A 70 year old woman complains that she can no longer do her housework or climb the stairs without frequent rests;and she gets very breathless. Her ankle swells as the day progresses, but improve after a nights rest.
On examination the doctor notes that her breathing is rapid, chest auscultation reveals basal crackles. Pulse is regular and arterial pressure normal. Central venous pressure of 18cmH2O.
Chest X ray shows cardiothoracic ratio of 0.69,congested pulmonary vessels and thin horizontal lines of intercepted oedema. ECG is normal.
a) what is the diagnosis
b) what are the chief roles of starling forces in humans
c) what key intracellular parameter triggers cardiac contraction and how does it change in cardiac failure
d) how can cardiac contractility be assessed in humans
e) what causes crepitation of the lungs
f) why does the ankle swelling get worse during the day.
maintains a normal volume of fluid within the blood vessels and interstitial fluid. it maintains a relative balance between the two compartments,
due to increased back pressure in the right heart, much fluid gets leaked from vessels into the interstitial spaces which collects by gravity at the ankles
1) A competitive inhibitor of one of the enzymes expressed by the HIV virus is being tested as a potential anti-retroviral therapy. The maximum solubility of the compound within the human body is found to be 2 µM; its KI is found to be 200 µM. By what factor is the KM of the viral enzyme changed at this inhibitor concentration (2 uM)? Comment on the chances of this inhibitor being adopted as a potential therapy.
2) You are trying to reproduce experimental enzymatic activity data from a previous student in the lab. He reported that the enzyme under investigation has a kcat of 1875 s-1 and a catalytic efficiency of 7.5×107 M-1 s-1.
a) What is the Km of this enzyme? (Answer in μM)
b) In repeating the measurements, you want to have a Vmax of 10 mM s-1 (as this is easy to measure). What concentration of enzyme should you use? Provide your result in μM.