Scientists have identified two genetic variations that account for 57 percent of cases of thyroid cancer, a finding that could lead to earlier detection among people at high risk for the disease. Gene Study Finds Link to Cancer of Thyroid
By NICHOLAS WADE
The report, from the Icelandic company Decode Genetics, may also lead to a resurgence of interest in the quest for the genetic roots of other common maladies like heart disease and schizophrenia. Genetic variants for many such diseases have been identified, but most have turned out to account for a disappointingly small percentage of cases.
A scientific team led by Julius Gudmundsson of Decode Genetics reported Friday in the journal Nature Genetics that the two variants each lie at a site on the human genome near genes that control development of the thyroid gland. The variants are changes in a single chemical unit of the genome, which is some three billion units in length.
Compared with people who have neither variant, “the risk associated with these variants was almost sixfold, which is quite extraordinary,” said Dr. Erich M. Sturgis, a head and neck surgeon at the M. D. Anderson Cancer Center in Houston who was not connected with the research.
Dr. James A. Fagin, chief of endocrinology at the Memorial Sloan-Kettering Cancer Center in New York, said the new study was a significant advance, noting that the Decode Genetics scientists had bolstered their results by replicating the findings among Icelanders in two other populations of European descent, in Columbus, Ohio, and in Spain.
About 4 percent of people of European descent carry both variants, the scientists reported; they did not have information on other ethnic groups.
There are some 35,000 cases of thyroid cancer in the United States each year, but because of an effective treatment — removing the gland and giving patients replacement thyroid hormone — only about 1,500 people die of the disease. It would probably not be worth screening the whole population for the two new variants, at least not until the cost of genetic tests was substantially reduced.
But the test could be useful in groups at special risk, including families where one member has thyroid cancer, said Dr. Kari Stefansson, chief executive of Decode Genetics.
Dr. Fagin agreed that the ability to give such people more predictability “could be a real advantage.”
The Decode Genetics scientists found that subjects with the two variants had lower levels of thyroid-stimulating hormone in their bloodstream. That hormone, produced by the pituitary gland, directs the thyroid gland to generate its own hormones.
The thyroid-stimulating hormone also makes cells of the thyroid gland mature. Dr. Stefansson said it was conceivable that in people with the double variants the thyroid cells were not properly differentiated, and that the immature cells might be the cause of cancer. If so, supplying extra thyroid-stimulating hormone could make the cells mature and reduce the cancer risk.
Dr. Stefansson and other scientists emphasized that for now, that was just speculation.
Most genetic variants found to be associated with common diseases have turned out to account for just 1 percent or so of cases. Dr. Stefansson said the problem was that the variants had been expected to be common, and the gene chips used to analyze patients’ genomes were designed to look for common variants, not for rare ones. But it is the rare ones, he said, that now seem likely to account for most genetic disease. Evidently, natural selection winnows out disease-causing genes before they get to be common.
Dr. Stefansson said Decode Genetics had developed new and cost-effective methods to search the Icelandic population for rare variants. Those, he said, “will allow us to capture much more of the total genetic risk of common diseases.”
“You wait till Larry comes and I tell him my theory!” The bids, duly sealed, were given into the keeping of the commissary officer to be put in his safe, and kept until the day of judgment, when all being opened in public and in the presence of the aspirants, the lowest would[Pg 188] get the contract. It was a simple plan, and gave no more opportunity for underhand work than could be avoided. But there were opportunities for all that. It was barely possible—the thing had been done—for a commissary clerk or sergeant, desirous of adding to his pittance of pay, or of favoring a friend among the bidders, to tamper with the bids. By the same token there was no real reason why the commissary officer could not do it himself. Landor had never heard, or known, of such a case, but undoubtedly the way was there. It was a question of having the will and the possession of the safe keys. "Well, I believe our boys 's all right. They're green, and they're friskier than colts in a clover field, but they're all good stuff, and I believe we kin stand off any ordinary gang o' guerrillas. I'll chance it, anyhow. This's a mighty valuable train to risk, but it ought to go through, for we don't know how badly they may need it. You tell your engineer to go ahead carefully and give two long whistles if he sees anything dangerous." "Fine-looking lot of youngsters," he remarked. "They'll make good soldiers." "That's just what he was, the little runt, and we had the devil's own time finding him. What in Sam Hill did the Captain take him for, I'd like to know? Co. Q aint no nursery. Well, the bugler up at Brigade Headquarters blowed some sort of a call, and Skidmore wanted to know what it meant. They told him that it was an order for the youngest man in each company to come up there and get some milk for his coffee tomorrow morning, and butter for his bread. There was only enough issued for the youngest boys, and if he wanted his share he'd have to get a big hustle on him, for the feller whose nose he'd put out o' joint 'd try hard to get there ahead o' him, and get his share. So Skidmore went off at a dead run toward the sound of the bugle, with the boys looking after him and snickering. But he didn't come back at roll-call, nor at tattoo, and the smart Alecks begun to get scared, and abuse each other for setting up a job on a poor, innocent little boy. Osc Brewster and Ol Perry, who had been foremost in the trick had a fight as to which had been to blame. Taps come, and he didn't get back, and then we all became scared. I'd sent Jim Hunter over to Brigade Headquarters to look for him, but he came back, and said they hadn't seen anything of him there. Then I turned out the whole company to look for him. Of course, them too-awfully smart galoots of Co. A had to get very funny over our trouble. They asked why we didn't get the right kind of nurses for our company, that wouldn't let the members stray out of their sight? Why we didn't call the children in when the chickens went to roost, undress 'em, and tuck 'em in their little beds, and sing to 'em after they'd said 'Now I lay me down to sleep?' I stood it all until that big, hulking Pete Nasmith came down with a camp-kettle, which he was making ring like a bell, as he yelled out, 'Child lost! Child lost!' Behind him was Tub Rawlings singing, 'Empty's the cradle, baby's gone.' Then I pulled off my blouse and slung it into my tent, and told 'em there went my chevrons, and I was simply Scott Ralston, and able to lick any man in Co. A. One o' their Lieutenants came out and ordered them back to their quarters, and I deployed the company in a skirmish-line, and started 'em through the brush toward Brigade Headquarters. About three-quarters o' the way Osc Brewster and Ol Perry, when going through a thicket, heard a boy boo-hooing. They made their way to him, and there was little Skidmore sitting on a stump, completely confused and fagged out. He'd lost his way, and the more he tried to find it the worse he got turned around. They called out to him, and he blubbered out: 'Yes, it's me; little Pete Skidmore. Them doddurned fools in my company 've lost me, just as I've bin tellin' 'em right along they would, durn 'em.' Osc and Ol were so tickled at finding him that they gathered him up, and come whooping back to camp, carrying him every step of the way." And the rush stopped. Cadnan waited for a second, but there was no more. "Dara is not to die," he said. Then he saw Orion hanging over him, very low in the windy sky, shaking with frost. His eyes fixed themselves on the constellation, then gradually he became aware of the sides of a cart, of the smell of straw, of the movement of other bodies that sighed and stirred beside him. The physical experience was now complete, and soon the emotional had shaped itself. Memory came, rather sick. He remembered the fight, his terror, the flaming straw, the crowd that constricted and crushed him like a snake. His rage and hate rekindled, but this time without focus—he hated just everyone and everything. He hated the wheels which jolted him, his body because it was bruised, the other bodies round him, the stars that danced above him, those unknown footsteps that tramped beside him on the road. Farewell to Jane and Caroline!" HoME大香蕉色人阁 ENTER NUMBET 0017
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MDMA: Utopian Pharmacology
Transhumanism: Brave New World?
Critique of Aldous Huxley's Brave New World
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