clinical conditions Flashcards
1
Q
what drug is given to alcoholics and how does it work
A
disulfiram - inhibits aldehyde dehydrogenase
2
Q
what are the results of prolonged alcohol consumption
A
- the increased acetyl CoA causes a fatty liver
- the decreased amount of NAD+ leads to lactic acidosis, gout and hypoglycaemia
3
Q
what is marasmus
A
deficiency in all nutrients leading to inadequate energy intake
4
Q
what is kwashiorkor
A
protein deficiency but adequate energy intake
5
Q
what are the consequences of kwashiorkor
A
develop fatty liver as theres no proteins too mobilise the fats in the liver
also oedema as albumin cant be produced so this lowers the oncotic pressure in the blood
6
Q
what is refeeding syndrome
A
when those suffering from marasmus and kwashiorkor are given too much foo too fast and so they don’t have the enzymes to break down the food leading to a build up of ammonia
7
Q
name some inhibitors of the ETC
A
cyanide and carbon monoxide
8
Q
how do ETC inhibitors work
A
they bind to the terminal translocating complex preventing oxygen from binding
9
Q
name some ETC uncouplers
A
dinitophenol, thermogenin, fatty acids
10
Q
how do uncouplers work
A
they increase the permeability of the inner mitochondrial membrane, dissipating the hydrogen ion gradient, reducing the proton motive force
11
Q
what drug is given to patients with high cholesterol levels and how does it work
A
statins works by inhibiting the enzyme HMG CoA reductase
12
Q
what do ROS cause
A
lipid peroxidation, disulphide bridge formation, DNA damage, protein damage
13
Q
what are the cellular defences against ROS
A
- superoxide dismutase converts superoxide to hydrogen peroxide then catalase converts this to oxygen and water
- glutathione
- vitamins A,C and E
14
Q
what is galactosemia
A
deficiency in either galactokinase, UDP-galactose epimerase or uridyl transferase (most common)
15
Q
what are symptoms of galactosemia
A
cataracts, renal failure, vomiting, brain damage
16
Q
why does galactosemia lead to oxidative stress
A
the build up of galactose is converted by aldose reductase into galacticol (causing cataracts) this uses NADPH needed for cellular defence
17
Q
what type of drug depletes NADPH
A
anti-malarials
18
Q
how does a G6PDH deficiency affect ROS
A
less NADPH is produced which is used to reform glutathione
19
Q
what is seen in a G6PDH deficiency
A
Heinz bodies which are aggregates of cross linked haemoglobin in RBC due to protein damage from ROS
20
Q
how is paracetamol normally metabolised
A
broken down in the hepatocyte and conjugated with sulphate
21
Q
what happens in a paracetamol overdose
A
NAPQI is produced which Is conjugated with glutathione but this gives less cellular defences against ROS
22
Q
what drug is given in a paracetamol overdose
A
acetylcysteine which replenishes glutathione
23
Q
what is the heel prick test
A
blood screen test in newborns to test for various diseases such as sickle cell, PKU
24
Q
what is phenylketonuria
A
deficiency in phenylalanine hydroxylase giving s build up of phenylalanine which is converted to phenylketonuria
25
what is the treatment for PKU
low phenylalanine diet, avoid food high in protein
26
what are the symptoms of PKU
intellectual disability, seizures, hypopigmentation
27
what cant be produced in PKU
tyrosine
28
what is homocystinuria
deficiency in cystathioine beta synthase so methionine cant be broken down into cysteine giving a build up of homocysteine
29
what co factor is required by cystathioine beta synthase
vitamin B6
30
what is Von Gierke's disease
deficiency in glucose 6 phosphatase
31
what occurs in lactose intolerance
don't have the enzyme lactase so cant break down lactose in glucose and galactose
32
what are the different types of lactose intolerance
primary - occurs in adults as their lactase allele doesn't persist
secondary - seen in children due to injury of small intestine
congenital - defect in the lactase gene
33
what occurs in type 1 hyperlipoproteinaemia
where there is a defective lipoprotein lipase
34
what occurs in type IIa hyperlipoproteinaemia
defective LDL receptor
35
what occurs in type 3 hyperlipoproteinaemia
defective apoE
36
what are the treatments for hyperlipoproteineamia
statins, bile salt seqestrants, increasing exercise, increasing fibre, reduce smoking
37
how do bile salt seqestrants help in hyperlipoproteinaemia
they bind to bile acids so that more are secreted meaning more cholesterol has to be used to make more bile
38
what are the symptoms of hypercholesterolaemia
xanthelasma, tendon xanthoma and corneal arcus
39
how do LDLs lead to atherosclerotic plaques
due to their long half lives they are susceptible to oxidative damage. they are then engulfed by macrophages becoming foam cells which accumulate in the blood vessel walls
40
what do vit B12 deficiencies result from
dietary deficiency, autoimmune disease causing reduced IF production e.g. crohns
41
what can cause reduced erythropoiesis
- chronic kidney disease
- chemotherapy giving empty bone marrow
- viruses
- bone marrow infiltration by cancer cells
42
what are myrloproliferative disorders
overproduction of bone marrow cells
43
in hereditary spherocytosis which membrane proteins are affected
ankyrin and protein 4.2
44
what is haemolytic anaemia
increased RBC destruction
45
name 2 bone marrow tests
- trephine biopsy (remove bone marrow from iliac crest)
| - aspiration (remove bone marrow cells)
46
what is haemochromatosis
excess iron causing organ failure due to deposition
47
what gene is mutated in hereditary haemochromatosis
HFE - now the HFE cant bind to transferrin receptors meaning too much iron enters cells
48
what does hepcidin do
binds to ferroportin channels preventing iron absorption from erythrocytes
49
when and where is hepcidin secreted
from the kidneys in iron overload
50
what is tested to look for an iron deficiency
ferritin levels (but this is an acute phase protein) and reticulocyte count (low in thalasaemias)
51
what is histologically seen in hyposplenism
Howell jolly bodies - DNA remnants in RBCs as the spleen isn't removing these RBCs
52
what infections are patients with hyposplenism particularly at risk from with hyposplenism
pneumococcus, haemophilius influenza, meningococcus (encapsulated bacteria)
53
when is eosinophilia seen
asthma, parasite infection, allergic reactions, drug hypersensitivity
54
what is the most common cause of a goitre world wide
iodine deficiency
55
what is the most common cause of a goitre in the uk
multinodular goitre
56
what causes hypothyroidism
autoimmune (Hashimotos disease), TSH/TRH deficiency, inadequate iodine, removal of glands failure of gland
57
what are the symptoms of hypothyroidism
obesity, intolerance to cold, hoarse voice, bradycardia, puffy face, hair loss, menorrhagia
58
what is hypothyroidism in infants called
cretinism - gives dwarfed statue, poor bone development, muscle weakness
59
what is hypothyroidism in adults called
myxoedema - thick puffy skin, muscle weakness, mental deterioration
60
what is the treatment for hypothyroidism
oral thyroid hormone
61
what happens to TSH/TRH levels in hypothyroidism
they increase
62
what is used to view the thyroid glands
technetium 99
63
what are the causes of hyperthyroidism
toxic adenoma, toxic multinodular goitre, graves disease
64
what are the symptoms of hyperthyroidism
weight loss, intolerance to heat, tachycardia, increased appetite, warm sweaty hands, lid lad and starring eyes
65
what symtoms are specific to graves disease
pre-tibial myxoedema and bulging eyes
66
what is used to treat hyperthyroidism and how does it work
carbimazole which is converted into methimazole which prevents thyroid peroxidase
67
what is lingual thyroid
when part of the thyroid gland stays on the tongue
68
what is thyroglossal duct cyst
not all of the thyroglossal duct degenerates - it moves up on tongue protrusion
69
which cancers have osteoclastic bone metastases
breast, lung, thyroid, renal
70
what cancer has osteoblastic bone metastases
prostrate
71
what cancer produced parathyroid hormone related peptide
squamous tumours
72
what is primary hyperparathyroidism
PTH secreting adenoma
73
what is secondary hyperparathyroidism
when the parathyroid glands become hyperplastic either due to osteomalacia or renal osteodystrophy
74
what is osteomalacia
lack of vitamin D
75
what is renal osteodystrophy
renal failure giving low serum calcium
76
what are the symptoms of hyperparathyroidism
MOANS - tired, depressed
BONES - bone and muscle aches
STONES - kidney stones
GROANS - abdominal pain, constipation, ulcers
77
what is the difference between osteomalacia and osteoporosis
osteomalacia is where there is also a loss of minerals as well as bone
78
what can ALP show about bone turnover
it has increased showing osteoblast activity
79
what symptoms are seen in hypocalaemia
tingling and tetany
80
pituitary tumours impinging on the optic chiasm result in what
bitemporal hemi-anopia vision and headache
81
what does a deficiency in growth hormone result in in children
dwarfism
82
what are non-functioning pituitary adenomas
tumours which block the movement of hormones from the hypothalamus to the anterior pituitary gland therefore the pituitary gland is not stimulated
83
what is prolactinoma
prolactin secreting tumour
84
what are the effects of prolactinoma
menstrual disturbances, fertility problems, galactorrhoea,
85
what do you treat a prolactinoma with
dopamine as this is a prolactin inhibitor
86
if the prolactin level is above 5000 what is the likely cause
prolactin secreting tumour
87
if the prolactin level is increased but is still below 5000 what is the likely cause
non-functioning pituitary adenoma
88
how do you treat a non-functioning pituitary adenoma
surgery
89
what pituitary hormones require a dynamic blood test
GH and ATCH
90
what do dynamic blood tests involve
stimulation and suppression tests
91
what condition results from an excess of GH
acromegaly
92
what results from an ADH deficiency `
diabetes insipidus - causes more aqua porins to be placed in the kidneys so you lose more water giving large volumes of pale urine
93
what is ADH also known as
vasopressin
94
what is pheachromocytoma
a chromaffin cell tumour which secretes catecholamines
95
what Is primary hyperaldosterone
where there is a defect in the adrenal cortex this could be hyperplasia of the cortex or an aldosterone secreting tumour (Conn's syndrome)
96
what is Conn's syndrome
hyperaldosterone caused by an aldosterone secreting tumour
97
what is secondary hyperaldosterone
high aldosterone due to problems with RAAS
98
would renal artery stenosis cause primary or secondary hyperaldosterone
secondary
99
what are the symptoms of hyperaldosterone
high bp, LV hypertrophy, hypernatraemia, hypokalaemia, stroke
100
what is given to treat hyperaldosterone
spironolactone which is a mineralcorticoid antagonist
101
what enzyme is missing in congenital adrenal hyperplasia
2,1-hydroxylase
102
what happens in congenital adrenal hyperplasia
an enzyme defect meaning that glucocorticoids and mineralcorticoids cant be produced so there are more androgens produced
103
give an example of a synthetic cortisol
prednisolone
104
what is cushings syndrome
excess cortisol
105
what are the causes of cushings syndrome
- cushing disease = ATCH secreting pituitary adenoma
- cortisol secreting adrenal tumour
- non-pituitary adrenal tumour (squamous tumour)
106
what are the symptoms of cushings syndrome
fat redistribution to the abdomen, back (buffalo hump), face
thin arms and legs and purple stretch marks due to protein breakdown
107
what is addisons disease
cortisol deficiency
108
what are the signs of addisons disease
hypotension, weight loss, increased skin pigmentation, hypoglycaemia
109
why do you get increased skin pigmentation in addisons disease
ATCH is increasing which comes from the POMC gene which also codes for MSH causing the activation of melanocytes
110
how do you treat addisons disease
lifelong treatment of synthetic cortisols
111
what are synthetic cortisols also used to treat
inflammatory diseases such as asthma, rheumatoid arthritis
112
what is an addisonian crisis
when there is very low cortisol levels causing nausea, vomiting, pyrexia, hypotension
113
what do you give to someone in an addisonian crisis
IV fluids and synthetic cortisol
114
what happens in type 1 diabetes
autoimmune disease destroying beta cells through auto antibodies
115
what happens in type 2 diabetes
there is a reduced sensitivity of the insulin receptors
116
what are the symptoms of type 1 diabetes
polyuria, polydipsia, weight loss and tiredness
117
if left untreated what can type one diabetes lead to
hyperglycaemia, ketoacidosis, dehydration
118
why does type 1 diabetes lead to ketoacidosis
there is a decrease in insulin so less cholesterol is produced and so the acetyl CoA is used to produce ketone bodies instead
119
why does ketoacidosis lead to hyperventilation
to try and expel the acidic CO2 to reduce acidity
120
what are the microvascular complications of type 1 diabetes
diabetic eye disease, retinopathy, nephropathy, neuropathy, diabetic foot
121
what are the macrovascular complication of type 1 diabetes
stroke, MI, poor circulation to peripheries
122
what tests would you use to look for diabetes
urine dipstick
HbA1c
smell of acetone
finger prick
123
what is a HbA1c test
looks for bound glucose to RBCs which shouldn't be above 6.5
124
what are the normal glucose levels
3.6-6 mmol/L
125
what is the renal threshold for glucose
10 mmol/L
126
what is the management for type 1 diabetes
insulin, diet and exercise
127
what is the management for type 2 diabetes
metformin and sulphonylureas to increase insulin sensitivity
insulin
diet and exercise
