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Archive - 2013

November 21st

New Study Links Gene Variant to Marital Satisfaction

What makes some people more prone to wedded bliss or sorrow than others? Researchers at the University of California (UC) Berkeley and Northwestern University have found a major clue in our DNA. A gene involved in the regulation of serotonin can predict how much our emotions affect our relationships, according to a new study that may be the first to link genetics, emotions, and marital satisfaction. The study was conducted at UC Berkeley. “An enduring mystery is, what makes one spouse so attuned to the emotional climate in a marriage, and another so oblivious?” said UC Berkeley psychologist Dr. Robert W. Levenson, senior author of the study published online on October 7, 2013 in the journal Emotion. “With these new genetic findings, we now understand much more about what determines just how important emotions are for different people.” Specifically, researchers found a link between relationship fulfillment and a gene variant, or “allele,” known as 5-HTTLPR (serotonin-transporter-linked polymorphic region). Identified in the mid-1990s, 5-HTTLPR has been extensively investigated, particularly in connection with neuropsychiatric disorders. All humans inherit a copy of this gene variant from each parent. Study participants with two short 5-HTTLPR alleles were found to be most unhappy in their marriages when there was a lot of negative emotion, such as anger and contempt, and most happy when there was positive emotion, such as humor and affection. By contrast, those with one or two long alleles were far less bothered by the emotional tenor of their marriages. “We are always trying to understand the recipe for a good relationship, and emotion keeps coming up as an important ingredient,” said Dr.

November 21st

“Zone in with Zon”—Gene Patents, Louis XVI, Sasquatch, and Jurassic Beer

Dr. Gerald Zon’s latest “Zone in with Zon” blog post, dated November 18, 2013, and published by TriLink BioTechnologies of San Diego, departs from Dr. Zon’s usuaul thematic approach and covers a wide variety of interesting topics only loosely linked by involving sequencing in some fashion. In this wide-ranging blog, Dr. Zon moves from a discussion of gene patenting based on an October 8, 2013 provocative article in Nature Biotechnology (http://www.nature.com/nbt/journal/v31/n10/full/nbt.2703.html) by Kevin McKernan, co-founder and CSO of Courtagen Life Sciences, Inc., et al., to a the use of DNA testing to identify a putative blood sample from French King Louis XVI executed during the French revolution and to verify the results by testing tissue from the preserved heart of his presumptive son. Then, at the risk of jeopardizing any possible future Nobel Prize consideration, Dr. Zon even devotes a few paragraphs to the Sasquatch Genome Project and separate DNA studies on the “Abominable Snowman” by famed geneticist Dr. Bryan Sykes. Finally, as if to subtly imply the origin of these unusual musings, he ends with a discussion of “Jurassic Beer.” Apparently, Cano & Borucki reported in Science in 1995 that they had extracted, revived, cultured and identified bacterial spores from the abdominal contents of extinct Proplebeia dominicana bees. The bees had been preserved in 25- to 40-million-year-old amber. Dr. Zon says that Dr. Cano later filed a patent application for manufacturing a fermented beverage (e.g., beer) from a novel yeast strain recovered and cultured from a 44-million-year-old piece of amber. Dr. Cano now co-owns Fossil Fuel Brewing Co., which is utilizing ancient yeast strains to brew beer. Dr. Zon does issue one caveat.

November 20th

Ancient Siberian Genome Reveals Genetic Origins of Native Americans

The genome sequence of a 24,000-year-old Siberian individual has provided a key piece of the puzzle in the quest for Native American origins. The ancient Siberian demonstrates genomic signatures that are basal to present-day western Eurasians and close to modern Native Americans. The breakthrough was reported online on November 20, 2013 in Nature by an international team of scientists, led by researchers from the University of Copenhagen. The search for Native American ancestors has been focused in northeastern Eurasia. In late 2009, researchers sampled, at the Hermitage Museum, St. Petersburg, the remains of a juvenile individual (MA-1) from the Upper Palaeolithic site of Mal’ta in south-central Siberia. The MA-1 individual dated to approximately 24,000 years ago. Now, the team reports genomic results from the MA-1 individual which unravel the origins of the First Americans – ancestors of modern-day Native Americans. “Representing the oldest anatomically modern human genome reported thus far, the MA-1 individual has provided us with a unique window into the genetic landscape of Siberia some 24,000 years ago,” says Dr. Maanasa Raghavan from the Centre for GeoGenetics and one of the lead authors of the study. “Interestingly, the MA-1 individual shows little to no genetic affinity to modern populations from the region from where he originated - south Siberia.” Instead, both the mitochondrial and nuclear genomes of MA-1 indicate that he was related to modern-day western Eurasians. This result paints a picture of Eurasia 24,000 years ago which is quite different from the present-day context. The genome of MA-1 indicates that prehistoric populations related to modern western Eurasians occupied a wider geographical range into northeast Eurasia than they do today.

NCI Awards Labcyte $1 Million for Development of High-Throughput Cancer Biomarker Detection Process

In a November 20, 2013 press release, Labcyte Inc., the acoustic dispensing company, announced that it has been awarded $1 million to create an innovative process to detect cancer-related proteins in samples, with initial work in breast cancer detection. The unsurpassed precision and accuracy of Labcyte acoustic liquid handling enables biomarker detection by measuring multiple proteins with a MALDI mass spectrometer. Recent work with the Canary Center at Stanford, also supported by the National Cancer Institute, showed the ability to achieve the sensitivity required for quantifying very small amounts of proteins associated with ovarian cancer. Measuring the amount of multiple proteins, and at lower cost, is an essential step in developing new diagnostic tools for disease treatment and monitoring. This cutting-edge process encompasses stable standards and capture of biomarkers with antibodies and expects to achieve greater throughput than traditional liquid chromatography-mass spectrometric approaches. The utility of this technique will be tested by simultaneously analyzing 16 different biomarkers, run in quadruplicate, to simulate the analysis of 64 unique biomarkers. The process has the potential to expand to a greater number of biomarkers as well. It may enable significant advances in diagnostics and discovery. "I am particularly enthusiastic about participating with Labcyte on the further development of their protein multiplexed biomarker detection platform,” said Dr. Mark Stolowitz, Director of the Proteomics Core Facility at the Canary Center at Stanford for Cancer Early Detection. “This novel immunoaffinity mass spectrometry-based approach exploits MALDI-TOF-MS for detection of proteotypic peptides.

November 19th

mTOR: A Key Brain Signaling Mechanism for Rapidly Acting Antidepressants

Two years ago, mammalian target of rapamycin or mTOR, a signaling protein, was identified as a key mediator of the antidepressant effects of ketamine, the first rapidly acting antidepressant medication to be identified. Later, a group at the National Institutes of Mental Health Intramural Program reported that scopolamine (image), a muscarinic acetylcholine receptor antagonist, also produced rapidly appearing antidepressant effects, similar to the actions of ketamine. Together these findings represent one of the most significant advances in the field of depression in recent years. Now, new results reported in the November 15, 2013 issue of Biological Psychiatry by researchers at the Yale University School of Medicine demonstrate that scopolamine causes rapid activation of mTOR signaling and increased number of synaptic connections in the prefrontal cortex. The prefrontal cortex is an important brain region, involved in executive and cognitive functioning, decision-making, planning, and the expression of personality. It is also implicated in the pathophysiology and treatment of depression. "These effects are similar to the actions of ketamine, showing that two drugs with completely different receptor blocking profiles have common downstream actions linked to rapid antidepressant responses," said Dr. Ronald Duman, senior author on the project. "Moreover, the increase in synaptic connections reverses the deficit caused by stress and depression and thereby reinstates the normal control of mood and emotion." "It would be very important to know if all of the new generation of rapidly acting antidepressant medications acted through a final common signaling pathway within neurons.

November 18th

New Study Suggests “Anti-Ketamine” Might Also Treat Depression

Thirteen years ago, an article in Biological Psychiatry first reported that the anesthetic medication, ketamine, showed evidence of producing rapid antidepressant effects in depressed patients who had not responded to prior treatments. Ketamine works by blocking one of the targets for the neurotransmitter glutamate in the brain, the N-methyl-D-aspartate (NMDA) glutamate receptor. Now, a new study printed in the November 15, 2013 issue of Biological Psychiatry reports that enhancing, instead of blocking, that same target – the NMDA glutamate receptor – also causes antidepressant-like effects. Scientists theorize that NMDA receptor activity plays an important role in the pathophysiology of depression, and that normalizing its functioning can, potentially, restore mood to normal levels. Prior studies have already shown that the underlying biology is quite complex, indicating that both hyperfunction and hypofunction of the NMDA receptor is somehow involved. But, most studies have focused on antagonizing, or blocking, the receptor, and until now, studies investigating NMDA enhancement have been in the early phases. Sarcosine is one such compound that acts by enhancing NMDA function. Collaborators from China Medical University Hospital in Taiwan and the University of California in Los Angeles studied sarcosine in an animal model of depression and, separately, in a clinical trial of depressed patients. “We found that enhancing NMDA function can improve depression-like behaviors in rodent models and in human depression,” said Dr. Hsien-Yuan Lane, the corresponding author on the article. In the clinical portion of the study, they conducted a 6-week trial where 40 depressed patients were randomly assigned to receive sarcosine or citalopram (Celexa), an antidepressant already on the market that was used as a comparison drug.

November 15th

Wind Turbines Killed 600,000 Bats in U.S. Last Year by Conservative Estimates

More than 600,000 bats were killed by wind energy turbines in 2012, a serious blow to creatures who pollinate crops and help control flying insects, according to a new study from the University of Colorado (CU) Denver, described in a November 15, 2013 press release from the University. "The development and expansion of wind energy facilities is a key threat to bat populations in North America," said study author Mark Hayes, Ph.D., research associate in integrated biology at CU Denver. "Dead bats are being found underneath wind turbines across North America. The estimate of bat fatalities is probably conservative." The study, which analyzed data on the number of dead bats found at wind turbine sites, will be published next week in the journal BioScience. Dr. Hayes said areas near the Appalachian Mountains like Buffalo, Tennessee, and Mountaineer, West Virginia had the highest bat fatality rates. Little information is available on bat deaths at wind turbine facilities in the Rocky Mountain West or the Sierra Nevadas. The bats are killed when they fly into the towering turbines which spin at up to 179 mph with blades that can stretch 130 feet. Earlier estimates of bat deaths ranged from 33,000 to 880,000. Dr. Hayes said his estimates are likely conservative for two reasons. First, when a range of fatality estimates were reported at a wind facility, he chose the minimum estimate. Secondly, the number of deaths was estimated for just migratory periods, not the entire year, likely leaving out many other fatalities. "The number could be as high as 900,000 dead," he said. There are 45 known bat species in the contiguous U.S., many of which have important economic impacts. Not only do they control flying insects like mosquitoes, they also pollinate commercial crops, flowers, and various cacti.

New Mutations in P. vivax Malaria Parasite May Increase Human Susceptibility

Researchers at Case Western Reserve University and Cleveland Clinic Lerner Research Institute have discovered recent genetic mutations in a parasite that causes over 100 million cases of malaria annually—changes that may render tens of millions of Africans who had been considered resistant, susceptible to infection. Dr. Peter A. Zimmerman, professor of international health, biology, and genetics at the Case Western Reserve School of Medicine, and Dr. David Serre, a scientific staff member of the Genomic Medicine Institute at Lerner and assistant professor of genomics at Case Western Reserve, report their findings at the American Society of Tropical Medicine and Hygiene annual meeting today, Friday, November 15, 2013. They and fellow researchers describe the changes in the Plasmodium vivax genome in papers scheduled to be published in the journal PLoS Neglected Tropical Disease on November 21 and December 5, 2013. To learn the functions of the mutations, and whether the parasite is evolving around a natural defense, Drs. Zimmerman and Serre have received a $3.5 million grant from the National Institute of Allergy and Infectious Disease at the National Institutes of Health. They will begin their field study in early 2014. "We've found a duplication of a gene known to enable the parasite to infect red blood cells and two possible additional components to a more complex red cell invasion mechanism," Dr. Zimmerman said. Researchers have long thought that P. vivax infects a person one way: a protein on the parasite, called the Duffy binding protein, latches onto a Duffy receptor on the surface of the person's red blood cell and works itself through the membrane. People who lack the receptor are called Duffy-negative and are resistant to infection.

Ash Fungus Might Have Mechanism to Define Territory and Combat Viruses

The fungus which causes Chalara dieback of ash trees has the potential to defend itself against virus attacks, research by British scientists has shown. Plant pathologists Dr. Joan Webber, from Forest Research, the research agency of the Forestry Commission, and Professor Clive Brasier found that the defense mechanisms which the Chalara fraxinea (C. fraxinea) fungus uses to defend its territory could make it more resistant to virus-based control methods. Their research findings will be published in the December 2013 issue of Fungal Ecology and are available online now. Professor Brasier and Dr. Webber studied C. fraxinea’s genetic recognition system, called a vegetative compatibility (vc) system, in samples of the fungus from three different UK sites. Their results suggest that for most of these UK samples the fungal colonies are likely to be vegetatively incompatible with each other. This has implications for studying the biology of the fungus and for controlling its spread. Vegetative compatibility (vc) systems are a fungal equivalent of the tissue rejection systems in humans, enabling the fungus to distinguish between self and non-self. Fungal colonies of the same vc-type can fuse to form a single individual, but those of a different vc-type cannot. Vc systems are central to the ecology and survival of a fungus, enabling it to define its territory, to resist viral attack and to promote outbreeding. Initial results show that the vc system of C. fraxinea generates a reaction between incompatible colonies which makes their filaments (the mycelium) collapse, creating a zone between the two colonies where growth is inhibited.

November 14th

Blood Test Shows Promise for Early Detection of Breast Cancer

What could someday be the first blood test for the early detection of breast cancer was shown in preliminary studies to successfully identify the presence of breast cancer cells from serum biomarkers, say the Houston Methodist Research Institute scientists who are developing the technology. With a New York University Cancer Institute colleague, the researchers reported online on October 21, 2013 in Clinical Chemistry that the mixture of free-floating blood proteins created by the enzyme carboxypeptidase N (CPN) accurately predicted the presence of early-stage breast cancer tissue in mice and in a small population of human patients. "In this paper we link the catalytic activity of carboxypeptidase N to tumor progression in clinical samples from breast cancer patients and a breast cancer animal model," said biomedical engineer Tony Hu, Ph.D., who led the project. "Our results indicate that circulating peptides generated by CPN can serve as clear signatures of early disease onset and progression." The technology is not yet available to the public, and may not be for years. More extensive clinical tests are needed, and those tests are expected to begin in early 2014. There are currently no inexpensive laboratory tests for the early detection of breast cancer, providing the impetus for researchers around the world to invent them. "What we are trying to create is a non-invasive test that profiles what's going on at a tissue site without having to do a biopsy or costly imaging," Dr. Hu said. "We think this could be better for patients and -- if we are successful -- a lot cheaper than the technology that exists.