Talk:Phagocyte/Archive 2

Evolution of phagocytes

Do we know or have any guesses about the evolutionary origin of phagocytes? 138.78.98.196 (talk) 00:37, 5 February 2009 (UTC)

• This is an interesting point and should most likely be included in the article if it has any hopes for FA. Here is one link to an online book (Evoultion of the Innate Immune System) that discusses the possible evolution of macrophages from amoebas. However, the evolutionary pathway is unkown. I will continue looking for references. Thank you for your concerns about this article. --Eulemur2008 (talk) 00:42, 8 February 2009 (UTC)

I would suggest using : to "tab in" when you respond, eulemur. Any who, the article phagocytes is looking pretty good. FA attempt soon? Might I suggest, as aforementioned, you look for more references. That being said, there isn't a mandatory or "bottom limit" prerequisite for references to attain FA, however, you might find some opposition when large blocks of textual information are presented with only one resource as factual backup. Otherwise I would have to say that you've found more information on your subject than mine... although that might attributed to article relevancy and research availability... Good luck! Food_Puma 00:54, 8 February 2009 (UTC)

• Reference number 7 may have some information that can be added to the evolution section. --Eulemur2008 (talk) 02:59, 15 February 2009 (UTC)

Tolerance

17592494, 17120464 --Eulemur2008 (talk) 17:29, 15 February 2009 (UTC)

Brother Paul

and Paul Ehrlich were awarded jointly the 1908 Nobel Prize in Physiology or Medicine. I'm somewhat curious. Paul is mentioned twice (introduction and history) as jointly receiving credit. However, there is no mention of his contributions other than "tag on" referencing the Noble Prize. It seems a tad like writing a summary of Watson's work on DNA and then simply stating some other guy named Crick gets credit as well. Did Paul do anything? Does he deserve additional text beyond merely name dropping here? --JimmyButler (talk) 22:33, 15 February 2009 (UTC)

History section.

This section is my least favorite. The prose seems choppy and disconnected. A couple of points:

During the late nineteenth and early twentieth centuries a debate developed between the supporters of the cellular and humoral theories of immunity. A brief description as to the fundamental differences of these two views seems necessary to understand the text that follows. In the late nineteenth century two distinctly different views existed regarding the bases of immunity. One perspective, cellular immunity, was the view ...... The other, humoral immunity, ........--JimmyButler (talk) 22:43, 15 February 2009 (UTC)

To test his idea he inserted small thorns from a tangerine tree into the larvae. His "idea", needs clearer identification. Perhaps, To validate the importance of motile cells in immunity he inserted.... —Preceding unsigned comment added by JimmyButler (talk • contribs) 22:48, 15 February 2009 (UTC)

Mechnikov knew that in animals that have a vascular system, leukocytes migrate from the blood stream during an infection. It is unclear whether this knowledge is unique to him or whether it was common knowledge. Prior research by xxxx had demonstrated that in animals with vascular systems....--JimmyButler (talk) 22:53, 15 February 2009 (UTC)

He deduced that these leukocytes might migrate from the blood to engulf I have a personal dislike for the word "might". It seems like he was guessing or non-committal on the chances of such a thing occurring.--JimmyButler (talk) 22:58, 15 February 2009 (UTC)

Mechnikov went to Vienna and explained his ideas to Carl Could he "travel" to Vienna . Did he need to explain the ideas to Carl or could he just share them. The first implies Carl was not swift enough to get it without a tutorial!--JimmyButler (talk) 23:02, 15 February 2009 (UTC)

were not known until much later. A week later? A month later. Can you nail this down... until the late 1900's or something.

Sorry for the disorganized critique. I prefer bullets and only one signature; however, I was trying to watch Oprah and provide feedback simultaneously! --JimmyButler (talk) 23:07, 15 February 2009 (UTC)

I agree, these are valid arguments; however, I was trying to watch Being Human :-) At this stage of a potential FA, these are exactly the pointers that are needed. Thanks. Graham. Graham Colm ^Talk 23:35, 15 February 2009 (UTC)

Monocytes

A few thoughts:

• monocytes are slightly larger than neutrophils. A pookie is slightly larger than a gumje. The comparisons are meaningless. In this case you need to state the size or seek a reference that is more widely understood. The neutrophils have yet to be introduced in the article.
• Monocytes also have granules. This is the classic pitfall of technical writing. First, assuming that a nonexpert would have a clue what is a granule and second failing to state why that is relevant.
• Did every sentence in this section start with the word Monocyte? Such repetition bespeaks of a boring topic. Spice it up a tad.
• Most monocytes leave circulation to travel to tissues and organs Would blood stream be accurate? --JimmyButler (talk) 23:21, 15 February 2009 (UTC)

Don't forget the lymphatic system Mr. Butler. :-) Graham. Graham Colm ^Talk 23:38, 15 February 2009 (UTC)

Which reinforces the need to define which or both if applicable!--JimmyButler (talk) 23:52, 15 February 2009 (UTC)

Good points Mr. Butler; repetition does make for a boring article. Also, comparisons are meaningless unless they have some concrete numbers. Finally the importance of having a granule is that when a monocyte becomes a macrophage--I did not explicitly state this in the article and I should have--it loses its granules (macrophages have lysosomes). Lysosomes and granules are important because they contain the essentials for intracellular killing (and depending on which one a phagocyte has can mean slightly different intracellular killing methods). --Eulemur2008 (talk) 23:45, 15 February 2009 (UTC)

(edit conflict) And, when I, and my colleagues, teach our students, we say "monocytes are slightly larger than neutrophils", but we also point out the difference in the morphology of the nucleus. Some neutrophils are the same size as are monocytes, (by Giemsa stain) there is polymorphism. I think slightly is OK here.Graham Colm ^Talk 23:58, 15 February 2009 (UTC)

Disambiguating Links

N. Some of your links dead-end at lists of possible meanings instead of the intended page. I messed around with a few (ATP and granule, I think) but there are about ten or so others. Try using this tool it makes everything so much easier. --Yohmom (talk) 06:21, 22 February 2009 (UTC)

Review by Colin

I've managed to review the first two sentences so far (this version):

• Per WP:LEAD, "the first sentence should give a concise definition: where possible, one that puts the article in context for the nonspecialist." and also answer two questions: What is the subject and why is it notable. We don't normally begin this sentence with the etymology of the word, and including it weakens the lead sentence considerably (flow disrupted, my mind is thinking about how to get from "kutos" to "cytes" rather than the definition to come). The lead sentence currently does not fully define the term, missing off the key aspect (they consume stuff) while adding over-specific aspects. Based on other dictionary definitions I looked at, the key points are "cell" and words like "injest/consume/engulf/digest" and probably "immune".
• Would you not consider "bone marrow" to be a "tissue"? Many dictdefs just say "blood and tissues". Do you have a good source for where in the body phagocytes are found?
• "vertebrates and invertebrates". Both the sources here are specialist papers whose purpose can hardly be said to be providing the scope of living organisms in which phagocytes are found. Why not just "animals"? To the lay person, those two groups (vertebrates/invertebrates) appear to be opposites and hence one wonders why mention both. Do you have a source that clearly describes which (and only which) organisms phagocytes are found in? If the precise scoping is complex, let's move that down the lead. Lastly, those two sources are only used by the lead, which is always a warning sign.
• The definition of what they ingest is sourced to a review paper on "mononuclear phagocytes". We need a source that covers all phagocytes.
• The word "pathogenic" is a little bit erudite here and may put off the reader ("harmful" might do) and I wonder if "microorganisms" might replace "pathogenic, infectious".
• The concept of "host" is jargon and I suspect you could drop that word and the definition is still correct.
• Consider replacing "foreign agents" (which makes me think of spies) with "foreign particles".
• Some dictdefs say "waste material", which isn't included in this list.

Colin°^Talk 14:21, 23 February 2009 (UTC)

Colin, thanks for taking the time to provide this help; it's very useful. Graham. Graham Colm ^Talk 16:38, 23 February 2009 (UTC)

Reviewing the lead of (this version)

• I don't know what the difference is between innate and adaptive immune systems (well I do sort of. I know we have those two types but wouldn't have been able to give you their names). It wouldn't take long to briefly explain the difference, but we probably don't have that luxury in the lead. I'm also struggling at this stage to understand the difference between "basis of" and "central role", and neither term is particularly informative as to what the role is.
• I've never heard the word "hemolymph" before. Not sure how to deal with that here.
• The "In vertebrates ... myeloid progenitor cells." sentence doesn't seem to have a source. That mpc term has lost me now. Did I need to know that at this stage? I suspect the lead should be composed of stuff I should probably be able to remember and need to know in order to have some idea of the topic. Do I need to know about myeloid progenitor cells in the lead paragraph? Hmm. The term isn't used in the article body.
• The PMID 17967061 source (used only twice by the lead) is an article on wasp parasitoid infection of fruit flies. I can barely follow it but I think the key phrase is "The Drosophila cellular response is mediated by the lymph gland (the hematopoietic organ) and the hemocytes, and is responsible for the phagocytosis of foreign cells and the hemocytic encapsulation of the larger macroparasites." This only really tells me about fruit flies, not the other 98% of all animal species that invertebrates form. I suspect that the best source for this sort of fact would be a book or chapter on "invertebrate immunology" rather than a specialist paper.
• The phagocytes are split into the two groups based on their "main function" and I'm guessing the professional group's main function is to be a phagocyte and ingest things. But both the phagocytosis and the dendritic cells articles tell me that dendritic cells' main function is not phagocytosis. The Mast cell article doesn't mention phagocytosis. I'm not disputing the definition, merely saying I've got a bit confused here. Then I get a second rule for distinguishing them: that the professionals have certain receptors.
• I've sneaked ahead to the section on NPPs. I am told there are cells that phagocytose other than "macrophages and neutrophils" and that these are non-professionals. But what about the monocytes, dendritic cells, and mast cells that are also professionals? I'm a bit puzzled that two separate sources are used to tell me "there are others" and "they are these". Then I look up the second source (PMID 11083817) and here I read

"Apoptotic cells and an increasing number of organisms have been shown to be phagocytosed by cells other than macrophages and neutrophils. These nonmyeloid cells, including epithelial, endothelial, and mesenchymal cells, have been designated nonprofessional phagocytes (NPP), emphasizing that, in contrast to macrophages and neutrophils, phagocytosis is not their principal function"

That is almost identical to the article wording. Too close. I note that this source cites PMID 14732160, which sounds ideal if you can get it.

• I don't know what "complement factors" are. The term is completely opaque.
• The Janeway source is a big book. I'm not sure what the purpose of the URL is as it only seemed to give me a chapter description. For a book we need the book name (we've got the chapter name instead) and some page numbers and an edition. This book is cited several times so perhaps should go in the bibliography section?
• The Lange source has a URL that points to the PubMed abstract. We generally only supply the url to freely available fulltext.
• The access date parameter is showing as an ISO format data (whether logged-in or not, and we must consider the 99% of readers who are not logged in). If this article is in US English, then the dates should be also. See WP:MEDMOS#Citing medical sources for notes on whether access dates are always required.
• A quick scan of the contents list makes me suspect the lead isn't a full summary of the article body.
• The lead is the hardest part, and the easiest section to criticise.

My main concern so far is the use of specialist papers for basic facts I would expect to find in a textbook. I'm being particularly picky about this use of sources because there are moves on FAC to tighten the quality of sourcing beyond that required by WP:V/WP:RS. In addition to not being the first-choice of source that a professional encyclopeadia writer might consult, they tend not to be general enough when making comments about all phagocytes in all animals. I'm slightly concerned too about the use of the Microbiology and Immunology On-Line Textbook. How does this compare to some standard textbook in its 7th edition? Colin°^Talk 23:58, 1 March 2009 (UTC)

• Thanks again Colin for this very helpful review. Eulemur, there is a serious problem with accessibility as the article now stands. Brian Boulton, in his peer-review, highlighted the same issue. This, in part, may be due to overuse of specialist sources (which Colin also noted) and (commendable) attempts to make the article comprehensive. All the essential information is there now, but here comes the hardest part—we have to make it understandable by the average, intelligent, non-specialist. The Janeway source is respected and should go to the bibliography and I will add another textbook later which we can use to replace some of the more specialist PubMed references. The wikilinks do not seem to be helping much with the "jargon" (I hate this word), so it might come to having to say "eat" instead of "phagocytose" for example. We need to get the Lead as near to perfect as we can, and then if something in the body of the article is not mentioned in the Lead, it is probably redundant material. These are my thoughts at the moment. Graham. Graham Colm ^Talk 19:24, 2 March 2009 (UTC)

• I agree that the article lacks accessibility and will try to address this and the other concerns mentioned by both Colin and Brian when I get free time. All of you have been great help and I thank you all for your efforts to help improve the article. --Eulemur2008 (talk) 23:35, 2 March 2009 (UTC)

• I have edited the Lead, let me know what you think, is this the direction to go? Graham. Graham Colm ^Talk 00:13, 3 March 2009 (UTC)

• It does look better and more accessible to someone with limited knowledge. This strategy could be applied lightly to the rest of the article: ensuring a mostly accessible article, but a comprehensive one at the same time. I will work on it tomorrow, hopefully. --Eulemur2008 (talk) 01:55, 3 March 2009 (UTC)

Some more comments on this version.

I haven't read more than a third of the article, but I've got questions in my head. Perhaps some are answered later...

• What's the relationship between white blood cells and phagocytes.
• Why do we need several kinds. Do some specialise in bacteria, some in viruses, etc? Do some live in certain tissues/blood?
• How long do they live for. What causes them to die.
• How long does it take to eat something.
• How often can they eat or how many times can they eat.
• Do they get used up?
• Do things attack them to avoid being eaten or do they just hide from them.
• Does the body produce more in response to being attacked. If so, does anything help or hinder this process?
• Contrast/compare these and other attributes between the phagocytes.

Some of these questions are answered in white blood cells, which is quite readable. But if this is heading to FA, you need to answer the important questions too.

Monocytes. The statement in that article: "Monocytes which migrate from the bloodstream to other tissues will then differentiate into tissue resident macrophages or dendritic cells." is better put that the awkward two statements in this article. Do we know what proportion migrate and why?

Neutrophil. The other articles describe these in a much more direct, dynamic and interesting way. Contrast what this article says about them with the others. I don't see much "interesting" information. These guys lead the advance party into war, die after eating only a few microbes and their dead bodies make the puss you see in an infected would. Wow! BTW, why say "have long been recognized for" rather than just "have".

Macrophages. What I learned in the other articles: These live longer than neutrophils and unlike them, they additionally do this antigen presentation malarky that is how the body learns immunity. "Macrophages can digest more than 100 bacteria before they finally die due to their own digestive compounds." The macrophage article says they can live up to several months, but this one only gives 3-6 weeks (but there seem to be many kinds of macrophages, so perhaps some live longer than others).

Dendritic cells. The Dendritic cell article says these are mammalian. So which of the phagocytes are found in which animals?

One could write a general summary of each of these phagocyte types much like you would for the white blood cell article. But since this is an article on phagocytes, I suppose the main focus in each description should be on how they do phagocytosis and the differences between them in that regard. Then a minor discussion on the other things the cells does. Each of these sections needs to begin like "Monocytes are ..." because I have no idea what these all are so starting off with some technical aspect of what they do, where they are found, etc, is less helpful.

Perhaps the article could start (maybe after the history) with a "Role in the immune system" sort of overview. I need to get my bearings and work out how these play their part in the bigger picture of immunity.

Review all the facts that are included in the article to make sure they are helping to build a picture and tell a story. For example, "Monocytes form two groups: a circulating group and a marginal group (approximately 70% are in the marginal group)." I have no idea why there are two groups, what the difference is between them and why the proportion should matter. This is a "useless fact" at present. Another example is "Mast cells have been shown to express working MHC class II molecules". This would be fine if I know what "MHC class II molecules" are, why they might not be working, why anyone might doubt this (i.e., why not just say "Mast cells express ...") and what purpose the immune system has for this ability. The information in that sentence doesn't strike me as worth remembering because I can't find a use for it. If the article built on it then I might remember it. Otherwise it is better to remove the distracting noise even if an expert reader would understand its significance.

One technique is to study the overview/conclusion pages of textbook chapters to find out what they regard as the vital key facts the chapter is going to get across. Then make sure your article explain these key facts and they stand out from the less vital points. Take the reader there by the hand if necessary. Graham knows this stuff: the virus article's paragraph on size (in the Structure section) is great.

Another idea for making the article more accessible is to entertain the reader with statistics. You've got to get me caring about phagocytes and wanting to learn more about them than just what the lead offers. For example, in virus we learn "An enormous variety of genomic structures can be seen among viral species; as a group they contain more structural genomic diversity than the entire kingdoms of either plants, animals, or bacteria." There's a sentence from someone who lives and loves viruses and is proud of it. Can we find some fascinating stats about phagocytes? Would the immune system work without them, or one kind of them? What proportion of the body/blood do they form? What common diseases occur if they are lacking or over-abundant or otherwise misbehaving?

Lastly, I'm not sure the "Hess, Charles" web pages are the best sources you can use.

Cheers, Colin°^Talk 21:59, 4 March 2009 (UTC)

Colin, thanks once more. Bye the way, and if I have done my arithmetic correctly, a litre of human blood contains between 3,000,000,000 to 7,000,000,000 neutrophils and 300,000,000 to 700,000,000 monocytes. This can double or treble during a bacterial infection. Of the other white blood cells, the next major players are the lymphocytes and there are between 2-3 billion of these in a litre of blood. They aren't very good a phagocytosis but they make antibodies which help the other two to get on with the job. These antibodies can knock out viruses by themselves and in a viral infection, by contrast, the numbers of lymphocytes increases. Meningitis is a FAC at the moment and there is a section in the article which explains that you can differentiate viral from bacterial meningitis by examining the fluid that surrounds the brain to see whether it contains neutrophils of lymphocytes. Of the other white blood cells, eosinophils are interesting, we have about 10 to 100 million of these in a litre of blood and they increase during infections by parasites such as worms. Graham. Graham Colm ^Talk 20:21, 5 March 2009 (UTC)

Graham, I agree with your numbers. I wonder whether lay readers will find the ranges confusing since the bounds are not absolute? I have no problem with what you've added, but an alternative might be to provide just the center of each range, and precede it with "about". The idea is just the ballpark figure, right? --Scray (talk) 23:42, 5 March 2009 (UTC)

Right. I'll fix this later when I am fully awake. Thanks. Graham. Graham Colm ^Talk 07:10, 6 March 2009 (UTC)