May 4, 2011, 4:09 PM CT
Hitting target in cancer fight
The ability to use nanoparticles to deliver payloads of cancer-fighting drugs to tumors in the body could herald a fundamental change in chemotherapy therapy. But researchers are still at a relatively early stage in the implementation of this technology.
Eventhough developing nanoparticles that work as "magic bullets" � selectively targeting tumors while sparing normal, healthy tissues � is still the goal, the reality is that most of these nanocarriers are removed through the liver and spleen before ever reaching their intended target. And a number of of the encapsulated drugs can be lost while the carriers circulate in the blood or degraded on the way to tumors.
In a study recently reported in the journal ACS Nano
, UCLA researchers report that by using engineered mesoporous silica nanoparticles (MSNPs) as delivery vehicles, they were able to achieve significant increases in the percentage of drug-carrying nanoparticles that reach and are retained at tumor sites.
The MSNP platform allows for the introduction of multiple and customized design features that can help optimize the delivery of chemotherapeutic drugs to a variety of cancer types, said the researchers, led by Dr. Andre Nel, a professor of medicine, pediatrics and public health and chief of the nanomedicine division in the UCLA Department of Medicine, and Jeffrey Zink, a professor in the UCLA Department of Chemistry and Biochemistry. Nel and Zink are also members of the California NanoSystems Institute at UCLA.........
Posted by: Janet Read more Source
April 29, 2011, 8:44 AM CT
Alcohol, Mood and Me
Thanks in part to studies that follow subjects for a long time, psychology experts are learning more about differences between people. In a new article published in Current Directions in Psychological Science, a journal of the Association for Psychological Science, the author describes how psychology experts can use their data to learn about the different ways that people's minds work.
Most psychology research is done by asking a big group of people the same questions at the same time. "So we might get a bunch of Psych 101 undergrads, administer a survey, ask about how much they use alcohol and what their mood is, and just look and see, is there a relationship between those two variables," says Daniel J. Bauer of the University of North Carolina at Chapel Hill, the author of the article.
But a one-time survey of a bunch of college students can only get you so far. For example, it might find that sad people drink more, but it can't tell us whether people drink more at times when they are unhappy, whether the consequences of drinking instead result in a depressed mood, or whether the relationship between mood and alcohol use is stronger for some people than others.
One way psychology experts have used to learn more about people is collecting data from people over a longer time period. For example, they might give each subject an electronic device to record blood pressure and stress several times a day, or ask them to log on to a website every night to answer a survey. In one case, Bauer's colleague, Andrea Hussong, asked adolescents to complete daily diaries with ratings of their mood and alcohol use over 21 days. The data showed that the relationship between mood and alcohol use is not the same for everyone. Adolescents with behavioral problems drink more in general, irrespective of mood, but only adolescents without behavioral problems drink more often when feeling depressed.........
Posted by: JoAnn Read more Source
April 29, 2011, 8:36 AM CT
MRI locates prostate cancer recurrence
A pelvic MRI scan with IV contrast and rectal balloon is highly effective in identifying local recurrence even at low PSA values in patients with prostate cancer with a rising or persistently elevated PSA after prostatectomy, as per a research studypresented April 29, 2011, at the Cancer Imaging and Radiation Therapy Symposium in Atlanta. The symposium is co-sponsored by the American Society for Radiation Oncology (ASTRO) and the Radiological Society of North America (RSNA).
Scientists at MD Anderson Cancer Center in Houston reviewed 389 postprostatectomy patients treated between January 2004 and October 2010, with 143 receiving a pelvic MRI to determine if cancer cells were still present in the area of the surgical bed. Thirty-five of those patients had suspicious MRI findings suggesting local recurrence. Twenty-six patients were then biopsied, with 23 showing cancer.
The study showed that about one-third of patients with a biopsy-proven recurrence after suspicious MRI finding had a PSA of less than 1, with several having a PSA as low as 0.3.
A scan of the surgical bed is typically performed after a prostatectomy and before salvage radiation treatment therapy in patients with prostate cancer with a rising PSA to determine a potential recurrence and location of recurrence. An MRI is able to differentiate between soft tissues better than a traditional Computerized axial tomography scan, so the high rates of cancer recurrence picked up by the MRI were not surprising to researchers. What was surprising was the low PSA levels at which the MRI could determine recurrent disease.........
Posted by: Mark Read more Source
April 29, 2011, 8:34 AM CT
Interval post-treatment mammogram not needed
An annual mammogram is sufficient follow-up after breast conserving treatment (BCT) for patients with breast cancer, as per a research studypresented today, at the Cancer Imaging and Radiation Therapy Symposium in Atlanta. This symposium is co-sponsored by the American Society for Radiation Oncology (ASTRO) and Radiological Society of North America (RSNA).
In this study, scientists wanted to determine the clinical relevance and utility of an interval mammogram (IM) after BCT. BCT is when a patient is treated with a lumpectomy and radiation rather than a mastectomy for early-stage breast cancer.
As per the study, annual mammograms are frequently conducted after BCT; however, some radiologists recommend an IM to take place at six months after the first post-treatment mammogram (five months after the completion of radiation therapy on average) to ensure stability, to check for recurrence or to check for any new cancers.
For this trial, 88 out of 467 BCT patients from Abington Memorial Hospital in Abington, Pa., received an IM. The IM led to four biopsies that yielded no recurring or new breast cancers. Patients returned to receiving their annual mammograms after receiving the IM.
Scientists determined that eliminating the IM would result in lower health care costs without a significant impact on the outcome of the patient.........
Posted by: Janet Read more Source
April 29, 2011, 8:32 AM CT
Frequently hospitalized patients
Declining rates of hospitalization have discouraged primary care doctors from seeing their patients in the hospital and encouraged the growing use of "hospitalists," a new doctor specialty focused on the care of hospitalized patients. Further developments in the field mean that frequently hospitalized patients also may need a specialist focused on their care, as per an expert on hospital care at the University of Chicago.
The model defining the role of hospitalists, who practice only in hospitals, was first identified in a 1996 article in the New England Journal (NEJM), said David O. Meltzer, an associate professor of medicine and director of the University of Chicago's Center for Health and the Social Sciences.
"Since that time, hospitalists have become the fastest-growing medical specialty in the United States, providing more than one-third of all general medical care in the United States," Meltzer wrote in the paper, "Coordination, Switching Costs and the Division of Labor in General Medicine: An Economic Explanation for the Emergence of Hospitalists in the United States," published by the National Bureau of Economic Research.
Meltzer discussed the growth of the field as well as the potential need for a new specialty � the comprehensive care physician, who would specialize in care of the seriously ill Friday at a conference organized by the Milton Friedman Institute at the University of Chicago. The conference, "Individuals and Institutions in the Health Care Sector," also will look at issues such as technology and insurance.........
Posted by: Sue Read more Source
April 18, 2011, 7:03 AM CT
First look at the mechanics of membrane proteins
University of Illinois biophysics professor Klaus Schulten (right) and postdoctoral researcher James Gumbart used cryo-EM images as well as detailed structural information about the ribosome and other molecules to construct an atom-by-atom model of the system that threads a growing protein into the cellular membrane.
Credit: L. Brian Stauffer
In two new studies, scientists provide the first detailed view of the elaborate chemical and mechanical interactions that allow the ribosome � the cell's protein-building machinery � to insert a growing protein into the cellular membrane.
The first study, in Nature Structural and Molecular Biology
, gives an atom-by-atom snapshot of a pivotal stage in the insertion process: the moment just after the ribosome docks to a channel in the membrane and the newly forming protein winds its way into the membrane where it will reside.
A collaboration between computational theoretical researchers at the University of Illinois and experimental researchers at University of Munich made this work possible. Using cryo-electron microscopy to image one moment in the insertion process, the scientists in Munich were able to get a rough picture of how the a number of individual players � the ribosome, membrane, membrane channel and newly forming protein � come together to get the job done. Each of these structures had been analyzed individually, but no prior studies had succeeded in imaging all of their interactions at once.
"The computational methodology contributed by the Illinois group was crucial in interpreting the new cryo-EM reconstruction in terms of an atomic level structure, and testing the interpretation through simulation," said co-author Roland Beckmann at the University of Munich. "Our joint study is unique in so closely and successfully combining experimental and computational approaches".........
Posted by: Scott Read more Source
April 18, 2011, 6:59 AM CT
Missing the gorilla
University of Utah psychologist Jason Watson displays a famous video showing people passing a basketball while a person in a gorilla suit walks across the screen. When unsuspecting viewers were asked to count how many times the basketball is passed, more than 40 percent failed to see the person in the gorilla suit. Watson and his colleagues conducted new research expanding on earlier work by psychologists Christopher Chabris and Daniel Simons -- authors of the 2010 book "The Invisible Gorilla" -- and showing that a better "working memory capacity" explains why 58 percent of people to see the gorilla even if they are focusing on counting basketball passes.
Credit: Janelle Seegmiller, U of Utah, and Daniel Simons, U of Illinois.
University of Utah psychology experts have learned why a number of people experience "inattention blindness" � the phenomenon that leaves drivers on cell phones prone to traffic accidents and makes a gorilla invisible to viewers of a famous video.
The answer: People who fail to see something right in front of them while they are focusing on something else have lower "working memory capacity" � a measure of "attentional control," or the ability to focus attention when and where needed, and on more than one thing at a time.
"Because people are different in how well they can focus their attention, this may influence whether you'll see something you're not expecting, in this case, a person in a gorilla suit walking across the computer screen," says the study's first author, Janelle Seegmiller, a psychology doctoral student.
The study � explaining why some people are susceptible to inattention blindness and others are not � would be reported in the recent issue of The Journal of Experimental Psychology: Learning, Memory and Cognition
Seegmiller conducted the research with two psychology faculty members � Jason Watson, an assistant professor, and David Strayer, a professor and leader of several studies about cell phone use and distracted driving.........
Posted by: JoAnn Read more Source
April 18, 2011, 6:56 AM CT
New therapeutic target for asthma
Michael Croft, Ph.D., a researcher at the La Jolla Institute for Allergy & Immunology, has discovered a molecule's previously unknown role as a major trigger for airway remodeling, which impairs lung function, making the molecule a promising therapeutic target for chronic asthma, chronic obstructive pulmonary disease (COPD) and several other lung conditions. A scientific paper on Dr. Croft's finding was published online today in the prestigious journal, Nature Medicine
The finding marks Dr. Croft's second major discovery with therapeutic potential for asthma. His prior finding, of a novel molecular mechanism driving lung inflammation, is the basis for a potential asthma therapy now in Phase II human clinical trials.
"Dr. Croft's continued efforts to uncover the cellular pathways influencing asthma and other lung disorders have produced remarkable results," said Mitchell Kronenberg, Ph.D., La Jolla Institute president and chief scientific officer. "He is a researcher of the highest caliber and I believe his discoveries will someday improve the lives of millions of people around the world".
In his Nature Medicine paper entitled, "The tumor necrosis factor family member LIGHT is a target for asthmatic airway remodeling," Dr. Croft showed that blocking LIGHT's interactions with its two receptors significantly inhibited the process of airway remodeling in mouse models of chronic asthma. Airway remodeling refers to inflammation-fueled structural changes in the lungs, including fibrosis, which can occur over time and result in declining lung function that strongly contributes to conditions such as COPD, chronic asthma, and several other respiratory disorders.........
Posted by: JoAnn Read more Source
April 7, 2011, 8:45 AM CT
Molecular probe to study disease
This shows enhanced detection of endogenous protease activity.
Credit: Abeer Jabaiah
Chemical engineers at UC Santa Barbara expect that their new process to create molecular probes may eventually result in the development of new drugs to treat cancer and other illnesses.
Their work, published in the journal Chemistry & Biology
, published by Cell Press, describes a new strategy to build molecular probes to visualize, measure, and learn about the activities of enzymes, called proteases, on the surface of cancer cells.
Patrick Daugherty, senior author and professor of chemical engineering at UCSB, explained that the probes are effective at understanding proteases involved in tumor metastasis.
"Tumor metastasis is widely regarded as the cause of death for cancer patients," said Daugherty. "It's not commonly the primary tumor that causes death. Metastasis is mediated by proteases, like the one we are studying here. These proteases can enable tumor cells to separate and degrade surrounding tissue, and then migrate to sites distant from the primary tumor. The tumor doesn't just fall apart. There are a number of events that must occur for a tumor to release malignant cells into the blood stream that can circulate and end up in other tissues such as liver or bone".
The probes allowed the researchers, for the first time, to measure directly the activity of a protease involved in metastasis. They did this by adding their probe into a dish of tumor cells. They then measured the activity of this protease that breaks down collagen �� the single most abundant protein (by mass) in the human body.........
Posted by: Scott Read more Source
April 7, 2011, 8:43 AM CT
Parkinson's disease and prostate cancer
University of Utah School of Medicine scientists have found compelling evidence that Parkinson's disease is linked to an increased risk of prostate cancer and melanoma, and that this increased cancer risk also extends to close and distant relatives of individuals with Parkinson's disease. Eventhough a link between Parkinson's disease and melanoma has been suspected before, this is the first time that an increased risk of prostate cancer has been reported in Parkinson's disease.
Parkinson's disease (PD) is a progressive neurologic condition that leads to tremors and difficulty with walking, movement, and coordination. Most studies demonstrate that individuals with PD have an overall decreased rate of cancer, with the notable exception of melanoma, the most serious form of skin cancer. Prior research has suggested a possible genetic link between PD and melanoma, but these studies have been limited to first-degree relatives who often share a similar environment, making it difficult to distinguish between genetic and environmental risk factors.
"Neurodegenerative disorders such as Parkinson's disease may share common disease-causing mechanisms with some cancers," says Stefan-M. Pulst, MD, professor and chair of the department of neurology, at the University of Utah, and co-author on this study. "Using the Utah Population Database, we were able to explore the association of PD with different types of cancer by studying cancer risk in individuals with PD, as well as their close and distant relatives".........
Posted by: Daniel Read more Source