new_n_lost
Forum Hero
Topics: 724
Posts: 6,388
|
Which of the following could prevent an allergen from reacting with a specific IgE molecule present on the mast cell membrane?
A. Antihistamine
B. Blocking antibody
C. Cromolyn sodium
D. Epinephrine
E. Theophylline
___________________
"never argue with a fool, they'll bring you down to their level and beat you with experience" FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."
|
| paheli
It'sAllAboutGoodKarma
Topics: 197
Posts: 2,720
|
B, blocking Ab
___________________
Prepare as if you're the worst, Perform as if you're the best! As you dream, so you manifest. So, DREAM BIG!! When you face hardship, remember, God never gives you more than you can handle. Keep your face to the sunshine and you cannot see the shadows. Internship, Here I come!!
|
| PGI2alpha
Forum Elite
Topics: 7
Posts: 447
|
C?is tht how it prevents rupture of mast cells?
|
| SURVIVOR
Forum Junior
Topics: 9
Posts: 75
|
B
|
| hope4dabest
Forum Elite
Topics: 19
Posts: 438
|
B..IgG
|
| onc
Forum Junior
Topics: 11
Posts: 46
|
B
|
| new_n_lost
Forum Hero
Topics: 724
Posts: 6,388
|
paheli wrote:
B, blocking Ab
Some of you guys are well prepared.
___________________
"never argue with a fool, they'll bring you down to their level and beat you with experience" FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."
|
| new_n_lost
Forum Hero
Topics: 724
Posts: 6,388
|
The correct answer is B.
Blocking antibody is generally an IgG antibody against the allergen. It is induced in the allergic patient by administering small amounts of allergen over a period of time. When the person is again exposed to the allergen, the IgG reacts with the allergen before it can reach the IgE-coated mast cell.
Antihistamines (choice A) would block histamine receptors but would not react with the allergen before it could reach the IgE-coated mast cell.
Cromolyn sodium (choice C) is a drug that stabilizes mast cell membranes, thus inhibiting degranulation, but would have no effect on allergen binding to IgE on mast cells.
Epinephrine (choice D) is the mainstay of therapy in severe cases of immediate hypersensitivity (anaphylaxis). It increases intracellular cyclic AMP, thus decreasing mast cell degranulation, and causes smooth muscle dilation in the airways. Epinephrine would have no effect on the binding of the allergen to IgE on mast cells.
Cyclic AMP is degraded in cells by the enzyme phosphodiesterase. Theophylline (choice E) inhibits this enzyme, thereby increasing mast cell cyclic AMP levels and making degranulation less likely without affecting the binding of the allergen to IgE on mast cells.
___________________
"never argue with a fool, they'll bring you down to their level and beat you with experience" FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."
|
| Ig F
Forum Elite
Topics: 3
Posts: 440
|
___________________
i m not perfect but i wanna get close to it......
|
|
| |
| | | | | | | | | |
