Health Agency

Researchers continue to make solid progress in detailing the biochemical mechanisms by which calorie restriction extends healthy life: "Calorie restriction (CR), the only non-genetic intervention known to slow aging and extend life span in organisms ranging from yeast to mice, has been linked to the down-regulation of Tor, Akt, and Ras signaling. In this study, we demonstrate that the serine/threonine kinase Rim15 is required for yeast chronological life span extension caused [by] calorie restriction. ... Deletion of stress resistance transcription factors Gis1 and Msn2/4, which are positively regulated by Rim15, also caused a major although not complete reversion of the effect of calorie restriction on life span. ... Notably, the anti-aging effect caused by the inactivation of both pathways is much more potent than that caused by CR." Enumerating the required parts of the chain, one by one, is an early step in the process of building a full understanding - and then reproducing and improving upon natural longevity-inducing biochemistry. Interestingly, Rim15 is also required for the recently demonstrated set of genetic tweaks that boost yeast life-span ten-fold - even though that did not involve calorie restriction.

View the Article Under Discussion: http://pmid.us/18225956
Read More Longevity Meme Commentary: http://www.longevitymeme.org/news/

It seems there is a whole business ecosystem out there revolving around very short, single-topic educational video clips. In addition to the VideoJug question and answer sessions with biomedical gerontologist Aubrey de Grey - collected on the Methuselah Foundation website - you can find more of the same at Big Think. From the perspective of an advocate, I certainly see the value of collected short answers to many pertinent questions about healthy life extension, the science of repairing aging, and plans to develop real anti-aging therapies. It remains to be seen whether any of these businesses find enough profit in this venture to build a sustaining architecture dedicated to this sort of educational content.

View the Article Under Discussion: http://www.bigthink.com/experts/browse-by-name/aubrey-de-grey/1
Read More Longevity Meme Commentary: http://www.longevitymeme.org/news/

The results of a Phase IIa clinical trial of BrachySil for the treatment of advanced, inoperable pancreatic cancer were presented at American Society of Clinical Oncolgy-GI (ASCO-GI) this weekend in a poster presented by Dr. Paul Ross, Chief Investigator in the study and Consultant Medical Oncologist at Guy's and St. Thomas' NHS Foundation Trust.

The trial, designed as a safety study, successfully showed that BrachySilTM, in combination with standard chemotherapy (gemcitabine), was well tolerated with no clinically significant adverse events related to BrachySil. Data showed disease control in 82% of patients and an overall median survival of 309 days. BrachySil was found to be easily deliverable by endoscopic ultrasound. BrachySilTM is a novel oncology product which comprises a combination of BioSiliconTM, a proprietary porous silicon, and the isotope 32Phosphorus, a proven anti-cancer therapeutic.

"These findings are very interesting, and although this was a small study and was not designed to prove efficacy, these results are encouraging," said Dr. Ross.

In the trial, seventeen patients were treated with BrachySil injected directly into the primary tumors via endoscopic ultrasound (used to assist in locating the delivery point). All patients had advanced inoperable pancreatic cancer and received gemcitabine in addition to BrachySil. CT assessments of response were performed at weeks 8, 16 and 24. The study was conducted at three major centers for cancer therapy: Guy's and St Thomas' NHS Foundation Trust, UK, University Hospital Birmingham NHS Foundation Trust, UK and Singapore General Hospital.

Pancreatic cancer is the fourth most frequent cause of cancer death, and at least 80% of patients present with inoperable locally advanced or metastatic disease. The median survival for these patients following diagnosis is typically less than six months with standard chemotherapy. Accordingly, there is significant clinical and market demand for more effective therapies.

Dr Paul Ashton, Managing Director of pSivida Limited, the company that developed BrachySil and sponsored the trial, said, "We are very pleased with the favorable results of this study of BrachySil for the treatment of advanced, inoperable pancreatic. Our next step for BrachySil is a dose-ranging study planned to commence this quarter."

http://psivida.com/

A new study sheds light on the relationship between women who smoke while pregnant or are exposed to second-hand smoke and an increased risk of SIDS to their babies.

Researchers at McMaster University have found a mechanism that explains why an infant's ability to respond to oxygen deprivation after birth-or a hypoxic episode-is dramatically compromised by exposure to nicotine in the womb, even light to moderate amounts.

The findings are published online in the journal Federation of American Societies for Experimental Biology (FASEB) and will appear in the May 2008 print issue.

"While cigarette smoke contains many different compounds, we found there is a direct impact of one component, nicotine, on the ability of certain cells to detect and respond to oxygen deprivation," says Josef Buttigieg, lead author and a PhD graduate student in the department of Biology. "When a baby is lying face down in bed, for example, it should sense a reduction in oxygen and move its head. But this arousal mechanism doesn't work as it should in babies exposed to nicotine during pregnancy."

The research, which was conducted on laboratory rats in collaboration with Dr. Alison Holloway, explains the critical role that catecholamines-a group of hormones released by the adrenal glands-play in a baby's transition to the outside world.

During birth, the baby is exposed to low oxygen, which signals the adrenal glands to release the catecholamines, which contain adrenaline, or the 'fight or flight' hormone, explains Buttigieg.

It is these catecholamines that signal the baby's lungs to reabsorb fluid, to take its first breath, and help the heart to beat more efficiently. And for some months after birth, the adrenal gland still acts as an oxygen sensor, aiding in the baby's arousal and breathing responses during periods of apnea or asphyxia. But the ability to release catecholamines during these moments-a critical event in the adaptation of life outside the womb-is impaired due to nicotine exposure.

"At birth, the nervous control of the adrenal gland is not active and so a baby relies on these direct oxygen sensing mechanisms to release catecholamines," says Colin Nurse, academic advisor on the study and a professor in the department of Biology. "But nicotine causes premature loss of these mechanisms, which would normally occur later in development after nervous control is established. Thus, the infant becomes much more vulnerable to SIDS."

http://www.mcmaster.ca/

For some women, digital mammography may be a better screening option than film mammography, according to newly published results from a national study led by a University of North Carolina at Chapel Hill researcher.

The results, from the Digital Mammographic Imaging Screening Trial (DMIST), appear in the February issue of Radiology. UNC's Dr. Etta D. Pisano is principal investigator and lead author of the study, which found that digital mammography performed better than film mammography for pre- and perimenopausal women under age 50 with dense breasts.

"We looked at a cross-section of characteristics," Pisano said. "This paper confirms that if you are under 50, pre- or perimenopausal, and have dense breasts, you should definitely be screened with digital rather than film."

Pisano is Kenan professor of radiology and biomedical engineering and vice dean for academic affairs and in the UNC School of Medicine. She is also director of the Biomedical Research Imaging Center and a member of UNC Lineberger Comprehensive Cancer Center.

DMIST enrolled 49,528 women at 33 centers in the U.S. and Canada. The women underwent both digital and film mammography. Breast cancer status was determined for 42,760 women.

"The original DMIST results showed that digital was statistically similar to film in the overall screening population but performed better than film in pre- and perimenopausal women under 50," Pisano said.

For this paper, the researchers sought to retrospectively compare the accuracy of digital mammography versus film mammography in subgroups defined by combinations of age, menopausal status and breast density, using either biopsy results or follow-up information.

They compared results in 10 different subgroups of women: pre- and perimenopausal women under age 50 with fatty breasts, pre- and perimenopausal women under age 50 with dense breasts, postmenopausal women under 50 with fatty breasts, postmenopausal women under 50 with dense breasts, pre- and perimenopausal women between the ages of 50 and 64 with fatty breasts, pre- and perimenopausal women age 50 to 64 with dense breasts, postmenopausal women age 50 to 64 with fatty breasts, postmenopausal women age 50 to 64 with dense breasts, women over age 65 with fatty breasts and women over 65 with dense breasts.

The results confirmed the trial's original findings in favor of improved diagnostic accuracy of digital mammography over film for pre- and perimenopausal women under 50 years old with dense breasts. The findings also showed a trend toward improved diagnostic accuracy of film over digital mammography for women over 65 with fatty breasts. However, this finding was not statistically significant, and further investigation is needed to determine the reason that film performed slightly better in this subgroup. For other groups evaluated, there was no significant difference.

http://www.unc.edu/