August 11, 2010, 7:03 AM CT
Breast cancer among progestin HRT users
Salman Hyder, the Zalk Endowed Professor in Tumor Angiogenesis and professor of biomedical sciences in the College of Veterinary Medicine and the Dalton Cardiovascular Research Center.
Progestins are used in hormone replacement therapies to counteract the negative effects of estrogen on the uterus and reduce the risk of uterine cancer. However, evidence in recent studies and clinical trials has demonstrated that progestins increase the risk of breast cancer. Now, University of Missouri scientists have compared four types of progestins used in hormone replacement therapies and found significantly different outcomes on the progression of breast cancer in an animal model depending on the type of progestins used.
"Synthetic progestins have different biological effects, due to differences in their structure, stability and how they interact in the body," said Salman Hyder, the Zalk Endowed Professor in Tumor Angiogenesis and professor of biomedical sciences in the College of Veterinary Medicine and the Dalton Cardiovascular Research Center. "Clinical use of progestins requires caution. These powerful steroids should only be prescribed when a person has no latent, or dormant, cancer and does not have a family history of cancer. However, it is difficult to diagnose latent tumor cells in women since there are no symptoms".
In the study, scientists compared the effects of four clinically relevant progestins on breast cancer tumors in an animal model. The progestins used in the study were the synthetic progestin medroxporgresterone acetate (MPA), norgesterel (N-EL), norethindrone (N-ONE) and megestrol acetate (MGA). In the United States, most women on hormone replacement treatment are treated with MPA, the progestin in Prempro, Hyder said.........
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August 11, 2010, 6:58 AM CT
Menstrual cramps on brain structure
Primary dysmenorrhea (PDM), or menstrual cramps, is the most common gynecological disorder in women of childbearing age. Lower abdominal pain starts with the onset of menstrual flow and this ongoing pain stimulus can cause alterations throughout the nervous system. In a study scheduled for publication in the recent issue of PAIN
, scientists report abnormal changes in the structure of the brain in PDM patients, whether or not they are in fact experiencing pain.
Lead investigator, Professor Jen-Chuen Hsieh, MD, PhD, Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan, commented, "Our results demonstrated that abnormal GM [gray matter] changes were present in PDM patients even in absence of pain. This shows that not only sustained pain but also cyclic occurring menstrual pain can result in longer-lasting central changes. Eventhough the functional consequences remain to be established, these results indicate that the adolescent brain is vulnerable to menstrual pain. Longitudinal studies are needed to probe hormonal interaction, fast-changing adaptation (intra-menstrual cycle) and whether such changes are reversible or not".
32 PDM patients and 32 age- and menstrual-cycle-matched controls took part in the study. MRI scans of each subject were obtained when the PDM patients were not experiencing pain, and maps of gray matter (GM) were created. Both the total GM volume and the GM volume of specific brain areas were determined for both PDM patients and controls.........
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August 10, 2010, 7:13 AM CT
Stress gets under our skin
Everyone experiences social stress, whether it is nervousness over a job interview, difficulty meeting people at parties, or angst over giving a speech. In a new report, UCLA scientists have discovered that how your brain responds to social stressors can influence the body's immune system in ways that may negatively affect health.
Main author George Slavich, a postdoctoral fellow at the UCLA Cousins Center for Psychoneuroimmunology, and senior author Shelley Taylor, a UCLA professor of psychology, show that individuals who exhibit greater neural sensitivity to social rejection also exhibit greater increases in inflammatory activity to social stress.
And eventhough such increases can be adaptive, chronic inflammation can increase the risk of a variety of disorders, including asthma, rheumatoid arthritis, cardiovascular disease, certain types of cancer, and depression.
The study appears in the current online edition of the journal Proceedings of the National Academy of Sciences
"It turns out, there are important differences in how people interpret and respond to social situations," Slavich said. "For example, some people see giving a speech in front of an audience as a welcome challenge; others see it as threatening and distressing. In this study, we sought to examine the neural bases for these differences in response and to understand how these differences relate to biological processes that can affect human health and well-being." .........
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August 10, 2010, 7:12 AM CT
Daily vitamin D intake
Anthony Norman, a leading international expert in vitamin D, proposes worldwide policy changes regarding people's vitamin D daily intake amount in order to maximize the vitamin's contribution to reducing the frequency of a number of diseases, including childhood rickets, adult osteomalacia, cancer, autoimmune type-1 diabetes, hypertension, cardiovascular disease, obesity and muscle weakness.
"A reduction in the frequency of these diseases would increase the quality and longevity of life and significantly reduce the cost of medical care worldwide," said Norman, a distinguished professor emeritus of biochemistry and biomedical sciences at the University of California, Riverside. "It is high time that worldwide vitamin D nutritional policy, now at a crossroads, reflects current scientific knowledge about the vitamin's a number of benefits and develops a sound vision for the future".
Currently, the recommended daily intake of vitamin D in the United States is 200 international units (IU) for people up to 50 years old; 400 IU for people 51 to 70 years old; and 600 IU for people over 70 years old. Today there is a wide consensus among researchers that the relative daily intake of vitamin D should be increased to 2,000 to 4,000 IU for most adults.
"Worldwide public health is best served by a recommendation of higher daily intakes of vitamin D," Norman said. "Currently, more than half the world's population gets insufficient amounts of this vitamin. At present about half of elderly North Americans and Western Europeans and probably also of the rest of the world are not receiving enough vitamin D to maintain healthy bone."........
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August 10, 2010, 7:06 AM CT
A "Magnetic" Solution for Tumors
Human lung epithelial tumor cell among healthy epithelial cells
Though a valuable weapon against malignant tumors, radiation treatment often harms healthy tissue as it tries to kill cancerous cells. Now, Prof. Israel Gannot of Tel Aviv University's Department of Biomedical Engineering is developing a new way to destroy tumors with fewer side effects and minimal damage to surrounding tissue.
His innovative method, soon to be reported in the journal Nanomedicine, uses heat to kill the tumor cells but leaves surrounding healthy tissue intact. Using specific biomarkers attached to individual tumors, Prof. Gannot's special mixture of nano-particles and antibodies locates and binds to the tumor itself.
"Once the nano-particles bind to the tumor, we excite them with an external magnetic field, and they begin to heat very specifically and locally," says Prof. Gannot. The magnetic field is manipulated to create a targeted rise in temperature, and it is this directed heat elevation which kills the tumors, he says.
The therapy has been proven effective against epithelial cancers, which can develop in almost any area of the body, such as the breast or lung. By using a special feedback process, also developed in his laboratory, the process can be optimized for individual therapy.A cure without casualty
The specialized cocktail of nano-particles and antibodies is administered safely and simply, through topical local injection or injection into the blood stream. As an added benefit, the mixture washes out of the body without leaving a trace, minimizing side effects.........
Posted by: Janet Read more Source
August 10, 2010, 7:03 AM CT
The price of prison for children
It comes as no surprise that a number of children suffer when a parent is behind bars. But as rates of incarceration grew over the past 30 years, scientists were slow to focus on the collateral damage to children.
The best estimate says that at any one time, 1.7 million (about 2.3 percent) of all American children have a parent in prison, says Julie Poehlmann, a professor in the School of Human Ecology and investigator at the Waisman Center at the University of Wisconsin-Madison.
"By age 14, more than half of black children with a low-education parent, will have an imprisoned parent," she says.
About 10 years ago, the problem finally began to spark interest from social scientists, Poehlmann says.
"School personnel and child welfare personnel are now seeing more and more children who have a current or past incarcerated parent. There is a greater awareness of the volume, and greater need to understand what's going on. What are the risks, what are the outcomes, and how can we better help these children?" Poehlmann says.
Eventhough a definitive cause-and-effect relationship has not been established, children of incarcerated parents tend to have more arrests, and more problems with behavior, relationships, school, and substance abuse. "It's all the things you would expect," says Poehlmann.........
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August 10, 2010, 7:01 AM CT
Exploring the brain wiring
The circuit tracing method allows the study of incoming and outgoing signals from any two brain centers.
The brain has been mapped to the smallest fold for at least a century, but still no one knows how all the parts talk to each other.
A study in Proceedings of the National Academy of Sciences answers that question for a small area of the rat brain and in so doing takes a big step toward revealing the brain's wiring.
The network of brain connections was thought too complex to describe, but molecular biology and computing methods have improved to the point that the National Institutes of Health have announced a $30 million plan to map the human "connectome".
The study shows the power of a new method for tracing brain circuits.
USC College neuroresearchers Richard H. Thompson and Larry W. Swanson used the method to trace circuits running through a "hedonic hot spot" correlation to food enjoyment.
The circuits showed up as patterns of circular loops, suggesting that at least in this part of the rat brain, the wiring diagram looks like a distributed network.
Neuroresearchers are split between a traditional view that the brain is organized as a hierarchy, with most regions feeding into the "higher" centers of conscious thought, and a more recent model of the brain as a flat network similar to the Internet.
"We started in one place and looked at the connections. It led into a very complicated series of loops and circuits. It's not an organizational chart. There's no top and bottom to it," said Swanson, a member of the National Academy of Sciences and the Milo Don and Lucille Appleman Professor of Biological Sciences at USC College.........
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August 10, 2010, 6:57 AM CT
How to fix a broken heart?
University of Washington
Experiments in a culture dish show that chick heart cells (red) do grow in the scaffold channels (green) at densities similar to those in a living heart.
These days people commonly don't die from a heart attack. But the damage to heart muscle is irreversible, and most patients eventually succumb to congestive heart failure, the most common cause of death in developed countries.
Stem cells now offer hope for achieving what the body can't do: mending broken hearts. Engineers and physicians at the University of Washington have built a scaffold that supports the growth and integration of stem cell-derived cardiac muscle cells. A description of the scaffold, which supports the growth of cardiac cells in the lab and encourages blood vessel growth in living animals, is published this week in the Proceedings of the National Academy of Sciences.
"Today, if you have a heart attack there's nothing that doctors can do to repair the damage," said main author Buddy Ratner, a UW professor of bioengineering. "You are, in essence, sentenced to a downhill slide, developing congestive heart failure that greatly shortens your lifespan."
"Your body can't make new heart cells, but what if we can deliver vital new cells in that damaged portion of the heart?".
Ratner and colleagues built a tiny tubular porous scaffold that supports and stabilizes the fragile cardiac cells and can be injected into a damaged heart, where it will foster cell growth and eventually dissolve away. The new scaffold not only supports cardiac muscle growth, but potentially accelerates the body's ability to supply oxygen and nutrients to the transplanted tissue. Eventually, the idea is that doctors would seed the scaffold with stem cells from either the patient or a donor, then implant it when the patient is treated for a heart attack, before scar tissue has formed.........
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August 10, 2010, 6:50 AM CT
Breast Cancer and Body Rhythms
For years, researchers thought that the function of biological clocks was relatively straightforward. Now, NSF-supported research by Jonathan Arnold, a geneticist, Heinz-Bernd Schuttler, a computational physicist, and their colleagues at the University of Georgia is showing that the number of genes in bread mold (Neurospora crassa) under the control of the biological clock is dramatically higher than anyone ever suspected. "We're just now beginning to see why the clock is so far-reaching in its effects on the organism," says Arnold. Read more details in this discovery.
Credit: Andrew Tucker, University of Georgia
"One minute you're a healthy person, the next minute you have breast cancer".
Ettamay (last name withheld) is up early these days. She lives a much different life than she did when she was a nurse working the night shifts. She would be just getting to sleep at this early morning hour.
"I was always exhausted," she says. "I don't know any of the nurses, particularly the night shift gals, that weren't exhausted all the time".
She wonders if her crazy work schedule might have contributed to her breast cancer.
Virginia Tech molecular biologist Carla Finkielstein says studies back up Ettamay's suspicions. "There are many epidemiological studies that show women working night shifts have a higher occurence rate of breast cancer," she says.
Finkielstein is studying this question microscopically, one cell at a time. She wants to know the impact of night-shift work on a woman's physiology. Can working odd hours actually alter a woman's body chemistry--turning healthy cells into cancer cells?
"What we're trying to understand is how changes in environmental conditions influence the expression of genes that regulate cell division," explains Finkielstein.
With support from the National Science Foundation (NSF), Finkielstein uses frog embryos to help figure out on a molecular basis the physiological changes in women who work the night shift. She says studies show that working "night owls" have abnormal levels of specific proteins in their cells, which act by turning on and off genes that regulate how cells grow and divide. Finkielstein injects some of the molecules into frog cells to study their effects.........
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August 9, 2010, 7:25 AM CT
Surgery, radiation or hormone
Surgery for localized prostate cancer offers a significantly higher survival rate than either external-beam radiation or hormonal therapies, as per a newly released study led by scientists at UCSF.
The differences among therapies were more prominent at higher levels of cancer risk, and suggest, the scientists say, that in a number of cases surgery should play a greater role in therapy strategies for prostate cancer patients that is likely to recur or spread.
The study is available online in the journal "Cancer," the journal of the American Cancer Society, at this site
Most prior reports comparing therapy outcomes among different therapy options have looked only at PSA responses to therapy, rather than at the more important long-term survival outcomes, as per the researchers. Measuring levels of PSA, or prostate-specific antigen, in the blood, is intended to help determine whether prostate cancer has recurred or spread, eventhough in a number of cases a rising PSA level does not necessarily mean the cancer will progress.
Roughly one man in six will be diagnosed with prostate cancer, which is the second leading cause of cancer death in American men, as per the American Cancer Society.........
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