all Harvard-MIT Division of Health Sciences and Technology stories

Bone marrow stem cells may help control inflammatory bowel disease

404132862 — Wed, 20 Aug 2008 16:37:21 -0400

Massachusetts General Hospital (MGH) and Harvard Medical School investigators have found that infusions of a particular bone marrow stem cell appeared to protect gastrointestinal tissue from autoimmune attack in a mouse model. In their report published in the journal Stem Cells, the team from the MGH Center for Engineering in Medicine report that mesenchymal stem cells (MSCs), known to control several immune system activities, allowed the regeneration of the gastrointestinal lining in mice with a genetic mutation leading

Five faculty members named young innovators by Technology Review

404132862 — Tue, 19 Aug 2008 12:24:12 -0400

Work on flying robots, surgical tape modeled on gecko feet, energy tips gleaned from plants, new ways to grow stem cells, and dramatically smaller medical imaging equipment has landed five Harvard faculty members on a list of the world’s top 35 young innovators.

The annual list is compiled by Technology Review magazine and features what the editors and a panel of judges see as the 35 top innovators in business and technology who are under the age of 35.

Previously unknown regulator of fat and cholesterol production discovered in mice

404132862 — Tue, 24 Jun 2008 11:13:03 -0400

Researchers have discovered an unknown regulator of fat and cholesterol production in the liver of mice, a significant finding that could eventually lead to new therapies for lowering unhealthy blood levels of cholesterol and fats.

The team led by scientists from the Harvard School of Public Health (HSPH) showed how this might work in an animal model, demonstrating that turning off the regulatory molecule — known as XBP1 — dramatically reduced blood levels of cholesterol and triglyceride fats. Importantly, there were no apparent adverse effects on the liver.

Grapefruit compound may help combat hepatitis C infection

yvette — Mon, 04 Feb 2008 16:44:36 -0500

A compound that naturally occurs in grapefruit and other citrus fruits may be able to block the secretion of hepatitis C virus (HCV) from infected cells, a process required to maintain chronic infection. A team of researchers from the Massachusetts General Hospital Center for Engineering in Medicine (MGH-CEM) report that HCV is bound to very low-density lipoprotein (vLDL, a so-called “bad” cholesterol) when it is secreted from liver cells and that the viral secretion required to pass infection to other cells may be blocked by the common read more

Viviany Taqueti: Writer, doctor, public servant

50443248 — Tue, 02 Oct 2007 10:29:40 -0400

As a young girl, Viviany Taqueti followed her doctor father as he made rounds in the two hospitals he built in the jungles of Brazil. Sitting on the banks of the muddy, mighty Amazon River, Taqueti decided that she wanted to be like him, a person who improves the lives of others and who believes that you can do anything you set your mind to.

Today, she sits near the banks of the Charles River, a petite 25-year-old who just earned her M.D. from Harvard Medical School and who has learned not to think much about the obstacles to becoming a physician, scientist, teacher, and writer — all at once.

Sengupta wins $4.1 million 'Era of Hope' award for breast cancer advances

50443248 — Wed, 03 Oct 2007 11:32:46 -0400

An assistant professor of medicine at Harvard has won a $4.1 million "Era of Hope" scholar award from the U.S. Defense Department's Breast Cancer Research Program in support of his cutting-edge, interdisciplinary research aimed at fighting breast and other types of cancer.

Shiladitya Sengupta, an assistant professor in the Harvard-MIT Division of Health Sciences and Technology and an associate bioengineer at Brigham and Women's Hospital, said the award has transformed his plans for his year-old lab, located in the Partners Research Building on Landsdowne Street in Cambridge.

Body art for the faint of heart

70652986 — Mon, 26 Mar 2007 05:46:35 -0400

Ever wish you could get rid of that tattoo of barbed wire around your wrist, or the forearm-length dragon you once thought of as so stylish or macho?

It's not easy. You can go through a long, expensive series of laser treatments, and still not get it completely erased. You can have it sanded off, literally, but that could leave a scar.

Finding a fossilized needle in an Arctic haystack

70652986 — Mon, 26 Mar 2007 06:27:54 -0400

The first season searching Arctic Canada for a fossil that would illuminate how our ancestors first crawled onto land proved Harvard Professor Farish Jenkins' explorer's maxim: Never go any place for the first time.

A crew of six trudged through a barren landscape during the summer of 1999, finding the wrong sort of rocks scattered across the wrong sort of terrain. In addition to dealing with the frustration and isolation, researchers had to keep a wary eye peeled for predators, since the islands of Arctic Canada are the stomping grounds for polar bears. So along with their scientific gear, the researchers carried rifles in case of an encounter.

Mad cow protein found to have a sane side

70652986 — Mon, 26 Mar 2007 06:26:46 -0400

It's a devastating disease, changing behavior, causing uncontrolled movements, blindness, coma, and, finally, death. And we all have the makings of it in our heads.

When it topples cows, it's known as mad cow disease. The human form is called Creutzfeldt-Jakob disease. In sheep, it's scrapie. It's a rare malady caused by a misshapen protein known as prion protein, or PrP. The big mystery is why people, cows, sheep, and other mammals have so much of the protein in their bodies, particularly in the brain.

"It's intriguing to find that PrP, which, when 'misfolded,' subjects people and animals to these ravaging diseases, is so abundant in our brains," notes Jeffrey Macklis, an associate professor of surgery at Harvard Medical School and Massachusetts General Hospital. "Why is it kept in the system if it has the ability to wreak so much havoc? It must have an important function."

In proteins, form determines function. The strings of amino acids of which proteins are made can twist in one way and be beneficial to a body, but if they fold in another way they can be disastrous to the same body. When a small amount of PrP misfolds, it influences normal PrPs near it, causing them to assume the same shape, a wrecking ball that breaks the brain from the inside out.

Macklis, along with Harvard postdoctoral fellows Jason Emsley and Hande Ozdinler, teamed up with Susan Lindquist and her student Andrew Steele at the Whitehead Institute for Biomedical Research to try to find out what value the Jekyll and Hyde protein might offer.

They studied mice in which the gene that makes PrP was knocked out, and compared it to another group in which the protein was overproduced. Their investigation revealed that PrP is present where nerve cells form in the developing brain of embryonic mice. They also located PrP in a few spots in the adult brain. In both places, PrP increases the number of precursor cells that develop into brain and other nerve cells. In the knockout mice, this new cell production was delayed. But when additional PrP was available, new cells formed at a much faster rate.

"The more PrP a cell has, the faster it becomes a mature nerve cell," notes Steele.

The good side of PrP was discovered.

Newly found species fills evolutionary gap between fish and land animals

70652986 — Mon, 26 Mar 2007 06:26:14 -0400

Paleontologists have discovered fossils of a species that provides the missing evolutionary link between fish and the first animals that walked out of water onto land about 375 million years ago. The newly found species, Tiktaalik roseae, has a skull, a neck, ribs, and parts of the limbs that are similar to four- legged animals known as tetrapods, as well as fishlike features such as a primitive jaw, fins, and scales.

"This previously unknown, extinct animal represents the beginning of the emergence of fish onto land, and the evolutionary transformation of fins into limbs," says Farish A. Jenkins Jr., Alexander Agassiz Professor of Zoology at Harvard and curator of mammalogy and vertebrate paleontology at Harvard's Museum of Comparative Zoology.

These fossils, found on Ellesmere Island in Arctic Canada, are the most compelling examples yet of an animal that was at the cusp of the fish-tetrapod transition. The new find is described by scientists at Harvard University, the University of Chicago, and the Academy of Natural Sciences in Philadelphia in two related research articles highlighted on the cover of the April 6, 2006 issue of Nature.

"Tiktaalik blurs the boundary between fish and land-living animal both in terms of its anatomy and its way of life," says Neil Shubin, professor and chairman of organismal biology at the University of Chicago.

Bulyk searches for DNA on-off switches

70652986 — Mon, 26 Mar 2007 06:22:53 -0400

Martha Bulyk held what looked like an ordinary glass slide up to the large window that is much of one wall of her Harvard Medical School office. The slide seemed to be blank, but a puff of breath exposed row after row of tiny dots, appearing like the hidden writing of a secret message.

But the dots are more decoder ring than secret code, an array made up of bits of DNA that Bulyk is using to understand mysterious proteins called transcription factors that are critical in understanding DNA because they turn individual genes on and off.

"I'm interested in understanding how it is that the genome is organized," Bulyk said. "We get such complex life forms and processes and all the instructions are included in the genome somehow."

Bulyk, assistant professor of medicine, of pathology, and of health sciences and technology at Harvard Medical School, has pioneered the use of microarray technology in the analysis of transcription factors. Her advance promises to dramatically cut the time needed to characterize transcription factors and their associated genes from weeks and months to just a day.

Her work, published in December 2004 in the journal Nature Genetics, won her recognition from the Massachusetts Institute of Technology's Technology Review Magazine, which listed her among the top 35 technology innovators under age 35.

"Martha has been a pioneer in assays for DNA-protein interactions and the computational analysis of the resulting large data sets," said Harvard Medical School Genetics Professor George Church.

Scientists have long known that the blueprint of life is contained in DNA - long, double-stranded helical molecules in the nucleus of every cell in our bodies. DNA itself is made up of a series of base pairs, whose order determines everything from eye color and hair color to number of legs and body shape.

The encoded genes are put into action through a process called transcription, where a special enzyme breaks the DNA strands apart, reads the code, and creates an RNA molecule that carries that code elsewhere in the cell to be translated into action. The transcription process itself is regulated by proteins that bind to specific DNA regulatory elements on either side of the gene. It is these proteins, called transcription factors, and their DNA binding sites that have caught Bulyk's eye.

In her work with the microarrays, Bulyk and her lab team first created microarrays by dotting bits of DNA onto glass slides and then exposed the arrays to a possible transcription factor. They knew that a transcription factor would bind to the DNA at specific sites, and so they gently washed the chip to remove protein that wasn't bound. The remaining proteins, which had been tagged with a fluorescent molecule, glowed. To find what they were looking for, all the researchers had to do was look for the glowing dots.

Health care reform in China discussed

50443248 — Fri, 20 Jul 2007 15:25:48 -0400

Health care in the People's Republic of China is unequal and too expensive, and there's not enough of it, but the Chinese government is aware of the problems and is moving to address them, China's vice minister of health said Sept. 8 at Harvard Medical School.
During an hour-long speech, "Healthcare for Tomorrow's China," sponsored by the Harvard-MIT Division of Health Sciences and Technology, Vice Minister Jiefu Huang painted an unflattering picture of health care in the Asian nation, saying that reforms over the past two decades have been ineffectual.

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.

Decoding the babel of brain cells

70652986 — Mon, 26 Mar 2007 06:17:45 -0400

If brain cell messages could be separated from the "noise" of other brain activity and clearly understood, researchers would be closer to repairing damage caused by a number of nervous system diseases paralyzing injuries and combat wounds.

Researchers at Harvard Medical School and Massachusetts General Hospital in Boston have actually done this with mice. They managed to isolate distinct types of nerve cells then identify the genes and molecules responsible for their development. This feat sets the stage for using nervous system stem cells to repair nerve cells damaged by spinal cord injuries or affected by diseases such as amyotrophic lateral sclerosis (ALS or "Lou Gehrig's disease"). For example, some of the genes and molecules might be manipulated to enhance the survival of damaged motor cells in the brain, or to coax stem cells into replacing non-functioning nerve cells.

Both treatments might someday help disabled people walk again.

Close interaction seen between blood vessel development and fat tissue formation

70652986 — Mon, 26 Mar 2007 05:32:25 -0400

Findings from researchers at Massachusetts General Hospital could eventually help to solve problems ranging from cancer, to obesity, to the development of replacement organs. The findings involve the key physiological processes of angiogenesis, the growth of new blood cells, and adipogenesis, the development and growth of fat cells, which appear to be so closely interwoven that interfering with one process also halts the other. Better understanding of the interaction between angiogenesis and adipogenesis and the development of ways to control and direct the processes could have a wide range of medical applications. Anti-angiogenesis compounds are already being evaluated as cancer-fighters, and the current results suggest they may be useful in combating obesity as well. The observation that blood vessels growing in response to adipogenesis form organized networks - in contrast to the inefficient networks that develop in and around tumors - might help with efforts to grow new organs and tissues, since the development of a circulatory system is a key challenge in the field of tissue engineering. The study was scheduled to be printed in the Oct. 31, 2003 issue of Circulation Research. It was published via the journal's website on Oct. 2.