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Hepatitis C Virus Life Cycle. The mammalian immune system has evolved complex methods for addressing and adapting to foreign antigens. At the same time, viruses have co-evolved evasion machinery to address the many ways that host organisms attempt to eradicate them.
Antigenic escape, immune escape, immune evasion or escape mutation occurs when the immune system of a host, especially of a human being, is unable to respond to an infectious agent: the host's immune system is no longer able to recognize and eliminate a pathogen, such as a virus.
Antigenic variation or antigenic alteration refers to the mechanism by which an infectious agent such as a protozoan, bacterium or virus alters the proteins or carbohydrates on its surface and thus avoids a host immune response, making it one of the mechanisms of antigenic escape. It is related to phase variation. Antigenic variation not only ...
Immune tolerance encompasses the range of physiological mechanisms by which the body reduces or eliminates an immune response to particular agents. It is used to describe the phenomenon underlying discrimination of self from non-self, suppressing allergic responses, allowing chronic infection instead of rejection and elimination, and preventing ...
Thermodynamically the flow of substances from one compartment to another can occur in the direction of a concentration or electrochemical gradient or against it. If the exchange of substances occurs in the direction of the gradient, that is, in the direction of decreasing potential, there is no requirement for an input of energy from outside the system; if, however, the transport is against ...
Cellular hypertrophy is an increase in cell size and volume. If enough cells of an organ hypertrophy the whole organ will increase in size. Hypertrophy may involve an increase in intracellular protein as well as cytosol (intracellular fluid) and other cytoplasmic components.
The exact mechanism(s) underpinning aldosterone escape are an active subject of research, though several mechanisms have been proposed. [ 3 ] Proposed mechanisms for this phenomenon do not include a reduced sensitivity of mineralocorticoid receptors to aldosterone, because low serum potassium is often seen in these patients, which is the direct ...
A white-headed dwarf gecko with tail lost due to autotomy. Autotomy (from the Greek auto-, "self-" and tome, "severing", αὐτοτομία) or 'self-amputation', is the behaviour whereby an animal sheds or discards an appendage, [1] usually as a self-defense mechanism to elude a predator's grasp or to distract the predator and thereby allow escape.