[SN Today] from [ScienceNews]
[SN Tosay]
50 million chemicals and counting
By Janet Raloff
Web edition : Tuesday, September 8th, 2009
Bring out the helium balloons, confetti and a noisemaker or two. Today, researchers the world over have reason to raise a toast. This afternoon, the Chemical Abstracts Service — an American Chemical Society subsidiary — identified the 50 millionth compound known. Arylmethylidene heterocycle — the molecule that qualified for the momentous spot during the long holiday weekend — is a future candidate for reducing neuropathic pain.
Since 1907, the Columbus, Ohio-based Chem Abstracts has maintained a registry of all publicly disclosed chemicals. Over the years, this registry has become the definitive one-stop shopping site for tracking down any and every known compound, including the names for each (as some compounds have as many as 1,000 monikers), a compound’s structure and any general characteristics (such as melting point).
“Thirty years ago, we felt six or seven million substances might be about it,” says Roger Schenck, who manages content planning at Chem Abstracts. He says there had been a suspicion that once chemists had characterized all of these, his group might become little more than caretakers of a static database. However, chemical designers continue to keep his group plenty busy.
The 40 millionth compound that his organization identified was a synthetic analog to the anticancer drug taxol. To keep things simple, we’ll just refer to that member of the azulenobenzofuran family as 1073662-18-6 (its structure appears below). In the intervening nine months since that chemical was added to the database, Chem Abstracts has identified yet an additional 10 million novel chemicals.
To search for new candidates, Chem Abstracts’ staff pores over journal articles, data filed with 59 patent authorities around the world, commercial chemical suppliers’ catalogs and announcements, and reports surfacing on the Internet. In all, “we cover over 50 languages,” Schenck says.
For instance, Chem Abstracts noted that the 50 millionth entrant "was identified by [its] scientists in the Examples section of a nearly 200-page patent document" that was issued on Aug. 13, 2009. The molecule's formal name is a mouthful: (5Z)-5-[(5-Fluoro-2-hydroxyphenyl)methylene]-2-(4-methyl-1-piperazinyl)-4(5H)-thiazolone.
Tracking down each and every qualifying chemical has become a bit more than the chemists at Schenck's organization can manage on their own. Computers now sift through machine-readable files, so “we don’t have to manually review each one,” he explains. Good thing, too, since it’s hard to imagine how a staff of 1,300 people could collectively screen and then add some 36,000 new chemicals to the database every day — year in and year out — complete with files describing who developed or first found a chemical and when; citations detailing the chemical’s isolation, function and properties; a chemical structure for the molecule; and often magnetic-resonance or other characteristic spectra.
With 50 million novel compounds in this database, how can anyone find what they're looking for? Explains Schenck: “If someone knows a molecule’s name, they can search for that. Or if they even have a fragment of a name, we will look it up and find matches.” Input a known or suspected structure, he says, and if that chemical resides in the database, “we’ll get them an exact match. Or if someone only knows a piece of a structure, we can find all of the things in our collection that have that same piece in them.”
As you might expect, patent attorneys and patent examiners are key users of this encyclopedic, cross-indexed list of chemicals. So are synthetic chemists looking to cook up the next boffo plastic, alloy or pharmaceutical.
This summer, my daughter and her adviser worked in a materials science lab as part of a project funded by the National Science Foundation. Their goal: the development of novel quaternary diamondlike semiconductor crystals. My enterprising undergraduate successfully cooked up two such crystals possessing never-before-reported recipes. She was promised first authorship on a paper that reports their structures.
So I asked Schenck: When a paper comes out describing my daughter’s crystals, will each of them get added to Chem Abstracts’ database? “You bet,” he said, “with her name on them.”
I passed the information along to her over the weekend. And her typically nuanced response: “Sweeeeeet!”
[SN Today]
Dopamine primes kidneys for a new host
Transplant patients may fare better if brain-dead organ donors receive an infusion of the compound before surgery
By Nathan Seppa
Web edition : Tuesday, September 8th, 2009
Giving dopamine infusions to brain-dead organ donors while they still have a heartbeat seems to fortify their kidneys against the rigors of transplant, a new study shows. Patients receiving a kidney from such donors are less likely to require multiple sessions of blood-cleansing dialysis immediately after the transplant operation, researchers report in the Sept. 9 Journal of the American Medical Association.
What’s more, treating a donor with dopamine seems to prevent some of the damage to kidneys that happens while the organs wait to be transplanted, the scientists find.
Brain-dead donors supply the majority of kidneys for transplant. Such donors often have suffered trauma or brain hemorrhage and have no chance of regaining brain function.
Although dopamine is best known as a neurotransmitter that guides brain signaling, the chemical has been used in intensive care units to stabilize blood pressure in patients, says study coauthor Benito Yard, an immunologist at the University Clinic of Mannheim in Germany. Dopamine can also quell inflammation and preserve blood vessel cells, both of which might benefit a kidney headed for transplant.
In the new study, 122 brain-dead organ donors received infusions of dopamine while 137 similar donors did not. All donors had a heartbeat when they received the dopamine, but they had no brain function as measured by electroencephalography and they needed a ventilator to breathe.
After each organ transplant, the scientists monitored the health of the kidney recipient. Of recipients getting dopamine-exposed kidneys, 25 percent needed multiple kidney dialysis sessions during the week after transplant. Of those getting a kidney not exposed to dopamine, 35 percent needed the multiple sessions.
“This is a big deal for the recipient,” Yard says. A need for dialysis indicates that a donor kidney hasn’t started to filter blood yet. “The sooner it starts to function, the better it will be,” for the patients’ long-term prospects, he says.
In this study, recipients who needed multiple dialysis sessions in the week after surgery were more than three times as likely to have their new kidney fail within three years as were people who got only one dialysis session or none.
Dopamine may be particularly protective in kidneys that face delays before transplant. It usually takes several hours or even a day to get a kidney from donor to recipient, during which time the organ must be kept cold to slow tissue damage. In patients receiving a kidney that had been in storage for more than 17 hours — which was one-fourth of the kidneys in this study — 91 percent of dopamine-exposed kidneys were still functioning three years later compared with only 74 percent of kidneys whose donors didn’t get dopamine. In addition to preserving blood vessel health, Yard says, dopamine exposure before transplant seems to mitigate inflammation in the kidney that can attract the attention of the recipient’s immune system and raise rejection risk.
“I think this study is very elegant, especially since dopamine is routinely used in intensive care medicine,” says Duska Dragun, a transplant nephrologist at Charité Hospital in Berlin. “At least in Europe, it is very difficult to estimate how long a kidney will be in cold storage,” she says. Dragun argues that the new trial is good enough to warrant use of dopamine for kidney transplants.
[SN Tosay]
50 million chemicals and counting
By Janet Raloff
Web edition : Tuesday, September 8th, 2009
Bring out the helium balloons, confetti and a noisemaker or two. Today, researchers the world over have reason to raise a toast. This afternoon, the Chemical Abstracts Service — an American Chemical Society subsidiary — identified the 50 millionth compound known. Arylmethylidene heterocycle — the molecule that qualified for the momentous spot during the long holiday weekend — is a future candidate for reducing neuropathic pain.
Since 1907, the Columbus, Ohio-based Chem Abstracts has maintained a registry of all publicly disclosed chemicals. Over the years, this registry has become the definitive one-stop shopping site for tracking down any and every known compound, including the names for each (as some compounds have as many as 1,000 monikers), a compound’s structure and any general characteristics (such as melting point).
“Thirty years ago, we felt six or seven million substances might be about it,” says Roger Schenck, who manages content planning at Chem Abstracts. He says there had been a suspicion that once chemists had characterized all of these, his group might become little more than caretakers of a static database. However, chemical designers continue to keep his group plenty busy.
The 40 millionth compound that his organization identified was a synthetic analog to the anticancer drug taxol. To keep things simple, we’ll just refer to that member of the azulenobenzofuran family as 1073662-18-6 (its structure appears below). In the intervening nine months since that chemical was added to the database, Chem Abstracts has identified yet an additional 10 million novel chemicals.
To search for new candidates, Chem Abstracts’ staff pores over journal articles, data filed with 59 patent authorities around the world, commercial chemical suppliers’ catalogs and announcements, and reports surfacing on the Internet. In all, “we cover over 50 languages,” Schenck says.
For instance, Chem Abstracts noted that the 50 millionth entrant "was identified by [its] scientists in the Examples section of a nearly 200-page patent document" that was issued on Aug. 13, 2009. The molecule's formal name is a mouthful: (5Z)-5-[(5-Fluoro-2-hydroxyphenyl)methylene]-2-(4-methyl-1-piperazinyl)-4(5H)-thiazolone.
Tracking down each and every qualifying chemical has become a bit more than the chemists at Schenck's organization can manage on their own. Computers now sift through machine-readable files, so “we don’t have to manually review each one,” he explains. Good thing, too, since it’s hard to imagine how a staff of 1,300 people could collectively screen and then add some 36,000 new chemicals to the database every day — year in and year out — complete with files describing who developed or first found a chemical and when; citations detailing the chemical’s isolation, function and properties; a chemical structure for the molecule; and often magnetic-resonance or other characteristic spectra.
With 50 million novel compounds in this database, how can anyone find what they're looking for? Explains Schenck: “If someone knows a molecule’s name, they can search for that. Or if they even have a fragment of a name, we will look it up and find matches.” Input a known or suspected structure, he says, and if that chemical resides in the database, “we’ll get them an exact match. Or if someone only knows a piece of a structure, we can find all of the things in our collection that have that same piece in them.”
As you might expect, patent attorneys and patent examiners are key users of this encyclopedic, cross-indexed list of chemicals. So are synthetic chemists looking to cook up the next boffo plastic, alloy or pharmaceutical.
This summer, my daughter and her adviser worked in a materials science lab as part of a project funded by the National Science Foundation. Their goal: the development of novel quaternary diamondlike semiconductor crystals. My enterprising undergraduate successfully cooked up two such crystals possessing never-before-reported recipes. She was promised first authorship on a paper that reports their structures.
So I asked Schenck: When a paper comes out describing my daughter’s crystals, will each of them get added to Chem Abstracts’ database? “You bet,” he said, “with her name on them.”
I passed the information along to her over the weekend. And her typically nuanced response: “Sweeeeeet!”
[SN Today]
Dopamine primes kidneys for a new host
Transplant patients may fare better if brain-dead organ donors receive an infusion of the compound before surgery
By Nathan Seppa
Web edition : Tuesday, September 8th, 2009
Giving dopamine infusions to brain-dead organ donors while they still have a heartbeat seems to fortify their kidneys against the rigors of transplant, a new study shows. Patients receiving a kidney from such donors are less likely to require multiple sessions of blood-cleansing dialysis immediately after the transplant operation, researchers report in the Sept. 9 Journal of the American Medical Association.
What’s more, treating a donor with dopamine seems to prevent some of the damage to kidneys that happens while the organs wait to be transplanted, the scientists find.
Brain-dead donors supply the majority of kidneys for transplant. Such donors often have suffered trauma or brain hemorrhage and have no chance of regaining brain function.
Although dopamine is best known as a neurotransmitter that guides brain signaling, the chemical has been used in intensive care units to stabilize blood pressure in patients, says study coauthor Benito Yard, an immunologist at the University Clinic of Mannheim in Germany. Dopamine can also quell inflammation and preserve blood vessel cells, both of which might benefit a kidney headed for transplant.
In the new study, 122 brain-dead organ donors received infusions of dopamine while 137 similar donors did not. All donors had a heartbeat when they received the dopamine, but they had no brain function as measured by electroencephalography and they needed a ventilator to breathe.
After each organ transplant, the scientists monitored the health of the kidney recipient. Of recipients getting dopamine-exposed kidneys, 25 percent needed multiple kidney dialysis sessions during the week after transplant. Of those getting a kidney not exposed to dopamine, 35 percent needed the multiple sessions.
“This is a big deal for the recipient,” Yard says. A need for dialysis indicates that a donor kidney hasn’t started to filter blood yet. “The sooner it starts to function, the better it will be,” for the patients’ long-term prospects, he says.
In this study, recipients who needed multiple dialysis sessions in the week after surgery were more than three times as likely to have their new kidney fail within three years as were people who got only one dialysis session or none.
Dopamine may be particularly protective in kidneys that face delays before transplant. It usually takes several hours or even a day to get a kidney from donor to recipient, during which time the organ must be kept cold to slow tissue damage. In patients receiving a kidney that had been in storage for more than 17 hours — which was one-fourth of the kidneys in this study — 91 percent of dopamine-exposed kidneys were still functioning three years later compared with only 74 percent of kidneys whose donors didn’t get dopamine. In addition to preserving blood vessel health, Yard says, dopamine exposure before transplant seems to mitigate inflammation in the kidney that can attract the attention of the recipient’s immune system and raise rejection risk.
“I think this study is very elegant, especially since dopamine is routinely used in intensive care medicine,” says Duska Dragun, a transplant nephrologist at Charité Hospital in Berlin. “At least in Europe, it is very difficult to estimate how long a kidney will be in cold storage,” she says. Dragun argues that the new trial is good enough to warrant use of dopamine for kidney transplants.
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