CSI Case 1 & 2 Flashcards
What viruses can cause the common cold?
Rhino virus, corona virus, influenza virus and adeno virus.
What allows influenza to bind to a cell?
Haemagglutinin bind to sialic acid.
What allows the influenza virus to leave the cell?
Neuraminidase cleaves bond to sialic acid.
What does covid bind to?
ACE2 Receptor.
What does covid do that leads to acute lung injury?
Downregulated ACE2 which causes angiotensin II to build up.
What is Angiotensin II?
Vasoconstricter hormone.
How many polypeptide chains make up haemoglobin?
4
What is haemoglobin S?
Mutant form of beta chain in haemoglobin A.
What is the difference between haemoglobin S and haemoglobin A?
One amino acid. Glutamate to valine at position 6.
Why is sickle cell haemoglobin fibres sticky?
Polymerization of haemoglobin s.
What is the hydrophobic pocket?
This is where the haemoglobin fibres stick in sickle cell disease. Valine is hydrophobic so fibres stick.
Why does oxy haemoglobin not stick?
Oxygen interferes with the polymerisation of haemoglobin s. Hydrophobic knob/groove is exposed more in deoxygenated haemoglobin s.
What makes up haemoglobin A?
2 alpha and 2 beta chains.
Why do the different types of haemoglobin form different bands?
Different mass.
Why is haemoglobin F seen in a sickle cell patient?
Haemoglobin F is regulated due to a lack of haemoglobin A.
Why does vaso occlusion happen in sickle cell patients?
Sickle cells stick to endothelium of capillaries.
Why does hypoxia happen in sickle cell patients?
Sickle cells get stuck to endothelium in capillaries and reduce amount of oxygen that tissues get.
Why is jaundice caused in sickle cell patients?
Red blood cells are dying faster than the liver can filter them out. Bilirubin from broke down cells builds up.
Why does exercise leads to crisis in sickle cell patients?
More deoxygenated haemoglobin, more polymerisation of haemoglobin s.
Why does cold make sickle cell disease worse?
Cold can cause vasoconstriction which can increase vaso-oclussion. Reduced oxygen delivery.
Why does infection make sickle cell disease worse?
Basal metabolic rate increases, more o2 required. More deoxy haemoglobin which leads to greater sickling and vaso oclussion.
Why does dehydration make sickle cell disease worse?
Red blood cells are likely to aggregate. Blood becomes more thick.
How do you manage sickle cell patients in hospitals?
Opiods (painkillers). Hydration (IV Fluid). Antibiotics. Blood transfusion. Blood thinners (heparin). Given oxygen. Refer to specialist. Drug called hydroxycarbamide.
How does hydroxycarbamide work?
Increases concentration of foetal haemoglobin. Reduces polymerisation and sickling of red blood cells.
What should you ask a sickle cell patient?
Ideas, concerns and expectations.
What kind of mutation is sickle cell disease?
Autosomal reccesive.
Why does adult haemoglobin move further than sickle cell haemoglobin?
Adult haemoglobin is more negative as glutamate is negative while valine is neutral.
