Blood Chemistry For Diagnosis Flashcards
Chromogranin A conc raised?
Could be carcinoid syndrome
Used as tumour marker
Why is somatostatin receptor scintography used?
Use a compound to bind to somatostatin receptors on tumour
Serotonin means
Carcinoid tumours in lung and gut
Oxytocin and ADH for
Posterior pituitary, serum competing is a cleavage product for ADH
Serum calcitonin for…
Medullary c cells of thyroid
Circadian rhythm of pituitary hormones is controlled by?
Supraoptic nucleus
Neural tube defects?
Maternal serum alpha-fetoprotein, feral ultrasound
Alpha fetoprotein?
Produced by yolk sac and feral liver, most abundant protein
Alpha fetoprotein high and low levels?
High- spina bifida
Low- downs
In hyperventilation, respiratory alkalosis what happens?
Calcium binds to albumin, hydrogen leaves to bind to bicarbonate
What does nitrous oxide do?
Convert B12 from active monovalent to inactive bivalent.
Active b12 is coenzyme for methionine synthase needed to create methyl groups for synthesis of DNA.
Meningism?
Headache, neck stiffness, photophobia often with nausea and vomiting
Requirements for CSF labels?
- Microbiology
- Biochemistry
- Decreasing cell count
Subarachnoid haemorrhage diagnosis?
6hour delay CSF will show bilirubin
Most common cause of subarachnoid haemorrhage?
Berry aneurysm
Meningitis glass test?
With blanching if rash doesn’t fade, then meningitis.
Why is protein high in meningitis?
More permeable blood brain barrier allowing more proteins to enter CSF
Difference in bacterial meningitis and tuberculous meningitis?
WBC raised in both, but in bacterial it’s polymorphs and tuberculous lymphocytic
Protein levels in meningitis?
Tuberculous very high 6mol, bacterial more than 2.5
Fungal elevated and viral less than 1.5
Glucose in meningitis?
Viral more than 50%, fungal less than 50%, bacterial and tuberculous less than 2.5 mol
Multiple sclerosis testing?
Oligoclonal banding; positive in CSF not serum
How to diagnose Alzheimer’s from CSF?
Low conc of Abets42 in CSF and high tau.
Apolipoprotein E in plaque formation?
ApoE4 promotes plaque formation and ApoE2 inhibits
Drippy nose, nasal secretions?
Test for asialotransferrin which is high in CSF only
Altered states of consciousness:
AEIOU TIPS?
Alcohol Epilepsy, electrolyte disorders, hepatic encephalopathy Insulin, in born errors of metabolism Opiates, overdose, oxygen(hypoxia) Uraemia Trauma, temp, toxins, tumour Infection- sepsis, men,enca Psychogenic, poisons Space occupying, stroke, seizure and shock
How to test for hypoxia brain injury?
Neuron specific enolase, released after neuronal cell death.
What can cause cerebral oedema?
Diabetic ketoacidosis, hyperosmolar hyperglycaemia with insulin, hyponatraemia
What can cause hyponatraemia?
Excessive IV of hypotonic fluids
Syndrome of inappropriate ADH secretion
Ectopic ADH-small cell lung carcinoma
MDMA
Signs of encephalitis?
Altered consciousness for more than 24hours, lethargy change in personality
Fever
Seizures
High WBC in CSF
Low serum caeruloplasmin copper?
Wilson’s disease
Accumulation of amino acids?
Phenyketonuria
Accumulation of carbohydrates?
Galactosaemia
Accumulation of mucopolysaccharides?
Hurler syndrome
Accumulations of sphingolipids?
Gaucher disease
Why is phenytoin used?
For epilepsy, 10-20mg/L
Higher dose causes a much greater conc
Phenytoin on fit d metabolism?
Phenytoin activates enzyme that inactivate vit d leading to decreased calcium absorption. Low calcium causes parathormone secretion to release calcium from bone.
Hoe does risperidone cause increased prolactin?
Risperidone blocks dopamine receptor, anterior pituitary, prolactin releasing cells cause high serum prolactin.
How to treat bipolar
Lithium
Effect of lithium on endocrine?
Hypothyroidism, because its taken up by the gland reducing thyroxine release
Increased sensitivity to ADH causing polyuria
Hypercalcaemia- I adjusts calcium receptors in parathyroid glans causing increase parathyroid secretion
Effects of opiates on hypogonadism?
Reduced gonadotrophin secretion, hyperprolactinaemia, antiepileptics increase SHGB and suppress HPA axis
Pseudocholinesterase deficiency?
Prolonged effect of suxamethonium
Test for neural tube defects?
Maternal serum alpha fetoprotein
Test for meningitis?
Increased white blood cells
Test for subarachnoid haemorrhage?
Xanthocromia
Test for multiple sclerosis?
Oligoclonal banding
Test for Alzheimer’s
Elevated tau and low Abeta42
Test for drippy nose?
Beta transferrin
Test for hypoxia brain injury?
Neuron specific enolase
Test for encephalitis
Increased white blood cells
Test for night blindness
Vit a deficiency in blood
Drug monitoring for epilepsy?
Phenytoin
Drug monitoring for bipolar disorders
Lithium
