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16 Cards in this Set
- Front
- Back
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Resistance to DNA alkylating agents?
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0^6 methylguanine methyltransferase (MGMT)
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Melarsoprol enters parasite via?
and is expelled from parasite via? |
P2 adenosine transporter
TbMRPA (ABC transporter) |
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Melarsoprol resistance as a result of?
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Loss of uptake into cell.
Detoxification. |
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Macrolide antibiotics & resistance associated?
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Inhibit protein synthesis by binding to 23S ribosomal subunit.
1Alteration of target --> Methylation of rRNA & plasma encoded methyl transferase. 2.Reduced cellular concentrations --> Plasma encoded efflux pumps |
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Benzimidazoles mechanism of action?
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High affinity irreversible binding to B tubulin --> disruption of polymerisation of microtubule -> Cytoskeleton disruption --> decrease in glucose uptake.
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DNA alkylating agent resistance?
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overexpression of 0^6 methylguanine methyltransferase - repair enzyme (MGMT)
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Melarsoprol enters and leaves parasite via?
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1. P2 adenosine transporter.
2. TbMRPA (abc transporter) |
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Most common mechanism of resistance?
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ABC transporter mediated efflux
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Macrolide antibiotics & mechanism of resistance?
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Bind to 23s ribosomal subunit.
1. Resistance by alterations to target. -Methylation of rRNA -Plasma encoded methyl transferase 2.Reduced cellular concentrations -Plasma encoded efflux pumps. |
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Sensitivity & resistance to benzimidazoles?
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Mutation of (Phe --> Tyr) at position 200 of the B tubulin
Mammals naturally possess tyrosine at position 200. |
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The ABC transporters are?
and function? and also known as what? |
P-Glycoprotein
MDR 2. Limit ingress of drugs & result in resistance. 3. Efflux pumps |
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Blood brain barrier consists of what?
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brain capillary endothelical cells connected by tight junctions & astrocytes.
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Types of active transport?
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1 ATP dependant
- ion pumps -P Glycoproteins -MDR proteins 2. Sodium gradient -mammalian transporters usually expressed in specific tissue 3. H+ gradient -Most protozoan transporters |
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Diffusion transport?
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Only lipophilic
Not specific & widely distributed (steroids) Need a very high dose & toxicity increased penetration across brain barrier |
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Facilitated diffusion?
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Same as diffusion but need transporters.
Mostly Hydrophilic. Specific: need appropriate receptor Equilibritive, same as normal diffusion. |
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Active transport
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ATP dependant
Very specific against conc gradient Intracellular conc can exceed plasma --> Increase specificity of drug. (lower dose) Uni directional |
