiGEorge, Kallman, Williams
- DNA denatured, Fluorescent probe added which is complimentary to DNA sequence you want to identify.
- If that DNA is present –> binds and you detect signal
Metaphase FISH:
- Like above but cells need to be in GROWTH PHASE.
Interphase FISH:
- Cells dont need to be in growth phase
- USed in anueploid cells.
Incidence vs prevelance
Incidence - number of NEW cases
Prevelance - number of ALL Cases
Relative Risk
PRobability of event occuring in exposed / prob of event occuring in unexposed.
Types of Analysis
Intention to treat}:
- similar to clinical situation
- Includes ALL participants , incl. those who drop out
- good for compliance
Completer Analysis:
- Only those that complete trial
- Smaller smaple size and BIAS
Pre-protocol analysis :
- Even stricter than completer analysis
Severity analysis:
- look at how robust an assesment is by seeing if changing method –> Changes results.
Absolute risk reduction
ARR = Relative Risk x Placebo event rate.
relative risk = experemential event rate/control event rate
DNA investigations - Microarray analysis
Microarray analysis:
- Looks at transcription activity by converting RNA –> DNA:
- Compafres RNA
DNA investiations - PRotein Aanlysis
Protein analysis:
- Measures all protein in cell by Mass Spectometr.
- compare healthy and disease tissues.
DNA investigations - PCR
1) Primer + DNA Template + DNA polymerase
2) heat –> Single strand DNA
3) Coooled –> primers bind to template
4) HEat –> activated DNA polymerase –> amplification
Uses of PCR :
- Mutation detection
- detect bacteria/virus in tissues
- Single cell genetic test of in-vitro fertilised embyos
Reverse transcription PCR:
- ooks at only transcribed genes
1) Reverse transcriptase used 1st
2) mRNA –> DNA –> analysis as above
Monoclonal Antibodies
Grown by injecting rat spleen with Antigen –> collect and combine with myeloma –> incrase antibody
Humanisation of Mab:
- chimeric Antiboody = mouse variable region and Fc = human
- decreased chane of recognised as foreign, btu still small chance
Ligand gated ion channels
5 subunits 0 alpha-2/beta-2/gamma
binding to alpha –> conformational change
e. g:
- ACH-R/GABA/GLutamte/G;ycerione
Tyrosine Kinase
Susbtrated –> binds receptor –> activates TK–> dimerisation –> autophosphorhylation
Insuline/IGF-1/PDGF
GPCR
Couling of extracellular signal –> Second messenger.
3 subunits alpha/beta/gamma
in inactive state GDP is bound to alpha
Ligand binds –> GDP –> GTP –> alpha dissociates –> alpha-GTP or gamma –> activates 2nd messengers (Gi or Gs)
inactivation of alpha-GTP –> GTP –> GDP ( alpha-GTPase)
exampleS:
- MUSCARINIC Achr
- alpha + beta adrenergic-receptors
- Rhodopsin
Dx assoc:
- Cholera
- pit adenoma
- Mcune Albrights
- Aldbrights hereditary osteroedystrophhy
What fruit is associated with LAtex allergy
KIWI
Calculating Clearance
(U x V)/P
U = Urine concentration of drg (mg/ml) V = volume of urine in (ml/Min) P = plasma concentration (mg/Ml)
Cholera mechanism of action
GM-1 Agonism
Study design and levels of evidence
1a = meta-anaylsis of RCTs 1b = at least 1 RCT 2a = well designed controlled trial but not an RCT 2b = one well designed experiental trial 3 = case/comparative/correlation studies 4= panel of experts
Standard deviation and variance
Standard deviation = Square of the variance
Standard error = SD / square root of number in study
What are seen in biopsies of sarcoid granulomas
Asteroid bodies
Which HLA is seen in hyperacute rejection?
HLA-C
Interleukina
IL-1 - prod by MAc - acute inflamm + fever
Il-2 - TH1 –> Growth + Tcell differentiation
IL-3 - TH1 –> myeloif progenitor cells
IL-4 - TH2 –> B cells
IL-5 = TH2 –> Eosinphils
IL-6 - TH2 + Mac –> B cells + fever
IL8 - MAc –> Neutrophil chemotaxos
IL-10 + TH2 - inhibits TH1
IL-12 - dendritic/MAc/Bcells –> activates NK and TH1 prod
IFN-gamma - TH1 –> aMAcrophage
TNFa - MAc –> Feveer + neutrophil chemotaxis
Homocystinuria
Deficiency in cystathionine beta snthase
marfanoid
lens dislocation - downward
LEarning difficulty
Cyanide-nitroprusside test
Tx = pyridoxine
raised anion gap metabolic acidosis
C - CO/Cyanide/ CHFx
A =- Aminoglyclosides
T - Toluene/Tehoophylline
M- MEthanol U - Uraemia D- DKA/Starvation Keto/ Alcoholic ketoacidosis P - Paraceetamol/ I - Inborn error/ Iron/ Isoniazid L- lactic acidosis E- Ethanol/ Ethylene glycol S - Salicylates/ASA/Aspirin
Acute intermittent porphyria - drugs the precipitate attack
BArbituates alothane BZD EtOH OCP Suphonamides
Variance and 95% confidence interval
S.D. - Square root of variance
Stander error = SD / sq root of.n
95% CI limit is mean +/- 2x SE
