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Showing posts with label fibroblasts. Show all posts
Showing posts with label fibroblasts. Show all posts

Saturday, June 25, 2016

BACTERIA vs HUMAN CELLS: 1 to 1 (FINAL) PT2/3

PART 1 is HERE
PART 3 is HERE

NOW AVAILABLE AS A PODCAST EPISODE
HERE
&
HERE 


by @sciencemug

Oooh, welcome back my dearest English speaking-thinking-reading visitor, welcome to the second part of the postHow to use the hologram of a white rhino called <<Slim Tim>> to cook spaghetti, wash your conscience and put up a bolero dance act in the middle of the dining room of the President of the Guatemalan branch of  <<The Authority For The Perfect Fonduta>> while he/she’s having a private conversation with his/her lawyer about the lawsuit filed for misleading advertising against the city of Cheeseville (43°28′08″N 88°04′50″W”)"… Ooops, nope, sorry, eheh, just confused the posts, this one‘s still under scrutiny of the “Commission of Weary Neurons and Short Sleeve Shirts with Ties” to get the “go” for publication.

Ok, then, let’s start again.

Oooooh, welcome back etc. to the second part of the post which tells the story of a student, a doctor and a professor (Mr. Sender,  Dr. Fuchs & Prof. Milo aka the SFMs) who don’t enter a bar but instead show how the commonly accepted notion that, in the ecosystem the human body is, bacteria outnumber human cells by 10 to 1 (in an adult, healthy, 20-30 years old, 1.70m tall, 70kg* heavy reference man (1) here friendly called Mr. Ref) is not true.

The SFMs first collect evidence –as the Part1 of this post reports- that the number of bugs in&on human bodies is not, as estimated till now, in the order of 1014, but rather of a factor of 10 smaller. It is, indeed, 3.9x1013.

The three happy researchers then proceed to update the second number that is used for the 10 to 1 ratio (the first one being that of the bacteria): the number of the actual human cells in the human body.

And what follows is the tale of how they do that.

Reference  man aka Mr. Ref (by @sciencemug)
Reference  man aka Mr. Ref (by @sciencemug)

The SFMs once again start checking the scientific literature. They find that, in papers from 1985 to 2013, the amount of the human cells is reported as ranging between 1012 and 1014.

Our curious scientists, in their study, mention only three different kind of approaches followed in the years by their colleagues to calculate how many little bricks make the human building.

The first approach switches from the fit 70kg Mr. Ref to a bigger 100kg man, and then divides the mass of this hulk by the 10-12 - 10-11kg mass (“assuming cell volumes of 1,000-10,000 µm3, respectively” Sender et al, 2016; (P)) of what is considered to be the “representative” (P) mammalian cell. This method clearly doesn’t consider that human body’s mass is also made by extracellular stuff, besides the cells themselves. Anyway it is a clear and rather concise way to get to a final result: human cells are between 1013 and 1014.

The second approach is based on DNA. It starts valuating the number of cells in a mouse. No, its name is not Mickey. No, it does not show its compulsive germ phobia by always wearing a pair of white gloves. And no, its best friend is not a talking biped dog with wide spaced beaver front teeth which for some inexplicable reason has evolved while the other dog of the situation just barks, wags its tail, walks on all fours and probably farts regardless of anything and anybody. The mouse here is a 25gr thing, with 20mg of DNA in it (the Mickey guy instead has tons of DNA, but that’s Disney Narrative Appeal, not DeoxyriboNucleic Acid). This total gloveless mouse body amount of DNA is divided by that of a single diploid gloveless mouse cell (namely 6x10-12g) to get a total of about 3x109 cells forming the above mentioned gloveless mouse body.

This second method, then, makes a proportion between a Mr. Ref’s mass and the tiny mouse mass, and, like that, calculates that the 3x109 cells of the gloveless mouse correspond to about 1013 cells in a human body.

by @sciencemug
by @sciencemug

  [The mouse (PC) and mouse (animal) images are Public Domain pics adapted by @sciencemug (source: Wikimedia Commons)]


The third approach to calculate the totality of human cells in a human being that the SFMs mention is the one used by Bianconi et al in 2013 [(2); oh, visitor, try to remember this name ‘cause I’ll mention it again and again in this post since the SFMs often use the Bianconis’ research as a reference source of data to compare their own data to. Ok, let’s help you out on this: let’s make that every time I’ll recall the Bianconis’ study I also contextually write the symbol “§”, that is not logically linked in whatsoever way to the issue, but it’s strange and complicated and unique and mysterious, so it should stick to your mind. So “§” - besides possibly being one of the five symbols (the other four are up to you to be found) that switch on, via hypnotic suggestion, some dormant cell of spies from Planet X that has the order to cut every single bottle of whisky on Earth with 9.576ml of juice of squeezed algae of the Sargasso Sea so to slightly alter and worst the whisky taste, depress the by this confused and disconcerted whisky purists, weaken their will, and start from them to create a fifth column which will help to eventually fulfill Planet X prime directive: to globally destabilize human civilization by stealing every single stamp on Earth which portray the Elvis (the first Planet X undercover agent ever who’s now collecting funds to sustain his 2018 “Khan of Planet X” campaign) - will be there to remind you of the Bianconis’ paper].

The Bianconi’s § lab bunch doesn’t focus on the elusive “average” human cell, but instead estimate the “number of cells in the body by type or organ system [and] the cell count [is] obtained by either a literature reference or by a calculation based on direct count in histological cross sections”(P_Rx). Aaand, like that, dear human visitor, these patient science people check all yours 56 cells types and get to