Chemical Biology Flashcards
Commonest cause of hypercalcemia
primary hyperparathyroidism parathyroid adenoma
High calcium, PTH supressed, increased ALP
malignancy
no longer sensitive to PTH so high PTH despite high calcium
Tertiary hyperparathyroidism
This condition expresses 1 alpha reductase and causes hypercalcemia
sarcoid
The three commonest causes of hypercalcemia
primary hyperthyroidism, cancer, sarcoid
Rememberpatient coming over with constipation, kidney stones and some psychiatry symptoms, bone pain
malignacy
What is the best treatment of hypercalcemia
fluids, fluids, fluids,
Baby with seizures - Low Ca, Low PTH:
DiGeorge
The calcium stones in hypercalcemia have Ca in them and they are
radiopaque
What is secondary treatment of hypercalcemia?
Then after 4l of fluid within 24h was given, give frusemide
give IV pamidoronate in the patient with known cancer
If the patient has known cancer then you give X for hypercalcemia
IV pamidronate
What would the X-ray show of person with hypercalcemia?
Radial aspect cystic changes
If you have a patient with sarcoid –
give them steroids
how does sarcoidosis cause hypercalcemia?
Macropages express 1 alpha hydroxylase
What would the glucose be in someone with Impaired Glucose Tolerance, 2hr after a OGTT
Impaired glucose tolerance (IGT) is defined as fasting plasma glucose less than - 7.0 mmol/l and OGTT 2-hour value greater than or equal to 7.8 mmol/l but less than 11.1 mmol/l
raised ALT and AST
Cirrhosis
Woman with colicky abdominal pain, raised ALP markedly, others might have been deranged, unsure
Complete biliary obstruction
can cause hepatic cirrhosis and portal hypertension in some and cardiomyopathy in others
Haemachromatosis
Markers of synthetic function
Clotting albumin and PT
HONK
↓K, high glucose, high serum osmolality >320, high bicarb bicarbonate >15mmolL
Low sodium, high serum osmolality, 50 year old woman
Diabetes mellitus - high lipids create a pseudohyponatraemia with normal osmolality
3 days post prostatectomy with low sodium and everything else normal - fluid overload (they give plain water in TURP)
Post prostatectomy
↓K, ↑Na (hypertension), inadequate aldosterone synthesis, hyperandrogenism
Congenital adrenal hyperplasia-11 beta hydroxylase deficency
Pt with HTN - high Na, Low K, high aldosterone:low renin
Conns
The commonest cause of congenital adrenal hyperplasia
21 hydrozylase deficiency
Wchich metabolite would be raised in 21 hydroxylase deficiency?
17 hydrocyprogesterone
Increased levels are seen in the urine of CAH patients?
preganetriol
What is used to diagnose SIDAH
serum osmolality
Pt becomes drowsy 24 hours after RTA - high Na
Diabetes insipidus
Dementia/dermatitis/diarrhoea -
niacin (=pellagra): B3
Diet poor in veggies, nuts yeas. In coeliac disease, also caused by drugs
Folate
Indian lady who is vegan with tiredness and Imacrocytic anaemia -
B12
Coeliac disease with swollen tongue and macrocytic anaemia -
B12
Someone ‘lacking intrinsic factor’.
B12
Crohn’s and macrocytic megaloblastic anaemia
could be methotrexate causing folate deficiency
Crohn’s – [as terminal ileum required to absorb and this is commonly affected in Crohn’s]
B12 deficiency
Woman with hypothyroidism, T1DM, adrenal failure (polyendocrinopathies – autoimmune and is hinting towards pernicious anaemia): autoimmune anthropic gastritis
B12, Shmidt Disease
High LH, FSH, everything else normal
Premature Ovarian Failure
Very high prolactin and everything else suppressed
prolactinoma/Macroadenoma
High GH, high prolactin? everything else suppressed
acromegaly
All values were within normal range
non-‐functioning adenoma
Everything normal but low TSH
subclinical hypothyroidism
Everything normal but high TSH and high prolactin (but less than 1000):
primary hypothyroidism
high TSH, low T3, T4, everything else normal
Myxoedema
(any tumor that secrets IGF-2) hypoglycaemia – incomplete low glucose, insulin, C peptide, FFA and ketones
non-islet cell tumor
○ Neonates: ■ Ketones present:
IUGR
Neonantes, ketones absent
inherited metabolic disorder
high prolactin as it presses on the stalk causing pituitary failure -> low dopamine and high prolactin
Non-functioning pituitary adenoma
Patient can’t fit in her shoes or put on her wedding ring and has prognathism,
Acromegalic symptoms – OGTT – (GH elevated), IGF (high through the day). Glucose normally suppresses the GH
Thin skin, proximal myopathy, impaired fasting glucose -> what test do you need to do to confirm
dexamethasone suppression test
Pt with ↓Na, ↑K + postural hypotension what test do you need to do to confirm
short synACTHen test. This is addisions, one causes of hyperkalemia (renal failure, drugs. adrenals)
Addison’s disease: investigations
In a patient with suspected Addison’s disease the definite investigation is a ACTH stimulation test (short Synacthen test). Plasma cortisol is measured before and 30 minutes after giving Synacthen 250ug IM. Adrenal autoantibodies such as anti-21-hydroxylase may also be demonstrated.
If a ACTH stimulation test is not readily available (e.g. in primary care) then sending a 9 am serum cortisol can be useful:
> 500 nmol/l makes Addison’s very unlikely
< 100 nmol/l is definitely abnormal
100-500 nmol/l should prompt a ACTH stimulation test to be performed
Associated electrolyte abnormalities are seen in around one-third of undiagnosed patients:
- hyperkalaemia
- hyponatraemia
- hypoglycaemia
- metabolic acidosis
Patient with low sodium, potassium: normal, low plasma osmolality and urine osmolality was 70
water deprivation test
To distinguish if it is cranial or nephrogenic diabetes insipidus you do
Vasopressin test
Polyuria, polydipsia, hyponatraemia and high ish serum osmolality -> blood glucose, as high lipids can cause pseudohyponatraemia.
OGGT
Impaired fasting glucose -
6.1-6.9
Impaired glucose tolerance -
2 hours post glucose ≥7.8 and <11.1
Diabetes - fasting glucose
fasting glucose ≥7.0, or 2 hour glucose ≥11.1. you do OGGT if fasting is less <7 mMN ○ Need symptoms + one of these tests OR ○ Both of these tests ○ WHO also recommends HbA1c ≥48
Rate limiting enzmye in Haem synthesis
ALA synthase
Deficiency resulting in urate overproduction
-linked HGPRT = Leach Nyhan (self mutilating, choreiform movements, mentally retarded, gout)
Seen in the kidney of someone with T1DM - renal sclerosis
AA
Emphysema in someone who hasn’t smoked
A1AT deficiency
Raised in someone with mumps
amylase
Boys with the salt-losing form typically present at 7-14 days of life with vomiting, weight loss, lethargy, dehydration, hyponatraemia and hyperkalaemia and can present in shock.
CAH – salt losing crisis (21 hydroxylase deficiency – presents at birth)
ALP + pain defecating
metastases
Fatty acid oxidation defects testing
blood spot for acylcarnitine profile
You take a urine sample from a hypoglycaemic neonate.Lab tells you amount of urine is not enough to do all tests. Which test/substance would you want to rule out ASAP?
Galactosaemia - commonest is Gal-1-PUT and is also the most severe
Vomiting since 5 years of age, followed by the failure to thrive.
Tyrosinaemia
Diarrhoea and bloody stools, vomiting, poor weight gain, extreme sleepiness, irritability, ‘cabbage like odour’ to skin or urine
Tyrosinaemia
Succinylacteonate is pathognomic
of tyrosinaemia
Muscular hypotonia, seizures, hepatic dysfunction, dysmorphia
Perioxisomal - disorders in metabolism of very long chain fatty acids
Perioxisomal disorders have LD and more eye signs
Zellweger
inverted nipples and subcutaneous fat pads-lipodystrophy
Glycosylation
cherry spot’ on the retina
Tay-Sachs
fat accumulation in the liver
Gaucherie Disease