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Sunday, August 07, 2005placenta going to turn out to be the salvation of mankind? (An argument could be made that it already is, since none of us would be here without it): Scientists looking for easier and less-controversial alternatives to stem cells from human embryos said on Friday they found a potential source in placentas saved during childbirth. They described primitive cells found in a part of the placenta called the amnion, which they coaxed into forming a variety of cell types and which look very similar to sought-after embryonic stem cells. In addition to being researchers at the University of Pittsburgh, the researchers are also shareholders in a company called Stemnion, a biotechnology company that runs the business side of their research. Nothing wrong with that, except that it puts added pressure on them to succeed - or at least give the appearance of succeeding. The news reports say that the team got their placenta cells to transform into liver, pancreas, heart, and nerve cells, but the abstract of their paper suggests they merely hypothesize this could happen. (I could be wrong. The paper may go into more detail, but it's only available at a price.) What they did do, according to the abstract and the substance of their interviews, is analyze the contents and gene expression of the cells that make up the inside lining of the amnion, the transparent sac that surrounds the developing baby. (what is sometimes called the caul.) What they found is rather fascinating, and certainly has the potential to be a stem cell substitute. They found two genes switched on in the amniotic epithelial cells that heretofor were believed to only be expressed in embryonic stem cells. The first is the utiltarian named octamer-binding protein 4, a protein that plays a key role in controlling the expression of other genes, such as the second gene the researchers found switched on in their epithelial cells - the more imaginatively named nanog. It is this nanog gene, or so science assumes, that is the key to a stem cell's ability to turn into just about any type of tissue cell. It is also the gene that allows the embryonic stem cell to divide in perpetuity, hence its name, derived from Tir Nan Og, the land of the Ever Young in Celtic mythology. However, embryonic stem cells have something else going for them that keeps them ever young, an enzyme called telomerase, which repairs a cell's chromosomes as it divides into new cells. Ominously, telomerase, although absent in most adult cells, is also present in cancer cells. It may, in fact, be the key to what turns a normal cell into a cancer cell and sends it into an out of control cycle of propagation, growing and spreading throughout the body. Thus the concern that embryonic stem cells will have the unwanted complication of causing cancer. Amniotic epithelial cells, to their credit, do not have telomerase. They would thus appear to have the best of both worlds - the genes that allow embryonic cells to differentiate into different types of tissue cells, but no association with cancer. There's great potential there. In fact, amniotic epithelial cells have already repaired guinea pig ears and transformed into skin. The key word, though, as in all stem cell research, is potential. There is much about the inner workings of our cells that we have yet to discover. We won't truly understand their true potential until we completely understand their biology. Until that day, their therapeutic promise remains just as ephemeral as Tir-Nan-Og. UPDATE: Dr. Potato emails from the Phillipines to share another superstition about the caul - that it's associated with a sixth sense. She also shares a ghost story. posted by Sydney on 8/07/2005 11:20:00 AM 0 comments
Saturday, August 06, 2005Moral of the Story: The next time you're tempted to think in Brady Bunch stereotypes, remember that Mr. Brady was a deeply unhappy man and Mrs. Brady dated her older son. posted by Sydney on 8/06/2005 08:07:00 AM 0 comments
Friday, August 05, 2005Nigel Hill and his team asked the parents of 126 children aged 2-15 with head louse infestations to use pharmacy-bought insecticide products or the wet combing method, called Bug Busting, after washing the hair with normal shampoo and conditioner. Overall, 56 of the children were treated using the Bug Busting method and 70 using over-the-counter delousing products. The researchers then checked how many still had head lice two to four days after the volunteers had finished their treatment. The cure rate of the Bug Busting method was far higher than that of the chemical treatment - 57% compared to 13%. The authors said: "For every two or three people using the Bug Buster kit rather than pediculicides an extra person would be cured." However, only one dose of insecticide was used in the study as recommended by manufacturers. Here's a wet-combing method taught to me by a nurse: After each pass of the comb through wet hair, rinse the comb by swirling it in a bowl or glass of water. Discard the water and replenish it with fresh when it's cloudy. Repeat until the water no longer gets cloudy when the comb is rinsed. It works, but it's extremely time consuming. posted by Sydney on 8/05/2005 01:32:00 PM 0 comments
Thursday, August 04, 2005"The night Bob died, we lost my mom too," Ms. Sherrill told the Texas jury of seven men and five women. "She's very depressed." Ms. Sherrill cried repeatedly during her testimony, which lasted about an hour. Some people in the courtroom audience also cried, and the jury appeared to be paying close attention to her. ...Ms. Sherrill said that her mother had endured a difficult life before meeting Mr. Ernst in 1997. After divorcing her first husband about 16 years before, Ms. Ernst raised her four children as a single mother, Ms. Sherrill said. During that period, Ms. Ernst rarely dated, devoting her life to her children, and later earning a college degree. But when she met Mr. Ernst on a date arranged by another of her daughters, they fell in love almost immediately, Ms. Sherrill said. They married three years later. "She was happy, very happy," Ms. Sherrill said. "Had you ever seen her this happy your entire life?" asked Lisa Blue, a lawyer for plaintiffs. "No," Ms. Sherrill said. "They were together all the time, doing stuff all the time." She added, "He embraced our family and we embraced him," and then began to cry. Mr. Ernst's death devastated Ms. Ernst and she remains severely depressed, Ms. Sherrill said. "It's just hard. Every day is hard." When Ms. Blue asked, "How do you think the death of Bob has changed your mother?" Ms. Sherrill sobbed for several seconds. Isn't this the part where the attorney for the other side pipes up and objects that this testimony isn't relevant to the case? Surely, the family would be just as devastated by their step-father/husband's death regardless of the cause - wouldn't they? Yes, this case is about monetary compensation, so the suffering of the survivors counts, but shouldn't it be kept separately from the finding of guilt? How about a simple judicial reform that requires a trial to focus on the evidence of whether or not someone is guilty of causing the harm, making the decision of guilty or not guilty, then saving the emotional witnessing for the sentencing? If you think this is something that only big corporations need to worry about, think again. Anyone could find themselves the only survivor of an auto accident that wasn't their fault and end up in court facing the same sort of testimony. Call me naive, but I always thought our courts at looked at the facts, not the emotional impact, of a case. P.S. Medically speaking, this case is short on evidence that Vioxx killed the man: Mr. Ernst's death certificate lists an arrhythmia as his cause of death. Lawyers for Merck say that Vioxx has never been shown to cause arrhythmias, and so Vioxx cannot have caused Mr. Ernst's death. But W. Mark Lanier , a lawyer for Mr. Ernst's family, has told the jury that a blood clot caused by Vioxx led to the arrhythmia that killed Mr. Ernst. Even though the autopsy showed no evidence of a blood clot, several witnesses for plaintiffs, including Dr. Maria M. Araneta, the coroner who conducted the autopsy, have backed Mr. Lanier's theory and said that it was more likely than not that Vioxx caused Mr. Ernst's death. posted by Sydney on 8/04/2005 01:53:00 PM 0 comments
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