Clinical Sciences Flashcards
Macrophage activation syndrome
- severe, potentially life-threatening, complication of several chronic rheumatological diseases
- high ferritin, cytopaenias, hypertriglyceridemia, and hypofibrinogenaemia
- Interferon I3
Difference between Marfans and homocysteineuria
Prescence of learning difficulties indicates homocystieneuria
Mitochondrial inherrited diseases
Leber’s optic atrophy
symptoms typically develop at around the age of 30 years
central scotoma → loss of colour vision → rapid onset of significant visual impairment
MELAS syndrome: mitochondrial encephalomyopathy lactic acidosis and stroke-like episodes
MERRF syndrome: myoclonus epilepsy with ragged-red fibres
Kearns-Sayre syndrome: onset in patients < 20 years old, external ophthalmoplegia, retinitis pigmentosa. Ptosis may be seen
sensorineural hearing loss
Turner’s syndrome features
hort stature, ovarian agenesis, melanocytic naevi, left-sided cardiac abnormalities, webbed neck and multiple other structural abnormalities.
The majority of women with Turner’s have normal intelligence.
Blue sclera can be present in Turner’s however it is rare
What is the primary mechanism whereby Vitamin D increases calciu,
Increases Ca re-absorbtion in the small intenstine (duodenum) via Vit D dependent recoptors
Dermatitis herpatiformis associated with which HLA?
HLA- DR3
Homocysteinuria features
Marfanoid body habitus
DVTs
Downward dislocation of lens
Learning difficulties
Atherosclerosis/TIA
Complement associated with SLE
C1, C2, C4
which cell surface protein does the Ebstein-Barr virus bind to
CD21
(21 yos kissing -> EBV of 21: too old for epstein)
To drink at a Barr (in the USA) you need to be 21 years old
Interleukins in sepsis - which one causes hypotension (1) and which causes fever (2)
1 - IL 1
2 - IL 6 and IL 1
interleukins = Hot T-bone stEAk
IL1 - fever
IL2 - T cell stimulator
IL3 - Bone marrow stimulator
IL4 - IgE class switching from IgG, B cell growth
IL5 - IgA, eosinophilia
% of values lie within 1 SD of the mean
68.3%
% of values lie within 2 SD of the mean
95.4%
Deficiency of alpha-galactosidase A is the correct answer because Fabry disease is caused by a deficiency of this enzyme, leading to the accumulation of globotriaosylceramide (Gb3) in various tissues. This causes the hallmark symptoms of Fabry disease, such as burning neuropathic pain (particularly in the hands and feet), angiokeratomas (red, raised skin lesions), proteinuria, and renal dysfunction. The patient’s history of chronic fatigue, gastrointestinal issues, and family history of early renal failure all suggest Fabry disease. The presentation of these symptoms in adulthood, particularly the involvement of the skin and kidneys, makes this diagnosis likely.
Deficiency of beta-glucosidase is incorrect because this enzyme deficiency causes Gaucher disease, which presents with symptoms such as hepatosplenomegaly, bone pain, and pancytopenia. Unlike Fabry disease, it does not typically cause the specific symptoms seen in this case, such as burning pain in the hands and feet or angiokeratomas.
Deficiency of galactose-1-phosphate uridyltransferase is incorrect because this enzyme deficiency leads to galactosaemia, which typically presents in infants with feeding difficulties, jaundice, hepatomegaly, and developmental delay, rather than adult-onset neurological and renal symptoms seen in Fabry disease.
Deficiency of hexosaminidase A is incorrect because this causes Tay-Sachs disease, characterised by developmental regression and a cherry-red spot on the retina, with severe neurological decline, particularly in infants. This differs from the adult-onset symptoms and organ involvement seen in Fabry disease.
Deficiency of sphingomyelinase is incorrect because this causes Niemann-Pick disease, which is associated with hepatosplenomegaly, developmental delay, and neurological decline, not the burning pain, angiokeratomas, or renal involvement characteristic of Fabry disease.
Familial Mediterranean Fever inheritance pattern
Autosomal Recessive
AR = ARab
Acute interstitial nephritis classic triad
rash, fever and eosinophilia
he urine sediment, if present, is more likely to be white cell (and/or red cell) casts/pyuria
Phases of ATN
oliguric phase
polyuric phase
recovery phase
Scurvy is classically associated with issues of the 4 Hs:
haemorrhage (i.e. bleeding gums), hyperkeratosis (skin thickening), hypochondriasis (anxiety and other mental health illness), and haematologic abnormalities (i.e. anaemia & coagulopathies)
Fabry disease inheritance pattern
lysosomal storage disorder, X linked recessive
Abetalipoproteinaemia
Abetalipoproteinaemia is caused by vitamin E deficiency which can present with peripheral neuropathy and cerebellar ataxia.
Type I error
This describes the chances of incorrectly rejecting the null hypothesis. Essentially, this means the chance of a false positive. In this case, this would mean the chance of detecting a difference between those in the herbal remedy and placebo groups when in fact, there is no difference.
Type II error
Type II error is the probability of accepting a false null hypothesis. This means the probability of failing to detect a difference between groups when indeed, a difference exists.
Relative risk ratio
Relative risk = EER / CER
Relative risk (RR) is the ratio of risk in the experimental group (experimental event rate, EER) to risk in the control group (control event rate, CER). The term relative risk ratio is sometimes used instead of relative risk.
To recap
EER = rate at which events occur in the experimental group
CER = rate at which events occur in the control group
Incidence
The incidence is the number of new cases per population in a given time period.
prevalence
The prevalence is the total number of cases per population at a particular point in time. It can be divided into two types:
point prevalence = number of cases in a defined population / number of people in a defined population at the same time
period prevalence = number of identified cases during a specified period of time / total number of people in that population
p53
p53 is a tumour suppressor gene located on chromosome 17p. It is the most commonly mutated gene in breast, colon and lung cancer
p53 - plays a crucial role in the cell cycle, preventing entry into the S phase until DNA has been checked and repaired
Li-Fraumeni syndrome is a disorder of p53
Bohr effect
increasing acidity (or pCO2) means O2 binds less well to Hb
Haldane effect
increase pO2 means CO2 binds less well to Hb
Kearns-Sayer syndrome
Kearns-Sayer syndrome, which is a mitochondrial disease. It is characterised by ptosis, external ophthalmoplegia occurring in the first or second decades of life, retinitis pigmentosa and cardiac conduction defects (atrioventricular nodal block, often requiring cardiac pacing).
Diagnosis is confirmed by muscle biopsy which is characteristic with ‘ragged red fibres’
Down’s syndrome risk
1/1,000 at 30 years then divide by 3 for every 5 years
Power
Power - the probability of (correctly) rejecting the null hypothesis when it is false
1-the probability of a Type II error
recurrent proteus mirabilis infections predispose individuals to
Struvite stones
Hering-Breuer reflex
physiological mechanism that prevents over-inflation of the lungs. It involves stretch receptors in the lung parenchyma, which send inhibitory signals to the medullary respiratory centres via the vagus nerve when the lungs become overly distended during inspiration. This ultimately results in a decrease in the respiratory rate and volume, protecting against potential lung damage from over-inflation.
Adult T cell lymphoma associated with what
HTLV-1, or Human T-cell lymphotropic virus type 1, is a retrovirus that has been strongly linked with the development of Adult T-cell leukaemia/lymphoma (ATL). ATL is a rare and aggressive form of non-Hodgkin lymphoma where HTLV-1 infects the CD4+ T-cells. It is endemic in certain areas such as Japan, the Caribbean, parts of South America and Africa.
trinucleotide repeats:
trinucleotide repeats:
* GAA: Friedrich Ataxia(multiple A)
* CTG: Myotonic dystrophy(T in the middle)
* CGG: Fragile X syndrome(GG=X)
* CAG: Huntington’s chorea(Hunt or CAGe)
Homocisteineuia treatment/thing that might help
Vit B6, pyridoxine
Homocystinuria is an autosomal recessive disorder characterized by the deficiency of the enzyme cystathionine beta-synthase, which uses vitamin B6 (pyridoxine) as a cofactor. This deficiency leads to elevated levels of homocysteine in blood and urine. Pyridoxine supplementation has been shown to reduce homocysteine levels in some patients with this disorder, hence improving their condition.
standard error of the mean
Standard error of the mean = standard deviation / square root (number of patients)
Phentolamine
Drug to reverse adrenaline in fingers - a1 antagonist
Trinucleotide repeat disorders
- CAG - Huntington’s - think of HUNTing and then CAGing an animal
- GAA - Friedrich’s ataxia - Lots of A’s in GAA as well as AtAxiA
- CTG - Myotonic dystrophy - Both CTG and myotonic have a T in the middle
- CGG - Fragile X syndrome - think of the GG as equivalent to XX
Trinucleotide repeat disorders
- CAG - Huntington’s - think of HUNTing and then CAGing an animal
- GAA - Friedrich’s ataxia - Lots of A’s in GAA as well as AtAxiA
- CTG - Myotonic dystrophy - Both CTG and myotonic have a T in the middle
- CGG - Fragile X syndrome - think of the GG as equivalent to XX
Fomepizole
Fomepizole is used in ethylene glycol poisoning by acting to prevent the breakdown of these toxins into their active toxic metabolites. Fomepizole is a competitive inhibitor of the enzyme alcohol dehydrogenase found within the liver. This enzyme plays a key role in the metabolism of ethylene glycol, and methanol. This is the first-line agent used. Haemodialysis may also be employed in situations where organ damage is evident or significant metabolic acidosis.
