All blood stories

A Genetic Cause for Iron Deficiency

yvette — Wed, 09 Apr 2008 17:07:01 -0400

The discovery of a gene for a rare form of inherited iron deficiency may provide clues to iron deficiency in the general population – particularly iron deficiency that doesn’t respond to iron supplements. The finding was published online by the journal Nature Genetics on April 13.

Drug based on MGH discovery may significantly improve treatment of dangerous blood disorder

yvette — Mon, 04 Feb 2008 15:51:43 -0500

Two clinical trials of the novel drug romiplostim (Nplate) show that it significantly improved platelet levels in patients with chronic immune thrombocytopenic purpura (ITP), a hematologic disorder that can cause uncontrolled bleeding. An international research team reports Phase 3 trial results for the drug, which duplicates the action of a natural hormone discovered by a Massachusetts General Hospital (MGH) investigator, in the February 2 issue of The Lancet.

Blood stem cells fight invaders

404132862 — Thu, 29 Nov 2007 14:21:28 -0500

No other stem cell is more thoroughly understood than the blood, or hematopoietic, stem cell. These occasional and rare cells, scattered sparingly throughout the marrow and capable of replenishing an entire blood system, have been the driving force behind successful bone marrow transplants for decades. Scientists, for the most part, have seen this as the hematopoietic stem cell’s (HSC) singular role: to remain in the bone marrow indefinitely and to replenish blood and immune system cells only when called upon.

Cocoa shows promise as next wonder drug

Wed, 11 Jul 2007 10:28:50 -0400

A big problem facing Americans and Europeans is the dangerous rise in blood pressure with age, increasing their risk of heart disease and diabetes. Kuna Indians living off the Caribbean coast of Panama don't have that problem. Norman Hollenberg, a professor of radiology at Harvard Medical School, is convinced that it's because they drink more than five cups of cocoa a day.

Over-the-counter pain relievers increase the risk of high blood pressure in men

Wed, 11 Jul 2007 10:20:12 -0400

Researchers from Brigham and Women's Hospital (BWH) have found that the three most commonly used drugs in the United States, acetaminophen, ibuprofen, and aspirin, increase the risk of developing high blood pressure in middle-aged men. These findings are published in the Feb. 26 issue of the Archives of Internal Medicine.

"Given the high levels of consumption of these drugs and the increasing rate of hypertension, these over-the-counter analgesics should be taken with greater caution," says John P. Forman of the Renal Division at BWH, a Harvard-affliated hospital. "This is a potentially preventable cause of high blood pressure."

Cells that work themselves to death

Thu, 12 Jul 2007 09:57:33 -0400

When you're fighting flu or any other infection, your body mobilizes battalions of cells to defend against the invading viruses or bacteria. But once the invaders have been defeated and you've recovered from aches, fever, headaches, and a sore throat, your body has to get rid of the now-unneeded fighting cells. If left alone, they can attack healthy tissues.

One way to muster them out is signaling them to commit suicide. Sounds cruel, but it's a natural protective process called "apoptosis." It is the same strategy that the human immune system uses to get rid of tumor cells.

Schepens scientists first to discover angiogenesis switch inside blood vessel cells

70652986 — Mon, 26 Mar 2007 06:27:34 -0400

Scientists at Schepens Eye Research Institute, an affiliate of Harvard Medical School, are the first to discover a switch inside blood vessel cells that controls angiogenesis (new blood vessel growth).

The switch, they learned, is turned on and off by the balance between two enzymes (known as PI3K and PLCg) that compete for the use of the same lipid membrane to fulfill opposite missions, growth and regression, respectively. This finding could lead to new, more targeted drugs for diseases such as cancer, diabetic retinopathy, and macular degeneration. The study, titled "Regulating angiogenesis at the level of PtdIns-4,5P2," is published in The EMBO Journal (May 17, 2006).

Scientists discover new genetic subtypes of common blood cancer

70652986 — Mon, 26 Mar 2007 06:26:07 -0400

Scientists at Dana-Farber Cancer Institute and collaborators have identified four distinct genetic subtypes of multiple myeloma, a deadly blood cancer, that have different prognoses and might be treated most effectively with drugs specifically targeted to those subtypes.

A new computational tool based on an algorithm designed to recognize human faces plucked the four distinguishing gene patterns out of a "landscape" of many DNA alterations in the myeloma genome, the researchers report in the April 2006 issue of Cancer Cell.

These results "define new disease subgroups of multiple myeloma that can be correlated with different clinical outcomes," wrote the authors, led by Ronald DePinho, MD, director of Dana- Farber's Center for Applied Cancer Science.

International multi-center study confirms value of blood test to diagnose heart failure

70652986 — Mon, 26 Mar 2007 05:42:32 -0400

Congestive heart failure, which occurs when an impaired heart muscle cannot pump blood efficiently, is a growing health problem and major cause of cardiac death. The diagnosis of heart failure may be challenging because its symptoms can overlap those of other conditions.

Now a large-scale international study has demonstrated the usefulness of a blood test to confirm or exclude the diagnosis of acute heart failure in emergency room patients and shows that the test also can identify patients at a higher risk for death. The report from investigators in the U.S., the Netherlands, Spain and New Zealand also clarifies the importance of age-specific levels of a protein called NT-proBNP that definitively diagnose heart failure. The report appeared in the European Heart Journal.

Coffee gets cleared of blood pressure risk

70652986 — Mon, 26 Mar 2007 05:41:57 -0400

Harvard researchers set out to test the idea that a lot of coffee isn't good for your circulation. They followed 155,000 female nurses for 12 years, questioning them regularly about their caffeine-drinking habits and their blood pressure. No connection was found between their coffee intake and a risky rise in blood pressure.

In fact, results went the other way. Women who drank the most coffee seemed to develop some protection against the problem. The investigators continue to look into this possibility.

Caffeine may not be the reason, however. The researchers found that things went the other way when women drank copious amounts of caffeine-containing colas. Sugared or diet, the soft drinks increased their risk of high blood pressure by as much as 44 percent, compared with those who drank very little soda.

Tea drinking produced mixed results. That beverage increased hypertension risk in younger but not older women. The study did not collect information on that warming winter favorite - hot chocolate.

The results are reported in the Nov. 9, 2005 issue of the Journal of the American Medical Association.

Stroke patients with mild symptoms may still need clot- dissolving drug

70652986 — Mon, 26 Mar 2007 06:22:26 -0400

"Our primary finding was that about 30 percent of those patients judged 'too good to treat' either died or were discharged to a rehabilitation facility," says Eric Smith, MD, FRCPC, of MGH Neurology, the study's lead author. "Unfortunately we were not able to find any features that could predict which of the untreated patients would have problems."

When a stroke is caused by a blocked blood vessel, tPA can safely dissolve the clot if given within three hours of symptom onset, sometimes completely reversing the effects of the stroke. Many patients do not arrive at a hospital soon enough to receive the drug, but even when they do, physicians must weigh the small but significant risk that tPA treatment could cause a brain hemorrhage, a potentially devastating complication. Because of this risk, patients with less severe symptoms may not receive tPA in the hopes that they will get better on their own. An observation from an earlier study suggested that many of those patients would not do well and led to the current investigation.

The research team reviewed records on more than 400 patients with ischemic (clot-related) stroke that came to the MGH Emergency Department from 2002 to 2004. Of 128 patients who arrived within the three-hour safe treatment window, 71 did not receive tPA. More than half the untreated patients had been considered "too good to treat," primarily because their symptoms were stable and mild or improved rapidly. Out of those 41 patients, two died during their hospitalization and nine were discharged to a rehabilitation facility because of continuing neurological problems.

Smith explains that rapid symptom improvement seen early in the course of a stroke could reflect the affected area of the brain "borrowing" blood from nearby areas. But if the initial blockage affects the primary blood supply and is not removed, symptoms may eventually worsen.

"Right now we can only recommend that physicians be a little more cautious in deciding against tPA treatment," he adds. "We can suggest that more attention be paid to patients' ability to walk - something that often is not evaluated - since gait disturbance was a reason why several could not go home. But we really need to find ways to predict who will do poorly without tPA, and for that we'll need larger trials involving several institutions." Smith is an instructor in neurology at Harvard Medical School.

The study was supported by grants from the National Institutes of Health and the Centers for Disease Control and Prevention.

High blood glucose levels in early pregnancy may deprive embryo of oxygen

70652986 — Mon, 26 Mar 2007 06:22:16 -0400

Research appearing in the October 2005 issue of the American Journal of Physiology: Endocrinology and Metabolism suggests that high blood glucose levels early in pregnancy deprive the embryo of oxygen, interfering with its development.

"Until recently, it was not understood how diabetic pregnancy could cause birth defects. My laboratory wanted to explore this research because the more we know about the effects of the mother's diabetes on the embryo, the more tools we have to identify therapies that may prevent birth defects in diabetic pregnancy," said the study's lead investigator, Mary R. Loeken, an investigator in Joslin's Section on Developmental and Stem Cell Biology and assistant professor of Medicine at Harvard Medical School.

A new look at anemia

70652986 — Mon, 26 Mar 2007 06:22:09 -0400

Leonard Zon and his colleagues at the Harvard Medical School were trying to find out how hemoglobin forms by studying zebrafish, small piscians whose transparent bodies allow their inner workings to be easily seen while they are alive. The effort centered on a mutated strain of fish known as "shiraz." The researchers name their mutants after red or white wines, depending on whether red or white blood cells are involved. The shiraz fish lacks hemoglobin, the molecule that binds with oxygen in the cells of all red-blooded animals. Other mutants have names such as "chianti" and "chardonnay."

The zebrafish is so important to researchers that its genome has been sequenced along with that of humans. Zon and his team used this information to find and clone the gene that makes shiraz so pale. The gene has a less fun name, glutaredoxin 5, or grx5 for short.

More scientific detective work revealed that yeast has its own version of the same gene. That's strange because yeast doesn't have blood, so it doesn't need hemoglobin. But yeast does need iron and its grx5 gene is involved in manipulating iron in this fungus, best known for making beer and wine.

Zon and his team then made a mutant zebrafish with a doctored rendering of the yeast gene. "That rescued the fish," Zon declares. "It could now make hemoglobin. Without hemoglobin, zerbrafish embryos lacking grx5 can absorb oxygen from water through their skin. But eventually they die, most likely from their anemia."

Blood vessel drugs halt cancer growth

70652986 — Mon, 26 Mar 2007 06:20:58 -0400

After decades of surviving peer rejection of his theory of cancer treatment by blocking tiny blood vessels, Judah Folkman has gone on to develop drugs that did what he predicted they would do.

Folkman's endostatin, the drug Fortune magazine called a failure, was used to treat 486 patients with lung cancer in China. At Dana-Farber Cancer Institute in Boston, it has helped adult and pediatric cancer patients.

A related drug, called Avastin, is now used in 28 countries, including the U.S. It is also being tested on patients with kidney, breast, and ovarian cancers.

Folkman, a professor of pediatric surgery and cell biology at Harvard Medical School and Children's Hospital in Boston, came up with the idea that tumors secrete proteins able to stimulate the growth of hair-thin blood vessels that bring them nutrients and carry away their wastes in 1961, while studying mice. He applied the name "angiogenesis," meaning "birth of blood vessels," to this process.

By 1997, Folkman and his colleagues at Boston's Children's Hospital found a natural compound they called endostatin, which blocks the growth of blood vessels and shrinks tumors without the usual harsh side effects of chemotherapy.

The battle over endostatin's efficacy as a drug, however, still rages, but Avastin enjoys good press, suggesting that the angiogenesis-blocker boom is on.

Blood test can accurately diagnose heart failure in emergency patients

70652986 — Mon, 26 Mar 2007 06:20:25 -0400

"We found that testing with the NT-proBNP assay was an extremely accurate way to identify or exclude heart failure in patients with shortness of breath," says James Januzzi Jr., M.D., of the MGH Cardiology Division and the paper's lead author.

Since current standards of treatment are inconsistent, Januzzi says, this new test could prove a major development.

The role of testing for natriuretic peptides in cardiovascular disease has been widely studied recently. In 2002, the newest generation of natriuretic peptide assays became available, and soon thereafter the PRIDE study was launched to determine the usefulness of a test for NT-proBNP in evaluating emergency patients.