Featured series 
Tag: Harvard Medical School
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Health
Hormone receptor variation linked to cancer risk
Endometrial cancer is the fourth most common cancer in women in this country, according to National Cancer Institute statistics. Progesterone’s important protective role showed up three decades ago, articulated in the unopposed estrogen theory. In the early 1970s, researchers documented that a woman on unopposed estrogen replacement therapy had a 10 times higher chance of…
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Dual signals may drive early breast cancer
Researchers from the lab of Joan Brugge, Harvard Medical School professor of cell biology, may have uncovered one of the central mechanisms of breast cancer. They found that dual signals provided by ErbB2, a cancer-associated gene commonly known as HER2, appear to be required to disrupt the framework of a breast gland during early tumor…
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Genes found that regulate brain size
A gene that builds bigger brains, called beta-catenin, was discovered in the laboratory of Christopher A. Walsh, Bullard Professor of Neurology at Harvard Medical School. Researchers there engineered increased activity into the beta-catenin gene in mice, and the mice brains grew to almost twice the usual size. Not only that, but the cerebral cortex, seat…
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Mammalian teeth regrown in lab
A study involved seeding cells from the immature teeth of six-month old pigs onto biodegradable polymer scaffolds. The researchers then placed these structures into rat hosts. Within 30 weeks, small, recognizable tooth crowns had formed. These contained dentin; odontoblasts, cells that secrete dentin-forming protein; a well-defined pulp chamber; Hertwig’s root sheath epithelia; cementoblasts, which form…
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Science & Tech
Report documents health effect of biodiversity
A new report catalogues the connections between biodiversity and human health. The interim executive summary was presented at the United Nations in late October 2002, following the U.N. World Summit on Sustainable Development in Johannesburg, South Africa. The report is the first product from a project called “Biodiversity: Its Importance to Human Health,” headed by…
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Chili peppers and inflammation
Researchers have discovered that the burinng pain of arthritis is similar to the pain associated with eating chili peppers. “The receptor activated by chili peppers in the mouth and other tissues also increases in the terminals of sensory neurons in the skin after inflammation, and this contributes to pain hypersensitivity,” says Clifford Woolf, director of…
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Researchers isolate key part of cells’ ‘death’ signals
In the cover article of the September 2002 issue of the journal Cancer Cell, researchers from Dana-Farber Cancer Institute reported that peptide subunits of cell-signaling “BH3” proteins could out-maneuver opposing “anti-death” proteins and trigger the suicide process. Cell suicide or “apoptosis” prevents wayward cells from growing out of control and becoming cancerous. “Many cancer cells…
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Health
Protein seen to animate cell skeleton
The cytoskeleton is made up of arrays of actin filaments that are arranged into widely different structures — parallel arrays that mediate muscle contraction, networks of branched filaments at the leading edge of migratory cells, and parallel bundles required to pinch cells apart at the end of cell division. The critical juncture of filament growth…
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Alzheimer’s-associated enzyme elevated in key brain areas
A research report that appears in the September 2002 issue of the journal Archives of Neurology may improve understanding of the most common form of Alzheimer’s disease. “Our key finding is that beta-secretase activity — the efficiency of how the enzyme works — is increased in Alzheimer’s diseased brains specifically in those areas affected by…
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Science & Tech
Pregnancy and delivery deadly for many Afghan women
Lynn Amowitz, a researcher at Brigham and Women’s Hospital an a medical instructor at Harvard Medical School, found that women in the Herat province of Afghanistan receive some of the most inferior maternal healthcare in the world. Many clinics in the province lacked the basic medical supplies necessary for healthy delivery, such as forceps and…
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Studies find milk consumption, use of HRT, and pregnancy may influence hormone levels associated with cancer risk in women
IGF-1 is a hormone important to the growth and function of many organs. Higher levels of IGF-1 have been associated independently with an increased risk of a number of cancers, including prostate, colon, lung and breast cancer. Two studies examined the relationship between modifiable lifestyle factors and circulation levels of IGF-1 to potentially define new…
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Health
Experimental drug shows promise in treating severe, often-lethal complication of stem cell transplants
An experimental drug called defibrotide reversed severe veno-occlusive disease (VOD) of the liver in more than one third of the stem cell transplant recipients enrolled in a study. VOD is a type of potentially fatal liver damage that can result from the high doses of chemotherapy given prior to a transplant. The findings, to be…
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Health
Maternal history influences risk of asthma in children exposed to cats
Recent studies have gathered evidence that cat exposure during infancy can be protective against asthma. Research at Brigham and Women’s Hospital confirmed these findings in all but one situation: when the child’s mother has asthma. Researchers found that in a group of children with non-asthmatic mothers, those exposed to a cat were 40 percent less…
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Science & Tech
Information Age will change doctors’ role in healing
Even as the Internet allows patients access to information previously only available through their doctors, patients still trust the information they get from their doctors more than they do from Web sites, current surveys suggest. Because of this, doctors may fill the role of advisers or consultants, helping patients not only sort through the information…
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Health
Resistance mutation found for Gleevec
The drug Gleevec was stunningly successful in treating patients with chronic myelogenous leukemia (CML) at early stages of disease, but quickly stopped working in most patients with more advanced forms of CML. Last year, researchers at UCLA headed by Charles Sawyers found that some resistant patients carried a mutant version of Bcr-Abl. The original mutation,…
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Brake on Axon regrowth discovered
Since nerve cell axons in the mature central nervous system do not regrow, neurologists have no way of fully treating paralysis due to injury. “About a hundred years ago, people started asking why it was impossible to get the axon to regenerate upon injury,” said Zhigang He, Harvard Medical School assistant professor of neurology at…
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Combined kidney and bone marrow transplantation allows patients to discontinue anti-rejection drugs
Megan Sykes, head of the bone marrow transplantation section of the Massachusetts Transplantation Biology Research Center and professor of surgery at Harvard Medical School, recently described how infusing kidney transplant recipients with bone marrow from their donors immediately after the transplant surgery induced a state of mixed chimerism, a blending of donor and recipient immune…
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Scientists discover chemical switch that determines muscle fiber type
Published in the Aug. 15, 2002 issue of the journal Nature, findings from a multi-institutional team describe the pivotal role of a molecule called PGC-1 in transforming “fast twitch” fibers (Type II) to “slow twitch” fibers (Type I). “Fast twitch” fibers create the bulkier, strong but quickly fatigued muscles of weightlifters or sprinters. Most muscles…
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Medical student engineers protein to dissolve blood clots
Heart attacks and strokes are caused by blood clots called thrombi that block blood flow in the arteries of the heart and of the brain. Body tissues become deprived of needed oxygen and nutrients, eventually dying. Cardiovascular disease is the number one killer of Americans each year — and has been since 1900 with the…
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How the brain keeps extra calories from becoming extra pounds
What determines whether excess calories are turned into fat or are burned off? The key lies in a process known as diet-induced thermogenesis, an intricate system of communications masterminded by the brain which literally means “heat production,” according to the senior author of a new study, Bradford B. Lowell, of Beth Israel Deaconess Medical Center’s…
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Practice makes perfect
Harvard Medical School researchers conducted a study in which people were taught to type a sequence of keys on a computer keyboard as quickly and accurately as possible. A group trained in the morning and then re-tested 12 hours later were able to improve their performance by about two percent. However, the performance of those…
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Early administration of clot-buster drug may improve outcome for heart attack patients
The immediate goal of the treatment of heart attack patients is reperfusion, or the swift opening of the blocked artery and the restoration of blood flow to the heart muscle. Early reperfusion minimizes the extent of heart muscle damage and preserves the pumping function of the heart. Optimal benefit is obtained if reperfusion can be…
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Maternal bone lead levels pose toxic prenatal risk
Although much attention has been paid to public health efforts to reduce lead exposure in children between the ages of six months and five years, when environmental lead exposures (such as from leaded paint in old houses) tend to be greatest, less attention has been paid to understanding the transfer of lead from mother to…
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Investigators discover method to stimulate brain rewiring after stroke
After a stroke, brain cells die and their connections to other parts of the brain are lost. In a study with rats conducted at Children’s Hospital in Boston, a naturally occurring substance called inosine was shown to stimulate nerve cells in undamaged parts of the brain to grow new connections into brain areas that had…
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Science & Tech
RNA technology thwarts HIV
RNA interference (RNAi) is a naturally occurring phenomenon by which cells guard themselves against viruses. The process involves post-transcriptional gene silencing in which specific RNA sequences get chopped into small pieces after binding to complementary short interfering RNAs (siRNA). These siRNAs can target either host mRNAs or viral genomic or messenger RNAs. As a consequence,…
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Six new breast cancer-susceptibility genes found
The discovery of six new cancer-susceptibility genes grew out of more than 10 years of research by Alan D’Andrea into Fanconi anemia, a condition known to affect only 500 families in the United States. Children born with the condition usually develop bone marrow failure early in life, leaving them unable to produce oxygen-carrying red blood…
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Science & Tech
The next big thing in mining the genome
About 99.9 percent of the 3.1 billion base pairs in the human genome are the same from person to person. The remaining 0.1 percent of differences comprises more than 10 million common single-letter genetic variations (and many more rare variants) scattered through the genome. By the numbers, a comprehensive search for the multiple genetic contributions…
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One in five women iron deficient, many children also at risk
Iron-deficient anemia reduces the oxygen-carrying capacity of red blood cells, thus decreasing energy and endurance. When there is not enough iron, the red blood cells are not able to produce enough hemoglobin (the oxygen-transporting pigments found in red blood cells). Those affected may have pale skin and be excessively tired and ineffective at work or…
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Imaging test may detect gene for genetic cardiac disease
Hypertrophic cardiomyopathy (HCM) is the most common cause of cardiac death among young people and affects one in every 500 individuals, including professional athletes. It is characterized by an enlargement of the left ventricle, the heart’s main pumping chamber. This enlargement results in a thickening of the walls of the heart, which then prevents the…