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.
Common side effects of amitriptyline include dry mouth, loss of appetite, dizziness, drowsiness and blurred vision. Other side effects may include trouble concentrating, nightmares, and a decreased sex drive. Amitriptyline can be taken at anytime of the day, either with or without food.