(Press-News.org) Researchers at the University of California, San Diego School of Medicine and Sun Yat-sen University in China have shown that acute glaucoma in mice is largely an inflammatory disease and that high pressure in the eye causes vision loss by setting in motion an inflammatory response similar to that evoked by bacterial infections.
The study, published in this week's issue of the Proceedings of the National Academy of Sciences, has immediate clinical relevance in treating the tens of millions of people worldwide from what is known as acute closed-angle glaucoma.
"Our research is the first to show an inflammatory mechanism by which high ocular pressure causes vision loss in acute glaucoma patients," said co-senior author Kang Zhang, MD, PhD and professor of ophthalmology.
The second leading cause of irreversible blindness globally, glaucoma refers to a group of eye diseases associated with elevated intraocular pressure broadly classified as either open-angle or closed-angle. Open-angle is sometimes called the silent thief of sight because of its slow, often overlooked progression. By contrast, acute closed-angle glaucoma often is a painful ophthalmologic emergency in which there is a sudden rise in eye pressure and immediate damage to eyesight.
Less than 10 percent of glaucoma patients in America have the closed-angle form, but in parts of Asia it accounts for almost half of all cases. The higher prevalence of closed-angle glaucoma in Asians and women is believed to be due to a shallower anterior (frontal) eye chamber.
In the study, researchers showed that a rapid, sustained large increase in eye pressure in mice turns on a gene (TLR4) that activates a protein known as caspase-8. This signaling protein in turn triggers the production of inflammatory proteins that normally help mammals fight microbial infections.
"This immune response is a double-edge sword because, while these proteins protect us from infection in a normal situation, they stimulate apoptosis (programmed cell death) in retinal cells in cases of acute glaucoma," said Zhang, who is also a staff physician at the Veterans Affairs San Diego Healthcare System.
To further confirm the mechanism linking high eye pressure to retinal damage, researchers showed that they could slow retinal cell death in mice with acute glaucoma by suppressing either the TLR4 gene or caspace-8 protein.
The latter is particularly significant because caspace-8 inhibitors are currently in clinical trials for treating cancer and stroke. "By injecting these inhibitors into the eyes of acute glaucoma patients, it may be possible to evaluate and bring them vision-sparing treatments more quickly," said co-author Robert N. Weinreb, MD, chairman and Distinguished Professor of Ophthalmology.
INFORMATION:
Co-authors include Wei Chi, Fei Li, Hongrui Chen, Yandong Wang, Yingting Zhu, Xuejiao Yang, Jian Ge and Yehong Zhuo, Sun Yat-sen University, China.
This study was funded by the National Natural Science Foundation of China.
Acute glaucoma discovered to be an inflammatory disease
2014-07-14
ELSE PRESS RELEASES FROM THIS DATE:
CRISPR system can promote antibiotic resistance
2014-07-14
CRISPR, a system of genes that bacteria use to fend off viruses, is involved in promoting antibiotic resistance in Francisella novicida, a close relative of the bacterium that causes tularemia. The finding contrasts with previous observations in other bacteria that the CRISPR system hinders the spread of antibiotic resistance genes.
The results are scheduled for publication in PNAS Early Edition.
The CRISPR system has attracted considerable attention for its potential uses in genetic engineering and biotechnology, but its roles in bacterial gene regulation are still ...
Older adults nearly twice as likely to have memories affected by distractions
2014-07-14
Older people are nearly twice as likely as their younger counterparts to have their memory and cognitive processes impaired by environmental distractions (such as irrelevant speech or written words presented along with target stimuli), according to a new study from psychologists at Rice University and Johns Hopkins University School of Medicine. Whereas other studies had found that older adults are distracted by memories of prior similar events, this was the first study to convincingly demonstrate across several tasks an impairment from environmental distractions.
"Cognitive ...
EARTH Magazine: Parasites spread across the Arctic under the 'new normal'
2014-07-14
Alexandria, Va. — The last several decades have seen Arctic sea-ice minimums drop by more than half in area and more than three-quarters in volume. With current models predicting further reductions, scientists are calling it the "new normal" and are trying to grasp its implications — one of which is the occurrence of pathogens never before seen in the Arctic.
Ice is a major eco-barrier for pathogens, but with Arctic ice diminishing rapidly amid the changing climate, pathogens have an opportunity to move into new areas and spread disease as mammals increase their ranges ...
Capturing cancer: A powerful new technique for early diagnosis
2014-07-14
Despite impressive medical strides, cancer remains a leading killer and overwhelming burden to healthcare systems, causing well over a half million fatalities per year with a projected cost of $174 billion by 2020, according to the National Cancer Institute. Reducing the human and economic toll will require diagnosis and intervention at early stages of illness, when the best prognosis for a cure exists.
In recent years, aggressive research and substantial financial investments have been directed at discovering pre-symptomatic indicators of cancer, known as biomarkers. ...
Labs characterize carbon for batteries
2014-07-14
Lithium-ion batteries could benefit from a theoretical model created at Rice University and Lawrence Livermore National Laboratory that predicts how carbon components will perform.
The model is based on intrinsic characteristics of materials used as battery electrodes. These include limitations on quantum capacitance (the ability of the material to absorb charge) and the material's absolute Fermi level, which determines how many lithium ions may bond to the electrodes.
Subtle changes in the structure, chemistry and shape of an electrode will alter how strongly lithium ...
Study: Young women with sexy social media photos seen as less competent
2014-07-14
BEND, Ore. – Girls and young women who post sexy or revealing photos on social media sites such as Facebook are viewed by their female peers as less physically and socially attractive and less competent to perform tasks, a new study from Oregon State University indicates.
"This is a clear indictment of sexy social media photos," said researcher Elizabeth Daniels, an assistant professor of psychology who studies the effect of media on girls' body image. Daniels' findings are based on an experiment she conducted using a fictitious Facebook profile.
"There is so much ...
Penn researchers successfully alleviate pulmonary inflammation with targeted drug delivery
2014-07-14
(PHILADELPHIA) – Pulmonary inflammation can cause shallow breathing and the lungs to become brittle in patients who experience multiple blood transfusions, sepsis, lung surgery and acute lung trauma. This complication can leave patients on ventilators, which can further traumatize the lungs, and often results in a mortality rate of 30 to 40 percent. To date, no medication has been successful at preventing or mitigating the damage caused by lung inflammation. Now, a multidisciplinary research team led by David Eckmann, MD, PhD, Horatio C. Wood Professor of Anesthesiology ...
Babies born in Canada to immigrant mothers have lower risk of cerebral palsy: Study
2014-07-14
TORONTO, July 14, 2014—Babies born to mothers who immigrated to Ontario from other countries have significantly lower rates of cerebral palsy than those of Canadian-born mothers, especially those from the Caribbean and East Asia, new research has found.
"Predicting who is at highest risk of having a child with CP remains an international priority," said lead author Dr. Joel Ray, who notes that CP rates have not declined much over the last decade.
CP is the most common motor disability in childhood and appears by the age of four. The underlying injury to the brain with ...
Avoiding abuse: Empathy, realistic expectations key to raising a child with disabilities
2014-07-14
ST. LOUIS – Children with developmental disabilities are at higher risk for abuse and neglect from parents than children developing at a typical rate. So far, there was little evidence of specific parental behaviors that were associated with the risk, but a SLU study finds inappropriate expectations and lack of empathy play a significant role in triggering the risk.
Debra Zand, Ph.D., associate professor of pediatrics at Saint Louis University and the principal investigator of the project, conducted the study in a small group of parents in St. Louis with 67 participants. ...
Rethinking fish farming to offset its public health and environmental risks
2014-07-14
As government agencies recommend greater consumption of seafood for its health benefits, a new analysis led by researchers from the Johns Hopkins Center for a Livable Future urges medical and public health professionals to consider the environmental and health impact of seafood sourcing, particularly aquaculture, or the farming of fish, shellfish and crustaceans. The paper appears in the July 2014 issue of the Journal of Current Environmental Health Reports.
Nearly half of all seafood consumed around the world comes from fish farms. Increasing seafood consumption has ...