sid_melo blogreen: 06/11/14

quarta-feira, 11 de junho de 2014

Guidelines address long-term needs of prostate cancer survivors

The guidelines are designed to promote optimal health and quality of life for the posttreatment prostate cancer survivor by facilitating the delivery of comprehensive posttreatment care by primary care clinicians. They are based on recommendations set forth by an expert panel convened as part of the work of the National Cancer Survivorship Resource Center, a collaboration between the American Cancer Society and The George Washington University Cancer Institute, funded by a 5-year cooperative agreement from the Centers for Disease Control and Prevention (CDC).

Prostate cancer survivors represent more than four in ten male cancer survivors and one in five of all cancer survivors in the United States. While guidelines exist for treatment and surveillance for recurrent disease, availability of guidelines for long-term posttreatment care is limited. The American Cancer Society Prostate Cancer Survivorship Care guidelines were developed using a combined approach of evidence synthesis and expert consensus. They address health promotion, surveillance for recurrence and screening for second primary cancers, and the assessment and management of physical and psychosocial long-term and late effects resulting from prostate cancer and its treatment. A key challenge to the development of the guidelines was the limited availability of published evidence informing the clinical management of prostate cancer survivors after treatment.

Among the recommendations:

Since information needs evolve as patients transition from treatment through various stages of survivorship, survivor and caregiver information needs should be assessed regularly, with information and support services provided or referred to as necessary.
Primary care clinicians should provide regular evaluations of survivors to determine appropriate levels of participation in health promotion and lifestyle modification programs.
Primary care clinicians should conduct routine assessments of body mass index among survivors across the prostate cancer survivorship continuum, with recommendations for limiting consumption of high-calorie foods and beverages for survivors who are overweight or obese.
Primary care clinicians should educate survivors regarding the association between physical activity and lower overall and prostate cancer-specific mortality and improved quality of life.
Since smoking after treatment of prostate cancer increases the risk of cancer recurrence and second cancers, primary care clinicians should assess for tobacco use and offer or refer survivors to cessation counseling and resources.
While existing evidence is not definitive with regard to frequency of monitoring for recurrence using PSA testing, a leading clinical practice guideline, The NCCN guidelines for prostate cancer treatment recommend measuring serum PSA levels every 6 to 12 months for the first 5 years after definitive treatment, and then to recheck annually.
Clinicians should be aware of a small increased risk of second primary cancers after radiation therapy compared with men receiving surgery. While evidence does not support increased frequency or intensity of screening, adherence to routine ACS screening guidelines for the early detection of any new cancers is recommended.
Survivors should be assessed for physical (e.g.: urinary, sexual, bowel) and psychosocial effects of prostate cancer and its treatment; the focus of assessment should be tailored to the type of cancer treatment received and current disease state to trigger appropriate self-management and clinical management strategies for support and therapy.
Estimates indicate that as many as 30% of patients with prostate cancer experience clinically relevant general distress, 25% have increased anxiety, and nearly 10% experience major depressive disorder. These guidelines affirm early identification, treatment, and ongoing assessment for psychological distress as important aspects of prostate cancer survivorship care.

"We are hopeful that the hard work that went into the development of these much-needed guidelines will pay off in improved care for the approximately 240,000 men diagnosed with prostate cancer every year," said Rebecca Cowens-Alvarado, MPH, principal investigator for the National Cancer Survivorship Resource Center, director of Cancer Control Mission Strategy at the American Cancer Society and co-author of the report. "The adoption of these guidelines will be a critical step forward to improve the delivery of prostate cancer survivorship care."

Malaria: Blood cells behaving badly

June 10, 2014

American Institute of Physics (AIP)

New insight into how malaria parasites perturb flow, turning infected cells into sticky capillary cloggers, may lead to new and better treatments. All the billions of flat, biconcave disks in our body known as red blood cells (or erythrocytes) make three basic, tumbling-treadmill-type motions when they wend their way through the body's bloodstream ferrying oxygen from our lungs to our brains and other tissues. That is, unless they are infected with malaria parasites, in which case their motions are completely different.

New insight into how malaria parasites perturb flow, turning infected cells into sticky capillary cloggers, may lead to new and better treatments.

A team of researchers at the National University of Singapore (NUS) has discovered this striking difference by comparing the flow dynamics of healthy vs. malaria-infected red blood cells. Reported this week in the Journal of Applied Physics, from AIP Publishing, their work may provide insights into developing better-targeted drug treatments for malaria in the future.

"By gaining a better understanding of why and how erythrocytes undergo changes in geometry and physical properties, we hope to elucidate such changes as possible targets for possible effective treatment of malaria," said Nhan Phan-Thien, a professor in the Department of Mechanical Engineering at the National University of Singapore.

Malaria, a life-threatening disease caused by Plasmodium parasites, afflicts hundreds of millions of people each year and is responsible for more than half a million deaths -- mostly children living in Sub-Saharan Africa. Transmitted through the saliva of a female Anopheles mosquito, the parasites have a complicated, multi-stage life cycle part of which is spent inside the red blood cells of their human host.

Once the mosquito takes a blood meal and infects a person, malaria parasites invade red blood cells, making the cells stiffer and stickier. These cells also morph from a bi-concave shape to a more spherical form during the late "schizont stage" of malaria, which occurs 36 to 48 hours after onset of the infection. When red blood cells become stiff and deformed, they can become stuck in narrow capillaries and cause anemia, because fewer blood cells can flow to deliver oxygen to the different organs in the body, including the brain.

In the new paper, the NUS team reports how they used a particle-based method called "dissipative particle dynamics" to zero in on the three typical modes of motion of a cell or capsule in shear flow -- tank-treading, tumbling, or trembling -- and uncover the behavior of healthy and malaria-infected erythrocytes.

"Tank-treading mode is a steady state, in which a cell remains stationary while its membrane rotates around the internal fluid continuously," Phan-Thien explained. "Tumbling mode is an unsteady state in which the cell flips or tumbles periodically in its original shape as a rigid body. And the trembling mode is a transitional state between the two other modes, and is characterized by a shape variation and an angular oscillation."

The team discovered that, when experiencing the same shear rate, if a healthy erythrocyte undergoes a tumbling motion, the malaria-infected cell instead exhibits only a tumbling motion.

What advantage can malaria parasites gain by affecting the tumbling motion of erythrocytes? "Tumbling may allow the red blood cell to make better contact with the blood vessel wall and provide an opportunity to adhere to it," said Phan-Thien. The advantage to the parasite in making the red blood cell stick could be that it stalls the cells and keeps them from circulating and be cleared by the spleen or the immune system.

The researchers also found that at rates where a healthy erythrocyte undergoes a trembling motion, a malaria-infected cell can't exhibit the tank-treading motion. "And if a healthy erythrocyte undergoes a tank-treading motion, the malaria-infected one will exhibit any one of the three dynamic motions," noted Phan-Thien.

Mammography has led to fewer late-stage breast cancers

In the last 30 years, since mammography was introduced, late-stage breast cancer incidence has decreased by 37 percent, a new study from the University of Michigan Comprehensive Cancer Center finds.

The analysis takes into account an observed underlying trend of increased breast cancer incidence present since the 1940s, a sort of inflation rate for breast cancer.

Researchers looked at early-stage and late-stage breast cancer diagnoses between 1977-1979, before mammography became popular, and compared it to diagnoses between 2007-2009. Based on trends observed in the pre-mammography period of the 1940s to the 1970s as well as continued trends over time, the researchers took into account a central estimated increase in breast cancer incidence of 1.3 percent per year. This is called an annual percentage change, or APC.

Think of the APC like the inflation rate: $1 from 1977 does not go as far in 2007. Just as the cost of money rises, the number of breast cancer diagnoses is increasing, independently of efforts to detect it earlier.

In the current paper, published in Cancer, the researchers looked at the late 1970s data and projected incidence of early-stage and late-stage breast cancer in 2007-2009 based on the APC. They then compared the projected rates to actual rates.

Late-stage breast cancer incidence decreased 37 percent from the projected rate, and early-stage breast cancer incidence correspondingly increased 48 percent from 1977-1979 to 2007-2009. They also conducted similar analyses with other APC values, ranging from 0.5 percent to 2 percent. All estimates showed a substantial decrease in late-stage disease.

"When you factor in this temporal trend, our analysis shows that there has been a shift from late-stage to early-stage breast cancer over the last 30 years. This is what you would expect with a successful screening program. Not only are we detecting more early-stage cancer, but we are decreasing the number of late-stage cases that tend to be more challenging to treat and more deadly," says senior study author Mark Helvie, M.D., professor of radiology and director of breast imaging at the U-M Comprehensive Cancer Center.

There are many reasons why breast cancer incidence is increasing over time, including reproductive, dietary and environmental factors. Prior estimates showed a 1 percent to 3 percent annual increase in the United States and Europe before mammography screening began. In countries in Africa, Asia and Eastern Europe with no routine screening mammography, breast cancer rates are increasing as much as 3 percent to 5 percent per year.

Importantly, the current study also found that since mammography was introduced, there has been an overall 9 percent decrease in invasive breast cancer, when factoring in a 1.3 percent annual percentage increase. This has been offset by an increase in ductal carcinoma in situ, so-called stage 0 breast cancer, which is not invasive.

"While we have seen an increase in overall breast cancer incidence over the last 30 years, the drop in late-stage diagnoses is a positive benefit of mammography and our heightened awareness of early detection. The decrease in late-stage disease, together with improved treatments, contributes to the decreased mortality from breast cancer in the United States in the last 20 years," Helvie says.

Story Source:

The above story is based on materials provided by University of Michigan Health System. Note: Materials may be edited for content and length.

Journal Reference:

Mark A. Helvie, Joanne T. Chang, R. Edward Hendrick, Mousumi Banerjee. Reduction in late-stage breast cancer incidence in the mammography era: Implications for overdiagnosis of invasive cancer. Cancer, 2014; DOI: 10.1002/cncr.28784

New biometric watches use light to non-invasively monitor glucose, dehydration, pulse

In a pair of papers published in The Optical Society's (OSA) open-access journal Biomedical Optics Express, groups of researchers from the Netherlands and Israel describe two new wearable devices that use changing patterns of scattered light to monitor biometrics: one tracks glucose concentration and dehydration levels, and the other monitors pulse.

The glucose sensor is the first wearable device that can measure glucose concentration directly but noninvasively, the authors say.

And while other wearable devices have been made to monitor pulse, the authors claim their new design would be less sensitive to errors when the wearer is in motion, for example while walking or playing sports

Both of the watches described in the two papers make use of the so-called "speckle" effect, the grainy interference patterns that are produced on images when laser light reflects from an uneven surface or scatters from an opaque material. When the material that is scattering the light is moving -- say, in the case of blood flowing through the circulatory system -- "the speckle pattern changes with changes in the flow," explained biomedical engineer Mahsa Nemati, a graduate student in the Optics Research Group at the Delft University of Technology in the Netherlands and the lead author of the Biomedical Optics Express paper on monitoring pulse. Those light variations are a valuable source of information, she says.

The 'Holy Grail' of Diagnostics

In the first paper, bioengineer Zeev Zalevsky of Israel's Bar-Ilan University and his colleagues describe a new wearable biometric system that uses the speckle effect to directly monitor the glucose concentration in the bloodstream, as well as the wearer's relative hydration level.

"Glucose is the holy grail of the world of biomedical diagnostics, and dehydration is a very useful parameter in the field of wellness, which is one of our main commercial aims," Zalevsky said.

The watch-like device consists of a laser to generate a wavefront of light that illuminates a patch of skin on the wrist near an artery, and a camera that measures changes over time in the light that is backscattered off the skin. Unlike other chemicals present in the blood, glucose exhibits a so-called Faraday effect. This means that in the presence of an external magnetic field (generated by a magnet attached to the device) the glucose molecule alters the polarization of the wavefront and thus influences the resulting speckle patterns. Analyzing these changing patterns provides a direct measurement of the glucose concentration. Because one of the main signs of mild to moderate dehydration is muscle weakness, which will alter the strength of the signals, the same device can also be used to indicate the relative dehydration level of the user as it changes over time.

Zalevsky and his colleagues are now working to reduce the margin of error in the device's readings. "Around 96 percent of our in vivo measurements were within a range of 15 percent deviation from the readout of a medical reference glucometer device," Zalevsky noted. "The main factor for errors now is the stability of our device on the wrist of the user. We are currently investing efforts in deriving proper calibration and motion cancellation procedures that will allow us to reduce this sensitivity."

Zalevsky says this is the first step toward non-invasive, continuous in vivo measurement of glucose that is based on sensing an effect that is directly related to glucose concentration. The team expects a commercial version of the device to reach the market within two to three years.

Pulse Tracker

In the second Biomedical Optics Express paper, Nemati and her colleagues at Delft and at Phillips Research developed a method that could be used to monitor pulse non-invasively with a sensor that isn't thrown off by the wearer's movement.

Using simulated heart beats generated in milk and measurements performed on the finger of a volunteer, they found that speckle changes can be used to accurately measure flow pulsations -- that is, the heart rate -- even when the light source used to create the speckle pattern is also moving, as would be the case with a wearable biometric sensor. The researchers found that just a couple of pixels from the image were sufficient to extract the pulse rate.

"This paper shows for the first time that a speckle pattern generated from a flowing liquid can give us the pulsation properties of the flow in spite of motion-induced artifacts," Nemati said. "Sophisticated optics is not necessary to implement this, so the costs for devices can be kept low. Another advantage is that the devices can be non-contact or far from the sample," she added.

The team is currently working with companies to integrate their motion-friendly pulse-monitoring technique into existing sensors, for potential use clinically as well as in sports, Nemati said.

Smokers, passive smokers more likely to suffer hearing loss, study shows

Giving up or reducing smoking and avoiding passive exposure to tobacco smoke may reduce your risk of hearing loss, new research shows.

Smokers and passive smokers more likely to suffer hearing loss, study shows

Current smokers have a 15.1% higher odds of hearing loss than non-smokers The University of Manchester study, funded by Action on Hearing Loss, Medical Research Council and the National Institute for Health Research, found.

Passive smoking also increased the likelihood of hearing loss by 28%.

But ex-smokers had a slightly reduced risk of going deaf -- which may be because once they quit they adopt a more healthy life style overall.

The study is published in the Journal of the Association for Research in Otolaryngology today.

Researchers looked at 164,770 UK adults aged 40 to 69 years of age who took hearing tests between 2007 and 2010 when they joined UK Biobank, a national project to improve health.

Dr Piers Dawes, from the Centre for Human Communication and Deafness at The University of Manchester who led the research, said: "Given around 20% of the UK population smoke and up to 60% in some countries, smoking may represent a significant cause of hearing loss worldwide.

"We found the more packets you smoke per week and the longer you smoke, the greater the risk you will damage your hearing."

The link between smoking and hearing loss is still unclear but many smokers also often had heart disease.

Dr Dawes added: "We are not sure if toxins in tobacco smoke affect hearing directly, or whether smoking-related cardiovascular disease causes microvascular changes that impact on hearing, or both."

The increased risk among passive smokers -- higher than that for smokers -- could be because smokers were compared to both complete non-smokers and passive non-smokers but passive smokers were only compared to non-smokers.

This means the association with smoking and hearing loss maybe under estimated, the researchers say.

Dr Ralph Holme, Head of Biomedical Research at Action on Hearing Loss, said "Hearing loss affects 10 million people in the UK and with an aging population is set to become a major public health issue.

"Hearing loss is often viewed as an inevitable consequence of aging, but as the research published today shows, this may not always be the case. Giving up smoking and protecting your ears from loud noise are two practical steps people can take today to prevent hearing loss later in life."

Story Source:

The above story is based on materials provided by Manchester University. Note: Materials may be edited for content and length.

Journal Reference:

Piers Dawes, Karen J. Cruickshanks, David R. Moore, Mark Edmondson-Jones, Abby McCormack, Heather Fortnum, Kevin J. Munro. Cigarette Smoking, Passive Smoking, Alcohol Consumption, and Hearing Loss. Journal of the Association for Research in Otolaryngology, 2014; DOI: 10.1007/s10162-014-0461-0