Neutrophils and two other cell types (eosinophils and basophils), are known as granulocytes (because they have granules in their cytoplasm) or polymorphonuclear cells (PMNs) due to their distinctive lobed nuclei.
Neutrophil granules contain a variety of toxic substances that kill or inhibit growth of bacteria and fungi. The main products of the neutrophil are strong oxidizing agents. These include hydrogen peroxide, free oxygen radicals and hypochlorite. Neutrophils are the most abundant type of phagocyte, with 50 to 60% of the total circulating leukocytes. They are usually the first cells to arrive at the site of an infection. The bone marrow of a normal healthy adult produces more than 100 billion neutrophils per day, and more than 10 times that many per day during acute inflammation.
Dendritic cells (DC) are phagocytic cells present in tissues that are in contact with the external environment, mainly the skin (where they are often called Langerhans cells), and the inner mucosal lining of the nose, lungs, stomach and intestines. Dendritic cells are very important in the process of antigen presentation, and serve as a link between the innate and adaptive immune systems.
Basophils and eosinophils are cells related to the neutrophil (see above). When activated by a pathogen encounter, basophils releasing histamine are important in defense against parasites, and play a role in allergic reactions (such as asthma). When they are activated, eosinophils secrete a range of highly toxic proteins and free radicals that kill bacteria and parasites. The same chemicals also cause tissue damage during allergic reactions. Activation and toxin release by eosinophils is therefore tightly regulated to prevent any inappropriate tissue destruction.
Natural killer cells, or NK cells, are a part of the innate immune system which does not directly attack invading microbes. Instead, NK cells destroy compromised host cells, such as tumor cells or virus-infected cells. It recognises such cells by a condition known as "missing self". This term describes cells with low levels of a cell-surface marker called MHC I (major histocompatibility complex). This can occur in viral infections of host cells. They were named "natural killer" because they do not require activation in order to kill cells that are "missing self".
Antimicrobial peptides, or host defence peptides, are part of the innate immune response. They are found among all classes of life. These peptides are potent, broad spectrum antibiotics. They kill both gram negative and gram positive bacteria, mycobacteria (including "Mycobacterium tuberculosis"), enveloped viruses, fungi and even transformed or cancerous cells.
Marine fish sources have high levels of antimicrobial compounds. Testing with live fish showed that fish peptides used in food/feed ingredients worked well.
Adolphe-Marie Hardy
Adolphe-Marie Hardy (23 May 1868 in Dison – 19 June 1954 in Laeken) was a Belgian writer first published in 1888 He rose to be a major figure in French literature.
Hardy was educated at Herve, before starting at the University of Louvain in 1886, studying law. After getting his doctorate he returned to Dison, where he carried on his literary work as well as working as a lawyer.
Hardy was editor or assistant editor of several literary journals from 1900 onwards, including Rappel de Charleroi, Dépêche de Liège and the Journal de Bruxelles.
In 1931 Hardy received the Grand Prix de Langue française from the French Academy. He was the first Belgian to win the prize, and he won it for his poem "Le Cortège des mois".
In 1935 he married Madeleine Verhelst. In 1940, they escaped to Issigeac, France. After his wife's death, in 1941, he married Germaine Van Den Boeck.
In May 1954 he was made a Freeman of the City of Dison, and died at Laeken on June 19 of that year.
Charles Ranhofer, chef at Delmonico's honoured Hardy early in his publishing career by naming a goose liver pate after him, and Ranhofer's book "The Epicurean", also lists a chicken dish, "Cotelettes De Poulet A La Adolphe Hardy".
Gnarls Barkley
"Not to be confused with Charles Barkley."
Gnarls Barkley is a music group with DJ and music producer Danger Mouse and American rapper Cee Lo Green. The group had a hit song in 2006 with "Crazy". "Rolling Stone" later named the song as one of the "Best Songs of the 2000s". Gnarls Barkley has released two albums: "St. Elsewhere" in 2006, and "The Odd Couple" in 2008.
In 2006 Gnarls Barkley released their first album "St. Elsewhere". It went straight to number one in the UK. The album's first single "Crazy" was the best-selling song of 2006 in the UK. The song won a Grammy Award for Best Urban/Alternative Performance in 2007. In 2008 Gnarls Barkley released their second album "The Odd Couple". It had a less pop sound than their first album. It was nominated for the Grammy for Best Alternative Album.
All Saints (group)
The All Saints are an English-Canadian pop group. They were founded in 1993. The members of All Saints are British Melanie Blatt, Shaznay Lewis and Canadian sisters Natalie and Nicole Appleton. The group were one of the most successful pop groups in the UK in the 1990s with nine Top 10 singles, two platinum albums and two gold albums. The group biggest was the 1997 single "Never Ever".
Oxygen difluoride
Oxygen difluoride is the chemical compound with the formula OF. It has a V-shaped molecular structure like HO, but has different properties. It is a strong oxidizer.
Oxygen difluoride was first prepared in 1929. It was made by the electrolysis of molten potassium fluoride and hydrofluoric acid. The chemicals had a small amount of moisture. Nowadays, it is prepared by the reaction of fluorine with a dilute aqueous solution of sodium hydroxide. Sodium fluoride is left as a side-product:
It is a very powerful oxidizing agent. This is proved by the oxidation number of +2 for the oxygen atom. This oxidising number is quite unusual. Above 200 °C, OF decomposes to oxygen and fluorine.
OF reacts with many metals. It produces oxides and fluorides. Nonmetals also react with it. Phosphorus reacts with OF to form PF and POF. Sulfur produces SO and SF with it. A noble gas, xenon also reacts with it. It produces XeF and xenon oxyfluorides.
Oxygen difluoride reacts very slowly with water to form hydrofluoric acid:
Oxygen difluoride oxidizes sulfur dioxide to sulfur trioxide:
However, in the presence of UV radiation the products are sulfuryl fluoride, , and pyrosulfuryl fluoride, :
OF is a dangerous chemical. This is because it is highly oxidising.
Phosphorus pentafluoride
Phosphorus pentafluoride, PF, is a phosphorus halide. It's a colorless gas at room temperature and pressure. It can be formed when OF reacts with phosphorus.
Adaptive immune system
The adaptive immune system is made of specialized cells and processes which kill pathogens or prevent their attack.
The adaptive immune system is switched on by the evolutionarily older innate immune system. This older system is non-specific, whereas the adaptive system is tailored to specific targets.
Whereas the innate immune system is found in all metazoa, the adaptive system is only found in vertebrates. It is thought to have arisen in the first jawed vertebrates.
The adaptive immune response gives the vertebrate immune system the ability to recognize and remember specific pathogens. The system mounts stronger attacks each time a particular pathogen is encountered. It is "adaptive" immunity because the body's immune system prepares itself for future challenges.
The immune system protects organisms from infection with layered defences. In simple terms, physical barriers prevent pathogens such as bacteria and viruses from entering the organism.
If a pathogen breaches these barriers, the innate immune system provides an immediate, but non-specific response. Innate immune systems are found in all plants and animals.