Science

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depyrogenation

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Depyrogenation refers to the removal of pyrogens from solution, most commonly from injectable pharmaceuticals.
A pyrogen is defined as any substance that can cause a fever. A pyrogen can either be an endotoxin or an exotoxin, although most pyrogens are endogenous. Endotoxins are lipopolysaccharide (LPS) molecules found as part of the cell wall of gram-negative bacteria (see right), and are released primarily upon cell lysis. Endotoxins are typically only toxic when found in the bloodstream, and gram-negative bacteria exist routinely in human intestines, but do not cause a pyrogenic effect.
The fever inducing aspect of pyrogens does not refer to fever as part of a normal immune response, as may be the case with the flu, for example. Rather, the fever is caused as a direct result of pyrogen exposure and is one of the symptoms of septic shock. When the LPS is released upon cell lysis, "Lipid A" binds to LPS-binding proteins in the bloodstream, which interact with CD14 receptors on endothelial cells (esp. macrophages and monocytes) and causes them to secrete increased levels of pro-inflammatory cytokines and nitric oxide, which leads to septic shock.

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colloid

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A colloid is a substance microscopically dispersed evenly throughout another one.[1]
A colloidal system consists of two separate phases: a dispersed phase (or internal phase) and a continuous phase (or dispersion medium). A colloidal system may be solid, liquid, or gaseous.
The dispersed-phase particles have a diameter of between approximately 5 and 200 nanometers.[2] Such particles are normally invisible to an optical microscope, though their presence can be confirmed with the use of an ultramicroscope or an electron microscope. Homogeneous mixtures with a dispersed phase in this size range may be called colloidal aerosols, colloidal emulsions, colloidal foams, colloidal dispersions, or hydrosols. The dispersed-phase particles or droplets are affected largely by the surface chemistry present in the colloid. e.g. milk

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lectin

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Lectins are sugar-binding proteins or glycoproteins that are highly specific for their sugar moieties. They play a role in biological recognition phenomena involving cells and proteins. For example, some viruses use lectins to attach themselves to the cells of the host organism during infection. Lectins may be disabled by specific mono- and oligosaccharides, which bind to them and prevent their attachment to cell membranes.[1]

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moiety

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The word moiety is often used synonymously to "functional group," but, according to the IUPAC definition,[3] a moiety is a part of a molecule that may include functional groups as substructures. For example, an ester is divided into an alcohol moiety and an acyl moiety, but has an ester functional group.

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polyethylene glycol

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Polyethylene glycol (PEG) is a polyether compound with many applications from industrial manufacturing to medicine. PEG is used in a number of toothpastes as a dispersant; it binds water and helps keep gum uniform throughout the toothpaste. It is also under investigation for use in body armor and tattoos to monitor diabetes.[15][16]
Low-molecular-weight (PEG 400) is used in Hewlett-Packard designjet printers as a ink dissolvent and lubricant for the print heads.
PEG is a commonly used precipitant for protein crystallization. X-ray diffraction of protein crystals can reveal the atomic structure of proteins.
Polymer segments derived from PEG polyols impart flexibility to polyurethanes for applications such as elastomeric fibers (spandex) and foam cushions.