But for some reason all the noise is made about embryonic research. I really do not understand why

I'll take a shot at this.

The existing treatments utilizing adult stem cells are all for treatment of blood borne cancers (ie, leukemia). The treatment consists of harvesting (patient or someone else's) bone marrow, processing it in some way, and freezing it for later infusion. You then give the patient a most excellent collection of poisons which destroy the existing bone marrow. You then reinfuse the frozen bone marrow (stem) cells to (hopefully) repopulate the patient's bone marrow. The difference between "bone marrow transplant" and "stem cell transplant" lies only in the processing. When this works it is resurrection. When it doesn't it is a fate worse than death.

The promise of NEW stem cell therapy is that you could harvest that same bone marrow (or fat cell, or whatever), process it, and use it to treat some completely unrelated-to-blood disease (like heart disease or spinal cord injury). This idea is that because embryonic stem cells are earlier in the stem cell lineage, they can differentiate into more cell types and are hence in come way "better". Multiple reports have shown (and been reported here) that you can take most any stem cell and turn it into any other cell type, so there is no real benefit to using stem cells of embryonic lineage.

For what it's worth, at least some "religious freaks" are perfectly capable of differentiating between stem cells of embryonic origin versus autologous stem cells. I have a number of colleagues who have (successfully) lobbied for funding from some of these same people to support their own stem cell work (adult autologous only). The message "don't just stand against things, be in favor of a solution" has been very, very powerful for people who do not consider themselves to be either hypocrites or freaks.

Modern medicine has no sense of humor. There is a form of colitis caused by Clostridium difficile which results from destruction of the normal colonic flora by antibiotic use. It frequently recurs and can be lethal. There is currently on ongoing clinical trial evaluating the use of stool transplantation to prevent recurrence of this infection.

While TFS is indeed inflammatory, your post is factually incorrect. Specifically, gram negative bacteria are very much more virulent than gram positive bacteria (or, for that matter, organisms that don't gram stain at all). The gram negatives are the only class of bacteria that express lipopolysaccharide endotoxin. The human immune system has specific receptors (like CD14) for this toxin, resulting in an extreme inflammatory response which is the pre-death phenomenon called 'sepsis'.

We saw these pathogens emerge in our ICU three years ago and have been using colistin. The side effects are real but not nearly as common with modern supportive care as they were 40 years ago. Which is good, because when the colistin quits working, well, your patient is dead. Currently these pathogens only emerge after many weeks of critical illness and multiple runs of strong intravenous antibiotics.

We go through fairly draconian measures to limit any spread of these organisms, which so far seem to work. Negative pressure rooms, isolation gowns and masks for simply entering the room, disposable stethoscopes, etc. all help. Rooms and gear are disinfected by two different individuals so that personal tendencies don't allow transmission. And we wash our hands. A lot.

Your statement is true for pure water instilled directly into the bloodstream, but not for ingested water. The human digestive system is a polymer (poly-phospholipid) lined tube that is impervious to water absorption. Water and ions have separate transport mechanisms that allow them to be absorbed in specific parts of the intestines. If you drink a sufficient amount of any fluid which is not a balanced salt solution, you will eventually throw yourself into an electrolyte imbalance state.

The fluid which eventually reaches the gut bacteria has a ton of secretions in it, from the salivary glands all the way down to the liver and pancreas, and bears no resemblance to the originally swallowed fluid. As such makes no physiological sense that drinking pure water is toxic to the beneficial gut bacteria (any more so than drinking whiskey).

Maybe. The lack of ethical standards certainly is hindering Chinese researchers from publishing in medical journals. The lack of an institutional review board for human research, or its equivalent for animals, is grounds to reject a manuscript out of hand for most reputable journals. It is disturbing, the number of manuscripts from Chinese researchers I personally have reviewed with sentences like "we administered repeated electrical shocks to the dog until its hindlimb fractured."

It's not quite that simple. The CT scanner is set up with a distinct scanning protocol for whatever part of the body you're imaging. If you're trying to get a detailed image of the bones of the pelvis you have to use more power than if you're imaging the lungs. The scan is further individualized by patient size. Given that infants and very large people are imaged on the same scanner, the software has to vary radiation dose over a reasonably wide range, and it's a different setting for every scan.

The spleen is composed of blood and a thin filigree of tissue that separates this blood from the main circulation. The WBCs are about the only interesting thing on a tissue slice of spleen. I agree with everything you say in the second paragraph. They use flow because it's super sensitive and high throughput- the guy in our lab can sort/count 15 different antigens from a 100 microliter sample. If this discovery turns out to be useful they would tie their antibody to a fluorophore so that a blood analyzer could see it.

After I got through laughing I realized that I can and will ask the lab to do exactly that on the next shattered spleen I take out word

With respect, your assertion about the difficulty of identifying different WBC types in the blood is also incorrect. It's done by looking at the characteristics of the nuclei. Categorizing and counting the different WBC types is now routinely done by automated systems (google "blood analyzer").

The important discovery here is not that the spleen has monocytes in it, because you do in fact see a ton of them when you look at splenic tissue under the microscope. The interesting thing about this discovery is that the spleen can (evidently) release a bunch of those cells in response to an injury. The bone marrow does this too, but the WBCs it releases are immature, and we know that there are changes in the way WBCs function as they age. It would appear that "spleen" WBCs are optimized for their tissue repair properties, while "bone marrow" WBCs are better for fighting infection.

It will be interesting to see if this holds true in humans. Lots of animals have spleens that seem more functional than ours. Cats and dogs, for example, can "transfuse" themselves with the blood from their spleen in response to bleeding, but this does not hold true for humans.

The technique is interesting. The normal body reaction to a new antigen is to form antibodies, which bind to and mark the antigen for destruction (in this case, transplanted pancreatic islet cells, which would cure diabetes). Currently in transplant medicine, that response is dampened by large doses of steroids at the time of transplant, followed by lifelong immunosuppression.

The authors hypothesized that all of those circulating antibody-antigen complexes might shut down further antibody production for a short period of time, as a normal protective mechanism (too many complexes are known to be toxic to lung and kidney). They induced this condition and then performed the transplant. Eighty percent graft survival with no further immunosuppression is pretty remarkable, especially since they demonstrate that the host immune response seems to return to normal quite quickly.

As you say, a bunch of ifs, but this technique as described is readily reproducible in any medical school immunology lab.

I don't mind the bubble so much. If I close my eyes it goes away!

Amen.

There is a common belief that embryonic stem cells, because they have the potential to differentiate into any cell line instead of just one or two, are somehow "better" than the other myriad types of cells. This ignores the fact that it's much harder to stop ESCs from continuing to differentiate, which is why you get tumors at an alarming rate.

This is in turn rooted in another common incorrect notion, namely that stem cells repair injury by differentiating into new cells and tissue. The first decade of research in this field has largely disproved this notion. Instead, stem cells seem to alter the host response to injury, such that normal repair mechanisms function much more effectively. Stem cells tend to get stuck in the lungs when given intravenously, but still result in improved repair at remote sites; conversely, after direct injection of cells into a site of injury, most of those cells are someplace else in the body after 24 hours.

This is why the Geron trial is limited to spinal cord injuries that are less than two weeks old. Once scar formation has occurred, this therapeutic target is gone, and there is currently no notion of how to truly "reconstruct" a spinal cord in a long-standing paraplegic patient.

Not sure which number you consider bogus, but if it's the reference for the >100,000 dead Iraqis, you want, look no further than the New England Journal of Medicine, January 31, 2008 issue, pages 484-493. The article is entitled "Violence-Related Mortality in Iraq from 2002-2006".

This is the first war that has had a careful statistical study of civilian deaths. Since the entire world knew this war was going to happen well in advance, the WHO sent researchers to perform what's called cluster analysis- they identified 10,000 households and then visited them repeatedly over the next three years to determine actual mortality. They then extrapolated to the population of the country as a whole.

Result: 151,000 excess violent deaths (95% CI, 104000-233000).