Antigenic variation is employed by a number of different protozoan parasites. Trypanosoma brucei (the model for study of protozoan antigenic variation) and Plasmodium falciparum are some of the most well studied examples of protozoan parasites that exhibit antigenic variation.ntigenic variation is the expression of various alternative forms of antigen on the cell surface. Whereas phase variation is the phenotypic switch that is usually reversible and is referred to as an ON-OFF switch.
NO: Amitriptyline is a tricyclic antidepressant for depression and some forms of anxiety, sometimes used for chronic pain or migraine. Xanax is a triazolobenzodiazepine or a benzodiazepine with an extra triazole ring structure. It is quite addicting and has a short half-life.
Descriptions. Amitriptyline is used to treat symptoms of depression. It works on the central nervous system (CNS) to increase levels of certain chemicals in the brain. This medicine is a tricyclic antidepressant (TCA).This medicine is available only with your doctor's prescription.mitriptyline is used to treat symptoms of depression. It works on the central nervous system (CNS) to increase levels of certain chemicals in the brain. This medicine is a tricyclic antidepressant (TCA).