November 9, 2009, 8:22 AM CT

Prostate biopsy is not always necessary

Scientists at Wake Forest University School of Medicine and the University of Wisconsin-Madison have discovered that some elevated prostate-specific antigen (PSA) levels in men appears to be caused by a hormone normally occurring in the body, and are not necessarily a predictor of the need for a prostate biopsy.

Elevated levels of PSA have traditionally been seen as a potential sign of prostate cancer, leading to the widespread use of PSA testing. However, the scientists observed that parathyroid hormone, a substance the body produces to regulate calcium in the blood, can elevate prostate-specific antigen (PSA) levels in healthy men who do not have prostate cancer. These "non-cancer" elevations in PSA could cause a number of men to be biopsied unnecessarily, which often leads to unnecessary therapy.

"PSA picks up any prostate activity, not just cancer," said lead investigator Gary G. Schwartz, Ph.D., M.P.H., an associate professor of cancer biology and epidemiology and prevention at the School of Medicine. "Inflammation and other factors can elevate PSA levels. If the levels are elevated, the man is commonly sent for a biopsy. The problem is that, as men age, they often develop microscopic cancers in the prostate that are clinically insignificant. If it weren't for the biopsy, these clinically insignificant cancers, which would never develop into fatal prostate cancer, would never be seen"......... Posted by: Mark      Read more         Source

November 9, 2009, 8:21 AM CT

Predictive value of lung cancer response on PET scan

A rapid decline in metabolic activity on a PET scan after radiation treatment for non-small cell lung cancer is correlated with good local tumor control, as per a research studypresented by scientists at Thomas Jefferson University Hospital at the 51st ASTRO Annual Meeting.

In addition, the scientists also observed that the higher the metabolic activity and tumor size on a PET scan before therapy, the more likely a patient is to die from lung cancer.

"PET scanning is an emerging tool of molecular imaging in lung cancer, in contrast to Computerized axial tomography scans and MRI scans which are anatomic imaging," said Maria Werner-Wasik, associate professor of Radiation Oncology at Jefferson Medical College of Thomas Jefferson University, and the study's main author. "It has become an important tool in the assessment of lung cancer staging and assessment of therapy response".

Dr. Werner-Wasik and his colleagues conducted a retrospective analysis of 50 lung cancer patients who received PET imaging before and after radiation treatment. They analyzed the prognostic factors for tumor local failure. They measured the metabolic activity using the maximum Standardized Uptake Value (mSUV). They also measured the tumor size, or the Metabolic Tumor Volume.

The risk of local failure decreased for each unit decline in mSUV by the first post-therapy scan. When in comparison to the pre-therapy PET scan, the mSUV of the primary tumor declined by 72 percent in the by the first post-therapy scan, 76 percent by the second scan......... Posted by: Scott      Read more         Source

November 9, 2009, 8:18 AM CT

Learning bacterial communications

Using imaging mass spectrometry, scientists at the University of California, San Diego have developed tools that will enable researchers to visualize how different cell populations of cells communicate. Their study shows how bacteria talk to one another an understanding that may lead to new therapeutic discoveries for diseases ranging from cancer to diabetes and allergies.

In the paper reported in the November 8 issue of Nature Chemical Biology, Pieter C. Dorrestein, PhD, assistant professor at UC San Diego's Skaggs School of Pharmacy and Pharmaceutical Sciences, and his colleagues describe an approach they developed to describe how bacteria interface with other bacteria in a laboratory setting. Dorrestein and post-doctoral students Yu-Liang Yang and Yuquan Xu, along with Paul Straight from Texas A&M University, utilized technology called natural product MALDI-TOF (Matrix Assisted Laser Desorption Ionization-Time of Flight) imaging mass spectrometry to uniquely translate the language of bacteria.

Microbial interactions, such as signaling, have generally been considered by researchers in terms of an individual, predominant chemical activity. However, a single bacterial species is capable of producing a number of bioactive compounds that can alter neighboring organisms. The approach developed by the UCSD research team enabled them to observe the effects of multiple microbial signals in an interspecies interaction, revealing that chemical "conversations" between bacteria involve a number of signals that function simultaneously......... Posted by: Mark      Read more         Source

November 9, 2009, 8:17 AM CT

Nanomedicine may help spinal cord injuries

Scientists at Purdue University have discovered a new approach for repairing damaged nerve fibers in spinal cord injuries using nano-spheres that could be injected into the blood shortly after an accident.

The synthetic "copolymer micelles" are drug-delivery spheres about 60 nanometers in diameter, or roughly 100 times smaller than the diameter of a red blood cell.

Scientists have been studying how to deliver drugs for cancer therapy and other therapies using these spheres. Medications might be harbored in the cores and ferried to diseased or damaged tissue.

Purdue scientists have now shown that the micelles themselves repair damaged axons, fibers that transmit electrical impulses in the spinal cord.

"That was a very surprising discovery," said Ji-Xin Cheng, an associate professor in the Weldon School of Biomedical Engineering and Department of Chemistry. "Micelles have been used for 30 years as drug-delivery vehicles in research, but no one has ever used them directly as a medicine".

Findings are detailed in a research paper appearing Sunday (Nov. 8) in the journal Nature Nanotechnology.

A critical feature of micelles is that they combine two types of polymers, one being hydrophobic and the other hydrophilic, meaning they are either unable or able to mix with water. The hydrophobic core can be loaded with drugs to treat disease......... Posted by: Daniel      Read more         Source

November 9, 2009, 8:10 AM CT

Hormone replacement therapy and breast cancer

The use of postmenopausal hormone treatment has decreased over time in the United States, which scientists suggest may play a key role in the declining rate of atypical ductal hyperplasia, a known risk factor for breast cancer.

"Postmenopausal hormone therapy is linked to increased rates of non-malignant breast biopsies, and early and late stages of cancer. Atypical ductal hyperplasia is linked to the use of postmenopausal hormone therapy and its rates have decreased with the decline in use of this therapy," said researcher Tehillah Menes, M.D., who was the chief of breast service in the Department of Surgery at Elmhurst Hospital Center, New York, when this study was conducted.

Details of the findings appear in Cancer Epidemiology, Biomarkers & Prevention, which is a journal of the American Association for Cancer Research.

Atypical ductal hyperplasia is abnormal cells that grow in the milk ducts of the breast. Prior research has shown that women who are diagnosed with atypical ductal hyperplasia are at a three- to five-fold increased risk of developing breast cancer.

Using data from the Breast Cancer Surveillance Consortium, Menes and his colleagues examined the rates of atypical ductal hyperplasia to determine risk factors and rates for more than 2.4 million mammography studies with and without breast cancer......... Posted by: Janet      Read more         Source

November 9, 2009, 7:56 AM CT

Women with denser breasts have higher cancer recurrence

A newly released study finds that women treated for breast cancer are at higher risk of cancer recurrence if they have dense breasts. Reported in the December 15, 2009 issue of Cancer, a peer-evaluated journal of the American Cancer Society, the study's results indicate that patients with breast cancer with dense breasts appears to benefit from additional therapies following surgery, such as radiation.

Prior studies indicate that women with dense breast tissue are at increased risk of breast cancer. Scientists have suspected that high breast density may also increase the risk of cancer recurrence after lumpectomy, but this theory has not been thoroughly studied.

Scientists led by Steven A. Narod, MD, of the Women's College Research Institute in Toronto, evaluated the medical records of 335 patients who had undergone lumpectomy for breast cancer. Investigators monitored the patients for cancer recurrence and compared recurrence with breast density as seen on mammogram, categorized as low density (<25 percent dense tissue), intermediate density (25 percent to 50 percent dense tissue) or high density (>50 percent dense tissue).

The scientists observed that patients with the highest breast density had a much greater risk of cancer recurrence than did women with the lowest breast density. Over ten years, women in the highest breast density category had a 21 percent chance of cancer recurrence, compared with a 5 percent chance among women in the lowest category. The difference in the recurrence rates at ten years was even more pronounced for women who did not receive radiation. In those women, 40 percent with high-density breast tissue had a recurrence compared with none of the patients with low density......... Posted by: Janet      Read more         Source

November 6, 2009, 8:56 AM CT

New Synthetic Molecules Trigger Immune Response

Scientists at Yale University have developed synthetic molecules capable of enhancing the body's immune response to HIV and HIV-infected cells, as well as to prostate cancer cells. Their findings, published online in the Journal of the American Chemical Society, could lead to novel therapeutic approaches for these diseases.

The molecules - called "antibody-recruiting molecule targeting HIV" (ARM-H) and "antibody-recruiting molecule targeting prostate cancer" (ARM-P) - work by binding simultaneously to an antibody already present in the bloodstream and to proteins on HIV, HIV-infected cells or cancer cells. By coating these pathogens in antibodies, the molecules flag them as a threat and trigger the body's own immune response. In the case of ARM-H, by binding to proteins on the outside of the virus, they also prevent healthy human cells from being infected.

"Instead of trying to kill the pathogens directly, these molecules manipulate our immune system to do something it wouldn't ordinarily do," said David Spiegel, Ph.D., M.D., assistant professor of chemistry and the corresponding author of both papers.

Because both HIV and cancer have methods for evading the body's immune system, therapys and vaccinations for the two diseases have proven difficult. Current therapy options for HIV and prostate cancer - including antiviral drugs, radiation and chemotherapy - involve severe side effects and are often ineffective against advanced cases. While there are some antibody drugs available, they are difficult to produce in large quantities and are costly. They also must be injected and are accompanied by severe side effects of their own......... Posted by: Scott      Read more         Source

November 6, 2009, 8:55 AM CT

Research Study On Near Vision

The Cornea and Laser Eye Institute is participating in a research study to determine if an investigational corneal inlay can safely and effectively reduce the need for reading glasses. Dr. Peter Hersh, the study doctor, will perform the procedures.

The investigational AcuFocus Corneal Inlay (ACI) is intended to improve near vision in patients with presbyopia, which is the loss of near vision, and reduce dependency on reading glasses. Qualified participants will receive the procedure at no charge.

Presbyopia, the loss of near vision happens when the eye's natural lens loses the ability to focus light from both far and near objects. As a result, near tasks like reading or computer work are blurry. However, it is possible for far objects to still be clear. Presbyopia is a natural occurrence that happens to most of us by age 45. Patients 45 to 60 years are eligible to participate.

Smaller than a contact lens, the ACI Corneal Inlay looks like a small brown ring. It is 5 microns thick and 3.8 mm across with a small hole in the center. Over 8,000 tiny holes throughout the ACI help maintain the health of the cornea. It is placed within the body of the cornea, directly in front of the pupil. The ACI lets the central rays of light continue on to the retina while blocking out some of the more out-of-focus rays. This is similar to the effect seen when one looks through a small pinhole. This increased focus may improve near vision. With the ACI placed in one eye, the depth of focus is anticipated to provide improved near and in-between vision while having little effect on far away vision......... Posted by: Mike      Read more         Source

November 6, 2009, 8:54 AM CT

Air pollution and infants' bronchiolitis

Infants who are exposed to higher levels of air pollution are at increased risk for bronchiolitis, as per a newly released study.

The study appears in the November 15 issue of the American Thoracic Society's American Journal of Respiratory and Critical Care Medicine.

"There has been very little study of the consequences of early life exposure to air pollution," said Catherine Karr, M.D. PhD, assistant professor of pediatrics at the University of Washington and the paper's main author. "This study is unique in that we were able to look at multiple sources including wood smoke in a region with relatively low concentrations of ambient air pollution overall".

The scientists analyzed nearly 12,000 diagnoses of infant bronchiolitis between 1999 and 2002 in southwestern British Columbia, with respect to the individual's ambient pollution exposure based on monitored levels of nitric oxide (NO), nitrogen dioxide (NO2), carbon monoxide (CO), sulfur dioxide (SO2), and particulate matter from monitoring stations within 10 km of the infants' homes. They also used land-use regression maps to assess concentrations of ambient pollution with respect to traffic and wood smoke. They analyzed pollution exposure by dividing subjects into four categories, or quartiles, of concentration......... Posted by: Janet      Read more         Source

November 6, 2009, 8:52 AM CT

Nanoparticles for diagnosis, monitoring and treatment

Whether it's magnetic nanoparticles (mNPs) giving an army of 'therapeutically armed' white blood cells direction to invade a deadly tumour's territory, or the use of mNPs to target specific nerve channels and induce nerve-led behaviour (such as the life-dependant thumping of our hearts), mNPs have come a long way in the past decade.

The future for mNPs however appears even brighter. With the design of 'theranostic' molecules, mNPs could play a crucial role in developing one-stop tools to simultaneously diagnose, monitor and treat a wide range of common diseases and injuries.

Multifunctional particles, modelled on viral particles such as the flu and HIV, are being researched and developed to carry signal-generating sub-molecules and drugs, able to reach target areas through a safe sprinkling of tiny mNPs and external magnetic forces, creating a medical means to confirm specific ailments and automatically release healing drugs while inside a living system.

A landmark selection of review articles published this week in IOP Publishing's Journal of Physics D: Applied Physics, 'Progress in Applications of Magnetic Nanoparticles in Biomedicine', shows just how far magnetic nanoparticles for application in biomedicine have come and what exciting promise they hold for the future......... Posted by: Scott      Read more         Source