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Viva Flashcards

1
Q

List 4 methods for investigating macroprolactin.

A

PEG precipitation
LCMS
Size exclusion chromatography
Testing on a different platform

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2
Q

List tests apart from glucose that can be used in the investigation of adult hypoglycaemia.

A

Insulin
C-Peptide
Ketones
Cortisol
Lactate
EUC
pH(Blood gas)
IGF-1

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3
Q

List four causes of an artefactual high potassium.

A

EDTA contamination
High WCC/PLT
Delayed separation
Haemolysis
Cold temperatures

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4
Q

List 4 causes of a high anion gap

A

M- Methanol
U- Uremia
D - DKA
P - propylene glycol
I- Iron, inborn errors of metabolism
L - Lactic acidosis
E - Ethanol, Ethylene Glycol
S - Salicylates

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5
Q

List four possible causes of an isolated out-of-range EQA result.

A

incorrect sample preparation
Incorrect units
Sampling error
Dilution error
Transcription error

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6
Q

List 4 causes of a false positive overnight dexamethasone test.

A

Patients taking Estrogens
Acute physical or emotional stress
Pseudo-Cushings syndrome(alcohol, depresion, or obesity)

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7
Q

List 4 causes of a serum/plasma alkaline phosphatase elevation.

A

Liver (Cholestasis)
Bone (increased osteoblastic activity) Pagets, Bone Metastases (Prostate and Breast)
Regan isoenzyme (placental-type ALKP expressed in some tumours - gonadal and urologic

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8
Q

List 5 tests that require, or benefit from, patient fasting.

A

Iron studies (benefit)
Glucose
Lipids
Lactose tolerance
OGTT

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9
Q

What is RCV?

A

The “reference change value” (RCV) allows you to decide whether a change in two serial lab results is likely due to chance alone.

RCV (%) = 21/2* Z*(CVA2+CVI2)1/2
Z is 1.96 for two-sided approach (P < .05), coefficient of variation (CVA) is analytical imprecision, and CVI is within-subject BV.

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10
Q

List the properties of an ideal internal quality control material.

A

QC material should resemble patient sample.
QC material should be stable for prolonged periods without any interfering preservatives.
QC material should be free of communicable diseases
QC material should have a known concentration of the analytes.

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11
Q

List 4 causes of an elevated serum cholesterol.

A

Primary - Familial hypercholesterolaemia
Secondary - Biliary obstruction, hypothyroidism, nephrotic syndrome

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12
Q

List 4 methods for the measurement of glycated Hb.

A

Immunoassay
Boronate Affinity HPLC
Ion-Exchange HPLC
Enzymatic
Capillary Electrophoresis

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13
Q

List 4 causes of a solitary serum/plasma transaminase elevation.

A

AST - Muscular damage Skeletal or Cardiac
NAFLD
Alcohol-related liver disease

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14
Q

List 4 rules that can be used for assessment of internal quality control.

A
  • 1X2s = one control observation exceeding the mean +/- 2s - Warning
    • 1X3s = one control observation exceeding the mean +/- 3s - Action required Sensitive to random error
    • 2X2s = two consecutive control observations exceeding the same mean +2s or - 2s limit - Action required Sensitive to systemic error
    • R4s = one observation exceeding the mean by +2s and anther exceeding the mean -2s - Action required Sensitive to random error
    • 4X1s = Four consecutive observations exceeding the mean + 1s or the mean -1s - Warning - Sens to systemic error
      10x = 10 consecutive control observations falling on one side of the mean (above or below with no other requirement on the size of the deviations) - sensitive to systemic error
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15
Q

List 4 methods used for the measurement of urinary free cortisol.

A

LCMS
24hr urine Free cortisol Immunoassay
Spot urine free cortisol IA
HPLC

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16
Q

List 4 causes of troponin elevation other than acute coronary syndrome and cardiac
failure.

A

Heterophile/HAAA
Macrotroponin
Fibrin strands
Sepsis
PE
myocarditis
Cardiotoxic chemotherapy
Debfibilator shocks

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17
Q

List causes of hyponatraemia where the serum osmolality is normal

A

Pseudohyponatraemia - (Hyperlipidaemia & Hyperproteinaemia)

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18
Q

List causes of hyponatraemia where the serum osmolality is high

A

Hyperglycaemia (translocational [Na] + [glu] / 4 for effective Na+
Mannitol, Ethanol

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19
Q

List causes of hyponatraemia where the serum osmolality is low and volume status is low.

A

UNa+> 20 Renal loss, Addisons, Salt losing Nephritis, Cerebral salt wasting
UNa+<20 GIT loss, Sweat

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20
Q

List causes of hyponatraemia where the serum osmolality is low and volume status is High.

A

UNa+> 20 ARF,CRF
UNa+ <20 Nephrotic , Cirrhosis, CCF

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21
Q

List causes of hyponatraemia where the serum osmolality is low and volume status is Euvolaemic

A

UOsm >100 SIADH, Hypothyroid, Cortisol Def, SSRI - meds
UOsm<100 Severe polydypsia, Beer potomania, Excess IV fluids

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22
Q

List 4 causes of an elevated urate.

A

Gout
Pregnancy-induced hypertension
diuretics
fasting
hyperlactataemia
low dose salicylates

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23
Q

List 4 causes of a decreased urate.

A

low purine intake
SIADH
Hypouricaemia drugs (e.g allopurinol)
rare condition Xanthinuria

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24
Q

List 4 causes of raised total bilirubin.

A

Haemolysis
Megaloblastic anaemia
Gilberts Syndrome
Physiological jaundice in neonates

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25
Q

List causes for raised conjugated bilirubin.

A

Cholestasis
biliary Atresia
Dubin-Johnson Syndrome
Rotor Syndrome

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26
Q

What is the difference between Crigler-Najjar type 1 and 2 and Gilbert’s Syndrome?

A

Increased unconjugated Bilirubin.
Crigler-Najjar type 1 is a rare fatal Autosomal Recessive disorder with absent UGT1A1 activity.
Crigler-Najjar type 2 is Autosomal Dominant with reduced UGT1A1 activity - can only form monoglucoronidated bilirubin.
Gilbert’s is less pronounced than type 2 CN, is AR activity of UGT1A1 is
~ 30%

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27
Q

What is the difference between Dubin-Johnson and Rotor Syndrome?

A

Increased conjugated bilirubin.
Dubin-Johnson is AR, with a decrease in secretion of conjugated bilirubin., due to a missing transfer protein. The liver is darkly pigmented.
Rotor syndrome is AR, multiple defects in hepatocyte uptake and excretion of bilirubin. This has a normal looking liver.

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28
Q

List 4 causes of in vitro haemolysis.

A

Cold temperatures
fist pumping
small gaged needle with larger tube( Vacuume)
Syringe collect transfer with increased pressure.

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29
Q

List 4 biochemical analytes that change with dehydration.

A

Na
Creatinine & urea
EGFR
urine sp gravity
serum and urine osmolality

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30
Q

List 4 hormones that are increased by stress.

A

PL
Cortisol
Epinephrine
norepinephrone

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31
Q

What tests are useful in investigating PCOS?

A

LH/FSH ratio
Testosterone
FAI

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32
Q

What tests are useful in investigating hyperprolactinaemia?

A

PEG (MacroPL)
Stress
TFT (TRH stimulation)
Renal function (Decreased clearance)
IGF-1 (Association with GH secreting tumours)
Other pituitary hormones ACTH,LH,FSH (May be supressed in prolactinoma)
Testo/E2
Diuretics
Dopamine blockers (SSRI etc)

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33
Q

What tests are useful in investigating multiple myeloma?

A

Serum protein electrophoresis,
immunofixation, bone marrow aspiration.
increased globulin fraction of TP, rouleux on PBF

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34
Q

What tests are useful in diagnosing haemochromatosis?

A

Raised ferritin, raised transferrin saturation %, HFE gene mutations, C282Y, H63D & S65C

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35
Q

What are the 4 forms of homocystinuria?

A

All Autosomal Recessive
Cystathionine synthase deficiency
Decreased affinity of cystathionine synthase for pyridoxal phosphate
methionine synthase deficiency
MTHFR deficiency

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36
Q

What pathologies are associated with homocystinuria

A

Atherosclerosis
Kyphosis
Mental retardation

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37
Q

What is thiopurine methyltransferase?

A

a.k.a TPMT used to treat acute lymphoblastic leukemia, inflammatory bowel disease and autoimmune disorders, organ transplant recipients.

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38
Q

What is the faecal elastase test used for?

A

To differentiate malabsorptive/maldigestion due to pancreatic causes (exocrine insufficiency) from other causes, and/or to assess efficacy of treatment.

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39
Q

What are the key elements of a quality management system?

A

Quality policies
quality objectives
quality procedures
Training
Risk Management
Evidence-based decision making
Continuous improvement

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40
Q

List causes for hypokalaemia.

A

Decreased intake - Poor diet, Starvation
increased excretion - Mg2+ depletion - increases renal K+ loss
Mineralocorticoid excess - 1’ Aldosteronism, Cushing Syndrome, Renin producing tumour, Licorice excess.
Bartter Syndrome Thick Ascending LOH, Defect in Na-2K-Cl transporter (like loop diuretics- NaCl wasting, hypercalciuria and mild hypoMg2+ (LOOP DIURETICS LOSE CA)
Gitelmann syndrome - DCT, defect in Na-Cl co-transporter (like Thiazide diuretics), NaCl Wasting hypercalciuria and hypoMg (Thiazides PRESERVE Ca2+)
Liddle Syndrome - Collecting duct, continuous activation of ENaC leading to increased Na absorption, severe hypertension with low renin and aldosterone- Tx with ENaC blockers Amiloride, triamterene.
Transcellular shifts
Insulin/Glucose
Beta agonists
Alkalosis
Hypokalaemic period paralysis

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41
Q

List potential causes for hypertension

A

Primary hypertension (Essential hypertension) - atherosclerosis
Secondary hypertension -
Adrenal gland tumours - Conn’s(Low renin, high Aldosterone), Phaeochromacytosis (high norepinephrine, epinephrine, 3MT)
Renin secreting tumours (High renin, high aldosterone)
Liddle Syndrome - Low renin and Aldo.

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42
Q

List bone formation markers.

A

ALP - early marker
P1NP
Osteocalcin - late marker

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43
Q

List bone resorption markers.

A

CTX
NTX
DPD
PYD

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44
Q

How do you calculate specificity?

A

Specificity = FP/FP+TN.

number of people without disease testing negative

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45
Q

How do you calculate sensitivity?

A

Sensitivity = TP/TP+FN.

number of people with disease testing positive

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46
Q

How do you calculate PPV?

A

PPV = TP/TP+FP %

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47
Q

How do you calculate NPV?

A

NPV= TN/TN +FN %

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48
Q

How do you calculate LR+?

A

LR+ = Sensitivity/1-Specificity

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49
Q

How do you calculate LR-?

A

LR- = 1-Sensitivity/Specificity

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50
Q

List 4 causes of raised triglycerides.

A

Alcoholism
Hypothyroidism
Pancreatitis
Oral contraceptive
Corticosteroid medication

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51
Q

List 4 molecular forms of HCG.

A

hCG
Sulfated hCG
Hyperglycosylated hCG
free beta hCG
nicked hCG

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52
Q

List 4 assay procedures (include analyte and initial reaction only) which utilise
a peroxidase-based Trinder reaction in the method.

A

L-Lactate + O2&raquo_space;>LOD»> Pyruvate + H2O2
Total Cholesterol (CE) + H20&raquo_space;>Chol esterase» Cholesterol + FFA
B-D Glucose + O2 + H2O&raquo_space;> GO»> D-Gluconic acid + H2O2
Enz Creatinine - Creatinine + H2O&raquo_space;> Creatininase»> Creatine

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53
Q

What is the test C282Y used for?

A

Genetic test for HH

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54
Q

What is the test ΔF508 used for?

A

Most common mutation of the CFTR gene (Cystic Fibrosis)

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55
Q

What is the test HLA DQ2 DQ8 used for?

A

The two main celiac disease genes

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56
Q

What is the test KRAS used for?

A

KRAS, HRAS and NRAS are part of the RAS family of oncogenes. Important for apoptosis.

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57
Q

What tests are useful in diagnosing Cushing’s syndrome.

A

Late night cortisol
24hr urine free cortisol
1 mg overnight Dexamethasone Suppression test.

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58
Q

Differential diagnosis of chronic diarrhoea

A

infection - Bacterial, parasitic, viral
Endocrinopathies - Hyperthyroidism, diabetes
Maldigestive and malabsorptive disorders (Celiac, lactose intolerance, exocrine pancreatic insufficiency.
gut-brain interaction (IBS)
inflammatory conditions (Crohn’s, ulcerative colitis)
Medications (Laxatives)

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59
Q

What tests are useful when investigating Vitamin B12 deficiency

A

IF- antibodies
b12/Fol
Holotranscobalamin
Fe studies

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60
Q

What tests are useful when investigating hypercalcaemia

A

C,M,P, ALKP, EUC
PTH - reduced/Lower 1/2 RI- Check Vit D, PTHrP
- increased / upper 1/2 RI - Check CaE >32 PHPT <32 FHH

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61
Q

What further test would you order when TSH low and fT4/fT3 high?

A

TRaB - TSH receptor antibody associated with Graves Disease,
TSI - Thyroid stimulating autoantibodies

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62
Q

What further test would you order when TSH Low and fT4/fT3 normal?

A

Could be subclinical rpt TFT in 1-3 months

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63
Q

What further test would you order when TSH high and fT4/fT3 low?

A

primary hypothyroidism
Check anti - TPO

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64
Q

What further test would you order when TSH high and fT4 high?

A

rule out preanalytical factors, fibrin, heterophile Ab etc
possible TSHoma, Thyroid hormone resistance

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65
Q

CA125 is a tumour marker for?

A

CA 125 is a marker used for serous carcinoma, especially carcinoma of the ovary, but elevations are also seen in peritoneal disease of any cause.

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66
Q

CA 19.9 is a tumour marker for ?

A

CA 19.9 is a marker used for gastrointestinal malignancy, especially carcinoma of the pancreas.

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67
Q

CA 15.3 is a tumour marker for?

A

Breast malignancy

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68
Q

NEURON-SPECIFIC ENOLASE is a tumour marker for?

A

Monitoring progress of neural crest tumours including small cell carcinoma of lung

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69
Q

ALPHA-FETOPROTEIN is a tumour marker for?

A

Hepatocellular carcinoma
Germ cell tumour
Ovarian,
Testicular

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70
Q

What is a Bland-Altman plot used for?

A

Difference plot. Plots the difference between measurements against their average. the mean difference is the estimated bias, and the standard deviation of the differences measures the random fluctuations around the mean.
If there is a consistent bias, it can be adjusted for by subtracting the mean difference from the new method.

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71
Q

List 4 detection systems used in HPLC.

A

UV/VIS HPLC detector - e.g diode array
Electrochemical detector
Mass spec
Fluorescence

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72
Q

List 4 causes of an elevated serum prolactin.

A

MacroPL
Stress
Prolactinoma
Dopamine increasing medications (Antidepressants)

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73
Q

What is the formula for the calculation of Osmolarity?

A

Calc Osm = 2xNa + urea + glucose

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74
Q

What is the formula for the calculation of AG?

A

AG = (Na+ + K+) - (HCO3 + Cl-)

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75
Q

List 4 causes of a high anion gap metabolic acidosis

A

Methanol, Ethanol, ureamia,
DKA, iron, lactate

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76
Q

List two mediums used for serum electrophoresis.

A

Agarose
Polyacrylamide

77
Q

List two stains used in
serum protein electrophoresis.

A

Amido black
Coomassie Brillant blue
Ponceau S

78
Q

List 4 causes of hypoglycaemia in an adult.

A

Preanalytical - Delayed testing PST
Prolonged fasting
Insulinoma
alcohol, timing or taking too much diabetes medications

79
Q

List 4 analytes that might be affected by the “high dose hook effect” in clinical
practice

A

uALb
Urine protein
any immunochromogenic test Quant hCG
Serum free light chains

80
Q

List 4 causes of a raised CK

A

Preanalytical- Adenylate Kinase cross reactivity - haemolysis
Macro-CK
Rhabdomyolysis
ACS

81
Q

List 4 causes of hypoalbuminaemia.

A

Preanalytical- IV dilution
Pregnancy
Inflammatory process
Liver disease
Malnutrition

82
Q

how is Serum or plasma bilirubin measured?

A

Diazo methods
diazotised sulfanilic acid + bilirubin&raquo_space;> Colour complex
with accelerator = Total bilirubin (Indirect)
without accelerator = conjugated (direct) pH~1
Enzymatic - bilirubin oxidase to convert bilirubin to biliverdin. measuring a fall in absorbance

83
Q

what testing is performed for suspected Carcinoid syndrome?

A

5HIAA, 5-HT platelets (Serotonin)

84
Q

List 3 tests that help explain the hypercalcaemia in a patient with a
malignancy

A

PTH
PTHrP
24hr urine Calcium - CaE

85
Q

List 4 procedures used to detect heterophilic antibody interference.

A

Serial dilution - non linear response
HBT - eg SCANTIBODIES
Testing on different platform
PEG

86
Q

What condition(s) are being investigated when calcitonin is requested?

A

Medullary carcinoma of the thyroid, MEN 2 investigation.
Dynamic test - Pentagastrin stimulation test (increased stimulation with Med Thyroid Cx)

87
Q

What condition(s) are being investigated when pyruvate is requested?

A

For Lactate/Pyruvate ratio
> L:P indicates 1’ lactic acidosis.
Normal L:P ratio indicates 1’ pyruvic acidosis( e.g pyruvate dehydrogenase deficiency)

88
Q

What condition(s) are being investigated when holo-transcobalamin is requested?

A

B12 deficiency

89
Q

What condition(s) are being investigated when Human epididymis protein 4 is requested?

A

Tumour marker for ovarian cancer.

90
Q

What is a Youden plot?

A

aka box plot, typically used as part of EQA evaluation. Scatterplots of 2 EQA results with elliptical confidence areas around them. Used to compare all labs, Method specific, Platform specific, Manufacturing specific. Results in top right show pos bias, bottom left shows negative bias. Top left and bottom right imprecision although arbitrary with only 2 results.

91
Q

What are the main differences between type 1 and type diabetes mellitus ?

A
  • Type 1 * Type 2
    earlier onset usually later onset (>30 y.o.)
    80% under the age of 10 linked to obesity
    unknown trigger family history
    associated with autoantibodies progressive
    associated with other autoimmune disease often asymptomatic
    symptomatic on presentation * insulin resistant
  • insulin deficiency – higher insulin needed to maintain
    normoglycaemia
  • Autoantibodies * Autoantibodies
    • Ab positive in only 85-90% - 5-10% Caucasian adults with T2DM
      have Ab
  • Negative Ab seen in African or Asian - Usually positive Anti-GAD65
  • Positive multiple Ab associated with >95% risk of T1DM
92
Q

List Diabetes Autoantibodies.

A
  • Islet cell autoantibodies (ICA) - Ab to islet cell-cytoplasm
  • Anti-GAD - Ab to 65 kDa isoform of glutamic acid decarboxylase
  • IAA or IA-2 or IA-2A antibodies - Ab to two tyrosine phosphatase-like islet antigens
  • Insulin autoantibodies - previous exposure to insulin therapy
93
Q

List different types of diabetes?

A

Diabetes mellitus 1 & 2
Neonatal diabetes mellitus - genetic defects of the beta cells
Latent Autoimmune Diabetes in Adults - After 30 years of age; “type 1 diabetes in old people” Requires insulin or presents with acute keto-acidosis.
Mature onset Diabetes in the young - Genetic mutations e.g Glucose Kinase
Gestational Diabetes
Diabetes Insipidus

94
Q

Describe the main differences between DKA and HONK (Hyperosmolar Non Ketotic Coma).

A
  • DKA * HONK
    ▪ Type 1 ▪ Type 2
    ▪ Ketones elevated ▪ Ketones not elevated
    ▪ Can be very acidotic ▪ Not very acidotic (pH>7.3)
    ▪ Tend to have severe vomiting and abdo pain ▪ Tend not to have abdo pain or
    vomiting
    ▪ BSL 14-33 mmol/L ▪ BSL often >33 mmol/L
95
Q

List 4 causes for a raised parathyroid hormone (PTH).

A

Primary Hyperthyroidism
Secondary Hyperthyroidism (Renal)
Severe calcium deficiency
Severe vitamin D deficiency

96
Q

List 4 drugs that can cause a positive opiate immunoassay screen.

A

Rifampin
Poppy seeds
Heroin
Morphine

97
Q

List causes of Hypoglycaemia in a (non-diabetic) adult.

A

Preanalytical- delayed testing PST
Prolonged fasting
Insulinoma
Exogenous insulin , Alcohol,

98
Q

Further investigation of raised plasma ammonia

A

Preanalytical - ictereus , haemolysis
High protein diet
Urea cycle defects - genetics defects affecting any of the 6 enzymes or 2 transporters that are directly involved in the urea cycle. Most AR (carbamoylphosphate synthetase 1, mitochondrial ornithine transporter, argininosuccinate lyase, arginase 1, N-acetylglutamate synthase, glutamate dehydrogenase, glutaminase)except most common cause X-linked OTC deficiency.
Valporate therapy

99
Q

What is the test for procalcitonin used for?

A

Diagnosis of bacterial sepsis
Monitoring the progression of sepsis and its response to treatment.
can also be raised post surgery, trauma.

100
Q

How do you calculate creatinine clearance from 24 urine?

A

Creatinine clearance (mL/Min) = (urine creatinine (mmol/L) X urine volume (mL) X 16.7/ plasma creatinine mmol/L x 24 (hours)

Normal > 70 mL/Min in young adult

101
Q

List 4 analytes that change in iron deficiency (include the direction of the
changes).

A

MCV decreases
Hb decreases
HCT decreases
Ferritin decreases (except for in ACD)
transferrin Saturation % decreases

102
Q

List 4 dietary components that should be restricted when preparing to collect
a 24 hour urine for 5-HIAA.

A

5-Hydroxyindoleactic acid (5- HIAA)
Acidified 24 hour urine
Restriction of Bananas, Avocados, Pineapples, chocolate

103
Q

what condition is being screened for when testing for acetylcholine receptor antibodies?

A

Myasthenia gravis - a chronic autoimmune, neuromuscular disease that causes weakness in the skeletal muscles (the muscles that connect to your bones and contract to allow body movement in the arms and legs, and allow for breathing).

104
Q

What are deamidated gliadin antibodies used to test for?

A

Gliadin is one of the main proteins in gluten. The test is used to help find out whether you have celiac disease.

105
Q

what is CYP2D6 used to test for?

A

CYP2D6 is a gene that encodes the cytochrome P450 family 2 subfamily D member 6 (CYP2D6) protein. This protein belongs to the cytochrome P450 superfamily of enzymes, which are involved in the metabolism of various drugs and synthesis of cholesterol, steroids, and other lipids. CYP2D6 is primarily expressed in the liver and plays a crucial role in metabolizing approximately 25% of commonly prescribed drugs.

106
Q

What is UGT1A1 used to test for?

A

UGT1A1 encodes for the uridine diphosphate glucuronosyltransferase (UGT) 1A1 enzyme

107
Q

List drugs that can cause a positive amphetamine type substance
immunoassay screen.

A

Dexamphetamines
Pseudoephedrine
Methamphetamines

108
Q

List 8 changes to biochemical analytes that occur in pregnancy (include the
direction of the changes).

A

increased RCC
Increased Plamsa volume
Mild fasting hypoglycaemia
Prolonged post prandial hyperglycaemia
Greater suppression of glucagon
Peripheral insulin resitance
increased FAA, TG and Cholesterol
decreased Amino acids and insulin
decreased iron
decreased Hb and HCT

109
Q

List 4 causes for a low plasma cholinesterase activity.

A

poisoning with organophosphate insecticide.
Genetic - enzyme deficiency (important to know before administering succinylcholine containing anesthesia)
Liver disease
CHF

110
Q

Why do we perform Newborn Screening?

A

Population screening program for inherited (genetic) diseases.

Pre-symptomatic detection and treatment of metabolic genetic disease.
Guthrie card bloodspot at 48-72h of age.
Mass Spectrometry
Amino acid panel : Phenyalanine, tyrosine, methionine, Citruline
Acylcarnitine panel: 21 compounds of FA oxidation and organic acid abnormalities.
Other tests Congenital hypothyroidism, CF, galactosaemia.

Repeat testing of borderline results, recall for confirmatory testing.

111
Q

What causes PKU?

A

Defect in the gene responsible for Phenylalanine hydroxylase or Pterin cofactor defect. Leading to decreased conversion of Phenylalanine to tyrosine.

112
Q

What is Citrulinemia?

A

Citrullinemia is an inherited urea cycle disorder that causes increased ammonia.
Type I citrullinemia (Classic, ASS1 gene) Argininosuccinate synthase 1 deficiency.
Type II citrullinemia, mutations in the SLC25A13 gene. Encodes for transport protein Citrin.

113
Q

What is Argininosuccinic Aciduria caused by?

A

Argininosuccinic aciduria is a rare genetic disorder characterized by deficiency or lack of the enzyme argininosuccinate lyase (ASL)

114
Q

What is methylmalonic acidemia?

A

The methylmalonic acidemias are organic acidemias caused by an enzymatic defect in the metabolism of four amino acids (methionine, threonine, isoleucine and valine).
The disorder may be caused by a deficiency of one or more of the enzymes methylmalonyl CoA mutase, methylmalonyl racemase, or adenosylcobalamin synthetic enzymes.

115
Q

What is Galactosemia?

A

Galactosemia is a disorder that affects how the body processes a simple sugar called galactose.
Classic galactosemia, also known as type I, is the most common and most severe form of the condition. If infants with classic galactosemia are not treated promptly with a low-galactose diet, life-threatening complications appear within a few days after birth.
Galactosemia type II (also called galactokinase deficiency)
type III (also called galactose epimerase deficiency)

116
Q

What is Maple syrup urine disease ?

A

Maple syrup urine disease (MSUD) is a rare inherited disease that causes the urine to have a characteristic maple syrup smell. Without treatment, it can lead to potentially life threatening complications.
Decreased or decreased efficiency of human branched-chain alpha-ketoacid dehydrogenase complex (BCKAD) enzymes, meaning the body cannot breakdown isoleucine, Leucine and valine a.a .

117
Q

What is MCAD?

A

Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is one of the most common fatty acid ß-oxidation disorders. It is an autosomal recessive disorder that has a good prognosis if management is started early. If not managed correctly, a metabolic crisis may result.

118
Q

What is Cystic fibrosis?

A

CF is an AR disorder caused by changes to CFTR gene.
CFTR is a channel that sits on the surface of cells and transports chloride and other molecules, such as bicarbonate. The abnormal electrolyte transport system in CF causes the cells in the respiratory system to absorb too much sodium and water, leading to thick secretions in the lungs and increased risk for frequent respiratory infections.

119
Q

What are the MEN subtypes?

A

MEN 1
Pancreas/GI endocrine pituitary (Parathyroid)
Hyperparathyroidism
Hypercalcemia
Possible ZE syndrome
Various Pit path-Acromegaly, Cushing, Galctorrhea

Men 2a (RET mut)
Phaeochromocytoma
Medullary thyroid Cx
Parathyroid
Hyperparathyroidism
hypercalemia
medullary carcinoma
increased calcitonin
increased catecholamines

Men2b (RET mut)
Mucosal neuromas
Mucosal nodules
marfanoid body habitus (long limbs, chest deformities)
medullary carcinoma
Increased calcitonin
Increased catecholamines

120
Q

What is electrophoresis?

A

A separation technique in which charged particles migrate under the influence of an electric field. An electric field is applied to a solution through opposite charged electrodes. The particles migrate toward the electrode of the opposite charge. Mobility of the particles based on particle charge, shape and size). These are effected by -pH of buffer
-Pore size of support
medium
-Voltage applied
- Conductivity (ions present
to carry the charge)
- Time

121
Q

What are the components of each band in Protein electrophoresis?

A

SPE separates proteins into multiple band using an electric field and agarose gel. The fractions are separated by charge and size.
Its used to distinguish between hyperglobulinemia caused by innate or acquired immune response (acute phase reaction or polyclonal gammopathy) and hyperglobulinemia caused by neoplastic proliferation (monoclonal gammopathy)

Albumin is the most abundant followed by 5 globulin bands.

Alpha 1 - Alpha-1-antitrypsin, thyroid-binding globulin, and transcortin.

Alpha2 - Ceruloplasmin, alpha2-macroglobulin, and haptoglobin

Beta1- transferrin

Beta2- beta-lipoprotein, complement proteins

Gamma- IgA, IgM, and IgG,

122
Q

When might a SEP be performed?

A

High Globulin fraction in LFTs, Rouleux formation on PBF.
Suspected multiple myeloma, Waldenström’s macroglobulinemia, primary amyloidosis.

123
Q

What would you see on a SEP of a patient with Waldenstroms macroglobulinemia?

A

IgM M protein present

Affected patients have hyperviscosity and hypercellular bone marrow with extensive infiltration by lymphoplasma cells.

124
Q

What would you see on a SEP of a patient with Heavy chain disease?

A

The M protein has an incomplete heavy chain and no light chain, after immunofixation.

125
Q

What would you see on a SEP of a patient with MM?

A

M protein appears as a narrow spike in the gamma, beta, or alpha2 regions.

M-protein level is usually greater than 3 g per dL.
S
keletal lesions (e.g., lytic lesions, diffuse osteopenia, vertebral compression fractures) are present in 80 percent of patients.

Diagnosis requires 10 to 15 percent plasma cell involvement on bone marrow biopsy.

Anemia, pancytopenia, hypercalcemia, and renal disease may be present.

126
Q

Describe how immunofixation is done.

A

Patient’s serum diluted in alkaline buffer is placed into five separate wells within agarose gel plus one normal control, which is placed in an electrophoretic chamber, and a standardized voltage is applied to allow separation of the major protein groups by electrophoresis.

The result is five identical tracks of separated proteins. the first track is the normal control (reference tract) is treated with a protein fixative.
The remaining tracks are treated with specific heavy chain and light chain antisera that react with specific immunoglobulins in the separated protein tracks, causing them to be immunofixed in the agarose. All proteins not reactive with the antisera in the five treated tracks are removed in a wash step, followed by staining. After a second wash, fixed protein bands can be observed and compared with the bands found in the reference track, in order to identify the type of immunoglobulin by its heavy chain and light chain.

  • To identify and further characterise abnormal protein bands
  • Fixative and antisera are applied directly on the surface of the gel
     ELP track
     Anti-IgG
     Anti-IgA
     Anti-IgM
     Anti-kappa
     Anti- lambda
  • Staining with acid violet
  • More sensitive that electrophoresis alone
127
Q

What is IEF?

A
  • Isoelectric focussing electrophoresis separates amphoteric (charged) compounds in a medium possessing a stable pH gradient
    o pH gradient is created with carrier ampholytes
  • The protein becomes “focussed” at a point on the gel as it migrates to a zone where the pH of the gel matches the protein’s isoelectric point (pI)
  • At this point the charge of the protein becomes zero, and migration ceases
  • Protein zones are very sharp because the region associated with a given pH is very narrow
  • IEF is widely used in neonatal screening programs to test for variant haemoglobins
    o Sensitive and widely used at low costs
    o Separates Hb according to isoelectric point  migrate in a pH gradient to the point where net charge become zero
  • Also used to detect oligoclonal bands in gamma-globulin
128
Q

Describe the process of identification and quantitation of Bence Jones proteins.

A

Quantification of Bence Jones proteins (monoclonal free kappa or lambda light chains in urine) is through urine protein electrophoresis. Identification is by immunofixation.
Urine protein electrophoresis by Sebia Hydrasys gel electrophoresis:
1. Urine is concentrated by centrifugation in a concentrator tube (Amicon Ultra-4 centrifugal filter)
2. Urine is pipetted (using Sebia Assist, not manually) onto an applicator comb
3. Applicator comb is applied to the Hydragel agarose gel containing alkaline tris-barbital buffer and an electric current run through the gel to separate the proteins (migration time 7 minutes, drying time 10 minutes)
4. The agarose gel is then stained with amido black (18 minutes), washed and destained
5. Electrophoretograms are interpreted visually for pattern abnormalities
6. Densitometry (Sebia Assist “scanner”) is used to provide quantification of individual zones/bands in g/L (perpendicular cut).

129
Q

What is an ampholyte?

A
  • An ampholyte is a water soluble molecule that can perform as either a basic or acidic molecule depending on the pH of the buffer it is in
    o Eg amino acids
    o COOH  COO-
    o NH2 NH3+
  • It becomes positively charged in a solution that is more acidic than its isoelectric point (pI) and migrates to cathode
    o if pH < pI the ampholyte carries a positive net charge (the larger the difference the larger the amount of positive charge)
  • In a more alkaline solution it becomes negatively charged and migrates towards anode
    o if pH > pI the ampholyte carries a negative net charge (the larger the difference the larger the amount of negative charge)
  • If pH = pI the net charge will be 0
  • Proteins contain many ionisable amino (-NH2) and carboxyl (-COOH) groups
    o Behave as ampholytes in solution
  • Nucleic acid bases may be positively or negatively charged
    o Behave as ampholytes in solution
  • Ampholytes under action of an electric field (electrophoresis) will move at different speeds and in different directions
    o Therefore electrophoresis can allow the separation of electrical charged species
130
Q

What factors affect the separation of molecules by electrophoresis?

A

The rate at which molecules move in an electric field is determined by molecular size, shape and charge, as well as factors of the electrophoretic system.
Electrophoretic system

  • Strength of the electric field (V)
  • Temperature of the system
  • Buffer (pH of the buffer, Concentration of the buffer)
  • Support medium (Pore size of the gel, concentration of the gel)
  • Time
131
Q

What are Western, Southern and Northern blots?

A

Western blot (protein immunoblot)
* is a transfer technique used to detect specific proteins/ Abs
* Type of immunoblot

Southern blot
* classic method for DNA analysis
- DNA is extracted from a sample using a phenolic reagent and then enzymatically digested using restriction endonucleases to produce DNA fragments
- These fragments are then separated by agarose gel electrophoresis
- The separated DNA fragments are denatured and transferred to a solid support medium – most commonly, nitrocellulose or a charged nylon membrane. The transfer occurs by the capillary action of a salt solution, transferring DNA to the membrane, or using an electric current to transfer the DNA
- When the DNA is on the membrane, a labelled probe is added that binds to the complementary base sequence and appears as a band.

  • Northern blot – technique for detection of RNA molecules or species with defined sequences.
  • similar to southern blot. RNA is extracted, digested, electrophoresed, blotted and finally probed
132
Q

Discuss the principles of separation and identification of substances by electrophoresis in the clinical laboratory.

A

Electrophoresis is a method of separating proteins based on their physical properties. Serum or concentrated urine is placed in sample wells on an agarose gel, and a charge is applied. The net charge and the size and shape of the protein determine the ‘zone’ the protein migrates to. The gel is stained, and the protein densities are calculated electronically, using protein and albumin concentrations obtained by routine automation chemistry methods. Protein subtypes can be determined by using immunoglobulin anti-sera , causing a precipitation reaction, known as immunofixation.
Protein Electrophoresis is most commonly used for identifying and monitoring monoclonal gammopathies. Monoclonal gammopathies are associated with a clonal process that is malignant or potentially malignant, e.g multiple myeloma, Waldenstrom’s macroglobulinemia, monoclonal gammopathy of undetermined significance MGUS, plasma cell leukaemia, and amyloidosis.

If the examination is normal but multiple myeloma, Waldenström’s macroglobulinemia, primary amyloidosis, or a related disorder is still suspected, the more sensitive serum free light chains (Nephelometry) and immunofixation also should be performed.
An M protein is characterized by the presence of a sharp, well-defined band with a single heavy chain and a similar band with a kappa or lambda light chain. Once a monoclonal gammopathy is identified by SPE, the subtype must be determined, usually by immunofixation.

For diagnosis, the quantity of the M-protein is important, the % of plasma cells in the BM and presents/absence of CRAB symptoms.
C: Calcium elevation (>2.75mmol/L)
R: Renal dysfunction (creatinine >173umol/L)
A: Anaemia (Hb <100g/L)
B: Bone disease (lytic lesions or osteoporosis)

133
Q

What is Fagans nonogram?

A

A graphical tool for estimating how much the result on a diagnostic test changes the probability that a patient has a disease.

Contains pre-test probability, Likelihood ratio and post-test probability

134
Q

RCV formulae

A

RCV=2.77 x(CVa2 + CVi2)1/2

135
Q

What does p-value express?

A

The level of statistical significance. The smaller the p-value the better (usually <0.05)

136
Q

What are the key differences between parametric and nonparametric tests?

A

A parametric test assumes that the data is normally distributed. Non-parametric does not require this assumption.
Parametric is more powerful, can detect smaller differences between groups but can be sensitive to outliers.
e.g T-test, regression analysis, pearson correlation coefficient.
Nonparametric (Aka distribution free statistics) is more flexible e.g Chi-squared test, Wilcoxon signed rank test.

137
Q

List redistribution causes for hyperK+

A

Tissue damage- Burns, Trauma, Rhabdo, tumour(necrosis/cytotoxics)

Hypoinsulinaemia
Digitalis
HyperK+ periodic paralysis
Succinyl choline
hyperosmolality
Arginine
Acidosis

138
Q

List renal causes for hyperK+

A

ARF
CRF
K sparing diuretics
Addisons
Tubular decrease response to Mineralcorticoids

CAH - 21OHlase deficiency
11BOHlase deficiency
1’ K transport defect- eg sickle cell anaemia

139
Q

Further tests to investigate HyperK+

A

Urine K+ increased - Renal ARF, CRF
Urine K+ decreased - decreased mineralcorticoids, K sparing diuretics

140
Q

Causes of elevated Ca2+?

A

Malignancies - solid, haematological - skeletal involvement, ectopic PTH
Primary hyperparathyroidism - Adenoma, hyperplasia, malignancy. MEN1 (Pit & pancr tumour) MEN2(Phaeo & med.Thy)
Vitamin D excess or Vit A.
post renal failure/dialysis.
dehydration/tourniquet (increased albumin)
Thiazide diuretics
immobilisation
Lithium
Sarcoidosis

141
Q

Causes of HypoCa2+.

A

Hypoalbuminemia - malnutrition, cirrhosis, nephrotic syndrome
Renal failure - skeletal resistance to PTH
Post parathyroidectomy/thyroidectomy
TPN (reduced intake)
Acute pancreatitis
Mg deficiency - decreased released/response to PTH

142
Q

Causes of hyperphosphataemia?

A

Delayed sep/Haemolysis
Renal failure
Malignant - hypercalcaemia
insulin deficiency
chemotherapy - Tumour lysis
Vit D toxicity

143
Q

Causes of Hypophosphatemia?

A

nutritional recovery
respiratory alkalosis
d.K.A treated
alcoholism
antacid therapy
hypothyroidism
thiazide diuretics
rickets/osteomalcia
genetic

144
Q

Causes of Metabolic alkalosis

A

Loss of acid
-vomiting
-Diuretic therapy
-mineralcorticoid excess
-hypokalaemia
-Cong Cl- losing diarrhoea
Excess HCO3
-NaHO3 infusion
-Milk-Alkali syn
-Lactate infusion
-Citrate

post hypercapnia

Decreased AG
-Dilution
-Hypoalbumineamia
underestimation of [Na] - hyperNa, hyperviscosity
overestimation of Chloride- bromide

retained nonNa+ cations.
-paraproteinaemia
-hypercalcaemia
-hypermag
-Li

145
Q

Causes of a NAGMA?

A

early uraemic acidosis
obstructive uropathy
carbonic anhydrase therapy
mineral corticoid deficiency
RTA

146
Q

List causes of resp acidosis

A

Central depression
- Drug overdose (narcotics)
CNS trauma, tumour, degenerative disorders
-CNS infection
-central hypoventilation

Primary pulmonary
-Chronic obstructive lung dx
- Acute severe asthma
-Severe pulmonary infections
-ARDS
Neurological dx affecting respiratory muscles.

147
Q

List causes of Respiratory Alkalosis

A

Central
-Anxiety
-hypoxaemia
-GN septicaemia
-Salicylate
-intoxication
-pregnancy

Pulmonary
- pneumonia
- Asthma
- PE
-early interstial lung dx
- Congestive heart failure

148
Q

List causes of a mixed respiratory acidosis and metabolic acidosis

A

Cardiopulmonary arrest
severe pulmonary oedema
Drug OD with central respiratory depression

149
Q

List causes of a respiratory alkalosis with metabolic alkalosis

A

hepatic failure and diuretics
mechanical ventilation and nasogastric suction

150
Q

List causes of respiratory alkalosis with metabolic acidosis

A

septic shock
renal failure with sepsis
Salicylate toxicity

151
Q

List causes of respiratory acidosis with metabolic alkalosis

A

chronic obstructive lung disorder with diuretics

152
Q

List causes of metabolic acidosis with metabolic alkalosis

A

Renal failure with vomiting
Vomiting with hypotension. (lactic acidosis)

153
Q

List causes of cholestasis

A

Extra hepatic
Cholelithiasis
Tumour - Pancreatic
Biliary structure
Biliary atresia

154
Q

How would you differentiate between RTAs?

A

Type 1 Distal - can’t excrete H+, Urine pH >5.5, <15 HCO3 to compensate. assoc with renal stones.
Type 2 proximal - impaired HCO3 reabsorption - can excrete H+ urine pH <5.5 to compensate. higher HCO3.
Type 4 - impaired Cation exchange in distal tubule - high K+, HCO3 >15

155
Q

Name cause of type 1 RTA

A

Type 1 Distal (Classic)
autoimmune (Sjogrens, SLe, thyroiditis)
nephrocalcinosis (Primary hyperparathyroidism, Vit D intox)
nephrotoxins(amphotericin B, Toluene inhalation)
Obstructive nephropathy

156
Q

Name causes of type 2 RTA.

A

Proximal
hereditary
part of Fanconi syndrome(proximal tubular defects with impaired reabsorption of glucose, phosphate and amino acids as well as HCO3)
vit D deficiency
Cystinosis
lead nephropathy

157
Q

Name causes of type 1V RTA

A

Tubular hyperK+ (defect in cation-exchange in the distal tubule with reduced secretion of both H+ and K+)

associated with renal failure caused by disorders affecting the renal interstiitium
Aldo def
Aldo resistance - Drugs - NSAIDS, ACE inhibitors, ARBs, sprironolactone

158
Q

Name secondary causes of hyperlipidaemia

A

Diabetes/Metabolic syndrome
Hypothyroidism
High fat diet
Nephrotic syndrome
Cholestasis
Glucocorticoids
Acute pancreatitis

159
Q

Name Primary causes of hyperlipidaemia

A

Familial Hypercholesterolemia - LDL-R, APO-B, PCSK9 - gain of function
Polygenic hypercholesterolemia
Autosomal recessive hypercholesterolemia
Familial dysbetalipoproteinaemia
Famial combined hyperlipidemia

160
Q

Name 4 causes of an elevated TP

A

Prolonged venous stasis
Dehydration
Hypergammaglobulinaemia
- Polyclonal - liver cirrhosis, Chronic infections, Autoimmune
- Monoclonal - Multiple myleloma, Waldenstroms, macroglobulinaema

161
Q

Name 4 causes of a low TP

A

Drip contamination
Overhydration - IV
Protein synthesis reduced
- Decreased intake-
malnutrition
malabsorption
liver dx

Protein Loss
- haemorrage
- Burns
-Nephrotic syndrome
-Protein losing enteropathy

162
Q

What is an Exudate ?

A

Fluid that leaks out of the blood vessels into nearby tissues due to inflammation or local cellular damage.

163
Q

What is a Transudate?

A

Fluid that leaves the vascular system due to changes in hydrostatic pressure eg. Cirrhosis , heart failure, Nephrotic syndrome (there is no inflammation of the vessels so proteins don’t move out)

164
Q

Name causes of an increased GGT

A

Intra or post hepatic biliary obstruction.
Cholastasis
Hepatic cX
Alcohol intake
Acute or chronic pancreatitis

165
Q

Name causes of a low GGT

A

Chronic renal failure
hypothyroidism
hypothalamic disorders

166
Q

What is Ehrlich’s reagent used for?

A

Ehrlich’s aldehyde test is used to confirm diagnosis of acute intermittent porphyria. Urinary porphobilinogen test.

Sulfonamides may produce a false-pos
degradation to urobilin may give false-neg

also used as indole test in micro

167
Q

What is DeRitis ratio?

A

AST/ALT ratio used as a marker of alcohol-related liver disease, liver fibrosis and muscle disease

168
Q

What is Passing-Bablok used for?

A

Linear regression procedure - uses non-parametric technique for method comparison.
y = mx + C
where m = slope C= y-intercept
r2= value ideally close to 1.00

169
Q

What is orotic acid used to test for?

A

Differential diagnosis of hyperammonemia and hereditary orotic aciduria. The allopurinol test can be used to determine whether a female is heterzygous for x-linked OTC deficiency. When OTC deficient patient has been id in family. (cannot have urate lowering medication)

170
Q

Describe finding in Wilson’s disease.

A

Low ceruloplasmin (< 0.2-0.4 g/L)
High 24 hour urinary copper excretion (>1.0 umol/day)

Sternlieb criteria
- Kayser-Fleischer rings
- typical neurological symptoms - slurred speech, parkinsonism
- low ceruloplasmin

Gold std is liver biopsy copper of > 250ug/g of dry weight (RI <50 ug/g)

171
Q

What is the gold std for measuring GFR?

A

Inulin clearance

172
Q

What is the principle behind urinary dipstick glucose?

A

Uses glucose oxidase method.

b-D-Glucose + O2 + H2O»GO»> D-gluconic acid + H2O2
H2O2 + Chromogen&raquo_space; Peroxidase»> red dye

GO is sensitive to Vit C interference, haemoglobin, bilirubin

173
Q

What Ketones does a urinary dipstick test for?

A

Uses Nitroprusside to detect acetoacetate and acetone, but not B-hydroxybutarate.

174
Q

What 3 basic principles increase risk of nephrolithiasis?

A

Decreased urinary solvent (dehydration)
Decreased stone inhibitors
-decreased urine citrate
- pH changes
Increased solutes
- Increased Ca(urine) - increased PTH, PTHrP
- Decreased Ca reabsorption - Loop diuretic,
- Increased oxalate(urine)

175
Q

List different renal stone compositions with causes.

A

Calcium Oxalate - low citrate - type II RTA, PHP, PTHrP, loop diuretics
Calcium Phosphate - high pH - type I RTA, PHP, PTHrP, loop diuretics
Struvite stones (staghorn) - Mg, Phos, Ammonia - precipitation - High pH - bacteria (urease enzyme - Proteus, Pseudomonas, Klebsiella - increase ammonia)
Cystine stones - low pH - chronic diarrhoea, type I RTA, Genetic dx (child) decreased reabsorption of cystine
Uric acid - low pH, type II RTA, loss of GI HCO3, Gout, tumour lysis, Diabetes M, high purine diet

176
Q

List causes of a raised ALP

A
  • 3rd trimester pregnancy
  • Children growth spurts
  • increased bone metabolism - fracture healing, 1’ & 2’ hyperparathyroidism with sketal involvement
  • osteomalcia/rickets
    Bone disease- Pagets, bone cancer
    Liver disease - extra hepatic bilary obstruction, cholastasis, hepatocellular necrosis
177
Q

List components of bile

A

Cholic acid
oxycholic acid
bilirubin
water
phospholipids
cholesterol

178
Q

What Apo-proteins are present on chylomicrons?

A

Present in exogenous pathway.

Apo-E (binds to LDL-r or LRP on liver) & ApoCII (binds to sk&cardiac muscle receptors and adipocytes reacts with LPL) - donated from HDL
Apo-B48 - from enterocyte rER

179
Q

What apo-Proteins are present on VLDL?

A

Endogenous pathway

Apo-B100 from liver
Apo-CII (binds to muscle and adipocyte receptors and activates LPL) & Apo-E (binds LDL-r on liver) donated from HDL

180
Q

What Apo-proteins are present on HDL?

A

Reverse transport

ApoA1 - can removes some chol from foam cells (ABCa1 and ABCg)
ApoE
ApoCII
Also contain LCAT with ApoA1 to return chol to liver binds to SRBI receptor

181
Q

What factors would you consider when choosing a method?

A

Check QAP report methods in use in other labs and their performance
consider interferences
Labour
Equipment
TAT

182
Q

List causes of an elevated PSA

A

Prostasis - UTI
Benign prostate hyperplasia
Prostate cancer

when PSA is <10 can add free PSA (tends to be low in Cx) - Can avoid ~20% of unnecessary biopsies.

183
Q

List uses for AMH

A

Diagnosis of PCOS
Estimating egg count - fertility treatment
Gender prediction

184
Q

List causes of an elevated ammonia level

A

Haemolysis
Delayed sep
Temp
Acute/Chronic liver failure - LFTs
Type I distal RTA
Medications - Valproate

Urea cycle metabolic disorder
-Ornitine transcarbamylase deficiency
carbomyl phosphate synthase I deficiency
Citrulineamia

185
Q

List markers for AKI

A

NGAL
KIM-1
Cystatin-C
IL-18
FABP

186
Q

Discuss Cyclosporin

A

Immunosupressant medication / inflammatory conditions/transplant pts. (Inhibits T cell activation calcineurin inhibitor)
Derived from fungus Beavveria.nivea
Whole blood sample- competitive
IV or oral
Lipophilic
Liver P450 metabolism, elimination after sulfate conjugation urinary excretion

187
Q

Discuss Phenytoin

A

Follows zero order kinetics
95% protein bound
A.K.A Dilantin
Anti-seizure medication
Oral or IV
Cytochrome P450 metabolism
Elimination mostly kidneys,
Non- specific sodium channel blocker, targets most voltage gated sodium channel subtypes, prevent seizure by inhibiting the positive feedback loop that results in neuron propagation of high frequency action potential.

188
Q

Discuss Sodium valproate

A

Anti-convulsant medication 80-90% protein bound.
MOA- Blockade of voltage-gated sodium channels and increased brain levels of GABA, inhibits succinic semialdehyde dehydrogenase.
Metabolised by glucoronide conjugation
Excretion by kidneys
hepatotoxic and teratogentic

189
Q

Discuss Carbamazepine

A

A.K.A Tegretol
Anti-Convulsant medication
inhibits Na channels (decrease action potentials)
70-80% bound, absorption increased with high fat meals
Liver metabolism CYP3A4 - hepatic glucotonidation by UGT2 enzyme B7
urinary elimination

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