As recovering spring breakers are regretting binge drinking escapades, it may be hard for them to appreciate that there is a positive side to the nausea, sleepiness, and stumbling. University of Utah neuroscientists report that when a region of the brain called the lateral habenula is chronically inactivated in rats, they repeatedly drink to excess and are less able to learn from the experience. The study, published online in the open-access journal PLOS ONE on April 2, 2014, has implications for understanding behaviors that drive alcohol addiction. While complex societal pressures contribute to alcoholism, physiological factors are also to blame. Alcohol is a drug of abuse, earning its status because it tickles the reward system in the brain, triggering the release of feel-good neurotransmitters. The dreaded outcomes of overindulging serve the beneficial purpose of countering the pull of temptation, but little is understood about how those mechanisms are controlled. University of Utah professor of neurobiology and anatomy Sharif Taha, Ph.D. and colleagues, tipped the balance that reigns in addictive behaviors by inactivating in rats the lateral habenula. When these rats were given intermittent access to a solution of 20% alcohol over several weeks, they escalated their alcohol drinking more rapidly, and drank more heavily than control rats. "In people, escalation of intake is what eventually separates a social drinker from someone who becomes an alcoholic," said Dr. Taha. "These rats drink amounts that are quite substantial. Legally they would be drunk if they were driving." The lateral habenula is activated by bad experiences, suggesting that without this region the rats may drink more because they fail to learn from the negative outcomes of overindulging.
U.S. Forest Service Southern Research Station (SRS) scientists co-authored an article published on March 4, 2014 in an open-access article in the journal Genome Biology that reports the sequencing, assembly, and annotation of the loblolly pine (Pinus taeda) genome. As the primary source of pulpwood and saw timber for the U.S. forest industry, loblolly pine is of great economic importance to the South and to the nation. Dr. David Neale, professor of plant sciences at the University of California, Davis, led the loblolly pine genome project. “The project was a huge undertaking because at 22 gigabases, the loblolly pine genome is about eight times larger than the human genome,” said Dr. C. Dana Nelson, SRS Southern Institute for Forest Genetics (SIFG) project leader and research geneticist. “The group chose loblolly pine both because of its economic importance, and the knowledge gained from 60 years of breeding the species and managing millions of trees in genetic trials.” As part of the project, researchers identified a candidate for a gene involved in resistance to fusiform rust, a disease that infects southern pines. SIFG biological science technician Katherine Smith worked with Dr. John M. Davis, professor and associate director of the School of Forest Resources and Conservation at the University of Florida (UF), to compare mapped sections of the genome with sections found in loblolly specimens previously inoculated with the pathogen that causes fusiform rust. “Fusiform rust is the most damaging disease of southern pines—and one of the most complex, due to genetic interactions between the pathogen and its host,” said Dr. Davis, who also serves as faculty and Executive Committee member at the UF Genetics Institute.
Wounds may heal more quickly if exposed to low-intensity vibration, report researchers at the University of Illinois at Chicago (UIC). The finding, in mice, may hold promise for the 18 million Americans who have type 2 diabetes, and especially the quarter of them who will eventually suffer from foot ulcers. Their wounds tend to heal slowly and can become chronic or worsen rapidly. Dr. Timothy Koh, UIC professor of kinesiology and nutrition in the UIC College of Applied Health Sciences, was intrigued by studies at Stony Brook University in New York that used very low-intensity signals to accelerate bone regeneration. "This technique is already in clinical trials to see if vibration can improve bone health and prevent osteoporosis," Dr. Koh said. Dr. Koh and his coworkers at UIC collaborated with Dr. Stefan Judex of Stony Brook to investigate whether the same technique might improve wound healing in diabetes. The new study, using an experimental mouse model of diabetes, is published online on March 11, 2014 in the open-access journal PLOS ONE. The low-amplitude vibrations are barely perceptible to touch. "It's more like a buzz than an earthquake," said Dr. Eileen Weinheimer-Haus, UIC postdoctoral fellow in kinesiology and nutrition, the first author of the study. The researchers found that wounds exposed to vibration five times a week for 30 minutes healed more quickly than wounds in mice of a control group. Wounds exposed to vibration formed more granulation tissue, a type of tissue important early in the wound-healing process. Vibration helped tissue to form new blood vessels -- a process called angiogenesis -- and also led to increased expression of pro-healing growth factors and signaling molecules called chemokines, Dr. Weinheimer-Haus said.
Dogs are known to be man's best friend. No other pet has adjusted to man's lifestyle as has this four-legged animal. Scientists at the Messerli Research Institute at the Vetmeduni Vienna, in Austria, have been the first to investigate the evolution of dogs' attentiveness in the course of their lives and to what extent they resemble man in this regard. The outcome: dogs' attentional and sensorimotor control developmental trajectories are very similar to those found in humans. The results were published on February 7, 2014 in an open-access article in the journal Frontiers in Psychology. Dogs are individual personalities, possess awareness, and are particularly known for their learning capabilities, or trainability. To learn successfully, they must display a sufficient quantity of attention and concentration. However, the attentiveness of dogs' changes in the course of their lives, as it does in humans. The lead author Dr. Lisa Wallis and her colleagues investigated 145 border collies aged 6 months to 14 years in the Clever Dog Lab at the Vetmeduni Vienna and determined, for the first time, how attentiveness changes in the entire course of a dog's life using a cross-sectional study design. To determine how rapidly dogs of various age groups pay attention to objects or humans, the scientists performed two tests. In the first situation, the dogs were confronted with a child's toy suspended suddenly from the ceiling. The scientists measured how rapidly each dog reacted to this occurrence and how quickly the dogs became accustomed to it. Initially all dogs reacted with similar speed to the stimulus, but older dogs lost interest in the toy more rapidly than younger ones did. In the second test situation, a person known to the dog entered the room and pretended to paint the wall.
A team led by evolutionary and developmental biologist Dr. Ulrich Technau at the University of Vienna has discovered that sea anemones display a genomic landscape with a complexity of regulatory elements similar to that of fruit flies or other animal model systems. This suggests, that this principle of gene regulation is already 600 million years old and dates back to the common ancestor of human, fly, and sea anemone. On the other hand, sea anemones are more similar to plants rather thn to vertebrates or insects in their regulation of gene expression by short regulatory RNAs called microRNAs. These surprising evolutionary findings were published on March 18, 2014 in two open-access articles in Genome Research. Our appearance, the shape we have and how our body works is, in addition to environmental influences, largely the result of the action of our genes. However, genes are rarely single players, they rather act in concert and regulate each other's activity and expression in gene regulatory networks. In the last decades, the sequencing of the human and many animal genomes has shown that anatomically simple organisms such as sea anemones have a surprisingly complex gene repertoire similar to that of higher model organisms. This implies, that the difference in morphological complexity cannot be easily explained by the presence or absence of individual genes. Some researchers hypothesized that the individual genes do not code for more complex body plans, but that this is determined by how the genes are wired and linked between each other. Accordingly, researchers expected that these gene networks are less complex in simple organisms than in human or "higher" animals. A measurement of the complexity of gene regulation could be the distribution and density of regulatory sequences in the genome.
Scientists have identified a gene that may influence the timing of puberty, according to research presented on Mrch 25, 2014 at the Society for Endocrinology annual BES conference in Liverpool, United Kingdom. Until now, very little has been known about the genetic control of puberty. More than 4% of adolescents suffer from early or late-onset puberty, which is associated with health problems including obesity, type-2 diabetes, cardiovascular disease, and cancer. The findings of the study are expected to make diagnosis easier and more efficient, reducing the risk of disease. Researchers from Queen Mary University of London scanned the genomes of seven families experiencing delayed puberty. The genetic profiles were analyzed to identify specific genes that were different in these families, compared to individuals who started puberty normally. The researchers identified 15 candidate genes that were then examined in a further 288 individuals with late-onset puberty. One gene was found to have common variants in nine families. The gene appears to contribute to the early development of gonadotropin-releasing hormone (GnRH) neurons in the brain. At puberty, a surge of GnRH is released, signaling to the pituitary gland to release further hormones that act on the ovaries and testes, triggering reproductive function (sexual maturation). If development of the GnRH neurons is delayed, the surge of GnRH that initiates these signals is also delayed. Dr. Sasha Howard, who led the study, said, “Studies estimate that 60-80% of variation in the timing of puberty is genetically determined, yet this is one of the first genes with major impact to be identified.
Over the last 20 years, China has more than halved its tuberculosis (TB) prevalence, with rates falling from 170 to 59 per 100 000 population. This unrivalled success has been driven by a massive scale-up of the directly observed, short-course (DOTS) strategy, from half the population in the 1990s to the entire country after 2000, according to findings from a 20-year-long analysis of national survey data, published online on March 18, 2014 in The Lancet. "One of the key global TB targets set by the Stop TB Partnership aims to reduce tuberculosis prevalence by 50% between 1990 and 2015. This study in China is the first to show the feasibility of achieving such a target, and China achieved this 5 years earlier than the target date," says study leader Dr. Yu Wang from the Chinese Center for Disease Control and Prevention in Beijing, China. "Huge improvements in TB treatment, driven by a major shift in treatment from hospitals to local public health centers implementing the DOTS strategy, were largely responsible for this success." China is a major contributor to the TB pandemic, with 1 million new TB cases every year, accounting for 11% of all new cases globally. Two national surveys of tuberculosis prevalence in 1990 and 2000 showed that levels of TB were reduced by around 30% in the 13 provinces where the DOTS program was adopted. However, national TB prevalence fell by just 19% over the decade. Another survey was done in 2010 to re-evaluate the national TB burden, providing an opportunity to assess the effect of the nationwide expansion of the DOTS program. Nearly 253,000 individuals aged 15 years and older were surveyed in 2010 at 176 investigation points chosen from all 31 mainland provinces. The results showed that between 2000 and 2010, national TB prevalence fell by 57%—tripling the reduction of the previous decade.
Researchers from the British Antarctic Survey and the University of Reading reported online in the Cell Press journal Current Biology on March 17, 2014 that Antarctic mosses can essentially come back to life after 1,500 completely inactive years under the ice. Prior to this finding, direct regeneration from frozen plant material had been demonstrated after 20 years at most. Beyond that, only microbes had been shown to be capable of revival after so many years on hold. "These mosses were basically in a very long-term deep freeze," says Dr. Peter Convey of the British Antarctic Survey. "This timescale of survival and recovery is much, much longer than anything reported for them before." The findings in mosses have special relevance for Antarctic ecosystems and climate, Dr. Convey adds, because mosses are primary producers on land in both northern and southern polar regions. In the north in particular, mosses are responsible for storing most of the fixed carbon. If mosses can survive in this way for such long periods of time, then regrowth once the ice retreats wouldn't require long-distance, transoceanic colonization events. Dr. Convey and his colleagues primarily study polar moss cores because they provide a novel archive of past climate conditions. The researchers use them to assess growth rates over time and as proxies to reconstruct aspects of the environment and environmental change over time. The oldest moss banks of the type under study in the Antarctic date back 5,000 to 6,000 years. The one the researchers focused on in the current work is nearly 2,000 years old at its base. In the beginning, the researchers weren't sure that mosses frozen for more than a decade or two would remain viable. When they began to see the 1,500-year-old mosses start to regrow, it came as a real surprise.
Using genome sequencing, National Institutes of Health (NIH) scientists and their colleagues have tracked the evolution of the antibiotic-resistant bacterium Klebsiella pneumoniae sequence type 258 (ST258), an important agent of hospital-acquired infections. While researchers had previously thought that ST258 K. pneumoniae strains spread from a single ancestor, the NIH team showed that the strains arose from at least two different lineages. The investigators also found that the key difference between the two groups lies in the genes involved in production of the bacterium's outer coat, the primary region that interacts with the human immune system. Their results, which appeared online on March 17, 2014 in PNAS, promise to help guide the development of new strategies to diagnose, prevent. and treat this emerging public health threat. ST258 K. pneumoniae is the predominant cause of human infections among bacteria classified as carbapenem-resistant Enterobacteriaceae (CRE), which kill approximately 600 people annually in the United States and sicken thousands more. Most CRE infections occur in hospitals and long-term care facilities among patients who are already weakened by unrelated disease or have undergone certain medical procedures. In the new study, scientists from the NIH's National Institute of Allergy and Infectious Diseases (NIAID) and their colleagues sequenced the complete genomes of ST258 K. pneumoniae strains collected from two patients in New Jersey hospitals. By comparing these reference genomes with gene sequences from an additional 83 clinical ST258 K. pneumoniae isolates, the scientists found that the strains divided broadly into two distinct groups, each with its own evolutionary history.
Colon cancer incidence rates have dropped 30 percent in the U.S. in the last 10 years among adults 50 and older due to the widespread uptake of colonoscopy, with the largest decrease in people over age 65. Colonoscopy use has almost tripled among adults ages 50 to 75, from 19 percent in 2000 to 55 percent in 2010. The findings come from Colorectal Cancer Statistics, 2014, published online on March 17, 2014 in CA: A Cancer Journal for Clinicians. The article and its companion report, Colorectal Cancer Facts & Figures, were released today by American Cancer Society researchers as part of a new initiative by the National Colorectal Cancer Roundtable to increase screening rates to 80 percent by 2018. Colorectal cancer, commonly called colon cancer, is the third most common cancer and the third leading cause of cancer death in men and women in the United States. Its slow growth from precancerous polyp to invasive cancer provides a rare opportunity to prevent cancer through the detection and removal of precancerous growths. Screening also allows early detection of cancer, when treatment is more successful. As a result, screening reduces colorectal cancer mortality both by decreasing the incidence of disease and by increasing the likelihood of survival. Using incidence data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program and the Centers for Disease Control and Prevention's National Program of Cancer Registries, as provided by the North American Association of Central Cancer Registries (NAACCR), researchers led by Rebecca Siegel, M.P.H., found that during the most recent decade of data (2001 to 2010), overall incidence rates decreased by an average of 3.4 percent per year. However, trends vary substantially by age.