Purpose of Appendix Believed Found 235
CambodiaSam sent in this story, which opens: "Some scientists think they have figured out the real job of the troublesome and seemingly useless appendix: It produces and protects good germs for your gut.
That's the theory from surgeons and immunologists at Duke University Medical School, published online in a scientific journal this week.
For generations the appendix has been dismissed as superfluous. Doctors figured it had no function. Surgeons removed them routinely. People live fine without them.
The function of the appendix seems related to the massive amount of bacteria populating the human digestive system, according to the study in the Journal of Theoretical Biology. There are more bacteria than human cells in the typical body. Most are good and help digest food.
But sometimes the flora of bacteria in the intestines die or are purged. Diseases such as cholera or amoebic dysentery would clear the gut of useful bacteria. The appendix's job is to reboot the digestive system in that case."
Paper Abstract (Score:5, Informative)
The human vermiform ("worm-like") appendix is a 5 to 10 cm long and 0.5 to 1
cm wide pouch that extends from the cecum of the large bowel. The architecture of the
human appendix is unique among mammals, and few mammals other than humans have
an appendix at all. The function of the human appendix has long been a matter of debate,
with the structure often considered to be a vestige of evolutionary development despite
evidence to the contrary based on comparative primate anatomy. The appendix is thought
to have some immune function based on its association with substantial lymphatic tissue,
although the specific nature of that putative function is unknown. Based (a) on a recently
acquired understanding of immune-mediated biofilm formation by commensal bacteria in
the mammalian gut, (b) on biofilm distribution in the large bowel, (c) the association of
lymphoid tissue with the appendix, (d) the potential for biofilms to protect and support
colonization by commensal bacteria, and (e) on the architecture of the human bowel, we
propose that the human appendix is well suited as a "safe house" for commensal bacteria,
providing support for bacterial growth and potentially facilitating re-inoculation of the
colon in the event that the contents of the intestinal tract are purged following exposure to a pathogen.
complete lie (Score:1, Informative)
Re:Polio, Asthma & Allergies (Score:5, Informative)
From my research and discussions with doctors etc I've come to learn that bacteria adapt to antibiotics because these agents are very precise and destroy a very narrow type of microorganism, whereas alcohol, chlorine bleach, and all other cleaning agents wipe everything out. There has been no (to my knowledge) increase in resistance to bleach used in the kitchen for instance. It would be like gaining resistance to fire. The properties of these antibacterial agents is just too violent against the cell for evolution to do anything about it.
I'm sure this could have been said better, but basically antibacterial soap will not create super-deadly strains of bacteria, whereas continued use of antibiotics has and will.
Re:Reboot? (Score:4, Informative)
When a computer is turned on, it needs to load some code to run. In order to do this, it needs some code to tell it which code to load. In order to load that code, it needs some code to tell it what to load, and so on. The solution is to have the computer metaphorically pick itself up by its bootstraps to get the first bit loaded. The code it then runs became known as the bootstrap, and later the term was corrupted to boot loader, and other variations.
Re:Evolution would have gotten rid of it (Score:5, Informative)
No. Evolution would have gotten rid of it if it caused a net increase in the risk of death between menarche and menopause (males simply don't matter here).
Now, we might presume at first glance that since appendicitis can kill, and a not-inconsiderable portion of the population will at some point get it. But the lower incidence in underdeveloped countries suggests that its modern danger to us may result largely from lifestyle; and, as we currently chop it out at the first sign of inflammation, we may also overstate the actual risk of death from appendicitis in the absence of treatment.
Evolution/God does their work quite well I guess.
You can believe what you want about a deity, and what mechanisms it put into place to run the universe. But beware of animism by ascribing "intent" to abstract statistical descriptions of phenomena.
Re: Evolution would have gotten rid of it (Score:5, Informative)
It is not exactly true that evolution would get rid of a part that has become useless. Evolution through natural selection would tend to remove mainly deleterous (harmful) structures, but structures that are neither harmful nor helpful are masked from natural selection. To explain the loss of the vestigial structures, we must realize that the individual organism has only so many resources (energy, molecules, etc) with which to survive. This causes natural selection to select against structures that use up the organism's resources without contributing to its survival (for example in whales, who still have vestigial hips and leg bones, which serve no function and are much reduced in size).
This leads to the question of why the structure is still present. There are two major reasons why we would still observe the structure today: time and cost.
If natural selection only started working on removing the structure in recent time (geologically speaking), it would not be finished instantly in one generation, as natural selection works by tiny modifications that are build on generation after generation. Hence the canon of natural history: Natura non facit saltum (nature makes no leap).
A second possibility for its continued presence is that further reduction in its size or its total absence would be more disadvantageous the organism's fitness than its presence. This seems to be what the study is suggesting, that even though it is not used to the full extent it once was, there is some tiny function that is still useful enough to justify the resources the organism spends on it.
Keeping kids healthy (Score:5, Informative)
1. Breastfeed. Not just for 6 weeks either. Worldwide average weaning age is 3-4yrs. U.S. is about the worst at this.
2. Let your kids eat dirt. No, don't encourage it. Just don't freak when it happens.
3. Be very conservative with immunizations. How many middle class US children are really going to get exposed to Hep? And since thermerisol has finally been removed from vaccination products, the autism rate has finally stopped exploding (despite the fact that studies show no link between the two).
4. LOTS of physical contact! Breastfed babies get this. It stimulates brain development.
5. Love the little knuckleheads despite everything.
6. Learn basic biology and medicine yourself. Your offspring, your responsibility. Knowledge and common sense go a long way towards health.
We're still learning about biology and medicine. Oh shit, you mean bacteria can evolve to become resistant to antibiotics, and that blanketing the population with antibiotics (antibaterical handsoap, anyone?) causes bigger problems than it solves? I've never heard of a staph infection from a home birth. When women give birth at home around all the same germs they are exposed to anyway, postpartum infections are almost nonexistent.
OTOH, I will take exception to the idea that there were no allergies and less sickness among rural populations 2 generations ago. There were. The difference is that those kids were just labeled "sickly" and often died back then. Is it a bad thing that those kids have a chance now?
Re:another body part that is often yanked (Score:2, Informative)
Outside of some religious circles, the practice of butchering newborns is a very new one. A recent study has shown men who have been butchered have only a fraction of the sexual pleasure as normal, intact men.
Re:Polio, Asthma & Allergies (Score:4, Informative)
I like your fire analogy, though. Very apt.
Re:Polio, Asthma & Allergies (Score:5, Informative)
I think you may have it backwards: You are saying that there are no farmers with asthma because working on a farm prevents asthma. It's more likely that there are no farmers with asthma because people with asthma do not become farmers. Even though I (someone who has had asthma my entire life) have helped bale hay, milk cows and shovel manure, there is no way that I would *think* of becoming a farmer. Wearing a dust mask while baling hay or doing other chores on the farm is no fun. Being in the barn without some sort of mask is a surefire recipe for having a meeting with Mr. Albuterol later in the day.
I could come-up with a parallel to your "I've never known farmers with asthma" story by saying "I've never seen a one-armed crab fisherman on the Discovery TV show "Deadliest Catch". I could infer from watch the Deadliest Catch that crab fishing must be a pretty safe line of work because there are no one-armed guys working the crab pots. The reality is there are no one-armed crab fisherman because the one-armed guys do not sign-up for a job that they know would be extremely hazardous for them to do with just one arm.
This is why I recommend against anyone installing an air purifier in their home. It's a great idea--if you never plan on leaving your home.
I'm sorry, I didn't catch the name of the medical school you graduated from or where you did your residency in allergy/asthma. Could you post that information one more time? I have an IQAir HealthPro Plus http://www.iqair.us/residential/roomairpurifiers/healthproplus.php [iqair.us] that runs in my bedroom every night. That air purifier filters the dust, pollen and other allergens out of air inside my house so that I can breathe more easily - especially during the spring and fall when thing like tree pollen, ragweed and alternaria are bad. The indoor air purifiers also help when local "air quality alerts" are issued. Even if the air outside is filled with small pollutants that are harmful to my lungs, I can come home at the end of the day, run the IQAir and have decent breathable air.
Here is a little more background on local air quality issues:
http://dnr.wi.gov/org/aw/air/health/status.asp [wi.gov]
Regarding your comment about air purifiers being a bad idea,
I can't
Re:Keeping kids healthy (Score:2, Informative)
Re:Polio, Asthma & Allergies (Score:5, Informative)
If you are talking about immunotherapy for the treatment of allergies, the frequency of the injections is more than "every few months". It's more like "once a week". The injections provide an ever-increasing amount of the substance the patient is allergic to in an effort to get the patient's immune system to "chill out". The last time I was receiving these shots, I was getting them every five days (Mon, Fri, Wed, Mon, Fri, etc.). I spent a lot of time sitting in the waiting room at the allergy clinic (you have to sit in the clinic after receiving the shot so the clinic staff can monitor you for an adverse reaction to the shot).
http://www.allergycapital.com.au/Pages/immth.html [allergycapital.com.au]
Re:Keeping kids healthy (Score:4, Informative)
But just to reinforce your point, I'll add 7. Don't slather on the antibiotic ointment when you get a paper cut. Don't use Lysol in your kitchen - use a bleach solution if soap is not going to cut it.
Re:Keeping kids healthy (Score:2, Informative)
I concur. My father-in-law, a farming Depression baby, suffered from asthma his whole life, and the last twenty years of his life were a state of constant illness, mostly from the damage he'd suffered pre-treatment. (Though in the later years, there was certainly an element of drugs to treat the side effects of the drugs to treat the primary problem. Certain things stack up over time.)
The irony is that he outlived his "healthy" siblings, every one.
Re:So we're all scumbags .. (Score:4, Informative)
The blurb posted on slashdot states that in the human body, there are MORE BACTERIA than there are HUMAN CELLS. Which would suggest that a minimum of 51% of the human body is made up of bacteria and only 49% (or less) of our body is made of things like . . . water, carbon and other . . . you know . . . human composition stuff.
One meaning of "more bacteria than human cells" means simply that there are a larger number of bacteria than they are human cells, not a larger mass of bacteria than human cells. For example, e. coli is about 1/100 the size of a human cell. So if there was an equal number of e. coli cells and human cells in the body, it would make the mass proportion of e. coli cells about 1% not 50%.
By the way, bacteria are also made of water, carbon and other ... you now ... organic composition stuff. Humans don't have a monopoly on that composition.
Re:Polio, Asthma & Allergies (Score:1, Informative)
Re:Reboot? (Score:3, Informative)
In the old days, you might enter the bootstrap on a front panel (in the snow over your head uphill both ways). In it's simplest form a set of toggle switches connected to the address and data bus and a pushbutton to strobe the write line (yes, manually, CPU not yet running). Eventually, the bootstrap code started being placed in a ROM and instead of forcing an address into the program counter, it would go to a defined value when reset strobes (which the chipset does when the power supply stabilizes).
For that matter, when entered manually, the bootstrap program was likely just barely enough to load a second stage bootstrap from somewhere that would then load the OS.
Now get off my lawn :-)
Re:Polio, Asthma & Allergies (Score:5, Informative)