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Archive - Aug 21, 2013

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MERS Virus Discovered in Bat Near Site of Human Outbreak in Saudi Arabia

A 100% genetic match for Middle East Respiratory Syndrome (MERS) virus has been discovered in an insect-eating bat in close proximity to the first known case of the disease in Saudi Arabia. The discovery points to the likely animal origin for the disease, although researchers say that an intermediary animal is likely also involved. Led by a team of investigators from the Center for Infection and Immunity (CII) at Columbia University's Mailman School of Public Health, EcoHealth Alliance, and the Ministry of Health of the Kingdom of Saudi Arabia, the study is the first to search for an animal reservoir for MERS in Saudi Arabia, and the first to identify such a reservoir by finding a genetic match in an animal. The results appear online in the November 2013 issue of Emerging Infectious Diseases, a journal of the U.S. Centers for Disease Control and Prevention. "There have been several reports of finding MERS-like viruses in animals. None were a genetic match. In this case, we have a virus in an animal that is identical in sequence to the virus found in the first human case. Importantly, it's coming from the vicinity of that first case," says W. Ian Lipkin, M.D., director of the Center for Infection and Immunity and a co-author of the study. MERS was first described in September 2012 and continues to spread. Close to 100 cases have been reported worldwide, 70 of them from Saudi Arabia. The causative agent, a new type of coronavirus, has been determined; however, the origin of the virus has been unknown until now. Over a six-week period during field expeditions in October 2012 and April 2013, the researchers collected more than 1,000 samples from seven bat species in regions where cases of MERS were identified in Bisha, Unaizah, and Riyadh.

Schizophrenia Symptoms Linked to Faulty Switch in Brain

Scientists at The University of Nottingham in the UK have shown that psychotic symptoms experienced by people with schizophrenia could be caused by a faulty ‘switch’ within the brain. In a study published in an open-access article in the August 21, 2013 issue of Neuron, the researchers have demonstrated that the severity of symptoms such as delusions and hallucinations, which are typical in patients with the psychiatric disorder, is caused by a disconnection between two important regions in the brain — the insula and the lateral frontal cortex. This discovery, say the academics, could form the basis for better, more targeted treatments for schizophrenia with fewer side effects. The four-year study, led by Professor Peter Liddle and Dr. Lena Palaniyappan in the University’s Division of Psychiatry and based in the Institute of Mental Health, centered on the insula region, a segregated ‘island’ buried deep within the brain, which is responsible for seamless switching between inner and outer world. Dr. Palaniyappan, a Wellcome Trust Research Fellow, said: “In our daily life, we constantly switch between our inner, private world and the outer, objective world. This switching action is enabled by the connections between the insula and frontal cortex. This switching process appears to be disrupted in patients with schizophrenia. This could explain why internal thoughts sometime appear as external objective reality, experienced as voices or hallucinations in this condition. This could also explain the difficulties in ‘internalizing’ external material pleasures (e.g., enjoying a musical tune or social events) that result in emotional blunting in patients with psychosis.

Impaired Autophagy Associated with Age-Related Macular Degeneration

A new study published online on July 29, 2013 in the open-access journal PLOS ONE changes our understanding of the pathogenesis of age-related macular degeneration (AMD). The researchers found that degenerative changes and loss of vision are caused by impaired function of the lysosomal clean-up mechanism, or autophagy, in the fundus of the eye. The results open new avenues for the treatment of the dry form of AMD, which currently lacks an efficient treatment. The University of Eastern Finland played a leading role in the study, which also involved research groups from Italy, Germany and Hungary. AMD is the most common cause of visual impairment in the Western world, and the number of AMD patients is expected to soar in the upcoming decades. AMD is divided into the dry and wet form of the disease, and 85% of AMD patients suffer from dry AMD. Unfortunately, an efficient treatment involving injections into the eye only exists for the wet form of the disease. AMD is a storage disease in which harmful protein accumulations develop behind the retina. These accumulations are indicative of the severity of the disease. As the disease progresses, retinal sensory cells in the central vision area are damaged, leading to loss of central vision. The cell biological mechanisms underlying protein accumulations remain largely unknown. For the first time ever, the present study showed that AMD is associated with impaired lysosomal autophagy, which is an important clean-up mechanism of the fundus of the eye. This renders the cells in the fundus of the eye unable to dispose of old, deformed or otherwise faulty proteins, which, in turn, leads to the development of protein accumulations and loss of vision.

Tokyo Scientists Show Dogs Yawn More Often in Response to Owners' Yawns

Dogs yawn contagiously when they see a person yawning, and respond more frequently to their owner's yawns than to those of a stranger, according to research published online on August 7, 2013 in the open-access journal PLOS ONE by Dr. Teresa Romero and colleagues from the University of Tokyo. Pet dogs in the study watched their owner or a stranger yawn, or mimic a yawning mouth movement, but yawned significantly more in response to their owners' actions than to the strangers' yawns. The dogs also responded less frequently to the fake movements, suggesting they have the ability to yawn contagiously. Previous research has shown that dogs yawn in response to human yawns, but it was unclear whether this was a mild stress response or an empathetic response. The results of this study suggest the latter, as dogs responded more to their owners' genuine yawns than to those of a stranger. The researchers observed no significant differences in the dogs' heartbeats during the experiments, making it unlikely that their yawns were a distress response. Explaining the significance of the results, Dr. Romero says, "Our study suggests that contagious yawning in dogs is emotionally connected in a way similar to humans. Although our study cannot determine the exact underlying mechanism operative in dogs, the subjects' physiological measures taken during the study allowed us to counter the alternative hypothesis of yawning as a distress response." [Press release] [PLOS ONE article]