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{{redirect|Neutrophil|organisms that grow in neutral pH environments|neutrophile}}
[[File:Potomac green water.JPG|upright|thumb|The eutrophication of the [[Potomac River]] is evident from the bright green water, caused by a dense bloom of [[cyanobacteria]].]]
{{Infobox Anatomy |
'''Eutrophication''' ([[greek language|Greek]]: ''eutrophia''—healthy, adequate nutrition, development; {{lang-de|Eutrophie}}) or more precisely '''hypertrophication''', is the ecosystem response to the addition of artificial or natural substances, such as [[nitrate]]s and [[phosphate]]s, through [[fertilizer]]s or [[sewage]], to an aquatic system.<ref>''Over fertilization of the World's Freshwaters and Estuaries.'' University of Alberta Press. p. 1.</ref> One example is the "bloom" or great increase of [[phytoplankton]] in a water body as a response to increased levels of nutrients. Negative environmental effects include [[Hypoxia (environmental)|hypoxia]], the depletion of oxygen in the water, which induces reductions in specific fish and other animal populations. Other species (such as [[Nomura's jellyfish]] in Japanese waters) may experience an increase in population that negatively affects other [[species]].
Name = Eutriphication |
Latin = | Utrophilis Tripolis
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Image = Neutrophils.jpg|
Caption = Neutrophils with a segmented nuclei surrounded by [[erythrocytes]], the intra-cellular granules are visible in the [[cytoplasm]] ([[Giemsa stain]]ed) |
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Code = {{TerminologiaHistologica|2|00|04.1.02012}} |
}}


'''Eutrophication''' are the most abundant type of [[white blood cell]]s in mammals and form an essential part of the [[innate immune system]]. In general, they are referred to as either '''neutrophils''' or '''polymorphonuclear neutrophils''' (or '''PMNs'''), and are subdivided into '''segmented neutrophils''' (or '''segs''') and '''[[band cell|banded neutrophils]]''' (or '''bands'''). They form part of the polymorphonuclear cell family (PMNs) together with [[basophils]] and [[eosinophils]].<ref name="Witko">{{cite journal
==Lakes and rivers==
| last = Witko-Sarsat
Eutrophication can be human-caused or natural. Untreated sewage effluent and agricultural run-off carrying fertilizers are examples of human-caused eutrophication. However, it also occurs naturally in situations where nutrients accumulate (e.g. depositional environments), or where they flow into systems on an ephemeral basis. Eutrophication generally promotes excessive plant growth and decay, favouring simple algae and plankton over other more complicated plants, and causes a severe reduction in water quality. Phosphorus is a necessary nutrient for plants to live, and is the limiting factor for plant growth in many freshwater ecosystems. The addition of phosphorus increases algal growth, but not all phosphates actually feed algae.<ref>{{cite web|last=Hochanadel|first=Dave|title=Limited amount of total phosphorus actually feeds algae, study finds|url=http://www.lakescientist.com/2010/limited-amount-of-total-phosphorus-actually-feeds-algae-study-finds|publisher=Lake Scientist|accessdate=June 10, 2012|date=December 10, 2010|quote=[B]ioavailable phosphorus – phosphorus that can be utilized by plants and bacteria – is only a fraction of the total, according to Michael Brett, a UW engineering professor ...}}</ref> These algae assimilate the other necessary nutrients needed for plants and animals. When algae die they sink to the bottom where they are decomposed and the nutrients contained in organic matter are converted into inorganic form by bacteria. The decomposition process uses oxygen and deprives the deeper waters of oxygen which can kill fish and other organisms. Also the necessary nutrients are all at the bottom of the aquatic ecosystem and if they are not brought up closer to the surface, where there is more available light allowing for photosynthesis for aquatic plants, a serious strain is placed on algae populations. Enhanced growth of aquatic vegetation or [[phytoplankton]] and [[algal bloom]]s disrupts normal functioning of the ecosystem, causing a variety of problems such as a lack of [[oxygen]] needed for fish and [[shellfish]] to survive. The water becomes cloudy, typically coloured a shade of green, yellow, brown, or red. Eutrophication also decreases the value of rivers, lakes, and estuaries for recreation, fishing, hunting, and aesthetic enjoyment. Health problems can occur where [[eutrophic]] conditions interfere with drinking [[water treatment]].<ref name="Bartram 1999">Bartram, J., Wayne W. Carmichael, Ingrid Chorus, Gary Jones, and Olav M. Skulberg. 1999. Chapter 1. Introduction, In: ''Toxic Cyanobacteria in Water: A guide to their public health consequences, monitoring and management''. [[World Health Organization]]. URL: [http://www.who.int/water_sanitation_health/resourcesquality/toxicyanbact/en/ WHO document]</ref>
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The name ''neutrophil'' derives from staining characteristics on [[hematoxylin]] and [[eosin]] (H&E) [[histology|histological]] or [[cell biology|cytological]] preparations. Whereas [[basophilic]] white blood cells stain dark blue and [[eosinophilic]] white blood cells stain bright red, neutrophils stain a neutral pink. Normally, neutrophils contain a nucleus divided into 2–5 lobes.
Eutrophication was recognized as a [[water pollution]] problem in European and North American lakes and reservoirs in the mid-20th century.<ref name="Rohde 1969">Rodhe, W. 1969 Crystallization of eutrophication concepts in North Europe. In: ''Eutrophication, Causes, Consequences, Correctives''. National Academy of Sciences, Washington D.C., Standard Book Number 309-01700-9, 50-64.</ref> Since then, it has become more widespread. Surveys showed that 54% of lakes in [[Asia]] are [[eutrophic]]; in [[Europe]], 53%; in [[North America]], 48%; in [[South America]], 41%; and in [[Africa]], 28%.<ref name="ILEC">ILEC/Lake Biwa Research Institute [Eds]. 1988-1993 Survey of the State of the World's Lakes. Volumes I-IV. International Lake Environment Committee, Otsu and United Nations Environment Programme, Nairobi.</ref>


Neutrophils are normally found in the [[blood]] stream. During the beginning ([[acute (medical)|acute]]) phase of [[inflammation]], particularly as a result of [[bacteria]]l [[infection]], environmental exposure,<ref name="Jacobs">{{cite journal
Although eutrophication is commonly caused by human activities, it can also be a natural process particularly in lakes. Eutrophy occurs in many lakes in temperate grasslands, for instance. [[paleolimnology|Paleolimnologists]] now recognise that climate change, geology, and other external influences are critical in regulating the natural productivity of lakes. Some lakes also demonstrate the reverse process ([[meiotrophication]]), becoming less nutrient rich with time.<ref>Walker, I. R. 2006. Chironomid overview. pp.360-366 in S.A. EIias (ed.) Encyclopedia of Quaternary Science, Vo1. 1, Elsevier,</ref><ref>Whiteside. M. C. 1983. The mythical concept of eutrophication. Hydrobiologia 103, 107-111.</ref>
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</ref> neutrophils are one of the first-responders of inflammatory cells to migrate towards the site of inflammation. They migrate through the blood vessels, then through [[:wikt:interstitial|interstitial]] tissue, following chemical signals such as [[Interleukin-8]] (IL-8), [[C5a]], [[N-Formylmethionine leucyl-phenylalanine|fMLP]] and [[Leukotriene B4]] in a process called [[chemotaxis]]. They are the predominant cells in [[pus]], accounting for its whitish/yellowish appearance.


Neutrophils are recruited to the site of injury within minutes following trauma and are the hallmark of acute inflammation.<ref>Cohen, Stephen. Burns, Richard C. Pathways of the Pulp, 8th Edition. St. Louis: Mosby, Inc. 2002. page 465.</ref>
Eutrophication can also be a natural process in seasonally inundated tropical floodplains. In the [[Barotse Floodplain]] of the [[Zambezi River]], the first floodwaters of the [[rainy season]] are usually [[Hypoxia (environmental)|hypoxic]] because of material such as cattle manure and previous decay of vegetation which grew during the dry season. These so-called "red waters" kill many fish.<ref name="IUCN">[http://www.cbd.int/doc/case-studies/inc/cs-inc-iucn-12-en.pdf "Barotse Floodplain, Zambia: local economic dependence on wetland resources."] ''Case Studies in Wetland Valuation #2'': IUCN, May 2003.</ref> The process can be made worse by the use of fertilizers in crops such as maize, rice, and sugarcane grown on the floodplain.


==Characteristics==
Human activities can accelerate the rate at which nutrients enter [[ecosystem]]s. Runoff from [[agriculture]] and development, pollution from [[septic system]]s and [[sanitary sewer|sewers]], and other human-related activities increase the flow of both inorganic nutrients and organic substances into ecosystems. Elevated levels of atmospheric compounds of [[nitrogen]] can increase nitrogen availability. [[Phosphorus]] is often regarded as the main culprit in cases of eutrophication in lakes subjected to "point source" pollution from sewage pipes. The concentration of algae and the trophic state of lakes correspond well to phosphorus levels in water. Studies conducted in the Experimental Lakes Area in Ontario have shown a relationship between the addition of phosphorus and the rate of eutrophication. Humankind has increased the rate of [[Phosphorus cycle|phosphorus cycling]] on Earth by four times, mainly due to agricultural fertilizer production and application. Between 1950 and 1995, an estimated 600,000,000 [[tonne]]s of phosphorus were applied to Earth's surface, primarily on croplands.<ref name="Carpenter, S.R. 1998">Carpenter, S.R., N.F. Caraco, and V.H. Smith. 1998. Nonpoint pollution of surface waters with phosphorus and nitrogen. Ecological Applications 8:559-568.</ref> Policy changes to control point sources of phosphorus have resulted in rapid control of eutrophication.{{cn|date=June 2012}}
[[Image:NeutrophilerAktion.png|thumb|Neutrophil granulocyte migrates from the blood vessel to the matrix, sensing proteolytic enzymes, in order to determine intercellular connections (to the improvement of its mobility) and envelop bacteria through phagocytosis.]]
Neutrophil granulocytes have an average diameter of 12–15 [[micrometre|micrometers]] (µm) in [[blood film|peripheral blood smears]]. When analyzing a pure neutrophil suspension on an automated cell counter, neutrophils have an average diameter of 8–9&nbsp;µm.


With the [[eosinophil granulocyte|eosinophil]] and the [[basophil granulocyte|basophil]], they form the class of ''polymorphonuclear cells'', named for the [[cell nucleus|nucleus]]'s multilobulated shape (as compared to [[lymphocyte]]s and [[monocyte]]s, the other types of white cells). The nucleus has a characteristic lobed appearance, the separate lobes connected by [[chromatin]]. The nucleolus disappears as the neutrophil matures, which is something that happens in only a few other types of nucleated cells.<ref>Zucker-Franklin, p. 168.</ref> In the cytoplasm, the [[Golgi apparatus]] is small, [[mitochondria]] and [[ribosome]]s are sparse, and the rough [[endoplasmic reticulum]] is absent.<ref name=ZF170>Zucker-Franklin, p. 170.</ref> The cytoplasm also contains about 200 granules, of which a third are [[Azurophilic granule|azurophilic]].<ref name=ZF170/>
==Ocean waters==
Eutrophication is a common phenomenon in coastal waters. In contrast to freshwater systems, nitrogen is more commonly the key limiting nutrient of marine waters; thus, [[nitrogen]] levels have greater importance to understanding eutrophication problems in salt water. [[Estuary|Estuaries]] tend to be naturally eutrophic because land-derived nutrients are concentrated where run-off enters a confined channel. Upwelling in coastal systems also promotes increased productivity by conveying deep, nutrient-rich waters to the surface, where the nutrients can be assimilated by [[algae]].


A minor difference is found between the neutrophils from a male subject and a female subject. The cell nucleus of a neutrophil from a female subject shows a small additional X chromosome structure, known as a "neutrophil drumstick".<ref>Zucker-Franklin, p. 174.</ref>
The [[World Resources Institute]] has identified 375 hypoxic coastal zones in the world, concentrated in coastal areas in Western Europe, the Eastern and Southern coasts of the US, and East Asia, particularly Japan.<ref>
Selman, Mindy (2007) ''Eutrophication: An Overview of Status, Trends, Policies, and Strategies.'' World Resources Institute.</ref>


Neutrophils will show hypersegmentation (many segments of nucleus) in B12 and folate deficiency.
In addition to runoff from land, atmospheric [[Nitrogen fixation|fixed nitrogen]] can enter the open ocean. A study in 2008 found that this could account for around one third of the ocean’s external (non-recycled) nitrogen supply, and up to 3% of the annual new marine biological production.<ref>Duce, R A and 29 others (2008) ''Impacts of Atmospheric Anthropogenic Nitrogen on the Open Ocean'' Science. Vol 320, pp 893–89</ref> It has been suggested that accumulating reactive nitrogen in the environment may prove as serious as putting carbon dioxide in the atmosphere.<ref>[http://www.eurekalert.org/pub_releases/2008-05/uov-at051208.php ''Addressing the nitrogen cascade''] Eureka Alert, 2008.</ref>


[[Image:Reference ranges for blood tests - white blood cells.png|thumb|400px|left|[[Reference ranges for blood tests]] of white blood cells, comparing neutrophil amount (shown in pink) with that of other cells.]]
==Terrestrial ecosystems==
Terrestrial ecosystems are subject to similarly adverse impacts from eutrophication.<ref name="APIS 2005">APIS. 2005. Website: [http://www.apis.ac.uk/overview/issues/overview_eutrophication.htm Air Pollution Information System] Eutrophication</ref> Increased nitrates in soil are frequently undesirable for plants. Many terrestrial plant species are endangered as a result of soil eutrophication, such as the majority of orchid species in Europe.<ref>{{cite book |last= Pullin |first= Andrew S. |title= Conservation biology |publisher= Cambridge University Press |year= 2002 |isbn= 0-521-64482-8}}</ref> Meadows, forests, and bogs are characterized by low nutrient content and slowly growing species adapted to those levels, so they can be overgrown by faster growing and more competitive species. In meadows, tall grasses that can take advantage of higher nitrogen levels may change the area so that natural species may be lost. Species-rich [[fen]]s can be overtaken by reed or reedgrass species. Forest undergrowth affected by run-off from a nearby fertilized field can be turned into a nettle and bramble thicket.


Neutrophils are the most abundant white blood cells in humans (approximately 10<sup>11</sup> are produced daily); they account for approximately 50-70% of all white blood cells (leukocytes). The stated normal range for human blood counts varies between laboratories, but a neutrophil count of 2.5–7.5 x 10<sup>9</sup>/L is a standard normal range. People of [[Africa]]n and [[Middle East]]ern descent may have lower counts, which are still normal. A report may divide neutrophils into segmented neutrophils and [[band cell|bands]].
Chemical forms of nitrogen are most often of concern with regard to eutrophication, because plants have high nitrogen requirements so that additions of nitrogen compounds will stimulate plant growth. Nitrogen is not readily available in soil because N<sub>2</sub>, a gaseous form of nitrogen, is very stable and unavailable directly to higher plants. Terrestrial ecosystems rely on [[microbe|microbial]] [[nitrogen fixation]] to convert N<sub>2</sub> into other forms such as [[nitrate]]s. However, there is a limit to how much nitrogen can be utilized. Ecosystems receiving more nitrogen than the plants require are called nitrogen-saturated. Saturated terrestrial ecosystems then can contribute both inorganic and organic nitrogen to freshwater, coastal, and marine eutrophication, where nitrogen is also typically a [[Limiting factor|limiting nutrient]].<ref name="Hornung 1995">Hornung M., Sutton M.A. and Wilson R.B. [Eds.] (1995): Mapping and modelling of critical loads for nitrogen&nbsp;— a workshop report. Grange-over-Sands, Cumbria, UK. UN-ECE Convention on Long Range Transboundary Air Pollution, Working Group for Effects, 24–26 October 1994. Published by: Institute of Terrestrial Ecology, Edinburgh, UK.</ref> This is also the case with increased levels of phosphorus. However, because [[phosphorus]] is generally much less [[soluble]] than nitrogen, it is [[Leaching (agriculture)|leached]] from the soil at a much slower rate than nitrogen. Consequently, [[phosphorus]] is much more important as a limiting nutrient in aquatic systems.<ref name="Smith 1999">{{cite journal| last=Smith| first= V.H.| coauthors= G.D. Tilman, and J.C. Nekola| year= 1999| title= Eutrophication: impacts of excess nutrient inputs on freshwater, marine, and terrestrial ecosystems| journal=Environmental Pollution| volume=100| pages=179–196| doi= 10.1016/S0269-7491(99)00091-3| pmid=15093117| issue=1–3}}</ref>


When circulating in the bloodstream and unactivated, neutrophils are spherical. Once activated, they change shape and become more amorphous or amoeba-like and can extend pseudopods as they hunt for antigens.<ref name=edwards>{{cite book|last=Edwards|first=Steven W.|title=Biochemistry and physiology of the neutrophil|publisher=Cambridge University Press|year=1994|pages=6|isbn=0-521-41698-1|url=http://books.google.com.au/books?id=S7o3YYskc-oC&pg=PA6&dq=%22surface+receptors%22+neutrophil&hl=en&ei=0Bx1Tp7qBI-aiAeaiMDHDQ&sa=X&oi=book_result&ct=result&resnum=2&ved=0CDUQ6AEwAQ#v=onepage&q=%22surface%20receptors%22%20neutrophil&f=false}}</ref>
==Ecological effects==
[[Image:Caspian Sea from orbit.jpg|thumb|upright|Eutrophication is apparent as increased [[turbidity]] in the northern part of the [[Caspian Sea]], imaged from orbit.]]
Many ecological effects can arise from stimulating [[primary production]], but there are three particularly troubling ecological impacts: decreased biodiversity, changes in species composition and dominance, and toxicity effects.
* Increased biomass of [[phytoplankton]]
* Toxic or inedible phytoplankton species
* Increases in blooms of gelatinous [[zooplankton]]
* Increased [[Biomass (ecology)|biomass]] of [[benthic]] and [[epiphytic]] [[algae]]
* Changes in [[macrophyte]] species composition and biomass
* Decreases in water transparency (increased [[turbidity]])
* Colour, smell, and water treatment problems
* [[Oxygen saturation|Dissolved oxygen]] depletion
* Increased incidences of [[fish kill]]s
* Loss of desirable fish species
* Reductions in harvestable fish and [[shellfish]]
* Decreases in perceived aesthetic value of the water body


==Life span==
===Decreased biodiversity===
[[Image:Hematopoiesis simple.svg|thumb|400px|HSC=[[Hematopoietic stem cell]], Progenitor=[[Progenitor cell]], L-blast=[[lymphoblast]], [[Lymphocyte]], Mo-blast=[[Monoblast]], [[Monocyte]], [[Myeloblast]], Pro-M=[[Promyelocyte]], [[Myelocyte]], Meta-M=[[Metamyelocyte]], [[Neutrophil]], [[Eosinophil]], [[Basophil]], Pro-E=[[Proerythroblast]], Baso-E=[[Basophilic erythroblast]], poly-e=[[Polychromatic erythroblast]], Ortho-E=[[orthochromatic erythroblast]], [[Erythrocyte]], [[Promegakaryocyte]], [[megakaryocyte]], [[Platlet]] ]]
When an ecosystem experiences an increase in nutrients, primary producers reap the benefits first. In aquatic ecosystems, species such as algae experience a population increase (called an [[algal bloom]]). Algal blooms limit the sunlight available to bottom-dwelling organisms and cause wide swings in the amount of dissolved oxygen in the water.
Oxygen is required by all aerobically [[Respiration (physiology)|respiring]] plants and animals and it is replenished in daylight by [[photosynthesis|photosynthesizing]] plants and algae. Under eutrophic conditions, dissolved oxygen greatly increases during the day, but is greatly reduced after dark by the respiring algae and by microorganisms that feed on the increasing mass of dead algae. When dissolved oxygen levels decline to [[hypoxia (environmental)|hypoxic]] levels, fish and other marine animals suffocate. As a result, creatures such as fish, shrimp, and especially immobile bottom dwellers die off.<ref name="Horrigan 2002">{{cite journal| doi=10.1289/ehp.02110445| last=Horrigan| first= L.| coauthors= R. S. Lawrence, and P. Walker| year= 2002| title= How sustainable agriculture can address the environmental and human health harms of industrial agriculture| journal= Environmental health perspectives| volume=110| pages=445–456| pmid=12003747| issue=5| pmc=1240832}}</ref> In extreme cases, [[Anaerobic organism|anaerobic]] conditions ensue, promoting growth of bacteria such as ''[[Clostridium botulinum]]'' that produces [[toxins]] deadly to birds and mammals. Zones where this occurs are known as [[Dead zone (ecology)|dead zones]].


The average lifespan of (non-activated [[human]]) neutrophils in the circulation is about 5.4 days.<ref>Pillay J, den Braber I, Vrisekoop N, Kwast LM, de Boer RJ, Borghans JA, Tesselaar K, Koenderman L. [http://bloodjournal.hematologylibrary.org/cgi/content/full/116/4/625 In vivo labeling with 2H2O reveals a human neutrophil lifespan of 5.4 days] Blood. 2010 Jul 29;116(4):625-7.</ref> Upon activation, they marginate (position themselves adjacent to the blood vessel endothelium), and undergo [[selectin]]-dependent capture followed by [[integrin]]-dependent adhesion in most cases, after which they migrate into tissues, where they survive for 1–2 days.<ref name=Wheater/>
===New species invasion===
Eutrophication may cause competitive release by making abundant a normally [[Limiting factor|limiting nutrient]]. This process causes shifts in the species composition of ecosystems. For instance, an increase in nitrogen might allow new, [[invasive species|competitive species]] to invade and out-compete original inhabitant species. This has been shown to occur<ref name="Bertness 2001">Bertness et al. 2001</ref> in [[New England]] [[salt marsh]]es.


Neutrophils are much more numerous than the longer-lived [[monocyte]]/[[macrophage]] phagocytes. A [[pathogen]] (disease-causing microorganism or virus) is likely to first encounter a neutrophil. Some experts hypothesize that the short lifetime of neutrophils is an [[evolution]]ary adaptation. The short lifetime of neutrophils minimizes propagation of those pathogens that [[parasite|parasitize]] phagocytes because the more time such parasites spend outside a host [[cell (biology)|cell]], the more likely they will be destroyed by some component of the body's defenses. Also, because neutrophil [[antimicrobial]] products can also damage host [[tissue (biology)|tissue]]s, their short life limits damage to the host during [[inflammation]].<ref name=Wheater>{{cite book |author=Wheater, Paul R.; Stevens, Alan |title=Wheater's basic histopathology: a colour atlas and text |publisher=Churchill Livingstone |location=Edinburgh |year=2002 |pages= |isbn=0-443-07001-6 |oclc= |doi= |accessdate= |url=http://www.ecc-book.com/ACINFLMPDF1.pdf}}</ref>
===Toxicity===
Some [[algal bloom]]s, otherwise called "nuisance algae" or "harmful algal blooms", are [[toxic]] to plants and animals. Toxic compounds they produce can make their way up the [[food chain]], resulting in animal mortality.<ref name="Anderson 1994">Anderson D.M. 1994. Red tides. Scientific American 271:62-68.</ref> Freshwater algal blooms can pose a threat to livestock. When the algae die or are eaten, [[neurotoxin|neuro]]- and [[hepatotoxins]] are released which can kill animals and may pose a threat to humans.<ref name="Lawton 1991">{{cite journal| last=Lawton| first= L.A.| coauthors= G.A. Codd| year= 1991| title= Cyanobacterial (blue-green algae) toxins and their significance in UK and European waters| journal= Journal of Soil and Water Conservation| volume=40| pages=87–97}}</ref><ref name="Martin 1994">{{cite journal| last=Martin| first= A.| coauthors= G.D. Cooke| year= 1994| title= Health risks in eutrophic water supplies| journal= Lake Line| volume= 14| pages=24–26}}</ref>
An example of algal toxins working their way into humans is the case of [[shellfish]] poisoning.<ref name="Shumway 1990">{{cite journal| last= Shumway| first= S.E.| year= 1990| title= A review of the effects of algal blooms on shellfish and aquaculture| journal= Journal of the World Aquaculture Society| volume= 21| pages=65–104| doi= 10.1111/j.1749-7345.1990.tb00529.x| issue= 2}}</ref> Biotoxins created during algal blooms are taken up by shellfish (mussels, oysters), leading to these human foods acquiring the toxicity and poisoning humans. Examples include [[paralysis|paralytic]], neurotoxic, and [[Diarrhea|diarrhoetic]] shellfish poisoning. Other marine animals can be [[Vector (epidemiology)|vectors]] for such toxins, as in the case of [[ciguatera]], where it is typically a predator fish that accumulates the toxin and then poisons humans.


Neutrophils will often be [[phagocytosed]] themselves by macrophages after digestion of pathogens. [[PECAM-1]] and [[phosphatidylserine]] on the cell surface are involved in this process.
==Sources of high nutrient runoff==
{| class="wikitable" style="float:right; margin:1em;"
|+''Characteristics of point and nonpoint sources of chemical inputs (<ref name="Carpenter, S.R. 1998"/> modified from Novonty and Olem 1994)''
|-
|'''Point sources'''
<small>
* Wastewater effluent (municipal and industrial)
* Runoff and leachate from waste disposal systems
* Runoff and infiltration from animal feedlots
* Runoff from mines, oil fields, unsewered industrial sites
* Overflows of combined storm and sanitary sewers
* Runoff from construction sites less than 20,000 m² (220,000&nbsp;ft²)
* Untreated sewage</small>
<br>
'''Nonpoint sources'''
<small>
* Runoff from agriculture/irrigation
* Runoff from pasture and range
* Urban runoff from unsewered areas
* Septic tank leachate
* Runoff from construction sites >20,000 m²
* Runoff from abandoned mines
* Atmospheric deposition over a water surface
* Other land activities generating contaminants
</small>
|}
In order to gauge how to best prevent eutrophication from occurring, specific sources that contribute to nutrient loading must be identified. There are two common sources of nutrients and organic matter: point and [[Nonpoint source pollution|nonpoint]] sources.


===Point sources===
==Chemotaxis==
Neutrophils undergo a process called [[chemotaxis]], which allows them to migrate toward sites of infection or inflammation. Cell surface receptors allow neutrophils to detect chemical gradients of molecules such as [[interleukin-8]] (IL-8), [[interferon gamma]] (IFN-gamma), [[C5a]], and [[Leukotriene B4]], which these cells use to direct the path of their migration.
[[Point source (pollution)|Point sources]] are directly attributable to one influence. In point sources the nutrient waste travels directly from source to water. Point sources are relatively easy to regulate.


Neutrophils have a variety of specific receptors, including complement receptors, cytokine receptors for interleukins and [[interferon gamma]] (IFN-gamma), receptors for chemokines, receptors to detect and adhere to [[endothelium]], receptors for leptins and proteins, and [[Fc receptor]]s for opsonin.<ref>{{cite book|last= Charles N. Serhan, Peter A. Ward, Derek W. Gilroy|title=Fundamentals of Inflammation|publisher=Cambridge University Press|year=2010|pages=53–54|isbn=0-521-88729-1|url=http://books.google.com.au/books?id=cJq1RMPKEYkC&pg=PA54&dq=receptors+neutrophils&hl=en&ei=QUl1TsyaCoXdmAXO3YXfDA&sa=X&oi=book_result&ct=result&resnum=5&ved=0CEMQ6AEwBA#v=onepage&q=receptors%20neutrophils&f=false}}</ref>
===Nonpoint sources===
Nonpoint source pollution (also known as 'diffuse' or 'runoff' pollution) is that which comes from ill-defined and diffuse sources. Nonpoint sources are difficult to regulate and usually vary spatially and temporally (with [[season]], [[Precipitation (meteorology)|precipitation]], and other [[act of god|irregular events]]).


==Anti-microbial function==
It has been shown that nitrogen transport is correlated with various indices of human activity in watersheds,<ref name="Cole 1993">Cole J.J., B.L. Peierls, N.F. Caraco, and M.L. Pace. (1993). Nitrogen loading of rivers as a human-driven process. Pages 141-157 in M.J. McDonnell and S.T.A. Pickett, editors. Humans as components of ecosystems. Springer-Verlag, New York, New York, USA.</ref><ref name="Howarth 1996">Howarth R.W., G. Billen, D. Swaney, A. Townsend, N. Jaworski, K. Lajtha, J.A. Downing, R. Elmgren, N. Caraco, T. Jordan, F. Berendse, J. Freney, V. Kudeyarov, P. Murdoch, and Zhu Zhao-liang. 1996. Regional nitrogen budgets and riverine inputs of N and P for the drainages to the North Atlantic Ocean: natural and human influences. Biogeochemistry 35:75-139.</ref> including the amount of development.<ref name="Bertness 2001"/> [[Plough]]ing in [[agriculture]] and [[urban planning|development]] are activities that contribute most to nutrient loading.
Being highly [[motility|motile]], neutrophils quickly congregate at a focus of [[infection]], attracted by [[cytokine]]s expressed by activated [[endothelium]], [[mast cell]]s, and [[macrophage]]s. Neutrophils express<ref>{{cite journal |author=Ear T, McDonald PP |title=Cytokine generation, promoter activation, and oxidant-independent NF-kappaB activation in a transfectable human neutrophilic cellular model |journal=BMC Immunol. |volume=9|pages=14 |year=2008 |pmid=18405381 |pmc=2322942 |doi=10.1186/1471-2172-9-14 |url=}}</ref> and release [[cytokines]], which in turn amplify inflammatory reactions by several other cell types.
There are three reasons that nonpoint sources are especially troublesome:<ref name="Smith 1999"/>


In addition to recruiting and activating other cells of the immune system, neutrophils play a key role in the front-line defence against invading pathogens. Neutrophils have three strategies for directly attacking micro-organisms: [[phagocytosis]] (ingestion), release of soluble anti-microbials (including granule proteins), and generation of [[neutrophil extracellular traps]] (NETs).<ref name="NatRev">{{cite journal
====Soil retention====
| last = Hickey
Nutrients from human activities tend to accumulate in [[soil]]s and remain there for years. It has been shown<ref name="Sharpley 1996">Sharpley A.N., T.C. Daniel, J.T. Sims, and D.H. Pote. 1996. Determining environmentally sound soil phosphorus levels. Journal of Soil and Water Conservation 51:160-166.</ref> that the amount of [[phosphorus]] lost to surface waters increases linearly with the amount of phosphorus in the soil. Thus much of the nutrient loading in soil eventually makes its way to water. Nitrogen, similarly, has a turnover time of decades or more.
| first = MJ
| coauthors = Kubes P
| title = Intravascular immunity: the host–pathogen encounter in blood vessels
| journal = Nature Reviews Immunology
| volume = 9
| issue = (5)
| pages = 364–75
| year = 2009
| publisher = Nature Publishing Group
| doi = 10.1038/nri2532
| pmid = 19390567
}}</ref>


===Phagocytosis===
====Runoff to surface water and leaching to groundwater====
Neutrophils are phagocytes, capable of ingesting microorganisms or particles. For targets to be recognised, they must be coated in [[opsonin]]s—a process known as [[antibody opsonization]].<ref name=edwards/> They can internalize and kill many [[microbe]]s, each phagocytic event resulting in the formation of a phagosome into which [[reactive oxygen species]] and hydrolytic enzymes are secreted. The consumption of oxygen during the generation of reactive oxygen species has been termed the "[[respiratory burst]]", although unrelated to respiration or energy production.
Nutrients from human activities tend to travel from land to either surface or ground water. Nitrogen in particular is removed through [[storm drains]], sewage pipes, and other forms of [[surface runoff]].
Nutrient losses in runoff and [[leachate]] are often associated with [[agriculture]]. Modern agriculture often involves the application of nutrients onto fields in order to maximise production. However, farmers frequently apply more nutrients than are taken up by crops<ref name="Buol 1995">Buol S. W. 1995. Sustainability of Soil Use. Annual Review of Ecology and Systematics 26:25-44.</ref> or pastures. Regulations aimed at minimising nutrient exports from agriculture are typically far less stringent than those placed on sewage treatment plants<ref name="Carpenter, S.R. 1998"/> and other point source polluters. It should be also noted that lakes within forested land are also under surface runoff influences. Runoff can wash out the mineral nitrogen and phosphorus from detritus and in consequence supply the water bodies leading to slow, natural eutrophication.<ref>P. Klimaszyk, P. Rzymski. Surface Runoff as a Factor Determining Trophic State of Midforest Lake. Polish Journal of Environmental Studies. 2010, 20(5), 1203-1210</ref>


The respiratory burst involves the activation of the [[enzyme]] [[NADPH oxidase]], which produces large quantities of [[superoxide]], a reactive oxygen species. Superoxide dismutates, spontaneously or through catalysis via enzymes known as superoxide dismutases (Cu/ZnSOD and MnSOD), to hydrogen peroxide, which is then converted to [[hypochlorous acid]] HClO, by the green heme enzyme [[myeloperoxidase]]. It is thought that the bactericidal properties of HClO are enough to kill bacteria phagocytosed by the neutrophil, but this may instead be a step necessary for the activation of proteases.
====Atmospheric deposition====
<ref name="SegalRev">{{cite journal
Nitrogen is released into the air because of [[ammonia]] [[volatilization]] and nitrous oxide production. The [[combustion]] of [[fossil fuels]] is a large human-initiated contributor to atmospheric nitrogen pollution. Atmospheric deposition (e.g., in the form of [[acid rain]]) can also affect nutrient concentration in water,<ref name="Paerl 1997">Paerl H. W. 1997. Coastal Eutrophication and Harmful Algal Blooms: Importance of Atmospheric Deposition and Groundwater as "New" Nitrogen and Other Nutrient Sources. Limnology and Oceanography 42:1154-1165.</ref> especially in highly industrialized regions.
| last = Segal
| first = AW | title = How neutrophils kill microbes
| journal = Annu Rev Immunol
| volume = 9
| issue = (5)
| pages = 197–223
| year = 2005
| pmid = 15771570
| doi = 10.1146/annurev.immunol.23.021704.115653
| pmc = 2092448
}}</ref>


===Other causes===
===Degranulation===
Neutrophils also release an assortment of proteins in three types of granules by a process called [[degranulation]]. The contents of these granules have antimicrobial properties, and help combat infection.
Any factor that causes increased nutrient concentrations can potentially lead to eutrophication. In modeling eutrophication, the rate of water renewal plays a critical role; [[stagnant water]] is allowed to collect more nutrients than bodies with replenished water supplies. It has also been shown that the drying of [[wetlands]] causes an increase in nutrient concentration and subsequent eutrophication blooms.<ref name="Mungall 1991">Mungall C. and D.J. McLaren. 1991. Planet under stress: the challenge of global change. Oxford University Press, New York, New York, USA.</ref>


{| class="wikitable"
==Prevention and reversal==
| '''Granule type''' || '''Protein'''
Eutrophication poses a problem not only to [[ecosystem]]s, but to humans as well. Reducing eutrophication should be a key concern when considering future policy, and a [[sustainable agriculture|sustainable solution]] for everyone, including farmers and ranchers, seems feasible. While eutrophication does pose problems, humans should be aware that natural runoff (which causes algal blooms in the wild) is common in ecosystems and should thus not reverse nutrient concentrations beyond normal levels.
|-

| [[specific granule]]s (or "secondary granules") || [[alkaline phosphatase]], [[lysozyme]], [[NADPH oxidase]], [[collagenase]], [[Lactoferrin]] and [[Cathelicidin]]
===Effectiveness===
|-
Cleanup measures have been mostly, but not completely, successful. [[Finland|Finnish]] phosphorus removal measures started in the mid-1970s and have targeted rivers and lakes polluted by industrial and municipal discharges. These efforts have had a 90% removal efficiency.<ref name="Raike 2003">Raimammake A., O.P. Pietilainen, S. Rekolainen, P. Kauppila, H. Pitkanen, J. Niemi, A. Raateland, J. Vuorenmaa. 2003. Trends of phosphorus, nitrogen, and chlorophyll ''a'' concentrations in Finnish rivers and lakes in 1975-2000. The Science of the Total Environment 310:47-59.</ref> Still, some targeted point sources did not show a decrease in runoff despite reduction efforts.
| [[azurophil]]ic granules (or "primary granules") || [[myeloperoxidase]], [[bactericidal/permeability-increasing protein]] (BPI), [[Defensin]]s, and the [[serine protease]]s [[neutrophil elastase]] and [[cathepsin G]]

|-
===Minimizing nonpoint pollution: future work===
| tertiary granules || [[cathepsin]] and [[gelatinase]]
Nonpoint pollution is the most difficult source of nutrients to manage. The literature suggests, though, that when these sources are controlled, eutrophication decreases. The following steps are recommended to minimize the amount of pollution that can enter aquatic ecosystems from ambiguous sources.
|}

====Riparian buffer zones====
Studies show that intercepting non-point pollution between the source and the water is a successful means of prevention.<ref name="Carpenter, S.R. 1998"/> [[riparian|Riparian buffer zones]] are interfaces between a flowing body of water and land, and have been created near waterways in an attempt to filter pollutants; [[sediment]] and nutrients are deposited here instead of in water. Creating buffer zones near farms and roads is another possible way to prevent nutrients from traveling too far. Still, studies have shown<ref name="Agnold 1997">Angold P. G. 1997. The Impact of a Road Upon Adjacent Heathland Vegetation: Effects on Plant Species Composition. The Journal of Applied Ecology 34:409-417.</ref> that the effects of atmospheric nitrogen pollution can reach far past the buffer zone. This suggests that the most effective means of prevention is from the primary source.

====Prevention policy====
Laws regulating the discharge and [[treatment of sewage]] have led to dramatic nutrient reductions to surrounding ecosystems,<ref name="Smith 1999"/> but it is generally agreed that a policy regulating agricultural use of [[fertilizer]] and animal waste must be imposed. In Japan the amount of nitrogen produced by livestock is adequate to serve the fertilizer needs for the agriculture industry.<ref name="Kumazawa 2002">Kumazawa K. 2002. Nitrogen fertilization and nitrate pollution in groundwater in Japan: Present status and measures for sustainable agriculture. Nutrient Cycling in Agroecosystems 63:129-137.</ref> Thus, it is not unreasonable to command livestock owners to clean up animal waste—which when left stagnant will [[Leaching (pedology)|leach]] into ground water.

Policy concerning the prevention and reduction of eutrophication can be broken down into four sectors: Technologies, public participation, economic instruments, and cooperation.<ref name="ReferenceA">"Planning and Management of Lakes and Reservoirs: An Integrated Approach to Eutrophication." United Nations Environment Programme, Newsletter and Technical Publications. International Environmental Technology Centre. Ch.3.4.</ref> The term technology is used loosely, referring to a more widespread use of existing methods rather than an appropriation of new technologies. As mentioned before, nonpoint sources of pollution are the primary contributors to eutrophication, and their effects can be easily minimized through common agricultural practices. Reducing the amount of pollutants that reach a watershed can be achieved through the protection of its forest cover, reducing the amount of erosion leeching into a watershed. Also, through the efficient, controlled use of land using sustainable agricultural practices to minimize land degradation, the amount of soil runoff and nitrogen-based fertilizers reaching a watershed can be reduced.<ref>Control of Eutrophication. R. T. Oglesby and W. T. Edmondson. Journal (Water Pollution Control Federation), Vol. 38, No. 9 (Sep., 1966), pp. 1452-1460</ref> Waste disposal technology constitutes another factor in eutrophication prevention. Because a major contributor to the nonpoint source nutrient loading of water bodies is untreated domestic sewage, it is necessary to provide treatment facilities to highly urbanized areas, particularly those in underdeveloped nations, in which treatment of domestic waste water is a scarcity.<ref>Eutrophication of Surface Water: Lake Tahoe. E. J. Middlebrooks, E. A. Pearson, M. Tunzi, A. Adinarayana, P. H. McGauhey and G. A. Rohlich. Journal (Water Pollution Control Federation), Vol. 43, No. 2 (Feb., 1971), pp. 242-251</ref> The technology to safely and efficiently reuse waste water, both from domestic and industrial sources, should be a primary concern for policy regarding eutrophication.

The role of the public is a major factor for the effective prevention of eutrophication. In order for a policy to have any effect, the public must be aware of their contribution to the problem, and ways in which they can reduce their effects. Programs instituted to promote participation in the recycling and elimination of wastes, as well as education on the issue of rational water use are necessary to protect water quality within urbanized areas and adjacent water bodies.

Economic instruments, “which include, among others, property rights, water markets, fiscal and financial instruments, charge systems and liability systems, are gradually becoming a substantive component of the management tool set used for pollution control and water allocation decisions."<ref name="ReferenceA"/> Incentives for those who practice clean, renewable, water management technologies are an effective means of encouraging pollution prevention. By internalizing the costs associated with the negative effects on the environment, governments are able to encourage a cleaner water management.

Because a body of water can have an effect on a range of people reaching far beyond that of the watershed, cooperation between different organizations is necessary to prevent the intrusion of contaminants that can lead to eutrophication. Agencies ranging from state governments to those of water resource management and non-governmental organizations, going as low as the local population, are responsible for preventing eutrophication of water bodies.

====Nitrogen testing and modeling====
Soil Nitrogen Testing (N-Testing) is a technique that helps farmers optimize the amount of fertilizer applied to crops. By testing fields with this method, farmers saw a decrease in fertilizer application costs, a decrease in nitrogen lost to surrounding sources, or both.<ref name="Huang 2001">Huang W. Y., Y. C. Lu, and N. D. Uri. 2001. An assessment of soil nitrogen testing considering the carry-over effect. Applied Mathematical Modelling 25:843-860.</ref> By testing the soil and modeling the bare minimum amount of fertilizer needed, farmers reap economic benefits while reducing pollution.

====Organic farming====
There has been a study that found that organically fertilized fields "significantly reduce harmful nitrate leaching" over conventionally fertilized fields.<ref name='PNAS 2006-3-21'>{{cite doi|10.1073/pnas.0600359103}}</ref> However, a more recent study found that eutrophication impacts are in some cases higher from organic
production than they are from conventional production.<ref>Williams, A.G., Audsley, E. and Sandars, D.L. (2006) Determining the environmental burdens and resource use in the production of agricultural and horticultural commodities. Main Report. Defra Research Project IS0205. Bedford: Cranfield University and Defra.
</ref>


===Neutrophil Extracellular Traps (NETs)===
==Cultural eutrophication==
In 2004, Brinkmann and colleagues described a striking observation that activation of neutrophils causes the release of
[[File:Water pollution.jpg|thumb|300px|right| ]]
web-like structures of DNA; this represents a third mechanism for killing bacteria.<ref name="Science">{{cite journal
| last = Brinkmann
| first = Volker
| coauthors = Ulrike Reichard, Christian Goosmann, Beatrix Fauler, Yvonne Uhlemann, David S. Weiss, Yvette Weinrauch, Arturo Zychlinsky
| title = Neutrophil Extracellular Traps Kill Bacteria
| journal = [[Science (journal)|Science]]
| volume = 303
| issue = 5663
| pages = 1532–1535
| date = 5 March 2004
| publisher = AAAS
| url = http://www.sciencemag.org/cgi/content/full/303/5663/1532
| accessdate = 2007-04-09
| doi = 10.1126/science.1092385
| pmid = 15001782
| issn = 0036-8075 }}</ref> These [[neutrophil extracellular traps]] (NETs) comprise a web of fibers composed of [[chromatin]] and [[serine protease]]s that trap and kill microbes extracellularly. It is suggested that NETs provide a high local concentration of antimicrobial components and bind, disarm, and kill microbes independent of phagocytic uptake. In addition to their possible antimicrobial properties, NETs may serve as a physical barrier that prevents further spread of pathogens. Trapping of bacteria may be a particularly important role for NETs in sepsis, where NET are formed within blood vessels.<ref name="NatMed">{{cite journal
| last = Clark
| first = SR
| coauthors = Ma AC, Tavener AS, McDonald B, Goodarzi Z, Kelly MM, Patel KD, Chakrabarti S, McAvoy E, Sinclair GD, Keys EM, Allen-Vercoe E, DeVinney R, Doig CJ, Green FHY and Kubes P
| title = Platelet Toll-Like Receptor-4 Activates Neutrophil Extracellular Traps to Ensnare Bacteria in Endotoxemic and Septic Blood
| journal = Nature Medicine
| volume = 13
| issue = (4)
| pages = 463–9
| year = 2007
| publisher = Nature Publishing Group
| url = http://www.nature.com/nm/journal/v13/n4/pdf/nm1565.pdf
| doi = 10.1038/nm1565
| pmid = 17384648
| month = Apr
| last1 = Clark
| first1 = SR
| last2 = Ma
| first2 = AC
| last3 = Tavener
| first3 = SA
| last4 = Mcdonald
| first4 = B
| last5 = Goodarzi
| first5 = Z
| last6 = Kelly
| first6 = MM
| last7 = Patel
| first7 = KD
| last8 = Chakrabarti
| first8 = S
| last9 = Mcavoy
| first9 = E
| issn = 1078-8956
}}</ref> Recently, NETs have been shown to play a role in inflammatory diseases, as NETs could be detected in [[preeclampsia]], a pregnancy-related inflammatory disorder in which neutrophils are known to be activated.<ref name="preeclampsia">{{cite journal
| last = Gupta
| first = AK
| coauthors = Hasler P, Holzgreve W, Hahn S.
| title = Neutrophil NETs: a novel contributor to preeclampsia-associated placental hypoxia?
| journal = Semin Immunopathol
| volume = 29
| issue = 2
| pages = 163–7
| year = 2007
| doi = 10.1007/s00281-007-0073-4
| pmid = 17621701
| month = Jun
| last1 = Gupta
| first1 = AK
| last2 = Hasler
| first2 = P
| last3 = Holzgreve
| first3 = W
| last4 = Hahn
| first4 = S
| issn = 1863-2297}}</ref> In addition, NETs are known to exhibit pro-thrombotic effects both ''in vitro'' <ref>{{cite journal|last=Fuchs|first=TA|coauthors=Brill, A, Duerschmied, D, Schatzberg, D, Monestier, M, Myers DD, Jr, Wrobleski, SK, Wakefield, TW, Hartwig, JH, Wagner, DD|title=Extracellular DNA traps promote thrombosis.|journal=Proceedings of the National Academy of Sciences of the United States of America|date=2010 Sep 7|volume=107|issue=36|pages=15880–5|pmid=20798043|doi=10.1073/pnas.1005743107|pmc=2936604}}</ref> and ''in vivo''.<ref>{{cite journal|last=Brill|first=A|coauthors=Fuchs, TA, Savchenko, A, Thomas, GM, Martinod, K, De Meyer, SF, Bhandari, AA, Wagner, DD|title=Neutrophil Extracellular Traps Promote Deep Vein Thrombosis in Mice.|journal=Journal of thrombosis and haemostasis : JTH|date=2011 Nov 1|pmid=22044575|doi=10.1111/j.1538-7836.2011.04544.x}}</ref><ref>{{cite journal|last=Borissoff|first=JI|coauthors=ten Cate, H|title=From neutrophil extracellular traps release to thrombosis: an overshooting host-defense mechanism?|journal=Journal of thrombosis and haemostasis : JTH|date=2011 Sep|volume=9|issue=9|pages=1791–4|pmid=21718435|doi=10.1111/j.1538-7836.2011.04425.x}}</ref>


==Role in disease==
'''Cultural eutrophication''' is the process that speeds up natural eutrophication because of human activity.<ref>[http://www.britannica.com/EBchecked/topic/146210/cultural-eutrophication Cultural eutrophication] (2010) ''Encyclopædia Britannica''. Retrieved April 26, 2010, from Encyclopædia Britannica Online:
Low neutrophil counts are termed ''[[neutropenia]]''. This can be [[congenital disorder|congenital]] ([[genetic disorder]]) or it can develop later, as in the case of [[aplastic anemia]] or some kinds of [[leukemia]]. It can also be a [[adverse effect (medicine)|side-effect]] of [[medication]], most prominently [[chemotherapy]]. Neutropenia makes an individual highly susceptible to infections. Neutropenia can be the result of colonization by intracellular neutrophilic parasites.
</ref> Due to clearing of land and building of towns and cities, [[land runoff]] is accelerated and more nutrients such as [[phosphates]] and [[nitrate]] are supplied to lakes and rivers, and then to coastal [[estuaries]] and bays. Extra nutrients are also supplied by treatment plants, golf courses, fertilizers, and farms.


In [[alpha 1-antitrypsin deficiency]], the important neutrophil enzyme [[elastase]] is not adequately inhibited by [[alpha 1-antitrypsin]], leading to excessive tissue damage in the presence of inflammation – the most prominent one being [[emphysema|pulmonary emphysema]].
These nutrients result in an excessive growth of plant life known as an [[algal bloom]]. This can change a lake's natural food web, and also reduce the amount of dissolved oxygen in the water for organisms to breathe. Both these things cause animal and plant death rates to increase as the plants take in poisonous water while the animals drink the poisoned water. This contaminates water, making it undrinkable, and sediment quickly fills the lake. Cultural eutrophication is a form of [[water pollution]].


In [[Familial Mediterranean fever]] (FMF), a mutation in the ''pyrin'' (or ''[[marenostrin]]'') gene, which is expressed mainly in neutrophil granulocytes, leads to a constitutively active [[acute-phase protein|acute-phase response]] and causes attacks of [[fever]], [[arthralgia]], [[peritonitis]], and – eventually – [[amyloidosis]].<ref name="fmf">{{cite journal
Cultural eutrophication also occurs when excessive fertilizers run into lakes and rivers. This encourages the growth of algae (algal bloom) and other [[aquatic plant]]s. Following this, overcrowding occurs and plants compete for sunlight, space and oxygen. Overgrowth of water plants also blocks sunlight and oxygen for aquatic life in the water, which in turn threatens their survival. Algae also grows easily, thus threatening other water plants no matter whether they are floating, half-submerged, or fully submerged. Not only does this cause algal blooming, it can cause an array of more long term effects on the water such as damage to [[coral reef]]s and deep sea animal life. It also speeds up the damage of both marine and also affects humans if the effects of algal blooming is too drastic. Fish will die and there will be lack of food in the area. [[Nutrient pollution]] is a major cause of algal blooming, and should be minimized.
| last = Ozen
| first = S
| title = Familial mediterranean fever: revisiting an ancient disease
| journal = European Journal of Pediatrics
| volume = 162
| issue = 7–8
| pages = 449–54
| year = 2004
| url = http://www.springerlink.com/content/58qkf57xwkb58enf
| doi = 10.1007/s00431-003-1223-x
| pmid = 12751000
| month = Jul
| last1 = Ozen
| first1 = S
| issn = 0340-6199 }}</ref>


==Media==
The [[Experimental Lakes Area]] (ELA), [[Ontario]], [[Canada]] is a fully equipped, year-round, permanent field station that uses the whole [[ecosystem approach]] and long-term, whole-lake investigations of freshwater focusing on [[cultural eutrophication]]. ELA is currently cosponsored by the Canadian Departments of Environment and Fisheries and Oceans, with a mandate to investigate the aquatic effects of a wide variety of stresses on lakes and their catchments <ref name="article.pubs.nrc-cnrc.gc.ca">Schindler, David William. 2009.“[http://article.pubs.nrc-cnrc.gc.ca/RPAS/rpv?hm=HInit&journal=cjfas&volume=66&calyLang=eng&afpf=f09-134.pdf A personal history of the Experimental Lakes Project] [1]” ''Canadian Journal of Fisheries and Aquatic Sciences.'' 66 (11): 1837–1847.</ref><ref>Schindler, David W., Vallentyne, John R. 2008. ''The Algal Bowl : Overfertilization of the World's Freshwaters and Estuaries. '' University of Alberta Press. p. x.</ref>
<gallery widths=300 heights=300>
Image:S1-Polymorphonuclear Cells with Conidia in Liquid Media.ogg|A rapidly moving neutrophil can be seen taking up several [[conidia]] over an imaging time of 2 hours with one frame every 30 seconds.
Image:S15-Competitive Phagocytosis Assay in Collagen.ogg|A neutrophil can be seen here selectively taking up several [[Candida (genus)|Candida yeast]]s ([[Fluorescent labelling|fluorescently labeled]] in green) despite several contacts with ''[[Aspergillus fumigatus]]'' conidia (unlabeled, white/clear) in a 3-D [[collagen]] matrix. Imaging time was 2 hours with one frame every 30 seconds.
</gallery>
[http://www.plosone.org/article/fetchSingleRepresentation.action?uri=info:doi/10.1371/journal.pone.0004652.s001] Neutrophils display highly directional amoeboid motility in infected footpad and phalanges. Intravital imaging was performed in the footpad path of LysM-eGFP mice 20 minutes after infection with LM.<ref>{{cite journal | author = Graham D.B., Zinselmeyer B.H., Mascarenhas F., Delgado R., Miller M.J., Swat W. | year = 2009 | title = ITAM signaling by Vav family Rho guanine nucleotide exchange factors regulates interstitial transit rates of neutrophils in vivo | url = | journal = PLoS ONE | volume = 4 | issue = | page = e4652 | doi = 10.1371/journal.pone.0004652 |pmc=2645696 | pmid=19247495}}</ref>


==See also==
==Additional images==
<gallery>
{{wiktionarypar}}
Image:Neutrophil with anthrax copy.jpg|A [[scanning electron microscope]] image of a single neutrophil (yellow), engulfing [[anthrax]] bacteria (orange)
{{div col|colwidth=20em}}
Image:Illu blood cell lineage.jpg|Blood cell lineage
* [[Algal bloom]]
Image:Hematopoiesis (human) diagram.png|More complete lineages (very large)
* [[Anaerobic digestion]]
</gallery>
* [[Auxanography]]
* [[Biodilution]]
* [[Biogeochemical cycle]]
* [[Coastal fish]]
* [[Drainage basin]]
* [[Fish kill]]
* [[Hypoxia (environmental)]]
* [[Hypoxia in fish]]
* [[Lake Erie]]
* [[Lake ecosystem]]
* [[Limnology]]
* [[Nitrogen cycle]]
* [[No-till farming]]
* [[Outwelling]]
* [[Phoslock]]
* [[Riparian zone]]
* [[Upland and lowland (freshwater ecology)]]
{{div col end}}


==References==
==References==
{{reflist|30em}}
{{reflist|2}}


==External links==
===Cited text===
*{{cite book|last=Zucker-Franklin|first=Dorothy|coauthors=Greaves, M.F.; Grossi, C.E.; Marmont, A.M.|title=Atlas of Blood Cells: Function and Pathology|publisher=Lea & Ferbiger|location=Philadelphia|year=1988|edition=2nd ed.|volume=1|chapter=Neutrophils|isbn=0-8121-1094-3}}
* [http://www.initrogen.org/ International Nitrogen Initiative]
* [http://www.lakescientist.com/learn-about-lakes/water-quality/eutrophication.html/ What is Eutrophication?]


{{blood}}
{{aquatic ecosystem topics}}
{{marine pollution}}
{{immune system}}
{{pollution}}


{{DEFAULTSORT:Neutrophil Granulocyte}}
[[Category:Water pollution]]
[[Category:Environmental chemistry]]
[[Category:Cell biology]]
[[Category:Environmental issues with water]]
[[Category:Granulocytes]]
[[Category:Greek loanwords]]
[[Category:Phagocytes]]
[[Category:Aquatic ecology]]
[[Category:Human cells]]
[[Category:Articles containing video clips]]


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[[dv:ނޫޓްރަފިލް]]
[[ca:Eutrofització]]
[[el:Ουδετερόφιλα - πολυμορφοπύρηνα]]
[[cs:Eutrofizace]]
[[da:Eutrofiering]]
[[es:Neutrófilo]]
[[de:Eutrophierung]]
[[eu:Neutrofilo]]
[[et:Eutrofeerumine]]
[[fa:نوتروفیل]]
[[fr:Granulocyte neutrophile]]
[[el:Ευτροφισμός]]
[[es:Eutrofización]]
[[gl:Neutrófilo]]
[[hak:Chûng-sin Pha̍k-hiet-khiû]]
[[eo:Plantoziĝo]]
[[eu:Eutrofizazio]]
[[id:Neutrofil]]
[[it:Granulocita neutrofilo]]
[[fr:Eutrophisation]]
[[he:נויטרופיל]]
[[gl:Eutrofización]]
[[kk:Нейтрофилді лейкоциттер]]
[[ko:부영양화]]
[[id:Eutrofikasi]]
[[lt:Neutrofilas]]
[[nl:Neutrofiele granulocyt]]
[[is:Ofauðgun]]
[[it:Eutrofizzazione]]
[[ja:好中球]]
[[no:Nøytrofil granulocytt]]
[[he:אאוטריפיקציה]]
[[pl:Neutrofil]]
[[kk:Эвтрофтану]]
[[pt:Granulócito neutrófilo]]
[[ht:Etwofizasyon]]
[[ro:Granulocit neutrofil]]
[[lv:Eitrofikācija]]
[[ru:Нейтрофильные гранулоциты]]
[[lt:Eutrofikacija]]
[[sq:Granulocite neutrofile]]
[[hu:Eutrofizáció]]
[[simple:Neutrophil]]
[[mk:Еутрофикација]]
[[nl:Eutrofiëring]]
[[sl:Nevrofilec]]
[[ja:富栄養化]]
[[sr:Neutrofil]]
[[oc:Eutrofizacion]]
[[sh:Neutrofil]]
[[sv:Neutrofil granulocyt]]
[[pl:Eutrofizacja]]
[[ta:நடுவமைநாடி]]
[[pt:Eutrofização]]
[[tr:Nötrofil]]
[[ru:Эвтрофикация]]
[[vi:Bạch cầu trung tính]]
[[sk:Eutrofizácia]]
[[sl:Evtrofikacija]]
[[zh:中性粒细胞]]
[[sr:Цветање воде]]
[[fi:Rehevöityminen]]
[[sv:Övergödning]]
[[ta:தூர்ந்துபோதல்]]
[[tr:Ötrofikasyon]]
[[uk:Евтрофікація]]
[[zh:富营养化]]

Revision as of 22:33, 19 January 2013

"Neutrophil" redirects here. For organisms that grow in neutral pH environments, see neutrophile.
Eutriphication
Neutrophils with a segmented nuclei surrounded by erythrocytes, the intra-cellular granules are visible in the cytoplasm (Giemsa stained)
Identifiers
MeSHD005068
Anatomical terminology

Eutrophication are the most abundant type of white blood cells in mammals and form an essential part of the innate immune system. In general, they are referred to as either neutrophils or polymorphonuclear neutrophils (or PMNs), and are subdivided into segmented neutrophils (or segs) and banded neutrophils (or bands). They form part of the polymorphonuclear cell family (PMNs) together with basophils and eosinophils.[1][2][3]

The name neutrophil derives from staining characteristics on hematoxylin and eosin (H&E) histological or cytological preparations. Whereas basophilic white blood cells stain dark blue and eosinophilic white blood cells stain bright red, neutrophils stain a neutral pink. Normally, neutrophils contain a nucleus divided into 2–5 lobes.

Neutrophils are normally found in the blood stream. During the beginning (acute) phase of inflammation, particularly as a result of bacterial infection, environmental exposure,[4] and some cancers,[5][6] neutrophils are one of the first-responders of inflammatory cells to migrate towards the site of inflammation. They migrate through the blood vessels, then through interstitial tissue, following chemical signals such as Interleukin-8 (IL-8), C5a, fMLP and Leukotriene B4 in a process called chemotaxis. They are the predominant cells in pus, accounting for its whitish/yellowish appearance.

Neutrophils are recruited to the site of injury within minutes following trauma and are the hallmark of acute inflammation.[7]

Characteristics

Neutrophil granulocyte migrates from the blood vessel to the matrix, sensing proteolytic enzymes, in order to determine intercellular connections (to the improvement of its mobility) and envelop bacteria through phagocytosis.

Neutrophil granulocytes have an average diameter of 12–15 micrometers (µm) in peripheral blood smears. When analyzing a pure neutrophil suspension on an automated cell counter, neutrophils have an average diameter of 8–9 µm.

With the eosinophil and the basophil, they form the class of polymorphonuclear cells, named for the nucleus's multilobulated shape (as compared to lymphocytes and monocytes, the other types of white cells). The nucleus has a characteristic lobed appearance, the separate lobes connected by chromatin. The nucleolus disappears as the neutrophil matures, which is something that happens in only a few other types of nucleated cells.[8] In the cytoplasm, the Golgi apparatus is small, mitochondria and ribosomes are sparse, and the rough endoplasmic reticulum is absent.[9] The cytoplasm also contains about 200 granules, of which a third are azurophilic.[9]

A minor difference is found between the neutrophils from a male subject and a female subject. The cell nucleus of a neutrophil from a female subject shows a small additional X chromosome structure, known as a "neutrophil drumstick".[10]

Neutrophils will show hypersegmentation (many segments of nucleus) in B12 and folate deficiency.

Reference ranges for blood tests of white blood cells, comparing neutrophil amount (shown in pink) with that of other cells.

Neutrophils are the most abundant white blood cells in humans (approximately 1011 are produced daily); they account for approximately 50-70% of all white blood cells (leukocytes). The stated normal range for human blood counts varies between laboratories, but a neutrophil count of 2.5–7.5 x 109/L is a standard normal range. People of African and Middle Eastern descent may have lower counts, which are still normal. A report may divide neutrophils into segmented neutrophils and bands.

When circulating in the bloodstream and unactivated, neutrophils are spherical. Once activated, they change shape and become more amorphous or amoeba-like and can extend pseudopods as they hunt for antigens.[11]

Life span

HSC=Hematopoietic stem cell, Progenitor=Progenitor cell, L-blast=lymphoblast, Lymphocyte, Mo-blast=Monoblast, Monocyte, Myeloblast, Pro-M=Promyelocyte, Myelocyte, Meta-M=Metamyelocyte, Neutrophil, Eosinophil, Basophil, Pro-E=Proerythroblast, Baso-E=Basophilic erythroblast, poly-e=Polychromatic erythroblast, Ortho-E=orthochromatic erythroblast, Erythrocyte, Promegakaryocyte, megakaryocyte, Platlet

The average lifespan of (non-activated human) neutrophils in the circulation is about 5.4 days.[12] Upon activation, they marginate (position themselves adjacent to the blood vessel endothelium), and undergo selectin-dependent capture followed by integrin-dependent adhesion in most cases, after which they migrate into tissues, where they survive for 1–2 days.[13]

Neutrophils are much more numerous than the longer-lived monocyte/macrophage phagocytes. A pathogen (disease-causing microorganism or virus) is likely to first encounter a neutrophil. Some experts hypothesize that the short lifetime of neutrophils is an evolutionary adaptation. The short lifetime of neutrophils minimizes propagation of those pathogens that parasitize phagocytes because the more time such parasites spend outside a host cell, the more likely they will be destroyed by some component of the body's defenses. Also, because neutrophil antimicrobial products can also damage host tissues, their short life limits damage to the host during inflammation.[13]

Neutrophils will often be phagocytosed themselves by macrophages after digestion of pathogens. PECAM-1 and phosphatidylserine on the cell surface are involved in this process.

Chemotaxis

Neutrophils undergo a process called chemotaxis, which allows them to migrate toward sites of infection or inflammation. Cell surface receptors allow neutrophils to detect chemical gradients of molecules such as interleukin-8 (IL-8), interferon gamma (IFN-gamma), C5a, and Leukotriene B4, which these cells use to direct the path of their migration.

Neutrophils have a variety of specific receptors, including complement receptors, cytokine receptors for interleukins and interferon gamma (IFN-gamma), receptors for chemokines, receptors to detect and adhere to endothelium, receptors for leptins and proteins, and Fc receptors for opsonin.[14]

Anti-microbial function

Being highly motile, neutrophils quickly congregate at a focus of infection, attracted by cytokines expressed by activated endothelium, mast cells, and macrophages. Neutrophils express[15] and release cytokines, which in turn amplify inflammatory reactions by several other cell types.

In addition to recruiting and activating other cells of the immune system, neutrophils play a key role in the front-line defence against invading pathogens. Neutrophils have three strategies for directly attacking micro-organisms: phagocytosis (ingestion), release of soluble anti-microbials (including granule proteins), and generation of neutrophil extracellular traps (NETs).[16]

Phagocytosis

Neutrophils are phagocytes, capable of ingesting microorganisms or particles. For targets to be recognised, they must be coated in opsonins—a process known as antibody opsonization.[11] They can internalize and kill many microbes, each phagocytic event resulting in the formation of a phagosome into which reactive oxygen species and hydrolytic enzymes are secreted. The consumption of oxygen during the generation of reactive oxygen species has been termed the "respiratory burst", although unrelated to respiration or energy production.

The respiratory burst involves the activation of the enzyme NADPH oxidase, which produces large quantities of superoxide, a reactive oxygen species. Superoxide dismutates, spontaneously or through catalysis via enzymes known as superoxide dismutases (Cu/ZnSOD and MnSOD), to hydrogen peroxide, which is then converted to hypochlorous acid HClO, by the green heme enzyme myeloperoxidase. It is thought that the bactericidal properties of HClO are enough to kill bacteria phagocytosed by the neutrophil, but this may instead be a step necessary for the activation of proteases. [17]

Degranulation

Neutrophils also release an assortment of proteins in three types of granules by a process called degranulation. The contents of these granules have antimicrobial properties, and help combat infection.

Granule type Protein
specific granules (or "secondary granules") alkaline phosphatase, lysozyme, NADPH oxidase, collagenase, Lactoferrin and Cathelicidin
azurophilic granules (or "primary granules") myeloperoxidase, bactericidal/permeability-increasing protein (BPI), Defensins, and the serine proteases neutrophil elastase and cathepsin G
tertiary granules cathepsin and gelatinase

Neutrophil Extracellular Traps (NETs)

In 2004, Brinkmann and colleagues described a striking observation that activation of neutrophils causes the release of web-like structures of DNA; this represents a third mechanism for killing bacteria.[18] These neutrophil extracellular traps (NETs) comprise a web of fibers composed of chromatin and serine proteases that trap and kill microbes extracellularly. It is suggested that NETs provide a high local concentration of antimicrobial components and bind, disarm, and kill microbes independent of phagocytic uptake. In addition to their possible antimicrobial properties, NETs may serve as a physical barrier that prevents further spread of pathogens. Trapping of bacteria may be a particularly important role for NETs in sepsis, where NET are formed within blood vessels.[19] Recently, NETs have been shown to play a role in inflammatory diseases, as NETs could be detected in preeclampsia, a pregnancy-related inflammatory disorder in which neutrophils are known to be activated.[20] In addition, NETs are known to exhibit pro-thrombotic effects both in vitro [21] and in vivo.[22][23]

Role in disease

Low neutrophil counts are termed neutropenia. This can be congenital (genetic disorder) or it can develop later, as in the case of aplastic anemia or some kinds of leukemia. It can also be a side-effect of medication, most prominently chemotherapy. Neutropenia makes an individual highly susceptible to infections. Neutropenia can be the result of colonization by intracellular neutrophilic parasites.

In alpha 1-antitrypsin deficiency, the important neutrophil enzyme elastase is not adequately inhibited by alpha 1-antitrypsin, leading to excessive tissue damage in the presence of inflammation – the most prominent one being pulmonary emphysema.

In Familial Mediterranean fever (FMF), a mutation in the pyrin (or marenostrin) gene, which is expressed mainly in neutrophil granulocytes, leads to a constitutively active acute-phase response and causes attacks of fever, arthralgia, peritonitis, and – eventually – amyloidosis.[24]

Media

  • A rapidly moving neutrophil can be seen taking up several conidia over an imaging time of 2 hours with one frame every 30 seconds.
  • A neutrophil can be seen here selectively taking up several Candida yeasts (fluorescently labeled in green) despite several contacts with Aspergillus fumigatus conidia (unlabeled, white/clear) in a 3-D collagen matrix. Imaging time was 2 hours with one frame every 30 seconds.

[1] Neutrophils display highly directional amoeboid motility in infected footpad and phalanges. Intravital imaging was performed in the footpad path of LysM-eGFP mice 20 minutes after infection with LM.[25]

Additional images

References

  1. ^ Witko-Sarsat, V (2000). "Neutrophils: molecules, functions and pathophysiological aspects". Lab Invest. 80 (5): 617–53. doi:10.1038/labinvest.3780067. PMID 10830774. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  2. ^ Klebanoff, SJ (1978). "The Neutrophil: Function and Clinical Disorders". Elsevier/North-Holland Amsterdam. ISBN 0-444-80020-4. {{cite journal}}: Cite journal requires |journal= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  3. ^ Nathan, Carl (2006). "Neutrophils and immunity: challenges and opportunities". Nature Reviews Immunology. 6 (March): 173–82. doi:10.1038/nri1785. ISSN 1474-1733. PMID 16498448. {{cite journal}}: More than one of |first1= and |first= specified (help); More than one of |last1= and |last= specified (help); Unknown parameter |month= ignored (help)
  4. ^ Jacobs, L; Nawrot, Tim S; De Geus, Bas; Meeusen, Romain; Degraeuwe, Bart; Bernard, Alfred; Sughis, Muhammad; Nemery, Benoit; Panis, Luc (2010). "Subclinical responses in healthy cyclists briefly exposed to traffic-related air pollution". Environmental Health. 9 (64): 64. doi:10.1186/1476-069X-9-64. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: unflagged free DOI (link)
  5. ^ Waugh, DJ; Wilson (2008). "The interleukin-8 pathway in cancer". Clinical Cancer Research. 14 (21): 6735–41. doi:10.1158/1078-0432.CCR-07-4843. ISSN 1078-0432. PMID 18980965. {{cite journal}}: More than one of |author2= and |last2= specified (help); Unknown parameter |month= ignored (help)
  6. ^ De Larco, JE; Wuertz; Furcht (2004). "The Potential Role of Neutrophils in Promoting the Metastatic Phenotype of Tumors Releasing Interleukin-8". Clinical Cancer Research. 10 (15): 4895–900. doi:10.1158/1078-0432.CCR-03-0760. ISSN 1078-0432. PMID 15297389. {{cite journal}}: More than one of |author2= and |last2= specified (help); More than one of |author3= and |last3= specified (help); Unknown parameter |month= ignored (help)
  7. ^ Cohen, Stephen. Burns, Richard C. Pathways of the Pulp, 8th Edition. St. Louis: Mosby, Inc. 2002. page 465.
  8. ^ Zucker-Franklin, p. 168.
  9. ^ a b Zucker-Franklin, p. 170.
  10. ^ Zucker-Franklin, p. 174.
  11. ^ a b Edwards, Steven W. (1994). Biochemistry and physiology of the neutrophil. Cambridge University Press. p. 6. ISBN 0-521-41698-1.
  12. ^ Pillay J, den Braber I, Vrisekoop N, Kwast LM, de Boer RJ, Borghans JA, Tesselaar K, Koenderman L. In vivo labeling with 2H2O reveals a human neutrophil lifespan of 5.4 days Blood. 2010 Jul 29;116(4):625-7.
  13. ^ a b Wheater, Paul R.; Stevens, Alan (2002). Wheater's basic histopathology: a colour atlas and text (PDF). Edinburgh: Churchill Livingstone. ISBN 0-443-07001-6.{{cite book}}: CS1 maint: multiple names: authors list (link)
  14. ^ Charles N. Serhan, Peter A. Ward, Derek W. Gilroy (2010). Fundamentals of Inflammation. Cambridge University Press. pp. 53–54. ISBN 0-521-88729-1.{{cite book}}: CS1 maint: multiple names: authors list (link)
  15. ^ Ear T, McDonald PP (2008). "Cytokine generation, promoter activation, and oxidant-independent NF-kappaB activation in a transfectable human neutrophilic cellular model". BMC Immunol. 9: 14. doi:10.1186/1471-2172-9-14. PMC 2322942. PMID 18405381.{{cite journal}}: CS1 maint: unflagged free DOI (link)
  16. ^ Hickey, MJ (2009). "Intravascular immunity: the host–pathogen encounter in blood vessels". Nature Reviews Immunology. 9 ((5)). Nature Publishing Group: 364–75. doi:10.1038/nri2532. PMID 19390567. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  17. ^ Segal, AW (2005). "How neutrophils kill microbes". Annu Rev Immunol. 9 ((5)): 197–223. doi:10.1146/annurev.immunol.23.021704.115653. PMC 2092448. PMID 15771570.
  18. ^ Brinkmann, Volker (5 March 2004). "Neutrophil Extracellular Traps Kill Bacteria". Science. 303 (5663). AAAS: 1532–1535. doi:10.1126/science.1092385. ISSN 0036-8075. PMID 15001782. Retrieved 2007-04-09. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  19. ^ Clark, SR; Ma, AC; Tavener, SA; Mcdonald, B; Goodarzi, Z; Kelly, MM; Patel, KD; Chakrabarti, S; Mcavoy, E (2007). "Platelet Toll-Like Receptor-4 Activates Neutrophil Extracellular Traps to Ensnare Bacteria in Endotoxemic and Septic Blood" (PDF). Nature Medicine. 13 ((4)). Nature Publishing Group: 463–9. doi:10.1038/nm1565. ISSN 1078-8956. PMID 17384648. {{cite journal}}: More than one of |first1= and |first= specified (help); More than one of |last1= and |last= specified (help); Unknown parameter |coauthors= ignored (|author= suggested) (help); Unknown parameter |month= ignored (help)
  20. ^ Gupta, AK; Hasler, P; Holzgreve, W; Hahn, S (2007). "Neutrophil NETs: a novel contributor to preeclampsia-associated placental hypoxia?". Semin Immunopathol. 29 (2): 163–7. doi:10.1007/s00281-007-0073-4. ISSN 1863-2297. PMID 17621701. {{cite journal}}: More than one of |first1= and |first= specified (help); More than one of |last1= and |last= specified (help); Unknown parameter |coauthors= ignored (|author= suggested) (help); Unknown parameter |month= ignored (help)
  21. ^ Fuchs, TA (2010 Sep 7). "Extracellular DNA traps promote thrombosis". Proceedings of the National Academy of Sciences of the United States of America. 107 (36): 15880–5. doi:10.1073/pnas.1005743107. PMC 2936604. PMID 20798043. {{cite journal}}: Check date values in: |date= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  22. ^ Brill, A (2011 Nov 1). "Neutrophil Extracellular Traps Promote Deep Vein Thrombosis in Mice". Journal of thrombosis and haemostasis : JTH. doi:10.1111/j.1538-7836.2011.04544.x. PMID 22044575. {{cite journal}}: Check date values in: |date= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  23. ^ Borissoff, JI (2011 Sep). "From neutrophil extracellular traps release to thrombosis: an overshooting host-defense mechanism?". Journal of thrombosis and haemostasis : JTH. 9 (9): 1791–4. doi:10.1111/j.1538-7836.2011.04425.x. PMID 21718435. {{cite journal}}: Check date values in: |date= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  24. ^ Ozen, S (2004). "Familial mediterranean fever: revisiting an ancient disease". European Journal of Pediatrics. 162 (7–8): 449–54. doi:10.1007/s00431-003-1223-x. ISSN 0340-6199. PMID 12751000. {{cite journal}}: More than one of |first1= and |first= specified (help); More than one of |last1= and |last= specified (help); Unknown parameter |month= ignored (help)
  25. ^ Graham D.B., Zinselmeyer B.H., Mascarenhas F., Delgado R., Miller M.J., Swat W. (2009). "ITAM signaling by Vav family Rho guanine nucleotide exchange factors regulates interstitial transit rates of neutrophils in vivo". PLoS ONE. 4: e4652. doi:10.1371/journal.pone.0004652. PMC 2645696. PMID 19247495.{{cite journal}}: CS1 maint: multiple names: authors list (link) CS1 maint: unflagged free DOI (link)

Cited text

  • Zucker-Franklin, Dorothy (1988). "Neutrophils". Atlas of Blood Cells: Function and Pathology. Vol. 1 (2nd ed. ed.). Philadelphia: Lea & Ferbiger. ISBN 0-8121-1094-3. {{cite book}}: |edition= has extra text (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
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