COS cells

COS is a fibroblast-like cell line derived from monkey kidney tissue. COS cells are obtained by immortalizing CV-1 cells with a version of the SV40 virus that can produce large T antigen but has a defect in genomic replication. The CV-1 cell line in turn was derived from the kidney of the African green monkey.

The acronym "COS" is derived from the cells being CV-1 (simian) in Origin, and carrying the SV40 genetic material. Two forms of COS cell lines commonly used are COS-1 and COS-7.

Applications

The COS cell line is often used by biologists when studying the monkey virus SV40. Cells from this line are also often transfected to produce recombinant proteins for molecular biology, biochemistry, and cell biology experiments.

When an expression construct with an SV40 promoter is introduced into COS cells, the vector can be replicated substantially by the large T antigen.

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Cos

Cos, COS, CoS, "coS" or Cos. may refer to:

Mathematics, science and technology

Medicine

Così

Così is a play by Australian playwright Louis Nowra which was first performed in 1992 at the Belvoir St Theatre in Sydney, Australia. Set in a Melbourne mental hospital in 1971, Così is semi-autobiographical, and is the sequel to his previous semi-autobiographical play, Summer of the Aliens.

The play was adapted into the 1996 film Cosi.

Plot summary

Set several years after the events of Summer of the Aliens, Lewis is now in a strained relationship with a bossy woman named Lucy, and in a friendship with political extremist, Nick. Lewis is always desperate for work as he states "I need the money". The venue is a theatre that smells of "burnt wood and mould", the cast are patients with very diverse needs, and the play is Mozart's Così fan tutte. Through working with the patients, Lewis eventually discovers a new side of himself which allows him to become emotionally involved and to value love, while anti-Vietnam war protests erupt in the streets outside.

Characters

The patients make up a wide spectrum including Roy, a manic-depressive with a passion for theatre; Cherry, who has a food obsession and is a Lewis-addicted romantic; Ruth, suffering from obsessive–compulsive disorder (OCD) and is shown as obsessed with counting and distinguishing between illusions and reality; Doug, a pyromaniac, who loves sexual innuendo; Julie, dependent on drugs in the outside world; Henry, an older, silent man, previously a lawyer; and Zac, a drugged-up pianist.

Écos

Écos is a commune in the Eure department in northern France.

Population

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Cell (biology)

The cell (from Latin cella, meaning "small room") is the basic structural, functional, and biological unit of all known living organisms. A cell is the smallest unit of life that can replicate independently, and cells are often called the "building blocks of life". The study of cells is called cell biology.

Cells consist of cytoplasm enclosed within a membrane, which contains many biomolecules such as proteins and nucleic acids. Organisms can be classified as unicellular (consisting of a single cell; including bacteria) or multicellular (including plants and animals). While the number of cells in plants and animals varies from species to species, humans contain more than 10 trillion (10¹³) cells. Most plant and animal cells are visible only under the microscope, with dimensions between 1 and 100 micrometres.

The cell was discovered by Robert Hooke in 1665, who named the biological unit for its resemblance to cells inhabited by Christian monks in a monastery.Cell theory, first developed in 1839 by Matthias Jakob Schleiden and Theodor Schwann, states that all organisms are composed of one or more cells, that cells are the fundamental unit of structure and function in all living organisms, that all cells come from preexisting cells, and that all cells contain the hereditary information necessary for regulating cell functions and for transmitting information to the next generation of cells. Cells emerged on Earth at least 3.5 billion years ago.

Beta cell

Beta cells (β cells) are a type of cell found in the pancreatic islets of the pancreas. They make up 65-80% of the cells in the islets.

Function

The primary function of a beta cell is to store and release insulin. Insulin is a hormone that brings about effects which reduce blood glucose concentration. Beta cells can respond quickly to spikes in blood glucose concentrations by secreting some of their stored insulin while simultaneously producing more.

Control of insulin secretion

Voltage-gated calcium channels and ATP-sensitive potassium ion channels are embedded in the cell surface membrane of beta cells. These ATP-sensitive potassium ion channels are normally open and the calcium ion channels are normally closed. Potassium ions diffuse out of the cell, down their concentration gradient, making the inside of the cell more negative with respect to the outside (as potassium ions carry a positive charge). At rest, this creates a potential difference across the cell surface membrane of -70mV.

Alpha cell

Alpha cells (more commonly alpha-cells or α-cells) are endocrine cells in the pancreatic islets of the pancreas. They make up to 20% of the human islet cells synthesizing and secreting the peptide hormone glucagon, which elevates the glucose levels in the blood.

Functions

To elevate glucose levels, glucagon binds to receptors on hepatocytes (liver cells) and some other cells (e.g. kidney cells). This activates an enzyme, glycogen phosphorylase, inside the hepatocyte to hydrolyse glycogen to glucose. This process is called glycogenolysis. In rodents, alpha cells are located in the periphery of the islets, however in humans the islet architecture is generally less organized and alpha cells are frequently observed inside the islets as well. When being viewed by an electron microscope, alpha cells can be identified by their characteristic granules with a large dense core and a small white halo.

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